Bacterial profile and antimicrobial susceptibility patterns of isolates from surgical site infections at Luwero hospital

Abstract

Background: A surgical site infection (SSI) is an infection that develops within at most 30 days following a surgical procedure or after one year in case if an implant was placed. The American Centers for Disease Control (CDC), classifies these infections as; Superficial incisional SSI which occurs just in the area of the skin where the incision was made, Deep incisional SSI which occurs beneath the incision area in muscle and the tissues surrounding the muscles and Organ or space SSI where the infection can be in any area of the body other than skin, muscle, and surrounding tissue that was involved in the surgery including a body organ or a space between organs. SSIs account for about 20% to 25% of the total Hospital acquired infections (HAI) throughout the world a serious problem to patients who undergo surgery. SSIs are linked to a 2-11 increment in the risk of mortality. Objectives: The main objective of this study was to determine the prevalence and bacterial profile in SSIs in Luwero Hospital. Specific objectives were to determine commonest bacterial agents and their anti-microbial susceptibility profiles and risk factors associated with SSIs in Luwero Hospital. Methods: The study was a cross sectional study which was conducted from February to May 2023 at Luwero Hospital. A total of 200 patients who had undergone surgery were recruited in the study during the study period. Surgical wounds were swabbed and samples processed following standard microbiological techniques at the Makerere University Clinical Microbiology Laboratory. Demographic data and patient information was collected using structured questionnaire and from patient files. Results: We analyzed data for 179 participants who had under gone different surgical procedures at Luwero Hospital. Of these, 139 (77.7%) were females. About 71.5% of the participants belonged to the age group of 18-30 years, and who had average age of 28.7 ± 0.82 years old (Range 18 – 84 years). The overall prevalence of SSI from this study was 27.4% (49/179). About 69.8% (34/49) of these had deep SSI and 30.6% (15/49) had superficial SSIs. Nobody had organ space SSI. Total number of bacteria isolated from this study was 56 with S.aureus being the commonest bacterial isolate. We also isolated Enterococcus spp, E.coli, K.pnuemoniae, Acinetobacter spp and other Gram negatives. Patients had both single and mixed bacterial SSIs. Majority of the Gram negatives were less susceptible to commonly used antibiotics. All ESBL positives and other Gram negatives were 100% susceptible to imipenem. All S.aureus were 100% susceptible to vancomycin. The main risk factors to development of SSIs were longer operation lengths and shorter duration of antibiotics after surgery (aOR = 0.03, 95% CI 0.007-0.109, p-value <0.001) and (aOR = 11.69, 95% CI 2.530-54.031, p-value 0.002) respectively. Conclusion: We isolated MDR bacterial organisms and majority of them were among Enterobacterales. This highlights the agent need of involving routine culture and sensitivity services in Luwero Hospital. This will help clinicians to treat infections depending on culture and sensitivity results hence reducing increase in MDR emergency. For now, clinicians can use our antibiogram results when prescribing antibiotics so as to improve on the patient outcome in case of SSI event since they don’t do culture and sensitivity routinely.