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This study aimed to examine the effects of selenium (Se) and vitamin E (vitE) supplementation on blood cell counts and blood metabolite concentrations in goats and their kids. Fifteen Saanen goats (average age 6 years of age; average initial body weight of 70 ± 10 kg) and 21 ½ Saanen × ½ Pardo Alpine crossbred goat kids (average body weight of 3.70 ± 0.64 kg) were used. Animals were distributed in a completely randomized design with five replicates per diet for mother goats and seven for goat kids and randomly assigned into three groups in the following diets: CON, control basal diet; Se, inclusion of 3.2 mg of Se/kg DM; SevitE, inclusion of 3.2 mg Se/kg DM and 1145 IU/day vitE/kg DM. Effects of time were observed on red blood cells, hemoglobin, hematocrit, mean corpuscular volume, and mean corpuscular hemoglobin in goats and goat kids. Effects of time were observed on differential counts of leucocytes, lymphocytes, and monocytes in goat kids. Interaction was observed for high-density lipoprotein and total protein in goats and for triglycerides, beta-hydroxybutyrate (BHBA), and gamma-glutamyltransferase (GGT) in goat kids. Effects of time were observed on low-density lipoprotein, triglycerides, glucose, lactate, BHBA, non-esterified fatty acids (NEFA), creatinine, aspartate-aminotransferase, and GGT in goats and all blood metabolites in goat kids. Selenium, vitE, or association in the evaluated levels are not sufficient to change blood cell counts when supplied in diets for goats or goat kids. However, the effect of time or interaction between time and diets change the blood metabolite concentrations in the animals.
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Cabras , Selenio , Animales , Dieta/veterinaria , Suplementos Dietéticos , Periodo Periparto , Selenio/farmacología , Vitamina ERESUMEN
BACKGROUND: Infections caused by Shewanella spp. have been increasingly reported worldwide. The advances in genomic sciences have enabled better understanding about the taxonomy and epidemiology of this agent. However, the scarcity of DNA sequencing data is still an obstacle for understanding the genus and its association with infections in humans and animals. RESULTS: In this study, we report the first isolation and whole-genome sequencing of a Shewanella algae strain from a swine farm in Brazil using the boot sock method, as well as the resistance profile of this strain to antimicrobials. The isolate was first identified as Shewanella putrefaciens, but after whole-genome sequencing it showed greater similarity with Shewanella algae. The strain showed resistance to 46.7% of the antimicrobials tested, and 26 resistance genes were identified in the genome. CONCLUSIONS: This report supports research made with Shewanella spp. and gives a step forward for understanding its taxonomy and epidemiology. It also highlights the risk of emerging pathogens with high resistance to antimicrobial formulas that are important to public health.
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Granjas , Genoma Bacteriano/genética , Shewanella/genética , Shewanella/aislamiento & purificación , Animales , Antibacterianos/farmacología , Brasil , ADN Bacteriano/genética , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Farmacorresistencia Bacteriana Múltiple/genética , Microbiología Ambiental , Pruebas de Sensibilidad Microbiana , Filogenia , ARN Ribosómico 16S/genética , Shewanella/clasificación , Shewanella/efectos de los fármacos , Porcinos , Factores de Virulencia/genéticaRESUMEN
UNLABELLED: The aim of this study was to verify the presence of lipolytic and proteolytic Pseudomonas spp. during milking and storage of refrigerated raw milk. We also intended to compare samples collected during rainy and dry seasons, from farms with manual and mechanical milking systems. For this, samples of milkers' hands, cows' teats, water, expansion tanks, equipment, and utensils used during milking were analyzed regarding Pseudomonas spp. COUNT: Positive samples were tested for the production of lipolytic and proteolytic enzymes. Microorganisms of the genus Pseudomonas were isolated from all sampling points. A higher isolation rate of the bacterium was found in the rainy season except for 6 sampling points, with all of these associated with mechanical milking systems. Pseudomonas spp. exhibiting lipolytic activity were found to be predominant during the dry season, since no activity was detected during the rainy season in 26 of the 29 sampling sites. The highest number of lipolytic Pseudomonas isolates was obtained from water. Presence of lipase-producing Pseudomonas spp. was verified in 7 and 36% of the samples collected from farms with manual and mechanical milking, respectively. When analyzing raw milk collected from expansion