Prevalence, antibiogram, and virulence attributes of avian pathogenic E. coli in pigeons

Avian pathogenic Escherichia coli (APEC) is a major threat because it can infect both domesticated and wild birds. Studies on the frequency of APEC in wild and migratory birds are scarce, especially compared with data on other bird species. The significance of the pigeon as a significant vector and reservoir of APEC transmission to other bird species was particularly neglected.

This investigation was conducted with the express goal of examining whether or not the pigeon's extraintestinal tissues contained multidrug-resistant APEC.

Tissue specimens were collected from domesticated birds either freshly dead or in a moribund state and examined for the isolation and identification of E. coli using traditional culture methods, followed by serological identification. Screening for virulence-associated genes was performed using PCR. Included in this group of genes are astA, temperature-sensitive hemagglutinin (tsh), and iron outer membrane receptor (iroN). Drug resistance profiling was performed using the disk diffusion method.

The results recorded in this investigation revealed the isolation of E. coli at 40% from the examined pigeon samples. Isolation of E. coli from extraintestinal tissues was successful at 40%, 30%, 20%, 20%, and 20% from the examined liver, kidney, heart, gizzard, and joints, respectively. Serological identification of the isolated E. coli revealed serotyping of five serotypes, namely E. coli O2:H6, E. coli O26: H11, E. coli O55: H7, E. coli O78:H-, and E. coli O119:H4, which were recovered at 26.92%, 23.07%, 19.23%, 19.23%, and 7.69%, respectively. The recovered isolates harbored virulence attributes at variable rates. The recovered E. coli isolates should be marked with drug resistance, particularly to ampicillin, cephalothin, nalidixic acid, and penicillin.

Consequently, the fact that pigeons could be multidrug-resistant APEC carriers should be seriously considered.