图们江下游部分牧场硬蜱区系及生态特点调查

对图们江下游部分牧场黄牛体表寄生蜱调查表明，该地区的蜱有血蜱属长角血蜱（Ｈａｅｍａｐｈｙｓａｌｉｓ ｌｏｎｇｉｃｏｒｎｉｓ和硬蜱属全沟硬蜱（Ｉｘｏｄｅｓ ｐｅｒｓｕｌｃａｔｕｓ），２种蜱分别占９３．２１％和６．７７％；黄牛的感染率为１００％，感染强度为１２１￣３２７０只；在２个硬蜱生境地带２种蜱的分布基本相同。当地优势种长角血蜱在宿主体表的分布无规律性，但以宿主前躯寄生数量较多。长角血蜱的若虫、成     

四种硬蜱的实验室人工饲养和部分生物学特性的观察

为了给蜱及蜱传疾病研究提供充足、有效的实验材料，我们对镰形扇头蜱(Rhipicephalus haemphysa loides haentaphysaloides)、亚洲璃眼蜱(Hyalomma asiaticum asiaticum)、微小牛蜱(Boophilus microplus)和嗜群血蜱(Haemaphysalis concinna)进行了实验室人工饲养。在25℃，92％相对湿度，黑暗条件下．以兔为唯一饲血动物，四种硬蜱均可完成整个生活史的发育。镰形扇头蜱完成一代需86一l20天，亚洲璃眼蜱需l04一l47天，微小牛蜱需50一74天，嗜群血蜱需88一l25天。通过实验室人工饲养，成功进行了单雌蜱蜱群的繁殖。除微小牛蜱外，其他三种蜱均可进行大量增殖。     

东北地区蜱携带的肝原虫分子检测

为检测东北地区蜱传肝原虫,于2015年4—6月通过布旗法在吉林省和黑龙江省采集蜱2 767只,其中森林革蜱168只、草原革蜱212只、全沟硬蜱1 629只、嗜群血蜱378只、长角血蜱380只。根据蜱种和地区分组,每组约15只,提取基因组DNA,应用巢式PCR方法检测肝原虫18S rRNA,阳性样本克隆、测序并进行系统进化分析,利用MLE(Maximum Likelihood Estimation)法计算感染率。东北地区蜱的肝原虫感染率为1.6%(43/189),森林革蜱、草原革蜱、全沟硬蜱、嗜群血蜱和长角血蜱的肝原虫感染率分别为2.8%(4/12)、1.5%(3/16)、2.0%(29/110)、0.5%(2/26)和1.1%(5/25),吉林省和黑龙江省肝原虫感染率最高的蜱种分别为森林革蜱(2.8%)和全沟硬蜱(2.1%),进化分析结果显示东北地区蜱携带的肝原虫为2个不同基因型,且均与日本貂(Martes melampus melampus)肝原虫的同源性为99%,均能在草原革蜱和全沟硬蜱中检出,而且在不同地区蜱的感染率存在一定差异。本研究确定东北地区存在蜱感染肝原虫,但是其分类地位及动物宿主还需进一步鉴定。     

四川省巴中市嗜群血蜱的调查与防治

１９９９年３￣６月四川省巴中市的４３个乡（镇）２１２个村严重暴发了侵袭人和畜禽的外寄生虫，经鉴定为嗜群血蜱（Ｈａｅｍａｐｈｙｓａｌｉｓ ｃｏｎｃｉｎｎａ）。受虫害面积达４１０ｋｍ＾２，抽样调查牛感染率为１００％，山羊１００％，猪２７．０％，鸡１００％，鸭８９．０％，感染强度１￣２２４１只，疫区灌木丛含蜱量以人工步旗５００ｍ为２６３５只。经用三氯杀螨醇，敌百虫喷雾灭蜱后，其灌木丛人工步旗５００ｍ含蜱     

