Retracted: Vacuolating cytotoxin A (vacA) and cytotoxin‐associated gene A (cagA) genotypes of resistant Helicobacter pylori strains isolated from raw and pasteurized milk

Abstract

Foods with animal origins play a considerable role in transmission of Helicobacter pylori. The current study was done to evaluate the genotyping patterns and antibiotic resistance properties of H. pylori strains isolated from raw and pasteurized milk. Three hundred and fifty raw and pasteurized milk samples were collected. Samples were cultured on Wilkins Chalgren media. Antibiotic resistance pattern and genotyping were done using the disk diffusion and polymerase chain reaction, respectively. Sixty‐eight out of 350 milk samples (19.42%) were positive for H. pylori. Prevalence of H. pylori in raw and pasteurized milk samples were 44.00% and 1.00%, respectively. Helicobacter pylori strains exhibited the maximum prevalence of resistance against tetracycline (94.11%), ampicillin (91.17%), amoxicillin (88.23%), and erythromycin (69.11%). VacA s1a (98.52%), m1a (88.23%), m2 (79.41%), and s2 (77.94%) and also vacA s1am1a (61.76%), s1am2 (51.94%), s2m2 (51.94%), and s2m1a (50.00%) were the most frequently detected genotypes. VacA s2/cagA+ (50.00%), s1a/cagA+ (47.05%), m1a/cagA+ (41.17%), and m2/cagA+ (33.82%) were the most frequently detected combined genotyping patterns. Boost prevalence of H. pylori in raw and pasteurized milk exhibits that they may be the natural reservoirs of bacteria. Similar vacA and cagA genotyping patterns of H. pylori strains recommends that they have similar routes of infection.Practical applicationsDue to the high consumption rate of raw and pasteurized milk samples, they should have a high microbial quality. Foods with animal origins and especially milk are considered as a probable source of Helicobacter pylori infections. The incidence of contamination of milk by H. pylori is fairly high, and nearly all of the isolates showed resistance against several types of antibiotics and harbored pathogenic vacA and cagA genotypes, so the risk of probable foodborne diseases caused by H. pylori in such products should not be neglected. Additionally, raw and pasteurized milk samples may act as a reservoir of H. pylori with ability to transfer antibiotic resistance and virulent genotypes.