Changes in skin discoloration according to clofazimine dosage in nontuberculous mycobacterial pulmonary disease.

Although clofazimine is currently one of the standard regimens for Mycobacterium abscessus, it frequently causes skin discoloration, posing esthetic concerns for patients. We studied thirteen Asian patients with pulmonary nontuberculous mycobacterial disease treated with clofazimine at the NHO Kinki Chuo Chest Medical Center. In three patients (two women and one man) whose dosing regimens were altered owing to skin discoloration, we continuously measured luminance (L*), red-green (a*), and yellow-blue (b*) values (using a colorimeter) in both sun-exposed and sun-unexposed skin areas at each visit. Compared to baseline L* and a* values, the ΔL* values were negative (decreased brightness) and Δa* values were positive (increased redness) while patients received daily clofazimine. After switching to intermittent or reduced dosing, these changes gradually diminished. If such a dose reduction does not affect the therapeutic outcome, an even lower clofazimine dose may be attempted to minimize skin adverse effects.

Efficacy of an oscillating positive expiratory pressure device in patients with Mycobacterium avium complex pulmonary disease.

Patients with Mycobacterium avium complex pulmonary disease (MAC-PD) often suffer from chronic symptoms such as sputum production, which reduces quality of life. Oscillatory positive expiratory pressure (OPEP) devices are used in physiotherapy to promote the clearance of respiratory secretions. We report two cases of improved lung function and improved scores on the Leicester Cough Questionnaire (LCQ) and the Breathlessness, Cough and Sputum Scale (BCSS) after the use of OPEP in patients with MAC-PD where treatment with guideline-based therapy, including amikacin liposome inhalation suspension, had proved ineffective for symptoms. Use of OPEP might maximize the efficacy of therapy and thereby improves outcomes in patients with MAC-PD. It is important to use both guideline-based therapy and OPEP, especially in patients whose health-related quality of life is affected by sputum symptoms. Further prospective studies are warranted to assess the benefit of adding OPEP to guidelines concerning therapy for patients with MAC-PD and sputum symptoms.

Cases of severe Mycobacterium avium lung disease occurred in a married couple caused by identical strain.

Bacteria of the Mycobacterium avium complex, which are environmental organisms found in soil and water, have been found to cause human lung diseases. Although infection is reported to occur in cohabiting patients, the incidence of infection from the single clone remains rarely documented. Herein, we report a case of M. avium lung disease caused by specimens with the same clone strains in a married couple. The wife, a 67-year-old female, had severe M. avium lung disease despite receiving multidrug chemotherapy for eleven years. The husband, a 68-year-old male, died of acute lung injury complicated by M. avium pleurisy. The result of the variable-number tandem-repeat analysis of isolates from serial sputum specimens of both patients indicated that the severe M. avium lung disease in a married couple was caused by the isolates with identical pattern. This case were considered to have acquired clarithromycin resistance during each clinical course, revealing the possibility of infection with a strain that may induce severe pulmonary condition.

The feasibility of rifampicin Re-administration in patients with tuberculosis and Clostridioides difficile infection.

BACKGROUND: The effects of a rifampicin (RIF) on the evolution of Clostridioides difficile infection (CDI) have not previously been investigated and there is currently no consensus on whether RIF re-administration is feasible. METHODS: This retrospective observational study included consecutive tuberculosis (TB) patients diagnosed with comorbid RIF-associated CDI (RA-CDI) using strict diagnostic criteria. We investigated the association between RA-CDI and clinical outcomes, and also examined the feasibility of re-administering RIF. RESULTS: Out of the 11,230 patients were admitted to TB ward at our hospital, 156 TB patients (1.4%) were diagnosed with CDI and the overall incidence of CDI was calculated as 2.1 cases per 10,000 patient-days. Of 156 patients with CDI, 86 were diagnosed with RA-CDI, of whom 28 (32.6%) were re-administered with RIF. In the re-administration group, time to initial sputum smear conversion was significantly shorter than for patients who were not re-administered with RIF (42 days [interquartile range, IQR: 35-65] vs. 55 days [IQR: 44-70], p = 0.041). Further, RIF re-administration significantly reduced length of hospital stay (69 days [IQR: 66-82] vs. 81 days [IQR: 72-89], p = 0.014). Ten patients (35.7%) had recurrent CDI after RIF re-administration. On the other hand, 15 patients (53.6%) were able to continue their TB treatment, including the RIF regimen. CONCLUSIONS: The present study strengthens the argument for including RIF in the list of antibiotics that can induce CDI, particularly in elderly men suffering from underlying conditions. Although careful attention must be paid to the possibility of CDI recurrence, a strategy of re-administration of RIF is feasible.

