Abstract:
Streptococcus gallolyticus (SG) is a Gram-positive cocci found as commensal gut flora in animals and humans. SG has emerged as a cause of disease in young poults between 1 and 3 wk of age. SG is associated with septicemia resulting in acute mortality with no premonitory signs in turkeys. Three SG isolates were obtained from clinical field cases of acute septicemia of commercial turkeys and used in three independent experiments. In Experiment 1, embryos were inoculated 25 d of embryogenesis with varying concentrations of SG1, SG2, or SG3. In Experiment 2, day of hatch, poults were inoculated with varying concentrations using different routes of administration of SG1, SG2, or SG3. In Experiment 3, day of hatch, poults were inoculated with only isolate SG1 using different paths. Poults were randomly selected for necropsy on d 8 and d 15 and sampled to collect spleen, heart, and liver for SG on d 21, the remaining poults were necropsied and cultured. Samples were plated on Columbia nalidixic acid and colistin agar (CNA) (40°C, 18-24 h). Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) confirmed suspect colonies. Data were analyzed using the chi-square test of independence, testing all possible combinations to determine significance (P < 0.05). Weight data were subjected to ANOVA using JMP with significance (P < 0.05). No differences were found in BW or BWG on d 0, 8, 15, or 22. Splenomegaly, focal heart necrosis, and pericarditis were observed in all groups in experiments 1 through 3. In Experiment 3, only airsacculitis was observed in a negative control in separate isolation (P > 0.05). On d 21 of Experiment 3, increased (P < 0.05) recovery of SG from spleens were observed in co-housed negative controls, as well as poults challenged by oral gavage (P > 0.05 for d 7 and d 14). These results confirm numerous previous studies indicating that SG subsp. pasteurianus is a primary infectious microorganism that causes septicemia in young poults.
摘要:
溶胆链球菌(SG)是在动物和人类中作为共生肠道菌群发现的革兰氏阳性球菌。SG已成为1至3周龄的幼鸟的疾病原因。SG与败血症相关,导致火鸡急性死亡,没有先兆迹象。从商业火鸡急性败血症的临床现场病例中获得了三个SG分离物,并用于三个独立的实验。在实验1中,用不同浓度的SG1,SG2或SG3接种胚胎25d。在实验2,孵化日,使用SG1、SG2或SG3的不同给药途径,用不同浓度接种小孢子。在实验3,孵化日,使用不同的路径仅用分离物SG1接种小孢子。在第8天和第15天随机选择尸体进行尸检,并取样收集脾脏,心,第21天,肝脏为SG,剩余的细菌进行尸检和培养。将样品铺在Columbia萘啶酸和粘菌素琼脂(CNA)上(40°C,18-24小时)。基质辅助激光解吸/电离飞行时间质谱(MALDI-TOFMS)证实了可疑菌落。数据采用独立性卡方检验进行分析,测试所有可能的组合以确定显著性(P<0.05)。使用JMP对体重数据进行ANOVA,具有显著性(P<0.05)。在第0、8、15或22天,BW或BWG没有发现差异。脾肿大,局灶性心脏坏死,在实验1至3中,所有组都观察到心包炎。在实验3中,在单独隔离的阴性对照中仅观察到气囊炎(P>0.05)。在实验3的第21天,在共同饲养的阴性对照中观察到脾脏中SG的恢复增加(P<0.05)。以及经口灌胃攻击的家禽(第7天和第14天P>0.05)。这些结果证实了许多先前的研究,表明SG亚种。巴氏菌是一种主要的感染性微生物,在幼小的家禽中引起败血症。