Marcela Uhart

Publications of Marcela Uhart

• Squirrel Monkey Cytomegalovirus Antibodies in Free-ranging Black Howler Monkeys (Alouatta caraya), Misiones, Argentina.

  Authors: Hebe Ferreyra, Hernan Argibay, Miguel A Rinas, Marcela Uhart

  Journal of wildlife diseases. 04/2012; 48(2):512-3.

  Serum from four black howler monkeys (Alouatta caraya) was screened for antibodies to seven viruses by dot immunoassay. Cytomegalovirus antibodies were detected in three of four individuals andSerum from four black howler monkeys (Alouatta caraya) was screened for antibodies to seven viruses by dot immunoassay. Cytomegalovirus antibodies were detected in three of four individuals and provide the first evidence of exposure by black howler monkeys to this virus.

• Phylogenetic analysis of H6 influenza viruses isolated from rosy-billed pochards (Netta peposaca) in Argentina reveals the presence of different HA gene clusters.

  Authors: Agustina Rimondi, Kemin Xu, Maria Isabel Craig, Hongxia Shao, Hebe Ferreyra, Maria Virginia Rago, Marcelo Romano, Marcela Uhart, Troy Sutton, Andrea Ferrero, Daniel R Perez, Ariel Pereda

  Journal of virology. 12/2011; 85(24):13354-62.

  Until recently, influenza A viruses from wild waterfowl in South America were rarely isolated and/or characterized. To explore the ecology of influenza A viruses in this region, a long-termUntil recently, influenza A viruses from wild waterfowl in South America were rarely isolated and/or characterized. To explore the ecology of influenza A viruses in this region, a long-term surveillance program was established in 2006 for resident and migratory water birds in Argentina. We report the characterization of 5 avian influenza viruses of the H6 hemagglutinin (HA) subtype isolated from rosy-billed pochards (Netta peposaca). Three of these viruses were paired to an N2 NA subtype, while the other two were of the N8 subtype. Genetic and phylogenetic analyses of the internal gene segments revealed a close relationship with influenza viruses from South America, forming a unique clade and supporting the notion of independent evolution from influenza A viruses in other latitudes. The presence of NS alleles A and B was also identified. The HA and NA genes formed unique clades separate from North American and Eurasian viruses, with the exception of the HA gene of one isolate, which was more closely related to the North American lineage, suggesting possible interactions between viruses of North American and South American lineages. Animal studies suggested that these Argentine H6 viruses could replicate and transmit inefficiently in chickens, indicating limited adaptation to poultry. Our results highlight the importance of continued influenza virus surveillance in wild birds of South America, especially considering the unique evolution of these viruses.

• Isolation of Salmonella spp. from yacare caiman (Caiman yacare) and broad-snouted caiman (Caiman latirostris) from the Argentine Chaco.

  Authors: Marcela Uhart, Hebe Ferreyra, Rosana Mattiello, María Inés Caffer, Raquel Terragno, Adriana Schettino, Walter Prado

  Journal of wildlife diseases. 04/2011; 47(2):271-7.

  Presence of Salmonella spp. was evaluated in yacare caiman (Caiman yacare) and broad-snouted caiman (Caiman latirostris) from a ranching facility in the Argentine Chaco. Crocodilian ranching programsPresence of Salmonella spp. was evaluated in yacare caiman (Caiman yacare) and broad-snouted caiman (Caiman latirostris) from a ranching facility in the Argentine Chaco. Crocodilian ranching programs are based on captive breeding of wild-harvested eggs and release of excess hatchlings into the wild. Samples for bacterial isolation were collected from 102 captive (35 C. yacare and 67 C. latirostris) and seven free-ranging caiman (four C. yacare and three C. latirositris) between 2001 and 2005 and from three artificially incubated C. yacare wild eggs. Two Salmonella spp. of known zoonotic potential, S. infantis and S. nottingham, were isolated from captive caiman in 2001 and 2002, respectively. This is the first report for S. nottingham in reptiles and of S. infantis in caiman. Salmonella spp. prevalence varied significantly between years, with a 77% prevalence peak in 2002. Although the cause of this increase was not confirmed, we found no correlation with the type of enclosure, caiman species, or body weight. Deteriorated physical condition of caiman hatchlings due to dietary changes in 2002 could have influenced Salmonella spp. shedding. However, external sources such as food, water, or enclosures could not be ruled out. Pathogenic Salmonella spp. present a risk for human infection. Inadvertent introduction of Salmonella spp. or other bacteria into the environment when caiman are released could pose a threat to wild caiman populations. Prophylactic measures to detect and decrease Salmonella spp. presence in caiman ranching facilities are recommended to reduce risk to humans and make caiman-ranching a sound conservation strategy for crocodilian species.

