RESUMO
Our objective was to identify transcriptional biomarkers in peripheral blood mononuclear cells (PBMC) that discriminate individuals with latent tuberculosis infection (LTBI) from those with pulmonary tuberculosis (PTB) in subjects with non-insulin-dependent diabetes mellitus (NIDDM) and in individuals without NIDDM. Using gene expression microarrays we identified differentially expressed genes from lungs of mice infected with Mycobacterium tuberculosis (Mtb) or a mutant (ΔsigH) representing a non-inflammatory model. Genes expressed in blood, with inflammatory related functions were evaluated in humans by RT-qPCR. NCF1 and ORM transcripts have the better discriminatory capacity to identify PTB subjects from LTBI and non-infected controls (NICs) independently of the presence of NIDDM. The sequential evaluation of the mRNA levels of NCF1 and ORM as multiple diagnostic tests showed 95% Sensitivity (Se) and 80% Specificity (Sp). In addition, FPR2 promises to be a good biomarker for the PTB detection in subjects with NIDDM (Se=100%; Sp=90%).
Assuntos
Biomarcadores , Diabetes Mellitus Tipo 2/complicações , Regulação da Expressão Gênica , Tuberculose Pulmonar/complicações , Tuberculose Pulmonar/diagnóstico , Adulto , Idoso , Animais , Análise por Conglomerados , Feminino , Perfilação da Expressão Gênica , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Tuberculose Pulmonar/fisiopatologiaRESUMO
The characteristics of tuberculosis (TB) patients related to a chain of recent TB transmissions were investigated. Mycobacterium tuberculosis (MTB) isolates (120) were genotyped using the restriction fragment length polymorphism-IS6110 (R), spacer oligotyping (S) and mycobacterial interspersed repetitive units-variable number of tandem repeats (M) methods. The MTB isolates were clustered and the clusters were grouped according to the similarities of their genotypes. Spearman's rank correlation coefficients between the groups of MTB isolates with similar genotypes and those patient characteristics indicating a risk for a pulmonary TB (PTB) chain transmission were ana- lysed. The isolates showing similar genotypes were distributed as follows: SMR (5%), SM (12.5%), SR (1.67%), MR (0%), S (46.67%), M (5%) and R (0%). The remaining 35 cases were orphans. SMR exhibited a significant correlation (p < 0.05) with visits to clinics, municipalities and comorbidities (primarily diabetes mellitus). S correlated with drug consumption and M with comorbidities. SMR is needed to identify a social network in metropolitan areas for PTB transmission and S and M are able to detect risk factors as secondary components of a transmission chain of TB.
Assuntos
Técnicas de Genotipagem/métodos , Mycobacterium tuberculosis/genética , Tuberculose Pulmonar/microbiologia , Tuberculose Pulmonar/transmissão , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Cidades , Comorbidade , DNA Bacteriano/isolamento & purificação , Feminino , Genótipo , Humanos , Sequências Repetitivas Dispersas/genética , Masculino , México/epidemiologia , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Epidemiologia Molecular/métodos , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/isolamento & purificação , Polimorfismo de Fragmento de Restrição/genética , Fatores de Risco , Fatores Sociológicos , Estatísticas não Paramétricas , Sequências de Repetição em Tandem/genética , Tuberculose Pulmonar/epidemiologia , Tuberculose Pulmonar/genética , População Urbana , Adulto JovemRESUMO
Tuberculosis (TB) is an infectocontagious respiratory disease caused by members of the Mycobacterium tuberculosis complex. A 7 base pair (bp) deletion in the locus polyketide synthase (pks)15/1 is described as polymorphic among members of the M. tuberculosis complex, enabling the identification of Euro-American, Indo-Oceanic and Asian lineages. The aim of this study was to characterise this locus in TB isolates from Mexico. One hundred twenty clinical isolates were recovered from the states of Veracruz and Estado de Mexico. We determined the nucleotide sequence of a ± 400 bp fragment of the locus pks15/1, while genotypic characterisation was performed by spoligotyping. One hundred and fifty isolates contained the 7 bp deletion, while five had the wild type locus. Lineages X (22%), LAM (18%) and T (17%) were the most frequent; only three (2%) of the isolates were identified as Beijing and two (1%) EAI-Manila. The wild type pks15/1 locus was observed in all Asian lineage isolates tested. Our results confirm the utility of locus pks15/1 as a molecular marker for identifying Asian lineages of the M. tuberculosis complex. This marker could be of great value in the epidemiological surveillance of TB, especially in countries like Mexico, where the prevalence of such lineages is unknown.
