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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Produce Safety and Microbiology Research » Research » Publications at this Location » Publication #309780
Title: Antimicrobial resistance in Escherichia coli O157 and non-O157 recovered from feces of domestic farm animals in Northwestern Mexico

Author
item AMÉZQUITA-LÓPEZ, BIANCA - Autonomous University Of Sinaloa
item Quinones, Beatriz
item SOTO-BELTRAN, MARCELA - Autonomous University Of Sinaloa
item Lee, Bertram
item Yambao, Jaszemyn
item LUGO-MELCHOR, OFELIA - Centro De Investigación Y Asistencia En Tecnología Y Diseño Del Estado De Jalisco
item CHAIDEZ, CHRISTOBAL - Former ARS Employee

Submitted to: Antimicrobial Resistance and Infection Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/18/2015
Publication Date: 1/5/2016
Publication URL: :http://aricjournal.biomedcentral.com/articles/10.1186/s13756-015-0100-5
Citation: Amézquita-López, B.A., Quinones, B., Soto-Beltran, M., Lee, B.G., Yambao, J.C., Lugo-Melchor, O.Y., Chaidez, C. 2016. Antimicrobial resistance in Escherichia coli O157 and non-O157 recovered from feces of domestic farm animals in Northwestern Mexico. Antimicrobial Resistance and Infection Control. doi: 10.1186/s13756-015-0100-5.

Interpretive Summary: Antimicrobial resistance is becoming one of the most serious health threats. Recent studies have documented infections from resistant bacteria have been commonly observed among the population, resulting in the resistance to multiple types or classes of antibiotics. The inappropriate use of antimicrobials in human and animal therapy has been associated with the increased acquired antibiotic resistance in bacteria. The acquisition of resistance is mainly associated with mobile genetic elements that are integrated into the genome of an organism that is in contact with. For example, the class 1 integrons are located on mobile plasmids and may facilitate the emergence and spread of antimicrobial resistance among Shiga toxin-producing Escherichia coli (STEC) in both humans and animal foods. STEC O157 and non-O157 cause severe gastroenteritis, hemorrhagic colitis and hemolytic-uremic syndrome (HUS) in humans. Several scientific reports have documented a significant increase of antimicrobial resistance in STEC O157 and non-O157. The antimicrobial therapy is not recommended to treat STEC infections because it can cause bacterial lysis and the release of the Shiga toxins, causing an increase in the in vivo cytotoxic effects caused by Shiga toxins. However, some other studies have suggested that if the antibiotic is administered early in the infection, disease progression to the HUS can be prevented. Domestic farm animals may act as reservoirs of resistant bacteria that can be transmitted to humans or via the food chain. The STEC strains examined in this study were isolated previously from small farms located in rural communities in the agricultural Culiacan Valley in Northwestern Mexico. The objective of the present study was to determine the antimicrobial resistance profiles in the recovered STEC O157 and non-O157 to obtain some fundamental information that would aid in the surveillance to track resistance patterns in an important agricultural region in Mexico.

Technical Abstract: Antimicrobial resistance in Shiga toxin-producing Escherichia coli (STEC) O157 and non-O157 is a matter of increasing concern. Inappropriate antimicrobial use in human and animal therapy has been associated with an acquired resistance in enteric microorganisms. The aim of the present study was to determine the antimicrobial resistance profiles in a collection of STEC O157 and non-O157 strains, recovered from feces of domestic farm animals in the agricultural Culiacan Valley in Northwestern Mexico. The antibiotic resistance profiles were determined according to the Clinical and Laboratory Standards Institute procedure, which employed the Kirby-Bauer disk diffusion method with 15 antibiotics. Among the total number of STEC stains examined, 70% (21/30) of the strains showed resistance to at least one of the antimicrobial agents tested, and in some cases to more than one. Resistance to at least one antibiotic was observed in 84% (11/13) of the STEC O157 strains examined. In particular, resistance to ampicillin, cephalotin and cefoperazone were the most commonly observed in the STEC O157 and non-O157, resulting in 14 antibiotic resistance profiles. No relationship was observed between the resistance profile and serotypes or sampling sites. In conclusion, the observed antibiotic resistance of STEC strains with distinct serotypes in agricultural regions provides some supporting evidence for the need of surveillance to track resistance patterns as well as on the proper use of antimicrobials in agriculture.