Effects of Dietary Zinc Manipulation on Growth Performance,Zinc Status and Immune Response during Giardia lamblia Infection: A Study in CD-1 Mice

Associations between Giardia lamblia infection and low serum concentrations of zinc have been reported in young children. Interestingly, relatively few studies have examined the effects of different dietary zinc levels on the parasite-infected host. The aims of this study were to compare the growth performance and zinc status in response to varying levels of dietary zinc and to measure the antibody-mediated response of mice during G. lamblia infection. Male CD-1 mice were fed using 1 of 4 experimental diets: adequate-zinc (ZnA), low-zinc (ZnL), high-zinc (ZnH) and supplemented-zinc (ZnS) diet containing 30, 10, 223 and 1383 mg Zn/kg respectively. After a 10 days feeding period, mice were inoculated orally with 5 × 10⁶ G. lamblia trophozoites and were maintained on the assigned diet during the course of infection (30 days). Giardia-free mice fed ZnL diets were able to attain normal growth and antibody-mediated response. Giardia-infected mice fed ZnL and ZnA diets presented a significant growth retardation compared to non-infected controls. Zinc supplementation avoided this weight loss during G. lamblia infection and up-regulated the host’s humoral immune response by improving the production of specific antibodies. Clinical outcomes of zinc supplementation during giardiasis included significant weight gain, higher anti-G. lamblia IgG antibodies and improved serum zinc levels despite the ongoing infection. A maximum growth rate and antibody-mediated response were attained in mice fed ZnH diet. No further increases in body weight, zinc status and humoral immune capacity were noted by feeding higher zinc levels (ZnS) than the ZnH diet. These findings probably reflect biological effect of zinc that could be of public health importance in endemic areas of infection.     

Incidence of Giardia lamblia Subspecies by PCR-RFLP in Stool Specimens of Hospitalized Children at Urmia Mutahhari Hospital,West Azerbaijan Province,Iran

Background

Giardia lamblia is one of the most prevalent intestinal flagellate protozoa that infects a wide range of vertebrate hosts causing severe intestinal disorder in children.This study was performed to determine subspecies of G.lamblia by the PCR-RFLP method, targeting the glutamate dehydrogenase(gdh)locus, in hospitalized children at Urmia Mutahhari Hospital, West Azerbaijan Province,Iran and determining the infection transformational storages in this area.

Methods

Overall, 720 stool specimens were collected from the hospitalized children, 34 samples were positive and Giardia cysts were detected under the microscope. Cysts were partially purified by the sucrose density gradient method and then washed with sterile distilled water to remove effectively the PCR inhibitors. Genomic DNA of G. lamblia isolates was extracted by freeze-thaw cycles followed by phenol/ chloroform/isoamyl alcohol method. The single step PCR-RFLP assay was used to differentiate the assemblages between A and B, which were found in humans. In this method, 432 bp expected size was amplified, and then for detection of subspecies, specific restriction RsaI and BspLI enzymes were used.

Results

Totally 34 samples were positive in terms of Giardia cyst out of 720 examined samples microscopically, so the parasite spread rate is reported 4.72%. Analysis PCR-RFLP on these samples revealed that 28 samples (93.3%) have the genotype BIII and 2 samples (6.7%) belong to the subgroup BIV.

Conclusion

PCR-RFLP is a proper analytical method for determining the genotype among parasite types, using the glutamate dehydrogenizes zone’s genes. Based on the results, an animal origin of infection cycle is suggested.     

Prevalence of Giardia duodenalis Infection in Household Cats of Ahvaz District,South-West of Iran

Background

The occurrence of Giardia duodenalis in cats is of potential significance from both clinical and public health perspectives. The object of this study was antigenic detection of G. duodenalis in household cats of Ahvaz district, South-West of Iran.

Methods

The prevalence of G. duodenalis was determined in fecal samples by two techniques: centrifugation-flotation and a commercial Giardia Antigen Test Kit (immunochromatography assay) in 150 household cats of different ages among referred cases to Veterinary Hospital of Ahvaz University from January 2008 to February 2010.

