Urinary exosome as a potential biomarker for urinary tract infection.

Unlike urinary tract infection (UTI), asymptomatic bacteriuria (ABU) should not be treated, with some exceptions such as pregnant women and patients who will undergo traumatic urologic interventions. However, there has been no clinically available marker for their differential diagnosis. Exosomes or small extracellular vesicles carry proteins contained in cells from which they are derived, thus having the potential as a biomarker of several diseases. On the basis of the hypothesis that the molecular signature of exosomes in urine may differ between UTI and ABU patients, we examined if urinary exosomes could serve as a marker for their differential diagnosis. Exosomes were isolated by ultracentrifugation or affinity-based method from cell culture medium of monocytic THP-1 and uroepithelial SV-HUC-1 cells and human urine. Protein expression was examined by Western blot analysis, ELISA, and CLEIA. The results showed that the levels of intracellular signalling molecules Akt and ERK and transcription factor NF-κB increased in exosomes isolated from THP-1 and SV-HUC-1 cells cocultured with Escherichia coli and/or treated with lipopolysaccharide. In urinary exosomes of UTI patients, Akt significantly diminished, and an exosomal marker CD9 showed a trend to decrease after treatment with antimicrobial agents. More importantly, Akt and CD9 levels in urinary exosomes were higher in UTI patients than in ABU patients, which was also observed after correction by urine creatinine. Collectively, these results suggest that Akt and CD9 in urinary exosomes could be useful markers for differential diagnosis of UTI and ABU.

Diagnostic utilities of a fully automated molecular test for toxigenic Clostridium difficile.

Laboratory underdiagnosis of toxigenic Clostridium difficile can lead to inappropriate management of C. difficile infection (CDI). A fully automated molecular test (FAMT), BD MAX, and enzyme immunoassays for C. difficile glutamate dehydrogenase (GDH) and for toxin A/B antigen test were evaluated using clinical specimens. Laboratory analysis of 231 fecal specimens from patients suspected with CDI, indicated that the sensitivity (Sn), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV) of FAMT was 98.1%, 98.9%, 96.3%, and 99.4%, while that of toxin A/B antigen was 52.8%, 100.0%, 100.0%, and 87.7%, respectively, compared to toxigenic culture. Sn, Sp, PPV, and NPV of GDH test compared to toxigenic culture was 92.5%, 94.4%, 83.1%, and 97.7%, respectively. FAMT can support the accurate laboratory diagnosis of toxigenic C. difficile and be an effective tool for appropriate treatment of CDI.

Evaluation of a simultaneous detection kit for the glutamate dehydrogenase antigen and toxin A/B in feces for diagnosis of Clostridium difficile infection.

Rapid detection kits for toxin A/B in feces are widely used as a diagnostic tool for Clostridium difficile infection (CDI). Their low sensitivity, however, has been considered a problem. In this study, we evaluated a new rapid diagnostic kit for simultaneous detection of the glutamate dehydrogenase (GDH) antigen and toxin A/B, C. DIFF QUIK CHEK COMPLETE. A total of 60 stool specimens from 60 patients with antibiotic-associated diarrhea were examined. Using C. difficile culture as the reference method, the GDH portion of this kit indicated a sensitivity, specificity, and negative predictive value of 100, 93.3, and 100%, respectively. The toxin A/B portion showed a sensitivity and specificity of 78.6 and 96.9%, respectively, compared to the culture results of toxin B-positive C. difficile (toxigenic culture). Of the 23 specimens that showed "dual positives" for GDH and toxin A/B, 22 were toxigenic culture positive, whereas C. difficile culture was negative in all the 28 specimens that showed "dual negatives" for GDH and toxin A/B. Of the nine "GDH-positive and toxin A/B-negative" specimens, six exhibited positive results by toxigenic culture. Results showing "dual positives" and "dual negatives" for GDH and toxin A/B can be reported as "true positive" and "true negative," respectively, whereas additional testing for confirmation, such as toxigenic culture, is required for specimens with discrepant results. Diagnostic algorithms, utilizing the simultaneous detection kit for GDH and toxin A/B as an initial screening test, may be useful for accurate and efficient diagnosis of CDI as well as the control of healthcare-associated infections.

Severe Acute Pancreatitis in Autopsies Associated With Surgeries and Severe Inflammatory Diseases.

OBJECTIVE: We clarified clinicopathological characteristics of acute pancreatitis in terminal patients. METHODS: Pathological changes in the entire pancreas from serial autopsies (N = 183) classified lesions into the following 3 categories: focal neutrophil infiltration, focal necrotizing pancreatitis, and diffuse necrotizing pancreatitis. The former two are possible precursors of diffuse necrotizing pancreatitis. Immunohistochemical staining was performed to analyze pancreatic stellate cells and inflammatory cells. RESULTS: There were pathologically acute pancreatitis in 45 patients (24.6%), and no patients were diagnosed with it before autopsy. Focal neutrophil infiltration was present in 22 cases, focal necrotizing pancreatitis in 18 cases, and diffuse necrotizing pancreatitis in 5 cases. Severe inflammatory disease and surgery were associated with acute pancreatitis. Sepsis due to viral or bacterial infection was the most common cause of acute pancreatitis. Patients with diffuse necrotizing pancreatitis showed low white blood cell counts, while amylase levels were not increased. Increase in α-smooth muscle actin and nestin-positive stellate cell numbers in acute pancreatitis was correlated to increase in numbers of CD34-positive vascular endothelium, CD68- or CD163-positive macrophages, CD138-positive plasmacytes, CD3-positive T lymphocytes, and myeloperoxidase-positive leucocytes. CONCLUSIONS: Necrotizing pancreatitis without typical clinical signs was frequently detected in autopsy samples. Clinicians must be mindful of necrotizing pancreatitis in terminal patients.

[An epidemic of rotavirus infection in a nursing home for the elderly in Japan].

An outbreak of diarrheal disease in a Japanese home for aged is reported. Out of 202 residents, 47 cases complained of diarrhea (23.3%) during a month. Clinical symptom were diarrhea (100%) vomiting (40.4%) and fever (31.9%). Fecal examination of 9 cases revealed positive A-group rotavirus antigen. Bacterial and small round shaped virus infection was excluded. Examination of rotavirus antibody, CF titer was positive in about 50% in each age group but the titer decreased year by year. In Japan, rotavirus infection has been epidemic only in nursing home for baby and titer of antigen has been believed to be sustain by repeated provocation. However, Japanese situation is changing to be west Europe and north America.

[Control of hospital infection of influenza: administration of neuraminidase inhibitor and cohort isolation of influenza patients].

Influenza can spread rapidly to patients and staff in hospitals when influenza is introduced by visitors, staff, or patients. In order to prevent and control outbreaks of influenza in hospitals, systematic management is important. This consists of a rapid diagnostic test, cohort isolation and administration of neuraminidase inhibitor. In the 2002-2003 season, 53 elderly patients were admitted to our hospital under the control of the system. The mean age was 78.8 years. We set 2 isolation rooms (10 beds) for influenza patients. Patients were isolated in the room for three days, administered oseltamivir immediately. Oral oseltamivir was well tolerated. Mean hospital stay was 10.7 days. 36 cases developed complications requiring antibiotics, and one patient developed a catheter related infection. Under the system, we could avoid cross infection of influenza. In two cases, nose swabs were taken for virus isolation every 12 hours and a rapid decline in virus shedding was observed after treatment.