Publications by authors named "Julio Loureiro"

7 Publications

  • Page 1 of 1

Breeding program in rehabilitated bottlenose dolphins (Tursiops truncatus gephyreus) from the Southwestern Atlantic Ocean.

Zoo Biol 2021 May 19;40(3):208-217. Epub 2021 Feb 19.

Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, Buenos Aires, Argentina.

Tursiops truncatus gephyreus is only found in the inshore waters of the Southwestern Atlantic Ocean. They are organized in small socially, structured groups, which lead to low genetic variability and high anthropogenic threats. Currently, the information about their reproductive biology and management is still insufficient. Thus, this study aims to present novel information recorded for 20 years regarding reproductive parameters in a small population of captive T. t. gephyreus. Three of the animals involved were found stranded in La Plata River estuary and, the other two were born at the oceanarium. Thirteen semen evaluations showed high-quality semen with a low percentage of sperm abnormalities. Twelve pregnancies and parturitions were observed. There was a clear calving seasonality during austral spring and summer. The duration of phase-2 of labor was approximately 80 min, being the caudal presentation the most frequent. The average inter-birth interval (IBI) was about 33 months. This is the first report that closely monitored parturition, IBI, and seminal evaluation in this species. Information gathered during this program will allow the development of adequate conservation plans for free-ranging populations.
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http://dx.doi.org/10.1002/zoo.21592DOI Listing
May 2021

Adaptations to a semiaquatic lifestyle in the external ear of southern pinnipeds (Otariidae and Phocidae, Carnivora): Morphological evidences.

Zoology (Jena) 2019 04 27;133:66-80. Epub 2019 Feb 27.

CONICET, Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina; Laboratorio de Histología y Embriología descriptiva, experimental y comparada (LHYEDEC), Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, Buenos Aires, Argentina.

Pinnipeds are semiaquatic carnivorans that spend most of their lives in water and use coastal terrestrial, or ice pack, environments to breed, molt and rest. Certain characteristics of the ear have been linked to ecological aspects. In our contribution we focus on the study of the macroscopic and microscopic morphology of the external ear (with the exception of the osseous outer ear canal) of six species of Southern pinnipeds. In order to recognize the different components of tissues, sections were stained following several routine protocols. In addition, double-staining and enzymatic clearing (Alcian blue-alizarin red) was performed to assess the arrangement of skeletal elements in the OEC. The basic structure of the pinna in the southern otariids studied match those previously analyzed for Northern Hemisphere species. The cartilage macro anatomy of the OEC of Mirounga leonina and Arctocephallus gazella is different from that of the Northern Hemisphere species, with only one plate of cartilage, but markedly different between them. The histology of the otariids OEC is homogeneous along the entire extension, but phocids has three different regions (distal, middle, and proximal). The cartilage histology of most phocids is also different from that of analyzed otariids, with an elastic cartilage that resembles a myxoid-like tissue, but is not present in M. leonina, were the tissue around the OEC is very rich in adipocytes. The southern elephant seal M. leonina OEC has a combination of features similar to both the rest of the phocids and to the otariids. An auditory organ that is functional both over and under water could be essential for social behavior in these species.
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http://dx.doi.org/10.1016/j.zool.2019.02.006DOI Listing
April 2019

Avian Malaria ( Plasmodium spp.) in Captive Magellanic Penguins ( Spheniscus magellanicus ) from Northern Argentina, 2010.

J Wildl Dis 2016 07 10;52(3):734-7. Epub 2016 Jun 10.

1 Laboratório de Patologia Comparada de Animais Selvagens, Departamento de Patologia, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Avenida Orlando Marques de Paiva 87, São Paulo SP 05088-000, Brazil;

We report two cases of lethal avian malaria in Magellanic Penguins (Spheniscus magellanicus) captive at San Clemente del Tuyú, Argentina, approximately 560 km north of Argentinean breeding colonies of Magellanic Penguins. Blood smears revealed both penguins were concurrently infected by Plasmodium (Haemamoeba) tejerai, Plasmodium (Huffia) sp., and Plasmodium (Novyella) sp.
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http://dx.doi.org/10.7589/2015-08-219DOI Listing
July 2016

Novel gastric helicobacters and oral campylobacters are present in captive and wild cetaceans.

Vet Microbiol 2011 Aug 22;152(1-2):138-45. Epub 2011 Apr 22.

Physics Department, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina.

The mammalian gastric and oral mucosa may be colonized by mixed Helicobacter and Campylobacter species, respectively, in individual animals. To better characterize the presence and distribution of Helicobacter and Campylobacter among marine mammals, we used PCR and 16S rDNA sequence analysis to examine gastric and oral samples from ten dolphins (Tursiops gephyreus), one killer whale (Orcinus orca), one false killer whale (Pseudorca crassidens), and three wild La Plata river dolphins (Pontoporia blainvillei). Helicobacter spp. DNA was widely distributed in gastric and oral samples from both captive and wild cetaceans. Phylogenetic analysis demonstrated two Helicobacter sequence clusters, one closely related to H. cetorum, a species isolated from dolphins and whales in North America. The second related cluster was to sequences obtained from dolphins in Australia and to gastric non-H. pylori helicobacters, and may represent a novel taxonomic group. Dental plaque sequences from four dolphins formed a third cluster within the Campylobacter genus that likely represents a novel species isolated from marine mammals. Identification of identical Helicobacter spp. DNA sequences from dental plaque, saliva and gastric fluids from the same hosts, suggests that the oral cavity may be involved in transmission. These results demonstrate that Helicobacter and Campylobacter species are commonly distributed in marine mammals, and identify taxonomic clusters that may represent novel species.
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http://dx.doi.org/10.1016/j.vetmic.2011.04.023DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3142288PMC
August 2011

In vitro susceptibility testing of Mycobacterium tuberculosis complex strains isolated from seals to antituberculosis drugs.

