三种处理方式对体外鸡蛔虫卵灭活作用比较试验

取鸡雌性蛔虫子宫内成熟卵,用平皿滤纸培养法置30℃恒温箱中孵化7 d(168 h),每天在显微镜下观察了解虫卵各发育期的形态并照相;另将成熟卵分别通过药物(Ⅰ)、太阳光照(Ⅱ)、粪便堆沤(Ⅲ)处理,洗净后经30℃恒温箱中孵化7 d,显微镜下观察虫卵成活情况。结果表明:虫卵发育各期形态可分为单细胞卵、二个胚泡期卵、四个胚泡期卵、八个胚泡期卵、前桑椹期卵、桑椹期卵、蝌蚪期卵、虫样期卵、感染期卵9种;第Ⅰ组3份样灭活率分别为9.78%、21.72%和98.88%,虫卵随药物作用时间增长,灭活率增高;第Ⅱ组3份样灭活率分别为61.12%、96.47%和97.27%,虫卵随太阳光照时间增长,灭活率增高,光照1 h和2 h的灭活率差异不大;第Ⅲ组3份样灭活率均为100%。虫卵发育停止于八个胚泡虫卵期,后期均为"0"。灭活作用以第Ⅲ组最好,第Ⅱ组次之,第Ⅰ组较差。     

不同驱虫药对伊犁马驱虫效果及血液生理指标的影响

[目的]探究不同驱虫药驱虫前后伊犁马粪便中虫卵种类及数量的变化以及驱虫药对马匹血液生理指标的影响。[方法]选择平均体重（265.5±35.6）kg、出生日期相近的1岁伊犁马40匹,随机分为5组,每组8匹,分别为对照组、试验Ⅰ组、试验Ⅱ组、试验Ⅲ组和试验Ⅳ组。在相同的饲养管理和日粮营养水平条件下,试验Ⅰ组给予伊维菌素,试验Ⅱ组给予吡喹酮,试验Ⅲ组给予阿苯达唑,试验Ⅳ组给予伊维菌素和阿苯达唑的混合药剂驱虫,对照组不驱虫。在驱虫前及驱虫后1、2、3、7、14 d采集马匹粪便样本,进行虫卵鉴别与计数,计算寄生虫感染率;驱虫后14 d采集马匹血液样品,测定血液生理指标。[结果](1)驱虫后14 d,除对照组粪便中虫卵种类和数量较多,试验Ⅱ组粪便中有少量虫卵外,其余试验组均未发现虫卵;与对照组相比,试验Ⅰ组、试验Ⅲ组、试验Ⅳ组马匹粪便中每克粪便虫卵数（eggs per gram,EPG）均降低了612.50个（P<0.01）,试验Ⅱ组EPG降低了562.50个（P<0.01）。(2)试验Ⅰ组单核细胞数量极显著（P<0.01）低于对照组;试验Ⅳ组嗜碱性粒细胞数量极显著（P<0...     

不同处理方式对发酵床模式下猪主要寄生虫病防治效果

探讨发酵床养猪模式下寄生虫病防控效果,构建寄生虫病防控规程。将发生寄生虫病的表层垫料混匀,添加4组发酵床表层,将60头35日龄苏钟猪随机分为4组:A组(垫料翻耙后进猪,定期药物驱虫2次)、B组(垫料堆积发酵后进猪)、C组(垫料发酵后进猪,定期药物驱虫2次)、D组(垫料翻耙后进猪,感染寄生虫时药物治疗1次),试验期120 d。垫料堆积发酵组垫料发酵温度极显著高于垫料翻耙组(P0.01),并且堆积发酵后垫料中未检出寄生虫卵,试验第45、90天在垫料和粪便中的蛔虫卵、鞭虫卵、球虫卵数量均处于低水平;采用药物驱虫程序可有效降低猪粪便中的蛔虫卵、鞭虫卵、球虫卵数量和对应寄生虫的感染率,但不能避免垫料中寄生虫的重复感染; B、C组末重、总增重、平均日增重均显著高于A组(P0.05)和D组(P0.01),A组末重、总增重、平均日增重也均显著高于D组(P0.05)。综上所述,在发酵床养猪模式下,采用进猪前药物驱虫、垫料堆积发酵,猪群饲养阶段定期驱虫,同时注意养殖管理器具消毒,可有效降低寄生虫感染率。     

