Acanthamoeba Sequence Types and Allelic Variations in Isolates from Clinical and Different Environmental Sources in Italy.

The genus Acanthamoeba comprises free-living amoebae distributed in a wide variety of environments. These amoebae are clinically significant, causing opportunistic infections in humans and other animals. Despite this, limited data on Acanthamoeba sequence types and alleles are available in Italy. In the present study, we analyzed all Acanthamoeba sequences deposited from Italy with new positive Acanthamoeba clinical samples from symptomatic AK cases, to provide an overview of the genetic variants' spatial patterns from different sources within the Italian context. A total of 137 Acanthamoeba sequences were obtained. Six sequence types were identified: T2/6, T3, T4, T11, T13, and T15. Only T4 and T15 were found in both sources. The Acanthamoeba T4 sequence type was found to be the most prevalent in all regions, accounting for 73% (100/137) of the Italian samples analyzed. The T4 sequence type demonstrated significant allelic diversity, with 30 distinct alleles from clinical and/or environmental samples. These outcomes enabled a better understanding of the distribution of Acanthamoeba isolates throughout Italy, reaffirming its well-recognized ubiquity. Acanthamoeba isolates analysis from keratitis, together with the environmental strains monitoring, might provide important information on different genotypes spreading. This might be useful to define the transmission pathways of human keratitis across different epidemiological scales.

Detection and genotyping of Dientamoeba fragilis from symptomatic patients: New insights from Italy into a little-known gastrointestinal protozoan.

Dientamoeba fragilis (D. fragilis) represents a common protozoan in both high and low income countries. Despite this, epidemiological data on dientamoebiasis are still limited, and it is possible that the actual prevalence rates of D. fragilis have been underestimated due to the challenges in its detection and identification. In the present study, symptomatic patients from Rome (Central Italy) were surveyed for two years to determine D. fragilis percentage of infection and genotypes. Stool samples collection was performed over 864 patients, DNA extracted, and RT-PCR performed by the SeeGene Allplex™ Gastrointestinal Parasite Panel Assays. Seventy-nine resulted positive for D. fragilis (9.1%). Co-infections were detected in 22 isolates: 21 displayed Blastocystis sp. + D. fragilis (27.8%). Based on the sequence of a central fragment of the SSU rRNA gene, only genotype 1 was identified. These findings are among the few available data regarding genetic diversity of D. fragilis in Italy. Large-scale human and animal research are required to enhance our knowledge of prevalence, host range, genetic variability and zoonotic transmission of this little-known intestinal protozoan.

The effect of COVID-19 on the frequency of Pneumocystis jirovecii pneumonia: a monocentric, retrospective, and observational study.

BACKGROUND: Pneumocystis jirovecii pneumonia (PCP) and SARS-CoV2 share some similarities in their effects on the respiratory system, clinical presentation, and management. The COVID-19 pandemic required rapid action to curb transmission and mitigate its lethiferous impact. Non-pharmaceutical interventions (NPIs) were globally adopted. We hypothesized that these measures reduced the transmission and acquisition of P. jirovecii in both hospital and community settings. METHODS: We conducted a retrospective observational study on 2950 respiratory specimens from patients with suspected pulmonary infection, analyzed at the Laboratory of Parasitology Unit of the Policlinico Tor Vergata of Rome, Italy, from January 2014 to December 2022. RESULTS: We show a significant reduction in the frequency of PCP in the COVID-19 pandemic era compared to the previous period. Among the four sequence types of P. jirovecii identified, genotype 1 was the most prevalent (37%). We observed a non-significant trend of decreasing cases with genotype 1 and increasing cases with genotype 3 over the study period. CONCLUSIONS: The nationwide implementation of NPIs against COVID-19 may have changed the microbiological landscape of exposure, thereby decreasing the exposure to P. jirovecii and consequently reducing the incidence of PCP.

The behavioral immune system in action: Psychological correlates of pathogen disgust sensitivity in healthcare professionals working in a COVID-19 hospital.

