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International Journal of Environmental... Nov 2019Drinking water outbreaks occur worldwide and may be caused by several factors, including raw water contamination, treatment deficiencies, and distribution network...
Drinking water outbreaks occur worldwide and may be caused by several factors, including raw water contamination, treatment deficiencies, and distribution network failure. This study describes two drinking water outbreaks in Finland in 2016 (outbreak I) and 2018 (outbreak II). Both outbreaks caused approximately 450 illness cases and were due to drinking water pipe breakage and subsequent wastewater intrusion into the distribution system. In both outbreaks, the sapovirus was found in patient samples as the main causative agent. In addition, adenoviruses and (outbreak I), and noroviruses, astroviruses, enterotoxigenic and enterohemorragic (ETEC and EHEC, respectively) and (outbreak II) were detected in patient samples. Water samples were analyzed for the selected pathogens largely based on the results of patient samples. In addition, traditional fecal indicator bacteria and host-specific microbial source tracking (MST) markers (GenBac3 and HF183) were analyzed from water. In drinking water, sapovirus and enteropathogenic (EPEC) were found in outbreak II. The MST markers proved useful in the detection of contamination and to ensure the success of contaminant removal from the water distribution system. As mitigation actions, boil water advisory, alternative drinking water sources and chlorination were organized to restrict the outbreaks and to clean the contaminated distribution network. This study highlights the emerging role of sapoviruses as a waterborne pathogen and warrants the need for testing of multiple viruses during outbreak investigation.
Topics: Bacterial Infections; Disease Outbreaks; Drinking Water; Feces; Finland; Humans; Virus Diseases; Wastewater; Water Microbiology; Water Purification
PubMed: 31717479
DOI: 10.3390/ijerph16224376 -
Mikrobiyoloji Bulteni Oct 2019Aim of the present study was to identify protozoones which are difficult to define through wet slide in fresh fecal samples by using different fixatives with modified...
Aim of the present study was to identify protozoones which are difficult to define through wet slide in fresh fecal samples by using different fixatives with modified Trichrome stain within five minutes. Two different fixatives prepared for the alternative approach. The slides were fixed by two different fixatives, one of them (fixative-1) was based ethylalcohol, formalin, acetic acid, distilled water and the other one (fixative-2) based ethylalcohol, formalin, citric acid, distilled water included a mordant [divalent or polyvalent metals which make coordination complex with some dyes] consisted copper sulphate pentahydrate (CuSO4 .5H2 O). Slides prepared by the two different fixatives were stained by a different modification of Gomori's trichrome stain that we made. Samples fixed by Schaudinn fixative including mercury chloride were stained by Wheatley modification of Gomori's trichrome stain as a gold standard for control and comparison. We worked with 50 fecal samples which we thought included human intestinal protozoones after the wet slide examination. Comparing the methods, slides prepared with the method including citric acid gave almost similar results with the classical method excluded Entamoeba coli cystes. Slides prepared with the methode including acetic acid gave low performance compared with the classical method especially E.coli cystes and Blastocystis spp., Endolimax nana, Iodamoeba bütschlii, E.hartmanni. Both new fixatives gave superior performance at the slides included Dientamoeba fragilis and approximately shorten the procedure process ten times than the classical method. When the both alternative methods compared in each other, the slides prepared with fixative-2 exposed better performance for the protozoones Blastocystis spp., E.nana, I.bütschlii and E.hartmanni while the fixative-1 displayed minimal superiority for D.fragilis including criterias that we based. The fixative-2 and modified stain methode that we used in our study, makes available the diagnostic phase ten times faster than the classical method in human stool parasitological tests excluding the E.coli cystes at parasitology and microbiolgy laboratories. It seems to be a good option to the classical method for routine usage.
Topics: Eukaryota; Feces; Fixatives; Formaldehyde; Humans; Microscopy; Parasitic Diseases; Parasitology
PubMed: 31709939
DOI: 10.5578/mb.68633 -
PLoS Neglected Tropical Diseases Sep 2019Visceral leishmaniasis (VL) caused by Leishmania donovani remains of public health concern in rural India. Those at risk of VL are also at risk of other neglected...
