Global burden of HIV-negative multidrug-and extensively drug-resistant tuberculosis based on Global Burden of Disease Study 2021

Background:Tuberculosis(TB),caused by Mycobacterium tuberculosis,remains the second leading cause of death from a single infectious disease globally and poses a significant economic and clinical burden in the world in 2022.Of particular concern is the emergence of drug-resistant TB,accounting for 15%-20%of TB deaths.It is imperative to delve into the global trends of incidence and death rate for multidrug-resistant tuberculosis(MDRTB)and extensively drug-resistant tuberculosis(XDR-TB),drawing upon the comprehensive Global Burden of Disease(GBD)2021 drug-resistant tuberculosis dataset.Methods:From the GBD 2021,data on incidence,prevalence,disability-adjusted life years(DALYs),and death of MDR-TB and XDR-TB from 1990 to 2021 were collected.We calculated the estimated annual percentage changes in age standardized incidence rate(ASIR)and age-standardized death rate(ASDR),segmented by age,sex,and socio-demographic index(SDI).The impacts of various risk factors on MDR-TB and XDR-TB were also analyzed.Results:In 2021,there were an estimated 443,680(95%uncertainty interval[UI]:259,196-766,545)incident cases of MDR-TB,and an estimated 106,818(95%UI:41,612-211,854)death cases of MDR-TB,while there were an estimated 24,036(95%UI:17,144-34,587)incident cases of XDR-TB and 7,946(95%UI:3,326-14,859)death cases of XDR-TB.The incidence and death cases of MDR-TB were lowest in high SDI regions,whereas the incidence rates of XDR-TB in high-middle SDI regions were higher than those in middle SDI and high SDI regions.Conclusion:This study reported the disease burden of drug-resistant TB from 1990 to 2021.Until 2021,drugresistant TB is still a serious problem in low SDI countries,especially for high-risk age populations with highrisk factors.Controlling drug-resistant TB requires effective control strategies and healthcare systems.

Prolonged use of bedaquiline in two patients with pulmonary extensively drug-resistant tuberculosis: Two case reports

BACKGROUND Bedaquiline is among the prioritized drugs recommended by the World Health Organization for the treatment of extensively drug-resistant tuberculosis(XDRTB).Many patients have not achieved better clinical improvement after bedaquiline is stopped at 24 wk.However,there is no recommendation or guideline on bedaquiline administration beyond 24 wk,which is an important consideration when balancing the benefit of prognosis for XDR-TB against the uncertain safety concerning the newer antibiotics.CASE SUMMARY This paper reported 2 patients with XDR-TB(a female of 58 years of age and a female of 18 years of age)who received bedaquiline for 36 wk,as local experience to be shared.The 2 cases had negative cultures after 24 wk of treatment,but lung imaging was still positive.After discussion among experts,the consensus was made to bedaquiline prolongation by another 12 wk.The 36-wk prolonged use of bedaquiline in both cases achieved a favorable response without increasing the risk of cardiac events or new safety signals.CONCLUSION Longer regimen,including 36-wk bedaquiline treatment,might be an option for patients with XDR-TB.More studies are needed to explore the effectiveness and safety of prolonged use of bedaquiline for 36 wk vs standard 24 wk in the treatment of multidrug-resistant/XDR-TB or to investigate further the biomarkers and criteria indicative for extension of bedaquline to facilitate clinical use of thisnovel drug.

