Giardia lamblia and Helicobacter pylori coinfection in gastrointestinal biopsies: A retrospective single-center analysis from Switzerland.

BACKGROUND: The protozoan Giardia lamblia (GL) and the bacterium Helicobacter pylori (HP) are common causes of gastrointestinal disease. Coinfection is common and has been reported in studies from Africa, Europe, North America and Asia, but data for Switzerland are scarce. AIM: To investigate GL and HP prevalence and coinfection rate in gastrointestinal biopsies from the Zurich area of Switzerland. METHODS: Cases were retrieved from the laboratory information system (Medica Institute of Clinical Pathology, Zurich, Switzerland). Histological slides of cases with GL were reviewed, as were the concurrent gastric biopsies, where available. RESULTS: Between January 1, 2013 and December 31, 2020, GL was found in 88 (0.14%) of 62,402 patients with a small intestine biopsy and HP in 10,668 (15.5%) of 68,961 patients with a gastric biopsy. 74/88 (84.1%) of patients with GL had unremarkable small intestine biopsies, 13/88 (14.8%) had increased intraepithelial lymphocytes, 5/88 (5.7%) showed villous atrophy and 2/88 (2.3%) acute inflammation. 71/88 patients (80.7%) with GL had an available gastric biopsy, of which 12/71 (16.9%) were unremarkable, 28/71 (39.4%) had HP-associated gastritis, 11/71 (15.5%) showed reactive gastropathy and 1/71 (1.4%) had autoimmune gastritis. CONCLUSION: Coinfection with HP is common in patients with GL in gastrointestinal biopsies from the Zurich area of Switzerland. Therefore, gastroenterologists should consider sampling the stomach when GL is suspected for evaluation of possible concurrent HP-associated gastritis. Likewise, pathologists should scrutinize any small intestine biopsy for the presence of GL when HP-associated gastritis is seen, and vice versa.

Treatment of feline giardiasis during an outbreak of diarrhoea in a cattery: potential effects on faecal Escherichia coli resistance patterns.

OBJECTIVES: An outbreak of diarrhoea involving 16 cats at a cattery in Norway was investigated. Treatment and control of the outbreak were the primary objectives, but the effects of treatment on the antimicrobial resistance profiles of Escherichia coli isolated from faeces were also investigated. METHODS: Faecal samples were investigated for Giardia cysts by immunofluorescence microscopy, and multi-locus genotyping was performed to determine the Giardia genotype. Faecal E coli were assessed, before and after treatment for giardiasis, for antimicrobial resistance. RESULTS: The outbreak was probably caused by Giardia duodenalis, Assemblage F. Although infection was eliminated in most cats following treatment with fenbendazole, over 30% of the infected cats required a second treatment round (combined fenbendazole and metronidazole). Investigation of sensitivity to antibacterial drugs of E coli that had been isolated both prior to and following treatment demonstrated that fenbendazole treatment may select for resistant bacteria. CONCLUSIONS AND RELEVANCE: Controlling Giardia infections in dense cat populations can be challenging, and requires strict hygiene measures. In cases where fenbendazole alone does not result in treatment success, a combination treatment with fenbendazole and metronidazole may be effective. Although this study did not include untreated controls, we suggest that the potential for changes in gut microbiota and antimicrobial resistance development should be considered when choosing antiprotozoal drugs, particularly in cases of treatment failure and where repeat treatment is required.

Quantitative microbial risk assessment of Cryptosporidium and Giardia in well water from a native community of Mexico.

Cryptosporidium and Giardia are gastrointestinal disease-causing organisms transmitted by the fecal-oral route, zoonotic and prevalent in all socioeconomic segments with greater emphasis in rural communities. The goal of this study was to assess the risk of cryptosporidiosis and giardiasis of Potam dwellers consuming drinking water from communal well water. To achieve the goal, quantitative microbial risk assessment (QMRA) was carried out as follows: (a) identification of Cryptosporidium oocysts and Giardia cysts in well water samples by information collection rule method, (b) assessment of exposure to healthy Potam residents, (c) dose-response modelling, and (d) risk characterization using an exponential model. All well water samples tested were positive for Cryptosporidium and Giardia. The QMRA results indicate a mean of annual risks of 99:100 (0.99) for cryptosporidiosis and 1:1 (1.0) for giardiasis. The outcome of the present study may drive decision-makers to establish an educational and treatment program to reduce the incidence of parasite-borne intestinal infection in the Potam community, and to conduct risk analysis programs in other similar rural communities in Mexico.

Anti-giardial activity of Sambucus ebulus.