tanks immediately (0 h) and 24h after milking, we observed that for dairy properties with manual milking process, 10% of the Pseudomonas isolates were positive for lipolytic activity. The percentage increased to 12% 48h after milking. Mean averages were 32, 33, and 39% immediately after, 24 and 48h after milking, respectively, for farms with mechanical milking. All sampling points showed the presence of proteolytic strains of Pseudomonas. The highest proteolytic activity was found during the rainy season, except for the samples collected from milkers' hands before milking, buckets, and teat cup inner surfaces after milking and from the water in dairy farms with mechanical milking system. Of these samples, 72, 56, and 50%, respectively, were positive for proteolysis during the dry season. For the water samples, a statistical difference was observed between mechanical (50%) and manual (7%) milking systems in the percentage of proteolytic activity. No production of proteolytic enzyme was detected in the samples from milkers' hands taken after milking and no statistically significant difference was found among manual (19.91%) and mechanical (47.85%) milking. During the rainy months, no proteolysis was detected in the samples taken from cows' teats after the predipping. It is evident, therefore, that preventive measures capable of minimizing the contamination with Pseudomonas spp. during milking and storage of refrigerated raw milk are needed, regardless of season.
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Industria Lechera/métodos , Almacenamiento de Alimentos/métodos , Lipólisis , Leche/química , Proteolisis , Pseudomonas/metabolismo , Animales , Leche/microbiología , Refrigeración , Estaciones del AñoRESUMEN
ß-Casomorphin-7 (BCM-7) is a peptide released through the proteolysis of ß-casein (ß-CN), which is considered a bioactive peptide displaying evidence of promoting the binding and activation of the µ-opioid receptor located in various body parts, such as the gastrointestinal tract, the immune system and potentially the central nervous system. The possible effects of BCM-7 on health are a theme rising in popularity due to evidence found in several studies on the modulation of gastrointestinal proinflammatory responses that can trigger digestive symptoms, such as abdominal discomfort. With the advancement of studies, the hypothesis that there is a correlation of the possible effects of BCM-7 with the microbiota-gut-brain axis has been established. However, some studies have suggested the possibility that these adverse effects are restricted to a portion of the population, and the topic is controversial due to the small number of in vivo studies, which makes it difficult to obtain more conclusive results. In addition, a threshold of exposure to BCM-7 has not yet been established to clarify the potential of this peptide to trigger physiological responses at gastrointestinal and systemic levels. The proportion of the population that can be considered more susceptible to the effects of BCM-7 are evidenced in the literature review. The challenges of establishing the adverse effects of BCM-7 are discussed, including the importance of quantifying the BCM-7 release in the different ß-CN genotypes. In summary, the reviewed literature provides plausible indications of the hypothesis of a relationship between ß-CN A1/BCM-7 and adverse health effects; however, there is need for further, especially in vivo studies, to better understand and confirm the physiological effects of this peptide.
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The concern with human health has increased the interest in producing foods enriched with polyunsaturated fatty acids (PUFA), directly or naturally, by inclusion in the animals' diet. The positive effects such as antithrombotic, anti-inflammatory, and hypolipidemic have been observed in pigs and rats, used as human models for study. The present study evaluated the effect of cow's milk with different lipid profiles on performance, serum fatty acid profile, biochemical analysis, and a complete blood count of gilts used as a human model. At 34 days, thirty gilts were equally distributed in three treatments. Experimental treatments were milk from cows without the oil supplementation (C), milk from cows fed an enriched diet with linseed oil (n-3), and milk from cows fed an enriched diet with soybean oil (n-6). Milk supplementation was performed until 190 days old, provided once in the morning. The n-3 and n-6 milk reduced the concentration of myristic acid in the blood and increased the leukocytes. Milk enriched with n-3 compared to n-6 reduced the stearic acid. In conclusion, milk with a better PUFA profile can reduce saturated fatty acids in the blood and alter the concentration of cells in the defense system.
