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Biomedical subjects

G W Gorman

Publications and source records attributed to G W Gorman.

30 records · Page 2Linked to original sources
PubMed1980

Pittsburgh pneumonia agent: direct isolation from human lung tissue.

Pittsburgh pneumonia agent (PPA) was recently cultivated from infected egg yold on charcoal yeast extract agar. PPA has now been isolated both from infected egg yolk and human lung tissue on charcoal yeast extract agar and on a new medium, buffered charcoal yeast extract agar. PPA resembles Legionella pneumophila and other Legionella-like organisms in requirements for growth and composition of fatty acids. It differs in genetic relatedness, antigenic composition, and colonial morphology and has distinctive characteristics that allow it to be identified. The name Legionella pittsburgensis species nova is proposed for this organism.

Animals↗
PubMed1980

Laboratory studies of disinfectants against Legionella pneumophila.

Legionella pneumophila suspended in tap water was exposed to biocides recommended for inhibiting biological growth in cooling towers and evaporative condensers of air-conditioning systems. Chlorine, 2,2-dibromo-3-nitrilopropionamide, and a compound containing didecyldimethylammonium chloride and isopropanol were effective in destroying concentratiois of 10(5) to 10(6) viable cells per ml. Formulations consisting of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one, disodium ethylene bis(thiocarbamate) and sodium dimethyl dithiocarbamate, and a phenolic with pentachlorophenate and sodium salts of other chlorophenols were less effective.

1-Propanol↗
PubMed1979

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.

Adult↗
PubMed1979

Charcoal-yeast extract agar: primary isolation medium for Legionella pneumophila.

Charcoal-yeast extract agar is a new bacteriological medium that supports excellent growth of the Legionella pneumophila. It results from modifications made in an existing L. pneumophila medium, F-G agar. Yeast extract, instead of an acid hydrolysate of casein, serves as the protein source. Beef extractives and starch are not added. Activated charcoal (Norit A or Norit SG) is included at 0.20% (wt/vol). Comparison of charcoal-yeast extract and F-G agars showed that a greater number of colony-forming units of L. pneumophila was recovered from a standardized tissue inoculum on charcoal-yeast extract agar (4.35 x 10(6) colony-forming units) than on F-G agar (4.85 x 10(4) colony-forming units). Macroscopic colonies of L. pneumophila were visible on the new medium within 3 days, whereas 4 days of growth was required on F-G agar.

Agar↗
PubMed1978

Primary isolation media for Legionnaires disease bacterium.

Yolk sac suspensions infected with the Legionnaires disease bacterium (LDB) were plated onto 17 different bacteriological agar media. The LDB grew only on Mueller-Hinton agar supplemented with 1% Iso Vitale X and 1% hemoglobin (MH-IH). This medium was subsequently analyzed to determine the components required to support growth of the LDB. L-Cysteine hydrochloride can replace the Iso Vitale X reagent, and soluble ferric pyrophosphate can replace hemoglobin. A new medium, F-G agar, was formulated incorporating these chemicals. Different cultures conditions (oxygen tension, temperature, and pH) were also evaluated. The LDB grew optimally at 35 degrees C under 2.5% CO2 on the F-G agar adjusted to pH 6.9. When infected tissues were inoculated onto both F-G agar and MH-IH, the F-G agar produced colonies of the LDB more rapidly and in greater numbers than did MH-IH.

Bacteria↗
PubMed1975

Epidemiologic studies of serotype antigens common to groups B and C Neisseria meningitidis.

Antisera to strains of group B Neisseria meningitidis (Frash) were used to serotype strains of group C N. meningitidis by an agar gel double diffusion technique. Serotupe antigen(s) were found in most strains examined, and the presence of group B serotype 2 antigen was associated with associated with sulfonamide resistance in group C strains isolated from sporadic cases and from cases and carriers in military and civilian epidemics of disease caused by sulfonamide-resistant group C organisms. Serotyping by the agar diffusion test apperars to be a useful tool for epidemiologic studies of disease caused by groups B and C N. meningitidis.

Animals↗
PubMedDate not supplied

Prevalence of antibodies to Legionella pneumophila among workers exposed to a contaminated cooling tower.

A serosurvey for antibodies to Legionella pneumophila was conducted among 206 employees of a power-generating plant. L. pneumophila serotype 6 and a non-typable L. pneumophila organism were isolated from cooling-tower water specimens at the plant, and antibody titers in workers were measured using homologous antigens prepared from these isolates. For the serotype 6 water isolate, none of workers with low cooling tower exposure, 4.6% with intermediate exposure, and 7.6% with high exposure levels had titers equal to or greater than 1:128 (P less than .05, Kruskal-Wallis test). For the non-typable L. pneumophila isolate, a similar trend was observed, but differences among workers in the three exposure groups were not statistically significant. No association was observed between antibodies to L. pneumophila serotypes isolated from cooling water and workers' age, race, smoking status, or duration of job assignment. None of the study employees had findings suggesting the occurrence of L. pneumophila pneumonia since the plant had been in operation. Use of respiratory protection devices by workers exposed to aerosols from cooling towers was not recommended.

Adult↗