The behavioral immune system includes a set of proactive mechanisms that inhibit contact with pathogens in the first place. These mechanisms offer a sort of psychological and behavioral prophylaxis against infection. The aim of this study was to assess the functionality of the behavioral immune system under conditions of strong ecological validity. Our hypothesis was that the emotional and more primitive component of the behavioral immune system (i.e. pathogen disgust sensitivity) acts as a powerful predictor of fear of infection. The sample was made up of 101 healthcare professionals working in a COVID-19 hospital when vaccination was not yet available. We conducted a hierarchical regression analysis to assess the role of germ-related disgust in modulating levels of fear. After controlling for the significant effects of depressive symptoms and exposure to people with a confirmed diagnosis of COVID-19, we found that fear of infection was more intense in those healthcare workers who reported higher levels of germ-related disgust. Fear of infection was not related to perceived infectability, an individual variable informed by more rational cognitive appraisals. These findings show that, even in healthcare workers who can take advantage of their professional knowledge and acquired skills for rational appraisals, the most primitive component of the behavioral immune system still plays a major role in eliciting fear of COVID-19. It is likely that the psychological reactions elicited by the behavioral immune system promote preventive health behaviors in modern environments as well.

Giardia duodenalis in Wildlife: Exploring Genotype Diversity in Italy and across Europe.

Fragmented data are so far available on genotype diversity of G. duodenalis in wildlife in different countries in Europe, in particular, in Italy. In the present study, G. duodenalis sequences obtained from different Italian wild animals [12 porcupines (Hystrix cristata), 4 wild boars (Sus scrofa), 1 wolf (Canis lupus italicus), 6 Alpine chamois (Rupicapra rupicapra rupicapra)] were compared with those available from wild host species in Europe to add new data on the geographic distribution of Giardia assemblages/sub-assemblages and their transmission patterns among natural hosts. Thirty-eight sequences were obtained by MLG analysis (SSU-rRNA, bg, gdh, and tpi genes) and subsequently compared by phylogenetic and network analyses with those from wild species monitored in the last decades in Europe. The results revealed the presence of potentially zoonotic (A-AI, A-AII from wild boar; B from porcupine) and host-adapted (D from wolf; E, A-AIII from chamois) assemblages and sub-assemblages and represent the first report for Italian wild boar. The analysis did not find any evidence of spatial or host segregation for specific genetic variants, mostly shared between different hosts from different European countries. However, conflicting evidence was found in genotypic assignment, advocating for data improvement and new genomic approaches.

Pneumocystis jirovecii pneumonia in patients with previously untreated acute myeloid leukaemia.

BACKGROUND: Several studies in immunocompromised patients, such as those with HIV infection, undergoing cancer chemotherapy or organ transplant, have led to the development of guidelines on the use of prophylaxis to prevent Pneumocystis jirovecii pneumonia (PJP), in these specific conditions. Instead, since the association between PJP and acute myeloid leukaemia (AML) is not clearly defined, the role of prophylaxis in patients with AML is not yet established. METHODS: We retrospectively analysed 251 consecutive patients with newly diagnosed non-M3-AML, admitted at the Hematology Unit of University Tor Vergata in Rome, during the period 2010-2020. The aim of the study was to evaluate the incidence of PJP among AML patients during their first hospital admission, and to identify subjects at a high risk to develop PJP. RESULTS: Among 251 consecutive patients with non-M3-AML, 67 bronchoalveolar lavages (BAL) were performed. PJP was proven in 11/67 (16.7%) subjects undergoing BAL (11 males, median age 71 years), with an incidence of 4.3%. The most common reason for BAL execution were radiological findings such as ground-glass opacities (6/11, 55%) and atypical patterns like consolidations and nodules (5/11, 45%). One patient died because of PJP after 11 days of trimethoprim/sulfamethoxazole therapy. In multivariate analysis older age and smoking habit were independent factors significantly associated with PJP (p = .021 and 0.017 respectively). CONCLUSION: We conclude that PJP infection is not uncommon among patients with AML. If intensive chemotherapy is planned, physicians should be aware of this risk and prophylaxis should be considered, particularly in older patients.

Fear of COVID-19 among Healthcare Workers: The Role of Neuroticism and Fearful Attachment.

Fear of becoming infected is an important factor of the complex suite of emotional reactions triggered by the COVID-19 pandemic. Among healthcare workers (HWs), fear of infection can put at risk their psychological well-being and occupational efficiency. The aim of this study was to analyze the role of personality (i.e., the big five traits) and adult attachment in predicting levels of fear (as measured by the FCV-19S) in 101 HWs employed in a COVID-19 university hospital. The three significant predictors retained by the stepwise regression model were age (beta = 0.26, t = 2.89, p < 0.01), emotional stability (i.e., the inverse of neuroticism) (beta = -0.26, t = -2.89, p < 0.01), and fearful attachment (beta = 0.25, t = 2.75, p < 0.01). Older HWs with higher levels of neuroticism and fearful attachment reported more intense fear of COVID-19. Our results can be useful to identify vulnerable subgroups of HWs and to implement selective programs of prevention based on counseling and psychological support.

