Optimizing the Antimicrobial Activity of Sodium Hypochlorite (NaClO) over Exposure Time for the Control of Salmonella spp. In Vitro.

Fish is a nutritionally rich product; however, it is easily contaminated by pathogenic microorganisms, such as Salmonella spp. Therefore, this study aimed to identify the best concentration of sodium hypochlorite (NaClO), exposure time, and water temperature that allow the most effective antimicrobial effect on the viable population of Salmonella spp. Thus, Salmonella Enteritidis ATCC 13076 and Salmonella Schwarzengrund were exposed to different time frames, ranging from 5 min to 38.5 min, temperatures between 5 and 38.5 °C, and NaClO concentrations ranging from 0.36 to 6.36 ppm, through a central composite rotational design experiment (CCRD). The results demonstrated that the ATCC strain exhibited a quadratic response to sodium hypochlorite when combined with exposure time, indicating that initial contact would already be sufficient for the compound's action to inhibit the growth of the mentioned bacteria. However, for S. Schwarzengrund (isolated directly from fish cultivated in aquaculture), both NaClO concentration and exposure time significantly influenced inactivation, following a linear pattern. This suggests that increasing the exposure time of NaClO could be an alternative to enhance Salmonella elimination rates in fish slaughterhouses. Thus, the analysis indicates that the Salmonella spp. strains used in in vitro experiments were sensitive to concentrations equal to or greater than the recommended ones, requiring a longer exposure time combined with the recommended NaClO concentration in the case of isolates from aquaculture.

Genomic features and heat resistance profiles of Escherichia coli isolated from Brazilian beef.

AIMS: Characterize Escherichia coli and E. coli -producing (STEC) isolates from Brazilian beef to determine heat resistance and the presence of the transmissible locus of stress tolerance (tLST). METHODS AND RESULTS: Twenty-two STEC previously isolated from beef and characterized as STEC by PCR were subjected to different heat survival challenges (60°C and 71°C). Furthermore, the three tLST-positive isolates and one tLST-negative isolate by PCR were selected for WGS analysis. Phenotypic results indicated that 3/22 (13.64%) were heat resistant, 12/22 (54.54%) were moderately resistant, and 7/22 (31.82%) were sensitive to heat treatments. WGS analyses showed that three isolates with heat resistance showed tLST with up to 80% and 42% of similarity by BLAST analysis, with the major tLST genes being responsible for the homeostasis module. However, WGS showed the absence of stx genes associated with tLST-positive isolates, albeit with virulence and resistance genes found in extraintestinal pathogenic E. coli (ExPEC). CONCLUSION: Our findings demonstrate the presence of heat-resistant E. coli as well as confirm some tLST genes in E. coli isolated from Brazilian beef.

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

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

Antimicrobial Resistance of Listeria monocytogenes from Animal Foods to First- and Second-Line Drugs in the Treatment of Listeriosis from 2008 to 2021: A Systematic Review and Meta-Analysis.

First-line drugs for the treatment of listeriosis are the same around the world, but particular conditions might reduce their efficacy, including antimicrobial resistance. Therefore, this study aimed to verify, based on a systematic review and meta-analysis, whether the prevalence of antimicrobial resistance in Listeria monocytogenes from animal foods is higher for first- or second-line antimicrobials. From the total of 302 identified studies, 16 met all the eligibility criteria from 2008 to 2021 and were included in this meta-analysis. They comprised a dataset of 1152 L. monocytogenes isolates, obtained from different animal food products, food processing environment, and live animals. The included studies were developed in South America (n = 5), Europe (n = 4), Asia (n = 3), Africa (n = 2), and North America (n = 2), testing a total of 35 different antimicrobials, 11 of them classified as first-line drugs. Complete lack of antimicrobial resistance across the studies (all L. monocytogenes isolates tested as susceptible) was only observed for linezolid, while widespread antimicrobial resistance (all L. monocytogenes isolates tested resistant) was described for amoxicillin, benzylpenicillin, cefoxitin, fusidic acid, imipenem, sulfamethoxazole, and vancomycin. Overall, the meta-analysis results indicated no evidence that antimicrobial resistance in L. monocytogenes isolated from animal-based food is higher for first-line antimicrobials compared to second-line compounds (p=0.37). A greater volume of publication, together with better characterization of the isolates, is still needed for a more precise estimate of the real prevalence of antimicrobial resistance in L. monocytogenes.