麻点璃眼蜱生活史的研究

在实验室条件下，将麻点璃眼蜱（Hyalomma rufipes）幼蜱至若蜱置于牛体或兔体、成蜱置于羊体摄食；若蜱蜕化、饱血雌蜱产卵和孵化在28℃、相对湿度约80％的培养箱中完成。在此条件下，对从甘肃省永靖县羊体获得的麻点璃眼蜱在实验室进行了生活史研究。试验证实，该种蜱为二宿主蜱，一个生活周期需要经过幼蜱、若蜱、成蜱和卵4个发育阶段。幼蜱5－7d饱血，蜕化为若蜱后不离开前一变态期蜱的寄生部位，继续在宿主体上叮咬吸血，经14－24d若蜱饱血脱落。若蜱蜕化期为18－63d，平均40.5d。雌蜱饱血需8－16d，平均12.0d。雌蜱产卵前静止期6－43d，产卵期16－29d，平均22．5d。卵经20－41d孵出幼蜱，平均31．5d。该种蜱在实验室完成一个生活周期需要91－226d。     

南山牧场乳牛瑟氏泰勒虫病的防治报告

南山牧场乳犊牛的奇生虫病主要是蜱及蜱传梨形虫病，严重威胁着牧场养牛业的发展．历年来，我场奶犊牛因该病引起死亡达15％以上，尤其是疫区权力评中队的犊牛年平均发病率为45．2％，患病死亡率达98．6％．1993年始，我们与北京农业大学专家一道，对该病的发生和诊断进行了试验，现报告如下．1流行病学调查传播梨形虫病的中间宿主一蜱，主要是血蜱属的三宿主蜱—长角血蜱，它的成虫、若虫、幼虫都寄生于中体，成虫在2月份开始增多，4～7月份为高峰．若虫在2月份出现，高峰期3～6月，幼虫在4月份出现，高峰期8～10月．奶犊牛发病始于每年5月…     

蜱感染后兔体炎性细胞数量的变化

通过应用免疫增强剂或免疫抑制剂改变兔体的非特异性免疫功能，观察长角血蜱幼虫感染后兔体炎性细胞数量的变化，结果发现免疫增强组兔淋巴细胞和嗜中性粒细胞在长角血蜱幼虫感染前和感染后变化不大；免疫抑制组淋巴细胞数量降低，而嗜中性粒细胞数量增加；不用药组幼虫叮咬后相比淋巴细胞数量稍降低，嗜中性粒细胞数量稍增加，嗜酸性粒细胞、单核细胞和嗜碱性粒细胞数量变化不明显。     

革蜱的某些生物学特性的研究

本文在室内条件下，系统地观察研究了新疆优势蜱种－－地蜱和草原革蜱各变态期的吸血前后形态变化及共孵化、蜕化等，得到了有关参数，据试验认为各变态期血蜱体重，雌蜱可达吸血前的１５２～１７０倍，幼蜱为１１～１２倍若蜱为４３～８６倍，革蜱在一个生活周期可吸食７９８ｍｇ宿主动物的血液（不包括蜱体内消化，吸收的血量），共繁殖成活率为７７％～１００％。     

天津西部地区蜱种类调查

通过对天津西部地区德丰羊场波尔山羊蜱进行调查,结果表明,该地区的蜱均为硬蜱科,共分两个属两个种,即璃眼蜱属残缘璃眼蜱和血蜱属长角血蜱。两种蜱分别占8313％和16．7％,当地优势种为残缘璃眼蜱,残缘璃眼蜱在宿主的体表分布无规律性,多寄生在后躯部,以股内侧为多。长角血蜱在宿主体表分布亦无规律性,但以宿主前驱寄生数量较多,主要在耳部,颈部和腹内侧。     

