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Environmental Mycobacteria (environmental + mycobacteria)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Therapy of environmental mycobacterial infections

DERMATOLOGIC THERAPY, Issue 3 2008
Caterina Fabroni
ABSTRACT: Environmental mycobacteria are the causative factors of an increasing number of infections worldwide. Cutaneous infections as a result of environmental mycobacteria are often misdiagnosed, and their treatment is difficult because these agents can show in vivo and in vitro multidrug resistance. The most common environmental mycobacteria that can cause cutaneous infections are Mycobacterium fortuitum and Mycobacterium marinum. All mycobacteria are characterized by low pathogenicity and they can contaminate affected or traumatized skin only in immunocompetent subjects (mainly in fishermen, swimming-pool attendants, and aquarium owners) whereas medical and esthetic procedures are at risk for the infections because of the quick-growing mycobacteria. Immunocompromised subjects can instead easily develop environmental mycobacterial infections of differing degrees of severity. [source]

Vaccination of neonatal calves with Mycobacterium bovis BCG induces protection against intranasal challenge with virulent M. bovis

CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 1 2005
J. C. Hope
Summary Vaccination of neonates with Mycobacterium bovis bacillus Calmette,Guérin (BCG) may be a strategy that overcomes reduced vaccine efficacy associated with exposure to environmental mycobacteria in humans and cattle. Preliminary comparisons indicated that 2-week-old calves produced an immune response to vaccination at least as intense as that observed in adults. Subsequently, five gnotobiotic hysterotomy derived calves aged 1 day were inoculated with BCG and 3 months later were challenged intranasally with virulent M. bovis. The number of tissues with lesions and the pathological extent of these lesions was reduced significantly in vaccinates. Furthermore, lesions were evident in the lung or associated chest lymph nodes of four of five controls but none of five vaccinates. BCG vaccination reduced significantly the level of bacterial colonization. However, lesions in the head associated lymph nodes were observed in three of five BCG-vaccinated cattle. Levels of interferon gamma (IFN-,) detected by enzyme-linked immunosorbent assay (ELISA) or enzyme-linked immunospot (ELISPOT) in individual vaccinated animals at challenge did not correlate with subsequent resistance and in general immune responses post-challenge were lower in vaccinated calves. Low IL-10 responses were evident but IL-4 was not detected. Responses to ESAT-6 and/or CFP-10 were evident in four of four control calves that had lesions. Two of the BCG vaccinates with lesions did not produce a response to ESAT-6 and CFP-10, indicating that these antigens did not distinguish vaccinated immune animals from vaccinated animals with lesions. Overall, vaccination of neonatal calves with BCG induced significant protection against disease and has potential as a strategy for the reduction of the incidence of bovine tuberculosis. [source]

Interferon-, and skin test responses of schoolchildren in southeast England to purified protein derivatives from Mycobacterium tuberculosis and other species of mycobacteria

CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 2 2003
R. E. WEIR
SUMMARY The immune responses of schoolchildren in southeast England to Mycobacterium tuberculosis and other species of mycobacteria were studied prior to vaccination with bacille Calmette-Guérin (BCG). Data are presented for tuberculin (Heaf) skin test and interferon- , (IFN- ,) responses to M. tuberculosis purified protein derivative (PPD), and IFN- , responses to PPDs from eight other environmental mycobacteria, measured in 424 schoolchildren (13,15 years of age). Responses to M. tuberculosis PPD were detected in 27% of schoolchildren by in vitro IFN- , response and in 20% by the Heaf test. IFN- , responses were more prevalent to PPDs from species of mycobacteria other than M. tuberculosis, predominantly those of the MAIS complex and M. marinum (45,60% responders). Heaf test and IFN- , responses were associated (P < 0·001) for M. tuberculosis, MAIS and M. marinum. These findings have implications for appropriate implementation of vaccination against tuberculosis. [source]