Prevalence and analysis of Pseudomonas aeruginosa in chinchillas

P. aeruginosa was isolated from 41.8% of the 67 chinchillas included in the study. Slide agglutination and pulsed-field gel electrophoresis discriminated 5 serotypes and 7 unique patterns, respectively. For the antibiotic susceptibility test, 40.9% of isolates were susceptible to gentamicin, 77.3% to ciprofloxacin, 77.3% to imipenem, and 72.7% to ceftazidime. DNA analyses confirmed that none of the isolates contained the gene encoding extended-spectrum β-lactamases; however, 2 of the total 23 isolates were found to have a gene similar to the pilL gene that has been identified in the pathogenicity island of a clinical isolate of P. aeruginosa.P. aeruginosa is widely spread in chinchillas, including strains with reduced susceptibility to the antibiotics and highly virulent strains. The periodic monitoring should be performed to help prevent the propagation of this pathogen and reduce the risk of infection from chinchillas to humans.Chinchillas (Chinchilla laniger) are in the Rodentia order, Hystricognathi suborder and the Chinchillidae family. Since chinchillas are small and easy to breed, they are popular as pets. Chinchillas have a large tympanum and cochlear duct similar to the human organ; therefore, they are also often used as laboratory animals for otolaryngological studies [1-4].Pseudomonas aeruginosa is a Gram-negative rod-shaped bacterium and an opportunistic pathogen that causes various serious diseases in humans and animals. Recently, this pathogen has acquired resistance to many therapeutic antibiotics and, in particular, emergence of P. aeruginosa isolates with extended-spectrum β-lactamases (ESBLs) has become a serious problem in laboratories and hospitals [5-8]. Thus, it is important not only to investigate the occurrence of P. aeruginosa infection but also to assess the existence of antibiotic-resistant P. aeruginosa strains to ensure the health of humans and animals. It is known that chinchillas are sensitive to P. aeruginosa infection and are therefo