Natalia Nikolaitchouk

Microbial invasion and cytokine response in amniotic fluid in a Swedish population of women with preterm prelabor rupture of membranes

Background.  Previous studies have shown an association between intra‐amniotic microbial invasion and/or inflammation and spontaneous preterm birth. The aim of this study was to investigate the occurrence of intra‐amniotic microorganisms and cytokines [interleukin (IL)‐6 and IL‐8] in a Swedish population, with low incidence of preterm birth, of women with preterm prelabor rupture of membranes and their correlation to preterm birth.

The lower genital tract microbiota in relation to cytokine-, SLPI- and endotoxin levels: application of checkerboard DNA-DNA hybridization (CDH).

In the present study the lower genital tract microbiota in asymptomatic fertile women (n=34) was identified and quantified by culturing vaginal secretions. Also, vaginal and cervical samples were analyzed by a semiquantitative checkerboard DNA‐DNA hybridization technique (CDH) based on genomic probes prepared from 13 bacterial species (Bacteroides ureolyticus, Escherichia coli, Fusobacterium nucleatum, Gardnerella vaginalis, Mobiluncus curtisii ss curtisii, Prevotella bivia, Prevotella disiens, Prevotella melaninogenica, Atopobium vaginae, Lactobacillus iners, Staphylococcus aureus ss aureus, Streptococcus anginosus, and Streptococcus agalactiae). The bacterial species found by either culture or CDH were correlated with proinflammatory cytokines (IL‐1α, IL‐1β, IL‐6, IL‐8), secretory leukocyte protease inhibitor (SLPI), and endotoxin in the cervicovaginal samples. Grading the women into healthy, intermediate, or bacterial vaginosis (BV) as based on Gram staining of vaginal smears, the viable counts of lactobacilli (L. gasseri) and of streptococci‐staphylococci combined were highest in the intermediate group. In BV, particularly the high concentrations of Actinomyces urogenitalis, Atopobium vaginae, and Peptoniphilus harei were noted (≥1011 per ml). The total viable counts correlated with both cervical IL‐1α and IL‐1β. A strong negative correlation was observed between L. iners and total viable counts, G. vaginalis, or cervical IL‐1α, while it correlated positively with SLPI. Analysis of vaginal and cervical samples from 26 out of the 34 women by CDH showed that anaerobic bacteria were more frequently detected by CDH compared to culture. By this method, A. vaginae correlated with G. vaginalis, and L. iners with S. aureus. With regard to cytokines, B. ureolyticus correlated with both cervical and vaginal IL‐1α as well as with cervical IL‐8, while F. nucleatum, S. agalactiae, S. anginosus, or S. aureus correlated with vaginal IL‐1α. Furthermore, all Gram‐negative bacteria taken together, as measured by CDH, correlated with vaginal endotoxin and inversely with vaginal SLPI. The significance of the results is discussed. In summary, mapping of the identity and quantity of vaginal bacterial species and their association with locally produced host innate immune factors will help in defining various types of abnormal vaginal microbiota, developing new ways of assessing the risk of ascending subclinical infections, and in treating them. CDH appears to be a suitable tool for future analyses of large numbers of clinical samples with an extended number of bacterial probes.

Interleukin-18 in cervical mucus and amniotic fluid: relationship to microbial invasion of the amniotic fluid, intra-amniotic inflammation and preterm delivery.

Objective To evaluate the relationship between interleukin (IL)‐18 in cervical mucus and amniotic fluid and microbial invasion of amniotic fluid, preterm delivery and intra‐amniotic inflammation in women in preterm labour, with preterm prelabour rupture of membranes and at term.

Actinomyces funkei sp. nov., isolated from human clinical specimens.

Three strains of a previously undescribed Actinomyces-like bacterium were isolated from human clinical specimens. Phenotypic studies indicated that the strains were members of the genus Actinomyces and were presumptively identified as Actinomyces turicensis. Comparative 16S rRNA gene sequencing studies showed that although the bacterium is phylogenetically closely related to Actinomyces turicensis, it nevertheless constitutes a new sub-line within the genus Actinomyces. Based on phenotypic and molecular chemical and molecular genetic evidence, it is proposed that the unknown Actinomyces-like bacterium from human clinical specimens be classified as Actinomyces funkei sp. nov. The type strain of Actinomyces funkei is CCUG 42773T (= CIP 106713T).

