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PubMed2002

Recent taxonomic changes and terminology update of clinically significant anaerobic gram-negative bacteria (excluding spirochetes).

Because of access to 16S rDNA sequencing, changes in the taxonomy and nomenclature of anaerobic gram-negative bacteria have occurred lately. New genera and species have been described, and existing taxa have been reclassified. The present article compiles a list of clinically relevant anaerobes and provides synonyms as well as the old nomenclature used for these bacteria. Although names and classifications of anaerobic bacteria are changing quickly, it is important to keep track of new bacterial names to work toward better description and recognition of bacterium-disease associations.

Bacteroides↗
PubMed2004

Antimicrobial resistance in Brachyspira pilosicoli with special reference to point mutations in the 23S rRNA gene associated with macrolide and lincosamide resistance.

A point mutation in the 23S rRNA gene causes macrolide and lincosamide resistance in Brachyspira hyodysenteriae. The possible occurrence of a similar mutation in Brachyspira pilosicoli was studied and the MICs of six antimicrobial agents for Swedish field isolates of B. pilosicoli were determined. Of 10 isolates with high MICs of macrolide and lincosamide antibiotics, six had a mutation in nucleotide position 2058 or 2059 in the 23S rRNA gene as compared to the wild type of Escherichia coli, whereas none of 10 tylosin-susceptible isolates were mutated in this region. The mutations found in position 2058 were A --> T transversions, and in position 2059 either A --> G transitions or A --> C transversions. The MICs at which 90% of the B. pilosicoli field isolates were inhibited by tylosin, erythromycin, clindamycin, virginiamycin, tiamulin, and carbadox, were >256, >256, >4, 4, 2, and 0.125 microg/ml, respectively. In conclusion, point mutations in positions 2058 and 2059 of the 23S rRNA gene can cause macrolide and lincosamide resistance in B. pilosicoli. Macrolide resistance is widespread among Swedish field isolates of B. pilosicoli. Notably also a few isolates with elevated MICs of tiamulin were found.

Animals↗
PubMed2006

Quality-control ranges for antimicrobial susceptibility testing by broth dilution of the Brachyspira hyodysenteriae type strain (ATCC 27164T).

There are no approved standards for antimicrobial susceptibility testing of the fastidious spirochete Brachyspira hyodysenteriae. An interlaboratory study was performed to establish MIC quality control ranges for six antimicrobial agents for the type strain of B. hyodysenteriae using broth dilution. The results showed that B. hyodysenteriae B78T ATCC 27164T is a suitable quality control strain. This is a first step toward standardization of methods regarding this anaerobe.

Animals↗
PubMed1979

Modified Steiner method for the demonstration of spirochetes in tissue.

The substitution of lead nitrate for uranium nitrate as used in the Steiner silver impregnation method for demonstrating spirochetes in tissue sections is described. The use of lead nitrate provides a chemical substitute free of any potential radiation hazard without loss of staining specificity. The use of lead nitrate in place of uranium nitrate in the Dieterle method for staining Legionnaires' disease organisms is proposed.

Histological Techniques↗
PubMedDate not supplied

Epidemiology and clinical similarities of human spirochetal diseases.

Lyme disease, first identified in 1975, is the most recently recognized of the seven human spirochetal diseases; the evolving clinical picture of Lyme disease indicates it shares many features with the other diseases. These similarities are striking in view of the diverse epidemiology of the seven diseases, which are caused by Treponema species (spread by human-to-human contact) or Leptospira or Borrelia species (zoonoses). These similarities include the following: (1) skin or mucous membrane as portal of entry; (2) spirochetemia early in the course of disease, with wide dissemination through tissue and body fluid; and (3) one or more subsequent stages of disease, often with intervening latent periods. Lyme disease shares with many spirochetal diseases a tropism for skin and neurologic and cardiovascular manifestations, whereas chronic arthritis is unique to Lyme disease. These similarities and dissimilarities offer opportunities to discover which properties unique to the pathogenic spirochetes are responsible for clinical manifestations and suggest that certain clinical features of patients with spirochetal diseases other than Lyme disease may someday be recognized in patients with Lyme disease.

Animals↗
PubMedDate not supplied

Current taxonomy of medically important nonsporing anaerobes.

