Effects of Disinfection Methods, Antimicrobial Sensitivity, and Environmental Conditions on Bacterial Contamination of Surgical Instruments During Canine Ovariohysterectomy

Surgical site infections (SSIs) pose a threat to animal health and potentially compromise recovery after surgical procedures. Antimicrobial resistance (AMR) also exacerbates SSI. Therefore, preventive measures are needed to reduce the risk of SSI during surgery, as well as surveillance of bacteria and antibiotic susceptibility. The present study aimed to observe the risk factors and prevention of SSI in canine ovariohysterectomy (OH), bacterial sensitivity to antibiotics commonly used in veterinary practice, and assess the association of surgical room environment and bacterial contamination. Nine mongrel dogs underwent OH procedures, with surgical instruments (thumb forceps, scissors, and hemostatic forceps) subjected to three intraoperative disinfection methods (70% alcohol, 10% povidone-iodine, or no treatment). Each of the surgical instruments on each disinfection method was swabbed at three points in time (0, 30, and 60 minutes) intraoperatively. Environmental conditions (humidity and temperature) of the surgical room were monitored at each sampling interval. The bacterial identification was performed using conventional microbiological methods. The identified bacteria were tested for antimicrobial susceptibility to doxycycline, enrofloxacin, cefadroxil, and gentamicin using the Kirby-Bauer method. Results indicated that 70% alcohol reduced bacterial contamination in two-thirds (2/3) of replicates, compared to 10% povidone-iodine (0/3) and untreated control (0/3). The bacteria that were identified were Bacillus cereus, Bacillus megaterium, Staphylococcus aureus, and Klebsiella spp. Most of the bacteria identified were susceptible to all antibiotics tested, except Klebsiella spp., which displayed resistance to gentamicin and cefadroxil, while doxycycline and enrofloxacin remained susceptible. The bacterial contamination also might be supported by the humidity and temperature of the surgical room, which is above the standard requirement. The present study findings highlighted the importance of standardized intraoperative disinfection protocols, surveillance of antimicrobial susceptibility, and environmental control in veterinary surgical procedures.