Dissecting erm(41)-Mediated Macrolide-Inducible Resistance in Mycobacterium abscessus.

Macrolides are the cornerstone of Mycobacterium abscessus multidrug therapy, despite that most patients respond poorly to this class of antibiotics due to the inducible resistance phenotype that occurs during drug treatment. This mechanism is driven by the macrolide-inducible ribosomal methylase encoded by erm(41), whose expression is activated by the transcriptional regulator WhiB7. However, it has been debated whether clarithromycin and azithromycin differ in the extent to which they induce erm(41)-mediated macrolide resistance. Herein, we show that macrolide resistance is induced more rapidly in various M. abscessus isolates upon exposure to azithromycin than to clarithromycin, based on MIC determination. Macrolide-induced expression of erm(41) was assessed in vivo using a strain carrying tdTomato placed under the control of the erm(41) promoter. Visualization of fluorescent bacilli in infected zebrafish demonstrates that azithromycin and clarithromycin activate erm(41) expression in vivo That azithromycin induces a more rapid expression of erm(41) was confirmed by measuring the ß-galactosidase activity of a reporter strain in which lacZ was placed under the control of the erm(41) promoter. Shortening the promoter region in the lacZ reporter plasmid identified DNA elements involved in the regulation of erm(41) expression, particularly an AT-rich motif sharing partial conservation with the WhiB7-binding site. Mutation of this motif abrogated the macrolide-induced and WhiB7-dependent expression of erm(41). This study provides new mechanistic information on the adaptive response to macrolide treatment in M. abscessus.

Cyclipostins and cyclophostin analogs inhibit the antigen 85C from Mycobacterium tuberculosis both in vitro and in vivo.

An increasing prevalence of cases of drug-resistant tuberculosis requires the development of more efficacious chemotherapies. We previously reported the discovery of a new class of cyclipostins and cyclophostin (CyC) analogs exhibiting potent activity against Mycobacterium tuberculosis both in vitro and in infected macrophages. Competitive labeling/enrichment assays combined with MS have identified several serine or cysteine enzymes in lipid and cell wall metabolism as putative targets of these CyC compounds. These targets included members of the antigen 85 (Ag85) complex (i.e. Ag85A, Ag85B, and Ag85C), responsible for biosynthesis of trehalose dimycolate and mycolylation of arabinogalactan. Herein, we used biochemical and structural approaches to validate the Ag85 complex as a pharmacological target of the CyC analogs. We found that CyC7ß, CyC8ß, and CyC17 bind covalently to the catalytic Ser124 residue in Ag85C; inhibit mycolyltransferase activity (i.e. the transfer of a fatty acid molecule onto trehalose); and reduce triacylglycerol synthase activity, a property previously attributed to Ag85A. Supporting these results, an X-ray structure of Ag85C in complex with CyC8ß disclosed that this inhibitor occupies Ag85C's substrate-binding pocket. Importantly, metabolic labeling of M. tuberculosis cultures revealed that the CyC compounds impair both trehalose dimycolate synthesis and mycolylation of arabinogalactan. Overall, our study provides compelling evidence that CyC analogs can inhibit the activity of the Ag85 complex in vitro and in mycobacteria, opening the door to a new strategy for inhibiting Ag85. The high-resolution crystal structure obtained will further guide the rational optimization of new CyC scaffolds with greater specificity and potency against M. tuberculosis.

The TetR Family Transcription Factor MAB_2299c Regulates the Expression of Two Distinct MmpS-MmpL Efflux Pumps Involved in Cross-Resistance to Clofazimine and Bedaquiline in Mycobacterium abscessus.

