Natural coinfection by Streptococcus agalactiae and Francisella noatunensis subsp. orientalis in farmed Nile tilapia (Oreochromis niloticus L.)

© 2016 John Wiley & Sons Ltd.

Bibliographische Detailangaben
Veröffentlicht in:Journal of fish diseases. - 1998. - 40(2017), 1 vom: 08. Jan., Seite 51-63
1. Verfasser: Assis, G B N (VerfasserIn)
Weitere Verfasser: Tavares, G C, Pereira, F L, Figueiredo, H C P, Leal, C A G
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2017
Zugriff auf das übergeordnete Werk:Journal of fish diseases
Schlagworte:Journal Article MLST glcK REP-PCR coinfection francisellosis streptococcosis
Beschreibung
Zusammenfassung:© 2016 John Wiley & Sons Ltd.
Streptococcus agalactiae and Francisella noatunensis subsp. orientalis (Fno) are important pathogens for farm-raised tilapia worldwide. There are no reports of coinfection caused by S. agalactiae and Fno in fish. This study aimed to determine the aetiology of atypical mortalities in a cage farm of Nile tilapia and to characterize the genetic diversity of the isolates. Fifty-two fish were sampled and subjected to parasitological and bacteriological examination. The S. agalactiae and Fno isolates were genotyped using MLST and REP-PCR, respectively. Whole-genome sequencing was performed to confirm the MLST results. Seven fish were shown coinfected by S. agalactiae and Fno. Chronic hypoxia and a reduction in the water temperature were determined as risk factors for coinfection. Fno isolates were shown clonally related in REP-PCR. The MLST analysis revealed that the S. agalactiae isolates from seven coinfected fish were negative for the glcK gene; however, these were determined to be members of clonal complex CC-552. This is the first description of coinfection by S. agalactiae and Fno in farm-raised Nile tilapia. The coinfection was predisposed by chronic hypoxia and was caused by the main genotypes of S. agalactiae and Fno reported in Brazil. Finally, a new S. agalactiae genotype with glcK gene partially deleted was described
Beschreibung:Date Completed 03.05.2017
Date Revised 30.09.2020
published: Print-Electronic
GENBANK: NC_004368.1, CP003919.1
Citation Status MEDLINE
ISSN:1365-2761
DOI:10.1111/jfd.12493