Blastocystis sp. is the most common eukaryotic parasite in the intestinal tract of humans. Due to its strong impact in public health, in this study, we determined the frequency of different Blastocystis subtypes in patients in France. We hypothesized on the mode of transmission and tested a possible relationship between the subtype and symptomatic status. We obtained a total of 40 stool samples identified as positive for Blastocystis by microscopic examination of smears. Participants consisted of 25 symptomatic and 15 asymptomatic patients, for whom clinical and parasitological data were collected. For nested-polymerase chain reaction and genotyping, DNA was extracted directly from fecal samples or from fecal cultures. Morphological forms observed in fecal cultures were uncorrelated with symptomatic status. Genotyping using partial small subunit rRNA gene analysis identified a total of 43 Blastocystis isolates corresponding to 37 single infections and three mixed infections by two different subtypes. These 43 isolates belonged to five subtypes (1, 2, 3, 4, and 7) with predominance of subtype 3 (53.5%). Patient symptomatic status was uncorrelated with Blastocystis subtype.

Water samples were collected along transects from the shore to the centre of two French lakes: the deep, volcanic, oligomesotrophic and low allochthonic-impacted Lake Pavin, and the productive and higher allochthonic-impacted Lake Aydat. The biodiversity was analysed using two approaches: the classical approach consisting of cloning/sequencing of the 18S, ITS1, 5.8S, ITS2 and partial 28S region using primers designed for fungus sequences, and the pyrosequencing of 18S rRNA hypervariable V2, V3 and V5 regions using two primer sets (one universal for eukaryotes and one for fungi). The classical approach yielded 146 (Lake Pavin) and 143 (Lake Aydat) sequences, corresponding to 46 and 63 operational taxonomic units (OTUs) respectively. Fungi represented half of the OTUs identified in Lake Pavin and 30% in Lake Aydat, and were dominated by sequences from Chytridiomycota found throughout Lake Pavin but mostly in the central pelagic zone of Lake Aydat. The pyrosequencing approach yielded 42,064 (Pavin) and 61,371 (Aydat) reads, of which 12-15% and 9-19% reads were assigned to fungi in Lakes Pavin and Aydat respectively. Chytridiomycota members were also dominant among these reads, with OTUs displaying up to > 33-fold overrepresentation in the centre compared with the riparian areas of Lake Aydat. Besides fungi, both approaches revealed other major eukaryote groups, with the highest diversity in the central areas of lakes. One of the major findings of our study was that the two lakes displayed contrasting spatial distributions, homogenous for Lake Pavin and heterogeneous for Lake Aydat, which may be related to their peculiarities. This study represents the first unveiling of microbial eukaryote and fungus diversity assessed with two complementary molecular methods, and is considered a major milestone towards understanding the dynamics and ecology of fungi in freshwater lake ecosystems, which are directly link to the abundance and distribution of taxa.

Giriş: Blastocystis spp. neden olduğu klinik semptomlar nedeniyle günümüzde önem kazanan enterik bir protozoondur. Prevalansı dünyanın farklı bölgelerinde değişmekle birlikte gelişmekte olan ülkelerde daha sık görüldüğü bildirilmektedir. Bugüne kadar insanlarda 9 Blastocystis spp. alt tipi saptanmıştır ve bu lerin farklı klinik semptomlar ile ilişkili olabileceği öne sürülmüştür. Gereç Yöntem: Bu çalışmada formol-etil asetat yöntemi ile Blastocystis spp. varlığı saptanan 50 semptomatik hastadan elde edilen izolatlarının iki farklı besiyerinde kültürleri yapılmış, bu izolatların alt tip dağılımı sekanslama yöntemi ile belirlenmiş, alt tipler ile klinik bulgular arasındaki ilişkiler incelenmiştir. Bulgular: Örneklerden 40 (%80)'ı her iki besiyerinde de üremiş, 5 (%10)'i iki besiyerinde de ürememiş, 5 (%10) örnek ise iki besiyerinden sadece birinde üremiştir. 39 (%78) örnekte tek bir alt tip saptanırken, 11 (%22) örnekte birden fazla alt tip varlığı saptanmıştır. Örnekler arasında en sık ST3 saptanırken bunu sırasıyla ST1, ST5, ST2 ve ST4 takip etmiştir. Karın ağrısı 23 (%46) hastada olmak üzere en sık rastlanan klinik semptom olup, allerjik semptomlar ise 17 (%34) hastada gözlenmiştir. Bunun dışında hastalarda çeşitli gastrointestinal semptomlar ve eklem ağrısı varlığı da gözlenmiştir. Klinik semptomlar ile alt tipler arasında anlamlı bir ilişki saptanamamıştır. Sonuç: Çalışmamızda, gastrointestinal ve allerjik semptomları olan hastalarda ST3 alt tipi en sık saptanmıştır. Ayrıca her ne kadar az sayıda olgu bildirilmiş olsa da bir hastada eklem ağrısı saptanmış olması Blastocystis spp.'nin artrit ile ilişkisi olabileceğini ve klinisyenler tarafından göz önünde bulundurulması gerektiğini düşündürmektedir. Her ne kadar çalışmamızda klinik bulgular ile alt tipler arasında anlamlı bir ilişki bulunamamış olsa da Blastocystis spp. alt tiplerinin, klinik bulgularla ilişkilerinin anlaşılması için daha fazla araştırmaya ihtiyaç vardır. Anahtar Kelimeler: Blastocystis spp., alt tip, klinik belirtiler Introduction: Blastocystis spp. is an enteric protozoon that has grown in importance with recent knowledge of the symptoms, disorders it may cause. Its prevalence varies in different countries, but it is most frequently detected in developing countries. Nine subtypes (ST) of Blastocystis spp. have been detected in humans and it is suggested that these subtypes can be related to its varying clinical symptoms.

