Identification of Novel Chemical Scaffolds that Inhibit the Growth of Mycobacterium tuberculosis in Macrophages

Mycobacterium tuberculosis is an important global pathogen for which new drugs are urgently required. The ability of the organism to survive and multiply within macrophages may contribute to the lengthy treatment regimen with multiple drugs that are required to cure the infection. We screened the MyriaScreen II diversity library of 10,000 compounds to identify novel inhibitors of M. tuberculosis growth within macrophage-like cells using high content analysis. Hits were selected which inhibited the intramacrophage growth of M. tuberculosis without significant cytotoxicity to infected macrophages. We selected and prioritized compound series based on their biological and physicochemical properties and the novelty of the chemotypes. We identified five chemical classes of interest and conducted limited catalog structure-activity relationship studies to determine their tractability. We tested activity against intracellular and extracellular M. tuberculosis, as well as cytoxicity against murine RAW264.7 and human HepG2 cells. Benzene amide ethers, thiophene carboxamides and thienopyridines were only active against intracellular bacteria, whereas the phenylthiourea series was also active against extracellular bacteria. One member of a phenyl pyrazole series was moderately active against extracellular bacteria. We identified the benzene amide ethers as an interesting series for further work. These new compound classes serve as starting points for the development of novel drugs to target intracellular M. tuberculosis.

Identification of novel chemical scaffolds that inhibit the growth of Mycobacterium tuberculosis in macrophages

Mycobacterium tuberculosis is an important global pathogen for which new drugs are urgently required. The ability of the organism to survive and multiply within macrophages may contribute to the lengthy treatment regimen with multiple drugs that are required to cure the infection. We screened the MyriaScreen II diversity library of 10,000 compounds to identify novel inhibitors of M. tuberculosis growth within macrophage-like cells using high content analysis. Hits were selected which inhibited the intramacrophage growth of M. tuberculosis without significant cytotoxicity to infected macrophages. We selected and prioritized compound series based on their biological and physicochemical properties and the novelty of the chemotypes. We identified five chemical classes of interest and conducted limited catalog structure-activity relationship studies to determine their tractability. We tested activity against intracellular and extracellular M.tuberculosis, as well as cytoxicity against murine RAW264.7 and human HepG2 cells. Benzene amide ethers, thiophene carboxamides and thienopyridines were only active against intracellular bacteria, whereas the phenylthiourea series was also active against extracellular bacteria. One member of a phenyl pyrazole series was moderately active against extracellular bacteria. We identified the benzene amide ethers as an interesting series for further work. These new compound classes serve as starting points for the development of novel drugs to target intracellular M. tuberculosis.

Love, sex, drugs and women’s sub-optimal adherence to MDR-TB treatment in South Africa: Opportunities for enhanced health education

Objective: Rising incidence of acquired multidrug-resistant tuberculosis (MDR-TB) in South Africa suggests low knowledge and implementation of infection prevention and control strategies in household and congregate settings. This study contributes to the under-researched area of non-biomedical responses to sub-adherence to treatment. Design: The study utilises a quasi-ethnographic qualitative case study of 10 women aged 18 to 34 years to understand their treatment adherence behaviours through the lens of their sex, gender, age, cultural beliefs and socio-economic status. Setting: This study investigated reasons for young women’s sub-optimal adherence to treatment for acquired MDR-TB in eThekwini Metro, KwaZulu-Natal province, South Africa, which records high burdens of tuberculosis (TB), MDR-TB and HIV. Methods: Primary data were collected from 20 participants who were selected through criterion, purposive and snowball sampling. Data were gathered through focus group discussions with women being treated for transmitted MDR-TB and key informant interviews with their family members, health workers and KwaZulu-Natal Provincial Department of Health personnel. Results: Anti-MDR-TB treatment affects women’s sexuality, intimate relationships, family planning intentions and reproductive health. Some vulnerable women struggle to persevere on noxious and lengthy treatment regimes that affect their reproductive and psychological health. Women may skip doses or abandon treatment when high pill burdens and adverse events make intimate and sexual relations with male partners, on whom they may depend for their livelihoods, difficult. Conclusion: It is important to consider the effects of lengthy treatment on young people’s social and sexual lives and self-esteem when (re)designing MDR-TB counselling approaches. This paper advances an evidence-based treatment education and counselling strategy to contribute to improving MDR-TB treatment adherence and success.

