Genetic diversity and clonal relatedness of Aeromonas hydrophila strains isolated from hemorrhagic septicemia’s cases in common Carp (Cyprinus carpio) farms

Abstract

The objective of this study was to determine molecular typing and comparison analysis of 24 Aeromonas hydrophila isolated from the diseased fish with hemorrhagic septicemia in freshwater ponds and cage in Mosul and Duhok cities, Iraq. A total of 24 A. hydrophila isolates that were collected from various fish ponds and cage, were used in this study. Identification of isolates was made by the standard microbiological and molecular methods. ERIC-PCR was done with different primers to establish the genetic relationship between strains. ERIC-PCR typing showed that 24 strains of A. hydrophila were classified into 11 ERIC types (genotypes). Genotypes 9 and 7 represented the most prevalent clone. All A. hydrophila strains that were isolated from the same fish were genetically diverse. There was minimal genetic similarity between some strains which were retrieved from the same geographical source area. Also, some isolates from different geographic source area were showed a 100% genetically similar. Aeromonas hydrophila was genotypically heterogeneous and clonally dispersed among different fish ponds and cage in Mosul and Duhok cities, Iraq. Besides, one fish can be infected with more than one strains of A. hydrophila.