title: Rapid and quantitative detection of blood Serratia marcescens by a real-time PCR assay: its clinical application and evaluation in a mouse infection model.
abstract: 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.
authors.affiliation: Division of Bacteriology, Department of Infectious Disease Control and International Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8510, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Iwaya
authors.forename: Saori
authors.initials: S
authors.lastname: Nakagawa
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Iwakura
authors.forename: Ikue
authors.initials: I
authors.lastname: Taneike
authors.forename: Mizuki
authors.initials: M
authors.lastname: Kurihara
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kuwano
authors.forename: Fumio
authors.initials: F
authors.lastname: Gondaira
authors.forename: Miyoko
authors.initials: M
authors.lastname: Endo
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Hatakeyama
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Yamamoto
mesh_terms: 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*
chemical_list: D015780:Carbapenems; D004269:DNA, Bacterial