Two New Cases of Pulmonary Infection by Mycobacterium shigaense, Japan.

We report 2 case-patients in Japan with Mycobacterium shigaense pulmonary infections. One patient was given aggressive treatment and the other conservative treatment, according to distinctive radiologic evidence. A close phylogenetic relationship based on whole-genome sequencing was found between strain from the conservatively treated patient and a reference strain of cutaneous origin.

Bacterial population kinetics in heteroresistant Mycobacterium tuberculosis harbouring rare resistance-conferring mutations in gyrA and rpoB imply an epistatic interaction of mutations in a pre-XDR-TB patient.

OBJECTIVES: Bacterial population kinetics of strains harbouring drug resistance-conferring mutations within a patient often show cryptic resistance in clinical practice. We report a case that showed emergence and dominance of Mycobacterium tuberculosis with uncommon rpoB and gyrA mutations, followed by an rpoC compensatory mutation, during treatment. METHODS: A pre-XDR-TB patient showed heteroresistance to rifampicin and levofloxacin during treatment as a result of intermittent self-cessation. WGS was applied to investigate intra-host strain composition using five pairs of isolates from sputum samples. RESULTS: The subclone in this study possessed rare mutations conferring resistance to rifampicin (rpoB V170F) and levofloxacin (gyrA S91P) and it rapidly outcompeted other subclones during treatment that included levofloxacin but not rifampicin (<7 days). The high-probability compensatory mutation rpoC V483A also emerged and became dominant subsequent to the rpoB V170F mutation. CONCLUSIONS: To the best of our knowledge, this is the first case showing the emergence of such a rare variant that dominated the population within a patient during treatment of TB.

Effective treatment for clarithromycin-resistant Mycobacterium avium complex lung disease.

Clinical management of macrolide-resistant Mycobacterium avium complex (MR-MAC) lung disease is difficult. To date, there only exist a limited number of reports on the treatment of clarithromycin-resistant MAC (CR-MAC) lung disease. This study aimed to evaluate prognostic factors and identify effective treatments in CR-MAC lung disease. We retrospectively collected clinical data of patients newly diagnosed with CR-MAC lung disease at the Kinki-Chuo Chest Medical Center between August 2010 and June 2018. Altogether, 37 patients with CR-MAC lung disease were enrolled. The median age was 69 years; 30, 22, and 21 patients received clarithromycin, ethambutol, and rifampicin, respectively, on their own or in drug combination. The observed sputum culture conversion rate was 29.7% (11/37 patients). In univariate analysis, ethambutol significantly increased the rate of sputum culture conversion (p = 0.027, odds ratio (OR) 10; 95% confidence interval (CI) 1.11-89.77). Multivariate analysis confirmed that ethambutol increased sputum culture conversion rate (p = 0.026; OR 21.8; 95% CI 1.45-329) while the existence of lung cavities decreased it (p = 0.04; OR 0.088; 95% CI 0.009-0.887). The combined use of ethambutol with other drugs may improve sputum culture conversion rate in CR-MAC lung disease.

Mycobacterium caprae Infection in Captive Borneo Elephant, Japan.

In 2016, disseminated tuberculosis caused by Mycobacterium caprae was diagnosed in a captive Borneo elephant in Japan. The bacterium was initially identified from clinical isolates. An isolate collected during a relapse showed isoniazid monoresistance and a codon 315 katG mutation.

Performance evaluation of Xpert MTB/RIF in a moderate tuberculosis incidence compared with TaqMan MTB and TRCRapid M.TB.

