Neglected tropical diseases, including zoonoses such as leptospirosis, have a major impact on rural and poor urban communities, particularly in developing countries. This has led to major investment in antipoverty vaccines that focus on diseases that influence public health and thereby productivity. While the true, global, impact of leptospirosis is unknown due to the lack of adequate laboratory diagnosis, the WHO estimates that incidence has doubled over the last 15 years to over 1 million cases that require hospitalization every year. Leptospirosis is caused by pathogenic Leptospira spp. and is spread through direct contact with infected animals, their urine or contaminated water and soil. Inactivated leptospirosis vaccines, or bacterins, are approved in only a handful of countries due to the lack of heterologous protection (there are > 250 pathogenic Leptospira serovars) and the serious side-effects associated with vaccination. Currently, research has focused on recombinant vaccines, a possible solution to these problems. However, due to a lack of standardised animal models, rigorous statistical analysis and poor reproducibility, this approach has met with limited success. We evaluated a subunit vaccine preparation, based on a conserved region of the leptospiral immunoglobulin-like B protein (LigB(131–645)) and aluminium hydroxide (AH), in the hamster model of leptospirosis. The vaccine conferred significant protection (80.0–100%, P < 0.05) against mortality in vaccinated animals in seven independent experiments. The efficacy of the LigB(131–645)/AH vaccine ranged from 87.5–100% and we observed sterile immunity (87.5–100%) among the vaccinated survivors. Significant levels of IgM and IgG were induced among vaccinated animals, although they did not correlate with immunity. A mixed IgG1/IgG2 subclass profile was associated with the subunit vaccine, compared to the predominant IgG2 profile seen in bacterin vaccinated hamsters. These findings suggest that LigB(131–645) is a vaccine candidate against leptospirosis with potential ramifications to public and veterinary health.

a b s t r a c tListeria monocytogenes is a foodborne bacterial pathogen of great concern to food industry. This is mainly due to its capacity to grow at low temperatures, its wide distribution in the environment and ability to adhere to various surfaces that come into contact with food. The aim of this study was to investigate the clonal relationship among L. monocytogenes isolates. Our purpose was to better understand the diversity of this pathogen in foods and food production chains in southern Rio Grande do Sul (Brazil). Forty four L. monocytogenes strains were characterized by serotyping and PFGE. Six different serotypes were found in the food and food environment (1/2a, 1/2b, 1/2c, 3a, 4b, 4e) and combination of macrorestriction patterns using AscI and ApaI, yielded 29 different pulsotypes. Strains with identical restriction patterns were isolated from foods of different sources and environments at different times. The presence of persistent strains of L. monocytogenes emphasizes the importance of cross-contamination in these food processing environments. It is likely that this occurs mainly due to ineffective cleaning and sanitization procedures, which allow for the survival and adaptation of these strains in the food processing environment, thereby causing persistence and contamination of final products.

Listeria monocytogenes is a ubiquitous food-borne pathogen, and its presence in food or production facilities highlights the importance of surveillance. Increased understanding of the surface exposed antigens on Listeria would provide potential diagnostic and therapeutic targets. In the present work, using mass spectrometry and genetic cloning, we show that fructose-1,6-bisphosphate aldolase (FBA) class II in Listeria species is the antigen target of the previously described mAb-3F8. Western and dot blot assays confirmed that the mAb-3F8 could distinguish all tested Listeria species from close-related bacteria. Localization studies indicated that FBA is present in every fraction of Listeria cells, including supernatant and the cell wall, setting Listeria spp. as one of the few bacteria described to have this protein on their cell surface. Epitope mapping using ORFeome display and a peptide membrane revealed a 14-amino acid peptide as the potential mAb-3F8 epitope. The target epitope in FBA allowed distinguishing Listeria spp. from closely-related bacteria, and was identified as part of the active site in the dimeric enzyme. However, its function in cell surface seems not to be host cell adhesion-related. Western and dot blot assays further demonstrated that mAb-3F8 together with anti-InlA mAb-2D12 could differentiate pathogenic from non-pathogenic Listeria isolated from artificially contaminated cheese. In summary, we report FBA as a novel immunogenic surface target useful for the detection of Listeria genus.