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Suplementos Dietéticos , Leche , Animales , Bovinos , Dieta/veterinaria , Ácidos Grasos/análisis , Ácidos Grasos Insaturados , Femenino , Lactancia , Aceite de Linaza , Leche/química , Ratas , Sus scrofa , PorcinosRESUMEN
Functional oils are known for their compounds with antioxidant, antimicrobial and anti-inflammatory properties, and are used in ruminant nutrition as alternatives to chemicals in order to improve performance. This study aimed to compare the influence of castor and cashew nut shell oils with pure organic selenium (hydroxy-selenomethionine) plus vitamin E, which are known and well-stablished antioxidants, on the performance traits, shelf life and microbial quality of the meat, physiological functions and oxidative stress control of lambs. Thirty-two Dorper x Santa Ines lambs (initial bodyweight of 22.42 ± 3.9 kg and 60 days of age) were submitted to a diet consisting of Cynodon dactylon hay (6%) and concentrate (94%). The animals were divided into four treatments: control, without additives; functional oils (FO), 0.50 g/kg DM of castor and cashew nut shell oils; hydroxy-selenomethionine and vitamin E (SeE), 0.50 mg/kg of organic selenium and 100 IU/kg DM of vitamin E; FO plus SeE, at the same doses as the other groups. Blood samples were collected after 1, 30 and 53 days on feed. After 54 days, the lambs were slaughtered and rumen health, carcass and meat traits, shelf life, and microbiological quality were evaluated. There were no differences in performance or carcass traits. A higher muscle and serum Se concentration (p < 0.0001), lower lipid peroxidation in meat during display (p < 0.0001), and a lower count of psychrotrophic microorganisms on day 5 were observed in the SeE and FO plus SeE groups. The treatments reduced the counts of Enterobacteriaceae, and Staphylococcus spp. FO animals showed higher GSH-Px activity on day 30, while the peroxidase activity was higher in FO plus SeE animals (p = 0.035). SeE and FO plus SeE animals had lower serum ALT and AST levels. Functional oils improved the microbiological quality of meat. Hydroxy-selenomethionine and vitamin E prevented oxidative stress, lipid peroxidation, and microbial spoilage.
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The species of the Bacillus cereus group have the ability to adhere to and form biofilms on solid surfaces, including stainless steel, a material widely used in food industries. Biofilms allow for recontamination during food processing, and the "clean-in-place" (CIP) system is largely used by industries to control them. This study thus proposes to evaluate the efficacy of peracetic acid and sodium hypochlorite against biofilms induced on stainless-steel surfaces. The SAMN07414939 isolate (BioProject PRJNA390851), a recognized biofilm producer, was selected for biofilm induction on AISI 304 stainless steel. Biofilm induction was performed and classified into three categories: TCP (Tindalized, Contaminated, and Pasteurized milk), TCS (Tindalized milk Contaminated with Spores), and TCV (Tindalized milk Contaminated with Vegetative cells). Subsequently, the coupons were sanitized simulating a CIP procedure, on a pilot scale, using alkaline and acid solutions followed by disinfectants (peracetic acid and sodium hypochlorite). Microorganism adhesion on the surfaces reached 6.3 × 105 to 3.1 × 107 CFU/cm-2. Results did not show significant differences (p > 0.05) for surface adhesion between the three tested categories (TCP, TCS, and TCV) or (p > 0.05) between the two disinfectants (peracetic acid and sodium hypochlorite). Microbial populations adhered to the stainless-steel coupons are equally reduced after treatment with peracetic acid and sodium hypochlorite, with no differences in the control of B. cereus s.s. biofilms on AISI 304 stainless-steel surfaces.
