Natural coinfection by Streptococcus agalactiae and Francisella noatunensis subsp. orientalis in farmed Nile tilapia (Oreochromis niloticus L.)
© 2016 John Wiley & Sons Ltd.
Veröffentlicht in: | Journal of fish diseases. - 1998. - 40(2017), 1 vom: 08. Jan., Seite 51-63 |
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1. Verfasser: | |
Weitere Verfasser: | , , , |
Format: | Online-Aufsatz |
Sprache: | English |
Veröffentlicht: |
2017
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Zugriff auf das übergeordnete Werk: | Journal of fish diseases |
Schlagworte: | Journal Article MLST glcK REP-PCR coinfection francisellosis streptococcosis |
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 |
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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 |