Multidrug-Resistant <i>Escherichia coli</i>, <i>Klebsiella pneumoniae</i> and <i>Staphylococcus</i> spp. in Houseflies and Blowflies from Farms and Their Environmental Settings

• Main Authors: Anil Poudel, Terri Hathcock, Patrick Butaye, Yuan Kang, Stuart Price, Kenneth Macklin, Paul Walz, Russell Cattley, Anwar Kalalah, Folesade Adekanmbi, Chengming Wang
• Format: Article
• Language: English
• Published: MDPI AG 2019-09-01
• Series: International Journal of Environmental Research and Public Health
• Subjects: antimicrobial resistance; flies; escherichia coli; klebsiella pneumoniae; staphylococcus aureus; esbl
• Online Access: https://www.mdpi.com/1660-4601/16/19/3583

<i>Background:</i> Antimicrobial resistance is rising globally at an alarming rate. While multiple active surveillance programs have been established to monitor the antimicrobial resistance, studies on the environmental link to antimicrobial spread are lacking. <i>Methods:</i> A total of 493 flies were trapped from a dairy unit, a dog kennel, a poultry farm, a beef cattle unit, an urban trash facility and an urban downtown area to isolate <i>Escherichia coli</i>, <i>Klebsiella pneumoniae</i> and <i>Staphylococcus</i> spp. for antimicrobial susceptibility testing and molecular characterization. <i>Results</i>: <i>E. coli</i>, <i>K. pneumoniae</i> and coagulase-negative <i>Staphylococcus</i> were recovered from 43.9%, 15.5% and 66.2% of the houseflies, and 26.0%, 19.2%, 37.0% of the blowflies, respectively. In total, 35.3% of flies were found to harbor antimicrobial-resistant bacteria and 9.0% contained multidrug-resistant isolates. Three <i>Staphylococcus aureus</i> isolates were recovered from blowflies while three extended spectrum beta lactamase (ESBL)-carrying <i>E. coli</i> and one ESBL-carrying <i>K. pneumoniae</i> were isolated from houseflies. Whole genome sequencing identified the antimicrobial resistance genes <i>bla_CMY-2</i> and <i>bla_CTXM-1</i> as ESBLs. <i>Conclusion:</i> Taken together, our data indicate that flies can be used as indicators for environmental contamination of antimicrobial resistance. More extensive studies are warranted to explore the sentinel role of flies for antimicrobial resistance.