CTX-M-15-type extended-spectrum beta-lactamases-producing Escherichia coli from wild birds in Germany

Area of Science:

• Microbiology
• Veterinary Science
• Epidemiology

Background:

• Escherichia coli producing extended-spectrum beta-lactamases (ESBLs) are a growing public health concern.
• Wild birds are increasingly recognized as potential reservoirs for antimicrobial-resistant bacteria.

Purpose of the Study:

• To investigate the prevalence and characteristics of ESBL-producing E. coli in wild birds in Germany.
• To identify the specific ESBL genes and genetic relatedness of the isolates.

Main Methods:

• Isolation and identification of E. coli from wild bird samples.
• Detection of CTX-M-15 genes using molecular methods.
• Pulsed-field gel electrophoresis (PFGE) for assessing clonal relationships.
• Multilocus sequence typing (MLST) to determine sequence types (STs).

Main Results:

• Four CTX-M-15-producing E. coli strains were isolated from 172 wild bird samples (2.3%).
• The affected birds included Eurasian Blackbirds, a Rock Pigeon, and a Greater White-fronted Goose.
• All CTX-M-15-producing strains belonged to a single clone, identified as ST 648 by PFGE and MLST.

Conclusions:

• The findings indicate the emergence of a novel, epidemiologically significant clone of CTX-M-15-producing E. coli.
• Wild bird species, beyond waterfowl, may serve as important reservoirs for ESBL-producing Enterobacteriaceae.