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Biomedical subjects

G K Morris

Publications and source records attributed to G K Morris.

10 recordsLinked to original sources
PubMed1979

Comparison of four plating media for isolating Vibrio cholerae.

Two brands of thiosulfate citrate bile salts sucrose agar and Monsur taurocholate tellurite gelatin (TTG) agar were compared with two newly developed media, sucrose tellurite teepol agar and Vibrio parahaemolyticus agar for isolation and identification of Vibrio cholerae. The thiosulfate citrate bile salts sucrose and TTG agars were the best selective media, whereas sucrose tellurite teepol agar was the poorest. Both TTG and sucrose tellurite teepol agars were good for use in follow-up serological tests, whereas only TTG agar could be used for follow-up oxidase tests. In our opinion TTG agar has more advantages for cholera research laboratories routinely culturing large numbers of patients for cholera on a daily basis and where media needs can be accurately predicted. In contrast, in smaller clinical laboratories or in laboratories investigating epidemics, thiosulfate citrate bile salts sucrose agar is best because it is commercially available and easy to prepare and can be used to distinguish colonies of suspect V. cholerae from V. parahaemolyticus.

Bangladesh↗
PubMed1979

A major focus of Legionnaires' disease in Bloomington, Indiana.

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.

Adult↗
PubMed1979

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.

Air Conditioning↗
PubMed1977

Yersinia enterocolitica: a review of the bacterium and recommended laboratory methodology.

Only in the last few years has Yersinia enterocolitica been recognized as an etiologic agent. The organism, however, is widespread in both the animate and inanimate environments. It has been isolated and recovered from a variety of sources including fecal material, foodstuffs, and water, but vehicles of disease transmission are not fully delineated or understood. The bacteriology of Y. enterocolitica is reviewed and recommended laboratory methodology is described.

Bacteriological Techniques↗
PubMed1976

Warfarin sodium in prevention of deep venous thrombosis and pulmonary embolism in patients with fractured neck of femur.

In a prospective controlled randomised trial, the prophylactic value of warfarin sodium (in doses aimed at maintaining a "Thrombotest" value of 10% and given from the day of admission until independent mobility had been achieved or for 3 mo, whichever was the sooner) was assessed in 160 elderly patients who had sustained a fracture of the femoral neck. Treatment significantly reduced the frequency of deep venous thrombosis (D.V.T.), whether indicated by the 125I-fibrinogen test during life or assessed by detailed post-mortem studies. Pulmonary embolism was eliminated in treated patients, but the difference in mortality between the treatment and control groups was not significant, indicating that causes of death other than pulmonary embolism are of major importance in these elderly patients. A case is made out for prophylactic anticoagulation on a selective basis.

Aged↗
PubMed1976

Laboratory investigation of diarrhea in travelers to Mexico: evaluation of methods for detecting enterotoxigenic Echerichia coli.

A laboratory investigation was conducted on cultures collected from travelers before, during, and after a trip to Mexico to characterize the etiology of traveler's diarrhea. Four laboratory methods for detecting enterotoxigenicity of Escherichia coli were evaluated: the infant mouse assay, the Chinese hamster ovary (CHO) cell assay, the Y1 adrenal cell assay, and the rabbit ileal loop. Although a number of common enteric pathogens were identified as a cause of traveler's diarrhea, including six serotypes of Salmonella, two serotypes of Shigella, Vibrio parahaemolyticus, Giardia lamblia, and Entamoeba histolytica, enterotoxigenic Escherichia coli was most commonly isolated. Strains were identified that produced only heat-labile enterotoxin (LT), only heat-stable enterotoxin (ST), or both LT and ST. The infant mouse assay yielded results falling into two distinct groups, providing a clear separation of positive and negative cultures. The CHO assay also formed two groups, with positive cultures producing 11% or more of the elongated cells. There was good agreement between the CHO and the Y1 adrenal cell assays for detection of LT. The adrenal cell system for detection of LT was more suitable than the CHO assay for processing large numbers of specimens because of the miniculture modification of this method utilized in this study. The infant mouse method was a simple and reliable method for detecting ST.

Animals↗
PubMed1975

Diarrhoea associated with heat-stable enterotoxin-producing strains of Escherichia coli.

Five patients who developed acute watery diarrhoea while travelling in Mexico in October, 1974, were found to have enterotoxigenic Escherichia coli in their stool which produced heat-stable enterotoxin (S.T.) without producing heat-labile enterotoxin (L.T.). These S.T.-only E. coli, which have previously been described as causing diseases in animals, must now be regarded as pathogenic for humans as well.

Adult↗