Repurposing existing drugs: identification of SARS-CoV-2 3C-like protease inhibitors.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for coronavirus disease 2019 (COVID-19). Since its emergence, the COVID-19 pandemic has not only distressed medical services but also caused economic upheavals, marking urgent the need for effective therapeutics. The experience of combating SARS-CoV and MERS-CoV has shown that inhibiting the 3-chymotrypsin-like protease (3CLpro) blocks the replication of the virus. Given the well-studied properties of FDA-approved drugs, identification of SARS-CoV-2 3CLpro inhibitors in an FDA-approved drug library would be of great therapeutic value. Here, we screened a library consisting of 774 FDA-approved drugs for potent SARS-CoV-2 3CLpro inhibitors, using an intramolecularly quenched fluorescence (IQF) peptide substrate. Ethacrynic acid, naproxen, allopurinol, butenafine hydrochloride, raloxifene hydrochloride, tranylcypromine hydrochloride, and saquinavir mesylate have been found to block the proteolytic activity of SARS-CoV-2 3CLpro. The inhibitory activity of these repurposing drugs against SARS-CoV-2 3CLpro highlights their therapeutic potential for treating COVID-19 and other Betacoronavirus infections.

The long-term effect of bundle care for catheter-related blood stream infection: 5-year follow-up.

OBJECTIVE: To address the importance of bundle care for catheter-related infection (CRBSI) on the basis of long-term observation in a catheter-abundant cardiovascular intensive care unit (CVICU). DESIGN: Prospective longitudinal cohort study. SETTING: CVICU of a tertiary referring medical centre in northern Taiwan. PARTICIPANTS: Around 1400 critically ill patients annually for 5 years in the CVICU (from January 2010 to June 2015). CRBSI bundle care has been applied ever since by a multidisciplinary team. MAIN OUTCOME MEASURES: CRBSI per 1000 catheter days, bloodstream infection (BSI) per 1000 inpatient days, and catheter utilisation rates. RESULTS: From January 2010 to June 2015 (22 quarters), there were in total 45 140 inpatient days and 24 163 catheter days, with an overall central venous catheter utilisation rate of 53.5%. The duration of the indwelled catheter was 6.3±1.2 days. The beginning CRBSI rate was 7.0 per 1000 catheter days and was significantly decreased to 0.7 per 1000 catheter days (p<0.001). Regarding the time series, cubic polynomial function depicted the CRBSI decrement most vividly (R2=0.501, p=0.005). In addition, the improvement in overall BSIs (2010 Q1, 4.4 per 1000 inpatient days to 2015 Q2, 0.5 per 1000 inpatient days, p<0.001) significantly correlated with the decrease in CRBSI (r=0.86, p<0.001). CONCLUSIONS: Through the bundle care, we successfully reduced CRBSIs. After 5 years of follow-up, we observed that the effect of bundle care was stepwise and persistent, as long as we kept working on this integrated project.

Ergosterol peroxide blocks HDV infection as a novel entry inhibitor by targeting human NTCP receptor.

Hepatitis D virus (HDV), which co-infects or superinfects patients with hepatitis B virus, is estimated to affect 74 million people worldwide. Chronic hepatitis D is the most severe form of viral hepatitis and can result in liver cirrhosis, liver failure, and hepatocellular carcinoma (HCC). Currently, there are no efficient HDV-specific drugs. Therefore, there is an urgent need for novel HDV therapies that can achieve a functional cure or even eliminate the viral infection. In the HDV life cycle, agents targeting the entry step of HDV infection preemptively reduce the intrahepatic viral RNA. Human sodium taurocholate co-transporting polypeptide (hNTCP), a transporter of bile acids on the plasma membrane of hepatocytes, is an essential entry receptor of HDV and is a promising molecular target against HDV infection. Here, we investigated the effect of ergosterol peroxide (EP) on HDV infection in vitro and in vivo. EP inhibited HDV infection of hNTCP-expressing dHuS-E/2 hepatocytes by interrupting the early fusion/endocytosis step of HDV entry. Furthermore, molecular modeling suggested that EP hinders LHBsAg binding to hNTCP by blocking access to S267 and V263. In addition, we generated hNTCP-expressing transgenic (Tg) C57BL/6 mice using the Cre/loxP system for in vivo study. EP reduced the liver HDV RNA level of HDV-challenged hNTCP-Cre Tg mice. Intriguingly, EP downregulated the mRNA level of liver IFN-γ. We demonstrate that EP is a bona fide HDV entry inhibitor that acts on hNTCP and has the potential for use in HDV therapies.

