Prevalence and molecular characterization of multidrug-resistant M. tuberculosis in Jiangxi province, China

Transmission of multidrug-resistant tuberculosis in Jiangxi, China, and associated risk factors

In order to effectively combat the urgent threat of multidrug-resistant tuberculosis (MDR-TB), it is imperative to gain a comprehensive understanding of the drug-resistant profiles, transmission dynamics, and associated risk factors. Our study encompassed a population-based retrospective analysis with 130 MDR-TB patients from 2018 to 2021. The research methodology incorporated whole-genome sequencing, drug susceptibility testing , and logistic regression analysis to discern the risk factors of genomic clustering linked to recent transmission. The findings from phenotypic drug resistance assessments revealed notable resistance rates: ethambutol at 62.3% (81/130), streptomycin at 72.3% (94/130), levofloxacin at 51.5% (67/130), and moxifloxacin at 50.0% (65/130). Furthermore, among all patients, 38 individuals (29.23%, 38/130) were found to be part of 17 clusters, indicating instances of recent MDR-TB transmission. The genomic clustering patients were deeply investigated. Lineage 2.2.1 was established as the primary sub-lineage (86.15%, 112/130), followed by lineage 4 (9.23%, 12/130). Moreover, the logistic regression analysis underscored that unemployment, farming occupations, and prior TB treatment were identified as significant risk factors for recent transmission.

IMPORTANCE

The high prevalence of multidrug-resistant tuberculosis (MDR-TB) in Jiangxi Province highlights the importance of understanding the genetic background and drug resistance patterns of these strains. This knowledge is crucial for developing effective control methods. Furthermore, in light of the significance of preventing transmission among tuberculosis patients, whole-genome sequencing was utilized to investigate the recent transmission of MDR-TB and identify associated risk factors. The findings revealed that individuals in the farming sector, those who are unemployed, and patients with a history of tuberculosis treatment are at elevated risk. Consequently, targeted public interventions for these at-risk groups are imperative.

Extensively and multidrug-resistant bacterial strains: case studies of antibiotics resistance

The development of antibiotic resistance compromises the effectiveness of our most effective defenses against bacterial infections, presenting a threat to global health. To date, a large number of research articles exist in the literature describing the case reports associated with extensively drug-resistant (XDR) and multidrug-resistant (MDR) bacterial strains. However, these findings are scattered, making it time-consuming for researchers to locate promising results and there remains a need for a comparative study to compile these case reports from various geographical regions including the Kingdom of Saudi Arabia. Additionally, no study has yet been published that compares the genetic variations and case reports of MDR and XDR strains identified from Saudi Arabia, the Middle East, Central Europe, and Asian countries. This study attempts to provide a comparative analysis of several MDR and XDR case reports from Saudi Arabia alongside other countries. Furthermore, the purpose of this work is to demonstrate the genetic variations in the genes underlying the resistance mechanisms seen in MDR and XDR bacterial strains that have been reported in Saudi Arabia and other countries. To cover the gap, this comprehensive review explores the complex trends in antibiotic resistance and the growing risk posed by superbugs. We provide context on the concerning spread of drug-resistant bacteria by analyzing the fundamental mechanisms of antibiotic resistance and looking into individual case reports. In this article, we compiled various cases and stories associated with XDR and MDR strains from Saudi Arabia and various other countries including China, Egypt, India, Poland, Pakistan, and Taiwan. This review will serve as basis for highlighting the growing threat of MDR, XDR bacterial strains in Saudi Arabia, and poses the urgent need for national action plans, stewardship programs, preventive measures, and novel antibiotics research in the Kingdom.

RpoB Gene Mutation Characteristics of Rifampicin-resistant Tuberculosis in Anqing, China

Background: Rifampicin resistant tuberculosis is a serious problem faced by tuberculosis control in China, and rapid detection of rifampicin resistance is urgently needed. Objectives: This study aimed to describe the molecular characteristics and frequency of RNA polymerase β subunit (rpoB) gene mutations in rifampicin-resistant tuberculosis (RR-TB) in the Anqing area. Methods: The rpoB gene fragment was amplified by polymerase chain reaction (PCR), and all isolates were sequenced for mutations in the rpoB gene. The mutations were obtained by comparing the sequencing results with the MUBII database. In addition, logistic regression was used to analyze the relationship between rpoB mutations and rifampicin (RIF) resistance. Results: There were 152 males and 42 females in this study, and the mean age was 56.60 ± 17.91 years. Mutations in the rpoB gene were a risk factor for rifampicin resistance (β = 5.271, P < 0.001 OR = 195.192). Among the 19 RR-TB strains, 16 (84.21%) had mutations in the ropB gene, and three (1.71%) of 175 rifampicin-sensitive strains were mutated. The mutation sites of five strains (31.58%) were at the codon 526 and five strains (31.58%) at the codon 531. However, there were two strains at the codon 513 and two strains at the codon 533 (15.79%), and two strains (10.53%) were double mutations. Conclusions: The mutation characteristics of the rpoB gene in the Anqing area are complex, and rpoB mutation detection can be used as an indicator to screen drug resistance of RIF.

