Gut microbiota related to Giardia duodenalis, Entamoeba spp. and Blastocystis hominis infections in humans from Côte d'Ivoire.

INTRODUCTION: Literature data provide little information about protozoa infections and gut microbiota compositional shifts in humans. This preliminary study aimed to describe the fecal bacterial community composition of people from Côte d'Ivoire harboring Giardia duodenalis, Entamoeba spp., and Blastocystis hominis, in trying to discover possible alterations in their fecal microbiota structure related to the presence of such parasites. METHODOLOGY: Twenty fecal samples were collected from people inhabiting three different localities of Côte d'Ivoire for copromicroscopic analysis and molecular identification of G. duodenalis, Entamoeba spp., and B. hominis. Temporal temperature gradient gel electrophoresis (TTGE) was used to obtain a fingerprint of the overall bacterial community; quantitative polymerase chain reaction (qPCR) was used to define the relative abundances of selected bacterial species/group, and multivariate statistical analyses were employed to correlate all data. RESULTS: Cluster analysis revealed a significant separation of TTGE profiles into four clusters (p < 0.0001), with a marked difference for G. duodenalis-positive samples in relation to the others (p = 5.4×10-6). Interestingly, qPCR data showed how G. duodenalis-positive samples were related to a dysbiotic condition that favors potentially harmful species (such as Escherichia coli), while Entamoeba spp./B. hominis-positive subjects were linked to a eubiotic condition, as shown by a significantly higher Faecalibacterium prausnitzii-Escherichia coli ratio. CONCLUSIONS: This preliminary investigation demonstrates a differential fecal microbiota structure in subjects infected with G. duodenalis or Entamoeba spp./B. hominis, paving the way for using further next-generation DNA technologies to better understand host-parasite-bacteria interactions, aimed at identifying potential indicators of microbiota changes

Gut microbiota related to Giardia duodenalis, Entamoeba spp. and Blastocystis hominis infections in humans from Côte d'Ivoire

Introduction: Literature data provide little information about protozoa infections and gut microbiota compositional shifts in humans. This preliminary study aimed to describe the fecal bacterial community composition of people from Côte d’Ivoire harboring Giardia duodenalis, Entamoeba spp., and Blastocystis hominis, in trying to discover possible alterations in their fecal microbiota structure related to the presence of such parasites. Methodology: Twenty fecal samples were collected from people inhabiting three different localities of Côte d’Ivoire for copromicroscopic analysis and molecular identification of G. duodenalis, Entamoeba spp., and B. hominis. Temporal temperature gradient gel electrophoresis (TTGE) was used to obtain a fingerprint of the overall bacterial community; quantitative polymerase chain reaction (qPCR) was used to define the relative abundances of selected bacterial species/group, and multivariate statistical analyses were employed to correlate all data. Results: Cluster analysis revealed a significant separation of TTGE profiles into four clusters (p < 0.0001), with a marked difference for G. duodenalis-positive samples in relation to the others (p = 5.4×10-6 ). Interestingly, qPCR data showed how G. duodenalis-positive samples were related to a dysbiotic condition that favors potentially harmful species (such as Escherichia coli), while Entamoeba spp./B. hominis-positive subjects were linked to a eubiotic condition, as shown by a significantly higher Faecalibacterium prausnitzii-Escherichia coli ratio. Conclusions: This preliminary investigation demonstrates a differential fecal microbiota structure in subjects infected with G. duodenalis or Entamoeba spp./B. hominis, paving the way for using further next-generation DNA technologies to better understand host-parasite-bacteria interactions, aimed at identifying potential indicators of microbiota changes

A programmed cell death pathway in the malaria parasite Plasmodium falciparum has general features of mammalian apoptosis but is mediated by clan CA cysteine proteases

Several recent discoveries of the hallmark features of programmed cell death (PCD) in Plasmodium falciparum have presented the possibility of revealing novel targets for antimalarial therapy. Using a combination of cell-based assays, flow cytometry and fluorescence microscopy, we detected features including mitochondrial dysregulation, activation of cysteine proteases and in situ DNA fragmentation in parasites induced with chloroquine (CQ) and staurosporine (ST). The use of the pan-caspase inhibitor, z-Val-Ala-Asp-fmk (zVAD), and the mitochondria outer membrane permeabilization (MOMP) inhibitor, 4-hydroxy-tamoxifen, enabled the characterization of a novel CQ-induced pathway linking cysteine protease activation to downstream mitochondrial dysregulation, amplified protease activity and DNA fragmentation. The PCD features were observed only at high (μM) concentrations of CQ. The use of a new synthetic coumarin-labeled chloroquine (CM-CQ) showed that these features may be associated with concentration-dependent differences in drug localization. By further using cysteine protease inhibitors z-Asp-Glu-Val-Asp-fmk (zDEVD), z-Phe-Ala-fmk (zFA), z-Phe-Phe-fmk (zFF), z-Leu-Leu-Leu-fmk (zLLL), E64d and CA-074, we were able to implicate clan CA cysteine proteases in CQ-mediated PCD. Finally, CQ induction of two CQ-resistant parasite strains, 7G8 and K1, reveals the existence of PCD features in these parasites, the extent of which was less than 3D7. The use of the chemoreversal agent verapamil implicates the parasite digestive vacuole in mediating CQ-induced PCD