规模化羊场粪便自然堆肥发酵技术

近年来,在规模化羊场经营和发展的过程中,自然堆肥发酵技术得到了越来越广泛的应用。借助于该项技术的有效应用,能够将羊粪转化为营养物质含量丰富的堆肥。既能够有效的解决规模化羊场的粪便处理问题,又能够为农业生产领域提供大量的有机肥料。本文就规模化羊场粪便自然堆肥发酵技术做了相关的阐述与分析。     

伊维菌素微球在山羊体内的药效学研究

探讨新型制剂伊维菌素微球在山羊体内的药效学。选取32只山羊〔平均体重(27.05±1.20)kg〕,随机分成4组(Ⅰ^Ⅳ),每组7Ⅳ),每组7⁹只。Ⅰ组0.3 mg/kg体重,皮下注射伊维菌素注射液;Ⅱ和Ⅲ组3 mg/kg体重,分别皮下注射伊维菌素PLA5微球和PLGA微球混悬液;Ⅳ组作为对照组,不给药,对山羊粪便虫卵数(EPG)进行检测。Ⅰ、Ⅱ组和Ⅲ组山羊在第14天虫卵减少率均为100%,虫卵全部转阴;在给药后91 d虫卵减少率分别为0、74.3%和80.0%、;在给药后123 d分别为0、61.8%和0。伊维菌素对山羊胃肠道线虫虫卵具有较好的驱除作用,PLGA微球和PLA5微球的药效维持长达120 d左右,表现出长效作用。     

不同堆积高度对羊粪堆肥效果的影响

研究以0.6m、0.8m、1.0m(分别记为处理1、2、3)堆积高度的羊粪进行高温堆肥发酵试验。结果显示,处理1、2、3维持高温时间分别为14d、14d、17d,其中处理3的温度上升最快,维持高温时间最长;均完全达到国家粪便无害化卫生标准(GB7975-2002)维持高温天数的要求;全氮、全磷、全钾浓度均表现为上升趋势;C/N在堆肥的第10d时,处理3最先小于20,在堆肥腐熟进程上,快于其它2个处理。堆肥结束时,3个处理的总养分(N+P2O5+K2O)含量分别为5.95%、5.61%、6.03%,处理3的养分较高;而且3个处理的种子发芽率都超过80%,均已达到腐熟。结果表明,不同堆积高度的羊粪堆肥结果符合粪便无害化卫生标准,羊粪高度以1.0m堆肥效果最佳。     

不同处理牛羊粪便堆积发酵试验效果比较

利用发酵菌剂对不同处理的试验Ⅰ组、试验Ⅱ组、试验Ⅲ组、试验Ⅳ组、试验Ⅴ组和对照组进行堆积发酵试验,在发酵过程中比较了不同试验组的温度、水分、挥发性总固体、pH、细菌群落的变化,以及对牧草籽发芽率、虫卵杀除率和总养分的影响。     

乙酰氨基阿维菌素浇泼剂对奶牛线虫病的疗效试验

为探索治疗奶牛线虫病疗效好、方便、对奶牛应激反应小的药物和剂型,将乙酰氨基阿维菌素研制成2种配方的浇泼剂,即配方Ⅰ和配方Ⅱ。在同一个奶牛小区将37头自然感染线虫病的奶牛分为8个组:配方Ⅰ低剂量组(0.05 mL/kg)、配方Ⅰ中剂量组(0.10 mL/kg)、配方Ⅰ高剂量组(0.20 mL/kg);配方Ⅱ低剂量组(0.05 mL/kg)、配方Ⅱ中剂量组(0.10 mL/kg)、配方Ⅱ高剂量组(0.20 mL/kg);进口伊维菌素浇泼剂对照组;空白对照组。除药物对照组2头奶牛外,其余每组5头奶牛。在投药前和投药后d7、d14、d21、d28、d35、d42、d49、d56、d63采集试验奶牛粪便检测线虫和前后盘吸虫虫卵数量。结果显示,投药后d7,6个试验组和1个药物对照组的奶牛粪便中线虫虫卵全部转阴,这表明研制的乙酰氨基阿维菌素配方Ⅰ和配方Ⅱ的低剂量组、中剂量组、高剂量组对奶牛的线虫病治疗具有很好效果。     

