Characterization of native Escherichia coli populations from bovine vagina of healthy heifers and cows with postpartum uterine disease.

Even though Escherichia coli are common bacteria of the bovine vaginal microbiota, they represent an important pathogen that causes diseases in the reproductive tract and subfertility. However, the actual endometrial virulence profile of E. coli is poorly understood. The present study aims to characterize the phylogenetic structure and virulence potential of native vaginal populations of E. coli from healthy heifers (H), and cows with postpartum uterine diseases (PUD), such as metritis/endometritis (MT) or repeat breeder cows (RB). To this end, the virulence repertoire of 97 E. coli isolates was genotypically and phenotypically assessed. Most of them were assigned to phylogenetic group A (74%), followed by B1 (17%) and D (9%); RB strains were significantly (p < 0.05) more represented by B1. Seven of the 15 evaluated virulence genes (VFG) were detected and the most prevalent were fimH (87%), agn43 (41%) and csgA (35%); while traT (27%), fyuA (11%), hlyA (5%) and kpsMT II (5%) were observed in a lower proportion. Particularly, fyuA was significantly higher (p < 0.05) in MT cows whereas csgA showed the same behavior in PUD animals (p < 0.05). When comparing H and PUD strains, these last ones were associated to positive expression of biofilm, fimbriae curli/cellulose and motility; yet RB strains did not show motility. Vaginal B1 E. coli populations, that possess VFG (fyuA and csgA) as well as the expression of motility, curli fimbriae/cellulose and biofilm, may represent risk factors for endometrial disorders; specifically, those that also, have kpsMT II may have a pathogenic potential for causing the RB syndrome. Future research focusing on the detection of these strains in the vaginal microbiota of cows with postpartum uterine diseases should be done since the control of their presence in vagina could reduce the risk that they access the uterus during the postpartum period.

Influence of autochthonous adjunct cultures on ripening parameters of Argentinean goat's milk cheeses.

BACKGROUND: Argentinean semi-hard goat's cheeses manufactured with and without the addition of autochthonous adjunct cultures of Lactobacillus plantarum ETC17, Lactobacillus rhamnosus ETC14 and Enterococcus faecium ETC3 were analysed to evaluate the effect of these strains on ripening parameters. RESULTS: Gross composition was similar among cheeses. Microbiological analysis indicated that lactic acid bacteria added to cheeses reached high levels. None of the strains assayed affected the primary proteolysis. Overall, E. faecium had a clearer effect on the peptide and lipolysis profiles of cheeses. Analysis of the volatile fraction of cheeses indicated that the levels of several compounds involved in the overall flavour of goat's cheeses were affected by the presence of E. faecium. This could explain the differences detected in the global perception of cheeses made with this strain compared with control cheeses. CONCLUSION: The present work represents a first contribution to knowledge of the ripening process of Argentinean goat's cheeses made with the addition of autochthonous adjunct cultures. The results suggest that E. faecium ETC3 showed a significant effect during ripening, which was reflected both in the profiles of proteolysis, lipolysis and volatile compounds and in the global sensory perception of cheeses.

Effects of probiotic administration in swine.

In the present work we evaluated the effects of probiotic strains administration in pigs. On the 35th day of age, 30 pigs were distributed into 2 groups: the non-treated control group (initial average BW: 8.3+/-0.6 kg) and a probiotic supplemented fed group (initial average BW: 8.7+/-0.4 kg). Each experimental group was fed ad libitum on a commercial diet with free access to tap water for 35 days. A mixed probiotic culture (10(8) CFU/ml) was orally delivered, every day, to the animals of the probiotic supplemented fed group. Body weight (BW), feed intake (FI), efficiency (BW: Feed), and faecal microflora, were studied before and throughout the experimental trial. At the end of the fifth week, 5 animals of each dietary treatment were slaughtered and intestinal samples were taken for histology. The results obtained showed that the group receiving probiotic bacteria exhibited lower FI values and better efficiency than control group (P

beta-Glucuronidase method to determine mastitis levels in goat milk.

Mastitis is a general term that refers to the inflammation of the mammary gland. It is the most common illness in dairy farms and it has different causes, mainly a great number of germs that infect the gland. These infectious diseases induce gross variations in milk composition, reflected by physical, chemical, and bacteriological changes. They produce milk jellification, a decrease in important components such as lactose, casein, and fats and minerals such as calcium, phosphorus, and potassium and increases in other unimportant technological components, such as serum proteins and chlorides; all these affect the cheese efficiency and the starter culture action. Assuming that cheese making is the principal use of goat milk in industry, an evaluation of the quality of the milk used as the raw material is of fundamental importance. It is impossible to obtain quality products by using milk with an anomalous chemical composition. Somatic cell count (SCC) is the indicator most used for mastitis detection. These cells, which are contained in milk, can be grouped into three types: epithelial cells, blood cells, and cytoplasmatic particles. During an attack of mastitis, the immune defenses of the udder are activated, polynucleated leukocytes pass from the blood toward the mammary gland in large numbers, and the number of somatic cells in the milk increases. The level of somatic cells in goat milk is characterized by great variability between different countries and between regions of the same country. Different authors show averages between 750,000 and 5,400,000 cells/mL. These values differ greatly between cow and goat milk, mainly because normally nonleukocytic cell-like particles can be found as a result of the particular apocrine secretion process in the goat mammary gland. These particles are large fragments of cytoplasm originating from the distal portion of alveolar secretory cells and are of similar size (5-30 microm in diameter) to milk leukocytes. They contain abundant RNA-positive granular material (associated with dilated cisternae of the rough endoplasmic reticulum), large amounts of protein, and some lipids, but no DNA. Thus it is important to use techniques that disregard these other substances and allow only a count of somatic cells.