Antituberculous Agents Research Articles

Biological evaluation and synthesis of new pyrimidine-2(1H)-ol/-thiol derivatives derived from chalcones using the solid phase microwave method

Twenty-five new hydroxy- and methoxy-substituted 4,6-diarylpyrimidin-2(1H)-ol (20-34) and 4,6-diarylpyri\-midine-2(1H)-thiol derivatives (35-44) were synthesized from the reaction of the corresponding 1,3-diaryl-2-propene-1-one compounds (1-19) with urea or thiourea using the solid-phase microwave method. All the new synthetic compounds (20-44) were evaluated with regard to their $\alpha $-glucosidase activity. However, only compounds 22-25, 27,31,34, 35,37, and 40 exhibited a greater inhibitory effect than standard acarbose. The IC$_{50}$ values of the active compounds ranged between 2.36 and 13.34 $\mu $M. The 25 new compounds were also screened for their in vitro pancreatic lipase activity and compounds 20-27and 35-39 were found to be active. Of these compounds 26, 27, and 39 exhibited the best antilipase activities at concentrations of 0.40 $\pm $ 0.06, 0.26 $\pm $ 0.07, and 0.29 $\pm $ 0.026 $\mu $M. All the new compounds (20-44) were evaluated for their in vitro antimicrobial activity for nine test microorganisms. Compounds 20-24 and 35-39 were determined to possess a significant broad spectrum against the gram-positive bacteria Escherichia faecalis , Staphylococcus aureus , and Bacillus cereus among the tested bacterial agents. Compounds 20-24 and 35-39 exhibit the best activity against Mycobacterium smegmatis, with minimum inhibitory concentrations of 62.5--500 $\mu $g/mL, indicating their potential use as antituberculous agents.

The Effect of Combining Natural Terpenes and Antituberculous Agents against Reference and Clinical Mycobacterium tuberculosis Strains.

Background: On account of emergence of multi- and extensively drug-resistant Mycobacterium tuberculosis (Mtb) strains, combinations of drugs with natural compounds were tested to search for antibiotic activity enhancers. In this work we studied terpenes (α-pinene, bisabolol, β-elemene, (R)-limonene, (S)-limonene, myrcene, sabinene), which are the main constituents of essential oil obtained from Mutellina purpurea L., a plant with described antitubercular activity, to investigate their interactions with antibiotics against reference Mtb strains and multidrug-resistant clinical isolates. Methods: The serial dilution method was used to evaluate the minimal inhibitory concentration (MIC) of tested compounds, while the fractional inhibitory concentration index (FICI) was calculated for characterization of interactions. Moreover, IC50 values of tested compounds were determined using monkey kidney epithelial cell line (GMK). Results: The combinations of all studied terpenes with ethambutol or rifampicin resulted in a synergistic interaction. Bisabolol and (R)-limonene decreased the MIC for rifampicin at least two-fold for all tested strains, however no synergistic action was observed against virulent strains. The tested terpenes showed slight (bisabolol) or no cytotoxic effect against normal eukaryotic cells in vitro. Conclusions: The obtained enhanced activity (FICI < 0.5) of ethambutol and rifampicin against H37Ra strain under the influence of the studied terpenes may be correlated to the capability of essential oil constituents to modify bacterial resistance mechanisms in general. The observed differences in avirulent and virulent bacteria susceptibility to terpenes tested separately and in combinations with antibiotics can be correlated with the differences in the cell wall structure between H37Ra mutant and all virulent strains.

Mycobacterium tuberculosis Strains H37ra and H37rv have equivalent minimum inhibitory concentrations to most antituberculosis drugs.

