The outbreak of the COVID-19 pandemic is a substantial threat to the health of all populations worldwide, and old age is a robust risk factor for poor prognosis of COVID-19 infection. To reduce the fatality rate of COVID-19 infection, further understanding of elderly patients with COVID-19 is necessary. We aimed to investigate the prognostic factors in elderly patients with COVID-19. This was a multicenter and retrospective study. Overall, 340 elderly patients with COVID-19 were enrolled in 3 hospitals in Daegu, South Korea. Death and severe pneumonia requiring oxygen treatment were defined as poor clinical outcomes. Of the patients studied, 15% died and 35.2% were classified as having severe pneumonia. In binary logistic regression analysis, activities of daily living (ADL) impairment, fever during hospitalization, initial infiltration on chest radiograph, and initial increased C-reactive protein (CRP) were significantly associated with severe pneumonia (OR = 5.33, p < 0.001; OR = 3.2, p = 0.002; OR = 2.32, p = 0.044; and OR = 1.33, p < 0.001, respectively). ADL impairment, comorbidity, fever during hospitalization, and initial increased CRP were significantly associated with death (OR = 7.13, p < 0.001; OR = 3.28, p = 0.005; OR = 3.15, p = 0.032, and OR = 1.18, p < 0.001, respectively). ADL impairment, fever, and initial CRP were poor prognostic factors in elderly patients with COVID-19. Understanding these poor prognostic factors is necessary to control the disease in elderly patients.

Background: Escherichia coli is among the most common uropathogens. Increased antibiotic resistance in Gram negative bacilli is global concern. Alternative therapeutic options including vaccines against uropathogenic E. coli (UPEC) have been developed. In this study, we compared the genotypic characteristics and antimicrobial susceptibility of UPEC according to phylogenetic groups. Methods: We retrospectively reviewed the medical records of pyelonephritis patients with UPEC between February 2015 and June 2018. The study was conducted at a medical center in Korea. We compared the clinical and genotypic characteristics of UPEC according to phylogenetic groups. The phylogenetic groups and 29 virulence factors were identified using multiplex polymerase chain reaction. Results: Phylogenetic group analysis revealed that most uropathogenic E. coli belonged to groups B2 and D: B2 (276, 77.7%), D (62, 17.5%), B1 (12, 3.4%), and A (5, 1.4%). Among the virulence factors, fyuA, fimH, traT, iutA, papG allele II, and papC were the most frequently observed. Phylogenetic group B2 was more closely related to virulence factors, including fimH, sfa/focED, focG, hlyA, cnf1, fyuA, and PAI, than group D. Groups B2 and D showed similar clinical presentations and complications. Group B2 had mostly healthcare-associated infections and antimicrobial resistance. Group D mostly had community-acquired infections. The K1 serotype was prevalent in group B2, and K5 was the most prevalent in group D. Conclusions: Phylogenetic group B2 had more proportions and types of virulence factors than group D. Group B2 showed a high presentation of virulence factors related to adhesions and toxins. An increased presentation of antimicrobial resistance and healthcare-associated infections was also noted. Considering the genetic characteristics of UPEC, alternative therapeutic options targeting frequent virulence factors might be considered in addition to antibiotics.

Hypervirulent Klebsiella pneumoniae (KP) is defined according to hypermucoviscosity or various virulence factors and is clinically associated with community-acquired liver abscess (CLA). In this study, we investigated the clinical and microbiological characteristics of KP and significant factors associated with hypervirulence. The clinical characteristics, antimicrobial susceptibility, hypermucoviscosity, serotypes, hypervirulence-related genes, and biofilm formation of 414 KP isolates collected from the Keimyung University Dongsan Hospital between December 2013 and November 2015 were analyzed according to CLA. Significant risk factors for hypervirulent KP (HvKP) associated with CLA were investigated using logistic regression analysis. Notably, 155 (37.4%) isolates were hypermucoviscous, and 170 (41.1%) harbored aerobactin. CLA was present in 34 cases (8.2%). Epidemiology and treatment outcomes did not differ significantly between the CLA and non-CLA groups. The CLA group had significantly higher antibiotic susceptibility, K1/K2, rmpA, magA, allS, kfu, iutA, string test-positive result, and biofilm mass. Multivariate logistic regression revealed rmpA (OR, 5.67; 95% CI, 2.09–15.33; p = 0.001), magA (OR, 2.34; 95% CI, 1.01–5.40; p = 0.047), and biofilm mass >0.80 (OR, 2.13; 95% CI, 1.00–4.56; p = 0.050) as significant risk factors for CLA. rmpA was identified as the most significant risk factor for CLA among KP strains, implying that it is an important factor associated with HvKP.

