土曲霉对小鼠肝氧化损伤及铁死亡相关指标的影响

旨在探究土曲霉引起小鼠肝损伤的机制。将20只昆明小鼠随机分为对照组和试验组,试验组腹腔注射0.3 mL （5×10⁷ CFU·mL^-1）土曲霉MSF2菌株孢子悬液,试验周期为7 d。采集小鼠肝用丙二醛（MDA）、谷胱甘肽（GSH）、谷胱甘肽过氧化酶（GSH-PX）、总超氧化物歧化酶（T-SOD）试剂盒检测肝氧化损伤相关指标;铁检测试剂盒检测肝铁离子含量;制备肝石蜡切片,进行HE染色和普鲁士蓝染色,观察其病理变化及铁沉积;透射电镜观察肝细胞超微结构;qPCR检测肝铁死亡相关基因mRNA相对转录水平。结果表明：土曲霉可引起试验组小鼠肝MDA含量极显著升高（P<0.01）,GSH含量、GSH-PX活力和T-SOD活力极显著降低（P<0.01）,铁离子含量极显著升高（P<0.01）,肝细胞肿胀、坏死,炎性细胞浸润,肝细胞中可见蓝染的铁离子沉积,肝细胞线粒体萎缩、嵴减少和膜密度增加,转铁蛋白1（TFR1）、二价金属离子转运体1（DMT1）、铁蛋白重链1（FTH1）和电压依赖性阴离子通道3（VDAC3）基因mRNA相对转录水平显著升高（P<0.05）,过氧化物酶4（GPX4）和胱氨酸/谷氨酸转运受体11（SLC7A11）基因mRNA相对转录水平显著降低（P<0.05）。综上表明,土曲霉MSF2菌株致小鼠肝损伤的机制是铁死亡,为深入研究土曲霉的致病机制提供参考资料。     

The pathology of natural and experimentally induced Campylobacter jejuni abortion in sheep

We describe here the gross and microscopic lesions in 18 experimentally induced and 120 natural Campylobacter abortions. In natural Campylobacter abortions, gross lesions were reported infrequently; placentitis was recorded in 6% and hepatic lesions in 4% of our field cases. Placentitis was the microscopic lesion identified most consistently in natural abortions (93%) and was often observed in association with abundant bacterial colonies in chorionic villi (54%) and less often with placental vasculitis (13%). In natural abortions, suppurative fetal pneumonia (48%), necrosuppurative hepatitis (16%), and purulent meningitis (7%) were also observed. The better-preserved specimens from experimentally induced abortions were utilized to define placental changes more precisely. Placentitis was identified in all 18 experimentally induced abortions and was observed most consistently in the chorionic villus stroma (100%), often accompanied by suppurative surface exudate (89%). An inflammatory infiltrate was less commonly identified in the cotyledonary hilus (39%) and intercotyledonary placenta (22%). Bacteria were visualized in H&E-stained sections in 89% of placentas from experimentally infected ewes, primarily as well-demarcated bacterial colonies within subtrophoblastic, sinusoidal capillaries (89%), in the cotyledonary villus stroma (89%), and within the cytoplasm of trophoblasts (22%). Transmission electron microscopy and immunohistochemistry confirmed that the vast majority of the well-demarcated bacterial colonies characteristic of Campylobacter abortion were within subtrophoblastic sinusoidal capillaries. The most characteristic microscopic lesions identified in cases of Campylobacter abortion in sheep were placentitis with placental bacterial colonies, placental vasculitis, and fetal pneumonia.     

Equine amnionitis and fetal loss: mare abortion following experimental exposure to Processionary caterpillars (Ochrogaster lunifer)

Reasons for performing study: In Australia, there have been recent reports of unusual abortions in mid‐ to late‐gestation mares. These were clinically distinct from other recognised causes of pregnancy loss and the term ‘equine amnionitis and fetal loss’ (EAFL) was adopted to describe this syndrome. Initial investigations concluded that possible causal factors included the presence on affected stud farms of Processionary caterpillars (Ochrogaster lunifer). Objectives: To determine if exposure of pregnant mares to Processionary caterpillars or their shed exoskeletons can induce EAFL. Methods: Processionary caterpillars and their shed exoskeletons were collected and stored frozen. Mid‐gestation mares were dosed with a slurry of caterpillars or shed exoskeleton by nasogastric intubation. Their clinical responses and times to abortion were recorded. All aborted fetuses were autopsied and samples taken for bacteriological and virological culture and histopathology. Results: Intubating mares in mid‐pregnancy with preparations of either whole Processionary caterpillars or shed caterpillar exoskeletons induced abortion with few impending clinical signs. The gross pathological and bacteriological findings of the aborted fetuses were similar to those observed in field cases of EAFL. Potential relevance: Possible exposure to Processionary caterpillars should be considered when examining cases of fetal loss in the mare. The present results provide a starting point to further explore the aetiology and pathogenesis of EAFL.     

