Antibiotic Sensitivity Pattern and Plasmid Profile of Bacteria Isolated from Diabetic Ulcers in Mbano Metropolis, Imo State, Southeastern Nigeria

Abstract

The study was undertaken to evaluate the bacteriology and antibiogram of isolates from diabetic patients with chronic foot ulcers in Nigeria. A total of 150 pus samples were collected and processed according to standard aerobic and anaerobic microbiological methods. Antibiogram was done using Kirby-Bauer method. Biofilm tests, ESBL & AmpC production was conducted using Congo red agar, Double disc synergy test and Cefoxitin disc test respectively. Total number of isolates obtained was 210. The Plasmid profiles of some of the Multi-Drug Resistance (MDR) isolates were carried out using the alkaline lysis method for plasmid extraction and electrophoresis on agarose gel with standard markers. The most frequently isolated aerobic organism in the study was Escherichia coli (32.1%) while the least occurring was Enterobacter spp (1.57%). For the anaerobes, Peptostreptococcus spp (40%) was the highest isolated bacterium. Percentage of Extended Spectrum -lactamase ( ESBL) producers among E. coli isolates was 44%. Percentages of biofilm formation potential among the isolates were: E. coli (36.8%), S. aureus (23.1%) and Proteus vulgaris (4.2%). Escherichia coli and S. aureus showed considerable levels of resistance to some common antibiotics. No methicilin resistant S. aureus was encountered. AmpC producers encountered were Klebsiella pneumonia (10%) and E. coli (8.1%). Post-curring antibiogram tests revealed that nine isolates carried plasmids, suggesting that the mode of resistance may be plasmid mediated. Keywords: Diabetic ulcers, Bacteria, Antibiogram, Plasmid profile