Staphylococcus aureus is a common causative agent of bovine mastitis in dairy cows and commonly associated with foodborne disease outbreaks. The aim of this study was to evaluate the presence of enterotoxin genes, agr typing, antimicrobial resistance, and genetic diversity of S. aureus isolated from milk of cows with mastitis in dairy farms from southern Brazil. Results showed that 7 (22.6%) of 31 S. aureus isolates were positive for enterotoxin genes. Specifically, the genes encoding for enterotoxins A ( n = 4), C ( n = 2), and B ( n = 1) were detected. Isolates belonging to the agr group III (10 of 31, 32.2%) and agr group I (7 of 31, 22.5%) were the most common. To our knowledge, this is the first report of both agr I and III in the same S. aureus isolate from milk of cows with bovine mastitis. The antimicrobial resistance test showed that 54% of the isolates were multiresistant to antimicrobial agents. The macrorestriction analysis produced 16 different major SmaI pulsed-field gel electrophoresis patterns, with up to two subpatterns. Moreover, the presence of some S. aureus clones in a distinct area was observed. Although this study characterized a limited number of S. aureus isolates, the presence of classical enterotoxin genes and resistance to multiple antimicrobial agents reinforces the importance of this microorganism to animal and human health. In addition, similar genetic profiles have been identified in distinct geographic areas, suggesting clonal dissemination of S. aureus in dairy herds from southern Brazil.

(GRAVESEN et al., 2000;UHITIL et al., 2004). L. monocytogenes é a principal espécie de Listeria envolvida em doenças em humanos (ROUCOURT; SEELIGER, 1985;FARBER;PETERKIN, 1991), entretanto, as outras espécies são importantes por apresentarem ecologia semelhante à deste patógeno, podendo ser consideradas indicadoras de sua presença (DELGADO et al., 1998;VITAS, AGUADO;GARCIA-JALON 2004).Um importante aspecto a ser considerado nas indústrias de alimentos é o fato de existirem cepas de L. monocytogenes persistentes, as quais são capazes de permanecer meses, ou até anos, no ambiente de processamento, podendo assim provocar contaminações recorrentes no produto final (MARKKULA et al., 2005). A dificuldade em eliminar esse microrganismo das indústrias é potencializada pelas condições de umidade, temperatura e presença de matéria orgânica nas plantas de processamento, que aliadas à habilidade do patógeno em produzir biofilmes, podem desencadear a colonização de superfícies de equipamentos e utensílios (UHITIL et al., 2004). AbstractListeria monocytogenes is a pathogenic bacterium which has become a huge challenge to the food industries, including the poultry industry, and to the health surveillance agencies. Although poultry production is in expansion in southern of Rio Grande do Sul, Brazil, there are not reports about this pathogen thus this study aimed at assessing the prevalence of L monocytogenes and its serotypes in the several segments of this productive chain. In the broilers flocks L. monocytogenes were isolated in 2.9% (1/35) from cloacal swabs samples. This microorganism was not isolated from broiler houses samples. In the abattoir, 11% of the samples presented L. monocytogenes contamination, and in the chilled chicken from retailers its prevalence was 33.3% (15/45). It was observed that 51.6% (16/31) from L. monocytogenes strains belonged to serotype 1/2b, 22.5% (7/31) to serotype 4e, 16,1% (5/31) to serotype 1/2a, 6,4% (2/31) to serotype 4b, and 3,2% (1/31) to serotype 1/2c. The spread of L. monocytogenes in the poultry production chain in southern Rio Grande do Sul and the presence of poultry serotypes in cases/outbreaks of listeriosis cause concern to public health. Keywords: Listeria monocytogenes; Listeria spp.; poultry establishments; slaughterhouse; chilled chicken. ResumoListeria monocytogenes é uma bactéria patogênica que se tornou um grande desafio para as indústrias de alimentos, entre elas a de frangos, assim como para os órgãos de vigilância sanitária. Apesar da produção de frangos estar em expansão na região sul do Rio Grande do Sul, não há relatos sobre esse patógeno, dessa forma, objetivou-se avaliar a prevalência de L. monocytogenes e de seus sorotipos nos diversos segmentos dessa cadeia produtiva. Nos aviários isolou-se L. monocytogenes em 2,9% (1/35) das amostras de swabs cloacais, não se isolando o microrganismo em amostras provenientes das camas de aviários. No abatedouro, 11,7% (15/128) das amostras apresentaram contaminação por L. monocytogenes e nos frangos resfriados procedentes do c...