This review deals mainly with the taxonomy of the genera and species in the family Bacteroidaceae. It has been proposed that the genus Bacteroides should be restricted to include the "Bacteroides fragilis group" and that the asaccharolytic black-pigmented Bacteroides species be transferred to a new genus, Porphyromonas. New Bacteroides, Fusobacterium, and Selenomonas species have been described. A high degree of heterogeneity is apparently present among Peptostreptococcus species. Mobiluncus is a novel genus including gram-variable curved rods isolated from the human vagina. Brachyspira has been proposed as the generic name for spirochetes isolated from patients with intestinal spirochetosis.

Bacteria, Anaerobic↗
PubMedDate not supplied

The enlarging spectrum of tick-borne spirochetoses: R. R. Parker Memorial Address.

The author reviews his changing interest in tick-borne spirochetoses during his career (1951-1985) as a medical entomologist at the U.S. Public Health Service's Rocky Mountain Laboratory. The discoveries of relapsing fevers in the western United States in the 1930s and 1940s led to well-supported epidemiologic research, including studies on the relationships between vectors and spirochetes. When tick-borne relapsing fever in the United States was shown to be a relatively rare and readily treatable disease, financial support was withdrawn, and ongoing research was limited or terminated. Interest in relapsing fever spirochetes, particularly the relation to the relapse phenomenon in animal hosts, resurfaced in the 1960s and 1970s with the introduction of immunofluorescence assays and with the development of Kelly's medium for continuous cultivation of certain spirochetes. This interest increased significantly in 1981 when the author discovered a tick-borne spirochete to be the causative agent of Lyme disease and of several clinically related disorders in Europe. The discovery of this agent, now known as Borrelia burgdorferi, has led not only to intensive clinical, epidemiologic, and ecologic investigations in the United States and abroad but also to the identification of molecular and immunochemical techniques necessary for the study of the complex biology of tick-borne spirochetes. Reference is also made to a new species of Borrelia that may be the etiologic agent of epizootic bovine abortion in the western United States.

Animals↗
PubMed1978

Analysis of gynandromorph survivals in Drosophila melanogaster infected with the male-killing SR organisms.

The effects of SRO (Sex-ratio organism; previously called SR spirochetes) infection on the viability of gynandromorphs of D. melanogaster were examined. A fraction of gynadromorphs, most of them with small areas of XO tissue, survived, but the majority were not viable when XO nuclei or cells are affected by the infecting SRO. Apparently the replacement of lethal XO nuclei or cells by adjacent XX ones does not take place. Some possibilities are discussed as to the time and the primary site of the lethal action of SRO.

Animals↗
PubMed1984

Enzyme-linked immunosorbent assay and indirect immunofluorescence assay for Lyme disease.

The sensitivity and specificity of an indirect immunofluorescence assay (IFA) and ELISA for Lyme disease were estimated. Sera from patients with Lyme disease, patients with other infections, and healthy individuals were examined. Significant cross-reactivity occurred only with sera from patients with syphilis, yaws, and pinta . All tested sera from patients with Lyme disease, however, gave negative results in the rapid reagin screening test and the microhemagglutination assay for antibodies to Treponema pallidum confirmatory for syphilis. When sera from patients with treponemal diseases were excluded from the analysis, the IFA and ELISA were highly specific, having 97% and 100% reliability, respectively. Sensitivity of both tests varied with the stage of disease but was 100% for both tests during complicated Lyme disease. The results indicate that both tests are highly specific and sensitive for complicated Lyme disease but relatively insensitive for patients with erythema chronicum migrans alone.

Antibodies, Bacterial↗
PubMed1984

Interactions of phagocytes with the Lyme disease spirochete: role of the Fc receptor.

The phagocytic capacity of murine and human mononuclear and polymorphonuclear phagocytes (including peripheral blood monocytes and neutrophils), rabbit and murine peritoneal exudate cells, and the murine macrophage cell line P388D1 against the Lyme disease spirochete was studied. All of these cells were capable of phagocytosing the spirochete; phagocytosis was measured by the uptake of radiolabeled spirochetes, the appearance of immunofluorescent bodies in phagocytic cells, and electron microscopy. Both opsonized and nonopsonized organisms were phagocytosed. The uptake of opsonized organisms by neutrophils was blocked by a monoclonal antibody specific for the Fc receptor and by immune complexes; these findings suggested that most phagocytosis is mediated by the Fc receptor. Similarly, the uptake of opsonized organisms by human monocytes was inhibited by human monomeric IgG1 and by immune complexes. These results illustrate the role of immune phagocytosis of spirochetes in host defense against Lyme disease.

Animals↗