Isolation of E. coli O157:H7 and non-O157 in the region of Thrace, Greece

Abstract number: 1733_81

Alepopoulou E., Panopoulou M., Maltezos E., Kartalis G., Kartali S.

Aim: The morbidity and mortality associated with several recent large outbreaks of gastrointestinal disease caused by Shiga toxin-producing E. coli has highlighted the threat these organisms pose to public health.

Methods: Two hundred fifteen stool specimens were examined for EHEC. One hundred five samples proceeded from patients with diarrhoea (group A) and 50 from healthy (group B). Stool specimens or rectal swabs were inoculated on MC agar, CT-SMAC agar and incubated at 37°C overnight in aerobic conditions. For the detection of enterohemolysin, five colonies of E. coli from MC agar and sorbitol negative colonies from CT-SMAC were inoculated in WBA (Washed Blood Agar) with CaCl2. For the detection of MUG activity Tryptone X-glucuronide Agar (OXOID) was used. The biochemical identification of the strains was performed by automated system VITEK 2 (bioMérieux) and serologic identification by slide-agglutination methods (Wellcolex * E. coli 157: H7, ABBOTT). Presence of eae, ehx, stx1, stx2 genes was detected by multiplex PCR. The PCR products 384 bp (eae), 534 bp (ehx), 181 bp (stx 1) and 255 bp (stx 2) were analysed by electrophoresis in 2% agar gel.

Results: From 1207 strains isolated, 38 did not ferment sorbitol and two of them produced small, turbid haemolytic zone on WBA with CaCl2 after overnight incubation. One strain (0.46%) was isolated from stool of adult patient (group A), belonged to serotype O157:H7 and it did not yield the eae, ehx, stx1, stx2 genes. From the remainder 37 strains, two (1.2%) have stx toxin genes. These strains were serotype non – O157:H7 E. coli and were isolated from two patients with diarrhoea. One of them has stx 1 and stx 2 toxins genes, and the other has stx 1 and ehx genes.

Conclusion: The isolation rate of E. coli O157:H7 in the region of Thrace, Greece is low. However, the percentage of E. coli non-O157:H7 isolated from stool of patients with diarrhoea is similar with that other of investigations in European countries.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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