Characterization of ESBL producing E. coli from chicken feces by phenotypic methods and MALDI-TOF MS

Abstract

E.coli from broiler is a reservoir for ESBL (extended spectrum beta-lactamase) and presence of ESBL is a growing concern for antibiotic resistance. The aim of the study was to investigate and characterize ESBL and AmpC beta-lactamases in E. coli with traditional and new-generation methods. As well as biochemical analyses, the identification of isolates was performed with the MALDI-TOF MS. Within the scope of phyloproteomic analysis, all components of MALDI-TOF MS-based Principal Component Analysis (PCA) (dendrogram, scatter plotting, composit corelation index (CCI) and variance,) were applied. In the present study which is the first report for Duzce (Türkiye), 28.6% of 122 CFEC (chicken feces E. coli) isolates were identified as CFEC -ESBL. blaCTX-M, blaCTX-M-1, blaCTX-M-15, blaSHV, blaTEM, blaOXA-10, AmpC, blaCIT, blaMOX, blaSHV, blaCIT, and blaMOX genes were explored with PCR and blaCTX-M-1 gene was detected with the highest rate (68.5%). At least one of the resistance genes was detected in the phenotype screening tests, except one of the isolates (CFEC-ESBL-90). On the other hand CFEC-ESBL-38 contained only bla CTX-M-15 and the fact that this isolate was the only atypical ESBL strain with indole (-) and lac (-) characteristics among all isolates explains the highest variance (41%) and the most different from other PCA components. Also, this isolate had a high degree of similarity (87%; CCI) with the other isolate (CFEC-ESBL-90), which had low similarity to CFEC-ESBLs. As a result, phyloproteomic analyses with MALDI-TOF MS are considered to be beneficial in the characterization of phenotypic bacterial behavior.