Inhibition of Escherichia coli Lipoprotein Diacylglyceryl Transferase Is Insensitive to Resistance Caused by Deletion of Braun's Lipoprotein.

Lipoprotein diacylglyceryl transferase (Lgt) catalyzes the first step in the biogenesis of Gram-negative bacterial lipoproteins which play crucial roles in bacterial growth and pathogenesis. We demonstrate that Lgt depletion in a clinical uropathogenic Escherichia coli strain leads to permeabilization of the outer membrane and increased sensitivity to serum killing and antibiotics. Importantly, we identify G2824 as the first-described Lgt inhibitor that potently inhibits Lgt biochemical activity in vitro and is bactericidal against wild-type Acinetobacter baumannii and E. coli strains. While deletion of a gene encoding a major outer membrane lipoprotein, lpp, leads to rescue of bacterial growth after genetic depletion or pharmacologic inhibition of the downstream type II signal peptidase, LspA, no such rescue of growth is detected after Lgt depletion or treatment with G2824. Inhibition of Lgt does not lead to significant accumulation of peptidoglycan-linked Lpp in the inner membrane. Our data validate Lgt as a novel antibacterial target and suggest that, unlike downstream steps in lipoprotein biosynthesis and transport, inhibition of Lgt may not be sensitive to one of the most common resistance mechanisms that invalidate inhibitors of bacterial lipoprotein biosynthesis and transport. IMPORTANCE As the emerging threat of multidrug-resistant (MDR) bacteria continues to increase, no new classes of antibiotics have been discovered in the last 50 years. While previous attempts to inhibit the lipoprotein biosynthetic (LspA) or transport (LolCDE) pathways have been made, most efforts have been hindered by the emergence of a common mechanism leading to resistance, namely, the deletion of the gene encoding a major Gram-negative outer membrane lipoprotein lpp. Our unexpected finding that inhibition of Lgt is not susceptible to lpp deletion-mediated resistance uncovers the complexity of bacterial lipoprotein biogenesis and the corresponding enzymes involved in this essential outer membrane biogenesis pathway and potentially points to new antibacterial targets in this pathway.

Mucus plugs and bronchial wall thickening on three-dimensional computed tomography in patients with unexplained chronic cough whose sputum yielded filamentous Basidiomycetes.

OBJECTIVES: This study was conducted in order to identify imaging features on three-dimensional computed tomography (CT) of unexplained chronic cough (UCC) patients with positive sputum cultures for filamentous Basidiomycetes (f-BM). METHODS: UCC outpatients who had been given various questionnaires for cough, pulmonary function tests, and fungal cultures of sputum were evaluated. Multidetector row CT (MDCT) was performed for three-dimensional CT analysis of the lungs. Retrospective analysis was carried out with three groups: f-BM culture-positive group, other fungal culture-positive group, and culture-negative group. The Kruskal-Wallis test, analysis of variance, Fischer exact test, χ2 test, Student's t test, Mann-Whitney U test, Spearman's correlation coefficient, and Dunn-Bonferroni post hoc method were used for statistical analysis. RESULTS: Of the 50 patients, 3 were excluded and the remaining 47 were included in the analysis. There were no significant differences in respiratory function or clinical characteristics among the three groups. The common features on high-resolution CT (HRCT) included tree-in-bud (TIB) pattern, multiple centrilobular nodules, and bronchial wall thickening. Bronchiolar mucus plugs were detected in 7 (15%) of 47 cases. Bronchiole wall thickness and %FEV1 appeared to be slightly correlated (p = 0.033, r = 0.357). The bronchiole walls were significantly thicker when mucus plugs were found (p = 0.010). Bronchiolar walls were the thickest and the score of mucus plugs was the highest in patients with f-BM culture-positive sputum (p = 0.008). CONCLUSIONS: Imaging findings for identifying f-BM culture-positive fungus-associated chronic cough (FACC) patients include high mucus plug scores and bronchiolar wall thickening on three-dimensional CT. KEY POINTS: • Three-dimensional computed tomography helps clinicians assess patients with unexplained chronic cough and identify those with fungus-associated chronic cough. • A retrospective single-center study showed that computed tomography images in patients with filamentous Basidiomycetes cultured from sputum had mucus plugs and bronchiolar wall thickening. • UCC patients with sputum cultures positive for filamentous Basidiomycetes may have fine airway lesions that could not be detected without three-dimensional computed tomography.

