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Pathogens (Basel, Switzerland) Jul 2023Tuberculosis is an ancient disease that humanity struggled with for centuries and continues to struggle with. The bacteria often infects the lungs through respiratory... (Review)
Review
Tuberculosis is an ancient disease that humanity struggled with for centuries and continues to struggle with. The bacteria often infects the lungs through respiratory transmission and manifests itself through various symptoms, including cutaneous infections. Cutaneous tuberculosis (CTB) comprises about 1% to 1.5% of all extrapulmonary manifestations and is often accompanied by polymorphous lesions, including papules, nodules, plaques, ulcers, gummas, and verrucous lesions. CTB is most commonly observed in low-income, HIV, and immunosuppressed populations, similar to intrapulmonary manifestations. The main pathogen for CTB is but less commonly with and BCG vaccine, and the modes of transmission are largely classified into exogenous and endogenous CTB. Current treatment options for CTB include oral therapy of antibiotic medications such as rifampicin, streptomycin, ethambutol, isoniazid, and pyrazinamide, which is occasionally combined with surgical intervention.
PubMed: 37513768
DOI: 10.3390/pathogens12070920 -
The Lancet. Microbe Dec 2023The increasing incidence of syphilis and the limitations of first-line treatment with penicillin, particularly in neurosyphilis, neonatal syphilis, and pregnancy,...
BACKGROUND
The increasing incidence of syphilis and the limitations of first-line treatment with penicillin, particularly in neurosyphilis, neonatal syphilis, and pregnancy, highlight the need to expand the therapeutic repertoire for effective management of this disease. We assessed the in-vitro efficacy of 18 antibiotics from several classes on Treponema pallidum subspecies pallidum (T pallidum), the syphilis bacteria.
METHODS
Using the in-vitro culture system for T pallidum, we exposed the pathogen to a concentration range of each tested antibiotic. After a 7-day incubation, the treponemal burden was evaluated by quantitative PCR targeting the T pallidum tp0574 gene. The primary outcome was the minimum inhibitory concentration (MIC) at which the quantitative PCR values were not significantly higher than the inoculum wells. We also investigated the susceptibility of macrolide-resistant strains to high concentrations of azithromycin, and the possibility of developing resistance to linezolid, a proposed candidate for syphilis treatment.
FINDINGS
Amoxicillin, ceftriaxone, several oral cephalosporins, tedizolid, and dalbavancin exhibited anti-treponemal activity at concentrations achievable in human plasma following regular dosing regimens. The experiments revealed a MIC for amoxicillin at 0·02 mg/L, ceftriaxone at 0·0025 mg/L, cephalexin at 0·25 mg/L, cefetamet and cefixime at 0·0313 mg/L, cefuroxime at 0·0156 mg/L, tedizolid at 0·0625 mg/L, spectinomycin at 0·1 mg/L, and dalbavancin at 0·125 mg/L. The MIC for zoliflodacin and balofloxacin was 2 mg/L. Ertapenem, isoniazid, pyrazinamide, and metronidazole had either a poor or no effect. Azithromycin concentrations up to 2 mg/L (64 times the MIC) were ineffective against strains carrying mutations associated to macrolide resistance. Exposure to subtherapeutic doses of linezolid for 10 weeks did not induce phenotypic or genotypic resistance.
INTERPRETATION
Cephalosporins and oxazolidinones are potential candidates for expanding the current therapeutic repertoire for syphilis. Our findings warrant testing efficacy in animal models and, if successful, clinical assessment of efficacy.
FUNDING
European Research Council.
Topics: Animals; Infant, Newborn; Humans; Treponema pallidum; Anti-Bacterial Agents; Azithromycin; Syphilis; Macrolides; Linezolid; Ceftriaxone; Globus Pallidus; Drug Resistance, Bacterial; Amoxicillin; Treponema
PubMed: 37827185
DOI: 10.1016/S2666-5247(23)00219-7 -
Emerging Microbes & Infections Dec 2023Diagnostic development must occur in parallel with drug development to ensure the longevity of new treatment compounds. Despite an increasing number of novel and...