Xpert MTB/RIF is an automated nucleic acid amplification test (NAT) that can detect the presence of Mycobacterium tuberculosis complex (MTC) in clinical specimens as well as rifampicin (RIF) resistance resulting from rpoB mutation. Despite its high sensitivity and specificity for diagnosing tuberculosis (TB) with or without RIF resistance, the clinical performance of the test is variable. In this study, we evaluated the performance of Xpert MTB/RIF in a setting of moderate TB burden and high medical resources. A total of 427 sputum specimens were obtained from 237 suspected TB cases. Of these, 159 were identified as active TB, while the other 78 were non-TB diseases. The overall sensitivity and specificity of MTC detection by Xpert MTB/RIF using culture results as a reference were 86.8% [95% confidence interval (CI): 81.8%-90.6%] and 96.8% (95% CI: 93.1%-98.5%), respectively. Among MTC-positive culture specimens, Xpert MTB/RIF positivity was 95.2% (95% CI: 91.2%-97.5%) in smear-positive and 44.7% (95% CI 30.1-60.3) in smear-negative specimens. Xpert MTB/RIF was similar to other NATs (TaqMan MTB and TRCRapid M.TB) in terms of performance. Xpert MTB/RIF detected 25 RIF-resistant isolates as compared to 22 with the mycobacterial growth indicator tube antimicrobial susceptibility testing system, yielding a sensitivity of 100% (95% CI: 85.1%-100%) and specificity of 98.3% (95% CI: 95.1%-99.4%). These results indicate that although sensitivity in smear-negative/culture-positive specimens was relatively low, Xpert MTB/RIF is a useful diagnostic tool for detecting TB and RIF resistance even in settings of moderate TB burden.

[CLINICAL STUDY OF 29 CASES OF ENDOBRONCHIAL TUBERCULOSIS].

[Background] Endobronchial tuberculosis (EBTB) is defined as a tuberculosis infection of the tracheobronchial tree and is often misdiagnosed as bronchial asthma or bron- chitis owing to a lack of typical imaging findings. [Aim] The aim of this study was to elucidate the clinical characteristics of EBTB. [Method] We retrospectively studied EBTB patients hos- pitalized at the National Hospital Organization Kinki-chuo Chest Medical Center (Sakai City, Japan) between January 2005 and April 2014. [Result] A total of 29 patients (8 men and 21 women) were enrolled in this study. The patients' ages ranged from 17 to 86 years. Cough was the most frequently reported symptom. The interval between the appearance of symptoms and an EBTB diagnosis was significantly longer than usual when there was an initial misdiagnosis of bronchial asthma. The most frequent finding of fiber-optic bronchoscopy performed after more than 1 month of treatment was a V-type scar based on Arai's classification system. [Conclusion] A misdiagnosis of EBTB as bronchial asthma leads to a significant delay in correct diagnosis and treat- ment. EBTB must be included in the differential diagnoses of chronic cough and airway constriction sound.

[Genetic analysis reveals misidentification of Mycobacterium lentiflavum as Mycobacterium intracellulare by the COBAS TaqMan MAI test].

OBJECTIVE: To evaluate COBAS TaqMan MAI test misidentification of Mycobacterium lentiflavum as Mycobacterium intracellulare. MATERIALS AND METHODS: Preliminary comparative analysis identified 13 clinical isolates used in this study as COBAS Amplicor MAV and MIN-negative but COBAS TaqMan MAI-positive. The COBAS TaqMan MAI test limit of detection and reproducibility were evaluated by tenfold dilution series from 3 x 10(8) CFU/mL. Isolate 16S rDNA nucleotide sequences were compared with Mycobacterium avium and M. intracellulare. RESULTS: Discrepancies were observed between isolates identified as M. lentiflavum by 16S rDNA sequencing and as M. intracellulare by the COBAS TaqMan MAI test. The false-positive results were verified by sequence comparison of a randomly sampled clinical isolate and the M. intracellulare reference strain. Sequence analysis of M. lentiflavum and M. intracellulare 16S rDNA amplification products showed at least 3 mismatches between species. The high identity in the sequence was found for M. intracellulare by COBAS TaqMan MAI. CONCLUSION: In Japan, commercially available nucleic acid probe- and amplification-based tests cannot identify M. lentiflavum. Correct identification, though challenging, is possible using standard cultivation procedures for colony growth. Misleading results using the COBAS TaqMan MAI kit may lead to erroneous diagnoses.

