scholarly journals Genome structure in the vole bacillus, Mycobacterium microti, a member of the Mycobacterium tuberculosis complex with a low virulence for humans

Microbiology ◽  
2004 ◽  
Vol 150 (5) ◽  
pp. 1519-1527 ◽  
Author(s):  
Cristiane C. Frota ◽  
Debbie M. Hunt ◽  
Roger S. Buxton ◽  
Lisa Rickman ◽  
Jason Hinds ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mycobacterium Tuberculosis Complex ◽  
Genome Structure ◽  
Biochemical Properties ◽  
Extensive Study ◽  
Tuberculosis Complex ◽  
Almost All ◽  
Mycobacterium Microti ◽  
Different Levels ◽  
Immunocompetent Patients

Mycobacterium microti, a member of the Mycobacterium tuberculosis complex, is phylogenetically closely related to M. tuberculosis, differing in a few biochemical properties. However, these species have different levels of virulence in different hosts; most notably M. microti shows lower virulence for humans than M. tuberculosis. This report presents genomic comparisons using DNA microarray analysis for an extensive study of the diversity of M. microti strains. Compared to M. tuberculosis H37Rv, 13 deletions were identified in 12 strains of M. microti, including the regions RD1 to RD10, which are also missing in Mycobacterium bovis BCG. In addition, four new deleted regions, named MiD1, RD1β, MiD2 and MiD3, were identified. DNA sequencing was used to define the extent of most of the deletions in one strain. Although RD1 of M. bovis BCG and M. microti is thought to be crucial for attenuation, in this study, three of the four M. microti strains that were isolated from immunocompetent patients had the RD1 deletion. In fact, only the RD3 deletion was present in all of the strains examined, although deletions RD7, RD8 and MiD1 were found in almost all the M. microti strains. These deletions might therefore have some relation to the different host range of M. microti. It was also noticeable that of the 12 strains studied, only three were identical; these strains were all isolated from immunocompetent humans, suggesting that they could have arisen from a single source. Thus, this study shows that it is difficult to ascribe virulence to any particular pattern of deletion in M. microti.

scholarly journals Differentiation among Members of the Mycobacterium tuberculosis Complex by Molecular and Biochemical Features: Evidence for Two Pyrazinamide-Susceptible Subtypes of M. bovis

2000 ◽  
Vol 38 (1) ◽  
pp. 152-157
Author(s):  
Stefan Niemann ◽  
Elvira Richter ◽  
Sabine Rüsch-Gerdes
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mycobacterium Tuberculosis Complex ◽  
Clinical Importance ◽  
Acid Hydrazide ◽  
Biochemical Properties ◽  
Molecular Characteristics ◽  
Tuberculosis Complex ◽  
Carboxylic Acid Hydrazide ◽  
Spoligotype Pattern ◽  
Group 3

ABSTRACT The variations in biochemical as well as molecular characteristics among several members of the Mycobacterium tuberculosis complex that are not M. tuberculosis have been assessed to facilitate an unambiguous species identification. Altogether, 96 M. tuberculosis complex strains including 52 M. bovis isolates and 44 M. africanum isolates were analyzed by spoligotyping. The strains could be clustered into five spoligotype groups. All M. bovis isolates showed the typical absence of the spacers 39 to 43 and typical biochemical properties. However, within these strains we found a group of strains that had a spoligotype pattern which is clearly defined by the additional absence of spacers 3 to 16 and that were uncommonly susceptible to pyrazinamide (PZA). This spoligotype pattern has previously been described as being typical for a caprine genotype because of its predominant isolation from sheep and goats. Due to the clinical importance of PZA resistance, we propose two M. bovis subtypes: M. bovis subtype bovis , which is resistant to PZA, and M. bovis subtype caprae , which is susceptible to PZA. Two additional strains that clustered in group 3 showed biochemical and genetic properties typical for M. bovis and were also sensitive to PZA; thus, they may represent a third PZA-susceptible M. bovis subtype. The M. africanum isolates could be clustered into two spoligotype groups which can be differentiated from M. bovis by hybridization to spacers 39 to 43. These groups correspond to the previously described M. africanum subtypes I and II and can be clearly distinguished from each other by spoligotyping and resistance to thiophen-2-carboxylic acid hydrazide. Our results demonstrate that spoligotyping is a useful tool for differentiation of M. bovis and M. africanum . Moreover, we describe two PZA-susceptible M. bovis subtypes and describe a method that facilitates an unambiguous differentiation of the two M. africanum subtypes.

scholarly journals Genomic Interrogation of the Dassie Bacillus Reveals It as a Unique RD1 Mutant within the Mycobacterium tuberculosis Complex

