Ethambutol toxicity manifesting as acute onset psychosis

Arabinogalactan enhances Mycobacterium marinum virulence by suppressing host innate immune responses

Arabinogalactan (AG) participates in forming the cell wall core of mycobacteria, a structure known as the mAGP complex. Few studies have reported the virulence of inartificial AG or its interaction with the host immune system. Using clustered regularly interspaced short palindromic repeats interference gene editing technology, conditional Mycobacterium marinum mutants were constructed with a low expression of embA or glfT2 (EmbA_KD or GlfT2_KD), which are separately involved in the biosynthesis of AG arabinose and galactose domains. High-performance gel permeation chromatography and high-performance liquid chromatography assays confirmed that the EmbA_KD strain showed a remarkable decrease in AG content with fragmentary arabinose chains, and the GlfT2_KD strain displayed less reduction in content with cut-down galactose chains. Based on transmission and scanning electron microscopy observations, the cell walls of the two mutants were found to be dramatically thickened, and the boundaries of different layers were more distinct. Phenotypes including the over-secretion of extracellular substances and enhanced spreading motility with a concomitant decreased resistance to ethambutol appeared in the EmbA_KD strain. The EmbA_KD and GlfT2_KD strains displayed limited intracellular proliferation after infecting murine J774A.1 macrophages. The disease progression infected with the EmbA_KD or GlfT2_KD strain significantly slowed down in zebrafish/murine tail infection models as well. Through transcriptome profiling, macrophages infected by EmbA_KD/GlfT2_KD strains showed enhanced oxidative metabolism. The cell survival measured using the CCK8 assay of macrophages exposed to the EmbA_KD strain was upregulated and consistent with the pathway enrichment analysis of differentially expressed genes in terms of cell cycle/apoptosis. The overexpression of C/EBPβ and the increasing secretion of proinflammatory cytokines were validated in the macrophages infected by the EmbA_KD mutant. In conclusion, the AG of Mycobacterium appears to restrain the host innate immune responses to enhance intracellular proliferation by interfering with oxidative metabolism and causing macrophage death. The arabinose chains of AG influence the Mycobacterium virulence and pathogenicity to a greater extent.

Mycobacterial ethambutol responsive genes and implications in antibiotics resistance

Mycobacterium tuberculosis (M. tuberculosis), the causative agent of tuberculosis (TB), remains a formidable threat in mortality and morbidity worldwide. Ethambutol (EMB) is one of the first-line drugs regimens for TB treatment. Arabinosyl transferases are established targets of EMB, which is involved in the biosynthesis of arabinogalactan (AG) and lipoarabinomannan (LAM). Mutations among embCAB operon are responsible for around 70% clinical EMB resistant M. tuberculosis. In this review, we summarised other potential factors associated with EMB resistance via analysing whole genome, proteome and transcriptome of M. tuberculosis exposed to EMB. This will help to design better diagnosis of EMB resistance.

Isoniazid-Induced Acute Psychosis in a Patient with Pleural Tuberculosis

Tuberculosis is one of the top 10 causes of death and the leading cause from a single infectious agent (above HIV/AIDS). Isoniazid is highly bactericidal against replicating tubercle bacilli and is a component of all antituberculous chemotherapeutic regimens currently recommended by the World Health Organization (WHO). Several neuropsychiatric adverse effects, following both therapeutic and overdose use of isoniazid, have been described and isoniazid-induced psychosis, although uncommon, has been reported in the literature. We describe the case of a 21-year-old black woman, with no prior psychiatric history, who developed a psychotic episode four days after she was started on isoniazid. This case highlights psychosis arising as a possible adverse effect of isoniazid and the importance of remaining vigilant when antituberculous therapy is started.

Antibiotics and mania: A systematic review

OBJECTIVES

Mania can occur secondary to a medical condition and can be elicited by various pharmacological treatments, both in patients with or without a history of affective disorder. Antibiotic-induced mania or antibiomania is suggested to be a rare phenomenon. We reviewed the literature in order to collect published reports of antibiomania and to summarize new insights about its mechanism and management.

METHODS

We performed a MEDLINE-search and used manual cross-referencing for reports of antibiotic-induced mania and included cases in which a (hypo)manic episode was diagnosed in close temporal relationship with the prescription of an antibiotic.

RESULTS

47 cases were published. Patients' ages ranged from 3 to 77 years (mean 40). Two-thirds of the cases were male. Twelve different anti-bacterial agents were implicated, with antitubercular agents, macrolides and quinolones being the most common causative groups.