Results

Five out of 150 fecal samples (3.33%) were positive for antigen of G. duodenalis by immunochromatography assay. The prevalence was significantly higher in young cats less than 6 months (15.79%) compared with adult cats 6 months – 3 years (1.37%) (P=0.027) and above 3 years (1.72%) (P=0.044). The infection had more prevalence in diarrheic cats (17.39%) compared with non-diarrheic cats (0.79%) and the difference was significant (P=0.02) as well. The prevalence was higher in male cats (3.41%) than females (3.23%) and in the season of autumn (6.06%), but the difference was not significant between the prevalence of infection relative to host gender and season (P>0.05). Microscopy examination on fecal samples showed that 2% of the studied cats were positive.

Conclusion

The parasite antigen was present as a zoonotic infection in Ahvaz district, South-west of Iran. More sensitive techniques, such as immunochromatography assay, might yield more reliable results, in the detection of low levels of Giardia in fecal samples of cats.     

Investigation of Possible Correlation between Giardia duodenalis Genotypes and Clinical Symptoms in Southwest of Iran

Background

Giardia duodenalis is one of the most important human enteric parasites throughout the world. Clinical symptoms of this parasite vary from asymptomatic infection to chronic diarrhea. Still it is not clear, whether different types of pathogenesis are due to different strains of organism or to variable host factors. The purpose of this study was to investigate possible correlation of clinical symptoms with assemblages among symptomatic and asymptomatic cases collected from southwest of Iran.

Methods

Fecal samples were collected from 100 symptomatic and asymptomatic cases, which were positive for G. duodenalis. The samples were subjected to semi-nested PCR and RFLP for gdh gene.

Results

Among symptomatic patients, 54% had mixed genotypes AII and BIII, 28% and 18% of samples indicated assemblages BIII and AII, respectively. In contrast, among asymptomatic cases, 64%, 26% and 10%samples had mixed genotypes, BIII and AII assemblages, respectively. Statistical analysis using Chi- Square test showed that there was no significant correlation between assemblage and clinical symptoms in current study.

Conclusion

High prevalence of mixed infection in both groups may affect this conclusion, therefore further study in more details are necessary to clarify these finding. Additionally, it is important to carry out investigations regarding human host factors as well.     

Giardia duodenalis infection and wastewater irrigation in Pakistan

The risk of Giardia duodenalis (Giardia) infection in farmers using untreated wastewater in agriculture was investigated in the city of Faisalabad, Pakistan, through a cross-sectional study. The study found a significantly increased risk of (asymptomatic) Giardia infection in wastewater farming households when compared with farming households using regular (non-wastewater) irrigation water (OR 3.3, 95% CI 2.5-4.4). Textile labourers who were employed in the city of Faisalabad but who lived in the same village as the wastewater farmers showed a risk of Giardia infection in between that of wastewater and non-wastewater farming households (OR 2.4, 95% CI 1.9-3.1). This study suggests that exposure to wastewater with high Giardia concentrations carries an increased risk for (asymptomatic) Giardia infection.     

Development of Sensitive Detection of Cryptosporidium and Giardia from Surface Water in Iran

Background

The protozoan parasites Cryptosporidium spp. and Giardia are known to occur widely in both raw and drinking waters. They are two of the causative agents of waterborne outbreaks of gastroenteritis throughout the world. In the present study, a PCR assay and FA were developed for detection of Cryptosporidium oocysts and Giardia cyst in environmental samples.

Methods

We have detected Cryptosporidium spp. oocysts and Giardia cysts in seeded and unseeded environmental water samples by PCR method. Water samples were spiked with oocysts (50, 100,300,500) and filtrated with a 1.2-µm pore size cellulose nitrate and follow by DNA extraction and purification by QIAamp DNA mini kit. Nested-PCR assay amplified an 850 bp fragment of 18s rRNA gene specific for Cryptosporidium and 435 bp fragment of glutamate dehydrogenase (GDH) target gene for Giardia. Also many river water from north of Iran, be checked by these methods.

Results

Cryptosporidium and Giardia DNAs were detected in seeded water sample and Giardia was detected in all 5 water samples from river in north of Iran by nested- PCR and FA. Also in one river water sample, Cryptosporidium was detected.

Conclusion

This protocol is effective for detection of these waterborne parasites in treated and untreated water samples. This study can also serve as a platform for further investigations and research water source in Iran.     

