G K Morris

Centers for Disease Control and Prevention, Atlanta, Michigan, United States

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Publications (45)367.27 Total impact

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    ABSTRACT: 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.
    Journal of Clinical Microbiology 12/1985; 22(5):714-8. · 4.07 Impact Factor
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    C M Patton, T J Barrett, G K Morris
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    ABSTRACT: 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.
    Journal of Clinical Microbiology 11/1985; 22(4):558-65. · 4.07 Impact Factor
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    ABSTRACT: The epidemiology of Campylobacter jejuni indicates that waterborne transmission is important; the organism has been isolated from seawater, fresh water, and estuarine sites. Membrane filtration, with and without use of an enrichment broth, has been the most common method for isolating C. jejuni from water. We evaluated two methods for isolating C. jejuni from water: membrane filtration and gauze filtration. The membrane filters evaluated included 0.22- and 0.45-micron-pore Millipore filters (Millipore Corp., Bedford, Mass.), 0.2- and 0.4-micron-pore Nuclepore filters (Nucleopore Corp., Pleasanton, Calif.), and a 0.45-micron-pore Zetapor filters (AMF Cuno, Meridian, Conn.). The gauze filters included both Moore and Spira swabs. Of the membrane filters evaluated, the 0.45-micron-pore Millipore and Zetapor filters were the most sensitive for recovery of C. jejuni from seeded waters. The 0.45-micron-pore Millipore filter placed in Oosterom broth was better for recovery of C. jejuni from seeded stationary surface waters than either the Spira or Moore swab. However, the 0.45-micron-pore Millipore filter placed on a plate or in enrichment broth was equivalent to the Spira gauze swab when used to examine water from Atlanta area streams. C. jejuni organisms were isolated from 9 of 24 surface water samples representing 5 of 12 streams.
    Applied and Environmental Microbiology 10/1985; 50(3):611-4. · 3.95 Impact Factor
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    ABSTRACT: 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.
    Journal of Clinical Microbiology 07/1985; 21(6):936-40. · 4.07 Impact Factor
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    ABSTRACT: A coagglutination system has been devised for typing heat-stable and heat-labile antigens of Campylobacter jejuni and C. coli. The use of protein A-positive Staphylococcus aureus cells carrying Campylobacter sp. serotype antibody and the treatment of Campylobacter sp. cells with DNase in the antigen suspension permitted rapid and specific coagglutination of rough (autoagglutinable) as well as smooth cultures. Cells of S. aureus were sensitized with Campylobacter sp. serotype antisera. Four to five types of sensitized S. aureus cells were pooled. A strain of Campylobacter sp. was first tested with the pools and then typed with the individual reagents of the reactive pool. After the described procedures, 68 serotype strains tested blindly as unknowns were correctly typed according to their heat-stable or heat-labile antigens. The two most commonly used typing schemes which are based separately on the heat-stable or the heat-labile antigens as assayed by passive hemagglutination and slide agglutination, respectively, can be utilized simultaneously in the coagglutination system for strain characterization. The coagglutination system is simple, yields results rapidly, conserves typing reagents, and offers the flexibility of formulating the pools of reagents according to the experimental design or the prevalence of serotypes in a geographic location. It should be a practical system for the typing of Campylobacter spp. in public health or clinical laboratories.
    Journal of Clinical Microbiology 06/1985; 21(5):702-7. · 4.07 Impact Factor
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    ABSTRACT: 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.
    Journal of Clinical Microbiology 02/1985; 21(1):129-32. · 4.07 Impact Factor
  • The Lancet 03/1984; 1(8374):449. · 39.06 Impact Factor
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    ABSTRACT: 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.
    Journal of Clinical Microbiology 10/1983; 18(3):512-20. · 4.07 Impact Factor
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    ABSTRACT: 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.
    Journal of Clinical Microbiology 06/1983; 17(5):853-5. · 4.07 Impact Factor
  • The Lancet 04/1983; 1(8326 Pt 1):702-3. · 39.06 Impact Factor
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    C A Bopp, J W Sumner, G K Morris, J G Wells
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    ABSTRACT: 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.
    Journal of Clinical Microbiology 05/1981; 13(4):714-9. · 4.07 Impact Factor
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    J G Wells, G K Morris
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    ABSTRACT: 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.
    Journal of Clinical Microbiology 05/1981; 13(4):789-90. · 4.07 Impact Factor
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    ABSTRACT: A new species of Legionella was isolated from soil collected from a creek bank. The name Legionella gormanii sp. nov. is proposed.
    Journal of Clinical Microbiology 12/1980; 12(5):718-21. · 4.07 Impact Factor
  • Annals of internal medicine 11/1980; 93(4):572-3. · 13.98 Impact Factor
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    ABSTRACT: 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.
    Applied and Environmental Microbiology 11/1980; 40(4):697-700. · 3.95 Impact Factor
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    M I Huq, A K Alam, D J Brenner, G K Morris
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    ABSTRACT: 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.
    Journal of Clinical Microbiology 07/1980; 11(6):621-4. · 4.07 Impact Factor
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    I Huq, A K Alam, G K Morris, G Wathen, M Merson
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    ABSTRACT: A family outbreak of foodborne shigellosis caused by an unusual strain of Shigella is described. The strain was a mannitol-positive variant of Shigella dysenteriae and agglutinated in antiserum prepared against provisional serotype 3341-55.
    Journal of Clinical Microbiology 05/1980; 11(4):337-9. · 4.07 Impact Factor
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    ABSTRACT: 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.
    Journal of Clinical Microbiology 05/1980; 11(4):385-8. · 4.07 Impact Factor
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    ABSTRACT: Thirty-nine cases of Legionnaires' disease in a 16-month period were identified in visitors to and residents of Bloomington, Indiana. Thirty-five patients had spent at least one night at the Indiana Memorial Union in the 2 weeks before becoming ill. Five of 32 sporadic cases nationwide between 1 January and 31 March 1978 were retrospectively shown to be in persons who had recently visited the Union. The risk of acquiring Legionnaires' disease as a Union visitor was at least 17 times greater than that for Bloomington residents 20 years or older. Employees who had worked at the Union 5 years or longer were more likely to be seropositive than workers in other Bloomington hotels. Legionnaires' disease bacterium was isolated from five environmental sites in Bloomington. A cooling tower may have been involved in disease spread, but it was not the only source. Hypochlorite solution was added to cooling tower water as a precautionary measure; however, one case was confirmed in a man with Union exposure 9 days after hypochlorite treatment had begun.
    Annals of internal medicine 05/1979; 90(4):587-91. · 13.98 Impact Factor
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    ABSTRACT: 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.
    Annals of internal medicine 05/1979; 90(4):664-6. · 13.98 Impact Factor

Publication Stats

1k Citations
367.27 Total Impact Points

Institutions

  • 1983–1985
    • Centers for Disease Control and Prevention
      • Division of Bacterial Diseases
      Atlanta, Michigan, United States
  • 1975
    • Johns Hopkins University
      Baltimore, Maryland, United States