Epidemiology of cercarial stage of trematodes in freshwater snails from Chiang Mai province,Thailand

Objective:To investigate the epidemiological situation of cercarial trematodes infection in freshwater snails from different water resources in Chiang Mai province,Thailand.Methods:The snail specimens were collected from 13 districts of Chiang Mai province during April 2008 to February 2012.The prevalence of cercarial infection in snails was investigated using the crushing method.The drawing was done with the help of a camera lucida for the morphological study.Results:A total of 2479 snail individuals were collected and classified into 7 families,11 genera,and 14 species,Among them,8 snails species were found to be infected with an overall prevalence of 17.27%(428/2479),which infected with nine groups of cercariae;gymnocephalous cercaria,strigea cercaria,megalurous cercaria,monostome cercaria,parapleurolophocercous cercaria(Haplorchis cercaria),pleurolophocercous cercaria,furcocercous cercaria(Transversotrema cercaria),xiphidiocercaria,and virgulate cercaria.The parapleurolophocercous cercaria was found to be the dominant type among the cercarial infection in the snails(64.25%).Conclusions:The various species of snails found in the research location act as the intermediate hosts for the high prevalence of parasitic infection of many species of mammals.This work will provide new information on both the distribution and first intermediate host of trematodes.

Food-borne parasitic zoonosis: Distribution of trichinosis in Thailand

Trichinosis is among the most common food-borne parasitic zoonoses in Thailand and many outbreaks are reported each year. This paper investigates the distribution of the disease in regions of north, north-east, central and south Thailand. Between the earliest recorded of outbreak of trichinosis in Mae Hong Son Province in 1962 and 2006, there have been 135 outbreaks involving 7340 patients and 97 deaths in Thailand. The highest number of cases, 557, was recorded in 1983. Most infected patients were in the 35-44 year age group, and the disease occurred more frequently in men than women during 1962-2003, with no significant sex difference during 2004-2006. Outbreaks were most common in the northern areas, especially in rural areas where raw and under-cooked pork and/or wild animals are eaten. Human infections occur annually in northern Thailand during communal feasts celebrating the Thai New Year. Trichinosis causes have been reported every year, supporting the need for planning education programs.

Larval stages of digenetic trematodes in Melanopsis praemorsa snails from freshwater bodies in Palestine

Objective:To detect the species of larval trematodes(cercariae) in Melanopsis praemorsa snails from 5 different fresh water bodies in Palestine.Methods:A total of 1 880 Melanopsis praemona snails were collected from different fresh water bodies in Palestine from October,2008 to November,2010.Cercariae in Melanopsis praemona snails were obtained by lighting and crushing methods.The behavior of cercariae was observed using a dissecting microscope.Results:Three different species of larval trematodes were identified from Melanopsis praemona snails collected only from Al-Bathan fresh water body,while snails from other water bodies were not infected. These species were microcercous cercaria,xiphidiocercaria and brevifurcate lophocercous cercaria.These cercariae called Cercaria melanopsi palestinia 1,Cercaria melanopsi palestinia H and Cercaria melanopsi palestinia III have not been described before from this snail in Palestine. The infection rate of Melanopsis praemona collected from Al-Bathan fresh water body was 5.7%, while the overall infection rate of snails collected from all fresh water bodies was 4.3%.Details are presented on the morphology and behavior of the cercariae as well as their development within the snail.Conclusions:These results have been recorded for the first time and these cercariae may be of medical and veterinary importance.

Human Invasion by Lesser Known Medically Important Trematodes in the Proximity of Tshwane,Gauteng Province,South Africa

It is well-documented that digenetic trematodes exhibit complex life cycles where the definitive hosts are vertebrates—mostly birds,other mammals and reptiles.It is also known that digenetic trematodes are host specific,but changes in our feeding habits, agricultural and social practices,have led to human beings infected with parasites that were previously regarded to be of no or insignificant medical importance. The objective of this study was to identify the less known digenetic parasites in the water bodies around Tshwane that may result in possible

