Vaginal microbial communities from synchronized heifers and cows with reproductive disorders.

AIM: To evaluate changes in the resident microbial population in the cranial vaginal mucosa induced by a progesterone-releasing intravaginal device (PRID) compared to the vaginal microbiota of cows with reproductive disorders. METHODS AND RESULTS: Vaginal discharge was evaluated by clinical examination and a Vaginitis Diagnosis Score was performed by exfoliative cytology. All samples classified as positive and some classified as negative by clinical evaluation were later diagnosed as positive for vaginitis by cytological analysis. Bacterial diversity profiles were performed by PCR-DGGE and clustered according to the reproductive health status of the specimens, revealing a correspondence between the structures of the communities in the vagina and the clinical profile. Representative bands from each group were sequenced and identified as Ruminococcus sp., Dialister sp., Escherichia sp./Shigella sp., Virgibacillus sp., Campylobacter sp., Helcoccoccus sp., Staphylococcus sp., Bacillus sp., Actinopolymorpha sp., Exiguobacterium sp., Haemophilus sp./Histophilus sp., Aeribacillus sp., Porphyromonas sp., Lactobacillus sp. and Clostridium sp. CONCLUSION: Our results contribute to the knowledge of the vaginal microbiome in synchronized heifers showing positive or negative clinical vaginitis. SIGNIFICANCE AND IMPACT OF THE STUDY: This study contributes to the understanding of a dynamic vaginal colonization by bacterial consortiums during the synchronization with a widely used PRID protocol. Also, the results reveal the presence of well-known metritis-related pathogens as well as emerging uterine opportunistic pathogens. The provided information will allow to carry out further studies to elucidate functional roles of these native micro-organisms in the bovine reproductive tract.

Probiotics for prevention of atopic diseases in infants: systematic review and meta-analysis.

Growing evidence underlines the pivotal role of infant gut colonization in the development of the immune system. The possibility to modify gut colonization through probiotic supplementation in childhood might prevent atopic diseases. The aim of the present systematic review and meta-analysis was to evaluate the effect of probiotic supplementation during pregnancy and early infancy in preventing atopic diseases. PubMed, Embase and Cochrane Library were searched for randomized controlled trials evaluating the use of probiotics during pregnancy or early infancy for prevention of allergic diseases. Fixed-effect models were used, and random-effects models where significant heterogeneity was present. Results were expressed as risk ratio (RR) with 95% confidence interval (CI). Seventeen studies, reporting data from 4755 children (2381 in the probiotic group and 2374 in the control group), were included in the meta-analysis. Infants treated with probiotics had a significantly lower RR for eczema compared to controls (RR 0.78 [95% CI: 0.69-0.89], P = 0.0003), especially those supplemented with a mixture of probiotics (RR 0.54 [95% CI: 0.43-0.68], P < 0.00001). No significant difference in terms of prevention of asthma (RR 0.99 [95% CI: 0.77-1.27], P = 0.95), wheezing (RR 1.02 [95% CI: 0.89-1.17], P = 0.76) or rhinoconjunctivitis (RR 0.91 [95% CI: 0.67-1.23], P = 0.53) was documented. The results of the present meta-analysis show that probiotic supplementation prevents infantile eczema, thus suggesting a new potential indication for probiotic use in pregnancy and infancy.

Changes of gut microbiota and immune markers during the complementary feeding period in healthy breast-fed infants.

INTRODUCTION: Little is known about changes in intestinal microbiota during the important period of complementary feeding (weaning). This descriptive study investigated changes of selected gut microbiota and markers of gut permeability and the immune system in breast fed infants during the complementary feeding period. METHODS: 22 healthy, exclusively breast fed infants (from birth to 4 months) with no antibiotic intake during the month prior to the study, were followed from 4 to 9 months of age. Faecal and saliva samples were collected at the start of the study (V0) and at monthly intervals (V1-V5) for measurement of selective gut microbiota (bifidobacteria, lactobacilli, vancomycin-insensitive lactobacilli, enterobacteria, enterococci, Clostridium perfringens) using semi-selective media. Immune markers (alpha-1-antitrypsin, eosinophil cationic protein (ECP), secretory IgA and TNF-alpha were measured in saliva and secretory IgA and TNF-alpha in faecal samples. RESULTS: High stool bifidobacteria counts at the start of the study (7.99 1 1.95 log10 CFU/g faeces) remained stable throughout the 5 months of complementary feeding while counts of enterobacteria and enterococci increased with age (P < 0.05 and P = 0.02 respectively). Vancomycin-insensitive lactobacilli increased significantly during weaning for V0 to V3 (P < 0.01), and then decreased slightly (V4). Faecal Clostridium perfringens remained below the detection limit during the study and parameters measured in saliva did not change. Faecal ECP decreased significantly from 1.011.4 (V0) to 0.510.9 mg/mg protein (V5) P = 0.03. CONCLUSION: Age and/or diet modifications during complementary feeding had no impact on faecal bifidobacteria counts but increased those of enterobacteria and enterococci. Transient increases in faecal lactobacilli and vancomycin-insensitive lactobacilli counts were observed. The reduction in faecal ECP may indicate a decrease in gut permeability (reinforcement of gut mucosa integrity) during the weaning period with age [corrected]

