Salmonella enterica serovar Enteritidis and Listeria monocytogenes in mango (Mangifera indica L.) pulp: growth, survival and cross-contamination

Abstract

BACKGROUND: This study examined the ability of Salmonella enterica serovar Enteritidis and Listeria monocytogenes to grow or survive in mango pulp stored at −20∘C, 4∘C, 10∘C and 25∘C, as well as to cross-contaminate mangoes by means of a knife contaminated with different levels of these pathogens. RESULTS: At 25∘C lag phase durations of 19 h and 7.2 h and generation times of 0.66 and 1.44 were obtained, respectively, for S. Enteritidis and L. monocytogenes. At 10∘C only the growth of L. monocytogenes was observed. At 4∘C both bacteria survived for 8 days. At −20∘C S. Enteritidis was able to survive for 5 months while L. monocytogenes survived for 8 months. Cross-contamination was observed for knives contaminated with 106, 105 and 104 CFU mL−1 of S. Enteritidis and 106 and 105 CFUmL−1 of L. monocytogenes. CONCLUSION: Both microorganisms can grow well in mango pulp at 25∘C, thus lower temperatures for the maintenance of the pulps are crucial to avoid growth of these microorganisms. A refrigeration temperature of 10∘C will avoid only the growth of S. Enteritidis. Thus good handling practices should be rigidly enforced to avoid any contamination as even at refrigeration and freezing temperatures survival of these pathogens may occur. © 2014 Society of Chemical Industry