Web and android-based application for monitoring tuberculosis (TB) patients in Kediri City

Tuberculosis (TB) is a chronic disease that is still a public health problem globally, including Indonesia, due to its easy transmission. Treatment for TB sufferers consist of several drug combinations that are intended to eradicate germs. For TB sufferers, the key to successful treatment is the patient's compliance with taking medication every day. The lengthy treatment time is usually at least six months allowing non-adherence to taking the medication by the patient. If not treated properly, there will be a risk of disease complications, such as tuberculosis bacteria resistant to drugs, making TB treatment more difficult. In this study, an Android-based was built to remind TB sufferers to take their medication during the treatment process. In addition to the mobile-based application, there is also a web application used by drug drinking supervisors (PMO; Petugas Minum Obat in Indonesia) in monitoring TB patients, where the application can also view patient compliance statistics in taking medication and historical data on TB patients’ medical treatment. After completion and development, the application will be given to PMO officers and patients to be tested. It is hoped that the application can help the TB treatment process become more effective and prevent treatment failure from the implementation.

Discovery of Amoebicidal Compounds by Combining Computational and Experimental Approaches

Pathogenic and opportunistic free-living amoebae such as Acanthamoeba spp. can cause keratitis (AK), which may ultimately lead to permanent visual impairment or blindness. Acanthamoeba can also cause a rare but usually fatal granulomatous amoebic encephalitis (GAE). Current therapeutic options for AK require a lengthy treatment with nonspecific drugs that often are associated with adverse effects. Recent developments in the field led us to target cAMP pathways, specifically phosphodiesterase. Guided by computational tools we targeted the Acanthamoeba phosphodiesterase, RegA. Computational studies led to the construction and validation of a homology model followed by a virtual screening protocol guided by induced-fit docking and chemical scaffold analysis using our MBC chemical library. Subsequently, 18 virtual screening hits were prioritized for further testing in vitro against A. castellanii, identifying amoebicidal hits containing piperidine and urea imidazole cores. Promising activities were confirmed in the resistant cyst form of the amoeba and in additional clinical Acanthamoeba strains, increasing their therapeutic potential. Mechanism of action studies revealed that these compounds produce apoptosis through ROS-mediated mitochondrial damage. These chemical families show promise for further optimization to produce effective anti-Acanthamoebal drugs.

Conservative Treatment of Puerpera with Severe Hemorrhagic Shock and Secondary Coagulopathy

Aim: The main aim is to show that the life of a patient depends on the decisions the doctor makes as well as the proper assessment of the case. The decision to avoid a surgical procedure and continuewith the conservative treatment following the vital parameters, was beneficial for the patient who was later discharged recovered.Case report: The case is about a patient who was in labor for the fifth time with the delivery complicated by severe postpartum hemorrhage in the secondary health care institution. Despite all conservative measures taken, the hemorrhage hasn’t stopped, therefore, the subtotal hysterectomy was performed, after which the patient was directed to the Clinical Centre Kragujevac. Regarding the fact that the postpartum hemorrhage hasn’t stopped and abdominal hematoma as well as intracranial hemorrhagewere diagnosed, the main dilemma was if the surgical procedure should be redone or if the conservative treatment should be continued. By applying the conservative treatment andcontinued consultations of the multidisciplinary team, the patient was discharged from the Clinical Centre Kragujevac.Conclusion: The main issue with severe cases like this one, is to define and direct the treatment towards the lower risk rate – repeated surgery could be fatal with the current state of the patient. The estimation was correct, at the end, the patient was released after the-lengthy treatment, recovered.

Artenimol–piperaquine in children with uncomplicated imported falciparum malaria: experience from a prospective cohort

Background Although malaria remains one of the major public health threats in inter-tropical areas, there is limited understanding of imported malaria in children by paediatricians and emergency practitioners in non-endemic countries, often resulting in misdiagnosis and inadequate treatment. Moreover, classical treatments (atovaquone-proguanil, quinine, mefloquine) are limited either by lengthy treatment courses or by side effects. Since 2010, the World Health Organization (WHO) has recommended the use of oral artemisinin-based combination therapy for the treatment of uncomplicated Plasmodium falciparum malaria worldwide. The benefits of artenimol–piperaquine in children have been validated in endemic countries but experience remains limited in cases of imported malaria. Methods This prospective observational study in routine paediatric care took place at the Emergency Department, Robert-Debré Hospital (Paris, France) from September 2012 to December 2014. Tolerance and efficacy of artenimol–piperaquine in children presenting with the following inclusion criteria were assessed: P. falciparum positive on thin or thick blood smear; and the absence of WHO-defined features of severity. Results Among 83 children included in this study, treatment with artenimol–piperaquine was successful in 82 children (98.8%). None of the adverse events were severe and all were considered mild with no significant clinical impact. This also applied to cardiological adverse events despite a significant increase of the mean post-treatment QTc interval. Conclusion Artenimol–piperaquine displays a satisfying efficacy and tolerance profile as a first-line treatment for children with imported uncomplicated falciparum malaria and only necessitates three once-daily oral intakes of the medication. Comparative studies versus artemether-lumefantrine or atovaquone-proguanil would be useful to confirm the results of this study.

