Mycobacteria

2012 ◽  
pp. 126-137
Author(s):  
Irene G. Sia
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Chest Pain ◽  
Physical Examination ◽  
Mycobacterial Infection ◽  
Milk Products ◽  
Natural Reservoir ◽  
Unpasteurized Milk ◽  
Hilar Adenopathy ◽  
Mycobacterium Africanum ◽  
Mycobacterium Microti

Mycobacterium tuberculosis complex is made up of Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium africanum, and Mycobacterium microti. Humans are the only natural reservoir of M tuberculosis. Mycobacterium bovis is caused by consumption of unpasteurized milk products from an infected cow. Cattle-to-human transmission also occurs. Patients with tuberculosis (TB) usually present with fever; less commonly, pleuritic chest pain, retrosternal or interscapular pain. Physical examination findings are usually normal. Hilar adenopathy is typical, often resolving in 1 year or more. Disease manifestations of other mycobacterial infection are also reviewed.

scholarly journals Novel Genetic Polymorphisms That Further Delineate the Phylogeny of the Mycobacterium tuberculosis Complex

2006 ◽  
Vol 188 (12) ◽  
pp. 4271-4287 ◽  
Author(s):  
Richard C. Huard ◽  
Michel Fabre ◽  
Petra de Haas ◽  
Luiz Claudio Oliveira Lazzarini ◽  
Dick van Soolingen ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Genomic Deletions ◽  
History Of ◽  
Species Specific ◽  
Mycobacterium Africanum ◽  
Mycobacterium Microti ◽  
First Time ◽  
Fine Tune

ABSTRACT In a previous report, we described a PCR protocol for the differentiation of the various species of the Mycobacterium tuberculosis complex (MTC) on the basis of genomic deletions (R. C. Huard, L. C. de Oliveira Lazzarini, W. R. Butler, D. van Soolingen, and J. L. Ho, J. Clin. Microbiol. 41:1637-1650, 2003). That report also provided a broad cross-comparison of several previously identified, phylogenetically relevant, long-sequence and single-nucleotide polymorphisms (LSPs and SNPs, respectively). In the present companion report, we expand upon the previous work (i) by continuing the evaluation of known MTC phylogenetic markers in a larger collection of tubercle bacilli (n = 125), (ii) by evaluating additional recently reported MTC species-specific and interspecific polymorphisms, and (iii) by describing the identification and distribution of a number of novel LSPs and SNPs. Notably, new genomic deletions were found in various Mycobacterium tuberculosis strains, new species-specific SNPs were identified for “Mycobacterium canettii,” Mycobacterium microti, and Mycobacterium pinnipedii, and, for the first time, intraspecific single-nucleotide DNA differences were discovered for the dassie bacillus, the oryx bacillus, and the two Mycobacterium africanum subtype I variants. Surprisingly, coincident polymorphisms linked one M. africanum subtype I genotype with the dassie bacillus and M. microti with M. pinnipedii, thereby suggesting closer evolutionary ties within each pair of species than had been previously thought. Overall, the presented data add to the genetic definitions of several MTC organisms as well as fine-tune current models for the evolutionary history of the MTC.

scholarly journals Identification of a New DNA Region Specific for Members of Mycobacterium tuberculosis Complex

1998 ◽  
Vol 36 (4) ◽  
pp. 937-943 ◽  
Author(s):  
Juana Magdalena ◽  
Anne Vachée ◽  
Philip Supply ◽  
Camille Locht
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Dna Amplification ◽  
Target Sequence ◽  
Two Component System ◽  
Tuberculosis Complex ◽  
Specific Pcr ◽  
Length Polymorphisms ◽  
Genes Encoding ◽  
Mycobacterium Africanum ◽  
Mycobacterium Microti

