Publications by authors named "Alexandre José Macedo"

62 Publications

Bacteria-invertebrate interactions as an asset in developing new antifouling coatings for man-made aquatic surfaces.

Environ Pollut 2021 Feb 16;271:116284. Epub 2020 Dec 16.

Laboratório de Biofilmes e Diversidade Microbiana - Faculdade de Farmácia e Centro de Biotecnologia da Universidade Federal do Rio Grande do Sul (UFRGS), Av. Ipiranga, 2752, Bairro Azenha, 90610-000, Porto Alegre, RS, Brazil. Electronic address:

Economic losses can result from biofouling establishment on man-made structures. Macrofouling causes damage to artificial substrates, which justifies the need for its control. However, the antifouling coatings employed nowadays are typically not safe for the environment. Microfouling can affect macrofouling colonization, and thus represents a potential target for alternative antifouling control. From both ecological and economical points of view, information on the ecology and interactions between micro- and macrofouling are crucial to develop successful and safe control strategies, which will prevent biofouling development on man-made structures while preserving water quality and the safety of non-target organisms. This study presents a metabarcoding analysis of biofilm-associated marine bacteria (16S-rRNA-gene) and fungi (ITS-region), with the aim to understand invertebrate settlement over time on hard substrates exposed to natural condition (Control) and two treatments (Antimicrobials and Antifouling Painted). Biofouling composition changed with exposure time (up to 12 days) and showed differences among Control and Antimicrobials and Painted treatments. Antimicrobial treatment influenced more the biofouling composition than traditional antifouling paint (CuO-based). Both treatments caused microbial resistance. Macrofouling establishment was strongly influenced by Gram-negative heterotrophic bacteria (mostly Proteobacteria and Bacteroidetes). Nevertheless, each macrofouling taxon settled in response to a specific biofilm bacterial composition, although other factors can also affect the biofouling community as the condition of the substrate. We suggest that proper friendly antifouling technologies should be focused on inhibiting bacterial biofilm adhesion.
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http://dx.doi.org/10.1016/j.envpol.2020.116284DOI Listing
February 2021

The antivirulence compound myricetin possesses remarkable synergistic effect with antibacterials upon multidrug resistant Staphylococcus aureus.

Microb Pathog 2020 Dec 16;149:104571. Epub 2020 Oct 16.

Departamento de Ciências Básicas da Saúde, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Rua Sarmento Leite, 245, Porto Alegre - RS, 90050-170, Brazil. Electronic address:

Staphylococcus aureus is an opportunistic pathogen involved in several human diseases and presents ability to produce many virulence factors and resistance to antibacterial agents. One of the current strategies to combat such multidrug resistant bacteria is the antibacterial combination therapy. Myricetin is a flavonoid capable of inhibiting several S. aureus virulence factors without influencing on bacterial growth. Therefore, the combination of antibacterials with the antivirulence compound myricetin may provide a positive interaction to control multidrug resistant-bacteria. This work aims to evaluate the effect of the combination of myricetin with oxacillin and vancomycin against methicillin resistant S. aureus (MRSA) and vancomycin intermediate resistant S. aureus (VISA) strains. Concentrations used in combination assays were determined according to the minimum inhibitory concentration (MIC) for antibacterials and to the biofilm minimum inhibitory concentration (BMIC) for myricetin. Checkerboard evaluations showed reduction in MIC for antibacterials in presence of myricetin and time-kill assays confirmed the synergism for these combinations, except for VISA strain when the flavonoid was combined with vancomycin. Importantly, when myricetin was combined with oxacillin, MRSA strain became susceptible to the antibacterial. Myricetin did not reduce staphyloxanthin production, indicating that the oxacillin susceptibility seems not to be related to this step of functional membrane microdomains. In vivo evaluations using Galleria mellonella confirmed the efficacy of oxacillin plus myricetin in treatment of MRSA infected-larvae when compared to the control groups, increasing in 20% host survival. The present work points out the potential of antibacterial and antivirulence compounds combinations as new alternative to control infections by multidrug resistant-bacteria.
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http://dx.doi.org/10.1016/j.micpath.2020.104571DOI Listing
December 2020

Pseudonajide peptide derived from snake venom alters cell envelope integrity interfering on biofilm formation in Staphylococcus epidermidis.

BMC Microbiol 2020 08 3;20(1):237. Epub 2020 Aug 3.

Laboratório de Biofilmes e Diversidade Microbiana, Faculdade de Farmácia and Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.

Background: The increase in bacterial resistance phenotype cases is a global health problem. New strategies must be explored by the scientific community in order to create new treatment alternatives. Animal venoms are a good source for antimicrobial peptides (AMPs), which are excellent candidates for new antimicrobial drug development. Cathelicidin-related antimicrobial peptides (CRAMPs) from snake venoms have been studied as a model for the design of new antimicrobial pharmaceuticals against bacterial infections.

Results: In this study we present an 11 amino acid-long peptide, named pseudonajide, which is derived from a Pseudonaja textilis venom peptide and has antimicrobial and antibiofilm activity against Staphylococcus epidermidis. Pseudonajide was selected based on the sequence alignments of various snake venom peptides that displayed activity against bacteria. Antibiofilm activity assays with pseudonajide concentrations ranging from 3.12 to 100 μM showed that the lowest concentration to inhibit biofilm formation was 25 μM. Microscopy analysis demonstrated that pseudonajide interacts with the bacterial cell envelope, disrupting the cell walls and membranes, leading to morphological defects in prokaryotes.

Conclusions: Our results suggest that pseudonajide's positives charges interact with negatively charged cell wall components of S. epidermidis, leading to cell damage and inhibiting biofilm formation.
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http://dx.doi.org/10.1186/s12866-020-01921-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7397659PMC
August 2020

N -benzyl-N -phenylquinazoline-2,4-diamine compound presents antibacterial and antibiofilm effect against Staphylococcus aureus and Staphylococcus epidermidis.

Chem Biol Drug Des 2020 12 4;96(6):1372-1379. Epub 2020 Aug 4.

Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.

