Susceptibility of Pathogenic Nontyphoidal Salmonella Serovars and Avirulent Salmonella LT2 to Elevated Hydrostatic Pressure and CitricidalTM

Abstract

Abstract Nontyphoidal Salmonella enterica serovars are the leading cause of foodborne hospitalization and death episodes in the United States. In a typical year, it is estimated that >1 million Americans experience illness due to foodborne nontyphoidal Salmonellosis. While the private industry and manufacturing rely heavily on results of validations studies for inactivation and decontamination of this prevalent and opportunistic pathogen of public health concern, availability of such studies conducted in realistic environments of manufacturing and processing is limited due to pathogenic nature of the organism. The current study investigated effects of elevated hydrostatic pressure and a bioactive product from grapefruit seed extract (CitricidalTM) for elimination of nontyphoidal Salmonella serovars. Additionally, sensitivity of an avirulent strain of the bacterium (Salmonella LT2) investigated relative to the pathogenic Salmonella serovars. Our results show that the avirulent strain utilized in the current study, has similar sensitivity to the treatments compared to nontyphoidal pathogenic Salmonella serovars. Thus, this non-pathogenic strain could be used interchangeably for public health microbiology hurdle validation studies as a surrogate for pathogenic Salmonella serovars. Additionally, we observed >5 log reduction of the pathogen (i.e. > 99.999%) due to treatments with elevated hydrostatic pressure at 500 MPa and at 300 MPa with presence of CitricidalTM. Our result additionally exhibits that combination of mild hydrostatic pressure and bioactive compounds such as CitricidalTM could be utilized to ensure safe and efficacious elimination of this prevalent pathogen of public health concern from common commodities.