Background: Multiple factors play a role in the transmission of secondary infections to patients during surgery. Epidemiological studies have clearly demonstrated the role of anesthesia equipment in causing surgical infections.
Objectives: This study aimed to investigate the level of bacterial contamination of endotracheal tubes and anesthesia devices in small animals.
Methods: In this study, 15 endotracheal tubes and the connecting tube attached to the anesthesia apparatus, the canister wall, and the soda lime were examined. Samples taken from the last 5 cm of the endotracheal tube after removing the distal balloon (piece one) were cultured on MacConkey agar, chocolate agar, mannitol salt agar, and Stereimide agar. After bacterial culturing, the next 5 cm of the tube was cut (piece two), and each sample was cultured on chocolate agar for colony-forming unit (CFU) counting. The samples were incubated for 48 hours at 37 o C. The ability of the isolated bacteria to produce biofilm was assessed by two methods: microscopic observation and microplate assay.
Results: In the direct bacterial culture method, 9 out of 15 endotracheal tubes showed growth, and in the overall colony count (CFU), bacterial growth was observed in 6 out of 15 samples. In the evaluation of biofilm production using the microscopic method, 7 out of 11 positive isolates were found, while the microplate method reported two positive samples, two weak samples, and 7 negative samples. The isolated bacteria included 4 cases of Acinetobacter, 2 cases of Staphylococcus, 2 cases of Corynebacterium/Sphingomonas, and one case each of Klebsiella, Bacillus, and Alkaligenes.
Conclusions: Based on the results of this study, anesthesia equipment can facilitate the transmission of microbial contamination to the respiratory tract. Since microbial biofilms are not eliminated by standard disinfection methods and play a significant role in antibiotic resistance, the presence of these contaminants in anesthesia equipment poses a serious risk to the health of animals in the surgical department.