Tags

Type your tag names separated by a space and hit enter

Molecular typing of Escherichia coli O157:H7 isolates from Swedish cattle and human cases: population dynamics and virulence.
J Clin Microbiol. 2014 Nov; 52(11):3906-12.JC

Abstract

While all verotoxin-producing Escherichia coli O157:H7 bacteria are considered potential pathogens, their genetic subtypes appear to differ in their levels of virulence. The aim of this study was to compare the distribution of subtypes of E. coli O157:H7 in the cattle reservoir and in human cases with and without severe complications in order to gain clues about the relationship between subtype and relative virulence. A lineage-specific polymorphism assay (LSPA-6), multilocus variable-number tandem-repeat analysis (MLVA), and a novel real-time PCR assay to identify clade 8 were applied to a large and representative set of isolates from cattle from 1996 to 2009 (n = 381) and human cases from 2008 to 2011 (n = 197) in Sweden. Draft genome sequences were produced for four selected isolates. The E. coli O157:H7 isolates in Swedish cattle generally belonged to four groups with the LSPA-6 profiles 211111 (clade 8/non-clade 8), 213111, and 223323. The subtype composition of the cattle isolates changed dramatically during the study period with the introduction and rapid spread of the low-virulence 223323 subtype. The human cases presumed to have been infected within the country predominantly carried isolates with the profiles 211111 (clade 8) and 213111. Cases progressing to hemolytic-uremic syndrome (HUS) were mostly caused by clade 8, with MLVA profiles consistent with Swedish cattle as the source. In contrast, infections contracted abroad were caused by diverse subtypes, some of which were associated with a particular region. The work presented here confirms the high risk posed by the clade 8 variant of E. coli O157:H7. It also highlights the dynamic nature of the E. coli O157:H7 subtype composition in animal reservoirs and the importance of this composition for the human burden of disease.

Authors+Show Affiliations

SLU Global Bioinformatics Centre, Swedish University of Agricultural Sciences, Uppsala, Sweden National Veterinary Institute (SVA), Uppsala, Sweden robert.soderlund@sva.se.The Public Health Agency of Sweden, Solna, Sweden.The Public Health Agency of Sweden, Solna, Sweden.The Public Health Agency of Sweden, Solna, Sweden.National Veterinary Institute (SVA), Uppsala, Sweden.SLU Global Bioinformatics Centre, Swedish University of Agricultural Sciences, Uppsala, Sweden.National Veterinary Institute (SVA), Uppsala, Sweden.

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

25143581

Citation

Söderlund, R, et al. "Molecular Typing of Escherichia Coli O157:H7 Isolates From Swedish Cattle and Human Cases: Population Dynamics and Virulence." Journal of Clinical Microbiology, vol. 52, no. 11, 2014, pp. 3906-12.
Söderlund R, Jernberg C, Ivarsson S, et al. Molecular typing of Escherichia coli O157:H7 isolates from Swedish cattle and human cases: population dynamics and virulence. J Clin Microbiol. 2014;52(11):3906-12.
Söderlund, R., Jernberg, C., Ivarsson, S., Hedenström, I., Eriksson, E., Bongcam-Rudloff, E., & Aspán, A. (2014). Molecular typing of Escherichia coli O157:H7 isolates from Swedish cattle and human cases: population dynamics and virulence. Journal of Clinical Microbiology, 52(11), 3906-12. https://doi.org/10.1128/JCM.01877-14
Söderlund R, et al. Molecular Typing of Escherichia Coli O157:H7 Isolates From Swedish Cattle and Human Cases: Population Dynamics and Virulence. J Clin Microbiol. 2014;52(11):3906-12. PubMed PMID: 25143581.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Molecular typing of Escherichia coli O157:H7 isolates from Swedish cattle and human cases: population dynamics and virulence. AU - Söderlund,R, AU - Jernberg,C, AU - Ivarsson,S, AU - Hedenström,I, AU - Eriksson,E, AU - Bongcam-Rudloff,E, AU - Aspán,A, Y1 - 2014/08/20/ PY - 2014/8/22/entrez PY - 2014/8/22/pubmed PY - 2015/10/13/medline SP - 3906 EP - 12 JF - Journal of clinical microbiology JO - J Clin Microbiol VL - 52 IS - 11 N2 - While all verotoxin-producing Escherichia coli O157:H7 bacteria are considered potential pathogens, their genetic subtypes appear to differ in their levels of virulence. The aim of this study was to compare the distribution of subtypes of E. coli O157:H7 in the cattle reservoir and in human cases with and without severe complications in order to gain clues about the relationship between subtype and relative virulence. A lineage-specific polymorphism assay (LSPA-6), multilocus variable-number tandem-repeat analysis (MLVA), and a novel real-time PCR assay to identify clade 8 were applied to a large and representative set of isolates from cattle from 1996 to 2009 (n = 381) and human cases from 2008 to 2011 (n = 197) in Sweden. Draft genome sequences were produced for four selected isolates. The E. coli O157:H7 isolates in Swedish cattle generally belonged to four groups with the LSPA-6 profiles 211111 (clade 8/non-clade 8), 213111, and 223323. The subtype composition of the cattle isolates changed dramatically during the study period with the introduction and rapid spread of the low-virulence 223323 subtype. The human cases presumed to have been infected within the country predominantly carried isolates with the profiles 211111 (clade 8) and 213111. Cases progressing to hemolytic-uremic syndrome (HUS) were mostly caused by clade 8, with MLVA profiles consistent with Swedish cattle as the source. In contrast, infections contracted abroad were caused by diverse subtypes, some of which were associated with a particular region. The work presented here confirms the high risk posed by the clade 8 variant of E. coli O157:H7. It also highlights the dynamic nature of the E. coli O157:H7 subtype composition in animal reservoirs and the importance of this composition for the human burden of disease. SN - 1098-660X UR - https://www.unboundmedicine.com/medline/citation/25143581/Molecular_typing_of_Escherichia_coli_O157:H7_isolates_from_Swedish_cattle_and_human_cases:_population_dynamics_and_virulence_ L2 - http://jcm.asm.org/cgi/pmidlookup?view=long&pmid=25143581 DB - PRIME DP - Unbound Medicine ER -