Antibiotic susceptibility of wound swab isolates in a tertiary hospital in Southwest Nigeria.

BACKGROUND

Wounds are commonly encountered in the clinical practice. Microbacterial colonization and infection negatively affect wound outcomes. With increasing emergence of antibiotic-resistant strains, it is essential to determine local patterns of wound microbiological profile and antibiotic susceptibility to guide rational empirical antibiotic use.

MATERIALS AND METHODS

Consecutive patients who presented to the plastic surgery unit were recruited to the study over a 6-month period. Wound swab cultures were performed at presentation using standard protocols and media. The wound swab was performed by the Levine technique and data were analyzed using a statistical software package.

RESULTS

Eighty-five microbial isolates were obtained from the eighty patients (55 males and 25 females) recruited. Gram-positive isolates were 35 (41.2%) and Gram-negative were 50 (58.8%). There was equal distribution of acute and chronic wounds. Pseudomonas aeruginosa was the most common isolate at 30.6%, followed by Staphylococcus aureus (27.1%), Escherichia coli (9.4%), Streptococcus species (8.2%), and Morganella morganii (7.1%). The isolates demonstrated resistance to amoxicillin-clavulanate, ampicillin, cloxacillin, cefuroxime, ceftazidime; low-to-moderate sensitivity to erythromycin, gentamicin, streptomycin, tetracycline, ciprofloxacin, and ofloxacin; and a moderate sensitivity to ceftriaxone and a high sensitivity to imipenem. There was significant difference in antibiotic resistance patterns between Gram-positive isolates from acute and chronic wound infections but not for acute and chronic wound Gram-negative isolates.

CONCLUSION

Most of the microbial isolates, particularly the Gram-negative isolates demonstrated low sensitivity to commonly used antibiotics and moderate-to-high sensitivity to less commonly used newer antibiotics.