小鼠由肺炎克雷伯氏菌引发疫病的报告

１９９７年２月，山医实验动物中心的二级ＢＡＬＢ／Ｃ小鼠２０只由二级饲育室转到一级动物饲育室，转移后的１个月中，小鼠出现零星死亡，存活小鼠出现呼吸道症状，共发病１２只，死亡７只，经临诊和实验室检查，确诊为肺炎克雷伯氏菌感染。１症状和病变症状病鼠食欲下降...     

鼠痘病毒检测方法的进展

鼠痘是由鼠痘病毒引起的实验小鼠的一种烈性传染病。本病多呈暴发性流行 ,致死率较高 ,常造成全群淘汰 ,危害极大。临床表现以四肢、尾和头部肿胀、溃烂、坏死甚至脚趾脱落为特征 ,故又称脱脚病。鼠痘病毒的感染一般分为急性感染、慢性感染、潜伏感染。急性感染表现为健康小鼠在一出现症状的几小时内就死亡 ,不能检测到抗体 ,剖检有广泛的肝、脾坏死灶。慢性感染表现为鼠群中有散在的小鼠死亡 ,临床症状为脚、尾、鼻端及耳下有溃疡性病灶。剖检有肝脾肿大、白色斑点状坏死灶、淋巴结肿大 ,肾有充血灶和坏死灶。此时抗体已产生 ,能检测到高滴…     

江西省部分单位实验小鼠鼠痘病毒感染的调查

采用敏感性和特异性较好的酶免疫试验（ＥＩＡ）对江西省一些饲养单位在普通环境下饲养的４个品系２３２只小鼠进行了鼠痘病毒抗体检查。结果发现阳性标本３３份，阳性率为１４．２％。其中昆明小鼠的阳性率为１８．１％（３３／１８２），其它３个品系未检出。阳性感染鼠群似呈地区性分布，吉安地区未发现。     

猪链球菌2型、7型及9型小鼠感染模型的初步建立

本实验为了研究猪链球菌2型(SS2)、猪链球菌7型(SS7)及猪链球菌9型(SS9)菌株对BALB/c小鼠的致病性,探究BALB/c小鼠作为猪链球菌动物感染模型的可行性以及作为后续实验的依据的可靠性。本研究通过腹腔注射猪链球菌感染BALB/c小鼠,对死亡小鼠进行无菌解剖分离菌株并培养,对培养的菌株进行革兰氏染色法和PCR鉴定;同时利用荧光定量的方法检测各个脏器细菌的载量和组织切片HE染色观察脏器的病理变化。实验结果显示：攻毒的小鼠出现典型的临床症状并死亡,经过实验验证后确定小鼠是由于感染猪链球菌而致病、致死;测定SS2、SS7及SS9的LD₅₀分别为3.7×10⁷、4.1×10⁷、7.9×10⁷ CFU/mL。因此BALB/c小鼠对猪链球菌易感,可以作为实验室研究猪链球菌良好的实验动物。     

猪葡萄球菌感染裸鼠及BALB/c小鼠模型的研究

用一株本室分离鉴定能够引起猪渗出性皮炎的猪葡萄球菌(S.hyicus GZ1)经肌肉注射裸鼠和BALB/C小鼠,意图研究裸鼠和BALB/C小鼠对猪葡萄球菌的易感性及猪葡萄球菌对裸鼠和BALB/C小鼠的致病性。结果表明裸鼠和BALB/C小鼠均可被感染,并表现各自的临床症状。裸鼠在感染后2到3d背部和面部皮肤开始出现大量小的红色囊泡,4到5d后部分囊泡消失,部分形成结痂。一些裸鼠眼睛还会有较多脓性分泌物渗出,感染两周后相继死亡。BALB/C小鼠感染该菌后多表现急性临床症状,感染后2到3d就相继死亡,因此表现不出明显的眼观病变,只有很少一部分小鼠皮肤上会出现炎性渗出,导致该处皮肤脱落。研究表明:BALB/C小鼠比裸鼠对猪葡萄球菌更易感,裸鼠感染后产生清晰可见的临床症状,而BALB/C小鼠在感染后往往还来不及表现明显的临床症状就相继死亡。可见,猪葡萄球菌不仅对猪有致病性,对裸鼠和BALB/C小鼠也都表现出不同程度的致病性。     

