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Nursing and healthcare-associated pneumonia (NHCAP) was proposed by the Japanese Respiratory Society in 2011. However, the clinical characteristics of NHCAP are still unclear. Thus, this study aimed to clarify its clinical characteristics.This multicenter prospective observational study included 596 patients with NHCAP from 73 centers in Japan between May 2014 and February 2016.Patient background was characterized by an older age (81.5 ± 10.1 years), most patients had complications (94.1%), and many patients had a high probability of aspiration pneumonia (68.6%). Among the isolates, Streptococcus pneumoniae was the most common (12.7%), while Pseudomonas aeruginosa was also isolated at 10.8%. The overall 30-day mortality rate for patients was 11.9%, and the factors affecting mortality were non-ambulatory status, high blood urea nitrogen level, impaired consciousness, and low albumin level. Sulbactam/ampicillin was the most commonly administered antibiotic, including in groups with high severity of illness and high risk of multidrug-resistant (MDR) pathogens. Both the A-DROP and I-ROAD scores were useful in predicting the prognosis of NHCAP. Confirmation of intention to provide do not attempt resuscitation (DNAR) instructions was given to 333 patients (55.9%), and 313 patients agreed to DNAR instructions.NHCAP tends to occur in elderly patients with underlying diseases. The risk of MDR pathogens and the mortality rate are intermediate for community-acquired pneumonia and hospital-acquired pneumonia. As NHCAP is considered an important concept in an aging society, such as in Japan, establishing a treatment strategy that considers not only prognosis but also quality of life would be beneficial.

Polymerase chain reaction (PCR) testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is necessary for confirming a diagnosis of Coronavirus disease 2019 (COVID-19). Here we present a COVID-19 case of an elderly woman whose SARS-CoV-2 PCR tests showed false negative repeatedly by evaluating with different sampling sites and procedures. Nasopharyngeal swabs, suctioned sputum, and tongue swabs were collected for SARS-CoV-2-PCR. As for tongue swabs, we compared between two different sample conditions; one obtained with dry condition and the other obtained with moistened condition inside the oral cavity. SARS-CoV-2-PCR showed positive for an extended period with suctioned sputum samples compared with nasopharyngeal swabs and tongue swabs. No SARS-CoV-2 from a nasopharyngeal swab sample obtained on day 46 after symptoms onset was isolated despite high viral load (183740.5 copies/5μL). An adequate production of neutralizing antibody in a serum sample on day 46 was also confirmed. The number of RNA copies of the tongue swab samples was higher with moistened condition than with dry condition. The present case suggests that the difference of sampling site or sample condition can affect PCR results. High loads viral RNA detection does not always correlate with infectivity.

Introduction Numerous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serological tests exists commercially; however, their performance using clinical samples is limited. Although insufficient to detect SARS-CoV-2 in the early phase of infection, antibody assays can be of great use for surveillance studies or for some coronavirus disease 2019 (COVID-19) patients presenting late to the hospital. Methods This study evaluated the sensitivity and specificity of four commercial SARS-CoV-2 lateral flow antibody tests using 213 serum specimens from 90 PCR-positive confirmed COVID-19 patients. Of 59 negative control sera, 50 were obtained from patients with other respiratory infectious diseases before COVID-19 pandemic began while nine were from patients infected with other respiratory viruses, including two seasonal coronaviruses. Results The varied sensitivities for the four commercial kits were 70.9%, 65.3%, 45.1%, and 65.7% for BioMedomics, Autobio Diagnostics, Genbody, and KURABO, respectively, between sick days 1 and 155 in COVID-19 patients. The sensitivities of the four tests gradually increased over time after infection before sick day 5 (15.0%, 12.5%, 15.0%, and 20.0%); from sick day 11–15 (95.7%, 87.2%, 53.2%, and 89.4%); and after sick day 20 (100%, 100%, 68.6%, and 96.1%), respectively. For severe illness, the sensitivities were quite high in the late phase after sick day 15. The specificities were over 96% for all four tests. No cross-reaction due to other pathogens, including seasonal coronaviruses, was observed. Conclusions Our results demonstrated the large differences in the antibody test performances. This ought to be considered when performing surveillance analysis.

A 60-year-old Japanese woman presented with subacute progressive muscle pain and weakness in her proximal extremities. She was diagnosed with influenza A (H3N2) infection a week before the onset of muscle pain. At the time of admission, she exhibited weakness in the proximal muscles of the upper and lower limbs, elevated serum liver enzymes and creatinine kinase, and myoglobinuria. She did not manifest renal failure and cardiac abnormalities, indicating myocarditis.Electromyography revealed myogenic changes, and magnetic resonance imaging of the upper limb showed abnormal signal intensities in the muscles, suggestive of myopathy. Muscle biopsy of the biceps revealed numerous necrotic regeneration fibers and mild inflammatory cell infiltration, suggesting immune-mediated necrotizing myopathy (IMNM). Necrotized muscle cells were positive for human influenza A (H3N2). Autoantibody analysis showed the presence of antibodies against the signal recognition particle (SRP), and the patient was diagnosed with anti-SRP-associated IMNM. She was resistant to intravenous methylprednisolone pulse therapy but recovered after administration of oral systemic corticosteroids and immunoglobulins. We speculate that the influenza A (H3N2)infection might have triggered her IMNM. Thus, IMNM should be considered as a differential diagnosis in patients with proximal muscle weakness that persists after viral infections., International Journal of Infectious Diseases, 103, pp.33-36: 2020

The treatment duration for candidemia with septic pulmonary embolism should be determined based on the clearance of fungus from the bloodstream and improvement of symptoms. The remaining lung nodules may not necessarily indicate persistent infection.