Visceral leishmaniasis (VL) caused by Leishmania donovani remains of public health concern in rural India. Those at risk of VL are also at risk of other neglected tropical diseases (NTDs) including soil transmitted helminths. Intestinal helminths are potent regulators of host immune responses sometimes mediated through cross-talk with gut microbiota. We evaluate a meta-taxonomic approach to determine the composition of prokaryotic and eukaryotic gut microflora using amplicon-based sequencing of 16S ribosomal RNA (16S rRNA) and 18S rRNA gene regions. The most abundant bacterial taxa identified in faecal samples from Bihar State India were Prevotella (37.1%), Faecalibacterium (11.3%), Escherichia-Shigella (9.1%), Alloprevotella (4.5%), Bacteroides (4.1%), Ruminococcaceae UCG-002 (1.6%), and Bifidobacterium (1.5%). Eukaryotic taxa identified (excluding plant genera) included Blastocystis (57.9%; Order: Stramenopiles), Dientamoeba (12.1%; Family: Tritrichomonadea), Pentatrichomonas (10.1%; Family: Trichomonodea), Entamoeba (3.5%; Family: Entamoebida), Ascaridida (0.8%; Family: Chromodorea; concordant with Ascaris by microscopy), Rhabditida (0.8%; Family: Chromodorea; concordant with Strongyloides), and Cyclophyllidea (0.2%; Order: Eucestoda; concordant with Hymenolepis). Overall alpha (Shannon's, Faith's and Pielou's indices) and beta (Bray-Curtis dissimilarity statistic; weighted UniFrac distances) diversity of taxa did not differ significantly by age, sex, geographic subdistrict, or VL case (N = 23) versus endemic control (EC; N = 23) status. However, taxon-specific associations occurred: (i) Ruminococcaceae UCG- 014 and Gastranaerophilales_uncultured bacterium were enriched in EC compared to VL cases; (ii) Pentatrichomonas was more abundant in VL cases than in EC, whereas the reverse occurred for Entamoeba. Across the cohort, high Escherichia-Shigella was associated with reduced bacterial diversity, while high Blastocystis was associated with high bacterial diversity and low Escherichia-Shigella. Individuals with high Blastocystis had low Bacteroidaceae and high Clostridiales vadin BB60 whereas the reverse held true for low Blastocystis. This scoping study provides useful baseline data upon which to develop a broader analysis of pathogenic enteric microflora and their influence on gut microbial health and NTDs generally.
Topics: Adolescent; Adult; Bacteria; Child; Child, Preschool; Cohort Studies; Eukaryota; Feces; Female; Gastrointestinal Microbiome; Humans; India; Leishmania donovani; Leishmaniasis, Visceral; Male; Middle Aged; Rural Population; Young Adult
PubMed: 31490933
DOI: 10.1371/journal.pntd.0007444 -
Parasitology Jan 2020The presence of bacterial DNA in Dientamoeba fragilis DNA extracts from culture poses a substantial challenge to sequencing the D. fragilis genome. However, elimination...
The presence of bacterial DNA in Dientamoeba fragilis DNA extracts from culture poses a substantial challenge to sequencing the D. fragilis genome. However, elimination of bacteria from D. fragilis cultures has proven difficult in the past, presumably due to its dependence on some unknown prokaryote/s. This study explored options for removal of bacteria from D. fragilis cultures and for the generation of genome sequence data from D. fragilis. DNA was extracted from human faecal samples and xenic D. fragilis cultures. Extracts were subjected to 16S ribosomal DNA bacterial diversity profiling. Xenic D. fragilis cultures were then subject to antibiotic treatment regimens that systematically removed bacterial species depending on their membrane structure (Gram-positive or Gram-negative) and aerobic requirements. The impact of these treatments on cultures was assessed by 16S amplicon sequencing. Prior to antibiotic treatment, the cultures were dominated by Gram-negative bacteria. Addition of meropenem to cultures eliminated anaerobic Gram-negative bacteria, but it also led to protozoan death after 5 days incubation. The seeding of meropenem resistant Klebsiella pneumoniae strain KPC-2 into cultures before treatment by meropenem prevented death of D. fragilis cells beyond this 5 day period, suggesting that one or more species of Gram-negative bacteria may be an essential nutritional requirement for D. fragilis. Gram-positive cells were completely eliminated using vancomycin without affecting trophozoite growth. Finally, this study shows that genome sequencing of D. fragilis is feasible following bacterial elimination from cultures as the result of the major advances occurring in bioinformatics. We provide evidence on this fact by successfully sequencing the D. fragilis 28S large ribosomal DNA subunit gene using culture-derived DNA.