[Considerations on uses of newly developed anti-tuberculosis drugs for multi-drug resistant tuberculosis].

We, group of tuberculosis experts, made discussions over how to improve the quality of treatment of multidrug resistant tuberculosis using a newly developed anti-tuberculosis drug, and at the same time, how to prevent the disadvantages of the treated patients and also that of persons who would be infected with newly produced drug-resistant bacilli, by preventing the emergence of resistance to the new drug. A series of proposals are made.

Amikacin liposome inhalation suspension for Mycobacterium avium complex pulmonary disease: A subgroup analysis of Japanese patients in the randomized, phase 3, CONVERT study.

BACKGROUND: CONVERT, a randomized, active-controlled, global, Phase 3 trial demonstrated that patients with treatment-refractory Mycobacterium avium complex (MAC) pulmonary disease were more likely to achieve culture conversion with amikacin liposome inhalation suspension (ALIS) plus guideline-based therapy (GBT) versus those continuing on GBT alone. This subgroup analysis reports the efficacy and safety of ALIS in Japanese patients enrolled in CONVERT. METHODS: Japanese patients aged ≥20 years with treatment-refractory MAC pulmonary disease from Japanese sites were included. Patients were randomized to receive once-daily 590 mg ALIS + GBT or GBT alone; patients converting by Month 6 remained in the study to complete 12-month treatment followed by a 12-month off-treatment period. Nonconverters exited the study at Month 8. The primary endpoint was the proportion of patients achieving culture conversion by Month 6. RESULTS: Of the 59 Japanese patients screened, 48 were randomized to receive ALIS + GBT (n = 34) or GBT alone (n = 14), and 41/48 (85.4 %) were women. The mean (standard deviation) age of patients was 64.5 (8.6) years, and 83.3 % of patients had bronchiectasis at baseline. By Month 6, sputum culture conversion was cumulatively achieved in 9/34 (26.5 %) patients receiving ALIS + GBT versus none receiving GBT alone. Treatment-emergent adverse events were reported in 94.1 % and 100.0 % of patients receiving ALIS + GBT and GBT alone, respectively. No deaths were reported. CONCLUSIONS: The efficacy observed in the Japanese subpopulation was largely consistent with that in the overall CONVERT study population, with more patients achieving culture conversion with ALIS + GBT versus GBT alone. Safety profiles were similar between the overall population and the Japanese subpopulation. CLINICAL TRIAL REGISTRATION: NCT02344004.

NAT2 genotype guided regimen reduces isoniazid-induced liver injury and early treatment failure in the 6-month four-drug standard treatment of tuberculosis: a randomized controlled trial for pharmacogenetics-based therapy.

OBJECTIVE: This study is a pharmacogenetic clinical trial designed to clarify whether the N-acetyltransferase 2 gene (NAT2) genotype-guided dosing of isoniazid improves the tolerability and efficacy of the 6-month four-drug standard regimen for newly diagnosed pulmonary tuberculosis. METHODS: In a multicenter, parallel, randomized, and controlled trial with a PROBE design, patients were assigned to either conventional standard treatment (STD-treatment: approx. 5 mg/kg of isoniazid for all) or NAT2 genotype-guided treatment (PGx-treatment: approx. 7.5 mg/kg for patients homozygous for NAT2 4: rapid acetylators; 5 mg/kg, patients heterozygous for NAT2 4: intermediate acetylators; 2.5 mg/kg, patients without NAT2 4: slow acetylators). The primary outcome included incidences of 1) isoniazid-related liver injury (INH-DILI) during the first 8 weeks of therapy, and 2) early treatment failure as indicated by a persistent positive culture or no improvement in chest radiographs at the 8th week. RESULTS: One hundred and seventy-two Japanese patients (slow acetylators, 9.3 %; rapid acetylators, 53.5 %) were enrolled in this trial. In the intention-to-treat (ITT) analysis, INH-DILI occurred in 78 % of the slow acetylators in the STD-treatment, while none of the slow acetylators in the PGx-treatment experienced either INH-DILI or early treatment failure. Among the rapid acetylators, early treatment failure was observed with a significantly lower incidence rate in the PGx-treatment than in the STD-treatment (15.0 % vs. 38 %). Thus, the NAT2 genotype-guided regimen resulted in much lower incidences of unfavorable events, INH-DILI or early treatment failure, than the conventional standard regimen. CONCLUSION: Our results clearly indicate a great potential of the NAT2 genotype-guided dosing stratification of isoniazid in chemotherapy for tuberculosis.

