Bacterial communities in artisanal raw bovine milk cheeses from the southern region of Brazil / Comunidades bacterianas em queijos artesanais de leite bovino cru da região sul do Brasil

The production of artisanal cheeses made with raw bovine milk has grown in the southern region of Brazil. It is important to obtain information about the risks of this practice, especially concerning food safety. In this study, next-generation sequencing was used to identify and characterize the bacterial communities of artisanal raw milk cheeses. We analyzed one pool of five raw milk samples (control group M1) from different dairy farms and nine pools (M2-M10) of 45 artisanal raw milk cheeses.The characterization of the bacterial communities included 199 species distributed across 59 different genera dispersed among the samples. Among the genera observed, 11 were classified as beneficial to the aroma, flavour, colour, and texture of the cheese. Thirty-one genera were classified as harmful to these characteristics. Another 17 were classified as potential pathogens for animals and humans, including Aeromonas, Bacillus, Cronobacter, Salmonella, Staphylococcus, and bacteria of the coliform group, including E. coli and Klebsiella. There was a significant difference (P < 0.05) in the number of bacterial communities identified between the control group (M1) and the two pools of artisanal raw milk cheeses (M2 and M8). This study demonstrated that next-generation sequencing provides in-depth information on the composition of the microbiota in artisanal raw milk cheeses, characterizing bacterial communities, identifying the wide microbial diversity, and identifying microbial benefits and risks.

Devido ao aumento da produção de queijos artesanais com leite bovino cru na região sul do Brasil, é importante obter informações sobre os riscos desta prática, principalmente no que se refere à segurança do alimento. Neste estudo foi utilizada a técnica de Next Generation Sequencing (NGS) para identificar e caracterizar comunidades bacterianas de queijos artesanais de leite cru. Foram analisados um pool de cinco amostras de leite cru como grupo controle (M1) de diferentes propriedades leiteiras localizadas na região norte do estado do Rio Grande do Sul, e nove pools (M2-M10) de 45 queijos artesanais de leite cru. A caracterização das comunidades bacterianas incluiu 199 espécies distribuídas em 59 gêneros diferentes dispersos entre as amostras. Dentre os gêneros observados, 11 foram classificados como benéficos ao aroma, sabor, cor e textura do queijo, enquanto 31 gêneros foram classificados como prejudiciais a essas características. Outros 17 foram classificados como potenciais patogênicos para animais e humanos, incluindo Aeromonas, Bacillus, Cronobacter, Salmonella, Staphylococcus, bactérias do grupo coliforme como Escherichia coli e Klebsiella. Houve diferença significativa (P < 0,05) entre o número de comunidades bacterianas identificadas no grupo controle (M1) e dois pools de queijos artesanais de leite cru (M2 e M8). Este estudo demonstra que o NGS fornece informações detalhadas sobre a composição da microbiota em queijos artesanais de leite cru, caracterizando comunidades bacterianas, identificando a ampla diversidade microbiana, os benefícios e riscos microbianos.

Biofilm forming antimicrobial-multiresistant Staphylococcus aureus / Multirresistência antimicrobiana de Staphylococcus aureus formadores de biofilme

Staphylococcus aureus is one of the main agents isolated from bovine mastitis cases, characterized by lower cure rates compared to other pathogens causing this disease. This phenomenon is mainly explained by the multiresistance acquisition to antimicrobials and the ability of S. aureus to form biofilms on biotic and abiotic surfaces. In this work 15 samples of S. aureus isolated from the automated milking facility were analyzed regarding the resistance profile to antimicrobials, virulence factors (capsule production, hemolysin, and protease) and adhesion capacity under different temperatures (42±1°C, 36±1°C, 25±1°C, 9±1°C, and 3±1°C). All isolates showed methicillin-resistant (MRSA) characteristics and multidrug resistance profile to the antimicrobials tested (penicillin G, chloramphenicol, oxacillin, cephalexin, tetracycline, amoxicillin + clavulanic acid, sulfa + trimetropim, gentamicin, doxycycline, ceftiofur, neomycin, and vancomycin) with an IRMA index between 0.5 and 1.0. Five isolates were resistant to vancomycin (VRSA), two were resistant to all active principles, and the others to at least six of these drugs. Adhesion capacity and biofilm formation were found in 3 of the 5 evaluated temperatures, including the cooling conditions. Regarding the virulence factors, 86.7% of the isolates formed capsules, 60% revealed the presence of protease, 26.7% expressed the α-hemolysin factor, and 13.3% of them presented β-hemolysin. The fact that all isolates presented MRSA characteristics represents a potential risk to those exposed to this agent, and the formation of biofilm in liners even after the use of detergents and sanitization highlights the urgency of searching for alternatives for dispersion of the biofilm by S. aureusin the automated milking facility.