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The genomes of 262 Bacillus cereus isolates were analyzed including 69 isolates sampled from equipment, raw milk and dairy products from Brazil. The population structure of isolates showed strains belonging to known phylogenetic groups II, III, IV, V and VI. Almost all the isolates obtained from dairy products belonged to group III. Investigation of specific alleles revealed high numbers of isolates carrying toxin-associated genes including cytK (53.62%), hblA (59.42%), hblC (44.93%), hblD (53.62%), nheA (84.06%), nheB (89.86%) and nheC (84.06%) with isolates belonging to groups IV and V having significant higher prevalence of hblACD and group IV of CytK genes. Strains from dairy products had significantly lower prevalence of CytK and hblACD genes compared to isolates from equipment and raw milk/bulk tanks. Genes related to sucrose metabolism were detected at higher frequency in isolates obtained from raw milk compared to strains from equipment and utensils. The population genomic analysis demonstrated the diversity of strains and variability of putative function among B. cereus group isolates in Brazilian dairy production, with large numbers of strains potentially able to cause foodborne illness. This detailed information will contribute to targeted interventions to reduce milk contamination and spoilage associated with B. cereus in Brazil.
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Bacillus cereus/genética , Microbiología de Alimentos , Genoma Bacteriano/genética , Genómica , Animales , Bacillus cereus/clasificación , Bacillus cereus/aislamiento & purificación , Brasil/epidemiología , ADN Bacteriano/genética , Productos Lácteos/microbiología , Enterotoxinas/genética , Microbiología Ambiental , Enfermedades Transmitidas por los Alimentos/epidemiología , Enfermedades Transmitidas por los Alimentos/microbiología , Variación Genética , Genotipo , Filogenia , Análisis de Secuencia de ADNRESUMEN
The Taenia saginata-cysticercosis complex is an important zoonosis for public health and an important cause of economical losses for beef supply chain in developing and industrialized countries. Despite some risk factors for high-occurrence areas have already been described, further studies are required to better understand its global epidemiology. So, this study focused on establishing the prevalence, spatial distribution and environmental and human population aspects correlated with bovine cysticercosis prevalence in the state of Mato Grosso do Sul, Brazil. To this, we used data of 7,415,998 animals slaughtered from all 79 municipalities located in this state. Cysticercosis prevalence showed spatial distribution dependence (Moran Index=0.375, p=0.01) and some areas presented higher risk. Positive correlations of bovine cysticercosis prevalence with human population density (R=0.5712, p=3.85 e-08) and rainfall index (R=0.631, p=0.03) were observed. A negative correlation (R=-0.4637, p=2.096 e-05) with cattle population size was also established. These results highlight the importance of adopting sanitary measures to prevent environment contamination, besides other prophylactic measures like the treatment of human patients in order to reduce the Taenia saginata-cysticercosis complex occurrence.
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This present research focused on establishing the prevalence, geospatial distribution and epidemiological risk factors for bovine cysticercosis in the state of São Paulo, Brazil, in cattle slaughtered for human comsumption. Data about the inspection of 104,180 bovine carcasses from 215 farms and from 70 municipalities were gathered between January and December of 2012. A cluster analysis was performed in order to correlate some variables: prevalence of bovine cysticercosis, total coffee harvesting area (hectares), orange producing areas (hectares) and Human Development Index. Afterwards, distribution maps were created in order to help the results interpretation. An average prevalence of 2.9% was established in the state of São Paulo during the studied period. The Administrative regions of São José do Rio Preto and Campinas had higher risk for cysticercosis (OR >1 and 95% CI >1). The cluster analysis showed a grouping (G1 cluster) of the variables: prevalence of bovine cysticercosis, total area of sugar cane harvested, total area of orange harvested and total area of coffee harvested. This agrroupment allows us to infer that cyticercosis cases in this region are correlated with those variables distribution. Such aspects indicate that the presence of temporary rural workers and other socioeconomic and cultural features in each region can contribute to bovine cysticercosis dissemination in some areas.
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This study focused on estimating the prevalence and evaluating the geospatial distribution of bovine cysticercosis in the state of Mato Grosso, Brazil. To this, we used data of 6,200,497 animals slaughtered during the years of 2013 and 2014, and from 141 municipalities of the state. The prevalence observed for this period was 0.0873% (95% CI 0.0851-0.0897). Regarding the cysticerci detected, the calcified ones were the most frequent (74.43%). The high odds ratios were observed in animals reared in the Administrative Regions of Sinop, Barra do Garças, Água Boa, Cáceres, Barra do Bugres, Cuiabá, Pontes Lacerda, Rondonópolis, Matupa, São Félix do Araguaia and Lucas do Rio Verde, respectively. Furthermore, the results indicate the existence of a relation between the areas with high cysticercosis prevalence and human population density. We highlight the need of the development of a risk model based on the origin to improve cysticercosis detection in endemic areas.