Molecular Characterization of Drug-Resistant Beijing Family Isolates of Mycobacterium Tuberculosis from Tianjin,China

Objective Tuberculosis remains a severe public health issue, and the Beijing family of mycobacterium tuberculosis （M. tuberculosis） is widespread in East Asia, especially in some areas in China, like Beijing and Tianjin. This study aimed at determining the mutation patterns of drug-resistant Beijing strains of M. tuberculosis isolated from Tianjin, China. Methods A total of 822 M. tuberculosis isolates were screened for drug resistance by an absolute concentration method and the genotype was identified by PCR. 169 drug-resistant isolates of the Beijing family were analyzed for the potential mutations in the rpoB, katG, inhA promoter region and in rpsL, rrs and embB genes, which are associated with resistance to rifampin （RFP）, isoniazid （INH）, streptomycin （SM） and ethambutol （EMB） respectively by PCR and DNA sequencing. Results Fifty-eight out of 63 RFP-resistant isolates were found to carry the mutations within the 81-bp RFP resistance determining region （RRDR） of the rpoB gene and the most frequent mutations occurred at codon 531 （44.4%）, 526 （28.6%）, and 516 （7.9%） respectively. 16 mutation pattems affecting 12 different codons around the RRDR of rpoB were found. Of 116 INH-resistant isolates, 56 （48.3%） had the mutation of katG 315 （AGC→ACC） （Ser→Thr）, 3 （2.6%） carried S315N （AGC→AAC） and 27 （16.0%） had the mutation of inhA-15A→T. 84 out of 122 SM-resistant isolates （68.9%） displayed mutations at the codons 43 or 88 with AAG→AGG （Lys→Arg） of the rpsL gene and 22 （18.0%） with the mutations at positions 513A→C, 516C→T or 905 A→G in the rrs gene. Of 34 EMB-resistant isolates, 6 had mutation with M306V （ATG→GTG）, 3 with M306I （ATG→ATT）, 1 with M306I （ATG→ATA）, 1 with D328Y （GAT→TAT）, 1 with V348L （GTC→CTC）, and 1 with G406S （GGC→AGC） in the embB gene. Conelusion These novel findings extended our understanding of resistance-related mutations in the Beijing strains of M. tuberculosis and may provide a scientific basis for development of new strategies for diagnosis and control of tuberculosis in China and other countries where Beijing strains are prevalent.

Extensively drug-resistant bacteria are an independent predictive factor of mortality in 130 patients with spontaneous bacterial peritonitis or spontaneous bacteremia

AIM: To evaluate the epidemiology and outcomes of culture-positive spontaneous bacterial peritonitis (SBP) and spontaneous bacteremia (SB) in decompensated cirrhosis.METHODS: We prospectively collected clinical, laboratory characteristics, type of administered antibiotic, susceptibility and resistance of bacteria to antibiotics in one hundred thirty cases (68.5% males) with positive ascitic fluid and/or blood cultures during the period from January 1, 2012 to May 30, 2014. All patients with SBP had polymorphonuclear cell count in ascitic fluid > 250/mm3. In patients with SB a thorough study did not reveal any other cause of bacteremia. The patients were followed-up for a 30-d period following diagnosis of the infection. The final outcome of the patients was recorded in the end of follow-up and comparison among 3 groups of patients according to the pattern of drug resistance was performed.RESULTS: Gram-positive-cocci (GPC) were found in half of the cases. The most prevalent organisms in a descending order were Escherichia coli (33), Enterococcus spp (30), Streptococcus spp (25), Klebsiella pneumonia (16), S. aureus (8), Pseudomanas aeruginosa (5), other Gram-negative-bacteria (GNB) (11) and anaerobes (2). Overall, 20.8% of isolates were multidrug-resistant (MDR) and 10% extensively drug-resistant (XDR). Health-care-associated (HCA) and/or nosocomial infections were present in 100% of MDR/XDR and in 65.5% of non-DR cases. Meropenem was the empirically prescribed antibiotic in HCA/nosocomial infections showing a drug-resistance rate of 30.7% while third generation cephalosporins of 43.8%. Meropenem was ineffective on both XDR bacteria and Enterococcus faecium (E. faecium). All but one XDR were susceptible to colistin while all GPC (including E. faecium) and the 86% of GNB to tigecycline. Overall 30-d mortality was 37.7% (69.2% for XDR and 34.2% for the rest of the patients) (log rank, P = 0.015). In multivariate analysis, factors adversely affecting outcome included XDR infection (HR = 2.263, 95%CI: 1.005-5.095, P = 0.049), creatinine (HR = 1.125, 95%CI: 1.024-1.236, P = 0.015) and INR (HR =1.553, 95%CI: 1.106-2.180, P = 0.011).CONCLUSION: XDR bacteria are an independent life-threatening factor in SBP/SB. Strategies aiming at restricting antibiotic overuse and rapid identification of the responsible bacteria could help improve survival.

