Search PubMed⌕ Search

Biomedical subjects

G K Morris

Publications and source records attributed to G K Morris.

At least 37 records · Page 2Linked to original sources
PubMed1985

Addition of three new serotypes of Shigella boydii to the Shigella schema.

No new serotypes have been added to the Shigella schema since 1958, although several provisional serotypes have been described. We conducted biochemical and serological studies on three provisional Shigella boydii serotypes. Four strains of serotype 2710-54 from four widely separated countries, 7 strains of serotype 3615-53 from three different countries, and 31 strains of serotype 1344-78 (E10163) from six different countries were included. Reactions of all three serotypes were consistent with those of S. boydii. On the basis of these results and other published research, we propose that these three provisional serotypes be admitted to the Shigella schema as S. boydii 16, 17, and 18.

Asia↗
PubMed1985

Biochemical and genetic characteristics of atypical Campylobacter fetus subsp. fetus strains isolated from humans in the United States.

During a 2-year period, 14 biochemically atypical Campylobacter fetus subsp. fetus-like strains were received by the Campylobacter Reference Laboratory at the Centers for Disease Control. Sources of the isolates were blood, nine strains; stools, two strains; amniotic fluid, one strain; and abscesses, two strains. Atypical phenotypic characteristics exhibited by one or more strains were growth at 42 degrees C, 10 strains; no H2S by lead acetate paper, 3 strains; resistance to a 30-micrograms cephalothin disk, 2 strains; and nonmotility, 1 strain. By DNA-DNA hybridization, all 14 isolates and the type strain of C. fetus subsp. fetus (ATCC 27374) were 94 to 100% related in reassociation reactions at 50 degrees C, with 0.0 to 0.5% divergence, and were 86 to 100% related in reassociation reactions at 65 degrees C. Thus, all of these atypical strains were C. fetus subsp. fetus. MICs of 11 antimicrobial agents for these 14 strains were variable. All strains were susceptible to chloramphenicol, erythromycin, gentamicin, and tetracycline, and most were susceptible to ampicillin, clindamycin, and penicillin. Eleven strains were resistant to cephalothin (MIC greater than or equal to 16 micrograms/ml), nine were resistant to rifampin (MIC greater than or equal to 8 micrograms/ml), and all were resistant to nalidixic acid (MIC greater than 32 micrograms/ml) and vancomycin (MIC greater than 32 micrograms/ml). One can expect to see biochemical variability in C. fetus subsp. fetus strains and to encounter such strains from a variety of human sources, the most important of which appears to be blood.

Campylobacter Infections↗
PubMed1985

Comparison of the Penner and Lior methods for serotyping Campylobacter spp.

We compared two Campylobacter serotyping systems by using 1,405 isolates of Campylobacter collected from human, animal, and environmental sources during epidemiologic investigations and special studies. We found 96.1% of isolates to be typable by the Penner method for heat-stable antigens, which involved the use of an indirect hemagglutination technique, and 92.1% of isolates to be typable by the Lior method for heat-labile antigens, which involved the use of a slide agglutination technique and absorbed antisera. Absorbed antisera were not required for the Penner method, making that method less difficult to implement. The Lior method was simpler to perform and gave more rapid results than did the Penner method. Cultures frequently reacted in multiple antisera with the Penner method, whereas multiple reactions were rare with the Lior method. Thus, results were easier to interpret with the Lior system. Strains of a single serotype in one system were sometimes found to be multiple serotypes in the other system; hence, the two methods have the potential to be complementary. Both systems were comparable in serotyping isolates from human and nonhuman sources and for evaluating the relationship of strains collected during outbreak investigations.

Agglutination Tests↗
PubMed1985

Comparison of four hippurate hydrolysis methods for identification of thermophilic Campylobacter spp.

The test for hippurate hydrolysis is critical for separation of Campylobacter jejuni and C. coli strains. Glycine and benzoic acid are formed when hippurate is hydrolyzed by C. jejuni. The test used in most laboratories is one of several variations of the ninhydrin tube test described by Hwang and Ederer (M. Hwang and G. M. Ederer, J. Clin. Microbiol. 1:114-115, 1975) for detection of glycine. We evaluated three modifications of the Hwang and Ederer method and the gas-liquid chromatographic (GLC) method described by Kodaka et al. (H. Kodaka, G. L. Lombard, and V. R. Dowell, Jr., J. Clin. Microbiol. 16:962-964, 1982) for detecting benzoic acid. Campylobacter strains comprised 22 C. jejuni, 11 C. coli, and 8 C. laridis strains. The species identification of each strain was confirmed by DNA relatedness. All strains of C. jejuni were positive and all strains of C. coli and C. laridis were negative by the GLC method for detecting hippurate hydrolysis, whereas three strains of C. jejuni gave negative or variable results in the tube tests. The GLC method is more sensitive than the tube methods for detecting hippurate hydrolysis and should be used on cultures yielding variable or questionable test results.

Bacteriological Techniques↗
PubMed1984

O:13a,13b, a new pathogenic serotype of Yersinia enterocolitica.

Forty strains of a new Yersinia enterocolitica serotype isolated in the United States from nonhuman primates and humans were characterized as serotype O:13a,13b. Most of the human strains were isolated from a large multistate outbreak of milkborne enteritis. A common antigenic factor between this new serotype and four previously described Y. enterocolitica (O:7,13; O:18; O:44; and O:44,45) led to recharacterization of the latter as serotypes O:7,13a,13b; O:18,13b; O:44,13a; and O:44,13a,45.

