Antibiotic Resistance Profile of Wound Infection Isolates: High Resistance to Cephalosporins and Penicillin Among Ghanaian Patients in a Cross-Sectional Study

Background and Aim: Antibiotics remain among the most frequently prescribed medications in clinical practice. However, antimicrobial resistance (AMR) is an inevitable and irreversible consequence of bacterial adaptation to antimicrobial exposure. Despite its clinical importance, data on antibiotic resistance patterns of bacteria from wound infections in Ghana are limited. This study evaluated the prevalence and magnitude of antibiotic resistance among bacterial isolates from infected wounds in a Ghanaian population. Methods: This experimental cross-sectional study enrolled 300 patients with suspected wound infections receiving care at MDS-Lancet Laboratories. Wound swabs were collected, cultured on standard media, and incubated at 37°C for 18–24 h, with a second overnight reading. Bacterial identification was based on colony morphology, Gram staining, biochemical testing, and API 20 E/NE. Antimicrobial susceptibility was determined using the disc diffusion method. Data analysis was conducted using SPSS v26.0 and GraphPad v9.5. Results: The predominant isolates were Escherichia coli (23.2%), Pseudomonas aeruginosa (19.8%), Klebsiella spp. (19.2%), and Staphylococcus aureus (15.2%). Gram-negative isolates were most susceptible to aminoglycosides (Amikacin, Gentamicin), carbapenems (Ertapenem, Imipenem, Meropenem), and Tigecycline, whilst showing high resistance to 2nd, 3rd and 4th generation cephalosporins (Cefuroxime, Ceftriaxone, and Cefepime, respectively) and Amoxicillin. Gram-positive isolates, including S. aureus and coagulase-negative staphylococci, were most susceptible to Gentamicin, Clindamycin, and Erythromycin, but resistant to 1st- and 2nd-generation cephalosporins (Cefazolin and Cefoxitin respectively), penicillins (Augmentin and Cloxacillin), and Tetracycline. Extended-spectrum β-lactamase (ESBL) producers accounted for 30.3% of isolates, predominantly E. coli (50%) and Klebsiella spp. (43.9%). Methicillin-resistant S. aureus (MRSA) and methicillin-resistant coagulase-negative staphylococci (MRCNS) were observed in 34.7% and 66.7% of isolates, respectively. Conclusion: Aminoglycosides and Linezolid are most effective against Gram-positive and Gram-negative bacteria causing wound infections. However, both Gram-positive and Gram-negative bacteria are resistant to 2nd generation cephalosporins and penicillin. High resistance to cephalosporins and penicillin calls for the necessity of culture-guided therapy for effective wound infection management.