31,415 results match your criteria Infection and Immunity[Journal]


The autotransporter IcsA promotes biofilm formation in presence of bile salts.

Infect Immun 2019 Apr 15. Epub 2019 Apr 15.

Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, 22908

is an intracellular bacterial pathogen that invades epithelial cells in the colonic mucosa, leading to bloody diarrhea. A previous study showed that forms biofilm in the presence of bile salts, through an unknown mechanism. Here, we investigated the potential role of adhesin-like autotransporter proteins in biofilm formation. Read More

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http://dx.doi.org/10.1128/IAI.00861-18DOI Listing

New Zealand White rabbits effectively clear B31 despite the bacteria's functional antigenic variation system.

Infect Immun 2019 Apr 15. Epub 2019 Apr 15.

Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical; Sciences, Texas A&M University, College Station, TX 77843, USA

is a tick-borne bacterium responsible for approximately 300,000 annual cases of Lyme disease (LD) in the USA with increasing incidents in other parts of the world. The debilitating nature of LD is mainly attributed to the ability of to persist in patients for many years despite strong anti- antibody responses. Antimicrobial treatment of persistent infection is challenging. Read More

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http://dx.doi.org/10.1128/IAI.00164-19DOI Listing

A strain expressing OVA stimulates an antigen-specific CD4 T cell response in mice.

Infect Immun 2019 Apr 15. Epub 2019 Apr 15.

Department of Microbiology, Harvard Medical School, Boston, MA 02115

Antigen-specific CD4 T cells against are crucial for driving bacterial clearance and mediating protection against reinfection. Although the protein Cta1 has been identified as a dominant murine CD4 T cell antigen, its level of expression during the bacterial developmental cycle and precise localization within the host cell is unknown. Newly developed tools for genetic manipulation have allowed us to generate a strain expressing a heterologous CD4 T cell epitope from ovalbumin, OVA By tagging proteins expressed in with OVA, we can begin to understand how protein expression, developmental regulation, and subcellular compartmentalization affect the potential of those proteins to serve as antigens. Read More

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http://iai.asm.org/lookup/doi/10.1128/IAI.00837-18
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http://dx.doi.org/10.1128/IAI.00837-18DOI Listing
April 2019
1 Read

The type III effector EseJ suppresses the expression of type 1 fimbriae leading to decreased bacterial adherence to host cells.

Infect Immun 2019 Apr 15. Epub 2019 Apr 15.

State Key Laboratory of Freshwater Ecology and Biotechnology, and Key Laboratory of Aquaculture Diseases Control, Ministry of Agriculture, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.

The type III secretion system (T3SS) of plays a crucial role in its pathogenesis. Our previous study has indicated that the T3SS effector protein EseJ inhibits the bacterium's adhesion to epithelioma papillosum cyprini (EPC) cells, while the mechanism of the inhibition remains elusive. In this study, we revealed that EseJ negatively regulates the gene as demonstrated by comparative transcription analysis on Δ and wild-type (WT) strains. Read More

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http://dx.doi.org/10.1128/IAI.00187-19DOI Listing

Role of Sialic Acid in Adhesion to Pig Colonic Mucins.

Infect Immun 2019 Apr 15. Epub 2019 Apr 15.

Department of Medical Biochemistry and Cell biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden

Infection with results in mucoid hemorrhagic diarrhea. This pathogen is associated with the colonic mucus layer, mainly composed of mucins. Infection regulates mucin -glycosylation in the colon and increases mucin secretion as well as binding sites on mucins. Read More

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http://dx.doi.org/10.1128/IAI.00889-18DOI Listing

Functional antibodies against placental malaria parasites are variant-dependent and differ by geographic region.

Infect Immun 2019 Apr 15. Epub 2019 Apr 15.

Laboratory of Malaria Immunology & Vaccinology, National Institute of Allergy and Infectious Disease, NIH, Bethesda - USA

During pregnancy, infected erythrocytes (IE) accumulate in the intervillous spaces of the placenta by binding to chondroitin sulfate A (CSA), and elicit inflammatory responses that are associated with poor pregnancy outcomes. Primigravid women lack immunity to IE that sequester in the placenta, and thus are susceptible to placental malaria (PM). Women become resistant to PM over successive pregnancies as antibodies to placental IE are acquired. Read More

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http://dx.doi.org/10.1128/IAI.00865-18DOI Listing
April 2019
3.731 Impact Factor

Antigen-specific CD4 T cell-derived IFNγ is both necessary and sufficient for clearing from the small intestine but not the large intestine.

Infect Immun 2019 Apr 8. Epub 2019 Apr 8.

