Organization and Characterization of the Promoter Elements of the rRNA Operons in the Slow-Growing Pathogen .

The slow-growing, nontuberculous mycobacterium possesses two rRNA operons, and , located downstream from the and genes, respectively. Here, we report the sequence and organization of the promoter regions of these two operons. In the operon, transcription can be initiated from the two promoters, named P1 and PCL1, while in , transcription can only start from one, called P1 .

Corrigendum: Iron deprivation enhances transcriptional responses to growth arrest of .

[This corrects the article DOI: 10.3389/fmicb.2022.

Iron deprivation enhances transcriptional responses to growth arrest of .

The establishment of (Mtb) long-term infection depends on several factors, one of which is the availability of key nutrients such as iron (Fe). The relation between Fe deprivation inside and outside the granuloma, and the capacity of Mtb to accumulate lipids and persist in the absence of growth is not well understood. In this context, current knowledge of how Mtb modifies its lipid composition in response to growth arrest, depending on iron availability, is scarce.

Hypoxia Is Not a Main Stress When Is in a Dormancy-Like Long-Chain Fatty Acid Environment.

The capacity of () to sense, respond and adapt to a variable and hostile environment within the host makes it one of the most successful human pathogens. During different stages of infection, is surrounded by a plethora of lipid molecules and current evidence points out the relevance of fatty acids during the infectious process. In this study, we have compared the transcriptional response of to hypoxia in cultures supplemented with a mix of even long-chain fatty acids or dextrose as main carbon sources.

Whole-genome sequence analysis of the Mycobacterium avium complex and proposal of the transfer of Mycobacterium yongonense to Mycobacterium intracellulare subsp. yongonense subsp. nov.

Bacterial whole-genome sequences contain informative features of their evolutionary pathways. Comparison of whole-genome sequences have become the method of choice for classification of prokaryotes, thus allowing the identification of bacteria from an evolutionary perspective, and providing data to resolve some current controversies. Currently, controversy exists about the assignment of members of the Mycobacterium avium complex, as is for the cases of Mycobacterium yongonense and 'Mycobacterium indicus pranii'.

First description of natural and experimental conjugation between Mycobacteria mediated by a linear plasmid.

Background: In a previous study, we detected the presence of a Mycobacterium avium species-specific insertion sequence, IS1245, in Mycobacterium kansasii. Both species were isolated from a mixed M. avium-M.

Alignment of multiple complete genomes suggests that gene rearrangements may contribute towards the speciation of Mycobacteria.

To more accurately define the taxonomic relationships among species belonging to the genus Mycobacterium we have applied and compared three complete genome sequence comparison procedures to existing systems. These included a nucleotide sequence comparison including both coding and no-coding regions of the genome and two genomic-order comparisons using MAUVE and M-GCAT software to provide comparative gene synteny. These methods clearly differentiated a panel of genomes from reference mycobacterial species.

Characterization of mycobacteria from a major Brazilian outbreak suggests that revision of the taxonomic status of members of the Mycobacterium chelonae-M. abscessus group is needed.

An outbreak of postsurgical infections caused by rapidly growing mycobacteria has been ongoing in Brazil since 2004. The degrees of similarity of the rpoB and hsp65 sequences from the clinical isolates and the corresponding sequences from both the Mycobacterium massiliense and the M. bolletii type strains were above the accepted limit for interspecies variability, leading to conflicting identification results.

Transcriptional analysis of Mycobacterium fortuitum cultures upon hydrogen peroxide treatment using the novel standard rrnA-P1.

Background: The ability of an intracellular pathogen to establish infection depends on the capacity of the organism to survive and replicate inside the host. Mycobacterium fortuitum is a bacteria that contains genes involved in the detoxification of the oxygen reactive species such as those produced by the host during the infection. In this work, we investigate the effects of hydrogen peroxide on the transcription and expression of these genes by developing a real time quantitative PCR technique (qRT-PCR) using the ribosomal promoter region (rrnA-P1) as reference product for quantification of the mRNA levels.

Genome analysis shows a common evolutionary origin for the dominant strains of Mycobacterium tuberculosis in a UK South Asian community.

We have investigated the Mycobacterium tuberculosis strain types present in the South Asian population of the UK, in which tuberculosis is particularly prevalent. In contrast to the widespread Beijing strains which have the variable number tandem repeats (VNTR) profile 42435, isolates with the VNTR profile 42235, jointly with 02335 or 42234 profiles, appear more frequently in tuberculosis patients of South Asian ethnic origin (SA-strains) in the UK than in any other ethnic group. Using microarray-based comparative genomics to distinguish total or partially deleted genes, we found that three of the common deleted regions in the SA-strains were identical to some deleted genes in the strain CH, which caused an outbreak among South Asian patients in Leicester in 2001 but were different from genomic deletions found in Beijing/W strains.

Molecular features of Mycobacterium avium human isolates carrying a single copy of IS1245 and IS1311 per genome.

Human clinical isolates of the Mycobacterium avium complex, from hospitals in Bogotá, were studied using a wide range of molecular tests including PCR restriction-enzyme analysis (PRA) of the hsp65 gene. Up to 21 of the isolates were identified as M. avium PRA variant III (Mav III), a variant obtained only from isolates on the American continent.

Mycobacterium colombiense sp. nov., a novel member of the Mycobacterium avium complex and description of MAC-X as a new ITS genetic variant.

Forty-five mycobacterial strains isolated from 23 Colombian HIV-positive patients were identified as members of the Mycobacterium avium complex (MAC) and were characterized using different molecular approaches. Seven of the isolates showed characteristic features that allowed them to be differentiated from other members of the complex. The isolates had a novel 16S-23S rRNA internal transcribed spacer (ITS 1) gene sequence which is described as a new sequevar, MAC-X.

A member of the cAMP receptor protein family of transcription regulators in Mycobacterium tuberculosis is required for virulence in mice and controls transcription of the rpfA gene coding for a resuscitation promoting factor.

Deletion of gene Rv3676 in Mycobacterium tuberculosis coding for a transcription factor belonging to the cAMP receptor protein (CRP) family caused growth defects in laboratory medium, in bone marrow-derived macrophages and in a mouse model of tuberculosis. Transcript profiling of M. tuberculosis grown in vitro identified 16 genes with significantly altered expression in the mutant compared with the wild type.

[Distribution of PRA patterns of clinical isolates of the Mycobacterium avium complex from Spain and South America].

Mycobacterium avium complex (MAC) infections are the most frequent systemic infections associated with advanced AIDS. DNA probes for accurate identification of mycobacteria are available but are very expensive in many Latin American settings. Consequently, most Latin American diagnostic laboratories employ inaccurate and outdated tests for mycobacteria identification.

IS6110 mediates increased transcription of the phoP virulence gene in a multidrug-resistant clinical isolate responsible for tuberculosis outbreaks.

Drug resistance in Mycobacterium tuberculosis complex strains is solely due to chromosomal mutations that could affect bacterial virulence. Molecular epidemiology studies have shown that resistant strains are less likely to be clustered than susceptible strains. However, a few multidrug-resistant (MDR) M.