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1.
Life (Basel) ; 13(12)2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-38137925

RESUMO

A profile of the microbial safety and hygiene of cheese in central Italy was defined based on an analysis of 1373 cheeses sampled under the Italian National Control Plan for Food Safety spanning the years 2013 to 2020 and tested according to Commission Regulation (EC) No. 2073/2005 (as amended). A total of 97.4% of cheese samples were assessed as being satisfactory for food safety criteria and 80.5% for process hygiene criteria. Staphylococcal enterotoxin was found in 2/414 samples, while Salmonella spp. and Listeria monocytogenes were detected in 15 samples out of 373 and 437, respectively. Escherichia coli and coagulase-positive staphylococci counts were found unsatisfactory in 12/61 and 17/88 cheese samples, respectively. The impact of milking species, milk thermal treatment, and cheese hardness category was considered. A statistically significant association (p < 0.05) was found between milk thermal treatment and the prevalence of coagulase-positive staphylococci and Listeria monocytogenes and between hardness and unsatisfactory levels of Escherichia coli. The data depict a contained public health risk associated with these products and confirm, at the same time, the importance of strict compliance with good hygiene practices during milk and cheese production. These results can assist in bolstering risk analysis and providing insights for food safety decision making.

2.
Microorganisms ; 11(10)2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37894225

RESUMO

The monophasic variant of S. Typhimurium 4,[5],12:i:- (MVST) is the third most commonly reported Salmonella serovar involved in human infections (8.8%) in the EU and ranks after S. Enteritidis (54.6%) and S. Typhimurium (11.4%). In Italy, in contrast, the MVST has achieved peculiar epidemiological and ecological success which has allowed it to be, since 2011, the serovar most frequently isolated from humans. In the summer of 2022, a foodborne outbreak of the MVST involving 63 people occurred in the Marche Region (Central Italy). A common food exposure source among some human cases was a roasted, ready-to-eat (RTE) pork product, porchetta, which is a typical product of Central Italy. This paper describes the results of investigations conducted to clarify this outbreak. The porchetta was produced by a local manufacturing plant and distributed to at least two local retail stores, one of which was the retail outlet for the manufacturing plant. The MVST was isolated from surface samples collected at the porchetta manufacturing plant and at both local retail stores via bacterial analysis, and the porchetta sampled at one store contained the MVST. These data confirm this type of RTE pork product can be a source of Salmonella infection in humans.

3.
Antibiotics (Basel) ; 12(8)2023 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-37627712

RESUMO

The Arcobacter genus comprises a group of bacteria widely distributed in different habitats that can be spread throughout the food chain. Fluoroquinolones and aminoglycosides represent the most common antimicrobial agents used for the treatment of Arcobacter infections. However, the increasing trend of the antimicrobial resistance of this pathogen leads to treatment failures. Moreover, the test implementation and interpretation are hindered by the lack of reference protocols and standard interpretive criteria. The purpose of our study was to assess the antibiotic resistance pattern of 17 A. butzleri strains isolated in Central Italy from fresh vegetables, sushi, chicken breast, and clinical human samples to provide new and updated information about the antimicrobial resistance epidemiology of this species. Antimicrobial susceptibility testing was carried out by the European Committee on Antimicrobial Susceptibility Testing (EUCAST)'s disc diffusion method. All the strains were multidrug resistant, with 100% resistance to tetracyclines and cefotaxime (third generation cephalosporins). Some differences were noticed among the strains, according to the isolation source (clinical isolates, food of animal origin, or fresh vegetables), with a higher sensitivity to streptomycin detected only in the strains isolated from fresh vegetables. Our data, together with other epidemiological information at the national or European Union (EU) level, may contribute to developing homogeneous breakpoints. However, the high prevalence of resistance to a wide range of antimicrobial classes makes this microorganism a threat to human health and suggests that its monitoring should be considered by authorities designated for food safety.

