Genomic tracing and resolution of environmental Klebsiella pneumoniae ST307 CTX-M-15 linked to a nosocomial urinary tract infection in a cat: a veterinary teaching hospital case study

Hospital-acquired infections (HAIs) are a significant concern in human medicine and have increasingly been reported in veterinary settings as well. Veterinary Teaching Hospitals may present a heightened risk for HAIs, partly due to the lack of standardized infection control measures and screening protocols. In May 2022, a cat previously hospitalized at a Veterinary Teaching Hospital for urinary tract obstruction developed a catheter-associated urinary tract infection (CAUTI). A multidrug-resistant (MDR) strain of Klebsiella pneumoniae was isolated. To investigate the suspected HAI and assess the presence of other MDR Gram-negative bacteria, an environmental screening of different hospital surfaces was conducted using both phenotypic and genotypic analyses. A total of 70 swabs were collected from environmental surfaces, 51 before and 19 after cleaning procedures. Sterility was observed in 19.6% (10/51) of samples collected before cleaning and in 26.3% (5/19) of those collected afterward. Four Klebsiella pneumoniae strains were isolated: two from the environment (a keyboard in the ultrasound room and a cattery cage) and two from the patient (urine and a bladder clot). All four isolates were identified as a single clone of K. pneumoniae sequence type ST307, carrying the CTX-M-15 gene, the GyrA-83I and ParC-80I point mutations, and the oqxA and oqxB resistance genes, which confer resistance to disinfectants. Environmental screening also yielded 13 Gram-negative bacterial isolates, including Enterobacter cloacae (7/13), K. pneumoniae (2/13), Acinetobacter lwoffii (1/13), Pantoea agglomerans (1/13), Escherichia coli (1/13), and Stenotrophomonas maltophilia (1/13). Among these, the most frequently detected resistance genes were blaTEM and blaCTX-M1. Notably, although the isolates were phenotypically sensitive to carbapenems, the presence of blaVIM and blaIMP carbapenemase genes was also detected. Genomic analysis confirmed the dissemination of MDR K. pneumoniae within the hospital environment. Given the high prevalence of MDR bacteria in the hospital environment, this study highlights the critical need to establish robust infection control programs in veterinary teaching hospitals. Strategies such as the rotation of antibiotics and disinfectants, strict adherence to hygiene protocols, and regular microbiological surveillance are essential to prevent hospital-acquired infections (HAIs) and to limit the dissemination of zoonotic multidrug-resistant organisms (MDROs).