Comparison of diagnostic modalities for Mycoplasma pneumoniae detection in pediatric respiratory infections: A single-centre cross-sectional study from India.

BACKGROUND

Mycoplasma pneumoniae (MP) is a key cause of community-acquired pneumonia (CAP) in children. Accurate laboratory diagnosis is essential for appropriate therapy and prevention of complications. However, variable clinical presentation and uncertainty regarding optimal diagnostic tests contribute to underdiagnosis in India.

AIM AND

OBJECTIVE

To evaluate and compare the diagnostic performance of culture, serology, and polymerase chain reaction (PCR) for early diagnosis of MP pneumonia in children, assess pulmonary and extrapulmonary manifestations, and determine the prevalence of macrolide-resistant strains among confirmed cases.

METHODS

Between April and November 2021, 81 children aged 6 months to 15 years with clinical features of CAP were enrolled. Throat and nasopharyngeal swabs were cultured using pleuropneumonia-like organism (PPLO) media and tested by PCR targeting the P1-adhesin gene. Serum samples were analyzed for specific IgM and IgG antibodies. PCR-positive samples were further evaluated for macrolide resistance using 23S rRNA gene targets.

RESULTS

MP infection was detected in 30/81 (37.04%) children by culture and/or serology and/or PCR. Positivity by culture was observed in 3/81 (3.70%) cases, serology in 17/81 (20.98%), and PCR in 15/81 (18.5%). Higher serological positivity likely reflected delayed presentation after symptom onset and reduced PCR sensitivity associated with upper respiratory tract specimens. Both serology and PCR were positive in 9 (11.11%) cases. All culture-positives were also positive by serology and PCR. Macrolide resistance was detected in 60% of PCR-positive samples.

CONCLUSION

The high proportion of macrolide resistance highlights the need for combined ELISA-based serology and PCR, including resistance detection, for timely diagnosis and optimal therapeutic management.