Department of Microbiology, Immunology, and Molecular Genetics, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229

The genital tract pathogen is frequently detected in the gastrointestinal tract but the host immunity that regulates chlamydial colonization in the gut remains unclear. In a -C57 mouse model, chlamydial organisms are cleared from the genital tract in ∼4 weeks but the genital organisms can spread to the gastrointestinal tract. We found that the gastrointestinal chlamydial organisms were cleared from the small intestine by day 28, paralleling their infection course in the genital tract, but persisted in the large intestine for long periods of time. Read More

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http://dx.doi.org/10.1128/IAI.00055-19DOI Listing

Identification of conserved candidate vaccine antigens in the surface proteome of .

Infect Immun 2019 Apr 8. Epub 2019 Apr 8.

Department of Medicine, University of California, San Diego, La Jolla, California, USA

, one of the most common protozoal infections of the human intestine, is an important worldwide cause of diarrheal disease, malabsorption, malnutrition, delayed cognitive function in children, and protracted post-infectious syndromes. Despite its medical importance, no human vaccine is available against giardiasis. A crude veterinary vaccine has been developed, and experimental vaccines based on expression of multiple variant-specific surface proteins have been reported, but poorly defined vaccine components and excessive antigen variability are problematic for pharmaceutical vaccine production. Read More

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http://dx.doi.org/10.1128/IAI.00219-19DOI Listing

Pathogenic invades differentiated bovine airway epithelial cells.

Infect Immun 2019 Apr 8. Epub 2019 Apr 8.

Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK

The Gram-negative bacterium is the primary bacterial species associated with bovine respiratory disease (BRD) which is responsible for significant economic losses to the livestock industries worldwide. Healthy cattle are frequently colonised by commensal serotype A2 strains, but disease is usually caused by pathogenic strains of serotype A1. For reasons that are poorly understood, a transition occurs within the respiratory tract and a sudden explosive proliferation of serotype A1 bacteria leads to the onset of pneumonic disease. Read More

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http://iai.asm.org/lookup/doi/10.1128/IAI.00078-19
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http://dx.doi.org/10.1128/IAI.00078-19DOI Listing
April 2019
2 Reads

Transmission-blocking vaccines: old friends and new prospects.

Infect Immun 2019 Apr 8. Epub 2019 Apr 8.

Immunology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana

In the progression of the life cycle of , a small proportion of asexual parasites differentiate into male or female sexual forms called gametocytes. Gametocytes just like their asexual counterparts are contained within the infected host's erythrocytes. However, unlike their asexual partners, they do not exit the RBC until they are taken up in a blood meal by a mosquito. Read More

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http://dx.doi.org/10.1128/IAI.00775-18DOI Listing

The rate of CD4 T cell entry into the lungs during infection is determined by partial and opposing effects of multiple chemokine receptors.

Infect Immun 2019 Apr 8. Epub 2019 Apr 8.

T Lymphocyte Biology Unit, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA

The specific chemokine receptors utilized by Th1 cells to migrate into the lung during infection is unknown. We previously showed in mice that CXCR3 Th1 cells enter the lung parenchyma and suppress Mtb growth, while CX3CR1KLRG1 Th1 cells accumulate in lung vasculature and are non-protective. Here we quantify the contributions of these chemokine receptors to the migration and entry rate of Th1 cells into Mtb-infected lungs using competitive adoptive transfer migration assays and mathematical modeling. Read More

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http://dx.doi.org/10.1128/IAI.00841-18DOI Listing

Suppression of obesity by an intestinal helminth through interactions with intestinal microbiota.

Infect Immun 2019 Apr 8. Epub 2019 Apr 8.

Department of Parasitology, National Institute of Infectious Diseases, Tokyo, Japan

Obesity is increasingly causing lifestyle diseases in developed countries where helminthic infections are rarely seen. Here, we investigated whether an intestinal nematode, (Hp), has a suppressive role for diet-induced obesity in mice. Infection with Hp suppressed weight gain in obese mice, which was associated with increased uncoupling protein 1 (UCP1) expression in adipocytes and a higher serum norepinephrine (NE) concentration. Read More

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http://dx.doi.org/10.1128/IAI.00042-19DOI Listing
April 2019
2 Reads

Study of effector domains revealed novel and prevalent phosphatidylinositol 3-phosphate binding domains.

Infect Immun 2019 Apr 8. Epub 2019 Apr 8.

Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, 69978, Israel

and other species replicate intracellularly using the Icm/Dot type-IV secretion system. In this system translocates >300 effectors into host cells and in the genus thousands of effectors were identified, the function of most of which is unknown. Twelve effectors were previously shown to specifically bind phosphoinositides (PIs) using dedicated domains. Read More

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http://dx.doi.org/10.1128/IAI.00153-19DOI Listing

A Genomic Approach to Identify and Strains with Enhanced Competitive Fitness in the Lungs During Multi-Strain Pneumonia.

