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Tatlockia and Fluoribacter: Two new genera of organisms resembling Legionella pneumophila
Abstracts of Recent Literature Submitted by Robert Fekety, M.D. Chief, Infectious Disease Section University Hospital University of Michigan MedicalSchool Ann Arbor, Michigan 48109 EDITOR'S NOTE: Dr. Fekctypreparesabstracts of current, pertinentliteraturefor his staffand has kindlyconsentedto sharethemwithus. Theywillappear hereperiodicallyas space permits.
T. F. Keys, 1980. Legionnaires' disease. A review of the epidemiology and clinical manifestations of a newly recognized infection. Mayo Clin. Proc. 55:129-137. From 1977 to 1979, 26 patients with Legionnaires' disease were seen at the Mayo Clinic. The median age was 51 years, and about a half of the patients were immunologically compromised. Hectic fever, cough, and diarrhea were common symptoms. Diagnosis was made by indirect fluorescent antibody (FA) tests in most of the patients, but FA was never diagnostic during the first week. In seven patients, the diagnosis was established by FA tests on lung tissue, in two patients by cultures of lung, and in one each by FA on sputum or bronchial washings. About 1207oof the patients had severe renal failure, and 19% died. The author noted a favorable clinical response to erythromycin and believes that this drug, in combination with rifampin, is the treatment of choice. Treatment should be given for three weeks in order to prevent relapse. This is an excellent review not only of the clinic's cases but of the literature. P. H. Edelstein, et al. 1980. Laboratory diagnosis of Legionnaires' disease. Am. Rev. Respir. Dis. 121: 317-327.
The disease was diagnosed in 32 patients with nosocomially acquired pneumonia using direct FA examination of respiratory tract secretions, indirect FA titers, and/or culture of the organism from respiratory secretions. The authors believe all three tests should be performed for optimal sensitivity and specificity and that transtracheal aspiration should be used for collection of respiratory tract secretions. Cultures were positive in 13 of 21 patients from whom appropriate specimens were submitted. Sputum specimens were not considered appropriate for culture because oral flora rapidly overgrows the organism on selective or nonselective media. Many of the positive cultures were obtained from aseptically collected postmortem specimens. When a positive culture was used to define the disease, the sensitivity of the direct FA was 62°70 and that of indirect FA serology was 7507o. G. A. H~rbert, et ai. 1980. The rickettsia-like organisms TATLOCK (1943) and HEBA (1959): Bacteria phenotypically similar but genetically distinct from Legionella pneumophila and the WIGA bacterium. Ann. Intern. Med. 92:45-52. Two rickettsia-like organisms, TATLOCK and HEBA, isolated from human blood via guinea pigs and embryonated eggs in 1943 and 1959 have been cultured on charcoalyeast extract (CYE) agar and characterized. They have identical cultural, biochemical, and other characteristics and have similar characteristics to L. pneumophila and WlGA. DNA studies, however, showed that these bacteria are not
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genetically related to either of the other organisms. G. A. H~rbert, et al. 1980. "Pittsburgh Pneumonia Agent": A bacterium phenotypically similar to Legionellapneumophila and identical to TATLOCK bacterium. Ann. Intern. Med. 92:53-54. The Pittsburgh Pneumonia Agent has been cultured on artificial media and characterized. It has identical characteristics to the TATLOCK and HEBA bacteria. The plot with these new organisms is not only thickening; it is becoming so difficult to comprehend and manage that one might say it is curdling. G. M. Garrity, et al. 1980. Tatlockia and Fluoribacter: Two new genera of organisms resembling Legionella pneumophila. Int. J. Syst. Bacteriol. 30:609-614. DNA homology studies were performed with strains of L. pneumophila and a group of seven previously unclassified bacteria that resemble L. pneumophila, including PPA, TATLOCK, WIGA, and other ALLO (atypical legionella-like organisms). Results of hybridization experiments suggest that these previously unclassified organisms are not related to L. pneumophila at the genus level; thus two new genera within the family Legionellaceae are proposed for them: Tatlockia and Fluoribacter. The type species are T. micdadei and F. bozemanae. Colonies of Fluoribacter fluoresce brightly when illuminated with longwave ultraviolet light, a characteristic that distinguishes the organism from Legionella and Tatlockia.