Background Before advance care planning, it is essential to understand the differences in preferences for medical care of terminal-phase pneumonia in elderly patients among the patients, their families, and their doctors. This study aimed to clarify these differences and investigate the actual care provided to elderly patients with pneumonia in nursing hospitals. Methods Multicenter questionnaire surveys of 179 patients admitted to nursing homes and long-term care beds in hospitals of three healthcare corporations, their families, and their physicians were conducted between January and August 2018. The questionnaires mainly assessed preferences for life-prolonging medical care procedures, including antibiotic treatments, in terminal-phase pneumonia. A follow-up survey regarding the prognosis and the actual care provided by the physicians was conducted 1 year after the first survey. Results Only 16.2% of the patients had sufficient prior discussions with their families about their care. More families preferred cardiac massage, intubation, and tracheostomy, while fewer families preferred peripheral intravenous fluids or antibiotics than physicians. A total of 30 patients’ families (16.7%) answered to withhold antibiotic treatment, while all physicians supported antibiotic administration. The only significant factor related to withholding antibiotics was high age (P = 0.0057). The follow-up survey administered to the doctors revealed that 49 patients (35.7%) had died within one year. Of the 137 patients, 54 patients (39.4%) had developed pneumonia during this observation period and all were treated with antibiotics. Conclusions This study revealed large discrepancies between patients/families and physicians regarding preferences for care. Medical staff should make efforts to fill the gap by ensuring advance care planning.

Endobronchial volatile sulfur compounds in patients with lung abscess or lung cancer were measured using the Oral Chroma™ gas chromatograph. High levels of hydrogen sulfide and methyl mercaptan were observed in some patients with lung abscess but not in patients with lung cancer. Measuring endobronchial volatile sulfur compounds could be useful for the rapid diagnosis of lung abscess caused by obligate anaerobes.

Gastrointestinal colonization has been considered as the primary source of candidaemia; however, few established mouse models are available that mimic this infection route. We therefore developed a reproducible mouse model of invasive candidiasis initiated by fungal translocation and compared the virulence of six major pathogenic Candida species. The mice were fed a low-protein diet and then inoculated intragastrically with Candida cells. Oral antibiotics and cyclophosphamide were then administered to facilitate colonization and subsequent dissemination of Candida cells. Mice infected with Candida albicans and Candida tropicalis exhibited higher mortality than mice infected with the other four species. Among the less virulent species, stool titres of Candida glabrata and Candida parapsilosis were higher than those of Candida krusei and Candida guilliermondii. The fungal burdens of C. parapsilosis and C. krusei in the livers and kidneys were significantly greater than those of C. guilliermondii. Histopathologically, C. albicans demonstrated the highest pathogenicity to invade into gut mucosa and liver tissues causing marked necrosis. Overall, this model allowed analysis of the virulence traits of Candida strains in individual mice including colonization in the gut, penetration into intestinal mucosa, invasion into blood vessels, and the subsequent dissemination leading to lethal infections., Scientific Reports, 10(1), art.no.3814; 2020

Bacterial culture remains the gold standard for the diagnosis of legionellosis. However, past reports indicate that most physicians use the urinary antigen test (UAT) alone. Combining it with other tests is important, especially in patients with negative UAT results. The aim of this study was to investigate the current situation of legionellosis diagnostics and clarify the issues that need to be addressed.Between March 1, 2021 and April 30, 2021, a questionnaire survey was conducted in an anonymous manner among physicians working in Japan. Questionnaires were generated on a website and asked questions in a multiple-choice format.Valid responses were received from 309 physicians during the study period. Most (92.9%) physicians reported using UAT as the initial test for patients suspected of having legionellosis, and10% reported using other tests (e.g., culture, nucleic acid amplification test [NAAT], Gimenez staining, and serum antibody titer measurement [ATM]). When the initial test result was negative, 63% of physicians reported not conducting additional tests. Even when they chose to run additional tests, at most 27.8%, 23.6%, 12.3%, and 10.4% of all physicians used NAAT, culture, Gimenez staining, and serum ATM, respectively. The major reasons for not using tests other than UAT were "unavailability in the medical facility," "long turn-around time," and "difficult to collect sputum."The present survey revealed that most physicians in Japan used UAT alone for diagnosing legionellosis. Eliminating barriers to creating a reasonable environment and edification of physicians are needed to improve the current situation.

