Heat-resistant and biofilm-forming Escherichia coli in pasteurized milk from Brazil.

Escherichia coli harboring a transmissible locus of stress tolerance (tLST) and the ability to form biofilms represent a serious risk in dairy production. Thus, we aimed to evaluate the microbiological quality of pasteurized milk from two dairy producers in Mato Grosso, Brazil, with a focus on determining the possible presence of E. coli with heat resistance (60 °C/6 min), biofilm-forming potential phenotypes and genotypes, and antimicrobial susceptibility. For this, fifty pasteurized milk samples from producers named A and B were obtained for 5 weeks to investigate the presence of Enterobacteriaceae members, coliforms, and E. coli. For heat resistance, E. coli isolates were exposed to a water bath at 60 °C for 0 and 6 min. In antibiogram analysis, eight antibiotics belonging to six antimicrobial classes were analyzed. The potential to form biofilms was quantified at 570 nm, and curli expression by Congo Red was analyzed. To determine the genotypic profile, we performed PCR for the tLST and rpoS genes, and pulsed-field gel electrophoresis (PFGE) was used to investigate the clonal profile of the isolates. Thus, producer A presented unsatisfactory microbiological conditions regarding Enterobacteriaceae and coliforms for weeks 4 and 5, while all samples analyzed for producer B were contaminated at above-the-limit levels established by national and international legislation. These unsatisfactory conditions enabled us to isolate 31 E. coli from both producers (7 isolates from producer A and 24 isolates from producer B). In this way, 6 E. coli isolates (5 from producer A and 1 from producer B) were highly heat resistant. However, although only 6 E. coli showed a highly heat-resistant profile, 97% (30/31) of all E. coli were tLST-positive. In contrast, all isolates were sensitive to all antimicrobials tested. In addition, moderate or weak biofilm potential was verified in 51.6% (16/31), and the expression of curli and presence of rpoS was not always related to this biofilm potential. Therefore, the results emphasize the spreading of heat-resistant E. coli with tLST in both producers and indicate the biofilm as a possible source of contamination during milk pasteurization. However, the possibility of E. coli producing biofilm and surviving pasteurization temperatures cannot be ruled out, and this should be investigated.

Evaluation of VITEK® 2 and MALDI-TOF/MS automated methodologies in the identification of atypical Listeria spp. isolated from food in different regions of Brazil.

Listeria monocytogenes is a pathogen responsible for listeriosis, a foodborne disease with high mortality rates (20-30%). It mainly affects the elderly, pregnant women, and immunocompromised people. Although not pathogenic, the isolation and identification of Listeria innocua are critical since they can indicate L. monocytogenes' presence as they are closely related and widely distributed in the environment and food processing plants. The objective of this study was to evaluate the effectiveness of the automated methods VITEK® 2 and MALDI-TOF/MS in identifying 94 strains of the genus Listeria with atypical identification profile. The resulting identification by Polymerase Chain Reaction (PCR), using specific primers for the most common species of Listeria, was considered the correct identification and presented a total of 31 strains identified as Listeria innocua (LI), 54 as L. monocytogenes (LM), 8 as Listeria welshimeri (LW) and 1 as Listeria grayi (LG). The VITEK® 2 automated system correctly identified, on average, 79% of the LI strains, 16% of the LM strains, and 88.0% of the LW strains. In the analysis by MALDI-TOF/MS, on average, 73% of LM strains were correctly identified, few LW strains were correctly identified, and all LI strains were incorrectly identified. Both VITEK® 2 and MALDI-TOF/MS correctly identified the LG strain in both analyzes. The results demonstrate that automated methodologies could not discriminate atypical strains of the Listeria genus and point to the need for the use of complementary tests, such as PCR and chromogenic media, for the correct identification of these strains.

Seroprevalence of Listeria monocytogenes in HIV infected pregnant women from Brazil.

