Buruli ulcer is a destructive skin and soft tissue infection caused by Mycobacterium ulcerans . T... more Buruli ulcer is a destructive skin and soft tissue infection caused by Mycobacterium ulcerans . The disease is characterized by progressive skin ulceration, which can lead to permanent disfigurement and long-term disability. Currently, the major hurdles facing disease control are incomplete understandings of both the mode of transmission and environmental reservoirs of M. ulcerans . As decades of spasmodic environmental sampling surveys have not brought us much closer to overcoming these hurdles, the Buruli ulcer research community has recently switched to using comparative genomics. The significance of our research is in how we used both temporal associations and the study of the mycobacterial demographic history to estimate the contribution of humans as a reservoir in Buruli ulcer transmission. Our approach shows that it might be possible to use bacterial population genomics to assess the impact of health interventions, providing valuable feedback for managers of disease control p...
Introduction L’infection a Mycobacterium ulcerans (IMU) est la troisieme maladie mycobacterienne ... more Introduction L’infection a Mycobacterium ulcerans (IMU) est la troisieme maladie mycobacterienne la plus repandue apres la tuberculose et la lepre. A ce jour, les voies de transmission de son reservoir environnemental aux humains sont encore inconnues. En Amerique du sud, la Guyane francaise a le plus grand nombre d’IMU sur le continent. Cette etude visait a caracteriser l’epidemiologie de l’IMU en Guyane francaise entre 1969 et 2013. Materiel et methodes Les donnees ont ete recueillies prospectivement par les medecins du seul service de dermatologie de Guyane a l’hopital de Cayenne entre 1969 et 2013. Elles portaient sur l’âge, la date du diagnostic, le sexe, la residence, la localisation de la lesion, le type de lesion, les symptomes associes et les elements diagnostiques (frottis, culture, PCR, histopathologie) pour tous les cas d’IMU. Nous avons calcule les incidences moyennes d’IMU, presentees comme le nombre de cas pour 100 000 personnes–annees, a partir des donnees demographi...
Mycobacterium ulcerans causes extensive ulcers (Buruli ulcers) in the skin of humans. Analysis of... more Mycobacterium ulcerans causes extensive ulcers (Buruli ulcers) in the skin of humans. Analysis of the 3'-terminal region of the 16S rRNA gene sequence of 17 strains of M. ulcerans from Africa, the Americas, and Australia revealed three subgroups corresponding to the continent of origin, and some variable phenotypic characteristics. This sequence is useful for the rapid detection of M. ulcerans and discriminates M. marinum and M. shinshuense from M. ulcerans.
Our studies show that microaerophilic conditions promote the growth of Mycobacterium genavense in... more Our studies show that microaerophilic conditions promote the growth of Mycobacterium genavense in semisolid medium. The growth of M. genavense at 2.5 or 5% oxygen was superior to that obtained at 21% oxygen in BACTEC primary cultures (Middlebrook 7H12, pH 6.0, without additives). By using nondecontaminated specimens, it was possible to detect growth with very small inocula (25 bacilli/ml) of 12 different M. genavense strains (from nude mice) within 6 weeks of incubation under low oxygen tension; conversely, with 21% oxygen, no growth of 8 of 12 (66.7%) M. genavense strains was detected (growth index, <10). The same beneficial effect of 2.5 or 5% oxygen was observed in primary cultures of a decontaminated clinical specimen. Low oxygen tension (2.5 or 5%) is recommended for the primary isolation of M. genavense . Microaerophilic cultivation of other atypical mycobacteria, especially slow-growing (e.g., Mycobacterium avium ) and difficult-to-grow (e.g., Mycobacterium ulcerans ) spec...
The effect of low oxygen concentration on the growth of 15 strains of Mycobacterium ulcerans was ... more The effect of low oxygen concentration on the growth of 15 strains of Mycobacterium ulcerans was evaluated in the BACTEC system. Reduced oxygen tension enhanced the growth of M. ulcerans , suggesting that this organism has a preference for microaerobic environments. Application of this observation may improve rates of isolation of M. ulcerans in primary culture from clinical samples and promote isolation of the bacterium from environmental sources.
The fatty acids and mycolic acids of 16 clinical isolates of Mycobacterium malmoense were studied... more The fatty acids and mycolic acids of 16 clinical isolates of Mycobacterium malmoense were studied by gas chromatography and thin-layer chromatography. All strains contained 2-methyleicosanoic and 2,4,6-trimethyltetracosanoic acids and alpha-, alpha'-, and keto-mycolic acids. The reported findings suggest that lipid analysis is a very useful approach in the species identification of M. malmoense.
