Listeria innocua and serotypes of Listeria monocytogenes isolated from clinical cases in small ruminants in the northwest of Uruguay / Listeria innocua e serotipos do Listeria monocytogenes isoladas dos casos clínicos em pequenos ruminantes no noroeste do Uruguai

Listeriosis is an infectious disease caused by bacteria of the genus Listeria, the neurological form being more common in ruminants. There are many reports of listeriosis in small ruminants in the region that includes Brazil, Argentina and Uruguay. However, these diagnoses were mainly based on histological lesions in the central nervous system (CNS) without the isolation and characterization of the involved Listeria strains. The aim of this study was to report sheep and goats listeriosis cases from 2016 to 2021 in northwestern Uruguay. The diagnosis was made according to lesions observed at histopathology, plus Listeria isolation in CNS, identifying it at specie and serotype level. Nine animals (n=9) of three outbreaks and five sporadic cases of listeriosis were studied. Sheep was the species with more cases in relation to goats, and adults were the category most affected. Cases occurred in spring and less frequently in winter. All presented neurological clinical signs and the lesions in the CNS were consistent with suppurative meningoencephalitis and micro-abscesses in the brainstem. In eight of nine CNS samples, Listeria strains were isolated (seven L. monocytogenes and one L. innocua). All the L. monocytogenes isolates carried the inlA gene; serotyping showed that four strains belonged to serotype 1/2b, two isolates belonged to serotype 4b, and one to serotype 1/2a. Considering that listeriosis is a common disease in this region and the fact that isolates are scarcely recovered from small ruminants, it would be important to emphasize the need for Listeria isolation to better characterize the strains that affect animals. Not only to improve knowledge about the epidemiology of disease but also with the objective of developing serotype specific vaccines for animal use.

Listeriose uma doença bacteriana causada pelo gênero Listeria, a forma nervosa é a mais comum em ruminantes. No Brasil, Argentina e Uruguai há vários relatos de listeriose em pequenos ruminantes com diagnóstico baseado na histopatologia do sistema nervoso central (SNC), sem o isolamento e a caracterização do agente. O objetivo deste trabalho foi relatar uma série de casos diagnosticados em ovinos e caprinos no período 2016-2021 no noroeste do Uruguai. O diagnóstico foi feito basado nas lesões observadas na histopatologia, e caracterização das cepas de Listeria recuperadas do SNC quanto à espécie e sorotipo. Nove animais (n=9) do três surtos e cinco casos isolados de listeriose foram estudados. Os ovinos foram a espécie com o maior número de casos em relação aos caprinos, sendo os animais adultos a categoria mais afetada em ambas espécies. A doença ocorreu principalmente na primavera com alguns casos observados no inverno. Todos os casos apresentavam sinais clínicos nervosos e as lesões no SNC caracterizavam-se por meningoencefalite supurativa com presença de microabscessos no tronco encefálico. Em oito de nove amostras do SNC foram isoladas cepas de Listeria (sete L. monocytogenes e uma L. innocua). Todos os isolados de L. monocytogenes continham o gene inlA; a sorotipagem apresentou quatro cepas do serotipo 1/2b, duas cepas serotipo 4b e uma cepa 1/2a. Levando em consideração que nesta região a listeriose é uma doença frequente e que existem poucos isolados recuperados de casos clínicos em pequeño ruminantes, torna-se relevante o isolamento deste agente para caracterização das cepas que afetam os animais. Não só para melhorar o conhecimento sobre a epidemiologia da doença, mas também com o objetivo de desenvolver vacinas sorotipo-especificas para uso animal.

Activity of rosemary (Rosmarinus officinalis - Family: Lamiaceae) essential oil compared to peracetic acid in Listeria monocytogenes biofilms

The objective of this study was to evaluate the activity of Rosmarinus officinalis essential oil (EO) compared to peracetic acid (PA) regarding formation and elimination of Listeria monocytogenes biofilms on polystyrene surface. The minimum inhibitory concentration (MIC) was determined according to standard protocol. Isolates were inoculated according to MIC standards polystyrene plate wells, which were then incubated at 37°C/96 hours for evaluation of biofilm formation. Regarding the evaluation of biofilm elimination, the biofilms were treated under MIC for 10 minutes. The MIC obtained were 2.0 and 3.0 mg mL-1 for EO and 0,015% for PA. Therefore, the results showed a reduction in the formation of biofilm with the presence of EO and PA, EO being more efficient (p < 0.05). Both compounds had a good capacity of eliminating biofilms, however the EO reduced the biofilm formation when compared to PA, highlighting its potential as an antibacterial agent and antibiofilm.(AU)

Cultivo associado de Leuconostoc mesenteroides lb10. 4 e Lactococcus lactis l4a8: propriedades antimicrobianas e potencial aplicação / Associated culture of Leuconostoc mesenteroides lb10. 4 and Lactococcus lactis l4a8: antimicrobial properties and potential application / Cultivo asociado de Leuconostoc mesenteroides lb10. 4 y Lactococcus lactis l4a8: propiedades antimicrobianas y aplicación potencial

O interesse por produtos lácteos funcionais tem motivado o estudo e a prospecção de novas bactérias lácticas. Neste contexto o objetivo deste trabalho foi explorar a potencial associação de Leuconostoc mesenteroides LB10.4 e Lactococcus lactis L4A8 isolados de leite de búfala e identificar aplicações em matriz alimentar. Foram realizados testes de atividade antimicrobiana, influência das bacteriocinas e avaliação da eficiência das bactérias ácido lácticas (BAL) individualmente e associadas frente a espécie de Listeria monocytogenes ATCC 7644 aplicadas em caldo Tryptic Soy Broth e em matriz láctea. Na avaliação da atividade antimicrobiana, Leuconostoc mesenteroides LB 10.4 e Lactococcus lactis L4A8 foram capazes de inibir Staphylococcus aureus ATCC 25923 e Listeria monocytogenes ATCC 7644 com halos de inibição variando de 8 a 16 mm e 6 a 18 mm, respectivamente, pelos dois métodos testados. Na avaliação do efeito das bacteriocinas, os resultados demonstraram melhor controle inibitório dos patógenos pela nisina nas concentrações de 1% e 2%, com halos de inibição entre 14 a 24 mm. A avaliação da eficiência das BAL individualmente e associadas frente a espécie de Listeria monocytogenes ATCC 7644, demonstrou que os isolados em associação são capazes de inibir com mais efetividade a bactéria patogênica, sendo observada uma redução na contagem de L. monocytogenes de 2,67x107 UFC/g para 1,35x104 UFC/g após 240 horas, em matriz alimentar. As bactérias lácticas Leuconostoc mesenteroides LB10.4 e Lactococcus lactis L4A8 apresentaram características promissoras quanto ao seu potencial inibitório, não sendo inibidas pela pediocina. Destaca-se com esses resultados, a importância de estudar o leite de búfala como fonte de novos candidatos de bactérias lácticas autóctones para aplicação em alimentos.(AU)