OBJECTIVE: To describe the prevalence and factors associated with serologic response to Listeria monocytogenes in HIV infected and uninfected pregnant women in Brazil. METHODS: Cross-sectional study, pregnant women after 14 weeks of gestational age were enrolled. Positive serologic test for L. monocytogenes was defined as titers >1:80 (agglutination test). Comparisons were performed using logistic regression. RESULTS: A total of 213 women were enrolled, 73 (34%) were HIV infected. 55 women were seroreactive for L. monocytogenes, 27 (37%) HIV-infected and 28 (20%) HIV-uninfected (p < 0.01). Considering the diet record, white cheese consumption was associated with seroreactivity (p < 0.01). In the group of pregnant women living with HIV, the variables associated with L. monocytogenes positive serology were: lower CD4+ cells count at study entry OR=4.8 (95%CI=1.1-19.8) and having neonates admitted to the intensive care unit OR=5.9 (95%CI=1.01-34.9). CONCLUSION: Positive serology for Listeria monocytogenes was associated with HIV infection. Brazilian women should avoid white cheese during pregnancy.

Prevalence of Listeria monocytogenes fecal carriers in HIV-infected and -uninfected pregnant women from Brazil.

OBJECTIVE: The aim of this study is to describe the prevalence of Listeria spp. in feces of HIV-infected and -uninfected pregnant women in Brazil. METHODS: Cross-sectional study. Women on their second or third trimester of pregnancy were submitted to a clinical questionnaire and feces collection. The feces were inoculated on selective media and identification by biochemical tests combined with PCR. RESULTS: A total of 213 pregnant women were enrolled: 73 (34%) HIV-infected and 140 (66%) -non-infected. The prevalence of Listeria spp. and L. monocytogenes in feces of HIV-infected women were 8.2% and 2.7%. In the HIV-uninfected were 8.6% and 2.9% (p-values = 0.98 and 0.66, respectively). CONCLUSION: The prevalence of fecal carriers of Listeria spp. and L. monocytogenes was not associated with HIV infection during pregnancy.

Characterization of Enterococcus faecium E86 bacteriocins and their inhibition properties against Listeria monocytogenes and vancomycin-resistant Enterococcus.

In the present scenario of a major demand for new compounds with antimicrobial activity, bacteriocin and bacteriocin-like inhibitory substances (BLIS) are promising tools against deteriorating and pathogenic microorganisms, thus having potential applications in both the food industry and infectious disease control. In the present report, we describe the genetic and phenotypic characteristics of BLIS produced by Enterococcus faecium E86, a strain previously isolated and sequenced by our group, focusing on the structural genes of two bacteriocins identified: enterocin TW21 and enterocin P. Transcription of all four genes associated with the biosynthesis and immunity of enterocin P and enterocin TW21 were confirmed by RT-PCR. However, Sanger sequencing confirmed a truncation of the structural gene of enterocin TW21 due to one base pair deletion (A/T). Thus, although E. faecium E86 was shown to carry two bacteriocinogenic gene clusters, only one cluster encodes a functional bacteriocin, enterocin P. Enterocin P was able to inhibit different strains of Listeria monocytogenes and vancomycin-resistant enterococci (both Enterococcus faecalis and Enterococcus faecium), showing intense bacteriolytic activity, in most cases.

Evaluation of MALDI-TOF MS as a tool for detection of Listeria spp. directly from selective enrichment broth from food and stool samples.

We evaluated the detection of Listeria spp. using MALDI-TOF MS directly in enrichment broths, without isolated colonies, with naturally contaminated food and stool samples. The success rate was 77%. Considering the reduced time for diagnosis and the success rate, this is a promising screening tool, but more tests are needed to determine its viability.

Rapid detection of Yersinia enterocolitica serotype O:3 using a duplex PCR assay.

Yersinia enterocolitica, a member of the Enterobacteriaceae family, is a zoonotic agent that causes gastrointestinal diseases and some extraintestinal disorders in humans. Y. enterocolitica ssp. palearctica bioserotype 4/O:3 is the primary pathogenic bioserotype in Europe, where it has a high public health relevance. The isolation and identification of Y. enterocolitica from various sources on selective media have been seldom successful due to several reasons. In an attempt to overcome the problems associated with traditional culture-based methods, we developed a single duplex PCR assay for the detection of Y. enterocolitica ssp. palearctica bioserotype 4/O:3 using DNA extracted from a source. We combined the primer for tufA (elongation factor Tu) with the primer for rfbC (the biosynthesis of the O side chain) in one single reaction, which showed good results when we analyzed 88 Yersinia strains and when it was tested in the DNA from stool samples of two groups of pregnant women, one comprising HIV-positive women and the other comprising of HIV-negative women. Furthermore, the duplex PCR assay was found to be 16 times better in detecting Yersinia spp. in stool samples than the culture-based method. In addition, it was found to be a rapid screening method for the detection of Y. enterocolitica serotype O:3, and it could still detect other Y. enterocolitica serotypes and Yersinia species as well. We anticipate that the duplex PCR assay could be a useful tool for hospital and veterinary surveillance studies on Yersinia worldwide.