Listeria monocytogenes and Pseudomonas spp. Distribution in a Processing Facility of Spotted Sorubim (Pseudoplatystoma corruscans) in Brazil.

ABSTRACT: The ecology of Listeria monocytogenes and Pseudomonas spp. during the slaughtering of spotted sorubim (Pseudoplatystoma corruscans) in a fish processing facility was assessed. Fish samples (n = 28) were obtained in different points of slaughtering (A, arrival; B, washing; C, gutting; and D, cooling) and subjected to detection of L. monocytogenes and enumeration of Pseudomonas spp. High frequencies of Listeria spp. (17 of 28 to 22 of 28) and L. monocytogenes (6 of 28 to 9 of 28) were identified in all slaughtering points but were not significantly different (P ≥ 0.05). All L. monocytogenes isolates (n = 33) were identified as belonging to serogroup IVb (serotype 4b) and subjected to macrorestriction with ApaI and AscI. The results indicated a continuous entry of L. monocytogenes in the facility, as well as a temporary persistence of a specific pulsotype. Pseudomonas spp. counts significantly decreased between points A and D (P < 0.05), but the mean counts in the end products (D) remained higher than 3 log CFU/g, suggesting the potential for fast spoilage. The obtained results show that L. monocytogenes and Pseudomonas spp. are widely distributed during spotted sorubim slaughtering, indicating the need for proper hygienic procedures to control these bacteria in the processing facility.

Salmonella spp. in Aquaculture: An Exploratory Analysis (Integrative Review) of Microbiological Diagnoses between 2000 and 2020.

The present study aimed to characterize, through descriptive statistics, data from scientific articles selected in a systematic integrative review that performed a microbiological diagnosis of Salmonella spp. in aquaculture. Data were obtained from research articles published in the BVS, Scielo, Science Direct, Scopus and Web of Science databases. The selected studies were published between 2000 and 2020 on samples of aquaculture animal production (fish, shrimp, bivalve mollusks, and other crustaceans) and environmental samples of aquaculture activity (farming water, soil, and sediments). After applying the exclusion criteria, 80 articles were selected. Data such as country of origin, categories of fish investigated, methods of microbiological diagnosis of Salmonella spp., sample units analyzed and most reported serovars were mined. A textual analysis of the word cloud and by similarity and descending hierarchical classification with the application of Reinert's algorithm was performed using R® and Iramuteq® software. The results showed that a higher percentage of the selected articles came from Asian countries (38.75%). Fish was the most sampled category, and the units of analysis of the culture water, muscle and intestine were more positive. The culture isolation method is the most widespread, supported by more accurate techniques such as PCR. The most prevalent Salmonella serovars reported were S. Typhimurium, S. Weltevreden and S. Newport. The textual analysis showed a strong association of the terms "Salmonella", "fish" and "water", and the highest hierarchical class grouped 25.4% of the associated text segments, such as "aquaculture", "food" and "public health". The information produced characterizes the occurrence of Salmonella spp. in the aquaculture sector, providing an overview of recent years. Future research focusing on strategies for the control and prevention of Salmonella spp. in fish production are necessary and should be encouraged.

Salmonella in the processing line of farmed Tambatinga (Colossoma macropomum x Piaractus brachypomus) in Mato Grosso, Brazil: serotypes of occurrence and antimicrobial profile.

The objective of this study was to evaluate the dispersion dynamics and antimicrobial resistance profiles of Salmonella in the processing of Tambatinga (Colossoma macropomum x Piaractus brachypomus). Thirty fish were monitored during four processing stages (reception, first wash, evisceration, and prepackage area) in a fish slaughterhouse. One hundred and twenty fish surface samples were collected and tested through bacteriological analysis, PCR, serotyping, and antimicrobial resistance profile (disk-diffusion). Of these samples, 7.5% (9/120) were positive for Salmonella, with 0.83% being observed in the pre-packaging phase, indicating a low occurrence at this stage. All the analyzed stages were positive for Salmonella, with the prevalent serovars being Ndolo, Mbandaka, Typhimurium, Rough, and O:16. All strains were sensitive to various antimicrobials. Improvements in microbiological control during all processing stages should be implemented to ensure a Salmonella-free product.