Characterization of Actinomyces isolates from samples from the human urogenital tract: description of Actinomyces urogenitalis sp. nov.

Three strains of a previously undescribed Actinomyces-like bacterium were isolated from human clinical sources (urine, urethra and vaginal secretion). Biochemical testing and PAGE analysis of whole-cell proteins indicated that the strains were phenotypically homogeneous and distinct from previously described Actinomyces and Arcanobacterium species. Comparative 16S rRNA gene sequencing studies showed the bacterium to be a hitherto unknown subline within a group of Actinomyces species which includes Actinomyces bovis, the type species of the genus. Based on phylogenetic and phenotypic evidence it is proposed that the unknown bacterium from humans be classified as Actinomyces urogenitalis sp. nov. The type strain of Actinomyces urogenitalis is CCUG 38702T (= CIP 106421T).

Streptococcus ovis sp. nov., isolated from sheep

Seven strains of an unknown Gram-positive catalase-negative chain-forming coccus-shaped organism isolated from clinical specimens from sheep were characterized by phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies demonstrated that the bacterium represents a new sub-line within the genus Streptococcus. The unknown bacterium was readily distinguished from recognized streptococcal species by biochemical tests and electrophoretic analysis of whole-cell proteins. Based on phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Streptococcus ovis sp. nov. The type strain of Streptococcus ovis is CCUG 39485T (= LMG 19174T).

Transfer of members of the genus Falcivibrio to the genus Mobiluncus, and emended description of the genus Mobiluncus

It has long been thought that the genera Mobiluncus and Falcivibrio contain the same organisms. Using a polyphasic approach, it was found that Mobiluncus curtisii and Mobiluncus mulieris were the same as Falcivibrio vaginalis and Falcivibrio grandis, respectively. As the genus name Mobiluncus takes precedence, it is proposed that F. vaginalis and F. grandis be transferred to the genus Mobiluncus. In agreement with previous studies, results from phenotypic tests did not support the separation of M. curtisii strains into its two subspecies, M. curtisii subsp. curtisii and M. curtisii subsp. holmesii. Phenotypic complexity within M. curtisii dictates that the species should be treated as a complex until more in-depth analyses of the species have been performed. Phylogenetic analyses, based on 16S rRNA gene sequences, demonstrated that the genus Mobiluncus was associated with Varibaculum cambriense and the two subspecies of Actinomyces neuii, and that A. neuii is only distantly related to Actinomyces sensu stricto.

Luteococcus peritonei sp. nov., isolated from the human peritoneum.

An unusual catalase-positive pleomorphic Gram-positive rod isolated from a human clinical specimen was subjected to a polyphasic taxonomic analysis. Comparative 16S rRNA gene sequence analysis revealed the unknown bacterium was a member of the high G+C branch of the Gram-positive bacteria (Actinobacteria), and was phylogenetically a member of the family Propionibacteriaceae, with Luteococcus japonicus as its nearest relative. Based on both phenotypic and phylogenetic evidence, it is proposed that the unknown bacterium be classified in the genus Luteococcus, as Luteococcus peritonei sp. nov. The type strain of Luteococcus peritonei is CCUG 38120T.

Lactobacillus coleohominis sp. nov., isolated from human sources

Four strains of a hitherto unrecognized gram-positive, catalase-negative, facultatively anaerobic, rod-shaped bacterium isolated from human sources were characterized using phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing demonstrated that the bacterium represents a new subline within the Lactobacillus casei/Pediococcus rRNA group of the genus Lactobacillus. The unknown bacterium was readily distinguished from all other described Lactobacillus species and related taxa by biochemical tests and electrophoretic analysis of whole-cell proteins. On the basis of phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Lactobacillus coleohominis sp. nov. The type strain of Lactobacillus coleohominis is CCUG 44007T (= CIP 106820T).