ISSN 2736-1756
Advanced Journal of Microbiology Research ISSN 2241-9837 Vol. 13 (3), pp. 001-008, March, 2019. © International Scholars Journals
Full Length Research Paper
A study of multiple resistance and role of extended spectrum -lactamases in environmental Pseudomonas isolates
Chikwendu C. I.1*, S. N. Ibe2 and G. C. Okpokwasili2
1Department of Microbiology, School of Science, Federal University of Technology, P. M. B. 1526, Owerri, Imo State, Nigreia.
2Department of Microbiology, Faculty of Science, University of Port Harcourt, Choba, Rivers State, Nigreia.
Accepted 15 January, 2019
Abstract
The activity of 13 antimicrobials was studied, to determine multiple antimicrobial resistances, against 208 Pseudomonas strains (125 Pseudomonas sp and 83 Pseudomonas aeruginosa) isolated from river and aquaculture samples. Isolates were confirmed with API 20 NE. Isolates from both sources reported high resistance rates for similar antibiotics. These were: Ampicillin (100, 100%), cefuroxime (96.8, 81.9%), streptomycin (93.6, 78.6%), cefotaxime (93.6, 77.1%), for river water and aquaculture samples respectively. While resistances were high for ofloxacin, norfloxacine, mezlocillin, ceftazidime, kanamycin and enrofloxacine (70 to 85.5%) among the river water isolates, they were moderate among the aquaculture isolates (50 to 69.4%). Ninety seven (97.2%) percent of isolates from river water and 78.9% from aquaculture were resistant to at least three or more antimicrobials and were termed multi-resistant. Results of plasmid profiling showed the presence of multiple plasmids ranging in size between 639 and 11845 bp. Preliminary tests for -lactamase detection by double-disk approximation were positive with high resistances to imipenem, aztreonam, cefpodoxime and cefotaxime. PCR of amplified genomic DNA was positive for the detection of blaSHV and blaTEM -lactamase genes. However, up to 50% of all isolates tested were found to be resistant to the -lactamase inhibitor of combination amoxicillin+clavulanic acid. The results infer the presence of multi resistant organisms as well as genes conferring -lactamase resistance in environmental samples.
Key words: blaSHV, blaTEM, beta-lactamase, multi-resistant, Pseudomonas sp., environmental sources.