O Staphylococcus aureus é um dos principais agentes isolados de casos de mastite bovina, caracterizado por menores taxas de cura em comparação com outros patógenos desta enfermidade. Esse fenômeno é explicado principal-mente pela aquisição de resistência à antimicrobianos e a capacidade do S. aureus formar biofilmes em superficies bióti-cas e abióticas. Neste trabalho foram utilizadas 15 amostras de S. aureus isolados de ordenhadeira, analisados quanto ao perfil de resistência à antimicrobianos, fatores de virulência (produção de cápsula, hemolisina e protease) e capacidade de adesão sob diferentes temperaturas (42±1°C, 36±1°C, 25±1ºC, 9±1ºC e 3±1ºC). Todos os isolados apresentaram perfil de multirresistência aos antimicrobianos testados (penicilina G, cloranfenicol, oxacilina, cefalexina, tetraciclina, amoxicilina + ácido clavulônico, sulfa + trimetropim, gentamicina, doxiciclina, ceftiofur, neomicina e vancomicina) com índice IRMA entre 0,5 a 1,0. Duas cepas foram resistentes a todos os princípios ativos e as demais a pelo menos seis destes fármacos. Os isolados avaliados apresentaram característica de meticilina-resistentes (MRSA) e destes, 33,34% (5/15) foram resistentes à vancomicina (VRSA). Houve capacidade de adesão e formação de biofilmes em 3 das 5 tem-peraturas avaliadas, incluindo as temperaturas de refrigeração. Em relação aos fatores de virulência, 86,7% dos isolados formaram cápsula, 60% presença de protease, 26,7% expressaram o fator α-hemolisina e 13,3% β-hemolisina. O fato de todos isolados apresentarem característica MRSA representa um risco potencial aos expostos a esse agente. Já a for-mação de biofilmes em teteiras, mesmo após detergência e sanitização, destacam a urgência de alternativas de dispersão de biofilmes no ambiente de ordenha.

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)

Biofilm forming antimicrobial-multiresistant Staphylococcus aureus / Multirresistência antimicrobiana de Staphylococcus aureus formadores de biofilme

Staphylococcus aureus is one of the main agents isolated from bovine mastitis cases, characterized by lower cure rates compared to other pathogens causing this disease. This phenomenon is mainly explained by the multiresistance acquisition to antimicrobials and the ability of S. aureus to form biofilms on biotic and abiotic surfaces. In this work 15 samples of S. aureus isolated from the automated milking facility were analyzed regarding the resistance profile to antimicrobials, virulence factors (capsule production, hemolysin, and protease) and adhesion capacity under different temperatures (42±1°C, 36±1°C, 25±1°C, 9±1°C, and 3±1°C). All isolates showed methicillin-resistant (MRSA) characteristics and multidrug resistance profile to the antimicrobials tested (penicillin G, chloramphenicol, oxacillin, cephalexin, tetracycline, amoxicillin + clavulanic acid, sulfa + trimetropim, gentamicin, doxycycline, ceftiofur, neomycin, and vancomycin) with an IRMA index between 0.5 and 1.0. Five isolates were resistant to vancomycin (VRSA), two were resistant to all active principles, and the others to at least six of these drugs. Adhesion capacity and biofilm formation were found in 3 of the 5 evaluated temperatures, including the cooling conditions. Regarding the virulence factors, 86.7% of the isolates formed capsules, 60% revealed the presence of protease, 26.7% expressed the α-hemolysin factor, and 13.3% of them presented β-hemolysin. The fact that all isolates presented MRSA characteristics represents a potential risk to those exposed to this agent, and the formation of biofilm in liners even after the use of detergents and sanitization highlights the urgency of searching for alternatives for dispersion of the biofilm by S. aureusin the automated milking facility.(AU)

O Staphylococcus aureus é um dos principais agentes isolados de casos de mastite bovina, caracterizado por menores taxas de cura em comparação com outros patógenos desta enfermidade. Esse fenômeno é explicado principal-mente pela aquisição de resistência à antimicrobianos e a capacidade do S. aureus formar biofilmes em superficies bióti-cas e abióticas. Neste trabalho foram utilizadas 15 amostras de S. aureus isolados de ordenhadeira, analisados quanto ao perfil de resistência à antimicrobianos, fatores de virulência (produção de cápsula, hemolisina e protease) e capacidade de adesão sob diferentes temperaturas (42±1°C, 36±1°C, 25±1ºC, 9±1ºC e 3±1ºC). Todos os isolados apresentaram perfil de multirresistência aos antimicrobianos testados (penicilina G, cloranfenicol, oxacilina, cefalexina, tetraciclina, amoxicilina + ácido clavulônico, sulfa + trimetropim, gentamicina, doxiciclina, ceftiofur, neomicina e vancomicina) com índice IRMA entre 0,5 a 1,0. Duas cepas foram resistentes a todos os princípios ativos e as demais a pelo menos seis destes fármacos. Os isolados avaliados apresentaram característica de meticilina-resistentes (MRSA) e destes, 33,34% (5/15) foram resistentes à vancomicina (VRSA). Houve capacidade de adesão e formação de biofilmes em 3 das 5 tem-peraturas avaliadas, incluindo as temperaturas de refrigeração. Em relação aos fatores de virulência, 86,7% dos isolados formaram cápsula, 60% presença de protease, 26,7% expressaram o fator α-hemolisina e 13,3% β-hemolisina. O fato de todos isolados apresentarem característica MRSA representa um risco potencial aos expostos a esse agente. Já a for-mação de biofilmes em teteiras, mesmo após detergência e sanitização, destacam a urgência de alternativas de dispersão de biofilmes no ambiente de ordenha.(AU)