Infect Immun 2019 Apr 1. Epub 2019 Apr 1.

Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA

Microbial competition is most often studied at the genus or species level, but interstrain competition has been less thoroughly examined. is an important pathogen in the context of hospital-acquired pneumonia, and a better understanding of strain competition in the lungs could explain why some strains of this bacterium are more frequently isolated from pneumonia patients than others. We developed a barcode-free method called "StrainSeq" to simultaneously track the abundance of ten strains in a murine pneumonia model. Read More

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http://dx.doi.org/10.1128/IAI.00871-18DOI Listing
April 2019
2 Reads

NOD- Mouse Model is suitable to Study Osteoarticular Brucellosis and Vaccine Safety.

Infect Immun 2019 Apr 1. Epub 2019 Apr 1.

Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA.

Osteoarticular brucellosis is the most common complication in -infected humans regardless of age, sex, or immune status. The mechanism of bone destruction caused by species remained partially unknown due to the lack of a suitable animal model. Here, to study this complication, we explored the suitability of the use of the NOD- mouse to study osteoarticular brucellosis and examined the potential use of this strain to evaluate the safety of live attenuated vaccine candidates. Read More

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http://dx.doi.org/10.1128/IAI.00901-18DOI Listing
April 2019
3 Reads

The Second Messenger c-di-AMP Regulates Diverse Cellular Pathways Involved in Stress Response, Biofilm Formation, Cell Wall Homeostasis, SpeB Expression and Virulence in .

Infect Immun 2019 Apr 1. Epub 2019 Apr 1.

Department of Biology, Indiana State University, Terre Haute, Indiana 47809

Cyclic di-adenosine monophosphate (c-di-AMP) is a recently discovered second messenger in bacteria. The cellular level of c-di-AMP in is predicted to be controlled by the synthase DacA and two putative phosphodiesterases, GdpP and Pde2. To investigate the role of c-di-AMP in , we generated null mutants in each of these proteins by gene deletion. Read More

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http://dx.doi.org/10.1128/IAI.00147-19DOI Listing
April 2019
1 Read

Low-level Parasite Persistence Drives Vasculitis and Myositis in Skeletal Muscle of Mice Chronically-infected with.

Infect Immun 2019 Apr 1. Epub 2019 Apr 1.

Laboratory of Molecular Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), Bethesda, Maryland, United States of America.

In chronic () infection, the cause of Chagas disease, life-threatening inflammatory diseases develop over time in the heart, esophagus, and colon of some patients. C57BL/6 mice infected with the myotropic strain of model many of the immunologic and parasitologic features of the human infection but succumb to chronic paralyzing myositis and skeletal muscle vasculitis, not cardiomyopathy or gastrointestinal disease. Here we show that T cell depletion in the chronic phase of this model increased tissue parasitism to acute phase levels, and induced neutrophilic skeletal muscle inflammation. Read More

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http://dx.doi.org/10.1128/IAI.00081-19DOI Listing

Bacteriophage resistance alters antibiotic mediated intestinal expansion of enterococci.

Infect Immun 2019 Apr 1. Epub 2019 Apr 1.

Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, USA, 80045

is a human intestinal pathobiont with intrinsic and acquired resistance to many antibiotics, including vancomycin. Nature provides a diverse and virtually untapped repertoire of bacterial viruses, or bacteriophages (phages), that could be harnessed to combat multi-drug resistant enterococcal infections. Bacterial phage resistance represents a potential barrier to the implementation of phage therapy, emphasizing the importance of investigating the molecular mechanisms underlying the emergence of phage resistance. Read More

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http://iai.asm.org/lookup/doi/10.1128/IAI.00085-19
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http://dx.doi.org/10.1128/IAI.00085-19DOI Listing
April 2019
2 Reads

Group A T-antigens have a highly conserved structure concealed under a heterogeneous surface that has implications for vaccine design.

Infect Immun 2019 Apr 1. Epub 2019 Apr 1.

Maurice Wilkins Centre, The University of Auckland, Auckland, New Zealand

Group A (GAS, ) is an important human pathogen associated with significant global morbidity and mortality for which there is no safe and efficacious vaccine. The T-antigen, a protein that polymerises to form the backbone of the GAS pilus structure, is a potential vaccine candidate. Previous surveys of the gene, which encodes the T-antigen, have identified 21 different -types and subtypes such that any T-antigen-based vaccine must be multivalent and carefully designed to provide broad strain coverage. Read More

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http://iai.asm.org/lookup/doi/10.1128/IAI.00205-19
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http://dx.doi.org/10.1128/IAI.00205-19DOI Listing
April 2019
1 Read

Combining MPL, CpG ODN, and QS-21 adjuvants induce strong and persistent functional antibodies and T cell responses against cell-traversal protein for ookinetes and sporozoites (CelTOS) of in BALB/c mice.

