Sinobronchial Syndrome Patients with Suspected Non-Tuberculous Mycobacterium Infection Exacerbated by Exophiala dermatitidis Infection.

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.

Detection of Representative Mutant Strains and a Case of Prolonged Infection by SARS-CoV-2 with Spike 69/70 Deletion in Japan.

There is a concern that the spread of mutant strains of SARS-CoV-2 will increase the number of severe COVID-19 patients and weaken vaccine effectiveness in the world. The mutants of the spike region of SARS-CoV-2, such as N501Y, E484K, P681H, and deletion H69/V70 (del 69/70), were studied in 25 COVID-19 patients admitted from December 2020 to April 2021; there were no patients with N501Y and P681H, but nine patients had E484K alone. Their symptoms, laboratory data, and course of their disease were similar to those of the other patients with the non-mutant virus. One patient with del69/70 alone showed prolonged inflammation, viral excretion, and late exacerbation 18 days after onset. Del69/70 may be independently associated with evasion of immunity, as previously reported, and it is present in Japan.

Severe Pulmonary Mycobacterium abscessus Cases Due to Co-Infection with Other Microorganisms Well Treated by Clarithromycin and Sitafloxacin in Japan.

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.

A Household Microsporum canis Dermatophytosis Suggested by Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry Analysis.

BACKGROUND Microsporum canis is a pathogenic dermatophyte that usually colonizes animals, and secondary infection of humans comes from pets. The infected patients show hair loss with erythema and are diagnosed as having dermatophytosis, but the transmission routes of M. canis from animals to others are sometimes unclear, although they are critical to the treatment of patients and infection control. To identify the pathogens and the transmission routes, morphological observations by microscopes and conventional polymerase chain reaction (PCR) have been used; however, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has recently become a useful tool. CASE REPORT A 4-year-old girl presented with pruritic, erythematous lesions on the head with alopecia. The dermatologists diagnosed dermatophytosis caused by fungal infection, and M. canis was suspected as the pathogen because of the morphologic characteristics. All of her family members subsequently showed similar hair findings and symptoms. The growth of M. canis was also observed in serial cultures, and all strains were confirmed to be identical, but different from the standard strain on MALDI-TOF MS. In this household infection case, abandoned cats were considered to be the origin of M. canis transmission, and the family members finally improved following oral administration of antifungal agents. CONCLUSIONS M. canis should be carefully investigated as the causative pathogen of dermatophytosis secondary to household infection. MALDI-TOF MS appears to be an excellent tool to confirm the transmission routes of the fungal pathogens among infected patients.

Mycobacterium abscessus Associated Peritonitis with CAPD Successfully Treated Using a Linezolid and Tedizolid Containing Regimen Suggested Immunomodulatory Effects.

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.

Evaluation of agar culture plates to efficiently identify small colony variants of methicillin-resistant Staphylococcus aureus.

Background: Small-colony variants of methicillin-resistant Staphylococcus aureus (SCV-MRSA) recently were described as slow-growing, thymidine-dependent strains; typically, SCV-MRSA were isolated from patients receiving sulfamethoxazole-trimethoprim, but detection of these strains frequently was delayed because of their small colony size and slow growth. Bacteremia cases due to SCV-MRSA sometimes become lethal when the initiation of treatment with intravenous anti-methicillin-resistant Staphylococcus aureus (MRSA) drugs starts too late. Methods: Here, we evaluated the use of general MRSA-specific agar plates in Japan, including MS-CFX, X-MRSA, and CHROMagar, for the efficient detection of SCV-MRSA, including the comparative detection efficiencies of these media for stock strains and clinical isolates. Results: Among the three MRSA-specific agar plates that were tested, X-MRSA and CHROMagar showed similar detection efficiencies for both 24 and 48 hrs culturing; in contrast, MS-CFS did not permit the detection of SCV-MRSA in stock strains. For clinical isolates of SCV-MRSA, X-MRSA plates permitted detection of the smallest and slowest-growing colonies of SCV-MRSA at 48 hrs of culturing; in contrast, CHROMagar and MS-CFX sometimes did not identify SCV-MRSA at 24 and 48 hrs. Conclusion: Optimization of media and incubation times will be necessary for efficient identification for SCV-MRSA, which would prevent delays in diagnosis and treatment with anti-MRSA drugs.

Evaluation of blood culture broths with lysis buffer to directly identify specific pathogens by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry methods.

BACKGROUND: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is now widely used to detect pathogens in clinical settings in Japan. METHOD: Here, we report the effects of adding lysis buffer in the MALDI-TOF MS method to directly detect bacteria from 3 blood culture systems and compare their detection efficiencies for each pathogen. RESULTS: Blood culture broths from BD, bioMérieux, and Oxoid showed similar detection efficiencies without lysis buffer use and Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa were efficiently detected in all broths when lysis buffer was used. However, Streptococcus pneumoniae was not detected in BD broth when lysis buffer was added. Furthermore, Haemophilus influenzae and Bacteroides fragilis were not detected in all 3 systems when lysis buffer was used. CONCLUSION: Optimization of blood culture system and lysis buffer is necessary according to each pathogen for direct identification by MALDI-TOF MS methods.