Effects of different concentrations of sodium azide and chloramphenicol on the preservation of raw milk samples / Efeitos de diferentes concentrações de azida sódica e cloranfenicol na preservação de amostras de leite cru

The preservation of milk samples for microbiological analyses by the Brazilian Network of Milk Quality Control Laboratories requires the addition of preservatives to maintain the microbiota from the time of sample collection to the moment of analysis. The number of microorganisms can change as a result of the active ingredients and concentration of the preservative, as well as due to interactions between the preservatives, incubation time, and packaging temperature. The objective of this research was to evaluate the conservation potential of different concentrations of sodium azide and chloramphenicol on the analytical shelf life of milk samples. Two farms were selected, one with a low bacterial count and one with a high bacterial count. The milk was dispensed into sterile vials and tested after the addition of the usual concentrations of sodium azide and chloramphenicol, doubled concentrations, tripled concentrations, and as a control, without preservatives. The samples were incubated at 3 ± 1 °C, 6 ± 1 °C, and 9 ± 1 °C for 14 days and analyzed daily for their bacterial count by flow cytometry. The tripled preservative concentrations improved conservation, increasing the timespan of the analytical viability of the samples without altering the results.(AU)

A conservação das amostras de leite destinadas para análises microbiológicas pela Rede Brasileira de Laboratórios de Controle da Qualidade do Leite requer adição de conservantes para a preservação da microbiota existente desde o momento da coleta até as análises. O número de microrganismos pode apresentar alterações decorrentes do princípio ativo e concentração do conservante, e ainda entre as interações conservante, tempo de incubação e temperatura de acondicionamento. O objetivo deste trabalho foi avaliar o potencial de conservação de diferentes concentrações de azida sódica e cloranfenicol sobre a vida útil analítica de amostras de leite. Foram selecionadas duas fazendas, sendo uma com baixa contagem bacteriana e outra com alta contagem bacteriana. O leite foi fracionado em frascos estéreis e testado nas seguintes condições: pastilhas com a concentração usual de azida sódica e cloranfenicol, com dupla concentração, com tripla concentração e sem a adição do conservante. As amostras foram incubadas por quatorze dias a 3 ± 1 °C, 6 ± 1 °C e 9 ± 1 °C, e analisadas diariamente por citometria de fluxo para a determinação da contagem bacteriana. A tripla concentração do conservante demonstrou maior conservação, possibilitando o aumento da viabilidade analítica das amostras sem alteração nos resultados.(AU)

Biofilm formation by Salmonella Enteritidis at different incubation temperatures

Background: The genus Salmonella, associated with poultry products, is considered the leading cause of foodborne outbreaks in humans in many countries. In Brazil, Salmonella Enteritidis (SE) is the serovar remains as one most frequentlyisolated from humans, and it is also a major serovar found in animals, food, animal feed, and environmental samples, despiteall the efforts to control this pathogen. Also, the bacterium is able to form biofilms on different surfaces, protecting cellsfrom both cleaning and sanitizing procedures in the food industries. This study aimed to verify the ability of SalmonellaEnteritidis isolates to form biofilm on polystyrene at different incubation temperatures.Materials, Methods & Results: A total of 171 SE samples were isolated from foodborne outbreaks (foods and stool cultures) and poultry products between 2003 and 2010. The biofilm-forming ability of samples was measured at four differenttemperatures (3°C, 9ºC, 25ºC, and 36ºC), for 24 h, simulating temperatures usually found in poultry slaughterhouses. Later,200 μL of each bacterial suspension was inoculated, in triplicate, onto 96-well, flat-bottomed sterile polystyrene microtiterplates, washed, after that, the biofilm was fixed with methanol. The plates were dried at ambient temperature, stained with2% Hucker’s crystal violet. Afterwards, absorbance was read using an ELISA plate reader and the optical density (OD)of each isolate was obtained by the arithmetic mean of the absorbance of three wells and this value was compared withthe mean absorbance of negative controls (ODnc). The following classification was used for the determination of biofilmformation: no biofilm production, weak biofilm production, moderate biofilm production and strong biofilm production.Results demonstrated all isolates from stool cultures and foods involved in foodborne outbreaks, at least one of the fourtemperatures tested, were able to form biofilm...