Salmonella Schwarzengrund, Akuafo, and O:16 isolated from vacuum-packaged beef produced in the state of Mato Grosso, Brazil.

INTRODUCTION: Salmonella spp. is a pathogen associated with foodborne infections, mainly in foods of animal origin. In this context, the present study investigated the occurrence of Salmonella serotypes, genotypes and the antimicrobial resistance profiles of strains in fresh beef produced in Mato Grosso, Brazil. METHODOLOGY: A total of 107 samples from 13 different slaughterhouses in the Mato Grosso were analyzed. Suggestive Salmonella spp. colonies detected during the biochemical screening were submitted to DNA extraction, and hilA gene amplification was used for the PCR reaction. Antimicrobial resistance analyses were performed using 17 antimicrobial agents from eight different classes by the disk diffusion method. Strains exhibiting multiple drug resistances were submitted to PCR genotyping based on repetitive sequences (rep-PCR), using a commercial semiautomatic DiversiLab® system. RESULTS: A total of 5.6% (6/107) of the samples tested positive by the conventional method and were confirmed by PCR, namely two S. Akuafo, two non-typable Salmonella enterica strains, one Salmonella O:16 serovar, and one S. Schwarzengrund. The antimicrobial resistance profiles indicated resistance to gentamicin (30%), tetracycline, nitrofurantoin, and trimethoprim + sulfamethoxazole (16%). Genotyping indicated a 70% difference between S. Schwarzengrund and the non-typable Salmonella strains. No genetic similarities were observed between the six Salmonella isolates based on rep-PCR, including two S. Akuafo. CONCLUSIONS: The results obtained herein corroborate that Salmonella serovar Schwarzengrund is commonly isolated in animal products in the state of Mato Grosso, Brazil, also highlighting the presence of two unusual Salmonella serovars in beef (Akuafo and O:16).

Inactivation of Multi-Drug Resistant Non-Typhoidal Salmonella and Wild-Type Escherichia coli STEC Using Organic Acids: A Potential Alternative to the Food Industry.

Salmonella and Escherichia coli are the main bacterial species involved in food outbreaks worldwide. Recent reports showed that chemical sanitizers commonly used to control these pathogens could induce antibiotic resistance. Therefore, this study aimed to describe the efficiency of chemical sanitizers and organic acids when inactivating wild and clinical strains of Salmonella and E. coli, targeting a 4-log reduction. To achieve this goal, three methods were applied. (i) Disk-diffusion challenge for organic acids. (ii) Determination of MIC for two acids (acetic and lactic), as well as two sanitizers (quaternary compound and sodium hypochlorite). (iii) The development of inactivation models from the previously defined concentrations. In disk-diffusion, the results indicated that wild strains have higher resistance potential when compared to clinical strains. Regarding the models, quaternary ammonium and lactic acid showed a linear pattern of inactivation, while sodium hypochlorite had a linear pattern with tail dispersion, and acetic acid has Weibull dispersion to E. coli. The concentration to 4-log reduction differed from Salmonella and E. coli in acetic acid and sodium hypochlorite. The use of organic acids is an alternative method for antimicrobial control. Our study indicates the levels of organic acids and sanitizers to be used in the inactivation of emerging foodborne pathogens.

Behavior of spoilage bacteria and Salmonella enterica subspecies enterica O:4,5 in vacuum-packaged beef during refrigeration / Comportamento de bactérias deteriorantes e Salmonella enterica subespécie entérica O:4,5 em carne bovina embalada a vácuo durante refrigeração

ABSTRACT: In this study, the kinetic parameters of mesophilic, psychrotrophic and lactic acid bacteria in vacuum-packed beef at 1 °C and 4 °C were estimated from experimental growth curves produced by samples stored during 21 and 60 days, respectively. In a separate experiment, the survival of multidrug resistant (MDR) Salmonella enterica O:4,5 at 1°C was also characterized. The shelf-life of vacuum-packed beef stored at 4 °C was estimated at 16.1 days (95% CI: 14.8 - 17.3 days), whereas at 1 °C it was longer than 21 days because the mesophiles count estimated towards the end of the experiment was 12.5 ln CFU.g-1 (95% CI: 11.8 - 13.3 ln CFU.g-1) which is lower than the shelf-life reference value. At 1 °C, inoculated Salmonella was reduced in 6.61 ln CFU.g-1 (2.87 log CFU.g-1). These results demonstrated the importance of establishing in legislation, especially in Brazil, standard values of deteriorating microorganisms in beef for maintaining product quality.