4.
Microorganisms ; 11(7)2023 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-37512831

RESUMO

In this study, we used both a WGS and an in vitro approach to study the virulence potential of nine Listeria monocytogenes (Lm) strains belonging to genetic clusters persisting in a meat processing plant in Central Italy. The studied clusters belonged to CC1-ST1, CC9-ST9, and CC218-ST2801. All the CC1 and CC218 strains presented the same accessory virulence genes (LIPI-3, gltA, gltB, and aut_IVb). CC1 and CC9 strains presented a gene profile similarity of 22.6% as well as CC9 and CC218 isolates. CC1 and CC218 showed a similarity of 45.2% of the same virulence profile. The hypervirulent strains of lineage I (CC1 and CC218) presented a greater ability to adhere and invade Caco-2 cells than hypovirulent ones (CC9). CC1 strains were significantly more adhesive and invasive compared with CC9 and CC218 strains, although these last CCs presented the same accessory virulence genes. No statistically significant difference was found comparing CC218 with CC9 strains. This study provided for the first time data on the in vitro adhesiveness and invasiveness of CC218-ST2801 and added more data on the virulence characteristics of CC1 and CC9. What we observed confirmed that the ability of Lm to adhere to and invade human cells in vitro is not always decipherable from its virulence gene profile.

5.
Front Microbiol ; 13: 930895, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35832815

RESUMO

In this study, we characterized 84 Listeria monocytogenes (Lm) strains having an atypical IVb-v1 profile and isolated in a meat producing plant of Central Italy. They were assigned to the new MLST type ST2801 (CC218). The new ST was widespread in the food-producing environment where it was able to persist for over a year even after cleaning and sanitation. Cluster analysis identified three main clusters genetically close to each other (0-22 allelic differences and 0-28 SNPs) from two different cgMLST types, suggesting a common source. The coexistence of closely related clusters over time could be the result of a different evolution path starting from a common ancestor first introduced in the plant and/or the consequence of the repetitive reintroduction of closely related clones probably by raw materials. All the strains presented several determinants for heavy metals resistance, stress response, biofilm production, and multidrug efflux pumps with no significant differences among the clusters. A total of 53 strains carried pLI100 and the j1776 plasmids, while in one strain, the pLM33 was found in addition to pLI100. Only the strains carrying plasmids presented cadA and cadC for cadmium resistance and the mco gene encoding a multicopper oxidase and gerN for an additional Na+/H+-K+ antiporter. All the strains presented a virulence profile including a full-length inlA gene and the additional LIPI-3. The isolation of a new ST with a large pattern of stress-adaptation genes and able to persist is an important contribution to deepening the current knowledge on the uncommon IVb-v1 and in general on the genomic diversity of Lm.

6.
Microorganisms ; 9(12)2021 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-34946066

RESUMO

Salmonellosis is the second most commonly reported gastrointestinal infection in humans after campylobacteriosis, and an important cause of foodborne outbreaks in the EU/EEA. The vast majority (72.4%) of the salmonellosis foodborne outbreaks reported in EU in 2019 were caused by Salmonella Enteritidis, even if their total number due to this serovar decreased. In spring 2020, a foodborne outbreak of S. Enteritidis occurred in the Marche region (Central Italy), involving 85 people. The common exposure source was a cheese, pecorino "primo sale", produced with raw sheep milk. The cheese batches were produced by two local dairies, with a livestock production facility, also including a sheep farm, being part of one dairy. Bacteriological analysis of samples collected allowed the detection of S. Enteritidis in animal faeces, environmental samples, raw-milk bulk tanks and milk taken from single animals. These data confirm that, despite the scarce scientific evidence, S. Enteritidis can infect sheep and be shed into the animals' milk. Hence, this is a real risk for public health when unpasteurized milk is used in production of such cheese. The present paper describes the results of the investigations conducted to clarify this outbreak.