The recent increase in cases of azole-resistant Aspergillus fumigatus (ARAf) infections is a major clinical concern owing to its treatment limitations. Patient-derived ARAf occurs after prolonged azole treatment in patients with aspergillosis and involves various cyp51A point mutations or non-cyp51A mutations. The prognosis of patients with chronic pulmonary aspergillosis (CPA) with patient-derived ARAf infection remains unclear. In this study, we reported the case of a patient with ARAf due to HapE mutation, as well as the virulence of the isolate.A 37-year-old male was presented with productive cough and low-grade fever. The patient was diagnosed with CPA based on the chronic course, presence of a fungus ball in the upper left lobe on chest computed tomography (CT), positivity for Aspergillus-precipitating antibody and denial of other diseases. The patient underwent left upper lobe and left S6 segment resection surgery because of repeated haemoptysis during voriconazole (VRC) treatment. The patient was postoperatively treated with VRC for 6 months. Since then, the patient was followed up without antifungal treatment but relapsed 4 years later, and VRC treatment was reinitiated. Although an azole-resistant isolate was isolated after VRC treatment, the patient did not show any disease progression in either respiratory symptoms or radiological findings. The ARAf isolated from this patient showed slow growth, decreased biomass and biofilm formation in vitro, and decreased virulence in the Galleria mellonella infection model compared with its parental strain. These phenotypes could be caused by the HapE splice site mutation.This is the first to report a case demonstrating the clinical manifestation of a CPA patient infected with ARAf with a HapE splice site mutation, which was consistent with the in vitro and in vivo attenuated virulence of the ARAf isolate. These results imply that not all the ARAf infections in immunocompetent patients require antifungal treatment. Further studies on the virulence of non-cyp51A mutations in ARAf are warranted.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19). Real-time RT-PCR is the most commonly used method for COVID-19 diagnosis. However, serological assays are urgently needed as complementary tools to RT-PCR. Hachim et al. 2020 and Burbelo et al. 2020 demonstrated that anti-nucleocapsid(N) SARS-CoV-2 antibodies are higher and appear earlier than the spike antibodies. Additionally, cross-reactive antibodies against N protein are more prevalent than those against spike protein. We developed a less cross-reactive immunoglobulin G (IgG) indirect ELISA by using a truncated recombinant SARS-CoV-2 N protein as assay antigen. A highly conserved region of coronaviruses N protein was deleted and the protein was prepared using an E. coli protein expression system. A total of 177 samples collected from COVID-19 suspected cases and 155 negative control sera collected during the pre-COVID-19 period were applied to evaluate the assay’s performance, with the plaque reduction neutralization test and the commercial SARS-CoV-2 spike protein IgG ELISA as gold standards. The SARS-CoV-2 N truncated protein-based ELISA showed similar sensitivity (91.1% vs. 91.9%) and specificity (93.8% vs. 93.8%) between the PRNT and spike IgG ELISA, as well as also higher specificity compared to the full-length N protein (93.8% vs. 89.9%). Our ELISA can be used for the diagnosis and surveillance of COVID-19., International Journal of Environmental Research and Public Health, 18(18), art. no. 9630; 2021

The relationship between microorganisms present in the lower respiratory tract and the subsequent incidence of pneumonia in patients with rheumatoid arthritis is unclear. A retrospective cohort study was designed to include a total of 121 patients with rheumatoid arthritis who underwent bronchoscopy at three hospitals between January 2008 and December 2017. Data on patient characteristics, microorganisms detected by bronchoscopy, and subsequent incidences of pneumonia were obtained from electronic medical records. Patients were divided into groups based on the microorganisms isolated from the lower respiratory tract. The cumulative incidence of pneumonia was assessed using the Kaplan–Meier method, and decision tree analysis was performed to analyze the relation between the presence of microorganisms and the occurrence of pneumonia. The most frequently isolated microbes were Pseudomonas aeruginosa, Staphylococcus aureus, and Haemophilus influenzae. Patients whose samples tested negative for bacteria or positive for normal oral flora were included in the control group. The rate of the subsequent incidence of pneumonia was higher in the P. aeruginosa group than in the control group (p = 0.026), and decision tree analysis suggested that P. aeruginosa and patient performance status were two important factors for predicting the incidence of pneumonia. In patients with rheumatoid arthritis, the presence of P. aeruginosa in the lower respiratory tract was associated with the subsequent incidence of pneumonia., Journal of Clinical Medicine, 10(16), art. no. 3552; 2021

Background This study aimed to clarify the involvement of anaerobes in aspiration pneumonia by measuring volatile sulfur compounds (VSCs), which are metabolites of anaerobic bacteria in the mouth. Methods This study included 84 older adult patients (mean age, 82.5 ± 7.34 years) who had dementia and were hospitalized for more than 6 months. We measured the VSCs in the patient's mouth with Oral Chroma and obtained the data of pneumonia development in the past 6 months. We also evaluated the association or correlation of VSCs and some factors which might be the risk factors of aspiration pneumonia. Results The development of pneumonia had no significant association with the VSCs in the patient's mouth. Conclusion The present pilot study suggests that anaerobes might not be the main causative pathogens of aspiration pneumonia in older adult patients.

