Reducing carbapenemase-producing Gram-negative bacilli in high-risk veterinary hospital units through targeted infection prevention and control.

This study aimed to evaluate the impact of targeted infection prevention and control (IPC) interventions on carbapenemase-producing Gram-negative bacilli (CP-GNB) contamination and colonization in high-risk veterinary hospital units, including the critical care unit (CCU), inpatient department (IPD), and operating room (OR). A ten-month quasi-experimental longitudinal study was conducted, comprising a three-month pre-intervention sampling period, a four-month IPC intervention period, and a three-month post-intervention sampling period. CP-GNB were collected from environmental surfaces, rectal swabs, and clinical specimens. During the pre-intervention sampling period, high frequencies of environmental CP-GNB contamination were detected-64.6% (42/66) in the CCU, 80.0% (44/55) in the IPD, and 39.3% (33/84) in the OR-with patient colonization rates of 55.0% (11/20) in the CCU and 45.0% (9/20) in the IPD. Carbapenemase-producing (CP) Acinetobacter baumannii (CP-Ab) predominated in the environment, whereas CP-Escherichia coli (CP-Ec) and CP-Klebsiella pneumoniae (CP-Kp) predominated in intestinal carriage. Molecular analysis revealed the clonal distribution of CP-Ab sequence type (ST) 16 and ST1359 carrying blaOXA-23; CP-Kp ST147 carrying blaOXA-181 or blaOXA-232; CP-Ec ST156 carrying blaNDM-5 and ST410 carrying blaNDM-5 and blaOXA-181; and CP-Enterobacter hormaechei ST121 carrying blaOXA-181, circulating among animal patients and hospital environments. Following the IPC interventions, CP-GNB contamination decreased significantly by 40.4% in the CCU, 68.1% in the IPD, and 87.8% in the OR (p < 0.001). CP-GNB colonization was also reduced by 36.4% in the CCU and 28.6% in the IPD. This study underscores the importance of hospital surveillance and the implementation of targeted IPC interventions to reduce CP-GNB contamination and clonal dissemination in veterinary hospital settings.