我国首例Paraconiothyrium cyclothyrioides感染致眼内炎的相关研究

目的报道我国首例由Paraconiothyrium cyclothyrioides引起的真菌性眼内炎,并分析其生物学特征、感染途径及治疗方法。方法通过形态学鉴定、生长温度试验、ITS测序等方法对我院1株眼外伤患者左眼前房沉积物中培养分离到的丝状真菌进行鉴定。结果该丝状真菌在PDA平板上在25℃生长快速,可见灰橄榄色周边有白色绒毛状菌落,表面皱褶,35℃生长缓慢,可见黄豆大小白色凸起菌落;25℃及35℃培养后镜下可见大量结节状菌丝,未见分生孢子,属于不产孢株;ITS测序结果为Paraconiothyrium cyclothyrioides。结论本病例是国内首次报导的由Paraconiothyrium cyclothyrioides引起的真菌性眼内炎。     

The first reported cases of human cryptosporidiosis caused by Cryptosporidium hominis in Slovak Republic

Cryptosporidiosis belongs to the important parasitic infections with zoonotic potential and the occurrence in European countries is rare. The first cases of cryptosporidiosis caused by Cryptosporidium hominis detected in the Slovak republic were described here. Collection of examined humans consisted of five family members. Faecal specimens were examined by formalin sedimentation, by the Sheather??s sugar flotation and by immunochromatography and visualised by the Ziehl?CNeelsen acid fast stain. A fragment of the Cryptosporidium small subunit ribosomal RNA gene was amplified by nested polymerase chain reaction and species was determined by restriction fragment length polymorphism analysis with the endonucleases SspI and VspI. C. hominis was found in faeces of two immunocompetent siblings (a 7-year-old boy and a 2-year-old girl). The symptoms occurred only in the boy as gastrointestinal disorders lasting 5?days, and manifested by abdominal pain, an elevated body temperature (37.2?°C), mild diarrhoea, accompanied by lassitude, depression and anorexia. Ultrasonic scan revealed enlarged spleen and mezenteric lymph nodes. Microscopic examination of the stool sample revealed numerous Cryptosporidium oocysts. The DNA typing identified C. hominis subtype IbA10G2. Cryptosporidium was also detected in the boy??s sister without any complications and symptoms. Their father, mother and grandmother were parasitologically negative. The source of infection remained unknown. Human cases in present study reflect necessity of systematic attention on intestinal parasites diagnostic inclusive of cryptosporidia.     

我国首见斑替支孢瓶霉引起脑脓肿1例

目的报道1例斑替支孢瓶霉引起脑脓肿。方法抽取脑脓液作直接镜检和真菌培养,分离菌株行DNA序列分析、KOH耐受试验、温度试验和明胶液化试验。结果脑脓液直接镜检发现大量棕色、分隔或不规则膨胀菌丝,SDA培养出灰黑色、绒状、纽扣样菌落,微量培养可见棕色、单支或分支特长的孢子链结构,DNA序列分析属于斑替支孢瓶霉。菌株具有耐碱性,不能液化明胶,可在25-42℃环境下生长。脓肿穿刺术、两性霉素B脂质体静脉滴注和脓腔内注射等治疗无明显疗效,放弃治疗后死亡。结论根据其形态学特点和DNA序列分析,菌株被鉴定为斑替支孢瓶霉。该菌引起的脑脓肿为国内首例报道,脓肿穿刺术和单用两性霉素B治疗无明显疗效。     

The first human case of Trichinella spiralis infection in Korea

Three cases of human infection by Trichinella spiralis were first confirmed by detecting encysted larvae in the biopsied muscle in December 1997, in Korea. The patients were one 35- and two 39-year-old males residing in Kochang-gun, Kyongsangnam-do. They had a common past history of eating raw liver, spleen, blood and muscle of a badger, Meles meles melanogenys, and complained of high fever, facial and periorbital edema, and myalgia. Hematologic and biochemical examinations revealed leukocytosis and eosinophilia, and highly elevated levels of GOT, GPT, LDH and CPK. In the gastrocnemius muscle of a patient, roundly coiled nematode larvae were detected. The larvae measured 0.775-1.050 (av. 0.908) mm in length, and 0.026-0.042 (av. 0.035) mm in maximum width. The specific IgG antibody levels in three patients' sera were significantly higher when compared with those of normal controls. The patients were treated with flubendazole and albendazole for 15-30 days, and discharged at 13-34 days post-admission. From the above findings, it was confirmed that T. spiralis is present in Korea, and the badger plays a role of as the natural host.     