• Population genetic structure of living and dead southern

  Authors: Luciano Oscar Valenzuela, Mariano Sironi, Victoria J Rowntree, Luciano La Sala, Luciana Pozzi, Nadia Mohamed, Luciana Musmeci, Julian Andrejuk, Marcela Uhart, Andrea Chirife, Carina Maron, Jon Seger

  06/2010; SC/62/BRG15:1-12.

  Strong site fidelity to breeding or feeding grounds may diminish an animal’s ability to find and use better areas

• Recent and Chronic Exposure of Wild Ducks to Lead in Human-modified Wetlands in Santa Fe Province, Argentina.

  Authors: Hebe Ferreyra, Marcelo Romano, Marcela Uhart

  Journal of wildlife diseases. 08/2009; 45(3):823-7.

  Poisoning of waterfowl due to ingestion of lead pellets is a worldwide problem in areas that are subject to hunting. No studies have assessed exposure of waterbirds to this heavy metal in Argentina,Poisoning of waterfowl due to ingestion of lead pellets is a worldwide problem in areas that are subject to hunting. No studies have assessed exposure of waterbirds to this heavy metal in Argentina, in spite of intense hunting activity, and the fact that only lead ammunition is commercially available. The objective of this study was to evaluate duck exposure to lead by examining gizzard and bone samples collected from 30 wild ducks, 16 Rosy-billed Pochard (Netta peposaca), and 14 Fulvous Whistling-Duck (Dendrocygna bicolor), provided by hunters in northern Santa Fe Province, Argentina, in July 2007. Radiographs, followed by dissection of the gizzards, showed that 31% of the Rosy-billed Pochards and 29% of the Fulvous Whistling-Ducks had ingested lead pellets (between one and four per animal). Lead in bone was found at concentrations associated with detrimental health effects. In spite of the small number of samples in this project, these results indicate high levels of lead exposure (both recent and chronic) in these species. This is the first report of a problem in Argentina that could represent a threat to the health and conservation of native aquatic species, their predators, and the wetlands they inhabit.

• Avian influenza virus isolated in wild waterfowl in Argentina: evidence of a potentially unique phylogenetic lineage in South America.

  Authors: Ariel J Pereda, Marcela Uhart, Alberto A Perez, María E Zaccagnini, Luciano La Sala, Julieta Decarre, Andrea Goijman, Laura Solari, Romina Suarez, María I Craig, Ariel Vagnozzi, Agustina Rimondi, Guido König, María V Terrera, Analía Kaloghlian, Haichen Song, Erin M Sorrell, Daniel R Perez

  Virology. 09/2008; 378(2):363-70.

  Avian influenza (AI) viruses have been sporadically isolated in South America. The most recent reports are from an outbreak in commercial poultry in Chile in 2002 and its putative ancestor from aAvian influenza (AI) viruses have been sporadically isolated in South America. The most recent reports are from an outbreak in commercial poultry in Chile in 2002 and its putative ancestor from a wild bird in Bolivia in 2001. Extensive surveillance in wild birds was carried out in Argentina during 2006-2007. Using RRT-PCR, 12 AI positive detections were made from cloacal swabs. One of those positive samples yielded an AI virus isolated from a wild kelp gull (Larus dominicanus) captured in the South Atlantic coastline of Argentina. Further characterization by nucleotide sequencing reveals that it belongs to the H13N9 subtype. Phylogenetic analysis of the 8 viral genes suggests that the 6 internal genes are related to the isolates from Chile and Bolivia. The analysis also indicates that a cluster of phylogenetically related AI viruses from South America may have evolved independently, with minimal gene exchange, from influenza viruses in other latitudes. The data produced from our investigations are valuable contributions to the study of AI viruses in South America.

• Multiple species production systems: reversing underdevelopment and nonsustainability in Latin America.

  Authors: Marcela Uhart, Fernando Milano

  Annals of the New York Academy of Sciences. 11/2002; 969:20-3.

  Latin America (LA) is suffering the environmental consequences of worldwide increased productivity and agricultural expansion as well as strong economic restrictions. To survive, LA landowners mustLatin America (LA) is suffering the environmental consequences of worldwide increased productivity and agricultural expansion as well as strong economic restrictions. To survive, LA landowners must turn to higher income products and/or increase productivity. Alternatives are few. But while intensification relies on unaffordable and nonsustainable subsidies, diversification is solely dependent on improved management of available resources. Diversified, multiple-species production systems (MSPS) add wildlife use to traditional production systems, promoting economic and ecological stability. We present examples of MSPS in Latin America. Although results are technically encouraging, their future sustainability is threatened by: i) local subvaluation of wildlife and ii) restricted international markets.