Bio-control of Some Food-Borne Pathogenic Bacteria by Bacteriophage

In recent years, researchers tended to bring new alternative to biological protective systems used in conservation of food and production of safe food. Use of bacteriophage against to pathogen bacteria in food was the most hopeful system in these methods about bio-control. Controls of bacteriophage for each pathogen species and subspecies and determination of phage-host originality are important because efficient bio-control was achieved. Researches concentrated on some food-borne pathogen bacteria such as E. coli O157：H7, Campylobacter, Salmonella and Listeria. In a consequence of these studies made as in vitro and in vivo, first commercial production of phage which will be used in foods was made in Netherlands. Also, it has been informed that use of phage is cost-efficient alternative as compared with other preservatives. This review, discussed application of bacteriophages as bio-control agents in food and advantages and disadvantages about uses of bacteriophages by taking into account antimicrobial characteristics of them.

Surgical outcomes of complicated cataract with pediatric trematode granulomatous uveitis

AIM:To describe the clinical characteristics and surgical outcomes of complicated cataract with pediatric trematodal granulomatous uveitis(TGU).METHODS:Patients of cataract with TGU in the membranous(inactive) stage underwent cataract surgery with intraocular lens(IOL) implantation.Preoperative history and ophthalmic examination were conducted for all cases,whereas Schimphlug imaging and corneal topography were done for some patients.Postoperative follow up was done on the 1st,2nd,and 5th postoperative days after surgery.Then,it was done at least at one,three,and six months postoperatively.Intraoperative and postoperative complications and the methods of their management were reported.RESULTS:Twelve eyes of 12 male children were included in this study ranging from 8 to 16y.The mean best corrected Snellen visual acuity(BCVA) was significantly improved from 0.09±0.06 preoperatively to 0.37±0.11 at the final visit 6mo postoperatively(P<0.001).Schimphlug imaging and corneal topography showed flattening of the anterior surface of the inferior cornea.Intraoperative difficulties and complications included the poor dilatability of the drown down pupil,strong posterior synechia between the anterior lens capsule and the iris at the site of the inferior retrocorneal vascularized membrane and hyphema.All cases underwent primary hydrophobic IOL implantation.CONCLUSION:Surgery for this type of cataract is relatively safe and effective.It is associated with some specific difficulties and complications that should be considered during surgery and follow up.

Phylogenetic analysis reveals cryptic species diversity within minute intestinal fluke,Stellantchasmus falcatus Onji and Nishio,1916(Trematoda,Heterophyidae)

Objective:To examine the taxonomic boundaries in the Stellantchasmus populations in different hosts and reveal the cryptic speciation of the Stellantchasmus in Thailand based on both morphological and molecular approaches.Methods:Stellantchasmus falcatus(S.falcatus) s.l.was collected from different hosts throughout Thailand.The worms were examined and measured.The nuclear ITS2 gene and the mitochondrial COI gene were used to investigate the S.falcatus s.l.from Dermogenus pusillus and Liza subviridis.Results:Stellantchasmus was one of food-borne trematode that widely distribute throughout Thailand.The comparison of S.falcatus s.l.from Dermogenus pusillus and Liza subviridis indicated a genetic divergence of nuD NA with 3.6% and mtD NA with 19.3%,respectively.Morphological characteristics were fairly different in the ratio of body size,length of prepharynx,and ratio of organ size.Conclusions:Our results provide initial evidence that S.falcatus s.l.from different hosts tend to be a different species based on both molecular and morphological characters.Cryptic species complexes are generally found among parasites that tend to have large populations and/or rapid evolution.The degree of genetic diversity existing would suggest the practice of targeted regimes to design and minimize these lections of anthelmintic resistance in the future.

齐齐哈尔市域淡水螺盾盘吸虫感染情况调查

目的了解齐齐哈尔市淡水螺体内盾盘吸虫的种类及其感染情况。方法于2022年9—12月在齐齐哈尔市内随机购买淡水螺数次,根据淡水螺形态鉴定螺的种类,并在解剖显微镜下解剖淡水螺,分离淡水螺内的吸虫,采用醋酸洋红进行染色、制片后进行虫种鉴定、统计不同种类淡水螺体内吸虫的感染情况。结果根据形态学特征鉴定所获本市淡水螺为中华圆田螺和东北田螺两种;共解剖淡水螺2603只,其中中华圆田螺2131只,东北田螺472只;发现本市淡水螺体内有盾盘吸虫寄生,且经鉴定为贝居盾盘吸虫;中华圆田螺体内发现盾盘吸虫202只,东北田螺体内发现盾盘吸虫0只。中华圆田螺感染率为8.81%,东北田螺感染率为0,中华圆田螺平均感染度为1.46。结论首次在嫩江水域中华圆田螺体内发现贝居盾盘吸虫,而东北田螺体内无寄生。

