Shiga-toxigenic Escherichia coli (STEC) are important human pathogens associated with diarrhea and in some cases haemorrhagic colitis. Contaminated food derived from cattle and wildlife species are ...often associated with disease outbreaks. In this study, we report the prevalence, serogroup diversity and virulence profiles of STEC strains derived from cattle, rusa deer and pig. Of the 422 samples analyzed, STEC were detected in 40% (80/200) of cattle, 27.0% (33/122) of deer and 13.0% (13/100) of pigs. STEC isolates belonged to 38 O-serogroups whereby 5.2% (24/462) of the isolates belonged to clinically important EHEC-7 serogroups: O26 (n = 2), O103 (n = 1), O145 (n = 3) and O157 (n = 18). Fourteen serogroups (O26, O51, O84, O91, O100, O104, O110, O117, O145, O146, O156, O157, O177 and ONT) displayed multiple virulence profiles. We also identified two serovars (O117 and O119) in deer which are not well-documented in epidemiological surveys. 73.7% (28/38) of recovered O-serogroups are known to be associated with serious human illnesses including haemolytic uremic syndrome (HUS) and bloody diarrhea. STEC isolates harboring single genotypes stx1, stx2, eae and hlyA accounted for 3.0% (14/462), 9.1% (42/462), 47.6% (220/462) and 1.7% (8/462) of all STEC isolates screened, respectively. Virulence combinations stx1 and stx2 were harboured by 1.3% of isolates while strains with genetic profiles eae/hlyA were the second most prevalent amongst STEC isolates. The full known virulent genotypes (stx2/eae, stx1/stx2/eae, stx1/stx2/hlyA and stx2/eae/hlyA) were present in 22 of the 462 STEC strains. A total of 10 different virulence patterns were recovered amongst animal species. Phylogeny of the gnd gene showed that amongst STEC strains, serovar O100 outlined the main cluster. Fourteen (n = 14) different sequence types (STs) were identified from a panel of twenty (n = 20) STEC isolates. One of the isolate (PG007B) possessed a unique ST (adk 10, fumC 693, gyrB 4, icd 1, mdh 8, purA 8, recA 2) that could not be assigned using MLST databases. None of the ST's recovered in deer were observed in domestic species. Our findings shows that food associated animals found on the tropical island of Mauritius carry a diversity of STEC strains with many serovars known to be associated with human disease. This report indicates that increased awareness, surveillance and hygienic attention at critical stages of the human food chain are warranted.
•Cattle, rusa deer and pigs are colonized by STEC, with cattle as the principal reservoir.•Retail beef accounted for over 85% of the 74 STEC-positive food samples.•73.7% (28/38) of O-serogroups were previously linked to HUS or bloody diarrhea.•Two rarely documented serovars (O117 and O119) were recovered in rusa deer.•38.5% of STEC strains had multiple toxigenic profiles involving stx2 and/or - eae.
Dehydration of meat by soaking in a concentrated solution of water, salt and corn syrup (DE21) generally results in a high water loss and moderate salt and sugar gains. This study was undertaken to ...better understand the role of corn syrup in the transfer of water and solutes, and particularly its limiting effect on salt impregnation. Corn syrup is composed of saccharides of molecular mass varying from 180
Da (glucose) to more than 1500
Da (oligo- and poly-saccharides), in variable proportion. In an attempt to clarify the role of these different saccharides on mass transfer, immersion trials in concentrated solutions of salt (constant molality
=
3.0) and polyethylene glycol (PEG, used a model solute) of varying molecular mass and molality were carried out. The influence of solution viscosity was also studied through the addition of agar agar as a viscosity agent. Results showed that water loss increased while salt and PEG gains decreased with increasing molecular mass of PEG in the range of 200–600
Da. In addition, an increasing molality of PEG from 0.6 to 1.6
mol/kg water led to increases in water loss and PEG gain but a decrease in salt gain. Under the prevailing experimental conditions, no significant influence of solution viscosity on mass transfer was found. Moreover, immersion trials were carried out to compare corn syrup with three different combinations of PEG with molecular mass distributions similar to that of corn syrup. The mixtures closely reproduced corn syrup behaviour with respect to salt gain. However, their impact on water loss and PEG gain (as compared to sugar gain) was significantly different from that of corn syrup. Information gathered in this study was used to propose a schematic representation of the mechanisms involved in the transfer of water and solutes during the immersion of meat in a ternary solution. The model is based on the development of a barrier layer of solutes at the periphery of the product, this barrier playing a key role in the control of subsequent mass transfer.