The interest in functional dairy products has motivated the study and prospection of new lactic bacteria. In this context, the aim of this study was to explore the potential association of Leuconostoc mesenteroides LB10.4 and Lactococcus lactis L4A8 isolated from buffalo milk and to identify applications in food matrix. Tests of antimicrobial activity, influence of bacteriocins and evaluation of the efficiency of lactic acid bacteria (LAB) individually and associated against the species of Listeria monocytogenes ATCC 7644 applied in Tryptic Soy Broth and in milk matrix were performed. In the evaluation of antimicrobial activity, Leuconostoc mesenteroides LB 10.4 and Lactococcus lactis L4A8 were able to inhibit Staphylococcus aureus ATCC 25923 and Listeria monocytogenes ATCC 7644 with inhibition halos ranging from 8 to 16 mm and 6 to 18 mm, respectively, by the two methods tested. In evaluating the effect of bacteriocins, the results showed better inhibitory control of pathogens by nisin at concentrations of 1% and 2%, with inhibition halos between 14 and 24 mm. The evaluation of the efficiency of LAB individually and associated against the species of Listeria monocytogenes ATCC 7644, showed that the isolates in association are able to more effectively inhibit the pathogenic bacteria, with a reduction in the L. monocytogenes count of 2.67x107 CFU /g to 1.35x104 CFU/g after 240 hours, in food matrix. The lactic acid bacteria Leuconostoc mesenteroides LB10.4 and Lactococcus lactis L4A8 showed promising characteristics regarding their inhibitory potential, not being inhibited by pediocin. With these results, attract attention the importance of studying buffalo milk as a source of new candid ates of autochthonous lactic acid bacteria for application in food.(AU)

El interés por los productos lácteos funcionales ha motivado el estudio y prospección de nuevas bacterias ácido lácticas. En este contexto, el objetivo de este trabajo fue explorar la asociación potencial de Leuconostoc mesenteroides LB10.4 y Lactococcus lactis L4A8 aislados de leche de búfala e identificar aplicaciones en matriz alimentaria. Se realizaron pruebas de actividad antimicrobiana, influencia de bacteriocinas y evaluación de la eficiencia de bacterias ácido lácticas (BAL) individualmente y asociadas frente a las especies de Listeria monocytogenes ATCC 7644 aplicadas en caldo Tryptic Soy Broth y en matriz de leche. En la evaluación de la actividad antimicrobiana, Leuconostoc mesenteroides LB10.4 y Lactococcus lactis L4A8 fueron capaces de inhibir Staphylococcus aureus ATCC 25923 y Listeria monocytogenes ATCC 7644 con halos de inhibición de 8 a 16 mm y de 6 a 18 mm, respectivamente, por los dos métodos probados. Al evaluar el efecto de las bacteriocinas, los resultados mostraron un mejor control inhibitorio de patógenos por parte de la nisina a concentraciones de 1% y 2%, con halos de inhibición entre 14 y 24 mm. La evaluación de la eficiencia de las BAL de forma individual y asociada frente a la especie de Listeria monocytogenes ATCC 7644, mostró que los aislados en asociación son capaces de inhibir más eficazmente las bacterias patógenas, con una reducción del recuento de L. monocytogenes de 2,67x107 UFC/g a 1,35x104 UFC/g después de 240 horas, en matriz alimentaria. Las bacterias del ácido láctico Leuconostoc mesenteroides LB10.4 y Lactococcus lactis L4A8 mostraron características promisorias en cuanto a su potencial inhibidor, no siendo inhibidas por la pediocina. Con estos resultados, se destaca la importancia de estudiar la leche de búfala como fuente de nuevos candidatos de bacterias ácido lácticas autóctonas para su aplicación en alimentos.(AU)

In Vitro Antimicrobial Efficacy Assessment of Ethanolic and Aqueous Extracts of Cinnamon (Cinnamomum Verum) Bark against Selected Microbes

To combat pathogens and reduce the major public health problem of antibiotic residues in animal products, scientists are looking for natural antibiotic substitutes that are effective against drug-resistant pathogenic microbes and spoilage fungi. The antimicrobial activity of three Cinnamomum verum extracts prepared with three different solvents (absolute ethanol, 50% ethanol, and aqueous extracts) was determined against two Gram-positive bacteria (Staphylococcus aureus and Listeria monocytogenes) and two Gram-negative bacteria (Salmonella Typhimurium and Escherichia coli) as well as two fungal strains. The antimicrobial activities of various Cinnamomum verum extracts against selected microbes were evaluated using the disc diffusion test, minimum inhibitory concentrations (MIC), minimum bactericidal concentrations (MBC), minimum fungicidal concentrations (MFC), and the poisoned food technique. Cinnamomum verum bark (CVB) extracts inhibited and killed microbial growth to varying degrees. Our findings also revealed that extracts prepared with alcoholic solvents, particularly absolute ethanol-CVB extract, were more active compared with aqueous solvents, suggesting that the cinnamon plant is a promising natural antimicrobial agent for food preservation.(AU)

Comparison between immunofluorescence and immunohistochemistry for Listeria monocytogenes detection in formalin-fixed paraffin-embedded tissues / Comparação entre imunofluorescência e imuno-histoquímica para detecção de Listeria monocytogenes em tecidos fixados e parafinizados

Listeria monocytogenes is a bacterium that infect humans and animals and causes a zoonotic disease characterized by encephalitis, septicemia or abortion. In addition, listeriosis leads to significant economic losses due to animal death and sacrifice. This research compared the technique of immunofluorescence (IF) and immunohistochemistry (IHC) for the diagnosis of L. monocytogenes in formalin-fixed and paraffin-embedded (FFPE) tissues. A total of 30 tissue blocks from 15 animals with history and/or lesions compatible with listeriosis were selected. For both IHC and IF, the same diluted (1:200) polyclonal primary antibody was used against L. monocytogenes serotypes 1 and 4. For IHC, a polymer secondary antibody conjugated to peroxidase (HRP) was used. For IF, samples were incubated with a fluorescein-labeled anti-rabbit IgG secondary antibody. Each sample was classified according to the presence and percentage of immunolabeling area. From 30 samples, 10 were positive at least for one technique, whereas eight samples were positive for both IHC and IF with similar score. There was strong immunolabeling in tissue samples from bovines experimentally infected with L. monocytogenes ATCC 7644, as well as in nervous tissues from naturally infected ruminants. Additionally, IF did not show any difference in sensitivity when compared to IHC. Using processed biological materials for IF, instead of fresh tissues, is a quite unique technique, since there are few protocols described. Therefore, this study demonstrated that both techniques are efficient to detect L. monocytogenes in FFPE tissues.

