Evaluation of bla SHV, bla TEM and bla OXA encoding Clinical Isolates from Chronic Tonsillitis using Phenotypic and Molecular Technique: First report from Pakistan

Abstract

Objective: To evaluate bla SHV, bla TEM and bla OXA encoding clinical isolates in chronic tonsillitis using phenotypic and molecular techniques.
Place and Duration:  The study was conducted in Department of Microbiology and Molecular Genetics, University of Punjab, Lahore from August 2016 to August 2017.
Methodology: Sample processing, identification and characterization of isolates was done by using (CLSI, 2016) criteria. Antibiotic susceptibility testing by using disc diffusion assay and biofilm forming ability was analyzed by ring test and slime production test. Combination disc test was used for phenotypic detection of antibiotic resistance genes. Multiplex-PCR assay was used to check the presence of bla SHV, bla TEM and bla OXA genes. 16S rRNA sequencing and phylogenetic analysis was performed.
Results: Here, variable resistance pattern was observed against applied antibiotics. 100 % resistance towards azotreonam and penicillin was observed. While 60-85 % resistances were observed against cephalosporins. Biofilm formation increased with the passage of time. 77% strains indicated positive combination disc test. Multiplex-PCR indicated 60% strains harbored tested genes. 40 % bla SHV genes, 30 % bla TEM genes and 60% bla OXA genes were observed among selected isolates. GenBank Accession number obtained for Klebsiella pneumoniae was KY810693 and for S. aureus was KY810692.
Conclusion: In conclusion, K. pneumoniae and S. aureus came out to be common causative agents of tonsillitis in the current study. Resistance towards multiple classes of antibiotics and strong biofilms of these micro-organisms explain the chronicity and recurrent nature of the infection. bla OXA genes were frequent among genes tested.