Mann E.,Institute of Milk Hygiene |
Mann E.,Research Cluster Animal Gut Health |
Schmitz-Esser S.,Institute of Milk Hygiene |
Schmitz-Esser S.,Research Cluster Animal Gut Health |
And 7 more authors.
PLoS ONE | Year: 2014
Dietary composition largely influences pig's gastrointestinal microbiota and represents a useful prophylactic tool against enteric disturbances in young pigs. Despite the importance for host-microbe interactions and bacterial colonization, dietary responses of the mucosa-associated bacterial communities are less well investigated. In the present study, we characterized the mucosa-associated bacterial communities at the Pars non-glandularis of the stomach, ileum and colon, and identified shifts in these communities in response to different dietary calcium-phosphorus (Ca-P) contents (100% versus 190% of the Ca and P requirements) in combination with two basal diets (wheat-barley- or corn-based) in weaned pigs. Pyrosequencing of 16S rRNA genes from 93 mucosal samples yielded 447,849 sequences, clustering into 997 operational taxonomic units (OTUs) at 97% similarity level. OTUs were assigned to 198 genera belonging to 14 different phyla. Correlation-based networks revealed strong interactions among OTUs at the various gastrointestinal sites. Our data describe a previously not reported high diversity and species richness at the Pars non-glandularis of the stomach in weaned pigs. Moreover, high versus adequate Ca-P content significantly promoted Lactobacillus by 14.9% units (1.4 fold change) at the gastric Pars nonglandularis (P = 0.035). Discriminant analysis revealed dynamic changes in OTU composition in response to dietary cereals and Ca-P contents at all gastrointestinal sites which were less distinguishable at higher taxonomic levels. Overall, this study revealed a distinct mucosa-associated bacterial community at the different gut sites, and a strong effect of high Ca-P diets on the gastric community, thereby markedly expanding our comprehension on mucosa-associated microbiota and their diet-related dynamics in weaned pigs. © 2014 Mann et al.
Maichin A.,Institute of Milk Hygiene |
Schoder D.,Institute of Milk Hygiene |
Laffa J.,Veterinarians without Borders Austria |
Lema B.,University of Dar es Salaam
Journal of Food Protection | Year: 2013
In Tanzania, pastoralists such as the Maasai and small urban farmers are responsible for the country's milk production, and 95% of the national milk supply is sold without regulation. This study was conducted using hygiene checklists and milk sampling to investigate milk quality and safety at various steps throughout the milk production chain. In regions of Dar es Salaam and Lake Victoria, 196 milk samples were collected: 109 samples of raw milk, 41 samples of packed or open served heat-treated products, and 46 samples of fermented products. Samples were taken from (1) the production level (pastoralists and urban farmers), (2) the collection level (middlemen and depots), (3) processors (dairies), and (4) retailers (kiosks). Samples were analyzed for hygiene criteria (total bacteria, total coliforms, Escherichia coli, and coagulase-positive staphylococci) and foodborne pathogens such as Salmonella, enterohemorrhagic E. Coli O157:H7, and Listeria monocytogenes. Adequate heating of milk for drinking was determined via heat labile alkaline phosphatase and lactoperoxidase analysis. Total bacterial counts indicated that only 67% (73 of 109) of raw milk samples and 46% (19 of 41) of heat-treated samples met national Tanzanian standards. Bulk milk samples taken from the traditional milking vessels of Maasai pastoralists had the lowest total bacterial counts: ≥1 × 102 CFU/ml. Foodborne pathogens such as E. Coli O157:H7 and Salmonella were isolated from 10.1% (11 of 109) of raw milk samples but were not detected in heat-treated or fermented products, and 83% of heat-treated milk samples were lactoperoxidase negative, indicating overpasteurization. Coliforms were detected in 41% (17 of 41) of processed milk samples, thus indicating a high rate of recontamination. A progressive decrease in microbial quality along the milk production chain was attributed to departures from traditional methods, inadequate milk containers, long transport distances, lack of cooling, and lack of a basic understanding of hygiene.