Diagnostic development must occur in parallel with drug development to ensure the longevity of new treatment compounds. Despite an increasing number of novel and repurposed anti-tuberculosis compounds and regimens, there remains a large number of drugs for which no rapid and accurate molecular diagnostic option exists. The lack of rapid drug susceptibility testing for linezolid, bedaquiline, clofazimine, the nitroimidazoles (i.e pretomanid and delamanid) and pyrazinamide at any level of the healthcare system compromises the effectiveness of current tuberculosis and drug-resistant tuberculosis treatment regimens. In the context of current WHO tuberculosis treatment guidelines as well as promising new regimens, we identify the key diagnostic gaps for initial and follow-on tests to diagnose emerging drug resistance and aid in regimen selection. Additionally, we comment on potential gene targets for inclusion in rapid molecular drug susceptibility assays and sequencing assays for novel and repurposed drug compounds currently prioritized in current regimens, and evaluate the feasibility of mutation detection given the design of existing technologies. Based on current knowledge, we also propose design priorities for next generation molecular assays to support triage of tuberculosis patients to appropriate and effective treatment regimens. We encourage assay developers to prioritize development of these key molecular assays and support the continued evolution, uptake, and utility of sequencing to build knowledge of tuberculosis resistance mechanisms and further inform rapid treatment decisions in order to curb resistance to critical drugs in current regimens and achieve End TB targets. ClinicalTrials.gov identifier: NCT05117788..
Topics: Humans; Antitubercular Agents; Microbial Sensitivity Tests; Pathology, Molecular; Mycobacterium tuberculosis; Tuberculosis; Tuberculosis, Multidrug-Resistant
PubMed: 36752055
DOI: 10.1080/22221751.2023.2178243 -
Journal of Microbiology, Immunology,... Dec 2023Pyrazinamide (PZA) and fluoroquinolone (FQ), particularly moxifloxacin (MXF), are essential drugs in the World Health Organization (WHO) recommended short-course regimen...
BACKGROUND
Pyrazinamide (PZA) and fluoroquinolone (FQ), particularly moxifloxacin (MXF), are essential drugs in the World Health Organization (WHO) recommended short-course regimen to treat drug-susceptible tuberculosis (TB).
METHODS
To understand the extent of PZA and MXF susceptibility in general TB cases in Taiwan, we conducted retrospective analyses of 385 conservative Mycobacterium tuberculosis complex (MTBC) isolates identified from 4 TB laboratories in different regions of Taiwan. The case information was obtained from the TB registry. Genotypic drug susceptibility testing (DST) was performed by sequencing drug-resistance associated genes, PZA (pncA) and FQ (gyrA, and gyrB). Phenotypic DST was determined using the Bactec MGIT 960 system or the agar proportion method. Genotyping was carried out using spacer oligonucleotide typing.
RESULTS
In this study, 4.7% (18/385) cases' isolates harbored pncA mutations and 7.0% (27/385) cases' isolates harbored gyrA or gyrB mutation. Notably, pncA mutation was associated with Beijing family genotypes (P = 0.028), East African-Indian (EAI) genotypes (P = 0.047) and MDR-TB (P < 0.001). Whereas, gyrA or gyrB mutation was associated with EAI genotypes (P = 0.020) and MDR-TB (P = 0.006). In addition, a statistically significant difference was found between the favorable outcomes using active and inactive PZA (P = 0.009) in 38 case isolates with any pncA, gyrA, or gyrB mutation.
CONCLUSION
We concluded that routine PZA and FQ susceptibility tests are recommended for guiding the treatment of TB.
Topics: Humans; Pyrazinamide; Antitubercular Agents; Mycobacterium tuberculosis; Fluoroquinolones; Microbial Sensitivity Tests; Taiwan; Retrospective Studies; Drug Resistance, Multiple, Bacterial; Amidohydrolases; Tuberculosis; Tuberculosis, Multidrug-Resistant; Mutation; Moxifloxacin
PubMed: 37690869
DOI: 10.1016/j.jmii.2023.08.013 -
PloS One 2023Tuberculosis stands as a prominent cause of mortality in developing countries. The treatment of tuberculosis involves a complex procedure requiring the administration of...