7.
Front Microbiol ; 12: 750065, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34803971

RESUMO

From May 2015 to March 2016, a severe outbreak due to Listeria monocytogenes ST7 strain occurred in Central Italy and caused 24 confirmed clinical cases. The epidemic strain was deeply investigated using whole-genome sequencing (WGS) analysis. In the interested area, the foodborne outbreak investigation identified a meat food-producing plant contaminated by the outbreak strain, carried by pork-ready-to-eat products. In the same region, in March 2018, the epidemic strain reemerged causing one listeriosis case in a 10-month-old child. The aim of this study was to investigate the phylogeny of the epidemic and reemergent strains over time and to compare them with a closer ST7 clone, detected during the outbreak and with different pulsed-field gel electrophoresis (PFGE) profiles, in order to identify genomic features linked to the persistence and the reemergence of the outbreak. An approach combining phylogenetic analysis and genome-wide association study (GWAS) revealed that the epidemic and reemergent clones were genetically closer to the ST7 clone with different PFGE profiles and strictly associated with the pork production chain. The repeated detection of both clones was probably correlated with (i) the presence of truly persistent clones and the repeated introduction of new ones and (ii) the contribution of prophage genes in promoting the persistence of the epidemic clones. Despite that no significant genomic differences were detected between the outbreak and the reemergent strain, the two related clones detected during the outbreak can be differentiated by transcriptional factor and phage genes associated with the phage LP-114.

8.
Artigo em Inglês | MEDLINE | ID: mdl-34769888

RESUMO

In the last decade, the incidence and severity of Clostridioides difficile infections (CDIs) in humans have been increasing and community-associated infections have been described. For these reasons, the interest in C. difficile in food and in food animals has increased, suggesting other possible sources of C. difficile acquisition. This study evaluated the presence of C. difficile on pig carcasses at the slaughterhouse and in pork products in Central Italy. The contamination rate on pig carcasses was 4/179 (2.3%). Regarding food samples, a total of 216 pork products were tested (74 raw meat preparations and 142 ready-to-eat food samples made by cured raw meat). The real-time PCR screening was positive for 1/74 raw meat preparation (1.35%) and for 1/142 ready-to-eat food samples (0.7%) C. difficile was isolated only from the raw meat preparation (pork sausage). All the isolated strains were toxigenic and susceptible to all the tested antibiotics. Strains isolated from carcass samples displayed A+B+CDTa+CDTb+ profile, were toxinotype IV and belonged to the same ribotype arbitrary named TV93, while the one isolated from food samples displayed A+B+CDTa-CDTb- profile and it was not possible to determine ribotype and toxinotype, because it was lost after freeze storage. It was concluded that the prevalence of C. difficile in the pork supply chain is very low.


Assuntos
Clostridioides difficile , Produtos da Carne , Carne de Porco , Carne Vermelha , Animais , Antibacterianos/farmacologia , Clostridioides , Clostridioides difficile/genética , Prevalência , Suínos
9.
Front Cell Infect Microbiol ; 11: 765540, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34746033

RESUMO

Listeria monocytogenes (Lm) is a foodborne pathogen causing listeriosis. Invasive forms of the disease mainly manifest as septicaemia, meningitis and maternal-neonatal infections. Lm-associated respiratory infections are very rare and little known. We reported two Lm respiratory infection cases occurred in Central Italy during the summer of 2020, in the midst of the SARS-CoV2 pandemic. In addition to collect the epidemiological and clinical characteristics of the patients, we used Whole Genome Sequencing to study the genomes of the Lm isolates investigating their virulence and antimicrobial profiles and the presence of genetic mobile elements. Both the strains belonged to hypervirulent MLST clonal complexes (CC). In addition to the Listeria Pathogenicity Island 1 (LIPI-1), the CC1 strain also carried LIPI-3 and the CC4 both LIPI-3 and LIPI-4. Genetic determinants for antimicrobial and disinfectants resistance were found. The CC1 genome presented prophage sequences but they did not interrupt the comK gene, involved in the phagosomal escape of Lm. None of the strains carried plasmids. Lm is an important, although rare, opportunistic pathogen for respiratory tract and lung infections. To avoid dangerous diagnostic delays of these severe clinical forms, it is important to sensitize hospital laboratories to this rare manifestation of listeriosis considering Lm in the differential diagnosis of respiratory infections.