Mycobacterium tuberculosis (Mtb) strains H37Ra and H37Rv are commonly used to study new and re-evaluate old antituberculous agents with respect to their pharmacodynamic effects in vitro. The differences in membrane proteins and, in particular, differences in carrier proteins between Mtb H37Ra and Mtb H37Rv may have an impact on antibiotic potency. The question of whether H37Ra can be used as a reliable surrogate for H37Rv and clinical strains has not been addressed sufficiently. The purpose of this study is to provide a full comparison of susceptibility data of the most common antituberculosis (TB) agents against both Mtb strains. In addition to a literature review, in vitro checkerboard susceptibility study was conducted comparing the in vitro minimum inhibitory concentration (MIC) of 16 common antituberculous drugs against H37Ra and H37Rv. Heifets-Sanchez TB agar drug susceptibility plates were utilized. Half of the antibiotics demonstrated similar growth inhibition against both strains, while slightly differing MIC values were found for 7 of 16 drugs. With the exception of rifampicin, no marked difference in MIC against H37Ra and H37Rv was observed. While neither the attenuated (H37Ra) nor the virulent strain (H37Rv) is a clinical strain, both strains predicted MICs of clinical isolates equally well, when comparing the current in vitro results to clinical susceptibility data in the literature. H37Ra comes with the benefits of lower experimental costs and less administrative barriers including the requirement of a biosafety Level III environment.

Osteomyelitis and Arthritis by Atypical Mycobacteria in Children: Three Cases

Introduction Osteoarticular infections caused by atypical mycobacteria are uncommon, with osteitis being more common and arthritis being rare. We describe two cases of subacute osteomyelitis and one of chronic osteomyelitis with arthritis. Case Reports Three boys, aged between 7 and 20 months. Clinical presentations: case 1—swelling of right forearm; case 2—limping and swelling of right hallux; case 3—pain and restriction of motion of right lower limb with effusion. None had fever. All had received Bacillus Calmette–Guérin (BCG) and none had contact with tuberculosis. All had thrombocytosis, and erythrocyte sedimentation rate was between 17 and 44 mm/1st hour. All had osteolytic lesions on X-ray with a sclerotic halo and swelling of the surrounding soft tissues, and invasion of the metaphysis and/or epiphysis. Bone histopathological studies revealed granulomatous inflammation or epithelioid cells in all cases. Microbiological identification was positive by culture in one case (Mycobacterium bovis) and by polymerase chain reaction in two cases (Mycobacterium spp. and M. avium). Immunodeficiency screening was negative in all cases. All were treated with antituberculous agents and made good clinical and radiological recoveries. Discussion Osteolytic lesions should raise suspicion of mycobacterial infection, including BCG vaccine, particularly in the presence of granulomatous inflammation. The prognosis was favorable in all patients. Although immune deficits were not identified in any of our three patients, it should be routinely tested for in such cases.

Lansoprazole-sulfide, pharmacokinetics of this promising anti-tuberculous agent.

Lansoprazole (LPZ) is a commercially available proton-pump inhibitor whose primary metabolite, lansoprazole sulfide (LPZS) was recently reported to have in vitro and in vivo activity against Mycobacterium tuberculosis. It was also reported that a 300 mg kg-1 oral administration of LPZS was necessary to reach therapeutic levels in the lung, with the equivalent human dose being unrealistic. A validated liquid chromatography-tandem mass spectrometric method (LC-MS/MS) for the simultaneous quantification LPZ and LPZS in rat plasma and lung homogenates was developed. We administered 15 mg kg-1 oral doses of LPZ to a healthy rat model to determine the pharmacokinetics of its active metabolite, LPZS, in plasma and lung tissue. We found that the LPZS was present in amounts that were below the limit of quantification. This prompted us to administer the same dose of LPZS to the experimental animals intraperitoneally (i.p.). Using this approach, we found high concentrations of LPZS in plasma and lung, 7841.1 and 9761.2 ng mL-1 , respectively, which were significantly greater than the minimum inhibitory concentration (MIC) for Mycobacterium tuberculosis. While oral and i.p. administration of LPZ resulted in significant concentrations in the lung, it did not undergo sufficient cellular conversion to its anti-TB metabolite. However, when LPZS itself was administered i.p., significant amounts penetrated the tissue. These results have implications for future in vivo studies exploring the potential of LPZS as an anti-TB compound.

