Introduction:
Pneumonia is common after OHCA but is difficult to diagnose in the first 72 hours following ROSC, this results in early untargeted antibiotic administration based on non-specific imaging and laboratory findings. Antibiotic resistance is rising, is influenced by untargeted antibiotic administration, and can increase patient morbidity and mortality as well as healthcare costs. Precision methods of bacterial pathogen detection in OHCA patients are needed to improve patient care. This proof-of-concept pilot study aimed to assess feasibility of bacterial pathogen sequencing and comparability of sequencing results to clinical culture after OHCA.
Methods:
Blood and bronchoalveolar lavage (BAL) were obtained from residual clinical specimens collected within 12 hours of ROSC. Bacterial DNA was extracted using the Qiagen PowerLyzer PowerSoil DNA kit, sequenced using the MinION nanopore sequencer, and analyzed with Oxford Nanopore Technologies’ EPI2ME bioinformatics software. Sequencing results were compared to culture results using McNemar’s chi-square statistic. Study-defined pneumonia was based on presence of at least two characteristics within 72 hours of ROSC: fever (temperature ≥38°C); persistent leukocytosis >15,000 or leukopenia <3,500 for 48 hours; persistent chest radiography infiltrates for 48 hours per clinical radiology read; bacterial pathogen cultured.
Results:
We enrolled 38 consecutive OHCA subjects: mean age 61.8 years (18.0); 16 (42%) female; 25 (66%) White, 7 (18%) Black, 6 (16%) “Other” race; 7 subjects (18%) survived and 31 (82%) died; 16 (42%) subjects had pneumonia. Sequencing results were available in 12 hours while culture results were available in 48-72 hours after collection. There was a non-significant difference in the proportion of the same pathogens identified for each method per McNemar’s chi-square: p = 0.38, difference of 0.095 (-0.095, 0.286).
Conclusions:
Nanopore sequencing detects pathogenic bacteria comparable to clinical microbiologic culture and in less time. This technology can produce a paradigm shift in early bacterial pathogen detection in OHCA survivors, which can improve patient care. The technology is applicable to other patient populations and for viral and fungal pathogens.
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