夏河县高原藏羊消化道寄生虫感染情况调查

研究旨在更好地了解夏河县高原藏羊消化道寄生虫感染情况,并为当地高原藏羊消化道寄生虫的防治提供参考。在春秋季节驱虫前,于甘南藏族自治州夏河县采集5个场点的藏羊新鲜粪便,采用虫卵漂浮法、沉淀法和麦克马斯特氏法对粪样进行显微镜检查并统计检查结果。结果显示,夏河县高原藏羊消化道寄生虫总阳性率达97.50%,其中消化道线虫阳性率为91.33%,平均感染强度为1 011.75个/g;消化道吸虫阳性率达11.45%,平均感染强度为195.24个/g;消化道绦虫阳性率为4.79%,平均感染强度为185.71个/g;消化道球虫阳性率为75.52%,平均感染强度为981.22个/g。研究表明,夏河县藏羊消化道寄生虫感染比较严重,其中线虫和球虫感染率高,感染强度大,仍需加强对藏羊寄生虫病的防治。

Progress on the melanoidins produced by the Maillard reaction of fermented food and traditional Chinese medicine

FMs(Food-borne melanoidins)are brown high molecular weight polymers formed by the Mailiard reaction between carbohydrates and nitrogen-containing compounds during the processing of food or Traditional Chinese Medicine(TCM),and are widely found in food-borne products such as TCM concoctions,bakery,brewing,soy sauce,ferment and other food-borne products.FMs not only have a variety of biological activities,such as antioxidant,antibacterial,immunomodulation,regulation of intestinal flora,etc.,and can change the color,aroma and taste of food.The diversity of its components has become a research hotspot at home and abroad in recent years,with a wide range of application prospects.Therefore,this paper summarizes the existing information on FMs at home and abroad,mainly describes their preparation process,physicochemical properties,structural characteristics and functional activity research progress.Typical FMs,such as coffee,biscuits,wine and soy sauce in daily food,and Polygonatum,Perilla oil,Black ginseng,and Red jujube in T,were highlighted.Summarising the current status of research between the chemistry and pharmacodynamics of relevant FMs and presenting challenges and future recommendations for melanoidin research.In future research on FMs,one should pay more attention to basic research,especially isolation and purification and generation mechanisms,to further demonstrate the biological activity of FMs in vivo and in clinical trials.Thus,the potential value of its existence is deeply exploited to meet the needs of technology,production and health.

魢新本尼登虫(单殖目:多室科)的发育

报道了寄生于海水养殖鱼类体表的新本尼登虫 (Neobenedeniagirellae)生活史各期的发育过程。虫卵在 2 5℃～ 2 8℃海水温度条件下 4～ 6d钩毛蚴发育成熟 ;用钩毛蚴人工感染一种鲻科鱼类———棱 (Lizacarinatus)获得成功。在 2 6℃～ 30℃实验室温度条件下 ,钩毛蚴感染棱 10～ 14d后虫体发育成熟 ,并在感染后的第 16天虫体开始产卵。本文对新本尼登虫的生活史发育各期幼虫的形态进行详细的观察、描述。

湖南目平湖钉螺血吸虫病原生物控制资源调查及感染试验

目的虽然一种贝类可作数种吸虫的中间宿主,但在各吸虫种类都存在的一自然环境中,它们共同贝类宿主的一个体通常只携带一种吸虫幼虫期。作者利用这一规律在湖南汉寿目平湖血吸虫病区进行媒介钉螺的调查,查到钉螺感染有日本血吸虫(Schistosoma japonicum)、外睾类吸虫(Exorchis)、斜睾类吸虫(Plagiorchis)、侧殖类吸虫(Asymphylodora)和背孔类吸虫(Notocotylus)5种吸虫的幼虫期。其中对生物控制媒介钉螺有利用价值的外睾类吸虫,其钉螺感染率为3.298%(96/2911),终宿主鲶鱼(Parasilurus asoyus)的感染率为99.31%(434/437)、平均每尾鲶鱼的感染强度为115.4条。先用外睾类吸虫虫卵感染钉螺后再感染日本血吸虫毛蚴,切片观察不同时间的实验螺,后侵入的血吸虫幼虫,全部受损害不能发育。