CONCLUSIONS

Antibiotic treatment can be associated with (hypo)mania. The paucity of reported cases precludes statements regarding incidence or antibiotic-specific warnings. In the event of an antibiotic-induced mania, the suspicious drug should be discontinued and manic symptoms can be treated lege artis. The pathophysiological mechanism of antibiomania remains elusive.

Cycloserine-induced psychosis in a young female with drug-resistant tuberculosis

OBJECTIVE

To report a case of cycloserine-induced acute psychosis in a young female while on second line antitubercular treatment (ATT) for tubercular meningitis.

METHOD

Case report.

RESULTS

A 20-year-old female, known case of tubercular meningitis on ATT since 8 months, presented with a 10-days history of headache, vomiting, and photophobia. A provisional diagnosis of drug-resistant tuberculosis was made, and second-line ATT including cycloserine (750 mg/day) and levofloxacin (750 mg/day) was added. Three days after the start of cycloserine and levofloxacin, the patient developed psychosis with delusions and hallucinations. Since the patient was on several drugs with potential to cause psychotic reaction, we considered a provisional diagnosis of drug-induced acute psychosis. Two days following cycloserine withdrawal, the patient improved significantly, and on the third day, she was absolutely normal with disappearance of psychotic symptoms.

CONCLUSION

Our case highlights the importance of awareness regarding psychiatric adverse events of antitubercular agents and the reversible nature of the adverse events on drug withdrawal. We also suggest that caution should be exercised while administering cycloserine in MDR-TB patients because of a higher risk of psychiatric adverse events.

A review of the interplay between tuberculosis and mental health

AIMS

Tuberculosis and mental illness share common risk factors including homelessness, HIV positive serology, alcohol/substance abuse and migrant status leading to frequent comorbidity. We sought to generate a comprehensive literature review that examines the complex relationship between tuberculosis and mental illness.

METHODS

A literature search was conducted in MedLine, Ovid and Psychinfo, with further examination of the references of these articles. In total 316 articles were identified. It was not possible to conduct a formal meta-analysis due to the absence of randomised controlled data.

RESULTS

Rates of mental illness of up to 70% have been identified in tuberculosis patients. Medications used in the treatment of common mental illnesses, such as depression, may have significant interactions with anti-tuberculosis agents, especially isoniazid and increasingly linezolid. Many medications used in the treatment of tuberculosis can have significant adverse psychiatric effects and some medications such as rifampicin may reduce the effective doses of anti-psychotics y their enzyme induction actions. Treatment with agents such as cycloserine has been associated with depression, and there have been reported cases of psychosis with most anti-tuberculous agents. Mental illness and substance abuse may also affect compliance with treatment, with attendant public health concerns.

CONCLUSIONS

As a result of the common co-morbidity of mental illness and tuberculosis, it is probable that physicians will encounter previously undiagnosed mental illness among patients with tuberculosis. Similarly, psychiatrists are likely to meet tuberculosis among their patients. It is important that both psychiatrists and physicians are aware of the potential for interactions between the drugs used to treat tuberculosis and psychiatric conditions.

Psychiatric morbidity and other factors affecting treatment adherence in pulmonary tuberculosis patients

As the overall prevalence of TB remains high among certain population groups, there is growing awareness of psychiatric comorbidity, especially depression and its role in the outcome of the disease. The paper attempts a holistic approach to the effects of psychiatric comorbidity to the natural history of tuberculosis. In order to investigate factors associated with medication nonadherence among patients suffering from tuberculosis, with emphasis on psychopathology as a major barrier to treatment adherence, we performed a systematic review of the literature on epidemiological data and past medical reviews from an historical perspective, followed by theoretical considerations upon the relationship between psychiatric disorders and tuberculosis. Studies reporting high prevalence rates of psychiatric comorbidity, especially depression, as well as specific psychological reactions and disease perceptions and reviews indicating psychiatric complications as adverse effects of anti-TB medication were included. In sum, data concerning factors affecting medication nonadherence among TB patients suggested that better management of comorbid conditions, especially depression, could improve the adherence rates, serving as a framework for the effective control of tuberculosis, but further studies are necessary to identify the optimal way to address such issues among these patients.

Isoniazid- and ethambutol-induced psychosis

Most cases of antituberculous agent–associated psychoses were caused by isoniazid (INH), with ethambutol (EMB)-induced psychosis being rare. The concomitant occurrence of INH- and EMB- induced psychosis and in a single individual is extremely uncommon. We report a case of 28-year-old male who developed psychotic symptoms on start of EMB initially and later on INH also. He was prescribed rifampicin, pyrazinamide, and ofloxacin and had no further psychotic symptoms.