Genetic diversity of drug and multidrug-resistant Mycobacterium tuberculosis circulating in Veracruz, Mexico

Genetic Diversity of Mycobacterium tuberculosis Strains Isolated from HIV-Infected Patients in Mexico

There has been very limited investigation regarding the genetic diversity of Mycobacterium tuberculosis (MTb) strains isolated from human immunodeficiency virus (HIV)-infected patients in Mexico. In this study, we isolated 93 MTb strains from pulmonary and extrapulmonary samples of HIV-infected patients treated in a public hospital in Mexico City to evaluate the genetic diversity using spoligotyping and mycobacterial interspersed repetitive unit-variable-number tandem-repeat (MIRU-VNTR) typing (based on 24 loci). The cohort comprised 80 male and 13 female individuals. There was a positive correlation between a high HIV viral load (>100,000 copies) and extrapulmonary tuberculosis (TB) (r = 0.306, p = 0.008). Lineage 4 was the most frequent lineage (79 strains). In this lineage, we found the H clade (n = 24), including the Haarlem, H3, and H1 families; the T clade (n = 22), including T1 and T2; the X clade (n = 15), including X1 and X3; the LAM clade (n = 14), including LAM1, LAM2, LAM3, LAM6, and LAM9; the S clade (n = 2); Uganda (n = 1); and Ghana (n = 1). We also found 12 strains in the EAI clade belonging to lineage 1, including the EAI2-Manila and EAI5 families. Interestingly, we identified one strain belonging to the Beijing family, which is part of lineage 2. One strain could not be identified. This study reports high genetic diversity among MTb strains, highlighting the need for a molecular epidemiological surveillance system that can help to monitor the spread of these strains, leading to more appropriate measures for TB control in HIV-infected patients.

Phenotypic and Genotypic Drug Resistance of Mycobacterium tuberculosis Strains Isolated from HIV-Infected Patients from a Third-Level Public Hospital in Mexico

BACKGROUND

Drug-resistant tuberculosis (TB) is associated with higher mortality rates in patients with human immunodeficiency virus (HIV). In Mexico, the number of deaths due to TB among the HIV-positive population has tripled in recent years.

METHODS

Ninety-three Mycobacterium tuberculosis strains isolated from the same number of HIV-infected patients treated in a public hospital in Mexico City were studied to determine the drug resistance to first- and second-line anti-TB drugs and to identify the mutations associated with the resistance.

RESULTS

Of the 93 patients, 82.7% were new TB cases, 86% were male, and 73% had extrapulmonary TB. Most patients (94%) with a CD4 T-lymphocyte count <350 cells/mm3 were associated with extrapulmonary TB (p <0.0001), whilst most patients (78%) with a CD4 T-lymphocyte count >350 cells/mm3 were associated with pulmonary TB (p = 0.0011). Eighty-two strains were pan-susceptible, four mono-resistant, four poly-resistant, two multidrug-resistant, and one was extensively drug-resistant. In the rifampicin-resistant strains, rpoB S531L was the mutation most frequently identified, whereas the inhA C15T and katG S315T1 mutations were present in isoniazid-resistant strains. The extensively drug-resistant strain also contained the mutation gyrA D94A.

CONCLUSIONS

These data highlight the need to promptly diagnose the drug resistance of M. tuberculosis among all HIV-infected patients by systematically offering access to first- and second-line drug susceptibility testing and to tailor the treatment regimen based on the resistance patterns to reduce the number of deaths in HIV-infected patients.

Comparative genomics of drug-resistant strains of Mycobacterium tuberculosis in Ecuador

BACKGROUND

Tuberculosis is a serious infectious disease affecting millions of people. In spite of efforts to reduce the disease, increasing antibiotic resistance has contributed to persist in the top 10 causes of death worldwide. In fact, the increased cases of multi (MDR) and extreme drug resistance (XDR) worldwide remains the main challenge for tuberculosis control. Whole genome sequencing is a powerful tool for predicting drug resistance-related variants, studying lineages, tracking transmission, and defining outbreaks. This study presents the identification and characterization of resistant clinical isolates of Mycobacterium tuberculosis including a phylogenetic and molecular resistance profile study by sequencing the complete genome of 24 strains from different provinces of Ecuador.

