Migratory birds as a potential overseas transmitter of Shiga toxin-producing Escherichia coli

Abstract

Shiga toxin-producing Escherichia coli (STEC) has a great public health importance. This study was conducted to investigate the potential role of migratory birds in the transmission of STEC. For this purpose, cloacal swabs were collected from 349 migratory birds (209 ducks and 140 quails) from Damietta governorate, Egypt. The collected swabs were cultured for isolation of STEC using the STEC CHROMagar. STEC isolates were identified based on colonial characteristics, Gram’s stain, conventional biochemical tests and molecular detection of stx1, stx2 and eae genes. Positive isolates were serotyped and examined for their antibiotic susceptibility pattern. Furthermore, gene sequencing was performed for genes stx1 and stx2 . Of the examined birds, two STEC isolates were a obtained with an overall occurrence rate 0.57% (2/349), one isolate carried stx2 gene from a migratory quail 0.71% (1/140), and another isolate from a migratory duck carried stx1 gene 0.48% (1/209), whereas both isolates were negative for eae gene. Moreover, the duck isolate was serotyped O86, while the quail isolate was serotyped O125; both isolates were multidrug resistant. The phylogenetic analysis of the obtained stx1 and stx2 genes revealed high genetic relatedness to those isolated from human cases in the countries where such birds either lived or were in their migratory pathway. In conclusion, this study highlights the potential role of migratory birds in transmitting multidrug-resistant STEC across their migratory pathway.

Pathogenic Bacteria in Free-Living Birds, and Its Public Health Significance

“…However, the distribution of these genes differs significantly among bird species; for the stx gene, the prevalence rate ranges from 91% in ravens up to 3% in songbirds, and for the eae gene, from 93% in hawks up to 4.6% in geese. Interestingly, the studies performed by Seleem et al [ 162 ] covering the phylogenetic analysis of the obtained stx genes revealed high genetic relatedness to those isolated from human cases in countries where such birds either lived or which were in their migratory pathway. In conclusion, the study underlines the potential role of migratory birds in spreading STEC across their migratory path.…”

Pathogenicity assessment of Shiga toxin-producing Escherichia coli strains isolated from wild birds in a major agricultural region in California

“…Wild birds were first identified as a source of STEC in 1997 ( Wallace et al, 1997 ), in which, 1–3% of bacterial isolates recovered from fecal samples of wild birds were STEC O157:H7. Ever since, diverse STEC strains have been detected and isolated from various bird species including pet birds worldwide ( Kobayashi et al, 2002 , 2009 ; Neher et al, 2016 ; Sanches et al, 2017 ; Navarro-Gonzalez et al, 2020 ; Seleem et al, 2021 ). Birds could disseminate STEC into environments and/or transmit STEC to other animals including humans directly or indirectly.…”