Acute liver failure due to severe Herpes simplex viral hepatitis in an elderly woman: A case of initial infection.

The high mortality rate due to severe Herpes simplex viral (HSV) hepatitis is associated with the difficulty of its diagnosis. We describe the extremely rapid disease course of a patient who died of severe HSV hepatitis. A 73-year-old woman was admitted for a bronchial asthma attack. Her symptoms improved with steroid treatment, but she developed a sore throat and painful swallowing. On day 12 after admission, she suddenly went into shock. Blood test results showed a significant increase in the liver enzyme levels, with remarkable disseminated intravascular coagulation. She died the same day. The autopsy revealed extensive coagulative necrosis of the liver. Viral inclusion of type A Cowdry bodies was found in the residual hepatocytes in the hepatic lobule. Immunostaining revealed HSV type 1 positivity. We diagnosed the cause of death as severe HSV hepatitis. On examination of a stored serum sample, the patient tested positive for the HSV immunoglobulin (Ig)-M antibody, and the HSV RNA level was very high (1 × 109 copies/mL). Remarkably, the HSV IgG test result was negative, and we diagnosed her as having had an initial HSV infection. Hepatitis due to HSV is very rare in healthy adults; however, there are many reports of immune-deficient cases. The presence of HSV IgG is decreasing in the elderly population because of the change in living environments/lifestyles. The increasing use of immunosuppressive drugs, such as steroids, for treating diseases in elderly patients could be linked to the increased prevalence of initial HSV infections, resulting in liver injury.

Real-Time PCR Detection of the Basidiomycetous Fungus Bjerkandera adusta: A Tool to Identify Itraconazole Responder Patients with Unexplained Chronic Cough.

BACKGROUND: Filamentous basidiomycetes (f-BMs) are involved in some unexplained chronic cough (UCC) cases that can be improved by the administration of antifungal agents. The disease concept was termed fungus-associated chronic cough (FACC). The current diagnostic criteria warrant environmental fungi isolation from respiratory specimens, which is hardly conceivable for such fungi. OBJECTIVES: This study aimed to detect the f-BMs Bjerkandera adusta, the most common pathogen in FACC, from respiratory specimens of patients with UCC using real-time polymerase chain reaction (PCR). It also evaluated the applicability of the PCR system to detect antifungal agent responders among patients with unexplained cough. METHODS: The PCR system specific to B. adusta was developed and its utility was evaluated using sputum samples from 23 patients with chronic cough. RESULTS: B. adusta was detected in 10 out of 14 patients with UCC (71.4%), in contrast to only 2 out of 9 patients with non-UCC (22.2%; p < 0.05 with the Fisher's exact test). The copy number of the samples correlated with the therapeutic impact score for cough symptoms following the oral administration of itraconazole. CONCLUSION: Development of the real-time PCR system enabled us to demonstrate that many patients with UCC might be influenced by B. adusta, a fact evidenced by the improvement of symptoms with itraconazole administration in most PCR-positive patients. This method would help in detecting itraconazole responders among patients with UCC when the isolation of f-BMs is not achievable.

Prevalence and causes of chronic cough in Japan.

BACKGROUND: Chronic cough is one of the most common symptoms of respiratory diseases and can adversely affect patients' quality of life and interfere with social activities, resulting in a significant social burden. A survey is required to elucidate the frequency and treatment effect of chronic cough. However, clinical studies that cover all of Japan have not yet been conducted. METHODS: Patients who presented with a cough that lasted longer than 8 weeks and visited the respiratory clinics or hospitals affiliated with the Japan Cough Society during the 2-year study period were registered. RESULTS: A total of 379 patients were enrolled, and those who did not meet the definition of chronic cough were excluded. A total of 334 patients were analyzed: 201 patients had a single cause, and 113 patients had two or more causes. The main causative diseases were cough variant asthma in 92 patients, sinobronchial syndrome (SBS) in 36 patients, atopic cough in 31 patients, and gastroesophageal reflux (GER)-associated cough in 10 patients. The time required to treat undiagnosed patients and those with SBS was significantly longer and the treatment success rate for GER-associated cough was considerably poor. CONCLUSIONS: We confirmed that the main causes of chronic cough were cough variant asthma, SBS, atopic cough, and their complications. We also showed that complicated GER-associated cough was more likely to become refractory. This is the first nationwide study in Japan of the causes and treatment effects of chronic cough.

