The dispersant Corexit 9500 and (dispersed) oil are lethal to coral endosymbionts.

Endosymbionts (Symbiodiniaceae) play a vital role in the health of corals. Seawater pollution can harm these endosymbionts and dispersants used during oil spill cleanup can be extremely toxic to these organisms. Here, we examined the impact of oil and a specific dispersant, Corexit-9500, on two representative endosymbionts - Symbiodinium and Cladocopium - from the Southwestern endemic coral Mussismilia braziliensis. The survival and photosynthetic potential of the endosymbionts decreased dramatically after exposure to the dispersant and oil by ~25 % after 2 h and ~50 % after 7 days. Low concentrations of dispersant (0.005 ml/l) and dispersed oil (Polycyclic Aromatic Hydrocarbons, 1132 µg/l; Total Petroleum Hydrocarbons, 595 µg/l) proved highly toxic to both Symbiodinium and Cladocopium. These levels triggered a reduction in growth rate, cell size, and cell wall thickness. After a few hours of exposure, cellular organelles were damaged or destroyed. These acute toxic effects underline the fragile nature of coral endosymbionts.

Description of an intramonocytic haemoparasite, Hepatozoon lainsoni sp. nov. (Apicomplexa: Adeleorina: Hepatozoidae), infecting Ameiva ameiva lizard (Reptilia: Squamata: Teiidae) in northern Brazil.

Haemogregarine (Apicomplexa: Adeleorina) parasites are considered to be the most common and widespread haemoparasites in reptiles. The genus Hepatozoon (Apicomplexa: Adeleorina: Hepatozoidae) can be found parasitizing a broad range of species and, in reptiles, they infect mainly peripheral blood erythrocytes. The present study detected and characterized a haemogregarine isolated from the lizard species, Ameiva ameiva, collected from the municipality of Capanema, Pará state, north Brazil. Blood smears and imprints from lungs, brain, heart, kidney, liver, bone marrow and spleen were observed using light microscopy and the parasite was genetically identified by molecular analysis. Morphological, morphometric and molecular data were obtained. Parasite gamonts were found in 49.5% (55/111) of the blood smears from A. ameiva, and were characterized as oval, averaging 12.0 ± 0.8 × 5.9 ± 0.6 µm2 in size, which displaced the nuclei of parasitized monocytes laterally. Parasite forms resembling immature gamonts were observed in the spleen and bone marrow of the lizards. Furthermore, phylogenetic analyses of 18S rRNA sequences did not reveal gene similarity with other Hepatozoon spp. sequences from reptiles. Thus, morphological and molecular analyses have identified a new species of Hepatozoon parasite, Hepatozoon lainsoni sp. nov., which infects monocytes of the A. ameiva lizard.

Anti-Sporothrix activity of novel copper-itraconazole complexes.

A series of new metal complexes, [Cu(ITZ)2Cl2]·5H2O (1), [Cu(NO3)2(ITZ)2] ·3H2O·C4H10O and [Cu(ITZ)2)(PPh3)2]NO3·5H2O (3) were synthesized by a reaction of itraconazole (ITZ) with the  respective copper salts under reflux. The metal complexes were characterized by elemental analyses, molar conductivity, 1H and 13C{1H} nuclear magnetic resonance, UV-Vis, infrared and EPR spectroscopies. The antifungal activity of these metal complexes was evaluated against the main sporotrichosis agents: Sporothrix brasiliensis, Sporothrix schenkii, and Sporothrix globosa. All three new compounds inhibited the growth of S. brasiliensis and S. schenckii at lower concentrations than the free azole, with complex 2 able to kill all species at 4 µM and induce more pronounced alterations in fungal cells. Complexes 2 and 3 exhibited higher selectivity and no mutagenic effect at the concentration that inhibited fungal growth and affected fungal cells. The strategy of coordinating itraconazole (ITZ) to copper was successful, since the corresponding metal complexes were more effective than the parent drug. Particularly, the promising antifungal activity of the Cu-ITZ complexes makes them potential candidates for the development of an alternative drug to treat mycoses.

Contribution of microscopy to a better understanding of the anatomy of pathogenic protists.