RESULTS

Genomic sequencing was used to identify the variants causing resistance. A total of 15/21 isolates were identified as MDR, 4/21 as pre-XDR and 2/21 as XDR, with three isolates discarded due to low quality; the main sub-lineage was LAM (61.9%) and Haarlem (19%) but clades X, T and S were identified. Of the six pre-XDR and XDR strains, it is noteworthy that five come from females; four come from the LAM sub-lineage and two correspond to the X-class sub-lineage. A core genome of 3,750 genes, distributed in 295 subsystems, was determined. Among these, 64 proteins related to virulence and implicated in the pathogenicity of M. tuberculosis and 66 possible pharmacological targets stand out. Most variants result in nonsynonymous amino acid changes and the most frequent genotypes were identified as conferring resistance to rifampicin, isoniazid, ethambutol, para-aminosalicylic acid and streptomycin. However, an increase in the resistance to fluoroquinolones was detected.

CONCLUSION

This work shows for the first time the variability of circulating resistant strains between men and women in Ecuador, highlighting the usefulness of genomic sequencing for the identification of emerging resistance. In this regard, we found an increase in fluoroquinolone resistance. Further sampling effort is needed to determine the total variability and associations with the metadata obtained to generate better health policies.

Whole genome characterization, and geographical distribution of M. tuberculosis in central region of Veracruz, Mexico

The purpose of this work was to perform by Whole Genomic Sequencing (WGS) a characterization of tuberculosis isolates circulating in the central region of Veracruz, Mexico, and to determine its geographical distribution. The genome of 25 clinical isolates of tuberculosis patients, recovered from central zone of Veracruz, Mexico, were sequenced and the information obtained was used to characterize lineage, prediction of drug resistance, identification of clonal complexes, and finally correlated with the geolocalization data. Isolates analyzed were included into seven L4 sublineages, most frequent was X3; X1 (4.1.1.3) in 35%. rpoBSer450Leu polymorphism was the most frequently found variant. Sublineage Haarlem (4.1.2) had the widest distribution, found in five municipalities. Of the of two clonal complexes found, the most abundant included eight isolates, with X3/X1 lineage, placed in two municipalities. Combination of WGS and geographic information system was very useful for the identification of sublineages, clonal complexes, and their geographical dispersion with important implications in the epidemiological surveillance and clinical control of TB.

Genetic diversity and drug susceptibility of Mycobacterium tuberculosis in a city with a high prevalence of drug resistant tuberculosis from Southeast of Mexico

Background

Mexico is on the top five countries with the highest number of TB cases in America continent, nevertheless, information about genotypes circulating is practically unknown. Considering the above this study aims to characterize the genetic diversity of TB in the city of Veracruz, México.

Methods

A cross-sectional study was conducted among positive smear samples from patients living in Veracruz City, samples were cultured, and first-line drug profiles determined. Genotyping was made by spoligotyping and MIRU-VNTR 24 loci. Associations of lineages, clusters, and variables were also analyzed.

Results

Among the 202 isolates analyzed resistance to at least one drug was observed in 60 (30%) isolates and 41(20%) were multidrug-resistant. Three major lineages were identified: L4/Euro-American (88%), L1/Indo-Oceanic (9%), and L2/East Asian (3%). The Euro-American lineage included more than six sublineages, the most abundant were: H (32%), T (23%), LAM (18%), and X (12%). 140 isolates (70%) were placed in 42 SITs patterns.

Conclusions

These results provide the first baseline data on the genetic structure of TB in the city of Veracruz. Sublineages H, X and LAM were predominant; however, it was founded an important diversity of genotypes that could contribute to the dispersion of TB and explain the high prevalence. This information might be useful for the development of further interventions to reduce impact of TB.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06904-z.

Characterization of genetic diversity and clonal complexes by whole genome sequencing of Mycobacterium tuberculosis isolates from Jalisco, Mexico

Whole genome sequencing (WGS) analysis in tuberculosis allows the prediction of drug-resistant phenotypes, identification of lineages, and to better understanding of the epidemiology and transmission chains. Nevertheless the procedure has been scarcely assessed in Mexico, in this work we analyze by WGS isolates of Mycobacterium tuberculosis circulating in Jalisco, Mexico. Lineage and phylogenetic characterization, drug resistant prediction, "in silico" spoligotyping determination, were provided by WGS in 32 M. tuberculosis clinical isolates. Lineage 4 (L4), with 28 isolates (87%) and eleven sublineages was dominant. Forty SNPs and INDELs were found in genes related to first-, and second-line drugs. Eleven isolates were sensitive, seven (22%) were predicted to be resistant to isoniazid, two resistant to rifampicin (6%) and two (6%) were multidrug-resistant tuberuclosis. Spoligotyping shows that SIT 53 (19%) and SIT 119 (16%) were dominant. Four clonal transmission complexes were found. This is the first molecular epidemiological description of TB isolates circulating in western Mexico, achieved through WGS. L4 was dominant and included a high diversity of sublineages. It was possible to track the transmission route of two clonal complexes. The WGS demonstrated to be of great utility and with further implications for clinical and epidemiological study of TB in the region.

