First report of mobile colistin resistance gene -1 in avian pathogenic isolated from turkeys in the Gaza Strip, Palestine.

BACKGROUND AND AIM

Colistin is used to treat avian pathogenic (APEC), a microorganism that affects turkey meat production in the Gaza Strip and worldwide. However, the recent emergence of plasmid-borne mobile colistin resistance () genes in pathogenic strains is a serious antimicrobial resistance (AMR) challenge for both human and animal health. In December 2018, colistin was banned as a veterinary antimicrobial in the Gaza Strip. This study aimed to detect and track the prevalence of colistin-resistant APEC isolated from turkey flocks in the Gaza Strip.

MATERIALS AND METHODS

This study investigated 239 APEC isolates from turkey flocks in the Gaza Strip between October 2018 and December 2021 (at 6-month intervals). The colistin-resistant APEC strains were detected using the broth microdilution method. The gene was identified using a polymerase chain reaction.

RESULTS

The overall colistin resistance among the isolated APECs was 32.2% during the study period. The average resistance in the first interval was 37.5%, which significantly decreased to 9.3% in the last interval. Among the 77 phenotypically resistant isolates, 32.4% were positive for . The average abundance of -1 in the first interval was 66.6%, which decreased to 25% in the last interval.

CONCLUSION

To the best of our knowledge, this is the first study reporting the presence of the gene among the APEC isolates from turkeys in the Gaza Strip. Banned veterinary use of colistin significantly decreased the percentage of resistant APEC isolates from turkeys in Gaza Strip. Further studies are needed to investigate other colistin resistance genes and track the emergence of AMR.