The successful use of DNA amplification for the detection of tuberculous mycobacteria crucially depends on the choice of the target sequence, which ideally should be present in all tuberculous mycobacteria and absent from all other bacteria. In the present study we developed a PCR procedure based on the intergenic region (IR) separating two genes encoding a recently identified mycobacterial two-component system named SenX3-RegX3. The senX3-regX3 IR is composed of a novel type of repetitive sequence, called mycobacterial interspersed repetitive units (MIRUs). In a survey of 116Mycobacterium tuberculosis strains characterized by different IS6110 restriction fragment length polymorphisms, 2 Mycobacterium africanum strains, 3 Mycobacterium bovis strains (including 2 BCG strains), and 1Mycobacterium microti strain, a specific PCR fragment was amplified in all cases. This collection included M. tuberculosis strains that lack IS6110 ormtp40, two target sequences that have previously been used for the detection of M. tuberculosis. No PCR fragment was amplified when DNA from other organisms was used, giving a sensitivity of 100% and a specificity of 100% in the confidence limit of this study. The numbers of MIRUs were found to vary among strains, resulting in six different groups of strains on the basis of the size of the amplified PCR fragment. However, the vast majority of the strains (approximately 90%) fell within the same group, containing two 77-bp MIRUs followed by one 53-bp MIRU.

Analysis of genetic polymorphisms affecting the four phospholipase C (plc) genes in Mycobacterium tuberculosis complex clinical isolates

Microbiology ◽  
2004 ◽  
Vol 150 (4) ◽  
pp. 967-978 ◽  
Author(s):  
C. Viana-Niero ◽  
P. E. de Haas ◽  
D. van Soolingen ◽  
S. C. Leão
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Phospholipase C ◽  
Genetic Polymorphisms ◽  
Blot Hybridization ◽  
Southern Blot Hybridization ◽  
Clinical Isolates ◽  
Significant Similarity ◽  
Genomic Deletions ◽  
Genes Encoding ◽  
Mycobacterium Africanum

The Mycobacterium tuberculosis genome contains four highly related genes which present significant similarity to Pseudomonas aeruginosa genes encoding phospholipase C enzymes. Three of these genes, plcA, plcB and plcC, are organized in tandem (locus plcABC). The fourth gene, plcD, is located in a different region. This study investigates variations in plcABC and plcD genes in clinical isolates of M. tuberculosis, Mycobacterium africanum and ‘Mycobacterium canettii’. Genetic polymorphisms were examined by PCR, Southern blot hybridization, sequence analysis and RT-PCR. Seven M. tuberculosis isolates contain insertions of IS6110 elements within plcA, plcC or plcD. In 19 of 25 M. tuberculosis isolates examined, genomic deletions were identified, resulting in loss of parts of genes or complete genes from the plcABC and/or plcD loci. Partial plcD deletion was observed in one M. africanum isolate. In each case, deletions were associated with the presence of a copy of the IS6110 element and in all occurrences IS6110 was transposed in the same orientation. A mechanism of deletion resulting from homologous recombination of two copies of IS6110 was recognized in a group of genetically related M. tuberculosis isolates. Five M. tuberculosis isolates presented major polymorphisms in the plcABC and plcD regions, along with loss of expression competence that affected all four plc genes. Phospholipase C is a well-known bacterial virulence factor. The precise role of phospholipase C in the pathogenicity of M. tuberculosis is unknown, but considering the potential importance that the plc genes may have in the virulence of the tubercle bacillus, the study of isolates cultured from patients with active tuberculosis bearing genetic variations affecting these genes may provide insights into the significance of phospholipase C enzymes for tuberculosis pathogenicity.

scholarly journals A Novel Tuberculosis DNA Vaccine in an HIV-1 p24 Protein Backbone Confers Protection against Mycobacterium tuberculosis and Simultaneously Elicits Robust Humoral and Cellular Responses to HIV-1

2012 ◽  
Vol 19 (5) ◽  
pp. 723-730 ◽  
Author(s):  
Xiaoman Li ◽  
Wei Xu ◽  
Sidong Xiong
Keyword(s):  
Mycobacterium Tuberculosis ◽  
T Cell ◽  
Dna Vaccine ◽  
Cellular Response ◽  
Mycobacterial Infection ◽  
T Cell Epitopes ◽  
Content Type ◽  
P24 Protein ◽  
Elevated Frequency ◽  
Hiv 1