Assuntos
Proteínas de Bactérias/genética , Genes Bacterianos/genética , Loci Gênicos/genética , Mycobacterium tuberculosis/genética , Policetídeo Sintases/genética , Adulto , Sequência de Bases , Farmacorresistência Bacteriana Múltipla/genética , Monitoramento Epidemiológico , Feminino , Marcadores Genéticos/genética , Humanos , Masculino , México , Pessoa de Meia-Idade , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/isolamento & purificação , Reação em Cadeia da Polimerase , Deleção de Sequência , Escarro/microbiologiaRESUMO
INTRODUCTION: Biomarkers are critical tools for finding new approaches for controlling the spread of tuberculosis (TB), including for predicting the development of TB therapeutics, vaccines, and diagnostic tools. METHODS: Expression of immune biomarkers was analyzed in peripheral blood cells stimulated and non-stimulated with M. tuberculosis antigens ESAT-6, CFP10 and TB7.7. in Warao indigenous individuals. These biomarkers may be able to differentiate TB states, such as active tuberculosis (ATB) cases and latent tuberculosis infection (LTBI) from non-infected controls (NIC). A real-time reverse transcription polymerase chain reaction (RT-qPCR) assay was performed on 100 blood samples under non-stimulation or direct ex vivo conditions (NS=50) and stimulation conditions (S=50). RESULTS: The findings are shown as the median and interquartile range (IQR) of relative gene expression levels of IFN-γ, CD14, MMP9, CCR5, CCL11, CXCL9/MIG, and uPAR/PLAUR immune biomarkers. MMP9 levels were significantly higher in the LTBI-NS and LTBI-S groups compared with the NIC-NS and NIC-S groups. However, CCR5 levels were significantly lower in the LTBI-S group compared with both NIC-NS and NIC-S groups. CCL11 levels were significantly lower in the LTBI-S group compared with the NIC-NS group. CONCLUSIONS: Preliminary findings showed that MMP9 immune biomarkers separated LTBI indigenous individuals from NIC indigenous individuals, while CCR5, CCL11, CD14, and IFN-γ did not differentiate TB states from NIC. MMP9 may be useful as a potential biomarker for LTBI and new infected case detection among Warao indigenous individuals at high risk of developing the disease. It may also be used to halt the epidemic, which will require further validation in larger studies.
Assuntos
Biomarcadores/sangue , Indígenas Norte-Americanos/estatística & dados numéricos , Tuberculose Latente/diagnóstico , Mycobacterium tuberculosis/imunologia , Adulto , Estudos de Casos e Controles , Estudos Transversais , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Tuberculose Latente/sangue , Masculino , México , Reação em Cadeia da Polimerase em Tempo RealRESUMO
INTRODUCTION:: Interferon-γ (IFN-γ) plays a crucial role in resistance to mycobacterial diseases; accordingly, variants of the gene encoding this cytokine may be associated with elevated risk of contracting pulmonary tuberculosis (TB). METHODS:: Blood samples were collected from 135 Warao indigenous individuals with newly diagnosed sputum culture-positive TB. Of these, 24 were diagnosed with active tuberculosis (ATB). The study comprised 111 participants, who were grouped as follows: 1) 14 tuberculin skin test (TST)-positive Warao indigenous individuals and 4 that were QuantiFERON-TB?Gold In-Tube (QFT-IT) test-positive, collectively comprising the latent TB infection group (LTBI), n = 18), and 2) healthy controls who were QFT-IT- and TST-negative, comprising the control group (CTRL, n = 93). Detection of the IFN γ gene (IFNG) +874A/T polymorphism was performed via PCR and quantification of IFNG expression via qPCR. RESULTS:: Relative to indigenous and white Americans, ATB and CTRL groups had a higher frequency of the IFNG SNP (+874A): 23 (95.8%) and 108 (97.3%), respectively. Indigenous Warao individuals homozygous for the IFNG (+874) A allele exhibited 3.59-fold increased risk of developing TB (95% confidence interval, 2.60-4.96, p =0.0001). A decreased frequency of the AT genotype was observed in individuals with pulmonary TB (4.16%) and controls (0.90%). The frequency of the TT genotype was decreased among controls (1.80%); none of the patients with TB were found to have this genotype. The differences in IFNG expression between the groups, under unstimulated and stimulated conditions, were not statistically significant. CONCLUSIONS:: Preliminary results demonstrate concordance between IFNG +874 A/A genotype and low expression of IFNG.
