Single Fecal Sample Research Articles

Predominance of Giardia intestinalis assemblage B in diarrhoeic children in Sharkia, Egypt

Background: Giardia intestinalis (G. intestinalis) is one of the most common human enteric protozoa that infect Egyptian children, causing most of the diarrhoeic outbreaks worldwide. Identification of G. intestinalis assemblage is important because of its role in determining sources of infection, in understanding the ecological and clinical impact of giardiasis, and hence its management and control.Objective: Study of this cross-sectional sample aimed to determine the genotypes of G. intestinalis isolated from the feces of diarrhoeic children attending outpatient clinic of Zagazig University hospital.Subjects and Methods: A single fecal sample was collected from each child (n=126). All samples were subjected to microscopic examination by direct wet mount before and after formal- ethyl acetate concentration. Positive samples were amplified by nested PCR (nPCR) and sequenced for intra and inter assemblage identification targeting tpi gene.Results: Microscopic examination revealed detection of G. intestinalis in 38 samples (30.2%). In 36 (28.6%) samples there was assemblage B predominance in 34 (94.4%) isolates, among which 24 (70.6%) were subgenotype BIV and 10 (29.4%) were sub-genotype BIII. Only 2 (5.6%) samples had assemblage A; all of them were AII subgenotype. All studied patient`s demographic and clinical data showed no significant association with Giardia infection or prevailing Giardia assemblages.Conclusion: G. intestinalis is the prevailing intestinal pathogen in diarrhoeic Egyptian children, with Giardia assemblage B predominance. These findings necessitate physicians’ attention and further genetic studies in Egypt and other endemic areas targeting different genetic loci, with the inclusion of larger population samples. This will lead to a better understanding of the ecological and clinical impact of giardiasis, its management and control.

PREVALENCE OF COMMON INTESTINAL PARASITES IN ADULT PATIENTS WITH CHRONIC LIVER DISEASES ASSOCIATED WITH HELICOBACTER PYLORI INFECTION

The present study investigated the prevalence of common intestinal parasites in association with H. pylori infection among a group of patients with the most common chronic disease prevalent in Egypt. These patients were known to be chronic liver disease with different etiology and followed up in gastroenterology out-patients clinic. They were 77 complaining of various abdominal symptoms either some or all symptoms such as; nausea, vomiting, abdominal pain, heart burn, flatulence, constipation, distension, melena and sometimes diarrhea. The diagnosis of chronic liver disease was confirmed by the history, clinical examination, laboratory investigations, and sonographic images. There were 37 males and 40 females with mean age (48.5+14.2). Types of liver diseases were liver cirrhosis in 28 patients and fatty liver in 49 patients (Non Alcoholic Fatty liver disease; NAFLD). None of the patients was diabetic. Afresh single fecal sample was collected from both patients and controls. Each sample was divided into two parts; one for examination of common intestinal parasites, and the other part for detection of H. pylori antigen by Copro-immunoassay. The results showed no significant difference among intestinal parasites in patients and controls. But, E. histolytic was the commonest parasite (48%) compared to; G. lamblia (4%), A. lumbricoides (5.3%), E. vermicularis (2.7%), S. mansoni (1.3%), 2/3 of patients with E. histolylica were co-infected with H. pylori infection. The prevalence of H. pylori infection was (81.8%) compared to controls (63%), with significant difference.

Prevalence of Common Intestinal Parasites in Adult Patients with Chronic Liver Diseases Associated with Helicobacter Pylori Infection

