Resistance Profiles to Second-Line Anti-Tuberculosis Drugs and Their Treatment Outcomes: A Three-Year Retrospective Analysis from South India

Background: Patients with first-line drug resistance (DR) to rifampicin (RIF) or isoniazid (INH) as a first-line (FL) line probe assay (LPA) were subjected to genotypic DST using second-line (SL) LPA to identify SL-DR (including pre-XDR) under the National TB Elimination Program (NTEP), India. SL-DR patients were initiated on different DR-TB treatment regimens and monitored for their outcomes. The objective of this retrospective analysis was to understand the mutation profile and treatment outcomes of SL-DR patients. Materials and Methods: A retrospective analysis of mutation profile, treatment regimen, and treatment outcome was performed for SL-DR patients who were tested at ICMR-NIRT, Supra-National Reference Laboratory, Chennai between the years 2018 and 2020. All information, including patient demographics and treatment outcomes, was extracted from the NTEP Ni-kshay database. Results: Between 2018 and 2020, 217 patients out of 2557 samples tested were identified with SL-DR by SL-LPA. Among them, 158/217 were FQ-resistant, 34/217 were SLID-resistant, and 25/217 were resistant to both. D94G (Mut3C) of gyrA and a1401g of rrs were the most predominant mutations in the FQ and SLID resistance types, respectively. Favorable (cured and treatment complete) and unfavorable outcomes (died, lost to follow up, treatment failed, and treatment regimen changed) were recorded in a total of 82/217 and 68/217 patients in the NTEP Ni-kshay database. Conclusions: As per the testing algorithm, SL- LPA is used for genotypic DST following identification of first-line resistance, for early detection of SL-DR in India. The fluoroquinolone resistance pattern seen in this study population corelates with the global trend. Early detection of fluoroquinolone resistance and monitoring of treatment outcome can help achieve better patient management.

Trends in rifampicin and isoniazid resistance in patients with presumptive TB

BACKGROUND: Early diagnosis of drug-resistant TB (DR-TB) is crucial in preventing the spread of the disease in the community. Introduction of upfront decentralised drug susceptibility testing to district-level as part of universal drug susceptibility testing (UDST) policy increased the feasibility of rapid and early testing for drug resistance closer to the patient and has resulted in reduced circumstances for transmission. The introduction of the first-line line-probe assay (FL-LPA), GenoType^® MTBDRplus v2, has had an extensive impact on the management of multidrug-resistant TB (MDR-TB) in India.MATERIALS and METHODS: Sputum samples of patients with presumptive TB and DR-TB from selected districts of Tamil Nadu received through National TB Elimination Programme (NTEP) were subjected to FL-LPA as per programme guidelines. In this study, we present trends in genotypic resistance to isoniazid (INH) and rifampicin (RIF) during the 4 years (2016-2019) among these patients. Band patterns were analysed as per the updated GLI (Global Laboratory Initiative) LPA interpretation and reporting guidelines.RESULTS: A total of 26,349 samples were received during the study period. Smear-positive samples (n = 20231) were directly subjected to FL-LPA; smear-negative samples were cultured in liquid media and M. tuberculosis-positive cultures were tested using FL-LPA. A total of 18,441 were MTB-positive on FL-LPA. INH monoresistance, RIF monoresistance and MDR-TB was observed in respectively 8.7%, 1.1% and 3.3% of the samples. There was a decreasing trend in all types of resistance observed particularly after 2017 (P < 0.001). MDR-TB showed a steady decrease from 5.6% to 1.8%. S531L (19.5%) and S315T (61.1%) were the most common mutations identified in the rpoB and katG genes, respectively. The percentage of inhA-c-15t promoter mutation, indicating low-level INH resistance, showed a consistent increase (P < 0.001).CONCLUSION: The impact of the UDST policy on the NTEP may have led to this decreasing trend in RIF and INH resistance observed in the study period. The increase in low-level INH resistance mutation inhA-c-15t may be associated with ethionamide/prothionamide resistance, and this should be taken into account when designing DR-TB regimen.

Topical preparations for the treatment of mild-to-moderate acne vulgaris: systematic review and network meta-analysis

BACKGROUND

Acne is very common and can have a substantial impact on wellbeing. Guidelines suggest first-line management with topical treatments, but there is little evidence regarding which treatments are most effective.

OBJECTIVES

To identify the most effective and best tolerated topical treatments for acne using network meta-analysis.

METHODS

CENTRAL, MEDLINE, Embase and World Health Organization Trials Registry were searched from inception to June 2020 for randomized trials that included participants with mild/moderate acne. Primary outcomes were self-reported improvement in acne, and trial withdrawal. Secondary outcomes included change in lesion counts, Investigator's Global Assessment, change in quality of life and total number of adverse events. Network meta-analysis was undertaken using a frequentist approach. Risk of bias was assessed using the Cochrane Risk of Bias Tool and confidence in evidence was assessed using CINeMA.