RESUMO: Neste estudo, os parâmetros cinéticos de bactérias mesófilas, psicrotróficas e ácido lácticas foram estimados em carne bovina embalada a vácuo a 1 °C e 4 °C, a partir de curvas experimentais produzidas em amostras estocadas durante 21 e 60 dias, respectivamente. Em um experimento separado, a sobrevivência de Salmonella enterica O:4,5 multirresistente (MDR) a 1°C também foi caracterizada. A vida de prateleira da carne bovina embalada a vácuo, estocada a 4°C, foi estimada em 16.1 dias (95% CI: 14.8 - 17.3 dias), enquanto que a 1 °C o período foi maior que 21 dias, porque a contagem estimada de mesófilos ao final do experimento foi de 12.5 ln UFC.g-1 (95% CI: 11.8 - 13.3 ln UFC.g-1), o qual é mais baixo que o valor referência de shelf-life. A 1 °C, Salmonella inoculada reduziu em 6.61 ln UFC.g-1 (2.87 log UFC.g-1). Estes resultados demonstram a importância de estabelecimento em legislação, especialmente no Brasil, de valores padrões para contagem de microrganismos deteriorantes em carnes visando manter a qualidade do produto.

Listeria monocytogenes in Export-approved Beef from Mato Grosso, Brazil: Prevalence, Molecular Characterization and Resistance to Antibiotics and Disinfectants.

The Brazilian state of Mato Grosso is the largest producer and exporter of beef in the country, but few studies of relevance have been conducted to evaluate the microbiological safety of its products. This study aimed to estimate the prevalence of Listeria monocytogenes (LM) in export-approved beef from Mato Grosso and to characterize the isolates in terms of molecular properties and antimicrobial resistance. From a total of 50 samples analyzed, Listeria sp. was isolated in 18 (36% prevalence). Listeria monocytogenes was confirmed in 6 (12% prevalence). Among the serotype groups assessed by multiplex PCR, serotype 4 (4b, 4d or 4e) was the most prevalent. Although antibiotic resistance was not an issue, two strains isolated from different plants showed high resistance to sodium hypochlorite. Overall, this scenario causes concern because it puts at risk not only the Brazilian customer, but also the population of countries that import beef from Mato Grosso.

Acetic Acid Increased the Inactivation of Multi-drug Resistant Non-typhoidal Salmonella by Large-Scaffold Antibiotic.

Salmonella is a gram-negative bacterium with intrinsic resistance to large-scaffold antibiotics due to the presence of an outer membrane. Based on the mode of action of the organic acids in outer membrane disintegration, and consequently, an enhancement in cell permeability, a combination of acetic acid and a large-scaffold antibiotic is it evaluated. Therefore, the aim of this study is to assess the combination of different levels of acetic acid with vancomycin, in order to determine whether or not the organic acid may overcome the cell wall and the intrinsic resistance in multi-drug resistant Salmonella. Screening of five wild-type Salmonella strains and one clinical strain was performed to select the strain more resistance to acid inhibition. Acetic acid was tested at 2.0, 1.75, 1.50, and 1.25% levels, separated or combined with 8 µg/mL vancomycin dose. An aliquot was collected after exposure and inoculated into the brain and heart infusion agar. The plates were counted and the data analyzed by ANOVA and a posthoc Tukey test (p < 0.05). The results indicate that 1.25 and 1.50% levels did not affect the vancomycin inactivation of multi-drug resistant Salmonella. However, at levels of 1.75 and 2.0%, an increase in microbial reduction is observed. Also, 2% level acetic acid and vancomycin had a threefold increase compared to vancomycin alone. Therefore, the use of acetic acid as prior treatment for Salmonella increased the inactivation rate of vancomycin. The combination of organic acid and antibiotics is a potential tool to overcome cases of antimicrobial resistance.

Worldwide Epidemiology of Salmonella Serovars in Animal-Based Foods: a Meta-analysis.

