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Biomedical subjects

M D Yates

Publications and source records attributed to M D Yates.

At least 37 records · Page 2Linked to original sources
PubMed1993

A bacteriological survey of tuberculosis due to the human tubercle bacillus (Mycobacterium tuberculosis) in south-east England: 1984-91.

The occurrence and nature of bacteriologically confirmed tuberculosis due to Mycobacterium tuberculosis in South-East England in the period 1984-91 is reported and compared with the results of a study for 1977-83. Registered new cases reached a low of 1028 in 1988 but increased to 1252 in 1991. This appeared to be due to a halt in the previous decline in new cases of European patients, a small increase in the number of Indian subcontinent (ISC) patients and an increase in patients from Africa. A total of 122 patients, mostly of European ethnic origin, were known to be HIV positive. As in the 1977-83 study, disease in the ISC group affected younger patients than in the European group, tubercle bacilli were more frequently isolated from a non-pulmonary site in the ISC group (45%) than in the European group (19%) and there was a higher incidence of the South Indian variant of M. tuberculosis in the former group (17%) than in the latter (9%). The overall incidence of drug resistance has not altered significantly since the 1977-83 study but 46 strains resistant to 3 or more drugs were isolated from 4099 ISC patients, compared with 3 of 4594 strains from European patients. Six of the 122 isolates from HIV positive patients were drug-resistant but none was multi-drug resistant. The slight rise in registered bacteriologically proven cases of tuberculosis, the presence of multi-drug resistant strains, the occurrence of HIV-related tuberculosis and reports of the emergence of multi-drug-resistant HIV-related tuberculosis in other countries strongly indicate the need for continued careful surveillance.

Adolescent↗
PubMed1993

Isolation of mycobacteria from patients seropositive for the human immunodeficiency virus (HIV) in south east England: 1984-92.

BACKGROUND: Tuberculosis and other mycobacterial infections are well recognised complications of HIV infection and surveillance is thus required. METHODS: All mycobacteria isolated from HIV positive subjects and referred to the Public Health Laboratory Service South East Regional Tuberculosis Centre (SERTC) from the first such case in 1984 until the end of 1992 were reviewed. RESULTS: A total of 803 mycobacteria isolated from 727 HIV positive subjects were referred to the SERTC during the study period. A single species was isolated from 660 patients: 150 members of the tuberculosis complex (146 M tuberculosis, two M bovis, and two M africanum), 356 M avium-intracellulare (MAI), and 154 other environmental mycobacteria. More than one mycobacterium was isolated from 67 patients. In 12 cases M tuberculosis and MAI were isolated from the same patient, almost always in that sequence, with an interval of 8-41 months between isolations. Most of the 407 isolates of MAI (74%) were considered to be clinically significant and often caused disseminated disease. In other cases single isolates of MAI were obtained from sputum or faeces and occasionally such isolates preceded disseminated disease by several months. Only 33 (14%) of the 229 isolates of environmental mycobacteria other than MAI were considered clinically significant. CONCLUSIONS: HIV related mycobacterial disease is increasing in incidence in south east England. Further studies are required to determine the significance of single isolates of MAI and other environmental mycobacteria as a guide to the need for preventive chemotherapy or immunotherapy.

AIDS-Related Opportunistic Infections↗
PubMed1992

Rapid detection of tuberculous and non-tuberculous mycobacteria by polymerase chain reaction amplification of a 162 bp DNA fragment from antigen 85.

A polymerase chain reaction (PCR) assay was developed for detection of mycobacteria using amplification of a 162 bp region of the genes coding for the mycobacterial antigen 85 complex. Strains belonging to the Mycobacterium tuberculosis complex were further differentiated from non-tuberculous mycobacteria by hybridization of the PCR derived Southern blot with an internal oligonucleotide probe and washing under stringent conditions. The method allowed rapid and sensitive detection of mycobacterial DNA in uncultured clinical samples. PCR results obtained for Mycobacterium tuberculosis in 206 specimens from 180 untreated patients gave a sensitivity of 93.9% and a specificity of 94.3% compared with the culture. PCR detected DNA from Mycobacterium tuberculosis in seven samples from patients with clinically evident tuberculosis in whom culture was negative. The results suggest that this PCR assay could be used for early and specific diagnosis of tuberculosis.

Antigens, Bacterial↗
PubMed1992

Survey of mycobacteria isolated from urine and the genitourinary tract in south-east England from 1980 to 1989.

Between 1980 and 1989, the Public Health Laboratory Service Regional Tuberculosis Centre, Dulwich, received cultures of mycobacteria isolated from urine and the genitourinary tract of 1392 new patients: 803 isolates were members of the tuberculosis complex (753 M. tuberculosis, 45 M. bovis, 4 M. africanum) and 589 were various species of environmental mycobacteria. The incidence of the latter isolations varied by region and by year and, with 17 exceptions (13 from endometrial curettings, 2 from hydrocele fluid, 1 from a scrotal abscess and 1 from a kidney), all isolations of environmental mycobacteria were from urine; very few of them appeared to be clinically significant. Those that could be significant included 1 isolate from a kidney, 1 from a post-renal transplant patient and 4 from patients with AIDS, 3 of whom had disseminated mycobacterial disease. Reports of clinically significant isolations of environmental mycobacteria from the genitourinary tract are reviewed.

