Advanced Techniques in Diagnostic Microbiology

486 J. Han
TABLE 27.5. List of pathogens amplified and detected by the Respiratory
Infections I panel.
Pathogen Targeted gene Target symbol
Mycoplasma pneumoniae MPN592 MPN
Legionella pneumophila mip LPN
Chlamydia pneumoniae ompA CPN
Neisseria meningitidis ctrA NMG
Streptococcus pneumoniae lytA SPN
Haemophilus influenzae (all strains) ompP2 HINF1
H. influenzae (all typeable strains) bexA HINF2, HINF3
Adenovirus types 3, 7, 21 hexon AVDB
Adenovirus type 4 hexon ADVE
Adenovirus types 1, 2, 5, 6 hexon ADVC
Acinetobacter baumannii Rec A ABM
Based on this panel and through collaborations with scientists at the CDC (Fields
et al., 2005, personal communication), we have developed two MDD systems that,
together, detect 23 pathogens that cause respiratory infections.
Tables 27.5 and 27.6 list the pathogens identified by the MDD systems for
Respiratory Infections I and II. We group these pathogens into two panels: the
first panel includes pathogens with DNA genomes, and the second panel includes
viruses with RNA genomes. Amplification for the DNA panel needs only a PCR
step; whereas the RNA panel needs a one-step or two-step RT-PCR reaction before
undergoing Templex PCR. Dean et al. (2005) reported that, if a random-primed reverse
transcription step is added before performing Templex, the sensitivity is at, or
close to, that of singleplex real-time PCR. If however, a one-step RT-PCR enzyme
system is used for Templex PCR, the sensitivity is about two logs less than that of
a comparable singleplex real-time PCR reaction. For the MDD system for Respiratory
Infections II (the DNA panel), Templex PCR is also less sensitive compared
with the real-time PCR method (Fields et al., 2005, personal communication).
TABLE 27.6. List of pathogens amplified and detected by the
Respiratory Infections II panel.
Pathogen Targeted gene Target symbol
SARS CoV N, pol SARS
Influenza A NS INFA
Influenza B NS INFB
Respiratory syncytial virus A NS RSVA
Respiratory syncytial virus B NS RSVB
Parainfluenza 1 N PIV1
Parainfluenza 2 N PIV2
Parainfluenza 3 N PIV3
Parainfluenza 4 N PIV4
Human metapneumovirus F hMPV
Rhinoviruses 5 ′ UTR RhV
Coxsackie viruses & echoviruses 5 ′ UTR CVEV