Alumiste hingamisteede bakterid ja seos kliinilise haigusega piimaveise vasikatel
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Kuupäev
2024
Kättesaadav alates
12.09.2024
Autorid
Anniste, Kendra
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Veiste hingamisteede haigus (ingl bovine respiratory disease - BRD) on üldine termin, mis hõlmab mitme eri etioloogia ja lokalisatsiooniga hingamisteede haigusi. Haigust võivad põhjustada mitmed tegurid, sealhulgas stressist tingitud vastupanuvõime vähenemine, viiruslikud ja bakteriaalsed patogeenid ning immuunvastusest sõltuvad tegurid. BRD diagnoosimine on produktiivloomadel suur väljakutse, kuna puudub üks kindel kuldstandard. Lõputöö eesmärkideks oli uurida, milliseid baktereid leidub Eesti piimaveisekarjade vasikate alumistes hingamisteedes ning analüüsida nende seost kliinilise haiguse esinemisega. Uuringusse kaasati 150 piimaveise vasikat 15 karjast, kellelt koguti trahhea-bronhiaal lavaaži proovid ning hinnati hingamisteede haiguse kliiniliste tunnuste esinemist. Kogutud proovidele teostati bakterioloogiline uuring ja Mycoplasmopsis bovis’e tuvastamiseks kasutati polümeraasi ahelreaktsiooni meetodit. Vähemalt üks bakter tuvastati 59,3% vasikatel. Kõige sagedamini tuvastatud alumiste hingamisteede bakterid olid Pasteurella multocida (34,7%), Mycoplasmopsis bovis (13,3%), Mannheimia spp. (7,3%), Streptococcus spp. (8,7%) ja Gallibacterium anatis (6,0%). California hindamissüsteemi järgi oli kliiniliselt haigeid vasikaid 21%. Alumistest hingamisteedest isoleeritud bakterite seost kliinilise haiguse esinemise osas analüüsiti logistilise regressioonanalüüsi mudelitega. Gallibacterium anatis esinemine seostus vasikatel kliinilise haiguse esinemisega (ŠS = 6,6, 95% UV 0,1–11,2). Trendi näitav seos kliinilise haigusega tuvastati ka Trueperella pyogenes’e puhul (ŠS = 3,6, 95% UV 0,7–18,7). Lõputöö tulemustest saab järeldada, et kliinilise hingamisteede haigusega seondusid eelkõige sekundaarsed bakterid, mistõttu üksnes kliiniliste haigustunnuste hindamisega tuvastatakse haigestunud vasikad haiguse hilisemas faasis.
Bovine respiratory disease (BRD) is a general term that encompasses several respiratory disorders with various aetiologies and localizations. The disease can be caused by multiple factors, including decreased resistance due to stress, viral and bacterial pathogens, and immune response-dependent factors. Diagnosing BRD in productive animals is a significant challenge as there is no single gold standard. This thesis aimed to investigate the bacteria found in the lower respiratory tracts of calves in Estonian dairy herds and to analyse their association with the occurrence of clinical disease. The study included 150 dairy calves from 15 herds, from which tracheobronchial lavage samples were collected, and the presence of clinical respiratory disease signs was assessed. A bacteriological examination was performed on the collected samples, and the polymerase chain reaction method was used to detect Mycoplasmopsis bovis. At least one bacterium was identified in 59.3% of the calves. The most identified bacteria in lower respiratory tract were Pasteurella multocida (34.7%), Mycoplasmopsis bovis (13.3%), Mannheimia spp. (7.3%), Streptococcus spp. (8.7%), and Gallibacterium anatis (6.0%). According to the California scoring system, 21% of the calves were clinically diseased. Logistic regression analysis models were used to analyze the association between bacteria isolated from the lower respiratory tract and the presence of clinical disease. The presence of Gallibacterium anatis was associated with the occurrence of clinical disease in calves (OR = 6.6, 95% CI 0.1–11.2). A trend indicating an association with the presence of a clinical disease was also identified for Trueperella pyogenes (OR = 3.6, 95% CI 0.7–18.7). The results of the thesis indicate that secondary bacteria were primarily associated with clinical respiratory disease, therefore only by assessing clinical signs of disease can affected calves be identified in the later stages of the disease.
Bovine respiratory disease (BRD) is a general term that encompasses several respiratory disorders with various aetiologies and localizations. The disease can be caused by multiple factors, including decreased resistance due to stress, viral and bacterial pathogens, and immune response-dependent factors. Diagnosing BRD in productive animals is a significant challenge as there is no single gold standard. This thesis aimed to investigate the bacteria found in the lower respiratory tracts of calves in Estonian dairy herds and to analyse their association with the occurrence of clinical disease. The study included 150 dairy calves from 15 herds, from which tracheobronchial lavage samples were collected, and the presence of clinical respiratory disease signs was assessed. A bacteriological examination was performed on the collected samples, and the polymerase chain reaction method was used to detect Mycoplasmopsis bovis. At least one bacterium was identified in 59.3% of the calves. The most identified bacteria in lower respiratory tract were Pasteurella multocida (34.7%), Mycoplasmopsis bovis (13.3%), Mannheimia spp. (7.3%), Streptococcus spp. (8.7%), and Gallibacterium anatis (6.0%). According to the California scoring system, 21% of the calves were clinically diseased. Logistic regression analysis models were used to analyze the association between bacteria isolated from the lower respiratory tract and the presence of clinical disease. The presence of Gallibacterium anatis was associated with the occurrence of clinical disease in calves (OR = 6.6, 95% CI 0.1–11.2). A trend indicating an association with the presence of a clinical disease was also identified for Trueperella pyogenes (OR = 3.6, 95% CI 0.7–18.7). The results of the thesis indicate that secondary bacteria were primarily associated with clinical respiratory disease, therefore only by assessing clinical signs of disease can affected calves be identified in the later stages of the disease.
Kirjeldus
Lõputöö
Veterinaarmeditsiini õppekaval
Märksõnad
magistritööd, vasikas, veiste hingamisteede haigus, bakterid, kliinilised tunnused