Plasmid Profile of Multi-drug Resistant Phenotypes of Pseudomonas aeruginosa Isolated among Patients with Indwelling Catheter in Northeastern Nigeria

Aims: This study was carried out to analyze the plasmid profile of multidrug resistant Pseudomonas aeruginosa isolated among catheterized patients attending the University of Maiduguri Teaching Hospital.

Place of Study: Department of Medical Microbiology (Laboratory Section), University of Maiduguri Teaching Hospital and Department of Biological Sciences, Abubakar Tafawa Balewa University, Nigeria.

Methodology: 244 samples (catheter tip, urethral swab, urine) were collected from catheterised patients and investigated via microscopy and culture on Blood agar and MacConkey agar. Suspect Pseudomonas aeruginosa isolates were further confirmed using biochemical tests. Kirby bauer disc diffusion test was used to determine the antimicrobial susceptibility pattern. Isolates confirmed to be multidrug resistant (MDR) were subjected to plasmid profile analysis using agarose gel electrophoresis.

Results: 21 yielded Pseudomonas aeruginosa which gives a recovery rate of 8.6%. A significant proportion was isolated from catheter tip samples collected from male patients (33.33%). The association between sex of patient and sample type in the isolation of Pseudomonas aeruginosa was statistically significant (X2 = 10.76, df = 2, P <.01). Isolates were most-sensitive/least-resistant to Ofloxacin and Ampiclox, and least-sensitive/most-resistant to Penicillin. All isolates identified were multi-drug resistant (MDR) with an average resistance rate of 3.28 antimicrobials per isolate. Plasmid analysis revealed that 57.14% of isolates possessed similar plasmid with a DNA fragment size of 300bp and a molecular weight of 31 ng/10 µl.

Conclusion: We establish a very high rate of multidrug resistance among Pseudomonas aeruginosa isolates. Plasmid profile analysis of MDR Pseudomonas aeruginosa observed revealed a high plasmid prevalence rate and since most isolates cannot express the resistance marker after plasmid curing, we suggest that this is indicative of the plasmidial origin of such a marker.