人体自然感染藐小棘隙吸虫首次发现

本文报道首次在安徽和县发现人体自然感染藐小棘隙吸虫。60条成虫测量结果显示,成虫呈长叶形,大小为1519.4—2056.3×466.4—564.0μm。头领发达,具头棘24枚,背部中央间断。体棘自头领开始,分布至后睾丸后缘。口吸盘大小为107.9—148.6×102.5—148.6μm。腹吸盘大小为205.0—240.9×205.0—235.8μm。消化道有口、前咽、咽、食道和肠管。睾丸两个,前后相接排列于虫体后1/3部处。阴茎囊位于肠叉后方与腹吸盘之间。卵巢较圆,卵黄腺发达。子宫短,通常只含1个虫卵。虫卵长椭圆形,大小为95.1—116.2×54.3—72.8μm。 采用2.5—40mg/kg剂量的吡喹酮顿服治疗39例患者,均驱得成虫,表明吡喹酮是治疗藐小棘隙吸虫的有效药物。

三苯双脒、青蒿琥酯和蒿甲醚抗华支睾吸虫及其他吸虫的实验研究进展

吡喹酮是目前用于治疗血吸虫病和其他吸虫病的主要药物。近年的实验研究发现,治疗肠道线虫感染的新药三苯双脒具有抗华支睾吸虫、麝猫后睾吸虫和卡氏棘口吸虫(Echinostoma caproni)的作用,特别是对感染华支睾吸虫的大鼠,其顿服接近治愈的剂量为300mg/kg,低于吡喹酮的治愈剂量375～500mg/kg。抗疟药青蒿琥酯和蒿甲醚不仅已被发展为预防血吸虫病的药物,而且发现它们对多种吸虫有效,特别是对华支睾吸虫,其顿服对大鼠华支睾吸虫感染的治愈或高效剂量为75mg/kg。本文系综述这些药物单用或联合用药治疗大鼠、小鼠、仓鼠或犬的华支睾吸虫及其他吸虫感染的实验研究进展。

白细胞介素17及其在寄生虫学上的研究新进展

白细胞介素17(Interleukin 17,IL-17)是一种多家族成员的细胞因子,包括IL-17A～F,受体有5种(IL-17RA～IL-17RE)。与IL-1、TNF-α信号传导途径类似,IL-17受RORγt调节,能激活NF-κB、MAP激酶和ERK1/2等信号分子,发挥其生物学功能。IL-17家族具有强大的致炎作用,能促进中性粒细胞增多且向局部组织浸润;可促进多细胞因子释放,积极参与机体体液免疫和细胞免疫,以及造血作用和家族成员间协同作用。IL-17虽在适应型免疫反应过程中产生,但其经典功能却主要在固有免疫调节反应中发挥,且与寄生虫对宿主的侵袭和致病关系紧密,在宿主抗寄生虫感染过程中起重要作用。因此,本文就IL-17及其在寄生虫学上的研究做一综述。

寄生性吸虫谷胱甘肽过氧化物酶生物信息学分析

目的分析几种重要医学吸虫谷胱甘肽过氧化物酶(glutathione peroxidase,GPx)基因及其编码蛋白的生物学信息,探讨吸虫GPx在生物系统发育中的进化地位。方法从网络数据库获取各类目标序列,用NCBI Blast、Clustal X、GeneDoc、PH YLIP和SECISearch等工具,以及比较基因组学方法进行信息学分析。结果获得来自6种不同吸虫共12个GPx基因,分析发现它们均属磷脂氢谷胱甘肽过氧化物酶(PHGPx)家族,各成员之间具有较高的序列同源性(35%～87%)。除卫氏并殖吸虫一PHGPx基因外,其他基因开放阅读框内均含有"TGA"密码子,编码硒半胱氨酸,且其3’-端非翻译区均含有硒半胱氨酸插入序列(SECIS)。除华支睾吸虫一GPx基因组结构由5个外显子和4个内含子组成外,其他均由6个外显子和5个内含子组成。而且,吸虫的GPx基因"内含子?外显子"结构和脊椎动物的PHGPx基因相似,高度保守。结论医学吸虫和脊椎动物宿主的PHGPx基因可能来源于共同的祖先,提示寄生虫与宿主之间的相容性和协同进化的特征。

