Actinomyces cardiffensis sp. nov. from human clinical sources

Eight strains of a previously undescribed catalase-negative Actinomyces-like bacterium were recovered from human clinical specimens. The morphological and biochemical characteristics of the isolates were consistent with their assignment to the genus Actinomyces, but they did not appear to correspond to any recognized species. 16S rRNA gene sequence analysis showed the organisms represent a hitherto unknown species within the genus Actinomyces related to, albeit distinct from, a group of species which includes Actinomyces turicensis and close relatives. Based on biochemical and molecular genetic evidence, it is proposed that the unknown isolates from human clinical sources be classified as a new species, Actinomyces cardiffensis sp. nov. The type strain of Actinomyces cardiffensis is CCUG 44997(T).     

PCR for Detection and Identification of Abiotrophia spp.

Members of the genus Abiotrophia, formerly known as nutritionally variant streptococci, are important pathogens causing septicemia and endocarditis. Cultivation and biochemical differentiation of Abiotrophia spp. are often difficult. Based on 16S rRNA sequences, two PCR assays for detection and identification of Abiotrophia spp. were developed. The first PCR assay was positive for all Abiotrophia spp. Subsequently performed restriction fragment length polymorphism analysis allowed the verification of the PCR amplicons and the differentiation of the three species. The second PCR assay was positive only for A. elegans, the most fastidious species of Abiotrophia. Both PCR assays were shown to be specific and sensitive and should facilitate the identification of Abiotrophia spp.     

Characterization of Actinomyces isolates from infected root canals of teeth: description of Actinomyces radicidentis sp. nov

Two strains of a previously undescribed Actinomyces-like bacterium were recovered in pure culture from infected root canals of teeth. Analysis by biochemical testing and polyacrylamide gel electrophoresis of whole-cell proteins indicated that the strains closely resembled each other phenotypically but were 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, we propose that the unknown bacterium isolated from human clinical specimens be classified as Actinomyces radicidentis sp. nov. The type strain of Actinomyces radicidentis is CCUG 36733.     

Predominant bacterial species in subgingival plaque in dogs

Dahlén G, Charalampakis G, Abrahamsson I, Bengtsson L, Falsen E. Predominant bacterial species in subgingival plaque in dogs. J Periodont Res 2012; 47: 354–364. © 2011 John Wiley & Sons A/S Background and Objective: The dog has been used extensively for experimental and microbiological studies on periodontitis and peri‐implantitis without detailed knowledge about the predominant flora of the subgingival plaque. This study was designed to evaluate the predominant cultivable bacterial species in dogs and compare them phenotypically and genotypically with corresponding human species. Material and Methods: Four subgingival samples were taken from two upper premolars in each of six Labrador retrievers. The samples from each dog were processed for anaerobic culture. From the samples of each dog, the five or six predominating bacteria based on colony morphology were selected and pure cultured. Each of the strains was characterized by Gram stain, anaerobic/aerobic growth and API‐ZYM test. Eighteen strains showing clear‐cut phenotypic differences were further classified based on DNA sequencing technology. Cross‐reactions of DNA probes from human and dog strains were also tested against a panel of both human and dog bacterial species. Results: Thirty‐one strains in the dogs were isolated and characterized. They represented 21 different species, of which six belonged to the genus Porphyromonas. No species was found consistently in the predominant flora of all six dogs. Porphyromonas crevioricanis and Fusobacterium canifelinum were the two most prevalent species in predominant flora in dogs. DNA probes from human and dog species cross‐reacted to some extent with related strains from humans and dogs; however, distinct exceptions were found. Conclusion: The predominant cultural subgingival flora in dogs shows great similarities with the subgingival bacteria from humans at the genus level, but distinct differences at the species level; however, a genetic relatedness could be disclosed for most strains investigated.     

Assessment and management of polymyalgia rheumatica in older adults.

