Multiplex PCR pneumonia panel compared to standard culture of respiratory specimens: Retrospective results from a...

Rapid identification of lower respiratory tract infection pathogens is critical for initiating early antimicrobial therapy. This study aimed at evaluating the role of multiplex polymerase chain reaction (mPCR) in detecting respiratory pathogens and antimicrobial resistance at a transplant centre.

The study was a single-centre, retrospective analysis, completed at a tertiary care transplant centre. Data were included from 242 patients admitted with lower respiratory tract infection during a 24-month period. Respiratory specimens were analysed through BioFire PCR. Blood mPCR specimens were excluded (n = 44). Multiplex PCR results were compared with the gold standard of culture and sensitivity testing.

A total of 198 patients were included in the study. The majority had a history of chronic hepatic or renal impairment (n = 95; 48%) or liver/kidney transplantation (n = 57; 28.8%). Chest imaging (n = 162) predominantly revealed pleural effusions (35.2%) and parenchymal infiltrates (28.4%). Most common sample types included sputum (n = 101; 51.0%) and tracheal aspirates (n = 93; 47.0%). Standard culture detected the following pathogens: 290 typical bacteria, 2 atypical organisms, and 95 viral detections. Klebsiella pneumoniae (32.3%) and Escherichia coli (28.8%) were most frequently identified. In n = 102 patients with corresponding culture results, mPCR had sensitivity of 76% and specificity of 59%, with 66.7% concordance between methods. Multiplex PCR and culture identified multiple bacterial species in 38 (37.3%) and 17 (16.7%) cases, respectively. Antimicrobial resistance gene analysis revealed high prevalence of CTX-M (30%), NDM (28%), and OXA-48-like (22%) mutations.

Multiplex PCR pneumonia panel demonstrated high sensitivity in detecting respiratory pathogens but had limitations in its specificity when compared to culture methods.