Reptile-associated Salmonellosis in Man, Italy

To the Editor: Reptiles are reservoirs of a wide variety of Salmonella serotypes, including all Salmonella enterica subspecies and S. bongori. In reptiles born in captivity or kept as pets, S. enterica subsp. enterica is frequently isolated (1). Salmonella strains are well adapted to reptiles, and they usually cause asymptomatic infections in such animals, while retaining pathogenicity for warm-blooded animals. For several years, reptiles have been recognized as a source of human salmonellosis. In North America, reptile-associated sal-monellosis (RAS) has been reported, particularly in children, the elderly, or immunocompromised persons; severe and fatal infections are described occasionally (2). In contrast, only a limited amount of information on RAS is available in Europe. We report a case of RAS that occurred in an adult man in Italy. A 32-year-old man had symptoms of enteritis. For 2 weeks, he had experienced intermittent watery diarrhea, mild fever, and abdominal pain. He was then treated with ciprofloxacin, and after 15 days of treatment, he recovered from enteritis. A stool sample , collected before treatment, underwent bacteriologic analysis, and Salmonella spp. were identified biochemically (api 20E, bioMérieux, Marcy l'Etoile, France) and by a poly-merase chain reaction assay specific for the invA gene of Salmonella spp. (3). Since the man was a reptile owner, RAS, rather than a foodborne infection, was initially suspected. He owned several cold-blooded animals; all had been tested for Salmonella spp. (at least 3 times at 2-to 3-week intervals), and results were negative. Three weeks before the onset of enteric symptoms, he acquired a boa (Boa imperator) that was subjected to routine analysis for Salmonella spp. in our laboratories (1). Salmonella spp. were isolated from a cloacal swab of the snake. Subsequently, both the human and reptile Salmonella isolates were characterized as S. enterica serovar Paratyphi B. In addition, both strains were found to be d-tartrate–fermenting (dT+) biovars (4), and ciprofloxacin and resistant to sul-famethoxazole and co-trimoxazole. By pulsed-field gel electrophoresis analysis of DNA, the strains displayed the same pattern, which suggests a clonal origin (4). The isolates were also assayed for virulence-associated genes. The SopE1 gene was detected in both isolates, and the avrA gene was not detected, which is consistent with an invasive pathovar of S. Paratyphi B (4). Conversely, the spvC, pef, and sef genes were not detected (5). In recent years, a general increase in RAS detection has been observed, which may be the result of the increasing …