Objective: Rare disease Background: Mycobacterium abscessus is one of the most important mycobacteria, but its associated peritonitis in patients on continuous ambulatory peritoneal dialysis (CAPD) appears relative rare, and the treatment regimen of the antibiotics are still unclear. Case Report: A 38-year-old female with chronic glomerulonephritis on CAPD who was diagnosed with M. abscessus-associated peritonitis. Symptoms exacerbated despite treatment with a 3-antibiotic regimen combining clarithromycin, imipenem/cilastatin (IPM/CS), and minocycline (MINO). However, after changing IPM/CS and MINO to linezolid (LZD), her condition and inflammation improved, and she was able to be maintained on oral tedizolid (TZD). Conclusions: Oxazolidinones such as LZD and TZD might be candidate antibiotics for the treatment of M. abscessus-associated diseases with chronic renal failure due to their immunomodulatory effects and non-renal excretion.

Background Exophiala dermatitidis is an environmental black fungus that rarely causes respiratory infections, yet its pathophysiological features and treatment regimens have not been established. Case Series Two cases of exacerbations of chronic bronchitis and sinusitis due to E. dermatitidis infection in Japan are presented. Both patients were women, and non-tuberculous Mycobacterium (NTM) infection was suspected based on chest radiological findings, but E. dermatitidis was detected from bronchial lavage fluid and nasal mucus, respectively. Both cases were successfully treated by antifungal agents such as liposomal amphotericin B, voriconazole, and itraconazole, but clarithromycin, rifampicin, ethambutol, and sitafloxacin for NTM were not effective. Conclusion E. dermatitidis can become a respiratory pathogen, especially in patients with chronic sinobronchial syndrome.

Background: Mycobacterium abscessus frequently causes severe infections, yet its pathophysiological features and treatment regimens have not been established. Case Report: We present five cases of severe pneumonia due to Mycobacterium abscessus infection in Japan. All cases were diabetic patients, with possible acceleration to pneumonia due to co-infection with other microorganisms. However, following a short period of hospitalization and combination therapy with intravenous imipenem/cilastatin and amikacin, all the cases were successfully treated as outpatients with oral clarithromycin and sitafloxacin. Conclusion: M. abscessus infections can become severe in the presence of diabetes mellitus and co-infection with other chronic infectious organisms. Sitafloxacin might be a key drug in the treatment of M. abscessus infection in future.

Human rhinovirus (HRV) is known as one of the most important respiratory pathogens, and the clinical characteristics of HRV infection might be similar to those of coronavirus disease 2019 (COVID-19). We identified 11 HRV-infected patients by polymerase chain reactions of the HRV genes among 151 outpatients with fever. All nine adult patients had underlying diseases and finally improved with the appropriate treatment in this COVID-19 pandemic period. Differential diagnosis between HRV and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection will be needed to save lives and medical resources.

Background: Due to the relatively high renal toxicity of vancomycin injection (VCM), setting an initial dose that achieves a trough that ranges between 10 and 20 μg/mL on day 3 is important to ensure safety and minimize side-effects, especially for patients with low renal function. To address these issues, the revised 2016 Therapeutic Drug Monitoring (TDM) Guidelines for Antimicrobial Agents (GL2016) proposed the use of a renal function-based, estimate glomerular filtration rate (eGFR) nomogram for setting the dose of VCM in Japan. Methods: Our hospital introduced the use of the GL2016 in September 2016 for the patients administered VCM. After setting the initial VCM dose using 1) a conventional VCM analysis software and 2) the GL2016 eGFR nomogram, the measured trough values on day 3 were compared and evaluated in this study. Results: With the VCM analysis software, the mean measured trough value in the a-total group (n = 53) was 12.8 ± 4.7 μg/mL. With the eGFR nomogram, the mean measured trough value in the b-total group (n = 13) was 9.6 ± 4.6 μg/mL. However, when the different severities of renal function were compared, the mean measured trough value was more significantly lower in the b-1 group than in the a-1 group among subjects with G2 and above (eGFR ≥ 60 mL/min/1.73 m 2), but it was similar between the a-2 group and the b-2 group among subjects with G3 and below