Morphological changes in the central vacuole ofBlastocystis hominis during in vitro culture

Summary Morphological changes in the central vacuole during the growth in in vitro culture ofBlastocystis hominis were investigated by light and electron microscopy. Most cells in log phase and an early stationary phase showed a positive staining reaction in the central vacuole with PAS or Sudan black B stain, whereas cells in late stationary phase showed few positive reactions. Electron microscopic observations revealed that 95% ofB. hominis cells in log phase and 50% of cells in early stationary phase, had a substantial accumulation of electron-dense material in the central vacuole. In contrast, only 25% of the organisms in late stationary phase had an electron-dense central vacuole, while more than 50% of cells had an electron-lucent central vacuole. These results indicate thatB. hominis accumulated carbohydrates and lipids in the central vacuole during cell growth and that the organism probably consumed these metabolic substances during stationary growth. Therefore, it is strongly suggested that the central vacuole is an important organelle for storage of metabolic substances, such as carbohydrates and lipids, required for cell growth.Abbreviations PBS phosphate-buffered saline - PAS periodic acid-Schiff     

Ultrastructural and histochemical observations on the tegument of Gastrodiscoides hominis (Paramphistoma: Digenea).

The tegument of the paramphistome, Gastrodiscoides hominis, is basically similar to that of other digeneans. It is folded into concentrically arranged furrows and ridges bearing numerous tightly packed tubercules, and extends into the oral cavity. An area of specialized tegument is present on the ventral surface, anterior to the disc region. Mitochondria are absent from the tegumental syncytium and underlying tegumental cells, suggesting that the tegument may serve principally as a protective layer rather than in active uptake phenomena. However, extensions of the lymph and parenchyma systems are closely associated with the base of the tegumental syncytium and may provide ATP for active processes. Ciliated and non-ciliated sensory papillae are present, particularly around the oral opening. Numerous lymph channels are present in the sub-tegument and may be involved in osmoregulation.     

Structure of Trichomonads as Revealed by Scanning Electron Microscopy*†

SYNOPSIS.
A scanning electron microscope (SEM) study of Hypotrichomonas acosta (Moskowitz), Trichomonas vaginalis Donné. Pentatrichomonas hominis (Davaine), and Tritrichomonas foetus (Riedmüller) provided new information about the structure of the periflagellar canal: emergence of the flagella from the cell body; structure of the undulating membrane; and position, shape, and size of the pelta. Of special interest were the spatial relationships of the attached part of the recurrent flagellum and the accessory filament in Hypotrichomonas and in the members of Trichomonadinae, i.e. Trichomonas and Pentatrichomonas.     

泌尿生殖道支原体培养及耐药性差异分析

目的检测本地区人群泌尿生殖道溶脲脲原体（Uu）和人型支原体（Mh）感染的发生率;分析其对9种抗生素的药物敏感性差异,用以指导临床的抗生素治疗。方法采用法国生物梅里埃Mycoplasma IST2试剂盒对支原体进行分离培养鉴定和药物敏感性试验;分析2008—2013年本地区支原体感染患者耐药性的差异。结果在本地区8168例疑似NGU的患者中检出支原体2564例,阳性检出率为31．39％,其中仅uu感染的患者1833例（22．44％）,Uu和Mh混合感染的患者623例（7．63％）,仅Mh感染的患者108例（1．32％）。仅uu感染的患者对PRI、JOS、DOT、TET、CLA、AZI、ERY、OFL和CIP九种抗生素的敏感率分别为99．8％、99．4％、96．3％、91．9％、90．O％、89．7％、69．7％、4．O％和0．5％;Uu和Mh混合感染的患者对9种抗生素的敏感率分别为96．3％、96．1％、94．8％、79．5％、12．0％、11．7％、1．4％、1．0％和0．3％;仅Mh感染的患者对9种抗生素的敏感率分别为100％、100％、100％、90．7％、0％、0％、O％、14．8％和13．9％。结论本地区泌尿生殖道支原体感染以Uu感染最为常见,Uu和Mh混合感染次之,Mh感染最为少见;对支原体的抗生素治疗首选PRI、JOS、DOT;TET、AZI、CLA可适当使用,而ERY、OFL、CIP则不宜选用。     

Detection of Pentatrichomonas hominis DNA in biological specimens by PCR

AIM: To develop a sensitive and specific polymerase chain reaction for the detection of Pentatrichomonas hominis in biological specimens. METHODS: Three primers, associated in two primer pairs, were designed to amplify a sequence from the SSU rRNA gene of P. hominis. The specificity of both primer pairs was established by testing DNA extractions of different Trichomonad species, protozoa, bacteria, yeasts, and human leucocytes. The analytical sensitivity was determined through testing dilutions of P. hominis trophozoites. The clinical specificity and applicability of the assay was evaluated on stool samples and self-administered vaginal swabs. CONCLUSIONS: A highly specific and sensitive PCR assay was developed. Both primer pairs performed equally well. SIGNIFICANCE AND IMPACT OF THE STUDY: The presence of P. hominis in vaginal specimens has not been reported before.     

