Version 2: A study on viruses and bacteria with particular interest on Mycoplasma pneumoniae in children with exacerbation of asthma from a tertiary care hospital in Sri Lanka

Asthma is a significant public health concern, particularly in children with severe symptoms. Exacerbation of asthma (EOA) is life-threatening and respiratory infections (RIs) play a crucial role. Though viruses  play a significant role in EOA,  patients are empirically treated with antibiotics which contribute to the development of antibiotic resistance. Although there are widely reported association of EOA with viral or M. pneumoniae infections, there are no published data in Sri Lanka. The present study aimed to identify the association of common respiratory viruses, typical respiratory bacterial pathogens, and M. pneumoniae in children with EOA   and relate them with the compatibility of antimicrobial use.

A case-control study was conducted in the pediatric unit of North Colombo Teaching Hospital, Sri Lanka, involving two groups of children between 5-15 years of age. Group-1: children with EOA, Group-2: children with stable asthma (SA). Each group consisted of 100 children. Sputum/throat swabs were tested for common respiratory viruses using virus specific  FITC-labelled monoclonal antibodies (MAbs),  bacteria by routine culture and M. pneumoniae by RT-PCR. Macrolide-resistance in M. pneumoniae was detected using conventional PCR and sequencing specific genetic mutations in the 23S rRNA gene. M. pneumoniae was genotyped using nested multilocus sequence typing (MLST), which targeted eight housekeeping genes  (ppa, pgm, gyrB, gmk, glyA, atpA, arcC, adk).

There was no significant difference in age, gender, demographic or geographical locations   between the two groups. In children with EOA, antibiotics were used in 66% (66/100) and macrolides in 42% (42/100) in children with EOA.  Samples consisted of 78% (78/100)  sputum and 22% (22/100) throat swabs. Adenovirus   was the most common   virus identified, and it was significantly higher in children with EOA compared to those with SA, but no significant difference in typical bacteria findings between the two groups.   M. pneumoniae was detected in one patient    with EOA, with none  detected in the SA group. The  M. pneumoniae was macrolide sensitive, and   it was ST14 by Multi Locus Sequence Typing. This study showed that the empiric use of antibiotics in children with asthma may be better targeted with prior pathogen screening to inform appropriate treatment to minimize antibiotic resistance.