OBJECTIVES: Giardia (G.) lamblia is a parasite that causes giardiasis in humans and other mammals. The common treatment produces unpleasant side effects. The ethnopharmacology for management of parasitic infections accelerates and guides the search for new chemical objects. This study assessed the in vitro cytotoxicity of Sambucus (S.) ebulus fruit against Cysts of G. lamblia. MATERIALS AND METHODS: Giardia cysts were isolated from patients' fecal specimens; the cysts were isolated by sucrose 0.85 M solution. The plant extract was used at concentrations of 1, 10, 50 and 100 mg/mL throughout the experiments. The extracts were incubated with several isolates of G. lamblia for 5, 10, 30 and 60 minutes and then the viability were distinguished by eosin 0.01%. RESULTS: S. ebulus extract at the concentration of 100 mg/ml for 60 minutes had the most anti-giardial activity (78 ± 4%) than other concentrations. CONCLUSIONS: Considering excellent antigiardial activity of S. ebulus in vitro, it seems to have potential for the treatment of the parasitic disease caused by the protozoan G. lamblia.

Assessing the infection risk of Giardia and Cryptosporidium in public drinking water delivered by surface water systems in Sao Paulo State, Brazil.

A survey of Giardia and Cryptosporidium was conducted in surface water used as drinking water sources by public water systems in four densely urbanized regions of Sao Paulo State, Brazil. A Quantitative Microbial Risk Assessment, based on protozoa concentrations, was performed to estimate the probability of protozoa infection associated with drinking water ingestion. A total of 206 source water samples were analyzed over a 24 month period using the USEPA Method 1623. The risk of infection was estimated using an exponential dose response model, children and adults exposure and a gamma distribution for (oo)cyst concentrations with three scenarios for treating censored data. Giardia was detected in 102 of the samples, and 19 of them were also positive for Cryptosporidium, with maximum concentrations of 97.0 cysts/L and 6.0 oocysts/L, respectively. Risk distributions were similar for the three scenarios. In the four regions, the estimated risk of Giardia infection per year, for adults and children, ranged from 0.29% to 2.47% and from 0.08% to 0.70%, respectively. Cryptosporidium risk infection varied from 0.15% to 0.29% for adults and from 0.04% to 0.08% for children. In both cases, the calculated risk surpassed the risk of infection of 10(-4) (1:10,000) defined as tolerable by USEPA for a yearly exposure. The probability of Giardia infection was very close to the rates of acute diarrheic disease for adults (1% to 3%) but lower for children (2% to 7%). The daily consumption of drinking water was an important contributing factor for these differences. The Microbiological Risk Assessment carried out in this study provides an indication of infection risks by Giardia and Cryptosporidium in the population served by these source waters. Strategies for source water protection and performance targets for the water treatment should be established to achieve the required level of public health risk.

Inflammation drives dysbiosis and bacterial invasion in murine models of ileal Crohn's disease.

BACKGROUND AND AIMS: Understanding the interplay between genetic susceptibility, the microbiome, the environment and the immune system in Crohn's Disease (CD) is essential for developing optimal therapeutic strategies. We sought to examine the dynamics of the relationship between inflammation, the ileal microbiome, and host genetics in murine models of ileitis. METHODS: We induced ileal inflammation of graded severity in C57BL6 mice by gavage with Toxoplasma gondii, Giardia muris, low dose indomethacin (LDI; 0.1 mg/mouse), or high dose indomethacin (HDI; 1 mg/mouse). The composition and spatial distribution of the mucosal microbiome was evaluated by 16S rDNA pyrosequencing and fluorescence in situ hybridization. Mucosal E. coli were enumerated by quantitative PCR, and characterized by phylogroup, genotype and pathotype. RESULTS: Moderate to severe ileitis induced by T. gondii (day 8) and HDI caused a consistent shift from >95% gram + Firmicutes to >95% gram - Proteobacteria. This was accompanied by reduced microbial diversity and mucosal invasion by adherent and invasive E. coli, mirroring the dysbiosis of ileal CD. In contrast, dysbiosis and bacterial invasion did not develop in mice with mild ileitis induced by Giardia muris. Superimposition of genetic susceptibility and T. Gondii infection revealed greatest dysbiosis and bacterial invasion in the CD-susceptible genotype, NOD2(-/-), and reduced dysbiosis in ileitis-resistant CCR2(-/-) mice. Abrogating inflammation with the CD therapeutic anti-TNF-α-mAb tempered dysbiosis and bacterial invasion. CONCLUSIONS: Acute ileitis induces dysbiosis and proliferation of mucosally invasive E. coli, irrespective of trigger and genotype. The identification of CCR2 as a target for therapeutic intervention, and discovery that host genotype and therapeutic blockade of inflammation impact the threshold and extent of ileal dysbiosis are of high relevance to developing effective therapies for CD.