包膜丁酸钠对球虫感染兔的影响研究

为研究日粮中添加包膜丁酸钠对家兔球虫病的影响。本研究选用35日龄健康、断奶实验兔,随机分为5个组。分别饲喂3种不同日粮,Ⅰ组和Ⅲ组为基础日粮对照组,Ⅱ组和Ⅳ组在基础日粮的基础上添加500 mg/kg包膜丁酸钠,Ⅴ组在基础日粮的基础上添加40 mg/kg托曲珠利。于试验第28 d,分别给予Ⅲ、Ⅳ、Ⅴ组实验兔口服接种5×10~5个大型艾美尔球虫孢子化卵囊,攻毒后10 d进行粪便球虫卵囊计数,攻毒后12 d采样,进行肠道形态以及相关寄生虫免疫指标的检测。结果显示:Ⅰ组实验兔的克粪便卵囊数(OPG)显著高于Ⅱ组(p0.05);Ⅲ组的OPG显著高于其它各组(p0.05)。空肠、回肠绒隐比(V/C),Ⅱ组显著高于Ⅰ组(p0.05),Ⅳ组显著高于Ⅲ组(p0.05)。空肠、回肠IFN-γ水平,Ⅱ组显著低于Ⅰ组(p0.05),Ⅳ组显著高于Ⅲ组和Ⅴ组(p0.05)。Ⅳ组空肠IL-2水平显著高于Ⅲ组(p0.05)。Ⅳ组血清可溶性CD4分子水平显著高于Ⅰ组(p0.05)。研究表明包膜丁酸钠能够提高家兔抵抗球虫感染的能力。     

补饲发酵芦笋下脚料对母猪粪便形态和乳汁质量的影响

本研究旨在探讨给妊娠后期和哺乳期母猪补饲发酵芦笋下脚料对母猪粪便形态和乳汁质量的影响。将15头膘情、胎次和预产期相近的妊娠母猪随机分配到Ⅰ组、Ⅱ组和Ⅲ组,每组5个重复,每个重复1头猪。Ⅰ组、Ⅱ组和Ⅲ组母猪每头每天分别补饲0、0.25和0.50 kg发酵芦笋下脚料。试验从母猪妊娠期的第85天开始到产后第21天结束。结果表明:1)给母猪补饲发酵芦笋下脚料能改善母猪的粪便形态。2)Ⅲ组母猪初乳中乳蛋白质、生长激素、胰岛素和免疫球蛋白G水平显著高于Ⅰ组(P0.05),肿瘤坏死因子-α水平显著低于Ⅰ组(P0.05)。3)Ⅱ组和Ⅲ组母猪第10天乳汁中总超氧化物歧化酶活性显著高于Ⅰ组(P0.05),而第21天乳汁中总超氧化物歧化酶活性则极显著高于Ⅰ组(P0.01);Ⅲ组母猪第21天乳汁中丙二醛、白细胞介素-1β、白细胞介素-6和肿瘤坏死因子-α水平分别显著低于Ⅰ组(P0.05)。由此得出,补饲发酵芦笋下脚料能减少妊娠后期和哺乳期母猪便秘的发生,并不同程度地改善母猪乳汁质量。     

Isolation of bovine herpesvirus III from diarrheic feces

A herpesvirus was isolated from the feces of a cow with diarrhea. The viral isolate was identified as a herpesvirus on the basis of morphology and chloroform sensitivity. It was serologically distinct from bovine Herpesvirus I (IBR) and II (mammillitis virus) as well as equine herpesviruses and pseudorabies virus. It was serologically related to members of the bovine Herpesvirus III group.Experimentally inoculated calves developed a transient fever but no other clinical signs or lesions. The virus could be re-isolated from the calves and significant levels of virus neutralizing antibodies were present in the serum 40 days after inoculation.     

