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1.  Mycobacterium tuberculosis Strains of the Modern Sublineage of the Beijing Family Are More Likely To Display Increased Virulence than Strains of the Ancient Sublineage 
Journal of Clinical Microbiology  2014;52(7):2615-2624.
Strains of the Beijing genotype family of Mycobacterium tuberculosis are a cause of particular concern because of their increasing dissemination in the world and their association with drug resistance. Phylogenetically, this family includes distinct ancient and modern sublineages. The modern strains, contrary to the ancestral counterparts, demonstrated increasing prevalence in many world regions that suggest an enhanced bacterial pathogenicity. We therefore evaluated virulence of modern versus ancient Beijing strains with similar epidemiological and genotype characteristics. For this, we selected six strains that had very similar 24-locus mycobacterial interspersed repetitive-unit–variable-number tandem-repeat (MIRU-VNTR) typing profiles and belonged to the region of difference 181 (RD181) subgroup but differed using markers (mutT2 and mutT4 genes and NTF locus) that discriminate between modern and ancient Beijing sublineages. The strains were isolated from native patients in Brazil and Mozambique, countries with a low prevalence of Beijing strains. The virulence levels of these strains were determined in models of pulmonary infection in mice and in vitro macrophage infection and compared with that of a strain from Russia, part of the epidemic and hypervirulent Beijing clone B0/W148, and of the laboratory strain H37Rv. The results showed that two of the three modern Beijing strains were highly pathogenic, exhibiting levels of virulence comparable with that of the epidemic Russian strain. In contrast, all isolates of the ancient sublineage displayed intermediate or low virulence. The data obtained demonstrate that the strains of the modern Beijing sublineage are more likely to exhibit highly virulent phenotypes than ancient strains and suggest that genetic alterations characteristic of the modern Beijing sublineage favor selection of highly virulent bacteria.
PMCID: PMC4097719  PMID: 24829250
2.  Direct detection of Mycobacterium tuberculosis complex in bovine and bubaline tissues through nested-PCR 
Brazilian Journal of Microbiology  2014;45(2):633-640.
Post-mortem bacterial culture and specific biochemical tests are currently performed to characterize the etiologic agent of bovine tuberculosis. Cultures take up to 90 days to develop. A diagnosis by molecular tests such as PCR can provide fast and reliable results while significantly decreasing the time of confirmation. In the present study, a nested-PCR system, targeting rv2807, with conventional PCR followed by real-time PCR, was developed to detect Mycobacterium tuberculosis complex (MTC) organisms directly from bovine and bubaline tissue homogenates. The sensitivity and specificity of the reactions were assessed with DNA samples extracted from tuberculous and non-tuberculous mycobacteria, as well as other Actinomycetales species and DNA samples extracted directly from bovine and bubaline tissue homogenates. Regarding the analytical sensitivity, DNA of the M. bovis AN5 strain was detected up to 1.5 pg by nested-PCR, whereas DNA of M. tuberculosis H37Rv strain was detected up to 6.1 pg. The nested-PCR system showed 100% analytical specificity for MTC when tested with DNA of reference strains of non-tuberculous mycobacteria and closely-related Actinomycetales. A clinical sensitivity level of 76.7% was detected with tissues samples positive for MTC by means of the culture and conventional PCR. A clinical specificity of 100% was detected with DNA from tissue samples of cattle with negative results in the comparative intradermal tuberculin test. These cattle exhibited no visible lesions and were negative in the culture for MTC. The use of the nested-PCR assay to detect M. tuberculosis complex in tissue homogenates provided a rapid diagnosis of bovine and bubaline tuberculosis.
PMCID: PMC4166292  PMID: 25242951
bovine and bubaline tuberculosis; nested-PCR; real-time PCR; tissue; sanitary inspection
3.  Multidrug Resistant Mycobacterium tuberculosis: A Retrospective katG and rpoB Mutation Profile Analysis in Isolates from a Reference Center in Brazil 
PLoS ONE  2014;9(8):e104100.