The present study investigated the prevalence of common intestinal parasites in association with H. pylori infection among a group of patients with the most common chronic disease prevalent in Egypt. These patients were known to be chronic liver disease with different etiology and followed up in gastroenterology out-patients clinic. They were 77 complaining of various abdominal symptoms either some or all symptoms such as; nausea, vomiting, abdominal pain, heart burn, flatulence, constipation, distension, melena and sometimes diarrhea. The diagnosis of chronic liver disease was confirmed by the history, clinical examination, laboratory investigations, and sonographic images. There were 37 males and 40 females with mean age (48.5+14.2). Types of liver diseases were liver cirrhosis in 28 patients and fatty liver in 49 patients (Non Alcoholic Fatty liver disease; NAFLD). None of the patients was diabetic. Afresh single fecal sample was collected from both patients and controls. Each sample was divided into two parts; one for examination of common intestinal parasites, and the other part for detection of H. pylori antigen by Copro-immunoassay. The results showed no significant difference among intestinal parasites in patients and controls. But, E. histolytic was the commonest parasite (48%) compared to; G. lamblia (4%), A. lumbricoides (5.3%), E. vermicularis (2.7%), S. mansoni (1.3%), 2/3 of patients with E. histolylica were co-infected with H. pylori infection. The prevalence of H. pylori infection was (81.8%) compared to controls (63%), with significant difference.

Human Protoparvoviruses.

Next-generation sequencing and metagenomics have revolutionized the discovery of novel viruses. In recent years, three novel protoparvoviruses have been discovered in fecal samples of humans: bufavirus (BuV) in 2012, tusavirus (TuV) in 2014, and cutavirus (CuV) in 2016. BuV has since been studied the most, disclosing three genotypes that also represent serotypes. Besides one nasal sample, BuV DNA has been found exclusively in diarrheal feces, but not in non-diarrheal feces, suggesting a causal relationship. According to both geno- and seroprevalences, BuV appears to be the most common of the three novel protoparvoviruses, whereas TuV DNA has been found in only a single fecal sample, with antibody detection being equally rare. Moreover, the TuV sequence is closer to those of non-human protoparvoviruses, and so the evidence of TuV being a human virus is thus far insufficient. Interestingly, besides in feces, CuV has also been detected in skin biopsies of patients with cutaneous T-cell lymphoma and a patient with melanoma, while all other skin samples have tested PCR negative. Even if preliminary disease associations exist, the full etiological roles of these viruses in human disease are yet to be resolved.

Molecular Biology Can Change the Classic Laboratory Approach for Intestinal Protozoan Infections.

For many years microscopy has been considered the mainstay of the diagnosis of parasitic infections. In our laboratory, before the advent of molecular biology, the approach for the identification of parasitic infections in stools was the microscopic exam of three samples. Once we adopted molecular biology, a real-time PCR on one single sample was added to the classical coproparasitological exam of three samples. Given the high sensitivity of real-time PCR (Rt-PCR), we then decided to evaluate if a change of our routine was justified. In detail, we intended to assess if a much more practical routine, based on the analysis of a single fecal sample, was sufficiently sensitive to replace the routine described above. The new approach to be evaluated included, on the same and unique fecal sample, a classical coproparasitological exam plus Rt-PCR. The data obtained showed that the sensitivity of the new proposed approach remains very high, despite the reduction of coproparasitological exams from three to one, with the advantage of reducing costs and saving time, both for patients and for the laboratory.

The Gut-Brain Axis in Healthy Females: Lack of Significant Association between Microbial Composition and Diversity with Psychiatric Measures.

ObjectiveThis study examined associations between the composition and diversity of the intestinal microbiota and measures of depression, anxiety, eating disorder psychopathology, stress, and personality in a group of healthy adult females.MethodsFemale participants (n = 91) ages 19–50 years with BMI 18.5–25 kg/m2 were recruited from central North Carolina between July 2014 and March 2015. Participants provided a single fecal sample and completed an online psychiatric questionnaire that included five measures: (i) Beck Anxiety Inventory; (ii) Beck Depression Inventory-II; (iii) Eating Disorder Examination-Questionnaire; (iv) Perceived Stress Scale; and (v) Mini International Personality Item Pool. Bacterial composition and diversity were characterized by Illumina sequencing of the 16S rRNA gene, and associations were examined using Kendall’s tau-b correlation coefficient, in conjunction with Benjamini and Hochberg’s False Discovery Rate procedure.ResultsWe found no significant associations between microbial markers of gut composition and diversity and scores on psychiatric measures of anxiety, depression, eating-related thoughts and behaviors, stress, or personality in a large cohort of healthy adult females.DiscussionThis study was the first specifically to examine associations between the intestinal microbiota and psychiatric measures in healthy females, and based on 16S rRNA taxonomic abundances and diversity measures, our results do not suggest a strong role for the enteric microbe-gut-brain axis in normal variation on responses to psychiatric measures in this population. However, the role of the intestinal microbiota in the pathophysiology of psychiatric illness may be limited to more severe psychopathology.