茉莉花香型贵妃鸡蛋蛋品质的测定

为测定在日粮中添加茉莉花对贵妃鸡蛋品质的影响,本试验随机测定了300日龄贵妃鸡鸡蛋共124枚,平均分为4组,每组31枚,其中15枚用于蛋品质物理性状测定,16枚用于营养成分分析,营养成分分析组设四个重复,每个重复有四个鸡蛋,研究不同茉莉花添加量对贵妃鸡蛋品质的影响。分别在基础日粮中添加茉莉花量为0．0％（对照组）、1．0％（处理I）、2．O％（处理II）、4．0％（处理III）,主要分析茉莉花香型贵妃鸡鸡蛋的外部品质、内部品质和主要营养成分。结果表明：在外部品质方面,添加一定量的茉莉花能够提高贵妃鸡鸡蛋的全蛋重（对照组44．63g〈试验组I46．64g〈试验组III47．42g〈试验组II48．64g）和蛋比重（对照组1．079〈试验组I1．082〈试验组III1．083〈试验组II1．084）,降低蛋壳重（试验组I6．62g〈试验组III6．68g〈试验组II6．81g〈对照组7．OSg）,差异显著（P〈0．05）;在内部品质方面,添加一定量的茉莉花能够显著提高贵妃鸡鸡蛋的蛋清重（对照组22．33g〈试验组III24．25g〈试验组I24．49g〈试验组II25．42g）、蛋黄重（对照组15．29g〈试验组I15．53g〈试验组II16．42g〈试验组III16．54g）、哈氏单位（对照组75．03％〈试验组I76．91％〈试验组II77.21％〈试验组III81．85％）以及加深蛋黄颜色（对照组6．41〈试验组I7．07〈试验组III7．21〈试验组II7．87）,差异显著（P〈O．05）;在营养成分上,添加一定量的茉莉花能够提高贵妃鸡鸡蛋的粗蛋白（对照组11．01％〈试验组II11．35％〈试验组I11．46％〈试验组III11．81％）（P〈O．05）和粗脂肪（对照组8．46％〈试验组I9．11％〈试验组II9．71％〈试验组III10．23％）（P〈O．01）的含量;其他指标差异不明显（P〉O．05）。日粮中添加一定量茉莉花能够改善贵妃鸡蛋的风味,提高营养价值,提高蛋品质,为贵妃鸡蛋的推广开拓新市场。     

Effect of levamisole on the clinical and immunologic responses to oral vaccine of Treponema hyodysenteriae

Conventionally raised crossbred Hampshire pigs were vaccinated orally with attenuated Treponema hyodysenteriae in combination with an anthelmintic, levamisole or dichlorvos. Pigs in group I (n = 9) were treated with levamisole and vaccinated with attenuated T hyodysenteriae and those in group II (n = 9) were treated with levamisole and permitted to commingle (contact exposure) with group I. Pigs in group III (n = 9) were vaccinated in a similar manner and were treated with dichlorvos. Pigs in group IV (n = 9) were treated with dichlorvos and permitted to commingle with group III. Control pigs (group V; n = 9) were not given any anthelmintic, nor were they vaccinated; they were housed separately. During the 8-week interval between vaccination and challenge inoculation, 4 total days and 8 total days of diarrhea were observed in pigs in groups I and II, respectively. Likewise, 5 total days and 10 total days of diarrhea were seen in groups III and IV, respectively. In all groups, the pigs tended to shed the organism in their feces after they were vaccinated or challenge inoculated, as determined by a fluorescent antibody technique (FAT) and culture procedure (CP). Overall mean shedding patterns of 5.5% and 24.5% identified by CP and FAT, respectively, were seen in the 2 levamisole-treated groups (I and II). In contrast, mean shedding patterns of 4% and 18% of the isolation attempts were detected by CP and FAT, respectively, in the 2 dichlorvos-treated groups. Diarrhea and shedding of T hyodysenteriae in the controls (group V) did not occur.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pathological and immunological study of goose embryos and goslings inoculated with an attenuated strain of Derzsy's disease virus.

An attenuated Derzsy's disease virus strain, designated BAV, was studied in goose embryos. A total of 248 embryonated goose eggs, coming from a susceptible laying flock with no yolk-derived immunity (group I) and from a vaccinated laying flock (group II) were used. The eggs were inoculated into the allantoic cavity with 10(1.9), 10(2.9) or 10(3.9) EID 50/0.2 ml virus on day 12 or day 20 of incubation. Embryos were killed at 5-day intervals. The dead embryos and the hatched goslings (up to 2 weeks of age) were examined by gross and histopathological methods. Reisolation of the virus from the organs was attempted, serum samples were tested for the presence of antibodies, and lymphocytes separated from the circulating blood were used in the lymphocyte stimulation and immunorosette formation tests. Embryos of both groups I and II, inoculated at either time of incubation, showed a body mass gain inferior to that of the controls. Sixteen (group I) and 12 (group II) of the embryos inoculated on day 12 of incubation died. Some (group I: 15, group II: 6) of the embryos inoculated on day 20 of incubation failed to hatch. The pathomorphological changes seen in the embryos killed between days 17 and 22 of incubation were of degenerative character. In embryos killed later (between days 23 and 58 of incubation) the degenerative changes were accompanied by infiltration by inflammatory cells. Reisolation of the virus strain was mostly successful between postinoculation (PI) days 5 and 10. Specific virus-neutralizing antibodies and cellular immune response were demonstrable already at hatching.(ABSTRACT TRUNCATED AT 250 WORDS)     