Multidrug resistance is a critical factor in tuberculosis control. To gain better understanding of multidrug resistant tuberculosis in Brazil, a retrospective study was performed to compare genotypic diversity and drug resistance associated mutations in Mycobacterium tuberculosis isolates from a national reference center.
Methods and Findings
Ninety-nine multidrug resistant isolates from 12 Brazilian states were studied. Drug-resistance patterns were determined and the rpoB and katG genes were screened for mutations. Genotypic diversity was investigated by IS6110-RFLP and Luminex 47 spoligotyping. Mutations in rpoB and katG were seen in 91% and 93% of the isolates, respectively. Codon 315 katG mutations occurred in 82.8% of the isolates with a predominance of the Ser315Thr substitution. Twenty-five isolates were clustered in 11 groups with identical IS6110-RFLP patterns while 74 showed unique patterns with no association between mutation frequencies or susceptibility profiles. The most prevalent spoligotyping lineages were LAM (47%), T (17%) and Haarlen (12%). The Haarlen lineage showed a higher frequency of codon 516 rpoB mutations while codon 531 mutations prevailed in the other isolates.
Our data suggest that there were no major multidrug resistant M. tuberculosis strains transmitted among patients referred to the reference center, indicating an independent acquisition of resistance. In addition, drug resistance associated mutation profiles were well established among the main spoligotyping lineages found in these Brazilian multidrug resistant isolates, providing useful data for patient management and treatment.
PMCID: PMC4122415  PMID: 25093512
4.  Mycobacterium tuberculosis of the RDRio Genotype Is the Predominant Cause of Tuberculosis and Associated with Multidrug Resistance in Porto Alegre City, South Brazil 
Journal of Clinical Microbiology  2013;51(4):1071-1077.
Spoligotyping has shown Mycobacterium tuberculosis strains to be composed of different lineages, and some of them are not just geographically restricted but also affect specific ethnic populations and are associated with outbreaks and drug resistance. We recently described a particular subtype within the Latin American-Mediterranean (LAM) family, called RDRio, widespread in Brazil. Moreover, recent data also indicate that RDRio is present in many countries on all continents and is associated with cavitary disease and multidrug resistance (MDR). To further explore the relationship between RDRio and MDR, we conducted a study in a tuberculosis (TB) reference center responsible for the care of MDR patients in Rio Grande do Sul, the southernmost Brazilian state. From a collection of 237 clinical isolates, RDRio alone was responsible for one-half of all MDR cases, including one large group composed of strains with identical IS6110-restriction fragment length polymorphism (RFLP) and having the LAM5 signature. We additionally had complete data records for 96 patients and could make comparisons between the presence and absence of RDRio. No difference in clinical, radiological or laboratory features was observed, but a significantly greater number of cases with MDR were described in patients infected with an RDRio strain (P = 0.0015). Altogether, RDRio was responsible for 38% of all TB cases. These data support and confirmed previous findings that RDRio is the main agent responsible for TB in Brazil and is associated with drug resistance. Considering that RDRio is a globally distributed genotype, such findings raise concern about the increase in MDR in certain human populations.
PMCID: PMC3666761  PMID: 23325819
5.  Russian “Successful” Clone B0/W148 of Mycobacterium tuberculosis Beijing Genotype: a Multiplex PCR Assay for Rapid Detection and Global Screening 
Journal of Clinical Microbiology  2012;50(11):3757-3759.
We describe a multiplex PCR assay to detect the Mycobacterium tuberculosis Beijing genotype variant B0/W148, which is considered a “successful” clone of M. tuberculosis, widespread in Russia. Specificity and sensitivity of the assay were 100% based on the analysis of a collection of 516 M. tuberculosis isolates of different genotypes and origins. This assay may be used for accurate and simple detection and surveillance of this clinically and epidemiologically important variant of M. tuberculosis.
