Valid publication of the names Caecibacterium and Caecibacterium sporoformans.

Descriptions of the genus Caecibacterium and its proposed type species Caecibacterium sporoformans were published in the IJSEM by Onrust et al. (Int J Syst Evol Microbiol 2017;67:4589-4594). The type strain was deposited as LMG 27730 and DSM 26959. DSM 26959 is a patent strain, and therefore the names were effectively, but not validly, published based on Rule 30(4) of the International Code of Nomenclature of Prokaryotes. The type strain of C. sporoformans is now available from the Deutsche Sammlung von Mikroorganismen und Zellkulturen as DSM 103070 and no restrictions have been placed on its distribution. We here present new descriptions of the genus and its type species so that the names can be validly published.

Caecibacterium sporoformans gen. nov., sp. nov., an anaerobic, butyrate-producing, spore-forming bacterium isolated from chicken caecum.

Strains of a Gram-stain-negative, rod-shaped and immotile bacterium were isolated from broiler chicken caecal content. The isolates required strict anaerobic conditions for growth, formed spores, were catalase-positive and oxidase-negative. They produced butyrate as the major metabolic end product in reinforced clostridial medium broth. The genomic DNA G+C content of the isolated strains was 32.5-34.6 mol%. The major cellular fatty acids were C16 : 0 FAME, C14 : 0 FAME, C19 : 0CYC 9,10DMA and C16 : 0DMA. The fatty acid composition of the cell wall showed no similarity to any strain in the midi database. 16S rRNA gene sequence analysis showed that the nearest phylogenetic neighbours were Anaerostipes hadrus and Clostridium populeti (92 % sequence similarity) within Clostridium cluster XIVa of the phylum Firmicutes. Therefore, a novel genus is proposed, with the name Caecibacterium sporoformans gen. nov., sp. nov. The type strain of Caecibacterium sporoformans is LMG 27730T=DSM 26959T.

Harryflintia acetispora gen. nov., sp. nov., isolated from chicken caecum.

More than 100 isolates of a Gram-stain-negative, curved rod-shaped, so far uncultured bacterium were isolated from chicken caecal content. The strains were obligate anaerobes which formed endospores. They were catalase-positive, cytochrome-oxidase-negative and did not hydrolyse aesculin. The detected predominant metabolic end product in reinforced clostridial bedium broth was acetate. The DNA G+C content was 62.2 mol%. The cell fatty acid composition was dominated by C15 : 0 iso, C15 : 0anteiso, C16 : 0, C13 : 0 iso, C14 : 0 iso and C16 : 0DMA. Analysis of the 16S rRNA gene sequences of the novel isolates showed 99 % similarity to each other. Phylogenetically they are placed in Clostridium cluster IV. They exhibited 99 % 16S rRNA gene sequence similarity to uncultured bacterial clone SJTU_C_03_83 (GenBank accession no. EF404038.1) and to three other so far uncultured strains. The closest related type strains, Hydrogenoanaerobacterium saccharovorans SW51T and Anaerotruncus colihominis WAL 14565T, exhibited a 16S rRNA gene sequence divergence of at least 8 % to the newly described isolates. In addition, morphological and biochemical characteristics allowed differentiation of the novel isolates from these and other related and validly published species, including Clostridium methylpentosum and Acetanaerobacterium elongatum. Therefore, a new genus, Harryflintia gen. nov., is proposed for the isolated hitherto unknown strains with V20-281aT (=DSM 100433T =CECT 8892T) as the type strain of its type species, Harryflintia acetispora gen. nov., sp. nov.

Intestinal expression of TFF and related genes during postnatal development in a piglet probiotic trial.