A rapid procedure for the identification of cultured Mycobacterium isolates, based on the combina... more A rapid procedure for the identification of cultured Mycobacterium isolates, based on the combination of enzymatic amplification and restriction analysis, is described. The 16S rRNA genes (rDNA) of 99 strains belonging to 18 different species of the genus Mycobacterium were enzymatically amplified. Amplified rDNA restriction analysis with the enzymes CfoI, MboI, and RsaI was carried out. The combination of the amplified rDNA restriction analysis patterns obtained after restriction with CfoI and MboI enabled differentiation between Mycobacterium asiaticum (number of strains = 4), M. avium (n = 22), M. chelonae (n = 5), M. flavescens (n = 1), M. fortuitum (n = 6), M. gordonae (n = 6), M. intracellulare (n = 13), M. marinum (n = 7), M. nonchromogenicum (n = 1), M. simiae (n = 5), M. terrae (n = 5), the M. tuberculosis complex (n = 11), and 2 of 4 strains of M. xenopi. Further restriction with RsaI was necessary to differentiate between the species M. kansasii (n = 5), M. scrofulaceum (...
Twenty-seven strains belonging to 12 Mycobacterium species were studied for 3-hydroxy fatty acid ... more Twenty-seven strains belonging to 12 Mycobacterium species were studied for 3-hydroxy fatty acid composition. Mycobacterial cells were subjected to both mild and strong acid methanolysis, after which the liberated hydroxy fatty acids were purified and analyzed by gas chromatography-mass spectrometry as methyl ester trimethylsilyl ether derivatives. Altogether, 21 3-hydroxy fatty acids containing 14 to 28 carbon atoms were detected; 10 were straight chain, 6 were 2-methyl branched chain, and 5 were 2,4,6-trimethyl branched chain. The mycobacterial strains were classified in groups according to 3-hydroxy fatty acid patterns.
The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease, 2006
To evaluate the performance of the colorimetric resazurin microtiter assay (REMA) method for the ... more To evaluate the performance of the colorimetric resazurin microtiter assay (REMA) method for the detection of ofloxacin resistance. A panel of 120 multidrug-resistant Mycobacterium tuberculosis strains was tested blindly by the REMA method and compared with the results obtained using the BACTEC 460 method. A very good correlation was observed between the two methods. The REMA method is simple, rapid and can be an inexpensive alternative procedure for the rapid detection of anti-tuberculosis drug resistance in laboratories with limited resources.
The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease, 2005
A multicentre evaluation was performed to assess two rapid low-cost methods, MTT (3-[4.5-dimethyl... more A multicentre evaluation was performed to assess two rapid low-cost methods, MTT (3-[4.5-dimethylthiazol-2-yl]-2.5-diphenyltetrazolium bromide) and resazurin assays, for testing the susceptibility of Mycobacterium tuberculosis to the first-line anti-tuberculosis drugs rifampicin (RMP), isoniazid (INH), ethambutol (EMB) and streptomycin (SM). Thirty coded M. tuberculosis strains were sent to seven laboratories located in Latin America, representing six countries. Each site performed the colorimetric assays, MTT and resazurin, blind for the first-line drugs RMP, INH, EMB and SM. The minimum inhibitory concentration results obtained were compared to the conventional proportion method on Lowenstein-Jensen medium. After establishing the breakpoint concentrations, excellent results were obtained for RMP, INH and EMB, with levels of specificity and sensitivity of between 96% and 99%. MTT and resazurin assays are promising, accessible new alternative methods for middle- and low-resource cou...
Annales de la Société belge de médecine tropicale, 1993
The potential usefulness of ELISA based serological tests to assist in rapid, early and specific ... more The potential usefulness of ELISA based serological tests to assist in rapid, early and specific diagnosis of tuberculosis was investigated. The materials were selected, based on published data and on our preliminary findings. Initially screening tests were performed using crude antigens such as Purified Protein Derivate (PPD) and a BCG-filtrate. Unfortunately, the results with these antigens were not promising. The specificity of both antigens using sera from 94 healthy controls was 64%. As a consequence of these findings, the crude antigens were excluded from further tests, and the study was continued with purified antigens. The work focused on 2 purified proteins: Antigen 60 (A60), a lipopolysaccharide-protein complex, and P32, a stress protein produced in zinc deprived cultures, identified as Antigen 85 A in the BCG reference system, both isolated from Mycobacterium bovis BCG. The commercial A60 based ELISA and our own P32 based ELISA were used to test a total of 300 sera from H...