A 68-year-old Japanese man was admitted to our hospital for an acute febrile illness with shivering and impaired consciousness. He was a previous smoker and had a history of chronic obstructive pulmonary disease, for which he inhaled steroid with a long-acting bronchodilator. He had received a 23-valent pneumococcal polysaccharide vaccination 2 years previously. He was intubated and placed on a ventilator in intensive care unit because of acute respiratory failure and hypercapnia. Streptococcus pneumoniae was grown from his blood, sputum, and urine cultures, and he was diagnosed with invasive pneumococcal disease with acute renal failure. He was treated with intravenous beta-lactam and macrolide with continuous hemodiafiltration and was discharged 3 months later. The pneumococcus was identified as serotype 12F, and his serotype-specific IgG and opsonophagocytic index against serotype 12F indicating a lack of protection from IPD among PPV23 serotypes. This case highlights that some individuals may have a serotype-specific polysaccharide antibody failure that makes them susceptible to serotype 12F invasive pneumococcal disease. This case also illustrates the need for serotype-specific IgG and opsonophagocytic index titre cut-offs for each specific pneumococcal serotype in available vaccines to understand the vaccination protection for individual patients better.

Oral treatment for elderly outpatients with pneumonia is becoming increasingly important in this super-aged society from the perspective of cost-effectiveness and limited hospital capacities. We evaluated the efficacy and safety of two oral respiratory quinolones, sitafloxacin and garenoxacin, in elderly patients with pneumonia. This randomized, multicenter, open-label trial was conducted among patients aged ≥65 years with clinically and radiographically confirmed pneumonia in Japan. Patients were randomly assigned (1:1) to receive either sitafloxacin (100 mg/day) or garenoxacin (400 mg/day) for 3–10 days. The primary efficacy endpoint was the clinical cure rate at 5–10 days after the end of treatment. From December 2013 to November 2017, we enrolled 120 patients at 11 hospitals and randomly assigned 59 patients to the sitafloxacin group (1 patient withdrew) and 61 patients to the garenoxacin group. These included 30 patients with nursing and healthcare-associated pneumonia (NHCAP) (18 receiving sitafloxacin, 12 receiving garenoxacin) and 37 patients with aspiration pneumonia (16 receiving sitafloxacin, 21 receiving garenoxacin). The clinical cure rates in the sitafloxacin and garenoxacin groups were 88.5% (95% confidence interval: 76.6–95.6) and 88.9% (95% confidence interval: 77.4–95.8), respectively. No significant differences were observed in the incidence rates of drug-related adverse events between the sitafloxacin (20.7%; 12/58 patients) and garenoxacin (27.9%; 17/61 patients) groups. The most common adverse event was hepatic dysfunction, which occurred in seven patients in each group. We conclude that sitafloxacin and garenoxacin are comparably effective and safe for the treatment of pneumonia, including NHCAP and aspiration pneumonia, in elderly patients.

Background: Rapid diagnosis and appropriate treatment of Munchausen syndrome is important not only for the patient but also for health care workers because a delay in diagnosis can worsen patients' clinical outcomes, and result in a substantial medical cost. Case presentation: A young and previously healthy 24-year-old Japanese woman, a nurse, presented with complaints of refractory abscess on her left upper limb for 3 months. A physical examination on admission revealed low-grade fever and a subcutaneous abscess in her left forearm. Laboratory data suggested mild systemic inflammation and liver dysfunction, but no abnormalities of the immune system, including changes in the number of lymphocytes and neutrophils, neutrophil phagocytic capacity, and natural killer (NK) cell activity, were observed. A human immunodeficiency virus test was also negative. Multiple modalities, including positron emission tomography-computed tomography, failed to detect any cause and focus of infection except her left upper limb. Streptococcus mitis and Prevotella buccae were detected from the wound, but no microorganisms were detected in a blood culture. The cellulitis promptly resolved; however, exacerbation of the subcutaneous abscess with polymicrobial bacteremia repeatedly occurred unexpectedly. Because of this puzzling clinical course, the possibility of self-injury was finally suspected. Three syringes with needles, with a turbid liquid, were found in our patient's bag. Enterobacter cloacae and Enterococcus faecalis were detected in the liquid, and an analysis via repetitive element sequence-based polymerase chain reaction determined that Enterococcus faecalis in the wound and syringe contents were genetically identical. She was diagnosed as having Munchausen syndrome and treated with the collaboration of a psychiatrist. She finally confessed that she had injected her own saliva and toilet water into the drip line and wound. Conclusions: This case report is valuable in that it is the first case in which this syndrome was diagnosed by a genetic method. Munchausen syndrome should not be neglected as a possible cause of refractory and recurrent infection., Journal of Medical Case Reports, 13(1), art.no.287; 2019