Mycobacterium abscessus is a human pathogen responsible for severe respiratory infections, particularly in patients with underlying lung disorders. Notorious for being highly resistant to most antimicrobials, new therapeutic approaches are needed to successfully treat M. abscessus-infected patients. Clofazimine (CFZ) and bedaquiline (BDQ) are two antibiotics used for the treatment of multidrug-resistant tuberculosis and are considered alternatives for the treatment of M. abscessus pulmonary disease. To get insights into their mechanisms of resistance in M. abscessus, we previously characterized the TetR transcriptional regulator MAB_2299c, which controls expression of the MAB_2300-MAB_2301 genes, encoding an MmpS-MmpL efflux pump. Here, in silico studies identified a second mmpS-mmpL (MAB_1135c-MAB_1134c) target of MAB_2299c. A palindromic DNA sequence upstream of MAB_1135c, sharing strong homology with the one located upstream of MAB_2300, was found to form a complex with the MAB_2299c regulator in electrophoretic mobility shift assays. Deletion of MAB_1135c-1134c in a wild-type strain led to increased susceptibility to both CFZ and BDQ. In addition, deletion of these genes in a CFZ/BDQ-susceptible mutant lacking MAB_2299c as well as MAB_2300-MAB_2301 further exacerbated the sensitivity of this strain to both drugs in vitro and inside macrophages. Overall, these results indicate that MAB_1135c-1134c encodes a new MmpS-MmpL efflux pump system involved in the intrinsic resistance to CFZ and BDQ. They also support the view that MAB_2299c controls the expression of two separate MmpS-MmpL efflux pumps, substantiating the importance of MAB_2299c as a marker of resistance to be considered when assessing drug susceptibility in clinical isolates.

Mutations in the MAB_2299c TetR Regulator Confer Cross-Resistance to Clofazimine and Bedaquiline in Mycobacterium abscessus.

New therapeutic approaches are needed against Mycobacterium abscessus, a respiratory mycobacterial pathogen that evades efforts to successfully treat infected patients. Clofazimine and bedaquiline, two drugs used for the treatment of multidrug-resistant tuberculosis, are being considered as alternatives for the treatment of lung diseases caused by M. abscessus With the aim to understand the mechanism of action of these agents in M. abscessus, we sought herein to determine the means by which M. abscessus can develop resistance. Spontaneous resistant strains selected on clofazimine, followed by whole-genome sequencing, identified mutations in MAB_2299c, encoding a putative TetR transcriptional regulator. Unexpectedly, mutants with these mutations were also cross-resistant to bedaquiline. MAB_2299c was found to bind to its target DNA, located upstream of the divergently oriented MAB_2300-MAB_2301 gene cluster, encoding MmpS/MmpL membrane proteins. Point mutations or deletion of MAB_2299c was associated with the concomitant upregulation of the mmpS and mmpL transcripts and accounted for this cross-resistance. Strikingly, deletion of MAB_2300 and MAB_2301 in the MAB_2299c mutant strain restored susceptibility to bedaquiline and clofazimine. Overall, these results expand our knowledge with respect to the regulatory mechanisms of the MmpL family of proteins and a novel mechanism of drug resistance in this difficult-to-treat respiratory mycobacterial pathogen. Therefore, MAB_2299c may represent an important marker of resistance to be considered in the treatment of M. abscessus diseases with clofazimine and bedaquiline in clinical settings.

[Telephone-Based Psychological Counselling of Accident Victims: Initial Evaluation of a Pilot Project of the German Statutory Accident Insurance in the Healthcare and Welfare Services]. / Pilotprojekt "Telefonisch-psychologische Beratung Unfallverletzter" der Berufsgenossenschaft für Gesundheitsdienst und Wohlfahrtspflege ­ Wie wird das Angebot bewertet?

A telephone-based psychological counselling service was implemented and evaluated in four regional offices of the German statutory accident insurance in healthcare and welfare services (BGW). Insurance employees/caseworkers, psychotherapists, and insured persons were asked to rate the counselling service in terms of their experiences and satisfaction. 15.5% of all insured persons initially contacted made use of the counselling service. Those using the service reported a slightly higher level of psychological distress, were less likely to be able to work 3 months after using the service and were more likely to attend a subsequent psychotherapy session. Telephone-based counselling by psychotherapists was rated as helpful by most insured persons. Caseworkers and psychotherapists also rated the concept favorably. All in all, the implementation can be regarded as successful. In a next step, the approach should be evaluated regarding its efficacy in a randomized, controlled trial.

The prospective relationship between satisfaction with information and symptoms of depression and anxiety in breast cancer: A structural equation modeling analysis.