Biomedica 2004 Jun;24 Supp 1:85-91

Reference Laboratory of Tuberculosis for MERCOSUR-DILACOT-SENASA, National Service of Sanity and Agricultural Quality (SENASA), Buenos Aires, Argentina.

Mycobacteria strains belonging to the Mycobacterium tuberculosis complex were isolated from seals found in the South Atlantic. The animals were received in Mundo Marino installations and treated for Mycobacterium tuberculosis complex by conventional therapy of intensive care and enriched food supply; however, in all cases treatment failed. Necropsies of all animals revealed extensive lesions compatible with tuberculosis involving lungs, liver, spleen and lymphatic nodes. Classical biochemical methods as well as molecular techniques using the IS6110 probes were performed for mycobacterial identification. Furthermore, the LCx M. tuberculosis assay (Abbott Laboratories) identified all strains as Mycobacterium tuberculosis complex members. The in vitro susceptibility pattern was examined in mycobacterial strains isolated from seven seals and in 3 reference strains--BCG, H37Rv (M. tuberculosis) and AN5 (Mycobacterium bovis)--to 4 medications--isoniazid, rifampin, streptomycin and ethambutol. Minimal inhibitory drug concentrations were determined by the Mycobacterial Growth Indicator Tube (BD Argentina) method and a microdilution and colorimetric assay using 3-(4-5 dimethyltiazol-2)-2,5 diphenyltetrazolium bromide. All the isolates and the reference strains BCG and AN5 were inhibited by MIC values similar to those of H37Rv with good agreement obtained by both techniques. These findings suggest that a therapeutic regimen aimed to seals diagnosed with tuberculosis play an important role in the prevention of tuberculosis transmission from infected animals to humans that are in routine contact with them.
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June 2004

Tuberculosis in seals caused by a novel member of the Mycobacterium tuberculosis complex: Mycobacterium pinnipedii sp. nov.

Int J Syst Evol Microbiol 2003 Sep;53(Pt 5):1305-1314

Departamento de Micobacterias, DILACOT, Servicio Nacional de Sanidad y Calidad Agroalimentaria (SENASA), Avda A Fleming 1653, (1640) Martínez, Argentina.

A comparison of Mycobacterium tuberculosis complex isolates from seals (pinnipeds) in Australia, Argentina, Uruguay, Great Britain and New Zealand was undertaken to determine their relationships to each other and their taxonomic position within the complex. Isolates from 30 cases of tuberculosis in six species of pinniped and seven related isolates were compared to representative and standard strains of the M. tuberculosis complex. The seal isolates could be distinguished from other members of the M. tuberculosis complex, including the recently defined 'Mycobacterium canettii' and 'Mycobacterium caprae', on the basis of host preference and phenotypic and genetic tests. Pinnipeds appear to be the natural host for this 'seal bacillus', although the organism is also pathogenic in guinea pigs, rabbits, humans, Brazilian tapir (Tapirus terrestris) and, possibly, cattle. Infection caused by the seal bacillus is predominantly associated with granulomatous lesions in the peripheral lymph nodes, lungs, pleura, spleen and peritoneum. Cases of disseminated disease have been found. As with other members of the M. tuberculosis complex, aerosols are the most likely route of transmission. The name Mycobacterium pinnipedii sp. nov. is proposed for this novel member of the M. tuberculosis complex (the type strain is 6482(T)=ATCC BAA-688(T)=NCTC 13288(T)).
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http://dx.doi.org/10.1099/ijs.0.02401-0DOI Listing
September 2003

Evidence of Helicobacter sp. in dental plaque of captive dolphins (Tursiops gephyreus).

J Wildl Dis 2002 Jul;38(3):644-8

Radioisotope Laboratory, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina.

Gastrointestinal lesions have been extensively reported in wild and captive marine mammals. However, their etiology remains unclear. In humans and other animals, chronic gastritis and peptic ulcers have been associated with Helicobacter sp. Therefore, the aim of our study was to investigate the presence of Helicobacter sp. in the gastric juice, dental plaque, and saliva of marine mammals living in a controlled environment. Five dolphins (Tursiops gephyreus), one killer whale (Orcinus orca), one false killer whale (Pseudorca crassidens), three sea lions (Otaria flavescens), two elephant seals (Mirounga leonina), and two fur seals (Arctocephalus australis) were studied. Saliva, dental plaque, and gastric juice samples were examined for Helicobacter sp. using polymerase chain reaction. None of the gastric juice or saliva samples were positive for Helicobacter sp. However, Helicobacter sp. DNA was detected in dental plaque from two dolphins, suggesting the oral cavity might be a reservoir of this bacterium.
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http://dx.doi.org/10.7589/0090-3558-38.3.644DOI Listing
July 2002