Host cholesterol dependent activation of VapC12 toxin enriches persister population during Mycobacterium tuberculosis infection

A worldwide increase in the frequency of multidrug-resistant and extensively drug-resistant cases of tuberculosis is mainly due to therapeutic noncompliance associated with a lengthy treatment regimen. Depending on the drug susceptibility profile, the treatment duration can extend from 6 months to 2 years. This protracted regimen is attributed to a supposedly non-replicating and metabolically inert subset of the Mycobacterium tuberculosis (Mtb) population, called ‘persisters’. The mechanism underlying stochastic generation and enrichment of persisters is not fully known. We have previously reported that the utilization of host cholesterol is essential for mycobacterial persistence. In this study, we have demonstrated that cholesterol-induced activation of a ribonuclease toxin (VapC12) inhibits translation by targeting proT tRNA in Mtb. This results in cholesterol-specific growth modulation that increases the frequency of the generation of persisters in a heterogeneous Mtb population. Also, a null mutant strain of this toxin (ΔvapC12) failed to persist and demonstrated an enhanced growth phenotype in a guinea pig model of Mtb infection. Thus, we have identified a novel strategy through which cholesterol-specific activation of a toxin–antitoxin (TA) module in Mtb enhances persister formation during infection. In addition to identifying the mechanism, the study provides opportunity for targeting persisters, a new paradigm facilitating tuberculosis drug development.

Resolution of Post-Surgical Hypergranulation Tissue with Topical Aluminum Chloride

Hypergranulation is the extension of granulation tissue beyond the required amount to close a tissue defect. We report our experience using aluminum chloride to treat a series of two patients with hypergranulation tissue. Both patients had lengthy treatment courses after Mohs surgery with growth of hypergranulation tissue that resolved once aluminum chloride was placed on the wound. Aluminum chloride is a useful hemostatic agent frequently employed in dermatology. It is a readily available and low-cost option for management of hypergranulation after dermatologic procedures. Chronic wounds are a common treatment challenge for clinicians. Due to its affordability and availability, clinicians may consider topical aluminum chloride when managing post-surgical hypergranulation tissue.

Loss of Methyltransferase Function and Increased Efflux Activity Leads to Doxycycline Resistance in Burkholderia pseudomallei

ABSTRACT The soil-dwelling bacterium Burkholderia pseudomallei is the causative agent of the potentially fatal disease melioidosis. The lack of a vaccine toward B. pseudomallei means that melioidosis treatment relies on prolonged antibiotic therapy, which can last up to 6 months in duration or longer. Due to intrinsic resistance, few antibiotics are effective against B. pseudomallei. The lengthy treatment regimen required increases the likelihood of resistance development, with subsequent potentially fatal relapse. Doxycycline (DOX) has historically played an important role in the eradication phase of melioidosis treatment. Both primary and acquired DOX resistances have been documented in B. pseudomallei; however, the molecular mechanisms underpinning DOX resistance have remained elusive. Here, we identify and functionally characterize the molecular mechanisms conferring acquired DOX resistance in an isogenic B. pseudomallei pair. Two synergistic mechanisms were identified. The first mutation occurred in a putative S-adenosyl-l-methionine-dependent methyltransferase (encoded by BPSL3085), which we propose leads to altered ribosomal methylation, thereby decreasing DOX binding efficiency. The second mutation altered the function of the efflux pump repressor gene, amrR, resulting in increased expression of the resistance-nodulation-division efflux pump, AmrAB-OprA. Our findings highlight the diverse mechanisms by which B. pseudomallei can become resistant to antibiotics used in melioidosis therapy and the need for resistance monitoring during treatment regimens, especially in patients with prolonged or recrudesced positive cultures for B. pseudomallei.