Background: Escherichia coli is among the most common uropathogens. Increased antibiotic resistance to gram negative bacilli is global concern. Alternative therapeutic options including vaccines against uropathogenic E. coli (UPEC) have been developed. In this study, we compared the genotypic characteristics and antimicrobial susceptibility of UPEC according to phylogenetic groups. Methods: We retrospectively reviewed the medical records of pyelonephritis patients with UPEC between February 2015 and June 2018. We compared the clinical and genotypic characteristics of UPEC according to phylogenetic groups. The phylogenetic groups and 29 virulence factors were identified using multiplex polymerase chain reaction.Results: Phylogenetic group analysis revealed that most uropathogenic E. coli belonged to groups B2 and D: B2 (276, 77.7%), D (62, 17.5%), B1 (12, 3.4%), and A (5, 1.4%). Among the virulence factors, fyuA, fimH, traT, iutA, papG allele II, and papC were the most frequently observed. Phylogenetic group B2 was more closely related to virulence factors, including fimH, sfa/focED, focG, hlyA, cnf1, fyuA, and PAI, than group D. Groups B2 and D showed similar clinical presentations and complications. Group B2 had mostly healthcare-associated infections and antimicrobial resistance. Group D mostly had community-acquired infections. The K1 serotype was prevalent in group B2, and K5 was the most prevalent in group D.Conclusions: Phylogenetic group B2 had more proportions and types of virulence factors than group D. Group B2 showed a high presentation of virulence factors related to adhesions and toxins. An increased presentation of antimicrobial resistance and healthcare-associated infections was also noted. Considering the genetic characteristics of UPEC, alternative therapeutic options targeting frequent virulence factors might be considered in addition to antibiotics.

Background: The progression of coronavirus disease-2019 (COVID-19) is less well-studied in asymptomatic patients. The study aimed to understand the clinical characteristics of asymptomatic COVID-19 patients at the time of admission and follow-up their occurrence of symptoms during hospitalization.Methods: Patients were divided into two groups—those with no symptoms until discharge (group A) and those who had symptoms that developed during hospitalization (group B). Baseline and clinical characteristics were retrospectively measured, and logistic regression analysis was performed to identify risk factors for deterioration during hospital stay.Results: Overall, 223 patients were enrolled in the study, including 42 and 181 patients in groups A and B, respectively. Patients were older in group B than in group A. They developed cough as the most common symptom. Abnormal initial chest X-ray (CXR) and higher levels of C-reactive protein were frequently observed in group B than in group A. Moreover, 5 patients required mechanical support, including hi-flow nasal cannular and mechanical ventilation in group B. Five patients were transferred to tertiary hospitals owing to deterioration, and 4 patients succumbed to COVID-19. The risk factors for deterioration were age over 75 years, diabetes mellitus, and C-reactive protein > 1.Conclusions: Even when the patients have no symptoms at admission, we recommend close monitoring of symptoms during hospital stay in patients who present with risk factors at the time of admission.

Background: South Korea continues to report a considerable burden of drug-resistant tuberculosis (TB). Bedaquiline-containing regimens are recommended for multidrug-resistant pulmonary TB, but evidence regarding the optimal treatment for extrapulmonary manifestations such as spinal TB remains limited. Case presentation: Herein, we report two cases of drug-resistant tuberculous spondylitis that were successfully managed using bedaquiline-containing regimens. Case 1 involved a 67-year-old man who was receiving chemotherapy for lymphoma and had a history of spinal TB treated 20 years earlier. The patient presented with dysphagia and upper limb weakness. Cervical magnetic resonance imaging revealed C4–5 spondylitis with an epidural abscess. He underwent surgical treatment, and Mycobacterium tuberculosis resistant to rifampin was isolated from cultured intraoperatively obtained tissue specimens. The patient received an antibiotic regimen consisting of bedaquiline, levofloxacin, linezolid, cycloserine, and clofazimine. Clinical and radiological improvements were achieved after 12 months of this treatment; bedaquiline was included in the regimen for the first 6 months, while the other agents were continued for the entire course. Case 2 involved a 71-year-old man with T12–L2 spondylitis and a left psoas abscess. Tissue culture confirmed Mycobacterium tuberculosis resistant to isoniazid, rifampin, and ethambutol. The patient was started on the same bedaquiline-containing regimen. Clinical and radiological improvements were observed after 18 months of this therapy, including 6 months of bedaquiline. Conclusions: Our clinical experiences suggest that bedaquiline-containing regimens represent a feasible and effective therapeutic option for drug-resistant tuberculous spondylitis. Larger studies are warranted to establish the optimal management strategies for extrapulmonary drug-resistant TB infections.