Total Hip Arthroplasty Loosening Due to Mycobacterium Tuberculosis: A Case Report and Review of the Literature

Context:Prosthetic joint infection due to Mycobacterium tuberculosis with no previous history of pulmonary or extra pulmonary tuberculosis is an extremely rare complication.AimsTo report the case of a patient with tuberculous mycobacterial prosthetic hip infection, 14 years after surgery for post traumatic osteoarthritis, with no previous history of tuberculosis.MethodsA 46-year-old male presented an acetabular loosening of a cemented total hip arthroplasty with subnormal biologic parameters. A one stage revision surgery was planned. Intraoperative findings suggested mycobacterial tuberculous infection with presence of periacetabular yellowish rice-shaped granules.ResultsA one-stage prosthesis exchange was performed; Culture on Löwenstein-Jensen medium grew MTB days after inoculation and histological examination confirmed tuberculous infection. Patient was treated by antituberculous agents for 12 months with optimal clinical and biological response and no prosthetic loosening signs at eighteen months follow up.ConclusionsTotal hip arthroplasty loosening due to mycobacterium tuberculosis is a rare entity, which should be evoked even when no inflammatory signs are shown. Discovery of yellowish rice-shaped granules is an indicator to investigate for tuberculosis. Management of prosthetic joint infection due to M.tuberculosis must involve both medical and surgical approach.

Miliary Tuberculosis that Developed after Intravesical Bacillus Calmette-Guerin Therapy.

As a treatment for superficial transitional cell carcinoma, Bacillus Calmette-Guerin (BCG) intravesical instillation can rarely cause unpredictable systemic side effects. We describe a patient admitted due to continuous pyrexia and general fatigue. He was previously treated with intravesical BCG. Laboratory data indicated a hepatic disorder, and chest computed tomography revealed extensive bilateral miliary nodules. Transbronchial lung biopsy specimens showed several small noncaseating granulomas. The diagnosis was unsolved on the basis of acid fast staining, polymerase chain reaction and microbiological cultures, so we considered the possibility of BCG side effect-induced granuloma. Two months after treatment with antituberculous agents and corticosteroids, his clinical symptoms were improved.

Role of Vitamins B, C, and D in the fight against tuberculosis.

Worldwide, tuberculosis (TB) is still a serious and significant health concern, more so with the emergence of multidrug-resistant-TB. The inability of mankind to control this infection stems from the fact that the vaccines and drugs that were once effective against TB are no longer efficacious. This has led to a search for new antituberculous agents and adjuvant therapy. Vitamins are being revisited for their role in pathogenicity as well as for their antimycobacterial properties. Vitamins such as biotin and thiamin are essential for Mycobacterium tuberculosis and are required for establishment of infection. On the other hand, vitamins such as Vitamin C and Vitamin D have been shown to possess antimycobacterial properties. To combat M. tuberculosis, innovative strategies need to be devised, keeping in mind the efficacy of the agent to be used. Vitamins can prove to be useful agents capable of modifying the life cycle and biology of M. tuberculosis. We present here a brief overview of the available knowledge on thiamin, biotin, Vitamin C, and Vitamin D, keeping TB treatment and control in perspective.

Phenotypic low-level isoniazid resistance as a marker to predict ethionamide resistance in Mycobacterium tuberculosis

Tuberculosis is one of the most prevalent diseases in Pakistan. Pakistan has the highest burden of MDR-TB in the Eastern Mediterranean region. Ethionamide is an anti-tuberculous drug frequently used to treat MDR-TB. Its drug susceptibility testing is not easily available in resource limited settings. Since it acts on the same target protein as isoniazid (inhA protein encoded by inhA gene), we sought to find out if phenotypic isoniazid resistance can be a marker of ethionamide resistance. This was a retrospective observational study conducted at the Aga Khan University hospital section of microbiology. Data was retrieved between 2011 to 2014 for all culture positive MTB strains. All culture positive MTB isolates with susceptibilities to isoniazid and ethionamide recorded were included in the study. Isoniazid and ethionamide susceptibilities were performed using agar proportion method on Middlebrook 7H10 agar. Rate of Ethionamide resistance between low-level isoniazid resistant, high level isoniazid resistant and isoniazid sensitive MTB was compared. A total of 11,274 isolates were included in the study. A statistically significant association (P < 0.001) was found between Ethionamide resistance and low-level isoniazid resistance (26.6%) as compared to high-level isoniazid resistance (8.85%) and isoniazid sensitivity (0.71%) in MTB strains. However this association was not seen in XDR-TB strains. Low level isoniazid resistance may be used as marker for phenotypic ethionamide resistance and hence guide clinicians' choice of antituberculous agent for MDR-TB in Pakistan. Further studies involving detection of genotypic association of isoniazid and ethionamide susceptibilities are needed before a final conclusion can be derived.