Trefoil factor family (TFF) peptides provide protective and reparative effects by enhancing epithelial integrity and promoting mucosal restitution. TFF peptide expression is induced after mucosal damage. These processes are of central physiological relevance during the postnatal intestinal development and are strongly influenced during the weaning period. In piglets, weaning at early maturation stages frequently causes mucosal inflammation. The aim of this study was to evaluate postnatal intestinal TFF expression in a piglet probiotic trial. Low intestinal TFF2 expression was measured at early maturation stages. Weaning, however, was associated with a distinct response of increased TFF2 expression, indicating an important role in enhancing mucosal integrity. In the distal jejunum and ileum weaning could as well be associated with increased TFF3 mRNA levels. Differential TFF1 expression was not detected. Furthermore, TFF2 localization studies in different intestinal loci were performed by means of immunohistochemistry. Expression of selected genes (TGFA, EGFR, Cox-2) known to promote TFF signaling showed differential expression pattern as well, thereby providing further functional background. Furthermore, the expression patterns of EGFR observed in this study contribute to an advanced view of previous findings of EGFR regulation mainly obtained in rodents. An upregulated EGFR expression during early postnatal development suggests a local relevance to porcine intestinal maturation. However, a feed supplementation with the probiotic strain Enterococcus faecium did not influence TFF expression.

Influence of a probiotic strain of Enterococcus faecium on Salmonella enterica serovar Typhimurium DT104 infection in a porcine animal infection model.

The beneficial effects of probiotic Enterococcus spp. in different hosts, such as mice and humans, have previously been reported in several studies. However, studies of large domestic animals, as well as challenge studies with pathogenic microorganisms, are very rare. Here, we investigated the influence of oral treatment of pigs with the probiotic bacterium Enterococcus faecium NCIMB 10415 on Salmonella enterica serovar Typhimurium DT104 infections in weaning piglets. Clinical symptoms, fecal excretion, the organ distribution of Salmonella, and the humoral immune response (immunoglobulin G [IgG], IgM, and IgA levels) in serum were examined. A pool of 89 piglets was randomly divided into probiotic and control groups. The probiotic group received a feed supplement containing E. faecium starting on day 14 postpartum prior to challenge with Salmonella serovar Typhimurium DT104 at 28 days postpartum. After challenge with Salmonella serovar Typhimurium DT104, piglets in both groups showed no severe clinical signs of salmonellosis. However, fecal excretion and colonization of Salmonella in organs were significantly greater in piglets fed E. faecium. Likewise, the humoral immune response against Salmonella (serum IgM and IgA levels) was significantly greater in the probiotic group animals than in control animals. The results of this study suggest that E. faecium NCIMB 10415 treatment enhanced the course of infection in weaning piglets challenged with Salmonella serovar Typhimurium DT104. However, the probiotic treatment also appeared to result in greater production of specific antibodies against Salmonella serovar Typhimurium DT104.

Effects of Bacillus cereus var. toyoi on immune parameters of pregnant sows.

Changing immune parameters during pregnancy have previously been reported in humans and cattle, and have been suggested to contribute to increased susceptibility to infections. However, data regarding immune parameters during pregnancy in sows are rare. In this study, we investigated the peripartal immune status of sows using phenotypical (FACS analysis) as well as functional (proliferation assays, cytokine analysis) parameters of peripheral blood mononuclear cells (PBMCs) in pregnant sows. In previous studies, we reported a modulation of the immune system after feed supplementation of the probiotic Bacillus cereus var. toyoi in piglets [Schierack, P., Wieler, L.H., Taras, D., Herwig, V., Tachu, B., Hlinak, A., Schmidt, M.F., Scharek, L., 2007. Bacillus cereus var. toyoi enhanced systemic immune response in piglets. Vet. Immunol. Immunopathol. 118, 1-11]. Here, we extended these previous studies to include investigations of possible probiotic effects on the peripartal immune status of sows and their reproductivity. We show that immune parameters of sows change during pregnancy, the proliferative response of PBMCs to several bacterial antigens in control animals decreased from days 90 to 30 ante partum. Relative numbers (%) of CD3+CD8+, CD4+, cytotoxic T, CD14+ and CD21+ cells were reduced compared to non-pregnant sows. In contrast, the proliferative response of PBMCs of probiotic-treated sows increased during pregnancy. Bacterial antigens primarily stimulated the proliferation of naïve CD21+ cells and the relative CD21+ cell numbers were elevated in the probiotic group in the absence of effects on other immune cell populations. The clinical and microbial status of both control and probiotic sows was similar, excluding pre-existing health problems or infections as responsible for the immunological changes, and feed supplementation also had no significant effects on reproductivity. The results suggest that the probiotic B. cereus var. toyoi can alter the proliferative response of lymphocytes and affects the immune cell population ratios of pregnant sows. How and to what extent this may affect health and reproductivity should be the focus of further studies.