Escherichia coli O26 and O113:H21 on Carcasses and Beef from a Slaughterhouse Located in Mato Grosso, Brazil.

Shiga toxin-producing Escherichia coli (STEC) is a group of emerging pathogens that can cause human diseases, including hemolytic uremic syndrome (HUS) and hemorrhagic colitis (HC). Monitoring slaughtering stages and checking contamination points are crucial for the production of safe food. In this context, the aim of this study was to verify contamination by STEC strains, to determine the contamination points and evaluate the resistance profile to 12 antimicrobials used in both veterinary and human medicine. A total of 80 samples were obtained from eight collection points (pen floor, rectum, hide, carcass swabs and esophagus, diaphragm, masseter, and retail beef tissue samples). The isolates were collected by dilution plating on MacConkey agar with sorbitol, cefixime, and tellurite and analyzed by multiplex polymerase chain reaction for virulence genes. Serotyping of non-O157 was performed, and testing for 12 antibiotics by disk diffusion was carried out. A total of 18 STEC strains were isolated, presenting different virulence profiles. Contamination by STEC was observed in the rectum (5/18), carcass surface (5/18), hide (3/18), diaphragm (2/18), retail beef (2/18), and masseter muscle (1/18). Pen floor swabs and esophagus tissues showed no STEC contamination. Moreover, three strains were identified as O26 and three as O113:H21 strains, which have been linked to HUS and HC outbreak cases in Brazil. All STEC isolates were susceptible to all evaluated antimicrobials, except streptomycin. The presence of STEC strains is a direct risk to the consumer, especially when isolated from retail beef, and contamination can occur during different slaughter stages. However, antimicrobial resistance profiles did not identify multidrug-resistant strains, limiting potential antimicrobial resistance transmission to other pathogens.

Next-generation sequencing virulome analysis of a Yersinia enterocolitica subsp. palearctica bioserotype 4/O: 3 ST18 isolated from human blood in Brazil

Abstract Yersinia enterocolitica is a widespread Gram-negative bacterium that causes gastrointestinal disease and other clinical manifestations in humans. Potentially pathogenic Y. enterocolitica has been isolated in Brazil, from human, environmental, food, and animal sources. Herein we report a genome sequence of Y. enterocolitica subsp. palearctica strain YE 19, serotype O:3, biotype 4, sequence type 18, with virulence determinants isolated from human blood in Rio de Janeiro in 2005. The results corroborate other findings that this strain harbors a set of virulence determinants that could play a role in host pathoadaptation and may also justify the successful dissemination of bioserotype 4/O:3 in Brazil. The presence of strains harboring all of these virulence genes in Brazil is a potential threat to young children and immunocompromised individuals, for whom yersiniosis are a significant source of morbidity and mortality. The results of a genomic data analysis will help understand the virulence of Brazilian strains and provide data for Y. enterocolitica studies worldwide.

Next-generation sequencing virulome analysis of a Yersinia enterocolitica subsp. palearctica bioserotype 4/O:3 ST18 isolated from human blood in Brazil.

Yersinia enterocolitica is a widespread Gram-negative bacterium that causes gastrointestinal disease and other clinical manifestations in humans. Potentially pathogenic Y. enterocolitica has been isolated in Brazil, from human, environmental, food, and animal sources. Herein we report a genome sequence of Y. enterocolitica subsp. palearctica strain YE 19, serotype O:3, biotype 4, sequence type 18, with virulence determinants isolated from human blood in Rio de Janeiro in 2005. The results corroborate other findings that this strain harbors a set of virulence determinants that could play a role in host pathoadaptation and may also justify the successful dissemination of bioserotype 4/O:3 in Brazil. The presence of strains harboring all of these virulence genes in Brazil is a potential threat to young children and immunocompromised individuals, for whom yersiniosis are a significant source of morbidity and mortality. The results of a genomic data analysis will help understand the virulence of Brazilian strains and provide data for Y. enterocolitica studies worldwide.