Comparison on Major Gene Mutations Related to Rifampicin and Isoniazid Resistance between Beijing and Non-Beijing Strains of Mycobacterium tuberculosis: A Systematic Review and Bayesian Meta-Analysis

Objective: The Beijing strain of Mycobacterium tuberculosis (MTB) is controversially presented as the predominant genotype and is more drug resistant to rifampicin and isoniazid compared to the non-Beijing strain. We aimed to compare the major gene mutations related to rifampicin and isoniazid drug resistance between Beijing and non-Beijing genotypes, and to extract the best evidence using the evidence-based methods for improving the service of TB control programs based on genetics of MTB. Method: Literature was searched in Google Scholar, PubMed and CNKI Database. Data analysis was conducted in R software. The conventional and Bayesian random-effects models were employed for meta-analysis, combining the examinations of publication bias and sensitivity. Results: Of the 8785 strains in the pooled studies, 5225 were identified as Beijing strains and 3560 as non-Beijing strains. The maximum and minimum strain sizes were 876 and 55, respectively. The mutations prevalence of rpoB, katG, inhA and oxyR-ahpC in Beijing strains was 52.40% (2738/5225), 57.88% (2781/4805), 12.75% (454/3562) and 6.26% (108/1724), respectively, and that in non-Beijing strains was 26.12% (930/3560), 28.65% (834/2911), 10.67% (157/1472) and 7.21% (33/458), separately. The pooled posterior value of OR for the mutations of rpoB was 2.72 ((95% confidence interval (CI): 1.90, 3.94) times higher in Beijing than in non-Beijing strains. That value for katG was 3.22 (95% CI: 2.12, 4.90) times. The estimate for inhA was 1.41 (95% CI: 0.97, 2.08) times higher in the non-Beijing than in Beijing strains. That for oxyR-ahpC was 1.46 (95% CI: 0.87, 2.48) times. The principal patterns of the variants for the mutations of the four genes were rpoB S531L, katG S315T, inhA-15C > T and oxyR-ahpC intergenic region. Conclusion: The mutations in rpoB and katG genes in Beijing are significantly more common than that in non-Beijing strains of MTB. We do not have sufficient evidence to support that the prevalence of mutations of inhA and oxyR-ahpC is higher in non-Beijing than in Beijing strains, which provides a reference basis for clinical medication selection.

Recent Transmission and Prevalent Characterization of the Beijing Family Mycobacterium tuberculosis in Jiangxi, China

The Beijing genotype is the most common type of tuberculosis in Jiangxi Province, China. The association of population characteristics and their prevalence in the development of recent transmission is still unclear. 1,433 isolates were subjected to drug-resistant tests and MIRU-VNTR analysis. We compared differences in demographic characteristics and drug resistance patterns between the Beijing and non-Beijing family strains. We also explored the association of the clustering rate with the Beijing genotype of Mycobacterium tuberculosis. The Beijing genotype was dominant (78.16%). The results of MIRU-VNTR showed that 775 of 1,433 strains have unique patterns, and the remaining gather into 103 clusters. A recent transmission rate was 31.54% (452/1,433). The Beijing genotype strains were more likely to spread among the recurrent population (p = 0.004), people less than 50 years of age (p = 0.02 or 0.003), and the personnel in the northern regions (p = 0.03). Drug resistance patterns did not show significant differences between Beijing and non-Beijing genotype isolates. Furthermore, we found that HIV-positive cases had a lower clustering rate (p = 0.001). Our results indicated that the recurrent population and people under 50 years of age were more likely to be infected with the Beijing genotype of M. tuberculosis. The strains from the Beijing family were easier to cluster compared to strains isolated from the non-Beijing family. Social activity and AIDS substantially impacted the clustering rate of the Beijing genotype of M. tuberculosis. Multidrug resistant M. tuberculosis affected Beijing genotype transmission.

Transmission of multidrug-resistant tuberculosis within family households by DTM-PCR and MIRU-VNTR genotyping

Background

Drug-resistant tuberculosis (TB) continues to be a public health threat. There are few studies on transmission and genotyping of MDR-TB family households in China. This study aimed to investigate transmission of multidrug-resistant tuberculosis (MDR-TB) within family households by deletion-targeted multiplex polymerase chain reaction (DTM-PCR), mycobacterial interspersed repetitive unit variable number tandem repeats (MIRU-VNTR) genotyping.

Methods

Among 993 MDR-TB patients registered from Wuhan Institute for Tuberculosis Control, drug resistance and the time interval between the index patients and secondary patients were analyzed in 49 MDR-TB patients from 23 families, in which 22 MDR-TB strains from 11 families who had matched strains were genotyped by DTM-PCR and standard 24-loci MIRU-VNTR genotyping method.