Infect Immun 2019 Apr 1. Epub 2019 Apr 1.

Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran.

cell-traversal protein for ookinetes and sporozoites (PfCelTOS) is an advanced vaccine candidate that has a crucial role in the traversal of the malaria parasite in both mosquito and mammalian hosts. As recombinant purified proteins are normally poor immunogens, they require to be admixed with adjuvant(s); therefore, the objective of the present study was to evaluate the capacity of different vaccine adjuvants, MPL, CpG, and QS-21 alone or in combination MPL/CpG/QS-21 (MCQ) on the enhancement of the immunogenicity of -expressed PfCelTOS in BALB/c mice. This goal was achieved by the assessment of the anti-PfCelTOS IgG antibodies (level, titer, its IgG isotypes profile, its avidity, and its persistence), and the extracellular Th1 cytokines using enzyme-linked immunosorbent assay (ELISA) in post-immunized BALB/c mouse sera and PfCelTOS-stimulated splenocytes, respectively. Read More

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http://dx.doi.org/10.1128/IAI.00911-18DOI Listing

Uptake of sialic acid by non-typeable increases complement resistance through decreasing IgM-dependent complement activation.

Infect Immun 2019 Apr 1. Epub 2019 Apr 1.

Section Pediatric Infectious Diseases, Laboratory of Medical Immunology, Radboud Institute for Molecular Life Sciences, Radboudumc, Nijmegen, the Netherlands

Although non-typeable (NTHi) is a human-specific nasopharyngeal commensal bacterium, it also causes upper respiratory tract infections in children and lower respiratory tract infections in the elderly, resulting in frequent antibiotics use. The transition from symbiotic colonizing bacterium to opportunistic pathogen is not completely understood. Incorporation of sialic acids into lipooligosaccharides is thought to play an important role in bacterial virulence. Read More

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http://dx.doi.org/10.1128/IAI.00077-19DOI Listing
April 2019
1 Read

Prediction and validation of immunogenic domains of pneumococcal proteins recognized by human CD4 T-cells.

Infect Immun 2019 Mar 25. Epub 2019 Mar 25.

Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, The Netherlands

CD4 T-cell mechanisms are implied in protection against pneumococcal colonization; however, their target antigens and function are not well defined. In contrast to high-throughput protein arrays for serology, basic antigen tools for CD4 T-cell studies are lacking. Here we evaluate the potential of an bioinformatics tool prediction of immunogenicity as a method to reveal domains of pneumococcal proteins targeted by human CD4 T-cells. Read More

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http://dx.doi.org/10.1128/IAI.00098-19DOI Listing

Tracking of transmission from infected nymphs to mice.

Infect Immun 2019 Mar 25. Epub 2019 Mar 25.

Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Branisovska 31, 370 05 Ceske Budejovice, Czech Republic

Quantitative and microscopic tracking of transmission from infected nymphs has shown transmission cycle different from and are abundant in the guts of unfed nymphs and their numbers continuously decrease during feeding. spirochetes are present in murine skin within 1 day of tick attachment. In contrast, spirochetes were not detectable in salivary glands at any stage of tick feeding. Read More

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http://dx.doi.org/10.1128/IAI.00896-18DOI Listing
March 2019
1 Read

Epigenetic changes induced by toxin (BFT).

Infect Immun 2019 Mar 18. Epub 2019 Mar 18.

Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD USA

Enterotoxigenic (ETBF) is a gram negative, obligate anaerobe member of the gut microbial community in up to 40% of healthy individuals. This bacterium is found more frequently in people with colorectal cancer (CRC) and causes tumor formation in the distal colon of mice; tumor formation is dependent on ETBF-secreted toxin (BFT). Because of the extensive data connecting alterations in the epigenome with tumor formation, initial experiments attempting to connect BFT-induced tumor formation with methylation in colon epithelial cells (CECs) have been performed, but the effect of BFT on other epigenetic processes, such as chromatin structure, remains unexplored. Read More

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http://dx.doi.org/10.1128/IAI.00447-18DOI Listing

Contribution of YjbIH to virulence factor expression and host colonization in .

Infect Immun 2019 Mar 18. Epub 2019 Mar 18.