Ovine abortion and stillbirth due to purulent placentitis caused by Yersinia pseudotuberculosis

Yersinia pseudotuberculosis was isolated from an aborted placenta and stillborn lamb from a sheep flock having multiple abortions. Given intravenously, it caused elevated body temperatures and purulent placentitis in eight of nine ewes. Two ewes died following infection at 2.5 months of gestation. Two ewes infected at 3.5 months gestation aborted; three infected at four months gave birth to weak, premature, or moribund lambs. One ewe infected at 4.5 months gave birth to a healthy lamb. One lamb which died minutes after birth had focal necrotizing hepatitis, a lesion observed in a stillborn lamb during the original disease outbreak. Y. pseudotuberculosis was reisolated from endometrial, placental, and fetal lesions of experimentally infected animals.     

Aetiology of Bovine Abortion in Argentina

Necropsies were performed on 354 fetuses from dairy and beef herds submitted from 1994 to 2000 to the diagnostic laboratories at Instituto Nacional de Tecnología Agropecuaria, Balcarce, Argentina. Samples from the fetuses were examined for pathogenic organisms and processed for microscopic examination. An aetiological diagnosis was made for 161 (45.5%) of the fetuses. No diagnosis was made for 193 (54.5%) fetuses. Infectious agents were isolated from 122 (34.4%) of the fetuses, bacterial agents being involved in 80 (22.6%) of these. The most common bacterial agents isolated from the fetuses were Brucella abortus in 28 fetuses, Campylobacter fetus in 26 cases, and Escherichia coli in 9 cases. Bovine herpesvirus and bovine viral diarrhoea virus were found in 9 and 6 cases, respectively. Neospora caninum was detected by an immunohistochemical technique in 26 cases (7.3%). Congenital abnormalities, dystocia and mummifications were found in 8, 19 and 11 cases, respectively.     

空间条件对黄曲霉、米曲霉的诱变作用

为提高黄曲霉、米曲霉的蛋白酶活性及血粉发酵效果,将这两株菌的孢子于1988年8月卫星 搭载运行8d,然后对其诱变株的形态学、生理特性及发酵血粉的营养价值进行了观察和测定。结果,诱变 后的菌株生长速度快,孢子成熟早,米曲霉有10个菌落较对照组有明显变化。诱变后,黄曲霉碱性蛋白酶 活性平均提高230%,米曲霉平均提高200%;米曲霉中性蛋白酶活性平均提高223%。     

Swine abortion caused by Candida parapsilosis

In July 2020, a sow in a breeding herd in the Chiba Prefecture, Japan, suffered abortion. A necropsy revealed pale pulmonary foci scattered in the two fetuses. Histologically, multifocal pulmonary necrosis was detected with numerous yeasts. The yeast was positively stained using the periodic acid-Schiff reaction and Grocott’s silver stain. Molecular identification indicated that the yeast was Candida parapsilosis. In conclusion, our results suggested that C. parapsilosis caused multifocal necrotizing pneumonia in the two fetuses. This study is the first report of a swine abortion with C. parapsilosis infection.     

Association and General Notes

In a field disease outbreak, 60 female goats died over a 2–3 week period. Necropsies of seven of these does revealed that six had an acute exudative necrotising broncho-pneumonia, and moderate to high numbers of Pasteurella haemolytica were isolated from their lungs. Caprine herpesvirus, identified as Bovid herpesvirus type 6, was isolated from the lungs of two of these does, including one with pneumonia, and from nasal swabs of in-contact goats. Clinical disease was only observed in does, and deaths began 3 weeks after the introduction of a mob of goat hoggets from another farm.     

Seroprevalence of Neospora caninum infection following an abortion outbreak in a dairy cattle herd

OBJECTIVE: To investigate the seroprevalence of Neospora caninum infection in a commercial dairy cattle herd, 15 months after detection of an abortion outbreak. PROCEDURE: Sera from the whole herd (n = 266) were examined for N caninum antibodies by indirect fluorescent antibody test (IFAT) and immunoblot analysis. Herd records were reviewed to collate serological results with abortion history, proximity to calving, and pedigree data. RESULTS: The seroprevalence of N caninum infection was 24% (63/266) for IFAT titre > or = 160, 29% (78/266) for immunoblot positive (+ve), and 31% (82/266) for IFAT > or = 160 and/or immunoblot +ve; 94% (59/63) of animals with IFAT > or = 160 were immunoblot +ve. The association between seropositivity (IFAT > or = 160 and/or immunoblot +ve) and history of abortion was highly significant (P < 0.001); the seroprevalence was 86% (18/21) in aborting cows, compared with 30% (50/164) in non-aborting animals. The abortion rate for seropositive cows was 26% (18/68) compared with 3% (3/117) for seronegative animals. IFAT titres of infected cows were higher within 2 months of calving than at other times (P < 0.001). The association between seropositivity in dams and daughters was highly significant (P = 0.009). CONCLUSIONS: The abortions were associated with N caninum infection and there was evidence of reactivation of latent infection close to calving and congenital transmission of infection. Immunodominant antigens identified by immunoblots may prove useful for improved diagnostic tests.     

