Bacterial Typing Techniques ; Mycobacterium tuberculosis ; classification ; genetics ; pathogenicity

This is a report on attempts tp search for a suitable experimental animal model which is sensitive to the exocellular substances of M. ulcerans, prior to study of biochemical and pathogenic natures of the substances. Cells of M. ulcerans grown in a broth medium were harvested by filtration and washed with phosphate-buffered saline. The filtrate of culture supernatant was subjected to fractionation by addition of various amounts of ammonium sulfate. The washed cells and the preparations resulted from ammonium sulfate fractionation (ASF 45 and ASF 70) were inoculated by either foot-pad injection, subcutaneous or intradermal injection to the selected animal groups. Any skin response due to administration of the preparations; erythema, edema, pus formation, etc. was macroscopically observed along with time progression. Among the animals employed, such as guinea pig, mouse, and rabbit, the rabbit was the only animal group showing strong skin response to the washed cells, ASF 45 and ASF 70. The heat-treated preparation of ASF 45 seemed to be inactive in elucidating skin response of rabbits. Dependence of skin response upon dose of the washed cells and the preparation of ASF 45 was also discussed.
Animal ; Erythema/etiology ; Guinea Pigs ; Intradermal Tests ; Mice ; Mycobacterium/pathogenicity* ; Rabbits

BACKGROUNDMycobacterial interspersed repetitive units-variable number tandem repeat (MIRU-VNTR) and Beijing family typing based on detecting the deletion of RD105 sequence are two common genotyping methods used to study the molecular epidemiologic characteristics of Mycobacterium (M.) tuberculosis. We collected 218 strains of M. tuberculosis between 2004 and 2006 in the Linxia Hui Autonomous Prefecture of Gansu province in Northwest China.

METHODSMIRU-VNTR analysis and Beijing family typing based on detecting the deletion of RD105 sequence were used to type the 218 strains, and their typing power was evaluated to look for practical and efficient genotyping methods suitable for the region.

RESULTSThe MIRU typing yielded 115 distinct genotypes, including 98 unique isolates and 17 different clusters containing 120 isolates (55.05%); the cluster rate was 47.25%. By detecting the deletion of RD105 sequence, 188 of 218 (86.23%) isolates belonged to Beijing family. Combination of Beijing family typing and MIRU typing yielded 118 distinct patterns, including 101 unique isolates and 17 clusters containing 117 isolates (54.13%). The largest cluster contained 58 strains with MIRU genotype of 223325173533 which contained 50 strains belonging to Beijing family and 8 strains belonging to non-Beijing family.

CONCLUSIONSThe Beijing family strains occupied a large proportion and the Beijing family MIRU genotype 223325173533 is a dominant strain in Linxia of Gansu. Combining detecting the deletion of RD105 and MIRU typing together provides a simple, fast, and effective method which is low in cost and might be practical and suitable for M. tuberculosis genotyping in China.

Alleles ; China ; epidemiology ; Genotype ; Molecular Epidemiology ; Multiplex Polymerase Chain Reaction ; Mycobacterium tuberculosis ; genetics ; pathogenicity ; Tuberculosis ; epidemiology

OBJECTIVETo explore the influences of Mycobacterium tuberculosis on the levels of human acute monocytic leukemia cell line THP-1 apoptosis and death.

METHODSHuman acute monocytic leukemia cell line THP-1 were infected with Mycobacterium tuberculosis strains H37Ra, H37Rv, or Beijing genotype (BJTB), respectively, to construct the infection models. Cell apoptosis was detected using flow cytometry. The distribution of the apoptotic proteins was detected using immunofluorescent staining assays. The cells late apoptosis was detected using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining assays. The change of cell death was determined by Tyrpan blue staining assays.

RESULTSTHP-1 apoptosis was induced by Mycobacterium tuberculosis strains H37Ra, H37Rv, and BJTB. H37Ra strongly induced THP-1 apoptosis, H37Rv weakly induced THP-1 apoptosis, and BJTB induced THP-1 apoptosis at the lowest level among these three Mycobacterium tuberculosis strains. On the contrary, BJTB strongly induced THP-1 death, H37Rv weakly induced THP-1 death, and H37Ra induced THP-1 death at the lowest level.