Analysis of Human Gut Microbiota Composition Associated to the Presence of Commensal and Pathogen Microorganisms in Côte d'Ivoire.

BACKGROUND: The human gut microbiota is a microbial ecosystem contributing to the maintenance of host health with functions related to immune and metabolic aspects. Relations between microbiota and enteric pathogens in sub-Saharan Africa are scarcely investigated. The present study explored gut microbiota composition associated to the presence of common enteric pathogens and commensal microorganisms, e.g., Blastocystis and Entamoeba species, in children and adults from semi-urban and non-urban localities in Côte d'Ivoire. METHODS: Seventy-six stool samples were analyzed for microbiota composition by 16S rRDNA sequencing. The presence of adeno-, entero-, parechoviruses, bacterial and protozoal pathogens, Blastocystis, and commensal Entamoeba species, was analyzed by different molecular assays. RESULTS: Twelve individuals resulted negative for any tested microorganisms, 64 subjects were positive for one or more microorganisms. Adenovirus, enterovirus, enterotoxigenic Escherichia coli (ETEC), and Blastocystis were frequently detected. CONCLUSIONS: The bacterial composition driven by Prevotellaceae and Ruminococcaceae confirmed the biotype related to the traditional dietary and cooking practices in low-income countries. Clear separation in UniFrac distance in subjects co-harboring Entamoeba hartmanni and Blastocystis was evidenced. Alpha diversity variation in negative control group versus only Blastocystis positive suggested its possible regulatory contribution on intestinal microbiota. Pathogenic bacteria and virus did not affect the positive outcome of co-harbored Blastocystis.

PCR-based identification of thermotolerant free-living amoebae in Italian hot springs.

Several thermal areas, also used for leisure purposes, may represent suitable habitats for free-living amoebae (FLAs), but few studies have been carried out in search for these organisms. The aim of this study was to assess the presence and distribution of FLAs by culture detection and molecular identification, over a one year-round sampling of two sites in Central Italy. Two geothermal springs (Site A and Site B) were investigated for a total of 36 water samples. Four sets of primers were used to amplify FLA DNA from all cultures positive for amoebic growth at both 37 °C and 45 °C. Overall, 33 (91.6%) water samples produced PCR amplification. Eleven taxa were identified. The array of identified species varied over the sampling period, and differed between the two hot springs, Site A harbouring 11 taxa compared to 5 of site B. However, both sites were characterized by the most common species Vermamoeba vermiformis and Naegleria australiensis. Acanthamoeba genotypes T4 and T15 were found at low frequency. Differences in the composition between the two sites could reflect environmental changes in biotic and chemical/physical parameters. From a public health perspective, the detection of potentially pathogenic amoebae could unveil a potential risk for humans.

Characterization of prevalence and genetic subtypes of Blastocystis sp. in wild and domestic Suidae of central Italy aided by amplicon NGS.

Blastocystis spp. is a common single-celled intestinal symbiont, comprising several genetic subtypes (ST) and transmissible by animal-to-animal, human-to-human, animal-to-human and, possibly, human-to-animal routes. This work was designed to explore the presence of Blastocystis in sympatric domestic and wild suids and their ability to carry zoonotic STs, in a condition of widespread opportunity to come in contact with the microorganism through their shared water and food resources, and other carriers. We sampled 42 and 37 stool samples from wild boars and domestic pigs, respectively. STs were first identified by PCR followed by Sanger sequencing. Sequences represented in double-band PCR products or in Sanger chromatograms displaying multiple peaks, were resolved by next generation sequencing (NGS). Twenty-six (61.9%) wild boar and 26 (70.2%) pig samples were PCR-positive, respectively. ST3, ST5 and ST15 were found in 3.8%, 38.4% and 80.8% of the positive wild boars and 11.5%, 88.5%, 11.5% of the positive pigs, respectively. ST1 was found only in pigs (3.8%). STs 5 and 15 were common in both groups of animals, but in reversed proportions, suggesting preferential colonization. We found significantly different ST distributions among wild boars and domestic pigs. This might indicate that lifestyle differences between the two populations influence their risk for contracting certain subtypes, or that ST5 and ST15 can colonize preferentially wild or domestic animals. Based on the STs described here, wild boars and domestic pigs can act as reservoirs with zoonotic potential. The ability of suids to carry zoonotic STs appears to be higher when using NGS than Sanger sequencing, and resolution of complex sequencing profiles is imperative before excluding the presence of STs of human concern.