Recovery of nematode eggs and larvae in deer: evaluation of fecal preservation methods

Fresh fecal specimens from deer were examined for nematode eggs (primarily Haemonchus and Ostertagia), using a flotation technique (sugar, sp gr = 1.27), and then were reexamined for up to 200 days after storage in 2.5, 5, or 10% formalin, absolute methyl alcohol, or 70% ethyl alcohol at room temperature (20 C) or after storage without preservative at 4, 0, or -20 C. For long-term storage, 10% formalin was the best fixative for recovery of eggs (compared with the rate of recovery of eggs from fresh feces). Approximately 50% of the strongyle eggs were detected in feces stored in formalin for 200 days. However, between days 3 and 10 of storage, the recovery rate was low (less than 50%), presumably due to ion binding. Alcohols were unsuitable for preservation, and storage at 0 or -20 C resulted in an egg recovery rate of less than 50%. Storage at 4 C for 50 days resulted in approximately 90% recovery of nematode eggs. Number of Parelaphostrongylus tenuis larvae recovered from fecal specimens stored in 10% formalin for 24 days was greater than that recovered from fresh fecal specimens.     

The suppressive effects of lipopolysaccharide-induced acute phase response on hepatic cytochrome P450-dependent drug metabolism in rabbits

The acute phase response (APR) was induced by five separate intravenous (i.v.) injections of Escherichia coli lipopolysaccharide (LPS, 17 microg/kg each time) in rabbits, with intervals of 1 h. This model was used to study the effects of APR on the activities of hepatic microsomal cytochrome P450 (CYP)-dependent enzyme including drug metabolism. Five female rabbits were included in each of four groups, a control group and three LPS-treated groups (group I, II and III). The rabbits of the control, group I, II and III were killed at 1, 1, 3 and 7 days after saline (control only) or the LPS injection, respectively. The APR was confirmed by increases in rectal body temperature, plasma concentrations of interleukin-6 and C-reactive protein (CRP). Pharmacokinetics of antipyrine before death were examined in every group. Antipyrine was administered (5 mg/kg) at 24 h (control and group I), 3 days (group II) and 7 days (group III) after the first LPS injection. Total body clearance (Cl(tot)) of antipyrine tended to decrease in group I. All the livers were excised for measuring CYP-dependent activities. Total CYP content and several CYP-dependent activities (aminopyrine N-demethylation, aniline 4-hydroxylation and caffeine 3-demethylation) decreased in group I. The maximum velocity (Vmax) values of those enzymes, and the amount of CYP1A1/1A2 and CYP2E1 apoproteins appeared to decrease. Michaelis constant (Km) values of those enzymes were not affected by the APR. Rectal body temperature recovered to normal at 3 days after the first LPS injection in group II and III. The concentration of CRP, albumin, total CYP content and the plasma clearance of antipyrine returned to the control levels at 7 days after the first LPS injection. These results suggest that the metabolism of drugs, including CYP-dependent drug metabolizing activity, is suppressed markedly in incipient APR induction in rabbits, and the drug metabolizing capacity is returned to normal at 7 days after APR induction.     

Effect of milbemycin oxime against Ancylostoma caninum in dogs with naturally acquired infection

Twenty-six mixed-breed (14 males, 12 females) dogs were used in a double-blind study to evaluate the effect of milbemycin oxime against naturally acquired infection with Ancylostoma caninum. Dogs were ranked and paired, on the basis of number of hookworm eggs/g of feces, and treatment was randomly assigned. Each dog was given either the study drug or placebo (1 tablet/11.4 kg [0.5 mg/kg] of body weight). Eggs per gram of feces enumeration was done on days 3 and 7 after treatment, and dogs were euthanatized on day 7. On day 3, 5 of the 13 dogs in the milbemycin-treated group had hookworm eggs in the feces (results of the McMaster test). In these dogs, mean number of eggs per gram of feces had decreased markedly (from 5,289 to 452) and, by day 7, was 114. At necropsy, 16 A caninum adults were recovered from 2 of the milbemycin-treated dogs. On day 3, 12 of the 13 dogs in the placebo-treated group had hookworm eggs in the feces. Mean number of eggs per gram of feces in these dogs decreased slightly (from 5,243 to 2,646), but did not decrease further by day 7. A mean number of 54.4 A caninum adults was recovered from 12 of the 13 placebo-treated dogs at necropsy. Milbemycin oxime had 97.8% efficacy against A caninum. Results also indicated that milbemycin oxime may be effective against Trichuris vulpis, but not against Dipylidium caninum.     