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Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/parasitología , Cisticercosis/veterinaria , Mataderos , Animales , Brasil/epidemiología , Bovinos , Cisticercosis/epidemiología , Cysticercus/aislamiento & purificación , Femenino , Inspección de Alimentos , Sistemas de Información Geográfica , Humanos , Modelos Logísticos , Masculino , Carne/parasitología , Prevalencia , Análisis EspacialRESUMEN
Background Infections caused by Shewanella spp. have been increasingly reported worldwide. The advances in genomic sciences have enabled better understanding about the taxonomy and epidemiology of this agent. However, the scarcity of DNA sequencing data is still an obstacle for understanding the genus and its association with infections in humans and animals. Results In this study, we report the first isolation and whole-genome sequencing of a Shewanella algae strain from a swine farm in Brazil using the boot sock method, as well as the resistance profile of this strain to antimicrobials. The isolate was first identified as Shewanella putrefaciens, but after whole-genome sequencing it showed greater similarity with Shewanella algae. The strain showed resistance to 46.7% of the antimicrobials tested, and 26 resistance genes were identified in the genome. Conclusions This report supports research made with Shewanella spp. and gives a step forward for understanding its taxonomy and epidemiology. It also highlights the risk of emerging pathogens with high resistance to antimicrobial formulas that are important to public health.
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A incidência e a quantidade dos microrganismos patogênicos, presentes na carne, varia de acordo com as condições de manejo durante a criação e com os cuidados higiênicos nas operações de abate dos animais e posterior manipulação das carcaças. Neste sentido, este trabalho promoveu uma análise microbiológica de microrganismos patogênicos presentes em quibe cru e cortes de frango temperado produzidos no município de Rio Verde, Goiás. No diagnóstico, foram encontradas prevalências de Salmonella spp., Bacillus cereus e Listeria spp, comprovando as falhas presentes na manipulação. Concluindo que há falhas e necessidades de adequações técnicas, como adequação na legislação vigente à realidade dos municípios.
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Bacillus cereus/aislamiento & purificación , Higiene Alimentaria , Listeria/aislamiento & purificación , Microbiología de Alimentos , Productos de la Carne/análisis , Salmonella/aislamiento & purificaciónRESUMEN
Bacillus cereus group includes not pathogenic and high pathogenic species. They are considered as a risk to public health due to foodborne diseases and as an important cause of economic losses to industries due to production of spoilage enzymes. Some researches have been performed in order to assess the possible factors that contribute to put public health into risk because of consumption of food contaminated with viable cells or toxins which have complex mechanisms of production. The control of these bacteria in food is difficult because they are resistant to several processes used in industries. Thus, in this way, this review focused on highlighting the risk due to toxins production by bacteria from B. cereus group in food and the consequences for food safety and dairy industries.(AU)
Diversas espécies fazem parte do grupo de Bacillus cereus, desde algumas apatogênicas até outras com alta patogenicidade. Consistem em risco à saúde pública decorrentes de toxinfecções alimentares, além de causarem importantes perdas econômicas para as indústrias em virtude da produção de enzimas deteriorantes. O controle da contaminação em alimentos por esses micro-organismos é difícil, visto que são resistentes a vários tratamentos utilizados pelas indústrias. Assim, diante do exposto, esta revisão objetivou fornecer informações em relação aos aspectos genéticos desse grupo de bactérias e seus mecanismos de produção de toxinas, além de ressaltar a importância e as novas estratégias de controle para as companhias alimentícias e de laticínios.(AU)
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Bacillus cereus/patogenicidad , Bacterias , Genoma , Inocuidad de los Alimentos , Enfermedades Transmitidas por los AlimentosRESUMEN
