Bacteriological profile and multidrug resistance of Gram-negative bacteria in wound infections at a secondary healthcare facility in Ghana.

backgroundGlobally, antimicrobial resistance is a major clinical and therapeutic challenge, causing significant morbidity and mortality, with wounds being a major reservoir of multi-drug resistant bacteria. Data on the prevalence of bacterial resistance in secondary health care settings, particularly in the middle belt of Ghana, remain limited, which hampers effective treatment and infection control measures. The aim of the study was to determine the bacteriological profile and the prevalence of multidrug-resistant Gram-negative bacteria in wounds at the Holy Family Hospital in Berekum, a secondary health care facility in the Central Belt of Ghana.

methodsThe cross-sectional study was performed between February and June 2021 and 210 patients (50.5% female) with wound infections were systematically recruited. Wound swabs were taken from participants and transported immediately to the laboratory. Bacteria were isolated and identified using standard culture and biochemical tests. Antimicrobial susceptibility was performed on Mueller Hinton agar using Kirby-Bauer disk diffusion method according to standards by the Clinical and Laboratory Standards Institute. Isolates resistant to one or more antibiotics in three or more antimicrobial classes were classified as multi-drug resistant.

resultsA total of 210 swabs were taken from study participants and 173 (82.4%) of these showed bacterial growth with 143/210 (68.1%) of being Gram-negative bacteria and 30/210 (14.3%) being Gram-positive bacteria. The major Gram-negative bacteria isolated were 24.8% Pseudomonas spp., 17.3% Citrobacter spp., 13.3% Enterobacter spp., and 10.4% Proteus mirabilis whilst Staphylococcus aureus (17.3%) was the only Gram-positive bacteria isolated. The prevalence of antibiotic resistance was high among the isolates tested being 90.6% for cefuroxime, 86.9% for ceftriaxone, 84.2% for tetracycline, 81.1% for ampicillin and cefotaxime, and 74.8% for meropenem. The prevalence of multidrug resistant Gram-negative bacteria was 136/143 (95.1%) with amikacin and ciprofloxacin being the most effective antibiotics with sensitivity rates at 83.6% and 57.5%, respectively.

conclusionsOur study showed that the most common Gram-negative bacteria found in infected wounds was Pseudomonas spp. We also observed a high prevalence of multidrug resistance in the Gram-negative bacteria tested against selected common antibiotics used in Ghana. The high resistance to carbapenems and third generation cephalosporins (cefotaxime and ceftriaxone) considered to be the antibiotics of last resort was a particularly worrying finding. This indicates the need to review first-line and last-line antibiotic regimens and to improve and maintain antimicrobial surveillance in secondary health care settings. In addition, empirical wound healing should be monitored on a regular basis to assess the development of resistance and to ensure that wound healing is still effective against wound infections.