Staphylococcus aureus and Staphylococcus epidermidis are the main agents involved with implant-related infections. Their ability to adhere to medical devices with subsequent biofilm formation is crucial to the development of these infections. Herein, we described the antibacterial and antibiofilm activities of a quinazoline-based compound, N -benzyl-N -phenylquinazoline-2,4-diamine, against both biofilm-forming pathogens. The minimum inhibitory concentrations (MIC) were determined as 25 µM for S. aureus and 15 µM for S. epidermidis. At sub-MIC concentrations (20 µM for S. aureus and 10 µM for S. epidermidis), the compound was able to inhibit biofilm formation without interfere with bacterial growth, confirmed by scanning electron microscopy. Moreover, surfaces coated with the quinazoline-based compound were able to prevent bacterial adherence. In addition, this compound presented no toxicity to human red blood cells at highest MIC 25 µM and in vivo toxicity assay using Galleria mellonella larvae resulted in 82% survival with a high dose of 500 mg/kg body weight. These features evidence quinazoline-based compound as interesting entities to promising applications in biomedical fields, such as antimicrobial and in anti-infective approaches.
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http://dx.doi.org/10.1111/cbdd.13745DOI Listing
December 2020

Trichomonas vaginalis NTPDase inhibited by lycorine modulates the parasite-neutrophil interaction.

Parasitol Res 2020 Aug 11;119(8):2587-2595. Epub 2020 Jun 11.

Laboratório de Pesquisa em Parasitologia, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Av. Ipiranga 2752, Porto Alegre, RS, 90610-000, Brazil.

Lycorine is an Amaryllidaceae alkaloid that presents anti-Trichomonas vaginalis activity. T. vaginalis causes trichomoniasis, the most common non-viral sexually transmitted infection. The modulation of T. vaginalis purinergic signaling through the ectonucleotidases, nucleoside triphosphate diphosphohydrolase (NTPDase), and ecto-5'-nucleotidase represents new targets for combating the parasite. With this knowledge, the aim of this study was to investigate whether NTPDase and ecto-5'-nucleotidase inhibition by lycorine could lead to extracellular ATP accumulation. Moreover, the lycorine effect on the reactive oxygen species (ROS) production by neutrophils and parasites was evaluated as well as the alkaloid toxicity. The metabolism of purines was assessed by HPLC. ROS production was measured by flow cytometry. Cytotoxicity against epithelial vaginal cells and fibroblasts was tested, as well as the hemolytic effect of lycorine and its in vivo toxicity in Galleria mellonella larvae. Our findings showed that lycorine caused ATP accumulation due to NTPDase inhibition. The alkaloid did not affect the ROS production by T. vaginalis; however, it increased ROS levels in neutrophils incubated with lycorine-treated trophozoites. Lycorine was cytotoxic against vaginal epithelial cells and fibroblasts; conversely, it was not hemolytic neither exhibited toxicity against the in vivo model of G. mellonella larvae. Overall, besides having anti-T. vaginalis activity, lycorine modulates ectonucleotidases and stimulates neutrophils to secrete ROS. This mechanism of action exerted by the alkaloid could enhance the susceptibility of T. vaginalis to host immune cell, contributing to protozoan clearance.
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http://dx.doi.org/10.1007/s00436-020-06739-8DOI Listing
August 2020

Remarkable capacity of brosimine b to disrupt methicillin-resistant Staphylococcus aureus (MRSA) preformed biofilms.

Microb Pathog 2020 Mar 3;140:103967. Epub 2020 Jan 3.

Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul (UFRGS), 91501-970, Porto Alegre, RS, Brazil; Programa de Pós-graduação em Ciências Farmacêuticas, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), 90610-000, Porto Alegre, RS, Brazil. Electronic address:

Methicillin-resistant Staphylococcus aureus (MRSA) is a major public health concern representing about 60% of S. aureus isolated from hospitalized patients in countries such as USA and Brazil in the last years. Additionally, the ability to adhere to surfaces and the development of biofilms are important properties of pathogenic bacteria involved in medical device-associated infections, and staphylococci are recognized as the major etiologic agents in these situations. The aim of this study is to evaluate three Brosimum acutifolium flavonoids, 4'-hydroxy-7,8(2″,2″-dimethylpyran)flavan (1), brosimine b (2) and 4-hydroxy-lonchocarpin (3), regarding their antibiofilm, antibacterial and antioxidant activities. Flavonoids 1 and 2 were able to reduce S. aureus viability within preformed biofilms in 73% at 50 μM while 2 also reduced biofilm biomass in 48% at 100 μM. Flavonoid 3 was not able to reduce biofilm biomass at assessed concentrations. When tested against methicillin-resistant S. aureus (MRSA) strains, 2 (100 μM) reduced 70%-98% of viable bacteria within 24h-old biofilms. The minimum inhibitory concentration against the methicillin-sensitive Staphylococcus aureus ATCC 25904 was 50 μM for the three compounds. In preliminary assays to evaluate cytotoxicity, 1 was highly hemolytic at concentrations above 50 μM while 2 and 3 did not cause significant hemolysis at 100 μM. The antioxidant activity was observed only in the ethanolic extract and 2. In vivo toxicity evaluations using Galleria mellonella larvae as alternative host model resulted in 83.3% survival for treatment with 1, 76.7% for 2, and 100% for 3 at 500 mg/kg. This study highlights the potential of these flavonoids, especially 2, as antibiofilm agent to control preformed S. aureus biofilms.
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http://dx.doi.org/10.1016/j.micpath.2020.103967DOI Listing
March 2020

Red pepper peptide coatings control Staphylococcus epidermidis adhesion and biofilm formation.

Int J Pharm 2020 Jan 5;574:118872. Epub 2019 Dec 5.

Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Av. Ipiranga, n. 2752, CEP 90610-000, Bairro Azenha, Porto Alegre, RS, Brazil.

Medical devices (indwelling) have greatly improved healthcare. Nevertheless, infections related to the use of these apparatuses continue to be a major clinical concern. Biofilms form on surfaces after bacterial adhesion, and they function as bacterial reservoirs and as resistance and tolerance factors against antibiotics and the host immune response. Technological strategies to control biofilms and bacterial adhesion, such as the use of surface coatings, are being explored more frequently, and natural peptides may promote their development. In this study, we purified and identified antibiofilm peptides from Capsicum baccatum (red pepper) using chromatography-tandem mass spectrometry, MALDI-MS, MS/MS and bioinformatics. These peptides strongly controlled biofilm formation by Staphylococcus epidermidis, the most prevalent pathogen in device-related infections, without any antibiotic activity. Furthermore, natural peptide-coated surfaces dislayed effective antiadhesive proprieties and showed no cytotoxic effects against different representative human cell lines. Finally, we determined the lead peptide predicted by Mascot and identified CSP37, which may be useful as a prime structure for the design of new antibiofilm agents. Together, these results shed light on natural Capsicum peptides as a possible antiadhesive coat to prevent medical device colonization.
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http://dx.doi.org/10.1016/j.ijpharm.2019.118872DOI Listing
January 2020

Alternative method in Galleria mellonella larvae to study biofilm infection and treatment.