CONCLUSIONSMycobacterial strains with different virulence induce different levels of apoptosis and death of THP-1 cells. Compared with highly virulent strains, attenuated strains induce more apoptosis and less death.

Apoptosis ; Cell Line, Tumor ; Humans ; In Situ Nick-End Labeling ; Leukemia, Monocytic, Acute ; Mycobacterium tuberculosis ; pathogenicity ; Virulence

Along with the rapid spread of HIV / AIDS and TB prevalence, prevention and control of AIDS and tuberculosis has become an urgent problem in the field of public health. Recent studies demonstrate dual infections of HIV and TB are not a simple superposition of two diseases, but a course of mutual promotion. This article has summarized the pathological mechanisms and mutual interactions of HIV/TB dual infections.
Acquired Immunodeficiency Syndrome ; complications ; epidemiology ; prevention & control ; Coinfection ; HIV-1 ; pathogenicity ; Humans ; Mycobacterium tuberculosis ; pathogenicity ; Prevalence ; Public Health ; Tuberculosis ; complications ; epidemiology ; prevention & control

Acid-fast microorganisms were isolated from 240 soil samples collected at two areas, Hiroshima, Japan and Seoul, Korea. The biological and biochemical characteristics of the isolated mycobacteria were tested and compared with those of 36 reference mycobacteria Strains. The isolation rate and distribution of these mycobacterial species from soil were compared using three kinds of media with emphasis on the two methods of isolation between the different geographical areas. One Strain from each of the 10 species among atypical mycobacteria isolated from soil in both areas was inoculated into ddY mice and the pathogenicity compared with that of Mycobacterium tuberculosis H37Rv up to 6 weeks. Susceptibility of the reisolated acid-fast bacilli to antimycobacterial agents was tested in vitro. Antibody responses against various mycobacterial antigens were tested using lepromatous type and tuberculoid type patient sera by the agar gel immunodiffusion. 1) No significant differences in the distribution of acid-fast bacilli were observed between soil samples from the two regions. 2) Rapid growers were by far the most frequent acid-fast bacilli isolated while no photochromogens were isolated from these soil samples. In addition, a minimal number of fastidious mycobacteria were isolated but not cultivable in subcultures. 3) Some of these soil acid-fast bacilli were capable of inducing only transient bacteriological and pathologic changes in mouse organs. 4) Acid-fast bacilli reisolated from organs of these infected mice were, in general, found to be resistant to antimycobacterial agents. 5) M. scrofulaceum antigen showed a precipitation reaction in agar gel immunodiffusion with the highest number of sera from leprosy patients.
Animal ; Leprosy/immunology ; Mice ; Mycobacteria, Atypical/drug effects ; Mycobacteria, Atypical/isolation & purification* ; Mycobacteria, Atypical/pathogenicity ; Mycobacterium/isolation & purification* ; Mycobacterium Infections/pathology ; Soil Microbiology*

Animals ; Disease Models, Animal ; Embryo, Nonmammalian ; microbiology ; Host-Parasite Interactions ; Mycobacterium Infections, Nontuberculous ; immunology ; microbiology ; Mycobacterium marinum ; pathogenicity ; Tuberculoma ; immunology ; microbiology ; Zebrafish ; embryology ; microbiology

BACKGROUNDGene chip array can differentiate isolated mycobacterial strains using various mycobacterium specific probes simultaneously. Gene chip array can evaluate drug resistance to isoniazid and rifampin of tuberculosis strains by detecting drug resistance related gene mutation. This technique has great potential for clinical application. We performed a retrospective study to investigate the capability of gene chip array in the rapid differentiation of species and detection of drug resistance in mycobacterium, and to evaluate its clinical efficacy.

METHODSWe selected 39 patients (54 clinical mycobacterium isolates), used gene chip array to identify the species of these isolates and detect drug resistance to isoniazid and rifampin in Mycobacterium tuberculosis isolates. Meanwhile, these patients' clinical data were analyzed retrospectively.