OBJECTIVE: Previous research has demonstrated associations between satisfaction with information and reduced emotional distress in cancer patients. However, as most studies were cross-sectional, the direction of this relationship remained unclear. We therefore aimed to test whether information satisfaction predicted subsequent depression and anxiety levels, and, reciprocally, depression and anxiety levels predicted subsequent information satisfaction, thus clarifying the direction of impact. METHODS: We performed a secondary analysis of a prospective cohort study with 436 female breast cancer patients (mean age 51 years). We measured information satisfaction with 2 self-developed items, symptoms of depression with the 2-item Patient Heath Questionnaire and symptoms of anxiety with the 2-item Generalized Anxiety Disorder Scale. We created 2 structural equation models, 1 for depression and 1 for anxiety, that examined the prediction of 1-year depression (or anxiety) levels by baseline information satisfaction and, in the same model, 1-year information satisfaction by baseline depression (or anxiety) levels (cross-lagged panel analysis). RESULTS: Baseline information satisfaction predicted 1-year levels of both depression (beta = -0.17, P < .01) and anxiety (beta = -0.13, P < .01), adjusting for the baseline scores of the outcome variables. Conversely, baseline levels of depression (beta = -0.12, P < .05) and anxiety (beta = -0.16, P < .01) predicted 1-year information satisfaction, adjusting for its baseline score. CONCLUSION: Our results suggest a bidirectional relationship between information satisfaction and symptoms of depression and anxiety. Thus, provision of information may reduce subsequent depression and anxiety, while reducing depression and anxiety levels may increase satisfaction with received information. Combining the provision of information with emotional support may be particularly beneficial.

Utilization of professional psychological care in a large German sample of cancer patients.

OBJECTIVE: Although one-third of cancer patients are perceived to have a need for psychological support based on the percentage of mental disorders, little is known about the actual utilization of psychological care in cancer. We aimed to assess cancer patients' reported use of psychological care and its correlates in a large, representative sample. METHODS: In a multicenter, cross-sectional study in Germany, 4020 cancer patients (mean age 58 years, 51% women) were evaluated. We obtained self-reports of use of psychotherapy and psychological counseling. We measured distress with the Distress Thermometer, symptoms of depression with the Patient Health Questionnaire, anxiety with the Generalized Anxiety Disorder Scale, and social support with the Illness-specific Social Support Scale. In a subsample of 2141, we evaluated the presence of a mental disorder using the Composite International Diagnostic Interview. RESULTS: In total, 28.9% (95% confidence interval 27.4%-30.4%) reported having used psychotherapy or psychological counseling or both because of distress due to cancer. Independent correlates of utilization included age (odds ratio [OR] = 0.97 per year], sex (male, OR = 0.55), social support (OR = 0.96), symptoms of depression (OR = 1.04) and anxiety (OR = 1.08), the diagnosis of a mental disorder (OR = 1.68), and a positive attitude toward psychosocial support (OR = 1.27). Less than half of those currently diagnosed with a mental disorder reported having taken up psychological support offers. CONCLUSION: Special efforts should be made to reach populations that report low utilization of psychological care in spite of having a need for support.

Symptoms of depression and anxiety as predictors of physical functioning in breast cancer patients. A prospective study using path analysis.

BACKGROUND: Although symptoms of depression and anxiety are linked to health-related quality of life (HRQoL), the nature of this relationship remained unclear. We therefore aimed to examine, in a prospective study, both possible directions of impact in this relationship. To avoid conceptual and measurement overlap between depressive and anxiety symptoms, on the one hand, and HRQoL, on the other hand, we focused on the physical functioning component of HRQoL. MATERIAL AND METHODS: We conducted a secondary analysis of a prospective cohort study with 436 female breast cancer patients (mean age 51 years). Both at baseline and after 12 months, we measured symptoms of depression and anxiety with the four-item Patient Heath Questionnaire (PHQ-4) and physical functioning with the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30). Using path analysis, we estimated (1) the predictive value of symptoms of depression/anxiety for subsequent physical functioning and (2) the predictive value of physical functioning for subsequent symptoms of depression/anxiety, in the same model. RESULTS: Baseline symptoms of depression/anxiety predicted 1-year levels of physical functioning (depression: standardized ß = -.09, p = .024; anxiety: standardized ß = -.10, p = .009), while the reciprocal paths linking baseline physical functioning to subsequent depressive and anxiety symptoms were not significant, adjusting for the baseline scores of all outcome variables. CONCLUSIONS: Depressive and anxiety symptoms were predictors of the physical functioning component of HRQoL. Thus, if this relation is causal, treating breast cancer patients' depressive and anxiety symptoms may have a favorable impact on their self-reported physical functioning.