Immunoprophylaxis pharmacotherapy against canine leishmaniosis: A systematic review and meta-analysis on the efficacy of vaccines approved in European Union.

Leishmania (L.) infantum is a vector-borne parasite currently endemic in several Southern countries of European Union (EU), and dogs represent the main reservoir and hosts. Data from clinical trials are inconsistent with respect to the efficacy of vaccination against L. infantum infection. Therefore, a quantitative synthesis via pairwise meta-analysis was performed in agreement with the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) to increase the strength of evidence and assess the real efficacy profile of vaccines against L. infantum currently approved in EU. Data obtained from 1,394 dogs were extracted from 10 studies. The overall analysis indicated that vaccination is significantly effective in protecting against L. infantum infection (RR 0.40, 95%CI 0.23-0.72; I2 70%; P < 0.01 vs. negative controls). The subset analysis performed by excluding the effect modifiers and by considering only the studies that assessed the efficacy of vaccines currently available in EU, indicated that CaniLeish® (RR 0.38, 95%CI 0.20-0.72; I2 0%), but not Letifend® (RR 0.43, 95%CI 0.15-1.22; I2 37%), significantly protected against L. infantum infection when compared to negative controls (P < 0.05). The number needed to treat analysis showed that 3.77 (95%CI 2.59-6.94) and 10.99 (95%CI 8.28-16.34) dogs had to be treated with CaniLeish® and Letifend®, respectively, to prevent one case of infection compared to negative controls. Vaccination is effective in protecting against the risk L. infantum infection, but further studies are needed to assess whether CaniLeish® and Letifend® are characterized by similar efficacy profile.

Prevention and Control of Legionella and Pseudomonas spp. Colonization in Dental Units.

Introduction: Dental Unit Waterlines (DUWLs) have shown to be a source of Legionella infection. We report the experience of different dental healthcare settings where a risk management plan was implemented. Materials and methods: In a Hospital Odontostomatology Clinic (HOC) and three Private Dental Clinics (PDCs) housing 13 and six dental units (DUs), respectively, an assessment checklist was applied to evaluate staff compliance with guideline recommendations. DUWLs microbial parameters were investigated before and after the application of corrective actions. Results: In the HOC a poor adherence to good practices was demonstrated, whereas protocols were carefully applied in PDCs. L. pneumophila sg 2-15 was isolated in 31% (4/13) and 33% (2/6) of DUs in HOC and PDCs, respectively, mainly from handpieces (32%, 6/19) with counts >102 colony-forming units per milliliter (CFU/L), often associated with P. aeruginosa (68%, 13/19). The shock disinfection with 3% v/v hydrogen peroxide (HP) showed a limited effect, with a recolonization period of about 4 weeks. Legionella was eradicated only after 6% v/v HP shock disinfection and filters-installation, whilst P. aeruginosa after the third shock disinfection with a solution of 4% v/v HP and biodegradable surfactants. Conclusions: Our data demonstrate the presence and persistence of microbial contamination within the DUWLs, which required strict adherence to control measures and the choice of effective disinfectants.

Anthelminthic medicinal plants in veterinary ethnopharmacology: A network meta-analysis following the PRISMA-P and PROSPERO recommendations.

Medicinal plants may be effective against helminthic infestation in animals, but to date few studies have investigated the real impact of anthelminthic medicinal plants in veterinary ethnopharmacology. The aim of this study was to assess the geographical use of anthelminthic medicinal plants in livestock in European Union (EU), and to quantify the anthelminthic efficacy of medicinal plants in comparison with anthelminthic drugs. Surveys on the use of anthelminthic traditional medicinal plants in livestock in the EU were included in the qualitative synthesis. Studies that investigated the efficacy of anthelminthic traditional medicinal plants in animals, compared with negative control and/or anthelminthic drugs, were included in the quantitative synthesis (network meta-analysis). Twelve surveys (9 in Italy, 2 in Spain, 1 in Austria) reported the use of anthelminthic medicinal plants in livestock living in EU Countries. Data obtained from 256 animals and extracted from 6 studies were included in the network meta-analysis. Medicinal plants and drugs were more effective than negative control (standardized mean difference [SMD]: -0.60 95%CrI -0.88 to -0.31, -0.73 95%CrI -1.08 to -0.38, respectively, P < 0.001). Overall, no difference was detected between anthelminthic medicinal plants and anthelminthic drugs, namely albendazole, ivermectin, fenbendazole, and doramectin (SMD: 0.26 95%CrI -0.02 to 0.55, P > 0.05). The most effective anthelminthic medicinal plants were Artemisia absintihium, Allium sativum, and Duranta erecta. There is the strong medical need of performing adequately powered randomized controlled trials in different livestock species aimed to improve the quality of the current evidence concerning the anthelminthic efficacy of medicinal plants compared to that of the currently available antiparasitic drugs.