Polymyalgia rheumatica (PMR) is a periarticular rheumatic condition characterized by pain and stiffness, primarily in the neck, shoulders, hips, and pelvic girdle. Temporal arteritis (TA) or giant cell arteritis, the most common primary vasculitis in older adults, is found in approximately 10% to 30% of people who have PMR. Left untreated, TA can result in sudden, irreversible blindness. Geriatric nurses need to familiarize themselves with these disorders to accurately assess and manage people with them.     

Primary identification of Microbacterium spp. encountered in clinical specimens as CDC coryneform group A-4 and A-5 bacteria.

Over nearly two decades, 13 yellow- or orange-pigmented, fermentative gram-positive rods belonging to the genus Microbacterium were encountered in clinical specimens. All 13 strains, 10 of which came from blood cultures, were initially identified as CDC coryneform group A-4 and A-5 bacteria according to the scheme of Hollis and Weaver for the identification of gram-positive rods. The clinical isolates were compared with the type strains of the six species constituting the genus Microbacterium as well as with three Microbacterium strains isolated from hospital environments. By biochemical methods only 5 of 13 clinical isolates could be identified to species level. Peptidoglycan analysis proved to be a valuable tool for differentiation between Microbacterium spp. and related genera, whereas cellular fatty acid analysis did not allow species identification within the genus Microbacterium. The 22 Microbacterium strains studied were, in general, susceptible to antimicrobial agents used in the treatment of infections caused by gram-positive rods. This report is the first one concerning the isolation of Microbacterium strains from clinical specimens. The sources as well as the mode of transmission remain to be established.     

Occurrence of the Southeast Asian/South American SVMNT haplotype of the chloroquine-resistance transporter gene in Plasmodium falciparum in Tanzania

Two main haplotypes, CVIET and SVMNT, of the Plasmodium falciparum chloroquine-resistance transporter gene (Pfcrt) are linked to 4-aminoquinoline resistance. The CVIET haplotype has been reported in most malaria-endemic regions, whereas the SVMNT haplotype has only been found outside Africa. We investigated Pfcrt haplotype frequencies in Korogwe District, Tanzania, in 2003 and 2004. The SVMNT haplotype was not detected in 2003 but was found in 19% of infected individuals in 2004. Amodiaquine use has increased in the region. The introduction and high prevalence of the SVMNT haplotype may reflect this and may raise concern regarding the use of amodiaquine in artemisinin-based combination therapies in Africa.     

Molecular epidemiology of the 1984-1986 outbreak of diphtheria in Sweden

Despite mass vaccination against diphtheria, many people have antibody titers below the protective level of 0.01 IU per milliliter. A recent outbreak of diphtheria in Sweden caused 17 clinical cases of diphtheria in the city of G?teborg; three of the patients died. A satellite outbreak occurred in Stockholm after a few months' delay. Using a new genetic probe, we analyzed 36 strains of Corynebacterium diphtheriae isolated in Sweden and Denmark during the period 1976 to 1986. Although the 36 strains can be classified in 17 different groups of C. diphtheriae (several of them containing toxigenic strains), all the clinical and fatal cases of diphtheria were caused by isolates from the same group, strongly suggesting that the outbreak in Sweden was caused by a single strain that possibly had a virulence factor separate from toxigenicity. This strain may have been imported into Sweden from Denmark, since it was isolated for the first time in Copenhagen in 1983, before the outbreak in Sweden.     

Epidemiology of diphtheria: Polypeptide and restriction enzyme analysis in comparison with conventional phage typing

Several methods for epidemiological typing ofCorynebacterium diphtheriae were compared with the well accepted phage typing analysis. For this purpose, isolates from outbreaks of diphtheria in specific areas of the FRG and Sweden were analyzed by phage typing, their bacterial polypeptide profiles were examined and their phage-DNA restriction enzyme patterns were compared. All techniques were able to identify whether certain outbreaks were epidemiologically linked or not. Phage typing and phage-DNA restriction enzyme fragment analysis were limited in their application to lysogenic strains, whereas bacterial polypeptide analysis was universally applicable. Analysis of bacterial polypeptides was superior to all methods, especially in terms of speed and simplicity.