Coinfection by Group <i>C Streptococcus dysgalactiae</i> subsp. <i>equisimilis</i> and <i>Flavobacterium davisii</i> in Nile Tilapia from the United States

Streptococcal disease and columnaris are common in tilapia aquaculture across the globe. Coinfections also but often overlooked or not reported. In present study, we describe clinical presentation of streptococcosis coinfection diseased Nile ( Oreochromis niloticus ), phenotypic (Lancefield grouping, hemolytic pattern, biochemical characteristics, antibiotic susceptibility) genotypic (multilocus sequence analysis for streptococci multiplex PCR flavobacteria) characterisation its etiological agents, namely Group C Streptococcus dysgalactiae subsp. equisimilis Flavobacterium davisii . We further fulfilled Koch’s postulates with S. isolate genetically improved tilapia.