Seroprevalence of salmonella and mycoplasma in commercial broilers, backyard chickens, and spent hens in the region of Triangulo Mineiro, state of Minas Gerais, Brazil

Avian salmonellosis and mycoplasmosis are infectious diseases that, in addition of causing lack of flock uniformity, represent a hazard to human health. The objective of the present study was to evaluate the seroprevalence of mycoplasmosis and salmonellosis in commercial broilers, backyard chickens, and spent hens slaughtered at a processing plant with local health inspection in Uberlandia, MG, Brazil. A total of 210 samples were randomly collected at the time of bleeding. Samples were submitted to rapid plate serum agglutination test (RSA) for the classification of Salmonella pullorum, Salmonella gallinarum, Mycoplasma gallisepticum and Mycoplasma synoviae. In order to increase result specificity, mycoplasmosis-positive samples were submitted to hemagglutination inhibition test (HI). No samples presented detectable antibodies against Salmonella pullorum or Salmonella gallinarum in the RSA test. Only Mycoplasma synoviae was detected in 14% of the backyard chickens and 0.74% in commercial broilers, whereas no antibodies were detected in spent hens. The seroprevalence rates found in the present study emphasize the need of keeping chicken flocks free from disease using effective biosafety systems.

Identification and characterization of regions of difference between the Salmonella Gallinarum biovar Gallinarum and the Salmonella Gallinarum biovar Pullorum genomes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Draft genome sequence of Salmonella enterica subsp. enterica Serovar gallinarum biovar pullorum strain FCAV198, a Brazilian chicken pathogen

Salmonella enterica subsp. enterica serovar Gallinarum biovar Pullorum is a bird-restricted pathogen which causes pullorum disease. The strain FCAV198 was isolated from a pool of chicken ovaries in Brazil, and its genome may be helpful for studies involving molecular mechanisms related to pathogenesis and other related applications.

Toxicogenetic effects of low concentrations of the pesticides imidacloprid and sulfentrazone individually and in combination in in vitro tests with HepG2 cells and Salmonella typhimurium

The insecticide imidacloprid and the herbicide sulfentrazone are two different classes of pesticides that are used for pest control in sugarcane agriculture. To evaluate the genotoxic potential of low concentrations of these two pesticides alone and in mixture, the comet assay and the micronucleus (MN) test employing fluorescence in situ hybridization (FISH) with a centromeric probe were applied in human hepatoma cell lines (HepG2), in a 24-h assay. Mutagenicity was assessed by Salmonella/microsome assay with TA98 and TA100 strains in the absence and presence of an exogenous metabolizing system (S9). The results showed significant inductions of MN in HepG2 cells by both pesticides, for all the tested concentrations. As evidenced in the comet assay, only the imidacloprid presented significant responses. When the two pesticides were associated, a significant induction of damage was observed in the HepG2 cells by the comet assay, but not by the MN test. Moreover, the MN induced by the mixtures of the pesticides appeared at lower levels than those induced by sulfentrazone and imidacloprid when tested alone. According to the FISH results, the damage induced by imidacloprid in the HepG2 cells resulted from a clastogenic action of this insecticide (76.6% of the MN did not present a centromeric signal). For the herbicide sulfentrazone and for the mixture of the pesticides, a similar frequency of MN with and without the presence of the centromeric signal (herbicide: 52.45% of the MN without centromeric signal and 47.54% of the MN with centromeric signal; mixture: 48.71% of the MN without centromeric signal and 51.42% of the MN with centromeric signal) was verified. Based on these results, it was concluded that each one of the pesticides evaluated interacts with the DNA of HepG2 cells and causes irreparable alterations in the cells. However, the combination of the pesticides showed an antagonistic effect on the cells and the damage induced was milder and not persistent in HepG2 cells. The results obtained by the Ames test did not point out significant results.

Differences in larval nutritional requirements and female oviposition preference reflect the order of fruit colonization of Zaprionus indianus and Drosophila simulans

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Clonal relatedness and resistance patterns of Salmonella Corvallis from poultry carcasses in a Brazilian slaughterhouse

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The role of nicotine, cotinine and caffeine on the electrochemical behavior and bacterial colonization to cp-Ti

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Perfil molecular e resistência a antimicrobianos de Salmonella isolada em linfonodos mesentéricos de suínos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Quantificação de enterobactérias e Clostridium spp. e detecção molecular de Clostridium perfringens, Escherichia coli e Salmonella spp. em pontos de cadeia produtiva da carne de frango

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Eradication of Salmonella Typhimurium in broiler chicks by combined use of P22 bacteriophage and probiotic

It has been reported that the phage therapy is effective in controlling the number of colony-forming unit (CFU) of Salmonella spp. in chicken gut. This paper describes the protective effect of phage and Lactobacilli administration on Salmonella infection in 1-day-old chicks. We administered the bacteriophage P22 in a single dose and a probiotic mixture of four species of bacteriocin-producing Lactobacillus once a day for one week. Samples were analyzed every 48 hours, and intestinal eradication of S. Typhimurium was confirmed after treatments. We observed an increase in the size of duodenal villi and cecal crypts, as well as an increase in body weight in groups that received daily doses of Lactobacilli. This study confirms the efficiency of bacteriophage therapy in controlling salmonellosis in chicks and the beneficial effect of Lactobacilli mixtures in the weight gain of the birds.