Impact of Schizophyllum sensitization on decline of lung function in asthma.

OBJECTIVE: There is increasing interest in the association between the severity of asthma and fungal sensitization, and lung function decline in relation to mold and dampness in the home has recently been reported. This study was performed to determine the correlation between sensitization to Schizophyllum commune and decline of lung function, and to elucidate the outcomes and risk factors, especially from Schizophyllum allergy. METHODS: The medical records of 50 patients with asthma who satisfied the following inclusion criteria were collected and reviewed retrospectively: (1) at least 5 years of follow-up with five evaluations; (2) intradermal skin tests including S. commune performed at the initial assessment; and (3) severity ranging from mild-to-moderate. Lung function decline (evaluated as adjusted delta FEV1/year) was compared in a cross-sectional manner with regard to gender, age, BMI, smoking habit, allergological characteristics and exacerbation frequency. RESULTS AND CONCLUSIONS: There were significant differences in lung function decline between females and males (p < 0.05), positive and negative results of late-phase skin reaction to S. commune (p < 0.001), and positive and negative late-phase skin reaction to Aspergillus (p < 0.05). Lung function decline was correlated with exacerbation frequency (r = 0.428, p = 0.002). On multiple regression analysis, the probability of lung function decline in asthma was found to be significantly associated with female gender and positive late-phase skin reaction against S. commune. Our results suggested that sensitization to S. commune may be one of the risk factors involved in lung function decline in asthmatic patients.

Chronic cough management: dealing with a sensation of mucus in the throat.

Among the various types of laryngeal paresthesia, the results of the study with use of a newly developed cough-related laryngeal sensation questionnaire suggested that a sensation of mucus in the throat (SMIT) can predict the presence of fungal colonization in chronic cough patients. Next to 'cough' or 'sputum', SMIT may become the third key clinical manifestation leading to successful prediction of the efficacy of antifungal therapy in chronic cough patients.

Chronic cough management: dealing with a sensation of irritation in the throat.

Among the various types of laryngeal paraesthesia suffered by chronic cough patients, we often encounter 'a sensation of irritation in the throat (SIT)'. Our study indicated that capsaicin cough threshold was significantly (P < 0.05) lower in the SIT-positive group (13.9 µmol/L) than in the SIT-negative group (49.6 µmol/L). The establishment of treatment strategies for SIT would be advantageous for treating chronic cough patients suffering from this laryngeal sensation.

Specific detection of Bjerkandera adusta by polymerase chain reaction and its incidence in fungus-associated chronic cough.

Chronic cough is a common symptom at outpatient care. An uncontrollable cough with difficulty in treatment is called chronic idiopathic cough. Recent reports have demonstrated that the presence of basidiomycetous fungi in sputum is an important clinical finding that assists in clarifying the cause of chronic cough in some cases. Research has suggested that Bjerkandera adusta is related to fungus-associated chronic cough (FACC). FACC is defined as a chronic cough associated with basidiomycetous fungi found in induced sputum and can be treated with antifungal medication. B. adusta is one of the basidiomycetous fungi that exist in cosmopolitan environments. The aim of this study was to develop a B. adusta detection method using polymerase chain reaction (PCR) with a specific primer set and to research the incidence of B. adusta in FACC. The new method successfully detected B. adusta from FACC patients. The incidence of B. adusta in FACC was 42.86 %. Antifungal drugs were effective in most cases. Significant differences in treatment duration between B. adusta patients and non-B. adusta patients were observed. It is therefore suggested that the presence of B. adusta may be one of the allergic intractable factors of chronic cough. This finding may provide identifiable differences in clinical manifestations between B. adusta and non-B. adusta in FACC and lead to possible differing remedies to treat the two forms. PCR can specifically detect B. adusta from patients suffering from chronic cough and provides a new diagnosis for FACC associated with B. adusta.