This study aimed to evaluate the occurrence of Bacillus cereus group in requeijões and especialidades lácteas tipo requeijão (regular and light) and to verify if there is differences in relation to this occurrence among different categories of these products. A set of 14 (35%) lots was contaminated with this bacterial group from the 40 lots with low counts (maximum 3.1 × 10 CFU/g), and no significant difference regarding counts or presence/absence were observed among the categories of the products. It can be concluded that contamination by B. cereus group in these products is unable to consist in risk to consumers, regarding adequate refrigeration during selling. This study was the first one to report this bacteria group for these dairy products and highlights the needs of further investigations to evaluate the impact of its spoilage during shelf life.(AU)
Este estudo objetivou avaliar a ocorrência de bactérias do grupo de Bacillus cereus em requeijões e especialidades lácteas (normais e light) e verificar se há diferença em relação a essa ocorrência entre as diferentes categorias desses produtos. Entre os 40 lotes avaliados, 14 (35%) estavam contaminados por bactérias desse grupo, com baixas contagens (máxima de 3,1 × 10 UFC/g) e sem diferenças significativas no que tange às contagens ou à presença/ausência entre as diversas categorias. Conclui-se que as bactérias do grupo de B. cereus em requeijões e especialidades lácteas são incapazes de consistir em risco aos consumidores desses produtos, desde que as condições de refrigeração sejam adequadas durante armazenamento e venda. O presente trabalho é o primeiro a relatar a presença de tal grupo de micro-organismos nesses tipos de produtos, porém, são necessários novos estudos para avaliar o impacto de sua ação deteriorante sobre o período em que passa na prateleira.(AU)
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Bacillus cereus , Bacterias , Productos Lácteos/microbiología , Inocuidad de los AlimentosRESUMEN
ABSTRACT: The study aimed to evaluate the equipment Ekomilk Scan® as an alternative to somatic cell count (SCC) in milk. For this individual cow milk samples of various ages and different stages of lactation in northeastern state of São Paulo region were collected. The analyzes performed were divided into variables related to the equipment: repeatability and reproducibility, and variables that could influencing the results as: use of preservatives, temperature, time between collection and analysis, breed and milk composition, besides analysis to relate the Ekomilk Scan® with the standard method-direct microscopy and reference-flow cytometry. As the result, for samples analysis, it shouldn't be added preservative and these should be conducted on the same day of collection; however, temperature sample did not significantly influence results. Furthermore, Ekomilk Scan® did not show good correlation of results with the method of direct microscopy; however, it was necessary to generate equations for a positive correlation between flow cytometry and Ekomilk Scan®. Therefore, it is concluded that the equipment tested is not accurate but it can be an alternative for SCC monitoring in productive units since it uses calibration equations of results.
RESUMO: O estudo objetivou avaliar o equipamento Ekomilk Scan® como uma alternativa para a contagem de células somáticas (CCS) no leite. Para isso, foram colhidas amostras individuais de leite de vaca de várias idades em diferentes estágios de lactação na região nordeste do estado de São Paulo. Foram realizadas análises referentes ao equipamento como repetibilidade e reprodutibilidade, e de variavéis que poderiam influenciar no resultado. Dentre elas: uso de conservante, temperatura, tempo entre a colheita e análise, raça e composição do leite, além de análises visando correlacionar o Ekomilk Scan® com o método padrão-microscopia direta e de referência-citometria de fluxo. Como resultado, foi observado que para as análises das amostras não se deve acrescentar conservante e estas devem ser realizadas no mesmo dia da colheita, porém a temperatura da amostra não possui influencia significativa nos resultados. O Ekomilk Scan® não demonstrou boa correlação dos resultados com o método de microscopia direta e citometria de fluxo, sendo necessário gerar equações para uma correlação positiva entre os métodos. Assim, conclui-se que o equipamento testado não apresenta resultados precisos, contudo pode ser uma alternativa para o monitoramento da CCS em unidades produtivas desde que utilize equações de calibração dos resultados.