Buruli ulcer is a destructive skin and soft tissue infection caused by Mycobacterium ulcerans . T... more Buruli ulcer is a destructive skin and soft tissue infection caused by Mycobacterium ulcerans . The disease is characterized by progressive skin ulceration, which can lead to permanent disfigurement and long-term disability. Currently, the major hurdles facing disease control are incomplete understandings of both the mode of transmission and environmental reservoirs of M. ulcerans . As decades of spasmodic environmental sampling surveys have not brought us much closer to overcoming these hurdles, the Buruli ulcer research community has recently switched to using comparative genomics. The significance of our research is in how we used both temporal associations and the study of the mycobacterial demographic history to estimate the contribution of humans as a reservoir in Buruli ulcer transmission. Our approach shows that it might be possible to use bacterial population genomics to assess the impact of health interventions, providing valuable feedback for managers of disease control p...
Introduction L’infection a Mycobacterium ulcerans (IMU) est la troisieme maladie mycobacterienne ... more Introduction L’infection a Mycobacterium ulcerans (IMU) est la troisieme maladie mycobacterienne la plus repandue apres la tuberculose et la lepre. A ce jour, les voies de transmission de son reservoir environnemental aux humains sont encore inconnues. En Amerique du sud, la Guyane francaise a le plus grand nombre d’IMU sur le continent. Cette etude visait a caracteriser l’epidemiologie de l’IMU en Guyane francaise entre 1969 et 2013. Materiel et methodes Les donnees ont ete recueillies prospectivement par les medecins du seul service de dermatologie de Guyane a l’hopital de Cayenne entre 1969 et 2013. Elles portaient sur l’âge, la date du diagnostic, le sexe, la residence, la localisation de la lesion, le type de lesion, les symptomes associes et les elements diagnostiques (frottis, culture, PCR, histopathologie) pour tous les cas d’IMU. Nous avons calcule les incidences moyennes d’IMU, presentees comme le nombre de cas pour 100 000 personnes–annees, a partir des donnees demographi...
Mycobacterium ulcerans causes extensive ulcers (Buruli ulcers) in the skin of humans. Analysis of... more Mycobacterium ulcerans causes extensive ulcers (Buruli ulcers) in the skin of humans. Analysis of the 3'-terminal region of the 16S rRNA gene sequence of 17 strains of M. ulcerans from Africa, the Americas, and Australia revealed three subgroups corresponding to the continent of origin, and some variable phenotypic characteristics. This sequence is useful for the rapid detection of M. ulcerans and discriminates M. marinum and M. shinshuense from M. ulcerans.
Our studies show that microaerophilic conditions promote the growth of Mycobacterium genavense in... more Our studies show that microaerophilic conditions promote the growth of Mycobacterium genavense in semisolid medium. The growth of M. genavense at 2.5 or 5% oxygen was superior to that obtained at 21% oxygen in BACTEC primary cultures (Middlebrook 7H12, pH 6.0, without additives). By using nondecontaminated specimens, it was possible to detect growth with very small inocula (25 bacilli/ml) of 12 different M. genavense strains (from nude mice) within 6 weeks of incubation under low oxygen tension; conversely, with 21% oxygen, no growth of 8 of 12 (66.7%) M. genavense strains was detected (growth index, <10). The same beneficial effect of 2.5 or 5% oxygen was observed in primary cultures of a decontaminated clinical specimen. Low oxygen tension (2.5 or 5%) is recommended for the primary isolation of M. genavense . Microaerophilic cultivation of other atypical mycobacteria, especially slow-growing (e.g., Mycobacterium avium ) and difficult-to-grow (e.g., Mycobacterium ulcerans ) spec...
The effect of low oxygen concentration on the growth of 15 strains of Mycobacterium ulcerans was ... more The effect of low oxygen concentration on the growth of 15 strains of Mycobacterium ulcerans was evaluated in the BACTEC system. Reduced oxygen tension enhanced the growth of M. ulcerans , suggesting that this organism has a preference for microaerobic environments. Application of this observation may improve rates of isolation of M. ulcerans in primary culture from clinical samples and promote isolation of the bacterium from environmental sources.
The fatty acids and mycolic acids of 16 clinical isolates of Mycobacterium malmoense were studied... more The fatty acids and mycolic acids of 16 clinical isolates of Mycobacterium malmoense were studied by gas chromatography and thin-layer chromatography. All strains contained 2-methyleicosanoic and 2,4,6-trimethyltetracosanoic acids and alpha-, alpha'-, and keto-mycolic acids. The reported findings suggest that lipid analysis is a very useful approach in the species identification of M. malmoense.