天津西部地区蜱种类调查

通过对天津西部地区德丰羊场波尔山羊蜱进行调查,结果表明,该地区的蜱均为硬蜱科,共分两个属两个种,即璃眼蜱属残缘璃眼蜱和血蜱属长角血蜱。两种蜱分别占8313％和16．7％,当地优势种为残缘璃眼蜱,残缘璃眼蜱在宿主的体表分布无规律性,多寄生在后躯部,以股内侧为多。长角血蜱在宿主体表分布亦无规律性,但以宿主前驱寄生数量较多,主要在耳部,颈部和腹内侧。     

Ixodid tick species attaching to dogs in Hungary

A survey was carried out to investigate the occurrence of hard tick species (Acari: Ixodidae) infesting domestic dogs in Hungary. Forty veterinary clinics from a wide geographical area were asked to collect hard ticks from dogs and to complete a questionnaire. In total, 25 veterinary clinics submitted 900 ticks from 310 dogs. Intensity of infestation ranged from one to 78 per dog. The most preferred sites of tick attachment in decreasing order were head, neck and legs. The majority of ticks (91.7%) were adults, which were identified to species level, the others were nymphs. Six species were found: Dermacentor reticulatus (48.9%), Ixodes ricinus (43.2%), Ixodes canisuga (5.6%), Haemaphysalis concinna (2%) and there was one specimen of both Dermacentor marginatus and Ixodes hexagonus. Single species infestation with I. ricinus or D. reticulatus was found on 145 (46.8%) and 120 animals (38.7%), respectively. Mixed infestation caused by these two species was detected on 24 dogs (7.7%). I. canisuga and H. concinna were found on seven and five dogs, respectively. D. reticulatus and I. ricinus were collected almost throughout the year, except for a single month. The activity peaks were in spring and in autumn for both species. Based on clinical signs, canine babesiosis was diagnosed by the veterinarians in 66 (21.3%) tick infested dogs. These dogs were more frequently infested with D. reticulatus than the others. Our data contribute to the understanding of geographical and seasonal distribution of ixodid tick species infesting dogs in Hungary. The implication of these data, for the risk of canine tick borne diseases is discussed.     

Ixodid ticks on ruminants, with on-host initiated moulting (apolysis) of Ixodes, Haemaphysalis and Dermacentor larvae

To screen the host-dependent abundance of hard tick (Acari: Ixodidae) developmental stages on ruminants in South Hungary, red and roe deer, as well as goats and sheep were examined in a season, when larvae and nymphs are active. Altogether 2271 ticks were collected. In the relevant period the prevalence of tick-infestation was significantly higher among goats, than among sheep kept in the very same area, most likely in association with the browsing habit of the former. Roe deer and goats were found to be important hosts for Ixodes ricinus and Haemaphysalis concinna larvae, in contrast to the view that this stage does not usually feed on medium-sized mammals. Interestingly, one third of I. ricinus larvae and one larva of H. concinna and of Dermacentor reticulatus collected from goats in the same herd in August have started the moulting process (showed apolysis) on their host, despite being three-host ticks. This is the first survey involving four species of domestic and wild ruminants in Europe to compare the host-preference of ixodid ticks in the same region.     

Temporal distribution of Ixodes ricinus, Dermacentor reticulatus and Haemaphysalis concinna in Hungary

A survey was carried out over a 4-year period to describe the temporal distribution of three 'anthropophilic' tick species, Ixodes ricinus, Dermacentor reticulatus and Haemaphysalis concinna in Hungary. Altogether 4658 adult ticks belonging to the three species were collected from 1931 red foxes (Vulpes vulpes) killed in an area of about 70,000 km(2) representing all major climatic areas of the country. The seasonal activity of the three species was different. I. ricinus ticks were most active between April and June with an activity peak in May. A less marked increase of activity was also observed in September and October. The highest activity of D. reticulatus ticks was seen between September and November with an activity peak in October, nevertheless, a marked increase of activity could also be observed in April. Small number of I. ricinus and D. reticulatus were collected in all other months. H. concinna ticks were active from May to July with an activity peak in June and completely disappeared between October and March. The temporal distribution of the three tick species might be used for predictions on the seasonality of tick-borne diseases in Hungary.     

