Surveillance of antimicrobial resistance and healthcare-associated infections in veterinary teaching hospitals

The role of small animal veterinary hospitals in the onset and dissemination of antimicrobial-resistant organisms (AMROs) is an emerging research field, and the implementation of internal surveillance programs is a cost-effective tool to better understand their impact. The aim of this PhD project was to develop a surveillance program in the Veterinary Teaching Hospital (VTH) of the Department of Veterinary Medical Sciences, University of Bologna, to obtain, analyze and compare data on AMROs and healthcare-associated infections (HAIs). The program was composed by passive surveillance, active surveillance on patients, active surveillance on the environment, outbreak surveillance and the communication system. Results from passive surveillance on 1342 clinical isolates highlighted a multi-drug resistance (MDR) percentage of 41.6%, with worrying non-susceptibility percentages detected for clindamycin (58.4%), amoxicillin-clavulanate (20.3%), piperacillin-tazobactam (15%) and enrofloxacin (45.8%). Whole genome sequencing on some selected MDR Enterobacterales isolates revealed the presence of multiple worrisome resistance genes, including the carbapenemase-encoding gene blaNDM-5. Considering only isolates from suspected HAIs (13.9% of the total), MDR percentage was considerably higher (71.7%). Active surveillance on patients showed a high in-hospital acquisition rate (25.6%) of commensal carbapenem-resistant gram-negative bacteria (CR-GNB) with multiple resistance genes, including blaNDM. Active surveillance on the environment detected high prevalence of methicillin- resistant Staphylococci (MRS, 19.5%). Active surveillance was also executed in a Spanish VTH, showing a lower AMROs frequency of detection at admission and in-hospital acquisition. Outbreak surveillance allowed to early detect and manage two outbreaks both caused by the Enterobacter cloacae complex. The communication system involved professionals from different fields and assisted the redaction of a new departmental biosecurity manual. Data collected from surveillance can serve as a basis to develop a tailored Infection Control Programs and underline the potential role of VTHs in the maintenance and dissemination of AMROs, including some considered highest priority for human medicine.