Usefulness of matrix-assisted laser desorption ionization time-of-flight mass spectrometry to identify pathogens, including polymicrobial samples, directly from blood culture broths.

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (TOF-MS) is now widely used to detect pathogens in clinical settings in Japan. Here, we report the ability of TOF-MS to detect bacteria from blood culture (BC) broths, and compare the efficacy of TOF-MS to that of conventional culture methods. Bacteria were correctly detected from 63 monomicrobial samples within 80 minutes; results matched those obtained by conventional BC methods, although the conventional methods took 2-3 days. In addition to the 63 monomicrobial samples, another three polymicrobial samples were tested; notably, the infecting bacteria were not correctly identified in two of these three samples. To better assess the TOF-MS detection of polymicrobial samples, we tested various ratios of mixed broth samples, including combinations of the bacteria that we were unable to detect in clinical samples. Combinations of Enterobacter cloacae and Pseudomonas aeruginosa were correctly detected at a culture ratio of 2:1, but not in the 3:1 mixture. These results suggested that TOF-MS is a strong tool for the rapid and correct detection of pathogens from monomicrobial BC samples, though results need to be carefully checked when handling known or suspected polymicrobial samples.

Ability of procalcitonin to diagnose bacterial infection and bacteria types compared with blood culture findings.

Procalcitonin (PCT) and C-reactive protein serve as biomarkers of infection in patients with sepsis/bacteremia. The present study assessed the clinical characteristics of 280 patients with suspected sepsis who were admitted to Tohoku Medical and Pharmaceutical University Hospital between January 2012 and December 2013. Among the patients, 133 and 147 were positive and negative for PCT, respectively. Patients who were PCT positive were older and more frequently male, had reduced levels of platelets and albumin, and increased levels of aspartate aminotransferase, alanine aminotransferase, blood urea nitrogen, creatinine, and C-reactive protein. Patients who were PCT positive had significantly higher blood culture positivity compared with those who were PCT negative, and the sensitivity and specificity of PCT for detecting positive blood cultures were 74.5% and 59.1%, respectively. Escherichia coli was detected in PCT-positive patients, whereas Staphylococcus epidermidis and Staphylococcus lugdunensis were frequently detected in PCT-negative patients. Levels of PCT were higher in the patients infected with gram-negative rods than those with gram-positive cocci. Furthermore, extended-spectrum ß-lactamase (ESBL)-producing bacteria cases showed higher levels of PCT than those of non-ESBL cases. These results suggest that PCT may be a useful biomarker of sepsis, and it might serve as a strong tool to detect patients with severe gram-negative rod bacteremia including ESBL-producing bacteria cases early due to its relative high sensitivity.

Association of influenza with severe pneumonia/empyema in the community, hospital, and healthcare-associated setting.

We presented three cases of influenza-related severe pneumonia/empyema that occurred in one season. CASE 1: A 76-year-old diabetic man, developed empyema as a result of severe community-acquired pneumonia (CAP) secondary to Haemophilus influenzae, as confirmed on sputum culture. Nasal swab was positive for influenza A antigen. After drainage of empyema, intravenous peramivir and piperacillin/tazobactam were administered for 3 days and 2 weeks, respectively, followed by oral levofloxacin for 2 weeks. Eventually, he recovered. In this case, the isolated H. influenzae was non-typeable and negative for beta-lactamase. CASE 2: A 55-year-old man with suspected cerebral infarction and diabetes mellitus (DM) developed severe pneumonia/empyema as result of hospital-acquired pneumonia (HAP). Although influenza A antigen was detected, no bacterium was isolated from the sputum, blood, or pleural effusion. He showed severe hypoxia, but recovered after administration of peramivir and levofloxacin with prednisolone for 5 days and 2 weeks, respectively. CASE 3: A 76-year-old woman with heart failure and DM was followed-up on an outpatient basis and was under nursing home care for four months. Subsequently, she developed pneumonia and was admitted to our hospital; influenza antigen was isolated from nasal swab. Healthcare-associated pneumonia (HCAP)/empyema were diagnosed and were effectively treated with peramivir and levofloxacin for 4 days and 1 week, respectively. In diabetic patients, influenza virus may possibly accelerate pneumonia/empyema due to bacterial coinfection. Although non-typeable H. influenzae is a rare causative pathogen of empyema, it can be expected as a result of "pathogen shift" due to the increased use of the H. influenzae type b vaccine in Japan.