-
BMC Research Notes Mar 2012Atopobium vaginae and Gardnerella vaginalis are major markers for bacterial vaginosis. We aimed to determine the MIC and MBC range of the broad-spectrum anti-infective...
BACKGROUND
Atopobium vaginae and Gardnerella vaginalis are major markers for bacterial vaginosis. We aimed to determine the MIC and MBC range of the broad-spectrum anti-infective and antiseptic dequalinium chloride for 28 strains, belonging to 4 species of the genus Atopobium, i.e. A. vaginae, A. minutum, A. rimae and A. parvulum.
METHODS
The MIC was determined with a broth microdilution assay.
RESULTS
The MIC and MBC for Atopobium spp. for dequalinium chloride ranged between < 0.0625 and 2 μg/ml.
CONCLUSIONS
This study demonstrated that dequalinium chloride inhibits and kills clinical isolates of A. vaginae at concentrations similar to those of clindamycin and lower than those of metronidazole.
Topics: Actinobacteria; Anti-Bacterial Agents; Bacteroides fragilis; Clindamycin; Culture Media; Dequalinium; Female; Humans; Metronidazole; Microbial Sensitivity Tests; Vagina; Vaginosis, Bacterial
PubMed: 22429611
DOI: 10.1186/1756-0500-5-151 -
Journal of Clinical Microbiology Sep 2011Acquired vancomycin resistance in Gram-positive anaerobes has been reported only in Australia and Canada from rare vanB-positive stool samples in the absence of...
Acquired vancomycin resistance in Gram-positive anaerobes has been reported only in Australia and Canada from rare vanB-positive stool samples in the absence of vancomycin-resistant enterococci (VRE). We report the emergence of VanB-type resistance in Clostridium clostridioforme and Atopobium minutum involved in human infections in France.
Topics: Actinobacteria; Clostridium; DNA, Bacterial; France; Genes, Bacterial; Gram-Positive Bacterial Infections; Humans; Male; Middle Aged; Molecular Sequence Data; Sequence Analysis, DNA; Vancomycin Resistance
PubMed: 21775552
DOI: 10.1128/JCM.00308-11 -
Applied and Environmental Microbiology Oct 2002Excessive NH(3) production in the rumen is a major nutritional inefficiency in ruminant animals. Experiments were undertaken to compare the rates of NH(3) production...
Ammonia production by ruminal microorganisms and enumeration, isolation, and characterization of bacteria capable of growth on peptides and amino acids from the sheep rumen.
Excessive NH(3) production in the rumen is a major nutritional inefficiency in ruminant animals. Experiments were undertaken to compare the rates of NH(3) production from different substrates in ruminal fluid in vitro and to assess the role of asaccharolytic bacteria in NH(3) production. Ruminal fluid was taken from four rumen-fistulated sheep receiving a mixed hay-concentrate diet. The calculated rate of NH(3) production from Trypticase varied from 1.8 to 19.7 nmol mg of protein(-1) min(-1) depending on the substrate, its concentration, and the method used. Monensin (5 micro M) inhibited NH(3) production from proteins, peptides, and amino acids by an average of 28% with substrate at 2 mg/ml, compared to 48% with substrate at 20 mg/ml (P = 0.011). Of the total bacterial population, 1.4% grew on Trypticase alone, of which 93% was eliminated by 5 micro M monensin. Many fewer bacteria (0.002% of the total) grew on amino acids alone. Nineteen isolates capable of growth on Trypticase were obtained from four sheep. 16S ribosomal DNA and traditional identification methods indicated the bacteria fell into six groups. All were sensitive to monensin, and all except one group (group III, similar to Atopobium minutum), produced NH(3) at >250 nmol min(-1) mg of protein(-1), depending on the medium, as determined by a batch culture method. All isolates had exopeptidase activity, but only group III had an apparent dipeptidyl peptidase I activity. Groups I, II, and IV were most closely related to asaccharolytic ruminal and oral Clostridium and Eubacterium spp. Group V comprised one isolate, similar to Desulfomonas piger (formerly Desulfovibrio pigra). Group VI was 95% similar to Acidaminococcus fermentans. Growth of the Atopobium- and Desulfomonas-like isolates was enhanced by sugars, while growth of groups I, II, and V was significantly depressed by sugars. This study therefore demonstrates that different methodologies and different substrate concentrations provide an explanation for different apparent rates of ruminal NH(3) production reported in different studies and identifies a diverse range of hyper-ammonia-producing bacteria in the rumen of sheep.
Topics: Animals; Bacteria; Fermentation; In Vitro Techniques; Monensin; Peptides; RNA, Ribosomal, 16S; Rumen; Sheep
PubMed: 12324340
DOI: 10.1128/AEM.68.10.4925-4931.2002 -
Journal of Clinical Microbiology Feb 2007Four bacterial isolates were recovered from the blood cultures of four patients, two of whom were from Hong Kong and two of whom were from Canada. The two Hong Kong...
Four bacterial isolates were recovered from the blood cultures of four patients, two of whom were from Hong Kong and two of whom were from Canada. The two Hong Kong strains were isolated from a 48-year-old man with intestinal obstruction and secondary sepsis (strain HKU16T) and from a 39-year-old man with acute appendicitis (strain HKU17), while the two Canadian strains were isolated from a 74-year-old man with biliary sepsis (strain CA1) and from a 66-year-old woman with metastatic carcinoma and sepsis (strain CA2). While the first three patients survived, the last patient died 2 weeks after the episode of bacteremia. All four isolates are strictly anaerobic, nonsporulating, gram-positive coccobacilli that were unidentified by conventional phenotypic tests and commercial identification systems. They grow on sheep blood agar as nonhemolytic pinpoint colonies after 48 h of incubation at 37 degrees C in an anaerobic environment. All are catalase positive and motile, with flagella. They produce acid from arabinose, glucose, mannose, and xylose. They do not produce indole or reduce nitrate. They are sensitive to penicillin, vancomycin, and metronidazole but resistant to cefotaxime. 16S rRNA gene sequence analysis showed 16.0%, 16.8%, and 21.0% base differences from Clostridium propionicum, Clostridium neopropionicum, and Atopobium minutum, respectively. The G+C content of strain HKU16T is 40.2% +/- 2.2%. Based on their phylogenetic affiliation, unique G+C content, and phenotypic characteristics, we propose a new genus and species, Catabacter hongkongensis gen. nov., sp. nov., to describe the bacterium, for which HKU16 is the type strain, and suggest that it be assigned to a new family, Catabacteriaceae. The gastrointestinal tract was probably the source of the bacterium for at least three of the four patients. The isolation of a catalase-positive, motile, nonsporulating, anaerobic gram-positive bacillus in clinical laboratories should raise the possibility of C. hongkongensis. Further studies should be performed to ascertain the epidemiology and other disease associations of this bacterium.
Topics: Adult; Aged; Anaerobiosis; Bacteremia; Bacterial Typing Techniques; Base Composition; Blood; Canada; Culture Media; Female; Gram-Positive Bacteria; Gram-Positive Bacterial Infections; Hong Kong; Humans; Male; Middle Aged; Molecular Sequence Data; Phenotype; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA
PubMed: 17122022
DOI: 10.1128/JCM.01831-06