Results

The time interval between the index patients and the secondary patients ranged from half a month to 110 months. Thirteen secondary patients developed active MDR-TB within two years and accounted for 50% (13/26) of all secondary patients. Among eleven pairs of MDR-TB families, six pairs had identical genotypes, the cluster rate was 54.5% (12/22); three pairs had a single MIRU-VNTR locus variation. If a single MIRU-VNTR locus variation was tolerated in the cluster definition, the cluster rate raised to 81.8% (18/22).

Conclusions

The family households of MDR-TB patients are at risk for infection of MDR-TB. To reduce transmission, MDR-TB patients should be diagnosed earlier and promptly treated in an effective manner, meanwhile, the close family contacts should be screened for TB infection.

Transmission of multidrug-resistant Mycobacterium tuberculosis in Wuhan, China: A retrospective molecular epidemiological study

How multidrug-resistant tuberculosis (MDR-TB) spreads and expands in Wuhan population is not clear. The study aimed to determine the transmission patterns of MDR-TB in Wuhan city, China, including 149 patients with MDR-TB.Tuberculosis isolates were genotyped by deletion-targeted multiplex polymerase chain reaction, mycobacterial interspersed repetitive unit-variable number tandem repeat typing, and sequencing of drug resistance-associated genes. The risk factors of genomic-clustering were analyzed with logistic regression. The genomic-clustering patients were deeply investigated.The analysis identified 111 unique and 11 clustered genotypes (38 isolates). The clustering rate was 25.50% and the minimum estimate proportion of recent transmission was 18.12%. Two clusters (5 isolates) shared the same mutation, the remain 9 clusters (33 isolates) had different mutation. Logistic regression showed that older than 60 years (adjusted OR 2.360, 95% CI:1.052-5.292) was an independent factor associated with the genomic-clustering of MDR-TB. Among the 38 genomic-clustering cases, 14 cases had epidemiological transmission links. The most common type of transmission link was social contact.The local transmission of MDR-TB in Wuhan was really an issue. The elderly population might be the high-risk groups for transmission of MDR-TB, and the community or public transportation might be the main transmission places.

Drug resistance characteristics of Mycobacterium tuberculosis isolates obtained between 2018 and 2020 in Sichuan, China

We investigated the drug resistance of Mycobacterium tuberculosis isolates from patients with tuberculosis (TB) and HIV, and those diagnosed with only TB in Sichuan, China. TB isolates were obtained from January 2018 to December 2020 and subjected to drug susceptibility testing (DST) to 11 anti-TB drugs and to GeneXpert MTB/RIF testing. The overall proportion of drug-resistant TB (DR-TB) isolates was 32.1% (n = 10 946). HIV testing was not universally available for outpatient TB cases, only 29.5% (3227/10 946) cases had HIV testing results. The observed proportion of multidrug-resistant TB (MDR-TB) isolates was almost double than that of the national level, with approximately 1.5% and 0.1% of the isolates being extensively drug resistant and universally drug resistant, respectively. The proportions of resistant isolates were generally higher in 2018 and 2019 than in 2020. Furthermore, the sensitivities of GeneXpert during 2018–2020 demonstrated a downward trend (80.9, 95% confidence intervals (CI) 76.8–85.0; 80.2, 95% CI 76.4–84.1 and 75.4, 95% CI 70.7–80.2, respectively). Approximately 69.0% (7557/10 946) of the TB cases with DST results were subjected to GeneXpert detection. Overall, the DR-TB status and the use of GeneXpert in Sichuan have improved, but DR-TB challenges remain. HIV testing for all TB cases is recommended.

The autophagy-resistant Mycobacterium tuberculosis Beijing strain upregulates KatG to evade starvation-induced autophagic restriction

Mycobacterium tuberculosis utilizes several mechanisms to block phagosome–lysosome fusion to evade host cell restriction. However, induction of host cell autophagy by starvation was shown to overcome this block, resulting in enhanced lysosomal delivery to mycobacterial phagosomes and the killing of the M. tuberculosis reference strain H37Rv. Nevertheless, our previous studies found that strains belonging to the M. tuberculosis Beijing genotype can resist starvation-induced autophagic elimination, though the mycobacterial factors involved remain unclear. In this study, we showed that KatG expression is upregulated in the autophagy-resistant M. tuberculosis Beijing strain (BJN) during autophagy induction by the starvation of host macrophages, while such increase was not observed in the H37Rv. KatG depletion using the CRISPR-dCas9 interference system in the BJN resulted in increased lysosomal delivery to its phagosome and decreased its survival upon autophagy induction by starvation. As KatG functions by catabolizing ROS, we determined the source of ROS contributing to the starvation-induced autophagic elimination of mycobacteria. Using siRNA-mediated knockdown, we found that Superoxide dismutase 2, which generates mitochondrial ROS but not NADPH oxidase 2, is important for the starvation-induced lysosomal delivery to mycobacterial phagosomes. Taken together, these findings showed that KatG is vital for the BJN to evade starvation-induced autophagic restriction.