Contribution of putative efflux pump genes to isoniazid resistance in clinical isolates of Mycobacterium tuberculosis.

Isoniazid (INH) resistance in Mycobacterium tuberculosis has been mainly attributed to mutations in katG (64%) and inhA (19%). However, 20%-30% resistance to INH cannot be explained by mutations alone. Hence, other mechanisms besides mutations may play a significant role in providing drug resistance. Here, we explored the role of 24 putative efflux pump genes conferring INH-resistance in M. tuberculosis. Real-time expression profiling of the efflux pump genes was performed in five INH-susceptible and six high-level INH-resistant clinical isolates of M. tuberculosis exposed to the drug. Isolates were also analyzed for mutations in katG and inhA. Four high-level INH-resistant isolates (minimum inhibitory concentration [MIC] ≥2.5 mg/L) with mutations at codon 315 (AGC-ACC) of katG showed upregulation of one of the efflux genes Rv1634, Rv0849, efpA, or p55. Another high-level INH-resistant isolate (MIC 1.5 mg/L), with no mutations at katG or inhA overexpressed 8/24 efflux genes, namely, Rv1273c, Rv0194, Rv1634, Rv1250, Rv3823c, Rv0507, jefA, and p55. Five of these, namely, Rv0194, Rv1634, Rv1250, Rv0507, and p55 were induced only in resistant isolates. The high number of efflux genes overexpressed in an INH-resistant isolate with no known INH resistance associated mutations, suggests a role for efflux pumps in resistance to this antituberculous agent, with the role of Rv0194 and Rv0507 in INH resistance being reported for the first time.

A Pulmonary Tuberculosis Case Presented with Tonsillar Involvement.

Tonsillar tuberculosis is a rare form of extra pulmonary tuberculosis. We reported a case with tonsillar tuberculosis secondary to pulmonary tuberculosis in this paper. A 26 year old, unimmunocompromised man admitted to head and neck surgery clinic with complaints of fever, throat ache and difficulty swallowing. The patient was consulted by infectious diseases clinic because of examination findings and his history. Asid fast basili was determined in tonsillar lesion smear, sputum and the patient was diagnosed as tonsillar and pulmonary tuberculosis. Antituberculous agents were started. Complaints of the patient were decreased and any adverse effect was developed. Treatment was completed in 9 months. In patients with long-term difficulty swallowing and fever, countries in which tuberculosis is prevalent, tonsillar tuberculosis should be considered, even if the patients were unimmunocompromised.

The Effectiveness and Safety of Fluoroquinolone-Containing Regimen as a First-Line Treatment for Drug-Sensitive Pulmonary Tuberculosis: A Systematic Review and Meta-Analysis.

BackgroundFluoroquinolone is recommended as a pivotal antituberculous agent for treating multi-drug-resistant pulmonary tuberculosis. However, its effectiveness as first-line treatment remains controversial. The present study was conducted to validate the fluoroquinolone-containing regimen for drug-sensitive pulmonary tuberculosis.MethodsWe searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials until June 5, 2015. Randomized controlled trials (RCTs) that compared antituberculous regimens containing fluoroquinolone with the standard regimen were included.ResultsEleven RCTs that included 6,334 patients were selected. Fluoroquinolone-containing regimens had a higher rate of sputum culture conversion at 2 months of treatment (M-H fixed odds ratio [OR], 1.36; 95% confidence interval [CI], 1.20–1.54). However, the outcomes were less favorable (M-H fixed OR, 0.69; 95% CI, 0.59–0.82) and the associated total adverse events were more frequent (M-H fixed OR, 1.84; 95% CI, 1.46–2.31) in the fluoroquinolone-containing regimen group, without a significant heterogeneity according to treatment duration. Treatment with the fluoroquinolone-containing regimen for 4 months showed a higher relapse rate.ConclusionsDespite a higher culture conversion rate at 2 months of treatment, the fluoroquinolone-containing regimen had limitations, including less favorable outcomes and more adverse events, as the first-line therapy for drug-sensitive pulmonary tuberculosis.