In this Inaugural Article the author briefly revises its scientific career and how he starts to work with parasitic protozoa. Emphasis is given to his contribution to topics such as a) the structural organization of the surface of protozoa using freeze-fracture and deep-etching; b) the cytoskeleton of protozoa, especially structures such as the subpellicular microtubules of trypanosomatids, the conoid of Toxoplasma gondii, microtubules and inner membrane complex of this protozoan, and the costa of Tritrichomonas foetus; c) the flagellulm of trypanosomatids, that in addition to the axoneme contains a complex network of filaments that constitute the paraflagellar rod; d) special organelles such as the acidocalcisome, hydrogenosome, and glycosome; and e) the highly polarized endocytic pathway found in epimastigote forms of Trypanosoma cruzi.

Mpox outbreak in Rio de Janeiro, Brazil: A translational approach.

Mpox is a zoonotic disease historically reported in Africa. Since 2003, limited outbreaks have occurred outside Africa. In 2022, the global spread of cases with sustained interhuman transmission and unusual disease features raised public health concerns. We explore the mpox outbreak in Rio de Janeiro (RJ) state, Brazil, in an observational study of mpox-suspected cases from June to December 2022. Data collection relied on a public healthcare notification form. Diagnosis was determined by MPXV-PCR. In 46 confirmed cases, anti-OPXV IgG was determined by ELISA, and seven MPXV genomes were sequenced. A total of 3095 cases were included, 816 (26.3%) with positive MPXV-PCR results. Most positive cases were men in their 30 s and MSM. A total of 285 (34.9%) MPXV-PCR+ patients live with HIV. Eight were coinfected with varicella-zoster virus. Anogenital lesions and adenomegaly were associated with the diagnosis of mpox. Females and individuals under 18 represented 9.4% and 5.4% of all confirmed cases, respectively, showing higher PCR cycle threshold (Ct) values and fewer anogenital lesions compared to adult men. Anti-OPXV IgG was detected in 29/46 (63.0%) patients. All analyzed sequences belonged to clade IIb. In RJ state, mpox presented a diverse clinical picture, represented mainly by mild cases with low complication rates and prominent genital involvement. The incidence in females and children was higher than usually reported. The observation of a bimodal distribution of Ct values, with few positive results, may suggest the need to review the diagnostic criteria in these groups.

Potent hydroxamate-derived compounds arrest endodyogeny of Toxoplasma gondii tachyzoites.

Toxoplasmosis is a zoonosis that is a worldwide health problem, commonly affecting fetal development and immunodeficient patients. Treatment is carried out with a combination of pyrimethamine and sulfadiazine, which can cause cytopenia and intolerance and does not lead to a parasitological cure of the infection. Lysine deacetylases (KDACs), which remove an acetyl group from lysine residues in histone and non-histone proteins are found in the Toxoplasma gondii genome. Previous work showed the hydroxamate-type KDAC inhibitors Tubastatin A (TST) and Vorinostat (Suberoylanilide Hydroxamic Acid, SAHA) were effective against T. gondii. In the present study, the effects of three hydroxamates (KV-24, KV-30, KV-46), which were originally designed to inhibit human KDAC6, showed different effects against T. gondii. These compounds contain a heterocyclic cap group and a benzyl linker bearing the hydroxamic acid group in para-position. All compounds showed selective activity against T. gondii proliferation, inhibiting tachyzoite proliferation with IC50 values in a nanomolar range after 48h treatment. Microscopy analyses showed that after treatment, tachyzoites presented mislocalization of the apicoplast, disorganization of the inner membrane complex, and arrest in the completion of new daughter cells. The number of dividing cells with incomplete endodyogeny increased significantly after treatment, indicating the compounds can interfere in the late steps of cell division. The results obtained in this work that these new hydroxamates should be considered for future in vivo tests and the development of new compounds for treating toxoplasmosis.

An alternative method to establish an early acute ocular toxoplasmosis model for experimental tests.

PURPOSE: To provide a simple alternative acute ocular toxoplasmosis model with great reproducibility for experimental tests that demand monitoring of the ocular lesion. METHODS: ME49-wt and ME49-GFP tachyzoites from cell culture were used to infect male C57BL6 mice by intraperitoneal injection. B1 expression by real-time polymerase chain reaction (qPCR) assay was used to detect the presence of T. gondii in ocular tissue at the beginning of the infection. Fluorescence microscopy and histopathology analysis were carried out to assess the evolution of the acute infection up to 20 days in both eyes of infected mice. RESULTS: All mice infected with the 104 tachyzoites showed B1 expression in the retina of both eyes, in the RPE (retinal pigment epithelium), and choroid structures, after 5 days of infection. Tachyzoites of the ME49-GFP strain were easily detected by fluorescence microscopy in the retina tissue of mice after 5 days post-infection. After 20 days, mice inflammatory cell infiltrates and a disorganized morphology of the retinal laminar architecture were observed. CONCLUSION: Infection of C57BL6 mice via intraperitoneal with 104 tachyzoites of the ME49-GFP strain from cell culture is a suitable model for acute ocular toxoplasmosis. This model has great reproducibility in establishing the ocular lesion since day 5 post-infection. This model can be suitable for experimental tests of chemotherapy and the investigation of the role of the immune response on the development of uveitis.