Genetic Diversity and Transmission of Multidrug Resistant Mycobacterium tuberculosis strains in Lusaka, Zambia

OBJECTIVE

Zambia is among the 30 high tuberculosis burden countries in the world. Despite increasing reports of multidrug resistant tuberculosis (MDR-TB) in routine surveillance, information on the transmission of MDR Mycobacterium tuberculosis strains is largely unknown. This study elucidated genetic diversity and transmission of MDR M. tuberculosis strains in Lusaka, Zambia.

METHODS

Eighty-five MDR M. tuberculosis samples collected from the year 2013 to 2017 at the University Teaching Hospital were used. Drug-resistance associated gene sequencing, spoligotyping, 24-loci mycobacterial interspersed repetitive units-variable number of tandem repeats, and multiplex PCR for RD-Rio sub-lineage identification were applied.

RESULTS

Clades identified were LAM (48%), CAS (29%), T (14%), X (6%) and Harlem (2%). Strains belonging to SITs 21/CAS1-Kili and 20/LAM1 formed the largest clonal complexes. Combined spoligotyping and 24 loci-MIRU-VNTR revealed 47 genotypic patterns with clustering rate of 63%. Ninety five percent of LAM strains belonged to RD-Rio sub-lineage.

CONCLUSION

The high clustering rate suggested that a large proportion of MDR-TB was due to recent transmission rather than independent acquisition of MDR. This spread was attributed to clonal expansion of SIT21/CAS1-Kili and SIT20/LAM1 strains. Therefore, TB control programs recommending genotyping coupled with conventional epidemiological methods can guide measures for stopping the spread of MDR-TB.

Analysis of the application of a gene chip method for detecting Mycobacterium tuberculosis drug resistance in clinical specimens: a retrospective study

Most Mycobacterium tuberculosis (Mtb) resistant to rifampicin (RIF) has mutations in the rpoB gene, while most Mtb resistant to isoniazid (INH) has mutations in the katG gene or inhA promoter. We used gene chip technology to detect mutations in these genes to determine the resistance of Mtb to RIF and INH. A total of 4148 clinical specimens with sputum smear positivity for acid-fast bacilli (AFB) were detected. Then, taking the results of the drug sensitivity test (DST) as the reference standard, the detection efficiency of sputum samples from different grades of positive smears was compared in detail. We found that the sensitivity of the gene chip method for detecting sputum samples with a grade ≥ AFB 2 + was higher than that of sputum samples with a grade ≤ AFB 1 + (P < 0.05). When the grade of the sample was ≤ AFB 1 +, the sensitivity of the gene chip method was 72.6% for RIF, 67.3% for INH, and 60.0% for MDR-TB. When the grade of the sample was ≥ AFB 2 +, the sensitivity of the gene chip method was 84.5% for RIF, 78.2% for INH, and 73.9% for MDR-TB. The results show that gene chip technology can be directly used to diagnose drug-resistant tuberculosis in clinical specimens, and the diagnostic efficiency for the detection of sputum specimens with a grade ≥ AFB 2 + is better than that of other sputum specimens.

Prevalence and Molecular Characteristics Based on Whole Genome Sequencing of Mycobacterium tuberculosis Resistant to Four Anti-Tuberculosis Drugs from Southern Xinjiang, China

Objective

Drug-resistant tuberculosis is a major public health problem, especially in the southern region of Xinjiang, China; however, there is little information regarding drug resistance profiles and mechanism of Mycobacterium tuberculosis in this area. The aim of this study was to determine the prevalence and molecular characteristics of M. tuberculosis resistant to four anti-tuberculosis drugs from this area.

Methods

Three hundred and forty-six isolates from the southern region of Xinjiang, China were included and used to perform phenotypic drug susceptibility testing and whole genome sequencing (WGS). Mutations in seven loci associated with drug resistance, including rpoB for rifampicin (RMP), katG, inhA promoter and oxyR-ahpC for isoniazid (INH), rrs 530 and 912 loops and rpsL for streptomycin (STR), and embB for ethambutol (EMB), were characterized.

Results

Among 346 isolates, 106, 60, 70 and 29 were resistant to INH, RMP, STR and EMB, respectively; 132 were resistant to at least one of the four anti-tuberculosis drugs and 51 were multi-drug resistant (MDR). Beijing genotype and retreated patients showed a significantly increased risk for developing MDR tuberculosis. Compared with the phenotypic data, the sensitivity and specificity for WGS to predict resistance were 96.7% and 98.6% for RMP, 75.5% and 97.1% for INH, 68.6% and 99.6% for STR, 93.1% and 93.7% for EMB, respectively. The most common mutations conferring RMP, INH, STR and EMB resistance were Ser450Leu (51.7%) in rpoB, Ser315Thr (44.3%) in katG, Lys43Arg (35.7%) in rpsL and Met306Val (24.1%) in embB.