Successful treatment of pyogenic ventriculitis caused by extensively drug-resistant Acinetobacter baumannii with multi-route tigecycline: A case report

BACKGROUND Pyogenic ventriculitis caused by extensively drug-resistant Acinetobacter baumannii(A.baumannii)is one of the most severe complications associated with craniotomy.However,limited therapeutic options exist for the treatment of A.baumannii ventriculitis due to the poor penetration rate of most antibiotics through the blood-brain barrier.CASE SUMMARY A 68-year-old male patient with severe traumatic brain injury developed pyogenic ventriculitis on postoperative day 24 caused by extensively drug-resistant A.baumannii susceptible to tigecycline only.Successful treatment was accomplished through multi-route administration of tigecycline,including intravenous combined with continuous ventricular irrigation plus intraventricular administration.The pus was cleared on the 3rd day post-irrigation,and cerebrospinal fluid cultures were negative after 12 d.CONCLUSION Our findings suggest that multi-route administration of tigecycline can be a therapeutic option against pyogenic ventriculitis caused by extensively drugresistant A.baumannii.

Risk Factors for Drug-Resistant Tuberculosis

Objective: Drug resistance is considered one of the main threats for tuberculosis control. Our aim was to identify risk factors for drug resistance in tuberculosis patients in the Northern Portugal. Study Design and Methods: Retrospective case-control study. The medical records and drug susceptibility test data from TB patients diagnosed between 31 March 2009 and 1 April 2010 were examined. We enrolled 119 patients with any drug resistance to first line anti-TB drugs and 238 with drug-susceptible TB, matched by age group. Variables analyzed included: gender, country of origin, employment situation, site of disease, previous treatment, presence of diabetes mellitus, HIV infection, alcohol abuse, intravenous drug use, abuse of other drugs and smoking habits. Multivariate conditional logistic regression was used to identify independent predictors for drug-resistant TB. Results: Diabetes mellitus [adjusted odds ratio (OR): 3.54;95% CI: 1.45 - 8.66], intravenous drug use (OR: 4.77;95% CI: 1.24 - 18.32) and previous TB treatment (OR: 2.48;95% CI: 1.12 - 5.49) were found to be risk factors for drug-resistant disease development. Conclusions: Diabetes mellitus, prior tuberculosis treatment, and intravenous drug use were risk factors for drug-resistant disease. The association between diabetes and drug-resistant TB should be further explored. Identifying clinical predictors of drug resistance can allow prompt identification of patients at risk for drug-resistant TB.

Multidrug-Resistant Tuberculosis Disease in North-Kivu Province, Democratic Republic of Congo

Introduction: The emergency of Mycobacterium tuberculosis resistant to the first line drug reduced access possibility to second line drugs for appropriate treatment and required for urgent action especially in le Democratic Republic of Congo (DRC), which counts among the highest tuberculosis (TB) burden countries in Africa. Objective: To present prevalence and describe multidrug-resistant tuberculosis cases in North-Kivu Province identified by using Genexpert technology. Methods: We conducted an observational prospective study on multidrug-resistant tuberculosis (MDR-TB) cases in North-Kivu Province, DRC from 2017 to 2018. All cases of MDR-TB identified by Genexpert MTB/ RIB were included in this series. Result: Of 15,544 tuberculosis cases registered during the study period, 19 cases of MDR-TB were identified. 57.9% was male, 89.5% was retreatment cases and 5.3% was coinfection HIV/TB cases. Conclusion: This new molecular technology diagnostic facilitates multidrug-resistance tuberculosis detection and improves the reporting of data lack.