The definitive diagnostic process and successful treatment for ABPM caused by Schizophyllum commune: a report of two cases.

BACKGROUND: Although mucoid impaction of the bronchi (MIB) is a well-known manifestation in allergic bronchopulmonary mycosis (ABPM), when unknown samples or plural eumycetes are cultured from bronchial materials, several problems are encountered which can affect the definitive diagnostic process or successful treatment. CASE SUMMARY: The definitive diagnostic process of two patients [a 58-(Case 1) and a 70-(Case 2) year-old female] with MIB was: 1) to identify the existence of any allergic respiratory disorder, 2) to detect the fungi obtained from bronchial materials, with use of the 28S rDNA sequencing and analysis, 3) to investigate whether the detected fungus was a probable etiologic antigen, and 4) to make the final diagnosis based on the results of the inhalation examinations using the antigenic solution of the fungi. As a treatment strategy, bronchial toilet and low dose itraconazole therapy were planned according to the clinical manifestations of each patient. DISCUSSION: The two patients with MIB were successfully diagnosed as ABPM caused by Schizophyllum commune (Sc-ABPM) accompanied with hyperattenuating mucoid impaction. The reliability of some allergological makers as a substitution for the bronchoprovocation test should be clarified in near future. Clinical manifestations demonstrated in our cases suggested that the allergic reaction such as eosinophilic bronchoalveolitis spreading around the mucus plug was a primary lesion underlying the Sc-ABPM. The success of the treatment for Sc-ABPM will be achieved by the strategy targeting to fundamental condition and by the control of the disease recurrence by means of effective environmental management.

Two cases of Schizophyllum asthma: is this a new clinical entity or a precursor of ABPM?

BACKGROUND: There is a close link between fungal sensitization and asthma severity. Although Schizophyllum commune (S. commune, "suehirotake" in Japanese), one of the basidiomycetous (BM) fungi, is a fungus that can cause allergic bronchopulmonary mycosis (ABPM) and allergic fungal sinusitis (AFS), whether the fungus causes or sensitizes subjects to asthma is unclear. METHODS: The bronchial provocation test using S. commune antigen was performed in two asthmatics who had demonstrated positive skin reactions to the S. commune antigen, and low dose of itraconazole (50 mg/day) was prescribed as an adjunctive therapy for 2 weeks. The allergological features and clinical manifestations of these patients are herein evaluated and discussed. RESULTS: Case 1 was a 71-year-old female, and case 2 was a 69-year-old male. Both patients demonstrated positive reactions to the inhalation test. A diagnosis of AFS or ABPM was excluded in both patients because of the lack of a history of pulmonary infiltrates, central bronchiectasis, a history of expectoration of brown plugs or flecks, or sinusoidal findings. Although the efficacy of itraconazole in our cases was unclear, the elevated titer of the specific IgG-for S. commune in case 2 gradually decreased during the period of antifungal therapy. CONCLUSIONS: The two patients described herein were diagnosed to have bronchial asthma caused by S. commune; so-called Schizophyllum asthma. S. commune may also be a causative fungal antigen of bronchial asthma.

The influence of Schizophyllum commune on asthma severity.

BACKGROUND: The sensitization and exposure to fungal allergens have been reported to be associated with asthma. The aim of this study was to clarify the impact of sensitization to Schizophyllum commune (S. commune) on the severity and exacerbations of asthma. METHODS: Ninety-two patients with asthma of various levels of severity [mild (n = 18), moderate (28), and severe (46)] and exacerbation severity [moderate (n = 43) and severe (6)] were retrospectively examined with regard to fungal sensitization such as specific IgE or intradermal skin reactions against S. commune and other common allergens. We also classified the patients into three groups: (1) three or more asthma attacks during the past year (F-BA) (n = 29),(2) one or two asthma attacks (NF-BA) (n = 20), and (3) no asthma attack (C-BA) (n = 43). RESULTS: The positive rate of late cutaneous reactions to S. commune was higher in patients with severe asthma (41.2%) than with moderate (26.1%) or mild asthma (6.7%), and was significantly different among the three groups (P < 0.05). Although the ratio did not show a significant difference between the patients with severe (83.3%) or moderate (36.1%) exacerbation, it was higher in F-BA (60.9%) than in NF-BA (21.1%) and C-BA patients (10.0%), and it was significantly different among the three groups (P = 0.0002). Multivariate analysis identified positive results for late-phase skin reactions to S. commune and the age of the patients as an independent determinant of asthma severity, and the skin results and %FVC an independent determinant of exacerbation frequency. CONCLUSION: This study demonstrated that S. commune is an environmental fungus that appears to enhance both the severity of asthma and the exacerbation frequency.

