Outer membrane vesicles reflect environmental cues in Gallibacterium anatis

TY - JOUR

T1 - Outer membrane vesicles reflect environmental cues in Gallibacterium anatis

AU - Bager, Ragnhild Jørgensen

AU - Persson, Gry

AU - Nesta, Barbara

AU - Soriani, Marco

AU - Serino, Laura

AU - Jeppsson, Marina

AU - Nielsen, Tine Kragh

AU - Bojesen, Anders Miki

PY - 2013/12/27

Y1 - 2013/12/27

N2 - The Gram-negative bacterium Gallibacterium anatis is a major cause of salpingitis and peritonitis in egg-laying chickens, leading to decreased egg-production worldwide. Increased knowledge of the pathogenesis and virulence factors is important to better understand and prevent the negative effects of G. anatis. To this end outer membrane vesicles (OMVs) are natural secretion products of Gram-negative bacteria, displaying an enormous functional diversity and promising results as vaccine candidates. This is the first study to report that G. anatis secretes OMVs during in vitro growth. By use of transmission electron microscopy (TEM) and SDS-PAGE, we showed that changes in in vitro growth conditions, including incubation time, media composition and temperature, affected the OMV production and protein composition. A large protein band was increased in its concentration after prolonged growth. Analysis by LC-MS/MS indicated that the band contained two proteins; the 320.1. kDa FHA precursor, FhaB, and a 407.8. kDa protein containing a von Willebrand factor type A (vWA) domain. Additional two major outer-membrane (OM) proteins could be identified in all samples; the OmpH-homolog, OmpC, and OmpA. To understand the OMV formation better, a tolR deletion mutation (δ. tolR) was generated in G. anatis. This resulted in a constantly high and growth-phase independent production of OMVs, suggesting that depletion of peptidoglycan linkages plays a role in the OMV formation in G. anatis.In conclusion, our results show that G. anatis produce OMVs in vitro and the OMV protein profile suggests that the production is an important and well-regulated ability employed by the bacteria, which may be used for vaccine production purposes.

AB - The Gram-negative bacterium Gallibacterium anatis is a major cause of salpingitis and peritonitis in egg-laying chickens, leading to decreased egg-production worldwide. Increased knowledge of the pathogenesis and virulence factors is important to better understand and prevent the negative effects of G. anatis. To this end outer membrane vesicles (OMVs) are natural secretion products of Gram-negative bacteria, displaying an enormous functional diversity and promising results as vaccine candidates. This is the first study to report that G. anatis secretes OMVs during in vitro growth. By use of transmission electron microscopy (TEM) and SDS-PAGE, we showed that changes in in vitro growth conditions, including incubation time, media composition and temperature, affected the OMV production and protein composition. A large protein band was increased in its concentration after prolonged growth. Analysis by LC-MS/MS indicated that the band contained two proteins; the 320.1. kDa FHA precursor, FhaB, and a 407.8. kDa protein containing a von Willebrand factor type A (vWA) domain. Additional two major outer-membrane (OM) proteins could be identified in all samples; the OmpH-homolog, OmpC, and OmpA. To understand the OMV formation better, a tolR deletion mutation (δ. tolR) was generated in G. anatis. This resulted in a constantly high and growth-phase independent production of OMVs, suggesting that depletion of peptidoglycan linkages plays a role in the OMV formation in G. anatis.In conclusion, our results show that G. anatis produce OMVs in vitro and the OMV protein profile suggests that the production is an important and well-regulated ability employed by the bacteria, which may be used for vaccine production purposes.

KW - Faculty of Health and Medical Sciences

KW - Gallibacterium anatis

KW - Outer membrane vesicles

KW - tolR deletion

KW - FhaB

KW - OmpC

KW - OmpA

U2 - 10.1016/j.vetmic.2013.09.005

DO - 10.1016/j.vetmic.2013.09.005

M3 - Journal article

C2 - 24090812

SN - 0378-1135

VL - 167

SP - 565

EP - 572

JO - Veterinary Microbiology

JF - Veterinary Microbiology

IS - 3-4

ER -