Revisiting the association between vitamin D deficiency and active tuberculosis: A prospective case-control study in Taiwan.

BACKGROUND: To revisit the association between vitamin D deficiency (VDD, defined as serum 25(OH)D < 20 ng/ml) and incident active tuberculosis (TB), after two potentially underpowered randomized trials showed statistically non-significant 13%-22% decrease in TB incidence in vitamin D supplementation groups. METHODS: We prospectively conducted an age/sex-matched case-control study that accounting for body-mass index (BMI), smoking, and other confounding factors to examine the association between VDD and active TB among non-HIV people in Taiwan (latitude 24°N), a high-income society which continues to have moderate TB burden. RESULTS: We enrolled 62 people with incident active TB and 248 people in control group. The TB case patients had a significantly higher proportion of VDD compared to the control group (51.6% vs 29.8%, p = 0.001). The 25(OH)D level was also significantly lower in TB patients compared to control group (21.25 ± 8.93 ng/ml vs 24.45 ± 8.36 ng/ml, p = 0.008). In multivariable analysis, VDD (adjusted odds ratio [aOR]: 3.03, p = 0.002), lower BMI (aOR: 0.81, p < 0.001), liver cirrhosis (aOR: 8.99, p = 0.042), and smoking (aOR: 4.52, p = 0.001) were independent risk factors for incident active TB. CONCLUSIONS: VDD is an independent risk factor for incident active TB. Future randomized trials examining the effect of vitamin D supplementation on TB incidence should focus on people with a low BMI or other risk factors to maximize the statistical power.

Klebsiella pneumoniae bacteremia and capsular serotypes, Taiwan.

Capsular serotypes of 225 Klebsiella pneumoniae isolates in Taiwan were identified by using PCR. Patients infected with K1 serotypes (41 isolates) had increased community-onset bacteremia, more nonfatal diseases and liver abscesses, lower Pittsburgh bacteremia scores and mortality rates, and fewer urinary tract infections than patients infected with non-K1/K2 serotypes (147 isolates).

A possible rare cause of renal failure in streptococcal infection.

To the best of our knowledge, this is the first biopsy-proven case of streptococcal infection-associated acute interstitial nephritis (AIN) with existence of streptococcal pyrogenic exotoxin B (SPE B) by a controlled immunohistochemical method. Both the intact tubular epithelial cells and oedematous interstitium had strong positive signals, whereas only interstitial inflammation was dominant without tubular necrosis. Reflective of the nature of AIN is that the injury from the hypersensitivity reaction was specific for renal interstitium instead of tubules. SPE B is potentially allergenic and may confuse the clinicians due to its clinical mimicry of drug-induced AIN. Although very rare, AIN might be included into the differential diagnosis of patients with streptococcal sepsis and acute renal failure.

Neglected human Rickettsia felis infection in Taiwan: A retrospective seroepidemiological survey of patients with suspected rickettsioses.

BACKGROUND: Current knowledge on Rickettsia felis infection in humans is based on sporadic case reports. Here we conducted a retrospective seroepidemiological survey of R. felis infection among febrile patients visiting a medical center in Taipei. METHODOLOGY/PRINCIPAL FINDINGS: A total of 122 patients with suspected rickettsioses presenting with fever of unknown origin (FUO) but tested negative for scrub typhus, murine typhus, or Q fever were retrospectively identified during 2009 to 2010. The archived serum samples were examined for the presence of antibodies against R. felis, Rickettsia japonica, and Rickettsia typhi using microimmunofluorescence (MIF) assay. Serological evidence of Rickettsia exposure was found in 23 (19%, 23/122) patients. Eight patients had antibodies reactive to R. felis, including four with current infection (a ≥4-fold increase in IgG titer between acute and convalescent sera). The clinical presentations of these four patients included fever, skin rash, lymphadenopathy, as well as more severe conditions such as pancytopenia, hepatomegaly, elevated liver enzymes/bilirubin, and life-threatening acute respiratory distress syndrome. One of the patients died after doxycycline was stopped after being tested negative for scrub typhus, Q fever, and murine typhus. CONCLUSIONS: Rickettsia felis is a neglected flea-borne pathogen in Taiwan, and its infection can be life-threatening. Further prospective studies of the prevalence of R. felis among patients with FUO and compatible clinical manifestations are warranted.

