Resistance to β-lactam and tetracycline in Campylobacter spp.isolated from broiler slaughterhouses in southern Brazil

摘要

The study was carried out to screen and analyze the genetic characteristics of antimicrobial resistance in Campylobacter spp. from poultry sources. A total of 141 strains of Campylobacter isolated from samples of broilers of slaughterhouses in southern Brazil was identified by phenotypic and genotypic methods. Campylobacter isolates were evaluated for its antimicrobial susceptibility and the presence of resistance genes. The strains were investigated for antimicrobial susceptibility against two agents (ampicillin and tetracycline) by disk diffusion method. PCR assay was used to confirm the specie and the presence of ampicillin (blaOXA-61), tetracycline tet(O), and the energy-dependent multi-drug efflux pump (cmeB) genes. Campylobacter jejuni was the most ubiquitous; its presence was determined in 140 samples out of 141 (99.3%), whereas Campylobacter coli was found only in one of the contaminated samples (0.70%). The results obtained showed 65% and 35.5% of Campylobacter isolates resistant to ?2-lactams and tetracyclines, respectively. The cmeB gene responsible for multidrug resistance was detected in 26 isolates out 141 strains (18.5%). Moreover, 36 out of 141 Campylobacter strains (25.6%) were found to be resistant to at least two different antimicrobia resistance markers (?2-lactams and tetracyclines). Index Terms??Campylobacter; tetracycline; ?2-lactam; efflux pump; resistance genes; PCR Resumo O presente estudo foi realizado para examinar e analisar as caracter?-sticas gen??ticas de resist?ancia antimicrobiana de Campylobacter spp. a partir de fontes av?-colas. Um total de 141 amostras de Campylobacter isolados em matadouros-frigor?-ficos de aves do estado do Rio Grande do Sul, Brasil, foi identificado por m??todos fenot?-picos e genot?-picos. Foi analisada a susceptibilidade antimicrobiana e a presen?§a de genes de resist?ancia. As cepas foram testadas para detectar sensibilidade frente a dois antimicrobianos (ampicilina e tetraciclina) pelo m??todo de difus?￡o em disco. A seguir, usando a rea?§?￡o em cadeia da polimerase foi confirmada a esp??cie e a presen?§a dos genes de resist?ancia ?? ampicilina (blaOXA-61) e tetraciclina tet(O), assim como a detec?§?￡o da bomba de efluxo (cmeB). Campylobacter jejuni foi a esp??cie mais isolada, sua presen?§a foi determinada em 140 amostras (99,3%), e Campylobacter coli foi encontrada em uma ?onica amostra (0,70%). Os resultados obtidos mostraram 65% e 35,5% de Campylobacter isolados resistentes a ?2-lact?￠micos e tetraciclinas, respectivamente. O gene cmeB respons??vel pela resist?ancia a m?oltiplos antimicrobianos foi detectado em 26 amostras (18,5%). Neste contexto, 36 das 141 amostras (25,6%) foram consideradas resistentes a dois grupos diferentes de antimicrobianos (?2-lact?￠micos e tetraciclinas). Termos de Indexa?§?￡o??Campylobacter; tetraciclinas; ?2-lact?￠micos; bomba de efluxo; genes de resist?ancia; PCR Introduction Campylobacter is recognized as the leading causes of bacterial foodborne diarrheal disease throughout the worldwide (Park 2002,Silva et al. 2011). Campylobacteriosis is estimated to cause about 1.3 million infections, 13,000 hospitalizations and 120 deaths each year in the United States (CDC 2013). It is also the most commonly reported antecedent infection in the development of Guillain Barr?? syndrome (GBS) and Miller Fisher syndrome (MFS) (Godschalk et al. 2004,Hardy et al. 2011,Van den Berg et al. 2014). A risk factor for human disease is the consumption of contaminated poultry products (Conlan et al. 2007,Ellstr??m et al. 2014). Transmission to man usually results in sporadic infection, and is often associated with improper handling or cooking of food (Moore et al. 2005). Campylobacter jejuni (C. jejuni) and Campylobacter coli (C. coli) are considered to be zoonotic pathogens, antimicrobial resistance among isolates in the animal reservoir has serious implications for the treatment in humans (Moore et al. 2006,EFSA 2011). The majority of cases of clinical Campylobacter spp. enteritis are generally mild or self-limiting disease not to require of antimicrobial chemotherapy (Moore et al. 2005). However, antimicrobial therapy may be used in a subset of patients with severe and prolonged systemic complications or to control infection (Avrain et al. 2003,Janssen et al. 2008). Currently, macrolides and fluoroquinolones are the antimicrobial agents of choice when therapeutic intervention is warranted (Engberg et al. 2001,Moore et al. 2005). Bacterial populations can respond to the threat of an antimicrobial agent by evolving some type of resistance mechanism(s) (Rowe-Magnus et al. 2002,Luangtongkum et al. 2009). These resistant bacteria may be transferred to humans either through the food supply or by direct contact with animals (Khachatourians 1998,Angulo et al. 2004). Ampicillin and tetracycline have activity against Campylobacter , but in general, are not recommended for the treatment of Campylobacter infections (Blaser 1995,Dasti et al. 200