Outbreak of swimmer's itch in Central Italy: Description, causative agent and preventive measures.

Swimmer's itch is caused by the penetration of free-swimming larvae of trematodes of the family Schistosomatidae in human skin. It is usually reported in people engaged in recreational water activities in freshwater bodies and in most of cases, it is provoked by bird schistosomes of the genus Trichobilharzia. In the summer 2017, many cases of dermatitis were recorded in people bathing in the waters of the Albano Lake (Rome, Italy) and a parasitological investigation was carried out in order to ascertain the causative agent of these cases. Snails of the family Lymnaeidae, natural intermediate hosts of bird schistosomes, were collected from lake shallow waters to detect the presence of trematodes of the genus Trichobilharzia. Pools of maximum 10 snails were placed in Petri dishes, and cercarial emergence was stimulated exposing snails to strong artificial light intensity at 25°C. Three hundred and thirty-seven snails were collected and screened for the shedding of cercariae. Furcocercariae of the family Schistosomatidae, with a morphology overlapping that of the genus Trichobilharzia, were detected in seven Petri dishes. Assuming that in each positive Petri dish just one snail was shedding furcocercariae, the minimum infectious rate was 2.1%. Molecular analysis of furcocercariae allowed ascribing them to the species Trichobilharzia franki. Snails of the species Radix auricularia were identified as intermediate hosts of the parasite. This is the second record of T. franki causing cercarial dermatitis in Central Italy, the third in Italy. The 2017 was in Italy exceptionally warm and dry. Trematodes are sensitive to changes in temperature, being cercarial production and emission rates temperature dependent. Small increases in water temperature would speed up parasite development and transmission, leading to a manifold increase in cercarial emergence. Moreover, high temperatures raise chances to acquire the infection, due to increased time spent in water by people.

Regional spread of contact lens-related Acanthamoeba keratitis in Italy.

Acanthamoeba ocular infections, known as Acanthamoeba keratitis, are an emerging problem among contact lens wearers. Infections mediated by Acanthamoeba are uncommon, but they can be underestimated due to poor awareness and delayed diagnosis. The routine use of rapid and cost-effective molecular methods like Real Time PCR for the diagnosis of this important pathogen could improve diagnosis and therapy outcome. This report describes the detection by Real Time PCR assay of six T4 and one T3 Acanthamoeba infections, as the first reported cases in Tuscany, Italy.

Pneumocystis jirovecii genotyping: experience in a tertiary-care hospital in Northern Italy.

Respiratory samples from Pneumocystis jirovecii pneumonia (PJP) cases collected at a tertiary-care university hospital in Modena were analyzed for the presence of specific polymorphisms in the mitochondrial large subunit ribosomal RNA (mtLSU-rRNA). Retrospectively, 57 cases were selected in a six-year period and 34 out of the 57 processed BAL samples returned PCR positive results, thus allowing further molecular analysis. The following P.jirovecii genotype distribution was observed: genotype 3 (50%), genotype 2 (23%), genotype 1 (18%), genotypes 1 or 4 (9%). These data add novel insights on P.jirovecii epidemiology, investigating a previously unstudied area of Northern Italy. A peculiar local distribution is highlighted with respect to other areas within the national panorama, thus encouraging further in-depth studies in an attempt to better understand the overall situation concerning P.jirovecii genotype circulation.

Diversity of Pneumocystis jirovecii Across Europe: A Multicentre Observational Study.

