ERIC-PCR-based molecular typing of multidrug-resistant Escherichia coli isolated from houseflies (Musca domestica) in the environment of milk and meat shops

The emergence and spread of antimicrobial resistance have become a major global public health concern. A component of this problem is the spread of antibiotic-resistant bacteria. Flies move freely between habitats of food-producing animals and human beings and thus have great potential for dissemination of antimicrobial-resistant bacteria from a contaminated environment to milk and meat markets, posing potential hazards for consumers. During the present study, a total of 150 houseflies were captured from milk and meat shops located in Durg and Raipur city of Chhattisgarh, India. The Escherichia coli were isolated from houseflies and characterized on the basis of cultural and molecular tests. Further, the isolates were subjected to antimicrobial susceptibility testing against frequently used antibiotics using the disk diffusion method. The antibiotic resistance genes and int1 gene were detected using polymerase chain reaction (PCR). A total of 45 E. coli isolates were obtained from the fly samples with an overall prevalence rate of 30 center dot 0%. Antibiogram results confirmed that E. coli isolates were resistant to multiple antibiotics. Out of the (45) isolates of E. coli, 17 (37 center dot 8%) isolates were extended-spectrum beta-lactamase (ESBL) producer and multi-drug-resistant (MDR). Out of the ESBL and MDR E. coli isolates, bla(CTX-M) (24 center dot 4%), bla(TEM) (11 center dot 1%), tetA (28 center dot 8%), tetB (26 center dot 7%), gyrA (26 center dot 7%), parC (31. 1%) and int1 genes (15 center dot 5%) were detected but none of the isolates were found positive for bla(SHV) gene. Findings of the present study confirm that MDR E. coli are widely distributed in houseflies and play an important role in the transmission of antibiotic-resistant bacteria from contaminated environments to milk and meat shop environment.

Automated summary

The emergence and spread of antimicrobial resistance, particularly antibiotic-resistant bacteria carried by flies, pose significant public health concerns globally. This study conducted in Durg and Raipur cities in Chhattisgarh, India, revealed a high prevalence of multidrug-resistant Escherichia coli in houseflies captured from milk and meat shops. The findings highlight the important role of houseflies in transmitting antibiotic-resistant bacteria from contaminated environments to food markets.