Giardiasis: An Overview

2019 ◽  
Vol 13 (2) ◽  
pp. 134-143 ◽  
Author(s):  
Alexander K.C. Leung ◽  
Amy A.M. Leung ◽  
Alex H.C. Wong ◽  
Consolato M. Sergi ◽  
Joseph K.M. Kam
Keyword(s):  
Giardia Lamblia ◽  
English Literature ◽  
Fluorescent Antibody ◽  
Giardia Duodenalis ◽  
Preventive Measure ◽  
Protozoan Parasite ◽  
Oral Route ◽  
Transmission Risk ◽  
Child Care Workers ◽  
Pubmed Search

Background: Giardiasis is an important cause of waterborne and foodborne diarrhea, daycare center outbreaks, and traveler's diarrhea. Objective: The study aimed to provide an update on the evaluation, diagnosis, and treatment of giardiasis. Methods: A PubMed search was completed in Clinical Queries using the key terms “giardiasis”, "Giardia lamblia", "Giardia duodenalis" and "Giardia intestinalis". The search strategy included metaanalyses, randomized controlled trials, clinical trials, observational studies, and reviews. The search was restricted to the English literature. Patents were searched using the key term “giardiasis” from www.freepatentsonline.com. Results: Giardiasis is caused by the protozoan parasite Giardia lamblia. The parasite is transmitted by the fecal-oral route, frequently through ingestion of contaminated water and food or person-to person transmission. Risk factors for infection include children in day-care settings, child-care workers, institutionalized individuals, travelers in endemic areas, ingestion of contaminated or recreational water, immunodeficiency, cystic fibrosis, and oral-anal sex. Approximately 50 to 75% of infected children are asymptomatic. Other children present acute or chronic diarrhea. Direct fluorescent antibody tests that detect intact organisms, enzyme immunoassays that detect soluble antigens, and multiplex real-time polymerase chain reaction assays that detect specific genes of the parasite in stool samples have improved sensitivity and specificity compared with microscopic examination of stool specimens for the detection of Giardia trophozoites or cysts. Drugs used in the treatment of symptomatic giardiasis are reviewed in this study. Moreover, recent patents related to the management of giardiasis are also discussed. Conclusion: Metronidazole, tinidazole, and nitazoxanide are drugs of choice. Resistance to common antigiardial drugs has increased in recent years, therefore, the search for new molecular targets for antigiardial drugs is urgently needed. In general, treatment of asymptomatic carriers is not recommended. Purification of water supply is an important preventive measure.

scholarly journals Efficacy of Bifidobacterium animalis subsp. lactis BB-12 against Giardia duodenalis trophozoites: an experimental study

2021 ◽  
Vol 233 ◽  
pp. 02048
Author(s):  
Fahu Yuan ◽  
Yufei Liu ◽  
Qian Gui ◽  
Qiuyi Huang ◽  
Qianyu Li ◽  
...  
Keyword(s):  
Experimental Study ◽  
Weight Loss ◽  
Giardia Lamblia ◽  
Intestinal Parasite ◽  
Giardia Duodenalis ◽  
Protozoan Parasite ◽  
Domestic Animals ◽  
New Drugs ◽  
Bifidobacterium Animalis ◽  
Clinical Drugs

Giardia duodenalis, formerly known as Giardia lamblia, is an important zoonotic protozoan parasite. It mainly infects the intestines of humans, dogs, cats and domestic animals, causing diarrhea, abdominal pain, indigestion and weight loss. At present, all the clinical drugs for the treatment of Giardia have problems such as side effects and drug resistance to varying degrees, and the development of new drugs for the treatment of Giardia is still a hot issue. There is growing interest in using probiotics as an anti-intestinal parasite strategy. The present study aimed to assess the effect of supernatants of Bifidobacterium Animalis Subsp. lactis BB-12 on giardia the growth of giardia trophozoites. In this study, the Bifidobacterium animalis subsp. lactis BB-12 were cultured in BBL liquid medium, and the effects of the supernatants on the growth and adhesion of trophozoites of Giardia were observed. The results showed that the growth of Giardia flagellate was significantly inhibited by the supernatant. The influence of the supernatant on the morphology of the trophozoites was observed by microscope, and it was found that the surface of the trophozoites was uneven, the shape was atrophied, the surface cell membrane was broken to some extent, and the contents were spilt. In summary, the results of this study suggest that the fresh-cultured supernatants of the probiotic Bifidobacterium Animalis subsp. lactis BB-12 have anti-Giardia effects.