Microb Pathog 2019 Dec 20;137:103756. Epub 2019 Sep 20.

Laboratório de Biofilmes e Diversidade Microbiana, Faculdade de Farmácia and Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil. Electronic address:

In vivo studies are crucial decision-maker step in order to translate in vitro data to an applied therapy. Considering this we describe a simple method that analyzes and quantifies biofilm formation inside the Galleria mellonella larvae. Toothbrush bristles were employed as an abiotic surface to mimic a medical device. A standardized inoculum of Staphylococcus aureus was systemically injected in the larvae together with the insertion of a bristle in the last proleg pair. After incubation adhered cells were detached from bristles and quantified by colony-forming units (CFU) counting using staphylococci-selective medium. About 3 × 10 CFU of S. aureus were recovered from bristles and scanning electron microscopy (SEM) images confirmed biofilm formation. Control group did not show adherent bacteria, as demonstrated by absence of CFU counting and SEM images, indicating that the insertion procedure is free of bacterial contamination. We present a feasible method to evaluate bacterial biofilm formation in vivo that in the near future can be used to evaluate antibiofilm compounds.
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http://dx.doi.org/10.1016/j.micpath.2019.103756DOI Listing
December 2019

Larvae as an Model to Evaluate the Toxicity of Polymeric Nanocapsules.

J Nanosci Nanotechnol 2020 03;20(3):1486-1494

Programa de Pós-GraduaÇão em Ciências Farmacêuticas, Faculdade de Farmácia and Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Av. Ipiranga, 2752, Porto Alegre, 90610-000, Brazil.

larvae is an invertebrate that has been extensively used as experimental model in the investigation of microbial virulence and efficacy of antimicrobial agents and can be used to provide faster and cheaper data than traditional test systems. Our objective was to propose the use of larvae as an model to evaluate the toxicity of lipid-core nanocapsule (LNC) formulations having different surface coatings. Blank LNC formulations were coated with polysorbate 80 (LNC-1), lecithin and polysorbate 80 (LNC-2), and lecithin, chitosan and polysorbate 80 (LNC-3). Subsequently, the formulations were systemically administered to larvae at doses of 3.75×10, 3.75×10, 3.75×10, 3.75×10 and 3.75×10 mols of LNC per kg of larvae. The results demonstrated that those nanocapsules having neutral (LNC-1), negative (LNC-2) or positive (LNC-3) surface did not show acute toxicity effects in larvae. larvae is a viable and promising alternative for nanotoxicological studies. We conclude that larvae can be used as an alternative model for the screening of the toxicity of polymeric nanocapsules functionalized with (i) polysorbate 80, (ii) lecithin and polysorbate 80, and (iii) lecithin, chitosan and polysorbate 80. Future studies can be now developed in order to evaluate their toxicity when loaded or functionalized with drugs.
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http://dx.doi.org/10.1166/jnn.2020.17170DOI Listing
March 2020

Surface coatings select their micro and macrofouling communities differently on steel.

Environ Pollut 2019 Nov 23;254(Pt B):113086. Epub 2019 Aug 23.

Laboratório de Microcontaminantes Orgânicos e Ecotoxicologia Aquática - Instituto de Oceanografia da Universidade Federal do Rio Grande (FURG), Programa de Pós-graduação em Oceanologia (PPGO), Caixa Postal, 474, CEP: 96203-900 Rio Grande, RS, Brazil.

Previous studies have shown the effect of surface coatings on biofouling; however, they did not take into account the interaction of the micro and macrofouling communities, the effect of substrate orientation and the zooplankton-zoobenthic coupling together. Therefore, the aim of this study was to evaluate the effect of Zn- and CuO-based coatings on micro and macrofouling on steel surfaces, while also observing the role of substrate orientation and zooplankton supply. An experiment was carried out in the Patos Lagoon Estuary in southern Brazil for three months between spring and summer, where ASTM-36 steel plates represented different coatings (Zn- and/or CuO-based) and orientations (vertical and horizontal). To assess the zooplankton supply, sampling was carried out weekly using a 200 μm plankton net. Zn-based coating positively affected microfouling density compared to uncoated surfaces. The same pattern was observed with macrofouling, associated with vagile fauna preference, which represented 70% of the settled macrofoulers. CuO-based antifouling painted surfaces showed the highest microfouling density inhibition, while Zn + CuO-based coating did not affect the bacteria adhesion but showed lower density compared to Zn-based coating alone. The coatings combination showed the highest invertebrate inhibition. In this way, the macrofouling community was more sensitive than microfouling was to the antifouling coatings tested. The substrate orientation only affected macrofouling, horizontal surfaces being more attractive than vertical. Meroplankton, tychoplankton and holoplankton were recorded on the surfaces, although their representation in plankton was not proportional to the recruits recorded on the substrates. This was probably due to fast dispersion, the interactions of other factors and/or ecological succession stage. Surface coating, substrate orientation, and zooplankton supply interacted with the biofouling process on steel in different ways depending on the organism evaluated. Therefore, copper oxide- and zinc-based coatings were not suitable as coatings to avoid the total biofouling establishment.
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http://dx.doi.org/10.1016/j.envpol.2019.113086DOI Listing
November 2019

Natural and non-toxic products from Fabaceae Brazilian plants as a replacement for traditional antifouling biocides: an inhibition potential against initial biofouling.

Environ Sci Pollut Res Int 2019 Sep 17;26(26):27112-27127. Epub 2019 Jul 17.

Laboratório de Microcontaminantes Orgânicos e Ecotoxicologia Aquática - Instituto de Oceanografia da Universidade Federal do Rio Grande (FURG), Caixa Postal, 474, Rio Grande, RS, CEP: 96203-900, Brazil.