Listeria monocytogenes é uma bactéria que infecta humanos e animais, podendo causar uma doença zoonótica caracterizada por encefalite, septicemia e abortos. Além disso, a listeriose resulta em perdas econômicas significativas pela morte e sacrifício de animais. O objetivo deste trabalho foi comparar a técnica de imunofluorescência (IF) e imuno-histoquímica (IHQ) para detecção de L. monocytogenes em tecidos fixados e parafinizados. Foram selecionados 30 blocos de tecidos de 15 animais com histórico e/ou lesões compatíveis com listeriose. Para ambas as técnicas, foi utilizado o mesmo anticorpo primário policlonal diluído (1:200) para detecção de L. monocytogenes sorotipos 1 e 4. Para a IHQ foi utilizado anticorpo secundário em polímero acoplado a peroxidase (HRP). Para a IF, as amostras foram incubadas com anticorpo secundário anti-IgG de coelho marcado com fluoresceína. Cada amostra foi classificada quanto à presença de imunomarcação e porcentagem de área positiva. Das 30 amostras, 10 foram positivas em pelo menos uma das técnicas, sendo oito amostras positivas em ambas IHQ e IF com o mesmo escore. Houve forte imunomarcação tanto em amostras de bovino experimentalmente infectado com L. monocytogenes ATCC 7644, como em amostras de tecido nervoso de ruminantes naturalmente infectados. Além disso, a IF não apresentou diferença na sensibilidade quando comparada com a IHQ. O uso de materiais biológicos processados para IF, ao invés de tecidos frescos, é algo inovador, uma vez que existem poucos protocolos descritos. Portanto, este estudo demonstrou que as duas técnicas foram eficientes para detectar L. monocytogenes em tecidos fixados em formol e parafinizados.

Influence of the food matrix on dual-species biofilm of Listeria monocytogenes and Pseudomonas fluorescens

In the food industry, the formation of biofilms results in serious microbial recontamination problem. This work aimed to study Listeria sp. obtained from sliced products and food handling surfaces, for the preparation of food of animal origin to be consumed cold. Listeria monocytogenes, Listeria innocua and Listeria seeligeri were detected. In the evaluation of antibiotic susceptibility, the isolates were sensitive to ampicillin and penicillin, which were the main antibiotics used in treatment. The isolates showed the ability to form biofilm in microplate, in stainless steel and polypropylene surfaces, with a variation of sessile cells between 4.29±0.23 and 7.03±0.01 log10 CFU cm-2 in TSBYE. This ability was also observed in food matrix composed of UHT whole milk in mono-species cultivation and in associated cultivation of L. monocytogenes with Pseudomonas fluorescens. The application of sanitizers peracetic acid and sodium hypochlorite revealed efficiency in the eradication of adhered cells and biofilms formed in stainless steel surfaces. Therefore, Listeria sp. showed to be persistent and able to form biofilm in mono-species cultivation or associated with P. fluorescens, under different conditions. Taking these aspects into account, the need for proper hygiene in the food production process is highlighted in order to avoid risks to the consumers health.(AU)

Listeriosis outbreak in sheep raised in feedlots in the Southern Region of Rio Grande do Sul state, Brazil

Background: A listeriosis outbreak in a sheep fattening feedlot in the Southern Region of Rio Grande do Sul State, Brazilis described. This disease is caused by Listeria monocytogenes and represents a risk to public health since it affects notonly ruminants but also humans. This agent is widely spread in the environment, such as in the soil and water. It is alsofound in decaying vegetable matter and the feces and fluids of domestic animals. The aim of this study was to describe alisteriosis outbreak in sheep raised in feedlots, its epidemiology, and to establish the importance of this disease in this typeof sheep management system, evaluate the possible sources of infection, and suggest ways to control it.Cases: Sheep were kept in a 2-sector shed, one with east solar orientation and the other with west solar orientation, thelatter with free access to domestic birds. Sheep were fed silage and concentrate. Seven sheep were affected, 5 died and 2recovered. Clinically, the sheep displayed loss of balance, excessive drooling, and tremors; one exhibited circling, headdeviation, apathy, nystagmus, lateral recumbency, paddling, and labored breathing. At necropsy, macroscopic lesions werenot found, and histologically several micro-abscesses and perivascular cuffs with lymphocytes, macrophages, and neutrophils were present in the brain stem. Listeria monocytogenes suspected colonies were observed in the microbiologicalculture, and the bacteria was identified by biochemical analysis. The immunohistochemistry test in brain stem sectionswas positive for the antibody BD DifcoTM Listeria O Antiserum Poly Serotypes 1 and 4.Discussion: A listeriosis outbreak in a feedlot sheep was confirmed through epidemiological findings, histological lesions,bacterial culture, and immunohistochemistry analysis. This infection is frequent...

Listeriosis outbreak in sheep raised in feedlots in the Southern Region of Rio Grande do Sul state, Brazil

Background: A listeriosis outbreak in a sheep fattening feedlot in the Southern Region of Rio Grande do Sul State, Brazilis described. This disease is caused by Listeria monocytogenes and represents a risk to public health since it affects notonly ruminants but also humans. This agent is widely spread in the environment, such as in the soil and water. It is alsofound in decaying vegetable matter and the feces and fluids of domestic animals. The aim of this study was to describe alisteriosis outbreak in sheep raised in feedlots, its epidemiology, and to establish the importance of this disease in this typeof sheep management system, evaluate the possible sources of infection, and suggest ways to control it.Cases: Sheep were kept in a 2-sector shed, one with east solar orientation and the other with west solar orientation, thelatter with free access to domestic birds. Sheep were fed silage and concentrate. Seven sheep were affected, 5 died and 2recovered. Clinically, the sheep displayed loss of balance, excessive drooling, and tremors; one exhibited circling, headdeviation, apathy, nystagmus, lateral recumbency, paddling, and labored breathing. At necropsy, macroscopic lesions werenot found, and histologically several micro-abscesses and perivascular cuffs with lymphocytes, macrophages, and neutrophils were present in the brain stem. Listeria monocytogenes suspected colonies were observed in the microbiologicalculture, and the bacteria was identified by biochemical analysis. The immunohistochemistry test in brain stem sectionswas positive for the antibody BD DifcoTM Listeria O Antiserum Poly Serotypes 1 and 4.Discussion: A listeriosis outbreak in a feedlot sheep was confirmed through epidemiological findings, histological lesions,bacterial culture, and immunohistochemistry analysis. This infection is frequent...(AU)

