PREVALENCE OF mcr-1 COLISTIN RESISTANCE GENE IN Escherichia coli ALONG BROILER MEAT SUPPLY CHAIN IN INDONESIA

Colistin is the last drug choice for dealing with carbapenem-resistant Enterobacteriaceae ; therefore, this drug is very crucial for human health. The discovery of a plasmid-mediated colistin resistance gene, mobilized colistin resistance-1 ( mcr-1 ), signals a significant global health threat. Colistin sulfate is an antimicrobial agent which has been approved for use in broilers in Indonesia. The purposes of this study were to measure the prevalence of colistin resistant E. coli and to detect the mcr-1 colistin resistance gene in E. coli, and E. coli O157:H7 in the entire supply chain of broilers in Bogor Regency, West Java Province, Indonesia. Samples were taken from flocks that use colistin sulfate (cloacal swabs, drinking water, and litters), small-scale poultry slaughterhouses (fresh meats and plucker swabs), traditional markets (fresh meats), and small restaurants (cooked meats). Isolation of E. coli was done on each sample and 493 isolates were obtained. All E. coli isolates were then tested for their susceptibility to colistin sulfate by the agar dilution method. Detection of mcr -1 gene from colistin resistant isolates (minimum inhibitory concentration > 2 µg/mL) was conducted using polymerase chain reaction. The prevalence of colistin resistant E. coli from all isolates was 11.76% (CI 95%; CL 9.21–14.91%), and the prevalence of mcr -1 gene was 10.55% (CI 95%; CL 8.13–13.57%). There was a very good agreement between colistin resistance phenotype and mcr-1 gene (ĸ = 0.939). The mcr-1 gene was found in 89.66% colistin resistant E. coli isolates. Two colistin resistance and mcr - 1 carrying gene isolates were identified as E. coli O157:H7 serotype. This study was the first research on mcr -1 gene in Indonesia which covers the entire supply chain of broiler meat from farms to consumers. These results showed the necessity to emphasize a reduced use of colistin sulfate in broiler management and to improve biosecurity measure, not only in farms but also in the entire supply chain of broiler meat.