The effect of parasite density on host colonisation success by a mobile avian ectoparasite

1. Full understanding of the dynamics of host–parasite interactions requires elucidation of the principles governing host colonisation. With respect to mobile parasites, little is known about their dispersal behaviour and the factors affecting host colonisation success. 2. Here, the effect of parasite density manipulations on the colonisation success of the carnid fly Carnus hemapterus, an avian ectoparasite, was experimentally explored. 3. Most host nests were colonised within the same breeding season, but the abundance of flies colonising the nests varied broadly both within and between years. 4. Experimental increase in the density of carnid flies in the vicinity of host nests did not result in higher parasite abundance in these nests. Host colonisation success in terms of parasite abundance was not related to indices of parasite density around host nests. 5. Parasite abundance in colonised host nests was positively related to host density and brood mass and negatively related to date. Host nests in trees held fewer carnid flies than those on cliffs and farmhouses. 6. The dispersal ability of C. hemapterus is apt for rapid colonisation of new host nests, but it is unable to explain the broad heterogeneity in parasite abundance between host nests.     

Absence of Wolbachia endobacteria in Chandlerella quiscali, an avian filarial parasite

Chandlerella quiscali is a filarial nematode parasite of the common grackle (Quiscalus quiscula), a widespread bird species found throughout most of North America. Worms collected from wild-caught birds were morphologically identified as C. quiscali and tested for the presence of Wolbachia, an alphaproteobacterial endosymbiont required for reproduction and maturation by many filarial species. Although various methods, including polymerase chain reaction, in situ hybridization, and immunohistology, were used, we were unable to detect evidence of colonization with Wolbachia. Due to the widespread distribution of the grackle host, localization within the host, and high prevalence, C. quiscali may be among the most easily obtainable of Wolbachia-free filarial species. Further studies of C. quiscali and other Wolbachia-free filarial species may help to clarify the reason(s) that some filarial species require Wolbachia but others do not.     

First human case of nocardiosis caused by Nocardia pseudobrasiliensis in Japan

Nocardia sp. IFM 0896, an actinomycete with biochemical characteristics that differed from Nocardia brasiliensis, was isolated from a 71-year-old Japanese man with a history of tuberculosis and cancer. Although the isolate was tentatively identified as N. brasiliensis, the morphological and physiological characteristics of strain IFM 0896 were different from those of N. brasiliensis IFM 0236^T. The results of 16S rRNA gene sequence phylogenies and PCR-RFLP analysis of a heat shock protein revealed that Nocardia sp. IFM 0896 belongs to the species N. pseudobrasiliensis. This is the first clinical isolation report of N. pseudobrasiliensis in Japan.This revised version was published online in October 2005 with corrections to the Cover Date.     

First human case of nocardiosis caused by Nocardia pseudobrasiliensis in Japan

Nocardia sp. IFM 0896, an actinomycete with biochemical characteristics that differed from Nocardia brasiliensis, was isolated from a 71-year-old Japanese man with a history of tuberculosis and cancer. Although the isolate was tentatively identified as N. brasiliensis, the morphological and physiological characteristics of strain IFM 0896 were different from those of N. brasiliensis IFM 0236T. The results of 16S rRNA gene sequence phylogenies and PCR-RFLP analysis of a heat shock protein revealed that Nocardia sp. IFM 0896 belongs to the species N. pseudobrasiliensis. This is the first clinical isolation report of N. pseudobrasiliensis in Japan.     