Quantificação de Staphylococcus aureus e bactérias mesófilas aeróbias para avaliar higienização de equipamentos de ordenha / Staphylococcus aureus and mesophilic aerobic bacteria quantification in hygienization process of milking equipment

Background: Milk’s composition is an excellent substrate for microorganism’s multiplication. Presence of Staphylococcusaureus and aerobic mesophilic bacteria are one of the most common problems in dairy farms. On dairy industry’s and milkfarms Clean in Place (CIP) system higyenization are commonly used, then the cleaning occurs as a closed process, forbetter results sanitizans are applied, in order to obtain a safety food. This project aim to evaluate Staphylococcus aureusand aerobic mesophilic bacteria reduction after two milking higyenization process.Materials, Methods & Results: This research was done on a Rio Grande do Sul North Milk farm, with mechanized milkingand Clean in Place system for cleaning. For liners and CIP tubes higyenization commercial products as Sodium Hipoclorite3% and phosphoric acid 11.3% are used for detergency, and peracetic acid 5% for sanitization. Milk bunk tank are higyenized with sodium hypoclorite 3.8% alcalin detergent. After higyenization steps liners, CIP’s water process, bulk milk tankand milk set were collected. At process 1, liners and CIP water were collected after milking, detergency and sanitizationthat occurred immediately at the detergency’s finish, while process 2 the sanitization was realized 8 h after detergency,before following milking. Cooling milk bulk tank was collected before and after detergency, and milk set after milkingsConvencional microbiology were used to count and results in log10 UFC.cm-2...

Biofilm formation by Salmonella Enteritidis at different incubation temperatures

Background: The genus Salmonella, associated with poultry products, is considered the leading cause of foodborne outbreaks in humans in many countries. In Brazil, Salmonella Enteritidis (SE) is the serovar remains as one most frequentlyisolated from humans, and it is also a major serovar found in animals, food, animal feed, and environmental samples, despiteall the efforts to control this pathogen. Also, the bacterium is able to form biofilms on different surfaces, protecting cellsfrom both cleaning and sanitizing procedures in the food industries. This study aimed to verify the ability of SalmonellaEnteritidis isolates to form biofilm on polystyrene at different incubation temperatures.Materials, Methods & Results: A total of 171 SE samples were isolated from foodborne outbreaks (foods and stool cultures) and poultry products between 2003 and 2010. The biofilm-forming ability of samples was measured at four differenttemperatures (3°C, 9ºC, 25ºC, and 36ºC), for 24 h, simulating temperatures usually found in poultry slaughterhouses. Later,200 μL of each bacterial suspension was inoculated, in triplicate, onto 96-well, flat-bottomed sterile polystyrene microtiterplates, washed, after that, the biofilm was fixed with methanol. The plates were dried at ambient temperature, stained with2% Huckers crystal violet. Afterwards, absorbance was read using an ELISA plate reader and the optical density (OD)of each isolate was obtained by the arithmetic mean of the absorbance of three wells and this value was compared withthe mean absorbance of negative controls (ODnc). The following classification was used for the determination of biofilmformation: no biofilm production, weak biofilm production, moderate biofilm production and strong biofilm production.Results demonstrated all isolates from stool cultures and foods involved in foodborne outbreaks, at least one of the fourtemperatures tested, were able to form biofilm...(AU)

Quantificação de Staphylococcus aureus e bactérias mesófilas aeróbias para avaliar higienização de equipamentos de ordenha / Staphylococcus aureus and mesophilic aerobic bacteria quantification in hygienization process of milking equipment

Background: Milks composition is an excellent substrate for microorganisms multiplication. Presence of Staphylococcusaureus and aerobic mesophilic bacteria are one of the most common problems in dairy farms. On dairy industrys and milkfarms Clean in Place (CIP) system higyenization are commonly used, then the cleaning occurs as a closed process, forbetter results sanitizans are applied, in order to obtain a safety food. This project aim to evaluate Staphylococcus aureusand aerobic mesophilic bacteria reduction after two milking higyenization process.Materials, Methods & Results: This research was done on a Rio Grande do Sul North Milk farm, with mechanized milkingand Clean in Place system for cleaning. For liners and CIP tubes higyenization commercial products as Sodium Hipoclorite3% and phosphoric acid 11.3% are used for detergency, and peracetic acid 5% for sanitization. Milk bunk tank are higyenized with sodium hypoclorite 3.8% alcalin detergent. After higyenization steps liners, CIPs water process, bulk milk tankand milk set were collected. At process 1, liners and CIP water were collected after milking, detergency and sanitizationthat occurred immediately at the detergencys finish, while process 2 the sanitization was realized 8 h after detergency,before following milking. Cooling milk bulk tank was collected before and after detergency, and milk set after milkingsConvencional microbiology were used to count and results in log10 UFC.cm-2...(AU)

Salmonella Enteritidis forms biofilm under low temperatures on different food industry surfaces / Salmonella Enteritidis forma biofilme sob baixas temperaturas em diferentes superfícies da indústria de alimentos

We evaluated the influence of temperature on the ability of Salmonella Enteritidis (SE) to form biofilms on stainless steel, polyethylene, and polyurethane surfaces under different hygiene procedures. These materials were placed on SE culture and incubated at 42±1 ºC, 36±1 ºC, 25±1 ºC, 9±1 ºC, and 3±1 ºC for 4, 8, 12, and 24 h. Hot water at 45 ºC and 85 ºC, 0.5% peracetic acid solution, and 1% quaternary ammonia were used for hygienization. Biofilm formation occurred at all temperatures evaluated, highlighting at 3 ºC which has not been reported as an ideal temperature for the adhesion of SE to these materials. The SE adhered more often to polyethylene surfaces than to polyurethane and stainless steel surfaces (P<0.05). Peracetic acid and water at 85 ºC had similar hygienization efficiency (P<0.05) followed by quaternary ammonia whereas water at 45 ºC was not effective. SE adhered to these materials under low temperatures which to date have been deemed safe for food preservation.(AU)

