Saprolegnia strains isolated from river insects and amphipods are broad spectrum pathogens

Mohammad Nasif Sarowar, Albert Hendrik van den Berg, Debbie McLaggan, Mark R. Young, Pieter van West

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Saprolegnia species are destructive pathogens to many aquatic organisms and are found in most parts of the world. Reports based on phylogenetic analysis suggest that Saprolegnia strains isolated from aquatic animals such as crustaceans and frogs are close to Saprolegnia strains isolated from infected fish or fish eggs and vice versa. However, it has often been assumed that host specificity occurs for each individual isolate or strain. Here we demonstrate that Saprolegnia spp. can have multiple hosts and are thus capable of infecting different aquatic organisms. Saprolegnia delica, Saprolegnia hypogyna, and 2 strains of Saprolegnia diclina were isolated from aquatic insects and amphipods while S. delica, Saprolegnia ferax, Pythium pachycaule, and a Pythium sp. were isolated from the water of a medium to fast flowing river. The ITS region of the rRNA gene was sequenced for all isolates. In challenge experiments, all four isolates from insects were found to be highly pathogenic to eggs of Atlantic salmon (Salmo salar) and embryos of the African clawed frog (Xenopus laevis). We found that Saprolegnia spp. isolated from salmon eggs were also able to successfully establish infection in nymphs of stonefly (Perla bipunctata) and embryos of X. laevis). These results suggest that Saprolegnia spp. are capable of infecting multiple hosts, which may give them an advantage during seasonal variation in their natural environments.
Original languageEnglish
Pages (from-to)752-763
Number of pages12
JournalFungal Biology
Volume117
Issue number11-12
Early online date21 Sep 2013
DOIs
Publication statusPublished - Nov 2013

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Keywords

  • aquatic insects
  • multiple hosts
  • salmo salar
  • saprolegniosis
  • Xenopus laevis

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