Inhomogeneity of the density of Parascaris spp. eggs in faeces of individual foals and the use of hypothesis testing for treatment decision making

Faecal egg counts (FEC) are used widely for monitoring of parasite infection in animals, treatment decision-making and estimation of anthelmintic efficacy. When a single count or sample mean is used as a point estimate of the expectation of the egg distribution over some time interval, the variability in the egg density is not accounted for. Although variability, including quantifying sources, of egg count data has been described, the spatiotemporal distribution of nematode eggs in faeces is not well understood. We believe that statistical inference about the mean egg count for treatment decision-making has not been used previously. The aim of this study was to examine the density of Parascaris eggs in solution and faeces and to describe the use of hypothesis testing for decision-making. Faeces from two foals with Parascaris burdens were mixed with magnesium sulphate solution and 30 McMaster chambers were examined to determine the egg distribution in a well-mixed solution. To examine the distribution of eggs in faeces from an individual animal, three faecal piles from a foal with a known Parascaris burden were obtained, from which 81 counts were performed. A single faecal sample was also collected daily from 20 foals on three consecutive days and a FEC was performed on three separate portions of each sample. As appropriate, Poisson or negative binomial confidence intervals for the distribution mean were calculated. Parascaris eggs in a well-mixed solution conformed to a homogeneous Poisson process, while the egg density in faeces was not homogeneous, but aggregated. This study provides an extension from homogeneous to inhomogeneous Poisson processes, leading to an understanding of why Poisson and negative binomial distributions correspondingly provide a good fit for egg count data. The application of one-sided hypothesis tests for decision-making is presented.

Molecular Characterization of Cryptosporidium Species and Giardia duodenalis from Symptomatic Cambodian Children.

BackgroundIn a prospective study, 498 single faecal samples from children aged under 16 years attending an outpatient clinic in the Angkor Hospital for Children, northwest Cambodia, were examined for Cryptosporidium oocysts and Giardia cysts using microscopy and molecular assays.Methodology/Principal FindingsCryptosporidium oocysts were detected in 2.2% (11/498) of samples using microscopy and in 7.7% (38/498) with molecular tests. Giardia duodenalis cysts were detected in 18.9% (94/498) by microscopy and 27.7% (138/498) by molecular tests; 82% of the positive samples (by either method) were from children aged 1–10 years. Cryptosporidium hominis was the most common species of Cryptosporidium, detected in 13 (34.2%) samples, followed by Cryptosporidium meleagridis in 9 (23.7%), Cryptosporidium parvum in 8 (21.1%), Cryptosporidium canis in 5 (13.2%), and Cryptosporidium suis and Cryptosporidium ubiquitum in one sample each. Cryptosporidium hominis and C. parvum positive samples were subtyped by sequencing the GP60 gene: C. hominis IaA16R6 and C. parvum IIeA7G1 were the most abundant subtypes. Giardia duodenalis was typed using a multiplex real-time PCR targeting assemblages A and B. Assemblage B (106; 76.8% of all Giardia positive samples) was most common followed by A (12.3%) and mixed infections (5.1%). Risk factors associated with Cryptosporidium were malnutrition (AOR 9.63, 95% CI 1.67–55.46), chronic medical diagnoses (AOR 4.51, 95% CI 1.79–11.34) and the presence of birds in the household (AOR 2.99, 95% CI 1.16–7.73); specifically C. hominis (p = 0.03) and C. meleagridis (p<0.001) were associated with the presence of birds. The use of soap was protective against Giardia infection (OR 0.74, 95% CI 0.58–0.95).Conclusions/SignificanceThis is the first report to describe the different Cryptosporidium species and subtypes and Giardia duodenalis assemblages in Cambodian children. The variety of Cryptosporidium species detected indicates both anthroponotic and zoonotic transmission in this population. Interventions to improve sanitation, increase hand washing after defecation and before preparing food and promote drinking boiled water may reduce the burden of these two parasites.