Establishment of extensively drug-resistant Pseudomonas aeruginosa pneumonia model in rat

Objective:To establish extensively drug-resistant Pseudomonas aeruginosa(XDR-PA)infection-induced pneumonia model in rats.Methods:Twenty-four male SD rats were randomly divided into blank group,low bacterial group,medium bacterial group,and high bacterial group.The low,medium and high bacterial groups were given intratracheal instillation of 0.1 mL of bacterial suspension(bacterial concentration in turn is 7.5×10^(9),3×10^(10),6×10^(10)CFU/mL),while the blank group were given the same volume of sterile normal saline.After modeling,the general conditions of rats in each group were observed,including mental state,hair,respiration,activity,eating,weight,and the survival curve was drawn.The pathological characteristics of lung tissue and the infiltration of inflammatory cells were observed.Pathogenic identification of each group was carried out by bacterial culture of lung tissue homogenate.Results:The general state of the blank group was normal,and the rats in other groups showed signs of mental depression,bristling,shortness of breath,even oral and nasal bleeding,decreased food intake and activity,and significant weight loss,and different degrees of death within 48 hours,the difference was statistically significant(P<0.05).Pathological results showed that the alveolar structure of rats in the blank group was complete,and the alveolar space was clear without exudation.The lung tissue of the low and medium bacterial groups showed obvious inflammatory cell infiltration,alveolar structure destruction,alveolar septum thickening,interstitial edema,but the pathological damage of the medium group was more severe,with a mortality rate of up to 50%,and the mortality rate of the low bacterial group was 17%.In the high bacterial group,red blood cells,inflammatory cells and a large amount of fibrin-like exudation can be seen in the alveolar space,which has the pathological characteristics of acute respiratory failure,and the mortality rate is as high as 67%.The results of bacterial culture of lung tissue homogenate showed that the blank group had no bacterial colonies,while PA colony growth can be seen in low,medium and high bacterial groups.Conclusion:9 Intratracheal instillation of low bacterial count(0.1 mL of 7.5×10^(9) CFU/mL)XDR-PA bacterial suspension can successfully construct a rat pneumonia model of XDR-PA infection.

Identification, Synthesis, Isolation and Spectral Characterization of Multidrug-Resistant Tuberculosis (MDR-TB) Related Substances

Several related substances were detected at trace level in (2R)-2,3-dihydro-2-methyl-6-nitro-2-[[4-[4-[4-(trifluoromethoxy)phenoxy]-1-piperidinyl] phenoxy] methyl]imidazo[2, 1-b]oxazole drug substance by a newly developed high-performance liquid chromatography method. All related substances were characterized rapidly but some impurities were found to be intermediates. Proposed structures were further confirmed by characterization using NMR, FT-IR, and HRMS techniques. Based on the spectroscopic data;unknown related sub-stances were characterized as 1-(Methylsulfonyl)-4-[4-(trifluoromethoxy) phenoxy]piperidine;4-{4-[4-(Tri-fluoromethoxy)-phenoxy]piperidin-1-yl}phenol and 4-{4-[4-(trifluoromethoxy)phenoxy]piperidin-1-yl}phenyl methane sulfonate;4-Bromophenyl methane sulfonate, Ethyl 3,6-dihydro-1(2H)-pyridine carboxylate, (2S)-3-(4-Bromophenoxy)-2-hydroxy-2-methylpropyl methane sulfonate, (2S)-3-(4-Bromophenoxy)-2-methylpropane-1,2-diyldimethane-sulfonate, (2S)-2-Methyl-3-(4-{4-[4-(trifluoromethoxy) phenoxy]-piperidin-1-yl} phenoxy)-propane-1,2-diyldimethane sulfonate, (S)-3-(4-Bromophenoxy)-2-methyl-propane-1,2-diol and corresponding Enantiomer, (2R)-2-[(4-Bromo-phenoxy)methyl]-2-methyloxirane and (2R)-2-[(4-bromophenoxy)methyl]-2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b][1,3]oxazole. A possible mechanism for the formation of these related substances is also proposed.

