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M D Yates

Publications and source records attributed to M D Yates.

At least 55 records · Page 3Linked to original sources
PubMed1985

Subdivision of Mycobacterium tuberculosis for epidemiological purposes: a seven year study of the "Classical' and 'Asian' types of the human tubercle bacillus in South-East England.

Human strains of Mycobacterium tuberculosis were divided into the 'Classical' and 'Asian' types according to their sensitivity to thiophen-2-carboxylic acid hydrazide. The isolation of these two types in South-East England was studied during a seven-year period (1977-1983). The 'Asian' type was more prevalent among ethnic Asian patients than among ethnic Europeans. Among Europeans there was a decline in the isolation rate of 'Classical' strains and a small but significant increase in 'Asian' strains during the study period, so that the proportion of the latter type in this group is increasing. The type of bacillus was unrelated to the site of isolation except that the incidence of lymphadenitis due to the 'Asian' type among European females was significantly higher than expected. In general, European patients tended to be older than Asian patients, and the differences in age distribution according to site of isolation and type of bacillus in each ethnic group were small. A notable exception occurred with European females infected with the 'Asian' type, whose age distribution was similar to the Asians. In view of the differences in behaviour of the two types of human tubercle bacilli in this country there is a need to continue a bacteriological surveillance and also to determine whether the nature of the host-pathogen interaction varies according to the type of bacillus.

Adolescent↗
PubMed1985

Mycobacterium xenopi and Mycobacterium kansasii in a hospital water supply.

A steady rise in the number of isolations of Mycobacterium xenopi from patients in a general hospital led to an examination of water taps. Most patients had been accommodated in a group of wards which had a common water supply. This organism was recovered from 35 of 69 outlets, mostly from hot and mixer taps in those wards. Mycobacterium kansasii was also isolated from 14, mostly cold and mixer taps. Ten strains of Myco. xenopi were recovered from 131 taps sampled at 10 other locations. We conclude that colonization of water supplies by mycobacteria is a likely source of contamination of clinical specimens.

England↗
PubMed1984

A study of the relationship between the resistance of Mycobacterium tuberculosis to isonicotinic acid hydrazide (isoniazid) and to thiophen-2-carboxylic acid hydrazide.

Thiophen-2-carboxylic acid hydrazide (TCH) is used to distinguish TCH-sensitive bovine, 'Asian human' and 'African' strains from TCH-resistant 'classical' human strains of Mycobacterium tuberculosis. It has been claimed that this test cannot be applied to isoniazid-resistant strains as these also become resistant to TCH. Although such cross-resistant mutants were readily isolated in vitro, a study of the incidence of TCH resistance in a large series of INH-sensitive and -resistant strains isolated from patients indicated that the emergence of this type of mutant is the exception rather than the rule in vivo. Thus, the use of TCH for subdividing the species M. tuberculosis remains valid for epidemiological purposes, irrespective of the occurrence of isoniazid resistance.

Asian People↗
PubMed1983

What is BCG?

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Animals↗
PubMed1982

"Classical" and "Asian" variants of Mycobacterium tuberculosis isolated in South East England 1977-1980.

Strains of Mycobacterium tuberculosis were divided into 'classical' and 'Asian' types according to their susceptibility to thiophen-2-carboxylic acid hydrazide (TCH). A study of 6638 new cases of tuberculosis showed that there was a much higher incidence of non-pulmonary disease among Asian than among European patients, and that the TCH-sensitive 'Asian' type of organism was much commoner among the former. There was, however, no correlation between the site of disease and the type of organism. Resistance to antituberculosis drugs was more frequent among strains from Asian patients but there was no correlation between such resistance and susceptibility to TCH. No evidence was therefore found to link differences in the clinical features of tuberculosis in the two populations of patients to the type to organism.

Adolescent↗
PubMed1982

Subdivision of Mycobacterium tuberculosis into five variants for epidemiological purposes: methods and nomenclature.

