Clinical features relating to pneumococcal colony phase variation in hospitalized adults with pneumonia.

Background. Streptococcus pneumoniae is a major causative bacteria of pneumonia and invasive pneumococcal disease (IPD); however, the mechanisms underlying its severity and invasion remain to be defined. Pneumococcal colonies exhibit opaque and transparent opacity phase variations, which have been associated with invasive infections and nasal colonization, respectively, in animal studies. This study evaluated the relationship between the opacity of pneumococcal colonies and the clinical presentation of pneumococcal pneumonia.Methods. This retrospective study included adult patients hospitalized with pneumococcal pneumonia between 2012 and 2019 at four tertiary medical institutions. Pneumococcal strains from lower respiratory tract specimens were determined for their serotypes and microscopic colony opacity, and the association between the opacity phase and the severity of pneumonia was evaluated. Serotypes 3 and 37 with mucoid colony phenotypes were excluded from the study because their colony morphologies were clearly different.Results. A total of 92 patients were included. Most patients were older adults (median age: 72 years) and males (67 %), and 59 % had community-acquired pneumonia. Of the 92 patients, 41 (45 %), 12 (13 %), and 39 (42 %) patients had opaque, transparent, and mixed variants in their pneumococcal colony, respectively. The opaque and non-opaque pneumococcal variants had no statistically significant difference in patient backgrounds. Although the pneumonia severity index score did not differ between the opaque and non-opaque groups, the rate of bacteremia was significantly higher in the opaque group than in the non-opaque group. Serotype distribution was similar between the groups.Conclusions. Opaque pneumococcal variants may cause pneumonia and invasive diseases in humans. This study could help elucidate IPD, and opacity assessment may serve as a predictor for IPD.

Infectious Pneumonia and Lower Airway Microorganisms in Patients with Rheumatoid Arthritis.

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.

Diagnostic evaluation of serum (1, 3)-ß-d-glucan levels using the Fungitec G-Test MK kit for Pneumocystis jirovecii pneumonia (PCP) in non-HIV patients.

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)-ß-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)-ß-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.

An adult case of invasive pneumococcal disease due to serotype 12F-specific polysaccharide antibody failure following a 23-valent polysaccharide vaccination.

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.

A case of bilateral emphysematous pyelonephritis caused by Candida albicans.

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.

[Factors Associated with Diagnostic Yield of Endobronchial Ultrasonography with a Guide Sheath for Peripheral Lung Cancer].

Endobronchial ultrasonography with a guide sheath (EBUS-GS) has recently been used for improved diagnostic yields for peripheral pulmonary lesions. This study retrospectively evaluated the factors related to the diagnostic yield of EBUS-GS for peripheral lung cancer. The medical records of 76 patients who had been diagnosed with lung cancer and had undergone bronchoscopy with EBUS-GS in our hospital between August 2014 and September 2015 were reviewed. The total diagnostic ratio of peripheral lung cancer was 71.1%. The following factors of the diagnostic yield were evaluated: location of pulmonary lesion; size; feature; bronchus sign; location of EBUS probe; EBUS detection; number of biopsies performed; procedure time; use of virtual bronchoscopic navigation; use of EBUS-guided transbronchial needle aspiration with EBUS-GS; CT slice thickness; operator's years of medical experience; and specialized training in bronchoscopy at the National Cancer Center. In all cases, lesion size ≧ 20 mm (80.8% vs. 50.0%, P = 0.006), EBUS probe location "within" (90.0% vs. 50.0%, P < 0.001), EBUS detection (80.7% vs. 28.6%, P < 0.001), number of biopsies ≧ 5 (78.0% vs. 47.1%, P = 0.013), and bronchoscopy training (81.6% vs. 60.5%, P = 0.043) significantly contributed to an increase in the diagnostic yield. Following a multivariate analysis, EBUS probe location "within" was found to be the most significant factor affecting the diagnostic yield (odds ratio 14.10, 95% CI 3.53-56.60, P < 0.001), and bronchoscopy training was the second most significant factor (odds ratio 6.93, 95% CI 1.86-25.80, P = 0.004). EBUS probe location "within" and bronchoscopy training are the most important factors for improved diagnostic yield by bronchoscopy with EBUS-GS for peripheral lung cancer.