Virulence genes and genetic relationship of L. monocytogenes isolated from human and food sources in Brazil

ABSTRACT The herein presented assay provided a bacteriological and molecular characterization of 100 samples of L. monocytogenes isolated from human (43) and food (57) sources, from several regions of Brazil, and collected between 1975 and 2013. Antigenic characterization defined 49% of serotype 4b samples, followed by 28% of serotype 1/2b, 14% of serotype 1/2c, 8% of serotype 1/2a, and 1% of serotype 3b. Both type of samples from human and food origin express the same serotype distribution. Multiplex PCR analysis showed 13 strains of type 4b with the amplification profile 4b-VI (Variant I). Virulence genes hly, inlA, inlB, inlC, inlJ, actA, plcA, and prfA were detected in all samples, highlighting a deletion of 105pb on the actA gene in 23% of serotype 4b samples. Macrorestriction profile with ApaI at PFGE showed 55 pulsotypes, with the occurrence of the same pulsotype in hospitalized patients in São Paulo in 1992 and 1997, and two other highly related pulsotypes in patients hospitalized in Rio de Janeiro in 2008. Recognized pulsotypes in listeriosis cases have also been detected in food. Thus, the prevalence of a serotype and the persistence of certain pulsotypes herald future problems.

Virulence genes and genetic relationship of L. monocytogenes isolated from human and food sources in Brazil.

The herein presented assay provided a bacteriological and molecular characterization of 100 samples of L. monocytogenes isolated from human (43) and food (57) sources, from several regions of Brazil, and collected between 1975 and 2013. Antigenic characterization defined 49% of serotype 4b samples, followed by 28% of serotype 1/2b, 14% of serotype 1/2c, 8% of serotype 1/2a, and 1% of serotype 3b. Both type of samples from human and food origin express the same serotype distribution. Multiplex PCR analysis showed 13 strains of type 4b with the amplification profile 4b-VI (Variant I). Virulence genes hly, inlA, inlB, inlC, inlJ, actA, plcA, and prfA were detected in all samples, highlighting a deletion of 105pb on the actA gene in 23% of serotype 4b samples. Macrorestriction profile with ApaI at PFGE showed 55 pulsotypes, with the occurrence of the same pulsotype in hospitalized patients in São Paulo in 1992 and 1997, and two other highly related pulsotypes in patients hospitalized in Rio de Janeiro in 2008. Recognized pulsotypes in listeriosis cases have also been detected in food. Thus, the prevalence of a serotype and the persistence of certain pulsotypes herald future problems.

Occurrence and antimicrobial resistance patterns of Listeria monocytogenes isolated from vegetables

Abstract Although the consumption of fresh and minimally processed vegetables is considered healthy, outbreaks related to the contamination of these products are frequently reported. Among the food-borne pathogens that contaminate vegetables is Listeria monocytogenes, a ubiquitous organism that exhibits the ability to survive and multiply at refrigerated temperatures. This study aimed to evaluate the occurrence of L. monocytogenes in vegetables as well as the antimicrobial resistance of isolates. The results showed that 3.03% of samples were contaminated with L. monocytogenes, comprising 2.22% of raw vegetables and 5.56% of ready-to-eat vegetables. Multiplex PCR confirmed the virulence potential of the isolates. Antimicrobial resistance profiling showed that 50% of the isolates were susceptible to the antibiotics used. The resistance of one isolate to penicillin G, a commonly employed therapeutic agent, and the presence of serotype 4b, a serotype commonly associated with food-borne outbreaks, could be potential health hazards for consumers.

Occurrence and antimicrobial resistance patterns of Listeria monocytogenes isolated from vegetables.

Although the consumption of fresh and minimally processed vegetables is considered healthy, outbreaks related to the contamination of these products are frequently reported. Among the food-borne pathogens that contaminate vegetables is Listeria monocytogenes, a ubiquitous organism that exhibits the ability to survive and multiply at refrigerated temperatures. This study aimed to evaluate the occurrence of L. monocytogenes in vegetables as well as the antimicrobial resistance of isolates. The results showed that 3.03% of samples were contaminated with L. monocytogenes, comprising 2.22% of raw vegetables and 5.56% of ready-to-eat vegetables. Multiplex PCR confirmed the virulence potential of the isolates. Antimicrobial resistance profiling showed that 50% of the isolates were susceptible to the antibiotics used. The resistance of one isolate to penicillin G, a commonly employed therapeutic agent, and the presence of serotype 4b, a serotype commonly associated with food-borne outbreaks, could be potential health hazards for consumers.

