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
Campylobacter species are the leading agents of bacterial gastroenteritis worldwide. C. jejuni and C. coli together are responsible for more than 95% of all cases of Campylobacter-induced diarrheal disease in the United States. Detection of campylobacteria in clinical samples by conventional culture is problematic and slow due to their complex taxonomy, fastidious growth requirements, and biochemical inertness. The current study describes a rapid, sensitive, and specific real-time polymerase chain reaction (PCR) assay capable of detecting and differentiating C. jejuni (hippuricase gene, hipO) and C. coli (serine hydroxymethyltransferase gene, glyA) in a single reaction, directly from clinical isolates and human feces. The analytical specificity of the assay was demonstrated with a diverse range of Campylobacter species, related organisms, and other diarrhea-inducing bacterial pathogens. The analytical sensitivity of the multiplexed, PCR assay was 10 genome copies for both C. jejuni and C. coli. Following a rapid DNA extraction method (QIAGEN QIAamp DNA stool Mini Kit), the multiplexed PCR identified C. jejuni or C. coli in 100% of fecal samples containing 10(3) colony-forming units (CFU) per gram of feces. This assay represents the first real-time PCR method capable of detecting and differentiating C. jejuni and C. coli in a single reaction.
