Molecular Analysis of Broad Spectrum Beta-Lactams Resistance Genes TEM, CTX-M and SHV in Escherichia coli Isolates from Traditional Pastry Samples in Yazd

Background and Aim: The variety of sweets along with significant difference level of hygiene in the production, supplies and high potential contamination of sweets ingredients with Escherichia coli, led to investigate the frequency of broad-spectrum beta lactamase strains of E. coli in sweets and determine the presence of SHV, TEM and CTX-M genes. Material and methods: In this descriptive cross-sectional study, 150 confectionery samples were collected from traditional confectionery workshops in Yazd. Detection of E. coli strains was carried out by standard biochemical tests and antibiotic susceptibility test was performed using CLSI guidelines. Via combined ESBL disk method on the muller hinton agar medium producing strains were identified. All the ESBL producing strains were evaluated using the PCR test for the existence of SHV, TEM and CTX-M genes. Results: In 30 isolates, (20%) E.coli was obtained. The results of antibiotic susceptibility test showed that the highest and the lowest antibiotic resistance was related to chloramphenicol l (22 isolates, 73.3%) and Imipenem (8 isolates, 26.6%). The results of the combined disk test was showed that only 9 isolates produced ESBL. The molecular analysis on considered genes indicated that 2, 4 and 3 isolates were positive for presence of TEM, SHV, and CTX-M genes, respectively. Conclusion: The prevalence of antibiotic-resistant isolates in traditional Yazd sweets in this study highlights the importance of more observing and control measures in the preparation and distribution of sweets.