A new study has revealed that salmonella strains collected from human salamonellosis patients are different from those of animal origin, paving the way for the development of treatment methods for foodborne illnesses.
Currently, Salmonella enterica is one of the most infectious foodborne pathogens that affect humans and is usually transmitted through consumption of meat and food products that have been contaminated with animal waste.
Over 2,300 types of S. enterica have been identified till date, and despite being epidemiologically useful, they offer limited information regarding bacterial diversity, evolutionary relatedness and pathogenicity. However, virulence determinants and degree of pathogenicity in a particular animal host are not yet well understood.
For the study the virulence capacities of 184 human and animal S. enterica isolates in mice were tested.
The results indicated that all 21 serovar typhimurium isolates derived from animals were virulent in mice, while only 16 of 41 serovar typhimurium isolates collected from human salmonellosis patients were virulent. Besides, only 10 of 29 serovar typhimurium isolates from gastroenteritis patients were virulent, in contrast to all animal and human bacteremia samples tested.
Last of all, among the serovar typhimurium isolates harboring virulent Salmonella, 6 of 31 from human salmonellosis patients were avirulent in mice, in clear contrast to the virulence exhibited by all the animal isolates studied.
"These studies suggest that Salmonella isolates derived from human salmonellosis patients are distinct from those of animal origin. The characterization of these bacterial strain variants may provide insight into their relative pathogenicities as well as into the development of treatment and prophylactic strategies for salmonellosis," said the researchers.
The findings of the study are published in the latest issue of the journal Applied and Environmental Microbiology.