近交系BALB/C小鼠感染附红细胞体

<正> 在制备单克隆抗体的工作中,规定采用近交系BALB/C小鼠,以获取淋巴细胞和腹水。自1991年以来,我室在实验过程中发现部分小鼠出现产仔率下降、产后死亡等现象。据1991年繁育资料统计:产仔鼠43窝。共计237只,平均产仔数5.5只;死亡84只,其中整窝死亡9窝计52只。成年鼠出现被毛脱落,皮肤粗糙、精神不振、食欲下降、活动力降     

国内外实验小鼠8种病毒检出情况分析

良好的实验动物质量是保证实验结果准确性的前提保障。感染疫病的实验动物,会对实验结果造成干扰,严重的可导致动物大量死亡,影响实验进度。有的疫病甚至可以感染实验人员。本研究对从美国、德国、日本进口的170批次不同品系的实验小鼠共计340只,来自于国内各科研单位119批次不同品系的实验小鼠共计232只,进行淋巴细胞性脉络丛脑膜炎病毒、汉坦病毒、鼠痘病毒、仙台病毒、小鼠肝炎病毒、小鼠细小病毒、小鼠微小病毒和小鼠脑脊髓炎病毒检测。结果表明,进口小鼠8项疫病均无检出,而国内小鼠肝炎病毒、小鼠脑脊髓炎病毒和仙台病毒检出率较高,小鼠微小病毒和小鼠细小病毒也有检出,检出率分别为54.6%、26.9%、9.2%、0.8%和0.8%。     

鼠痘病毒的分离鉴定及检测方法研究

实验小鼠是科学研究中最常用、最经济的一类实验动物。鼠痘(Mousepox)即小鼠脱脚病(Ectromelia),则是实验小鼠的一种高度接触性传染病。本病在世界各地的实验鼠群广泛流行,死亡率达95％。1992年,国家科委下达的实验动物微生物检测标准中,明确规定实验用鼠必须排除鼠痘病毒感染。为促进实验动物病毒病的研究,为使用于科研工作的实验动物早日达到标准化,我们对鼠痘病毒的病原形态、理化特性以     

应用BALB／c小鼠评价口蹄疫灭活疫苗的免疫效力

用不同剂量的口蹄疫灭活疫苗免疫3组雌性BALB／c小鼠，同时设空白对照组，每组8只。免疫后每7d采血一次，用液相阻断ELISA（LPB-ELISA）检测血清抗体水平；第28d用800LD50同源强毒攻击，攻毒后36h，每组随机选取3只BALB／c小鼠，采全血，分别用每只BALg／c小鼠全血注射12只乳鼠，每组共注射36只乳鼠，以乳鼠试验判定BALB／c小鼠的病毒血症和攻毒保护情况。结果表明，免疫组BALB／c小鼠均可产生特异性抗体，保护率分别为75．0％、63．9％、36．1％；对照组小鼠血清抗体为阴性。提示，BALB／c小鼠可以用来评价口蹄疫灭活疫苗的免疫效力。     

猪圆环病毒2型感染裸鼠及BALB/c小鼠的研究

用猪圆环病毒2型（PCV2）经腹腔注射BALB/c小鼠及裸鼠各15只,每隔2周1次,共感染3次.BALB/c小鼠初次、再次感染后均未出现明显的临床症状,仅有2只小鼠出现病理变化;从血清中可检测到PCV2核酸及其ORF2抗体;同时淋巴细胞增殖反应显著增强,NK和CTL细胞杀伤率显著升高;CD4^＋、CD8^＋、CD3^＋T淋巴细胞及CD19^＋B淋巴细胞数量显著减少.裸鼠也未出现明显的临床症状,从血清中可检测到PCV2核酸,但未检测到PCV2 ORF2抗体;除NK细胞杀伤率显著升高外,其余免疫学指标无显著改变.结果表明,BALB/c小鼠比裸鼠对PCV2易感,各项免疫学指标变化与PCV2感染猪一致,但不表现临床症状,仅个别BALB/c小鼠出现病理变化,说明BALB/c小鼠对PCV2不如猪易感.     