2004 ◽  
Vol 186 (1) ◽  
pp. 104-109 ◽  
Author(s):  
Serge Mostowy ◽  
Debby Cousins ◽  
Marcel A. Behr
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mycobacterium Bovis ◽  
Dna Content ◽  
Clinical Presentation ◽  
Mycobacterium Tuberculosis Complex ◽  
Biological Significance ◽  
The Other ◽  
Tuberculosis Complex ◽  
Procavia Capensis ◽  
Mycobacterium Microti

ABSTRACT Despite their remarkable genetic homology, members of the Mycobacterium tuberculosis complex express very different phenotypes, most notably in their spectra of clinical presentation. For example, M. tuberculosis is regarded as pathogenic to humans, whereas members having deleted RD1, such as Mycobacterium microti and Mycobacterium bovis BCG, are not. The dassie bacillus, an infrequent variant of the M. tuberculosis complex characterized as being most similar to M. microti, is the causative agent of tuberculosis (TB) in the dassie (Procavia capensis). Intriguingly, the dassie bacillus is not pathogenic to rabbits or guinea pigs and has never been documented to infect humans. Although it was identified more than a half-century ago, the reasons behind its attenuation are unknown. Because large sequence polymorphisms have presented themselves as the most obvious genomic distinction among members of the M. tuberculosis complex, the DNA content of the dassie bacillus was interrogated by Affymetrix GeneChip to identify regions that are absent from it but present in M. tuberculosis H37Rv. Comparison has led to the identification of nine regions of difference (RD), five of which are shared with M. microti (RDs 3, 7, 8, 9, and 10). Although the dassie bacillus does not share the other documented deletions in M. microti (RD1mic, RD5mic, MID1, MID2, and MID3), it has endured unique deletions in the regions of RD1, RD5, N-RD25, and Rv3081-Rv3082c (virS). RD1das, affecting only Rv3874-Rv3877, is the smallest natural deletion of the RD1 region uncovered and points to genes within this region that are likely implicated in virulence. Newfound deletions from the dassie bacillus are discussed in relation to their evolutionary and biological significance.

scholarly journals The rational use of nucleic acid amplification testing for the Mycobacterium tuberculosis complex

2004 ◽  
Vol 25 (4) ◽  
pp. 28
Author(s):  
Richard Lumb
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Nucleic Acid ◽  
Clinical Significance ◽  
Mycobacterium Bovis ◽  
Mycobacterium Tuberculosis Complex ◽  
Nucleic Acid Amplification ◽  
Tuberculosis Complex ◽  
Rational Use ◽  
Genus Mycobacterium ◽  
Mycobacterium Microti

On the basis of clinical significance, Mycobacterium tuberculosis is the most important member of the genus Mycobacterium. It is closely related genetically to Mycobacterium bovis, M. africanum, Mycobacterium microti, Mycobacterium bovis BCG (the bacillus of Calmette-Guerin) and the recently described Mycobacterium tuberculosis subspecies Canetti. Together they are termed the Mycobacterium tuberculosis complex (MTBC).

scholarly journals Spatial and Temporal Distribution of Mycobacterium tuberculosis Complex Infection in Eurasian Badger (Meles meles) and Cattle in Asturias, Spain

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1294
Author(s):  
Cristina Blanco Blanco Vázquez ◽  
Thiago Doria Barral ◽  
Beatriz Romero ◽  
Manuel Queipo ◽  
Isabel Merediz ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Road Traffic ◽  
Mycobacterium Tuberculosis Complex ◽  
Temporal Distribution ◽  
Meles Meles ◽  
Interspecies Transmission ◽  
Tuberculosis Complex ◽  
Serum Samples ◽  
Study Objective ◽  
Infection Pressure

The present work investigated the prevalence, spatial distribution, and temporal distribution of tuberculosis (TB) in free-ranging Eurasian badgers (Meles meles) and cattle in Asturias (Atlantic Spain) during a 13-year follow-up. The study objective was to assess the role of badgers as a TB reservoir for cattle and other sympatric wild species in the region. Between 2008 and 2020, 673 badgers (98 trapped and 575 killed in road traffic accidents) in Asturias were necropsied, and their tissue samples were cultured for the Mycobacterium tuberculosis complex (MTC) isolation. Serum samples were tested in an in-house indirect P22 ELISA to detect antibodies against the MTC. In parallel, data on MTC isolation and single intradermal tuberculin test results were extracted for cattle that were tested and culled as part of the Spanish National Program for the Eradication of Bovine TB. A total of 27/639 badgers (4.23%) were positive for MTC based on bacterial isolation, while 160/673 badgers (23.77%) were found to be positive with the P22 ELISA. The rate of seropositivity was higher among adult badgers than subadults. Badger TB status was spatially and temporally associated with cattle TB status. Our results cannot determine the direction of possible interspecies transmission, but they are consistent with the idea that the two hosts may exert infection pressure on each other. This study highlights the importance of the wildlife monitoring of infection and disease during epidemiological interventions in order to optimize outcomes.

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