Community-based management versus traditional hospitalization in treatment of drug-resistant tuberculosis:a systematic review and meta-analysis

Background:Multidrug drug resistant Tuberculosis(MDR-TB)and extensively drug resistant Tuberculosis(XDR-TB)have emerged as significant public health threats worldwide.This systematic review and meta-analysis aimed to investigate the effects of community-based treatment to traditional hospitalization in improving treatment success rates among MDR-TB and XDR-TB patients in the 27 MDR-TB High burden countries(HBC).Methods:We searched PubMed,Cochrane,Lancet,Web of Science,International Journal of Tuberculosis and Lung Disease,and Centre for Reviews and Dissemination(CRD)for studies on community-based treatment and traditional hospitalization and MDR-TB and XDR-TB from the 27 MDR-TB HBC.Data on treatment success and failure rates were extracted from retrospective and prospective cohort studies,and a case control study.Sensitivity analysis,subgroup analyses,and meta-regression analysis were used to explore bias and potential sources of heterogeneity.Results:The final sample included 16 studies involving 3344 patients from nine countries;Bangladesh,China,Ethiopia,Kenya,India,South Africa,Philippines,Russia,and Uzbekistan.Based on a random-effects model,we observed a higher treatment success rate in community-based treatment(Point estimate=0.68,95%CI:0.59 to 0.76,p<0.01)compared to traditional hospitalization(Point estimate=0.57,95%CI:0.44 to 0.69,p<0.01).A lower treatment failure rate was observed in community-based treatment 7%(Point estimate=0.07,95%CI:0.03 to 0.10;p<0.01)compared to traditional hospitalization(Point estimate=0.188,95%CI:0.10 to 0.28;p<0.01).In the subgroup analysis,studies without HIV co-infected patients,directly observed therapy short course-plus(DOTS-Plus)implemented throughout therapy,treatment duration>18 months,and regimen with drugs>5 reported higher treatment success rate.In the meta-regression model,age of patients,adverse events,treatment duration,and lost to follow up explains some of the heterogeneity of treatment effects between studies.Conclusion:Community-based management improved treatment outcomes.A mix of interventions with DOTSPlus throughout therapy and treatment duration>18 months as well as strategies in place for lost to follow up and adverse events should be considered in MDR-TB and XDR-TB interventions,as they influenced positively,treatment success.

Molecular Characterization and Drug-resistance of Mycobacterium tuberculosis Strains in Xuzhou, China

To understand the genetic diversity and drug resistance status of Mycobocterium tuberculosis （M. tuberculosis） circulating in Xuzhou of China, the spacer-oligonucleotide typing （Spoligotyping） and multi-loci VNTRs （variable number tandem repeats） analysis （MLVA） were utilized for the genotyping of the isolates. Drug susceptibility test （DST） was performed by the proportion method on the Lowenstein-Jensen （L-J） medium using isoniazid, rifampicin, ethambutol, and streptomycin. By Spoligotyping, 287 M. tuberculosis isolates were differentiated into 14 clusters. Then with 15-1oci MLVA, these strains could be divided into 32 clusters, 228 genotypes. Of 15 VNTRs, 6 loci had the highly discriminatory powers, 6 loci presented moderate discrimination and 3 loci demonstrated less polymorphism. The DST results showed that 46 strains were resistant to at least one first-line anti-tuberculosis agent. There was a difference in the isoniazid resistance between Beijing and non-Beijing genotype strains. We concluded that the combination of Spoligotyping and 15 VNTR loci as the genotyping in our study was applicable for this region, the drug resistant isolates were identified, and the Beijing family was the most prevalent genotype in the rural counties of Xuzhou.