A rapid procedure for the identification of cultured Mycobacterium isolates, based on the combina... more A rapid procedure for the identification of cultured Mycobacterium isolates, based on the combination of enzymatic amplification and restriction analysis, is described. The 16S rRNA genes (rDNA) of 99 strains belonging to 18 different species of the genus Mycobacterium were enzymatically amplified. Amplified rDNA restriction analysis with the enzymes CfoI, MboI, and RsaI was carried out. The combination of the amplified rDNA restriction analysis patterns obtained after restriction with CfoI and MboI enabled differentiation between Mycobacterium asiaticum (number of strains = 4), M. avium (n = 22), M. chelonae (n = 5), M. flavescens (n = 1), M. fortuitum (n = 6), M. gordonae (n = 6), M. intracellulare (n = 13), M. marinum (n = 7), M. nonchromogenicum (n = 1), M. simiae (n = 5), M. terrae (n = 5), the M. tuberculosis complex (n = 11), and 2 of 4 strains of M. xenopi. Further restriction with RsaI was necessary to differentiate between the species M. kansasii (n = 5), M. scrofulaceum (...
Twenty-seven strains belonging to 12 Mycobacterium species were studied for 3-hydroxy fatty acid ... more Twenty-seven strains belonging to 12 Mycobacterium species were studied for 3-hydroxy fatty acid composition. Mycobacterial cells were subjected to both mild and strong acid methanolysis, after which the liberated hydroxy fatty acids were purified and analyzed by gas chromatography-mass spectrometry as methyl ester trimethylsilyl ether derivatives. Altogether, 21 3-hydroxy fatty acids containing 14 to 28 carbon atoms were detected; 10 were straight chain, 6 were 2-methyl branched chain, and 5 were 2,4,6-trimethyl branched chain. The mycobacterial strains were classified in groups according to 3-hydroxy fatty acid patterns.
The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease, 2006
To evaluate the performance of the colorimetric resazurin microtiter assay (REMA) method for the ... more To evaluate the performance of the colorimetric resazurin microtiter assay (REMA) method for the detection of ofloxacin resistance. A panel of 120 multidrug-resistant Mycobacterium tuberculosis strains was tested blindly by the REMA method and compared with the results obtained using the BACTEC 460 method. A very good correlation was observed between the two methods. The REMA method is simple, rapid and can be an inexpensive alternative procedure for the rapid detection of anti-tuberculosis drug resistance in laboratories with limited resources.
The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease, 2005
A multicentre evaluation was performed to assess two rapid low-cost methods, MTT (3-[4.5-dimethyl... more A multicentre evaluation was performed to assess two rapid low-cost methods, MTT (3-[4.5-dimethylthiazol-2-yl]-2.5-diphenyltetrazolium bromide) and resazurin assays, for testing the susceptibility of Mycobacterium tuberculosis to the first-line anti-tuberculosis drugs rifampicin (RMP), isoniazid (INH), ethambutol (EMB) and streptomycin (SM). Thirty coded M. tuberculosis strains were sent to seven laboratories located in Latin America, representing six countries. Each site performed the colorimetric assays, MTT and resazurin, blind for the first-line drugs RMP, INH, EMB and SM. The minimum inhibitory concentration results obtained were compared to the conventional proportion method on Lowenstein-Jensen medium. After establishing the breakpoint concentrations, excellent results were obtained for RMP, INH and EMB, with levels of specificity and sensitivity of between 96% and 99%. MTT and resazurin assays are promising, accessible new alternative methods for middle- and low-resource cou...
Annales de la Société belge de médecine tropicale, 1993
The potential usefulness of ELISA based serological tests to assist in rapid, early and specific ... more The potential usefulness of ELISA based serological tests to assist in rapid, early and specific diagnosis of tuberculosis was investigated. The materials were selected, based on published data and on our preliminary findings. Initially screening tests were performed using crude antigens such as Purified Protein Derivate (PPD) and a BCG-filtrate. Unfortunately, the results with these antigens were not promising. The specificity of both antigens using sera from 94 healthy controls was 64%. As a consequence of these findings, the crude antigens were excluded from further tests, and the study was continued with purified antigens. The work focused on 2 purified proteins: Antigen 60 (A60), a lipopolysaccharide-protein complex, and P32, a stress protein produced in zinc deprived cultures, identified as Antigen 85 A in the BCG reference system, both isolated from Mycobacterium bovis BCG. The commercial A60 based ELISA and our own P32 based ELISA were used to test a total of 300 sera from H...
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