SENSITIVITY OF MOLECULAR DETECTION OF VIBRIOSIS ON PENAEID SHRIMP COMPARED TO CONVENTIONAL DETECTION METHOD
Pathogenic luminescent Vibrios have been causing significant economical loss in aquaculture industry. Vibriosis usually attack the hatchery eggs, shrimp larvae and environment. Vibrio bacteria that has reached quorum could change its nature from saprophyte to pathogen. The process of identification and detection using conventional method (agar spread and biochemical) are difficult to distinguish between pathogenic and non pathogenic bacteria. Early detection of bacteria cause Vibriosis is conducted through molecular method under PCR technique using specific primer, haemolysin (IAVh). Molecular detection using spesific primer can shorten detection time (1-2 days) before bacteria population reached its quorum. This research aimed to compared detection method of Vibriosis on Penaeid shrimp.
Development of this PCR (Polymerase Chain Reaction) based method is applied for Vibriosis detection in natural and artificial infection of the penaeid shrimp. Penaeid shrimp samples were collected from the shrimp brackishwater ponds in South Sulawesi, Situbondo (Districts of Paras Duwet, Panarukan, and Sletreng), and Lampung (Districts of Bakauheni and Kalianda). The artificial infection tests were conducted by injecting 100 µL of 102, 104 dan 106 CFU/mL of cultured pathogenic bacteria, V. harveyi to reared shrimp. Collected shrimp organ samples were included gills, carapacs, pleopods, pereipods, and caudal.
The results showed that haemolysin IAVh primer could detect Vibriosis directly from the shimp organs on density 102 - 103cfu/mL. While conventional method cannot detect pathogenic Vibrio using agar plate method. Primer IAVh more sensitive than conventional method that can only detect the density of bacteria in the >104 cfu/mL in laboratory and field scales.