Cost-effective 3D lung tissue spheroid as a model for SARS-CoV-2 infection and drug screening.

BACKGROUND: The SARS-CoV-2 pandemic has spurred an unparalleled scientific endeavor to elucidate the virus' structure, infection mechanisms, and pathogenesis. Two-dimensional culture systems have been instrumental in shedding light on numerous aspects of COVID-19. However, these in vitro systems lack the physiological complexity to comprehend the infection process and explore treatment options. Three-dimensional (3D) models have been proposed to fill the gap between 2D cultures and in vivo studies. Specifically, spheroids, composed of lung cell types, have been suggested for studying SARS-CoV-2 infection and serving as a drug screening platform. METHODS: 3D lung spheroids were prepared by coculturing human alveolar or bronchial epithelial cells with human lung stromal cells. The morphology, size, and ultrastructure of spheroids before and after SARS-CoV-2 infection were analyzed using optical and electron microscopy. Immunohistochemistry was used to detect spike protein and, thus, the virus presence in the spheroids. Multiplex analysis elucidated the cytokine release after virus infection. RESULTS: The spheroids were stable and kept their size and morphology after SARS-CoV-2 infection despite the presence of multivesicular bodies, endoplasmic reticulum rearrangement, tubular compartment-enclosed vesicles, and the accumulation of viral particles. The spheroid responded to the infection releasing IL-6 and IL-8 cytokines. CONCLUSION: This study demonstrates that coculture spheroids of epithelial and stromal cells can serve as a cost-effective infection model for the SARS-CoV-2 virus. We suggest using this 3D spheroid as a drug screening platform to explore new treatments related to the cytokines released during virus infection, especially for long COVID treatment.

Stimulation of microvesicle secretion in Trichomonas vaginalis.

Trichomonas vaginalis is an extracellular flagellate protozoan and the etiological agent of human trichomoniasis, a sexually transmitted infection (STI) with a high incidence. Several reports have shown that this protozoan releases microvesicles into the culture medium, which show high potential in modulating cell-to-cell communication and the host response to infections. However, the biogenesis of these vesicles has not been analyzed in detail. In the present study, high-resolution ion scanning microscopy (SEM) and transmission electron microscopy (TEM) were used to analyze the surface of control cells and cells incubated in the presence of Ca2+ alone or with A 23187 calcium ionophore. Two different strains of T. vaginalis were analyzed. Most control cells displayed relatively smooth surfaces, whereas cells incubated with Ca2+ had many surface projections of variable shape and size (from 40 nm to around 1 µm). Quantitative analyses were performed directly in the scanning electron microscope and showed a significant increase in the number of cells with surface projections after incubation in the presence of calcium. TEM showed that treated cells presented several cytoplasmic multivesicular structures, suggesting membrane fusion and exosomes in the extracellular medium. The amount and size of the released vesicles were quantitatively analyzed using light scattering and TEM on negatively stained samples. The observations show that incubation of both parasite strains in the presence of Ca2+ significantly increased the release of microvesicles into the extracellular medium in a time-dependent process. Sequential incubation in the presence of Ca2+ and the calcium ionophore A23187 increases the presence of vesicles on the parasite surface only at a short incubation time (5 min). Transmission electron microscopy showed that at least part of the vesicles are originated from cytoplasmic multivesicular structures. This information contributes to a better understanding of the biogenesis of extracellular vesicles secreted by T. vaginalis.

A cohort study examining individual factors influencing cycling as a transportation mode in São Paulo, Brazil.