Pathogenic bacteria load and safety of retail marine fish / Carga de bactérias patogênicas e segurança de peixes marinhos de varejo

This study was conducted to determine the pathogenic bacteria load of 14 species of marine fish obtained from two suppliers (in Bitlis city, Turkey), which provide fish for fish markets, and to reveal the safety of the marine fish in terms of microbiological quality. The counts of total mesophilic aerobic bacteria (TMAB), Staphylococcus aureus, and Escherichia coli, the presence of Salmonella spp. and Listeria monocytogenes were determined in anchovy, horse mackerel, salmon, red mullet, gilthead seabream, bonito, pilchard, common sole, sand smelt, axillary seabream, seabass, Mediterranean horse mackerel, bluefish, and garpike. It was determined that common sole, axillary seabream, seabass, bluefish and Mediterranean horse mackerel obtained from both suppliers were unacceptable in terms of the counts of TMAB. Twenty-four samples exceeded the critical limit of S. aureus and all the samples were unacceptable according to the critical limit of E. coli. While L. monocytogenes was isolated from 50.0% of the samples, Salmonella spp. was isolated from 39.3% of the samples. These results showed that the pathogenic bacteria load of the analyzed marine fish was quite high and they were unsafe in terms of microbiological quality.

Este estudo foi realizado para determinar a carga de bactérias patogênicas de 14 espécies de peixes marinhos obtidos de dois fornecedores (na cidade de Bitlis, Turquia), que fornecem peixes para mercados de peixes, e para revelar a segurança do peixe marinho em termos de qualidade microbiológica. As contagens de bactérias aeróbias mesófilas totais (TMAB), Staphylococcus aureus e Escherichia coli, a presença de Salmonella spp. e Listeria monocytogenes foram determinados em anchova, carapau, salmão, salmonete, dourada, bonito, sardinha, linguado, cheirado, dourada-axilar, robalo, carapau-do-mediterrâneo, anchova e garpike. Foi determinado que o linguado, o dourada-axilar, o robalo, a anchova e o carapau-do-mediterrâneo obtidos de ambos os fornecedores eram inaceitáveis nas contagens do TMAB. Vinte e quatro amostras excederam o limite crítico de S. aureus, e todas as amostras foram inaceitáveis de acordo com o limite crítico de E. coli. Enquanto L. monocytogenes foi isolada em 50.0% das amostras, Salmonella spp. foi isolado de 39.3% das amostras. Esses resultados mostraram que a carga de bactérias patogênicas dos peixes marinhos analisados era bastante alta e eles eram inseguros em termos de qualidade microbiológica.

Potentially pathogenic Staphylococcus aureus and Listeria spp. in Brazilian unpasteurized cheese production / Staphylococcus aureus e Listeria spp. potencialmente patogênicos na produção de queijos não pasteurizados

This study aimed to identify potentially pathogenic microorganisms (Listeria innocua, L. seeligeri, L. ivanovii, L. monocytogenes, Staphylococcus aureus, and several virulence genes) in unpasteurized cheese production in the northeastern region of the state of São Paulo, Brazil. Listeria species were detected in 68 (64.14%) out of 106 samples of bovine feces, swabs from milkers' and cheese handlers' hands, milking buckets, raw milk, whey, water, cheese processing surface,s and utensils. All the samples collected at one farm were contaminated with Listeria spp. L. innocua, L. seeligeri, L. ivanovii, or L. monocytogenes were not detected in the samples collected in this study. A set of 391 Staphylococcus spp. isolates were obtained in these samples, from which 60 (15.31%) were identified as S. aureus using PCR (Polymerase Chain Reaction). S. aureus carrying virulence genes (eta, hlg, seg, seh, sei) were detected in milk, in swabs from cheese handler's hands, whey, milk, sieves, buckets, and cheese. The hlg gene (encodes gamma hemolysin) was detected in all the S. aureus isolates. These findings show that poor hygienic practice is associated with a higher risk of pathogenic bacteria in milk or cheese, providing useful information for public health authorities to increase food safety surveillance and prevent the dissemination of pathogens.

O objetivo desse estudo foi identificar microrganismos potencialmente patogênicos (Listeria innocua, L. seeligeri, L. ivanovii, L. monocytogenes, Staphylococcus aureus e diversos genes de virulência) na produção de queijos de leite cru na região noroeste do Estado de São Paulo, Brasil. Listeria foram detectadas em 68 (64,14%) das 106 amostras obtidas de fezes bovinas, suabes das mãos de ordenhadores e queijeiros, baldes, leite cru, soro, água, superfícies e utensílios da produção de queijos. Todas as amostras coletadas em uma fazenda estavam contaminadas com Listeria spp. L. innocua, L. seeligeri, L. ivanovii, e L. monocytogenes não foram detectadas nas amostras coletadas nesse estudo. Um conjunto de 391 isolados de Staphylococcus spp. foram obtidos das amostras, e desses 60 (15,31%) foram identificados como S. aureus pela PCR (Polymerase Chain Reaction). S. aureus contendo genes de virulência (eta, hlg, seg, seh, sei) foram detectados em leite, mãos dos ordenhadores, soro, utensílios e queijos. O gene hlg (gama-hemolisina)foi detectado em todos os isolados de S. aureus.Esses resultados demonstram que práticas inadequadas de higiene estão associadas com um maior risco da presença de bactérias patogênicas no leite e queijos crus, fornecendo informações para as autoridades de saúde pública para incrementarem a vigilância e prevenirem a disseminação de patógenos.