Candida peritonitis is a crucial disease, however the optimal antifungal therapy regimen has not been clearly defined. Peritoneal fibrosis (PF)can be caused by abdominal surgery, intra-abdominal infection, and malignant diseases, and is also widely recognized as a crucial complication of long-term peritoneal dialysis. However, the influence of PF on Candida peritonitis prognosis remains unknown. Here, we evaluated the severity of Candida peritonitis within the context of PF and the efficacy of micafungin using mice. A PF mouse model was generated by intraperitoneally administering chlorhexidine gluconate. Candida peritonitis, induced by intraperitoneal inoculation of Candida albicans, was treated with a 7-day consecutive subcutaneous administration of micafungin. Candida infection caused a higher mortality rate in the PF mice compared with the control mice on day 7. Proliferative Candida invasion into the peritoneum and intra-abdominal organs was confirmed pathologically only in the PF mice. However, all mice in both groups treated with micafungin survived until day 20. Micafungin treatment tends to suppress inflammatory cytokines in the plasma 12 h after infection in both groups. Our results suggest that PF enhances early mortality in Candida peritonitis. Prompt initiation and sufficient doses of micafungin had good efficacy for Candida peritonitis, irrespective of the underlying PF., Scientific Reports, 9(1), art.no.9331; 2019

Emphysematous pyelonephritis (EPN) is a life-threatening renal infection characterized by the formation of gas within the renal parenchyma and collecting duct system, as well as perinephric tissues. We herein report a case of bilateral EPN accompanied by the urinary tract infection caused by spherical growth of Candida albicans in a patient with underlying diabetes mellitus and prostate cancer. The diagnosis was assisted by computed tomography, urography, and gram staining. Despite immediate percutaneous catheter drainage and a 4-week course of antifungal treatment, the C. albicans infection was refractory, as indicated by continuous isolation from the urine, and the patient eventually died. A local autopsy of urinary organs revealed C. albicans in the renal tissue. EPN caused by Candida species frequently occurs in men, and almost all cases have underlying poorly controlled diabetes. This condition is subject to delayed diagnosis, which may lead to extended disease and high mortality. Candida species should be considered as causative microorganism for refractory EPN in patients with poorly controlled diabetes who are receiving antibiotic treatment. Gram staining may contribute to an early diagnosis of EPN caused by Candida species, which may require long-term antifungal therapy.

Lemierre's syndrome is a serious disease that typically causes oropharyngeal infection with internal jugular vein thrombosis, followed by distant infection focus, such as septic pulmonary embolism. The main causative organisms are anaerobic bacteria in the oral cavity, namely Fusobacterium necrophorum. We encountered an extremely rare case of Lemierre's syndrome, where double vision was found to be the first symptom. The patient's blood culture results showed the presence of F. nucleatum, which spread from the sphenoid sinus to the skull base because of chronic sinusitis; the patient presented with longus colli abscess, clivus osteomyelitis, venous thrombosis, and hematogenous infection. Antibiotic treatment with sulbactam/ampicillin was continued for 14 weeks, and no recurrence has been observed so far. Lemierre's syndrome can be complicated with atypical symptoms such as double vision if the cranial nerves are involved. It might be important to consider this disease in the differential diagnosis in the presence of cranial nerve symptoms of unknown origin with fever or inflammatory findings.

Rheumatoid arthritis frequently complicates airway diseases and is associated with high rates of pneumonia and mortality. The relationship between microorganisms colonizing the lower respiratory tract and the subsequent incidence of pneumonia in patients with rheumatoid arthritis is unclear. In this study, we aimed to identify microorganisms colonizing the lower respiratory tract in patients with rheumatoid arthritis related to the risk of developing subsequent pneumonia in these patients.A retrospective cohort study was designed to include a total of 121 patients with rheumatoid arthritis (median age, 67 years; women, 78.5%) who underwent bronchoscopy at three hospitals from January 2008 to December 2017. The following information was extracted from their electronic medical records: patient characteristics, microorganisms detected by bronchoscopy, and subsequent incidences of pneumonia. The patients were divided into groups based on the microorganisms isolated from the lower respiratory tract and compared with control subjects. The cumulative incidence of pneumonia was assessed using the Kaplan–Meier method and log-rank test. Risk factors for pneumonia were analyzed using the Cox proportional-hazards analysis.The most frequently isolated microbes from the lower respiratory tract in descending order were Pseudomonas aeruginosa, Staphylococcus aureus, and Haemophilus influenzae. The annual incidence rates of pneumonia per 1000 patients were 100, 62, 132, and 38, in the P. aeruginosa, S. aureus, H. influenzae, and control group, respectively. Patients colonized with P. aeruginosa had a higher frequency of macrolide use and a higher degree of bronchiectasis than patients in the control group. The rate of the subsequent incidence of pneumonia was higher in the P. aeruginosa group (P = 0.038), and P. aeruginosa was an independent risk factor for pneumonia (hazard ratio, 3.504; 95% confidence interval, 1.153–10.330).The colonization of the lower respiratory tract by P. aeruginosa in patients with rheumatoid arthritis was associated with the subsequent incidence of pneumonia.