In this study, we screened for the antifouling activity of 15 species plant extracts from Brazilian the Brazilian Caatinga Fabaceae against the initial colonization of natural marine bacterial biofilm. We also investigated the potential toxicity of extracts against planktonic and benthic non-target organisms. Aqueous extracts of plants collected in the Caatinga biome (PE, Brazil) were prepared and tested at different concentration levels (0, 0.5, 1, 2, 4, and 8 mg mL). Natural marine bacterial consortium was inoculated in multi-well plates and incubated with the different treatments for 48 h. The biofilm and planktonic bacterial density and biomass inhibition were evaluated along with biofilm biomass eradication. The extracts that showed the highest bacterial biofilm inhibition were evaluated for toxicity against microalgae and crustaceans. The biofilm and planktonic bacterial inhibition potential were evaluated through flow cytometry and spectrophotometry. The selected treatments were evaluated for their toxicity using the microalgae Chaetoceros calcitrans, the copepod Nitokra sp., and the brine shrimp Artemia salina as bioindicators. Our work demonstrates the biotechnological potential of Fabaceae plant compounds as a safe antifouling alternative. Anadenanthera colubrina var. cebil fruits and Apuleia leiocarpa leaf extracts showed antibiofilm activity (≥ 80%), while Myroxylon peruiferum and Dioclea grandiflora leaf extracts showed antibiotic activity. These extracts were safe to planktonic and benthic non-target organisms. The results of this study point to potential substitutes to highly toxic antifouling paints and shed light on the prospect of a yet to be explored biome for more sustainable alternatives in biofouling research.
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http://dx.doi.org/10.1007/s11356-019-05744-4DOI Listing
September 2019

Nectandra as a renewable source for (+)-α-bisabolol, an antibiofilm and anti-Trichomonas vaginalis compound.

Fitoterapia 2019 Jul 21;136:104179. Epub 2019 May 21.

Laboratório de Produtos Naturais e Espectrometria de Massas (LaPNEM), Faculdade de Ciências Farmacêuticas, Alimentos e Nutrição (FACFAN), Universidade Federal de Mato Grosso do Sul (UFMS), 79070-900, Campo Grande, MS, Brazil. Electronic address:

Essential oils, mixtures of volatile compounds, are targets of research for new antimicrobial drugs. In order to verify the potential from species of the Nectandra genus, the present study evaluated the essential oils from Nectandra amazonum, Nectandra cuspidata, Nectandra gardineri, Nectandra hihua and Nectandra megapotamica to prospect samples with high concentration of a component and its antibacterial, antibiofilm and anti-Trichomonas vaginalis activities. The essential oils from the leaves and barks were extracted by steam distillation and analyzed by gas chromatography coupled to mass spectrometry (GC-MS). The concentrations of 10 and 100 μg/mL of the essential oil were evaluated and the inhibition of bacterial growth and biofilm formation were measured, while for the evaluation of anti-T. vaginalis trophozoite viability, the concentrations from 7.8 to 1000 μg/mL were tested. Seventy-three compounds were identified from essential oils, highlighted bicyclogermacrene (up to 49.9%), elemicin (up to 42.4%), intermedeol (up to 58.2%), (E)-asarone (up to 45.9%) and (+)-α-bisabolol (up to 93.7%). The essential oil from N. megapotamica leaves presented 93.7% of (+)-α-bisabolol and demonstrated the high capacity of inhibition of the biofilm formation, in particular, against Staphylococcus aureus methicillin resistant (MRSA) and Pseudomonas aeruginosa. This sample also had significant activity against T. vaginalis (IC of 98.7 μg/mL) and demonstrated cytotoxic and hemolytic effects in Vero cells and human erythrocytes. In general, the Nectandra genus revealed high chemical variability and a N. megapotamica specimen accumulated a compound on high concentration with great potential for biotechnological exploration as a new antibiofilm and anti-T. vaginalis.
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http://dx.doi.org/10.1016/j.fitote.2019.104179DOI Listing
July 2019

Macrocolony of NDM-1 Producing subsp. Generates Subpopulations with Different Features Regarding the Response of Antimicrobial Agents and Biofilm Formation.

Pathogens 2019 Apr 14;8(2). Epub 2019 Apr 14.

Faculty of Pharmacy and Center of Biotechnology, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul CE 90610-000, Brazil.

complex has been increasingly recognized as a nosocomial pathogen representing the third major Enterobacteriaceae species involved with infections. This study aims to evaluate virulence and antimicrobial susceptibility of subpopulations generated from macrocolonies of NDM-1 producing clinical isolates. Biofilm was quantified using crystal violet method and fimbrial genes were investigated by PCR. Susceptibility of antimicrobials, alone and combined, was determined by minimum inhibitory concentration and checkerboard assays, respectively. Virulence and efficacy of antimicrobials were evaluated in larvae. Importantly, we verified that some subpopulations that originate from the same macrocolony present different biofilm production ability and distinct susceptibility to meropenem due to the loss of encoding plasmid. A more in-depth study was performed with the 798 macrocolony subpopulations. Type 3 fimbriae were straightly related with biofilm production; however, virulence in larvae was not statistically different among subpopulations. Triple combination with meropenem-rifampicin-polymyxin B showed in vitro synergistic effect against all subpopulations; while in vivo this treatment showed different efficacy rates for 798-1S and 798-4S subpopulations. The ability of multidrug resistant isolates in generating bacterial subpopulations presenting different susceptible and virulence mechanisms are worrisome and may explain why these infections are hardly overcome.
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http://dx.doi.org/10.3390/pathogens8020049DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6631906PMC
April 2019

Anti-staphylococcal activity of Syagrus coronata essential oil: Biofilm eradication and in vivo action on Galleria mellonela infection model.

Microb Pathog 2019 Jun 6;131:150-157. Epub 2019 Apr 6.

Departamento de Bioquímica, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil. Electronic address:

In this study, essential oil extracted from Syagrus coronata seeds (SCEO) was evaluated for antibacterial and antibiofilm activities against Staphylococcus aureus; in addition, Galleria mellonella model was used as an in vivo infection model. SCEO was mainly composed by fatty acids (89.79%) and sesquiterpenes (8.5%). The major components were octanoic acid, dodecanoic acid, decanoic acid and γ-eudesmol. SCEO showed bactericidal activity (minimal bactericidal concentration from 312 to 1250 μg/mL) against all tested S. aureus clinical isolates, which showed distinct biofilm-forming and multiple drug resistance phenotypes. SCEO weakly reduced biomass but remarkably decreased cell viability in pre-formed biofilms of S. aureus isolate UFPEDA-02 (ATCC-6538). Electron microscopy analysis showed that SCEO treatments decreased the number of bacterial cells (causing structural alterations) and lead to loss of the roughness in the multiple layers of the three-dimensional biofilm structure. In addition, overproduction of exopolymeric matrix was observed. SCEO at 31.2 mg/kg improved the survival of G. mellonela larvae inoculated with UFPEDA-02 isolate and reduced the bacterial load in hemolymph and melanization. In conclusion, SCEO is an antibacterial agent against S. aureus strains with different resistance phenotypes and able to disturb biofilm architecture. Our results show SCEO as a potential candidate to drug development.
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http://dx.doi.org/10.1016/j.micpath.2019.04.009DOI Listing
June 2019

Triterpene Derivatives as Relevant Scaffold for New Antibiofilm Drugs.

