Bacterial species and antibacterial resistance among post caesarean section surgical site infections at Mulago hospital Kampala, Uganda

Abstract

The emerging multidrug resistant strains and changing antimicrobial resistance pose a challenge in treating infections from Surgical Site Infections (SSIs) following caesarean sections.(C/S) However, there is limited data on the spectrum of bacteria isolated from post C/S SSIs and their antimicrobial susceptibility patterns to guide SSIs-therapy in our setting. Methods A cross sectional study was done among patients with post C/S SSIs at Mulago Hospital Kampala, Uganda from November 2017 to April 2018. Wound swabs were taken for culture and sensitivity test. The initial colony characteristics were identified by the Gram stain and further identification was done by a set of biochemical tests. Antimicrobial susceptibility pattern of pathogens was determined by Kirby Bauer disc diffusion method. Logistic regression was used to compare bacterial species isolated from those with obstructed labour versus those with other indications for C/S. Results Of the 108 enrolled patients with SSIs (Mean age 25), 95% were HIV negative, 46% had obstructed labour as the indication for caesarean section and 87% had received IV antibiotics in the perioperative period. 93 swabs (86%) were culture positive with one or more organisms giving a total of 118 pathogens 69/118 (59%) were gram negative bacteria (GNB) and 49/118 (41%) gram positive bacteria (GPB). Among the GNB, the most predominant species was K. pneumoniae with 37.4% (44/118) and E. coli at 9.3% (11/118). Among the GPB bacteria, S. aureus contributed (28.8%) 34/118 while enterococcus species accounted for 12.7% (15/118). All GNB were 100% resistant to Ampicillin but 100% sensitive to Amikacin. ESBL resistance was found in 56% (35/63) of enterobacteriaceae. All the GPB were susceptible to Vancomycin. 88.2% were Methicillin resistant S. aureus (MRSA). The bacterial species isolated were not different between those with obstructed labor versus other indications for C/S but could be due to small sample size. Conclusion and recommendations GNB (Klebsiella spp and E. coli) and S. aureus cause the majority of SSIs post CS at Mulago National hospital. Vancomycin and Amikacin still show excellent susceptibility although may be prohibitive cost-wise. MRSA in higher proportions than previously reported calls for strengthening of infection control surveillance. The mechanism of resistance to third generation cephalosporins beyond ESBL production is an important area that requires further study