Assuntos
Indígenas Sul-Americanos/estatística & dados numéricos , Interferon gama/genética , Polimorfismo Genético/genética , Tuberculose Pulmonar/diagnóstico , Adulto , Estudos Transversais , Doenças Endêmicas , Feminino , Genótipo , Humanos , Interferon gama/metabolismo , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Teste Tuberculínico , Tuberculose Pulmonar/epidemiologia , Tuberculose Pulmonar/etnologia , Venezuela/epidemiologiaRESUMO
BACKGROUND: Rheumatoid arthritis (RA) is an inflammatory debilitating disease that affects the joints in the early and productive phases of an individual's life. Several cytokines have been linked to the disease pathogenesis and are known to contribute to the inflammatory state characteristic of RA. The participation of type I interferon (IFN) in the pathogenesis of the disease has been already described as well as the identity of the genes that are regulated by this molecule, which are collectively known as the type I IFN signature. These genes have several functions associated with apoptosis, transcriptional regulation, protein degradation, Th2 cell induction, B cell proliferation, etc. This article evaluated the expression of several genes of the IFN signature in different stages of disease and their correlation with the levels of anticitrullinated protein antibodies (ACPA) anticarbamylated protein (Anti-CarP) antibodies. METHODS: Samples from individuals with early and established RA, high-risk individuals (ACPA+ and ACPA-), and healthy controls were recruited at "Unidad de Artritis y Rheumatismo" (Rheumatism and Arthritis Unit) in Guadalajara Jalisco Mexico. Determinations of ACPA were made with Eurodiagnostica ACPA plus kit. Anti-CarP determinations were made according to previously described protocols. RNA was isolated, and purity and integrity were determined according to RNA integrity number >6. Gene expression analysis was made by RT-qPCR using specific primers for mRNAs of the type I IFN signature. Relative gene expression was calculated according to Livak and Schmitgen. RESULTS: Significant differences in gene expression were identified when comparing the different groups for MXA and MXB (P < 0.05), also when comparing established RA and ACPA- in both IFIT 1 and G15. An increased expression of ISG15 was identified (P < 0.05), and a clear tendency toward increase was identified for HERC5. EPSTRI1, IFI6, and IFI35 were found to be elevated in the chronic/established RA and early RA (P < 0.05). Significant correlations were identified for the IFN signature genes with the levels of ACPA and anti-CarP (P < 0.05). CONCLUSION: Our data confirm previous observations in the role of IFN signature and the pathogenesis of RA. Also, we provide evidence of an association between several genes of the IFN signature (that regulate Th2 cells and B cell proliferation) with the levels of anti-CarP antibodies and ACPA.
RESUMO
In order to identify the genetic characteristics of the strains of mycobacteria circulating in the Estado de México, one of the states with the lowest prevalence of tuberculosis in Mexico, spoligotyping and 12-loci MIRU-VNTR typing were used to genotype tuberculosis clinical isolates. The average age of the 183 patients analyzed was 50 (± 17) years, drug resistance was noted in 57 (31%) and multidrug resistance in 22 (12%) individuals. The results from the isolates recovered showed that 80% were located in four major Euro-American lineages: Haarlem (17%), LAM (15%), T (20%) and X (29%). Other lineages found in lower proportions were: EAI, S, Beijing, West African, Turkey, Vole and Bovis. Eighteen isolates were orphans. Only 57 isolates were grouped in nine clusters and the SIT119 (X1) showed the highest number of members (23). The LAM lineage showed an increased risk for development of drug resistance (RR=4, IC: 95%: 1.05-14.2, p = 0.03). Despite the important prevalence of four major lineages found and the diversity of strains circulating in the population, we found the presence of one of the largest populations of isolates clustered to the X lineage in a setting from a Latin American country.