Clinical effects of detailed nursing management interventions on medication adherence and disease perception in patients with drugresistant tuberculosis

BACKGROUND Tuberculosis(TB)is a chronic respiratory infectious disease that considerably jeopardizes human health,and there is no effective vaccine suitable for its prevention in the entire population.AIM To investigate the promotion of medication adherence and disease cognition in patients with drug-resistant(DR-)TB using detailed nursing management.METHODS In total,114 patients with DR-TB who were diagnosed and treated at our hospital between January 2019 and January 2023 were included in this study.Patients in the control group(n=57)were managed with conventional nursing care,while those in the observation group(n=57)were managed with detailed nursing care.Medication adherence,disease awareness scores,medication safety,and nursing satisfaction were compared between the two groups after the intervention.RESULTS The post-intervention medication compliance rate was 91.23%in the observation group and 75.44%in the control group,with the former being 15.79%higher than the latter(P<0.05).There was no statistically significant difference in the disease awareness scores between the two groups before the intervention;the disease awareness scores of the observation group were significantly higher than those of the control group after the intervention(P<0.05).The incidence of gastrointestinal reactions,joint swelling and pain,hearing loss,electrolyte disorders,and liver and kidney function abnormalities were lower in the observation group than those in the control group.The total nursing satisfaction of the observation group was higher than that of the control group(P<0.05).CONCLUSION Implementation of detailed nursing management for patients with DR-TB can effectively improve medication adherence,enhance awareness of the disease,ensure safety of medication,and improve satisfaction with nursing care.

Transmission of extensively drug-resistant and multidrug resistant Mycobacterium tuberculosis in families identified by genotyping

Background Diagnosis and appropriate treatment of multidrug-resistant tuberculosis （MDR-TB） remain major challenges. We sought to elucidate that persons who share a household with drug resistance tuberculosis patients are at high risk for primary drug resistance tuberculosis and how to prevent these outbreaks. Methods We used 12-locus mycobactedal interspersed repetitive unit and 7-locus variable-number tandem repeat to identify household transmission of extensively drug resistant and multiple drug resistant Mycobacterium tuberculosis in three families admitted in Shanghai Pulmonary Hospital affiliated with Tongji University. Drug susceptibility tests were done by the modified proportion method in the MGIT 960 system in the same time. Clinical data were also obtained from the subjects＇ medical records. Results All of the six strains were defined as Beijing genotype by the deletion-targeted multiplex PCR （DTM-PCR） identification on the genomic deletion RD105. Strains from family-1 had the same minisatellite interspersed repetitive unit （MIRU） pattern （232225172531） and the same MIRU pattern （3677235）. Strains from family-2 had the same MIRU pattern （2212261553323） and the same MIRU pattern （3685134）. Strains from family-3 did not have the same MIRU pattern and they differed at only one locus （223326173533, 223325173533）, and did not have the same VNTR pattern with two locus differed （3667233, 3677234）. Conclusions Household transmission exists in the three families. A clear chain of tuberculosis transmission within family exists. Tuberculosis susceptibility should be considered when there is more than one tuberculosis patients in a familv. Household tuberculosis transmission could be prevented with adequate treatment of source Patients.

The Role of Pyridoxine in the Prevention and Treatment of Neuropathy and Neurotoxicity Associated with Rifampicin-Resistant Tuberculosis Treatment Regimens: A Topic Review

Rifampicin-resistant tuberculosis (RR-TB) is a global public health problem caused by mycobacterium tuberculosis resistant to Rifampicin. Drug-induced peripheral neuropathy and neurotoxicity are well-known adverse effects of treatment regimens that cause significant morbidity. Pyridoxine is often added to treatment regimens for the prevention and/or treatment of these side effects. The basis and effectiveness of this practice are unclear. We conducted a systematic review to evaluate the effectiveness of pyridoxine in preventing and/or treating neuropathy and neurotoxicity associated with RR-TB treatment. We included studies with patients with RR-TB who experienced neuropathy or neurotoxicity attributed to RR-TB regimens and were given pyridoxine. Our findings showed contradicting evidence on the use of pyridoxine for preventing or treating neurotoxicity due to cycloserine in the treatment of RR-TB. Moreover, pyridoxine did not have a protective effect against neuropathy and/or neurotoxicity caused by other RR-TB regimens that do not contain isoniazid. In conclusion, we found that withdrawing or withholding medications such as linezolid, cycloserine, thioamides, fluoroquinolones, and ethambutol, implicated in causing neuropathy or neurotoxicity was more effective than using pyridoxine to stop the progression of symptoms, and in some instances, led to their reversal over time.