Increased uptake and improved outcomes of bowel cancer screening with a faecal immunochemical test: results from a pilot study within the national screening programme in England

BackgroundThe National Health Service Bowel Cancer Screening Programme (BCSP) in England uses a guaiac-based faecal occult blood test (gFOBt). A quantitative faecal immunochemical test (FIT) for haemoglobin (Hb) has many...

The detection and characterisation of Neospora /Hammondia-like oocysts from naturally infected dogs within the same urban region of Australia

This report describes the detection and molecular characterisation of Neospora/Hammondia-like oocysts from naturally infected dogs. Single faecal samples were collected from 160 individual greyhounds and multiple faecal samples were collected from 5 Labrador litters within a breeding kennel. Microscopy analysis detected Neospora/Hammondia like oocysts in 2 greyhounds and one litter of Labrador puppies. PCR protocols targeting the internal transcribed spacer region (ITS-1) and the large subunit (LSU) rDNA (D2/D3 domains) confirmed the presence of H. heydorni in both greyhounds and N. caninum in the Labrador litter. Dietary information obtained for all positive dogs indicate the source of infection was through regular exposure to a commercially obtained raw meat diet.These results report for the first time a natural infection with H. heydorni in dogs in Australia and also the first co-occurrence of N. caninum and H. heydorni in an Australian urban region.

Design of the PROUD study: PCR faeces testing in outpatients with diarrhoea.

BackgroundInfectious intestinal disease (IID) is an important cause of morbidity in developed countries and a frequent reason for general practitioner (GP) consultation. In recent years polymerase chain reaction (PCR) based techniques have gradually replaced conventional enteropathogen detection techniques like microscopy and culture in primary care patients suspected of IID. PCR features testing of multiple enteropathogens in a single faecal sample with shorter turnaround times and greater sensitivity compared to conventional techniques. However, the associated costs and benefits have not been quantified. Furthermore, primary care incidence and prevalence estimates of enteropathogens associated with IID are sparsely available and predominantly based on conventional techniques. The PROUD-study (PCR diagnostics in Outpatients with Diarrhoea) determines: 1) health (care) effects and 2) cost-effectiveness of PCR introduction in primary care patients suspected of IID; 3) occurrence of major enteropathogens in primary care patients suspected of IID.MethodsA before-after cohort study will be performed of patients with suspected IID consulting a GP in the Utrecht General Practitioner Network (UGPN), covering the before period (2010–2011) with conventional testing and the after period (2013–2014) with PCR testing. Prospective study data on patient characteristics and primary outcome measures (i.e. healthcare use and disease outcome) will be collected from electronic patient and laboratory records in 2015 and 2016. The effect of PCR introduction is investigated by comparing the primary outcome measures and their associated healthcare costs between the conventional period and the PCR period, and is followed by a cost-effectiveness analysis. To determine the occurrence of enteropathogens associated with IID in primary care, routine care faeces samples from the year 2014 will be screened using PCR.DiscussionThe PROUD-study will quantify the costs and effects of the introduction of PCR techniques for enteropathogens in primary care patients suspected of IID and generate up-to-date and sensitive estimates of enteropathogen occurrence among primary care patients.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-016-1371-z) contains supplementary material, which is available to authorized users.