In vivo anthelmintic activity of an aqueous extract from sisal waste (Agave sisalana Perr.) against gastrointestinal nematodes in goats

The resistance of gastrointestinal nematodes (GINs) of small ruminants to anthelmintics has required the investigation of new alternatives. The aim of the present study was to evaluate the in vivo anthelmintic activity of an aqueous extract from sisal waste (Agave sisalana) (AESW) against GINs in goats and to observe the animals for toxic effects. Thirty animals that were naturally infected with GINs were distributed into three groups: group I, was treated with daily doses of AESW (1.7 g/kg) for eight days; Group II, the positive control, was treated with a single dose of levamisole phosphate (6.3mg/kg); and group III, the negative control, was left untreated. Faecal eggs counts (FECs), coprocultures and post-mortem worm counts were performed to assess the efficacy of the treatments. Clinical and laboratory analyses were performed to evaluate any toxic effects associated with the treatment. In the goats in groups I and II, a significant reduction (p<0.05) of the number of eggs and infective larvae (L(3)) was observed. The maximum reductions of the FECs were 50.3% and 93.6% for groups I and II, respectively, whereas the percent reductions of the total number of L(3) larvae were 80% (group I) and 85.6% (group II). There was no difference between groups I and III with respect to worm burden, and the percent reductions were 28.8% and 63.4% for Oesophagostomum columbianum and Trichostrongylus colubriformis, respectively. No reduction was detected for the Haemonchus contortus. The positive control group demonstrated a 74% reduction of the parasites that were recovered from the digestive tract. There were no changes in clinical and haematological parameters. The levels of serum urea and creatinine were higher in group I, but remained within the normal range. At necropsy, pale mucous membranes, abomasitis and enteritis were associated with parasitism. In addition, a histological analysis of the liver and kidney did not reveal any changes suggestive of toxicity. A chemical analysis of the AESW demonstrated the presence of saponins, which after acid-hydrolyses reaction, gave the sapogenins hecogenin and tigogenin. The AESW had a low efficacy for the parasitic stages and was moderately effective against eggs and free-living stages. Furthermore, the treatment was not toxic to the goats.     

Immunolocalization and pathological alterations following Strongyloides venezuelensis infection in the lungs and the intestine of MHC class I or II deficient mice

The present study, investigated the mechanisms involved in the immune responses of Major Histocompatibility Complex class I or class II knockout mice, following Strongyloides venezuelensis infection. Wild-type C57BL/6 (WT), MHC II(-/-) and MHC I(-/-) mice were individually inoculated with 3000 larvae (L3) of S. venezuelensis and sacrificed on days 1, 3, 5, 8, 13 and 21 post-infection (p.i.). Samples of blood, lungs and small intestines were collected. The tissue samples were stained with hematoxylin-eosin for the pathological analysis. The presence of the parasite was demonstrated by immunoperoxidase analysis. MHC II(-/-) mice presented a significantly higher number of adult worms recovered from the small intestine on day 5p.i. and presented elevated numbers of eggs in the feces. The infection by S. venezuelensis was completely eliminated 13 days after infection in WT as well as in MHC I(-/-) mice. In MHC II(-/-) mice, eggs and adult worms were still found on day 21 p.i., however, there was a significant reduction in their numbers. In the lung, the parasite was observed in MHC I(-/-) on day 1 p.i. and in MHC II(-/-) mice on days 1 and 5 p.i. In the small intestine of WT mice, a larger number of parasites were observed on day 8 p.i. and their absence was observed after day 13 p.i. Through immunohistochemistry analysis, the parasite was detected in the duodenum of WT on days 5 and 8 p.i., and in knockout mice on days 5, 8 and 13 p.i.; as well as in posterior portions of the small intestine in MHC I(-/-) and MHC II(-/-) on day 13 p.i., a finding which was not observed in WT mice. We concluded that immunohistochemistry analysis contributed to a more adequate understanding of the parasite localization in immunodeficient hosts and that the findings aid in the interpretation of immunopathogenesis in Strongyloides infection.