Serum zinc and magnesium levels in patients with blastocystosis

The aim of the study was to investigate the total content of the essential elements of zinc and magnesium levels in patients infected with Blastocystis hominis. Zinc and magnesium concentrations were measured in 52 patients who were positive for the intestinal parasite Blastocystis hominis. Scores were obtained for the positives and their age- and sex-matched 60 Blastocystis hominis-negative healthy controls. For comparison of two groups of continuous variables, the independent samples t-test was used. The mean concentration of magnesium in blood was significantly lower in Blastocystis hominis-positive patients than in their controls both in females (p<0.05) and males (p<0.05). The average zinc concentration in Blastocystis hominis-positive female patients was 0.61±0.2 mg/L and 0.60±0.2 mg/L in controls (p>0.05). The mean values of the zinc in blood were 0.62±0.2 mg/L in Blastocystis hominis-positive male patients and 0.82±0.1 in controls (p>0.05). No correlation could be demonstrated between age and mean values of zinc and magnesium in Blastocystis-positive females/males and controls (p>0.05). No significant correlation could be found between blood zinc and magnesium levels in Blastocystis-positive female/male patients and controls (p>0.05). Magnesium levels were found to be clearly decreased, whereas no change was observed in zinc levels in the patients with Blastocystis compared to controls.     

Cryptosporidium hominis n. sp. (Apicomplexa: Cryptosporidiidae) from Homo sapiens

The structure and infectivity of the oocysts of a new species of Cryptosporidium from the feces of humans are described. Oocysts are structurally indistinguishable from those of Cryptosporidium parvum. Oocysts of the new species are passed fully sporulated, lack sporocysts. and measure 4.4-5.4 microm (mean = 4.86) x 4.4-5.9 microm (mean = 5.2 microm) with a length to width ratio 1.0-1.09 (mean 1.07) (n = 100). Oocysts were not infectious for ARC Swiss mice, nude mice. Wistar rat pups, puppies, kittens or calves, but were infectious to neonatal gnotobiotic pigs. Pathogenicity studies in the gnotobiotic pig model revealed significant differences in parasite-associated lesion distribution (P = 0.005 to P = 0.02) and intensity of infection (P = 0.04) between C. parvum and this newly described species from humans. In vitro cultivation studies have also revealed growth differences between the two species. Multi-locus analysis of numerous unlinked loci, including a preliminary sequence scan of the entire genome demonstrated this species to be distinct from C. parvum and also demonstrated a lack of recombination, providing further support for its species status. Based on biological and molecular data, this Cryptosporidium infecting the intestine of humans is proposed to be a new species Cryptosporidium hominis n. sp.     

Molecular epidemiology of human Blastocystis in a village in Yunnan province, China

The purpose of this study was to improve our understanding of the molecular epidemiology of human Blastocystis, focusing on 239 randomly selected individuals in a single village in Yunnan province, China. Emphasis was placed on the relative frequency of different Blastocystis subtypes and underlying risk factors. We used a cross-sectional study design, by employing a pre-tested questionnaire to obtain demographic data and behavioural risk factors, and collected faecal samples for culture and subsequent identification of Blastocystis. DNA was extracted from Blastocystis isolates and the subtypes were identified using 7 subtype-specific sequenced-tagged site (STS) primers. Overall, 78 faecal samples were Blastocystis culture-positive (32.6%, 95% confidence interval: 26.7–38.6%). The majority (n = 73, 93.6%) were single infections with one of the known subtypes, whereas 2 isolates consisted of 2 concurrent subtypes. The remaining 3 isolates could not be identified with the currently known STS primers. Risk factors for a Blastocystis infection were drinking unboiled water, consumption of raw water plants and pig ownership. The consumption of raw water plants was positively associated with subtype 1 infections, and drinking unboiled water with subtype 3 infections. In conclusion, human Blastocystis was common in this village in southwest China, and different subtypes were associated with distinct transmission routes or sources of infection, and hence Blastocystis subtypes might be linked to specific environmental compartments.     

A case of furuncular myiasis associated with systemic inflammation

Cutaneous myiasis is a common travel-associated dermatosis caused by fly larvae. We report an unusual case of furuncular myiasis caused by Dermatobia hominis that was associated with signs of systemic inflammation. In this case study, morphological and novel molecular approaches were used to identify and characterize the larvae responsible for human infestation.     

女性泌尿生殖道支原体感染及耐药性分析

目的通过分析深圳市人民医院2009年9月至2010年4月女性泌尿生殖道支原体感染状况及耐药性变迁,指导临床合理用药。方法采用法国生物梅里埃公司MyeoplasmaIST2支原体鉴定及药敏试剂盒,进行支原体检测及药敏分析。结果2135例患者总检出率为54．6％（1166／2135）,其中解脲脲支原体（Uu）阳性1017例（47．6％）;人型支原体（Mh）阳性32例（1．5％）;Uu＋Mh阳性117例（5．5％）。1166例患者支原体对9种抗生素够感性依次为原始霉素（99．8％）、交沙霉素（99．6％）、强力霉素（96．3％）、四环素（94．4％）、克拉霉素（85．6％）、阿奇霉素（77．6％）、红霉素（75．6％）、氧氟沙星（28．4％）和环丙沙星（22．8％）。结论支原体（尤其是Uu）感染已成为女性泌尿生殖系统炎症的主要病原体之一,治疗支原体感染应选择原始霉素、交沙霉素、强力霉素等敏感率高的药物及药敏试验显示敏感的药物,喹诺酮类药物耐药率较高,应引起临床重视。