Primary Klebsiella pneumoniae liver abscess complicated with metastatic meningitis or endophthalmitis is a globally emerging infectious disease. Its pathogenic mechanism remains unclear. The bacterial virulence factors were explored by comparing clinical isolates. Differences in mucoviscosity were observed between strains that caused primary liver abscess (invasive) and those that did not (noninvasive). Hypermucoviscosity correlated with a high serum resistance and was more prevalent in invasive strains (52/53 vs. 9/52; P < 0.0001). Transposon mutagenesis identified candidate virulence genes. A novel 1.2-kb locus, magA, which encoded a 43-kD outer membrane protein, was significantly more prevalent in invasive strains (52/53 vs. 14/52; P < 0.0001). The wild-type strain produced a mucoviscous exopolysaccharide web, actively proliferated in nonimmune human serum, resisted phagocytosis, and caused liver microabscess and meningitis in mice. However, magA − mutants lost the exopolysaccharide web and became extremely serum sensitive, phagocytosis susceptible, and avirulent to mice. Virulence was restored by complementation using a magA-containing plasmid. We conclude that magA fits molecular Koch's postulates as a virulence gene. Thus, this locus can be used as a marker for the rapid diagnosis and for tracing the source of this emerging infectious disease.

Pyogenic liver abscess has become a health problem in Taiwanese society. However, the extent of this problem has remained unclear because of the lack of a populationbased study. We therefore performed a nationwide analysis of pyogenic liver abscess in Taiwan from 1996 through 2004. We analyzed 29,703 cases from the Taiwan National Health Insurance database and 506 cases from National Taiwan University Hospital. Our analysis showed that the annual incidence of pyogenic liver abscess increased steadily from 11.15/100,000 population in 1996 to 17.59/100,000 in 2004. Diabetes, malignancy, renal disease, and pneumonia were associated with a higher risk for the disease. By contrast, death due to pyogenic liver abscess decreased over time, although population-based abscess-related death increased slightly. Renal disease, malignancy, pneumonia, and heart disease correlated with higher death rates; Klebsiella pneumoniae infection and therapeutic procedures were related to lower death rates. Diabetes did not signifi cantly change death rates for the 506 patients from the hospital.T he epidemiology of pyogenic liver abscess has changed dramatically in recent years (1). Previously, although incidence was considered rare, the condition was associated with high illness and death rates, usually due to underlying hepatobiliary diseases and polymicrobial infection (2), with Escherichia coli as the major pathogen (3). More recently, investigations in Taiwan suggest the role of cryptogenic or primary liver abscess, i.e., abscesses without underlying hepatobiliary diseases, in pyogenic liver abscess (4,5). These reports also indicate that diabetes is the major predisposing factor of liver abscess and that Klebsiella pneumoniae is the primary pathogen. However, these results were obtained from small-scale hospital-based surveys, which could not provide a panoramic view of the disease. To confi rm these observation-based results, we conducted a large-scale, unbiased investigation.In addition to epidemiology, the pathogenesis of liver abscess caused by Klebsiella spp. has also been extensively studied, but the mechanism is still not clear. MagA, an outermembrane protein contributing to capsular polysaccharide formation, coexists with serotype K1 and has been identifi ed as the major virulence factor of K. pneumoniae (6). MagApositive (or serotype K1) K. pneumoniae is accordingly recognized as the main pathogen of pyogenic liver abscess (7,8). Nevertheless, how diabetes increases the risk for Klebsiella spp. liver abscess is still not clear. Further research is needed on whether pyogenic liver abscess is affected by immunocompromised conditions, such as malignancy, renal failure, postorgan transplantation, or HIV infection.To clarify the epidemiology and pathogenesis of pyogenic liver abscess, we used information gathered by the Taiwan National Health Insurance (NHI) program, which was initiated in 1995 by the government to cover most Taiwanese citizens. In 2005, 91.25% of healthcare providers were enrolled in the program and 99% of Ta...