Twelve-Month and Lifetime Prevalence of Mental Disorders in Cancer Patients.

BACKGROUND: Psychological problems are common in cancer patients. For the purpose of planning psycho-oncological interventions and services tailored to the specific needs of different cancer patient populations, it is necessary to know to what extent psychological problems meet the criteria of mental disorders. The purpose of this study was to estimate the 12-month and lifetime prevalence rates of mental disorders in cancer patients. METHODS: A representative sample of patients with different tumour entities and tumour stages (n = 2,141) in outpatient, inpatient and rehabilitation settings underwent the standardized computer-assisted Composite International Diagnostic Interview for mental disorders adapted for cancer patients (CIDI-O). RESULTS: The overall 12-month prevalence for any mental disorder was 39.4% (95% CI: 37.3-41.5), that for anxiety disorders was 15.8% (95% CI: 14.4-17.4), 12.5% (95% CI: 11.3-14.0) for mood disorders, 9.5% (95% CI: 8.3-10.9) for somatoform disorders, 7.3% (95% CI: 6.2-8.5) for nicotine dependence, 3.7% (95% CI: 3.0-4.6) for disorders due to general medical condition, and 1.1% (95% CI: 0.7-1.6) for alcohol abuse or dependence. Lifetime prevalence for any mental disorder was 56.3% (95% CI 54.1-58.6), that for anxiety disorders was 24.1% (95% CI: 22.3-25.9), 20.5% (95% CI: 18.9-22.3) for mood disorders, 19.9% (95% CI: 18.3-21.7) for somatoform disorders, 18.2% (95% CI: 16.6-20.0) for nicotine dependence, 6.4% (95% CI: 5.4-7.6) for alcohol abuse or dependence, 4.6% (95% CI: 3.8-5.6) for disorders due to general medical condition, and 0.2% (95% CI: 0.1-0.6) for eating disorders. CONCLUSIONS: Mental disorders are highly prevalent in cancer patients, indicating the need for provision of continuous psycho-oncological support from inpatient to outpatient care, leading to an appropriate allocation of direct personnel and other resources.

Performance status and depressive symptoms as predictors of quality of life in cancer patients. A structural equation modeling analysis.

OBJECTIVE: This study aimed to examine whether depressive symptoms and performance status are independent predictors of both the physical and psychological domains of health-related quality of life (HRQoL) in cancer patients. METHODS: A sample of 4020 cancer patients (mean age 58 years, 51% women) was evaluated. Depressive symptoms were measured with the patient health questionnaire and HRQoL with the European Organisation for Research and Treatment of Cancer quality of life questionnaire core 30. The impact of the illness on everyday activities was assessed with physician ratings of both the Karnofsky performance status and the Eastern Cooperative Oncology Group performance status. The simultaneous effects of depression and performance status on quality of life outcomes were estimated using structural equation modeling. RESULTS: Both depressive symptoms and performance status independently predicted the physical and psychological domains of HRQoL. However, the impact of depressive symptoms on the physical HRQoL was stronger than the impact of performance status on the psychological HRQoL. CONCLUSION: Our results suggest that comorbid depressive symptoms are independently associated with both physical and psychological HRQoL in cancer patients after controlling for the physician-rated performance status. Thus, comorbid depression should be taken into account when evaluating reduced HRQoL in cancer patients. To support a causal impact of depression on HRQoL, intervention studies are needed to show that improving depression enhances cancer patients' HRQoL.