University of Kansas Medical Center, Department of Microbiology, Molecular Genetics and Immunology, Kansas City, KS, 66061

To persist within the host and cause disease, relies on its ability to precisely fine-tune virulence factor expression in response to rapidly-changing environments. During an unbiased transposon mutant screen, we observed that disruption of the two-gene operon, , resulted in decreased pigmentation and aureolysin activity relative to the wild-type strain. Further analyses revealed that YjbH, a predicted thioredoxin-like oxidoreductase, is mostly responsible for the observed mutant phenotypes, though a minor role exists for the putative truncated hemoglobin YjbI. Read More

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http://dx.doi.org/10.1128/IAI.00155-19DOI Listing

Microbiome Profiles of Ligature-Induced Periodontitis in Nonhuman Primates Across the Lifespan.

Infect Immun 2019 Mar 18. Epub 2019 Mar 18.

Center for Oral Health Research, University of Kentucky College of Dentistry

This investigation compared the microbiome colonizing teeth during the initiation, progression and resolution of periodontitis in nonhuman primates () at different ages. Subgingival plaque samples were collected at baseline, and at 0.5, 1 and 3 months following ligature-induced periodontitis and following naturally-occurring disease resolution at 5 months. Read More

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http://dx.doi.org/10.1128/IAI.00067-19DOI Listing
March 2019
1 Read
3.731 Impact Factor

Cooperative interactions between and associated bacteria enhance paracellular permeability of the cervicovaginal epithelium by dysregulating tight junctions.

Infect Immun 2019 Mar 11. Epub 2019 Mar 11.

School of Biological Science, University of Auckland, Auckland, New Zealand

The human protozoan is the causative agent of trichomoniasis, a prevalent sexually transmitted infection, which is accompanied by a species-diversified vaginal microbiota named community state type IV (CST-IV). Coincidently, CST-IV includes species associated with bacterial vaginosis (e.g. Read More

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http://dx.doi.org/10.1128/IAI.00141-19DOI Listing
March 2019
2 Reads

The plasmid-encoded pGP3 promotes evasion of acidic barriers in both stomach and vagina.

Infect Immun 2019 Mar 11. Epub 2019 Mar 11.

Department of Microbiology, Immunology & Molecular Genetics, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA

Although is a human genital tract pathogen, chlamydial organisms have been frequently detected in both vaginal and rectal swabs of animals and humans. The plasmid-encoded pGP3, a genital tract virulence factor, is essential for to colonize mouse gastrointestinal tract. However, intracolon inoculation to bypass the gastric barrier rescued the colonization of pGP3-deficient mutant, suggesting that pGP3 is required for to reach but not colonize the large intestine. Read More

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http://dx.doi.org/10.1128/IAI.00844-18DOI Listing
March 2019
1 Read

Transcriptional analysis shows a robust host response to during early and late chronic infection in both male and female mice.

Infect Immun 2019 Mar 11. Epub 2019 Mar 11.

Department of Medical Microbiology and Immunology, University of Wisconsin - Madison, 1550 Linden Drive, Madison, WI 53706

The long-term host effects caused by the protozoan parasite are poorly understood. RNA-seq analysis previously determined that the host response in the brain was higher and more complex at 28 versus 10 days postinfection. Here, we analyzed the host transcriptional profile of age- and sex- matched mice during very early (21 days), early (28 days), mid (3 months) and late (6 months) chronic infection. Read More

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http://dx.doi.org/10.1128/IAI.00024-19DOI Listing

Characterizing Early Stages of Human Alveolar Infection by the Q Fever Agent, .

Infect Immun 2019 Mar 4. Epub 2019 Mar 4.

Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205

Human Q fever is caused by the intracellular bacterial pathogen Q fever presents with acute flu-like and pulmonary symptoms or can progress to chronic, severe endocarditis. After human inhalation, is engulfed by alveolar macrophages and transits through the phagolysosomal maturation pathway, resisting lysosomal acidic pH to form a parasitophorous vacuole (PV) in which to replicate. Previous studies showed that replicates efficiently in primary human alveolar macrophages (hAMs) in human lung tissue. Read More

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http://dx.doi.org/10.1128/IAI.00028-19DOI Listing
March 2019
5 Reads

Metabolites involved in immune evasion by include the polyamine spermidine.

Infect Immun 2019 Mar 4. Epub 2019 Mar 4.

Department of Chemistry, Villanova University, Villanova, PA, 19085, USA.

Amphibians have been declining around the world for more than four decades. One recognized driver of these declines is the chytrid fungus, , which causes the disease chytridiomycosis. Amphibians have complex and varied immune defenses against , but the fungus also has a number of counter-defenses. Read More

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http://dx.doi.org/10.1128/IAI.00035-19DOI Listing
March 2019
1 Read

Analysis of invasive non-typeable isolates reveals a selection for the expression state of particular phase-variable lipooligosaccharide biosynthetic genes.

Infect Immun 2019 Mar 4. Epub 2019 Mar 4.

Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia

Non-typeable (NTHi) is a major human pathogen, responsible for several acute and chronic infections of the respiratory tract. The incidence of invasive infections caused by NTHi is increasing world-wide. NTHi is able to colonise the nasopharynx asymptomatically, and the exact change(s) responsible for transition from benign carriage to overt disease are not understood. Read More

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http://dx.doi.org/10.1128/IAI.00093-19DOI Listing
March 2019
1 Read

The mouse inhalation model of infection recapitulates strain virulence in humans and shows closely related strains can possess differential virulence.

Infect Immun 2019 Mar 4. Epub 2019 Mar 4.

Department of Microbiology and Immunology, University of Minnesota, Minneapolis, MN

Cryptococcal meningitis (CM) causes high rates of HIV-related mortality, yet factors influencing patient outcome are not well understood. Pathogen-specific traits, such as the strain genotype and degree of antigen shedding, are associated with clinical outcome but the underlying biology remains elusive. In this study, we examined factors determining disease outcome in HIV-infected cryptococcal meningitis patients infected with strains with the same multi-locus sequence type (MLST). Read More

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http://dx.doi.org/10.1128/IAI.00046-19DOI Listing

MroQ is a Novel Abi-domain Protein That Influences Virulence Gene Expression in via Modulation of Agr Activity.

Infect Immun 2019 Mar 4. Epub 2019 Mar 4.

Department of Cell Biology, Microbiology & Molecular Biology, University of South Florida, Tampa, Florida, USA

Numerous factors have to date been identified as playing a role in the regulation of Agr activity in , including transcription factors, antisense RNAs, and host elements. Herein we investigate the product of SAUSA300_1984 (termed MroQ), a transmembrane Abi-domain/M79 protease-family protein, as a novel effector of this system. Using a USA300 mutant we observed a drastic reduction in proteolysis, hemolysis and pigmentation that was fully complementable. Read More

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http://dx.doi.org/10.1128/IAI.00002-19DOI Listing
March 2019
2 Reads

Control of quorum sensing by a membrane-embedded peptidase.

Infect Immun 2019 Mar 4. Epub 2019 Mar 4.

Department of Microbiology and Immunology, Loyola University Chicago - Stritch School of Medicine, 2160 S. First Avenue, Maywood, IL 60153, USA

Gram-positive bacteria process and release small peptides or "pheromones" that act as signals for the induction of adaptive traits including those involved in pathogenesis. One class of small signaling pheromones is the cyclic auto-inducing peptides (AIPs), which regulate expression of genes that orchestrate virulence and persistence in a range of microbes including Staphylococci, Listeria, Clostridia, and Enterococci. In a genetic screen for secreted virulence factors, we identified a mutant containing an insertion in gene (), which encodes a putative membrane-embedded metalloprotease. Read More

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http://iai.asm.org/lookup/doi/10.1128/IAI.00019-19
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http://dx.doi.org/10.1128/IAI.00019-19DOI Listing
March 2019
7 Reads

Dual gene expression analysis identifies factors associated with virulence in diabetic mice.

Infect Immun 2019 Mar 4. Epub 2019 Mar 4.

Department of Pediatrics Columbia University New York, New York USA

is a major human pathogen of the skin. The global burden of diabetes is high, with a major complication of diabetic wound infections. We investigated how the diabetic environment influences skin infection and observed an increased susceptibility to infection in mouse models of both type I and type II diabetes. Read More

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http://iai.asm.org/lookup/doi/10.1128/IAI.00163-19
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http://dx.doi.org/10.1128/IAI.00163-19DOI Listing
March 2019
6 Reads

Characterization of the horizontal and vertical sexual transmission of genital infections in a new mouse model.

Infect Immun 2019 Mar 4. Epub 2019 Mar 4.

Department of Pathology and Laboratory Medicine, Medical Sciences I, Room D440, University of California, Irvine, Irvine, California 92697-4800, USA.

is the most common sexually transmitted bacterial pathogen worldwide and there is a need to control this epidemic. So far there is no established animal model in which both horizontal and vertical transmission of can be studied. To implement a horizontal sexual transmission model, male mice were inoculated in the meatus urethra with () and they were caged with naïve female mice. Read More

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http://dx.doi.org/10.1128/IAI.00834-18DOI Listing
March 2019
2 Reads

Loss of trefoil factor 2 sensitizes rat pups to systemic infection with the neonatal pathogen K1.

Infect Immun 2019 Mar 4. Epub 2019 Mar 4.