COVID-19-associated coagulopathy and disseminated intravascular coagulation.

The pathology of coronavirus disease 2019 (COVID-19) is exacerbated by the progression of thrombosis, and disseminated intravascular coagulation (DIC), and cytokine storms. The most frequently reported coagulation/fibrinolytic abnormality in COVID-19 is the increase in D-dimer, and its relationship with prognosis has been discussed. However, limits exist to the utility of evaluation by D-dimer alone. In addition, since the coagulation/fibrinolytic condition sometimes fluctuates within a short period of time, regular examinations in recognition of the significance of the examination are desirable. The pathophysiology of disseminated intravascular coagulation (DIC) associated with COVID-19 is very different from that of septic DIC, and both thrombotic and hemorrhagic pathologies should be noted. COVID-19 thrombosis includes macro- and microthrombosis, with diagnosis of the latter depending on markers of coagulation and fibrinolysis. Treatment of COVID-19 is classified into antiviral treatment, cytokine storm treatment, and thrombosis treatment. Rather than providing uniform treatment, the treatment method most suitable for the severity and stage should be selected. Combination therapy with heparin and nafamostat is expected to develop in the future. Fibrinolytic therapy and adsorption therapy require further study.

Potential mechanisms of nafamostat therapy for severe COVID-19 pneumonia with disseminated intravascular coagulation.

Nafamostat, a serine proteinase inhibitor with various actions including antithrombin, antiplasmin, and antitrypsin effects, has been used in clinical practice to treat disseminated intravascular coagulation (DIC) and pancreatitis. This case report describes the clinical course of a patient with COVID-19 pneumonia whose severe hypoxemia, probably caused by DIC and pulmonary embolism, showed remarkable improvement with combination heparin and nafamostat therapy. In addition, beneficial mechanisms of nafamostat against COVID-19 and the necessity of attention to hyperkalemia as an adverse effect are discussed.

The Japanese respiratory society guidelines for the management of cough and sputum (digest edition).

Cough and sputum are common complaints at outpatient visits. In this digest version, we provide a general overview of these two symptoms and discuss the management of acute (up to three weeks) and prolonged/chronic cough (longer than three weeks). Flowcharts are provided, along with a step-by-step explanation of their diagnosis and management. Most cases of acute cough are due to an infection. In chronic respiratory illness, a cough could be a symptom of a respiratory infection such as pulmonary tuberculosis, malignancy such as a pulmonary tumor, asthma, chronic obstructive pulmonary disease, chronic bronchitis, bronchiectasis, drug-induced lung injury, heart failure, nasal sinus disease, sinobronchial syndrome, eosinophilic sinusitis, cough variant asthma (CVA), atopic cough, chronic laryngeal allergy, gastroesophageal reflux (GER), and post-infectious cough. Antibiotics should not be prescribed for over-peak cough but can be considered for atypical infections. The exploration of a single/major cause is recommended for persistent/chronic cough. When sputum is present, a sputum smear/culture (general bacteria, mycobacteria), cytology, cell differentiation, chest computed tomography (CT), and sinus X-ray or CT should be performed. There are two types of rhinosinusitis. Conventional sinusitis and eosinophilic rhinosinusitis present primarily with neutrophilic inflammation and eosinophilic inflammation, respectively. The most common causes of dry cough include CVA, atopic cough/laryngeal allergy (chronic), GER, and post-infectious cough. In the last chapter, future challenges and perspectives are discussed. We hope that the clarification of the pathology of cough hypersensitivity syndrome will lead to further development of "pathology-specific non-specific therapeutic drugs" and provide benefits to patients with chronic refractory cough.