Assuntos
Mycobacterium bovis/genética , Mycobacterium tuberculosis/genética , Tuberculose Pulmonar/epidemiologia , Tuberculose Pulmonar/microbiologia , DNA Bacteriano/genética , Farmacorresistência Bacteriana Múltipla , Feminino , Variação Genética , Humanos , Masculino , México/epidemiologia , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Tipagem Molecular , Mycobacterium bovis/classificação , Mycobacterium bovis/isolamento & purificação , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/isolamento & purificação , PrevalênciaRESUMO
BACKGROUND AND AIMS: Type 2 diabetes mellitus (DM2) confers a higher risk for active tuberculosis (TB). However, information on associated risk factors for latent tuberculosis infection (LTBI) inpatients with DM2 is limited. We conducted a cross-sectional study to elucidate the prevalence of LTBI and its associated factors on Mexican adults with DM2 receiving medical care at the Mexican Social Security Institute (IMSS). METHODS: Six hundred patients with DM2 without a prior history of TB from outpatient diabetes clinics were enrolled in the study. The tuberculin-skin-test (TST) was performed. The presence of LTBI was defined by a TST value of ≥ 5 mm. A standardized interview and physical examination were conducted to obtain clinical, demographic, and LTBI risk factor information; all subjects were laboratory tested to determine the presence of exclusion criteria. Microscopic examination of sputum samples and chest x-rays was performed to identify potential active TB. Subjects with any finding suggesting active TB or malignancy were excluded. A logistic regression model was used to identify variables associated with LTBI. RESULTS: LTBI prevalence among patients with DM2 was 51.3%. Risk factors for LTBI were living with a relative with TB, having been in prison, having hemoglobin values >14 g/dL, and glycosylated hemoglobin (HbA1c) values of > 7%. Blood pressure, economic income, or anthropometric measurements were not associated risk factors. CONCLUSIONS: Over one half of patients with DM harbor LTBI. Exposure to certain environmental conditions and poorly controlled DM2 (HbA1c > 7.0%) were risk factors for having LTBI in persons with DM2.
Assuntos
Diabetes Mellitus Tipo 2/epidemiologia , Tuberculose Latente/epidemiologia , Estudos Transversais , Feminino , Humanos , Tuberculose Latente/diagnóstico , Modelos Logísticos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Teste TuberculínicoRESUMO
Abstract INTRODUCTION: Biomarkers are critical tools for finding new approaches for controlling the spread of tuberculosis (TB), including for predicting the development of TB therapeutics, vaccines, and diagnostic tools. METHODS: Expression of immune biomarkers was analyzed in peripheral blood cells stimulated and non-stimulated with M. tuberculosis antigens ESAT-6, CFP10 and TB7.7. in Warao indigenous individuals. These biomarkers may be able to differentiate TB states, such as active tuberculosis (ATB) cases and latent tuberculosis infection (LTBI) from non-infected controls (NIC). A real-time reverse transcription polymerase chain reaction (RT-qPCR) assay was performed on 100 blood samples under non-stimulation or direct ex vivo conditions (NS=50) and stimulation conditions (S=50). RESULTS: The findings are shown as the median and interquartile range (IQR) of relative gene expression levels of IFN-γ, CD14, MMP9, CCR5, CCL11, CXCL9/MIG, and uPAR/PLAUR immune biomarkers. MMP9 levels were significantly higher in the LTBI-NS and LTBI-S groups compared with the NIC-NS and NIC-S groups. However, CCR5 levels were significantly lower in the LTBI-S group compared with both NIC-NS and NIC-S groups. CCL11 levels were significantly lower in the LTBI-S group compared with the NIC-NS group. CONCLUSIONS: Preliminary findings showed that MMP9 immune biomarkers separated LTBI indigenous individuals from NIC indigenous individuals, while CCR5, CCL11, CD14, and IFN-γ did not differentiate TB states from NIC. MMP9 may be useful as a potential biomarker for LTBI and new infected case detection among Warao indigenous individuals at high risk of developing the disease. It may also be used to halt the epidemic, which will require further validation in larger studies.