Growth kinetics of Salmonella Typhimurium and Listeria monocytogenes in buffalo milk under different processing and storage conditions / Cinética de crescimento de Salmonella Typhimurium e Listeria monocytogenes em leite bubalino sob diferentes condições de processamento e armazenamento

Buffalo milk is rich in nutrients and can serve as a substrate for the proliferation of microorganisms. Thus, the objective of the present study was to evaluate the growth kinetics of Salmonella Typhimurium and Listeria monocytogenes in buffalo milk under different processing and storage conditions. Samples of raw and pasteurized milk were inoculated with 1 CFU of each bacterium, separately and together, per 25 mL. After contamination, samples were stored at 8 °C or 37 °C, and bacterial counts were performed at 24, 48, and 168 h. In addition, the accompanying microbiota growth, pH, and the effect of these variables on the growth kinetics of microorganisms were monitored. The pathogens tested were able to proliferate under most conditions tested, reaching high titers throughout the experimental period. At 37 °C, there was a decrease in pH and an increase in the accompanying microbiota that interfered with the microbial growth curve. It was also observed that pasteurized milk subjected to 8 °C provided better conditions for the multiplication of bacteria. Therefore, it was concluded that care throughout the production chain, storage, and commercialization of milk must be adopted to guarantee the microbiological safety of this food.

O leite bubalino é rico em nutrientes e pode servir de substrato para a proliferação de micro-organismos. Assim, o objetivo do presente estudo foi avaliar a cinética de crescimento de Salmonella Typhimurium e Listeria monocytogenes em leite bubalino, em diferentes condições de processamento e armazenamento. Para isso, utilizaram-se amostras de leite cru e pasteurizado, que foram inoculadas com 1 UFC/25 mL de cada bactéria separadamente e em conjunto. Após a contaminação, as amostras foram armazenadas nas temperaturas de 8 ºC e 37 ºC e realizadas contagens bacterianas em 24, 48 e 168h. Além disso, foi acompanhado o crescimento da microbiota acompanhante, o pH e o efeito dessas variáveis sobre a cinética de crescimento dos micro-organismos. Os patógenos testados conseguiram se proliferar na maioria das condições testadas, atingindo altos títulos durante todo o período experimental. Na temperatura de 37 ºC, houve uma diminuição do pH e um aumento da microbiota acompanhante, o que interferiu na curva de crescimento microbiana. Observou-se também que o leite pasteurizado e submetido a 8 ºC possibilitou melhores condições para a multiplicação das bactérias. Sendo assim, concluiu-se que cuidados durante toda a cadeia de produção, armazenamento e comercialização do leite devem ser adotados para garantir a segurança microbiológica desse alimento.

Growth kinetics of Salmonella Typhimurium and Listeria monocytogenes in buffalo milk under different processing and storage conditions / Cinética de crescimento de Salmonella Typhimurium e Listeria monocytogenes em leite bubalino sob diferentes condições de processamento e armazenamento

Buffalo milk is rich in nutrients and can serve as a substrate for the proliferation of microorganisms. Thus, the objective of the present study was to evaluate the growth kinetics of Salmonella Typhimurium and Listeria monocytogenes in buffalo milk under different processing and storage conditions. Samples of raw and pasteurized milk were inoculated with 1 CFU of each bacterium, separately and together, per 25 mL. After contamination, samples were stored at 8 °C or 37 °C, and bacterial counts were performed at 24, 48, and 168 h. In addition, the accompanying microbiota growth, pH, and the effect of these variables on the growth kinetics of microorganisms were monitored. The pathogens tested were able to proliferate under most conditions tested, reaching high titers throughout the experimental period. At 37 °C, there was a decrease in pH and an increase in the accompanying microbiota that interfered with the microbial growth curve. It was also observed that pasteurized milk subjected to 8 °C provided better conditions for the multiplication of bacteria. Therefore, it was concluded that care throughout the production chain, storage, and commercialization of milk must be adopted to guarantee the microbiological safety of this food.(AU)

O leite bubalino é rico em nutrientes e pode servir de substrato para a proliferação de micro-organismos. Assim, o objetivo do presente estudo foi avaliar a cinética de crescimento de Salmonella Typhimurium e Listeria monocytogenes em leite bubalino, em diferentes condições de processamento e armazenamento. Para isso, utilizaram-se amostras de leite cru e pasteurizado, que foram inoculadas com 1 UFC/25 mL de cada bactéria separadamente e em conjunto. Após a contaminação, as amostras foram armazenadas nas temperaturas de 8 ºC e 37 ºC e realizadas contagens bacterianas em 24, 48 e 168h. Além disso, foi acompanhado o crescimento da microbiota acompanhante, o pH e o efeito dessas variáveis sobre a cinética de crescimento dos micro-organismos. Os patógenos testados conseguiram se proliferar na maioria das condições testadas, atingindo altos títulos durante todo o período experimental. Na temperatura de 37 ºC, houve uma diminuição do pH e um aumento da microbiota acompanhante, o que interferiu na curva de crescimento microbiana. Observou-se também que o leite pasteurizado e submetido a 8 ºC possibilitou melhores condições para a multiplicação das bactérias. Sendo assim, concluiu-se que cuidados durante toda a cadeia de produção, armazenamento e comercialização do leite devem ser adotados para garantir a segurança microbiológica desse alimento.(AU)

Principais aspectos de listeria monocytogenes e sua importância para a saúde pública / Main aspects of l. Monocytogenes and its importance to public health

Esta revisão tem como objetivo descrever os principais aspectos relacionados a Listeria monocytogenes e sua ocorrência nos alimentos. Alimentos contaminados com L. monocytogenes representam importante risco para o desenvolvimento das doenças veiculadas por alimentos (DVA). Listeriose é uma doença grave para grupos de risco, como idosos, mulheres grávidas, recém-nascidos e pacientes imunocomprometidos, com taxas de letalidade que podem ultrapassar 80%. É um patógeno amplamente distribuído na natureza, pode ser isolado de diversos produtos de origem animal e vegetal, como carnes de frango, bovinos, suínos, embutidos, leite e derivados e hortaliças. Além disso, possui inúmeros fatores de virulência, que permitem que escape do sistema imune e mantenha a infecção. É um microrganismo capaz de crescer em temperaturas de refrigeração e formar biofilme, sendo esses fatores de risco quando associados às más práticas de manejo e controle da cadeia produtiva dos alimentos, já que estas características propiciam a contaminação cruzada. Como medidas de controle, faz-se necessário implementar métodos que assegurem as boas condições de manipulação dos alimentos na indústria, no varejo e nas residências. Muitas práticas previstas na legislação podem ser empregadas para controlar contaminação nos alimentos, como as Boas Práticas de Fabricação (BPF), os Procedimentos Padrão de Higiene Operacional (PPHO) e o sistema de Análise de Perigos e Pontos Críticos de Controle (APPCC). Porém, a falta de fiscalização pelos órgãos competentes pode ser um fator de incentivo para a não implementação destas práticas, o que pode comprometer a qualidade microbiológica dos alimentos e gerar riscos à saúde pública.