Cytomegalovirus infection during immunosuppressive therapy for diffuse parenchymal lung disease.

BACKGROUND AND OBJECTIVE: Cytomegalovirus (CMV) infection is a life-threatening condition in patients with diffuse parenchymal lung diseases (DPLDs), who are receiving immunosuppressive therapy. The aim of this study was to describe the clinical features of CMV infection and to propose a strategy for managing CMV infection in patients with DPLD who are receiving immunosuppressive therapy. METHODS: A retrospective longitudinal observational study was performed on 69 patients with DPLDs (39 with acute/subacute onset, 30 with chronic onset) who were receiving immunosuppressive therapy and were positive for CMV pp65 antigen (CMV-pp65Ag) in peripheral blood leukocytes (PBLs). RESULTS: Clinical CMV disease and subclinical CMV antigenaemia developed in 23 and 46 patients, respectively. The cut-off level of CMV-pp65Ag indicating clinical CMV disease, as determined by receiver operator characteristic curve analysis, was 7.5 cells per 5 × 10(4) PBLs. Multivariate analysis revealed that early CMV infection was associated with acute/subacute onset of underlying DPLD and with respiratory dysfunction at the commencement of immunosuppressive therapy. Multivariate analysis also suggested that the acute/subacute onset of underlying DPLD, a CMV-pp65Ag titre of >7.5 cells per 5 × 10(4) PBLs, and C-reactive protein levels ≥ 10 mg/L indicated a poor prognosis. CONCLUSIONS: We recommend that CMV-pp65Ag antigenaemia of >7.5 cells per 5 × 10(4) PBLs in patients with DPLD should be treated with ganciclovir. Patients with lower levels of CMV-pp65Ag antigenaemia should be closely monitored or treated with ganciclovir if the clinical findings suggest a poor prognosis.

[Biologics and mycobacterial diseases].