Gastrointestinal colonization by Candida species is considered the main source of candidemia. The ERG3 gene in Candida albicans encodes a sterol C5,6-desaturase, which is essential for ergosterol biosynthesis. Although ERG3 inactivation shows reduced virulence in mouse models of disseminated candidiasis, the role of ERG3 in intestinal infections is unknown. Here, we infected mice with the C. albicans strains CAE3DU3 and CAF2-1, containing mutant and wild-type ERG3, respectively, and studied gut infection and colonization by these strains. We found that the CAE3DU3 strain showed reduced colonization, pathogenesis, damage to gut mucosa, and chemokine production in the mouse model of invasive candidiasis. Additionally, mice inoculated with CAE3DU3 showed lower mortality than mice inoculated with CAF2-1 (p < 0.0001). Chemokines were less induced in the gut inoculated with CAE3DU3 than in the gut inoculated with CAF2-1. Histopathologically, ]although the wild-type gene was associated with a higher pathogenicity and invasion of the gut mucosa and liver tissues causing remarkable tissue necrosis, the erg3/erg3 mutant was associated with a higher accumulation of cells and lower damage to surrounding tissues than wild-type ERG3. These results establish that the ergosterol biosynthetic pathway may be associated with C. albicans gut colonization and subsequent dissemination., Pathogens, 10(1), art.no.23; 2021

Pneumocystis jirovecii pneumonia (PCP) is an opportunistic and life-threatening pulmonary infection with an increasing prevalence among individuals who are human immunodeficiency virus (HIV)-negative. Evidence regarding diagnostic testing of PCP in this patient population is insufficient. We evaluated the performance of serum (1, 3)-β-d-glucan (BDG) using the Fungitec G-test MK kit for diagnosing PCP in non-HIV patients. We retrospectively analyzed data from 219 non-HIV adult patients who underwent bronchoscopy and were tested for P. jirovecii DNA by PCR using lavage samples from the lower respiratory tract. Fifty PCP patients and 125 non-PCP patients were included. The most common underlying diseases were malignancies and systemic autoimmune diseases. Using the serum BDG Fungitec G-test MK test to diagnose PCP, the area under the receiver operating characteristic curve (AUC) was 0.924, whereas the modified cut-off value of 36.6 pg/mL had a sensitivity and specificity of 92.0% and 84.8%, respectively. The AUC for patients with systemic autoimmune diseases was 0.873, and the accuracy of serum BDG test declined when using methotrexate (MTX). In conclusion, the serum BDG test was useful for diagnosing PCP in non-HIV patients; however, the results should be carefully interpreted in case of MTX administration. Lay summary The Fungitec G-test MK kit for measuring serum (1, 3)-β-d-glucan (BDG) levels had a sufficient diagnostic performance for Pneumocystis jirovecii pneumonia (PCP) in human immunodeficiency virus-negative patients. However, the results should be carefully interpreted in case of MTX administration.

Objective To evaluate the annual variation in the frequency of patient-acquired azole-resistant Aspergillus fumigatus (ARAf), and correlate it to the amount of oral triazole prescribed, in Nagasaki, Japan. Methods A. fumigatus isolates from respiratory specimens collected in the Nagasaki University Hospital (NUH) between 1996 and 2017 were included in the study. The amount of oral triazole prescribed in NUH since 2001 was obtained from the medical ordering system. Mutations in cyp51A, hmg1, and erg6 genes of ARAf were also analysed. Results From a total of 240 ARAf strains, 12 (5%), 6 (2.5%), 15 (6.25%), and 3 (1.25%) strains were resistant to itraconazole (ITC), voriconazole (VRC), to either ITC or VRC, and both triazoles, respectively. The amount of prescribed VRC increased annually, and was three times as large as that of ITC in 2017. All eleven patients harbouring ITC-resistant strains had a history of prior ITC treatment, while only one of six patients harbouring VRC-resistant strains had a history of prior VRC treatment. cyp51A mutations were recorded in 10 strains; however, tandem repeat mutations of the promoter region of cyp51A were not observed. Several azole-resistant strains had non-cyp51A mutations. Conclusions The frequency of patient-acquired ARAf is not increasing in Nagasaki, Japan. Furthermore, the prevalence of VRC-induced ARAf was rare despite the remarkable increase in the amount of prescribed VRC. Mutations in genes other than cyp51A should also be considered when ARAf strains are obtained from patients treated with azole antifungals.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease that commonly has a lethal course caused by the tick-borne Huaiyangshan banyang virus [former SFTS virus (SFTSV)]. The viral load in various body fluids in SFTS patients and the best infection control measure for SFTS patients have not been fully established. CASE PRESENTATION: A 79-year-old man was bitten by a tick while working in the bamboo grove in Nagasaki Prefecture in the southwest part of Japan. Due to the occurrence of impaired consciousness, he was referred to Nagasaki University Hospital for treatment. The serum sample tested positive for SFTSV-RNA in the genome amplification assay, and he was diagnosed with SFTS. Furthermore, SFTSV-RNA was detected from the tick that had bitten the patient. He was treated with multimodal therapy, including platelet transfusion, antimicrobials, antifungals, steroids, and continuous hemodiafiltration. His respiration was assisted with mechanical ventilation. On day 5, taking the day on which he was hospitalized as day 0, serum SFTSV-RNA levels reached a peak and then decreased. However, the cerebrospinal fluid collected on day 13 was positive for SFTSV-RNA. In addition, although serum SFTSV-RNA levels decreased below the detectable level on day 16, he was diagnosed with pneumonia with computed tomography. SFTSV-RNA was detected in the bronchoalveolar lavage fluid on day 21. By day 31, he recovered consciousness completely. The pneumonia improved by day 51, but SFTSV-RNA in the sputum remained positive for approximately 4 months after disease onset. Strict countermeasures against droplet/contact infection were continuously conducted. CONCLUSIONS: Even when SFTSV genome levels become undetectable in the serum of SFTS patients in the convalescent phase, the virus genome remains in body fluids and tissues. It may be possible that body fluids such as respiratory excretions become a source of infection to others; thus, careful infection control management is needed., BMC infectious diseases, 20(1), art.no.281; 2020

