A multiplex polymerase chain reaction method for rapid identification of Citrobacter freundii and Salmonella species, including Salmonella Typhi.
OBJECTIVE
Salmonella enterica is one of the most common enteric pathogens worldwide. Conventional methods of isolation of Salmonella strains take 4-7 days to complete, are laborious and require substantial manpower. We devised a polymerase chain reaction (PCR) method that simultaneously uses three pairs of specific primers to detect inv, spv, and via genes of Salmonella.


METHODS
Three primer pairs were designed, including: SPVC-1 and SPVC-2, based on the nucleotide sequences of the spvC gene; INVA-1 and INVA-2, based on the invA gene; and VIAB-1 and VIAB-2, based on the viaB gene. PCR was performed using these three primers to identify 14 clinically important bacterial organisms, including Citrobacter freundii, S. enterica serovars Typhi and Paratyphi C, Dublin, and other non-typhoidal Salmonella that harbor a virulence plasmid.


RESULTS
The following strains were readily identified using the PCR: (1) C. freundii; (2) S. Typhi; and S. Paratyphi C; (3) S. Dublin (virulence antigen-positive); and (4) Salmonella serovars that harbor an spv-type virulence plasmid. S. enterica could also be identified, but required further testing to determine serovar.


CONCLUSIONS
This PCR method allows S. Typhi to be identified immediately so that appropriate antibiotic treatment can be initiated without delay.
Lin
Chia Ling
CL
Department of Pediatrics, Chang Gung Children's Hospital, Taoyuan, Taiwan.
Chiu
Cheng Hsun
CH
Chu
Chishih
C
Huang
Yhu Chering
YC
Lin
Tzou Yien
TY
Ou
Jonathan T
JT
D015373:Bacterial Typing Techniques / Q000379:methods*; D016971:Citrobacter freundii / Q000145:classification / Q000302:isolation & purification*; D017931:DNA Primers; D004756:Enterobacteriaceae Infections / Q000382:microbiology; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods*; D012475:Salmonella / Q000145:classification / Q000302:isolation & purification*; D012480:Salmonella Infections / Q000382:microbiology; D012485:Salmonella typhi / Q000145:classification / Q000302:isolation & purification*
D017931:DNA Primers