The Journal of Medical Microbiology, Vol 47, Issue 12 1105-1113, Copyright © 1998 by Society for General Microbiology

JOURNAL ARTICLE

Antibiotic resistance and putative virulence factors of Serratia marcescens with respect to O and K serotypes

H. M. Aucken and T. L. Pitt
Laboratory of Hospital Infection, Central Public Health Laboratory, London.

Serratia marcescens serotypes O6:K14, O8:K14 and O28:K28 are common in the natural environment, but rare in hospitals. Serotypes O14:K14 and O27:K14 predominate among clinical strains, but not in the environment, suggesting that the latter serotypes may be more suited for survival in the clinical setting. Consequently, 469 epidemiologically distinct strains of S. marcescens were tested for various putative virulence factors and analysed for associations with serotype. The factors positively associated with serotype O14:K14 were agglutination of five different species of red blood cells and expression of type 1 fimbriae. These were found in 63% and 53% of O14:K14 strains, respectively, compared with 7% and 12% of the three 'environmental serotypes'. Almost a quarter of the collection expressed the mannose-resistant haemagglutinin indicative of type 3 fimbriae, but this was not associated with any serotype. The production of DNAase, haemolysin, lipase, lecithinase, proteases and siderophores was almost universal and showed no serotype correlations. Almost half of the strains (46%) were resistant to serum and serotypes O27:K14 and O6:K14 were strongly associated with this characteristic. Serotype O27:K14 was also associated with higher proportions of antibiotic-resistant strains than other serotypes, but the same was not true of serotype O14:K14. All three 'environmental serotypes' were associated with low frequencies of antibiotic resistance; <12% were resistant to gentamicin, carbenicillin or piperacillin, or any combination of these three, compared with 20-25% of O14:K14 strains and >42-51% of O27:K14 strains. Pigment production was strongly associated with serotype. None of the O14:K14 or O27:K14 strains produced prodigiosin, but frequencies for the three 'environmental serotypes' ranged from 31% of O28:K28 strains to 85% of O6:K14 strains. The results of this study suggest that the adherence capability of S. marcescens strains may play a role in the colonisation of hospital patients, while the production of prodigiosin is a marker of environmental origin.

This article has been cited by other articles:

				S. Begic and E. A. Worobec The role of the Serratia marcescens SdeAB multidrug efflux pump and TolC homologue in fluoroquinolone resistance studied via gene-knockout mutagenesis Microbiology, February 1, 2008; 154(2): 454 - 461. [Abstract] [Full Text] [PDF]

				Y. Kida, H. Inoue, T. Shimizu, and K. Kuwano Serratia marcescens Serralysin Induces Inflammatory Responses through Protease-Activated Receptor 2 Infect. Immun., January 1, 2007; 75(1): 164 - 174. [Abstract] [Full Text] [PDF]

				S. J. Coulthurst, N. R. Williamson, A. K. P. Harris, D. R. Spring, and G. P. C. Salmond Metabolic and regulatory engineering of Serratia marcescens: mimicking phage-mediated horizontal acquisition of antibiotic biosynthesis and quorum-sensing capacities Microbiology, July 1, 2006; 152(7): 1899 - 1911. [Abstract] [Full Text] [PDF]

				N. K. Petty, I. J. Foulds, E. Pradel, J. J. Ewbank, and G. P. C. Salmond A generalized transducing phage ({phi}IF3) for the genomically sequenced Serratia marcescens strain Db11: a tool for functional genomics of an opportunistic human pathogen Microbiology, June 1, 2006; 152(6): 1701 - 1708. [Abstract] [Full Text] [PDF]

				A. K. P. Harris, N. R. Williamson, H. Slater, A. Cox, S. Abbasi, I. Foulds, H. T. Simonsen, F. J. Leeper, and G. P. C. Salmond The Serratia gene cluster encoding biosynthesis of the red antibiotic, prodigiosin, shows species- and strain-dependent genome context variation Microbiology, November 1, 2004; 150(11): 3547 - 3560. [Abstract] [Full Text] [PDF]

				K. B. Marty, C. L. Williams, L. J. Guynn, M. J. Benedik, and S. R. Blanke Characterization of a Cytotoxic Factor in Culture Filtrates of Serratia marcescens Infect. Immun., March 1, 2002; 70(3): 1121 - 1128. [Abstract] [Full Text] [PDF]

				R. PODSCHUN, A. FISCHER, and U. ULLMANN Characterisation of Hafnia alvei isolates from human clinical extra-intestinal specimens: haemagglutinins, serum resistance and siderophore synthesis J. Med. Microbiol., March 1, 2001; 50(3): 208 - 214. [Abstract] [Full Text] [PDF]