George W. Gorman

Isolation of Legionella pneumophila from Hospital Shower Heads

Legionella pneumophila serogroup 6 was isolated from nine of 16 shower heads in a Chicago hospital ward where three patients had contracted Legionnaires disease caused by serogroup 6 L. pneumophila. Each patient had showered there 2 to 10 days before the onset of disease symptoms. We also isolated the bacteria in two other hospitals, and found the same serogroups as had been causing Legionnaires disease in those hospitals: serogroup 1 in Pittsburgh and serogroups 1 and 4 in Los Angeles. However, showers from hospital wards where no patients had contracted Legionnaires disease also yielded L. pneumophila. Shower heads at the Chicago hospital were sterilized with ethylene oxide but rapidly became recontaminated, suggesting that the potable water at these hospitals may have contained the organism. The question of whether aerosols of shower water or other exposures to potable water containing L. pneumophila may cause nosocomial Legionnaires disease has not been resolved but deserves further study.

Isolation of the Legionnaires' disease bacterium from environmental samples.

We analyzed 24 environmental samples collected in or near the Indiana Memorial Union, where an epidemic of Legionnaires disease occurred in early 1978. We conducted fluorescent antibody analyses and culture on F-G and charcoal yeast extract agars of each sample directly; splenic tissue of guinea pigs inoculated with the sample; and yolk sacs from embryonated eggs inoculated with splenic tissue of guinea pigs injected with the sample. Legionnaires disease (LD) bacterium was isolated from seven of the 24 samples: one water sample from the air-conditioner cooling tower of the Union; three water samples from a stream near the Union; and three mud samples from the same stream. The LD bacterium strains were of three different serotypes. These findings indicate that LD bacteria may be widespread in nature.

Ten New Species of Legionella

Ten new Legionella species were characterized on the basis of biochemical reactions, antigens, cellular fatty acids, isoprenoid quinones, and deoxyribonucleic acid relatedness. Nine of the new species were isolated from the environment, and one, Legionella hackeliae, was isolated from a bronchial biopsy specimen obtained from a patient with pneumonia. The species all exhibited the following biochemical reactions typical of the legionellae: growth on buffered cysteine-yeast extract agar, but not on blood agar; growth requirement for cysteine; gram negative; nitrate negative; urease negative; nonfermentative; catalase positive; production of a brown pigment on tyrosine-containing yeast extract agar; liquefaction of gelatin; and motility. Legionella spiritensis was weakly positive for hydrolysis of hippurate; the other species were hippurate negative. Legionella cherrii, Legionella steigerwaltii, and Legionella parisiensis exhibited bluish white autofluorescence. Legionella rubrilucens and Legionella erythra exhibited red autofluorescence. The other species, L. spiritensis, L. hackeliae, Legionella maceachernii, Legionella jamestowniensis, and Legionella santicrucis did not autofluoresce bluish white or red. All species had cellular fatty acid contents qualitatively similar to those of previously described legionellae and had major amounts of ubiquinones with more than 10 isoprene units in the side chains. Each new species was serologically distinct from previously described Legionella species. As determined by the hydroxyapatite method at 60°C, two strains of L. maceachernii were 100% related, and four strains of L. cherrii were 94 to 99% related. The other new species were represented by single strains. The levels of relatedness of the new species to each other and to previously described legionellae ranged from 1 to 67%. L. maceachernii, L. jamestowniensis, and L. hackeliae were less than 25% related to other species. L. rubrilucens and L. erythra, and two red-autofluorescing species, were about 60% interrelated. L. spiritensis (a non-autofluorescing species) was 34% related to L. rubrilucens. L. santicrucis was 64% related to Legionella sainthelensi. The three bluish white-autofluorescing species, L. parisiensis, L. cherrii, and L. steigerwaltii, were most closely related to other bluish white-autofluorescing species, especially Legionella bozemanii, Legionella dumoffii, Legionella gormanii, and “Legionella anisa” (35 to 67%).

A New Legionella Species, Legionella feeleii Species Nova, Causes Pontiac Fever in an Automobile Plant

From 15 to 21 August 1981, Pontiac fever affected 317 automobile assembly plant workers. Results of serologic tests were negative for Mycoplasma, Chlamydia, respiratory tract viruses, and previously described legionellae. A gram-negative, rod-shaped organism (WO-44C) that did not grow on blood agar, required L-cysteine for growth, and contained large amounts of branched-chain fatty acids was isolated from a water-based coolant. The organism did not react with antisera against other legionellae, and on DNA hybridization the organism was less than 10% related to other Legionella species. Geometric mean titers found by indirect fluorescent antibody testing to WO-44C were significantly higher in ill employees than in controls (p = 0.0001). Attack rates by department decreased linearly with the departments distance from the implicated coolant system. The etiologic agent apparently was a new Legionella species; we propose the name Legionella feeleii species nova (AATC 35072). This is the first outbreak of nonpneumonic legionellosis in which the etiologic agent is not L. pneumophila, serogroup 1.