Assuntos
Humanos , Masculino , Feminino , Adulto , Biomarcadores/sangue , Indígenas Norte-Americanos/estatística & dados numéricos , Tuberculose Latente/diagnóstico , Mycobacterium tuberculosis/imunologia , Ensaio de Imunoadsorção Enzimática , Estudos de Casos e Controles , Estudos Transversais , Tuberculose Latente/sangue , Reação em Cadeia da Polimerase em Tempo Real , MéxicoRESUMO
BACKGROUND: Although epidemiologic and socioeconomic criteria and biomedical risk factors indicate high-priority for tuberculosis (TB) control in Mexico, molecular epidemiology studies of the disease in the country are scarce. METHODS: Complete sociodemographic and clinical data were obtained from 248 of the 432 pulmonary TB (PTB) cases confirmed from 2006 to 2010 on the population under epidemiological surveillance in the state of San Luis Potosí, México. From most PTB cases with complete data Mycobacterium tuberculosis complex (MTC) isolates were recovered and their spoligotypes, lineages and families, geographic distribution and drug resistance determined. RESULTS: Pulmonary tuberculosis incidence ranged from 2.4 to 33.4 (cases per 100,000 inhabitants) in the six state sanitary jurisdictions that were grouped in regions of low (jurisdictions I-II-III), intermediate (jurisdictions IV-V) and high incidence (jurisdiction VI) with 6.2, 17.3 and 33.4 rates, respectively. Most patients were poor, 50-years-median-age males and housewives. Among the 237 MTC spoligotyped isolates, 232 corresponded to M. tuberculosis (104 spoligotypes in 24 clusters) and five to M. bovis. The predominant Euro-American lineage was distributed all over the state, the East-Asian lineage (Beijing family) in the capital city, the Indo-Oceanic (Manila family) in eastern localities, and M. bovis in rural localities. CONCLUSIONS: In San Luis Potosí TB affects mainly poor male adults and is caused by M. tuberculosis and to a minor extent by M. bovis. There is great genotypic diversity among M. tuberculosis strains, the Euro-American lineage being much more prevalent than the Indo-Oceanic and East-Asian lineages. The frequency of resistant strains is relatively low and not associated to any particular lineage.
Assuntos
Variação Genética , Mycobacterium tuberculosis/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antituberculosos/farmacologia , Feminino , Genes Bacterianos , Humanos , Masculino , México , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose Pulmonar/microbiologia , Adulto JovemRESUMO
Abstract INTRODUCTION: Interferon-γ (IFN-γ) plays a crucial role in resistance to mycobacterial diseases; accordingly, variants of the gene encoding this cytokine may be associated with elevated risk of contracting pulmonary tuberculosis (TB). METHODS: Blood samples were collected from 135 Warao indigenous individuals with newly diagnosed sputum culture-positive TB. Of these, 24 were diagnosed with active tuberculosis (ATB). The study comprised 111 participants, who were grouped as follows: 1) 14 tuberculin skin test (TST)-positive Warao indigenous individuals and 4 that were QuantiFERON-TB?Gold In-Tube (QFT-IT) test-positive, collectively comprising the latent TB infection group (LTBI), n = 18), and 2) healthy controls who were QFT-IT- and TST-negative, comprising the control group (CTRL, n = 93). Detection of the IFN γ gene (IFNG) +874A/T polymorphism was performed via PCR and quantification of IFNG expression via qPCR. RESULTS: Relative to indigenous and white Americans, ATB and CTRL groups had a higher frequency of the IFNG SNP (+874A): 23 (95.8%) and 108 (97.3%), respectively. Indigenous Warao individuals homozygous for the IFNG (+874) A allele exhibited 3.59-fold increased risk of developing TB (95% confidence interval, 2.60-4.96, p =0.0001). A decreased frequency of the AT genotype was observed in individuals with pulmonary TB (4.16%) and controls (0.90%). The frequency of the TT genotype was decreased among controls (1.80%); none of the patients with TB were found to have this genotype. The differences in IFNG expression between the groups, under unstimulated and stimulated conditions, were not statistically significant. CONCLUSIONS: Preliminary results demonstrate concordance between IFNG +874 A/A genotype and low expression of IFNG.
