The present study was done to scrutinize the possible relation between virulence genes and antimicrobial resistance in some pathogenic bacteria. Considering the fact that the presence of recognized infective determinants among clinical isolates may promote the emergence of infections and persistence of pathogens.
A total of 60 bacterial isolates were obtained from College of Science/ University of Al-Kufa. After the maintenance and subcultured of these isolates, some phenotype tests were performed which included plate hemolysis, haemagglutination, serum resistance and biofilm formation. Then genotype study was investigated for some virulence genes (biofilm, FimH and Iss) and antibiotics resistance genes (blaAmpC, blaTEM, blaSHV-5 and blaCTX-M) by using PCR technique.
The results of plate hemolysis indicated that all isolates of Klebsiella pneumonia and Serratia marcescens were positive with 100%, while Shigella dysenteriae and Pseudomonas aeruginosa isolates showed the less percentage 40% among all bacterial isolates. Haemagglutination test revealed the highest percentage with isolates of Serratia marcescens 100%, whereas, the isolates of E. coli, Shigella dysenteriae and Salmonella typhi showed the less percentage 20%. All isolates of P. mirabillis were positive for serum resistance test with 100%, while the less percentage 14% observed with isolates of Pseudomonas aeruginosa. The results of biofilm formation test revealed that all bacterial isolates were perceived negative results except in isolates of E. coli, Proteus mirabillis and Enterococcus faecalis.
The genotype study investigated for three virulence genes and four antibiotics resistance genes. The results of virulence gene indicated that biofilm gene was the most prevalence gene, where appeared in 95% of bacterial isolates followed by Iss gene 86.66% and FimH gene 85%.
blaAmpC and blaTEM were significantly prevalence in all bacterial isolates compare with blaSHV-5 and blaCTX-M at P≤ 0.05. the percentage of the prevalence of blaAmpC and blaTEM were 93.33 and 71.66, respectively, while the less percentages were observed in blaSHV-5 20% and blaCTX-M 46.66%.
The current study showed a strong significant correlation between virulence and antibiotic resistance profile, where the statistical analysis revealed that the Person correlation was 0.957 between virulence and antibiotics determinants.
The present study demonstrated a positive relationship the ability of bacterial isolates to possess antibiotics resistance and the prevalence of virulence genes. The establishment of this correlations between resistance and virulence proﬁles could provide valuable input about the clinical evolution and recurrence rates of different bacterial infection.