Improvement of pneumococcal pneumonia diagnosis using quantitative real-time PCR targeting lytA in adult patients: a prospective cohort study
| Autor: | Esther Calbo, Beatriz Dietl, Lucía Boix-Palop, J. R. Perez, M. Xercavins, Javier Garau, Ester Picó-Plana, Meritxell Obradors, Lydia Canales |
|---|---|
| Rok vydání: | 2022 |
| Předmět: |
Adult
0301 basic medicine Microbiology (medical) medicine.medical_specialty Pneumonia severity index medicine.medical_treatment 030106 microbiology Urine Real-Time Polymerase Chain Reaction medicine.disease_cause Gastroenterology law.invention 03 medical and health sciences 0302 clinical medicine law Nasopharynx Internal medicine Streptococcus pneumoniae Humans Medicine Prospective Studies 030212 general & internal medicine Prospective cohort study Mechanical ventilation business.industry General Medicine Pneumonia Pneumococcal medicine.disease Intensive care unit Community-Acquired Infections Pneumonia Infectious Diseases Pneumococcal pneumonia business |
| Zdroj: | Clinical Microbiology and Infection. 28:138.e1-138.e7 |
| ISSN: | 1198-743X |
| DOI: | 10.1016/j.cmi.2021.05.049 |
| Popis: | Objectives The aim of the study was to assess the performance of real-time PCR targeting the lytA gene (rtPCR-lytA) in plasma, urine and nasopharyngeal (NP) samples for the diagnosis of pneumococcal community-acquired pneumonia (P-CAP). Methods Prospective observational study including all consecutive adults with CAP from November 2015 to May 2017. P-CAP was defined if pneumococcus was identified using conventional methods (CM) and/or a positive rtPCR-lytA was detected in blood, urine or NP samples (NP cut-off ≥8000 copies/mL). Diagnostic performance of each test was calculated. Results A total of 133 individuals with CAP were included. Of these, P-CAP was diagnosed in 62 (46.6%). The proportion of P-CAP diagnosed by rtPCR-lytA methods was significantly higher than that diagnosed by CM (87.1% versus 59.7%, p 0.005). The rtPCR-lytA identified Streptococcus pneumoniae in 25 patients (40.3% of all individuals with P-CAP) whose diagnosis would have been missed by CM. NP-rtPCR-lytA allowed diagnosis of 62.3% of P-CAP. A nasopharyngeal colonization density ≥2351 copies/mL predicted P-CAP diagnosis (area under the curve = 0.82, sensitivity 83.3%, specificity 80.9%). There was a positive correlation between increasing bacterial load in blood and CURB-65 score (Spearman correlation coefficient r = 0.4, p 0.001), pneumonia severity index (r = 0.3, p 0.02) and time to clinical stability (r = 0.33, p 0.01). Median bacterial load in blood was higher in P-CAP patients with bacteraemia (0.65 × 103 versus 0 × 103 copies/mL, p 0.002), intensive care unit admission (0.68 × 103 versus 0 × 103 copies/mL, p 0.04) or mechanical ventilation (7.45 × 103 versus 0 × 103 copies/mL, p 0.04). Conclusions The use of rtPCR-lytA methods significantly increased the diagnosis of P-CAP compared with CM. Nasopharyngeal swabs rtPCR-lytA detection, with an accurate cut-off value, was the most promising among molecular methods for the diagnosis of P-CAP. |
| Databáze: | OpenAIRE |
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