Comparative study on prevalence and association of some virulence factors with extended spectrum beta-lactamases and AmpC producing Escherichia coli

The aim of this study was to gain further insight into the interplay between both extended spectrum β-lactamase (ESBL) and AmpC enzymes and different virulence factors (VFs) among Escherichia coli (E. coli) isolated from Mansoura University Hospitals, Egypt. For this purpose 100 E. coli isolates were collected from different clinical sources. All isolates were investigated for production of ESBL and AmpC enzymes. The prevalence of VF encoding genes including: KPsMII (group2 capsule synthesis), FyuA (ferric yersiniabactin uptake), Afa/dra (Dr-binding a fimbrial adhesins), PapA (P fimbriae), PapC (formation of digalactoside-binding Pap pili), iutA (aerobactin receptor) and BssS (biofilm formation) and associations of these genes with both enzyme types were analyzed by polymerase chain reaction. ESBL was produced by 37% of the isolates while AmpC enzyme was produced by 29%. Virulence genes prevalence among ESBL phenotypes were 43.2% KPsMII, 51.35% FyuA, 62.1% Afa/dra, 43.2% PapA, 16.2% PapC, 67.56% iutA and 78.4% BssS. Regarding AmpC phenotypes, the prevalence of  virulence genes were: 51.7% KPsMII, 86.2% FyuA, 68.96% Afa/dra, 55.17% PapA, 24.1% PapC, 82.7% iutA and 100% BssS. Of the tested virulence factor encoding genes, BssS, FyuA and iutA were significantly more prevalent among AmpC producers. In addition, AmpC producers exhibited a statistically significant higher prevalence of multivirulence (MV) (MV≥4) than ESBL producers. Furthermore, AmpC phenotypes showed very significantly higher expression (P>0.01) of BssS gene than ESBLs phenotypes. Our results suggest a correlation between AmpC phenotypes and production of some factors that are reported to be involved in the virulence of E. coli. Key words: extended spectrum β-lactamase, AmpC enzymes, virulence factors, Escherichia coli.