Molecular Identification of Giardia duodenalis Isolates from Fars Province,Iran

Background

Giardia duodenalis is one of the most common human intestinal protozoan parasites worldwide and is endemic throughout the world with a vast range of mammalian hosts. The present study aimed to identify the prevalence of G. duodenalis isolates and determine the most common of its assemblages in the patients referring to health centers and hospitals in Fars province, Iran that will be subjected to further molecular investigation.

Methods

We collected 1000 human fecal samples from health centers and hospitals in Shiraz, Iran in a one year period from September 2009 to August 2010. Microscopic examination for the presence of G. duodenalis cysts and trophozoites was performed by direct wet mount before and after the concentration techniques. Extraction of DNA was performed by Phenol-Chloroform-Isoamylalcohol (PCI). G. duodenalis-positive specimens were analyzed by PCR. A fragment of the SSU-rDNA (292 bp) gene was amplified by PCR using the forward primer RH11 and the reverse primer RH4. Genotyping was performed using sequence analysis of G. duodenalis glutamate dehydrogenase gene using primers GDHeF, GDHiF, and GDHiR.

Results

The prevalence of Giardia infection was 10.7% (107/1000) examined based on microscopic examination. PCR identified 80% (40/50) of the samples as positive for G. duodenalis based on SSU-rDNA amplification on sucrose gradient samples. Besides, genotyping results indicated 32 isolates (80%) as assemblage AII and 8 isolates (20%) as assemblage BIII and BIV based on the DNA sequence analysis of the glutamate dehydrogenase locus of G. duodenalis.

Conclusion

The findings of this study emphasize that Iran (Fars Province) is a favorable area for giardiasis with an anthroponotic infection route.     

Zinc deficiency in low‐ and middle‐income countries: prevalence and approaches for mitigation

This review addresses the prevalence of zinc deficiency in Low‐ and Middle‐income Countries (LMICs) and assesses the available strategies for its alleviation. The paucity of national‐level data on the zinc deficiency in LMICs is partially a result of the lack of a reliable biomarker. Zinc deficiency appears to be a public health problem in almost all the LMICs, irrespective of the recommended indicators (plasma zinc concentration, dietary zinc adequacy and stunting prevalence) used. Based on plasma/serum zinc concentration (PZC), which is the most appropriate indicator at present, the prevalence of zinc deficiency in LMICs is of concern. Among the 25 countries for which national PZC data were available, 23 had a zinc deficiency prevalence of >20% for at least one physiological group. Zinc supplementation is largely restricted as an adjunct therapy for diarrhoea management in children, and the best platform and the most effective way of preventive zinc supplementation delivery remains to be established. Impact assessment for current zinc fortification programmes in LMICs and the effectiveness of zinc supplementation as part of a multi‐micronutrient powder is to be determined. Dietary diversification, though promising for LMICs, is in the nascent stages of development at present. Inclusion of meat and animal products can be an important way of improving zinc status. Programmatic experience with the promotion of home processing techniques to increase absorbable zinc in the diet is lacking. Conventional biofortification techniques are gaining recognition in LMICs; however, transgenic biofortification as a strategy remains controversial.     

Association between Serum Zinc and Toll-like-Receptor- Related Innate Immunity and Infectious Diseases in Well-Nourished Children with a Low Prevalence of Zinc Deficiency: A Prospective Cohort Study

Existing reports focus on zinc-associated immunity and infection in malnourished children; however, whether zinc also plays an important role in the immune homeostasis of the non-zinc-deficient population remained unknown. This study aimed to investigate the association between zinc status and toll-like receptor (TLR)-related innate immunity and infectious outcome in well-nourished children. A total of 961 blood samples were collected from 1 through 5 years of age. Serum zinc was analyzed, and mononuclear cells isolated to assess TNF-α, IL-6, and IL-10 production by ELISA after stimulation with TLR ligands. Childhood infections were analyzed as binary outcomes with logistic regression. The prevalence of zinc deficiency was 1.4–9.6% throughout the first 5 years. There was significant association between zinc and TLR-stimulated cytokine responses. Higher serum zinc was associated with decreased risk of ever having pneumonia (aOR: 0.94; 95% CI: 0.90, 0.99) at 3 years, and enterocolitis (aOR: 0.96; 95% CI: 0.93, 0.99) at 5 years. Serum zinc was lower in children who have had pneumonia before 3 years of age (72.6 ± 9 vs. 81.9 ± 13 μg/dL), and enterocolitis before 5 years (89.3 ± 12 vs. 95.5 ± 13 μg/dL). We emphasize the importance of maintaining optimal serum zinc in the young population.     