Biomolecules 2019 02 11;9(2). Epub 2019 Feb 11.

Laboratório de Fitoquímica e Síntese Orgânica, Faculdade de Farmácia, Universidade Federaldo Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, 90610-000, Brasil.

New medicines for the treatment of bacterial biofilm formation are required. For thisreason, this study shows the in vitro activity of betulinic acid (BA), ursolic acid (UA) and their twentyderivatives against planktonic and biofilm cells (gram-positive bacterial pathogens: Enterococcusfaecalis, Staphylococcus aureus and Staphylococcus epidermidis). We evaluated the antibiofilm activity(through the crystal violet method), as well as the antibacterial activity via absorbance (OD600) atconcentrations of 5, 25 and 100 μM. Likewise, the cytotoxicity of all compounds was evaluated on akidney African green monkey (VERO) cell line at the same concentration, by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) methodology. We verified for the first timewhether different groups at carbon 3 (C-3) of triterpenes may interfere in the antibiofilm activity withminimal or no antibacterial effect. After the screening of 22 compounds at three distinctconcentrations, we found antibiofilm activity for eight distinct derivatives without antibiotic effect.In particular, the derivative 2f, with an isopentanoyl ester at position C-3, was an antibiofilm activityagainst S. aureus without any effect upon mammalian cells.
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http://dx.doi.org/10.3390/biom9020058DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6406419PMC
February 2019

Anti-Trichomonas vaginalis activity of chalcone and amino-analogues.

Parasitol Res 2019 Feb 7;118(2):607-615. Epub 2018 Dec 7.

Laboratório de Pesquisa em Parasitologia, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Av. Ipiranga 2752, Porto Alegre, RS, 90610-000, Brazil.

Trichomoniasis is the most common non-viral sexually transmitted disease worldwide and can lead to serious consequences in reproductive health, cancer, and HIV acquisition. The current approved treatment present adverse effects and drug resistance data on this neglected parasitic infection is underestimated. Chalcones are a family of molecules that present biological applications, such as activity against many pathogenic organisms including protozoan pathogens. Chalcone (1) and three amino-analogues (2-4) were synthesized by Claisen-Schmidt condensation reaction and had their activity evaluated against the parasitic protozoan Trichomonas vaginalis. This bioassay indicated the presence and position of the amino group on ring A was crucial for anti-T. vaginalis activity. Among these, 3'-aminochalcone (3) presented the most potent effect and showed high cytotoxicity against human vaginal cells. On the other hand, 3 was not able to exhibit toxicity against Galleria mellonella larvae, as well as the hemolytic effect on human erythrocytes. Trophozoites of T. vaginalis were treated with 3, and did not present significant reactive oxygen species (ROS) accumulation, but induced a significantly higher ROS accumulation in human neutrophils after co-incubation. T. vaginalis pyruvate:ferredoxin oxidoreductase (PFOR) and β-tubulin gene expression was not affected by 3.
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http://dx.doi.org/10.1007/s00436-018-6164-4DOI Listing
February 2019

Promising Antibiofilm Activity of Peptidomimetics.

Front Microbiol 2018 13;9:2157. Epub 2018 Sep 13.

Univ Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR), UMR 6290, Rennes, France.

Pathogenic biofilms are a global health care concern, as they can cause extensive antibiotic resistance, morbidity, mortality, and thereby substantial economic loss. Scientific efforts have been made over the past few decades, but so far there is no effective treatment targeting the bacteria in biofilms. Antimicrobial peptidomimetics have been proposed as promising potential anti-biofilm agents. Indeed, these structurally enhanced molecules can mimic the action of peptides but are not susceptible to proteolysis or immunogenicity, the characteristic limitations of natural peptides. Here, we provide insights into antibiofilm peptidomimetic strategies and molecular targets, and discuss the design of two major peptidomimetics classes: AApeptides (-acylated--aminoethyl-substituted peptides) and peptoids (-substituted glycine units). In particular, we present details of their structural diversity and discuss the possible improvements that can be implemented in order to develop antibiofilm drug alternatives.
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http://dx.doi.org/10.3389/fmicb.2018.02157DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6146102PMC
September 2018

Brown propolis-metabolomic innovative approach to determine compounds capable of killing Staphylococcus aureus biofilm and Trichomonas vaginalis.

Food Res Int 2018 09 23;111:661-673. Epub 2018 May 23.

Laboratório de Produtos Naturais e Espectrometria de Massas (LaPNEM), Faculdade de Ciências Farmacêuticas, Alimentos e Nutrição (FACFAN), Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS 79070-900, Brazil. Electronic address:

Propolis, a resin produced by bees, is widely used in industrial products, including food, cosmetics, supplements, and pharmaceuticals. Extracts (ethanolic and hydroethanolic) and fractions, yielded by accelerated solvent extraction methodology, were obtained from different samples of Brazilian brown propolis (BBP). They were evaluated for antioxidant capacity, antibacterial, antibiofilm, and anti-Trichomonas vaginalis activities. The metabolomics profiling was determined by LC-DAD-MS and an innovative application of statistical analyses (univariate and chemometrics) was applied to correlate chemical compounds with biological activities. Eighty-six compounds were identified, including phenylpropanoic acids, flavonoids, chlorogenic acids, and prenylated phenylpropanoic acids. Propolis-fractions killed about 93% of Staphylococcus aureus in biofilm (at concentration of 125 μg/mL), showed activity against T. vaginalis with MIC at 400 μg/mL and significative antioxidant capacity (IC 2.32-3.80 μg/mL). Propolis extracts and fractions did not show antibacterial and antibiofilm activities against Pseudomonas aeruginosa. The prenylated phenylpropanoic acids positively correlated with both the antibiofilm (S. aureus) and anti-T. vaginalis activities, such as the metabolites artepillin C, drupanin, and baccharin.
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http://dx.doi.org/10.1016/j.foodres.2018.05.033DOI Listing
September 2018

Titanium Surface Chemical Composition Interferes in the Pseudomonas aeruginosa Biofilm Formation.