Assuntos
COVID-19 , Listeria monocytogenes , Listeriose , Humanos , Recém-Nascido , Listeria monocytogenes/genética , Listeriose/epidemiologia , Tipagem de Sequências Multilocus , RNA Viral , SARS-CoV-2
10.
Foods ; 10(8)2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34441721

RESUMO

Listeria monocytogenes (Lm) can persist in food processing environments (FPEs), surviving environmental stresses and disinfectants. We described an intensive environmental monitoring plan performed in Central Italy and involving food producing plants (FPPs) and retail grocery stores (RSs). The aim of the study was to provide a snapshot of the Lm circulation in different FPEs during a severe listeriosis outbreak, using whole genome sequencing (WGS) to investigate the genetic diversity of the Lm isolated, evaluating their virulence and stress resistance profiles. A total of 1217 samples were collected in 86 FPEs with 12.0% of positive surfaces at FPPs level and 7.5% at RSs level; 133 Lm isolates were typed by multilocus sequencing typing (MLST) and core genome MLST (cgMLST). Clonal complex (CC) 121 (25.6%), CC9 (22.6%), CC1 (11.3%), CC3 (10.5%), CC191 (4.5%), CC7 (4.5%) and CC31 (3.8%) were the most frequent MLST clones. Among the 26 cgMLST clusters obtained, 5 of them persisted after sanitization and were re-isolated during the follow-up sampling. All the CC121 harboured the Tn6188_qac gene for tolerance to benzalkonium chloride and the stress survival islet SSI-2. The CC3, CC7, CC9, CC31 and CC191 carried the SSI-1. All the CC9 and CC121 strains presented a premature stop codon in the inlA gene. In addition to the Lm Pathogenicity Island 1 (LIPI-1), CC1, CC3 and CC191 harboured the LIPI-3. The application of intensive environmental sampling plans for the detection and WGS analysis of Lm isolates could improve surveillance and early detection of outbreaks.

11.
Foodborne Pathog Dis ; 18(9): 675-682, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34042505

RESUMO

The public health risk posed by Listeria monocytogenes in ready-to-eat (RTE) foods depends on the effectiveness of its control at every stage of the production process and the strain involved. Analytical methods currently in use are limited to the identification/quantification of L. monocytogenes at the species level, without distinguishing virulent from hypovirulent strains. In these products, according to EU Regulation 2073/2005, L. monocytogenes is a mandatory criterion irrespective of strain virulence level. Indeed, this species encompasses a diversity of strains with various pathogenic potential, reflecting genetic heterogeneity of the species itself. Thus, the detection of specific L. monocytogenes virulence genes can be considered an important target in laboratory food analysis to assign different risk levels to foods contaminated by strains carrying different genes. In 2015-2016, a severe invasive listeriosis outbreak occurred in central Italy, leading to the intensification of routine surveillance and strain characterization for virulence genetic markers. A new multiplex real-time polymerase chain reaction targeting main virulence genes has been developed and validated against the enzyme-linked fluorescent assay (ELFA) culture-based method. Results of the improved surveillance program are now reported in this study.


Assuntos
Listeria monocytogenes , Listeriose , Microbiologia de Alimentos , Humanos , Itália , Listeria monocytogenes/genética , Listeriose/epidemiologia , Virulência/genética
12.
Microorganisms ; 9(2)2021 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-33668440