The aim of this study is to explore the relationship between individual-level factors and cycling for transportation in a cohort of participants living in São Paulo city, Brazil. The same participants (n = 1,431 adults) were interviewed in 2014/2015 (Wave 1) and 2020/2021 (Wave 2) as part of the 'São Paulo Health Survey-ISA: Physical Activity and Environment'. For the longitudinal transport cycling binary outcome, participants who reported cycling at both time-points and those who were cycling at Wave 2 only were coded as a positive longitudinal pattern for cycling. Those who were not cycling at either Waves, and those who were cycling at Wave 1 only, were grouped into a negative pattern for cycling. The relationship between the longitudinal patterns for transport cycling and sociodemographics, health characteristics, and behaviors at Wave 1 were tested using bivariate analysis, and the significant individual-level factors were then examined in a multivariable binary logistic regression model. The odds of being classified in the positive cycling pattern were lower for women [OR = 0.09; 95 % CI = 0.04---0.19], and higher for persons aged 30 - 39 [OR = 3.25; 95 % CI = 1.38---7.66], those who owned a bicycle [OR = 2.00; 95 % CI = 1.13---3.54], and those who engaged in ≥ 120 min/week of transport walking [OR = 2.07; 95 % CI = 1.24---3.47] or leisure-time physical activity [OR = 1.77; 95 % CI = 1.02---3.06]. Cycling interventions and promotion should target women, the mid-aged and involve facilitating bicycle access. Advocacy for physical activity interventions is needed to influence transport cycling.

Paracrine Signaling Mediated by the Cytosolic Tryparedoxin Peroxidase of Trypanosoma cruzi.

Peroxiredoxins are abundant and ubiquitous proteins that participate in different cellular functions, such as oxidant detoxification, protein folding, and intracellular signaling. Under different cellular conditions, peroxiredoxins can be secreted by different parasites, promoting the induction of immune responses in hosts. In this work, we demonstrated that the cytosolic tryparedoxin peroxidase of Trypanosoma cruzi (cTXNPx) is secreted by epimastigotes and trypomastigotes associated with extracellular vesicles and also as a vesicle-free protein. By confocal microscopy, we show that cTXNPx can enter host cells by an active mechanism both through vesicles and as a recombinant protein. Transcriptomic analysis revealed that cTXNPx induces endoplasmic reticulum stress and interleukin-8 expression in epithelial cells. This analysis also suggested alterations in cholesterol metabolism in cTXNPx-treated cells, which was confirmed by immunofluorescence showing the accumulation of LDL and the induction of LDL receptors in both epithelial cells and macrophages. BrdU incorporation assays and qPCR showed that cTXNPx has a mitogenic, proliferative, and proinflammatory effect on these cells in a dose-dependent manner. Importantly, we also demonstrated that cTXNPx acts as a paracrine virulence factor, increasing the susceptibility to infection in cTXNPx-pretreated epithelial cells by approximately 40%. Although the results presented in this work are from in vitro studies and likely underestimate the complexity of parasite-host interactions, our work suggests a relevant role for this protein in establishing infection.

Characterization of a new extra-axonemal structure in the Giardia intestinalis flagella.

The inner structure of the flagella of Giardia intestinalis is similar to that of other organisms, consisting of nine pairs of outer microtubules and a central pair containing radial spokes. Although the 9+2 axonemal structure is conserved, it is not clear whether subregions, including the transition zone, are present in the flagella of this parasite. Giardia axonemes originate from basal bodies and have a lengthy cytosolic portion before becoming active flagella. The region of the emergence of the flagellum is not accompanied by any membrane specialization, as seen in other protozoa. Although Giardia is an intriguing model of study, few works focused on the ultrastructural analysis of the flagella of this parasite. Here, we analyzed the externalization region of the G. intestinalis flagella using ultra-high resolution scanning microscopy (with electrons and ions), atomic force microscopy in liquid medium, freeze fracture, and electron tomography. Our data show that this region possesses a distinctive morphological feature - it extends outward and takes on a ring-like shape. When the plasma membrane is removed, a structure surrounding the axoneme becomes visible in this region. This new extra-axonemal structure is observed in all pairs of flagella of trophozoites and remains attached to the axoneme even when the interconnections between the axonemal microtubules are disrupted. High-resolution scanning electron microscopy provided insights into the arrangement of this structure, contributing to the characterization of the externalization region of the flagella of this parasite.

SARS-CoV-2 egress from Vero cells: a morphological approach.

