Microbial community structure in a host-parasite system: the case of Prussian carp and its parasitic crustaceans.

Aims: The aim of the study was to investigate the skin microbiota of Prussian carp infested by ectoparasites from the genera Argulus and Lernaea.

Methods And Results: Associated microbiota of skin of Prussian carp and ectoparasites were investigated by sequencing of the V3, V4 hypervariable regions of 16S rRNA using Illumina MiSeq sequencing platform.

Conclusions: According to the Spearman rank correlation test, the increasing load of ulcerations of the skin of Prussian carp was weakly negatively correlated with reduction in the abundance of the following taxa: Acrobacter, bacteria C39 (Rhodocyclaceae), Rheinheimera, Comamonadaceae, Helicobacteraceae and Vogesella. In this study, the microbiota of ectoparasites from the genera Lernaea and Argulus were characterized for the first time. The microbiota associated with L. cyprinacea was significantly different from microbial communities of intact skin mucosa of both infested and uninfested fish and skin ulcers (ADONIS, P ≤ 0·05). The microbiota associated with parasitic crustaceans L. cyprinacea were dominated by unclassified bacteria from Comamonadaceae, Aeromonadaceae families and Vogesella. The dominant microbiota of A. foliaceus were represented by Flavobacterium, Corynebacterium and unclassified Comamonadaceae.

Significance And Impact Of The Study: Results from these studies indicate that ectoparasites have the potential to alter skin microbiota, which can play a possible role in the transmission of secondary bacterial infections in fish, caused by pathogenic bacteria.