A comparison of assays for the detection of Cryptosporidium parvum in the feces of scouring calves

2022 ◽  
pp. 104063872110621
Author(s):  
Harveen K. Atwal ◽  
Erin Zabek ◽  
Julie Bidulka ◽  
Alecia DuCharme ◽  
Michael Pawlik ◽  
...  
Keyword(s):  
Cryptosporidium Parvum ◽  
Fluorescent Antibody ◽  
Protozoan Parasite ◽  
Oral Route ◽  
Lateral Flow ◽  
Lateral Flow Immunoassay ◽  
Direct Smear ◽  
Kappa Value ◽  
Life Threatening ◽  
Level Of Agreement

Cryptosporidium parvum is a zoonotic, protozoan parasite that causes potentially life-threatening diarrhea in the host and can be transmitted via the fecal-oral route. C. parvum can infect cattle and may be detected in their feces using a variety of tests. We compared the level of agreement, ease of procedure, and cost among PCR, lateral flow immunoassay, fluorescent antibody, and Kinyoun acid-fast stain direct smear tests. Over the course of 9 mo, 74 calf fecal samples were submitted and tested for C. parvum using all 4 tests. A Fleiss kappa value of 0.813 was obtained, indicating an excellent level of agreement among tests. Overall, the best test based on cost and ease of procedure was the Kinyoun acid-fast stain direct smear.

scholarly journals SARS-CoV-2-associated gastrointestinal and liver diseases: what is known and what is needed to explore

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dina Sweed ◽  
Eman Abdelsameea ◽  
Esraa A. Khalifa ◽  
Heba Abdallah ◽  
Heba Moaz ◽  
...  
Keyword(s):  
English Language ◽  
Data Extraction ◽  
Oral Route ◽  
Main Body ◽  
Disease Manifestation ◽  
Gi Symptoms ◽  
Septic Focus ◽  
Pubmed Search ◽  
Risk Patients ◽  
Respiratory Droplets

Abstract Background The pandemic of COVID19 which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first described in China as an unexplained pneumonia transmitted by respiratory droplets. Gastrointestinal (GI) and liver injury associated with SARS-CoV-2 infection were reported as an early or sole disease manifestation, mainly outside China. The exact mechanism and incidence of GI and liver involvement are not well elucidated. Main body We conducted a PubMed search for all articles written in the English language about SARS-CoV-2 affecting the GI and liver. Following data extraction, 590 articles were selected. In addition to respiratory droplets, SARS-CoV-2 may reach the GI system through the fecal-oral route, saliva, and swallowing of nasopharyngeal fluids, while breastmilk and blood transmission were not implicated. Moreover, GI infection may act as a septic focus for viral persistence and transmission to the liver, appendix, and brain. In addition to the direct viral cytopathic effect, the mechanism of injury is multifactorial and is related to genetic and demographic variations. The most frequently reported GI symptoms are diarrhea, nausea, vomiting, abdominal pain, and bleeding. However, liver infection is generally discovered during laboratory testing or a post-mortem. Radiological imaging is the gold standard in diagnosing COVID-19 patients and contributes to understanding the mechanism of extra-thoracic involvement. Medications should be prescribed with caution, especially in chronic GI and liver patients. Conclusion GI manifestations are common in COVID-19 patients. Special care should be paid for high-risk patients, older males, and those with background liver disease.

scholarly journals Multilocus Genotyping of Giardia duodenalis in Mostly Asymptomatic Indigenous People from the Tapirapé Tribe, Brazilian Amazon