Avaliou-se o efeito da temperatura na capacidade de Salmonella Enteritidis (SE) formar biofilme em superfícies de aço inoxidável, polietileno e poliuretano e diferentes processos de higienização. Corpos de prova destes materiais foram postos frente a culturas de SE e incubados a 42±1 ºC, 36±1 ºC, 25±1 ºC, 9±1 ºC e 3±1 ºC por 4, 8, 12 e 24 horas. Para a higienização foram testados água aquecida a 45ºC e 85 ºC e soluções de ácido peracético 0,5% e amônia quaternária 1%. Verificou-se a formação de biofilmes em todas as temperaturas avaliadas, ressaltando-se a 3 ºC, ainda não citada como propícia para adesão de SE. Houve maior adesão ao polietileno do que ao poliuretano e ao aço inoxidável (P<0.05). Para higienização, o ácido peracético e a água a 85 ºC tiveram ação semelhante (P<0.05), seguidos por amônia quaternária, enquanto que a água a 45 ºC não foi eficaz. Todos os materiais avaliados propiciaram a aderência de SE, mesmo sob temperaturas baixas, consideradas até então seguras para a conservação dos alimentos.(AU)

ATP-Bioluminescence and conventional microbiology for hygiene evaluation of cutting room surfaces in poultry slaughterhouse

Background: The hygiene procedures in poultry slaughterhouses consist in the use of hot water, detergent and sanitizing, configuring Sanitation Standard Operating Procedure (SSOP). These actions control contamination in food processing environments, especially by pathogenic microorganisms, which cause diseases with impact on public health and economic losses. The microbiological control of aerobic mesophiles, Staphylococcus aureus and Escherichia coli, are used as indicators of contamination. The hygienic-sanitary conditions on the surfaces of the poultry slaughterhouse cuttting room were evaluated, before and after cleaning and sanitizing procedures.Materials, Methods & Results: Conventional microbiology (Rodac plates and sponge for quantification of aerobic mesophiles, Staphylococcus aureus and Escherichia coli) and ATP-Bioluminescence were used to analyze the action of hot water and the active principles peracetic acid, quaternary ammonia and biguanide in the standard pre-operational hygiene procedure in the cutting room of the poultry slaughterhouse under Federal Inspection with slaughter capacity of more than 20.000 birds/h. The evaluations were performed on three lines of chicken thigh cuts at the same time and in a completely randomized manner on stainless steel surfaces, polyurethane belts and polyethylene boards. Samples were made in four replicates at the three surface totaling 108 assay for each microorganism. The samples were collected at the end of the cutting process, before and after washing the surfaces with hot water (between 45 and 50ºC) and after sanitization with 0.5% peracetic acid, 2% quaternary ammonia and 1% biguanide. The ATP-Bioluminescence method detected organic matter at all collected points and Rodac plates allowed a better recovery of microorganisms than sponges for quantification of aerobic mesophiles, E. coli and S. aureus.[...]

ATP-Bioluminescence and conventional microbiology for hygiene evaluation of cutting room surfaces in poultry slaughterhouse

Background: The hygiene procedures in poultry slaughterhouses consist in the use of hot water, detergent and sanitizing, configuring Sanitation Standard Operating Procedure (SSOP). These actions control contamination in food processing environments, especially by pathogenic microorganisms, which cause diseases with impact on public health and economic losses. The microbiological control of aerobic mesophiles, Staphylococcus aureus and Escherichia coli, are used as indicators of contamination. The hygienic-sanitary conditions on the surfaces of the poultry slaughterhouse cuttting room were evaluated, before and after cleaning and sanitizing procedures.Materials, Methods & Results: Conventional microbiology (Rodac plates and sponge for quantification of aerobic mesophiles, Staphylococcus aureus and Escherichia coli) and ATP-Bioluminescence were used to analyze the action of hot water and the active principles peracetic acid, quaternary ammonia and biguanide in the standard pre-operational hygiene procedure in the cutting room of the poultry slaughterhouse under Federal Inspection with slaughter capacity of more than 20.000 birds/h. The evaluations were performed on three lines of chicken thigh cuts at the same time and in a completely randomized manner on stainless steel surfaces, polyurethane belts and polyethylene boards. Samples were made in four replicates at the three surface totaling 108 assay for each microorganism. The samples were collected at the end of the cutting process, before and after washing the surfaces with hot water (between 45 and 50ºC) and after sanitization with 0.5% peracetic acid, 2% quaternary ammonia and 1% biguanide. The ATP-Bioluminescence method detected organic matter at all collected points and Rodac plates allowed a better recovery of microorganisms than sponges for quantification of aerobic mesophiles, E. coli and S. aureus.[...](AU)

Campylobacter jejuni e Campylobacter coli em carcaças de frango resfriadas e congeladas / Campylobacter jejuni and Campylobacter coli in chilled and frozen chicken carcasses