Effects of social isolation,re‐socialization and age on cognitive and aggressive behaviors of Kunming mice and BALB/c mice

Both Kunming (KM) mice and BALB/c mice have been widely used as rodent models to investigate stress‐associated mental diseases. However, little is known about the different behaviors of KM mice and BALB/c mice after social isolation, particularly cognitive and aggressive behaviors. In this study, the behaviors of KM and BALB/c mice isolated for 2, 4 and 8 weeks and age‐matched controls were evaluated using object recognition, object location and resident‐intruder tests. The recovery of behavioral deficits by re‐socialization was also examined for the isolated mice in adolescence. Our study showed that isolation for 2, 4 and 8 weeks led to cognitive deficits and increased aggressiveness for both KM and BALB/c mice. An important finding is that re‐socialization could completely recover spatial/non‐spatial cognitive deficits resulted from social isolation for both KM and BALB/c mice. In addition, age only impacted aggressiveness of KM mice. Moreover, isolation duration showed different impacts on cognitive and aggressive behaviors for both KM and BALB/c mice. Furthermore, BALB/c mice showed weak spatial/non‐spatial memory and low aggressiveness when they were at the same age and isolation duration, compared to KM mice. In conclusion, KM mice and BALB/c mice behaved characteristically under physiology and isolation conditions.     

牛源犬新孢子虫孕鼠感染模型的建立

为建立牛源犬新孢子虫孕鼠感染模型,深入研究牛源犬新孢子虫对孕鼠的致病作用,本试验以雌性BALB/c小鼠为试验动物,分离Vero细胞中培养的牛源犬新孢子虫速殖子,分不同剂量组腹腔接种雌性BALB/c小鼠后,与雄性BALB/c小鼠合笼,每天观察小鼠临床症状和发病情况,观察主要脏器组织的病理变化,应用PCR方法检测孕鼠脑、肝脏、脾脏等脏器组织及胎盘中犬新孢子虫Nc5基因,并测定孕鼠胎盘湿重和胎盘系数。结果显示,感染模型小鼠的最佳攻虫剂量为10⁵个虫体;感染犬新孢子虫孕鼠先后出现精神不振、共济失调等临床症状,并有不同程度死亡;病理学观察模型小鼠脑、肝脏、脾脏等脏器组织出现充血、出血、肿大等病理变化;在模型小鼠脑、肝脏、脾脏等脏器组织及胎盘中检测到犬新孢子虫Nc5基因;随攻虫天数的增加,模型小鼠胎盘重量和胎鼠重量均不断增加,胎盘系数逐步降低,在第12、14、16天时,模型组与对照组相比,胎盘重量和胎盘系数均差异显著（P < 0.05）。本试验成功建立了牛源犬新孢子虫孕鼠感染模型,为犬新孢子虫致病机制研究奠定了基础。     

Comparison of gastritis and gastric epithelial proliferation in Helicobacter heilmannii-infected nude and BALB/c mice

Gastric mucosal hypertrophy/nodular hyperplasia occurs as a consequence of Helicobacter infection in mice and humans. The pathogenesis of this hyperplastic response is not understood. To determine the role of host cellular immunity in gastric mucosal hypertrophy/hyperplasia, 6-8-week-old female euthymic BALB/c (n = 30) or NIH athymic nude (n = 40) mice were inoculated with H. heilmannii. Equal numbers of uninoculated mice of each strain served as controls. Mice from each group were euthanatized at 0.5, 6, 12, and 18 months postinoculation (PI). Lymphoplasmacytic gastritis and lymphoid follicle development were less severe in nude mice than in euthymic mice at <6 months PI. The prevalence of gastritis at 0.5, 6, 12, and 18 months PI was 0%, 17%, 67%, and 88%, respectively, in infected nude mice and 33%, 83%, 71%, and 100%, respectively, in infected BALB/c mice. CD4+ T cells in infected nude mice were evident at > or =6 months PI but were less numerous than in infected BALB/c mice at comparable time intervals. However, numbers of CD4+ T cells increased substantially throughout the experiment in infected BALB/c mice. The prevalence of nodular mucosal hyperplasia at 0.5, 6, 12, and 18 months PI was 0%, 0%, 33%, and 20%, respectively, in infected nude mice and 0%, 33%, 80%, and 80%, respectively, in infected BALB/c mice. Nodular hyperplasia occurred in association with the appearance of chronic lymphoplasmacytic inflammation and CD4+ T cells at 12 and 18 months PI in nude mice. H. heilmannii-associated gastritis and mucosal remodeling is reduced in immunodeficient mouse strains lacking normal CD4+ T cell numbers as compared with the response in immunocompetent mice. Additionally, CD4 immunocompetence is an integral aspect of the mucosal hypertrophy/nodular hyperplasia in experimental H. heilmannii-associated disease of mice.     