Role of nasal swab culture in guiding antimicrobial therapy for acute cellulitis in the era of community-acquired methicillin-resistant Staphylococcus aureus: A prospective study of 89 patients.

In this prospective study of 89 patients with acute cellulitis, we showed nasal swab culture of methicillin-resistant Staphylococcus aureus (MRSA), taken at enrollment, has a high specificity of 95% in predicting MRSA cellulitis among the 24 patients whose cellulitis became purulent. However, the sensitivity is only 20%.

The prevalence of rectal carriage of Klebsiella pneumoniae amongst diabetic patients and their clinical relevance in Taiwan: A five-year prospective study.

BACKGROUND/PURPOSE: Pyogenic liver abscess (PLA) and bacteremia caused by Klebsiella pneumoniae is a common complication among patients with diabetes mellitus (DM). The aim of this study is to investigate the prevalence of rectal carriage and serotype distribution of K. pneumoniae amongst DM patients and their clinical relevance. METHODS: We prospectively collected rectal swabs for K. pneumoniae culture in asymptomatic DM patients from March 2008 to June 2009. Seven capsular serotypes that were commonly associated with PLA were determined by capsular polysaccharide synthesis (cps) genotyping. Microbiologically confirmed bacterial infections were evaluated 1 and 5 years after initial enrolment of the patients. RESULTS: A total of 100 male and 62 female patients (mean age, 56.6 years) were enrolled. Of these, 77 (47.5%) had rectal K. pneumoniae colonization. Colonizers were older than non-colonizers (p = 0.03). Sex, fasting blood glucose, and initial HbA1C were not statistically different (p = 0.26, 0.18, and 0.31, respectively). Among the 65 available isolates, 22 (33.8%) belonged to the seven main serotypes. During the 5-year's follow-up, 21 patients developed microbiologically documented bacterial infections but none of them developed PLA and bacteremia. Risk factors for bacterial infection within 5 years included initial glycosylated hemoglobin (HbA1C) > 10% or first-year average HbA1C > 10%. CONCLUSION: Although nearly half of asymptomatic DM patients had rectal carriage of K. pneumoniae and one-third of them colonized by isolates belonging to the seven serotypes related to PLA, none of them subsequently developed PLA and colonized patients did not have higher risk of microbiologically confirmed bacterial infections.

Clinical features and outcome of tuberculosis in solid organ transplant recipients.

BACKGROUND: : Taiwan is an area with moderate to high incidence of Mycobacterium tuberculosis infection. The risk of M tuberculosis infection in transplantation recipients is considered to be significant. Our aim in this study was to investigate the clinical spectrums of M tuberculosis-infected transplantation recipients in a southeast Asian country, Taiwan. METHODS: : We retrospectively analyzed the demographic data, clinical features, treatment, and outcome of M tuberculosis infection in kidney, heart, and liver transplant recipients from May 1996 to April 2005 at the National Taiwan University Hospital. RESULTS: : Fifteen patients who had received solid organ transplantation developed tuberculosis (kidney = 6, heart = 7, liver = 2). The median duration from transplantation to diagnosis of tuberculosis was 31 months. The cumulative incidence of post-transplantation tuberculosis was 2.0% (15/760), ie, approximately 3 times that of the general population. Ten patients (66.7%) had pulmonary tuberculosis, 1 (6.7%) had extrapulmonary tuberculosis, and 4 (26.7%) had disseminated tuberculosis. Nine patients completed the anti-tuberculosis treatment; the median treatment duration was 12 months (pulmonary: 9 months; extrapulmonary: 13.5 months). No treatment failure was noted in patients receiving the complete treatment course. The graft failure and mortality rates of post-transplantation tuberculosis were 13.3% each (2/15). The tuberculosis-associated mortality rate was 6.7% (1/15). CONCLUSIONS: : Cumulative incidence of tuberculosis was slightly higher in transplant recipients than in the general population in Taiwan. Conventional 4-combined anti-tuberculosis regimen for 12 months can treat the potentially fatal infection successfully in post-transplantation tuberculosis patients without recurrence.

Prevalence and clinical features of Clostridium difficile-associated diarrhea in a tertiary hospital in northern Taiwan.