Whole genomic sequencing based genotyping reveals a specific X3 sublineage restricted to Mexico and related with multidrug resistance

Whole genome sequencing (WGS) has been shown to be superior to traditional procedures of genotyping in tuberculosis (TB), nevertheless, reports of its use in drug resistant TB (DR-TB) isolates circulating in Mexico, are practically unknown. Considering the above the main of this work was to identify and characterize the lineages and genomic transmission clusters present in 67 DR-TB isolates circulating in southeastern Mexico. The results show the presence of three major lineages: L1 (3%), L2 (3%) and L4 (94%), the last one included 16 sublineages. Sublineage 4.1.1.3 (X3) was predominant in 18 (27%) of the isolates, including one genomic cluster, formed by eleven multidrug resistant isolates and sharing the SIT 3278, which seems to be restricted to Mexico. By the use of WGS, it was possible to identify the high prevalence of L4 and a high number of sublineages circulating in the region, also was recognized the presence of a novel X3 sublineage, formed exclusively by multidrug resistant isolates and with restrictive circulation in Mexico for at least the past 17 years.

Population structure and genetic diversity of Mycobacterium tuberculosis in Ecuador

Tuberculosis (TB) is a significant public health problem in Ecuador with an incidence of 43 per 100,000 inhabitants and an estimated multidrug-resistant-TB prevalence in all TB cases of 9%. Genotyping of Mycobacterium tuberculosis (MTBC) is important to understand regional transmission dynamics. This study aims to describe the main MTBC lineages and sublineages circulating in the country. A representative sample of 373 MTBC strains from 22 provinces of Ecuador, with data comprising geographic origin and drug susceptibility, were genotyped using 24 loci-MIRU-VNTR. For strains with an ambiguous sublineage designation, the lineage was confirmed by Regions of Difference analysis or by Whole Genome Sequencing. We show that lineage 4 is predominant in Ecuador (98.3% of the strains). Only 4 strains belong to lineages 2-sublineage Beijing and two strains to lineage 3-sublineage Delhi. Lineage 4 strains included sublineages LAM (45.7%), Haarlem (31.8%), S (13.1%), X (4.6%), Ghana (0.6%) and NEW (0.3%). The LAM sublineage showed the strongest association with antibiotic resistance. The X and S sublineages were found predominantly in the Coastal and the Andean regions respectively and the reason for the high prevalence of these strains in Ecuador should be addressed in future studies. Our database constitutes a tool for MIRU-VNTR pattern comparison of M. tuberculosis isolates for national and international epidemiologic studies and phylogenetic purposes.

Characterization of Polymorphisms Associated with Multidrug-Resistant Tuberculosis by Whole Genomic Sequencing: A Preliminary Report from Mexico

Whole genome sequencing (WGS) has been proposed as a tool for the diagnosis of drug resistance in tuberculosis (TB); however, there have been few studies on its effectiveness in countries with significantly high drug resistance rates. This study therefore aimed to evaluate the effectiveness of WGS to identify mutations related to drug resistance in TB isolates from an endemic region of Mexico. The results showed that, of 35 multidrug-resistant isolates analyzed, the values of congruence found between the phenotypic drug susceptibility testing and polymorphisms were 94% for isoniazid, 97% for rifampicin, 90% for ethambutol, and 82% for pyrazinamide. It was also possible to identify eight isolates as potential pre-extensive drug resistant (XDR) and one as XDR. Twenty nine isolates were classified within L4 and two transmission clusters were identified. The results show the potential utility of WGS for predicting resistance against first- and second-line drugs, as well as providing a phylogenetic characterization of TB drug-resistant isolates circulating in Mexico.

Usefulness of 3'- 5' IS6110-RFLP genotyping and spoligotyping of Mycobacterium tuberculosis isolated in a tertiary hospital: a retrospective study detecting unsuspected epidemiological events

