Highly expressed amino acid biosynthesis genes revealed by global gene expression analysis of Salmonella enterica serovar Enteritidis during growth in whole egg are not essential for this growth

TY - JOUR

T1 - Highly expressed amino acid biosynthesis genes revealed by global gene expression analysis of Salmonella enterica serovar Enteritidis during growth in whole egg are not essential for this growth

AU - Jakociune, Dziuginta

AU - Herrero-Fresno, Ana

AU - Jelsbak, Lotte

AU - Olsen, John Elmerdahl

PY - 2016/5/2

Y1 - 2016/5/2

N2 - Salmonella enterica serovar Enteritidis (S. Enteritidis) is the most common cause of egg borne salmonellosis in many parts of the world. This study analyzed gene expression of this bacterium during growth in whole egg, and whether highly expressed genes were essential for the growth. High quality RNA was extracted from S. Enteritidis using a modified RNA-extraction protocol. Global gene expression during growth in whole egg was compared to growth in LB-medium using DNA array method. Twenty-six genes were significantly upregulated during growth in egg; these belonged to amino acid biosynthesis, di/oligopeptide transport system, biotin synthesis, ferrous iron transport system, and type III secretion system. Significant downregulation of 15 genes related to formate hydrogenlyase (FHL) and trehalose metabolism was observed. The results suggested that S. Enteritidis is starved for amino-acids, biotin and iron when growing in egg. However, site specific mutation of amino acid biosynthesis genes asnA (17.3 fold upregulated), asnB (18.6 fold upregulated), asnA/asnB and, serA (12.0 fold upregulated) and gdhA (3.7 fold upregulated), did not result in growth attenuation, suggesting that biosynthesis using the enzymes encoded from these genes may represent the first choice for S. Enteritidis when growing in egg, but when absent, the bacterium could use alternative ways to obtain the amino acids

AB - Salmonella enterica serovar Enteritidis (S. Enteritidis) is the most common cause of egg borne salmonellosis in many parts of the world. This study analyzed gene expression of this bacterium during growth in whole egg, and whether highly expressed genes were essential for the growth. High quality RNA was extracted from S. Enteritidis using a modified RNA-extraction protocol. Global gene expression during growth in whole egg was compared to growth in LB-medium using DNA array method. Twenty-six genes were significantly upregulated during growth in egg; these belonged to amino acid biosynthesis, di/oligopeptide transport system, biotin synthesis, ferrous iron transport system, and type III secretion system. Significant downregulation of 15 genes related to formate hydrogenlyase (FHL) and trehalose metabolism was observed. The results suggested that S. Enteritidis is starved for amino-acids, biotin and iron when growing in egg. However, site specific mutation of amino acid biosynthesis genes asnA (17.3 fold upregulated), asnB (18.6 fold upregulated), asnA/asnB and, serA (12.0 fold upregulated) and gdhA (3.7 fold upregulated), did not result in growth attenuation, suggesting that biosynthesis using the enzymes encoded from these genes may represent the first choice for S. Enteritidis when growing in egg, but when absent, the bacterium could use alternative ways to obtain the amino acids

KW - Salmonella

KW - RNA extraction

KW - Gene expression

KW - Egg

KW - Amino acids

U2 - 10.1016/j.ijfoodmicro.2016.02.015

DO - 10.1016/j.ijfoodmicro.2016.02.015

M3 - Journal article

C2 - 26945769

SN - 0168-1605

VL - 224

SP - 40

EP - 46

JO - International Journal of Food Microbiology

JF - International Journal of Food Microbiology

ER -