Elm1 is a serine/threonine kinase involved in multiple cellular functions, including cytokinesis, morphogenesis, and drug resistance in Saccharomyces cerevisiae; however, its roles in pathogenic fungi have not been reported. In this study, we created ELM1-deletion, ELM1-reconstituted, ELM1-overexpression, and ELM1-kinase-dead strains in the clinically important fungal pathogen Candida glabrata and investigated the roles of Elm1 in cell morphology, stress response, and virulence. The elm1Δ strain showed elongated morphology and a thicker cell wall, with analyses of cell-wall components revealing that this strain exhibited significantly increased chitin content relative to that in the wild-type and ELM1-overexpression strains. Although the elm1Δ strain exhibited slower growth than the other two strains, as well as increased sensitivity to high temperature and cell-wall-damaging agents, it showed increased virulence in a Galleria mellonella-infection model. Moreover, loss of Elm1 resulted in increased adhesion to agar plates and epithelial cells, which represent important virulence factors in C. glabrata. Furthermore, RNA sequencing revealed that expression levels of 30 adhesion-like genes were elevated in the elm1Δ strain. Importantly, all these functions were mediated by the kinase activity of Elm1. To our knowledge, this is the first report describing the functional characterization of Elm1 in pathogenic fungi., Scientific Reports, 10(1), art.no.9789; 2020

Background: The recent increase in cases of azole-resistant Aspergillus fumigatus (ARAf) infections is a major clinical concern owing to its treatment limitations. Patient-derived ARAf occurs after prolonged azole treatment in patients with aspergillosis and involves various cyp51A point mutations or non-cyp51A mutations. The prognosis of patients with chronic pulmonary aspergillosis (CPA) with patient-derived ARAf infection remains unclear. In this study, we reported the case of a patient with ARAf due to HapE mutation, as well as the virulence of the isolate. Case presentation: A 37-year-old male was presented with productive cough and low-grade fever. The patient was diagnosed with CPA based on the chronic course, presence of a fungus ball in the upper left lobe on chest computed tomography (CT), positivity for Aspergillus-precipitating antibody and denial of other diseases. The patient underwent left upper lobe and left S6 segment resection surgery because of repeated haemoptysis during voriconazole (VRC) treatment. The patient was postoperatively treated with VRC for 6 months. Since then, the patient was followed up without antifungal treatment but relapsed 4 years later, and VRC treatment was reinitiated. Although an azole-resistant isolate was isolated after VRC treatment, the patient did not show any disease progression in either respiratory symptoms or radiological findings. The ARAf isolated from this patient showed slow growth, decreased biomass and biofilm formation in vitro, and decreased virulence in the Galleria mellonella infection model compared with its parental strain. These phenotypes could be caused by the HapE splice site mutation. Conclusions: This is the first to report a case demonstrating the clinical manifestation of a CPA patient infected with ARAf with a HapE splice site mutation, which was consistent with the in vitro and in vivo attenuated virulence of the ARAf isolate. These results imply that not all the ARAf infections in immunocompetent patients require antifungal treatment. Further studies on the virulence of non-cyp51A mutations in ARAf are warranted., BMC Infectious Diseases, 21(1), art. no. 573; 2021