Tuberculosis stands as a prominent cause of mortality in developing countries. The treatment of tuberculosis involves a complex procedure requiring the administration of a panel of at least four antimicrobial drugs for the duration of six months. The occurrence of treatment failure after the completion of a standard treatment course presents a serious medical problem. The purpose of this study was to evaluate antimicrobial drug resistant features of Mycobacterium tuberculosis associated with treatment failure. Additionally, it aimed to evaluate the effectiveness of second line drugs such as amikacin, linezolid, moxifloxacin, and the efflux pump inhibitor verapamil against M. tuberculosis isolates associated with treatment failure. We monitored 1200 tuberculosis patients who visited TB centres in Lahore and found that 64 of them were not cured after six months of treatment. Among the M. tuberculosis isolates recovered from the sputum of these 64 patients, 46 (71.9%) isolates were simultaneously resistant to rifampicin and isoniazid (MDR), and 30 (46.9%) isolates were resistant to pyrazinamide, Resistance to amikacin was detected in 17 (26,5%) isolates whereas resistance to moxifloxacin and linezolid was detected in 1 (1.5%) and 2 (3.1%) isolates respectively. Among MDR isolates, the additional resistance to pyrazinamide, amikacin, and linezolid was detected in 15(23.4%), 4(2.6%) and 1(1.56%) isolates respectively. One isolate simultaneously resistant to rifampicin, isoniazid, amikacin, pyrazinamide, and linezolid was also identified. In our investigations, the most frequently mutated amino acid in the treatment failure group was Serine 315 in katG. Three novel mutations were detected at codons 99, 149 and 154 in pncA which were associated with pyrazinamide resistance. The effect of verapamil on the minimum inhibitory concentration of isoniazid and rifampicin was observed in drug susceptible isolates but not in drug resistant isolates. Rifampicin and isoniazid enhanced the transcription of the efflux pump gene rv1258 in drug susceptible isolates collected from the treatment failure patients. Our findings emphasize a high prevalence of MDR isolates linked primarily to drug exposure. Moreover, the use of amikacin as a second line drug may not be the most suitable choice in such cases.
Topics: Humans; Mycobacterium tuberculosis; Antitubercular Agents; Isoniazid; Pyrazinamide; Rifampin; Linezolid; Amikacin; Moxifloxacin; Tuberculosis, Multidrug-Resistant; Microbial Sensitivity Tests; Verapamil; Mutation
PubMed: 37883448
DOI: 10.1371/journal.pone.0293194 -
Journal of Neurosurgery. Case Lessons Jul 2023Tuberculosis is an airborne disease caused by Mycobacterium tuberculosis. Intracranial tuberculoma is a rare complication of extrapulmonary tuberculosis due to...
BACKGROUND
Tuberculosis is an airborne disease caused by Mycobacterium tuberculosis. Intracranial tuberculoma is a rare complication of extrapulmonary tuberculosis due to hematogenous spread to subpial and subependymal regions. Intracranial tuberculoma can occur with or without meningitis.
OBSERVATIONS
A 3-year-old male who had recently emigrated from Sudan presented to the emergency department with right-sided seizures lasting 30 minutes, which were aborted with levetiracetam and midazolam. Head computed tomography revealed a multilobulated left supratentorial mass with solid and cystic components and measuring 8.0 × 4.8 × 6.5 cm. The patient had successful resection of the mass, which was positive for M. tuberculosis. He was started on rifampin, isoniazid, pyrazinamide, ethambutol, and fluoroquinolone and was discharged home in stable condition.
LESSONS
A literature review on pediatric intracranial tuberculoma was performed, which included 48 studies (n = 49). The mean age was 8.8 ± 5.4 years with a slight female predilection (59%). Predominant solitary tuberculomas (63%) were preferentially managed with both resection and antituberculosis therapy (ATT), whereas multifocal tuberculomas were preferentially managed with ATT. Intracranial tuberculoma is a rare but treatable cause of space-occupying lesions in children. Clinicians should maintain a high level of suspicion in patients from endemic regions and involve the infectious disease service early.
PubMed: 37539871
DOI: 10.3171/CASE23236 -
Antimicrobial Agents and Chemotherapy Nov 2023Physiological changes during pregnancy may alter the pharmacokinetics (PK) of antituberculosis drugs. The International Maternal Pediatric Adolescent AIDS Clinical...
Pharmacokinetics and safety of first-line tuberculosis drugs rifampin, isoniazid, ethambutol, and pyrazinamide during pregnancy and postpartum: results from IMPAACT P1026s.
