Inhibitory Effect of Two Closely Related Phages on Vibrio parahaemolyticus .

is a foodborne pathogenic bacterium commonly found in seafood. The emergence of drug-resistant strains poses a threat to human public health and economic development. Therefore, there are increasing needs to develop new technologies in controlling multidrug-resistant strains and to evaluate their practical efficiency in seafood or mariculture. In this study, we screened two genetically related phages, F23s2 and H256D1, which belonged to the family and family, respectively. They showed 97.13% and 96.13% identity with phage vB_Vpap_MGD1, respectively. Both phages were stable at pH 4-11 and displayed temperature tolerance (<70°C). Meanwhile they showed a broad host spectrum for multidrug-resistant , and Phage F23s2 lysed 16 of all 23 strains, while phage H256D1 lysed 10 strains. Phage F23s2 and H256D1 had a good inhibitory effect on in shrimp meat. Compared with the negative group, the bacterial amount of experimental group with phage F23s2 decreased by 1.60 log colony-forming unit (CFU)/mL at 12 h. For phage H256D1, the bacterial concentration of shrimp meat contaminated with H256 increased to 5.65 log CFU/mL at 72 h, while the concentration of the experimental group in presence of phage H256D1 was 3.58 log CFU/mL. All live clams infected with died after 96 h in the absence of phage, whereas clams with phage F23s2 and H256D1 still had a survival rate of 12% and 4%, respectively. Understanding the gene function and biology of phages facilitates its application for control of contamination worldwide.