我国双身虫亚科(Diplozoinae)吸虫的研究

双身虫是我国广泛分布的鱼类寄生虫,但研究不多。本文就我国双身虫亚科的主要形态特征、区系组成和地理分布作了研究和总结。作者认为,双身虫生殖腺的位置以及精巢的结构和数目;体后部肠道的结构;固着铗的结构和大小顺序是分类的主要依据。目前我国已知4属28种,其中包括一新种——福建华双身虫Sindiplozoon fujianensis sp.nov.Paradiplozoon占71.43％,Sindiplozoon占17.86％,Inustiatus占7.14％,Endiplozoon占3.87％。多数种类具较强的寄主特异性。主要的经济养殖鱼类均遭侵袭。

十堰地区学生斯氏狸殖吸虫感染情况

目的了解十堰地区学生斯氏狸殖吸虫感染情况,为防治肺吸虫病提供依据。方法采集十堰地区大、中、小学学生血清标本1262份,采用ELISA法检测血清斯氏狸殖吸虫IgG抗体。结果斯氏狸殖吸虫IgG阳性率为8.2%,其中小学生、中学生和大学生的阳性率依次为16.1%,5.0%和4.7%,差异有统计学意义(P<0.01);城、乡学生的阳性率分别为4.2%和15.0%,差异有统计学意义(P<0.01);男、女生阳性率分别为8.4%和8.0%,差异无统计学意义(P>0.05)。斯氏狸殖吸虫感染者以无症状为主,仅少数出现咳嗽、腹痛、头痛等症状。结论十堰地区学生斯氏狸殖吸虫感染较为多见,有关部门应加强卫生宣传教育和肺吸虫病的预防控制。

脑型肺吸虫病的MRI表现

目的 :探讨脑型肺吸虫病的MRI表现特征及其诊断价值。方法 :搜集 3例经临床治疗和手术病理证实的病例 ,回顾性分析MRI影像表现特征及其与肺吸虫病发病机制的关系。 3例均行常规SE序列MRI扫描 ,1例复查扫描共计 3次 ,1例行Gd DTPA增强扫描。结果 :3例患儿发病年龄为 6～ 9岁 ,肺吸虫抗原皮下试验均为强阳性。所有扫描病例共计 14个病灶 ,10个病灶位于大脑 ,4个位于脑干和小脑部位。MRI表现为囊状和片絮状长T1长T2 信号 ,囊状病变囊壁呈短T1短T2 出血信号 ,1例显示特征性的“隧道征”。增强扫描有一定的意义 ,可显示囊壁无出血的病灶。结论 :脑型肺吸虫病多发生于儿童 ,MR表现相对较为典型 ,出血信号及“隧道征”具有特征性 ,MRI诊断该病具有重要价值。

日本血吸虫幼虫在先感染外睾吸虫后不同时间钉螺体内被生物控制效果的比较

前此实验显示:21d外睾吸虫阳性钉螺能使再侵入的全部血吸虫幼虫发育停留在异常早期母胞蚴阶段〔1-3〕。本文实验比较观察了感染外睾吸虫后不同时间(21d、35d、55d、70d及85d)的钉螺对再侵入的日本血吸虫幼虫生物控制的情况,发现外睾吸虫和血吸虫双重感染的钉螺,两者间隔时间愈长,后侵入的血吸虫幼虫被击毁程度愈强(图1-20);不同间隔时间双重感染的各组实验钉螺,血吸虫幼虫感染率及幼虫侵入率如下:间隔21d,75%(39/52)和25.5%(398/1560);间隔37d,77.8%(21/27)和35.6%(299/840);间隔55d,44.4%(8/18)和11.9%(19/160);间隔70d,100%(15/15)和10.6%(143/1350);间隔85d,43.3%(13/30)和5.8%(66/1140)。