Virulent strains of Mycobacterium tuberculosis isolated from humans are divisible into five variants by using four tests: oxygen requirement (aerobic or microaerophilic), nitrate reductase activity, susceptibility to pyrazinamide (60 micrograms/ml) and susceptibility to thiophene-2-carboxylic acid hydrazide (5 micrograms/ml). The five variants are referred to as Classical human, Asian human, bovine, African I and African II. The relation of these variants to previously described types is discussed. This simple division has been shown to be useful in epidemiological studies.

Humans↗
PubMed1982

Low incidence of rifampicin-resistant tubercle bacilli.

In a six-year survey 10(0.15%) of 6849 patients with European names and 31 (1.0%) of 3079 patients with non-European names yielded cultures of Mycobacterium tuberculosis that were resistant to rifampicin. Only two of each group had organisms resistant to rifampicin alone. Resistance to one or more other antituberculous drugs was found in eight of the European and 29 of the non-European group. Two patients in each group were known to have received treatment for the first time in the United Kingdom; 17 of the non-Europeans were known to have been treated abroad; precise information was not available for the other 12. The overall six-year incidence of patients with rifampicin-resistant M tuberculosis was only 0.41%. The very low incidence among Europeans is probably the result of stricter regimens than are possible in some other areas.

Drug Resistance, Microbial↗
PubMed1982

Purification and partial characterization of a macrophage cytotoxin from Pasteurella haemolytica.

A protein from Pasteurella haemolytica that was highly immunogenic and toxic toward bovine alveolar macrophages was partially purified. When isolated from culture supernatants of P haemolytica serotype 1 or serotype 6, the protein reacted on Ouchterlony immunodiffusion tests with antisera from 12 serotypes of P haemolytica, but did not cross-react with antisera to serotypes of P multocida. This indicated that the protein may be specific for P haemolytica. Bacteria were grown in dialysis culture in a brain-heart infusion and calf-serum growth medium. The protein was isolated from the medium by ultrafiltration and size-exclusion chromatography and has a molecular weight of approximately 150,000 daltons. The protein, which is highly immunogenic and has the characteristics of a virulence factor, is common to all serotypes of P haemolytica, and may be an effective agent for immunization against P haemolytica in cattle.

Antigens, Bacterial↗
PubMed1981

A study of bovine strains of Mycobacterium tuberculosis isolated from humans in South-East England, 1977-1979.

Bovine strains of Mycobacterium tuberculosis were isolated from 137 of 5021 cases of tuberculosis (2.7%) occurring in South East England during the years 1977 to 1979. These were divisible into 'classical' and 'Afro-Asian' bovine strains according to their susceptibility to pyrazinamide. Classical strains were the predominant type among the Europeans and Afro-Asian types were commoner in immigrants. Bovine strains caused a high incidence of extrapulmonary disease in both ethnic groups and there was a significant relationship between renal disease and 'classical' strains. The age and sex distributions of bovine strains were similar to those of human strains in both ethnic groups. It was considered that these bovine strains were transmitted from human to human by the pulmonary route.

Adolescent↗
PubMed1981

Sensitivity of opportunist mycobacteria to rifampicin and ethambutol.

A total of 1237 strains of opportunist mycobacteria were tested for sensitivity to rifampicin and ethambutol. Most strains of Mycobacterium kansasii and all strains of M. marinum tested were sensitive to both drugs. A variable pattern was given by M. xenopi strains, but a general resistance was observed with the M. avium--intracellulare--scrofulaceum group. All strains of M. fortuitum and M. chelonei were highly resistant. Scotochromogens were mostly sensitive to ethambutol, but there was variable resistance to rifampicin. These properties may be useful in identification of species. No acquired resistance was found in follow-up cultures from confirmed cases of mycobacterioses, but details of therapy, if any, were not known.

Drug Resistance, Microbial↗