Bacterial Contamination of the Surgical Site at the Time of Elective Caesarean Section in Belgian Blue Cows-Part 1: Identified by Bacterial Culture

Simple Summary To ovoid postoperative complications of elective cesarean section (CS) in Belgian blue cows, practitioners always administrate antibiotics. However, no one knows which bacteria are targeted by this antibiotic therapy. This study aimed to describe the bacteria encountered in the surgical site during elective caesarean section (CS) in order to improve the effectiveness of the used antibiotic therapy and to reduce the occurrence of antibiotic resistance. Bacterial cultures were performed on cotton swabs taken from the visceral and parietal peritoneum of 76 cows during the realization of CS. Bacteria were found in only a quarter of samples, while the other swabs were negative. A total of 32 strains belonging to 18 different species was identified. The majority of isolates were gram-negative aerobic species (62.5%), 34% were gram-positive aerobic bacteria and 3% were anaerobic gram-positive species. Due to the presence of bacteria in the quarter of elective CS, this surgery could be considered as a clean contaminated operation. Antibiotic treatment is advised in clean contaminated surgery. Nevertheless, it must be directed against the most identified bacterial population, in this case aerobic gram-negative strains. To improve the efficacy of preoperative antibiotics used in elective caesarean section (CS), we aimed to identify the bacteria contaminating the surgical site during this surgery. A study was conducted on 76 Belgian Blue cows. Bacteriology was performed on cotton swab sampled from the visceral and parietal peritoneum of each cow during the CS. Most of samples showed a negative culture (55/76; 72.37%), 19/76 (25%) were positive (p < 0.0001) and two samples were contaminated. In total, 32 isolates belonging to 18 species were identified. Most of them are aerobic (17/18; 94.44%) and half of them were gram-negative (G-). The most encountered bacteria were Acinetobacter sp. (6/32; 18.75%), Pseudomonas sp. (4/32; 12.5%), Aerococcus viridans (4/32; 12.5%), Psychrobacter sp. (3/32; 9.37%), and Escherichia coli (2/32; 6.25%). Among the identified isolates, 31/32 (96.87%) were aerobic and 1/32 (3.12%) was anaerobic (p = 0.0001). Furthermore, 20/32 (62.50%) strains were G- while 12/32 (37.5%) were gram-positive (G+) (p = 0.012). In fact, most of cultured strains were aerobic G- (20/32), 11/32 were aerobic G+ and 1/32 is anaerobic G+ (p < 0.0001). In conclusion, most of samples showed a negative bacteriology; however, aerobic G- strains were the most identified in positive swabs. Therefore, preoperative antibiotics should be aimed against these bacteria.

Automated summary

A study on 76 Belgian Blue cows undergoing elective caesarean section revealed that most samples had negative bacteriology, while positive swabs mainly identified aerobic gram-negative strains. Therefore, preoperative antibiotics should target these bacteria.