Drug Resistance Patterns and Multiple Antibiotic Resistance (MAR) Index of Pseudomonas aeruginosa Recovered from Patients at University of Calabar Teaching Hospital, Nigeria

Pseudomonas aeruginosa is a significant nosocomial pathogen with increasing antibiotic resistance worldwide. Understanding local resistance patterns is crucial for effective antimicrobial stewardship. This study aimed to determine the antibiotic resistance patterns and Multiple Antibiotic Resistance (MAR) index of Pseudomonas aeruginosa isolates from various clinical specimens at University of Calabar Teaching Hospital, Nigeria. One hundred clinical samples, including wound swabs (20), ear swabs (20), eye swabs (20), stool (20) and urine (20), were processed using standard microbiological techniques and inoculated onto cetrimide agar. Antibiotic susceptibility testing was performed using the Kirby-Bauer disc diffusion method, and MAR indices were calculated for all isolates. Ethical approval was obtained from the University of Calabar Teaching Hospital Ethics Committee. Fifty Pseudomonas aeruginosa isolates were obtained from wound swabs (20), ear swabs (14), eye swabs (9), stool (4), and urine (3). All isolates (100%) showed resistance to nalidixic acid, with high resistance to augmentin (90%) and pefloxacin (72%). Gentamicin showed moderate effectiveness with 60% sensitivity, while ofloxacin demonstrated 50% sensitivity and ciprofloxacin 40% sensitivity. The mean MAR index was 0.72, with all isolates exceeding the 0.2 threshold, indicating widespread multidrug resistance. Our findings reveal concerning levels of multidrug resistance among Pseudomonas aeruginosa isolates from University of Calabar Teaching Hospital. Resistance to commonly used antibiotics, including gentamicin, poses serious clinical challenges. The high MAR indices underscore the urgent need for enhanced infection control measures and antimicrobial stewardship programs.