Trixacarus caviae Fain,Howell & Hyatt 1972 (Acari: Sarcoptidae) as a cause of mange in guinea-pigs and papular urticaria in man

The clinical symptoms of infestation with Trixacarus caviae in guinea-pigs are described. In general large areas of thickened, denuded skin, with a heavy secondary bacterial infection, and sometimes neurological signs, are observed in mangy cases. Antiparasitic therapy was successful with one or several washings with 0.15% trichlorphon or 0.07% lindane solutions.Histological examination of the skin of mangy guinea-pigs revealed acanthosis, pronounced thickening of the epidermis and increased indentations of the cutis. The mites were embedded in epidermal debris in the folds of the skin. They were often found in the superficial part of the hair follicles. Inflammation of the subcutis was pronounced.Healthy guinea-pigs developed mild signs of mange approximately 10 days after exposure by skin contact to heavily infested animals. These experimentally infested guinea-pigs recovered without treatment. An itching papular urticarial condition in three human patients was found associated with trixacariasis of guinea-pigs. The lesions were usually located on the skin areas in frequent contact with the infected animals. This human affliction cleared after terminating contact with the mangy pig or after antiparasitic treatment of the animal.     

Investigation of domestic animals and pets as a reservoir for intimin- (eae) gene positive Escherichia coli types

Domestic animals belonging to seven different species (cattle, sheep, dogs, cats, pigs, chicken and goats) were investigated as natural reservoirs for attaching and effacing Escherichia coli (AEEC). For this, 2165 E. coli strains from faeces of 803 animals were examined for the presence of the intimin -(eae) gene as a characteristic of AEEC strains. Ten percent of the animals were found to excrete AEEC, most frequently found in sheep (19.2%) and pigs (17.6), followed by cattle (10.4%), dogs (7.2%), cats (6.5%) and poultry (2.3%). The 97 AEEC strains from animals were grouped into 44 serotypes. Only four E. coli serotypes (O2:H8, O26:[H11], O109:[H25] and O145:[H28] were found in more than one animal host species. AEEC O26:[H11] strains were most frequently isolated (13.4%) being present in cattle, poultry, pigs and sheep. A search for virulence markers associated with enterohemorrhagic E. coli (EHEC) revealed Shiga-toxin genes in three (3.1%) AEEC strains from sheep. Bundle forming pili genes as a trait of typical enteropathogenic E. coli (EPEC) were detected in four (4.1%) strains from dogs and cats. The remaining 90 AEEC strains were classified as atypical EPEC. Typing of intimin genes revealed intimin beta being present in 51.5% of the strains, followed by intimins theta (23.7%), epsilon (6.2%), kappa (5.2%), zeta (5.2%), alpha, eta and iota (each 1.0%). Our data indicate that domestic animals and pets constitute an important natural reservoir of AEEC strains, and some of these (O26:[H11], O103:H2, O128:H2, O145:[H28] and O177:[H11]) are known to occur as pathogens in humans.     

Immunological Identification and Characterization of Extracellular Serine Protease-Like Protein Encoded in a Putative espP2 Gene of Haemophilus parasuis

Haemophilus parasuis is known to produce a group of virulence-associated autotransporter (AT) proteins, VtaAs; however, no other ATs have been characterized yet. On the basis of the reported sequence of a putative espP2 gene for extracellular serine protease (ESP)-like protein of H. parasuis, this putative AT gene was successfully amplified from H. parasuis serotype 5 field strain HPS0819, cloned and sequenced. The confirmed ORF sequence showed 100% identity with the reported putative espP2 gene. The recombinant ESP-like protein purified from Escherichia coli with a pET expression system was used for immunological characterization. An approximately 85 kDa antigen was detected in cultured H. parasuis by using antiserum to the purified ESP-like protein, and antibodies against the recombinant ESP-like protein were detected in a selected serum from pigs with experimental H. parasuis infection. The results indicated that H. parasuis could produce ESP-like protein in vitro and in vivo. In an immune protection study using guinea pigs, 6 out of 10 animals immunized with the recombinant ESP-like protein survived after challenge with 5 × 10(9) bacteria of strain HPS0819, whereas 7 out of 10 animals immunized with formalin-inactivated H0819 bacterin survived after challenge. The results suggest that ESP-like protein could be one of the vaccine antigen candidates for H. parasuis infection.     