RESULTS

A total of 81 papers were included, reporting 40 trials with a total of 18 089 participants. Patient Global Assessment of Improvement was reported in 11 trials. Based on the pooled network estimates, compared with vehicle, benzoyl peroxide (BPO) was effective (35% vs. 26%) for improving self-reported acne. The combinations of BPO with adapalene (54% vs. 35%) or with clindamycin (49% vs. 35%) were ranked more effective than BPO alone. The withdrawal of participants from the trial was reported in 35 trials. The number of patients withdrawing owing to adverse events was low for all treatments. Rates of withdrawal were slightly higher for BPO with adapalene (2·5%) or clindamycin (2·7%) than BPO (1·6%) or adapalene alone (1·0%). Overall confidence in the evidence was low.

CONCLUSIONS

Adapalene in combination with BPO may be the most effective treatment for acne but with a slightly higher incidence of withdrawal than monotherapy. Inconsistent reporting of trial results precluded firmer conclusions.

Interventions for oral lichen planus: A systematic review and network meta-analysis of randomized clinical trials

BACKGROUND

Corticosteroids, calcineurin inhibitors, vitamin D, photodynamic therapy, herbal drugs are some of the interventions tried in clinical trials for treating oral lichen planus. We carried out the present network meta-analysis to compare the above-mentioned interventions.

METHODS

Electronic databases were searched for randomized clinical trials evaluating interventions in patients with symptomatic oral lichen planus. Clinical resolution, clinical score, pain resolution, pain score, and adverse effects were the outcomes evaluated.

RESULTS

Fifty-five (2831 patients) trials were included. Corticosteroids (OR: 13.6; 95% CI: 1.2, 155.4), pimecrolimus (OR: 14.7; 95% CI: 1.7, 125), purslane (OR: 18.4; 95% CI: 3.5, 97), and ozonized water/corticosteroids (OR: 52; 95% CI: 1.4, 1882.6) had better rates of clinical resolution compared to placebo. Corticosteroids (OR: 3.18; 95% CI: 1.2, 8.43), ozonized water/corticosteroids (OR: 9.9; 95% CI: 2.7, 36.2), aloe vera (OR: 13; 95%: 1.5, 111.8), pimecrolimus (OR: 18.8; 95% CI: 2, 177.4) and hyaluronic acid (OR: 24.8; 95% CI: 1.3, 457.6) were significantly associated with superior rates of pain resolution compared to placebo. Pimecrolimus and cyclosporine were associated with significantly higher risk of adverse effects than placebo.

CONCLUSION

Topical corticosteroids were the most effective drug class for treating oral lichen planus.

Pulmonary Mycobacterium abscessus and response to treatment in an outpatient setting: Case series

Pulmonary disease due to Mycobacterium abscessus (Mab) has become an increasing cause of health concern, particularly among individuals infected with nontuberculous mycobacteria. Since Mab is intrinsically resistant to many antibiotics, it is very challenging to treat patients with symptomatic disease. In this case series, we report four patients with symptomatic pulmonary Mab who had prior history of antituberculosis treatment intake and declared cured at the end of treatment. The current episode was confirmed to be due to Mab infection by molecular and clinical diagnosis and received species specific-antibiotics therapy. All were periodically monitored for the sputum smear and culture conversions throughout the treatment period. The clinical course was variable though all received similar antibiotic regimen and showed varied treatment outcomes. The time of diagnosis and the treatment outcome indicate that a better understanding of host-pathogen interactions is essential for the successful treatment of pulmonary Mab infection.

Powered toothbrushes for plaque control in fixed orthodontic patients: a network meta-analysis

BACKGROUND

Orthodontic patients are at greater risk due to the inability to clean around the components directly bonded to teeth. Hence, the aim of the present network meta-analysis is to compare the utility of powered toothbrushes in plaque control in patients with orthodontic brackets compared with manual tooth brushing.

METHODOLOGY

Necessary data were extracted and analysed for Risk of Bias. Heterogeneity was assessed using Chi-square and I² tests. Random effects model was used for both direct and mixed treatment comparisons. Standardized mean difference with 95% confidence interval was the effect estimate for plaque and bleeding scores and mean difference for pocket depth. Inconsistencies between the direct and indirect estimates were evaluated by H-statistics. GRADE approach was used to assess the quality of evidence.

RESULTS

Pooled results from 14 studies showed significantly higher plaque scores in patients using manual toothbrushes. Pooled results from 13 studies showed significant higher bleeding scores as well with manual brushes. There was a significant reduction in pocket depth with electric toothbrushes.