PMCID: PMC3486266  PMID: 22933595
6.  The use of microbead-based spoligotyping for Mycobacterium tuberculosis complex to evaluate the quality of the conventional method: Providing guidelines for Quality Assurance when working on membranes 
BMC Infectious Diseases  2011;11:110.
The classical spoligotyping technique, relying on membrane reverse line-blot hybridization of the spacers of the Mycobacterium tuberculosis CRISPR locus, is used world-wide (598 references in Pubmed on April 8th, 2011). However, until now no inter-laboratory quality control study had been undertaken to validate this technique. We analyzed the quality of membrane-based spoligotyping by comparing it to the recently introduced and highly robust microbead-based spoligotyping. Nine hundred and twenty-seven isolates were analyzed totaling 39,861 data points. Samples were received from 11 international laboratories with a worldwide distribution.
The high-throughput microbead-based Spoligotyping was performed on CTAB and thermolyzate DNA extracted from isolated Mycobacterium tuberculosis complex (MTC) strains coming from the genotyping participating centers. Information regarding how the classical Spoligotyping method was performed by center was available. Genotype discriminatory analyses were carried out by comparing the spoligotypes obtained by both methods. The non parametric U-Mann Whitney homogeneity test and the Spearman rank correlation test were performed to validate the observed results.
Seven out of the 11 laboratories (63 %), perfectly typed more than 90% of isolates, 3 scored between 80-90% and a single center was under 80% reaching 51% concordance only. However, this was mainly due to discordance in a single spacer, likely having a non-functional probe on the membrane used. The centers using thermolyzate DNA performed as well as centers using the more extended CTAB extraction procedure. Few centers shared the same problematic spacers and these problematic spacers were scattered over the whole CRISPR locus (Mostly spacers 15, 14, 18, 37, 39, 40).
We confirm that classical spoligotyping is a robust method with generally a high reliability in most centers. The applied DNA extraction procedure (CTAB or thermolyzate) did not affect the results in this study. However performance was center-dependent, suggesting that training is a key component in quality assurance of spoligotyping. Overall, no particular spacer yielded a higher degree of deviating results, suggesting that errors occur randomly either in the process of re-using membranes, or during the reading of the results and transferring of data from the film to a digital file. Last, the performance of the microbead-based method was excellent as previously shown by Cowan et al. (J. Clin. Microbiol. 2004) and Zhang et al. (J. Med. Microbiol. 2009) and demonstrated the proper detection of spacer 15 that is known to occasionally give weak signals in the classical spoligotyping.
PMCID: PMC3107175  PMID: 21527037
7.  Distinct genotypic profiles of the two major clades of Mycobacterium africanum 
Mycobacterium tuberculosis is the principal etiologic agent of human tuberculosis (TB) and a member of the M. tuberculosis complex (MTC). Additional MTC species that cause TB in humans and other mammals include Mycobacterium africanum and Mycobacterium bovis. One result of studies interrogating recently identified MTC phylogenetic markers has been the recognition of at least two distinct lineages of M. africanum, known as West African-1 and West African-2.
We screened a blinded non-random set of MTC strains isolated from TB patients in Ghana (n = 47) for known chromosomal region-of-difference (RD) loci and single nucleotide polymorphisms (SNPs). A MTC PCR-typing panel, single-target standard PCR, multi-primer PCR, PCR-restriction fragment analysis, and sequence analysis of amplified products were among the methods utilized for the comparative evaluation of targets and identification systems. The MTC distributions of novel SNPs were characterized in the both the Ghana collection and two other diverse collections of MTC strains (n = 175 in total).
The utility of various polymorphisms as species-, lineage-, and sublineage-defining phylogenetic markers for M. africanum was determined. Novel SNPs were also identified and found to be specific to either M. africanum West African-1 (Rv1332523; n = 32) or M. africanum West African-2 (nat751; n = 27). In the final analysis, a strain identification approach that combined multi-primer PCR targeting of the RD loci RD9, RD10, and RD702 was the most simple, straight-forward, and definitive means of distinguishing the two clades of M. africanum from one another and from other MTC species.