Salmonella spp. are among the most important foodborne pathogens and the third leading cause of human death among diarrheal diseases worldwide. Animals are the primary source of this pathogen, and animal-based foods are the main transmission route to humans. Thus, understanding the global epidemiology of Salmonella serovars is key to controlling and monitoring this bacterium. In this context, this study aimed to evaluate the prevalence and diversity of Salmonella enterica serovars in animal-based foods (beef, pork, poultry, and seafood) throughout the five continents (Africa, the Americas [North and Latin America], Asia, Europe, and Oceania). The meta-analysis consisted of a chemometric assessment (hierarchical cluster analysis and principal component analysis) to identify the main epidemiological findings, including the prevalence and diversity of the Salmonella serovars in each matrix. Regarding the serovar distribution, S Typhimurium presented a cosmopolitan distribution, reported in all four assessed matrices and continents; poultry continues to play a central role in the dissemination of the Enteritidis serovar to humans, and Anatum and Weltevreden were the most frequently found in beef and seafood, respectively. Additionally, we recommended careful monitoring of certain serovars, such as Derby, Agona, Infantis, and Kentucky. Finally, given the scientific data regarding the most frequently reported serovars and which matrices constitute the main vehicles for the transmission of this pathogen, control programs may be improved, and specific interventions may be implemented in an attempt to reduce the risk of this pathogen reaching humans.IMPORTANCE Salmonellosis is caused by Salmonella spp. and is the third leading cause of death among food-transmitted diseases. This pathogen is commonly disseminated in domestic and wild animals, and the infection's symptoms are characterized by acute fever, nausea, abdominal pain, and diarrhea. The animals are the primary source of salmonellae, and animal-based foods are the main transmission route to humans. Therefore, data collected from these sources could contribute to future global interventions for effective control and surveillance of Salmonella along the food chain. In light of this, the importance of our research is in identifying the prevalence of Salmonella serovars in four animal-based food matrices (pork, poultry, beef, and seafood) and to evaluate the importance that each matrix has as the primary source of this pathogen to humans.

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

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

Salmonella isolated from chicken carcasses from a slaughterhouse in the state of Mato Grosso, Brazil: antibiotic resistance profile, serotyping, and characterization by repetitive sequence-based PCR system.

Salmonella is one of the major causative agents of foodborne infections. Salmonellosis becomes more dangerous when strains resistant to several antibiotics are found in food, especially in chicken, one of the primary transmission vehicles of this pathogen for humans. The present study aimed to estimate the occurrence of Salmonella in chicken carcasses from the state of Mato Grosso, Brazil, as well as determine the antibiotic resistance profile and genotypic characteristic of multi-drug resistant (MDR) isolates. During a 15-month period, from 01/2014 to 05/2015, 850 samples of chilled fresh chicken carcasses were sampled from a slaughterhouse and submitted to Salmonella determinations according to the ISO-6579/2002 method, serotyping and multiplex PCR. The disc diffusion test was applied for 17 antibiotics, according to CLSI (2014). Five isolates were genotyped by repetitive sequence-based PCR using the semi-automated DiversiLab (bioMérieux®) system. The occurrence of Salmonella in chicken carcasses was of 3.7% (31/850), with only 4 strains (12.9%) presenting as MDR, and 6 strains (19.35%) displaying ESBL. The predominant serovars were Salmonella Infantis (35.4%, 11/31), and S. Abony (25.8%, 8/31), followed by serovars S. Agona (12.9%, 4/31), S. Schwarzengrund (9.7%, 3/31), S. Anatum and Salmonella enterica O:4,5 (6.5%, 2/31), and only one Salmonella enterica O:6,7 strain (3.2%, 1/31). All isolates were resistant to one to 5 classes of antibiotics in decreasing order: folate pathway inhibitors, ß-lactams (cephalosporins, penicillin, monobactams), tetracyclines, chloramphenicol, and gentamicin. However, strains sensitive to florfenicol, streptomycin, nalidixic acid, ciprofloxacin, enrofloxacin, and nitrofurantoin were also found in this study. Genotyping revealed 98 to 99% homology between 3 Salmonella strains, which displayed high phenotypic resistance similarity to ß-lactams and folate pathway inhibitors. Detection of MDR non-typhoid Salmonella in chicken slaughterhouses with quality assurance systems such as Hazard Analysis and Critical Points and Implemented Good Manufacturing Practices is a concern, reinforcing the need for constant monitoring of these pathogens, with the purpose of safeguarding the safety of their products.

