Department of Microbiology, Faculty of Veterinary Medicine, Uludag University, Gorukle Campus, 16059 Bursa, Turkey.
Vet Microbiol. 2010 Aug 26;144(3-4):319-24. doi: 10.1016/j.vetmic.2010.01.012. Epub 2010 Jan 28.
This study aimed to compare a real-time PCR (rPCR) test with improved detection limit to serology and culture for the detection of Mycoplasma gallisepticum (MG) infection in chicken breeder flocks. Six hundred and forty-six blood and tracheal swab samples belonging to 31 grandparent chicken breeder flocks were tested by rPCR. The detection limit of rPCR was 0.9 pg microl(-1), with pure MG S6 strain DNA and 100 colony forming units (CFUs) ml(-1), where both pure culture and tracheal swabs were artificially spiked with the same strain. The seropositive flock rate based on both MG RPA and HI were calculated as 48.4% (15/31) and 32.3% (10/31), respectively, while culture- and rPCR-positive flock rates were 16.1% (5/31) and 29.0% (9/31), respectively. On flock-based analysis, culture method detected 5 out of 10 MG seropositive flocks (sensitivity 50%, specificity 100%), whereas rPCR detected 8 out of 10 flocks (sensitivity 80%, specificity 95%). Agreements between serology and culture, and serology and rPCR were 83.9% and 90.3%, respectively. On individual sample-based analysis, culture method detected 26 out of 78 MG seropositive chicken (sensitivity 33%, specificity 100%), whereas rPCR detected 51 out of 78 MG seropositive chickens (sensitivity 65%, specificity 96%). There was 91.9% and 91.4% agreement between serology and culture, and serology and rPCR, respectively. Results of this study indicate that the rPCR with improved in vitro detection limit could detect MG in seropositive chicken flocks. Therefore, we advise the use of rPCR and/or culture for confirmation of serology results obtained from screening MG infection in chicken flocks.
本研究旨在比较实时 PCR (rPCR) 检测方法与血清学和培养法，以检测种鸡群中鸡毒支原体 (MG) 的感染。对 31 个祖代种鸡群的 646 份血样和气管拭子样本进行了 rPCR 检测。rPCR 的检测限为 0.9 pg μL(-1)，用纯 MG S6 株 DNA 和 100 个菌落形成单位 (CFU) mL(-1)进行检测，其中纯培养物和气管拭子均用相同的菌株进行人工接种。基于 MG RPA 和 HI 的血清阳性率分别计算为 48.4%（15/31）和 32.3%（10/31），而培养物和 rPCR 的阳性率分别为 16.1%（5/31）和 29.0%（9/31）。在鸡群水平的分析中，培养法检测到 10 个 MG 血清阳性鸡群中的 5 个（敏感性 50%，特异性 100%），而 rPCR 检测到 10 个鸡群中的 8 个（敏感性 80%，特异性 95%）。血清学与培养法和血清学与 rPCR 的一致性分别为 83.9%和 90.3%。在个体鸡水平的分析中，培养法检测到 78 个 MG 血清阳性鸡中的 26 个（敏感性 33%，特异性 100%），而 rPCR 检测到 78 个 MG 血清阳性鸡中的 51 个（敏感性 65%，特异性 96%）。血清学与培养法和血清学与 rPCR 的一致性分别为 91.9%和 91.4%。本研究结果表明，改进了体外检测限的 rPCR 可以检测到血清阳性鸡群中的 MG。因此，我们建议在鸡群中筛查 MG 感染时，使用 rPCR 和/或培养法来确认血清学结果。