Despite being extensively studied because of the current coronavirus disease 2019 (COVID-19) pandemic, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) interactions with mammalian cells are still poorly understood. Furthermore, little is known about this coronavirus cycle within the host cells, particularly the steps that lead to viral egress. This study aimed to shed light on the morphological features of SARS-CoV-2 egress by utilizing transmission and high-resolution scanning electron microscopy, along with serial electron tomography, to describe the route of nascent virions towards the extracellular medium. Electron microscopy revealed that the clusters of viruses in the paracellular space did not seem to result from collective virus release. Instead, virus accumulation was observed on incurved areas of the cell surface, with egress primarily occurring through individual vesicles. Additionally, our findings showed that the emission of long membrane projections, which could facilitate virus surfing in Vero cells infected with SARS-CoV-2, was also observed in non-infected cultures, suggesting that these are constitutive events in this cell lineage.

Implications of Flagellar Attachment Zone Proteins TcGP72 and TcFLA-1BP in Morphology, Proliferation, and Intracellular Dynamics in Trypanosoma cruzi.

The highly adaptable parasite Trypanosoma cruzi undergoes complex developmental stages to exploit host organisms effectively. Each stage involves the expression of specific proteins and precise intracellular structural organization. These morphological changes depend on key structures that control intracellular components' growth and redistribution. In trypanosomatids, the flagellar attachment zone (FAZ) connects the flagellum to the cell body and plays a pivotal role in cell expansion and structural rearrangement. While FAZ proteins are well-studied in other trypanosomatids, there is limited knowledge about specific components, organization, and function in T. cruzi. This study employed the CRISPR/Cas9 system to label endogenous genes and conduct deletions to characterize FAZ-specific proteins during epimastigote cell division and metacyclogenesis. In T. cruzi, these proteins exhibited distinct organization compared to their counterparts in T. brucei. TcGP72 is anchored to the flagellar membrane, while TcFLA-1BP is anchored to the membrane lining the cell body. We identified unique features in the organization and function of the FAZ in T. cruzi compared to other trypanosomatids. Deleting these proteins had varying effects on intracellular structures, cytokinesis, and metacyclogenesis. This study reveals specific variations that directly impact the success of cell division and differentiation of this parasite.

Expansion Microscopy of trichomonads.

Light microscopy has significantly advanced in recent decades, especially concerning the increased resolution obtained in fluorescence images. Here we present the Expansion Microscopy (ExM) technique in two parasites, Trichomonas vaginalis and Tritrichomonas foetus, which significantly improved the localization of distinct proteins closely associated with cytoskeleton by immunofluorescence microscopy. The ExM techniques have been used in various cell types, tissues and other protist parasites. It requires the embedment of the samples in a swellable gel that is highly hydrophilic. As a result, cells are expanded 4.5 times in an isotropic manner, offering a spatial resolution of ∼70 nm. We used this new methodology not only to observe the structural organization of protozoa in more detail but also to increase the resolution by immunofluorescence microscopy of two major proteins such as tubulin, found in structures formed by microtubules, and costain 1, the only protein identified until now in the T. foetus's costa, a unique rod-shaped like structure. The individualized microtubules of the axostyle were seen for the first time in fluorescence microscopy and several other details are presented after this technique.

Collapse of scallop Nodipecten nodosus production in the tropical Southeast Brazil as a possible consequence of global warming and water pollution.

Mollusc rearing is a relevant global socioeconomic activity. However, this activity has faced severe problems in the last years in southeast Brazil. The mariculture scallop production dropped from 51,2 tons in 2016 to 10,2 tons in 2022 in the Baia da Ilha Grande (BIG; Rio de Janeiro). However, the possible causes of this collapse are unknown. This study aimed to analyze decadal trends of water quality in Nodipecten nodosus spat and adult production in BIG. We also performed physical-chemical and biological water quality analyses of three scallop farms and two nearby locations at BIG in 2022 to evaluate possible environmental stressors and risks. Scallop spat production dropped drastically in the last five years (2018-2022: mean ± stdev: 0.47 ± 0.45 million). Spat production was higher in colder waters and during peaks of Chlorophyll a in the last 13 years. Reduction of Chlorophyll a coincided with decreasing spat production in the last five years. Warmer periods (>27 °C) of the year may hamper scallop development. Counts of potentially pathogenic bacteria (Vibrios) and Escherichia coli were significantly higher in warmer periods which may further reduce scallop productivity. Shotgun metagenomics of seawater samples from the five studied corroborated these culture-based counts. Vibrios and fecal indicator bacteria metagenomic sequences were abundant across the entire study area throughout 2022. The results of this study suggest the collapse of scallop mariculture is the result of a synergistic negative effect of global warming and poor seawater quality.