Influence of an Enterococcus faecium probiotic on the development of Peyer's patches B cells in piglets.

To study the interactions between a probiotic bacterium and the host's immune system, we undertook a feeding trial with Enterococcus faecium SF68 (NCIMB 10415). Starting at an age of 1 day, piglets received a daily oral dose of the probiotic bacteria. Immune cells were isolated from the blood and the distal continuous Peyer's patch (PP) of the piglets. While the percentage of B cells in the distal continuous PP was not influenced by the probiotic treatment, an elevated expression of CD1 on Peyer's patch B cells was observed after probiotic treatment. Furthermore, the fraction of CD4-CD8+ cells was decreased in this organ. In blood lymphocyte fractions of the probiotic-treated piglets, the proportion of CD16-positive cells was also diminished, whereas the portion of γδ T cells and CD4-positive T cells increased. The data indicate that early administration of the probiotic Enterococcus faecium can modulate the composition of blood lymphocyte populations in piglets.

Bacillus cereus var. toyoi enhanced systemic immune response in piglets.

Probiotic bacteria have been suggested to stimulate the host immune system. In this study we evaluated the immunomodulatory effects of probiotic Bacillus cereus var. toyoi on the systemic immunity of piglets. A pool of 70 piglets was divided into a probiotic or control group. We determined the ratios of peripheral blood mononuclear cell (PBMC) subsets and measured proliferative responses and cytokine production of PBMCs and effects on vaccination responses. Blood samples of probiotic-treated piglets showed a significantly lower frequency of CD8(high)/CD3+ T cells and CD8(low)/CD3+ T cells and a significant higher CD4+/CD8+ ratio. IL-4 and IFN-gamma production of polyclonally stimulated PBMCs was on average higher in the probiotic group. Specific proliferative responses of PBMCs to Influenza vaccination antigens were significantly higher and antibody titers against H3N2 Influenza and Mycoplasma vaccination antigens were on average higher in the probiotic group. In conclusion, B. cereus var. toyoi therefore alters the immune status of piglets as indicated by changes in the ratios as well as functionalities of systemic immune cell populations.

Throwing the dice for the diagnosis of vaginal complaints?

BACKGROUND: Vaginitis is among the most common conditions women are seeking medical care for. Although these infections can easily be treated, the relapse rate is high. This may be due to inadequate use of the diagnostic potential. METHODS: We evaluated the misjudgement rate of the aetiology of vaginal complaints. A total of 220 vaginal samples from women with a vaginal complaint were obtained and analysed for numbers of total lactobacilli, H2O2-producing lactobacilli, total aerobic cell counts and total anaerobic cell counts including bifidobacteria, Bacteroides spp., Prevotella spp. Additionally, the presence of Atopobium vaginae, Gardnerella vaginalis, Candida spp. and Trichomonas vaginalis was evaluated by DNA-hybridisation using the PCR and Affirm VPIII Microbial Identification Test, respectively. RESULTS: The participating physicians diagnosed Bacterial vaginosis (BV) as origin of discomfort in 80 cases, candidiasis in 109 cases and mixed infections in 8 cases. However, a present BV, defined as lack of H2O2-lactobacilli, presence of marker organisms, such as G. vaginalis, Bacteroides spp. or Atopobium vaginae, and an elevated pH were identified in only 45 cases of the women examined. Candida spp. were detected in 46 cases. Interestingly, an elevated pH corresponded solely to the presence of Atopobium vaginae, which was detected in 11 cases. CONCLUSION: Errors in the diagnosis of BV and candida vulvovaginitis (CV) were high. Interestingly, the cases of misjudgement of CV (77%) were more numerous than that of BV (61%). The use of Amsel criteria or microscopy did not reduce the number of misinterpretations. The study reveals that the misdiagnosis of vaginal complaints is rather high.