Artif Organs 2018 Feb;42(2):193-199

Centro Integrado de Inovação Tecnológica do Semiárido, Universidade Federal do Semi-Árido, Mossoró, Brazil.

Bacterial adhesion on three different surfaces: untreated Ti, plasma nitriding, and plasma carbonitriding Ti substrates were investigated. The samples were placed in bacterial cultures of Pseudomonas aeruginosa to assess biofilm formation. The correlation between the amount of bacteria attached to the surface after a lapse of time with nanotopography and physicochemical properties was performed. TiN showed the highest capacity to avoid bacterial adhesion, while presenting intermediate roughness and wettability. Although the surface of TiCN had the highest surface roughness and low contact angle (high wettability), bacterial adhesion was intermediate on this sample. Untreated Ti, even though presenting a smooth surface and low wettability, had the highest tendency to form biofilms.
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http://dx.doi.org/10.1111/aor.12983DOI Listing
February 2018

PgTeL, the lectin found in Punica granatum juice, is an antifungal agent against Candida albicans and Candida krusei.

Int J Biol Macromol 2018 Mar 7;108:391-400. Epub 2017 Dec 7.

Departamento de Bioquímica, Centro de Biociências, Universidade Federal de Pernambuco, 50670-420, Recife, Pernambuco, Brazil. Electronic address:

The pomegranate (Punica granatum) sarcotesta contains a chitin-binding lectin (PgTeL) with antibacterial activity against human pathogenic species. In this work, the structural stability of PgTeL was evaluated by fluorimetric analysis and the lectin was evaluated for cytotoxicity to human peripheral blood mononuclear cells (PBMCs) and antifungal activity against Candida albicans and Candida krusei. PgTeL folding was impaired when lectin was incubated at pH≥6.0. On the other hand, the lectin did not undergo unfolding even when heated at 100°C. PgTeL (1, 10, and 100μg/mL) was not cytotoxic to PBMCs. Antifungal activity was detected for C. albicans (MIC: 25μg/mL; MFC: 50μg/mL) and C. krusei (MIC and MFC of 12.5μg/mL). Treatment of yeast cells with PgTeL resulted in decrease of intracellular ATP content even at sub-inhibitory concentrations (½MIC and ¼MIC) and induced lipid peroxidation. In addition, PgTeL damaged the integrity of fungal cell wall of both species, with more pronounced effects in C. krusei. The lectin showed significant antibiofilm activity on C. albicans at sub-inhibitory concentrations (0.195 and 0.39μg/mL). In conclusion, PgTeL is an anti-Candida agent whose action mechanism involves oxidative stress, energetic collapse, damage to the cell wall and rupture of yeast cells.
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http://dx.doi.org/10.1016/j.ijbiomac.2017.12.039DOI Listing
March 2018

Trichomonicidal and parasite membrane damaging activity of bidesmosic saponins from Manilkara rufula.

PLoS One 2017 30;12(11):e0188531. Epub 2017 Nov 30.

Laboratório de Pesquisa em Parasitologia, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.

The infection caused by Trichomonas vaginalis is the most common but overlooked non-viral sexually transmitted disease worldwide. Treatment relies on one class of drugs, the 5-nitroimidazoles, but resistance is widespread. New drugs are urgently needed. We reported the effect of crude and purified saponin fractions of Manilkara rufula against Trichomonas vaginalis. The compound responsible for antitrichomonal activity was isolated and identified as an uncommon bidesmosic saponin, Mi-saponin C. This saponin eliminated parasite viability without toxicity against the human vaginal epithelial line (HMVII). In addition, the isolated saponin fraction improved the metronidazole effect against a metronidazole-resistant isolate and dramatically reduced the cytoadherence of T. vaginalis to human cells. Investigation of the mechanism of death showed that the saponin fraction induced the parasite death due to profound membrane damage, inducing a disturbance of intracellular content without nuclear damage. To the best of our knowledge, this is the first report of antitrichomonal activity in the bidesmosic saponins of Manilkara rufula.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0188531PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5708768PMC
December 2017

Peptides as a strategy against biofilm-forming microorganisms: Structure-activity relationship perspectives.

Eur J Pharm Sci 2018 Mar 11;114:114-137. Epub 2017 Nov 11.

Programa de Pós-Graduação em Ciências Farmacêuticas, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Av. Ipiranga, n.2752, CEP 90610-000, Bairro Azenha, Porto Alegre, Rio Grande do Sul, Brazil. Electronic address:

Biofilm forming microorganisms substantially enhance their virulence and drug resistance causing and alternatives are need to combat this health problem. In this context, peptides are an exceptional strategy in drug design and pharmaceutical innovation due to their diverse chemical features, biological activity and biotechnological relevance. Therefore, this study proposes a comprehensive assessment of a wide range of peptides, targeting biofilms. It provides chemical and molecular information and a Structural Activity Relationship perspective in order to delineate minimal requirements for antibiofilm activity and contributing to the development of new antibiofilm agents. In light of this, it was possible to propose a peptide design model (X-X-X-X-X-X-X-X-X-X-X-X-X-X-X-X-X-X-X-X) to be tested in the war against resistant microorganisms.
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http://dx.doi.org/10.1016/j.ejps.2017.11.008DOI Listing
March 2018

Trichomonas vaginalis clinical isolates: cytoadherence and adherence to polystyrene, intrauterine device, and vaginal ring.

Parasitol Res 2017 Dec 13;116(12):3275-3284. Epub 2017 Oct 13.

Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Av. Ipiranga 2752, Porto Alegre, RS, 90610-000, Brazil.

The parasitism by Trichomonas vaginalis is complex and in part is mediated by cytoadherence accomplished via five surface proteins named adhesins and a glycoconjugate called lipophosphoglycan (TvLPG). In this study, we evaluated the ability of T. vaginalis isolates to adhere to cells, plastic (polystyrene microplates), intrauterine device (IUD), and vaginal ring. Of 32 T. vaginalis isolates, 4 (12.5%) were strong adherent. The T. vaginalis isolates TV-LACM6 and TV-LACM14 (strong polystyrene-adherent) were also able to adhere to IUD and vaginal ring. Following chemical treatments, results demonstrated that the T. vaginalis components, lipophosphoglycan, cytoskeletal proteins, and surface molecules, were involved in both adherence to polystyrene and cytoadherence. The gene expression level from four adhesion proteins was highest in trophozoites adhered to cells than trophozoites adhered to the abiotic surface (polystyrene microplate). Our data indicate the major involvement of TvLPG in adherence to polystyrene, and that adhesins are important for cytoadherence. Furthermore, to our knowledge, this is the first report showing the T. vaginalis adherence to contraceptive devices, reaffirming its importance as pathogen among women in reproductive age.
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http://dx.doi.org/10.1007/s00436-017-5638-0DOI Listing
December 2017

Effects of Caatinga Plant Extracts in Planktonic Growth and Biofilm Formation in Ralstonia solanacearum.