Risk of Giardia infection for drinking water and bathing in a peri-urban area in Sao Paulo, Brazil.

A high incidence of waterborne diseases is observed worldwide and in order to address contamination problems prior to an outbreak, quantitative microbial risk assessment is a useful tool for estimating the risk of infection. The objective of this paper was to assess the probability of Giardia infection from consuming water from shallow wells in a peri-urban area. Giardia has been described as an important waterborne pathogen and reported in several water sources, including ground waters. Sixteen water samples were collected and examined according to the US EPA (1623, 2005). A Monte Carlo method was used to address the potential risk as described by the exponential dose response model. Giardia cysts occurred in 62.5% of the samples (<0.1-36.1 cysts/l). A median risk of 10⁻¹ for the population was estimated and the adult ingestion was the highest risk driver. This study illustrates the vulnerability of shallow well water supply systems in peri-urban areas.

An actin cytoskeleton with evolutionarily conserved functions in the absence of canonical actin-binding proteins.

Giardia intestinalis, a human intestinal parasite and member of what is perhaps the earliest-diverging eukaryotic lineage, contains the most divergent eukaryotic actin identified to date and is the first eukaryote known to lack all canonical actin-binding proteins (ABPs). We sought to investigate the properties and functions of the actin cytoskeleton in Giardia to determine whether Giardia actin (giActin) has reduced or conserved roles in core cellular processes. In vitro polymerization of giActin produced filaments, indicating that this divergent actin is a true filament-forming actin. We generated an anti-giActin antibody to localize giActin throughout the cell cycle. GiActin localized to the cortex, nuclei, internal axonemes, and formed C-shaped filaments along the anterior of the cell and a flagella-bundling helix. These structures were regulated with the cell cycle and in encysting cells giActin was recruited to the Golgi-like cyst wall processing vesicles. Knockdown of giActin demonstrated that giActin functions in cell morphogenesis, membrane trafficking, and cytokinesis. Additionally, Giardia contains a single G protein, giRac, which affects the Giardia actin cytoskeleton independently of known target ABPs. These results imply that there exist ancestral and perhaps conserved roles for actin in core cellular processes that are independent of canonical ABPs. Of medical significance, the divergent giActin cytoskeleton is essential and commonly used actin-disrupting drugs do not depolymerize giActin structures. Therefore, the giActin cytoskeleton is a promising drug target for treating giardiasis, as we predict drugs that interfere with the Giardia actin cytoskeleton will not affect the mammalian host.

[Lambliasis as differential diagnosis of MARSH type 3b]. / Lamblieninfektion als Differenzialdiagnose der Zöliakie in der Duodenalbiopsie.

Giardia lamblia is the most common human parasite with a worldwide distribution and fecal-oral way of transmission. Diagnostic procedures include stool examination and gastroduodenoscopy with biopsy or secret aspiration. In most cases histology reveals a dense accumulation of the parasites on the surface of the duodenal mucosa with no or only slight inflammation. In rare cases, a dense inflammatory infiltrate with severe mucosal atrophy and increased count of intraepithelial lymphocytes may be seen. If in such cases the amount of parasites is low, the histological picture may mimic celiac disease. The two presented cases demonstrate the close morphological relationship and show the importance of considering giardiasis in the differential diagnosis in patients with suspected celiac disease.

[Protozoan pathogens of genus Cryptosporidiumand Giardia. Part I. Occurrence in water environment and health risk]. / Pierwotniaki pasozytnicze z rodzaju Cryptosporidium i Giardia. Czesc I. Wystepowanie w srodowisku wodnym i zagrozenia zdrowotne.

Contamination of water, first of all drinking water, by protozoan pathogens from genus Cryptosporidium and/or Giardia can pose significant threat for public health. These pathogens live in the intestine of humans or animals (infected or carriers). There are found in soil, food, water or on surfaces that have been contaminated with infected human or animal feces. Numerous waterborne Cryptosporidium and Giardia outbreaks have been reported worldwide in the last few years. These outbreaks resulted from consumption of water contaminated by protozoan pathogens. Their potential prevalence in faecal polluted water supplies, resistance to conventional water treatment and low effective disinfection, as well as imperfection techniques of detection of oocysts and cysts presence necessitates the need for consistent and effective removal of these parasites from drinking water supply.