Various biologics such as TNF-alpha inhibitor or IL-6 inhibitor are now widely used for treatment of rheumatoid arthritis. Many reports suggested that one of the major issues is high risk of developing tuberculosis (TB) associated with using these agents, which is especially important in Japan where tuberculosis still remains endemic. Another concern is the risk of development of nontuberculous mycobacterial (NTM) diseases and we have only scanty information about it. The purpose of this symposium is to elucidate the role of biologics in the development of mycobacterial diseases and to establish the strategy to control them. First, Dr. Tohma showed the epidemiologic data of TB risks associated with using biologics calculated from the clinical database on National Database of Rheumatic Diseases by iR-net in Japan. He estimated TB risks in rheumatoid arthritis (RA) patients to be about four times higher compared with general populations and to become even higher by using biologics. He also pointed out a low rate of implementation of QuantiFERON test (QFT) as screening test for TB infection. Next, Dr. Tokuda discussed the issue of NTM disease associated with using biologics. He suggested the airway disease in RA patients might play some role in the development of NTM disease, which may conversely lead to overdiagnosis of NTM disease in RA patients. He suggested that NTM disease should not be uniformly considered a contraindication to treatment with biologics, considering from the results of recent multicenter study showing relatively favorable outcome of NTM patients receiving biologics. Patients with latent tuberculosis infection (LTBI) should receive LTBI treatment before starting biologics. Dr. Kato, a chairperson of the Prevention Committee of the Japanese Society for Tuberculosis, proposed a new LTBI guideline including active implementation of LTBI treatment, introducing interferon gamma release assay, and appropriate selection of persons at high risk for developing TB. Lastly, Dr. Matsumoto stressed the risk of discontinuing TNF-alpha inhibitor during treatment for tuberculosis. He showed from his clinical experience that TNF-alpha inhibitor can be safely used in active TB patient receiving effective antituberculosis chemotherapy and it is even more effective for prevention of paradoxical response. Active discussion was done about the four topics, including the matter beyond present guidelines. We hope these discussions will form the basis for the establishment of new guideline for the management of mycobacterial disease when using immunosuppressive agents including biologics. 1. The risk of developing tuberculosis (TB) and situations of screening for TB risk at administration of biologics-the case of rheumatoid arthritis: Shigeto TOHMA (Clinical Research Center for Allergy and Rheumatology, National Hospital Organization Sagamihara National Hospital) We calculated the standardized incidence ratio (SIR) of TB from the clinical data on National Database of Rheumatic Diseases by iR-net in Japan (NinJa) and compared with the SIR of TB from the data of the post-marketing surveillances of five biologics. Among 43584 patient-years, forty patients developed TB. The SIR of TB in NinJa was 4.34 (95%CI: 3.00-5.69). According to the post-marketing surveillances of 5 biologics, the SIR of TB were 3.62-34.4. The incidence of TB in patients with RA was higher than general population in Japan, and was increased more by some biologics. We have to recognize the risk of TB when we start biologics therapy to patients with RA. Although the frequency of implementation of QuantiFERON test (QFT) had gradually increased, it was still limited to 41%. In order to predict the risk of developing TB and to prevent TB, it might be better to check all RA patients by QFT at time time of biologics administration. 2. Biologics and nontuberculous mycobacterial diseases: Hitoshi TOKUDA (Social Insurance Central General Hospital) Several topics about the relationship between RA and nontuberculous mycobacterial (NTM) diseases were discussed, which is still poorly understood. It is well known that airway diseases often accompany RA, which may be considered as a possible etiology for development of NTM diseases, but conversely it may lead to overdiagnosis of NTM disease. Next, we evaluated justification for the contraindication of biologics in patients with NTM diseases. Recent multicenter study showed that prognosis of patients developing NTM diseases during treatment with biologics were not always poor, which throws doubt on uniform prohibition of biologics in NTM diseases. 3. Future guideline for treating latent tuberculosis infection: Seiya KATO (Research Institute of Tuberculosis, Japan AntiTuberculosis Association) The Japanese Society for Tuberculosis issued a joint statement on chemoprophylaxis with the Japan College of Rheumatology in 2004. However, issues and challenges due to changing circumstance indicate application of interferon gamma release assay (IGRA), increased variety and indication of biologics, dissemination of knowledge on strategy and system for latent tuberculosis infection (LTBI), etc. Future guideline should include 1) promoting LTBI treatment to achieve low incidence, 2) updated information on IGRAs, 3) treatment strategy and target: contact to infectious cases, immunosuppressive cases (especially HIV and patients treated with biologics), high risk groups, etc. 4) fundamental information on tuberculosis control strategies, especially DOTS. 4. Therapy for RA and tuberculosis in patients with RA and TB activated by anti-TNF treatment: Tomoshige MATSUMOTO (Osaka Prefectural Medical Center for Respiratory and Allergic Diseases) Biologics targeting TNF, including infliximab, have brought about a paradigm shift in the treatment of rheumatoid arthritis (RA). In 2001, tuberculosis, an ancient and also modem scourge, became spotlighted again, because Keane reported in the New England Journal of Medicine that infliximab administration induced reactivation of tuberculosis. How should we treat RA after we successfully treated tuberculosis? Decisions regarding the treatment of patients with refractory RA in the setting of active tuberculosis remain difficult. We successfully treated RA in patients with tuberculosis by anti-TNF therapy. These demonstrate that anti-TNF therapy can be considered for patients with refractory RA who have tuberculosis and in whom antituberculosis therapy can be maintained.

[Comparative evaluation of acid-fast staining for the detection of Mycobacterium fortuitum--clinical performance of fluorescent and Ziehl-Neelsen staining].