Pathogenicity for mice and swine of Erysipelothrix isolates from the tonsils of healthy cattle

The pathogenicity of 79 Erysipelothrix isolates from bovine tonsils for mice and swine was determined. Five (6.3%) isolates were lethal for mice. These isolates belonged to serovars 1b (one isolate), 2 (2), 19 (1) and 21 (1). The 50% lethal dose values of the isolates ranged from 0.33 to 5x10(2) CFUs in mice. Twenty Erysipelothrix isolates (25.3%) were weakly virulent inducing only emaciation while 12 (15.2%) inducing emaciation and ruffled hair. In swine, clinical signs of varying severity were observed. Four isolates were virulent, capable of inducing localized or generalized urticarial lesions accompanied with a rise in body temperature after intradermal inoculation. One isolate each of serovars 1b, 2 and 19 was highly virulent, capable of inducing generalized urticarial lesions while another Erysipelothrix isolate of serovar 2 induced only a localized urticarial lesion at the site of inoculation. Another isolate of serovar 1b induced itching and irritation without obvious urticarial lesion at the site of inoculation. On the other hand, one isolate of serovar 21 and two other isolates of serovar 2 could not induce experimentally any clinical sign of erysipelas other than rise in body temperature. There was a rise in growth agglutination (GA) titer of serum in all the inoculated swine. These observations suggest that Erysipelothrix isolates from cattle are pathogenic for mouse and swine, and may also be pathogenic for other animals and humans.     

Serotypes and virulence genes of bovine Shigatoxigenic Escherichia coli (STEC) isolated from a feedlot in Argentina

Grazing-fed cattle were previously demonstrated to be reservoir of non-O157 Shigatoxigenic Escherichia coli (STEC) serotypes in Argentina. The acid-resistance of some STEC strains makes it reasonable to assume the presence in feedlot of particular STEC serotypes. Fifty-nine animals were sampled every 2 weeks during 6 months by rectal swabs. Twenty-seven of 59 animals (45.8%) were shown to be Stx2(+); 3/59 (5.1%) carried Stx1(+) and 7/59 (11.9%) were Stx1(+) Stx2(+). Among 44 STEC isolates, 31 isolates were associated to 10 O serogroups (O2, O15, O25, O103, O145, O146, O157, O171, O174, O175) and 13 were considered non-typable (NT). Six H antigens (H2, H7, H8, H19, H21, H25) were distributed in 21 isolates whereas 23 were non-mobile (H-). Seventeen of 44 strains (38.6%) were eaeA(+) and 14 (31.8%) harbored the 60MDa plasmid. The megaplasmid (Mp) and eaeA gene were simultaneously found in a limited number of serotypes belonging to the enterohaemorrhagic E. coli (EHEC). E. coli O157:H7 strains, isolated from four (6.8%) animals, corresponded to the Stx2(+), eaeA(+), Mp(+) pattern. Three O157:H7 strains belonged to phage type 4 and the other strain was atypical. Many serotypes isolated from grain-fed cattle (O2:H25, O15:H21, O25:H19, O145:H-, O146:H-, O146:H21, O157:H7, O175:H8) also differed from those isolated by us previously from grazing animals. The serotypes O15:H21, O25:H19 and O175:H8 had not been identified at present as belonging to STEC. This work provides new data for the understanding of the ecology of STEC in grain-fed cattle and confirms that cattle are an important reservoir of STEC.