Conclusion

This study provides the first information on the prevalence and molecular characters of drug resistant M. tuberculosis in the southern region of Xinjiang, China, which will be helpful for choosing early detection methods for drug resistance (ig, molecular methods) and subsequently initiation of proper therapy of tuberculosis in this area.

Prevalence and molecular characteristics of drug-resistant Mycobacterium tuberculosis in Hainan, China: from 2014 to 2019

Background

The emergence of antimicrobial resistance against Mycobacterium tuberculosis (M. tuberculosis) has become the major concern in global tuberculosis control due to its limited therapy options and high mortality. However, the clinical and molecular characteristics of drug-resistant strains vary in different geographical areas. Hainan Island located in southern China, is a high drug-resistant tuberculosis burden area. This study aimed to determine the dynamic changes of drug-resistance patterns and drug-related gene mutation types of M. tuberculosis in Hainan from 2014 to 2019.

Results

A total of 1484 culture-confirmed M. tuberculosis were included in this study. It was found that the proportions of drug resistance to isoniazid and rifampin were 31.3 and 31.1% respectively. Overall the proportion of multidrug resistant M. tuberculosis was 24.9%. Multivariate logistic regression analysis showed that age and the treatment history were independent influencing factors of drug resistant tuberculosis. The proportions of drug-resistant tuberculosis in retreatment patients were considerably higher than those in new patients. The most common mutation types of isoniazid were Ser315 → Thr (66.3%), and the most common mutation types of rifampin were Ser531 → Leu (41.5%).

Conclusions

Our data suggests that the prevalence of drug resistant TB remains high in Hainan, and the risks for developing drug resistance with diversified mutation types increased significantly in retreatment patients. These results contribute to the knowledge of the prevalence of drug resistance in Hainan Province and expand the molecular characteristics of drug resistance in China simultaneously.

rpoB gene mutations in rifampin-resistant Mycobacterium tuberculosis isolates from rural areas of Zhejiang, China

Objective

The aim was to analyze genetic mutations in the rpoB gene of rifampin-resistant Mycobacterium tuberculosis isolates (RIF^R-MTB) from Zhejiang, China.

Methods

We prospectively analyzed RIF^R-associated mutations in 13 rural areas of Zhejiang. Isolates were subjected to species identification, phenotype drug susceptibility testing (DST), DNA extraction, and rpoB gene sequencing.

Results

A total of 103 RIF^R isolates were identified by DST (22 RIF^R only, 14 poly-drug resistant, 49 multidrug resistant, 13 pre-extensively drug resistant [pre-XDR], and 5 extensively drug resistant [XDR]) from 2152 culture-positive sputum specimens. Gene sequencing of rpoB showed that the most frequent mutation was S450L (37.86%, 39/103); mutations P280L, E521K, and D595Y were outside the rifampicin resistance-determining region (RRDR) but may be associated with RIF^R. Mutations associated with poly-drug resistant, pre-XDR, and XDR TB were mainly located at codon 445 or 450 in the RRDR.

Conclusions

The frequency of rpoB RRDR mutation in Zhejiang is high. Further studies are needed to clarify the relationships between RIF^R and the TTC insertion at codon 433 in the RRDR and the P280L and D595Y mutations outside the RRDR.

Drug-Resistant Mycobacterium tuberculosis Isolates from New and Previously Treated TB Patients in China, 2017-2019

INTRODUCTION

Mycobacterium tuberculosis (MTB) is a causative agent of tuberculosis (TB) that causes death worldwide.

METHODS

MTB was subjected to phenotypic drug-susceptibility tests (DST), and drug-resistant genes were sequenced.

RESULTS

Previously treated patients were more likely to have positive smear results and exhibit drug resistance. New patients were more likely to be mono SM-resistant and less likely to be INH- and RIF-resistant. The most common mutations were katG (S315T), rpoB (S450L), rpsL (K43R), and embB (M306V).

CONCLUSIONS

The proportion of mono-SM-resistant TB among new patients was higher.

Prevalence of Multidrug-Resistant Tuberculosis in Dalian, China: A Retrospective Study

Purpose

Multidrug-resistant tuberculosis (MDR-TB) is the cause of serious health and economic burdens worldwide. The present study aimed to explore the initial and acquired drug-resistance rates among TB patients from 2012 to 2019 in Dalian, China. The effectiveness of MDR-TB prevention and control strategies were then evaluated.