BACKGROUND AND PURPOSE: Although the clinical manifestations of and risk factors for Clostridium difficile-associated diarrhea (CDAD) have been extensively investigated in western populations, data from Taiwanese patients are comparatively limited. This study investigated the incidence density of CDAD in Taiwanese patients and also the risk factors and clinical manifestations of CDAD. METHODS: From September 21, 2003 to December 21, 2003, patients hospitalized in 2 infection wards and 6 medical intensive care units at National Taiwan University Hospital who were older than 20 years, had a history of antibiotic usage within the prior 6 weeks, and developed diarrhea without another identified etiology were classified as having antibiotic-associated diarrhea (AAD), and were enrolled for further study. The diagnosis of CDAD was established when toxin A of C. difficile was detected in stool. RESULTS: The incidence density of AAD was 1/100 person-days of antibiotics usage. CDAD accounted for 12.5% of AAD. Fever and abdominal discomfort developed in only less than half of CDAD patients. Pus cell in the stool sample was found in 100 percent of patients with CDAD. Univariate analysis revealed that presence of malignancy and treatment with antifungal agents within the previous 6 weeks were risk factors for CDAD development. In multivariate analysis, use of antifungal agents was the only independent risk factor for CDAD. CONCLUSION: The incidence density of CDAD in this study of Taiwanese patients with AAD was 12.5%. Prior usage of antifungal agents was the only independent factor associated with subsequent CDAD development in patients with AAD.

Time to positivity in blood cultures of adults with nontyphoidal Salmonella bacteremia.

BACKGROUND: Nontyphoidal Salmonella (NTS) is an important bacterial etiology of diarrheal disease, and it causes invasive diseases in immunocompromised hosts. For bacteremia from some species, blood culture with a rapid time to positivity (TTP) is associated with greater mortality. This study investigated TTP of NTS bacteremia and its relationship to clinical parameters and prognosis. METHODS: Adult patients with NTS bacteremia who were admitted to a tertiary care facility in northern Taiwan from January 2010 to December 2012 were enrolled. Demographics, clinical and microbiological characteristics, and treatment response were reviewed. The TTP for each patient was retrieved from the automated machine. RESULTS: Sixty-six adult patients (mean age, 66.1 years; range, 27-96 years) with NTS bacteremia were identified by the following serogroup distributions: serogroup B (23.4%), serogroup C1 (1.6%), serogroup C2 (6.3%), and serogroup D (68.8%). The in-hospital mortality, 14-day mortality, and 30-day mortality were 15.2%, 7.6%, and 12.1%, respectively. The TTP ranged 6.5-41.7 hours (median: 11.5 hours). Patients with rapid TTP (less than 10 hours), compared to patients without rapid TTP, were more likely to have liver cirrhosis (31.6% vs. 6.4%, p = 0.013), endovascular lesions (21.1% vs. 4.3%, p = 0.05), higher bacteremia score, intensive care unit admission (57.9% vs. 25.5%, p = 0.021), and septic shock (63.2% vs. 12.8%, p < 0.001). There were no significant differences in the in-hospital mortality and 14-day mortality between patients with TTP <10 hours and patients with TTP ≥10 hours. CONCLUSION: The TTP of blood cultures, interpreted with a cut-off point of <10 hours, in patients with NTS bacteremia may provide useful diagnostic and prognostic information.

Haemophilus parainfluenzae urethritis among homosexual men.

Haemophilus parainfluenzae is a common inhabitant of the human upper respiratory tract of the normal oral microflora. We report three men who had been having unprotected sex with men (MSM) and subsequently acquired H. parainfluenzae urethritis, which was confirmed by 16S rRNA gene sequencing analysis. Two men were treated with ceftriaxone and doxycycline, and the third man was treated with clarithromycin. All three patients responded to treatment. This case series highlights the potential role of H. parainfluenzae as a sexually transmitted genitourinary pathogen.

Predicting hospital-acquired infections by scoring system with simple parameters.

