Papain-cetylpyridinium chloride and pepsin-cetylpyridinium chloride; two novel, highly sensitive, concentration, digestion and decontamination techniques for culturing mycobacteria from clinically suspected pulmonary tuberculosis cases

Comparison of Sputum Treated with Power Ultrasound and Routine NALC-NaOH Methods for Mycobacterial Culture: A Prospective Study

Mycobacterial culture remains the gold standard for the diagnosis of active tuberculosis. However, an appropriate digestion and decontamination method is essential for the effective recovery of tubercle bacilli in culture. The study was designed to compare the efficacy of sputum treated with power ultrasound (PU) and routine NALC-NaOH methods for mycobacterial culture from clinically suspected cases of pulmonary tuberculosis. To evaluate the PU and routine NALC-NaOH methods, sputum specimens (n = 597) were studied (culturing on MGIT 960), and the performances were compared. Of the 597 samples, 89 (14.91%) sputum samples treated with the NaOH-NALC method were mycobacterial culture positive, including Mycobacterium tuberculosis (M.TB; n = 77, 12.90%) and nontuberculous mycobacteria (NTM; n = 12, 2.01%). One hundred and ten (18.43%) sputum samples treated with the PU method were culture positive, including M.TB (n = 87, 14.57%) and NTM (n = 23, 3.85%). The PU method detected 10 additional cases of M.TB and 11 additional cases of NTM when compared to the NALC-NaOH method. Statistical analysis showed that a significant difference was found in the culture-positive ratio of M.TB and NTM between the two method groups (p < 0.05). Compared with that of the NALC-NaOH method (8.04%), sputum treated with PU method (4.86%) had a significantly lower contamination rate (p < 0.05). In conclusion, our data indicate that, compared with the NALC-NaOH method, the PU method is a rapid and effective approach for mycobacterial culture when detecting active TB. However, its accurate mechanism has not been well addressed, and further investigation is still required.

Progress Report: Antimicrobial Drug Discovery in the Resistance Era

Antibiotic resistance continues to be a most serious threat to public health. This situation demands that the scientific community increase their efforts for the discovery of alternative strategies to circumvent the problems associated with conventional small molecule therapeutics. The Global Antimicrobial Resistance and Use Surveillance System (GLASS) Report (published in June 2021) discloses the rapidly increasing number of bacterial infections that are mainly caused by antimicrobial-resistant bacteria. These concerns have initiated various government agencies and other organizations to educate the public regarding the appropriate use of antibiotics. This review discusses a brief highlight on the timeline of antimicrobial drug discovery with a special emphasis on the historical development of antimicrobial resistance. In addition, new antimicrobial targets and approaches, recent developments in drug screening, design, and delivery were covered. This review also discusses the emergence and roles of various antibiotic adjuvants and combination therapies while shedding light on current challenges and future perspectives. Overall, the emergence of resistant microbial strains has challenged drug discovery but their efforts to develop alternative technologies such as nanomaterials seem to be promising for the future.

Pancreatin-Cetyl Pyridinium Chloride Digestion and Decontamination Method; A Novel, Sensitive, Cost-Effective Method for Culturing Mycobacterium tuberculosis

The present study evaluated the performance of newly developed pancreatin-cetylpyridinium chloride (pancreatin-CPC) digestion and decontamination method (DDM) with N-acetyl L-Cysteine-sodium hydroxide (NALC-NaOH) DDM for isolation of Mycobacteria from clinically suspected pulmonary tuberculosis (PTB) patients. For the study, sputum samples (n = 613) obtained from clinically suspected PTB cases were subjected to direct microscopy, pretreatment with NALC-NaOH DDM (reference method), and pancreatin-CPC DDM followed by culture, and the data were analyzed. The direct microscopy illustrated diagnostic accuracies of 60.4% (sensitivity), 99.77% (specificity), 98.9% (positive predictive value) and 88.3% (negative predictive value), respectively (against culture) for the detection of Mycobacterial species. The pancreatin-CPC DDM showed competitive diagnostic accuracies (against NALC-NaOH DDM) of 99.32% (sensitivity), 94.07% (specificity), 85.05% (positive predictive value), and 99.76% (negative predictive value), respectively, for the isolation of Mycobacterial species. In conclusion, pancreatin-CPC DMM was a highly sensitive, technically simple, and cost-effective method, suggesting its competence to substitute the currently used NALC-NaOH DDM.