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Objetivou-se verificar se as populações de Bacillus cereus presentes em leite em pó integral apresentam-se de acordo com a legislação vigente e também verificar diferença entre a presença desse microrganismo de acordo com o tipo de embalagem (lata e papel laminado). Para isso, foram adquiridas 40 amostras de leite em pó integral comercializadas no município de Ribeirão Preto, Estado de São Paulo. Cerca de 20% das amostras analisadas continham populações de B. cereus. Entretanto, todas estavam dentro dos limites aceitos pela legislação. Não foi verificada diferença significativa quando analisadas as populações presentes entre as diferentes apresentações do produto. Conclui-se que todas as amostras avaliadas estavam de acordo com a legislação vigente e, portanto, não há problemas na comercialização de leite em pó integral na região avaliada.
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Bacillus , Leche Entera en Polvo , Análisis de los AlimentosRESUMEN
ABSTRACT: This study focused on counting Staphylococcus spp. in curd cheeses “requeijão” and “especialidade láctea type requeijão” sold in Brazil, assessing the presence of mecA gene in obtained isolates and establishing antimicrobial resistance profile of the mecA gene positive isolates. To this, a set of 200 samples of these dairy products were evaluated. Low counts of Staphylococcus spp. were observed in these dairy products. All the isolates were determined as coagulase-negative strains using coagulase test and PCR. However, two isolates (3.70%) were carriers of mecA gene and they can be considered as risk for public health. These isolates presented resistance to penicillin, oxacillin and erythromycin. In conclusion, low counts of Staphylococcus were detected in curd cheese “requeijão” and “especialidade láctea type requeijão” sold in Brazil. However, coagulase-negative methicillin-resistant Staphylococcus spp. was detected in these dairy products. This is the first report of the detection of methicillin-resistant Staphylococcus spp. in heat-treated dairy products in Brazil. Results served as a warning to public sanitary authorities to control multidrug-resistant strains in veterinary and human medicine.
RESUMO: Este trabalho objetivou realizar a contagem de Staphylococcus spp. em queijos fundidos “requeijão” e “especialidade láctea tipo requeijão” comercializados no Brasil, verificar a presença do gene mecA nos isolados obtidos e estabelecer o perfil de resistência antimicrobiana dos isolados positivos para tal gene. Para isso, 200 amostras desses produtos lácteos foram avaliadas. Baixas contagens de Staphylococcus spp. foram observadas nas amostras. Todos os isolados foram considerados como coagulase-negativos através do teste da coagulase e através da PCR. Entretanto, em dois isolados (3,70%) foi possível detectar o gene mecA e representam potencial risco à saúde pública. Esses isolados apresentaram resistência a penicilina, oxacilina e eritromicina. Conclui-se que baixas contagens de Staphylococcus foram detectadas em queijos fundidos “requeijão” e “especialidade láctea type requeijão”. Entretanto, cepas de Staphylococcus spp. coagulase-negativas e resistentes à meticilina foram detectadas nesses derivados lácteos. Esse é o primeiro relato da ocorrência de cepas de Staphylococcus spp. resistentes à meticilina em produtos lácteos termicamente tratados comercializados no Brasil. Os resultados servem como um alerta para as autoridades sanitárias públicas nacionais para o controle de cepas multirresistentes em medicina veterinária e humana.
RESUMEN
ABSTRACT: With the objective to evaluate the hygienic and sanitary conditions of grated parmesan cheese acquired from the retail business, total 120 cheese samples were acquired: 60 of which were obtained from four different brands of cheese that were grated in factories, and the other 60 samples were obtained from another four brands of cheese that are normally acquired by retailers (supermarkets) in blocks and grated at the moment of sale. The population of heterotrophic mesophilic microorganisms ranged from 1.2×10³ to 1.1×107 colony-forming units (CFU)·g-1. All samples analyzed contained Staphylococcus spp. with populations varying from 1.2×10³ to 8.7×106CFU·g-1, from which 60.0% were classified as coagulase-positive Staphylococcus and 52.5% of the samples possessed populations above the permissible limit set by legislation. Staphylococcus aureus was detected in 57.5% of the samples. Population of molds and yeasts varied from <10 to 1.8×106CFU·g-1. Salmonella spp. was not isolated in this research. A difference was observed between the parmesan cheese grated in factories and that grated in supermarkets, where the former presented better microbiological quality than the latter. Thus, procedures must be proposed to minimize the presence of pathogenic agents reported in grated parmesan cheeses evaluated in the present study because of the public health risk associated with food bacterial contamination.