Patients and Methods

Drug susceptibility testing (DST) was performed for 6429 diagnosed, culture-positive, Mycobacterium tuberculosis (MTB) strains, including 4661 new cases and 1768 previously treated cases. Descriptive statistics were employed to calculate the frequencies and percentages of TB strains, and the average annual growth rates (AAGRs) for each strain were calculated. The Chi-square test was applied to examine the significance of linear drug-resistance trends over time during the study period.

Results

Over the eight-year study period, the percentages of both initial (from 9.01% to 4.82%) and acquired (from 40.85% to 9.09%) MDR-TB cases decreased significantly, AAGRs of 8.55% and 19.32%, respectively. Among new and previously treated TB patients, significant downtrends were observed for the rates of both initial and acquired MDR-TB among young and middle-aged individuals (P < 0.05). Additionally, among both new and previously treated TB patients, the percentages of individuals with drug resistance against isoniazid (INH), rifampicin (RFP), ofloxacin (OFX), and amikacin (AMK) decreased significantly (P < 0.05) from 2012 to 2019 in Dalian, China.

Conclusion

The initial and acquired multidrug resistance rates exhibited significantly decreasing trends from 2012 to 2019, suggesting that MDR-TB prevalence has been controlled effectively in Dalian, China. The MDR-TB epidemic was reversed in the short term by establishing feasible strategies for detection, diagnosis, treatment, and infection control.

Identification of a predominant genotype of Mycobacterium tuberculosis in Brazilian indigenous population

After nearly a century of vaccination and six decades of drug therapy, tuberculosis (TB) kills more people annually than any other infectious disease. Substantial challenges to disease eradication remain among vulnerable and underserved populations. The Guarani-Kaiowá people are an indigenous population in Paraguay and the Brazilian state of Mato Grosso do Sul. This community, marginalized in Brazilian society, experiences severe poverty. Like other South American indigenous populations, their TB prevalence is high, but the disease has remained largely unstudied in their communities. Herein, Mycobacterium tuberculosis isolates from local clinics were whole genome sequenced, and a population genetic framework was generated. Phylogenetics show M. tuberculosis isolates in the Guarani-Kaiowá people cluster away from selected reference strains, suggesting divergence. Most cluster in a single group, further characterized as M. tuberculosis sublineage 4.3.3. Closer analysis of SNPs showed numerous variants across the genome, including in drug resistance-associated genes, and with many unique changes fixed in each group. We report that local M. tuberculosis strains have acquired unique polymorphisms in the Guarani-Kaiowá people, and drug resistance characterization is urgently needed to inform public health to ensure proper care and avoid further evolution and spread of drug-resistant TB.

Molecular Analysis of Mycobacterium tuberculosis Isolated in the North Central Zone of Nigeria

Tuberculosis (TB) incidence in Nigeria is high, with a significant burden of TB/Human Immunodeficiency Virus (HIV). Genotyping and drug susceptibility of Mycobacterium tuberculosis Complex (MTBC) are important in order to improve the control of the disease. This study sought to determine drug susceptibility and genetic diversity of MTBC in the country. The sputum samples of 202 patients [133 (65.8%) males/69 (34.2%) females] were collected in the North Central zone of Nigeria and cultured using Lowenstein–Jensen medium. Immunochromatography for the primary identification and Drug Susceptibility Testing (DST) by proportion method, as well as IS6110 typing, regions of difference 1, 4, 9, 12, 702, and 711, and spoligotyping were carried out on the isolates. Following the DST on 202 isolates, 51 (25.2%) showed resistance to at least one drug. Multidrug resistance was observed in 29/202 (14.4%) cases. HIV positivity [37/202 (18.3%) patients] was associated with rifampicin 9/37 (24.3%) resistance (p = 0.012) as well as gender (p = 0.009). Of the 202 isolates, 150 (74.3%) were identified as the Cameroon sublineage, followed by the UgandaI, Haarlem, and West Africa 1 with 18 (8.9%), 10 (5%), and 6 (3%), respectively. The LAM10_CAM was the most prevalent genetic family [128/202 (63.4%)], with the shared international type 61 [111 (55%) isolates] the largest cluster. Gender (p = 0.038) and age (p = 0.015) had significant associations with the LAM10_CAM family but neither with HIV (p = 0.479) nor drug resistance. Rifampicin resistance in TB/HIV coinfected patient is a major concern in the study area. The Mycobacterium africanum lineage showed a marked decrease, and the need to educate females most at risk of TB/HIV coinfection is advocated.