ATYPICAL LEGIONELLA-LIKE ORGANISMS: FASTIDIOUS WATER-ASSOCIATED BACTERIA PATHOGENIC FOR MAN

A group of related bacteria designated atypical Legionella-like organisms (ALLO) has been identified. ALLO, like L. pneumophila, are fastidious gram-negative rods that grow well on charcoal yeast extract (CYE) agar and produce ground glass colonies and browning of modified yeast extract agar. Unlike L. pneumophila, ALLO do not grow well on Feeley-Gorman (FG) agar, and on CYE agar they fluoresce under longwave ultraviolet light. ALLO and L. pneumophila have a similar predominance of branched-chain forms among total cellular fatty acids but have distinctive fatty-acid profiles. 2 patients with culture-verified ALLO pneumonia and 10 with pneumonia of uncertain aetiology who seroconverted to ALLO offer evidence that ALLO may be a cause of community-acquired pneumonia. Like L. pneumophila, ALLO appear to be water-associated; both persons with culture-verified ALLO infection were exposed to fresh water or its contents before becoming ill, and two strains of ALLO were isolated from water or wet environments.

Hemophilus influenzae type b disease in a day-care center. Report of an outbreak.

Four episodes of serious Hemophilus influenzae type b infection occurred in three children attending a day-care center. This was 100 times the expected annual total. The pharyngeal carriage rate of Hib was 60% for siblings of patients, 20% for adult household contacts, and 5% for well children at the center. No carriers were found in control populations. Escherichia coli K100, which cross-reacts serologically with Hib, was found in rectal swabs of 20% of family contacts of patients and 3.5% of well children at the center. It was recovered from two of seven persons who carried Hib in the pharynx and two of 75 who did not (P = 0.035), suggesting that carriage of one organism may facilitate carriage of the other. In a randomized prospective trial with 85 patient contact, Hib carriage was eradicated in all of four carriers given ampicillin and in all of three given rifampin. There were no statistically significant differences in the rate of adverse reactions in the two treatment groups. No further cases were reported.

Nosocomial legionellosis, Paris, France. Evidence for transmission by potable water

During a five-week period in 1981, six cases of legionellosis due to Legionella pneumophila serogroup 1 were recognized in a hospital in Paris, France. Four cases were clearly nosocomial in origin. There was a direct association between development of disease and exposure to potable hot water (p = 0.003). The entire hot water system was contaminated with L. pneumophila serogroup 1; monoclonal antibody testing demonstrated that the case isolate and the potable water isolates belonged to the same subgroup. Although serogroup 1 was isolated from both the cooling tower and its drift, the cooling tower isolate was antigenically distant from the case isolate. In other nosocomial outbreaks of legionellosis, multiple sources have been found within the hospital environment, but an epidemiologic association of disease with potable water had not been shown. The significant association of cases with exposure to the potable hot water supply, and the identification of case and potable water isolates of the same subtype, suggest that the potable hot water was responsible for transmission of disease in this outbreak.

A Fifth Serogroup of Legionella pneumophila

Excerpt In September 1978, the Center for Disease Control (CDC) investigated an outbreak of Legionnaires disease among persons who had attended the national Veterans of Foreign Wars convention hel...

Isolation of Pittsburgh Pneumonia Agent from Nebulizers Used in Respiratory Therapy

Excerpt Pittsburgh pneumonia agent was recently reported by Pasculle and colleagues (1) to cause pneumonia. It was further characterized by Hebert and associates (2). Most cases of Pittsburgh pneum...

Effect of supplementall-tyrosine on pigment production in cultures of the Legionnaires' disease bacterium

The etiologic agent of Legionnaires disease grows on certain agar media. Cultures of this organism on supplemented Mueller-Hinton agar are characterized by the appearance of brown pigment in and around areas of bacterial growth. The major peptone source in Mueller-Hinton agar is an acid hydrolysate of casein. Legionnaires disease bacterium also grows on a medium in which the peptone source is 0.25% yeast extract, but no pigment is produced. If the yeast extract agar is enriched withl-tyrosine, pigment formation can occur. Pigmentation of cultures of Legionnaires disease bacterium may be mediated by a phenolo-monooxygenase, or tyrosinase.