Ruminococcus luti sp. nov., isolated from a human faecal sample.

A strain of an unidentified strictly anoxic, gram-postive, non-motile Ruminococcus-like bacterium was isolated from a human faecal sample. The organism used carbohydrates as fermentable substrates, produced acetate, succinate, and hydrogen as the major products of glucose metabolism, and possessed a G + C content of 43.3 mol%. The morphological and biochemical characteristics of the organism were consistent with its assignment to the genus Ruminococcus but it did not correspond to any recognized species of this genus. Comparative 16S rRNA gene sequencing showed the unidentified bacterium represents a previously unrecognised sub-line within the Clostridium coccoides rRNA group of organisms. The nearest relative of the unknown bacterium corresponded to Ruminococcus obeum but a 16S rRNA sequence divergence value of >3% demonstrated it represents a different species. Based on the presented findings a new species, Ruminococcus luti, is described. The type strain of Ruminococcus luti is BInIX(T) (DSM 14534T, CCUG 45635T).

Microbiota and SCFA in lean and overweight healthy subjects.

Obesity has recently been linked to the composition of human microbiota and the production of short chain fatty acids (SCFAs). However, these findings rely on experimental studies carried out using rather small and defined groups of volunteers or model animals. Our aim was to evaluate differences within the human intestinal microbiota and fecal SCFA concentration of lean and obese subjects. A total of 98 subjects volunteered to take part in this study. The BMI in kg/m(2) of 30 volunteers was within the lean range, 35 were overweight and 33 were obese. The fecal microbiota was characterized by real-time PCR analyses. With the primers used herein we were able to cover 82.3% (interquartile range of 68.3-91.4%) of the total microbiota detectable with a universal primer. In addition, the concentration of SCFA was evaluated. The total amount of SCFA was higher in the obese subject group (P = 0.024) than in the lean subject group. The proportion of individual SCFA changed in favor of propionate in overweight (P = 0.019) and obese subjects (P = 0.028). The most abundant bacterial groups in faeces of lean and obese subjects belonged to the phyla Firmicutes and Bacteroidetes. The ratio of Firmicutes to Bacteroidetes changed in favor of the Bacteroidetes in overweight (P = 0.001) and obese subjects (P = 0.005). Our results are in line with previous reports suggesting that SCFA metabolism might play a considerable role in obesity. However, our results contradict previous reports with regard to the contribution of various bacterial groups to the development of obesity and this issue remains controversial.

Veillonella magna sp. nov., isolated from the jejunal mucosa of a healthy pig, and emended description of Veillonella ratti.

A bacterium, designated strain lac18(T), was isolated in pure culture from the mucosal jejunum of a healthy pig, using a medium selective for anaerobic lactic acid bacteria and containing porcine gastric mucin as the main carbon and nitrogen source. Cells of this strain were coccus-shaped, arranged singly or in pairs and were Gram-stain-negative, oxidase-negative, non-spore-forming, anaerobic and microaerotolerant. An analysis based on 16S rRNA gene sequences indicated that strain lac18(T) should be assigned to the genus Veillonella, class Clostridia, phylum Firmicutes. 16S rRNA and dnaK gene sequence-based phylogenetic analyses both indicated that the most closely related species were Veillonella ratti ATCC 17746(T) (similarities of 96.6 and 84.5 %, respectively) and Veillonella criceti ATCC 17747(T) (similarities of 96.6 and 83.4 %, respectively). The results of DNA-DNA hybridizations between strain lac18(T) and these Veillonella species and the type species of the genus, Veillonella parvula DSM 2008(T), confirmed the genotypic distinctness of the novel isolate. Data from phenotypic studies also served to differentiate strain lac18(T) from related strains. Therefore strain lac18(T) represents a novel species of the genus Veillonella, for which the name Veillonella magna sp. nov. is proposed. The type strain is lac18(T) (=CCUG 55454(T)=CIP 109767(T)=DSM 19857(T)=JCM 15053(T)).