Rapid and simultaneous determination of ten anti-tuberculosis drugs in human plasma by UPLC-MS/MS with applications in therapeutic drug monitoring

Tuberculosis remains a global challenge, particularly with a growing number of resistant cases, which may become an obstacle to eliminating this disease. Standardized short-course therapy composed of first-line anti-tuberculosis drugs isoniazid (INH), rifampicin (RIF), ethambutol (EMB), and pyrazinamide (PZA) is playing vital roles for curbing the rapid spread of tuberculosis. However, some patients have poor responses to standardized short-course therapy. As the number of drug-resistant tuberculosis increase, some other anti-tuberculous drugs are needed to achieve better treatment outcomes. In this study, we established a UPLC-MS/MS method for simultaneous detection of ten anti-tuberculosis drugs in human plasma including INH, EMB, PZA, RIF, rifampin, rifapentine as well as four second-line antituberculosis drugs, i.e. ethionamide, protionamide, thiosemicarbazone and clofazimine. This study contains almost all the commonly used anti-tuberculosis drugs. The plasma samples were treated with acetonitrile to precipitate proteins, and doped with the isotope internal standard. A Shiseido CAPCELL RAK-ADME (2.1 mm × 50 mm, 3 μm) column was used for chromatographic separation, and acetonitrile-water (containing 0.1% formic acid) was the mobile phase. The separation used gradient elution with a flow rate of 0.4 mL/min. The column temperature was 40 °C, and the sample volume was 1 μL. The electrospray ionization source (ESI) and the positive ion multiple reaction monitoring (MRM) mode were used for the detection. The analysis time was as short as 7 min. The results show a good linear relationship under optimized conditions in the range of 5.00-7.50 × 10³, 1.00-1.50 × 10³, 5.00-5.00 × 10⁴, 5.00-7.50 × 10³, 1.00-3.00 × 10³, 1.00 × 10¹-1.00 × 10⁴, 1.00-3.00 × 10³, 1.00-3.00 × 10³, 2.00-4.00 × 10³, and 1.00 × 10^-1-2.00 × 10² ng/mL for INH, EMB PZA, RIF, rifabutin, rifapentine, ethionamide, protionamide, thiosemicarbazone, and clofazimine, respectively, with a linear correlation coefficient of R > 0.99. Finally, 34 patients with pulmonary TB were tested for therapeutic drug monitoring. The results showed that the presented method have significant advances in sensitivity, separation efficiency and simplicity.

Genomic Analysis Identifies Mutations Concerning Drug-Resistance and Beijing Genotype in Multidrug-Resistant Mycobacterium tuberculosis Isolated From China

Development of modern genomics provides us an effective method to understand the molecular mechanism of drug resistance and diagnose drug-resistant Mycobacterium tuberculosis. In this study, mutations in 18 genes or intergenic regions acquired by whole-genome sequencing (WGS) of 183 clinical M. tuberculosis strains, including 137 multidrug-resistant and 46 pan-susceptible isolates from China, were identified and used to analyze their associations with resistance of isoniazid, rifampin, ethambutol, and streptomycin. Using the proportional method as the gold standard method, the accuracy values of WGS to predict resistance were calculated. The association between synonymous or lineage definition mutations with different genotypes were also analyzed. The results show that, compared to the phenotypic proportional method, the sensitivity and specificity of WGS for resistance detection were 94.2 and 100.0% for rifampicin (based on mutations in rpoB), 90.5 and 97.8% for isoniazid (katG), 83.0 and 97.8% for streptomycin (rpsL combined with rrs 530 loop and 912 loop), and 90.9 and 65.1% for ethambutol (embB), respectively. WGS data also showed that mutations in the inhA promoter increased only 2.2% sensitivity for INH based on mutations in katG. Synonymous mutation rpoB A1075A was confirmed to be associated with the Beijing genotype. This study confirmed that mutations in rpoB, katG, rrs 530 loop and 912 loop, and rpsL were excellent biomarkers for predicting rifampicin, isoniazid, and streptomycin resistance, respectively, and provided clues in clarifying the drug-resistance mechanism of M. tuberculosis isolates from China.

Accuracy of a reverse dot blot hybridization assay for simultaneous detection of the resistance of four anti-tuberculosis drugs in Mycobacterium tuberculosis isolated from China

Background

Drug resistant tuberculosis poses a great challenge for tuberculosis control worldwide. Timely determination of drug resistance and effective individual treatment are essential for blocking the transmission of drug resistant Mycobacterium tuberculosis. We aimed to establish and evaluate the accuracy of a reverse dot blot hybridization (RDBH) assay to simultaneously detect the resistance of four anti-tuberculosis drugs in M. tuberculosis isolated in China.

Methods

In this study, we applied a RDBH assay to simultaneously detect the resistance of rifampicin (RIF), isoniazid (INH), streptomycin (SM) and ethambutol (EMB) in 320 clinical M. tuberculosis isolates and compared the results to that from phenotypic drug susceptibility testing (DST) and sequencing. The RDBH assay was designed to test up to 42 samples at a time. Pearson’s chi-square test was used to compute the statistical measures of the RDBH assay using the phenotypic DST or sequencing as the gold standard method, and Kappa identity test was used to determine the consistency between the RDBH assay and the phenotypic DST or sequencing.

