Detection of virulence genes and antimicrobial resistance profiles of Escherichia coli isolates from raw milk and artisanal cheese in Southern Brazil

Abstract

The serrano artisanal cheese is a typical product from South region of Brazil, which is produced by skilled cheesemakers using raw milk. The contamination of this food by Escherichia coli has a great impact on public health, since it could threat the consumers’ health. The study evaluated the presence of virulence genes, antimicrobial susceptibility profiles and bofilm-production ability of Escherichia coli isolates obtained from raw milk and artisanal cheese produced in Southern Brazil. A total of 117 isolates of E. coli were characterized by multiplex PCR to detect the following virulence genes: eae for enteropatogenic E. coli (EPEC), lt and st for enterotoxigenic E. coli (ETEC), stx for shiga toxin-producing E. coli (STEC), stx and eae for enterohemorrhagic E. coli (EHEC), ipaH for enteroinvasive E. coli (EIEC) and aggR for enteroaggregative E. coli (EAEC). In addition, antimicrobial susceptibility profile to 22 antimicrobial agents was also performed by disk diffusion method, and we searched for extended-spectrum beta-lactamases (ESBL) and/or carbapenemase- producing isolates. Isolates that were positive for ESBL and carbapenemase were further investigated for the presence of the genes: blaTEM, blaSHV, blaOXA, blaCTX-M, for ESBL and blaOXA-48 for carbapenemase. Further, isolates had their ability to form biofilms investigated by the red Congo agar method. Virulence genes of E. coli were identified in 21.37% of the tested isolates, which were classified as EPEC (the most prevalent pathotype) and ETEC or EAEC. Ten (8.55%) of the total studied E. coli isolates revealed a multidrug-resistant profile, since they were resistant to three or more antimicrobial classes; whereas four isolates (3.42%) were classified as ESBL-producers and showed the presence of blaTEM gene. None of the isolates exhibited carbapenemase activity nor did they carry carbapenemase genes. From the total of E. coli isolates, 79 (67.52%) were considered potential biofilm producers. These results address a serious public health issue, since artisanal cheeses pose a risk to consumers’ health, since may be sources of dissemination of diarrheogenic E. coli, that can cause from subclinical to severe and fatal infections in children and adults, and also emphasize the need to improve adaptations/adjustments in the manufacturing processes of these products.

Çiğ Sütlerde Karbapenem Dirençli Enterobacteriaceae ve blaKPC, blaNDM ve blaOXA-48 Gen Varlığının Moleküler Olarak İncelenmesi

“…In a study in Algeria, four E. coli isolates with identical PFGE profiles were obtained from the raw milk and teats of 34 healthy cows and carbapenem resistance was detected in all of E. coli isolates [31] . In a study carried out in Brazil, it is revealed that none of the 117 E. coli exhibited carbapenemase activity isolated from raw milk used in cheese production without any heat treatment, as a similar finding to current study [32] . In regard to these data, the main objective of this study was to determine the occurrence of CRE and carbapenemase in raw milk, in order to help clarify risk assessment with regard to potential human transfer through milk consumption.…”

Contamination of Kazakhstan cheeses originating from Escherichia coli and its resistance to antimicrobial drugs

“…Three bacterial genera belonging to the Enterobacteriaceae family, Escherichia , Enterobacter , and Citrobacter , were identified in samples of different types of cheese produced in Kazakhstan in this study. The first two genera are most often isolated from raw milk [ 28 ], and Serratia is also often found in commercial cheeses [ 29 , 30 ]. Although coliforms are considered to be thermolabile and cannot withstand pasteurization, 44.9% of the studied cheeses were found to be contaminated with them.…”

Prevalence, Characterization and PFGE profiles of multidrug resistance extended spectrum β-lactamase producing Escherichia coli strains in animal-derived food products from public markets in Eastern Turkey

“…The OXA-encoding gene was not detected in all five isolates. Different countries have reported different predominant ESBL genotypes of E. coli in milk and cheese samples, including CTX-M genotype in India (Batabyal et al, 2018) and TEM genotype in Brazil (Parussolo et al, 2019). Studies showing the presence of AGR genes and be-ta-lactamase resistance genes of E. coli cultured from food samples, performed in different countries, have varying results, which could be due to different geographical regions or the different practices in using antibiotics or antimicrobial agents, for example, in feed supplements.…”