A drug resistance survey involving Mycobacterium tuberculosis isolated from patients of a tertiary Hospital in the Rio de Janeiro city (RJ), Brazil, between the years 1996 and 1998 revealed a high frequency of isoniazid (H^R) resistance. These isolates were revisited and genotyped. Patients came from different RJ neighborhoods and municipalities, and 70% were outpatients. Applying the 3’ and 5’ IS 6110 -RFLP and the Spoligotype genotyping methods, the clonal structure of this population was investigated obtaining a snapshot of past epidemiological events. The 3’ clusters were subsequently 5’ IS 6110 -RFLP typed. Spoligotyping was analyzed in the SITVIT2 database. Epidemiological relationships were investigated. The major lineage was T (54.4%), and SIT 53/T1 and SIT 535/T1 were the most frequent. The T1 sublineage comprises 12.8% of resistant strains and SIT 535 were assigned for 31.8% of them. Orphan patterns corresponded to 12% and 73.3% and belonged to the T lineage. One pattern was unlisted in the SITVIT2. The 5’ IS 6110 -RFLP did not confirm 3/12 of the 3’ IS 6110 -RFLP clusters. A combination of all methods decreased the number of clusters to three. Nosocomial transmission was associated with one cluster involving a hospital cupbearer. This event was suspected in a multidrug resistant-TB inpatient caregiver who harbored a mixed infection. The 3’ IS 6110 clusters were associated with H^R (p=0.046). These genotypic retrospective data may reflect a fraction of more extensive recent transmission in different communities that may be corroborated by the concentration of H^R patients, and may serve as a database for further evolutionary and characterization evaluation of circulating strains and together with epidemiological data favors a more effective transmission control.

Whole genomic sequencing as a tool for diagnosis of drug and multidrug-resistance tuberculosis in an endemic region in Mexico

Background

Whole genome sequencing (WGS) has been proposed as a tool for diagnosing drug resistance in tuberculosis. However, reports of its effectiveness in endemic countries with important numbers of drug resistance are scarce. The goal of this study was to evaluate the effectiveness of this procedure in isolates from a tuberculosis endemic region in Mexico.

Methods

WGS analysis was performed in 81 tuberculosis positive clinical isolates with a known phenotypic profile of resistance against first-line drugs (isoniazid, rifampin, ethambutol, pyrazinamide and streptomycin). Mutations related to drug resistance were identified for each isolate; drug resistant genotypes were predicted and compared with the phenotypic profile. Genotypes and transmission clusters based on genetic distances were also characterized.

Findings

Prediction by WGS analysis of resistance against isoniazid, rifampicin, ethambutol, pyrazinamide and streptomycin showed sensitivity values of 84%, 96%, 71%, 75% and 29%, while specificity values were 100%, 94%, 90%, 90% and 98%, respectively. Prediction of multidrug resistance showed a sensitivity of 89% and specificity of 97%. Moreover, WGS analysis revealed polymorphisms related to second-line drug resistance, enabling classification of eight and two clinical isolates as pre- and extreme drug-resistant cases, respectively. Lastly, four lineages were identified in the population (L1, L2, L3 and L4). The most frequent of these was L4, which included 90% (77) of the isolates. Six transmission clusters were identified; the most frequent was TC6, which included 13 isolates with a L4.1.1 and a predominantly multidrug-resistant condition.

Conclusions

The results illustrate the utility of WGS for establishing the potential for prediction of resistance against first and second line drugs in isolates of tuberculosis from the region. They also demonstrate the feasibility of this procedure for use as a tool to support the epidemiological surveillance of drug- and multidrug-resistant tuberculosis.

rpoB, katG and inhA mutations in multi-drug resistant strains of Mycobacterium tuberculosis clinical isolates from southeast Mexico

INTRODUCTION

Previous knowledge of molecular mechanisms related with multi-drug resistances in tuberculosis is important if molecular diagnostic procedures want to be used in specific geographical regions. For that reason, the aim of this study was to investigate the mutations at rpoB, katG and inhA in multi-drug resistant tuberculosis isolates from Southeast Mexico.

METHODS

Isolates of tuberculosis with a confirmed resistance against rifampicin and isoniazid were collected and sequencing analysis was performed of the rpoB rifampicin resistance-determining region, the katG and the encoding region of inhA.

RESULT

Of 74 isolates with multidrug resistance, 34 (46%) presented six mutations in katG; the most abundant was katG315 in 29 (39%) isolates. At inhA, nine (11%) isolates presented three mutations; the most frequent was inhA21, located in five (6%) strains. Eleven polymorphisms were observed at rpoB in 61 (82%) isolates, prevailing rpoB531 and rpoB 526 in 48 (64%) and ten (12%) isolates, respectively. Eleven double combinations were observed in 39 (52%) isolates, the most common of which was rpoB531+katG315, found in 22 (29%) strains.

CONCLUSION

This study provides valuable information on the diversity of polymorphisms in genes related to multidrug-resistant tuberculosis, as well as the presence of new mutations not previously described; this information should be considered in the implementation of molecular diagnostic tests.