Microbiological diagnosis of pleural infections: a comparative evaluation of a novel syndromic real-time PCR panel.

Current microbial diagnostics for pleural infections are insufficient. Studies using 16S targeted next-generation sequencing report that only 10%-16% of bacteria present are cultured and that 50%-78% of pleural fluids containing relevant microbial DNA remain culture negative. As a rapid diagnostic alternative suitable for clinical laboratories, we wanted to explore a PCR-based approach. Based on the identification of key pathogens, we developed a syndromic PCR panel for community-acquired pleural infections (CAPIs). This was a pragmatic PCR panel, meaning that it was not designed for detecting all possibly involved bacterial species but for confirming the diagnosis of CAPI, and for detecting bacteria that might influence choice of antimicrobial treatment. We evaluated the PCR panel on 109 confirmed CAPIs previously characterized using culture and 16S targeted next-generation sequencing. The PCR secured the diagnosis of CAPI in 107/109 (98.2%) and detected all present pathogens in 69/109 (63.3%). Culture secured the diagnosis in 54/109 (49.5%) and detected all pathogens in 31/109 (28.4%). Corresponding results for 16S targeted next-generation sequencing were 109/109 (100%) and 98/109 (89.9%). For bacterial species included in the PCR panel, PCR had a sensitivity of 99.5% (184/185), culture of 21.6% (40/185), and 16S targeted next-generation sequencing of 92.4% (171/185). None of the bacterial species present not covered by the PCR panel were judged to impact antimicrobial therapy. A syndromic PCR panel represents a rapid and sensitive alternative to current diagnostic approaches for the microbiological diagnosis of CAPI.IMPORTANCEPleural empyema is a severe infection with high mortality and increasing incidence. Long hospital admissions and long courses of antimicrobial treatment drive healthcare and ecological costs. Current methods for microbiological diagnostics of pleural infections are inadequate. Recent studies using 16S targeted next-generation sequencing as a reference standard find culture to recover only 10%-16% of bacteria present and that 50%-78% of samples containing relevant bacterial DNA remain culture negative. To confirm the diagnosis of pleural infection and define optimal antimicrobial therapy while limiting unnecessary use of broad-spectrum antibiotics, there is a need for rapid and sensitive diagnostic approaches. PCR is a rapid method well suited for clinical laboratories. In this paper we show that a novel syndromic PCR panel can secure the diagnosis of pleural infection and detect all bacteria relevant for choice of antimicrobial treatment with a high sensitivity.

Pleural Empyema Caused by Streptococcus intermedius and Fusobacterium nucleatum: A Distinct Entity of Pleural Infections.

BACKGROUND: Many community-acquired pleural infections are caused by facultative and anaerobic bacteria from the human oral microbiota. The epidemiology, clinical characteristics, pathogenesis, and etiology of such infections are little studied. The aim of the present prospective multicenter cohort study was to provide a thorough microbiological and clinical characterization of such oral-type pleural infections and to improve our understanding of the underlying etiology and associated risk factors. METHODS: Over a 2-year period, we included 77 patients with community-acquired pleural infection, whereof 63 (82%) represented oral-type pleural infections. Clinical and anamnestic data were systematically collected, and patients were offered a dental assessment by an oral surgeon. Microbial characterizations were done using next-generation sequencing. Obtained bacterial profiles were compared with microbiology data from previous investigations on odontogenic infections, bacteremia after extraction of infected teeth, and community-acquired brain abscesses. RESULTS: From the oral-type pleural infections, we made 267 bacterial identifications representing 89 different species. Streptococcus intermedius and/or Fusobacterium nucleatum were identified as a dominant component in all infections. We found a high prevalence of dental infections among patients with oral-type pleural infection and demonstrate substantial similarities between the microbiology of such pleural infections and that of odontogenic infections, odontogenic bacteremia, and community-acquired brain abscesses. CONCLUSIONS: Oral-type pleural infection is the most common type of community-acquired pleural infection. Current evidence supports hematogenous seeding of bacteria from a dental focus as the most important underlying etiology. Streptococcus intermedius and Fusobacterium nucleatum most likely represent key pathogens necessary for establishing the infection.

A man in his eighties with gait problems and elevated CRP. / En mann i 80-årene med gangvansker og høy CRP-verdi.

BACKGROUND: Rapid detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in hospitals is essential for early isolation and treatment. However, false positive test results can have adverse consequences for patient safety. CASE PRESENTATION: A man in his eighties was admitted to hospital with fatigue and new-onset gait and balance difficulties, without fever or symptoms of focal infection, but with elevated C-reactive protein. On admission, he tested positive on screening for SARS-CoV-2 using a fully automated rapid reverse transcription polymerase chain reaction (RT-PCR) test. He was placed together with two patients with confirmed COVID-19 infection in cohort isolation. Due to very low exposure risk and nonspecific symptoms, the primary and multiple subsequent test swabs were analysed using RT-PCR analyses guided by laboratory personnel, and all gave negative results. The patient had several risk factors for developing severe COVID-19 illness, but fortunately he remained COVID-19 negative on repeated tests. INTERPRETATION: The case presentation highlights the danger of false-positive SARS-CoV-2 test results, and the importance of interpreting a diagnostic test in the context of pretest probability and test accuracy. It also underlines the risk of using cohort isolation instead of individual isolation.

[Exercise-induced rhabdomyolysis - a new trend?] / Treningsutløst rabdomyolyse ­ en ny tendens?

BACKGROUND: The purpose of this study was to investigate whether or not there has been an increase in the number of admissions for exercise-induced rhabdomyolysis at Stavanger University Hospital (SUS) in recent years. MATERIAL AND METHOD: The study is a retrospective review of patients discharged over the period January 2010 to March 2015 with a diagnosis of exercise-induced rhabdomyolysis and with maximum creatine kinase (CK) levels more than ten times the upper reference limit. RESULTS: A total of 33 patients, 21 women and 12 men, with a median age of 28 years (18 - 68), were included in the study. Of the 33 patients, three quarters (25) were admitted in 2014 - 15, compared with eight over the period 2010 - 13. One patient developed kidney failure that required dialysis. The treatment depended more on the attending physician and department than on the patient's clinical condition and CK-level, but this did not seem to affect the rate of complications. INTERPRETATION: The incidence of exercise-induced rhabdomyolysis at SUS increased from autumn 2014, and this coincided with increased media attention and a new exercise trend. We recommend standardising the treatment of exercise-induced rhabdomyolysis, as current treatment recommendations are based on rhabdomyolysis triggered by causes other than exercise.