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

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 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.

Molecular subtyping of Salmonella enterica serovar Typhi isolates from Colombia and Argentina.

Salmonella Typhi is the etiological agent of typhoid fever with 16 million annual cases estimated worldwide. In Colombia and Argentina it is a notifiable disease but many cases have only a clinical diagnosis. Molecular subtyping of S. Typhi is necessary to complement epidemiologic analysis of typhoid fever. The aims of this study were to determine the genetic relationships between the strains circulating in both countries and to evaluate possible variations in the distribution of 12 virulence genes. A total of 136 isolates were analyzed by pulsed-field gel electrophoresis (PFGE) with XbaI following PulseNet protocols and analysis guidelines. Eighty-three different PFGE patterns were identified, showing high diversity among the strains from both countries. Three outbreaks, two in Colombia and one in Argentina, were caused by strains of different PFGE types. In Colombia, two PFGE patterns were found predominantly, which included 36.6% of the isolates from that country. No association was found between the PFGE patterns and the year or place of isolation of the strains, the age of the patients or type of sample. However, several clusters were detected, which included isolates recovered predominantly either from Colombia or Argentina. Most of the strains (97%) exhibited a single virulence profile, suggesting that the pathogenicity markers analyzed are of limited value for strain discrimination and do not correlate with the origin of the isolates (intestinal vs. extra-intestinal). Since the creation of PulseNet Latin America, this was the first international study conducted in South America. The PFGE types identified were incorporated into the Regional S. Typhi PulseNet Database and are now available for comparison with those of strains isolated in other regions. This information will be used for active surveillance, future studies, and outbreak investigations.

Transporte de especímenes para diagnóstico / Specimen transport for diagnosis

Cuando se envían especímenes para diagnóstico, incluidos los materiales infecciosos, a laboratorios fuera de la Institución debe cumplirse con regulaciones de seguridad. Además, debe asegurarse la integridad de la muestra de manera de obtener un análisis exacto por parte del laboratorio destinatario. Las muestras deben ser empaquetadas y enviadas de manera de asegurarse que su contenido no se derrame o drene y que llegue en buenas condiciones. Las sustancias infecciosas se clasifican como envíos peligrosos de acuerdo con la legislación internacionalmente reconocida que se basa en las recomendaciones para el Transporte de Muestras Peligrosas de Naciones Unidas, y en legislaciones internas vigentes propias de cada país. En consecuencia, los envíos están sujetos a los requerimientos específicos de empaquetado, documentación, etiquetado y manipulación. Debe destacarse la importancia de establecer una relación entre los grupos involucrados: el remitente, el transportador y el destinatario para lograr un transporte seguro y eficiente de los materiales.