Results

The results showed that the concordances between phenotypic DST and RDBH assay were 95% for RIF, 92.8% for INH, 84.7% for SM, 77.2% for EMB and the concordances between sequencing and RDBH assay were 97.8% for RIF, 98.8% for INH, 99.1% for SM, 93.4% for EMB. Compared to the phenotypic DST results, the sensitivity and specificity of the RDBH assay for resistance detection were 92.4 and 98.5% for RIF, 90.3 and 97.3% for INH, 77.4 and 91.5% for SM, 61.4 and 85.7% for EMB, respectively; compared to sequencing, the sensitivity and specificity of the RDBH assay were 97.7 and 97.9% for RIF, 97.9 and 100.0% for INH, 97.8 and 100.0% for SM, 82.6 and 99.1% for EMB, respectively. The turnaround time of the RDBH assay was 7 h for testing 42 samples.

Conclusions

Our data suggested that the RDBH assay could serve as a rapid and efficient method for testing the resistance of M. tuberculosis against RIF, INH, SM and EMB, enabling early administration of appropriate treatment regimens to the affected drug resistant tuberculosis patients.

Distribution of Antibiotic Resistance Genes in Three Different Natural Water Bodies-A Lake, River and Sea

Currently, due to abuse in the use of human antibiotics and the weak regulatory control that the authorities have over sewage discharge and manure management, antibiotic resistance genes (ARGs) have become a new type of environmental pollutant. Three different natural water bodies (Poyang Lake, Haihe River and Qingdao No.1 Bathing Beach seawater) were sampled during the same periods to conduct a longitudinal comparison of distribution. The distribution and expression of 11 ARGs in 20 species were studied, and the correlations between the expression and the distribution of time and space of the ARGs in different water bodies were also analyzed. With the exception of ermA, blaNDM-1 and vanA, which were not detected in seawater, the other ARGs could be detected in all three water bodies. Tetracycline resistance genes (tetC, tetM and tetQ) in the seawater and Haihe River had even reached 100%, and sulfa ARGs (sul1 and sul2) in the seawater and Poyang Lake, as well as sul2 and sul3 in the Haihe River, had also reached 100%. The ARG pollution in Haihe River was much more serious, since 14 and 17 of 20 ARG species were significantly higher compared with seawater and Poyang Lake, respectively. Some ARGs also had a high absolute abundance. The absolute abundance of macrolide resistance genes (ermB) in seawater was as high as 8.61 × 10⁷ copies/L, and the anti-tuberculosis resistant genes (rpoB and katG) in the Haihe River Basin were highly abundant at 1.32 × 10⁶ copies/L and 1.06 × 10⁷ copies/L, respectively. This indicates that ARGs have gradually become more diverse and extensive in natural water bodies. The results of a redundancy analysis (RDA) of the three water bodies showed that although each water body is affected by different factors in space and time, overall, the presence of AGRs is closely related to the production and life of human beings and the migration of animals.

Developing and Validating an Adjustment Scale: The Adaptation Status Assessment of Drug-Resistant Tuberculosis Patients

Purpose

Drug-resistant tuberculosis (DR-TB) remains a major global public health issue. For DR-TB patients, effective adaptation is crucial to prevent disease progression, improve health outcomes and decrease mortality. To date, there is no appropriate tool for evaluating the adaptation status of DR-TB patients. In this work, we aim to develop an adjustment scale for DR-TB patients (AS-DRTBP) and to evaluate its psychometric properties.

Patients and Methods

The development of the AS-DRTBP was based on the theory of the Roy adaptation model (RAM). The scale was designed through a literature review, in-depth individual interviews, a Delphi survey, and pilot testing. In total, 433 patients with DR-TB were recruited to validate the instrument. The split-half reliability coefficient, Cronbach’s alpha coefficient, and test-retest reliability coefficient were calculated to assess the reliability of the instrument. Content validity, construct validity and concurrent validity tests were applied to calculate the validity of the instrument.

Results

The final AS-DRTBP consisted of four dimensions and 26 items. The Cronbach’s alpha coefficient, split-half reliability coefficient and test-retest reliability coefficient were 0.893, 0.954, and 0.853, respectively. The content validity index was 0.92. Four factors that explained 64.605% of the total variance were also further determined by confirmatory factor analysis (CFA). The CFA results showed that the fitting effect of the model was appropriate (CMIN/DF = 1.681, GFI = 0.832, AGFI = 0.799, RMSEA = 0.055, SRMR = 0.0684). The AS-DRTBP and adjustment scale had correlation in the total score, and the correlation coefficient was 0.355 (p<0.05).

Conclusion

The findings of this study demonstrate that the AS-DRTBP is a reliable and valid instrument for measuring the adaptation status of patients with DR-TB, allowing health providers to comprehend the adaptive level of DR-TB patients and thus laying the foundation for interventions to help these patients achieve a physiologically, psychologically and socially optimal outcome.