[Multiplex PCR assay in spinal fluid to identify simultaneously bacterial pathogens associated to acute bacterial meningitis in Chilean children].
BACKGROUND
Acute bacterial meningitis (ABM) is a serious disease that needs rapid diagnosis for an accurate treatment. The most important etiological agents are: Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae type b. Overall pathogen detection rate in patients with ABM in Chile is 83%.


OBJECTIVE
To evaluate a Polymerase Chain Reaction (PCR) protocol for simultaneous detection of several pathogens in patients with ABM.


METHODS
We designed and evaluated a multiplex PCR protocol for simultaneous specific genes identifications of S pneumoniae ( inverted exclamation markytA and ply genes), N meningitidis (ctrA, crgA) and H influenzae (bexA) in cerebrospinal fluid (CSF) samples from pediatric patients with suspected diagnosis of ABM. Sensitivity, specificity and minimum detection levels of DNA were determined. Amplifications ofrDNA 16S gene was done to confirm extraction of bacterial DNA.


RESULTS
Ninety nine CSF samples were studied, 90 from children with fever and negative CSF culture, and 9 from ABM and positive culture patients. The PCR protocol had a sensitivity of 89%, specificity of 100%, positive predictive value 100% and negative predictive value 99%.


CONCLUSIONS
We observed a high concordance (89%) between bacteriological cultures and the PCR protocol results. This diagnostic tool could increase identification of agents in specific settings such as patients previously treated with antibiotics.
Reyes S
Marcelo
M
Programa de Microbiología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
Torres T
Juan Pablo
JP
Prado J
Valeria
V
Vidal A
Roberto
R
D000208:Acute Disease; D002648:Child; D002677:Chile; D004269:DNA, Bacterial / Q000134:cerebrospinal fluid / Q000235:genetics; D019741:Haemophilus influenzae type b / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D016920:Meningitis, Bacterial / Q000134:cerebrospinal fluid* / Q000382:microbiology; D008583:Meningitis, Haemophilus / Q000134:cerebrospinal fluid / Q000382:microbiology; D008585:Meningitis, Meningococcal / Q000134:cerebrospinal fluid / Q000382:microbiology; D009345:Neisseria meningitidis / Q000235:genetics / Q000302:isolation & purification; D011008:Pneumococcal Infections / Q000134:cerebrospinal fluid / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D013296:Streptococcus pneumoniae / Q000235:genetics / Q000302:isolation & purification
D004269:DNA, Bacterial