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 206
Author(s):  
Pamela Carolina Köster ◽  
Antonio F. Malheiros ◽  
Jeffrey J. Shaw ◽  
Sooria Balasegaram ◽  
Alexander Prendergast ◽  
...  
Keyword(s):  
Triosephosphate Isomerase ◽  
Gastrointestinal Symptoms ◽  
Giardia Duodenalis ◽  
Protozoan Parasite ◽  
Indigenous Communities ◽  
Brazilian Amazon ◽  
Epidemiological Survey ◽  
Small Subunit ◽  
High Genetic Diversity ◽  
Cross Sectional

Little information is available on the occurrence and genetic variability of the diarrhoea-causing enteric protozoan parasite Giardia duodenalis in indigenous communities in Brazil. This cross-sectional epidemiological survey describes the frequency, genotypes, and risk associations for this pathogen in Tapirapé people (Brazilian Amazon) at four sampling campaigns during 2008–2009. Microscopy was used as a screening test, and molecular (PCR and Sanger sequencing) assays targeting the small subunit ribosomal RNA, the glutamate dehydrogenase, the beta-giardin, and the triosephosphate isomerase genes as confirmatory/genotyping methods. Associations between G. duodenalis and sociodemographic and clinical variables were investigated using Chi-squared test and univariable/multivariable logistic regression models. Overall, 574 individuals belonging to six tribes participated in the study, with G. duodenalis prevalence rates varying from 13.5–21.7%. The infection was positively linked to younger age and tribe. Infected children <15 years old reported more frequent gastrointestinal symptoms compared to adults. Assemblage B accounted for three out of four G. duodenalis infections and showed a high genetic diversity. No association between assemblage and age or occurrence of diarrhoea was demonstrated. These data indicate that the most likely source of infection was anthropic and that different pathways (e.g., drinking water) may be involved in the transmission of the parasite.

scholarly journals Re-Discovery of Giardiavirus: Genomic and Functional Analysis of Viruses from Giardia duodenalis Isolates

Biomedicines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 654
Author(s):  
Gianluca Marucci ◽  
Ilaria Zullino ◽  
Lucia Bertuccini ◽  
Serena Camerini ◽  
Serena Cecchetti ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Diarrheal Disease ◽  
Current Knowledge ◽  
Biological Significance ◽  
Giardia Duodenalis ◽  
Protozoan Parasite ◽  
Protein Translation ◽  
Mass Spectrometry Analysis ◽  
Animal Origin ◽  
Spectrometry Analysis

Giardiasis, caused by the protozoan parasite Giardia duodenalis, is an intestinal diarrheal disease affecting almost one billion people worldwide. A small endosymbiotic dsRNA viruses, G. lamblia virus (GLV), genus Giardiavirus, family Totiviridae, might inhabit human and animal isolates of G. duodenalis. Three GLV genomes have been sequenced so far, and only one was intensively studied; moreover, a positive correlation between GLV and parasite virulence is yet to be proved. To understand the biological significance of GLV infection in Giardia, the characterization of several GLV strains from naturally infected G. duodenalis isolates is necessary. Here we report high-throughput sequencing of four GLVs strains, from Giardia isolates of human and animal origin. We also report on a new, unclassified viral sequence (designed GdRV-2), unrelated to Giardiavirus, encoding and expressing for a single large protein with an RdRp domain homologous to Totiviridae and Botybirnaviridae. The result of our sequencing and proteomic analyses challenge the current knowledge on GLV and strongly suggest that viral capsid protein translation unusually starts with a proline and that translation of the RNA-dependent RNA polymerase (RdRp) occurs via a +1/−2 ribosomal frameshift mechanism. Nucleotide polymorphism, confirmed by mass-spectrometry analysis, was also observed among and between GLV strains. Phylogenetic analysis indicated the occurrence of at least two GLV subtypes which display different phenotypes and transmissibility in experimental infections of a GLV naïve Giardia isolate.

