Cats as a risk for transmission of antimicrobial drug-resistant Salmonella

Abstract

To determine whether cats were a risk for transmission of Salmonella to humans, we evaluated the excretion of Salmonella by pet cats. Rectal-swab specimens were taken from 278 healthy house cats, from 58 cats that died of disease, and from 35 group-housed cats. Group-housed cats were kept in one room with three cat trays and a common water and feed tray. Eighteen (51.4%) of 35 group-housed cats, 5 (8.6%) of 58 diseased cats (5/58), and 1 (0.36%) of 278 healthy house cats excreted Salmonella. Salmonella isolates were of serotypes Typhimurium, Enteritidis, Bovismorbificans and 4:i:-. Acquired antimicrobial resistance was found in serotype Typhimurium (resistance to ampicillin, chloramphenicol, and tetracycline; to ampicillin; and to chloramphenicol) and 4:i:- strains (resistance to ampicillin, chloramphenicol, sulfonamides, trimethoprim, and sulfamethoxazole/trimethoprim). Cats that excrete Salmonella can pose a public health hazard to people who are highly susceptible to Salmonella, such as children, the elderly, and immunocompromised persons.

Figure 1

Dendrogram obtained by unweighted pair group method using arithmetic averages clustering of the pulsed-field gel electrophoresis–XbaI patterns of serovar Typhimurium strains isolated from cats on the basis of the Dice coefficient.

Figure 2

Invasion of Salmonella strains in the human intestinal epithelial cell line T84. The y-axis shows the percentages of intracellular bacteria 2 hours postinfection, relative to the initial number of bacteria, incubated with the cells. The x-axis shows isolate numbers. All isolates derived from the group-housed cats had the same invasion percentage as strains 198 and 355 (data not shown). Isolates 55 and 1145 had the same invasion percentage as strain 1147 (data not shown). Data not sharing superscript numbers indicate statistically significant differences (p < 0.05).