Response of performance characteristics and fecal consistency to long-lasting dietary supplementation with the probiotic strain Bacillus cereus var. toyoi to sows and piglets.

As part of an interdisciplinary research project, we studied the performance response of sows and their litters to the probiotic strain Bacillus cereus var. toyoi as well as feces consistency of piglets. Gestating sows (n=26) were randomly allotted into two groups. The probiotic B. cereus var. toyoi was administered by dietary supplementation to one group of sows and their respective litters (probiotic group) whereas the second group (control group) received no probiotic supplementation. The duration of the application was nearly 17 weeks for sows (day 90 ante partum until day 28 post partum) and six weeks for piglets (day 15-56). Piglets were weaned after 28 days. Body weight and feed consumption were recorded weekly and fecal consistency of weaned piglets was studied daily. B. cereus var. toyoi was recovered from feces of sows and piglets as well as from digesta of piglets in the probiotic group, while being absent from all samples of control animals. In addition, the probiotic was detected in piglet feces and digesta before pre-starter feed was offered, indicating a second route of uptake besides diet. Sows of the probiotic group nursed numerically more piglets and supported a higher sum of total nursing days of all piglets within each litter than control sows (p = 0.04). In turn, body weight (BW) up to day 35 was greater for control piglets (p < 0.01), while average daily gain and gain to feed ratio (G:F) in weeks six and eight postweaning was higher in the probiotic group (p < 0.05). The overall G:F of the total postweaning period was 680 g/kg and 628 g/kg in the probiotic group and control group, respectively (p = 0.009). During the trial a high prevalence of liquid feces with its maximum in the second week after weaning was observed. Probiotic supplementation led to a reduction in the incidence of liquid feces and postweaning diarrhea by 38% and 59%, respectively (p < 0.001).

Treponema berlinense sp. nov. and Treponema porcinum sp. nov., novel spirochaetes isolated from porcine faeces.

Limit-dilution procedures were used to isolate seven, helically coiled bacterial strains from faeces of swine that constituted two unidentified taxa. Comparative 16S rRNA gene sequence analysis showed highest similarity values with species of the genus Treponema indicating that the isolates are members of this genus. Strain 7CPL208(T), as well as five further isolates, and 14V28(T) displayed the highest 16S rRNA gene sequence similarities with Treponema pectinovorum ATCC 33768(T) (92.3%) and Treponema parvum OMZ 833(T) (89.9%), respectively. Polar lipid profiles distinguished 7CPL208(T) and 14V28(T) from each other as well as from related species. Based on their phenotypic and genotypic distinctiveness, strains 7CPL208(T) and 14V28(T) are suggested to represent two novel species of the genus Treponema, for which the names Treponema berlinense sp. nov. and Treponema porcinum sp. nov. are proposed. The type strain for Treponema berlinense is 7CPL208(T) (=ATCC BAA-909(T)=CIP 108244(T)=JCM 12341(T)) and for Treponema porcinum 14V28(T) (=ATCC BAA-908(T)=CIP 108245(T)=JCM 12342(T)).

Reclassification of Eubacterium formicigenerans Holdeman and Moore 1974 as Dorea formicigenerans gen. nov., comb. nov., and description of Dorea longicatena sp. nov., isolated from human faeces.

Two strains of a gram-positively staining, obligately anaerobic, non-spore-forming, rod-shaped bacterium, designated strains 111-13A and 111-35T, were isolated from human faeces. Analysis of the 16S rRNA gene sequences indicated that these strains were members of the Clostridium coccoides rRNA group of organisms. The nearest relatives of the unknown bacterium were Eubacterium formicigenerans (having a sequence similarity of 94%) and an uncultured bacterium (similarity > 99%). Characterization studies indicated that the unidentified faecal bacterium was biochemically distinct from Eubacterium formicigenerans, members of the Clostridium coccoides group and all other described Eubacterium species. On the basis of the data from these studies, it is proposed that the hitherto unknown rod-shaped bacterium be designated a species of a novel genus, namely Dorea longicatena gen. nov., sp. nov., and that Eubacterium formicigenerans be transferred to this genus as Dorea formicigenerans gen. nov., comb. nov.