RESUMO

A total of 66 Listeria monocytogenes (Lm) isolated from 2013 to 2018 in a small-scale meat processing plant and a dairy facility of Central Italy were studied. Whole Genome Sequencing and bioinformatics analysis were used to assess the genetic relationships between the strains and investigate persistence and virulence abilities. The biofilm forming-ability was assessed in vitro. Cluster analysis grouped the Lm from the meat plant into three main clusters: two of them, both belonging to CC9, persisted for years in the plant and one (CC121) was isolated in the last year of sampling. In the dairy facility, all the strains grouped in a CC2 four-year persistent cluster. All the studied strains carried multidrug efflux-pumps genetic determinants (sugE, mdrl, lde, norM, mepA). CC121 also harbored the Tn6188 specific for tolerance to Benzalkonium Chloride. Only CC9 and CC121 carried a Stress Survival Islet and presented high-level cadmium resistance genes (cadA1C1) carried by different plasmids. They showed a greater biofilm production when compared with CC2. All the CC2 carried a full-length inlA while CC9 and CC121 presented a Premature Stop Codon mutation correlated with less virulence. The hypo-virulent clones CC9 and CC121 appeared the most adapted to food-processing environments; however, even the hyper-virulent clone CC2 warningly persisted for a long time. The identification of the main mechanisms promoting Lm persistence in a specific food processing plant is important to provide recommendations to Food Business Operators (FBOs) in order to remove or reduce resident Lm.

13.
Microorganisms ; 10(1)2021 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-35056510

RESUMO

Listeria monocytogenes (Lm) is the causative agent of human listeriosis. Lm strains have different virulence potential. For this reason, we preliminarily characterised via Whole-Genome Sequencing (WGS) some Lm strains for their key genomic features and virulence-associated determinants, assigning the clonal complex (CC). Moreover, the ability of the same strains to adhere to and invade human colon carcinoma cell line Caco-2, evaluating the possible correspondence with their genetic virulence profile, was also assessed. The clinical strains typed belonged to clonal complex (CC)1, CC31, and CC101 and showed a very low invasiveness. The Lm strains isolated from food were assigned to CC1, CC7, CC9, and CC121. All CC1 carried the hypervirulence pathogenicity island LIPI-3 in addition to LIPI-1. Premature stop codons in the inlA gene were found only in Lm of food origin belonging to CC9 and CC121. The presence of LIPI2_inlII was observed in all the CCs except CC1. The CC7 strain, belonging to an epidemic cluster, also carried the internalin genes inlG and inlL and showed the highest level of invasion. In contrast, the human CC31 strain lacked the lapB and vip genes and presented the lowest level of invasiveness. In Lm, the genetic determinants of hypo- or hypervirulence are not necessarily predictive of a cell adhesion and/or invasion ability in vitro. Moreover, since listeriosis results from the interplay between host and virulence features of the pathogen, even hypovirulent clones are able to cause infection in immunocompromised people.

14.
Foods ; 9(1)2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31936251

RESUMO

From January 2015 to March 2016, an outbreak of 23 human cases of listeriosis in the Marche region and one human case in the Umbria region of Italy was caused by Listeria monocytogenes strains showing a new pulsotype never described before in Italy. A total of 37 clinical strains isolated from patients exhibiting listeriosis symptoms and 1374 strains correlated to the outbreak were received by the Italian National Reference Laboratory for L. monocytogenes (It NRL Lm) of Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise (IZSAM) for outbreak investigation. A real-time PCR assay was purposely designed for a rapid screening of the strains related to the outbreak. PCR-positive strains were successively typed through molecular serogrouping, pulsed field gel electrophoresis (PFGE), and Next Generation Sequencing (NGS). Applying the described strategy, based on real-time PCR screening, we were able to considerably reduce time and costs during the outbreak investigation activities.

15.
Artigo em Inglês | MEDLINE | ID: mdl-30574578

RESUMO

We report the whole-genome sequence of a Listeria monocytogenes strain isolated from a child in central Italy. Interestingly, the sequence showed a difference of only 13 single-nucleotide polymorphisms (SNPs) from a strain responsible for a severe listeriosis outbreak that occurred between January 2015 and March 2016 in the same region.

