Factors affecting the isolation of fastidious bacteria from lower respiratory tract specimens in children / 中国感染与化疗杂志

ABSTRACT

Objective To investigate the factors affecting the isolation of fastidious bacteria such as Streptococcus pneumoniae and Haemophilus influenzae from lower respiratory tract specimens in children.Methods A total of 210 lower respiratory tract specimens from children were collected and inoculated on both blood agar plate and chocolate agar plate 0.5 h,2 h,6 h,12 h,and 24 h after collection.The effect of specimen turnaround time,transport medium,and inoculation medium on the isolation of fastidious bacteria was studied.Results The results of 200 qualified specimens showed that the isolation of S.pneumoniae and H.influenzae significantly decreased with the increasing of specimen turnaround time (P＜0.05),but no significant difference was observed between 0.5 h and 2 h timepoints.The isolation of fastidious bacteria in semi-solid medium was non-significantly higher than the other two transport medium (P＞0.05).No significant difference was found in the isolation and growth ofS.pneumoniae and H.influenzae on different inoculation media (P＞0.05).Conclusions The appropriate specimen turnaround time,transport medium,and inoculation medium are important for improving the isolation of fastidious bacteria from lower respiratory tract in children.