Characterisation of the first Australian isolate of Neospora caninum from cattle

OBJECTIVE: To isolate Neospora caninum from a congenitally infected calf. PROCEDURE: A calf was obtained from a N. caninum infected dam maintained in a dairy herd of Holstein-Friesian cattle located on the south coast of NSW near Nowra. The calf was euthanased and samples collected for serology and pathology. Samples of brain and spinal cord of the calf were homogenised and injected into immunocompromised mice in an attempt to recover protozoa by in vivo culture. Sequential passage of brain homogenate through IFNgammaPKO mice was performed and tissue culture flasks were inoculated with brain homogenate. Parasites were identified by electron microscopy and DNA sequencing. The antigen profile of the isolate was analysed using Western blotting. Pathogenicity was examined in BALB/c mice and transmission of the parasite during pregnancy was examined in Qs mice. RESULTS: The calf was seropositive for N. caninum and histopathological examination of sections of cerebrum identified lesions consistent with a very mild infection with N. caninum. The parasites isolated using tissue culture were identified as N. caninum, based on the sequence of the ribosomal DNA and electron microscopy. The antigen profile of the new isolate was similar to that of the NC-Liverpool isolate, but quite different from that of Toxoplasma gondii. In BALB/c mice inoculated with the new isolate, severe clinical signs developed in only three of ten infected mice, compared with six of ten mice infected with NC-Liverpool. Mild to moderate nonsuppurative encephalitis was observed in BALB/c mice infected with the new isolate, compared with mice infected with NC-Liverpool, that developed severe nonsuppurative encephalitis. Transplacental transmission of the isolate arising from an acute infection during pregnancy occurred in about 87% of pups. CONCLUSION: This is the first isolation of bovine Neospora caninum in Australia. This isolate, called NC-Nowra, appears to be a less virulent form and may prove to be a suitable candidate for vaccine development.     

A pregnant mouse model for bovine Tritrichomonas foetus infection

The economically important effects of Tritrichomonas foetus infection in cattle are abortion and infertility, yet there has not been an animal model to examine the parasite-host interactions during gestation. In this study, 5- and 7- to 8-week-old BALB/cAnNCr, BALB/cJ, and SCID/NCr mice on a BALB/c background were intravaginally infected with T. foetus. All BALB/cAnNCr and BALB/cJ mice, and 89% of SCID/NCr mice sustained infections for 13 weeks, if inoculated before 5 weeks of age. Infection rates were lower in all mouse strains inoculated at 7 weeks of age, although BALB/cAnNCr mice were significantly more susceptible than BALB/cJ or SCID/NCr mice. Vaginal bacterial flora did not account for the variation in mouse-strain susceptibility, although coagulase-negative staphylococci in vaginal flora were associated with failure of T. foetus to infect. As with infected cattle, T. foetus-specific vaginal immunoglobulin (Ig) G and IgA antibodies were elevated after infection. The number and viability of day-10 fetuses were reduced in mice infected at 5 weeks of age and bred 12 weeks after infection. Lesions in pregnant and nonpregnant infected mice, including suppurative and eosinophilic vaginitis; cervicitis; endometritis with distension of the uterine lumen; endometrial ulceration; and glandular ectasia, with neutrophils in the glandular lumen and loss of gland epithelium, were similar to those in cattle. The decidua and placenta were multifocally necrotic. Immunohistochemistry demonstrated trichomonads in vaginal folds and uterine glands, and adjacent to fetal tissues. In summary, experimentally infected BALB/cAnNCr mice showed many pathologic similarities to cattle and may serve as a model to study host-trichomonad interactions.     

Interleukin-6 is produced during both murine and avian Eimeria infections

The production of interleukin-6 (IL-6) during Eimeria infection was investigated in an attempt to gain a better understanding of the role of this multi-functional cytokine in resistance to this parasite. IL-6 production was measured in both chickens, in which the disease is of economic importance, and the better-characterised murine model system.Systemic and local IL-6 production in mice during E. vermiformis infection was investigated, in the relatively resistant BALB/c strain, and the relatively susceptible C57 BL/6 strain, using a murine IL-6 ELISA and the 7TD1 assay. Enhanced systemic production of IL-6 in serum was seen in infected BALB/c mice when compared to C57 BL/6 mice. This difference was also reflected in the draining lymph node of the site of infection, assessed by testing supernatants from stimulated mesenteric lymph node cells taken from infected mice at different times post-infection.Production of chicken IL-6-like factor activity was investigated using a murine IL-6 7TD1 bioassay. The presence of substantial quantities of IL-6-like factor activity was detected in serum taken from some chickens infected with E. tenella during the course of primary infection and, in a separate experiment, during the first few hours post-infection, a time when the pro-inflammatory capacity of IL-6 would influence the developing immune response. These results suggest that IL-6 is also important in the induction of immune effector responses to Eimeria infections in the chicken.     

