Rapid and quantitative detection of blood Serratia marcescens by a real-time PCR assay: Its clinical application and evaluation in a mouse infection model

• Published in: FEMS microbiology letters Vol. 248; no. 2; pp. 163 - 170
• Main Authors: Iwaya, Akira, Nakagawa, Saori, Iwakura, Nobuhiro, Taneike, Ikue, Kurihara, Mizuki, Kuwano, Tomoko, Gondaira, Fumio, Endo, Miyoko, Hatakeyama, Katsuyoshi, Yamamoto, Tatsuo
• Format: Journal Article
• Language: English
• Published: Oxford, UK Elsevier B.V 15.07.2005; Blackwell Publishing Ltd; Blackwell; Oxford University Press
• Subjects: Animals; Assaying; Bacteria; Bacteriology; Biological and medical sciences; Blood; Blood levels; Carbapenems - pharmacology; Clinical marker; Disease Models, Animal; DNA, Bacterial - genetics; Drug Resistance, Bacterial - genetics; Fatalities; Food processing industry; Fundamental and applied biological sciences. Psychology; Genes, Bacterial - genetics; Genetics; Hospitals; Humans; Male; Mice; Mice, Inbred C57BL; Microbiology; Mouse infection; Nosocomial infection; Nosocomial outbreaks; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; Polymerase Chain Reaction - methods; Real time; Real-time PCR; Sensitivity and Specificity; Sepsis - diagnosis; Septicaemia; Serratia Infections - diagnosis; Serratia marcescens; Serratia marcescens - drug effects; Serratia marcescens - genetics; Serratia marcescens - isolation & purification; Nosocomial outbreaks; Clinical marker; Mouse infection; Real-time PCR; Septicaemia; Serratia marcescens; Nosocomial infection; Animal model; Septicemia; Rodentia; Real time; Polymerase chain reaction; Vertebrata; Pulsed field electrophoresis; Mammalia; Mouse; Bacteria; Enterobacteriaceae; Quantitative analysis
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1016/j.femsle.2005.05.041

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.