Blastocystis sp. is the most common eukaryotic parasite in the intestinal tract of humans. Due to its potential impact in public health, we determined the Blastocystis sp. subtypes (STs) and their relative frequency in symptomatic patients living in or in the vicinity of two Italian cities (Rome and Sassari). A total of 34 Blastocystis sp. isolates corresponding to 26 single and 4 mixed infections were subtyped using partial small subunit ribosomal RNA gene sequencing. From this molecular approach, the ST distribution in the present Italian population was as follows: ST3 (47.1%), ST2 (20.6%), ST4 (17.7%), ST1 (8.8%), and ST7, and ST8 (2.9%). As in almost all countries worldwide, ST3 was the most common ST reinforcing the hypothesis of its human origin. Together with a previous preliminary report, a total of seven STs (with the addition of ST5) have been found in Italian symptomatic patients. The wide range of STs identified in the Italian population suggest that Blastocystis sp. infection is not associated with specific STs even if some STs (ST1-ST4) are predominant as reported in all other countries. Since most of the STs identified in Italian patients are zoonotic, our data raise crucial questions concerning the identification of animal reservoirs for Blastocystis sp. and the potential risks of transmission to humans.

Background Massive phytoplankton blooms, like the recurrent Phaeocystis proliferation observed every year in the Eastern English Channel (EEC), have a significant influence on the overall planktonic community structure and their food web dynamics. As well as being an important area for local fisheries, the EEC is an ideal ecosystem for work on microbial diversity. This is because, although its environmental context is relatively complex, it is reasonably well understood due to several years of monitoring and morphological observations of its planktonic organisms. The objective of our study was to better understand the under-explored microbial eukaryotic diversity relative to the Phaeocystis bloom. Methodology and Principal Findings The community structure of microplankton (diatoms, haptophytes, ciliates and dinoflagellates) was studied through morphological observations and tag pyrosequencing. During the annual Phaeocystis spring bloom, the phytoplankton biomass increased by 34-fold, while the microzooplankton biomass showed a 4-fold increase, representing on average about 4.6% of the biomass of their phytoplankton prey. Tag pyrosequencing unveiled an extensive diversity of Gymnodiniaceae, with G. spirale and G. fusiformis representing the most abundant reads. An extended diversity of Phaeocystales, with partial 18S rDNA genes sequence identity as low as 85% was found, with taxa corresponding to P. globosa, but also to unknown Phaeocystaceae. Conclusions Morphological analyses and pyrosequencing were generally in accordance with capturing frequency shifts of abundant taxa. Tag pyrosequencing allowed highlighting the maintenance of microplankton diversity during the Phaeocystis bloom and the increase of the taxa presenting low number of reads (minor taxa) along with the dominant ones in response to biotic and/or abiotic changing conditions. Although molecular approaches have enhanced our perception on diversity, it has come to light that the challenge of modelling and predicting ecological change requires the use of different complementary approaches, to link taxonomic data with the functional roles of microbes in biogeochemical cycles.

Besides possessing many physiological roles, nitric oxide (NO) produced by the immune system in infectious diseases has antimicrobial effects. Trichomoniasis, the most widespread non-viral sexually transmitted disease caused by the microaerophilic protist Trichomonas vaginalis, often evolves into a chronic infection, with the parasite able to survive in the microaerobic, NO-enriched vaginal environment. We relate this property to the finding that T. vaginalis degrades NO under anaerobic conditions, as assessed amperometrically. This activity, which is maximal (133 +/- 41 nmol NO/10(8) cells per minute at 20 degrees C) at low NO concentrations (< or = 1.2 microM), was found to be: (i) NADH dependent, (ii) cyanide insensitive and (iii) inhibited by O(2). These features are consistent with those of the Escherichia coli A-type flavoprotein (ATF), recently discovered to be endowed with NO reductase activity. Using antibodies against the ATF from E. coli, a protein band was immunodetected in the parasite grown in a standard medium. If confirmed, the expression of an ATF in eukaryotes suggests that the genes coding for ATFs were transferred during evolution from anaerobic Prokarya to pathogenic protists, to increase their fitness for the microaerobic, parasitic life style. Thus the demonstration of an ATF in T. vaginalis would appear relevant to both pathology and evolutionary biology. Interestingly, genomic analysis has recently demonstrated that Giardia intestinalis and other pathogenic protists have genes coding for ATFs.

An outbreak of infective mastitis due to Enterococcus faecalis occurred in an intensive sheep farm in north Sardinia (Italy). E. faecalis, which is only rarely isolated from sheep milk, was unexpectedly found in 22·3% of positive samples at microbiological examination. Forty-five out of the 48 E. faecalis isolates showed the same multi-drug resistance pattern (cloxacillin, streptomycin, kanamycin, clindamycin, oxytetracycline). E. faecalis isolates were analysed by pulsed-field gel electrophoresis, and all 45 multi-drug resistant strains showed an indistinguishable macrorestiction profile, indicating their clonal origin. To our knowledge, this is the first report of an outbreak of mastitis in sheep caused by E. faecalis.

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