ABSTRACTTuberculosis (TB) caused byMycobacterium tuberculosisremains a major infectious disease worldwide. Moreover, latentM. tuberculosisinfection is more likely to progress to active TB and eventually leads to death when HIV infection is involved. Thus, it is urgent to develop a novel TB vaccine with immunogenicity to bothM. tuberculosisand HIV. In this study, four uncharacterized T cell epitopes from MPT64, Ag85A, Ag85B, and TB10.4 antigens ofM. tuberculosiswere predicted, and HIV-1-derived p24, an immunodominant protein that can induce protective responses to HIV-1, was used as an immunogenic backbone.M. tuberculosisepitopes were incorporated separately into the gene backbone of p24, forming a pP24-Mtb DNA vaccine. We demonstrated that pP24-Mtb immunization induced a strongM. tuberculosis-specific cellular response as evidenced by T cell proliferation, cytotoxicity, and elevated frequency of gamma interferon (IFN-γ)-secreting T cells. Interestingly, a p24-specific cellular response and high levels of p24-specific IgG were also induced by pP24-Mtb immunization. When the protective effect was assessed after mycobacterial challenge, pP24-Mtb vaccination significantly reduced tissue bacterial loads and profoundly attenuated the mycobacterial infection-related lung inflammation and injury. Our findings demonstrated that the pP24-Mtb tuberculosis vaccine confers effective protection against mycobacterial challenge with simultaneously elicited robust immune responses to HIV-1, which may provide clues for developing novel vaccines to prevent dual infections.

scholarly journals Mycobacterium marinum infection drives foam cell differentiation in zebrafish infection

2018 ◽  
Author(s):  
Matt D. Johansen ◽  
Joshua A. Kasparian ◽  
Elinor Hortle ◽  
Warwick J. Britton ◽  
Auriol C. Purdie ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Lipid Metabolism ◽  
Foam Cell ◽  
Mycobacterial Infection ◽  
Foam Cells ◽  
Mycobacterium Marinum ◽  
Infection Model ◽  
Structural Components ◽  
Important Target ◽  
Zebrafish Infection

AbstractHost lipid metabolism is an important target for subversion by pathogenic mycobacteria such as Mycobacterium tuberculosis. The appearance of foam cells within the granuloma are well-characterised effects of chronic tuberculosis. The zebrafish-Mycobacterium marinum infection model recapitulates many aspects of human-M. tuberculosis infection and is used as a model to investigate the structural components of the mycobacterial granuloma. Here, we demonstrate that the zebrafish-M. marinum granuloma contains foam cells and that the transdifferentiation of macrophages into foam cells is driven by the mycobacterial ESX1 pathogenicity locus. This report demonstrates conservation of an important aspect of mycobacterial infection across species.

Suggests More Tests for Chest Pain Diagnosis

PEDIATRICS ◽  
1978 ◽  
Vol 61 (1) ◽  
pp. 143-144
Author(s):  
Michael F. Elmore ◽  
Glen A. Lehman
Keyword(s):  
Chest Pain ◽  
Physical Examination ◽  
Pediatric Patients ◽  
Laboratory Studies ◽  
Psychiatric Interview ◽  
X Ray ◽  
Pain Diagnosis ◽  
Chest X Ray ◽  
Pain Characteristics ◽  
Diagnostic Work

Driscoll et al. (Pediatrics 57:648, May 1976) reported a series of 43 patients with chest pain evaluated by history and physical examination, psychiatric interview, screening laboratory studies, ECG, and chest x-ray film. No organic cause was identified in 45% of patients, and various psychiatric aspects of the pain were discussed. The history obtained from pediatric patients is often suboptimal, and specific pain characteristics and associations cannot be defined. We therefore propose that more vigorous diagnostic work-ups are necessary before chest pain can be classed as "idiopathic."

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