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ARS Home » Plains Area » Manhattan, Kansas » Center for Grain and Animal Health Research » ABADRU » Research » Publications at this Location » Publication #405230

Research Project: Biology and Management of Dipteran Pests of Livestock and Other Animals

Location: Arthropod-borne Animal Diseases Research

Title: Multidrug resistant bacteria carried by house flies from Kansas cattle operations: implications for animal health, food safety and surveillance

item Nayduch, Dana
item PICKENS, VICTORIA - Kansas State University
item HALL, BRANDON - Kansas State University
item Purvis, Tanya
item BIRD, EDWARD - Kansas State University
item OLDS, CASSANDRA - Kansas State University

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/26/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: House flies colonize cattle operations where they have access to abundant microbe-rich larval developmental substrates like manure. House flies are pestiferous to cattle and pose additional animal health concerns when they transfer microbes among manure, animals, and the environment of the operation. House flies are well-established as reservoirs and vectors of pathogenic and antimicrobial-resistant (AMR) bacteria. This study determined the abundance and prevalence of bacteria, especially those with AMR phenotypes, carried by house flies at dairy and beef cattle operations in Kansas. Flies were collected from 3 dairy, 3 beef operations in KS in 2019 and bacteria were cultured from fly homogenate on non-selective media to enumerate overall bacteria and on violet-red bile agar to select and enumerate coliforms. Distinct coliform morphotypes were subcultured and initially screened for tetracycline resistance on selective media then tested for multi-drug resistance (MDR) to tetracycline, florfenicol, enrofloxacin, ceftiofur, and/or ampicillin using the Kirby-Bauer method. Isolates were taxonomically identified via 16S rRNA gene sequencing. House flies from beef operations carried a greater diversity of MDR coliform phenotypes than flies from dairies. The most common MDR taxa were Escherichia/Shigella spp. and Klebsiella spp. which were dual- or triple-resistant to tetracycline, florfenicol, and/or ampicillin. Our results implicate house flies as significant sources and disseminators of AMR and MDR bacteria which can have impacts on human or animal health.