CONCLUSION

Powered toothbrushes are a promising alternative for plaque control in patients with fixed orthodontic brackets. Stronger evidence can be established with addition of long-term clinical trials based on the recommendations.

Validation of bedaquiline drug-susceptibility testing by BACTEC MGIT 960 system for Mycobacterium tuberculosis

Background

Bedaquiline (BDQ) is a new antituberculosis (TB) drug effectively used for the treatment of multidrug-resistant and extensively drug-resistant TB. However, the reports on drug-susceptibility testing (DST) for BDQ are scarce. The study aimed to validate and standardize BDQ DST by BACTEC MGIT 960 system for Mycobacterium tuberculosis.

Methods

A panel of ten M. tuberculosis isolates comprising 8 BDQ sensitive and 2 BDQ resistant strains were used to test accuracy, repeatability, and reproducibility of BDQDST by MGIT 960. BDQ DST by Middlebrook 7H11 agar method using polystyrene tubes was used as a standard method to calculate the accuracy of the validation.

Results

DST by MGIT for BDQ showed 100% accuracy, repeatability, and reproducibility, although variations were observed in the growth units of the "test" MGIT tubes between technologist and drug stocks while testing for reproducibility.

Conclusion

BDQ DST by MGIT 960 system is accurate, repeatable, and reproducible and hence can be implemented in certified laboratories routinely performing DST by MGIT 960 system.

Comparison of implant supported mandibular overdentures and conventional dentures on quality of life: a systematic review and meta-analysis of randomized controlled studies

BACKGROUND

Conventional complete dentures and implant supported overdentures are commonly used by dentists to treat completely edentulous mandibular arches. There have been problems associated with retention and stability while treating completely edentulous mandibular arches compared to maxillary arches. Many factors have been attributed to this, primarily focusing on the decreased area available for support and increased resorption. Implant supported overdentures have increased the treatment options for resorbed ridges, especially the mandible. However, no reports have proved the superiority of one treatment option over the other, especially in terms of patient-centric outcome measures such as the Oral Health Impact Profile (OHIP). Hence, this meta-analysis was conducted.

METHODS

A literature search of Medline (via PubMed), the Cochrane Central Register of Clinical Trials (CENTRAL) and the Database of Abstracts of Reviews of Effects (DARE) was performed. The reviewers screened titles, abstracts and performed full-text screening of eligible studies. The references from these studies were further screened for additional relevant studies. A random effects model was applied to measure the significance of the per cent mean difference in OHIP scale improvement between implant and conventional dentures. The Cochrane Risk of Bias Tool was applied to assess the selection, ascertainment and selective reporting biases.

RESULTS

Five studies were reviewed and identified. Results of 441 patients (228 implant and 213 conventional) were pooled for analysis of primary outcome and other secondary outcomes. A forest plot of total OHIP scores and for secondary outcomes were obtained between the interventions. Results of 441 patients (228 implant and 213 conventional) were pooled for analysis of primary outcome with a mean difference [95% confidence interval] in the score of -30.72[-48.39, -13.05]; mean difference [95% confidence interval] in the score of -26.45[-43.56, -9.35] for functional limitation; -29.16[-60.89, 2.56] for physical pain; -77.61[-154.63, -0.60] for psychological discomfort; -33.70[-47.96, -19.44] for physical disability; -41.17[-55.93, -26.40] for psychological disability; -17.27[-29.44, 5.10] for social disability; and -28.45[-33.97, -22.92] for handicap. A statistically significant difference favouring the implant group was obtained except for physical pain.

CONCLUSIONS

The implant overdenture group performed better in regard to patient satisfaction as measured using the OHIP questionnaire. Further studies are required to identify superiority between the two treatment options.

Phage lysin to control the overgrowth of normal flora in processed sputum samples for the rapid and sensitive detection of Mycobacterium tuberculosis by luciferase reporter phage assay

Background

Phage lysin, extracted from three bacteriophages was used in place of antibiotics to control the overgrowth of normal flora in processed sputum samples leading to the sensitive detection of Mycobacterium tuberculosis using diagnostic luciferase reporter phage assay (DLRPA).

Methods

A total of 129 sputum samples were processed by modified Petroff’s method. Two Lowenstein Jensen slopes were inoculated from the processed sputum deposit thus obtained. The remaining deposits were transferred to 7 ml of Middlebrook 7H9 complete medium supplemented with phage lysin and incubated at 37°C. DLRPA was done using phAE129 at days 7, 9, 14 and 21. At the end of day 21, the samples were centrifuged and the pellets were inoculated on to 2 more LJ slopes to validate DLRPA results.

Results

The sensitivity and specificity of DLRPA in detecting M. tuberculosis from sputum specimens was 90% and 81% respectively compared to conventional LJ culture. The agreement between the methods was 87%. The rate of contamination for DLRPA using phage lysin was 9.3%.

