Department of Veterinary Pathology, Federal University of Agriculture, Abeokuta, Nigeria.
Department of Veterinary Pathology, Ahmadu Bello University, Zaria, Nigeria.
Acta Trop. 2019 Dec;200:105123. doi: 10.1016/j.actatropica.2019.105123. Epub 2019 Aug 8.
Salmonella Zega isolated from natural outbreaks that were characterized by high mortality in poultry farms in three Southwestern States of Nigeria was used to inoculate two week-old chicks through different routes in order to determine and compare the clinical signs, pathological and immunohistochemical changes in each route of infection. The birds were divided into 4 groups of 25 each as groups A (orally inoculated), B (intraperitoneally inoculated), C (inoculated per cloaca) and D (uninoculated control). All the birds were inoculated with 0.2 ml of 1 × 10 cfu of the bacteria. Clinical signs were observed and recorded according to the route of infection, and with the days post-infection from day 0 till day 10 post-infection. Two birds from each group were sacrificed every 24 h and examined for gross lesions, which were described and scored according to the route of infection and days post-infection. Samples of visceral organs were collected for bacteriology, histopathology and immunohistochemistry. Clinical signs in chicks infected orally and intraperitoneally were weakness, anoraexia lethargy, somnolescence, yellowish diarrhoea observed from 4 days till day 10 post infections. Mild sign of weakness was observed in chickes infected per cloaca, from day 3 to 7. The gross lesions were congestion, oedema and enlargement and necrosis in visceral organs from day 4 to 10 post infection in orally and intraperitoneally infected chicks, but mild vascular changes were observed in chicks infected per cloaca, except in the caecum were lesions of necrosis and infiltration of inflammatory cells were moderate to severe. Microscopic lesions were necrosis of host cells and infiltration by lymphocytes, heterophils and macrophages in multiple organs observed from day 4 to 10 post infection in orally and intraperitoneally infected chicks. Immunoreactions were observed in all the visceral organs examined. Clinical signs, pathological and immunohistochemical findings were mild in chicks infected per cloaca, except caecal lesions. Salmonella Zega isolated from an outbreak in poultry farms in Abeokuta, Nigeria was highly pathogenic in chicken and produced similar findings in oral and intraperitoneal infections; while per cloacal infection showed a localized infection of the caecum.
从尼日利亚西南部三个州的家禽养殖场自然爆发中分离出的肠炎沙门氏菌 Zega 被用于通过不同途径接种两周大的小鸡，以确定和比较每种感染途径的临床症状、病理和免疫组织化学变化。将这些鸟类分为 4 组，每组 25 只，分别为 A 组（口服接种）、B 组（腹腔内接种）、C 组（经肛门接种）和 D 组（未接种对照）。所有鸟类均接种 0.2ml 浓度为 1×10cfu 的细菌。根据感染途径和感染后第 0 天至第 10 天的天数观察和记录临床症状。每组每 24 小时牺牲 2 只鸡，并根据感染途径和感染后天数描述和评分进行大体病变检查。收集内脏器官样本进行细菌学、组织病理学和免疫组织化学检查。口服和腹腔内感染的雏鸡出现虚弱、厌食、昏睡、黄白色腹泻，从感染后第 4 天持续到第 10 天。经肛门感染的雏鸡从第 3 天到第 7 天出现轻微虚弱迹象。口服和腹腔内感染的雏鸡从感染后第 4 天到第 10 天，内脏器官出现充血、水肿和肿大以及坏死，但经肛门感染的雏鸡仅观察到轻度血管变化，除盲肠外，坏死和炎症细胞浸润病变为中度至重度。感染后第 4 天至第 10 天，在口服和腹腔内感染的雏鸡的多个器官中观察到宿主细胞坏死和淋巴细胞、异嗜细胞和巨噬细胞浸润的微观病变。在检查的所有内脏器官中均观察到免疫反应。经肛门感染的雏鸡除盲肠病变外，临床症状、病理和免疫组织化学发现均较轻。从尼日利亚阿贝奥库塔家禽养殖场爆发中分离出的肠炎沙门氏菌 Zega 在鸡中具有高度致病性，并在口服和腹腔内感染中产生类似的发现；而经肛门感染则显示盲肠的局部感染。