Espécies de Campylobacter spp. termotolerantes são agentes de surtos de campilobacteriose em humanos e os produtos de origem avícola são considerados uma importante fonte de infecção. Foram identificados Campylobacter jejuni e Campylobacter coli em carcaças de frango resfriadas e congeladas coletadas em três abatedouros entre 2014 e 2015. A detecção de Campylobacter spp. foi realizada por microbiologia convencional e a identificação de C. jejuni e C. coli por multiplex-PCR. Dentre as amostras avaliadas verificou-se Campylobacter spp. termotolerante em 63,8%, sendo 72,2% em carcaças resfriadas e 55,5% em carcaças congeladas. Destas, 83,3% foram positivas para C. jejuni e 66,6% para C. coli, enquanto 50% foram positivas para ambas as espécies. A presença de Campylobacter spp. termotolerante em carcaças de frangos de corte prontas para consumo representa uma importante fonte de transmissão destes patógenos para humanos.

Species of thermophilic Campylobacter spp. are agents of campylobacteriosis outbreaks in humans, and poultry products are implicated as major sources of infection. The detection of Campylobacter spp. was performed by conventional microbiology in poultry carcasses collected in slaughterhouses and species were identified by multiplex-PCR. Thermophilic Campylobacter spp. was verified in 63.8% of the samples, being 72.2% in chilled carcasses and 55.5% in frozen carcasses. Of these, 83.3% were positive for C. jejuni and 66.6% to C. coli, while 50% were positive for both. The presence of thermophilic Campylobacter spp. in ready-to-eat poultry products represents a potential source of human campylobacteriosis.

Campylobacter jejuni e Campylobacter coli em carcaças de frango resfriadas e congeladas / Campylobacter jejuni and Campylobacter coli in chilled and frozen chicken carcasses

Espécies de Campylobacter spp. termotolerantes são agentes de surtos de campilobacteriose em humanos e os produtos de origem avícola são considerados uma importante fonte de infecção. Foram identificados Campylobacter jejuni e Campylobacter coli em carcaças de frango resfriadas e congeladas coletadas em três abatedouros entre 2014 e 2015. A detecção de Campylobacter spp. foi realizada por microbiologia convencional e a identificação de C. jejuni e C. coli por multiplex-PCR. Dentre as amostras avaliadas verificou-se Campylobacter spp. termotolerante em 63,8%, sendo 72,2% em carcaças resfriadas e 55,5% em carcaças congeladas. Destas, 83,3% foram positivas para C. jejuni e 66,6% para C. coli, enquanto 50% foram positivas para ambas as espécies. A presença de Campylobacter spp. termotolerante em carcaças de frangos de corte prontas para consumo representa uma importante fonte de transmissão destes patógenos para humanos.(AU)

Species of thermophilic Campylobacter spp. are agents of campylobacteriosis outbreaks in humans, and poultry products are implicated as major sources of infection. The detection of Campylobacter spp. was performed by conventional microbiology in poultry carcasses collected in slaughterhouses and species were identified by multiplex-PCR. Thermophilic Campylobacter spp. was verified in 63.8% of the samples, being 72.2% in chilled carcasses and 55.5% in frozen carcasses. Of these, 83.3% were positive for C. jejuni and 66.6% to C. coli, while 50% were positive for both. The presence of thermophilic Campylobacter spp. in ready-to-eat poultry products represents a potential source of human campylobacteriosis.(AU)

Campylobacter in broiler slaughter samples assessed by direct count on mCCDA and Campy-Cefex agar

Campylobacter spp. cause foodborne illnesses in humans primarily through the consumption of contaminated chicken. The aim of this study was to evaluate the United States Department of Agriculture's (USDA) recommended methodology, protocol MLG 41.02, for the isolation, identification and direct plate counting of Campylobacter jejuni and C. coli samples from the broiler slaughtering process. A plating method using both mCCDA and Campy-Cefex agars is recommended to recover Campylobacter cells. It is also possible to use this method in different matrices (cloacal swabs and water samples). Cloacal swabs, samples from pre-chiller and post-chiller carcasses and samples of pre-chiller, chiller and direct supply water were collected each week for four weeks from the same flock at a slaughterhouse located in an abattoir in southern Brazil. Samples were analyzed to directly count Campylobacter spp., and the results showed a high frequency of Campylobacter spp. on Campy-Cefex agar. For the isolated species, 72% were identified as Campylobacter jejuni and 38% as Campylobacter coli. It was possible to count Campylobacter jejuni and Campylobacter coli from different samples, including the water supply samples, using the two-agar method. These results suggest that slaughterhouses can use direct counting methods with both agars and different matrices as a monitoring tool to assess the presence of Campylobacter bacteria in their products.(AU)

Salmonella spp. isolated by miniaturized most probable number and conventional microbiology in poultry slaughterhouses