Invasive Group A Streptococcus Infection among Children,Rural Kenya

To determine the extent of group A Streptococcus (GAS) infections in sub-Saharan Africa and the serotypes that cause disease, we analyzed surveillance data for 64,741 hospital admissions in Kilifi, Kenya, during 1998–2011. We evaluated incidence, clinical presentations, and emm types that cause invasive GAS infection. We detected 370 cases; of the 369 for which we had data, most were skin and soft tissue infections (70%), severe pneumonia (23%), and primary bacteremia (14%). Overall case-fatality risk was 12%. Incidence of invasive GAS infection was 0.6 cases/1,000 live births among neonates, 101/100,000 person-years among children <1 year of age, and 35/100,000 among children <5 years of age. Genome sequencing identified 88 emm types. GAS causes serious disease in children in rural Kenya, especially neonates, and the causative organisms have considerable genotypic diversity. Benefit from the most advanced GAS type–specific vaccines may be limited, and efforts must be directed to protect against disease in regions of high incidence.     

Consumption of Micronutrient Powder,Syrup or Fortified Food Significantly Improves Zinc and Iron Status in Young Mexican Children: A Cluster Randomized Trial

The objective of this study was to compare the effect of three micronutrient products on biomarkers of iron and zinc status of Mexican children 6–12 months of age. As part of research to improve the impact of a national program, 54 communities were randomly assigned to receive: (1) fortified food (FF), provided by the program at the time, or (2) micronutrient powders (MNP) or (3) syrup. Each product contained 10 mg each of zinc and iron, plus other micronutrients. Children consumed the product 6 days/week for four months. Primary outcomes were changes in serum zinc, ferritin, soluble transferrin receptor, hemoglobin concentrations, and their deficiencies. Zinc concentration increased significantly from baseline to follow-up in all groups, with the largest change in the syrup group (geometric mean difference: +4.4 µmol/L; 95%CI: 3.2, 5.5), followed by MNP (+2.9 µmol/L; 95%CI: 2.1, 3.6) and FF (+0.9 µmol/L; 95%CI: 0.3, 1.6). There was a significant increase in hemoglobin concentration (+5.5 g/L; 2.5, 8.4) and a significant reduction in anemia prevalence (44.2% to 26.8%, p < 0.01) only in the MNP group. Compliance differed significantly among groups (MNP vs. FF, p = 0.04; MNP vs. syrup, p = 0.04), but may not fully explain the greater improvement in zinc and iron status in the syrup and MNP groups. The food matrix may influence nutrient utilization from supplements.     

Cryptosporidium Spp. Infection in Human and Domestic Animals

Background

Cryptosporidium spp. is a coccidian parasite infected humans and animals. Prevalence rate of Cryptosporidium spp. infection associated with is some parameters such as sampling, age, season, country and contact to domestic animals. This study aimed to determine Cryptosporidium spp. Infection in humans and some animals in rural areas of Shushtar district from Khuzestan Province, south- west of Iran.

Methods

In this study, Stool specimens were randomly collected from 45 cattle, 8 buffalos, 35 calves, 22 turkeys, 3 sheep, 2 geese as well as 62 humans in different seasons selected from rural areas of Shushtar district located in Khuzestan in the south- west of Iran from August 2009 to April 2011. The collected stool samples were examined by modified Ziehl-Neelsen staining method.

Results

Altogether, 68/115 (59.1%) domestic animals and 9/62 (14.5%) of humans were showed Cryptosporidium spp. infection in the study areas.

Conclusion

In this study we found the high frequency of Cryptosporidium spp. infection in the studied areas.     