School of Pharmacy, University College London, London, United Kingdom

Gastrointestinal (GI) colonization of two-day-old (P2) rat pups with K1 results in translocation of the colonizing bacteria across the small intestine, bacteremia and invasion of the meninges, with animals frequently succumbing to lethal infection. Infection but not colonization is strongly age dependent: pups become progressively less susceptible to infection over the P2-P9 period. Colonization leads to strong down-regulation of the gene encoding trefoil factor 2 (Tff2), preventing maturation of the protective mucus barrier in the small intestine. Read More

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http://dx.doi.org/10.1128/IAI.00878-18DOI Listing
March 2019
2 Reads

Interleukin-10 produced by myeloid derived suppressor cells provides protection to Carbapenem-resistant ST258 by enhancing its clearance in the airways.

Infect Immun 2019 Feb 25. Epub 2019 Feb 25.

Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331010, Chile, Pontificia Universidad Católica de Chile, Chile.

Carbapenem-resistant ST258 (CRKP-ST258) can cause chronic infections in lungs and airways, with repeated episodes of bacteremia. In this report we addressed whether the recruitment of myeloid cells producing the anti-inflammatory cytokine interleukin 10 (IL-10) modulates the clearance of CKRP-ST258 in the lungs and establishes bacterial persistence. Our data demonstrate that during pneumonia caused by a clinical isolate of CRKP-ST258 (KP35) there is an early recruitment of Monocyte-Myeloid Derived Suppressor Cells (M-MDSCs) and neutrophils that actively produce IL-10. Read More

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http://dx.doi.org/10.1128/IAI.00665-18DOI Listing
February 2019
1 Read

lipophosphoglycan increases macrophage-dependent chemotaxis of CXCR6-expressing cells via CXCL16 induction.

Infect Immun 2019 Feb 25. Epub 2019 Feb 25.

Institut National de la Recherche Scientifique (INRS) - Institut Armand-Frappier, Laval, Quebec, Canada

CXCL16 is a multifunctional chemokine that is highly expressed by macrophages and other immune cells in response to bacterial and viral pathogens; however, little is known regarding the role of CXCL16 during parasitic infections. The protozoan parasite ) is the causative agent of visceral leishmaniasis. Even though chemokine production is a host defense mechanism during infection, subversion of the host chemokine system constitutes a survival strategy adopted by the parasite. Read More

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http://dx.doi.org/10.1128/IAI.00064-19DOI Listing
February 2019

Pla protein thwarts T cell defense against plague.

Infect Immun 2019 Feb 25. Epub 2019 Feb 25.

Trudeau Institute, Saranac Lake, New York, USA

Plague is a rapidly lethal human disease caused by the bacterium (Yp). This study demonstrates that the Yp plasminogen activator Pla, a protease that promotes fibrin degradation, thwarts T cell-mediated defense against fully-virulent Yp. Introducing a single point mutation into the active site of Pla suffices to render fully-virulent Yp susceptible to primed T cells. Read More

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http://dx.doi.org/10.1128/IAI.00126-19DOI Listing
February 2019
2 Reads

Differential recognition of OmpU by TLRs in monocytes and macrophages for the induction of pro-inflammatory responses.

Infect Immun 2019 Feb 25. Epub 2019 Feb 25.

Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Mohali, Manauli, Punjab 140306, India

is a human pathogen, and it is a major cause of severe gastroenteritis in the coastal areas. OmpU is one of the major outer-membrane porins of Host-immunomodulatory effects of OmpU (VpOmpU) have not been elucidated yet. In this study towards characterizing the role of VpOmpU for its effect on innate immune responses of the host, we observed that VpOmpU gets recognized by TLR1/2 hetero-dimer in THP-1 monocyte but in RAW 264. Read More

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http://dx.doi.org/10.1128/IAI.00809-18DOI Listing
February 2019
1 Read

Neutrophils dampen adaptive immunity in brucellosis.

Infect Immun 2019 Feb 25. Epub 2019 Feb 25.

Programa de Investigación en Enfermedades Tropicales (PIET), Escuela de Medicina, Veterinaria, Universidad Nacional, Heredia, Costa Rica.

organisms are intracellular stealth pathogens of animals and humans. These bacteria overcome the assault of innate immunity at early stages of the infection. Removal of neutrophils (PMNs) at the onset of adaptive immunity against , favored the bacterial elimination in mice. Read More

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http://dx.doi.org/10.1128/IAI.00118-19DOI Listing
February 2019

Interferon Lambda Inhibits Bacterial Uptake During Influenza Super-Infection.

Infect Immun 2019 Feb 25. Epub 2019 Feb 25.

Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA

Influenza kills 30-40,000 people each year in the United States, and causes ten times as many hospitalizations. A common complication of influenza is bacterial super-infection, which exacerbates morbidity and mortality from the viral illness. Recently, MRSA has emerged as the dominant pathogen found in bacterial super-infection, with a close second. Read More

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http://dx.doi.org/10.1128/IAI.00114-19DOI Listing
February 2019

Sortase-dependent proteins promote gastrointestinal colonization by enterococci.

