Survey of Salmonella sp in budgerigars (Melopsittacus undulatus) in Fortaleza, Brazil

ABSTRACT

Background: The budgerigars (Melopsittacus undulatus) are psittacine of the Psittacidae family which belongs in the Psittaciformes order. These birds do not belong in the free living fauna of Brazil, therefore almost all of these birds found in the home environment are derived from pet stores or free markets. The dissemination of Salmonella among psittacine and other birds, and men as well, is a theme of great scientific concern. Salmonellosis is a highly contagious disease and psittacine are susceptible, but may also act as reservoirs hosting Salmonella sp. in the intestines and presenting as a source of infection to humans and domestic animals. Therefore, this study aimed to isolate, identify and to assess the dissemination of Salmonella in budgerigars in Fortaleza city. Materials, Methods & Results: This study was performed between January and September, 2011. Two hundred and sixty four samples of drag and cloacal swabs were collected from budgerigars found in pet stores and breeders, of which 198 were individual cloacal swabs, 58 were drag swabs and 8 intestine samples were also collected during necropsy performed in birds that died during the experiment. The microbiological procedure was performed according to the following steps: pre-enrichment step, using tubes containing peptone water broth; selective enrichment step, in which pre-enriched cultures were transferred to tubes containing Rappaport-Vassiliadis broth and tubes containing Selenite-Cystine broth, added Novobiocin; and plating step, in which enriched samples were streaked in plates containing Brilliant Green agar and plates containing MacConkey agar. Based on the morphology and color, colonies were selected and inoculated in Triple-Sugar-Iron agar, Lysine-Iron agar and Sulphite-Indole-Motility agar for confirmation. Urease production was assessed to differentiate Proteus from Salmonella. A questionnaire was administered to fully comprehend the conditions in which the budgerigars were maintained and housed, comprising the following subjects: food type, antimicrobial use, cleaning products used and bird species housed per cage. No Salmonella sp. was detected in budgerigars commercialized and maintained in pet stores and commercial breeders in Fortaleza city, Brazil. The questionnaire results revealed that most establishments maintain the seeds provided for the budgerigars in sealed containers and also, feeders, drinkers, cages and facilities are cleaned once a day, though most use only water treated by the local company to do so. Discussion: The studies involving Salmonella sp. and budgerigars are scarce and show a low or absent prevalence of this pathogen in this bird. The results of the questionnaire administered to the bird owners also aided in understanding the absence of Salmonella sp. in the studied birds. In conclusion, according to the methodology applied, the budgerigars commercialized in Fortaleza city do not pose imminent risk of transmitting Salmonella to the local population. In spite the absence of positivity or low prevalence of Salmonella in budgerigars reported in this study as in other scientific literature consulted, it is still recommended that control measures should always be applied in order to avoid this pathogen, since important serotypes potentially harmful to human health have been previously identified in this avian species.