Coronavirus, uses the Angiotensin Converting Enzyme-2 Receptor to enter airway cells. Viral endocytosis is mediated by several factors, including clathrin, the adaptor protein-2 complex (AP2) and the adaptor-associated kinase-1 (AAK1). 2 According to a recent report, 3 COVID-19, the disease caused by SARS-CoV-2, is characterized by three clinical patterns: no symptoms, mild to moderate disease, severe pneumonia requiring admission to Intensive Care Unit (ICU) in up to 31% of the patients. 3 Thus far, there is no specific therapy for COVID-19 infection. No benefit of lopinavir-ritonavir treatment resulted in a recent trial. 4 Hydroxychloroquine, currently used in view of its "in vitro" observed effect of reduction of viral replication, seems unsatisfactory. 5 Elevated proinflammatory cytokine/chemokine responses seem associated with respiratory failure. 3 Recently, tocilizumab, an interleukin-6 inhibitor, was reported as effective in patients with severe COVID-19 pneumonia. 6 Baricitinib, another inhibitor of cytokine-release, seems an interesting anti-inflammatory drug. It is a Janus kinase inhibitor (anti-JAK) licensed for the treatment of rheumatoid arthritis (RA) with good efficacy and safety records. 7 Moreover it seems to have anti-viral effects by its affinity for AP2-associated protein AAK1, reducing SARS-CoV-2 endocytosis. 8 On this basis, we assessed the safety of baricitinib therapy combined with lopinavir-ritonavir in moderate COVID-19 pneumonia patients and we evaluated its clinical impact.All consecutive hospitalized patients (March 16th −30th) with moderate COVID-19 pneumonia, older than 18 years, were treated for 2 weeks with baricitinib tablets 4 mg/day added to ritonavir-lopinavir therapy. The last consecutive patients with moderate COVID-19 pneumonia receiving standard of care therapy (lopinavir/ritonavir tablets 250 mg/bid and hydroxychloroquine 400 mg/day/orally for 2 weeks) admitted before the date of the first baricitinib-treated patient served as controls. Antibiotics were scheduled only in the case of suspected bacterial infection.Inclusion criteria were: a. SARS-Co-V2 positivity in the nasal/oral swabs; b. presence of at least 3 of the following symptoms: fever, cough, myalgia, fatigue; c. evidence of radiological pneumonia . After discharge, patients treated with baricitinib were planned to be followed for additional 6 weeks. Exclusion criteria: history of thrombophlebitis (TP), latent tuberculosis infection (QuantiFERON Plus-test positivity, Qiagen, Germany 9 ), pregnancy and lactation.Mild to moderate COVID-19 disease definition: presence of bilateral pneumonia with or without ground glass opacity and in absence of consolidation, not requiring intubation at enrollment; arterial oxygen saturation (SpO2) > 92% at room-air, and ratio arterial oxygen partial pressure/fractional inspired oxygen (PaO2/FiO2) 10 0-30 0 mmHg. Parameters daily accessed were: fever, pulmonary function, Modified Early Warning Score (MEWS), 10 pulse rate, blood pressure. After the initial execution, r...

Clinical and laboratory data on severe acute respiratory syndrome (SARS), particularly on the temporal progression of abnormal laboratory findings, are limited. We conducted a prospective study on the clinical, radiologic, and hematologic findings of SARS patients with pneumonia, who were admitted to National Taiwan University Hospital from March 8 to June 15, 2003. Fever was the most frequent initial symptom, followed by cough, myalgia, dyspnea, and diarrhea. Twenty-four patients had various underlying diseases. Most patients had elevated C-reactive protein (CRP) levels and lymphopenia. Other common abnormal laboratory findings included leukopenia, thrombocytopenia, and elevated levels of aminotransferase, lactate dehydrogenase, and creatine kinase. These clinical and laboratory findings were exacerbated in most patients during the second week of disease. The overall case-fatality rate was 19.7%. By multivariate analysis, underlying disease and initial CRP level were predictive of death.