Preliminary report of epiphytic and endophytic colonization of black oat (Avena strigosa) and wheat (Triticum aestivum) by Curtobacterium flaccumfaciens pv. flaccumfaciens in Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The Effects of High Pressure Processing on Peanut Sauce Inoculated with Salmonella

Recent Salmonella outbreaks have prompted the need for new processing options for peanut products. Traditional heating kill-steps have shown to be ineffective in lipid-rich matrices such as peanut products. High pressure processing is one such option for peanut sauce because it has a high water activity, which has proved to be a large contributing factor in microbial lethality due to high pressure processing. Four different formulations of peanut sauce were inoculated with a five strain Salmonella cocktail and high pressure processed. Results indicate that increasing pressure or increasing hold time increases log10 reductions. The Weibull model was fitted to each kill curve, with b and n values significantly optimized for each curve (p-value < 0.05). Most curves had an n parameter value less than 1, indicating that the population had a dramatic initial reduction, but tailed off as time increased, leaving a small resistant population. ANOVA analysis of the b and n parameters show that there are more significant differences between b parameters than n parameters, meaning that most treatments showed similar tailing effect, but differed on the shape of the curve. Comparisons between peanut sauce formulations at the same pressure treatments indicate that increasing amount of organic peanut butter within the sauce formulation decreases log10 reductions. This could be due to a protective effect from the lipids in the peanut butter, or it may be due to other factors such as nutrient availability or water activity. Sauces pressurized at lower temperatures had decreased log10 reductions, indicating that cooler temperatures offered some protective effect. Log10 reductions exceeded 5 logs, indicating that high pressure processing may be a suitable option as a kill-step for Salmonella in industrial processing of peanut sauces. Future research should include high pressure processing on other peanut products with high water activities such as sauces and syrups as well as research to determine the effects of water activity and lipid composition with a food matrix such as peanut sauces.

Growth potential of Salmonella spp. and Listeria monocytogenes in nine types of ready-to-eat vegetables stored at variable temperature conditions during shelf-life

Growth potential (delta) is defined as the difference between the population of a microorganism at the end of shelf-life of specific food and its initial population. The determination of 6 of Salmonella and Listeria monocytogenes in RTE vegetables can be very useful to determine likely threats to food safety. However, little is known on the behavior of these microorganisms in several RTE vegetables. Therefore, the aim of this study was to determine the delta of both pathogens in nine different types of RTE vegetables (escarole, collard green, spinach, watercress, arugula, grated carrot, green salad, and mix for yakisoba) stored at refrigeration (7 degrees C) and abuse temperature (15 degrees C). The population of aerobic microorganisms and lactic acid bacteria, including those showing antimicrobial activity has been also determined. Results indicated that L monocytogenes was able to grow (delta >= 0.5 log(10)) in more storage conditions and vegetables than Salmonella. Both microorganisms were inhibited in carrots, although a more pronounced effect has been observed against L monocytogenes. The highest 5 values were obtained when the RTE vegetables were stored 15 degrees C/6 days in collard greens (delta=3.3) and arugula (delta=3.2) (L monocytogenes) and arugula (delta=4.1) and escarole (delta=2.8) (Salmonella). In most vegetables and storage conditions studied, the counts of total aerobic microorganisms raised significantly independent of the temperature of storage (p<0.05). Counts of lactic acid bacteria were higher in vegetables partially or fully stored at abuse temperature with recovery of isolates showing antimicrobial activity. In conclusion, the results of this study show that Salmonella and L monocytogenes may grow and reach high populations in RTE vegetables depending on storage conditions and the definition of effective intervention strategies are needed to control their growth in these products. (C) 2012 Elsevier B.V. All rights reserved.

Modeling the growth rate and lag time of different strains of Salmonella enterica and Listeria monocytogenes in ready-to-eat lettuce

The growth parameters (growth rate, mu and lag time, lambda) of three different strains each of Salmonella enterica and Listeria monocytogenes in minimally processed lettuce (MPL) and their changes as a function of temperature were modeled. MPL were packed under modified atmosphere (5% O-2, 15% CO2 and 80% N-2), stored at 7-30 degrees C and samples collected at different time intervals were enumerated for S. enterica and L monocytogenes. Growth curves and equations describing the relationship between mu and lambda as a function of temperature were constructed using the DMFit Excel add-in and through linear regression, respectively. The predicted growth parameters for the pathogens observed in this study were compared to ComBase, Pathogen modeling program (PMP) and data from the literature. High R-2 values (0.97 and 0.93) were observed for average growth curves of different strains of pathogens grown on MPL Secondary models of mu and lambda for both pathogens followed a linear trend with high R2 values (>0.90). Root mean square error (RMSE) showed that the models obtained are accurate and suitable for modeling the growth of S. enterica and L monocytogenes in MP lettuce. The current study provides growth models for these foodborne pathogens that can be used in microbial risk assessment. (C) 2011 Elsevier Ltd. All rights reserved.