The microbiological and physicochemical characteristics of several commercial beef, kudu and springbok biltong samples from South Africa were assessed in this study. Analysis of samples allowed their ...differentiation into ‘dry’ and ‘moist’ samples. Dry biltong showed low moisture content (21.5–25.3g/100g), a low water activity (0.65–0.68) and a high salt content (5.5–7.9g/100g), while moist biltong showed a higher moisture content (35.1–42.8g/100g), a higher water activity (0.85 to 0.89) and a lower salt content (3.8–5.6g/100g). The pH value did not vary significantly between both groups (5.00–6.26). The results showed that dry biltong presented a low total plate count (TPC) content, a high level of lactic acid bacteria (LAB) and a high level of d-lactic acid as compared to moist biltong. These results suggest that dry biltong complies with the standard hygienic quality (TPC<7logcfu/g in agreement with the Food Standards Agency), while moist biltong samples generally showed a low content of d-lactic acid and a low ratio LAB/TPC.
•The physicochemical and microbial characteristics of biltong from SA were analysed.•These characteristics were correlated with the LAB and l- and d-lactic acid.•The occurrence of 2 major groups of biltong, dry and wet biltongs was demonstrated.•Data indicated occurrence of products with fermented and non-fermented properties.
Textile effluents in natural waters pose environmental health problems if not treated to safe limits. Various bacterial species have the potential to degrade dyes. Here we studied the ability of
...Bacillus algicola
to decolourise red, blue and yellow azo dyes.
B. algicola
was isolated from soil samples taken from a sanitary landfill site. Isolation and screening were performed using mineral salt medium. Dye-decolourising isolates were assessed in their capacity to decolourise dyes. Experiments were conducted at pH 6, 7 and 8, and 25, 35 and 45 °C. Phytotoxicity of the dyes and biodegradation products was assessed by seed germination tests. Results show that
B. algicola
gave the highest decolourisation at pH 8.0 and 25 °C in the presence of yeast extract as media supplement.
B. algicola
degraded the red and blue azo dyes by over 95%. The phytotoxicity results indicated that biodegradation products of the red and blue azo dyes were not toxic. Biodegradation products of the yellow dye were, however, toxic and considerably hindered germination. From these results, we infer that
B. algicola
has good potential for degrading and decolourising the red and blue test azo dyes.
Analysis of genotype-by-environment interaction (GEI) is critical in the local potato breeding and selection programme to obtain information on the performance of the genotypes for yield adaptability ...and stability. The objective of this study was to assess the marketable tuber yield of 18 advanced potato clones compared to the commercial variety Spunta at four locations (Bigara, Réduit, St. Antoine and Rivière du Poste), representative of four major soil types in Mauritius. They were analysed for adaptability and stability using the additive main effects and multiplicative interaction (AMMI) model and genotype main effect and genotype x environment interaction (GGE) biplot. Five clones gave significantly the highest marketable tuber yield in terms of overall ranking with yield increase of 47.4% to 59.6% over the control variety Spunta. AMMI analysis of variance detected significantly (P < 0.001) higher proportion of variation in marketable tuber yield due to environment (42%); followed by genotype x environment interaction (21%) which justified multi-locational testing. AMMI1 biplot demarcated clones 142/161/2 and 142/161/5 as high yielding and most stable while AMMI 2 biplot identified the winning genotypes for a specific environment. Thus, clones142/161/4 and 161/142/16 had specific adaptation to Bigara, 29/5/2 and 21/5/3 were adapted to St. Antoine, 21/5/10 to Rivière du Poste whereas 29/5/3 was adapted to Réduit. The GGE biplots identified clones 142/161/2 and 142/161/5 as the two most desirable genotypes close to the “ideal genotype”. The “which- won- where” view of the GGE biplot further pointed to the presence of two mega-environments, which corresponded to the sub-humid irrigated/humid environments (Réduit, St. Antoine and Rivière du Poste) and the high altitude super-humid environment (Bigara). These results showed that in future both AMMI and GGE methods can be integrated in the local potato breeding programme to select superior genotypes through multi-year and multi-locational yield evaluation.