Effects of the encapsulation of usnic acid into liposomes and interactions with antituberculous agents against multidrug-resistant tuberculosis clinical isolates.

Mycobacterium tuberculosis (Mtb) has acquired resistance and consequently the antibiotic therapeutic options available against this microorganism are limited. In this scenario, the use of usnic acid (UA), a natural compound, encapsulated into liposomes is proposed as a new approach in multidrug-resistant tuberculosis (MDR-TB) therapy. Thus the aim of this study was to evaluate the effect of the encapsulation of UA into liposomes, as well as its combination with antituberculous agents such as rifampicin (RIF) and isoniazid (INH) against MDR-TB clinical isolates. The in vitro antimycobacterial activity of UA-loaded liposomes (UA-Lipo) against MDR-TB was assessed by the microdilution method. The in vitro interaction of UA with antituberculous agents was carried out using checkerboard method. Minimal inhibitory concentration values were 31.25 and 0.98 µg/mL for UA and UA-Lipo, respectively. The results exhibited a synergistic interaction between RIF and UA [fractional inhibitory concentration index (FICI) = 0.31] or UA-Lipo (FICI = 0.28). Regarding INH, the combination of UA or UA-Lipo revealed no marked effect (FICI = 1.30-2.50). The UA-Lipo may be used as a dosage form to improve the antimycobacterial activity of RIF, a first-line drug for the treatment of infections caused by Mtb.

Sternoclavicular Joint Tuberculosis: A rare extra pulmonary manifestation

The sternoclavicular joint is a rare site for extra pulmonary tuberculosis. Diagnosis may be delayed because of its rarity and unusual clinical presentation. Early diagnosis and prompt treatment with standard antituberculous agents would hasten complete recovery. We report a patient with sternoclavicular joint tuberculosis in association with pleural effusion.

Tuberculous Panophthalmitis with Lymphadenitis and Central Nervous System Tuberculoma.

Tuberculosis (TB) is a serious infectious disease that spreads globally. The ocular manifestations of TB are uncommon and diverse. TB panophthalmitis has been rarely reported. Here, we described a 38-year-old Thai man presenting with panophthalmitis of the right eye. Further investigation showed that he had concurrent TB lymphadenitis and central nervous system (CNS) tuberculoma, as well as HIV infection, with a CD4 cell count of 153 cells/mm3. Despite the initial response to antituberculous agents, the disease had subsequently progressed and enucleation was required. The pathological examination revealed acute suppurative granulomatous panophthalmitis with retinal detachment. Further staining demonstrated acid-fast bacilli in the tissue. Colonies of Mycobacterium tuberculosis were obtained from tissue culture. He was treated with antiretroviral agents for HIV infection and 12 months of antituberculous agents. Clinicians should be aware of the possibility of TB in the differential diagnosis of endophthalmitis and panophthalmitis, especially in regions where TB is endemic.

Biosynthesis of the antituberculous agent caprazamycin: Identification of caprazol-3"-phosphate, an unprecedented caprazamycin-related metabolite.

Biosynthesis of the antituberculous agent caprazamycin: Identification of caprazol-3"-phosphate, an unprecedented caprazamycin-related metabolite.

Fulminant Pulmonary Tuberculosis by Infliximab in Patient with Rheumatoid Arthritis

A 72-year-old Japanese woman who had been suffering from rheumatoid arthritis for five years started treatment with infliximab. The screening of a chest X-ray before initiating infliximab treatment showed no abnormal shadows. After a month of infliximab, she was admitted to the emergency hospital with a half-month history of a fever, fatigue, dyspnea, and cough. She was diagnosed with tuberculosis from a culture smear and referred to our hospital. The chest images showed a bilateral massive cavity and infiltration. Despite the administration of an anti-tuberculous agent, the cavity and infiltration were enlarged on a chest X-ray and the patient died due to respiratory failure. Cases of tuberculosis resulting in death after a short duration of infliximab treatment have been rarely reported. We speculate that chest CT and the interferon-gamma release assay (IGRA) for tuberculosis screening should be evaluated before starting infliximab treatment, and preventive administration of isoniazid should be considered with consultation with a pulmonologist.

