| Biography | |
|---|---|
 Dr. Rajib Deb Animal Biotechnology Center, ICAR-National Dairy Research Institute, India |
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| Title: Development of a nanoparticle captured amplification free visual assay for detecting Escherichia coli in cow milk | |
| Abstract: Back Ground For early diagnosis of infections, a rapid, sensitive and precise method to identify microbial DNA coming from veterinary clinical samples, such as milk of cows affected with mastitis, is fascinating. We developed an amplification-free visual assay for rapid and sensitive detection of specific DNA from Escherichia coli, particularly uid A gene encoding for beta-glucuronidase, isolated in milk of cows affected with mastitis, based on multiple gold nanoparticles (AuNPs) captured on a magnetic microbead surface, leading to plasmonic signal enhancement, thereby improving overall sensitivity of the assay. Methodologies We developed an amplification-free visual assay for rapid and sensitive detection of specific DNA from Escherichia coli, particularly uid A gene encoding for beta-glucuronidase, isolated in milk of cows affected with mastitis, based on multiple gold nanoparticles (AuNPs) captured on a magnetic microbead surface, leading to plasmonic signal enhancement, thereby improving overall sensitivity of the assay. This test does not require any expensive equipment, may be performed in 1-1.5 hours and the findings can be easily seen with the naked eye. Results E coli loads as low as 102 CFU/µl can be easily detected and, in comparison to polymerase chain reaction , the assay enables the identification of bacterial DNA as low as 1 pg by visual inspection. The same samples were also examined by PCR in combination with gel electrophoresis and a similar level (102 CFU/µl) of the visible assay could be detected. Furthermore, total bacterial genomic DNA with 10-fold serial dilutions (1 ng, 100 pg, 10 pg, 1 pg, 100 fg and10 fg /µl) were subjected to visual assay using either limited or excessive amount of PB2. The results revealed that the limit of detection of the assay touched as low as 1 pg/µl of targeted E coli specific DNA. The Relative accuracy (AC), Relative specificity (SP), and Relative Sensitivity (SE) values of the developed visual test were 96.52%, 93.1%, and 100%, respectively. Conclusion he proposed gold nanoparticle-based amplification-free assay was shown to be a promising alternative molecular technique for detecting Escherichia coli specific DNA in milk samples of cow affected with mastitis in a quick and easy manner. Visual examination of microbial DNA up to 1 pg level is possible with this test, which is equivalent to or even more sensitive than PCR. Thus, this preliminary assay could be a useful rapid detection tool for screening of E coli in clinical mastitis milk samples. | |
| Biography: Dr. Rajib Deb, MVSc, Ph.D having 10 years of experience as Scientist (Animal Biotechnology) at Indian Council of Agricultural Research, New Delhi, Govt. of India. He has made outstanding contributions in advanced molecular biology and genomics research of livestock especially dairy cattle, the prime animals in agriculture for the past eight years with a focus on improving the livelihood of dairy cattle farmers. His research reflects a continuum of high quality basic, strategic, and applied research in animal health and productivity. He has published more than 40 research articles in reputed journals, filed 9 Indian Patents, developed several technologies including diagnostic kits. He is recipient of different National and International awards including NASI Associate, INYAS Membership, NAAS Associate, TWAS Fellowship, ICAR Junior & Senior Research Fellowship, NAVS Associateship, Young Scientist Awards etc. | |