Topics: Anti-Bacterial Agents; Bacteria; Bacterial Physiological Phenomena; Culture Techniques; Dientamoeba; Genetic Variation; Genome, Protozoan; RNA, Ribosomal, 16S; RNA, Ribosomal, 28S
PubMed: 31452478
DOI: 10.1017/S0031182019001173 -
Euro Surveillance : Bulletin Europeen... Jul 2019BackgroundDespite the global distribution of the intestinal protozoan its clinical picture remains unclear. This results from underdiagnosis: microscopic screening...
BackgroundDespite the global distribution of the intestinal protozoan its clinical picture remains unclear. This results from underdiagnosis: microscopic screening methods either lack sensitivity (wet preparation) or fail to reveal (formalin-fixed sample).AimIn a retrospective study setting, we characterised the clinical picture of dientamoebiasis and compared it with giardiasis. In addition, we evaluated an improved approach to formalin-fixed samples for suitability in diagnostics.MethodsThis study comprised four parts: (i) a descriptive part scrutinising rates of findings; (ii) a methodological part analysing an approach to detect -like structures in formalin samples; (iii) a clinical part comparing demographics and symptoms between patients with dientamoebiasis (n = 352) and giardiasis (n = 272), and (iv) a therapeutic part (n = 89 patients) investigating correlation between faecal eradication and clinical improvement.ResultsThe rate of findings increased 20-fold after introducing criteria for -like structures in formalin-fixed samples (88.9% sensitivity and 83.3% specificity). A further increase was seen after implementing faecal PCR. Compared with patients with giardiasis, the symptoms in the group lasted longer and more often included abdominal pain, cramping, faecal urgency and loose rather than watery stools. Resolved symptoms correlated with successful faecal eradication (p < 0.001).ConclusionsPreviously underdiagnosed, has become the most frequently recorded pathogenic enteroparasite in Finland. This presumably results from improved diagnostics with either PCR or detection of -like structures in formalin-fixed samples, an approach applicable also in resource-poor settings. Symptoms of dientamoebiasis differ slightly from those of giardiasis; patients with distressing symptoms require treatment.
Topics: Abdominal Pain; Adult; Animals; Diarrhea; Dientamoeba; Dientamoebiasis; Feces; Female; Finland; Giardiasis; Humans; Male; Middle Aged; Polymerase Chain Reaction; Retrospective Studies; Sex Distribution
PubMed: 31339096
DOI: 10.2807/1560-7917.ES.2019.24.29.1800546 -
Turkiye Parazitolojii Dergisi Jun 2019Intestinal infections are common in the elderly, presented with atypical symptoms and may be the cause of mortality with a more severe clinical manifestation. The...
OBJECTIVE
Intestinal infections are common in the elderly, presented with atypical symptoms and may be the cause of mortality with a more severe clinical manifestation. The weakening of cellular and humoral immunity by aging affects the intestinal flora and increases the risk of infection in the presence of chronic diseases. The aim of this study was to investigate the presence of possible parasitic agents in the intestinal system of ≥65-year-old nursing home residents through fecal examination, and to determine the demographic features (age and gender) of this elderly group.
METHODS
A total of 82 stool samples were examined (100x, 40x) with saline and iodine preparations, formol-ethyl acetate concentration process, trichrome and modified Erlich Ziehl Neelsen stained preparations.
RESULTS
One or more parasitological agents were detected in 17 (20.7%) of the 82 stool samples examined. The most common agent was spp. (13.4%), followed by spp. (2.4%) and (2.4%).
CONCLUSION
In this study, it was determined that attention should be given to elderly population with regard to intestinal parasitic infections. Because of changes in the immune system, more opportunistic factors could be detected. More frequent screening in public areas such as nursing homes is important for preventing infections.