The multifunctional autophagy pathway in the human malaria parasite,Plasmodium falciparum

Autophagy is a catabolic pathway typically induced by nutrient starvation to recycle amino acids, but can also function in removing damaged organelles. In addition, this pathway plays a key role in eukaryotic development. To date, not much is known about the role of autophagy in apicomplexan parasites and more specifically in the human malaria parasite Plasmodium falciparum. Comparative genomic analysis has uncovered some, but not all, orthologs of autophagy-related (ATG) genes in the malaria parasite genome. Here, using a genome-wide in silico analysis, we confirmed that ATG genes whose products are required for vesicle expansion and completion are present, while genes involved in induction of autophagy and cargo packaging are mostly absent. We subsequently focused on the molecular and cellular function of P. falciparum ATG8 (PfATG8), an autophagosome membrane marker and key component of the autophagy pathway, throughout the parasite asexual and sexual erythrocytic stages. In this context, we showed that PfATG8 has a distinct and atypical role in parasite development. PfATG8 localized in the apicoplast and in vesicles throughout the cytosol during parasite development. Immunofluorescence assays of PfATG8 in apicoplast-minus parasites suggest that PfATG8 is involved in apicoplast biogenesis. Furthermore, treatment of parasite cultures with bafilomycin A₁ and chloroquine, both lysosomotropic agents that inhibit autophagosome and lysosome fusion, resulted in dramatic morphological changes of the apicoplast, and parasite death. Furthermore, deep proteomic analysis of components associated with PfATG8 indicated that it may possibly be involved in ribophagy and piecemeal microautophagy of the nucleus. Collectively, our data revealed the importance and specificity of the autophagy pathway in the malaria parasite and offer potential novel therapeutic strategies.     

The multifunctional autophagy pathway in the human malaria parasite,Plasmodium falciparum

Autophagy is a catabolic pathway typically induced by nutrient starvation to recycle amino acids, but can also function in removing damaged organelles. In addition, this pathway plays a key role in eukaryotic development. To date, not much is known about the role of autophagy in apicomplexan parasites and more specifically in the human malaria parasite Plasmodium falciparum. Comparative genomic analysis has uncovered some, but not all, orthologs of autophagy-related (ATG) genes in the malaria parasite genome. Here, using a genome-wide in silico analysis, we confirmed that ATG genes whose products are required for vesicle expansion and completion are present, while genes involved in induction of autophagy and cargo packaging are mostly absent. We subsequently focused on the molecular and cellular function of P. falciparum ATG8 (PfATG8), an autophagosome membrane marker and key component of the autophagy pathway, throughout the parasite asexual and sexual erythrocytic stages. In this context, we showed that PfATG8 has a distinct and atypical role in parasite development. PfATG8 localized in the apicoplast and in vesicles throughout the cytosol during parasite development. Immunofluorescence assays of PfATG8 in apicoplast-minus parasites suggest that PfATG8 is involved in apicoplast biogenesis. Furthermore, treatment of parasite cultures with bafilomycin A₁ and chloroquine, both lysosomotropic agents that inhibit autophagosome and lysosome fusion, resulted in dramatic morphological changes of the apicoplast, and parasite death. Furthermore, deep proteomic analysis of components associated with PfATG8 indicated that it may possibly be involved in ribophagy and piecemeal microautophagy of the nucleus. Collectively, our data revealed the importance and specificity of the autophagy pathway in the malaria parasite and offer potential novel therapeutic strategies.     

A comparison of the surface features of Philophthalmus megalurus and Philophthalmus gralli rediae by scanning electron microscopy.

General features observed on the surface of Philophthalmus megalurus and Philophthalmus gralli rediae include 2 rounded ambulatory buds, a tapered tail, a slitlike birth pore, and an oral opening surrounded by uniciliate sensory receptors. The tegument is folded in a ribbed pattern and is covered with small microvilli. The sensory receptors are concentrated on the lip of the oral opening but are less dense inside the buccal cavity. Both the birth pore and the buccal cavity are lined with a honeycomblike surface that may support the structural integrity of these highly extensible orifices. Major differences between the 2 species were noted in the structure of the sensory receptors. In P. megalurus they have flexible cilia that originate from a bulbous tegumental base. Receptors of P. gralli rediae are less dense, appear to have rigid cilia, and lack a bulbous base. In general P. megalurus rediae resemble more closely rediae of the philophthalmid Parorchis acanthus than they do those of P. gralli.