Salmonella spp. in the fish production chain: a review / Salmonella spp. na cadeia produtiva do peixe: uma revisão

ABSTRACT: Salmonella spp is a pathogen responsible for severe foodborne infections, can be introduced into the fish production chain through inadequate handling or hygiene or contact with contaminated water, and is not a biological contaminant originally reported in fish. Fish microbiological safety is a concern for consumers, industries and regulatory agencies worldwide, since fish, an important food category in the international trade and often exported to several countries, can act as a vehicle for Salmonella transmission throughout the production chain. In addition, concerns regarding the misuse of antibiotics in aquaculture are also an issue, as a result of the increased isolation of resistant and multiresistant Salmonella serovars. In this review, we examined aspects associated with the microbiological risks of the presence of Salmonella spp. in fish and their implication in the aquaculture production chain. In addition, incidence and antimicrobial resistance data are presented, as well as strategies for Salmonella prevention and control in fish.

RESUMO: Salmonella spp. é um patógeno responsável por uma grave infecção alimentar que pode ser introduzida na cadeia do pescado, por meio da manipulação e higiene inadequada ou por contato do peixe com águas contaminadas. Essa bactéria não é contaminante natural no pescado. Por isso, a segurança microbiológica do pescado é uma preocupação dos consumidores, indústrias e das agências reguladoras em todo mundo, uma vez que o pescado é importante produto para comércio internacional de alimentos, sendo frequentemente exportados para vários países podendo ser veículador da transmissão de Salmonella em toda a cadeia produtiva. Outro aspecto preocupante é quanto ao uso inadequado de antibióticos na aquicultura, o que vem resultando no aumento do isolamento de sorovares de Salmonella resistentes e multidroga resistentes. Nesta revisão, são examinados aspectos associados ao risco microbiológico da presença de Salmonella spp. no pescado e sua implicação na cadeia produtiva da aquicultura. Dados sobre a incidência e resistência antimicrobiana e estratégias de prevenção e controle de Salmonella no pescado no Brasil e no mundo são apresentados e discutidos.

Parâmetros de qualidade de polpas de frutas congeladas / Parameters of quality of frozen fruit

Neste trabalho foram avaliadas as qualidades microbiológica, física e química de polpas de frutas congeladas de diferentes sabores e marcas, comercializadas no município de Cuiabá – MT. O experimento foi conduzido em DIC, disposto em um arranjo fatorial 3 x 2, em amostras de três marcas (X, Y e Z) de dois períodos de coletas (junho/2014 e outubro/2014), e em triplicata. Foram realizadas análises de: coliformes a 35 oC e a 45 oC, Salmonella spp., fungos filamentosos e leveduras, cor (L*a*b*), pH, acidez titulável, sólidos solúveis, ratio e vitamina C. Todas as amostras de polpas de frutas congeladas analisadas, independentemente do sabor, da marca e do período de coleta, não apresentaram contagens de coliformes a 35 oC e a 45 oC, tampouco houve isolamento de Salmonella spp.; e baixas contagens de fungos filamentosos e leveduras foram detectadas. Houve variações dos valores de cor (L*a*b*), pH, acidez titulável, sólidos solúveis, ratio e vitamina C entre as marcas e os períodos de coletas em todas as amostras de polpas de frutas analisadas. Algumas amostras de polpas demonstraram valores fora dos limites preconizados pela IN nº 1 de 7 de janeiro de 2000 do MAPA, que indicaram padrões de identidade e de qualidade deficientes...