Assuntos
Humanos , Masculino , Feminino , Adulto , Polimorfismo Genético/genética , Tuberculose Pulmonar/diagnóstico , Indígenas Sul-Americanos/estatística & dados numéricos , Interferon gama/genética , Tuberculose Pulmonar/etnologia , Tuberculose Pulmonar/epidemiologia , Venezuela/epidemiologia , Teste Tuberculínico , Reação em Cadeia da Polimerase , Estudos Transversais , Interferon gama/metabolismo , Doenças Endêmicas , Genótipo , Pessoa de Meia-IdadeRESUMO
The characteristics of tuberculosis (TB) patients related to a chain of recent TB transmissions were investigated. Mycobacterium tuberculosis (MTB) isolates (120) were genotyped using the restriction fragment length polymorphism-IS6110 (R), spacer oligotyping (S) and mycobacterial interspersed repetitive units-variable number of tandem repeats (M) methods. The MTB isolates were clustered and the clusters were grouped according to the similarities of their genotypes. Spearman’s rank correlation coefficients between the groups of MTB isolates with similar genotypes and those patient characteristics indicating a risk for a pulmonary TB (PTB) chain transmission were ana- lysed. The isolates showing similar genotypes were distributed as follows: SMR (5%), SM (12.5%), SR (1.67%), MR (0%), S (46.67%), M (5%) and R (0%). The remaining 35 cases were orphans. SMR exhibited a significant correlation (p < 0.05) with visits to clinics, municipalities and comorbidities (primarily diabetes mellitus). S correlated with drug consumption and M with comorbidities. SMR is needed to identify a social network in metropolitan areas for PTB transmission and S and M are able to detect risk factors as secondary components of a transmission chain of TB.
Assuntos
Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Técnicas de Genotipagem/métodos , Mycobacterium tuberculosis/genética , Tuberculose Pulmonar/microbiologia , Tuberculose Pulmonar/transmissão , Cidades , Comorbidade , DNA Bacteriano/isolamento & purificação , Genótipo , Sequências Repetitivas Dispersas/genética , Testes de Sensibilidade Microbiana , México/epidemiologia , Epidemiologia Molecular/métodos , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/isolamento & purificação , Polimorfismo de Fragmento de Restrição/genética , Fatores de Risco , Fatores Sociológicos , Estatísticas não Paramétricas , Sequências de Repetição em Tandem/genética , Tuberculose Pulmonar/epidemiologia , Tuberculose Pulmonar/genética , População UrbanaRESUMO
Tuberculosis (TB) is an infectocontagious respiratory disease caused by members of the Mycobacterium tuberculosis complex. A 7 base pair (bp) deletion in the locus polyketide synthase (pks)15/1 is described as polymorphic among members of the M. tuberculosis complex, enabling the identification of Euro-American, Indo-Oceanic and Asian lineages. The aim of this study was to characterise this locus in TB isolates from Mexico. One hundred twenty clinical isolates were recovered from the states of Veracruz and Estado de Mexico. We determined the nucleotide sequence of a ± 400 bp fragment of the locus pks15/1, while genotypic characterisation was performed by spoligotyping. One hundred and fifty isolates contained the 7 bp deletion, while five had the wild type locus. Lineages X (22%), LAM (18%) and T (17%) were the most frequent; only three (2%) of the isolates were identified as Beijing and two (1%) EAI-Manila. The wild type pks15/1 locus was observed in all Asian lineage isolates tested. Our results confirm the utility of locus pks15/1 as a molecular marker for identifying Asian lineages of the M. tuberculosis complex. This marker could be of great value in the epidemiological surveillance of TB, especially in countries like Mexico, where the prevalence of such lineages is unknown.