Agglutination↗
PubMed1983

Selective enrichment broth medium for isolation of Campylobacter jejuni.

A new selective Campylobacter enrichment broth for the isolation of Campylobacter jejuni has been tested with fecal specimens of human, poultry, and bovine origin. We compared the isolation rate with that from the simultaneous direct plating of a duplicate specimen. Of the 380 duplicate specimens examined comparatively, we obtained a 46.3% increase in isolation of C. jejuni by using the new Campylobacter enrichment broth medium.

Animals↗
PubMed1983

Laboratory investigation of hemorrhagic colitis outbreaks associated with a rare Escherichia coli serotype.

Two outbreaks of hemorrhagic colitis, a newly recognized syndrome characterized by bloody diarrhea, severe abdominal pain, and little or no fever, occurred in 1982. No previously recognized pathogens were recovered from stool specimens from persons in either outbreak. However, a rare E. coli serotype, O157:H7, was isolated from 9 of 20 cases and from no controls. It was also recovered from a meat patty from the implicated lot eaten by persons in one outbreak. No recovery of this organism was made from stools collected 7 or more days after onset of illness; whereas 9 of 12 culture-positive stools had been collected within 4 days of onset of illness. The isolate was not invasive or toxigenic by standard tests, and all strains has a unique biotype. Plasmid profile analysis indicates that all outbreak-associated E. coli O157:H7 isolates are closely related. These results suggest that E. coli O157:H7 was the causative agent of illness in the two outbreaks.

Anti-Bacterial Agents↗
PubMed1981

Isolation of Legionella spp. from environmental water samples by low-pH treatment and use of a selective medium.

A selective medium was developed and used successfully to isolate Legionella pneumophila and Legionella-like organisms from environmental specimens previously positive by animal inoculation methods. This medium consists of charcoal-yeast extract agar to which have been added cephalothin (4 micrograms/ml), colistin (16 micrograms/ml), vancomycin (0.5 microgram/ml), and cycloheximide (80 micrograms/ml). Pretreating of the environmental water samples with an acid buffer (pH 2.2), followed by plating on the selective medium, improved the rate of recovery of both Legionella and Legionella-like organisms relative to that with direct plating on selective media.

Cephalothin↗
PubMed1981

Evaluation of transport methods for isolating Shigella spp.

Recovery of Shigella spp. from fecal specimens transported in buffered glycerol saline and Cary-Blair media held at frozen, refrigerated, or room temperature was compared with recovery by direct plating of fecal specimens. Buffered glycerol saline was the better transport medium for the recovery of Shigella spp. Refrigerated or frozen transport temperatures were superior to room temperature for recovery from either medium.

Animals↗
PubMed1981

Meptazinol and morphine compared: a study using systolic time intervals.

Changes in systolic time intervals following the administration of either morphine (0.1 mg/kg) or meptazinol (1 mg/kg) were studied in 12 patients admitted to hospital for intra-abdominal operations. The changes in these indices of cardiac performance were small. However, in 5 of the 6 patients who received morphine, the changes were in a direction suggesting negative inotropism, whereas the changes following meptazinol (6 patients) consistently suggested an improved ventricular performance.

Adult↗
PubMed1980

Prevention of venous thromboembolism. A survey of methods used by orthopaedic and general surgeons.

752 orthopaedic and 663 general surgeions were sent a questionnaire asking how they attempted to prevent venous thromboembolism; the survey concerned prophylaxis offered routinely to elderly patients with hip fractures, to patients undergoing elective hip replacement arthroplasty, and to patients undergoing major abdominal and thoracic operations. The response rate was more than 70%. The results suggest that the provision of prophylaxis against venous thromboembolism is inversely related to the frequency with which it occurs--e.g., the proportions of surgeons offering no routine prophylaxis or ambulation and physiotherapy only was 72% for hip fractures, 52% for hip replacement, and 38% for general surgery.

Early Ambulation↗
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↗
PubMed1980

Use of Moore swabs for isolating Vibrio cholerae from sewage.

The Moore swab method was shown to be a practical and sensitive technique for the isolation of Vibrio cholerae from sewage. In each of three instances in which cholera patients lived in homes connected to municipal sewers, V. cholerae was isolated from the community sewage plant intake at the time of the patients illness. Sewer systems became negative within 1 day after patients were treated with tetracycline. Sewer surveillance using the Moore swab also found evidence of infections occurring in areas where surveillance of diarrheal illness failed to detect cholera. Culturing community sewage by the Moore swab method proved to be an economical and effective way of determining areas where V. cholerae infections were occurring.

Bacteriological Techniques↗
PubMed1980

Isolation of Vibrio-like group, EF-6, from patients with diarrhea.

The Vibrio-like organism EF-6 was isolated from more than 500 patients with diarrhea in Bangladesh between October 1976 and June 1977. Bacteriological studies indicate that EF-6 is a member of the family Vibrionaceae and that it should be provisionally placed in the genus Vibrio. EF-6 was isolated from patients who had diarrhea, but was not conclusively implicated as the etiological agent. Pending further study, EF-6 should be considered a potential enteropathogen.

Culture Media↗
PubMed1980

Legionella gormanii sp. nov.

A new species of Legionella was isolated from soil collected from a creek bank. The name Legionella gormanii sp. nov. is proposed.

DNA, Bacterial↗