With this study, we have organized a series of consistent phylogenetically-relevant markers for each of the distinct MTC lineages that share the M. africanum designation. A differential distribution of each M. africanum clade in Western Africa is described.
PMCID: PMC2859774  PMID: 20350321
8.  Sequencing of hsp65 Gene for Identification of Mycobacterium Species Isolated from Environmental and Clinical Sources in Rio de Janeiro, Brazil▿ † 
Journal of Clinical Microbiology  2008;46(11):3822-3825.
This study evaluated the biodiversity of 28 clinical and 24 environmental Mycobacterium isolates from Rio de Janeiro, Brazil, by using hsp65 sequences, with the aim of contributing to a better understanding of the genetic diversity and usefulness of this marker. An extensive phylogenetic analysis was performed. The nucleotide diversity was similar between clinical (0.06508) and environmental (0.06221) isolates.
PMCID: PMC2576579  PMID: 18768653
9.  Correlations of mutations in katG, oxyR-ahpC and inhA genes and in vitro susceptibility in Mycobacterium tuberculosis clinical strains segregated by spoligotype families from tuberculosis prevalent countries in South America 
BMC Microbiology  2009;9:39.
Mutations associated with resistance to rifampin or streptomycin have been reported for W/Beijing and Latin American Mediterranean (LAM) strain families of Mycobacterium tuberculosis. A few studies with limited sample sizes have separately evaluated mutations in katG, ahpC and inhA genes that are associated with isoniazid (INH) resistance. Increasing prevalence of INH resistance, especially in high tuberculosis (TB) prevalent countries is worsening the burden of TB control programs, since similar transmission rates are noted for INH susceptible and resistant M. tuberculosis strains.
We, therefore, conducted a comprehensive evaluation of INH resistant M. tuberculosis strains (n = 224) from three South American countries with high burden of drug resistant TB to characterize mutations in katG, ahpC and inhA gene loci and correlate with minimal inhibitory concentrations (MIC) levels and spoligotype strain family. Mutations in katG were observed in 181 (80.8%) of the isolates of which 178 (98.3%) was contributed by the katG S315T mutation. Additional mutations seen included oxyR-ahpC; inhA regulatory region and inhA structural gene. The S315T katG mutation was significantly more likely to be associated with MIC for INH ≥2 μg/mL. The S315T katG mutation was also more frequent in Haarlem family strains than LAM (n = 81) and T strain families.
Our data suggests that genetic screening for the S315T katG mutation may provide rapid information for anti-TB regimen selection, epidemiological monitoring of INH resistance and, possibly, to track transmission of INH resistant strains.
PMCID: PMC2650697  PMID: 19228426
10.  Application of Sensitive and Specific Molecular Methods To Uncover Global Dissemination of the Major RDRio Sublineage of the Latin American-Mediterranean Mycobacterium tuberculosis Spoligotype Family▿ ‡ 
Journal of Clinical Microbiology  2008;46(4):1259-1267.