Background Mycoplasma pneumoniae strains with resistance to macrolides have been spreading worldwide. Here, we aimed to clarify which antimicrobial agent is a better treatment for patients with M. pneumoniae pneumonia in a setting with large epidemics of macrolide resistance. Methods Adult patients hospitalized with laboratory-confirmed M. pneumoniae pneumonia from 2010 to 2013 were identified from the Japanese Diagnosis Procedure Combination national database. Drug switching, length of stay (LOS), 30-day mortality, and total costs for patients who underwent macrolide, quinolone, and tetracycline therapy were compared using propensity score analyses. Results Eligible patients (N = 1650) from 602 hospitals were divided into the macrolide group (n = 508), quinolone group (n = 569), or tetracycline group (n = 573). We found that 52.8%, 21.8%, and 38.6% of patients in the macrolide, quinolone, and tetracycline groups, respectively, had to switch drugs (P, Clinical Infectious Diseases, 65(11), pp.1837-1842; 2017

The innate immune system plays an important role in early immunity against respiratory tract infection. Although airway epithelial cells produce mucus to eliminate pathogens and irritants, hypersecretion of mucus is harmful for the host as it may cause airway obstruction and inhibit influx of antimicrobial agents. It has been reported that several antimicrobial agents have an immunomodulatory effect in vitro and in vivo, but little is known about whether tedizolid, a novel oxazolidinone, can modulate immune responses. In this study, we evaluated whether tedizolid can suppress MUC5AC production in human airway epithelial cells stimulated by methicillin-resistant Staphylococcus aureus (MRSA). Compared with the control, tedizolid significantly inhibited MUC5AC protein production and mRNA overexpression at concentrations of both 2 and 10 μg/mL (representative of trough and peak concentrations in human epithelial lining fluid). Among the mitogen-activated protein kinase inhibitors tested, only extracellular signal-regulated protein kinase 1/2 (ERK1/2) phosphorylation was inhibited by tedizolid as indicated by western blot analysis. These results indicate that tedizolid inhibits the overproduction of MUC5AC protein by inhibiting phosphorylation of ERK1/2. This study revealed that tedizolid suppresses excessive mucin production in human airway epithelial cells. The immunomodulatory effect of tedizolid may improve outcomes in patients with severe respiratory infectious diseases caused by MRSA.

There is an urgent need for development of better diagnostic strategies to improve outcomes in patients with invasive pulmonary aspergillosis (IPA). We hypothesized that lung perfusion single-photon emission computed tomography (SPECT) may be more sensitive and specific than computed tomography (CT) of the chest for detection of IPA because it is an angioinvasive pulmonary infection with characteristics that are different from those of bacterial pneumonia. We used SPECT with injection of technetium-99m-labeled macroaggregated albumin ([99mTc]MAA) to measure pulmonary perfusion in noninfected mice, mice with IPA, and mice with bacterial pneumonia. Histopathologic analysis was performed to evaluate the correlation between the perfusion defect and mould invasion. We also attempted to quantitatively evaluate the SPECT images to identify differences in decreased perfusion levels in affected areas in the mouse lung. Histopathologic analysis in the IPA mouse model showed a clear match between areas with a perfusion defect and the presence of mold, indicating that the location of the perfusion defect on a SPECT image reflects angioinvasion of the mould in the lungs. Some of these perfusion defects could be seen before appearance of the infiltrate of CT images. Quantitative analysis confirmed that perfusion in the affected areas was significantly decreased in the IPA model but not in the bacterial pneumonia model (P

The novel arylamidine T-2307 exhibits broad-spectrum in vitro and in vivo antifungal activities against clinically significant pathogens. Previous studies have shown that T-2307 accumulates in yeast cells via a specific polyamine transporter and disrupts yeast mitochondrial membrane potential. Further, it has little effect on rat liver mitochondrial function., The novel arylamidine T-2307 exhibits broad-spectrum in vitro and in vivo antifungal activities against clinically significant pathogens. Previous studies have shown that T-2307 accumulates in yeast cells via a specific polyamine transporter and disrupts yeast mitochondrial membrane potential. Further, it has little effect on rat liver mitochondrial function. The mechanism by which T-2307 disrupts yeast mitochondrial function is poorly understood, and its elucidation may provide important information for developing novel antifungal agents. This study aimed to determine how T-2307 promotes yeast mitochondrial dysfunction and to investigate the selectivity of this mechanism between fungi and mammals. T-2307 inhibited the respiration of yeast whole cells and isolated yeast mitochondria in a dose-dependent manner. The similarity of the effects of T-2307 and respiratory chain inhibitors on mitochondrial respiration prompted us to investigate the effect of T-2307 on mitochondrial respiratory chain complexes. T-2307 particularly inhibited respiratory chain complexes III and IV not only in Saccharomyces cerevisiae but also in Candida albicans, indicating that T-2307 acts against pathogenic fungi in a manner similar to that of yeast. Conversely, T-2307 showed little effect on bovine respiratory chain complexes. Additionally, we demonstrated that the inhibition of respiratory chain complexes by T-2307 resulted in a decrease in the intracellular ATP levels in yeast cells. These results indicate that inhibition of respiratory chain complexes III and IV is a key factor for selective disruption of yeast mitochondrial function and antifungal activity.