Parasitos em alface-crespa (Lactuca sativa L. ) de plantio convencional, comercializada em supermercados de Cuiabá, Mato Grosso, Brasil / Parasites in conventionally planted curly lettuce (Lactuca sativa L. ) sold in supermarkets in Cuiabá, Mato Grosso, Brazil

Este trabalho objetivou avaliar a ocorrência de estruturas parasitárias em alfaces-crespas comercializadas em supermercados de Cuiabá-MT. Foram analisados 45 pés de alface coletadosaleatoriamente, em triplicata, de três redes de supermercados de grande porte (9 na rede A, 27 na B e 9 na C). Os pés de alface, oriundos de cinco diferentes fornecedores denominados F1, F2, F3, F4 e F5, foram analisados por duas técnicas de detecção de parasitos: sedimentação espontâneae centrifugação simples. Dentre as amostras, 66,7por cento (30/45) mostraram-se contaminadas,contendo 182 formas parasitárias, das quais 67 eram ovos de Ascaris sp. e um ovo de Enterobius vermicularis, 33 ovos e larvas de Ancilostomídeos, quatro larvas de Strongyloides sp. e 38 larvas de outros nematoides não identificados entre os helmintos. Já entre os protozoários, detectaram-se 23trofozoítos de Balantidium sp., 10 cistos de Entamoeba sp., 3 cistos de Endolimax nana, 2 cistos de Giardia sp. e 1 oocisto de Isospora spp. O ovo de Ascaris sp. foi encontrado nas amostras de todasas redes e seus fornecedores. No entanto, estruturas como ovo de Enterobius vermicularis, cistos deEndolimax nana e oocisto de Isospora spp. foram detectadas somente nos produtos dos fornecedores F1 e F2, respectivamente. Verificou-se que os maiores percentuais de amostras positivas foram dos helmintos, além de protozoários como o Balantidium sp. A presença tanto de helmintos quanto deprotozoários sugere a ocorrência de contaminação durante o cultivo e/ou distribuição desta hortaliça. Ressalta-se, portanto, a necessidade da implantação de medidas higiênico-sanitárias que previnam acontaminação desta hortaliça, preservando, assim, a saúde de seus consumidores.

Ocorrência de Staphylococcus coagulase positiva em leite e queijo: identificação, perfil enzimático e biotipagem / Occurrence of Staphylococcus coagulase positive in milk and cheese: identification, profile enzyme and biotyping

Setenta cepas de Staphylococcus coagulase positiva isoladas de leite de vacas com mastite subclínica e de queijo tipo Minas Frescal foram submetidas a testes bioquímicos para identificação das espécies e analisadas quanto a produção de algumas enzimas tais como: catalase, coagulase, linase, desoxirribonuclease (Dnase), hemolisinas, penicilinase, protease e termonuclease (TNase). Foram identificadas as espécies S. aureus, S. aureus subsp., anaerobius, S. delphini, S. hyicus, S. intermedius, S. schleiferi subsp. coagulans. As cepas que não tiveram sua identificação confirmada permaneceram com Staphylococcus coagulase positiva (SCP). A espécie predominante foi S. aureus (51,4 por cento) seguido dos SCP (22,8 por cento). Todas as cepas produziram pelo menos uma ou mais enzimas analisadas, sendo S. aureus a única espécie que apresentou resultados positivos na análise de todas as enzimas e obteve o maior percentual para a produção de TNase (50 por cento). Com relação à biotipagem, 93,3 por cento das cepas de S. aureus foram consideradas de origem bovina juntamente com 100 por cento das cepas SCP. A contaminação de alimentos por cepas patogênicas de Staphylococcus spp. pode resultar em problemas para a Saúde Pública, bem como em prejuízos para a indústria de alimentos.

Seventy strains of coagulase positive Staphylococcus isolated from the milk of cows with subclinical mastitis and white cheese were submitted to biochemical tests to identify the species and to check the production of the enzymes catalase, coagulase, lipase, deoxyribonuclease (DNase), hemolysin, penicillin, pro teaseand thermonuclease (TNase). Were identified the species S. aureus, S. aureus subsp. anaerobius, S. delphini, S. hyicus, S. intermedius, S. schleiferi subsp. coagulans. The strains that didn't have their identification confirmed remained as coagulase positive Staphylococcus (CPS). The predominant species was the S. aureus (51,4%) followed of the CPS (22,8%). In relation to the enzymes production, all the species produced at least one of the analyzed enzymes and the S. aureus was the unique species that presented positive results in the analyzes of all the enzymes. Besides, this microorganism showed the higher percentile of TNase production (50%). In the biotyping, 93,3% of the S. aureus and 100% of the CPS strains were considered of bovine source. Food contamination by Staphylococcus spp. pathogenic strains can result in Public Health problems and also in losses to the food industry.