New Associated Structures of the Anterior Flagella of Giardia duodenalis

2013 ◽  
Vol 19 (5) ◽  
pp. 1374-1376 ◽  
Author(s):  
Claudia Maia-Brigagão ◽  
Ana Paula Rocha Gadelha ◽  
Wanderley de Souza
Keyword(s):  
Electron Microscopy ◽  
Structural Organization ◽  
Giardia Duodenalis ◽  
Protozoan Parasite ◽  
Filamentous Structure ◽  
Marginal Plates ◽  
Favorable Conditions ◽  
And Behavior ◽  
Crossing Point ◽  
Scanning Electron

AbstractGiardia duodenalis is a protozoan parasite that causes intestinal disorders. The trophozoites present four pairs of flagella. Here we further analyze the structural organization of the anterior flagella associated structures of G. duodenalis. High resolution scanning electron microscopy of detergent-extracted trophozoites revealed novel aspects of the interaction of the anterior flagella axonemes with the marginal plates. Images of the marginal plates showed that it was located in the anterior region of the parasite, above the crossing point of the anterior flagella axonemes toward the periphery of the cell. Two well distinguished structures were seen associated with the anterior flagella. The first one corresponds to the “dense rods”, located just below the axoneme. The second one is a system of filaments located in the upper portion of the flagellum, facing the marginal plates and connecting these two structures. The thickness of the filaments is around 18 nm and they are spaced at intervals of 4–32 nm (average 18 nm). The length of the filaments may vary from 33 to 240 nm. We suggest that this filamentous structure of Giardia may help the dynamics and behavior of the anterior flagella of trophozoites during protozoan motility and adhesion, providing favorable conditions for the establishment of parasitism.

scholarly journals Thoracic Ossification of Ligamentum Flavum Caused By Skeletal Fluorosis: Breaking the Etiopathological Barrier -Answer to the Crippling Disease of the Society

2020 ◽  
Vol 3 (1) ◽  
Keyword(s):  
Ligamentum Flavum ◽  
English Literature ◽  
Spinous Process ◽  
Preventive Measure ◽  
Skeletal Fluorosis ◽  
Fluoride Level ◽  
Type D ◽  
Clinical Series ◽  
Ossification Of Ligamentum Flavum ◽  
A Prospective Study

Background: Thoracic ossification of ligamentum flavum (OLF) caused by skeletal fluorosis is rare [1]. Only six patients had been reported in the English literature. This study is the second study to the best of our knowledge in literature. Aims and Objectives: To evaluate the causation of ossification of ligamentum flavum due to fluorosis in accordance with reports from the first clinical series of this disease. Exact etiopathogenesis of thoracic ossification of yellow ligament is not known and causation due to fluorosis is rare, so this study was hypothesized [2]. Materials and Methods: This is a prospective study of patients with thoracic OLF due to skeletal fluorosis who underwent surgical management at the NIMS hospital between 2017 and 2018. A total of 16 cases were enrolled, (56.25%), 9 males and 7 (43.75%) females, age ranging from 37 to 62 years (mean 50.5 years). Imaging showed OLF together with ossification of interosseous membranes, including interosseous membranes of the forearm (14/16 patients 87.5%).Urinalysis showed a markedly high urinary fluoride level in 15 of 16 patients (93.75%).Ossified ligamentum flavum sent for estimation of fluoride levels in 16 patients showed high fluoride level in the bone ash prepared from the oyl in 15 patients and other structures sent as control were ,spinous process ,interspinous ligaments didn’t show any fluoride deposition. Results: Out of 16 patient 15 patient had fluoride levels more than 6000mg/kg, 7 patient had values between 6,000 – 7,000 mg/kg, 5 patient had values between 7,500 – 9,000 mg/kg and 3 patients had values > 8400 mg/kg. Controls were sent as spinous processes had normal fluoride level between 500-1000 mg/kg and interspinous ligaments sent showed no fluoride levels. Out of 16 patients 9 patients had multiple level dorsal OYL both contiguous and non-contiguous, contiguous in 4 patients and non – contiguous in 5 patients.7 patients had single level dorsal OYL. Most common segment involved in OYL is T9 and D10 level in 14 patients. Sato classification 6 were Type A, 5 were Type B, 3 were Type C, 2 were Type D Conclusion: This is the largest series of ossification of dorsal yellow ligament due to fluorosis. And consideration of fluorosis as one of the important etiological cause for OYL to be kept in mind and all patients with OYL to be screened for Fluorosis and this would also help as a preventive measure for the people around the surroundings of the affected person and would help the society from a crippling disability.