16.
Toxins (Basel) ; 10(12)2018 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-30563233

RESUMO

In summer 2017, a foodborne outbreak occurred in Central Italy, involving 26 workers employed in the post-earthquake reconstruction. After eating a meal provided by a catering service, they manifested gastrointestinal symptoms; 23 of them were hospitalized. The retrospective cohort study indicated the pasta salad as the most likely vehicle of poisoning. Foods, environmental samples, and food handlers' nasal swabs were collected. Bacillus cereus (Bc) and coagulase-positive staphylococci (CPS) including S. aureus, together with their toxins, were the targets of the analysis. CPS, detected in all the leftovers, exceeded 105 CFU/g in the pasta salad, in which we found Staphylococcal Enterotoxins (SEs) (0.033 ng SEA/g; 0.052 ng SED/g). None of the environmental and human swabs showed contamination. We characterized 23 S. aureus from foods. They all belonged to the human biotype, showed the same toxigenic profile (sea, sed, sej, and ser genes), and had the same Pulsed Field Gel Electrophoresis (PFGE) pattern; none of them harbored mecA or mupA genes. We also detected Bc contamination in the pasta salad but none of the isolates harbored the ces gene for the emetic toxin cereulide. The EU Reference Laboratory for CPS confirmed the case as a strong-evidence outbreak caused by the ingestion of SEs produced by a single strain of S. aureus carried by the same human source. This outbreak was successfully investigated despite the emergency situation in which it occurred.


Assuntos
Surtos de Doenças , Intoxicação Alimentar Estafilocócica/epidemiologia , Adulto , Terremotos , Enterotoxinas/isolamento & purificação , Contaminação de Alimentos/análise , Manipulação de Alimentos , Microbiologia de Alimentos , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Staphylococcus aureus/isolamento & purificação , Local de Trabalho , Adulto Jovem
17.
J Med Microbiol ; 67(9): 1351-1360, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30024370

RESUMO

PURPOSE: From May 2015 to March 2016, an outbreak due to Listeria monocytogenes serotype 1/2a and clinical pulsotype never previously isolated in Europe occurred in central Italy, involving 24 confirmed clinical cases. The article provides a description of the outbreak and the investigation carried out by a multidisciplinary network. METHODOLOGY: Epidemiological and microbiological surveillance was conducted to confirm the outbreak and to detect the food vehicle of infection. The origin and destination of the implicated food and its ingredients were investigated by tracing-back and -forward investigation. RESULTS: Next-generation sequencing confirmed the unique outbreak strain. On 4 January 2016, a L. monocytogenes strain with pulsotype indistinguishable from that isolated from clinical cases in the outbreak was detected in a sample of hog head cheese purchased from a retail supermarket by one of the patients. The hog head cheese was produced by a small meat processing plant in the Marche region, where microbiological investigation confirmed environmental and food contamination by the outbreak strain. Plant production was suspended and all contaminated batches of the hog head cheese were withdrawn from the market by 19 February by local health authority. We subsequently observed a sharp decline in clinical cases, the last being reported on 11 March 2016. CONCLUSION: The key factor in the timely conclusion of this investigation was intersectoral collaboration among epidemiologists, microbiologists, veterinarians, statisticians and health and food safety authorities at national, regional and local levels.


Assuntos
Contaminação de Alimentos/análise , Doenças Transmitidas por Alimentos/microbiologia , Listeria monocytogenes/isolamento & purificação , Listeriose/microbiologia , Produtos da Carne/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Pré-Escolar , Feminino , Manipulação de Alimentos , Doenças Transmitidas por Alimentos/epidemiologia , Humanos , Lactente , Itália/epidemiologia , Listeria monocytogenes/classificação , Listeria monocytogenes/genética , Listeriose/epidemiologia , Masculino , Pessoa de Meia-Idade , Filogenia , Suínos , Adulto Jovem
18.
Genome Announc ; 6(24)2018 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-29903806

RESUMO

We report the whole-genome sequences of two Listeria monocytogenes strains responsible for a severe invasive listeriosis outbreak in central Italy that occurred in 2015 and 2016. These two strains differ by a single band in their pulsed-field gel electrophoresis (PFGE) profiles.

