Abstract
A co-outbreak of verocytotoxin-producing Escherichia coli (VTEC) O145:H28 and O26:H11 infections among participants of two birthday parties in the province of Antwerp (Belgium) was detected in September 2007. Analysis of questionnaires revealed that all cases had consumed ice cream produced at a local dairy farm using pasteurized milk. Combining epidemiological and clinical data, five cases of hemolytic uremic syndrome (HUS) and seven cases of acute diarrhea were identified among the participants. Laboratory investigations were only performed for the HUS patients, and VTEC infection was confirmed in three cases. While both serotypes O145:H28 and O26:H11 were isolated from a two-year-old patient, only VTEC O145:H28 was isolated from an eight-year-old patient, and VTEC O145:H28 infection was confirmed by a positive serology test in a third case (11 years).
In order to trace the source of infection, an environmental study was performed. VTEC serotypes O145:H28 and O26:H11 were isolated from leftover ice cream from one of the birthday parties. Quantitative analysis showed a concentration of 2.4 CFU g-1 and 0.03 CFU g-1 of VTEC O145:H28 and O26:H11, respectively. Both serotypes were also detected in fecal samples from calves at the farm. Moreover, VTEC O145:H28 was found in animal feed (hay) and dust present in the positive calves' stable. However, no VTEC was isolated from raw milk. VTEC O145:H28 and O26:H11 isolated from patients and environmental samples respectively, showed indistinguishable patterns after PFGE analysis. PCR revealed that the VTEC O145 and O26 possessed VT2 and VT1 genes, respectively, while both were positive for eaeA and ehxA. It was shown that the VTEC O26 only possessed an incomplete O Island 122 (OI122) gene cluster, while the VTEC O145 contained a complete OI122. To our knowledge, this is the first description of a VTEC O145:H28 carrying a complete OI122 gene cluster.
We report a co-outbreak of two non-O157 VTEC serotypes, both belonging to seropathotype B. The lower number of HUS cases with VTEC O26:H11 infections may be due to the lower concentration of VTEC O26:H11 compared to that of VTEC O145:H28 in the ice cream, or to the differences in virulence profiles of these two strains.
In order to trace the source of infection, an environmental study was performed. VTEC serotypes O145:H28 and O26:H11 were isolated from leftover ice cream from one of the birthday parties. Quantitative analysis showed a concentration of 2.4 CFU g-1 and 0.03 CFU g-1 of VTEC O145:H28 and O26:H11, respectively. Both serotypes were also detected in fecal samples from calves at the farm. Moreover, VTEC O145:H28 was found in animal feed (hay) and dust present in the positive calves' stable. However, no VTEC was isolated from raw milk. VTEC O145:H28 and O26:H11 isolated from patients and environmental samples respectively, showed indistinguishable patterns after PFGE analysis. PCR revealed that the VTEC O145 and O26 possessed VT2 and VT1 genes, respectively, while both were positive for eaeA and ehxA. It was shown that the VTEC O26 only possessed an incomplete O Island 122 (OI122) gene cluster, while the VTEC O145 contained a complete OI122. To our knowledge, this is the first description of a VTEC O145:H28 carrying a complete OI122 gene cluster.
We report a co-outbreak of two non-O157 VTEC serotypes, both belonging to seropathotype B. The lower number of HUS cases with VTEC O26:H11 infections may be due to the lower concentration of VTEC O26:H11 compared to that of VTEC O145:H28 in the ice cream, or to the differences in virulence profiles of these two strains.
| Original language | English |
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| Title of host publication | Epidemiology and transmission of VTEC and other pathogenic E. coli |
| Publication status | Published - 25 Sep 2008 |
| Event | Finds and Results from the Swedish Cyprus Expedition: A Gender Perspective at the Medelhavsmuseet - Stockholm, Sweden Duration: 21 Sep 2009 → 25 Sep 2009 |
Conference
| Conference | Finds and Results from the Swedish Cyprus Expedition: A Gender Perspective at the Medelhavsmuseet |
|---|---|
| Country/Territory | Sweden |
| City | Stockholm |
| Period | 21/09/09 → 25/09/09 |
Keywords
- VTEC
- VTEC O145:H28 & O26:H11
- HUS outbreak
- ice cream
- Belgium