The serrano artisan cheese produced from raw milk of dairy cattle is a typical product of high-altitude farms in the states of Santa Catarina and Rio Grande do Sul. However, marketing of the cheeses occurs illegally because they lack the minimum maturation period required for cheese produced from raw milk. The production of artisan cheeses is required to follow strict hygiene standards. This study aimed to test the quality and safety of cheeses that were produced in 31 farms of the Serrana region in Santa Catarina after 14 and 28 days of maturation. Coliform count was measured at 35 °C, and presence of other microorganisms such as Escherichia coli, Staphylococcus, Listeria spp., and Salmonella spp. were also tested. Fat and protein percentages, acidity, salt content, and humidity were also evaluated. Data were subjected to statistical analyses using the SAS ® software. After 14 and 28 days of maturation, 74.19% (23/31) and 64.52% (20/31) of samples, respectively, showed higher numbers of coliforms at 35 °C than those permissible by law. Higher than permissible numbers of E. coli were observed in 45.16% (14/31) and 48.39% (15/31) of the samples analyzed after 14 and 28 days of maturation, respectively. Coagulasepositive staphylococci values above 10 3 CFU/g were observed in 54.84% (17/31) and 51.61% (16/31) of cheese samples after 14 and 28 days of maturation, respectively. Contamination with Salmonella spp. was not detected. However, Listeria monocytogenes serovar 4b was isolated in 3.23% (1/31) and 6.45% (2/31) of samples after 14 and 28 days of maturation, respectively. The results of humidity tests classified the cheese samples into three categories: low, medium, and high humidity. Semi fat cheeses were predominant in both maturation periods, although the samples were classified in thin, semi fat, and fat cheeses. The main variations in the compositions of analyzed samples occurred for salt and acidity levels. The maturation process has not proven to be effective in reducing microbiological contamination to compliance levels. Considering the heterogeneity of the analyzed cheese samples, the frequency of non-conformities with respect to microorganisms and pathogens present in the samples, this study indicates the necessity to improve the Serrano artisan cheese production system through adoption of good manufacturing practice measures. 3 UFC/g. Nenhuma das amostras avaliadas estava contaminada com Salmonella spp., porém Listeria monocytogenes sorovar 4b foi isolada em 3,23% (1/31) e em 6,45% (2/31) das amostras aos 14 e 28 dias de maturação, respectivamente. Em relação à umidade, os queijos foram classificados como de baixa, média e alta umidade. Em relação aos teores de gordura houve a predominância de queijos semigordos nos dois períodos de maturação, embora as amostras tenham sido enquadradas como queijos magros, semigordos e gordos. As principais variações na composição entre as amostras avaliadas ocorreram nos teores de sal e acidez. O processo de maturação não demonstrou ser efetivo na redução de ...
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.
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.
Among the meat products, ground beef presents a greater risk of contamination, due to excessive manipulation and greater surface contact. Staphylococcus indicates inadequate hygienic-sanitary conditions of food. Coagulase-negative Staphylococci (CoNS) cover most of the existing staphylococci species and among the virulence factors presented by this group, biofilm production and staphylococcal enterotoxins (SE) are the most prominent. The objective of this study was to detect the presence of enterotoxin and biofilm genes in coagulasenegative Staphylococci isolates obtained from ground beef samples. Twenty four strains of CoNS isolated from fresh bovine meat, phenotypically characterized as biofilm producers, were used. The samples were collected in twenty four commercial establishments (butchers and supermarkets) in Umuarama City from Paraná State, Brazil. The CoNS count found was between 1.0 x 10³ and 3.8 x 10 5 CFU/g of food. All 24 samples showed genes belonging to the ica operon, 21 (87.50%) carrying the icaA, icaC and icaD genes and 3 (12.50%) of the icaA and icaD genes. 95.83% (23/24) of the strains were carriers of the sea enterotoxin gene, being 9 (37.5%) only sea, one (4.2%) sea and seb, 7 (29.1%) sea and see and 6 (25.0%) sea, seb and see. One (4.2%) strain did not show any of the enterotoxin genes. The detection of enterotoxin and biofilm genes in CoNS demonstrate the pathogenic potential of this microorganism. The lack of epidemiological data neglects the actual fault of the CoNS in foodborne diseases.
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.
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...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.