Giardia y giardiasis / Giardia and giardiasis

Giardia lamblia es un protozoario parásito que habita el intestino delgado de los seres humanos y de muchos otros vertebrados y es una de las más comunes causas de diarrea en todo el mundo. Durante su ciclo de vida Giardia sufre significativos cambios bioquímicos y morfológicos que le permiten sobrevivir en ambientes y condiciones que de otro modo lo destruirían. Para sobrevivir fuera del intestino del hospedador, los trofozoítos de Giardia se diferencian a quistes, los que se caracterizan por poseer una rígida pared glicoproteica externa que les permiten sobrevivir inclusive frente a la acción de los desinfectantes más comunes. Otro de los mecanismos de adaptación de este parásito es la variación de los antígenos de superficie que le permite a los trofozoítos evadir la respuesta inmune del huésped y generar infecciones tanto agudas como crónicas o recurrentes en individuos infectados. Durante los últimos años se han producido importantes avances en el conocimiento de las bases moleculares de los procesos de enquistamiento y variación antigénica en Giardia que pronostican el pronto hallazgo de nuevos agentes quimioterapéuticos y/o inmunoprofilácticos contra este importante parásito intestinal.

Isolation, excystation and axenization of Giardia lamblia isolates: in vitro susceptibility to metronidazole and albendazole.

From 53 samples of human faeces containing Giardia lamblia cysts, 18 isolates were successfully excysted in vitro, and cultivated axenically in TYI-S-33 modified medium. The in vitro effects of metronidazole and albendazole on these isolates were evaluated by the trophozoite adherence inhibition method. The IC50 was between 2.4 and 11.5 micro M for metronidazole and 0.027 and 0.192 micro M for albendazole. These IC50 values were similar to those found for the ATCC 30888 and 30957 reference isolates. All isolates were susceptible to the antiparasitic drugs tested. These results suggest that resistance of G. lamblia to metronidazole and albendazole does not seem to be a significant problem in our population.

Fecal shedding of Giardia duodenalis, Cryptosporidium parvum, Salmonella organisms, and Escherichia coli O157:H7 from llamas in California.

OBJECTIVE: To evaluate fecal shedding of Giardia duodenalis, Cryptosporidium parvum, Salmonella organisms, and Escherichia coli O157:H7 from llamas in California with respect to host factors and management practices. ANIMALS: 354 llamas from 33 facilities. PROCEDURE: Fecal specimens were collected and examined for G. duodenalis and C. parvum by means of immunofluorescent microscopy. Salmonella organisms were cultured by placing feces into selenite enrichment broth followed by selective media. Escherichia coli O157:H7 was cultured by use of modified tryptocase soy broth followed by sorbitol MacConkey agar, with suspect colonies confirmed by means of immunofluorescent microscopy. RESULTS: 12 of 354 fecal specimens (3.4%) had G. duodenalis cysts. Younger llamas (crias) were more likely to be shedding cysts, compared with older llamas. Farm-level factors that increased the risk of shedding were large numbers of yearlings on the property (> 10), smaller pen sizes, large numbers of crias born during the previous year (> 10), and large pen or pasture populations (> 20). None of the 354 fecal specimens had C. parvum oocysts. Seventy-six (from 7 facilities) and 192 (from 22 facilities) llamas were tested for Salmonella organisms and E. coli O157:H7, respectively. All fecal specimens had negative results for these bacteria. CONCLUSIONS AND CLINICAL RELEVANCE: Shedding of G. duodenalis was primarily limited to crias 1 to 4 months old. Llamas from properties with large numbers of crias born in the previous year, resulting in large numbers of yearlings in the current year, were at greater risk of infection. In addition, housing llamas in smaller pens or pastures and managing llamas and crias in large groups also increased the risk of G. duodenalis shedding.

Influence of bacteria from the duodenal microbiota of patients with symptomatic giardiasis on the pathogenicity of Giardia duodenalis in gnotoxenic mice.