RESUMO: Com o objetivo de avaliar as condições higiênicas e sanitárias de queijos tipo parmesão ralados, vendidos no comércio varejista, foram realizadas análises microbiológicas em 120 amostras, sendo 60 destas de quatro marcas comerciais, as quais foram raladas industrialmente e outras 60 de quatro marcas, cujos queijos foram adquiridos pelos comércios varejistas em grandes peças e ralados no ato da venda. As populações de microrganismos heterotróficos mesófilos variaram de 1,2×10³ a 1,1×107UFC.g-1. Todas as amostras analisadas apresentaram Staphylococcus spp., com populações que variaram de 1,2×10³ a 8,7×106UFC.g-1, sendo que 60,0% dessas apresentaram Staphylococcus coagulase positivo e 52,5% delas com populações acima do limite estabelecido pela legislação. A presença de Staphylococcus aureus foi identificada em 57,5% das amostras. As populações de bolores e leveduras apresentaram variação de <10 a 1,8×106UFC.g-1 . Salmonella spp. não foi isolada no presente trabalho. Houve diferença entre os queijos ralados industrialmente e os queijos ralados nos supermercados, sendo que o primeiro grupo apresentou resultados de qualidade microbiológicas melhores do que o segundo grupo. Assim, medidas visando minimizar as populações de agentes contaminantes e deteriorantes encontradas nos queijos parmesão analisados no presente trabalho devem ser realizadas, visto que estas podem representar um risco à saúde pública.
RESUMEN
ABSTRACT: The present study focused on isolation Bacillus cereus during the UHT milk production and shelf life, to assess the enterotoxigenic production capacity of isolates and to evaluate the use of the RAPD-PCR technique to verify whether Bacillus cereus isolated at different phases of UHT milk processing belongs to the same strain. For this, six groups of milk samples composed of raw, pasteurized and UHT milk were collected from a processing plant. The results revealed that bacteria belonging to the Bacillus cereus group were isolated from 51.6%, 81.6% and from 13.8% of raw, pasteurized and UHT milk samples, respectively. About 50.0% of isolates from raw milk, 19.2% isolates from pasteurized milk and 70.7% isolates from UHT milk were capable of producing enterotoxins. It was confirmed the genetic similarity among Bacillus cereus isolates from raw, pasteurized and UHT milk, therefore demonstrating that the microorganism is able to withstand UHT treatment. These results should serve as a warning to health authorities, given that 13.8% of samples were not in accordance with standards established by the Department of Health for containing a potentially pathogen agent, therefore indicating that contamination of milk by sporulating bacteria should be avoided.
RESUMO: Objetivou-se realizar o isolamento de bactérias do grupo do Bacillus cereus e verificação da semelhança genética entre elas, através da PCR-RAPD, durante a produção e vida de prateleira do leite UAT, bem como verificar sua capacidade enterotoxigência. Para isso, foram colhidas em uma usina de beneficiamento seis grupos de amostras de leite compostos cada um por amostras de leite cru, pasteurizado e UAT. Os resultados obtidos evidenciaram que bactérias do grupo do Bacillus cereus foram isoladas de 51,6% das amostras de leite cru, de 81,6% das de leite pasteurizado e de 13,8% das de leite UAT. Demonstraram-se capazes de produzir enterotoxinas 50,0% dos isolados de leite cru, 19,2% de leite pasteurizado e 70,7% de leite UAT. Também se pode constatar a semelhança genética entre as cepas de Bacillus cereus isoladas do leite cru, pasteurizado e UAT, evidenciando assim que o micro-organismo é capaz de resistir ao tratamento por UAT. Tais resultados devem servir de alerta às autoridades sanitárias, tendo em vista que 13,8% deles estavam em desacordo com o estabelecido pelo Ministério da Saúde, por serem capazes de veicular um agente potencialmente patogênico, demonstrando assim que a contaminação do leite por bactérias esporuladas deve ser motivo de preocupação.