Gut colonization with methanobrevibacter smithii is associated with childhood weight development

To prospectively investigate the presence and counts of archaea in feces of 472 children in association with weight development from 6 to 10years of age. Within the KOALA Birth Cohort Study, a single fecal sample from each child was analyzed by quantitative polymerase chain reaction to quantify archaea (Methanobrevibacter smithii, Methanosphera stadtmanae). Anthropometric outcomes (overweight [body mass index {BMI}≥85th percentile], age- and sex-standardized BMI, weight, and height z-scores) were repeatedly measured at ages (mean±SD) of 6.2±0.5, 6.8±0.5, 7.8±0.5, and 8.8±0.5years. Generalized estimating equation was used for statistical analysis while controlling for confounders. Methanobrevibacter smithii colonization was associated with an increased risk of overweight (adjusted odds ratio [OR]=2.69; 95% confidence interval [CI] 0.96-7.54) from 6 to 10years of age. Children with high levels (>7 log10 copies/g feces) of this archaeon were at highest risk for overweight (OR=3.27; 95% CI 1.09-9.83). Moreover, M. smithii colonization was associated with higher weight z-scores (adj. β 0.18; 95% CI 0.00-0.36), but not with height. For BMI z-scores, the interaction (P=0.008) between M. smithii and age was statistically significant, implying children colonized with M. smithii had increasing BMI z-scores with age. Presence and higher counts of M. smithii in the gut of children are associated with higher weight z-scores, higher BMI z-scores, and overweight.

Faecal cortisol metabolites to assess stress in wildlife: evaluation of a field method in free‐ranging chamois

Summary Non‐invasive faecal cortisol metabolite (FCM) analysis is a well‐established tool to quantify stress in captive and free‐ranging species. While the method has great potential, its suitability in field studies might be limited when faecal samples from unknown individuals are used. Possible factors affecting final results and thus jeopardizing correct data interpretation are individual and sex‐specific variation, storage conditions and uneven distribution of metabolites in the faeces. We tested these factors on a population of free‐ranging Alpine chamois Rupicapra rupicapra rupicapra in the Austrian Alps. Faecal samples (n = 183) were analysed with an established enzyme immunoassay (EIA). To further validate the assay for FCM in chamois, a high‐performance liquid chromatography (HPLC) was performed. Sex‐specific differences in metabolite excretion were evaluated. Effects of storage length and temperature on FCM were tested with two experiments. The distribution of metabolites in the faeces was determined by the analysis of subsamples of single faecal samples. Potential individual effects on FCM levels and individually variable reactions to stressful events were evaluated with a simulation experiment. Patterns of immunoreactive peaks after HPLC separation were similar for different faecal samples, except in one sample of a male. In the stability tests, storage time at ambient temperature prior to freezing and the individual were the most important variables in modulating FCM. Concentrations within single samples varied significantly between pellets. Analysis of faecal samples collected from June to October showed a highly significant seasonal trend (P &lt; 0·001) and a considerable variance of FCM levels within the population. Simulations confirmed that individual reactions to stressors in terms of varying gradients and FCM levels can explain the observed FCM patterns. Using FCM to assess adrenocortical function requires measuring extensively metabolized products of glucocorticoids, whose excretion and detection in faeces depend on several environmental, endogenous and methodological factors. In free‐ranging wildlife, these factors and the intrinsic individual differences in FCM excretion generate systemic noise and substantially distort final results. Therefore, sampling of unknown individuals inevitably jeopardizes meaningful interpretation of data, if the above named factors are not taken into consideration.

Development of the larval migration inhibition test for comparative analysis of ivermectin sensitivity in cyathostomin populations