BACKGROUND: Hospital-acquired infections (HAI) are associated with increased attributable morbidity, mortality, prolonged hospitalization, and economic costs. A simple, reliable prediction model for HAI has great clinical relevance. The objective of this study is to develop a scoring system to predict HAI that was derived from Logistic Regression (LR) and validated by Artificial Neural Networks (ANN) simultaneously. METHODOLOGY/PRINCIPAL FINDINGS: A total of 476 patients from all the 806 HAI inpatients were included for the study between 2004 and 2005. A sample of 1,376 non-HAI inpatients was randomly drawn from all the admitted patients in the same period of time as the control group. External validation of 2,500 patients was abstracted from another academic teaching center. Sixteen variables were extracted from the Electronic Health Records (EHR) and fed into ANN and LR models. With stepwise selection, the following seven variables were identified by LR models as statistically significant: Foley catheterization, central venous catheterization, arterial line, nasogastric tube, hemodialysis, stress ulcer prophylaxes and systemic glucocorticosteroids. Both ANN and LR models displayed excellent discrimination (area under the receiver operating characteristic curve [AUC]: 0.964 versus 0.969, p = 0.507) to identify infection in internal validation. During external validation, high AUC was obtained from both models (AUC: 0.850 versus 0.870, p = 0.447). The scoring system also performed extremely well in the internal (AUC: 0.965) and external (AUC: 0.871) validations. CONCLUSIONS: We developed a scoring system to predict HAI with simple parameters validated with ANN and LR models. Armed with this scoring system, infectious disease specialists can more efficiently identify patients at high risk for HAI during hospitalization. Further, using parameters either by observation of medical devices used or data obtained from EHR also provided good prediction outcome that can be utilized in different clinical settings.

Disseminated Mycobacterium kansasii infection associated with hemophagocytic syndrome.

Disseminated infections with hemophagocytic syndrome caused by non-tuberculous mycobacteria (NTM) are rare. A 60-year-old woman, who presented with fever, chills, anorexia, and right upper quadrant pain, was admitted to our hospital. Hepatosplenomegaly, pancytopenia, elevated liver aminotransferases, and hyperferritinemia were noted after admission. A gallium scan and chest computed tomography revealed multiple mediastinal lymphadenopathy. A bone marrow examination revealed hemophagocytosis. Bone marrow and liver biopsies showed non-caseating granulomatosis and cultures from bone marrow and liver all yielded Mycobacterium kansasii. The patient responded well to azithromycin, isoniazid, rifampin, and ethambutol. No immunocompromised conditions such as malignancy, autoimmune disease, or HIV infection were detected initially. However, a right femoral tumor with pathological fracture was found five months later during follow-up at the outpatient clinic. Bone biopsy showed granulocytic sarcoma. To our knowledge, this is the first reported case of life-threatening hemophagocytosis due to M. kansasii. Patients with disseminated NTM infections should be closely monitored if any immunocompromising condition develops.

A multicenter study of risk factors and outcome of hospitalized patients with infections due to carbapenem-resistant Acinetobacter baumannii.

BACKGROUND: Risk factors and outcome in patients who acquire nosocomial infections due to carbapenem-resistant Acinetobacter baumannii (CRAB) are rarely investigated. METHODS: A multicenter retrospective study was conducted to analyze the clinical and microbiological data of patients with nosocomial infections due to A. baumannii in 10 hospitals around Taiwan from May 2004 to December 2006. Comparisons were made between patients with infections due to CRAB and patients with infections due to carbapenem-susceptible A. baumannii (CSAB). RESULTS: One hundred and twenty-one patients carrying CRAB (infections, n=91) and 127 patients carrying CSAB (infections, n=97) were recruited for analysis. Compared with patients with CSAB infections, patients with CRAB infections had a longer duration of hospital stay before A. baumannii was isolated (median 48 vs. 21 days, p<0.001) and were more likely to have had exposure to a carbapenem (adjusted odds ratio (AOR) 2.57, 95% confidence interval (95% CI) 1.43-5.35; p=0.02) and an intensive care unit (ICU) stay (AOR 3.42, 95% CI 1.76-5.26; p=0.008). Risk factors associated with CRAB bacteremia included duration of hospital stay before onset of bacteremia (AOR 1.009 per 1-day longer, 95% CI 1.03-1.24; p=0.049), prior colonization with A. baumannii (AOR 3.27, 95% CI 1.99-5.93; p=0.002), and hospitalization in the ICU (AOR 6.12, 95% CI 1.58-13.68; p=0.009). Patients with CRAB bacteremia had a higher mortality rate than patients with CSAB bacteremia (46.0% vs. 28.3%, p=0.04). Multivariate analysis showed that carbapenem resistance (AOR 5.31, 95% CI 1.88-13.25; p=0.002), central venous catheterization (AOR 3.27, 95% CI 1.55-10.56; p=0.009), and ICU stay (AOR 2.56, 95% CI 1.15-8.85; p=0.04) were independent variables associated with mortality in patients with A. baumannii bacteremia. CONCLUSIONS: Patients with CRAB infections have a higher mortality rate than those with CSAB infections. Longer hospital stay, colonization with A. baumannii, and admission to the ICU were associated with the development of CRAB bacteremia.