Epidemiological tools for effective surveillance of porcine cysticercosis in Africa

peer reviewe

Epidemiological tools for effective surveillance of porcine cysticercosis in Africa

peer reviewedaudience: researcher, professional, studen

Organic farming practices versus conventional production: associated pathogens and food safety concerns in a sustainable development.

Organic agriculture has been strongly enhanced in the last years, as a consequence of a great consumer demand, a great concern for environmental health and a constant effort for a sustainable development based on green economy. Antibiotic use is less intensive in organic production, which may have a key impact in the circulation of antibiotic resistances in the human population. Organic farm practices seems to contribute to the optimal health status and decrease the risk of developing chronic diseases, may due to the lower content of cadmium and synthetic fertilizers and pesticides. But on the other hand, organic foods could have an important charge of enteric pathogenic bacteria, toxins or others. Practices as the use of natural animal manure or water sources, can increase the risk of freshly organic products contamination and contribute to the spread of foodborne pathogens. The aim of this work was to investigated the urgent food risk notifications and product recalls from the market associated with organic production in the last nine years in Europe. We identify the most common foodborne risks associated with organic foods. Switching to organic agriculture brings promising prospects both in terms of welfare and nature improvement. In this work we highlight the presence of pathogenic microorganism, toxins of different origins, and organic compounds in food products which pose a potential risk for human health. We describe the most common implicated organic foods in product recalls in Europe, all in the context of global evolution towards a green economy

Assessment of bacterial superficial contamination in classical or ritually slaughtered cattle using metagenetics and microbiological analysis

The aim of this study was to investigate the influence of the slaughter technique (Halal vs. Classical slaughter) on the superficial contamination of cattle carcasses, by using traditional microbiological procedures and 16S rDNA metagenetics. The purpose was also to investigate the neck area to identify bacteria originating from the digestive or the respiratory tract. Twenty bovine carcasses (10 from each group) were swabbed at the slaughterhouse, where both slaughtering methods are practiced. Two swabbing areas were chosen: one “legal” zone of 1,600 cm2 (composed of zones from rump, flank, brisket and forelimb) and locally on the neck area (200 cm2). Samples were submitted to classical microbiology for aerobic Total Viable Counts (TVC) at 30°C and Enterobacteriaceae counts, while metagenetic analysis was performed on the same samples. The classical microbiological results revealed no significant differences between both slaughtering practices; with values between 3.95 and 4.87 log CFU/100 cm2 and 0.49 and 1.94 log CFU/100 cm2, for TVC and Enterobacteriaceae respectively. Analysis of pyrosequencing data showed that differences in the bacterial population abundance between slaughtering methods were mainly observed in the “legal” swabbing zone compared to the neck area. Bacterial genera belonging to the Actinobacteria phylum were more abundant in the “legal” swabbing zone in “Halal” samples, while Brevibacterium and Corynebacterium were encountered more in “Halal” samples, in all swabbing areas. This was also the case for Firmicutes bacterial populations (families of Aerococcaceae, Planococcaceae). Except for Planococcoceae, the analysis of Operational Taxonomic Unit (OTU) abundances of bacteria from the digestive or respiratory tract revealed no differences between groups. In conclusion, the slaughtering method does not influence the superficial microbiological pattern in terms of specific microbiological markers of the digestive or respiratory tract. However, precise analysis of taxonomy at the genus level taxonomy highlights differences between swabbing areas. Although not clearly proven in this study, differences in hygiene practices used during both slaughtering protocols could explain the differences in contamination between carcasses from both slaughtering groups

Comparison and molecular characterization of animal and human Clostridium difficile strains

The main objective of this study was to characterize and compare animal and human C. difficile strains with respect to the PCR-ribotype and the antibiotic resistance. Multilocus sequence typing analysis (MLST) was performed in order to study clonal relationships of the isolates

Challenge testing with Brochothrix thermosphacta on minced pork meat shows interest to couple metagenetics to metabolomics to study food spoilage