Microb Ecol 2018 Apr 17;75(3):555-561. Epub 2017 Sep 17.

Departamento de Bioquímica, Universidade Federal de Pernambuco (UFPE), Recife, Pernambuco, Brazil.

This study describes the first antibiofilm and antibacterial screening for plants from Caatinga against Ralstonia solanacearum, a causal agent of bacterial wilt that presents serious difficulties in control. There were prepared 22 aqueous extracts of plants collected in the Vale do Catimbau-PE, Brazil. The potential antibacterial activity was evaluated by absorbance in OD and the antibiofilm activity through the crystal violet method, both of them performed in microplate against isolates of R. solanacearum biofilm formers. The results of the screening showed that Jacaranda rugosa presented antimicrobial activity higher than 90%, while Harpochilus neesianus and Myroxylon peruiferum presented antibiofilm activity higher than 50% for all tested isolates. However, Croton heliotropiifolius showed both the activities, being thus very promising for application in the control of this phytopathogen. The search for viable alternatives to the development of new bioactive compounds safe for the environment, humans, and animals from an adverse and scarce environment such as the Caatinga and encouraged us to find plants that produce effective metabolites against phytopathogenic microorganisms. This in vitro screening is important to guide the development of new products in addition to guide research studies of bioactive compounds.
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http://dx.doi.org/10.1007/s00248-017-1073-0DOI Listing
April 2018

Diamine derivative anti-Trichomonas vaginalis and anti-Tritrichomonas foetus activities by effect on polyamine metabolism.

Biomed Pharmacother 2017 Nov 10;95:847-855. Epub 2017 Sep 10.

Laboratório de Pesquisa em Parasitologia, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Av. Ipiranga 2752, 90610-000, Porto Alegre, RS, Brazil. Electronic address:

Human and bovine trichomoniasis are sexually transmitted diseases (STD) caused by Trichomonas vaginalis and Tritrichomonas foetus, respectively. Human trichomoniasis is the most common non-viral STD in the world and bovine trichomoniasis causes significant economic losses to breeders. Considering the significant impact of the infections caused by these protozoa and the treatment failures, the search for new therapeutic alternatives becomes crucial. In this study the effect of diamines and amino alcohols in the in vitro viability of trichomonads was evaluated. Screening demonstrated the high activity of diamine 4 against these protozoa. Although cytotoxicity against HMVII cell line and slight hemolysis were observed in vitro, the compound showed no toxic effect on the Galleria mellonella in vivo model. Importantly, diamine 4 was active against both trichomonads species at 6h and 24h of incubation, and these effects was reverted by putrescine, a polyamine, suggesting competition for the same metabolic pathway. These findings indicate that the mechanism of action of diamine 4 is through the polyamine metabolism, a pathway distinct from that presented by metronidazole, the drug usually used to treat trichomoniasis and to which resistance is widely reported. These data demonstrate the importance of diamines as potential novel candidates as anti-T. vaginalis and anti-T. foetus agents.
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http://dx.doi.org/10.1016/j.biopha.2017.09.007DOI Listing
November 2017

What determines sclerobiont colonization on marine mollusk shells?

PLoS One 2017 13;12(9):e0184745. Epub 2017 Sep 13.

Departamento de Paleontologia e Estratigrafia, Instituto de Geociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.

Empty mollusk shells may act as colonization surfaces for sclerobionts depending on the physical, chemical, and biological attributes of the shells. However, the main factors that can affect the establishment of an organism on hard substrates and the colonization patterns on modern and time-averaged shells remain unclear. Using experimental and field approaches, we compared sclerobiont (i.e., bacteria and invertebrate) colonization patterns on the exposed shells (internal and external sides) of three bivalve species (Anadara brasiliana, Mactra isabelleana, and Amarilladesma mactroides) with different external shell textures. In addition, we evaluated the influence of the host characteristics (mode of life, body size, color alteration, external and internal ornamentation and mineralogy) of sclerobionts on dead mollusk shells (bivalve and gastropod) collected from the Southern Brazilian coast. Finally, we compared field observations with experiments to evaluate how the biological signs of the present-day invertebrate settlements are preserved in molluscan death assemblages (incipient fossil record) in a subtropical shallow coastal setting. The results enhance our understanding of sclerobiont colonization over modern and paleoecology perspectives. The data suggest that sclerobiont settlement is enhanced by (i) high(er) biofilm bacteria density, which is more attracted to surfaces with high ornamentation; (ii) heterogeneous internal and external shell surface; (iii) shallow infaunal or attached epifaunal life modes; (iv) colorful or post-mortem oxidized shell surfaces; (v) shell size (<50 mm2 or >1,351 mm2); and (vi) calcitic mineralogy. Although the biofilm bacteria density, shell size, and texture are considered the most important factors, the effects of other covarying attributes should also be considered. We observed a similar pattern of sclerobiont colonization frequency over modern and paleoecology perspectives, with an increase of invertebrates occurring on textured bivalve shells. This study demonstrates how bacterial biofilms may influence sclerobiont colonization on biological hosts (mollusks), and shows how ecological relationships in marine organisms may be relevant for interpreting the fossil record of sclerobionts.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0184745PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5597280PMC
October 2017

Population Pharmacokinetic Modeling as a Tool To Characterize the Decrease in Ciprofloxacin Free Interstitial Levels Caused by Pseudomonas aeruginosa Biofilm Lung Infection in Wistar Rats.

Antimicrob Agents Chemother 2017 07 27;61(7). Epub 2017 Jun 27.