scholarly journals Refractory Giardiasis in an Immunosuppressed Patient in Turkey

2018 ◽  
Vol 12 (03) ◽  
pp. 204-207
Author(s):  
Filiz Kaya ◽  
Ahmet Çağkan İnkaya ◽  
Salih Maçin ◽  
Yakut Akyön ◽  
Sibel Ergüven
Keyword(s):  
Small Intestine ◽  
Giardia Duodenalis ◽  
Protozoan Parasite ◽  
Chronic Diarrhoea ◽  
Immunosuppressed Patient ◽  
Predisposing Factor ◽  
Giardia Infection ◽  
Stool Samples ◽  
Higher Doses ◽  
Immunocompetent Patients

Giardiasis is an infection of the small intestine caused by the protozoan parasite Giardia duodenalis. In immunocompetent patients the infection is usually self-limited and no treatment may be needed. Immunodeficiency, however, is a predisposing factor for the development of severe Giardia infection. In this report, a case of recurrent giardiasis refractory to nitroimidazoles and nitazoxanides presented. A 28-year-old male patient with hypogammaglobulinemia admitted to our hospital because of chronic diarrhoea. Microscopic examination of stool revealed a high number of Giardia trophozoites and cysts. Treatment with higher doses and a longer course of metronidazole, trimethoprim-sulfamethoxazole, ornidazole and albendazole failed. Administration of nitazoxanide, which has been reported to be effective against Giardia duodenalis refractory to nitroimidazoles, was commenced, but his symptoms persisted and stool samples demonstrated Giardia trophozoites and cysts again.

scholarly journals Giardia duodenalis and Its Secreted PPIB Trigger Inflammasome Activation and Pyroptosis in Macrophages through TLR4-Induced ROS Signaling and A20-Mediated NLRP3 Deubiquitination

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3425
Author(s):  
Lin Liu ◽  
Yongwu Yang ◽  
Rui Fang ◽  
Weining Zhu ◽  
Jingxue Wu ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Defense Mechanisms ◽  
Giardia Duodenalis ◽  
Protozoan Parasite ◽  
Global Scale ◽  
Inflammasome Activation ◽  
Giardia Infection ◽  
Immune Effector ◽  
Nlrp3 Inflammasome Activation ◽  
Innate Immune Effector

The extracellular protozoan parasite Giardia duodenalis is a well-known and important causative agent of diarrhea on a global scale. Macrophage pyroptosis has been recognized as an important innate immune effector mechanism against intracellular pathogens. Yet, the effects of noninvasive Giardia infection on macrophage pyroptosis and the associated molecular triggers and regulators remain poorly defined. Here we initially observed that NLRP3 inflammasome-mediated pyroptosis was activated in Giardia-treated macrophages, and inhibition of ROS, NLRP3, or caspase-1 could block GSDMD cleavage, IL-1β, IL-18 and LDH release, and the cell viability reduction. We also confirmed that Giardia-induced NLRP3 inflammasome activation was involved in its K63 deubiquitination. Thus, six candidate deubiquitinases were screened, among which A20 was identified as an effective regulator. We then screened TLRs on macrophage membranes and found that upon stimulation TLR4 was tightly correlated to ROS enhancement, A20-mediated NLRP3 deubiquitination, and pyroptotic signaling. In addition, several Giardia-secreted proteins were predicted as trigger factors via secretome analysis, of which peptidyl-prolyl cis-trans isomerase B (PPIB) independently induced macrophage pyroptosis. This was similar to the findings from the trophozoite treatment, and also led to the TLR4-mediated activation of NLRP3 through K63 deubiquitination by A20. Collectively, the results of this study have significant implications for expanding our understanding of host defense mechanisms after infection with G. duodenalis.

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