Background: Salmonella spp. are frequently isolated from fowls, and their detection in poultry products varies according to the breeding system and the slaughtering process, bringing risks to the consumer and compromising the marketability. The control of Salmonella in poultry slaughterhouses is based on the detection of bacteria, but the quantification of the agent would be important in assessing risk, as well as in obtaining data to determine the capacity of each step of the process to decrease or increase bacterial contamination. The aims of this study were to propose a method for the quantification of Salmonella in poultry slaughterhouses, frequency of isolation and serovars identified. Materials, Methods & Results: Twenty-one broiler flocks from seven federally inspected slaughterhouses in southern Brazil, totaling 1,071 samples, were assessed by miniaturized most probable number (mMPN) and conventional microbiology. The samples were collected in triplicate at 17 points, which included cloacae, transportation cages before and after sanitization, water (scald tank, supply, pre-chiller and chiller), and carcasses (before and after scalding, defeathering, rinsing, evisceration, final rinsing, chilling at 4ºC, and freezing at -12C for 24 h, 30 and 60 days). Typical Salmonella colonies were submitted to TSI, LIA, SIM, urea, and polyvalent anti-O antiserum tests [...](AU)

Salmonella spp. isolated by miniaturized most probable number and conventional microbiology in poultry slaughterhouses

Background: Salmonella spp. are frequently isolated from fowls, and their detection in poultry products varies according to the breeding system and the slaughtering process, bringing risks to the consumer and compromising the marketability. The control of Salmonella in poultry slaughterhouses is based on the detection of bacteria, but the quantification of the agent would be important in assessing risk, as well as in obtaining data to determine the capacity of each step of the process to decrease or increase bacterial contamination. The aims of this study were to propose a method for the quantification of Salmonella in poultry slaughterhouses, frequency of isolation and serovars identified. Materials, Methods & Results: Twenty-one broiler flocks from seven federally inspected slaughterhouses in southern Brazil, totaling 1,071 samples, were assessed by miniaturized most probable number (mMPN) and conventional microbiology. The samples were collected in triplicate at 17 points, which included cloacae, transportation cages before and after sanitization, water (scald tank, supply, pre-chiller and chiller), and carcasses (before and after scalding, defeathering, rinsing, evisceration, final rinsing, chilling at 4ºC, and freezing at -12C for 24 h, 30 and 60 days). Typical Salmonella colonies were submitted to TSI, LIA, SIM, urea, and polyvalent anti-O antiserum tests [...]

Inoculação e quantificação de Campylobacter a partir de conteúdo cecal de frangos de corte comparando duas metodologias de contagem / Campylobacter inoculation and quantification from broiler cecal samples to compare two plate counting methodologies

Campylobacteriosis is a zoonosis, a disease transmitted to humans from animals or animal products. The primarily source of Campylobacter infection in human is believed to be the handling and/or consumption of contaminated meat, especially poultry meat. Although in humans such infections are generally self-limiting, complications can arise and may include bacteraemia, Guillain-Barré syndrome, reactive arthritis and abortion. In this study, 32 birds were divided in 2 groups: a control (C) group and an inoculated (I) group, with 16 birds each. The I group was inoculated orally with 108 CFU/mL of Campylobacter jejuni ATCC 33291, whereas the C group was inoculated with a saline solution. Four chicks per group were euthanized by cervical dislocation at 0, 7, 14 and 21 days post-inoculation (pi). Cecum samples were collected for microbiological analyses. The samples were processed by two plate count methodologies, one developed by the USDA (United States Department of Agriculture) in 2011 (B method) and the other a serial dilution direct count method (A method). All birds from the C group remained negative until day 21. For the I group, the B method was found to be statistically superior to the A method for counting the recovered cells from the cecal contents at 7, 14 and 21 days pi. The microbiological direct plating counting method is a cost effective and rapid method to determine the level of contamination in broilers to help risk assessment programs at the industry level.(AU)

Campilobacteriose é uma zoonose, uma doença transmitida para humanos por animais ou produtos de origem animal. As fontes primárias de infecções por Campylobacter em humanos se acredita ser o manuseamento e / ou o consumo de carne contaminada, carne de frangos especialmente. Embora em humanos tais infecções são geralmente auto-limitantes, as complicações podem surgir e podem incluir bacteremia, síndrome de Guillain-Barré, artrite reativa e aborto. Para o presente estudo, 32 aves foram divididos em 2 grupos identificados como grupos controle (C) com 16 aves e grupo inoculado (I) com 16 aves. O grupo I foi inoculado por via oral com 108 UFC / mL de Campylobacter jejuni ATCC 33291, enquanto o grupo C foi inoculado com solução salina. Quatro aves por grupo foram eutanaziados por deslocamento cervical nos dias 0, 7, 14 e 21 após a inoculação (pi) e as amostras de conteudo cecal foram coletadas para análises microbiológicas. As amostras foram processadas por duas metodologias de contagem em placa, uma desenvolvido pela USDA (método B) e outra, por diluição seriada com plaqueamento direto (método A). Todas as aves do grupo C permaneceram negativas até ao dia 21, e para o grupo I, as células recuperadas a partir de conteúdo cecal foram estatisticamente superior com o método B, quando comparados ao método A nos 7, 14 e 21 dias pi. A contagem microbiologica direta em placas é um método masi barato e rápido para determinar o nível de contaminação de frangos, servindo de auxilio nos programas de avaliação de risco a nível da indústria.(AU)

Número mais provável miniaturizado e microbiologia convencional para isolamento de Salmonella spp. em abatedouros de frangos de corte / Miniaturized most probable number and conventional microbiology for isolation of Salmonella spp. in poultry slaughterhouses

