Antimicrobial-Resistant and Extended-Spectrum β-Lactamase–Producing Escherichia coli in Raw Cow's Milk

Abstract

The occurrence of antimicrobial-resistant bacteria is an important public health issue. The aim of this study was the monitoring of resistant Escherichia coli in raw cow's milk with a focus on the detection of extended-spectrum β-lactamase (ESBL)-producing strains. In total, 263 samples of raw milk from 40 farms were collected and investigated in 2010 to 2013 in the Czech Republic. Detection of E. coli was performed and evaluated according to ISO 16649-2, and antibiotic resistance was screened by the disk diffusion method. The presence of E. coli was detected in 243 (92.4%) samples. In total, 270 isolates were obtained. Resistance to β-lactam (31.8%) and tetracycline (13.0%) antibiotics was detected most often and also multiresistant strains (5.5%) were observed. E. coli isolates found to be resistant to β-lactam, tetracycline, and quinolone antibiotics were assayed by PCR to detect selected genes encoding those resistance mechanisms. In isolates in which any bla genes were detected, a double-disk synergy test was performed. ESBL production was confirmed in 2 (0.7%) isolates. The genetic analysis identified the presence of the blaCTX-M gene and other resistance genes (tet(B) and qnrB). Both ESBL-positive isolates originated from the same farm and had an identical pulsed-field gel electrophoresis profile. The findings of our study indicate that milk can be a reservoir of bacteria carrying resistance genes with a potential for spreading through the food chain.

Presencia de Enterobacteriaceae productoras de betalactamasa de espectro extendido (ESBL) en leche de tanque a granel de granjas lecheras bovinas en Antioquia, Colombia

“…The frequency of ESBL-producing Enterobacteriaceae reported in this study (3.3%) agrees with other studies conducted in bulk-tank milk samples in Switzerland, Brazil, India, the Czech Republic, Indonesia, and Germany, which reported prevalences ranging between 0 and 9% (Geser et al, 2012;Nóbrega et al, 2013;Rasheed et al, 2014;Skočková et al, 2015;Sudarwanto et al, 2015;Odenthal et al, 2016).…”

“…Recently, studies of the characteristics and prevalence of ESBL-producing Enterobacteriaceae in animals have increased in different countries worldwide (Smet et al, 2010;Timofte et al, 2014;Skočková et al, 2015;Sudarwanto et al, 2015;Odenthal et al, 2016). However, relatively few studies have been conducted in Colombia on antibiotic resistance in foodproducing animals and their products (Vanegas López et al, 2012;Jiménez Velásquez et al, 2013;DonadoGodoy et al, 2015) compared to other countries and to our knowledge, this is the first study conducted to determine the occurrence of ESBL-producing Enterobacteriaceae in bulk-tank milk in Colombia.…”

Multidrug Resistance and the Predominance of <b><i>bla</i></b>_CTX-M in Extended Spectrum Beta-Lactamase-Producing Enterobacteriaceae of Animal and Water Origin

“…Similarly, one CTX-resistant E. coli was also recovered from bovine milk, a finding rarely reported from commensal enterobacteria from bovine or food products of bovine origin [Skočková et al, 2015].…”

A survey on antimicrobial resistant Escherichia coli isolated from unpasteurised cows’ milk in Northern Ireland

“…Food-producing animals (FPAs) can act as a reservoir of resistant zoonotic bacteria (Smith 1969, Shooter and others 1970, Levy and others 1976, Bertrand and others 2006, Skočkova and others 2015). …”

“…Although resistant E coli , including those expressing extended-spectrum beta lactamases (ESBL), have been isolated from several FPAs such as poultry (Costa and others 2009, Dierikx and others 2013, ECDC 2016; Parker and others 2016, VMD 2014b), cattle (Duse and others 2015a, b, Saini and others 2012, VMD 2014b), pigs (DARC 2004; VMD 2015) and food such as meat (ECDC 2016), currently there is a limited number of surveys of other important components of the human diet, such as milk (Nagy and others 2015, Skočkova and others 2015). …”