Biosensing system for the rapid multiplex detection of mastitis-causing pathogens in milk
Date
2018-04-13
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Abstract
Mastiit on udarapõletik, mis enamasti tekib patogeensete mikroorganismide sattumisel läbi nisajuha udaraveerandisse, olles peamine lüpsilehmade nakkushaigus. Mastiidi poolt põhjustatud kahju kogu maailma 271 miljoni piimalehma kohta on hinnanguliselt 16-26 miljardit eurot aastas.
Traditsiooniliste meetoditena mastiiti tekitavate bakterite identifitseerimiseks on tänapäeval kasutusel mikrobioloogilised analüüsid, mis võtavad aega 1-2 päeva ja laboratoorsetes tingimustes tehtavad patogeenide geenianalüüsid, mille tegemiseks kulub 6 tundi. Kuna ravi edukuse tagamiseks on selle täpsuse kõrval väga oluline ka selle võimalikult operatiivne alustamine, siis on vajalik välja töötada sellised analüüsimeetodid, mis võimaldavad patogeenide identifitseerimist oluliselt kiiremini kui praegu ning mida on võimalik kasutada farmides kohapeal. Tänasel päeval sellised meetodid puuduvad.
Doktoritöö käigus töötati välja biosensorsüsteem ja mõõtemetoodika kolme peamise mastiiti tekitava patogeeni – Staphylococcus aureus’e Escherichia coli ja Streptococcus uberis’e määramiseks nii eraldi kui ühtlasi ka kõikide nimetatud patogeenide koos määramiseks. Biosensorsüsteemi konstrueerimisel uuriti selle tundlikkust, tööpiirkonda, selektiivsust ja sobivust rakendamiseks keerulistes maatriksites nagu piim.
Biosensori selektiivsus kindla patogeeni määramiseks teiste bakterite olemasolul oli väga hea ning seda on võimalik kasutada mitme bakteri samaaegseks määramiseks.
Väljapakutud biosensorsüsteemil põhinevat mõõtesüsteemi on võimalik kasutada loomade tervise automatiseeritud kontrolliks farmis kohapeal ja seeläbi kiiresti identifitseerida juba varajases staadiumis potentsiaalne haigus. Varajane haiguse avastamine aitab alustada koheselt kiiret ja sobivat ravi, parandades seeläbi looma heaolu ja piima kvaliteeti ning vähendada tootmiskulusid ja majanduslikku kahju.
Mastitis, mostly caused by bacterial infection of the mammary gland, is a major health problem of dairy cows. The resulting decrease of milk production and reduction of its quality along with medication costs and probable premature culling of animals cause essential economic burden. The total mastitis caused losses in dairy industry are estimated to be 16–26 billion € annually in view of a global population of 271 million dairy cows. For the identification of mastitis-causing pathogens, the gold standard is microbiological culturing of bacteria, which in recent years has been partially replaced by polymerase chain reaction analyses of bacterial DNA. Although reliable, these methods require hours to obtain results, not allowing effective treatment of animals and optimal milk processing. Therefore to assure timely and correct treatment of animals, there is a great need for a method applicable for rapid automatic detection of mastitis causing pathogens in milk. A rapid method and an immuno-biosensing system have been proposed and applied for the rapid multiplex detection of major mastitis causing pathogens (Staphylococcus aureus, Escherichia coli and Streptococcus uberis) in milk. The key features of the biosensor development were its selectivity, sensitivity, working range and applicability for rapid automated analyses in complex biological sample matrix like milk. The selectivity of the biosensing system in the presence of several pathogens was very good and it was applicable for the multiplex detection of different pathogens. Based on the results of the present study, the proposed biosensing system has a great potential to serve as a tool for in-line automatic monitoring of milk and animal health in dairy farms.
Mastitis, mostly caused by bacterial infection of the mammary gland, is a major health problem of dairy cows. The resulting decrease of milk production and reduction of its quality along with medication costs and probable premature culling of animals cause essential economic burden. The total mastitis caused losses in dairy industry are estimated to be 16–26 billion € annually in view of a global population of 271 million dairy cows. For the identification of mastitis-causing pathogens, the gold standard is microbiological culturing of bacteria, which in recent years has been partially replaced by polymerase chain reaction analyses of bacterial DNA. Although reliable, these methods require hours to obtain results, not allowing effective treatment of animals and optimal milk processing. Therefore to assure timely and correct treatment of animals, there is a great need for a method applicable for rapid automatic detection of mastitis causing pathogens in milk. A rapid method and an immuno-biosensing system have been proposed and applied for the rapid multiplex detection of major mastitis causing pathogens (Staphylococcus aureus, Escherichia coli and Streptococcus uberis) in milk. The key features of the biosensor development were its selectivity, sensitivity, working range and applicability for rapid automated analyses in complex biological sample matrix like milk. The selectivity of the biosensing system in the presence of several pathogens was very good and it was applicable for the multiplex detection of different pathogens. Based on the results of the present study, the proposed biosensing system has a great potential to serve as a tool for in-line automatic monitoring of milk and animal health in dairy farms.
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