OBJECTIVE: Fluorescent staining is of paramount importance, not only for confirming the presence of mycobacteria in a given specimen but also for providing an estimated growth quantification. In this study, for rapidly growing Mycobacterium fortuitum, we evaluated the effectiveness of a rapid fluorescent staining method employing auramine-rhodamine (AR) fluorescent stain and acridine-orange (AO) fluorescent stain compared to that of the standard Ziehl-Neelsen (ZN) stain currently in use in our laboratory. METHOD: We evaluated the acid-fast nature of M. fortuitum strain ATCC6841 and 42 clinical isolates from each patient diagnosed at NHO Kinki-chuo Chest Medical Center. These isolates were preliminarily identified as M. fortuitum using DNA-DNA hybridization (DDH Mycobacteria; Kyokuto Pharmaceutical, Tokyo, Japan). These isolates were further identified by comparative sequence analysis of the ITS regions and the partial 16S rRNA gene. RESULTS: A total of 26 M. fortuitum strains (61.9%) demonstrated the lack of an acid-fast nature by AR staining, and slightly fewer demonstrated the same by AO staining. Sequence analysis of these 42 clinical isolates led to the identification of 35 M. fortuitum subsp. acetamidolyticum isolates (83.3%) and 7 closely M. fortuitum isolates. DISCUSSION: This work reported the loss of the acid-fast nature of specific M. fortuitum strains. It is likely that both the specific cell envelope of M. fortuitum and the staining mechanics could have been responsible for the loss of the acid-fast nature since the 2 different fluorescent stains yielded the same results. M. fortuitum is a mycobacterium species that does not stain with the commonly used fluorescence microscopy technique. Therefore, we suggested the use of an identification scheme for these organisms that employs ZN staining and the study of cultural characteristics (growth rate, temperature, and pigment production).

Increased lactate dehydrogenase reflects the progression of COVID-19 pneumonia on chest computed tomography and predicts subsequent severe disease.

Chest computed tomography (CT) is effective for assessing the severity of coronavirus disease 2019 (COVID-19). However, the clinical factors reflecting the disease progression of COVID-19 pneumonia on chest CT and predicting a subsequent exacerbation remain controversial. We conducted a retrospective cohort study of 450 COVID-19 patients. We used an automated image processing tool to quantify the COVID-19 pneumonia lesion extent on chest CT at admission. The factors associated with the lesion extent were estimated by a multiple regression analysis. After adjusting for background factors by propensity score matching, we conducted a multivariate Cox proportional hazards analysis to identify factors associated with severe disease after admission. The multiple regression analysis identified, body-mass index (BMI), lactate dehydrogenase (LDH), C-reactive protein (CRP), and albumin as continuous variables associated with the lesion extent on chest CT. The standardized partial regression coefficients for them were 1.76, 2.42, 1.54, and 0.71. The multivariate Cox proportional hazards analysis identified LDH (hazard ratio, 1.003; 95% confidence interval, 1.001-1.005) as a factor independently associated with the development of severe COVID-19 pneumonia. Increased serum LDH at admission may be useful in real-world clinical practice for the simple screening of COVID-19 patients at high risk of developing subsequent severe disease.

Mycobacterium avium Pleurisy with Bronchopleural Fistula Resulting in Rapidly Progressive Respiratory Failure Diagnosed by Transbronchial Autopsy.

Nontuberculous mycobacterial lung disease usually manifests as a chronic pulmonary infection. We herein report a fatal case of Mycobacterium avium pleurisy in a man with a refractory bronchopleural fistula that led to rapidly progressive pneumonia. A post-mortem transbronchial biopsy was performed. Histopathology revealed an acute lung injury pattern and epithelioid granulomas. Variable number tandem repeat analyses and drug susceptibility testing revealed Mycobacterium avium had acquired macrolide resistance during chemotherapy with rifampicin, ethambutol, and clarithromycin. Clinicians should be aware that Mycobacterium avium pleurisy with bronchopleural fistula can lead to fatal pneumonia, especially in patients with persistently positive cultures despite multidrug treatment.

A Case of Lymphangioleiomyomatosis Showing the Development of Mycobacterium abscessus subsp. massiliense Infection During Sirolimus Therapy.

Among nontuberculous mycobacterial pulmonary diseases (NTM-PDs), Mycobacterium abscessus species pulmonary disease (MABS-PD) is one of the most severe and intractable infections. We herein report a 45-year-old woman with advanced lymphangioleiomyomatosis (LAM) who developed MABS-PD while undergoing sirolimus therapy. MABS-PD was immediately controlled using antibiotic therapy, although the patient's lung transplant registration was significantly delayed. To our knowledge, this is the first case report on the development of NTM-PD in a patient with LAM before lung transplantation. This case suggests that the early diagnosis and optimal treatment of NTM-PD are crucial in patients with advanced LAM.