The Latin American-Mediterranean (LAM) family of Mycobacterium tuberculosis is believed to be the cause of ∼15% of tuberculosis cases worldwide. Previously, we defined a prevalent sublineage of the LAM family in Brazil by a single characteristic genomic deletion designated RDRio. Using the Brazilian strains, we pinpoint an Ag85C103 single nucleotide polymorphism (SNP) (screened by restriction fragment length polymorphism [RFLP] analysis) that correctly identified all LAM family strains. Importantly, all RDRio strains concomitantly possessed the RD174 deletion. These genetic signatures, along with a newly developed multiplex PCR for rapid differentiation between “wild-type” and RDRio strains, were then used to analyze an international collection of M. tuberculosis strains. RDRio M. tuberculosis was identified from four continents involving 11 countries. Phylogenetic analysis of the IS6110-RFLP patterns from representative RDRio and LAM strains from Brazil, along with all representative clusters from a South African database, confirmed their genetic relatedness and transcontinental transmission. The Ag85C103 SNP RFLP, as compared to results obtained using a PCR method targeting a LAM-restricted IS6110 element, correctly identified 99.8% of LAM spoligotype strains. Together, these tests were more accurate than spoligotyping at categorizing strains with indefinable spoligotypes and segregated true LAM strains from those with convergent spoligotypes. The fact that RDRio strains were identified worldwide highlights the importance of this LAM family sublineage and suggests that this strain is a global threat that should be specifically targeted by public health resources. Our provision of simple and robust molecular methods will assist the evaluation of the LAM family and the RDRio sublineage.
PMCID: PMC2292928  PMID: 18234868
11.  Discovery of a Novel Mycobacterium tuberculosis Lineage That Is a Major Cause of Tuberculosis in Rio de Janeiro, Brazil▿ † 
Journal of Clinical Microbiology  2007;45(12):3891-3902.
The current study evaluated Mycobacterium tuberculosis isolates from Rio de Janeiro, Brazil, for genomic deletions. One locus in our panel of PCR targets failed to amplify in ∼30% of strains. A single novel long sequence polymorphism (>26.3 kb) was characterized and designated RDRio. Homologous recombination between two similar protein-coding genes is proposed as the mechanism for deleting or modifying 10 genes, including two potentially immunogenic PPE proteins. The flanking regions of the RDRio locus were identical in all strains bearing the deletion. Genetic testing by principal genetic group, spoligotyping, variable-number tandem repeats of mycobacterial interspersed repetitive units (MIRU-VNTR), and IS6110-based restriction fragment length polymorphism analysis cumulatively support the idea that RDRio strains are derived from a common ancestor belonging solely to the Latin American-Mediterranean spoligotype family. The RDRio lineage is therefore the predominant clade causing tuberculosis (TB) in Rio de Janeiro and, as indicated by genotypic clustering in MIRU-VNTR analysis, the most significant source of recent transmission. Limited retrospective reviews of bacteriological and patient records showed a lack of association with multidrug resistance or specific risk factors for TB. However, trends in the data did suggest that RDRio strains may cause a form of TB with a distinct clinical presentation. Overall, the high prevalence of this genotype may be related to enhanced virulence, transmissibility, and/or specific adaptation to a Euro-Latin American host population. The identification of RDRio strains outside of Brazil points to the ongoing intercontinental dissemination of this important genotype. Further studies are needed to determine the differential strain-specific features, pathobiology, and worldwide prevalence of RDRio M. tuberculosis.
PMCID: PMC2168543  PMID: 17898156
12.  Mycobacterium tuberculosis complex genetic diversity: mining the fourth international spoligotyping database (SpolDB4) for classification, population genetics and epidemiology 
BMC Microbiology  2006;6:23.
The Direct Repeat locus of the Mycobacterium tuberculosis complex (MTC) is a member of the CRISPR (Clustered regularly interspaced short palindromic repeats) sequences family. Spoligotyping is the widely used PCR-based reverse-hybridization blotting technique that assays the genetic diversity of this locus and is useful both for clinical laboratory, molecular epidemiology, evolutionary and population genetics. It is easy, robust, cheap, and produces highly diverse portable numerical results, as the result of the combination of (1) Unique Events Polymorphism (UEP) (2) Insertion-Sequence-mediated genetic recombination. Genetic convergence, although rare, was also previously demonstrated. Three previous international spoligotype databases had partly revealed the global and local geographical structures of MTC bacilli populations, however, there was a need for the release of a new, more representative and extended, international spoligotyping database.
