Rapid and quantitative detection of blood Serratia marcescens by a real-time PCR assay: its clinical application and evaluation in a mouse infection model.
Large-scale nosocomial outbreaks of Serratia marcescens septicaemia in Japan have had a fatality rate of 20-60% within 48 h. As a countermeasure, a real-time PCR assay was constructed for the rapid diagnosis of S. marcescens septicaemia. This assay indeed detected S. marcescens in clinical blood specimens (at ca. 10(2)CFU ml(-1)), at a frequency of 0.5% in suspected cases of septicaemia. In mice, the assay provided estimates of blood S. marcescens levels at various infectious stages: namely, 10(7) to 10(8)CFU ml(-1) at a fatal stage (resulting in 100% death), 10(4)-10(5)CFU ml(-1) at a moderately fatal stage (resulting in 50% or more death), and <10(3)CFU ml(-1) at a mild stage (resulting in 100% survival), consistent with actual CFU measurements. Blood bacterial levels could be an important clinical marker that reflects the severity of septicaemia. The simultaneous detection of S. marcescens and the carbapenem resistance gene was also demonstrated.
Iwaya
Akira
A
Division of Bacteriology, Department of Infectious Disease Control and International Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8510, Japan.
Nakagawa
Saori
S
Iwakura
Nobuhiro
N
Taneike
Ikue
I
Kurihara
Mizuki
M
Kuwano
Tomoko
T
Gondaira
Fumio
F
Endo
Miyoko
M
Hatakeyama
Katsuyoshi
K
Yamamoto
Tatsuo
T
D000818:Animals; D015780:Carbapenems / Q000494:pharmacology; D004269:DNA, Bacterial / Q000235:genetics; D004195:Disease Models, Animal; D024881:Drug Resistance, Bacterial / Q000235:genetics; D005798:Genes, Bacterial / Q000235:genetics; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D016133:Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000175:diagnosis*; D016868:Serratia Infections / Q000175:diagnosis*; D012706:Serratia marcescens / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*
D015780:Carbapenems; D004269:DNA, Bacterial