保胎无忧散对小鼠诱导性流产的保胎作用

选择保胎无忧散预处理试验小鼠,观察保胎无忧散对米非司酮(RU486)诱导流产作用的抑制效果.结果显示,使用RU486在孕7d,颈部注射后,试验小鼠的流产率达到了100％;应用中药方剂保胎无忧散能有效对抗RU486诱导的小鼠流产,试验中动物模型的流产率从100％下降到40％;组织学观察发现,RU486诱导流产小鼠子宫内膜出现明显损伤,而在中药方剂组,试验小鼠子宫得到了有效的保护.     

禽源烟曲霉菌和黄曲霉菌的分离鉴定及几种中药抑菌作用研究

【目的】对保定市临床真菌感染病鸭进行菌株分离鉴定,并筛选分离菌株的体外抑菌药物。【方法】通过形态学观察、PCR扩增、测序及动物回归试验对菌株进行鉴定,并采用微量稀释法测定最小抑菌浓度(MIC)及体外药敏试验统计菌落数量和直径来探究石菖蒲、黄柏、决明子、苦参、辣蓼、白头翁和蒲公英对烟曲霉菌(Aspergillus fumigatus)和黄曲霉菌(Aspergillus flavus)的体外抑菌活性。【结果】成功分离到烟曲霉菌和黄曲霉菌。动物回归试验结果显示,雏鸡出现与病鸭相似的症状,剖检可见肝脏长出灰白色结节,且病变组织出现肉芽肿病变,说明2种病原菌均可使雏鸡感染。烟曲霉菌MIC₈₀结果显示,石菖蒲、黄柏、决明子和苦参MIC₈₀分别为8、16、32和64μg/μL,辣蓼、白头翁和蒲公英均为128μg/μL;黄曲霉菌的MIC₈₀结果显示,石菖蒲、决明子和黄柏MIC₈₀分别为8、16和32μg/μL,苦参和辣蓼均为64μg/μL,白头翁和蒲公英均为128μg/μL。体外药敏试验结果显示,在石菖蒲浓度为16...     

牛巴氏杆菌病的诊断及治疗试验

2009年4月及6月间,荣成市某肉牛场8月龄左右的育肥牛先后两次爆发疫病,均发生在新购买牛后不久。在流行病学调查的基础上,对采集的病料进行病原分离鉴定,并对病原进行了药敏试验。结果表明,该牛场发病是由长途运输应激引起,病原分别为多杀性巴氏杆菌和产气巴氏杆菌,此类菌对头孢菌素和土霉素较为敏感,经治疗,该牛场病情得到控制。     

高通量测序技术结合传统方法筛选及鉴定奶酒中曲霉菌

奶酒含有丰富的营养,且具有驱寒活血、开胃消食等保健功效。但由于传统的可培养方法对其微生物全貌的认识具有一定的局限性。因此,本文采用高通量测序技术,对奶酒的真菌生物多样性进行检测。结果表明,酵母菌属(Saccharomyces)和曲霉属(Aspergillus)是奶酒最主要的真菌群落,其中,酵母菌属为第一丰度的真菌,丰度约为62%。第二丰度的真菌为曲霉属,丰度为33%。通过进一步分离并采用16S鉴定出了一株曲霉菌,这可为奶酒发酵剂的开发提供依据。     

Bovine Erythrocyte Haemolysates Enhance Plasminogen Activation by Tissue-Type Plasminogen Activator

Yamada, M., Horiuchi, T., Oribe, T., Yamamoto, S., Sugie, I. and Gentry, P.A., 1997. Bovine erythrocyte haemolysates enhance plasminogen activation by tissue-type plasminogen activator. Veterinary Research Communications, 21 (2), 75-84An active fraction that accelerates plasminogen activation by tissue-type plasminogen activator (t-PA) was purified from a haemolysate of bovine erythrocytes. When the haemolysate was mixed with t-PA, it produced a 2- to 3-fold increase in plasminogen activation as measured by an insoluble fibrinolytic assay system and a soluble amidolytic assay system with the chromogenic substrate S-2251. Zymographic analysis showed that, while the haemolysate increased t-PA activity, it did not alter the electrophoretic characteristics of the t-PA nor did it induce any fibrinolysis in the absence of t-PA or plasminogen. The haemolysate was devoid of plasmin and plasminogen activator activity but was most effective in accelerating plasminogen activation by t-PA in the presence of substrate. Based on the purification characteristics of the active fraction in the haemolysate, it appears to have a molecular weight of less than 10 kDa.