Zinc Nutritional Status in a Series of Children with Chronic Diseases: A Cross-Sectional Study

Background: Zinc is an essential trace element for the normal growth and development of human beings. The main objective was to evaluate the nutritional status of zinc and its association with nutritional indicators in a series of children with chronic diseases. Methods: The prevalence of patients with dietary zinc deficiency or deficit zinc intake (<80% DRI: dietary reference intake) was analyzed through prospective 72 h dietary surveys, and serum zinc deficiency or hypozincemia (≤70 µg/dL in children under 10 years of age in both sexes and in females older than 10 years and <74 μg/dL in males older than 10 years) was measured through atomic absorption spectrophotometry. The participants were classified according to their nutritional status by body mass index (BMI). Results: Mean serum zinc level in obese (87 µg/dL), undernourished (85 µg/dL), and eutrophic children (88 µg/dL) were normal, but in the undernutrition (60% DRI) and eutrophic (67% DRI) groups the mean dietary zinc intake was low compared to that in the obesity group (81% DRI). There were different associations between nutritional parameters, dietary zinc intake, and serum zinc. All patients with hypozincemia had dietary zinc deficiency. Conclusions: In the whole series, 69% of participants showed a zinc intake lower than recommended and might be at high risk of zinc deficiency.     

Seasonal prevalence and incidence of Cryptosporidium spp. and Giardia duodenalis and associated diarrhoea in children attending pre-school in Kafue, Zambia

Prevalence, incidence and seasonal variation of Cryptosporidium and Giardia duodenalis were studied over a 12-month period in 100 children from four pre-schools in Kafue, Zambia. Questionnaire data and a single stool sample were collected monthly from each child. Samples were processed using a commercial kit (Meridian Diagnostics Inc., USA) and oo(cysts) visualised by immunofluorescence microscopy. Cryptosporidium was detected in 30.7% (241/786; 95% CI = 27.5-33.9) while G. duodenalis was detected in 29.0% (228/786; 95% CI = 25.8-32.2). A total of 86% experienced one or more episodes of cryptosporidiosis while 75% had giardiasis. Cumulative incidence per 100 children was 75.4 for Cryptosporidium and 49.0 for G. duodenalis. Both infections were significantly more common in the wet compared to the dry season (34.8%, 162/466 vs. 24.7%, 79/320, P = 0.003 and 35.2%, 164/466 vs. 20.0%, 64/320, P < 0.001, respectively). Thus, risk ratios (RR) were 1.41 (95% CI = 1.13-1.77) and 1.76 (95% CI = 1.38-2.27) for Cryptosporidium and Giardia, respectively. Diarrhoea was significantly associated with cryptosporidiosis (RR = 1.23, 95% CI = 1.03-1.47; P = 0.029) but not with giardiasis (RR = 1.12, 95% CI = 0.91-1.53; P = 0.26). We conclude that gastro-intestinal protozoal infections are highly prevalent among children attending pre-school in peri-urban Zambia highlighting the need for further studies of risk factors.     

Two New Species of the Genus Pallisentis Van Cleave, 1928 (Acanthocephala: Quadrigyridae) from the Intestine of Channa punctatus (Bloch, 1793) from the River Gomti at Lucknow,India

Background:

Acanthocephalans are fish parasites of worldwide distribution, penetrate their thorny proboscis into the intestinal wall of host and absorb nutrients. No diagnostic tool is available except postmortem investigations and identification by parasitologists. The aim of present study was to explore and assign taxonomical status to Pallisentis species prevalent in food fishes of river Gomti, Lucknow, India.

Methods:

A survey of fishes of river Gomti was carried out during the year 2011–2013. Acanthocephalans recovered from the intestine of Channa punctatus were kept in refrigerator for eversion of proboscis, fixed in A.F.A. fixative (50% alcohol, formalin and acetic acid in ratio of 100: 6: 2.5) for 24 hours further preserved in 70% ethanol. Camera Lucida diagrams of acetoalum carmine stained permanent mounts were made for morphometric studies.

Results:

Two new species of genus Pallisentis were identified and named as P. channai n. sp. and P. vinodai n. sp., their taxonomical status is based on major characters of proboscis hooks, spines of collar and trunk region, cement gland nuclei. On average 9 fishes were found infected with Pallisentis spp. out of 60 fishes examined randomly.

Conclusion:

Pallisentis spp. are important parasitic infection in Channidae fishes with the prevalence rate of 15%. Two new species of Pallisentis recognized from Channa punctatus of river Gomti, Lucknow, India and diagnostic features of genus are given.