The fourth international spoligotyping database, SpolDB4, describes 1939 shared-types (STs) representative of a total of 39,295 strains from 122 countries, which are tentatively classified into 62 clades/lineages using a mixed expert-based and bioinformatical approach. The SpolDB4 update adds 26 new potentially phylogeographically-specific MTC genotype families. It provides a clearer picture of the current MTC genomes diversity as well as on the relationships between the genetic attributes investigated (spoligotypes) and the infra-species classification and evolutionary history of the species. Indeed, an independent Naïve-Bayes mixture-model analysis has validated main of the previous supervised SpolDB3 classification results, confirming the usefulness of both supervised and unsupervised models as an approach to understand MTC population structure. Updated results on the epidemiological status of spoligotypes, as well as genetic prevalence maps on six main lineages are also shown. Our results suggests the existence of fine geographical genetic clines within MTC populations, that could mirror the passed and present Homo sapiens sapiens demographical and mycobacterial co-evolutionary history whose structure could be further reconstructed and modelled, thereby providing a large-scale conceptual framework of the global TB Epidemiologic Network.
Our results broaden the knowledge of the global phylogeography of the MTC complex. SpolDB4 should be a very useful tool to better define the identity of a given MTC clinical isolate, and to better analyze the links between its current spreading and previous evolutionary history. The building and mining of extended MTC polymorphic genetic databases is in progress.
PMCID: PMC1468417  PMID: 16519816
13.  Snapshot of Moving and Expanding Clones of Mycobacterium tuberculosis and Their Global Distribution Assessed by Spoligotyping in an International Study†  
Journal of Clinical Microbiology  2003;41(5):1963-1970.
The present update on the global distribution of Mycobacterium tuberculosis complex spoligotypes provides both the octal and binary descriptions of the spoligotypes for M. tuberculosis complex, including Mycobacterium bovis, from >90 countries (13,008 patterns grouped into 813 shared types containing 11,708 isolates and 1,300 orphan patterns). A number of potential indices were developed to summarize the information on the biogeographical specificity of a given shared type, as well as its geographical spreading (matching code and spreading index, respectively). To facilitate the analysis of hundreds of spoligotypes each made up of a binary succession of 43 bits of information, a number of major and minor visual rules were also defined. A total of six major rules (A to F) with the precise description of the extra missing spacers (minor rules) were used to define 36 major clades (or families) of M. tuberculosis. Some major clades identified were the East African-Indian (EAI) clade, the Beijing clade, the Haarlem clade, the Latin American and Mediterranean (LAM) clade, the Central Asian (CAS) clade, a European clade of IS6110 low banders (X; highly prevalent in the United States and United Kingdom), and a widespread yet poorly defined clade (T). When the visual rules defined above were used for an automated labeling of the 813 shared types to define nine superfamilies of strains (Mycobacterium africanum, Beijing, M. bovis, EAI, CAS, T, Haarlem, X, and LAM), 96.9% of the shared types received a label, showing the potential for automated labeling of M. tuberculosis families in well-defined phylogeographical families. Intercontinental matches of shared types among eight continents and subcontinents (Africa, North America, Central America, South America, Europe, the Middle East and Central Asia, and the Far East) are analyzed and discussed.
PMCID: PMC154710  PMID: 12734235
14.  Global Distribution of Mycobacterium tuberculosis Spoligotypes 
Emerging Infectious Diseases  2002;8(11):1347-1349.
We present a short summary of recent observations on the global distribution of the major clades of the Mycobacterium tuberculosis complex, the causative agent of tuberculosis. This global distribution was defined by data-mining of an international spoligotyping database, SpolDB3. This database contains 11,708 patterns from as many clinical isolates originating from more than 90 countries. The 11,708 spoligotypes were clustered into 813 shared types. A total of 1,300 orphan patterns (clinical isolates showing a unique spoligotype) were also detected.
PMCID: PMC2738532  PMID: 12453368
Mycobacterium tuberculosis; spoligotyping

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