S-layer gene as a molecular marker for identification of Lactobacillus helveticus.

The paper describes two methods that allow rapid and accurate identification of Lactobacillus helveticus strains based on the nucleotide sequence of the gene coding for the surface layer (S-layer) protein. The first method is based on a polymerase chain reaction amplification using primers targeting a specific fragment of the S-layer gene. The second method involved a portion of the S-layer gene of L. helveticus as a probe in a hybridisation test. The specificity of these protocols was checked for DNA samples isolated from various Lactobacillus strains.

Rapid amplified ribosomal DNA restriction analysis (ARDRA) identification of Lactobacillus spp. isolated from fecal and vaginal samples.

Amplified ribosomal DNA restriction analysis (ARDRA) was used to identify different species of Lactobacillus isolated from human faeces and vagina. PCR-ARDRA was performed using a set of four restriction enzymes, able to differentiate fourteen species of Lactobacillus. The PCR-ARDRA procedure described in this paper was shown to be a reliable and rapid method for identifying Lactobacillus species from intestinal and vaginal microflora at species and subspecies level.

Functions of S-layers.

Although S-layers are being increasingly identified on Bacteria and Archaea, it is enigmatic that in most cases S-layer function continues to elude us. In a few instances, S-layers have been shown to be virulence factors on pathogens (e.g. Campylobacter fetus ssp. fetus and Aeromonas salmonicida), protective against Bdellovibrio, a depository for surface-exposed enzymes (e.g. Bacillus stearothermophilus), shape-determining agents (e.g. Thermoproteus tenax) and nucleation factors for fine-grain mineral development (e.g. Synechococcus GL 24). Yet, for the vast majority of S-layered bacteria, the natural function of these crystalline arrays continues to be evasive. The following review up-dates the functional basis of S-layers and describes such diverse topics as the effect of S-layers on the Gram stain, bacteriophage adsorption in lactobacilli, phagocytosis by human polymorphonuclear leukocytes, the adhesion of a high-molecular-mass amylase, outer membrane porosity, and the secretion of extracellular enzymes of Thermoanaerobacterium. In addition, the functional aspect of calcium on the Caulobacter S-layer is explained.

Aggregation-promoting factor in pig intestinal Lactobacillus strains.

Autoaggregation was frequently encountered among intestinal lactobacilli isolated from weaned pigs. The aggregation mechanism was shown to be mediated by the production of a proteinaceous aggregation-promoting factor in two strains of Lactobacillus reuteri. A 32 kDa aggregation-promoting protein was detected in these strains by cross-reaction with rabbit polyclonal antibodies for Aggregation-Promoting Factor produced by the human isolate Lact. plantarum 4B2. Coaggregation reactions of Lact. reuteri strains with pathogenic and non-pathogenic Escherichia coli were detected.

Comparative Study of 35 Bacteriophages of Lactobacillus helveticus: Morphology and Host Range.

This survey included 23 phages isolated from cheese whey and 12 temperate phages induced with mitomycin from their lysogenic host strains. All of the phages had an isometric head and a tail with a contractile sheath. In addition, short-tailed (160-nm-long) and long-tailed (260-nm-long) phages were distinguished. Short-tailed phages were by far the most widespread in French cheese factories (32 of the 35 phages studied). The study of phage relationships enabled two large groups of strains to be distinguished: those not or slightly sensitive to phages and those very sensitive to phages. There was an obvious relationship in the first group between phage sensitivity (or resistance) and the geographic origin of the strains. The second group contained primarily strains from large international collections and those isolated from commercial starters. The relationships among short-tailed phages, either temperate or isolated as lytic, suggest that lysogenic strains could be the major source of phages in French cheese factories.