ABSTRACT
Aim: The present study aims to determine the antimicrobial resistance genes and some virulence factors produced by clinical isolates of E. coli and S. pyogenes isolated from different sources
Methods: A total of 60 E. coli and 42 S. pyogenes were studied for antibiotic susceptibility pattern, resistance genes, different resistance enzymes production and some virulence factors such as serum resistance, haemolysin, bacterial ability for colonization, haemagglutination, gelatinase, streptokinase and streptodornase
Results: Nearly 79.4% of the isolates are multiple resistant as they were resistant to all antimicrobial classes used in this study. All E. coli isolates and only 2 S. pyogenes were beta-lactamase producers. Detection of bla-TEM gene reveled that it was amplified on plasmid DNA of 23 isolates out of 25 E. coli isolates. AGIEs prepared from 19 E. coli and 11 S. pyogenes isolates exhibited variable inactivation percentages on different aminoglycosides. Chloramphenicol acetyltransferase [CAT] enzyme was detected among 55% of E. coli isolates. Gyr A gene was successfully amplified by a specific primer set on plasmid DNA of 36 isolates out of 39 tested E. coli isolates which were quinolone resistant. bla-TEM gene was amplified on plasmid DNA of 23 isolates out of 25 B-lactam resistant E. coli isolates. While for S. pyogenes, Gyr A was detected and amplified on genomic DNA of 14 quinolone resistant isolates and bla-TEM was detected and amplified on genomic DNA of 28 B-lactam resistant isolates. Among 60 E. coli isolates, 42 [70%] were serum resistant, 20 [33.3%] showed mannose-resistant haemagglutination, 16 [26.7%] showed mannose-sensitive haemagglutination, 37 [61.7%] were slime producers, 10 [16.7%] were hemolytic and none of E. coli isolates was positive gelatinase producer. Among 42 S. pyogenes isolates, streptodornase production was detected in 28 [66.7%] of S. pyogenes isolates while streptokinase activity was detected in 23 [55%] of S. pyogenes isolates