England↗
PubMed1992

Bacteriological survey of tuberculous lymphadenitis in southeast England, 1981-1989.

STUDY OBJECTIVE: The aim was to detect any changing trends in the nature and incidence of tuberculous lymphadenitis in southeast England and to determine whether there is any evidence for an increase in this disease that could be related to HIV infection. DESIGN: Mycobacteria isolated from patients with lymphadenitis in the years 1981 to 1989 were identified. Information was available on the age, sex, and ethnic origin of the patients and the anatomical site from which the mycobacterium was isolated. SETTING: The Public Health Laboratory Service Regional Tuberculosis Centre at Dulwich, which receives over 95% of mycobacteria isolated in southeast England. MAIN RESULTS: From 1980 to 1989, cultures were received from 1817 patients with mycobacterial lymphadenitis: 1677 were M tuberculosis, 25 M bovis, 21 M africanum, and 94 were other (environmental) species. In comparison with a survey conducted in the same region in 1973-80, the number of ethnic Indian subcontinent patients with lymphadenitis due to M tuberculosis had dropped by 30% and the number of European patients had dropped by 43% and showed a continuing decline and a shift towards an older age group. By contrast, there was a 20% increase in the number of cases due to environmental mycobacteria. The number of species causing such infections had increased and a greater proportion of patients were adults. Three patients infected by environmental mycobacteria were known to be HIV positive. CONCLUSIONS: The incidence of lymphadentis due to M tuberculosis is declining but cases due to environmental mycobacteria are increasing, with a greater diversity of species and more adult patients. There is no conclusive evidence for an impact of HIV infection on the incidence and nature of mycobacterial lymphadenopathy in southeast England, but this cannot be ruled out.

Adolescent↗
PubMed1989

Incidence and nature of human tuberculosis due to Mycobacterium africanum in South-East England: 1977-87.

A total of 210 new cases of tuberculosis due to Mycobacterium africanum were registered at the South-East Regional Centre for Tuberculosis Bacteriology, Dulwich, between 1977 and 1987 inclusive. This represented 1.25% of bacteriologically-confirmed cases of tuberculosis in South-East England, an incidence slightly higher than that of disease due to M. bovis. Two variants were identified: 150 strains were typed as African I (a type associated with East Africa) and 60 as African II (a type more prevalent in West Africa). Over half the patients infected with African I strains were of Indian subcontinent ethnic origin; patients of African ethnic origin predominated in the African II group while about a fifth o patients infected with either type were of European origin. The European patients with tuberculosis due to M. africanum were notably younger than those in the same region with disease due to other tubercle bacilli. The distribution of lesions due to M. africanum was similar to that due to other tubercle bacilli in the various ethnic groups, except that genito-urinary tuberculosis was uncommon. The importance of a clinical awareness that M. africanum is a highly pathogenic and transmissible tubercle bacillus rather than an opportunist or 'atypical' mycobacterium is stressed.

Adolescent↗
PubMed1988

Incidence and nature of human tuberculosis due to bovine tubercle bacilli in South-East England: 1977-1987.

A total of 201 new cases of tuberculosis due to bovine tubercle bacilli was confirmed in South-East England between 1977 and 1987 inclusive. This represents about 1% of all cases of tuberculosis in this region. Most cases occurred amongst older individuals of indigenous white British origin, although some younger patients of Southern European and Indian subcontinent ethnic origin were also diagnosed. The lung was the most frequent site of disease, followed by the genito-urinary tract. In view of the known risk of transmission of disease from man to cattle via the respiratory and urinary tracts, continued surveillance of this relatively uncommon form of tuberculosis is still indicated.

Adolescent↗
PubMed1988

Presumptive identification of nocardias in a clinical laboratory.

One hundred and thirty-six cultures of aerobic streptomycetes were examined by simple cultural and microscopical methods. Nocardia spp. were recognized by their resistance to lysozyme and identified to the three important species by casein, xanthine and tyrosine hydrolysis tests.

Actinomycetales↗
PubMed1986

The nature of mycobacterial disease in south east England, 1977-84.

The nature and incidence of bacteriologically confirmed mycobacterial disease in south east England over the eight year period 1977-84 has been determined by a study of cultures received by the PHLS Regional Centre for Tuberculosis Bacteriology at Dulwich. The number of cases of tuberculosis in the ethnic European population has shown a decline, more so among males than females, but there has not been a significant decline in cases among ethnic Asians. Most tuberculosis is due to the classical human tubercle bacillus but cases due to the Asian human type, the bovine type (M. bovis), and the African types (M. africanum) also occur. The number of cases of disease due to 'atypical' mycobacteria has doubled over the eight year period, and these now account for about 5% of bacteriologically diagnosed mycobacterial disease in this region. The continuing role of reference facilities for the surveillance of tuberculosis and the diagnosis and management of the growing numbers of other mycobacterial infections is stressed.

Antitubercular Agents↗