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.
Listeria monocytogenes is an opportunistic pathogen that causes listeriosis, a foodborne disease with low incidence but with high mortality rate in humans. This microorganism has been recovered from several dairy products, especially those produced with raw milk. The objective of this work was to investigate the presence of virulence genes, and also to defi ne the antimicrobial susceptibility profi le of L. monocytogenes isolates recovered from serrano artisanal cheese produced in Southern region of Brazil.Nine strains of L. monocytogenes (serotypes 1/2b and 4b) were evaluated through PCR to detect the presence of the virulence genes hly, inlA, inlC, inlJ, actA, plcB and iap, while antimicrobial susceptibility profi le was determined via disk diffusion method. All strains exhibited the presence of the genes hly and plcB, whereas the other genes (iap, actA, inlA, inlC and inlJ) were only detected in eight strains. We verifi ed that all strains were resistant to at least one antimicrobial agent and three of them showed multidrug resistance. These fi ndings demonstrated the serrano artisanal cheese offers risks to consumers' health and point to a need of adaptations and monitoring of manufacturing process of this food, in order to prevent the dissemination of L. monocytogenes.
Nenhum período de maturação avaliado garantiu a inocuidade do produto final. As propriedades apresentaram heterogeneidade nos procedimentos higiênico-sanitários. L. monocytogenes foi isolada nos quatro períodos de maturação da mesma propriedade. A fonte principal de contaminação do QAS pode ser pela manipulação inadequada.
In this work, we investigated the phenotypic profile of Staphylococcus spp. isolates recovered from raw milk and artisanal cheese, and their enterotoxigenic potential through the detection of classical enterotoxin genes (sea, seb, sec, sed and see). A total of 104 isolates (58 coagulase-positive Staphylococcus-CoPS; and 46 coagulasenegative Staphylococcus-CoNS) were used, of which 33 were retrieved from raw milk and 71 from artisanal cheese produced in the Serrana region of Santa Catarina. Identification of CoPS was conducted via biochemical tests. Detection of the genes sea, seb, sec, sed, and see was carried out by multiplex PCR technique. Among the 58 CoPS analyzed, 64% were identified as S. aureus, 22% as S. scheiferi coagulans, 12% as S. hyicus and as 2% S. intermedius. In the present study was noted that 40% of CoPS isolates retrieved from milk harbored seb gene, while only one from artisanal cheese was positive for gene sea. In this study all CoNS samples investigated were negative for enterotoxins genes. The enterotoxigenic potential of CoPS, is an issue of great importance for public health. For that reason, it is necessary that cheese factories strictly follow the safety processes involved in manufacturing.
Background:The thermophilic bacteria of the genus Campylobacter are important agents of alimentary gastroenteritis, called campylobacteriosis. These microorganisms multiply in temperatures ranging from 25ºC to 46ºC, however, low temperatures are incompatible with their multiplication. For this reason, the seasons of the year may interfere with the level of contamination by Campylobacter sp. The main sources of transmission are contaminated meat and giblets from poultry during poorly conducted slaughter operations. The disease may present itself with a different range of forms of disease: from mild signs of gastrointestinal infection to more severe cases, such as the Guillain-Barré syndrome. Material, Methods & Results: Due to the great importance of western Santa Catarina to the poultry industry, it was necessary to verify the occurrence of the pathogen in cold carcasses of broilers slaughtered in this region, and its variation through the seasons of the year. From January 2013 to February 2015 broiler carcasses were collected weekly, after the water cooling process, in slaughterhouses under Federal Inspection of the three largest microregions of western Santa Catarina in terms of number of broilers slaughtered, totaling 808 samples. The assessment of thermophilic Campylobacter was performed according to the methodology recommended by ISO 10272-1: 2006. Of the 808 samples analyzed, the frequency of isolation of thermophilic Campylobacter was 1.82% (8/440) in microregion 1, 4.95% (10/202) in microregion 2 and 13.86% (23/166) in the microregion 3, totaling 5.07% of positive samples (41/808). Comparing the microregions, it was verified that there was no significant difference (P > 0.05) between the isolation frequencies of microregions 1 and 2. However, there was a significant difference (P < 0.05) between the isolation rates of Microregion 3 in relation to microregions 1 and 2. Microregion 1 presented the lowest percentage of Campylobacter thermophilic isolates. Discussion: Although the rates found are lower than expected when compared to those already published, consumption of these products may provide risks to consumers, mainly through cross-contamination of foods that will be consumed raw, requiring greater controls in the entire poultry industry in order to ensure a safe product for the consumer. Analyzing each season of the year individually (winter and summer), 5.88% (14/238) of the samples processed during summer (October to March) were positive for the assessed microorganism and in 4,74% (27/570) of the samples analyzed in the winter (April to September), the presence of thermophilic Campylobacter was detected. Nevertheless, there was no significant difference (P > 0.05) between the seasons. However, it is evident the need for a longer study to evaluate the actual influence of the seasons (winter and summer) on the isolation rate of thermophilic Campylobacter in broiler carcasses shortly after the cooling process. Even though the study demonstrated low levels of thermophilic Campylobacter isolati...
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