Topics: Aged; Aged, 80 and over; Animals; Blastocystis Infections; Cryptosporidiosis; Dientamoebiasis; Entamoebiasis; Feces; Female; Giardia lamblia; Giardiasis; Humans; Intestinal Diseases, Parasitic; Male; Middle Aged; Nursing Homes; Prevalence
PubMed: 31204459
DOI: 10.4274/tpd.galenos.2019.6321 -
Epidemiology and Infection Jan 2019There is a scarcity of recent epidemiological data on intestinal parasitic infections in France. We conducted a prospective study aimed at estimating the prevalence of...
There is a scarcity of recent epidemiological data on intestinal parasitic infections in France. We conducted a prospective study aimed at estimating the prevalence of 10 enteric parasites in Marseille, France, using real-time polymerase chain reaction (PCR)-based diagnosis. A total of 643 faeces from 488 patients referred to the Parasitology-Mycology Laboratory of the University Hospital of Marseille over a 6 months period were included. DNA was extracted using a semi-automated method. Parasites of interest were detected using singleplex quantitative PCRs (qPCRs). For positive samples, the Blastocystis subtype was determined by sequence analysis. During the study, the overall prevalence of enteric parasites was 17%. Blastocystis sp. was the most frequent species (10.5%), followed by Dientamoeba fragilis (2.3%) and Giardia intestinalis (2.3%). The prevalence of other parasites was <1% each. The ST3 Blastocystis subtype was predominant (43.6%) and the other subtypes identified were ST1, ST2, ST4 and ST6. This is the first time that a qPCR-based diagnosis has been used to survey the prevalence of 10 enteric parasites in a French University Hospital. This study confirms that fast, specific, sensitive and simultaneous detection in a single stool sample by qPCR clearly outperforms conventional microscopy-based diagnosis. Furthermore, qPCR is particularly well suited to surveying gastroenteritis agents.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Child, Preschool; Feces; Female; France; Humans; Infant; Intestinal Diseases, Parasitic; Male; Middle Aged; Prevalence; Prospective Studies; Real-Time Polymerase Chain Reaction; Young Adult
PubMed: 30869032
DOI: 10.1017/S0950268819000165 -
Journal of Clinical Microbiology May 2019is a gastrointestinal trichomonad parasite whose pathogenicity is yet to be determined. The difficulty involved in microscopically diagnosing in feces led to the... (Comparative Study)
Comparative Study
is a gastrointestinal trichomonad parasite whose pathogenicity is yet to be determined. The difficulty involved in microscopically diagnosing in feces led to the development of real-time PCR methodologies for the detection of in stool samples. Prevalence studies in Europe show much higher levels of infection where a laboratory-developed real-time assay is the predominant assay for the detection of than in regions that use the EasyScreen assay for detection of gastrointestinal pathogens. The aim of this study was to compare a commercially available assay (Genetic Signatures EasyScreen assay) to a widely used laboratory-developed real-time PCR method. Two hundred fifty fecal samples were screened using the laboratory-developed real-time assay on four real-time PCR platforms producing a number of discrepant results. Limit-of-detection studies were undertaken to attempt to resolve sensitivity for each platform tested. The presence or absence of DNA in discrepant samples was shown using PCR amplicon next-generation sequencing. Eukaryotic 18S diversity profiling was conducted on discrepant samples to identify the presence or absence of additional protozoan species in samples that may be responsible for cross-reactivity seen in these samples. The results revealed the potential for multiple false-positive results when using the laboratory-developed real-time assay across multiple real-time platforms using manufacturer default settings. This report provides recommendations to resolve these issues where possible and suggestions for future prevalence studies, and it emphasizes the EasyScreen assay as the molecular method of choice as well as the need for standardization of detection assays across all nations screening for .
Topics: Cross-Sectional Studies; DNA, Protozoan; Dientamoeba; Dientamoebiasis; Europe; False Positive Reactions; Feces; High-Throughput Nucleotide Sequencing; Humans; Reagent Kits, Diagnostic; Real-Time Polymerase Chain Reaction; Sensitivity and Specificity
PubMed: 30814263
DOI: 10.1128/JCM.01466-18 -
Asian Pacific Journal of Cancer... Feb 2019Background: Intestinal parasitic infection in immunodeficient patients especially those with impaired cellular immunity, like neoplasia, renal or heart transplant needs...
