Potential Application of PCR Based Molecular Methods in Fish Pathogen Identification: A Review

Abstract

Molecular biology developments have led to fast growth in new methods for fish disease diagnosis. Molecular diagnostic methods are rapid and more specific, more sensitive than the culture of pathogens, serology, histology, and biochemical methods which are traditionally utilized to identify causative agent fish disease. Molecular diagnostic methods are valuable for detecting specific pathogens that are difficult to culture in vitro or require a long cultivation period and it significantly more rapid in providing results compared to culture. It enables earlier informed decision-making and rapid diagnosis of bacteremia, particularly for low levels of bacteria in specimens. Molecular techniques which have the major significance are mainly PCR-based molecular diagnostic methods including Polymerase Chain Reaction (PCR), Real-Time Polymerase Chain Reaction (RT-PCR), Multiplex Polymerase Chain Reaction (multiplexPCR), and Random Amplified Polymorphic DNA (RAPD). These have been increasingly utilized to diagnose fish disease for the last recent years. Molecular diagnostic methods can detect pathogens from asymptomatic fish, so disease outbreaks could be prevented. As a consequence, antibiotic treatment can be reduced and the development of antibiotic-resistant bacteria can be eliminated. In this review paper, we attempt to summarize the potentiality of PCR-based molecular diagnostic methods and their application in fish pathogen identification.

Early detection of Pseudocapillaria tomentosa by qPCR in four lines of zebrafish, Danio rerio (Hamilton 1882)

“…PCR‐based tests for fish pathogens are increasingly being used for screening populations and for disease diagnostics in aquaculture (Adams & Thompson, 2011; Ador et al, 2021), including zebrafish research facilities. PCR‐based screening tests have been developed for important pathogens of zebrafish and are now routinely employed in many zebrafish facilities and diagnostic laboratories (Barton et al, 2016; Collymore et al, 2016; Crim et al, 2017; Miller et al, 2019; Mocho, 2016; Murray et al, 2016).…”

Anguilla sp. diseases diagnoses and treatments: The ideal methods at the crossroads of conservation and aquaculture purposes

“…Also, in addition to the detection issues previously listed, infections may not be detected if the amount of pathogen present in the sample is below the test's sensitivity threshold (Adams & Thompson, 2011). The development of molecular techniques using PCR amplification of DNA can provide other possibilities of pathogen identification ( Ador et al., 2021 ) . The PCR methods allow rapid identification of genetic material from pathogens with results available within a day or less (Coleman et al., 1996).…”

Genotoxic potentials of some selected heavy metals exposure on Clarias gariepinus (Burchell, 1822) and Oreochromis niloticus (Linnaeus, 1758) using RAPD-PCR technique

“…Nested PCR and Multiplex Polymerase Chain Reaction (multiplexPCR), etc (Ador et al, 2022). Rapid Amplified Polymorphic DNA (RAPD)have been extensively used in this regard (Tajik-Esmaelili et al, 2017).…”

“…Though, RAPDs have low reproducibility and result can be difficult to interpret, among several PCR-based tools, Random Amplified Polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR) is a simple, robust, rapid and cost-effective tool (ReshmaRaj and Das, 2021). Therefore, highly standardized laboratory protocols are required because of their sensitivity to reaction conditions (Ador et al, 2022;Stefanska et al, 2022).The quality and concentration of template DNA, concentrations of PCR components, and the PCR cycling conditions greatly influence the outcome of RAPD. Also, to ensure reproducibility, purified and high molecular weight DNA is required for RAPD analyses (ReshmaRaj and Das, 2021).…”