Retrospective Identification of Bacterial Isolates From Emergency Laparotomy Surgical Site Infections in Horses.

The research article focuses on identifying bacterial strains and their antibiotic resistance associated with wound infections in horses following a surgical procedure known as laparotomy. The study is retrospective, examining past cases from one equine hospital over a four-year period.

Introduction and Methodology

• The study’s objective was to identify the bacterial strains that cause wound infection after a horse undergoes a laparotomy and to discern the antibiotic resistance patterns of these bacteria.
• The research was retrospective, meaning that the data reviewed were from past cases. The case series comprised medical records from a single equine hospital over a span of four years.
• The laparotomy procedure referred to in this study was the ventral midline exploratory laparotomy.

Results

• Out of 183 horses that successfully recovered from anesthesia post laparotomy, there was a 19% infection rate (24 out of 124) after the first surgery, and a substantial increase to 83% (19 out of 23) after the relaparotomy (second surgical procedure).
• The most commonly found bacterial strains post-surgery belonged to the Enterobacteriaceae family followed by Staphylococcus, Enterococcus, Streptococcus, and Bacteroides.

Antibiotic Resistance

• The Enterobacteriaceae bacteria family showed the least resistance to three groups of antibiotics: amphenicols, cephalosporins, and quinolones.
• Coagulase-positive Staphylococci were sensitive to amphenicols and only 33% of them showed resistance to a combination antibiotic, trimethoprim/sulfamethoxazole.
• Despite measures being taken to prevent infections, like the use of antibiotics like gentamicin and amoxicillin during and after the surgery, the rate of wound infection was still significant.

Limitations of the Study

• The study acknowledged several limitations, including a lack of control over various factors during the surgery, recovery time, and hospitalization period.
• There was a reliance on accurate record-keeping by others, which could potentially introduce bias or errors into the findings.
• There was also a lack of follow-up information once the animals were discharged from the hospital.

Conclusion

• The prevalence of surgical site infection (SSI) post laparotomy in horses is high, even with the use of antibiotic prophylaxis for a duration of five days. The most common bacteria isolated from these infections belong to the Enterobacteriaceae family and the genus Staphylococcus, both of which show significant resistance to commonly used antibiotics.