Molecular Serogrouping of Listeria monocytogenes from Brazil Using PCR.

We assessed the serotype distribution of Listeria monocytogenes isolates from clinical, beef, and environment samples using two PCR-based protocols for serogrouping. A panel of 134 isolates (22 clinical samples, 79 samples of beef cuts, and 33 samples from the beef processing environment) were subjected to conventional serology and identified as serotypes 1/2a (n = 12), 1/2b (n = 21), 1/2c (n = 71), and 4b (n = 30). Isolates from clinical samples were predominantly serotype 4b, and the most prevalent serotype among the beef cut and environment samples was 1/2c. The protocol described by M. Doumith, C. Buchrieser, P. Glaser, C. Jacquet, and P. Martin (J. Clin. Microbiol. 42:3819-3822, 2004) produced contradictory results for seven 1/2a isolates, which were positive for lmo1118 and had the profile IIc (serotypes 1/2c and 3c). Fifteen serotype 4b isolates amplified the target lmo0737, with the atypical profile IVb variant 1. The results obtained with the protocol described by M. K. Borucki and D. R. Call (J. Clin. Microbiol. 41:5537-5540, 2003) were in full agreement with those of the conventional serology. We recommend using this multiplex PCR approach by adding one pair of the reported primers to the panel to reduce total effort by one PCR while maintaining specificity. We present additional recommendations to improve the efficiency and reproducibility of this serogrouping assay.

Twenty Years of Listeria in Brazil: Occurrence of Listeria Species and Listeria monocytogenes Serovars in Food Samples in Brazil between 1990 and 2012.

Listeria spp. isolated from different food products and collected from 12 Brazilian states were sent to the Laboratory of Bacterial Zoonoses (Oswaldo Cruz Institute, Brazil) for identification. The aims of this study were to characterize these isolates, from 1990 to 2012, by using biochemical, morphological, and serotyping tests, and to analyze the distribution of L. monocytogenes serotypes on different food products and geographical locations. Serotyping was performed using polyclonal somatic and flagellar antisera. Of 5953 isolates, 5770 were identified as Listeria spp., from which 3429 (59.4%) were L. innocua, 2248 (38.9%) were L. monocytogenes, and 93 (1.6%) were other Listeria spp. L. innocua was predominantly isolated from 1990 to 2000, while L. monocytogenes was from 2001 to 2012. Regarding the serotype distribution in the foods, serotypes 1/2a and 4b were most common in processed meat and ready-to-eat products, respectively; serotypes 1/2a, 1/2b, and 4b were the most common in nonprocessed meat. The results above confirm the presence of the main serotypes of L. monocytogenes in different parts of the food chain from three regions of the country and emphasize the importance of improving the control measures, as tolerance zero policy and microbiological surveillance in Brazil.

Characterization of epidemic clones of Listeria monocytogenes serotype 4b isolated from humans and meat products in Brazil.

INTRODUCTION: Listeria monocytogenes is an important foodborne pathogen and the 4b serotype is responsible for many cases of human listeriosis reported in Brazil. Several listeriosis outbreaks worldwide have involved a small number of well-defined clonal groups, designated as epidemic clones (ECs). METHODOLOGY: We studied 71 strains of serotype 4b, including 25 isolates from human cases of listeriosis and 46 from meat-based foods, collected in Brazil between 1977 and 2010. The presence of ECs (I and II) markers and virulence genes (inlA, inlB, ilnC, inlJ and actA) were evaluated by PCR assay. The genetic relationship of ECs-positive strains was assessed by pulsed field gel electrophoresis. RESULTS: ECI and ECII markers were found both in human and food strains, with 19.7% positive for the ECI marker and 40.8% for ECII. Most strains (97.2%) were positive for the virulence genes that were studied. Nevertheless, the actA gene amplicons showed two distinct sizes, with all ECI positive strains exhibiting a 105bp deletion. Pulsed field gel electrophoresis (PFGE) analysis allowed the recognition of highly related strains, particularly from two outbreaks of neonatal listeriosis in São Paulo State occurred in 1992 and 1997, both ECII-positive; and two ECI strains from a human case (1982) and from bovine meat (2009). CONCLUSIONS: The presence of ECs among clinical samples and beef isolates of serotype 4b from some regions of Brazil highlights the need for rigorous control of production procedures. Furthermore, the association of ECII with two nosocomial outbreaks suggests its ability to spread in these settings.

