Evaluation of antimicrobial resistance patterns of bacteria isolates from chronic wounds on patients attending Murang’a level 5 hospital, Kenya

Abstract

Chronic wounds pose a serious public health risk. Therapy of chronic wound infections is significantly hampered by the unchecked and rapid spread of bacterial pathogens. A substantial amount of research has been done in developed countries on these chronic wounds. In Kenya there is a scarcity of the statistics on antimicrobial sensitivity and resistance of bacteria isolated from chronic wound infections. This study has determined the colonizing bacteria of chronic wounds and their antibacterial resistance pattern to most used antibiotics. Risk factors associated with chronic wounds was also evaluated. This analysis was carried out in Murang’a Level 5 Hospital which is located in rural area of Central region in Kenya. People in rural areas are presumed to be prone to wounds because of their lifestyles and nature of their works. It was a hospital-based cross-sectional study that was carried out from June 2023 to November 2023. Questionnaire was used to get social demographic characteristics and medical history from the patient. Swabs were aseptically picked from chronic wounds and transported in Amies transport media in a cooler box to Microbiology laboratory. Inoculation was done on Sheep Blood Agar and MacConkey Agar and incubated at 370 c for 24 to 48 hours. Gram stain followed for the provisional isolate’s identification. Further singling out was executed using a number of biochemical tests. The isolated microorganisms were evaluated for drug sensitivity and resistance using Kirby Bauer disk diffusion method on Mueller Hinton Agar. Descriptive statistics for frequency distribution of clinical bacterial pathogens and their antimicrobial susceptibility, were presented in tabular, graphical and chart form. The zone diameter breakpoints of all drug disks were evaluated in millimetres to determine whether they are sensitive or resistant. The potential association among variables was established using the Chi square tests. P-value <0.05 was regarded to be a statistical significance association. The total swabs tested were 300 and positivity rate was 81.3%, Staphylococcus aureus being the most predominant bacteria infecting chronic wounds at 29.7%. Pseudomonas aeruginosa (16.3%) was second and most frequent in Gram negatives. E. coli had a prevalence of 15.2%. Levofloxacin was the most sensitive antibiotic to S. aureus, doxycycline and gentamicin followed closely. It was resistant to penicillin, co-trimoxazole and Augmentin. All Gram negative bacteria in this study demonstrated high susceptibility to meropenem, piperacillin/tazobactam, gentamicin, imipenem, cefepime and ciprofloxacin in that order. They all showed resistance to ceftriaxone, Augmentin, co-trimoxazole and ampicillin. Of all Staphylococcus aureus isolated, 22.6% were methicillin resistance (MRSA) strains. Induced clindamycin resistance (ICR) strains were 5.95% and 2.38% had both MRSA and ICR strains. In all Enterobacteriaceae isolated, 19 (16.23%) are Extended spectrum beta-lactamase (ESBL) producing strains. E. coli accounted for 10 ESBL strains while the rest 9 ESBLs were from Klebsiella pneumoniae. Frequence monitoring of antimicrobial susceptibility pattern is necessary to curb the spread of antibacterial resistance. Microbiological results should be embraced into consideration when prescribing antibiotics whenever possible. The findings generated from this study will be forwarded for adoption to the health care practitioners for effective management and treatment of chronic wound infections.