Activities of Biapenem against Mycobacterium tuberculosis in Macrophages and Mice

Objective To assess the activities of biapenem against multidrug-resistant and extensively drug-resistant Mycobacterium tuberculosis. Methods Biapenem/clavulanate(BP/CL) was evaluated for in vitro activity against Mycobacterium tuberculosis(Mtb) multidrug-resistant(MDR) isolates, extensively drug-resistant(XDR) isolates, and the H37 RV strain. BP/CL activity against the H37 Rv strain was assessed in liquid cultures, in macrophages, and in mice. Results BP/CL exhibited activity against MDR and XDR Mtb isolates in liquid cultures. BP/CL treatment significantly reduced the number of colony forming units(CFU) of Mtb within macrophages compared with control untreated infected macrophages. Notably, BP/CL synergized in pairwise combinations with protionamide, aminosalicylate, and capreomycin to achieve a fractional inhibitory concentration for each pairing of 0.375 in vitro. In a mouse tuberculosis infection model, the efficacy of a cocktail of levofloxacin + pyrazinamide + protionamide + aminosalicylate against Mtb increased when the cocktail was combined with BP/CL, achieving efficacy similar to that of the positive control treatment(isoniazid + rifampin + pyrazinamide) after 2 months of treatment. Conclusion BP/CL may provide a new option to clinically treat MDR tuberculosis.

Application of PCR-SSCP in detecting rpoB drug resistant gene polymorphism of M. tuberculosis L-form from pneumoconiosis patients with tuberculosis

Objective: To study the relationship between the polymorphism of drug resistant gene rpoB and drug resistance against rifampicin(RFP) of M. tuberculosis L-forms, and to evaluate its clinical application. Methods: A total of 52 clinical isolated strains of M. tuberculosis L-forms were collected. rpoB gene polymorphism was analyzed by polymerase chain reaction and single-strand conformation polymorphism (PCR-SSCP) and conventional antimicrobial susceptibility test (AST). Their results were compared. Results: AST results showed that 38 of 52 clinical isolated strains were drug resistance (73.08％),while PCR-SSCP indicated 65.38％ (32/52) rpoB gene polymorphism. There was no statistic significance(χ2= 2.4914) between the 2 methods. Conclusion:Combined the application of PCR-SSCP with AST in detecting rpoB drug resistant gene polymorphism of M. tuberculosis L-form from pneumoconiosis patients with tuberculosis may have advantages at earlier diagnosis and guidance of clinical medications.

Detecting drug resistant genetic mutation among pneumoconiosis patients complicated with tuberculosis in Mycobacterium tuberculosis L-forms application of PCR-SSCP technique in Huainan mining district