Cyathostomins are the most prevalent parasitic pathogens of equids worldwide. These nematodes have been controlled using broad-spectrum anthelmintics; however, cyathostomin resistance to each anthelmintic class has been reported and populations insensitive to more than one class are relatively commonplace. The faecal egg count reduction test (FECRT) is considered the most suitable method for screening anthelmintic sensitivity in horses, but is subject to variation and is relatively time-consuming to perform. Here, we describe a larval migration inhibition test (LMIT) to assess ivermectin (IVM) sensitivity in cyathostomin populations. This test measures the paralysing effect of IVM on the ability of third stage larvae (L3) to migrate through a pore mesh. When L3 from a single faecal sample were examined on multiple occasions, variation in migration was observed: this was associated with the length of time that the L3 had been stored before testing but the association was not significant. Half maximal effective concentration (EC50) values were then obtained for cyathostomin L3 from six populations of horses or donkeys that showed varying sensitivity to IVM in previous FECRTs. Larvae from populations indicated as IVM resistant by FECRT displayed significantly higher EC50 values in the LMIT than L3 from populations classified as IVM sensitive or L3 from populations that had not been previously exposed to IVM or had limited prior exposure. The analysis also showed that EC50 values obtained using L3 from animals in which IVM faecal egg count reduction (FECR) levels had been recorded as <95% were significantly higher than EC50 values obtained using L3 from animals for which FECR was measured as >95%. For one of the populations, time that had elapsed since IVM administration had an effect on the EC50 value obtained, with a longer time since treatment associated with lower EC50 values. These results indicate that the LMIT has value in discriminating IVM sensitivity amongst cyathostomin populations, but several factors were identified that need to be taken into account when executing the test and interpreting the derived data.

Characteristics of Clostridium difficile colonization in Japanese children.

In children, asymptomatic colonization with Clostridium difficile is well known, but its prevalence in Japanese children is not fully understood. The objective of this study was to determine the colonization rate of C. difficile and to identify the risk factors for C. difficile colonization in Japanese children. Single fecal samples were prospectively collected from children hospitalized in Saitama City Hospital between August 1, 2012, and March 31, 2013. Samples were obtained from neonates, at 4-14 days after birth, and from non-neonatal children, principally within 2 days after admission, to determine community-associated colonization. The fecal samples were cultured for C. difficile, and isolated strains were tested for production of Clostridial toxins A/B. In 95 neonates, the colonization rate of C. difficile was 0%. The 251 non-neonatal children were divided into two subgroups, depending on the presence or absence of underlying disease. In the subgroup without underlying disease, the colonization rates of C. difficile and toxin-positive C. difficile were 21.6% and 9.0%, respectively, while in the subgroup with underlying disease, values were 30.8% and 23.1%, respectively. The proportion of toxin-positive C. difficile in all of the culture-isolated strains from the latter subgroup (75.0%) was statistically higher than that from the former subgroup (41.9%) (P = 0.049). Multivariate logistic regression analysis indicated an association of tube feeding with significantly higher colonization rates of C. difficile (Odds Ratio(OR) = 24.28; 95% confidence interval(CI)[4.70-125.34]; P < 0.001) and toxin-positive C. difficile (OR = 8.29; 95%CI[1.87-36.84]; P = 0.005). Further evaluations are recommended to assess the epidemiology and the role of C. difficile in Japanese children.

Host-centric Proteomics of Stool: A Novel Strategy Focused on intestinal Responses to the Gut Microbiota

The diverse community of microbes that inhabits the human bowel is vitally important to human health. Host-expressed proteins are essential for maintaining this mutualistic relationship and serve as reporters on the status of host-microbiota interaction. Therefore, unbiased and sensitive methods focused on host proteome characterization are needed. Herein we describe a novel method for applying shotgun proteomics to the analysis of feces, focusing on the secreted host proteome. We have conducted the most complete analysis of the extracellular mouse gut proteome to date by employing a gnotobiotic mouse model. Using mice colonized with defined microbial communities of increasing complexity or a complete human microbiota ('humanized'), we show that the complexity of the host stool proteome mirrors the complexity of microbiota composition. We further show that host responses exhibit signatures specific to the different colonization states. We demonstrate feasibility of this approach in human stool samples and provide evidence for a "core" stool proteome as well as personalized host response features. Our method provides a new avenue for noninvasive monitoring of host-microbiota interaction dynamics via host-produced proteins in stool.