Recent studies have shown that the intestinal microbiota is essential for the pathogenicity but not for the multiplication of Giardia duodenalis in the intestinal lumen. The microbial components responsible for this phenomenon are not known. Twenty-eight facultative and three strictly anaerobic micro-organisms were isolated from the dominant duodenal microbiota of five patients with symptomatic giardiasis. The bacterial combinations from each patient were associated with groups (GN) of germ-free mice. Five days after the association, when their faecal populations ranged from 10(7) to 10(9) cfu/g, all groups were inoculated intragastrically with 10(5) viable trophozoites of G. duodenalis strain BT6. Two groups of germ-free (GF) and conventional (CV1) mice were also infected. Gnotobiotic animals were killed 10 days after infection and GF and CV1 animals were killed 10, 20 and 30 days after infection. More marked pathological alterations were detected in CV1 mice when compared with GF animals. Gnotobiotic animals showed intermediate pathological alterations between CV1 and GF mice. The CV1 and GF groups became infected by day 3 and faecal cyst levels were similar in both groups throughout the experiment. Total and G. duodenalis-specific IgA levels in the intestinal fluid and G. duodenalis-specific IgM and IgG levels in the serum increased during the infection and were higher in CV1 animals at all times tested when compared with GF mice. The present results confirm the stimulatory activity of the intestinal microbiota on the pathogenicity of G. duodenalis, and some combinations of microbial components of the dominant duodenal ecosystem from patients with symptomatic giardiasis can partially develop this function. However, none of these combinations was able to stimulate the protozoan pathogenicity in the same manner as the entire intestinal microbiota.

Intragastric infection of conventional and germfree mice with Giardia lamblia.

The effects of experimental infection with Giardia lamblia were studied in 30-day old conventional and germfree CFW mice (7 animals in each group) of both sexes. Cysts were observed in the feces of both groups 6 to 7 days after intragastric infection of each animal with about 2.5 x 10(5) G. lamblia trophozoites. Fecal cyst level was statistically higher in germfree mice (about 10(5) cysts/g feces) when compared with the conventional group (about 10(4) cysts/g feces). The peak of infection in the conventional group apparently occurred on the 10th day after infection as indicated by an increase of fecal weight and by histopathological examination. Intense infiltration of the lamina propria and high reactional hyperplasia of the lymphoid component were observed in the conventional group. There was no infiltration or hyperplasia in germfree infected mice and fecal weight was relatively constant throughout the experiment. These results suggest that, as is the case for other intestinal pathogenic protozoa, the intestinal microflora is indispensable for the expression of the pathogenicity but not for the multiplication of G. lamblia.

Relación entre la IgE sérica total, la giardiasis humana y los signos alérgicos actuales / Association among total serum IgE human giardiasis and present allergic signs

La asocoación frecuente de la giardiasis humana con las lesiones dérmicas nos motivó a la evaluación de los niveles séricos de IgE a través de un sistema ultramicroanalítico en pacientes con gierdiasis clínica, confirmada parasitologicamente. Se hace un estudio de la posible estinulación de la respuesta IgE total, así como de su asociación con los signos alérgicos actuales y su relación con los pacientes que presentan giardiasis

Aspectos clínicos de la himenolepiasis en pediatría / Clinical aspects on hymenolepiasis in pediatrics

El presente estudio se realizó en 325 niños infectados con Hymenolepis nana, con el objeto de realizar un estudio clínico y de laboratorio de tipo integral. Los resultados mostraron que la himenolepiasis se encuentra entre las primeras cinco parasitosis intestinales en los niños escolares de la Ciudad de México, en la mayoría de los casos asociada a protozoos y otros helmintos, en especial con Giardia lamblia; generalmente la carga parasitaria es leve y sin embargo, la traducción clínica poco varía a pesar de ello. Las manifestaciones clínicas más importantes y constantes en los grupos de himenolepiasis pura y asociada son: dolor abdominal, hiporexia e irritabilidad. En cambio en las himenolepiasis en forma comparativa asociada a otras parasitosis con respecto a los casos donde no hay parásito intestinal, observamos que la pérdida de peso, meteorismo y flatulencia se presentan en las formas puras de himenolepiasis y en las asociaciones con G. lamblia; especialmente, la diarrea es una de las principales manifestaciones. Concluyendo, la himenolepiasis en nuestro medio es muy importante por su frecuencia en niños preescolares y escolares y tiene un cuadro clínico identificable en forma constante

[Characteristics of the immunity in typhoid infection associated with opisthorchiasis]. / Osobennosti immuniteta pri briushnotifoznoi infektsii, assotsiirovannoi s opistorkhozom.

Typhoid infection developing in persons with opisthorchiasis is characterized by the appearance of pronounced systemic immunity, that ensures a more favorable clinical course of this infection and promotes a decrease in the occurrence of diarrheal phenomena and bacteremia. At the same time, in typhoid patients, simultaneously affected by opisthorchiasis, a more intensive release of the infective agent into the environment is observed. This seemingly demonstrates the presence of disturbances in the local protective mechanisms regulating the process of the release of bacteria on the level of the gastrointestinal tract.