Bartonella (Rochalimaea) species as a cause of apparent "culture-negative" endocarditis.

Bartonella quintana (formerly Rochalimaea quintana) is a recently recognized cause of apparent "culture-negative" endocarditis. We describe a 39-year-old, homeless man who developed aortic valve endocarditis caused by B. quintana. He had a history of alcoholism and was seronegative for the human immunodeficiency virus. We established that B. quintana was the cause of the endocarditis on the basis of the isolation of B. quintana from blood cultures, the compatibility of histochemical stains of cardiac valve tissue, the reactivity of the polymerase chain reaction specific for B. quintana on cardiac valve tissue, and the failure to isolate an alternative causative organism despite extensive efforts. This is the second report of endocarditis caused by B. quintana and the fourth report of endocarditis caused by a Bartonella species. On the basis of the findings of this report and those of other recent reports, further study is warranted to determine the overall role of Bartonella species in apparent culture-negative endocarditis.

Detection of Bartonella (Rochalimaea) quintana by routine acridine orange staining of broth blood cultures.

Bartonella quintana was isolated from 34 BACTEC nonradiometric aerobic resin blood cultures for 10 adults. Nine patients were initially diagnosed by routine acridine orange staining of routine cultures that had been incubated for 8 days. All subcultures grew on chocolate agar within 3 to 12 days (median, 6 days). The PLUS 26 high-volume aerobic resin medium, combined with acridine orange stain and subculture, is an effective system for detection and isolation of B. quintana from blood.

Molecular evidence of person-to-person transmission of a pigmented strain of Corynebacterium striatum in intensive care units.

During a 14-month period, a unique strain of Corynebacterium striatum that produces a diffusible brown pigment was isolated from purulent sputa of nine patients and from nonrespiratory sites of two additional patients. Seven nonpigmented clinical isolates from the same period and three reference strains of C. striatum were compared with the brown isolates. Most patients had multiple sputum cultures with no coryneforms before the brown strain emerged, suggesting that the organism was hospital acquired. DNA restriction fragment patterns and Southern hybridization with the att site probe of Corynebacterium diphtheriae indicated that the brown isolates were a single strain which was distinct from the heterogeneous nonpigmented strains. A common source for the brown C. striatum was not recognized, although all of these patients were located in two adjoining intensive care units. All of the brown isolates, three of the nonpigmented clinical isolates, and two reference strains had positive CAMP reactions with Staphylococcus aureus, which has not been reported for C. striatum prior to this study.

Laboratory review of reference strains of Corynebacterium diphtheriae indicates mistyped intermedius strains.

All biotyped strains of Corynebacterium diphtheriae from the American Type Culture Collection (ATCC) were compared for morphology and biochemical reactions. Biotypes of all gravis strains and most mitis strains were confirmed, but intermedius strains were found to be misclassified. New lipid-dependent intermedius strains have been deposited with the ATCC.

Pursuit of the Corynebacterium striatum type strain.

The description of Corynebacterium striatum (Chester 1901) Eberson 1918AL in Bergey's Manual of Systematic Bacteriology has many inconsistencies with the identification scheme from the Centers for Disease Control and Prevention. We have studied the four C. striatum reference strains available from the American Type Culture Collection and the National Collection of Type Cultures and found that they fit the Centers for Disease Control and Prevention description of this species. However, it appears that the wrong strains were deposited for this species, because none of the reference strains fits the descriptions in the original publications. This is a substantial case for declaring it a nomen dubium, but the name could be rescued if a careful search reveals a strain that was used in making the original description. It is hoped that some readers may have the missing strains labeled with the early names Bacillus striatus, Bacillus flavidus, or Corynebacterium flavidum.

Evidence of multiple taxa within commercially available reference strains of Corynebacterium xerosis.

Attempts to identify coryneform isolates resembling Corynebacterium xerosis can lead clinical microbiologists to identification schemes with conflicting descriptions which result in confusing C. xerosis with Corynebacterium striatum. For the present study we purchased all available American Type Culture Collection and National Collection of Type Cultures reference cultures of C. xerosis (n = 10) and C. striatum (n = 4) and analyzed them as follows: (i) analysis of biochemical reactions in conventional tests and in the Rapid CORYNE system, (ii) whole-cell fatty acid analysis by using the gas-liquid chromatography research software of Microbial ID, Inc., and (iii) analysis of DNA homology in dot blot hybridizations. Three C. xerosis strains were indistinguishable from the C. striatum strains in whole-cell fatty acid analyses and DNA hybridizations and shared very similar biochemical reactions. The remaining seven strains of C. xerosis clustered into five groups on the basis of fatty acid patterns, DNA hybridizations, and biochemical tests. No reference strain of C. striatum fit the species description in Bergey's Manual of Systematic Bacteriology. The type strains of both C. striatum and C. xerosis fit their respective descriptions by the Centers for Disease Control and Prevention. This study suggests that the 10 commercially available reference strains of C. xerosis represent six different taxa which should be assigned to new species.