RESUMOO leite possui constituintes de grande valor nutricional e sua produção e consumo têm crescido a cada ano mundialmente. Associado à sua importância econômica, este produto é constantemente alvo de fraudes e adulterações, as quais trazem como consequência grandes prejuízos à indústria e preocupação aos órgãos de saúde pública. Neste sentido, objetivamos analisar, de forma retrospectiva, as causas que determinaram o não recebimento do leite cru refrigerado em usina de beneficiamento sob Inspeção Federal, da região do Agreste Meridional de Pernambuco, durante o período que compreendem os meses de março a outubro de 2016, com base no arquivo de registros da empresa. Foram identificados 122 casos de não recebimento de leite cru refrigerado. Destes, a principal causa foi a adição de água (34,5%), seguida por acidez acima do limite estabelecido pela empresa, máximo 0,16 g de ácido lático/100 mL de leite (30,3%), e presença de resíduos de antibióticos no leite (26,2%). Desta forma, reforçou-se a importância do controle de qualidade e de identidade do leite realizado pela empresa, para evitar que um leite adulterado seja processado pela indústria e disponibilizado ao consumidor. Reforçou-se, também, a necessidade de aprimoramento da política leiteira, para fins de esclarecer, orientar e incentivar os produtores com relação a implementação das Boas Práticas Agropecuárias de produção do leite, incluindo a necessidade da realização de uma Ordenha Higiênica, do respeito do tempo de carência dos ABSTRACT Milk has constituents of great nutritional value and its production and consumption have grown every year worldwide. Associated with its economic importance, this product is constantly the target of fraud and adulteration, which causes as a consequence great damages to the industry and concern to the public health organs. In this sense, we aimed to analyze, retrospectively, the causes that determined the non-receipt of the refrigerated raw milk in a dairy industry with Brazilian Federal Inspection, in the region of meridional "Agreste" of Pernambuco (Brazil), during the period that comprise the months of March to October 2016, based on files of the industry records. In this period, 122 cases of non-receipt of refrigerated raw milk by the industry were identified. Of these, the main cause was water addition (34.5%), followed by milk with acidity above the limit established by the industry, maximum 0.16 g of lactic acid/100 mL of milk (30.3%), and presence of antibiotic residues in milk (26.2%). Thus, the importance of quality and identity control of the milk performed by the company was reinforced, to prevent the industry from processing adulterated milk that will be later made available to the consumer. The need to improve milk policy was also reinforced for the purpose of educating, guiding and encouraging producers regarding the implementation of Good Agricultural Practices for milk production, including the need for a Hygienic Milking, respect for antibiotic withdrawal period, when it is used used in animal treatment ...

Listeria monocytogenes is of notable concern to the food industry, due to its ubiquitous nature and ability to grow in adverse conditions. This study aimed to determine the genotypic profile of L. monocytogenes strains isolated from refrigerated chickens marketed in the southern part of Rio Grande do Sul, Brazil. The strains of L. monocytogenes isolated were characterized by serotyping and Pulsed Field Gel Electrophoresis (PFGE). Three different serotypes (1/2a, 1/2b and 4e) were evaluated by PFGE, and the macrorestriction patterns utilizing enzymes AscI and ApaI, revealed five different pulsotypes. The presence of such varied genotypic profiles demonstrates the prevalence of L. monocytogenes contamination of chicken processing environments, which combined with ineffective cleaning procedures, allowing the survival, adaptation and proliferation of these pathogens, not only in the processing environment, but also in local grocery stores.