Immune responses of immunocompetent and immunocompromised mice experimentally infected with Bartonella henselae

The aim of this study is to understand host immune responses in immunocompetent and immunocompromised mice against Bartonella henselae infection. BALB/c and nude (BALB/c nu/nu) mice were inoculated intraperitoneally with 10(8) colony forming units of B. henselae (Houston-1 strain). Blood, brain, liver, spleen, kidney and bone marrow samples were collected 0, 3, 7, 14, 21 and 28 days after infection and submitted to bacteriological, serological and genetical examinations. B. henselae was isolated only from the liver 3 days after infection. DNA of the inoculums was detected by polymerase chain reaction from blood, liver, and spleen samples collected from BALB/c and blood from nude mice 3 and 7 days after infection. No bacterial DNA was detected from both BALB/c and nude mice thereafter during 4 weeks observation periods. These results indicate that the T-cell may not participate in the effective elimination of the organisms from mice. In addition, western blot analysis revealed that the antigens of 27.3- and 31.5-kDa reacted with IgM antibodies from the blood of BALB/c and nude mice after 3 days of infection, suggesting that these antigens were recognized by thymus-independent mechanism. Furthermore the antigens were detected from the culture-supernatants of B. henselae, indicating that these antigens were secreted from the organisms.     

Duration of strain 2308 infection and immunogenicity of Brucella abortus lipopolysaccharide in five strains of mice

A study was conducted to compare immunogenicity of a Brucella abortus lipopolysaccharide (LPS) and the duration of infection in 5 strains of mice. Mice of strains CBA/NJ, BALB/c, CD-1, C3H/HeN, and C3H/HeJ were allotted into 2 large groups (vaccinated with proteinase K-treated LPS or nonvaccinated) and 6 subgroups based on the intervals between challenge exposure to B abortus strain 2308 and the week the response data were obtained. Criteria used in comparing responses between the various strains of mice as well as between vaccinated and nonvaccinated mice were splenomegaly, colony-forming units (CFU) from spleens, and antibody titers. Responses were evaluated at 1, 2, 3, 5, 8, and 12 weeks after challenge exposure. Results indicated that all strains of mice became infected and maintained infection throughout the 12-week period, the percentages of mice infected were significantly (P less than 0.05) less in vaccinated mice for the first 5 weeks after challenge exposure, and there were no direct correlations between increased immunoglobulins (IgM and IgG titers) and reduction in CFU. Vaccinated mice of strains BALB/c, CD-1, C3H/HeN, and C3H/HeJ had increased titers when challenge exposed and also had significantly (P less than 0.05) smaller spleens and lower CFU. Vaccinated CBA/NJ mice did not have marked antibody titers. The overall results indicated that vaccination with LPS offers some initial protection against B abortus strain 2308 infection, but this protection disappears gradually and in various degrees in the 5 strains of mice studied.     

猪伪狂犬病病毒的分离和鉴定

从病猪脑部分离到1株病毒.该病毒接种Balb/c小鼠出现神经症状,病死率为60% ,接种PK-15细胞出现拉网病变.伪狂犬病阳性血清能特异性的中和该分离毒.根据基因库(GenBank)的PRV gE基因设计的引物能扩增出特异性片段,证实该病毒为伪狂犬病病毒.     

Immunization with recombinant surface antigens p26 with Freund's adjuvants against Babesia rodhaini infection

The surface proteins of Babesia rodhaini have previously been shown to induce a high degree of protective immunity. In the present study, one of those proteins, B. rodhaini antigen p26 was expressed in Escherichia coli and in insect cells infected with a recombinant baculovirus. These proteins were recognized by immune serum from a drug-cured BALB/c mouse. While BALB/c mice immunized with both recombinant antigens and Freund's adjuvants showed 40-100% survival rate against challenge infection with B. rodhaini, saponin failed to induce protection, although significant levels of B. rodhaini-specific antibodies were produced in both immunized mice (1:1,000-2,000 by indirect immunofluorescent antibody test). The immunization of IFN-gamma-deficient mice with the recombinant proteins was not protective against B. rodhaini infection, indicating that IFN-gamma is one of the important factors for the survival against lethal B. rodhaini infection.