This review aims to list the main aspects of Listeria monocytogenes and its occurrence in foods. Food contaminated with L. monocytogenes poses an important risk for the occurrence of foodborne illnesses. Listeriosis is a serious disease to risk groups, such as the elderly, pregnant women, newborns and immunocompromised patients, with mortality rates that can exceed 80%. It is a widely distributed pathogen in the environment and can be isolated from various animal and greens, such as chicken, beef, pork, sausages, dairy products and vegetables. In addition, the pathogen has numerous of virulence factors, that allows the microorganism to dodge the immune system and continue the infection. It is a microorganism capable of growing at refrigeration temperatures and forming biofilm, which is a risk factor when combined with poor management and control practices in the food production chain, as these features can lead to cross contamination. As control measures, it is necessary to implement methods that ensure good food handling conditions in industry, retail and households. Many practices provided in the legislation can be used to control food contamination, such as Good Manufacturing Practices (GMP), Standard Operating Hygiene Procedures (SOHP) and the Hazard Analysis and Critical Control Points (HACCP) system; however, the lack of inspection by competent bodies can be an encouragement factor for the non-implementation of these practices, which would be able to compromise the microbiological quality of the food and creates a threat to public health.

Principais aspectos de listeria monocytogenes e sua importância para a saúde pública / Main aspects of l. Monocytogenes and its importance to public health

Esta revisão tem como objetivo descrever os principais aspectos relacionados a Listeria monocytogenes e sua ocorrência nos alimentos. Alimentos contaminados com L. monocytogenes representam importante risco para o desenvolvimento das doenças veiculadas por alimentos (DVA). Listeriose é uma doença grave para grupos de risco, como idosos, mulheres grávidas, recém-nascidos e pacientes imunocomprometidos, com taxas de letalidade que podem ultrapassar 80%. É um patógeno amplamente distribuído na natureza, pode ser isolado de diversos produtos de origem animal e vegetal, como carnes de frango, bovinos, suínos, embutidos, leite e derivados e hortaliças. Além disso, possui inúmeros fatores de virulência, que permitem que escape do sistema imune e mantenha a infecção. É um microrganismo capaz de crescer em temperaturas de refrigeração e formar biofilme, sendo esses fatores de risco quando associados às más práticas de manejo e controle da cadeia produtiva dos alimentos, já que estas características propiciam a contaminação cruzada. Como medidas de controle, faz-se necessário implementar métodos que assegurem as boas condições de manipulação dos alimentos na indústria, no varejo e nas residências. Muitas práticas previstas na legislação podem ser empregadas para controlar contaminação nos alimentos, como as Boas Práticas de Fabricação (BPF), os Procedimentos Padrão de Higiene Operacional (PPHO) e o sistema de Análise de Perigos e Pontos Críticos de Controle (APPCC). Porém, a falta de fiscalização pelos órgãos competentes pode ser um fator de incentivo para a não implementação destas práticas, o que pode comprometer a qualidade microbiológica dos alimentos e gerar riscos à saúde pública.(AU)

This review aims to list the main aspects of Listeria monocytogenes and its occurrence in foods. Food contaminated with L. monocytogenes poses an important risk for the occurrence of foodborne illnesses. Listeriosis is a serious disease to risk groups, such as the elderly, pregnant women, newborns and immunocompromised patients, with mortality rates that can exceed 80%. It is a widely distributed pathogen in the environment and can be isolated from various animal and greens, such as chicken, beef, pork, sausages, dairy products and vegetables. In addition, the pathogen has numerous of virulence factors, that allows the microorganism to dodge the immune system and continue the infection. It is a microorganism capable of growing at refrigeration temperatures and forming biofilm, which is a risk factor when combined with poor management and control practices in the food production chain, as these features can lead to cross contamination. As control measures, it is necessary to implement methods that ensure good food handling conditions in industry, retail and households. Many practices provided in the legislation can be used to control food contamination, such as Good Manufacturing Practices (GMP), Standard Operating Hygiene Procedures (SOHP) and the Hazard Analysis and Critical Control Points (HACCP) system; however, the lack of inspection by competent bodies can be an encouragement factor for the non-implementation of these practices, which would be able to compromise the microbiological quality of the food and creates a threat to public health.(AU)

Chemical characterization and antimicrobial activity of Campomanesia aurea against three strains of Listeria monocytogenes / Caracterização química e atividade antimicrobiana de Campomanesia aurea contra três cepas de Listeria monocytogenes

The essential oil (EO) composition of leaves of Campomanesia aurea was analyzed by GC-MS. The plant was collected in April (EOA) and October (EOO) in São Francisco de Assis/RS. The essential oils were obtained by hydrodistillation in a modified Clevenger apparatus. The yields were 4.44% in April, and 6.15%, in October. Thirty-one compounds were identified in EOA, accounting for 96.87% of the total, and twenty-eight compounds were identified in EOO, accounting for 99.46% of the total. For EOA, the major identified monoterpene was p-cymene (8.33%) and the major identified sesquiterpene was alpha-cadinol (10.72%), while regarding EOO the major identified monoterpene was repeatedly Terpinolene (3.43%), whereas the major identified sesquiterpene was alpha-cadinol (12.79%). The antibacterial activity of the essential oil was evaluated against the three Listeria monocytogenes from the American Type Culture Collection (strains ATCC 7644, 19114 and 13932). The essential oil showed a MIC of 10 mg/mL against the strains ATCC 7644 and 19114, with bacteriostatic effect of 20 mg/mL and a MIC of 20 mg/mL for ATCC 13932. Regarding the antibiofilm activity, o EOO showed the best results with an inhibition of 90% in the sessile growth with an applied concentration of 4.0 mg/mL.(AU)