19.
Int J Food Microbiol ; 232: 7-14, 2016 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-27236076

RESUMO

In total 1095 samples from 675 pork products, 210 swine colon contents, and 210 swine carcass sponge swabs were collected in Umbria and Marche regions of Italy and examined for the presence of Shiga toxin-producing Escherichia coli (STEC), also known as Verotoxin-producing E. coli (VTEC). After an enrichment step, each sample was analysed by real-time PCR to detect the stx1, stx2, and eae genes. stx-Positive samples were further tested for the "top five" serogroup markers (O157, O26, O103, O111, O145) and cultured onto selective media. The isolates were assigned to stx subtypes and tested for the presence of aaiC and aggR genes. Out of 420 swine samples, 38.6% faecal samples and 13.8% carcass sponge swabs were stx-positive. In total, 33 E. coli STEC isolates were obtained from 30 samples (4 carcasses and 26 colon contents) indicating a culture-positive rate of 7.1%. A higher culture-positive rate was observed in faecal samples (12.4%) than in carcass sponge swabs (1.9%). Out of 675 pork samples, 19 (2.8%) were stx-positive. No STEC strains were isolated from stx-positive pork products. We concluded that STEC isolation from foodstuffs remains difficult, despite the application of ISO/TS 13136:2012. Furthermore, in accordance with the results of studies conducted in other countries, we observed that most of swine STEC strains carried stx2e gene and lacked of virulence genes, such as eae, aaiC and aggR, indicative of potential pathogenic characteristics for humans. Although the majority of STEC isolates did not express virulence factors correlating with severe human diseases, the association between swine STEC strains and human illness requires further investigations.


Assuntos
Produtos da Carne/microbiologia , Carne Vermelha/microbiologia , Toxina Shiga I/análise , Toxina Shiga II/análise , Escherichia coli Shiga Toxigênica/isolamento & purificação , Escherichia coli Shiga Toxigênica/patogenicidade , Suínos/microbiologia , Adesinas Bacterianas/análise , Adesinas Bacterianas/genética , Animais , Colo/microbiologia , Proteínas de Escherichia coli/análise , Proteínas de Escherichia coli/genética , Fezes/microbiologia , Microbiologia de Alimentos , Humanos , Itália , Prevalência , Reação em Cadeia da Polimerase em Tempo Real , Toxina Shiga I/genética , Toxina Shiga II/genética , Escherichia coli Shiga Toxigênica/genética , Transativadores/análise , Transativadores/genética , Virulência/genética , Fatores de Virulência/análise , Fatores de Virulência/genética
20.
Meat Sci ; 98(4): 575-84, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25089780

RESUMO

Lactic acid bacteria (LAB) from Ciauscolo salami produced in Marche Region of Central Italy, and LAB strains belonging to our laboratory collection were examined for their capability to survive at low pH and bile, to adhere to Caco-2 cells, and for antibiotic resistance. LAB from Ciauscolo were identified by ARDRA and RAPD-PCR. Our study showed that all LAB strains had good adaptation to gastric juice and moderate tolerance to bile. The adhesiveness was variable among strains but significantly lower in LAB from food. Antibiotic resistance was broadly spread among food strains, with level of resistance exceeding 15% for all the antibiotics tested. The resistance determinants erm(B) and tet(M) were found in nine strains of food origin (21.4%) while tet(L) in one strain of our collection (5%). Our work suggests that fermented foods are valuable sources of bacterial strains with functional traits of intestinal lactobacilli. These bacteria may be further studied for their use in probiotic applications.


Assuntos
Microbiologia de Alimentos/métodos , Lactobacillus/isolamento & purificação , Lactobacillus/fisiologia , Produtos da Carne/microbiologia , Aderência Bacteriana/fisiologia , Farmacorresistência Bacteriana/fisiologia , Fermentação , Humanos , Concentração de Íons de Hidrogênio , Itália
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