Infect Immun 2019 Feb 25. Epub 2019 Feb 25.

Department of Microbiology and Immunology, Pediatrics; Medical College of Wisconsin, Milwaukee WI

The human gastrointestinal tract (GIT) is inhabited by a dense microbial community of symbionts. Enterococci are one of the earliest members of this community and remain core members of the GIT microbiota throughout life. Enterococci have also recently emerged as opportunistic pathogens and major causes of nosocomial infections. Read More

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http://dx.doi.org/10.1128/IAI.00853-18DOI Listing
February 2019

PheWAS uncovers a pathological role of coagulation Factor X during infection.

Infect Immun 2019 Feb 19. Epub 2019 Feb 19.

Department of Pathology, Microbiology, & Immunology, Vanderbilt University Medical Center

Coagulation and inflammation are interconnected, suggesting coagulation plays a key role in the inflammatory response to pathogens. A Phenome-Wide Association Study (PheWAS) was used to identify clinical phenotypes of patients with a polymorphism in coagulation Factor X. Patients with this SNP were more likely to be hospitalized with hemostatic and infection-related disorders, suggesting Factor X contributes to the immune response to infection. Read More

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http://iai.asm.org/lookup/doi/10.1128/IAI.00031-19
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http://dx.doi.org/10.1128/IAI.00031-19DOI Listing
February 2019
6 Reads

subtilisin-like serine protease (SUB1) is crucial for parasite egress from host cells.

Infect Immun 2019 Feb 19. Epub 2019 Feb 19.

Infectious Diseases Division, Department of Internal Medicine, University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas 77555-0435.

Despite the severity and global burden of infection, treatments are less than optimal and there is no effective vaccine. Egress from host cells is a key process to the completion of the parasitic life cycle of apicomplexan parasites. For , subtilisin-like serine proteases (SUB1) is a key mediator of egress. Read More

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http://dx.doi.org/10.1128/IAI.00784-18DOI Listing
February 2019
1 Read

Dietary chitin particles, "mimetic fungi", ameliorate colitis in TLR2/CD14- and sex- dependent manners.

Infect Immun 2019 Feb 19. Epub 2019 Feb 19.

Florida Atlantic University Charles E. Schmidt College of Medicine and College of Science, Boca Raton, Florida, and Virginia Tech Carilion School of Medicine, Roanoke, Virginia.

Chitin is a natural N-acetyl glucosamine polymer and a major structural component of fungal cell walls. Dietary chitin is mucoadhesive; anti-inflammatory effects of chitin microparticles (CMPs, 1 - 10 μm diameters) have been demonstrated in models of inflammatory bowel disease (IBD). The goals in this study were to assess (i) whether CMPs among various chitin preparations are the most effective against colitis in male and female mice, and (ii) whether host chitin-binding TLR2 and CD14 are required for the anti-inflammatory effect of chitin. Read More

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http://dx.doi.org/10.1128/IAI.00006-19DOI Listing
February 2019
10 Reads

An alternative enzyme protection assay to overcome the drawbacks of gentamicin protection assay for measuring entry and intracellular survival of Staphylococci.

Infect Immun 2019 Feb 19. Epub 2019 Feb 19.

Department of Molecular Cell Biology, Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon 16419, Korea

Precise enumeration of living intracellular bacteria is the key step to estimate invasion potential of pathogens and host immune responses, and understand the mechanism and kinetics of bacterial pathogenesis. Therefore, quantitative assessment of host-pathogen interaction is essential for developing novel antibacterial therapeutics for infectious disease. Gentamicin protection assay (GPA) is the most widely used method for these estimations by counting the colony forming units (CFU) of intracellular living pathogens. Read More

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http://dx.doi.org/10.1128/IAI.00119-19DOI Listing
February 2019
3.731 Impact Factor

is critical for spirochete population expansion in the skin during early infection.

Infect Immun 2019 Feb 19. Epub 2019 Feb 19.

Division of Immunity and Pathogenesis, Burnett School of Biomedical Sciences, University of Central Florida College of Medicine, Orlando, Florida, 32827 USA.

Lyme disease is caused by the spirochete and is transmitted via the bite of an infected tick. enters the skin, disseminates via the bloodstream, and infects various distal tissues leading to inflammatory sequelae such as Lyme arthritis and Lyme carditis. linear plasmid 36 (lp36) is critical for mammalian infectivity, however, the full complement of lp36-encoded genes that contribute to this process remains unknown. Read More

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http://dx.doi.org/10.1128/IAI.00887-18DOI Listing
February 2019
2 Reads