Serotypes and Pulsotypes diversity of Listeria monocytogenes in a beef-processing environment.

Utensils and equipment from meat-processing facilities are considered relevant cross-contamination points of Listeria monocytogenes to foods, demanding tracking studies to identify their specific origins, and predict proper control. The present study aimed to detect L. monocytogenes in a beef-processing facility, investigating the diversity of serotypes and pulsotypes in order to identify the possible contamination routes. Surface samples from knives (n=26), tables (n=78), and employees hands (n=74) were collected before and during the procedures from a beef-processing facility, in addition to surface samples of end cuts: round (n=32), loin (n=30), and chuck (n=32). All samples were subjected to L. monocytogenes screening according ISO 11.290-1, and the obtained isolates were subjected to serotyping and pulsed-field gel electrophoresis. Listeria spp. were identified in all processing steps, in 61 samples, and L. monocytogenes was detected in 17 samples, not being found only in knives. Eighty-five isolates were identified as L. monocytogenes, from serotypes 1/2c (n=65), 4b (n=13), and 1/2b (n=7), being grouped in 19 pulsotypes. Considering these results, cross-contamination among hands, tables, and beef cuts could be identified. The obtained data indicated the relevance of cross-contamination in the beef-processing facility, and the occurrence of serotypes 1/2b and 4b in beef cuts distributed for retail sale is a public health concern.

Antibiotic Resistance of Listeria monocytogenes Isolated from Meat-Processing Environments, Beef Products, and Clinical Cases in Brazil.

The present study aimed to assess the antimicrobial resistance and the presence of virulence markers in 137 Listeria monocytogenes isolates obtained from meat-processing environments, beef products, and clinical cases. All isolates were subject to molecular serogrouping and their antibiotic resistance profiles were assessed against 12 antimicrobials. In addition, isolates were subjected to detection of virulence marker genes (inlA, inlC, inlJ). The isolates were classified into serogroups 4b, 4d, 4a, or 4c (46%), 1/2c or 3c (27%), 1/2a or 3a (13.9%), and 1/2b or 3b (13.1%). All tested isolates presented sensitivity to the majority of the tested antimicrobials, but most of them presented resistance or intermediate resistance to clindamycin (88.3%) and oxacillin (73.7%). Virulence markers were detected in all isolates, demanding further analysis to better characterize their pathogenic potential.

Phenotypic and genotypic analysis of bio-serotypes of Yersinia enterocolitica from various sources in Brazil.

INTRODUCTION: Yersinia enterocolitica is a well-known foodborne pathogen widely distributed in nature with high public health relevance, especially in Europe. METHODOLOGY: This study aimed to analyze the pathogenic potential of Y. enterocolitica isolated strains from human, animal, food, and environmental sources and from different regions of Brazil by detecting virulence genes inv, ail, ystA, and virF through polymerase chain reaction (PCR), phenotypic tests, and antimicrobial susceptibility analysis. Pulsed-field gel electrophoresis (PFGE) was used for the assessment of phylogenetic diversity. RESULTS: All virulence genes were detected in 11/60 (18%) strains of serotype O:3, biotype 4 isolated from human and animal sources. Ten human strains (4/O:3) presented three chromosomal virulence genes, and nine strains of biotype 1A presented the inv gene. Six (10%) strains were resistant to sulfamethoxazole-trimethoprim, seven (12%) to tetracycline, and one (2%) to amikacin, all of which are used to treat yersiniosis. AMP-CEF-SXT was the predominant resistance profile. PFGE analysis revealed 36 unique pulsotypes, grouped into nine clusters (A to I) with similarity ≥ 85%, generating a diversity discriminatory index of 0.957. Cluster A comprised all bio-serotype 4/O:3 strains isolated from animal and humans sources. CONCLUSIONS: This study shows the existence of strains with the same genotypic profiles, bearing all virulence genes, from human and animal sources, circulating among several Brazilian states. This supports the hypothesis that swine is likely to serve as a main element in Y. enterocolitica transmission to humans in Brazil, and it could become a potential threat to public health as in Europe.