The spoilage of perishable foods is mainly caused by bacterial activity. The risk of unwanted bacterial growth is particularly high in the minced pork meat. In this work, the natural microbial contaminants of the minced pork meat were followed by 16S ribosomal DNA deep sequencing (metagenetics) during aging tests at different temperatures. Brochothrix thermosphacta MM008 strain was selected as one of the main contaminants responsible for the spoilage of the meat. Minced pork meat previously sterilized by gamma irradiation was inoculated with B. thermosphacta MM008 for challenge tests measuring growth and then incubated at different temperatures. Minced meat samples were taken and analyzed by H-NMR 1D at time 0 and at final time (from 14 to 19 days, depending on the incubation temperature). Orthogonal partial least square discriminant analysis (OPLS-DA) showed that samples, regardless of the incubation temperature, could be splitted into 3 groups according to their spectral profile: 1) samples taken at time 0, 2) samples inoculated with B. thermosphacta and taken at final time, 3) samples uninoculated, taken at final time. From the analysis of the metabolomics data, higher concentrations of glycerol, glucose, taurine, lactate, carnitine, betaine and glycine were identified in the samples of uninoculated minced pork meat and an increased production of creatine, acetate and acetone was found in the samples of minced pork meat inoculated with B. thermosphacta MM008. These observations showed that -omics technologies (metagenetics and metabolomics) could be used conclusively to study microbial spoilage of minced pork meat

Clostridium difficile: an emerging zoonotic pathogen ?

Clostridium difficile is an anaerobic, spore-forming bacterium that remains the main cause of nosocomial diarrhoea in humans after use of antibiotics. C. difficile has also been described in other environments outside of hospitals, such as soil, river and seawater samples (Pasquale et al., 2011) and in animals, in which it can also cause enteric disease (Songer and Anderson, 2006). The possibility of transmission of C. difficile pathogenic isolates between animals, environments and humans has been suggested (Janezic et al., 2012). In recent years, the interest in C. difficile in food and in food animals has increased, leading to studying animals as a possible reservoir and a potential risk for food borne infections linked to C. difficile. Studies in various countries have determined differences in the prevalence of C. difficile in animals just before slaughter (Houser et al., 2012; Rodriguez et al., 2012) as well as in retail meat (Houser et al., 2012). In addition, many types, including PCR-ribotype 078, are present in humans, animals and meat (Janezic et al.; Weese et al., 2009). The objective of this study was to evaluate the presence of C. difficile at the slaughterhouse and in retail meat. Intestinal and carcass samples were collected from pigs and cattle at a single slaughterhouse. Raw meat (beef and pork) was obtained from the retail trade. C. difficile was isolated in 1% and 9.9% of the pig and cattle intestinal contents and in 7.9% and 7% of cattle and pig carcass samples respectively. From retail meat, C. difficile was recovered from 2.3% of the beef samples and from 4.7% of the pork samples. A total of 21 different PCR-ribotypes were identified with a large percentage of types 078 and 014. This study confirms that animals are carriers of C. difficile at slaughter, and that carcass contamination occurs inside the slaughterhouse. Furthermore the results obtained also reveal the presence of toxigenic C. difficile in retail meat in Belgium with a predominance of isolates correlated with the PCR-ribotypes involved in human C. difficile infections

First isolation of Clostrioides difficile from smoked and dried freshwater fish in Cambodia

In Cambodia, freshwater aquaculture is the most important source of food production. Fresh fish meat is considered a highly perishable food that requires the use of different manipulations and preservation techniques to inhibit the proliferation of undesirable bacteria. These bacteria are naturally present in the raw product or could be acquired during manipulation by cross-contamination. Many studies worldwide have investigated the epidemiology of Clostridioides difficile (C. difficile) in food, but to date, there are no publications about the bacterium in ready-to-eat fish or descriptions in Cambodia. The objective of this study was to assess the presence of C. difficile in one of the main food supplies of this country, smoked freshwater fish, originating from different provinces. A total of 25 samples were collected directly from local markets, yielding 4 C. difficile isolates and an overall recovery rate of 16%. Most of the isolates were toxigenic and classified as rare PCR profiles, and they were resistant to clindamycin. These findings indicate contamination during handling and/or contamination of the raw fish, followed by insufficient heat treatment to kill the spores. The presence of C. difficile in smoked and dried fish implies a potential risk of human exposure, contamination and infection