Pneumocystis jirovecii is an airborne human-specific ascomycetous fungus responsible for Pneumocystis pneumonia (PCP) in immunocompromised patients, affecting >500,000 patients per year (www.gaffi.org). The understanding of its epidemiology is limited by the lack of standardised culture. Recent genotyping data suggests a limited genetic diversity of P. jirovecii. The objective of the study was to assess the diversity of P. jirovecii across European hospitals and analyse P. jirovecii diversity in respect to clinical data obtained from the patients. Genotyping was performed using six already validated short tandem repeat (STR) markers on 249 samples (median: 17 per centre interquartile range [11-20]) from PCP patients of 16 European centres. Mixtures of STR markers (i.e., ≥2 alleles for ≥1 locus) were detected in 67.6% (interquartile range [61.4; 76.5]) of the samples. Mixture was significantly associated with the underlying disease of the patient, with an increased proportion in HIV patients (78.3%) and a decreased proportion in renal transplant recipients (33.3%) (p<0.001). The distribution of the alleles was significantly different (p<0.001) according to the centres in three out of six markers. In analysable samples, 201 combinations were observed corresponding to 137 genotypes: 116 genotypes were country-specific; 12 in two; six in three; and two in four and one in five countries. Nine genotypes were recorded more than once in a given country. Genotype 123 (Gt123) was significantly associated with France (14/15, p<0.001) and Gt16 with Belgium (5/5, p<0.001). More specifically, Gt123 was observed mainly in France (14/15/16 patients) and in renal transplant patient (13/15). Our study showed the wide population diversity across Europe, with evidence of local clusters of patients harbouring a given genotype. These data suggest a specific association between genotype and underlying disease, with evidence of a different natural history of PCP in HIV patients and renal transplant recipients.

Infectious disease ward admission positively influences P. jiroveci pneumonia (PjP) outcome: A retrospective analysis of 116 HIV-positive and HIV-negative immunocompromised patients.

P. jiroveci (Pj) causes a potentially fatal pneumonia in immunocompromised patients and the factors associated with a bad outcome are poorly understood. A retrospective analysis on Pj pneumonia (PjP) cases occurring in Tor Vergata University Hospital, Italy, during the period 2011-2015. The patients' demographic, clinical and radiological characteristics and the Pj genotypes were considered. The study population included 116 patients, 37.9% of whom had haematological malignancy or underwent haematological stem cell transplantation (HSCT), 22.4% had HIV infection, 16.4% had chronic lung diseases (CLD), 7.8% had a solid cancer, and 3.4% underwent a solid organ transplant (SOT). The remaining 12.1% had a miscellaneous other condition. At univariate analysis, being older than 60 years was significantly correlated with a severe PjP (OR [95%CI] 2.52 [0.10-5.76]; p = 0.031) and death (OR [95%CI] 2.44 [1.05-5.70]; p = 0.036), while a previous trimethoprim/sulfamethoxazole (TMP/SMX) prophylaxis were significantly associated with a less severe pneumonia (OR[95%CI] 0.35 [0.15-0.84], p = 0.023); moreover, death due to PjP was significantly more frequent in patients with CLD (OR[95%CI] 3.26 [1.17-9.05]; p = 0.019) while, admission to the Infectious Diseases Unit was significantly associated with fewer deaths (OR[95%CI] 0.10 [0.03-0.36], p = 0.002). At multivariate analysis, a better PjP outcome was observed in patients taking TMP/SMX prophylaxis and that were admitted to the Infectious Diseases Unit (OR[95%CI] 0.27 [0.07-1.03], p = 0.055, OR[95%CI] 0.16 [0.05-0.55]; p = 0.004, respectively). In conclusion, in our study population, TMP/SMX prophylaxis and infectious disease specialist approach were variables correlated with a better PjP outcome.

Update on Acanthamoeba jacobsi genotype T15, including full-length 18S rDNA molecular phylogeny.

Free-living amoebae of the genus Acanthamoeba are worldwide present in natural and artificial environments, and are also clinically important, as causative agents of diseases in humans and other animals. Acanthamoeba comprises several species, historically assigned to one of the three groups based on their cyst morphology, but presently recognized as at least 20 genotypes (T1-T20) on the basis of their nuclear 18S ribosomal RNA (rRNA) gene (18S rDNA) sequences. While strain identification may usually be achieved targeting short (<500 bp) 18S ribosomal DNA (rDNA) fragments, the use of full-length gene sequences (>2200 bp) is necessary for correct genotype description and reliable molecular phylogenetic inference. The genotype T15, corresponding to Acanthamoeba jacobsi, is the only genotype described on the basis of partial sequences (~1500 bp). While this feature does not prevent the correct identification of the strains, having only partial sequences renders the genotype T15 not completely defined and may furthermore affect its position in the Acanthamoeba molecular tree. Here, we complete this gap, by obtaining full-length 18S rDNA sequences from eight A. jacobsi strains, genotype T15. Morphologies and physiological features of isolated strains are reported. Molecular phylogeny based on full 18S rDNA confirms some previous suggestions for a genetic link between T15 and T13, T16, and T19, with T19 as sister-group to T15.

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.