Os produtos de origem avícola podem ser importantes veículos de transmissão de Salmonella spp. para humanos e, dentre os vários parâmetros que determinam a qualidade de um alimento, destacam-se os que definem suas características microbiológicas. Objetivou-se detectar e quantificar Salmonella spp. na tecnologia de abate de frangos de corte por microbiologia convencional (MC) e número mais provável miniaturizado (mNMP). As coletas foram realizadas em duas visitas a três abatedouros sob Inspeção Federal e em seis pontos de coleta em triplicata, definidos como: recepção das aves (swabs de cloaca e esponjas de gaiolas de transporte antes e após a higienização) e carcaças (após pré resfriamento em chiller, após o gotejamento e antes da embalagem primária e congeladas a -12oC por 24 horas), totalizando 108 amostras. Identificou-se Salmonella spp. em três dos seis pontos do fluxograma de abate e em dois dos três estabelecimentos amostrados, independentemente do método utilizado, perfazendo 5,5% de positividade, onde destaca-se a contaminação nas gaiolas de transporte das aves após a higienização. Não foi possível correlacionar os resultados da microbiologia convencional e do mNMP ou mesmo quantificar a contaminação ao longo da tecnologia de abate, o que indica a necessidade de se utilizar um método qualitativo aliado ao método de quantificação quando Salmonella estiver presente em quantidades inferiores ao limite de detecção do mNMP proposto (0,13 NMP/mL). Os sorovares identificados foram Typhimurium, Panama, Lexington e Rissen, consideradas paratíficos e, portanto, potencialmente capazes de causar infecções em humanos, embora estes sorovares não tenham sido isolados em produtos finais e sim na chegada dos frangos aos abatedouros (swabs de cloaca e gaiolas de transporte). A identificação de Salmonella spp. nas gaiolas de transporte após a higienização é um indicativo da necessidade de revisão e adequação dos métodos automatizados de lavagem atualmente utilizados nos abatedouros.(AU)

Poultry products can be important modes of transmission of Salmonella spp. to humans and, among several parameters used to determine food quality, microbiological characteristics play an essential role. The aim of this study was to determine and quantify Salmonella spp. at broiler slaughtering facilities. This was done by conventional microbiology and by the miniaturized most probable number (mMPN) methods. Three federally-inspected slaughterhouses were visited, where samples were collected in triplicate from six sites: reception of live birds (cloacal swabs and sponge samples from transport cages before and after sanitation) and carcass processing (after pre-chiller, after dripping, and before primary packaging and refrigeration at -12oC for 24h), totaling 108 samples. Three of the six surveyed sites and two of the three slaughterhouses were contaminated with Salmonella spp., showing an infection rate of 5.5% independently of the method used, and revealing that transport cages were contaminated after sanitation. No correlation could be established between the results of conventional microbiology and mMPN methods, and contamination along the slaughtering line could not quantified. This indicates the importance of combining qualitative and quantitative methods for the enumeration of Salmonella when detection rates are lower than the proposed mMPN limit (0.13 MPN/mL). Typhimurium, Panama, Lexington and Rissen, which are paratyphoid organisms and are potentially infectious to humans, were identified. However, these serovars were isolated at the reception of live birds (from cloacal swabs and from transport cages) rather than from the end products. Given that Salmonella spp. was detected in transport cages after sanitation, it is paramount that automated washing procedures currently used in slaughterhouses be reassessed and adjusted.(AU)

The use of vortex and ultrasound techniques for the in vitro removal of Salmonella spp. Biofilms

Background: The presence of biofilm is common to all types of surfaces, such as stainless steel. Once formed, biofilms act as a point of constant contamination releasing fragments or planktonic cells of microorganisms, such as Salmonella spp., and may impair the microbiological quality of products. The laboratory methods are being used and tested in vitro for removal and the subsequent quantification of biofilms, including the use of vortex and ultrasound. The aim of the study was to evaluate the effectiveness of these two laboratory methods for removing Salmonella spp. biofilms, in vitro cultured on stainless steel surface from the food industry.Materials, Methods & Results: Three strains were analyzed for biofilm formation by Salmonella spp., and they are S. Typhimurium ATCC 14028, S. Enteritidis ATCC 13076 and S. Enteritidis isolated from drag swab on poultry farm and genetically confirmed by Microarray, denominated P106. Coupons of stainless steel AISI 316, with an area of 1 cm² were used. These materials used for the coupons were obtained from the equipments at the cutting room in the poultry slaughterhouse. Biofilms were formed using TSB broth without glucose and incubated at 36°C for 24 h. Six replicates were performed for each microorganism in each removal method. After the biofilm formation, two methods were used in the removal stage, the vortexing, performed for 2 min, and the sonication method, with coupons maintained for 10 min in an ultrasound bath, at a frequency of 40 kHz and potency 81 W. Serial dilutions were made and transferred to PCA agar for quantification in log10CFU.mL-1. The microtopography was performed by scanning electron microscopy (SEM) of surfaces before the removal step. Statistical analysis of the results showed no significant difference between the two removal methods and between the three strains studied (P > 0.05).[...](AU)