Background: Intestinal parasitic infection in immunodeficient patients especially those with impaired cellular immunity, like neoplasia, renal or heart transplant needs careful consideration. The objective of this study is to evaluate the prevalence of intestinal parasites in different group of patients including cancer patients; organ transplants recipients, and primary immunodeficiency patients. Methods: Stool samples from 190 patients including 80 patients with Primary Immunodeficiency, 85 cancer patients and 25 organ transplant recipients were collected; a direct examination with Phosphate buffered saline (PBS) and formalin ether concentration was performed. The DNA was extracted from parasitologically confirmed patients and nested PCR and sequencing was performed and new obtained sequences of Cryptosporidium parvum and Enterocytozoon bieneusi were compared with deposited ones. Results: In general, the prevalence of parasites was 26/80 (32.5%) in primary immunodeficiency, 22/85(25.9%) in cancer group, and 7/25 (28%) in organ transplant. The prevalence of intestinal parasitic infections in primary immunodeficiency patients were Blastocystis hominis 13 (16.2%), Giardia lamblia 10 (12.5%), Cryptosporidium 1(1.2%), Chilomastix mesnilii 1 (1.2%), Dientamoeba fragilis 1(1.2%). Of 25 organ transplants, 6 (24%) Cryptosporidium sp were found, all of which were confirmed as Cryptosporidium parvum and one case of Microspora in a heart transplant recipient was confirmed as Enterocytozoon bieneusi by PCR sequencing. The predominant intestinal parasitic infection in cancer patients was 19 (22.3%) Blastocystis hominis followed by two (2.3%) Giardia lamblia and one Dientamoeba fragilis 1 (1.1%). Conclusion: The high rate of infection with Blastocystis hominis was found in cancer patients especially colorectal cancer patients, so careful consideration should be given by physicians. Cryptosporidium sp was found to be the major cause of parasitic intestinal infection in patients with organ transplant compared to primary immunodeficiency patients; so transplant recipients undergoing immunosuppressive therapy should be considered as a risk group for acquiring microsporidiosis and Cryptosporidium infection.
Topics: Adolescent; Adult; Aged; Animals; Child; Child, Preschool; Cross-Sectional Studies; Feces; Female; Follow-Up Studies; Humans; Immunologic Deficiency Syndromes; Intestinal Diseases, Parasitic; Iran; Male; Middle Aged; Neoplasms; Organ Transplantation; Parasites; Prevalence; Prognosis; Young Adult
PubMed: 30803212
DOI: 10.31557/APJCP.2019.20.2.495 -
Archives of Disease in Childhood Jul 2019To study the association between colonisation and faecal calprotectin to see whether the parasite is a harmless commensal or a gut pathogen.
OBJECTIVE
To study the association between colonisation and faecal calprotectin to see whether the parasite is a harmless commensal or a gut pathogen.
DESIGN
Cross-sectional study of previously collected stool samples.
SETTING AND PATIENTS
Two hundred stool samples originated from children aged 5-19 years with chronic abdominal pain and diarrhoea, who were seen in paediatric clinics in the Netherlands and Belgium and in whom somatic gastrointestinal disorders were excluded. Another 122 samples came from a healthy community-based reference population of the same age. All stool samples were analysed with real-time PCR for the detection of and with an ELISA for calprotectin-a biomarker of gastrointestinal inflammation.
MAIN OUTCOME MEASURES
Prevalence of colonisation and results of stool calprotectin testing.
RESULTS
was detected in 45% (95% CI 38% to 51%) of patients and in 71% (95% CI 63% to 79%) of healthy children. Median (IQR) concentrations of calprotectin in patients and healthy children with a positive PCR result were not different from those with a negative PCR result (40 (40-55) μg/g vs 40 (40-75) μg/g, respectively).
CONCLUSION
Since colonisation is most prevalent in healthy children and is not associated with an increase in faecal calprotectin concentration, our data do not support the inference that is a pathogenic parasite. Routinely testing for in children with chronic abdominal pain should therefore be discouraged.
Topics: Abdominal Pain; Adolescent; Belgium; Child; Child, Preschool; Cohort Studies; Cross-Sectional Studies; Dientamoeba; Dientamoebiasis; Feces; Female; Humans; Male; Netherlands; Prevalence; Prospective Studies; Real-Time Polymerase Chain Reaction; Retrospective Studies; Young Adult
PubMed: 30798256
DOI: 10.1136/archdischild-2018-316383