TITLE:
Low-Level Antibiotic Resistance among Staphylococcus aureus and Gram-Negative Pathogens from Infected Skin and Soft Tissues in Rural Kenya
AUTHORS:
Justin Nyasinga, Zubair Munshi, Lillian Musila, Ephantus Mbugua, Geoffrey Omuse, Gunturu Revathi
KEYWORDS:
S. aureus, MRSA, Gram-Negative Bacteria, Antimicrobial Resistance, SSTIs, Kenya
JOURNAL NAME:
Open Journal of Medical Microbiology,
Vol.14 No.1,
March
28,
2024
ABSTRACT: Introduction: Bacterial skin and
soft tissue infections (SSTIs) are a cause of frequent inpatient and outpatient
care visits whose causative agents are associated with a high antimicrobial
resistance burden. For insights on antimicrobial susceptibilities in a rural
setting, we examined specimens from suspected SSTIs from two public health
facilities in Kenya. We additionally assessed antibiotic use, appropriateness
of empiric therapy and risk factors for SSTI. Methodology: Between 2021
and 2023, 265 patients at Kisii and Nyamira County Referral hospitals were
enrolled. Wound swabs/aspirates were collected and processed following standard
microbiological procedures. Identification and antimicrobial susceptibility
were performed using the VITEK 2 Compact
platform. Demographic, clinical, and microbiological data were analyzed
with R Statistical software. Results: S. aureus was isolated in 16.2% (43/265) of patients with a
methicillin resistance (MRSA) proportion of 14% (6/43). While 13/15 drugs
elicited susceptibilities ranging from 84% - 100%, penicillin (16%) and trimethoprim-sulfamethoxazole [TMP-SXT] (23%) yielded
the lowest susceptibilities. Escherichia coli (n = 33), Klebsiella pneumoniae (n = 8), Pseudomonas aeruginosa (n = 8), and Citrobacter species (n = 4) were the most
commonly isolated gram-negative species. Gram-negative strains showed high
susceptibilities to most of the tested drugs (71% - 100%) with the exception of ampicillin (18%), TMP-SXT (33%), and first and second generation cephalosporins. Conclusions: The low
MRSA prevalence and generally high antibiotic susceptibilities for S. aureus and gram-negative
bacteria present opportunities for antibiotic stewardship in the study
setting. Diminished susceptibilities against penicillin/ampicillin and TMP-SXT
accord with prevailing local data and add a layer of evidence for their
cautious empiric use.