O óleo essencial (EO) das folhas de Campomanesia aurea foi analisado por CG-EM. O A planta foi coletada em abril (OEA) e outubro (OEO) em São Francisco de Assis/RS. Os óleos essenciais foram obtidos por hidrodestilação em aparelho Clevenger modificado. Os rendimentos foram de 4,44% em abril e 6,15% em outubro. Trinta e um compostos foram identificados no EOA, representando 96,87% do total, e vinte e oito compostos foram identificados no EOO, representando 99,46% do total. Para EOA, o principal monoterpeno identificado foi o p-cimeno (8,33%) e o principal sesquiterpeno identificado foi o alfa-candinol (10,72%), enquanto o EOO o maior monoterpeno identificado foi repetidamente Terpinolene (3,43%), enquanto o sesquiterpeno principal identificado foi alfa-cadinol (12,79%). A atividade antibacteriana do óleo essencial foi avaliada contra as três cepas de Listeria monocytogenes obtidas a partir da American Type Culture Collection (isolados ATCC 7644, 19114 and 13932). O óleo essencial apresentou uma CIM de 10 mg/mL contra as cepas ATCC 7644. e 19114, com efeito bacteriostático de 20 mg/mL e MIC de 20 mg/mL para ATCC 13932. Quanto à atividade antibiofilme, o EOO apresentou os melhores resultados com uma inibição de 90% no crescimento séssil com uma concentração aplicada de 4,0 mg/mL.(AU)

Standardization of a rapid quadruplex PCR method for the simultaneous detection of bovine, buffalo, Salmonella spp, and Listeria monocytogenes DNA in milk / [Padronização de um método rápido de PCR quadriplex para a detecção simultânea de DNA de bovino, bubalino, Salmonella spp. e Listeria monocytogenes em leite]

The objective of the present study was to Standardize a Polymerase Chain Reaction (PCR) protocol for the authentication of bovine and buffalo milk, and to detect the presence of Salmonella spp. and Listeria monocytogenes. For this, the target DNA was extracted, mixed, and subjected to a PCR assay. Milk samples were defrauded and experimentally contaminated with microorganisms to assess the detection of target DNA at different times of cultivation, bacterial titers, and concentration of genetic material. In addition, the protocol was tested with DNA extracted directly from food, without a pre-enrichment step. The proposed quadruplex PCR showed good accuracy in identifying target DNA sequences. It was possible to simultaneously identify all DNA sequences at the time of inoculation (0h), when the samples were contaminated with 2 CFU/250mL and with 6h of culture when the initial inoculum was 1 CFU/250mL. It was also possible to directly detect DNA sequences from the food when it was inoculated with 3 CFU/mL bacteria. Thus, the proposed methodology showed satisfactory performance, optimization of the analysis time, and a potential for the detection of microorganisms at low titers, which can be used for the detection of fraud and contamination.

O objetivo do presente estudo foi padronizar um protocolo de reação em cadeia da polimerase (PCR) para a autenticação de leite bovino e bubalino e a detecção da presença de Salmonella spp. e Listeria monocytogenes. Para isso, o DNA-alvo foi extraído, misturado e submetido ao ensaio de PCR. Amostras de leite foram fraudadas e contaminadas experimentalmente com os micro-organismos, para se avaliar a detecção do DNA-alvo em diferentes tempos de cultivo, os títulos bacterianos e a concentração de material genético. Além disso, o protocolo foi testado com DNA extraído diretamente do alimento, sem a etapa de pré-enriquecimento. A PCR quadriplex proposta mostrou boa precisão na identificação de sequências de DNA-alvo. Foi possível identificar simultaneamente todas as sequências de DNA no momento da inoculação (0h), quando as amostras estavam contaminadas com 2 UFC/250mL, e com seis horas de cultura, quando o inóculo inicial foi de 1 UFC/250mL. Também foi possível detectar diretamente as sequências de DNA do alimento quando este foi inoculado com 3 UFC/mL de bactérias. Dessa forma, a metodologia proposta apresentou desempenho satisfatório, otimização do tempo de análise e potencial para detecção de micro-organismos em baixos títulos, podendo ser utilizada para detecção de fraude e contaminação.

Growth kinetics of Salmonella Typhimurium and Listeria monocytogenes in buffalo milk under different processing and storage conditions / Cinética de crescimento de Salmonella Typhimurium e Listeria monocytogenes em leite bubalino sob diferentes condições de processamento e armazenamento

ABSTRACT: Buffalo milk is rich in nutrients and can serve as a substrate for the proliferation of microorganisms. Thus, the objective of the present study was to evaluate the growth kinetics of Salmonella Typhimurium and Listeria monocytogenes in buffalo milk under different processing and storage conditions. Samples of raw and pasteurized milk were inoculated with 1 CFU of each bacterium, separately and together, per 25 mL. After contamination, samples were stored at 8 °C or 37 °C, and bacterial counts were performed at 24, 48, and 168 h. In addition, the accompanying microbiota growth, pH, and the effect of these variables on the growth kinetics of microorganisms were monitored. The pathogens tested were able to proliferate under most conditions tested, reaching high titers throughout the experimental period. At 37 °C, there was a decrease in pH and an increase in the accompanying microbiota that interfered with the microbial growth curve. It was also observed that pasteurized milk subjected to 8 °C provided better conditions for the multiplication of bacteria. Therefore, it was concluded that care throughout the production chain, storage, and commercialization of milk must be adopted to guarantee the microbiological safety of this food.

RESUMO: O leite bubalino é rico em nutrientes e pode servir de substrato para a proliferação de micro-organismos. Assim, o objetivo do presente estudo foi avaliar a cinética de crescimento de Salmonella Typhimurium e Listeria monocytogenes em leite bubalino, em diferentes condições de processamento e armazenamento. Para isso, utilizaram-se amostras de leite cru e pasteurizado, que foram inoculadas com 1 UFC/25 mL de cada bactéria separadamente e em conjunto. Após a contaminação, as amostras foram armazenadas nas temperaturas de 8 ºC e 37 ºC e realizadas contagens bacterianas em 24, 48 e 168h. Além disso, foi acompanhado o crescimento da microbiota acompanhante, o pH e o efeito dessas variáveis sobre a cinética de crescimento dos micro-organismos. Os patógenos testados conseguiram se proliferar na maioria das condições testadas, atingindo altos títulos durante todo o período experimental. Na temperatura de 37 ºC, houve uma diminuição do pH e um aumento da microbiota acompanhante, o que interferiu na curva de crescimento microbiana. Observou-se também que o leite pasteurizado e submetido a 8 ºC possibilitou melhores condições para a multiplicação das bactérias. Sendo assim, concluiu-se que cuidados durante toda a cadeia de produção, armazenamento e comercialização do leite devem ser adotados para garantir a segurança microbiológica desse alimento.

