Idris Umelaalim, Lu Jingrang, Maier Marie, Sanchez Susan, Hofacre Charles L, Harmon Barry G, Maurer John J, Lee Margie D
Poultry Diagnostic and Research Center, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.
Appl Environ Microbiol. 2006 May;72(5):3441-7. doi: 10.1128/AEM.72.5.3441-3447.2006.
While characterizing the intestinal bacterial community of broiler chickens, we detected epsilon-proteobacterial DNA in the ilea of 3-day-old commercial broiler chicks (J. Lu, U. Idris, B. Harmon, C. Hofacre, J. J. Maurer, and M. D. Lee, Appl. Environ. Microbiol. 69:6816-6824, 2003). The sequences exhibited high levels of similarity to Campylobacter jejuni and Campylobacter coli sequences, suggesting that chickens can carry Campylobacter at a very young age. Campylobacter sp. was detected by PCR in all samples collected from the ilea of chicks that were 3 to 49 days old; however, it was detected only in the cecal contents of chickens that were at least 21 days old. In order to determine whether the presence of Campylobacter DNA in young chicks was due to ingestion of the bacteria in food or water, we obtained commercial broiler hatching eggs, which were incubated in a research facility until the chicks hatched. DNA sequencing of the amplicons resulting from Campylobacter-specific 16S PCR performed with the ileal, cecal, and yolk contents of the day-of-hatching chicks revealed that Campylobacter DNA was present before the chicks consumed food or water. The 16S rRNA sequences exhibited 99% similarity to C. jejuni and C. coli sequences and 95 to 98% similarity to sequences of other thermophilic Campylobacter species, such as C. lari and C. upsaliensis. The presence of C. coli DNA was detected by specific PCR in the samples from chicks obtained from a commercial hatchery; however, no Campylobacter was detected by culturing. In order to determine whether the same strains of bacteria were present in multiple levels of the integrator, we cultured Campylobacter sp. from a flock of broiler breeders and their 6-week-old progeny that resided on a commercial broiler farm. The broiler breeders had been given fluoroquinolone antibiotics, and we sought to determine whether the same fluoroquinolone-resistant strain was present in their progeny. The isolates were typed by pulsed-field gel electrophoresis, which confirmed that the parental and progeny flocks contained the same strain of fluoroquinolone-resistant C. coli. These data indicate that resistant C. coli can be present in multiple levels of an integrated poultry system and demonstrated that molecular techniques or more sensitive culture methods may be necessary to detect early colonization by Campylobacter in broiler chicks.
在对肉鸡肠道细菌群落进行特征分析时，我们在3日龄商品肉鸡雏鸡的回肠中检测到了ε-变形菌纲细菌的DNA（J. Lu、U. Idris、B. Harmon、C. Hofacre、J. J. Maurer和M. D. Lee，《应用与环境微生物学》69:6816 - 6824，2003年）。这些序列与空肠弯曲菌和结肠弯曲菌的序列具有高度相似性，表明鸡在非常小的年龄就能携带弯曲菌。通过PCR在从3至49日龄雏鸡回肠采集的所有样本中检测到了弯曲菌属；然而，仅在至少21日龄鸡的盲肠内容物中检测到了弯曲菌。为了确定幼雏中弯曲菌DNA的存在是否是由于摄入食物或水中的细菌所致，我们获取了商品肉鸡种蛋，将其在研究设施中孵化直至雏鸡孵出。对孵化当天雏鸡的回肠、盲肠和卵黄内容物进行弯曲菌特异性16S PCR扩增产物的DNA测序显示，在雏鸡消耗食物或水之前就已存在弯曲菌DNA。16S rRNA序列与空肠弯曲菌和结肠弯曲菌序列的相似性为99%，与其他嗜热弯曲菌物种（如海鸥弯曲菌和乌普萨拉弯曲菌）序列的相似性为95%至98%。通过特异性PCR在从商业孵化场获得的雏鸡样本中检测到了结肠弯曲菌DNA；然而，通过培养未检测到弯曲菌。为了确定整合体的多个层面中是否存在相同的细菌菌株，我们从一群肉鸡种鸡及其6周龄后代中培养弯曲菌属，这些鸡饲养在一个商业肉鸡场。肉鸡种鸡曾使用过氟喹诺酮类抗生素，我们试图确定其后代中是否存在相同的耐氟喹诺酮菌株。通过脉冲场凝胶电泳对分离株进行分型，证实亲本和后代鸡群中含有相同的耐氟喹诺酮结肠弯曲菌菌株。这些数据表明，耐氟喹诺酮结肠弯曲菌可存在于一体化家禽系统的多个层面，并证明可能需要分子技术或更灵敏的培养方法来检测肉鸡雏鸡中弯曲菌的早期定植。