Conclusion

Phage lysin can be used to decontaminate sputum samples for the detection of M. tuberculosis by DLRPA directly from processed sputum specimens.

Characterization of temperate phage Che12 and construction of a new tool for diagnosis of tuberculosis

A temperate phage, Che12, able to infect Mycobacterium tuberculosis, was isolated from soil samples taken from tuberculosis sanatorium area in Chennai, India. The plaque morphology of this phage showed varying grades of turbidity on lawns of M. tuberculosis. The temperate nature of Che12 was established by super infection immunity. Phage integration into the host genomic DNA was confirmed by Southern hybridization using Che12 DNA as a probe. PCR amplification and sequencing of a part of the integrated phage genome in a M. tuberculosis lysogen also confirmed the temperate nature of Che12. The morphology of the phage particles was observed by electron microscopy, revealing similarities to other mycobacteriophages like L5, D29 and TM4. A luciferase reporter phage, phAETRC16, was constructed by cloning firefly luciferase gene into Che12. Infection of viable M. tuberculosis cells by phAETRC16 resulted in expression of luciferase leading to sustained light output. Che12, a true temperate phage infecting M. tuberculosis, is thus ideally suited for developing a diagnostic tool facilitating rapid diagnosis of M. tuberculosis.

Construction and evaluation of luciferase reporter phages for the detection of active and non-replicating tubercle bacilli

The luciferase reporter phages (LRP) show great promise for diagnostic mycobacteriology. Though conventional constructs developed from lytic phages such as D29 and TM4 are highly specific, they lack sensitivity. We have isolated and characterized Che12, the first true temperate phage infecting M. tuberculosis. Since the tuberculosis (TB) cases among HIV infected population result from the reactivation of latent bacilli, it would be useful to develop LRP that can detect dormant bacteria. During dormancy, pathogenic mycobacteria switch their metabolism involving divergent genes than during normal, active growth phase. Since the promoters of these genes can potentially function during dormancy, they were exploited for the construction of novel mycobacterial luciferase reporter phages. The promoters of hsp60, isocitrate lyase (icl), and alpha crystallin (acr) genes from M. tuberculosis were used for expressing firefly luciferase gene (FFlux) in both Che12 and TM4 phages and their efficiency was evaluated in detecting dormant bacteria from clinical isolates of M. tuberculosis. These LRP constructs exhibited detectable luciferase activity in dormant as well as in actively growing M. tuberculosis. The TM4 ts mutant based constructs showed about one log increase in light output in three of the five tested clinical isolates and in M. tuberculosis H37Rv compared to conventional lytic reporter phage, phAE129. By refining the LRP assay format further, an ideal rapid assay can be designed not only to diagnose active and dormant TB but also to differentiate the species and to find their drug susceptibility pattern.

261.Probiotic Lactobacillus in seminal plasma

Commensal bacteria of the Lactobacillus genus are implicated in beneficial 'probiotic' roles in the gut and other mucosal tissues. Their presence reduces the incidence of pathogenic infections, both passively and via production of antimicrobial substances, and through Toll-like receptor-mediated activation of cytokine expression in host tissues. Lactobacilli are present in the female reproductive tract but have not been examined in the male. This study aimed to investigate, by selective culture techniques and real-time quantitative PCR, the prevalence in boar seminal plasma of Lactobacilli compared with other pathogenic bacteria. Using acidified Rogosa Agar, Lactobacilli were cultured from 3/3 fresh semen samples and were found to be most prevalent in the first fraction of the ejaculate. For PCR, DNA was extracted from reference bacterial cultures and archived seminal plasma samples from 40 healthy boars. Bacterial species-specific primers targeting Lactobacillus 16s and 16s-23s rDNA sequences, and Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus-specific Sau3AI, oprL, and 16s rDNA genes respectively, were used in real-time PCR assays employing SYBRgreen (Applied Biosystems) technology. Lactobacilli were detected in 22/40 (55%) of seminal plasma samples, while pathogenic bacteria were detected in <10% of samples (Staphylococcus aureus, 1/40; Pseudomonas aeruginosa, 2/40; and Bacillus, 3/40). The Lactobacillus content of individual boars ranged from 1.5 to 15 × 106 cells/mL, and within boars, content varied within 30% of the mean value in successive samples over a 6-month period. We conclude that Lactobacilli are present in abundance in boar seminal plasma compared to other potentially pathogenic bacteria. These bacteria may protect the male tract from pathogen infection, and after ejaculation, may influence the female immune response to male antigens. Ongoing studies will investigate whether Lactobacilli abundance in seminal plasma correlates with boar fertility, and examine the potential value of improving reproductive performance in pigs and other species by administration of probiotic agents.