Physiological changes during pregnancy may alter the pharmacokinetics (PK) of antituberculosis drugs. The International Maternal Pediatric Adolescent AIDS Clinical Trials Network P1026s was a multicenter, phase IV, observational, prospective PK and safety study of antiretroviral and antituberculosis drugs administered as part of clinical care in pregnant persons living with and without HIV. We assessed the effects of pregnancy on rifampin, isoniazid, ethambutol, and pyrazinamide PK in pregnant and postpartum (PP) persons without HIV treated for drug-susceptible tuberculosis disease. Daily antituberculosis treatment was prescribed following World Health Organization-recommended weight-band dosing guidelines. Steady-state 12-hour PK profiles of rifampin, isoniazid, ethambutol, and pyrazinamide were performed during second trimester (2T), third trimester (3T), and 2-8 of weeks PP. PK parameters were characterized using noncompartmental analysis, and comparisons were made using geometric mean ratios (GMRs) with 90% confidence intervals (CI). Twenty-seven participants were included: 11 African, 9 Asian, 3 Hispanic, and 4 mixed descent. PK data were available for 17, 21, and 14 participants in 2T, 3T, and PP, respectively. Rifampin and pyrazinamide AUC and in pregnancy were comparable to PP with the GMR between 0.80 and 1.25. Compared to PP, isoniazid AUC was 25% lower and was 23% lower in 3T. Ethambutol AUC was 39% lower in 3T but limited by a low PP sample size. In summary, isoniazid and ethambutol concentrations were lower during pregnancy compared to PP concentrations, while rifampin and pyrazinamide concentrations were similar. However, the median AUC for rifampin, isoniazid, and pyrazinamide met the therapeutic targets. The clinical impact of lower isoniazid and ethambutol exposure during pregnancy needs to be determined.
Topics: Adolescent; Female; Humans; Pregnancy; Antitubercular Agents; Ethambutol; HIV Infections; Isoniazid; Postpartum Period; Prospective Studies; Pyrazinamide; Rifampin; Tuberculosis; Multicenter Studies as Topic; Clinical Trials, Phase IV as Topic; Observational Studies as Topic
PubMed: 37882552
DOI: 10.1128/aac.00737-23 -
The Lancet. HIV Jul 2023The drug-drug interaction between rifampicin and dolutegravir can be overcome by supplemental dolutegravir dosing, which is difficult to implement in high-burden... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
The drug-drug interaction between rifampicin and dolutegravir can be overcome by supplemental dolutegravir dosing, which is difficult to implement in high-burden settings. We aimed to test whether virological outcomes with standard-dose dolutegravir-based antiretroviral therapy (ART) are acceptable in people with HIV on rifampicin-based antituberculosis therapy.
METHODS
RADIANT-TB was a phase 2b, randomised, double-blind, non-comparative, placebo-controlled trial at a single site in Khayelitsha, Cape Town, South Africa. Participants were older than 18 years of age, with plasma HIV-1 RNA greater than 1000 copies per mL, CD4 count greater than 100 cells per μL, ART-naive or first-line ART interrupted, and on rifampicin-based antituberculosis therapy for less than 3 months. By use of permuted block (block size of 6) randomisation, participants were assigned (1:1) to receive either tenofovir disoproxil fumarate, lamivudine, and dolutegravir plus supplemental 50 mg dolutegravir 12 h later or tenofovir disoproxil fumarate, lamivudine, and dolutegravir plus matched placebo 12 h later. Participants received standard antituberculosis therapy (rifampicin, isoniazid, pyrazinamide, and ethambutol for the first 2 months followed by isoniazid and rifampicin for 4 months). The primary outcome was the proportion of participants with virological suppression (HIV-1 RNA <50 copies per mL) at week 24 analysed in the modified intention-to-treat population. This study is registered with ClinicalTrials.gov, NCT03851588.
FINDINGS
Between Nov 28, 2019, and July 23, 2021, 108 participants (38 female, median age 35 years [IQR 31-40]) were randomly assigned to supplemental dolutegravir (n=53) or placebo (n=55). Median baseline CD4 count was 188 cells per μL (IQR 145-316) and median HIV-1 RNA was 5·2 log copies per mL (4·6-5·7). At week 24, 43 (83%, 95% CI 70-92) of 52 participants in the supplemental dolutegravir arm and 44 (83%, 95% CI 70-92) of 53 participants in the placebo arm had virological suppression. No treatment-emergent dolutegravir resistance mutations were detected up to week 48 in the 19 participants with study-defined virological failure. Grade 3 and 4 adverse events were similarly distributed between the study arms. The most frequent grade 3 and 4 adverse events were weight loss (4/108 [4%]), insomnia (3/108 [3%]), and pneumonia (3/108 [3%]).
INTERPRETATION
Our findings suggest that twice-daily dolutegravir might be unnecessary in people with HIV-associated tuberculosis.
FUNDING
Wellcome Trust.
Topics: Humans; Female; Adult; Infant; HIV Infections; Lamivudine; Rifampin; Isoniazid; South Africa; Tenofovir; Heterocyclic Compounds, 3-Ring; Anti-Retroviral Agents; Tuberculosis; RNA; Antitubercular Agents; Viral Load
PubMed: 37230101
DOI: 10.1016/S2352-3018(23)00081-4