L’île Rodrigues est connue pour ses produits traditionnels fabriqués à base de porc. Cependant, et contrairement à la production agricole y compris l’élevage porcin (1, 2, 3), le secteur de la ...transformation de la viande porcine a été peu étudié. Cette étude a été menée pour préciser les caractéristiques du secteur de la transformation de la viande de porc, notamment les profils socio-économiques des transformateurs, les types de produits fabriqués, les matières premières, ingrédients et additifs utilisés, les techniques et matériel de fabrication, ainsi que les modes de stockage et de conditionnement des produits finis. Une évaluation du niveau de conformité des unités de fabrication a également été effectuée au regard de la réglementation mauricienne sur l’hygiène alimentaire.Une enquête auprès de tous les transformateurs de porc recensés (n = 57) a été réalisée de décembre 2010 à janvier 2011 à l’aide d’un questionnaire et d’une liste de contrôle. Excepté pour deux unités semi-industrielles, le secteur est constitué de petites unités de fabrication de charcuterie, opérant majoritairement à temps partiel (96 p.100), et gérées principalement par des hommes (65 p.100). Les principaux produits fabriqués sont la saucisse chinoise, le jambon rodriguais et le boudin noir (figure 1). Le kitouz, le boucané, le rôti de porc, le porc salé, la galantine, la saucisse créole et le bacon rodriguais sont également produits mais surtout pour des occasions festives. Les techniques de fabrication les plus utilisées sont le salage et le séchage, la cuisson n’étant employée que pour certains produits, comme le rôti de porc et le boudin noir. La viande de porc provient d’élevages locaux, alors que les ingrédients comme les épices, le sel et le sucre sont importés de l’île Maurice.Tous les artisans charcutiers recensés (n = 57) fabriquaient leurs produits dans la cuisine familiale à l’aide de matériel de faible coût, et en adoptant une technologie rudimentaire et empirique, et des recettes traditionnelles. La plupart des transformateurs ne suivaient pas les codes de bonnes pratiques de fabrication et étaient bien en-deçà des normes d’hygiène requises par la réglementation mauricienne. Quatre-vingts pour cent d’entre eux n’avaient pas de système de contrôle de leur procédé de fabrication. Ainsi, par exemple dans la fabrication des saucisses chinoises, le degré de hachage de la viande pouvait varier d’un hachage grossier à très fin. Les quantités d’ingrédients étaient mesurées de façon approximative en utilisant des cuillères et des tasses. Parmi ces artisans, 88 p.100 n’étiquetaient pas leurs produits après l’emballage. Par ailleurs, en début de la chaîne de fabrication, l’abattage du porc s’effectuait souvent dans des conditions insalubres augmentant ainsi les risques de contamination microbiologiques de la carcasse. La plupart des artisans (95 p.100) stockait la viande fraîche à température ambiante, favorisant ainsi la multiplication des germes. Pour ces diverses raisons, les produits finis étaient clairement hétérogènes au niveau des dimensions, de la teneur en gras, de la couleur, de l’aspect général et de la durée de conservation.En conclusion, les fabricants devront mettre en oeuvre les bonnes pratiques de fabrication et d’hygiène de base, afin d’assurer une qualité standard des produits finis et d’améliorer leur qualité sanitaire. Une étude ultérieure sera réalisée pour mieux définir la qualité microbiologique des produits.
Rodrigues Island is a dependency of the Republic of Mauritius and is located at about 653 km northeast of it. Pig fattening is an important livestock activity in Rodrigues and pork is the most widely ...consumed meat (1). It is reported that Rodriguan pork has special sensorial attributes, firstly because pigs are fed with traditional starchy crops such as cassava, banana and sweet potato, and kitchen wastes, and secondly because of the rearing method which is mainly an outdoor system. In a previous study (2), the range of processed products made from pork and their processing techniques were described. The Rodriguan chinese sausage, a traditional dry-cured pork-based product, is one of the most popular products and is considered as an authentic product of Rodrigues (Figure 1). It could be eventually promoted and marketed with an appellation such as the geographical indication label. However, from a food safety standpoint, there is a lack of information on the microbiological and physico-chemical characteristics of the finished product.The main objective of this work was to determine the microbiological and physico-chemical characteristics of the Rodriguan chinese sausage with a view to establish the standard profile of the product. The study also aimed to identify weaknesses and make recommendations to improve safety, quality and shelf life of the product.Sausages were sampled thrice from ten random family-owned processing units in seven villages and retail outlets of Rodrigues from November 2013 to January 2014. At each outlet, two sausages were taken and air-transported in sealed plastic bags within two days to the Faculty of Agriculture laboratory for analysis. All analyses were carried out using ISO (International Organization for Standardization) protocols.The total viable count and lactic acid bacteria count ranged from 7.8 to 8.11 and from 7.08 to 7.50 log10 CFUg-1, respectively (Table I). The total coliform and Staphylococcus spp. counts were about 3 log10 CFUg-1 each. Neither Escherichia coli nor Salmonella spp. were detected in the samples analyzed. The water activity, pH and lactic acid content of the sausages fell within the range of values typical of dry-fermented sausages (Table II). However, significant variations between samples were noted with regard moisture, protein, fat and ash contents. Similarly, water activity and pH values showed marked variations between the sausages. In contrast, no significant differences were noted in the L*, a* and b* color attributes as defined by the Commission internationale de l’éclairage (CIE).Results confirmed that the Rodriguan chinese sausage satisfies the criteria of dry-cured raw meat products (3) and is overall a fairly safe and stable product. However, significant variations exist in its physico-chemical and microbiological characteristics probably due to variations in processing by the different artisans. There is thus a need to standardize the processing steps so as to improve the microbiological quality and safety of the sausage.
Fermented Poultry Sausages Arnaud, E; Santchurn, S.J; Collignan, A
Handbook of Fermented Meat and Poultry,
10/2014
Book Chapter
Growing interest in poultry and poultry products, especially 100% pure poultry products, has led to the development of a wide range of poultry delicatessen products. These are summarized in this ...chapter, which places particular emphasis on dry‐fermented poultry sausages. The manufacturing process for pure‐poultry dry‐fermented sausages is described and the two main technological constraints—the sanitary hazards of raw poultry and the poor technological properties of poultry fat—are discussed in relation to the sanitary and sensory qualities of the dry sausages. Promising means of overcoming these constraints are presented.
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