New morphological observations on the initial events of Toxoplasma gondii entry into host cells.

Toxoplasma gondii is an obligate intracellular protozoan of worldwide distribution. It is effective in the infection of various homoeothermic animals of economic importance. The process of T. gondii invasion of host cells occurs in less than 20 s by the active mechanism of penetration. First, a mobile junction is formed due to the association between the apical end of the parasite and the host cell surface. Then, the secretion of invasive and docking proteins allows the formation of the mobile junction before the complete internalization of the parasite. Here, using high-resolution microscopy, it was described new morphological observations of the early events of host cell invasion by tachyzoites of T. gondii. Attempts were made to synchronize the interaction process using low temperatures and treatment of the host cells with cytochalasin D, a drug that interferes with the actin dynamics. Images were obtained showing that the parasite and the host cells seem to release small vesicles with diameters varying from 25 to 100 nm. Furthermore, tunneling nanotubes emerge from the host cell surface and interact with the parasite even at long distance. These observations add new details of adhesion and entry events, such as surface projections of the host cell plasma membrane, pseudopods, and nanotubes radiating from the host cell toward the parasite. In addition, scanning microscopy revealed intense vesiculation, with a morphological characteristic of extracellular microvesicles, during the entry of the tachyzoite into the host cell.

Postmortem Ultrastructural Analysis of the Retina from COVID-19 Deceased Patients.

PURPOSE: COVID-19 (coronavirus disease 2019) is an infectious disease caused by SARS-CoV-2, first reported in 2019 in Wuhan, China. Among the common complications is a pro-inflammatory and hypercoagulative response that compromises the vasculature among various organs. METHODS: In this report, we present the postmortem retinal findings of five patients observed by means of optical microscopy and transmission and scanning electron microscopy techniques. RESULTS: Clinical manifestations such as retinal hemorrhages and exacerbated inflammatory infiltrate, altered ultra structure with swollen mitochondria and pyknotic cells in both layers of the retina were observed in all analyzed eyes. CONCLUSION: Our data point to the fragility of this tissue in cases of severe COVID-19.

Valorizing Constituents of Cashew Nut Shell Liquid toward the Sustainable Development of New Drugs against Chagas Disease.

Six new ether phospholipid analogues encompassing constituents from cashew nut shell liquid as the lipid portion were synthesized in an effort to valorize byproducts of the cashew industry toward the generation of potent compounds against Chagas disease. Anacardic acids, cardanols, and cardols were used as the lipid portions and choline as the polar headgroup. The compounds were evaluated for their in vitro antiparasitic activity against different developmental stages of Trypanosoma cruzi. Compounds 16 and 17 were found to be the most potent against T. cruzi epimastigotes, trypomastigotes, and intracellular amastigotes exhibiting selectivity indices against the latter 32-fold and 7-fold higher than current drug benznidazole, respectively. Hence, four out of six analogues can be considered as hit-compounds toward the sustainable development of new treatments for Chagas disease, based on inexpensive agro-waste material.

Ultrastructural Alterations of the Human Pathogen Giardia intestinalis after Drug Treatment.

This review presents the main cell characteristics altered after in vitro incubation of the parasite with commercial drugs used to treat the disease caused by Giardia intestinalis. This important intestinal parasite primarily causes diarrhea in children. Metronidazole and albendazole are the primary compounds used in therapy against Giardia intestinalis. However, they provoke significant side effects, and some strains have developed resistance to metronidazole. Benzimidazole carbamates, such as albendazole and mebendazole, have shown the best activity against Giardia. Despite their in vitro efficacy, clinical treatment with benzimidazoles has yielded conflicting results, demonstrating lower cure rates. Recently, nitazoxanide has been suggested as an alternative to these drugs. Therefore, to enhance the quality of chemotherapy against this parasite, it is important to invest in developing other compounds that can interfere with key steps of metabolic pathways or cell structures and organelles. For example, Giardia exhibits a unique cell structure called the ventral disc, which is crucial for host adhesion and pathogenicity. Thus, drugs that can disrupt the adhesion process hold promise for future therapy against Giardia. Additionally, this review discusses new drugs and strategies that can be employed, as well as suggestions for developing novel drugs to control the infection caused by this parasite.