Prolonged hospitalisation for immigrants and high risk patients with positive smear pulmonary tuberculosis

Tuberculosis (TB) occurring in immigrants and resistance to drugs are major problems for TB control in Western countries. Directly observed therapy (DOT) reduces disease transmission, but this approach may have poor results among illegal immigrants. Our aim was to evaluate a prolonged hospitalisation programme to improve early outcome of TB treatment in high risk patients. All the consecutive adult patients with sputum smear-positive pulmonary TB admitted to 2 Italian referral TB Centres were evaluated. Hospital-based DOT was provided to high risk patients up-to smear conversion. Demographic, microbiological and clinical conditions, as potential factors associated with confirmed smear conversion at 60 and 90 days of anti-tuberculous therapy were evaluated. 122 patients were studied, 45.9% of them were immigrants (20% illegal) from high-prevalence TB countries. HIV testing was negative in all cases. Twelve patients had M. tuberculosis resistant to > or = 1 first-line anti-tuberculous agents. The rate of defaulting from TB treatment was 73%. Sputum smear became negative in 84.4% cases after 60 days and 933% cases after 90 days. At such time, smear conversion rates were similar among different high risk subgroups such as illegal immigrants (95.9%), legal foreign-born (92.5%) and Italian persons (94.8%). Persistent sputum smear positivity was independently correlated with the extent of pulmonary lesions at 60 (p < 0.0001) and 90 days (p = 0.038) of hospital-based DOT. These findings suggest that prolonged hospitalisation for illegal immigrants and high risk TB patients, may positively influence the early outcome of TB treatment despite of drug resistance and legal status.

Genome sequence comparisons of serial multi-drug-resistant Mycobacterium tuberculosis isolates over 21 years of infection in a single patient.

We report a case of chronic pulmonary multi-drug-resistant tuberculosis. Despite 14 years of treatment, Mycobacterium tuberculosis was persistently isolated from sputum. Following treatment cessation the patient remained well, although M. tuberculosis was isolated from sputum for a further 8 years. Genome sequencing of eight serial M. tuberculosis isolates cultured between 1991 and 2011 revealed 17 mutations (0.8 mutations per genome year− 1). Eight of these were persisting mutations and only two mutations were detected in the 7 years following cessation of treatment in 2004. In four isolates there were mixed alleles, suggesting the likely presence of bacterial subpopulations. The initial 1991 isolate demonstrated genotypic resistance to isoniazid (katG W91R), rifampicin (rpoB S531L), ethambutol (embB M306V), streptomycin (gidB L16R), quinolones (gyrA S95T) and P-aminosalicylic acid (thyA T202A). Subsequent resistance mutations developed for pyrazinamide (pncA I31F) and ethionamide (ethA frameshift). Such information might have been instructive when developing a treatment regimen. In retrospect and with the benefit of high-resolution genomic hindsight we were able to determine that the patient received only one or two active anti-tuberculous agents for most of their treatment. Additionally, mutations in bacA and Rv2326c were detected, which may have contributed to the persistent but mild disease course. BacA is likely to be associated with maintenance of chronic infection and Rv2326c with a decreased bacterial metabolic state. These results expand our understanding of M. tuberculosis evolution during human infection and underline the link between antibiotic resistance and clinical persistence.

First case report of cavernous sinus tuberculoma in a child

Cavernous sinus tuberculoma is very rare. This is the first reported case in a child. A 3-year-old girl presented with progressive cavernous syndrome even though adequate antibiotics had been given. Neuroimaging could not conclusively differentiate other previously reported cavernous lesions such as lymphoma, meningioma, or fungal infection. A cavernous biopsy was not allowed by her parents, but antituberculous agents were given due to abnormal chest film, reactive tuberculin test, and positive Mycobacterium tuberculosisculture from the gastric contents. Complete recovery occurred without other medication. Cavernous tuberculoma was inferred from the therapeutic response to antituberculous agents.