Cryptocaryon irritans recombinant proteins as potential antigens for sero‐surveillance of cryptocaryonosis

Abstract

Cryptocaryonosis is a major problem for mariculture, and the absence of suitable sero-surveillance tools for the detection of cryptocaryonosis makes it difficult to screen Cryptocaryon irritans-infected fish, particularly asymptomatic fish. In this study, we proposed a serum-based assay using selected C. irritans proteins to screen infected and asymptomatic fish. Eight highly expressed genes were chosen from an earlier study on C. irritans expressed sequence tags and ciliate glutamine codons were converted to universal glutamine codons. The chemically synthesized C. irritans genes were then expressed in an Escherichia coli expression host under optimized conditions. Five C. irritans proteins were successfully expressed in E. coli and purified by affinity chromatography. These proteins were used as antigens in an enzyme-linked immunosorbent assay (ELISA) to screen sera from experimentally immunized fish and naturally infected fish. Sera from both categories of fish reacted equally well with the expressed C. irritans recombinant proteins as well as with sonicated theronts. This study demonstrated the utility of producing ciliate recombinant proteins in a heterologous expression host. An ELISA was successfully developed to diagnose infected and asymptomatic fish using the recombinant proteins as antigens.

Molecular remedies against Cryptocaryon irritans Brown, 1951—Practical difficulties

“…In an another study by Lokanathan et al. (2016), the phylogenetic data derived from iAg amino acid sequences of 9 isolates of C. irritans revealed only three clusters of iAg variants presumably the three serotypes. From these observations, we were tempted to suggest that Western blot analysis of serum antibodies against crude proteins of the different C. irritans isolates would have been helpful to discriminate the serotypes more or less precisely apart from rDNA sequencing, in vitro immobilization and ELISA.…”

“…In continuation, eight highly expressed genes were chosen from the ESTs and attempt was made to express in E. coli after the stop codons were replaced with universal glutamine codons. The resultant recombinant proteins were proved to be efficient to detect the immunized and naturally infected fish sera (Lokanathan et al., 2016). If these recombinant proteins were tested for their effect on the fish survival, possible antigenic proteins could be identified.…”

“…(2008) developed first polymerase chain reaction (PCR) assay for the rapid and specific detection of C. irritans infection in marine fish followed by the standardization of quantitative PCR by Taniguchi in 2011 (Table 1). Recently, an enzyme‐linked immunosorbent assay (ELISA) was also developed to diagnose the infected and asymptomatic fish using selected recombinant proteins as antigens (Lokanathan, Mohd‐Adnan, Kua, & Nathan, 2016). An actin‐depolymerizing factor gene (CiADF2) was cloned from C. irritans , and its transcripts were detected in all life cycle stages of the parasite.…”

Infectivity and genes differentially expressed between young and aging theront cells of the marine fish parasite Cryptocaryon irritans

“…outbreaks. Most research projects focus on understanding host fish's immune responses during C. irritans infections [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19], and on testing antigens for effective immunizations in fish [20][21][22][23]. However, little research has been dedicated to study gene expression in C. irritans: Lokanathan and colleagues sequenced more than 5,000 cDNA clones from C. irritans tomont cells in a pioneering study [24]; Mai et al compared proteins differentially expressed in the three key life stages of C. irritans [25], and Mo et al followed up with transcriptomic profiling using next generation sequencing [26].…”

Perbandingan Filogenetik Protein Antigen-I yang Berpotensi Sebagai Calon Diagnostik dan Vaksin terhadap Parasit Cryptocaryon irritans

“…Demong, Terengganu (Lokanathan et al 2016). Namun demikian, masalah penghasilan antibodi terhadap antigen-i yang spesifik serotip dengan tindakan yang lemah terhadap antigen-i serotip berlainan perlu dicari penyelesaian (Hatanaka et al 2008;Misumi et al 2011).…”