Dhillon A Singh, Shivaprasad H L, Schaberg D, Wier F, Weber S, Bandli D
Avian Health and Food Safety Laboratory, College of Veterinary Medicine, Washington State University, 7613 Pioneer Way E, Puyallup, WA 98371-4919, USA.
Avian Dis. 2006 Mar;50(1):55-8. doi: 10.1637/7411-071405R.1.
Day-old, straight-run broiler chickens were procured from a hatchery located in the Pacific Northwest. The chickens were subdivided individually into nine groups of 20 chickens. The chickens were tagged, housed in isolation chambers on wire, fed commercial broiler feed, and given water ad libitum. Three isolates of Campylobacter jejuni of poultry origin and one of human origin were tested in this study. Various C. jejuni cultures were inoculated into 9-day-old chickens by crop gavage. Four groups of 20 chickens were inoculated at a dose level of 0.5 ml of 1 x 10(2) colony-forming units (CFU)/ml. The other four groups were inoculated with 0.5 ml of 1 X 10(4) CFU/ml. One group of 20 chickens was kept as an uninoculated control group. Four randomly selected chickens from each of the inoculated and uninoculated groups were necropsied at 5, 12, and 19 days postinoculation (DPI). The C. jejuni was cultured and enumerated from a composite of the upper and midintestine and the cecum. Body weights of all chicken groups at 7 days of age and at 5, 12, and 19 DPI were measured and statistically analyzed. No significant differences were present in the mean body weights (MBWs) of 7-day-old, 5 DPI, and 12 DPI male and female broiler chickens inoculated with C. jejuni at both dose levels compared with uninoculated controls. Differences in MBWs of the male and female broilers at 19 DPI were observed in some of the groups. Results of the C. jejuni culture enumeration mean (CEM) of composite intestine samples at 5 DPI from all inoculated chicken groups, irrespective of the dose level, ranged from (2.5 +/- 5.0) x 10(2) to (2.8 +/- 4.8) x 10(5) CFU/g (mean +/- SD). Results of cecum C. jejuni CEM at 5 DPI inoculated at both dose levels ranged from (2.5 +/- 5.0) x 10(6) to (1 +/- 0.0) x 10(7) CFU/g in all treatment groups irrespective of the dose level. CEM results from the composite intestine samples at 12 and 19 DPI increased by 1 log unit, or sometimes more. Results of cecum C. jejuni CEM at 5 DPI inoculated at both dose levels ranged from (2.5 +/- 5.0) x 10(6) to (1 +/- 0.0) x 10(7) CFU/g in all treatment groups irrespective of the dose level. Increases of 2-5 log units in C. jejuni CEM was present in chicken groups inoculated with 1 X 10(2) CFU of C. jejuni, and a 2- to 3-log increase was present in groups inoculated with a higher dose level of C. jejuni at 12 DPI. The results of C. jejuni CEM from cecal samples at 19 DPI were similar to chicken groups at 12 DPI. Campylobacterjejuni was not isolated from the uninoculated control chickens at 5, 12, and 19 DPI. Clinical signs of illness or gross pathologic lesions were not present in any of the chicken groups during this study. No lesions were present on histopathologic evaluations in C. jejuni-inoculated chickens or uninoculated control chickens.
一日龄的未分性别的肉鸡购自太平洋西北部的一家孵化场。这些鸡被单独分成9组，每组20只。鸡被标记后，饲养在铁丝网上的隔离室中，喂食商业肉鸡饲料，并随意供水。本研究测试了三株家禽源空肠弯曲菌分离株和一株人源分离株。通过嗉囊灌喂将各种空肠弯曲菌培养物接种到9日龄的鸡中。四组每组20只鸡以0.5毫升1×10²菌落形成单位（CFU）/毫升的剂量水平接种。另外四组接种0.5毫升1×10⁴CFU/毫升。一组20只鸡作为未接种的对照组。在接种后5天、12天和19天（DPI），从接种组和未接种组中每组随机选取4只鸡进行剖检。从十二指肠上段、中段和盲肠的混合样本中培养并计数空肠弯曲菌。测量并统计分析了所有鸡组在7日龄以及接种后5天、12天和19天的体重。与未接种对照组相比，在两个剂量水平下接种空肠弯曲菌的7日龄、接种后5天和12天的雄性和雌性肉鸡的平均体重（MBW）没有显著差异。在19 DPI时，在一些组中观察到雄性和雌性肉鸡的MBW存在差异。所有接种鸡组在5 DPI时，无论剂量水平如何，混合肠样本的空肠弯曲菌培养计数平均值（CEM）范围为（2.5±5.0）×10²至（2.8±4.8）×10⁵CFU/克（平均值±标准差）。在两个剂量水平下接种的所有处理组中，5 DPI时盲肠空肠弯曲菌CEM范围为（2.5±5.0）×10⁶至（1±0.0）×10⁷CFU/克，无论剂量水平如何。在12 DPI和19 DPI时，混合肠样本的CEM结果增加了1个对数单位，有时更多。在两个剂量水平下接种的所有处理组中，5 DPI时盲肠空肠弯曲菌CEM范围为（2.5±5.0）×10⁶至（1±0.0）×10⁷CFU/克，无论剂量水平如何。接种1×10²CFU空肠弯曲菌的鸡组中，空肠弯曲菌CEM增加了2 - 5个对数单位，在12 DPI时接种较高剂量空肠弯曲菌的组中增加了2至3个对数。19 DPI时盲肠样本的空肠弯曲菌CEM结果与12 DPI时的鸡组相似。在5 DPI、12 DPI和19 DPI时，未接种的对照鸡中未分离到空肠弯曲菌。在本研究期间，任何鸡组均未出现疾病的临床症状或大体病理病变。在空肠弯曲菌接种鸡或未接种对照鸡的组织病理学评估中均未发现病变。
