ABSTRACT
A polyphasic analysis was undertaken of seven independent isolates of gram-negative cocci collected from pathological clinical samples from New York, Louisiana, Florida and Illinois and healthy subgingival plaque from a patient in Virginia, USA. The 16S rRNA gene sequence similarity among these isolates was 99.7-100â%, and the closest species with a validly published name was Neisseria lactamica (96.9â% similarity to the type strain). DNA-DNA hybridization confirmed that these isolates are of the same species and are distinct from their nearest phylogenetic neighbour, N. lactamica. Phylogenetic analysis of 16S and 23S rRNA gene sequences indicated that the novel species belongs in the genus Neisseria. The predominant cellular fatty acids were C16â:â0, summed feature 3 (C16â:â1ω7c and/or iso-C15â:â0 2-OH) and C18â:â1ω7c. The cellular fatty acid profile, together with other phenotypic characters, further supports the inclusion of the novel species in the genus Neisseria. The name Neisseria oralis sp. nov. (type strain 6332(T) â=âDSM 25276(T) â=âLMG 26725(T)) is proposed.
Subject(s)
Dental Plaque/microbiology , Gingiva/microbiology , Neisseria/classification , Phylogeny , Bacterial Typing Techniques , DNA, Bacterial/genetics , Fatty Acids/analysis , Humans , Molecular Sequence Data , Neisseria/genetics , Neisseria/isolation & purification , Nucleic Acid Hybridization , RNA, Ribosomal, 16S/genetics , RNA, Ribosomal, 23S/genetics , Sequence Analysis, DNA , United StatesABSTRACT
An analysis of 16S rRNA gene sequences from archived clinical reference specimens has identified two novel Neisseria species. For each species, two strains from independent sources were identified. Amongst species with validly published names, the closest species to the newly identified organisms were Neisseria canis, N. dentiae, N. zoodegmatis, N. animaloris and N. weaveri. DNA-DNA hybridization studies demonstrated that the newly identified isolates represent species that are distinct from these nearest neighbours. Analysis of partial 23S rRNA gene sequences for the newly identified strains and their nearest neighbours provided additional support for the species designation. Bayesian analysis of 16S rRNA gene sequences suggested that the newly identified isolates belong to distinct but related species of the genus Neisseria, and are members of a clade that includes N. dentiae, N. bacilliformis and N. canis. The predominant cellular fatty acids [16â:â0, summed feature 3 (16â:â1ω7c and/or iso-15â:â0 2-OH) and 18â:â1ω7c], as well as biochemical and morphological analyses further support the designation of Neisseria wadsworthii sp. nov. (type strain 9715(T) =DSM 22247(T) =CIP 109934(T)) and Neisseria shayeganii sp. nov. (type strain 871(T) =DSM 22246(T) =CIP 109933(T)).
Subject(s)
Neisseria/classification , Neisseria/isolation & purification , Neisseriaceae Infections/microbiology , Bacterial Typing Techniques , Cluster Analysis , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Fatty Acids/analysis , Humans , Molecular Sequence Data , Neisseria/chemistry , Neisseria/genetics , Nucleic Acid Hybridization , Phylogeny , RNA, Ribosomal, 16S/genetics , RNA, Ribosomal, 23S/genetics , Sequence Analysis, DNAABSTRACT
Although antibiotics are known to affect the intracellular growth of Chlamydia pneumoniae in acute infections, their efficacy in therapy for chronic infections, including atherosclerosis, remains debatable. Human monocyte-derived macrophages (MDM) obtained from monocytes of healthy donors were infected with C. pneumoniae AR-39 and treated with levofloxacin (8 microg/mL) immediately after infection (0 hours) or 24 hours after infection. Levofloxacin treatment at 24 hours, but not at 0 hours, resulted in a significant decrease in the number of C. pneumoniae inclusions within the MDM (p < 0.05). Also decreased were concentrations of proinflammatory cytokines tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, IL-6, and IL-8 in the extracellular medium (p < 0.01). Viable counts in titrations remained similar to those in untreated controls. In summary, levofloxacin administered to MDM at serum-attainable levels 24 hours after C. pneumoniae infection significantly decreased inclusion counts and proinflammatory cytokine production, but did not eliminate the C. pneumoniae infection.
Subject(s)
Anti-Bacterial Agents/pharmacology , Chlamydophila pneumoniae/drug effects , Cytokines/biosynthesis , Levofloxacin , Monocytes/drug effects , Ofloxacin/pharmacology , Cell Line , Hepatocytes/microbiology , Humans , Monocytes/immunology , Monocytes/microbiologyABSTRACT
We studied 20 Chlamydia pneumoniae isolates obtained from respiratory sites and atheroma tissue of patients from various geographic areas to determine the susceptibilities of these isolates to a new des-fluoroquinolone, garenoxacin, and to levofloxacin. In addition, we assessed the cultures with these isolates by PCR for the presence or absence of Mycoplasma sp. DNA. Both the MIC at which 90% of isolates are inhibited (MIC(90)) and the minimal bactericidal concentration at which 90% of isolates are killed (MBC(90)) for garenoxacin were 0.06 microg/ml, and both the MIC(90) and the MBC(90) for levofloxacin were 2.0 microg/ml. The activity of garenoxacin against C. pneumoniae was 32-fold greater than that of levofloxacin. Mycoplasma sp. DNA was detected by PCR in 17 of 20 cultures. Mycoplasma amplicons from five Mycoplasma DNA-positive C. pneumoniae cultures were sequenced and found to represent four Mycoplasma species. Our data demonstrate that C. pneumoniae cultures frequently contain Mycoplasma DNA and that its presence in C. pneumoniae cultures does not appear to affect the susceptibility results for the two fluoroquinolones that we tested.
