Advances in Animal and Veterinary Sciences
Seropositivity of Field Veterinarians for Listeric Infection by Indirect ELISAs Employing Recombinant and Wild-Type Listeriolysin O
Rahul Diliprao Suryawanshi1*, Bhushan Jayarao2, Sukhadeo Baliram Barbuddhe3, Sandeep Prabhakar Chaudhari4, Deepak Bhiwa Rawool1, Vysakh Mohan1, Jess Vergis1, Mamta Negi1, Satya Veer Singh Malik1*
1Division of Veterinary Public Health, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India. Pin– 243 122; 2Department of Veterinary and Biomedical Sciences, Pennsylvania State University, PA, U.S.A. Pin–16801; 3National Institute of Biotic Stress Management, Raipur, Chhatisgarh, India. Pin– 492 012; 4Department of Veterinary Public Health, Nagpur Veterinary College, Nagpur, Maharashtra, India. Pin–440 006.
*Corresponding author: svsmalik@gmail.com
ABSTRACT
Listeriolysin O (LLO) being an essential virulence marker produced by all the pathogenic strains of Listeria monocytogenes has been reported to be an immunodominant antigen for serodiagnosis of listeric infections. The present study explores the serodiagnostic potential of recombinant listeriolysin O (rLLO) vis–a–vis wild type LLO (wLLO) employed in an indirect plate ELISA for screening sera of 221 field veterinarians from Maharashtra, India. A higher seropositivity (73.30%) for antibodies against LLO (ALLO) was observed amongst field veterinarians in wLLO–based ELISA compared to 37.56% in rLLO–based ELISA. Further, adsorption of sera with streptolysin–O (SLO) resulted in more than three–fold reduction in the seropositivity for ALLO, which was observed to be 14.93% in wLLO–based ELISA and 13.57% in rLLO–based ELISA. The rLLO–based ELISA having advantage in terms of lesser cross–reactivity and ease of production of the employed antigen, appears to be a better option for serodiagnostic purposes than wLLO–based ELISA, which is classically employed as widely accepted reliable serodiagnostic test, especially on SLO adsorbed sera. However, rLLO based–ELISA needs to be further evaluated on the sera from known clinical cases of listeriosis, especially in the high risk groups of humans, for ascertaining its efficacy as rapid and reliable serodiagnostic test for mass screening. This study seems to be the first report on comparative diagnostic potential of rLLO and wLLO in plate ELISA.
Key Words: Recombinant LLO, Indirect ELISA, Field Veterinarians, Listeria monocytogenes