Impact of protozoan cell death on parasite-host interactions and pathogenesis

PCD in protozoan parasites has emerged as a fascinating field of parasite biology. This not only relates to the underlying mechanisms and their evolutionary implications but also to the impact on the parasite-host interactions within mammalian hosts and arthropod vectors. During recent years, common functions of apoptosis and autophagy in protozoa and during parasitic infections have emerged. Here, we review how distinct cell death pathways in Trypanosoma, Leishmania, Plasmodium or Toxoplasma may contribute to regulation of parasite cell densities in vectors and mammalian hosts, to differentiation of parasites, to stress responses, and to modulation of the host immunity. The examples provided indicate crucial roles of PCD in parasite biology. The existence of PCD pathways in these organisms and the identification as being critical for parasite biology and parasite-host interactions could serve as a basis for developing new anti-parasitic drugs that take advantage of these pathways

Gut microbiota related to Giardia duodenalis, Entamoeba spp. and Blastocystis hominis infections in humans from Côte d'Ivoire

Introduction: Literature data provide little information about protozoa infections and gut microbiota compositional shifts in humans. This preliminary study aimed to describe the fecal bacterial community composition of people from Côte d’Ivoire harboring Giardia duodenalis, Entamoeba spp., and Blastocystis hominis, in trying to discover possible alterations in their fecal microbiota structure related to the presence of such parasites. Methodology: Twenty fecal samples were collected from people inhabiting three different localities of Côte d’Ivoire for copromicroscopic analysis and molecular identification of G. duodenalis, Entamoeba spp., and B. hominis. Temporal temperature gradient gel electrophoresis (TTGE) was used to obtain a fingerprint of the overall bacterial community; quantitative polymerase chain reaction (qPCR) was used to define the relative abundances of selected bacterial species/group, and multivariate statistical analyses were employed to correlate all data. Results: Cluster analysis revealed a significant separation of TTGE profiles into four clusters (p < 0.0001), with a marked difference for G. duodenalis-positive samples in relation to the others (p = 5.4×10-6 ). Interestingly, qPCR data showed how G. duodenalis-positive samples were related to a dysbiotic condition that favors potentially harmful species (such as Escherichia coli), while Entamoeba spp./B. hominis-positive subjects were linked to a eubiotic condition, as shown by a significantly higher Faecalibacterium prausnitzii-Escherichia coli ratio. Conclusions: This preliminary investigation demonstrates a differential fecal microbiota structure in subjects infected with G. duodenalis or Entamoeba spp./B. hominis, paving the way for using further next-generation DNA technologies to better understand host-parasite-bacteria interactions, aimed at identifying potential indicators of microbiota changes

INTESTINAL PARASITES IN TWO RURAL COMMUNITIES LIVING IN THE CORDILLERAPROVINCE (PLURINATIONAL STATE OF BOLIVIA)

INTRODUCTION: In last years sanitary conditions of people living in Bolivia improved with more extended access to safe drinking water and sanitation (Eder et al., 2012, Rev Panam Salud Publica, 32:43-8). However, the situation is still suboptimal in some communities and undetermined in others. The research here reported, which is part of a complete parasitological screening, was aimed at collecting data about intestinal parasites affecting people of two rural communities: Bartolo and Ivamirapinta (SE Bolivia). MATERIALS AND METHODS: In 2013, a total of 220 faecal samples were collected and submitted to microscopic examination (directly and after Ridley concentration). Parasites were identified on the basis of their morphological features. Samples positive to Entamoeba histolytica complex and to Blastocystis were further analysed to identify the species/subtype (ST) involved in each infection. DNA was extracted and amplified (Nested-PCR and PCR followed by sequencing, respectively) following the described protocols (Solaymani et al., 2006, J Clin Microbiol, 44: 2258-61; Bohm-Gloning et al., 1997, Trop Med Int Health, 2: 771-8). RESULTS: In Bartolo, the overall infection rate was 81.2% (91/112), and the most commonly found protozoan was Blastocystis spp. (43.7%), followed by Entamoeba coli (37.5%), Entamoeba hartmanni (17.9%), Giardia intestinalis (14.3%), Iodamoeba butschlii (10.8%), Endolimax nana (8%), Chilomastix mesnili (8%), and E. histolytica complex (7.1%). Helminth eggs identified belonged to Hymenolepis nana (8%), Ascaris lumbricoides (3.6%) and hookworms (1.8%). In Ivamirapinta, infection figure was 79.7% (86/108), and the most commonly found protozoan was Blastocystis (60.2%), followed by E. hartmanni (36.1%), E. coli (25%), E. histolytica complex (13%), E. nana (11.1%), I. butschlii (10.2%), G. intestinalis (10.2%), C. mesnilii (2.8%). Moreover, H. nana (2.8%) and Strongyloides stercoralis (0.9%) were found. In Bartolo and in Ivamirapinta multiple infections amounted to 51.8% and 53.7%, respectively, and the second community proved significantly more affected by Blastocystis and E. hartmanni (P=0,02 and P=0.037, respectively). Most of the protozoa detected were scarcely pathogenic, however E. histolytica was identified in 6 subjects in the first community and in 8 people in Ivamirapinta. As for Blastocystis, in Bartolo were found ST1 (n=4) and ST3 (n=1), whereas in the other community also ST2 (n=2), beside ST1 (n=4) and ST3 (n=2), was identified. CONCLUSIONS: Being H. nana the most prevalent helminth found, the contamination with human fresh faeces is frequent in both communities. This finding contrasts with the almost absence of human geohelminths, probably consequence of the implemented program of preventive chemotherapy. Zoonotic opportunistic species like Balantidium coli and Cryptosporidium are not present, but most protozoa found in the presented study, G. intestinalis included, are anthropo-zooparasites that have pigs or dogs as possible additional sources of infection, therefore health educational programs should be improved