Performance evaluation of canine-associated Bacteroidales assays in a multi-laboratory comparison study

The contribution of fecal pollution from dogs in urbanized areas can be significant and is an often underestimated problem. Microbial source tracking methods (MST) utilizing quantitative PCR of dog-associated gene sequences encoding 16S rRNA of Bacteroidales are a useful tool to estimate these contributions. However, data about the performance of available assays are scarce. The results of a multi-laboratory study testing two assays for the determination of dog-associated Bacteroidales (DogBact and BacCan-UCD) on 64 single and mixed fecal source samples created from pooled fecal samples collected in California are presented here. Standardization of qPCR data treatment lowered inter-laboratory variability of sensitivity and specificity results. Both assays exhibited 100% sensitivity. Normalization methods are presented that eliminated random and confirmed non-target responses. The combination of standardized qPCR data treatment, use of normalization via a non-target specific Bacteroidales assay (GenBac3), and application of threshold criteria improved the calculated specificity significantly for both assays. Such measures would reasonably improve MST data interpretation not only for canine-associated assays, but for all qPCR assays used in identifying and monitoring fecal pollution in the environment.

Colonizing the Embryonic Zebrafish Gut with Anaerobic Bacteria Derived from the Human Gastrointestinal Tract

The zebrafish has become increasingly popular for microbiological research. It has been used as an infection model for a variety of pathogens, and is also emerging as a tool for studying interactions between a host and its resident microbial communities. The mouse microbiota has been transplanted into the zebrafish gut, but to our knowledge, there has been no attempt to introduce a bacterial community derived from the human gut. We explored two methods for colonizing the developing gut of 5-day-old germ-free zebrafish larvae with a defined anaerobic microbial community derived from a single human fecal sample. Both environmental exposure (static immersion) and direct microinjection into the gut resulted in the establishment of two species-Lactobacillus paracasei and Eubacterium limosum-from a community of 30 strains consisting of 22 anaerobic species. Of particular interest is E. limosum, which, as a strict anaerobe, represents a group of bacteria which until now have not been shown to colonize the developing zebrafish gut. Our success here indicates that further investigation of zebrafish as a tool for studying human gut microbial communities is warranted.

Comparison of real-time PCR and Kato smear microscopy for the detection of hookworm infections in three consecutive faecal samples from schoolchildren in Ghana

The classic technique used to detect hookworm infections in population-based surveys is microscopic examination of Kato thick smears of multiple faecal samples per person as variation in soil-transmitted helminth egg output is common. As an alternative to this time-consuming and logistically difficult procedure, a PCR-based method to detect hookworm infections was evaluated. Faecal samples collected from 65 Ghanaian school children during February-June 2006 were examined using both techniques. Thirty-one children with a hookworm infection were detected by Kato examination of three faecal samples compared with 30 children detected by PCR of a single faecal sample and 39 detected by PCR of three faecal samples. PCR provides a sensitive alternative to the conventional microscopic detection of hookworm infections.

Health and adult productivity: The relation between adult nutrition, helminths, and agricultural, hunting, and fishing yields in the Bolivian Amazon

Infectious disease and nutritional stress have both been associated with reductions in adult work productivity and work capacity in the context of wage labor, but less research has investigated their effects among groups relying on more traditional subsistence practices of horticulture and foraging. In this article, we examine the relations among measures of adult nutritional status (BMI, skinfold measurements, and fat-free mass) and infection (presence of soil transmitted helminth infections) and measures of adult work productivity. As part of a larger panel study among Tsimane', a foraging-horticulturalist group in the Bolivian Amazon, health surveys, anthropometric information, and the quantity of products (both crops and game) brought into the household were collected for 320 Tsimane' adults over a four-month period in 2003. In addition, a single fecal sample was collected for a sub-sample of 86 adults. Our analysis shows mixed associations between either BMI or the presence of parasitism and reported adult productivity. Muscularity was not clearly related to adult productivity. In contrast, body fatness (Skinfold z-score) was inversely associated with the average quantity of fish and game brought into the household, especially for men. These findings suggest that the effects of adult infection and nutritional stress may be less clearly identified outside of the context of wage labor. Further research linking adult physical activity levels and metabolic rates to productivity in diverse contexts is needed.