RESULTSAmong these 39 patients whose mycobacterium culture were positive, 32 patients' isolates were identified as Mycobacterium tuberculosis, all of them were clinical infection. Seven patients' isolates were identified as non-tuberculosis mycobacterium. Analyzed with their clinical data, only two patients were considered as clinical infection, both of them were diagnosed as hematogenous disseminated Mycobacterium introcellulare infection. The other five patients' isolates were of no clinical significance; their clinical samples were all respiratory specimens. Clinical manifestations of tuberculosis and non-tuberculous mycobacterial infections were similar. Isoniazid resistance was detected in two tuberculosis patients, while rifampin resistance was detected in one tuberculosis patient; there was another patient whose Mycobacterium tuberculosis isolate was resistant to both isoniazid and rifampin (belongs to multidrug resistance tuberculosis). The fact that this patient did not respond to routine anti-tuberculosis chemotherapy also confirmed this result.

CONCLUSIONSGene chip array may be a simple, rapid, and reliable method for the identification of most mycobacterial species and detection of drug resistance in Mycobacterium tuberculosis. It is useful in diagnosis, treatment, and hospital infection control of mycobacterial infections, and it may have a great potential for clinical application.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Antitubercular Agents ; therapeutic use ; Female ; Humans ; Isoniazid ; therapeutic use ; Male ; Middle Aged ; Mycobacterium ; classification ; genetics ; pathogenicity ; Mycobacterium tuberculosis ; genetics ; pathogenicity ; Oligonucleotide Array Sequence Analysis ; methods ; Rifampin ; therapeutic use ; Tuberculosis, Multidrug-Resistant ; genetics ; Young Adult

OBJECTIVETo clone and express the Rv3871 gene related to the virulent protein secretion of Mycobacterium tuberculosis and analyze its molecular structure, function and homology using bioinformatic approach.

METHODSA pair of primers was designed to amplify the Rv3871 gene, which was subcloned into the prokaryotic plasmid pET32a(+). The recombinant plasmid was identified by sequence analysis and the expressed recombinant protein by SDS-PAGE. The structure, function and homology alignment of Rv3871 were analyzed comparatively against other mycobacteria.

RESULTSThe restriction fragments through molecular cloning matched perfectly in size with our prediction. The gene sequence was consistent with the corresponding sequence in GenBank. The expression protein was detected by SDS-PAGE with a molecular weight of 84 kD. Two FtsK/SpoE III domains were found by bioinformatic analysis. The homology results showed distinct differences between Rv3871 of the pathogenic M. tuberculosis and its counterparts in non-pathogenic mycobacteria.

CONCLUSIONMolecular cloning, expression and sequencing identify the structural and functional characteristics of Rv3871. The structural and functional differences of the gene between pathogenic and non-pathogenic mycobacteria identified by bioinformatics provide some evidence for the pathogenesis and drug targets of tuberculosis.

Bacterial Proteins ; genetics ; metabolism ; Cloning, Molecular ; Computational Biology ; Mycobacterium tuberculosis ; genetics ; metabolism ; pathogenicity ; Recombinant Proteins ; genetics ; metabolism ; Virulence ; genetics

Tuberculosis ranks as the second deadly infectious disease worldwide. The incidence of tuberculosis is high in China. Refractory wound caused by Mycobacterium tuberculosis infection ranks high in misdiagnosis, and it is accompanied by a protracted course, and its pathogenic mechanism is still not so clear. In order to study its pathogenic mechanism, it is necessary to reproduce an appropriate animal model. Up to now the study of the refractory wound caused by Mycobacterium tuberculosis infection is just beginning, and there is still no unimpeachable model for study. This review describes two models which may reproduce a wound similar to the wound caused by Mycobacterium tuberculosis infection, so that they could be used to study the pathogenesis and characteristics of a tuberculosis wound in an animal.
Animals ; Disease Models, Animal ; Mycobacterium tuberculosis ; isolation & purification ; pathogenicity ; Surgical Wound Infection ; diagnosis ; microbiology ; Tuberculosis ; complications ; diagnosis ; microbiology