Lactic acid bacteria against Listeria monocytogenes

Listeria monocytogenes is a pathogenic bacterium that can contaminate food and cause public health problems due its ability to form biofilms and resistance to sanitizers, it is responsible for sanitary and economic losses in food producing establishments. The difficulties in controlling biofilms and increasing resistance to traditional antibacterial agents is motivating studies of alternative potential biological agents for the control of pathogenic biofilms, among which lactic acid bacteria (LABs) are included. The objective of this work was to evaluate the activity of LABs against Listeria monocytogenes biofilm formation on polystyrene plates, a surface commonly used in the food industry. Lyophilized commercial strains of Bifidobacterium animalis, Lactobacillus fermentum, Lactobacillus plantarum, Lactobacillus salivaris and Lactobacillus acidophilus were used. The strain of Listeria monocytogenes (L4) was isolated from polystyrene mats from a poultry slaughterhouse cutting room and demonstrated the ability to attach to microplates and resistance to sanitizers (sodium hypochlorite and hydrogen peroxide) at all times, temperatures and tested surfaces. The antimicrobial activity of LABs was evaluated by the agar diffusion method. The LABs that presented action on Listeria monocytogenes were selected for the inhibition and/or removal of biofilms in microplates, and all experiments were carried out in triplicate. Only Bifidobacterium animalis and Lactobacillus plantarum demonstrated action against Listeria monocytogenes in the agar diffusion assays and were selected for inhibition and competition assays. Furthermore, competition of LABs against Listeria monocytogenes adhesion was evaluated. There was no significant difference between LABs and L. monocytogenes, alone or in combination, at temperatures of 30ºC and 37ºC in the Listeria monocytogenes inhibition assays on polystyrene surface. The lactic acid bacteria evaluated did not demonstrate inhibition of L. monocytogenes adhesin testes with optical density visualization, however, it was possible to identify a reduction in L. monocytogenes counts with the application of Bifidobacterium animals and Lactobacillus plantarum in the testes of competition against biofilm formation. In competition tests Bifidobacterium animalis and Lactobacillus plantarum have an injunction in Listeria monocytogenes, indicating that these lactic acid bacteria can retard Listeria biofilm formation on polystyrene surfaces and thus help control the pathogen in the food industry. A potential mechanism to control biofilm adhesion and formation of pathogens for nutrients and fixation on surfaces, multiplication factors and surfaces are a challenge in controlling biofilms of pathogenic microorganisms, alternative measures to traditional methods for inactivating pathogens and biofilm formers bacteria are necessary. In this sense, lactic acid bacteria generate high levels of bacteriocin and are effective in inhibiting the biofilm of pathogenic bacteria, however, our study did not reveal this. We verified that Bifidobacterium animalis and Lactobacillus plantarum have an inhibitory action on Listeria monocytogenes, indicating that these lactic acid bacteria can be used to delay the formation of biofilms by Listeria on polystyrene surfaces, helping to control this pathogen in food industry.(AU)

Análise microbiológica de fatiadores de frios como ferramenta para capacitação em boas práticas de higiene de equipamentos para manipuladores de alimentos / Microbiological analysis of deli slicer as a tool for training good hygiene practices in equipments for food handlers

O objetivo deste estudo foi avaliar a condição microbiológica de fatiadores de frios a fim de subsidiar ações educativas em boas práticas de higiene de equipamentos para manipuladores de alimentos. O estudo ocorreu nos setores de panificação de dois supermercados de Piraquara, Paraná, por meio da quantificação microbiológica de microrganismos aeróbios mesófilos (Contagem Padrão em Placas - CPP), coliformes totais e pesquisa de Listeria monocytogenes. Foram realizadas três coletas com intervalos de quinze dias e, antes da última, foi realizada uma ação educativa baseando-se na metodologia da problematização sobre higienização de equipamentos. Apesar de observada redução bacteriana, constatada por meio da CPP, os resultados mantiveram-seacima dos limites preconizados. Não houve detecção de coliformes totais e na pesquisa de Listeria monocytogenes. As análises microbiológicas foram importantes para a avaliação da higienização dos fatiadores, subsidiando práticas educativas eficazes na consolidação de aprendizado.

The objective of this study was to evaluate microbiological of slicers to support educative activities to food handlers on good hygienic practices for equipment. The study occurred in the bakery of two supermarkets in Piraquara, Paraná, through the microbiological couting of aerobic mesophilic microorganisms (Standard Plate Count - SPC), total coliforms and Listeria monocytogenes research. Three collections were made with a 15-day interval and, before the last one, a educative activity was made based in problematization methodology about equipment hygienization. Despite the reduction in bacterial counting, verified by the CPP, the results remained above the recommended limits. There was no detection of total coliforms and in the investigation of Listeria monocytogenes. The microbiological analyses were important for the evaluation of the hygiene of the slicers, supporting effective educational practices in the learning consolidation.

Análise microbiológica de fatiadores de frios como ferramenta para capacitação em boas práticas de higiene de equipamentos para manipuladores de alimentos / Microbiological analysis of deli slicer as a tool for training good hygiene practices in equipments for food handlers

O objetivo deste estudo foi avaliar a condição microbiológica de fatiadores de frios a fim de subsidiar ações educativas em boas práticas de higiene de equipamentos para manipuladores de alimentos. O estudo ocorreu nos setores de panificação de dois supermercados de Piraquara, Paraná, por meio da quantificação microbiológica de microrganismos aeróbios mesófilos (Contagem Padrão em Placas - CPP), coliformes totais e pesquisa de Listeria monocytogenes. Foram realizadas três coletas com intervalos de quinze dias e, antes da última, foi realizada uma ação educativa baseando-se na metodologia da problematização sobre higienização de equipamentos. Apesar de observada redução bacteriana, constatada por meio da CPP, os resultados mantiveram-seacima dos limites preconizados. Não houve detecção de coliformes totais e na pesquisa de Listeria monocytogenes. As análises microbiológicas foram importantes para a avaliação da higienização dos fatiadores, subsidiando práticas educativas eficazes na consolidação de aprendizado.(AU)

The objective of this study was to evaluate microbiological of slicers to support educative activities to food handlers on good hygienic practices for equipment. The study occurred in the bakery of two supermarkets in Piraquara, Paraná, through the microbiological couting of aerobic mesophilic microorganisms (Standard Plate Count - SPC), total coliforms and Listeria monocytogenes research. Three collections were made with a 15-day interval and, before the last one, a educative activity was made based in problematization methodology about equipment hygienization. Despite the reduction in bacterial counting, verified by the CPP, the results remained above the recommended limits. There was no detection of total coliforms and in the investigation of Listeria monocytogenes. The microbiological analyses were important for the evaluation of the hygiene of the slicers, supporting effective educational practices in the learning consolidation.(AU)