Objective： To study the relationship between drug resistant genetic mutation and drug resistance in Mycobacterium tuberculosis L-form, discuss the internal relationship between drug resistances and drug-resistant related genes and explore the value of PCR- SSCP to clinical application. Methods： A total of 52 clinically isolated strains of tuberculosis L-form were collected among 97 pneumoconiosis patients complicated with tuberculosis. The gene mutations of katG, rpoB and rpsL were detected by PCR-SSCP, and the results were compared with those analyzed by traditional antimicrobial susceptibility test（AST）. Results： The gene muta- tion rates of katG, rpoB and rpsL by PCR-SSCP were respectively 57.70% （30/52）, 65.38% （32/52） and 40.38% （21/52）. The rate of reversion was 78.85%（41/52） and the result of drag-resistant genes was invariable. The results of AST showed that there were 40 （76.92%） multi-drug resistant strains in 52 clinically isolated strains. The number for three-drug resistant strain was 21 （40.38%） and that of two-drug resistant was 19（36.54%）, but only 12（23.08%） strains were one drug resistant. The rate of total drug-resistance was 100%, but there were 15 strains of allied mutation of three genes, 16 of two mutations and 6 of only one by PCR-SSCP. The coincidences were respectively 71.43%, 84.12% and 50.00%. Then there was no significant difference between the allied mutations of multi-drug resistant gene and the mutations of only one drug resistant gene （P 〉 0.05）. Conclusion： PCR-SSCP technique has a higher sensibility and specificity to detect the genes of katG, rpoB and rpsL in tuberculosis L-form among pneumoconiosis complicated with tuberculosis,and the detecting rate of two drug resistant strains and three drug resistant strains was higher. The combined application of PCR-SSCP and AST has advantages at earlier diagnosis and guidance of clinical medications.

Emerging bedaquiline resistance:A threat to the global fight against drug-resistant tuberculosis

Bedaquiline resistance is increasingly observed in the treatment of rifampicin-resistant tuberculosis(TB),yet standardized regimens for managing bedaquiline-resistant TB are lacking.Studies indicate a high proportion of bedaquiline-resistant cases have previously been treated for TB,and often involve strains resistant to quinolones.Regular monitoring of the culture status in patients receiving bedaquiline resistance treatment is advised.Methods such as experimental evolution,protein modeling,genome sequencing,and phenotypic analysis have been instrumental in identifying the mechanisms of bedaquiline resistance.Specifically,variants in the Rv0678 transcriptional repressor of the MmpS5-MmpL5 efflux system are linked to this type of resistance.Bayesian probability estimates show promise in determining the genotypic–phenotypic association for bedaquiline resistance,suggesting potential utility in clinical practice.Future research should explore the practical application of Bayesian probabilities in managing bedaquiline resistance.Sequencing-based technologies are anticipated to play a vital role in the early detection and management of drug-resistant TB strains.

Global prevalence of drug-resistant tuberculosis: a systematic review and meta-analysis

Background Tuberculosis is a bacterial infectious disease,which affects different parts of a human body,mainly lungs and can lead to the patient’s death.The aim of this study is to investigate the global prevalence of drug-resistant tuberculosis using a systematic review and meta-analysis.Methods In this study,the PubMed,Scopus,Web of Science,Embase,ScienceDirect and Google Scholar repositories were systematically searched to find studies reporting the global prevalence of drug-resistant tuberculosis.The search did not entail a lower time limit,and articles published up until August 2022 were considered.Random effects model was used to perform the analysis.The heterogeneity of the studies was examined with the I^(2) test.Data analysis was conducted within the Comprehensive Meta-Analysis software.Results In the review of 148 studies with a sample size of 318,430 people,the I^(2) index showed high heterogeneity(I^(2)=99.6),and accordingly random effects method was used to analyze the results.Publication bias was also examined using the Begg and Mazumdar correlation test which indicated the existence of publication bias in the studies(P=0.008).According to our meta-analysis,the global pooled prevalence of multi-drug resistant TB is 11.6%(95%CI:9.1–14.5%).Conclusions The global prevalence of drug-resistant tuberculosis was found to be very high,thus health authorities should consider ways to control and manage the disease to prevent a wider spread of tuberculosis and potentially subsequent deaths.

Impacts of a comprehensive tuberculosis control model on the quality of clinical services and the financial burden of treatment for patients with drug-resistant tuberculosis in China:a mixed-methods evaluation

Background:The China National Health Commission-GatesTB Project Phase III implemented a comprehensive TB control model including multiple interventions to address the burden of drug-resistant TB(DRTB).This study aims to evaluate the quality of DRTB clinical services and assess the financial burden of DRTB patients during the intervention period.