Detection of Vertical Transmission of the Bacterium Streptococcus Agalactiae in Rainbow Trout (Oncorhynchus Mykiss) Brooders Using the PCR of the Gene Scpb

Rashidi Monfared, Samira; Mirvaghefi, Alireza; Farahmand, Hamid; Nematollahi, Mohamadali; Poorbakhsh, Seyed Ali; Ashtari, Abbas

doi:10.22059/jfisheries.2013.35463

Detection of Vertical Transmission of the Bacterium Streptococcus Agalactiae in Rainbow Trout (Oncorhynchus Mykiss) Brooders Using the PCR of the Gene Scpb

Document Type : Research Paper

Authors

Samira Rashidi Monfared ¹

Alireza Mirvaghefi ¹

Hamid Farahmand ¹

Mohamadali Nematollahi ¹

Seyed Ali Poorbakhsh ²

Abbas Ashtari ²

¹ Department of Fisheries, Faculty of Natural Resources, University of Tehran, Karaj, Iran

² Razi Vaccine and Serum Research Institute

10.22059/jfisheries.2013.35463

Abstract

Streptococcus agalactiae (group B, GBS) is an important human and animal pathogen that
causes invasive infection in fish. The present study aims to investigate the detection of vertical
transmission S. agalactiae using the PCR of the gene scpB in the ovarian tissues. A group of 48
fishes were injected intramuscularly (i.m) with 0.5 ml bacterial suspension containing 3.5×107
CFU/0.5 ml in normal saline, This group was compared with a control group of 48 fishesthat
were injected with 0.5 ml sterile saline. In this study kidney tissue, ovarian tissue and ovarian
fluid were sampled from the fourth day after injection. DNA was extracted from both the direct
tissue and the bacteria isolated from the tissues, which were cultured in the BHI medium. The
extracted DNA was then used in the PCR. The PCR confirmed the existence of this bacterium
in 91.46% (44/48) and 68.75% (34/48) of the kidney and the ovarian tissues, respectively,
and 95.83% (46/48) and 87.5% (42/48) of bacteria isolated from the kidney and the ovarian
tissue cultures, respectively. The presence of S. agalactiaein rainbow trout ovarian tissue was
confirmed by PCR and sequencing that can be the evidence for vertical transmission of this
bacterium in rainbow trout brood stock.

Keywords

Oncorhynchus mykiss

PCR

scpB gene

Streptococcus agalactiae

vertical transmission

Subjects