Pharmaceutical Sciences Graduate Program, College of Pharmacy, Federal University of Rio Grande do Sul, Porto Alegre, Brazil

Biofilm formation plays an important role in the persistence of pulmonary infections, for example, in cystic fibrosis patients. So far, little is known about the antimicrobial lung disposition in biofilm-associated pneumonia. This study aimed to evaluate, by microdialysis, ciprofloxacin (CIP) penetration into the lungs of healthy and biofilm-infected rats and to develop a comprehensive model to describe the CIP disposition under both conditions. was immobilized into alginate beads and intratracheally inoculated 14 days before CIP administration (20 mg/kg of body weight). Plasma and microdialysate were sampled from different animal groups, and the observations were evaluated by noncompartmental analysis (NCA) and population pharmacokinetic (popPK) analysis. The final model that successfully described all data consisted of an arterial and a venous central compartment and two peripheral distribution compartments, and the disposition in the lung was modeled as a two-compartment model structure linked to the venous compartment. Plasma clearance was approximately 32% lower in infected animals, leading to a significantly higher level of plasma CIP exposure (area under the concentration-time curve from time zero to infinity, 27.3 ± 12.1 μg · h/ml and 13.3 ± 3.5 μg · h/ml in infected and healthy rats, respectively). Despite the plasma exposure, infected animals showed a four times lower tissue concentration/plasma concentration ratio (lung penetration factor = 0.44 and 1.69 in infected and healthy rats, respectively), and lung clearance (CL) was added to the model for these animals (CL = 0.643 liters/h/kg) to explain the lower tissue concentrations. Our results indicate that biofilm infection reduces the CIP free interstitial lung concentrations and increases plasma exposure, suggesting that plasma concentrations alone are not a good surrogate of lung concentrations.
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http://dx.doi.org/10.1128/AAC.02553-16DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5487627PMC
July 2017

The anti-Trichomonas vaginalis phloroglucinol derivative isoaustrobrasilol B modulates extracellular nucleotide hydrolysis.

Chem Biol Drug Des 2017 Nov 14;90(5):811-819. Epub 2017 May 14.

Laboratório de Pesquisa em Parasitologia, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.

Trichomonas vaginalis causes trichomoniasis, a neglected sexually transmitted disease. Due to severe health consequences and treatment failure, new therapeutic alternatives are crucial. Phloroglucinols from southern Brazilian Hypericum species demonstrated anti-T. vaginalis and anti-Leishmania amazonensis activities. The modulation of biochemical pathways involved in the control of inflammatory response by ectonucleotidases, NTPDase, and ecto-5'-nucleotidase represents new targets for combating protozoa. This study investigated the activity of phloroglucinol derivatives of Hypericum species from southern Brazil against T. vaginalis as well as its ability on modulating parasite ectonucleotidases and, consequently, immune parameters through ATP and adenosine effects. Phloroglucinol derivatives screening revealed activity for isoaustrobrasilol B (IC 38 μm) with no hemolytic activity. Although the most active compound induced cytotoxicity against a mammalian cell lineage, the in vivo model evidenced absence of toxicity. Isoaustrobrasilol B significantly inhibited NTPDase and ecto-5'-nucleotidase activities, and the immune modulation attributed to extracellular nucleotide accumulation was evaluated. The production of ROS and IL-6 by T. vaginalis-stimulated neutrophils was not affected by the treatment. Conversely, IL-8 levels were significantly enhanced. The associative mechanism of trophozoites death and ectonucleotidases modulation by isoaustrobrasilol B may increase the susceptibility of T. vaginalis to host innate immune cell like neutrophils consequently, contributing to parasite clearance.
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http://dx.doi.org/10.1111/cbdd.13002DOI Listing
November 2017

The Caatinga endemic Manilkara rufula possesses remarkable activity against Trichomonas vaginalis and Tritrichomonas foetus.

Exp Parasitol 2017 Feb 9;173:18-28. Epub 2016 Dec 9.

Laboratório de Pesquisa em Parasitologia, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Instituto Nacional do Semi-Árido (INSA), Núcleo de Bioprospecção da Caatinga (NBioCaat), Campina Grande, Pernambuco, Brazil. Electronic address:

Tritrichomonas foetus infects the bovine urogenital tract, causing bovine trichomoniasis. Significant economic losses may occur due to infertility and abortion among cattle. Trichomonas vaginalis is the causative agent of trichomoniasis; the most common but overlooked non-viral sexually transmitted disease worldwide. Human and bovine trichomoniasis present treatment restrictions and efforts to identify new alternatives are essential. The present study evaluated the anti-trichomonads activities of seven fractions from northwest endemic plant Manilkara rufula. Flavonoids and condensed tannins were identified from these fractions by LC-DAD-MS/MS and MALDI-MS/MS. Altogether, the results demonstrated for the first time the structural description of tannins from leaves of M. rufula and the relation of these compounds with anti-T. vaginalis and anti-T. foetus activities. Overall, this report reveals the potential of M. rufula fractions against both parasites and shows new alternatives to treat the infection caused by trichomonads.
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http://dx.doi.org/10.1016/j.exppara.2016.12.006DOI Listing
February 2017

Activity of pyrrolizidine alkaloids against biofilm formation and Trichomonas vaginalis.

Biomed Pharmacother 2016 Oct 9;83:323-329. Epub 2016 Jul 9.

Departamento de Farmácia, Universidade Federal do Rio Grande do Norte, Gustavo Cordeiro de Faria, SN, CEP 59010-180, Natal, RN, Brazil. Electronic address:

Crotalaria genus belongs to the subfamily Papilionoideae comprising about 600 species spread throughout tropical, neotropical and subtropical regions. In this study, seeds of Crolatalaria pallida were used to the isolation of usaramine, a pyrrolizidine alkaloid. Thus, Pseudomonas aeruginosa and Staphylococcus epidermidis were utilized as strains to test some activities of this alkaloid, such as antibiofilm and antibacterial. Meanwhile, monocrotaline obtained from Crotalaria retusa seeds, was used as the starting material for synthesis of necine base derivatives with anti-Trichomonas vaginalis potential. Alkaloids were characterized by 1D and 2D NMR techniques and GC-MS analysis. Usaramine demonstrated a highlighted antibiofilm activity against S. epidermidis by reducing more than 50% of biofilm formation without killing the bacteria, thus it could be assumed as a prototype for the development of new antibiofilm molecules for pharmaceutical and industrial purposes. Monocrotaline activity against T. vaginalis was evaluated and results indicated inhibition of 80% on parasite growth at 1mg/mL, in addition, neither cytotoxicity against vaginal epithelial cells nor hemolytic activity were observed. On the other hand, retronecine showed no anti-T. vaginalis activity while azido-retronecine was more active than monocrotaline killing 85% of the parasites at 1mg/mL. In conclusion, pyrrolizidine alkaloids are suggested as promising prototypes for new drugs especially for topical use.
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http://dx.doi.org/10.1016/j.biopha.2016.06.033DOI Listing
October 2016