T. F. Keys, 1980. Legionnaires' disease. A review of the epidemiology and clinical manifestations of a newly recognized infection. Mayo Clin. Proc. 55:129-137. From 1977 to 1979, 26 patients with Legionnaires' disease were seen at the Mayo Clinic. The median age was 51 years, and about a half of the patients were immunologically compromised. Hectic fever, cough, and diarrhea were common symptoms. Diagnosis was made by indirect fluorescent antibody (FA) tests in most of the patients, but FA was never diagnostic during the first week. In seven patients, the diagnosis was established by FA tests on lung tissue, in two patients by cultures of lung, and in one each by FA on sputum or bronchial washings. About 1207oof the patients had severe renal failure, and 19% died. The author noted a favorable clinical response to erythromycin and believes that this drug, in combination with rifampin, is the treatment of choice. Treatment should be given for three weeks in order to prevent relapse. This is an excellent review not only of the clinic's cases but of the literature. P. H. Edelstein, et al. 1980. Laboratory diagnosis of Legionnaires' disease. Am. Rev. Respir. Dis. 121: 317-327.
The disease was diagnosed in 32 patients with nosocomially acquired pneumonia using direct FA examination of respiratory tract secretions, indirect FA titers, and/or culture of the organism from respiratory secretions. The authors believe all three tests should be performed for optimal sensitivity and specificity and that transtracheal aspiration should be used for collection of respiratory tract secretions. Cultures were positive in 13 of 21 patients from whom appropriate specimens were submitted. Sputum specimens were not considered appropriate for culture because oral flora rapidly overgrows the organism on selective or nonselective media. Many of the positive cultures were obtained from aseptically collected postmortem specimens. When a positive culture was used to define the disease, the sensitivity of the direct FA was 62°70 and that of indirect FA serology was 7507o. G. A. H~rbert, et ai. 1980. The rickettsia-like organisms TATLOCK (1943) and HEBA (1959): Bacteria phenotypically similar but genetically distinct from Legionella pneumophila and the WIGA bacterium. Ann. Intern. Med. 92:45-52. Two rickettsia-like organisms, TATLOCK and HEBA, isolated from human blood via guinea pigs and embryonated eggs in 1943 and 1959 have been cultured on charcoalyeast extract (CYE) agar and characterized. They have identical cultural, biochemical, and other characteristics and have similar characteristics to L. pneumophila and WlGA. DNA studies, however, showed that these bacteria are not
....
I
-
-
genetically related to either of the other organisms. G. A. H~rbert, et al. 1980. "Pittsburgh Pneumonia Agent": A bacterium phenotypically similar to Legionellapneumophila and identical to TATLOCK bacterium. Ann. Intern. Med. 92:53-54. The Pittsburgh Pneumonia Agent has been cultured on artificial media and characterized. It has identical characteristics to the TATLOCK and HEBA bacteria. The plot with these new organisms is not only thickening; it is becoming so difficult to comprehend and manage that one might say it is curdling. G. M. Garrity, et al. 1980. Tatlockia and Fluoribacter: Two new genera of organisms resembling Legionella pneumophila. Int. J. Syst. Bacteriol. 30:609-614. DNA homology studies were performed with strains of L. pneumophila and a group of seven previously unclassified bacteria that resemble L. pneumophila, including PPA, TATLOCK, WIGA, and other ALLO (atypical legionella-like organisms). Results of hybridization experiments suggest that these previously unclassified organisms are not related to L. pneumophila at the genus level; thus two new genera within the family Legionellaceae are proposed for them: Tatlockia and Fluoribacter. The type species are T. micdadei and F. bozemanae. Colonies of Fluoribacter fluoresce brightly when illuminated with longwave ultraviolet light, a characteristic that distinguishes the organism from Legionella and Tatlockia.