Pathogens

Research

13 pages, 1537 KiB

Open AccessArticle

Evaluation of Fecal Egg Count Tests for Effective Control of Equine Intestinal Strongyles

by Manigandan Lejeune, Sabine Mann, Holly White, Danielle Maguire, Jaime Hazard, Rebecca Young, Charles Stone, Doug Antczak and Dwight Bowman

Pathogens 2023, 12(11), 1283; https://doi.org/10.3390/pathogens12111283 - 26 Oct 2023

Cited by 1 | Viewed by 1158

Abstract

The American Association of Equine Practitioners strongly advocates evidence-based intestinal strongyle control in horses. It recommends targeted treatment of all heavy egg shedders (>500 eggs per gram (EPG) of feces), while the low shedders (0–200 EPG) are left untreated. As 50–75% of adult [...] Read more.

The American Association of Equine Practitioners strongly advocates evidence-based intestinal strongyle control in horses. It recommends targeted treatment of all heavy egg shedders (>500 eggs per gram (EPG) of feces), while the low shedders (0–200 EPG) are left untreated. As 50–75% of adult horses in a herd are low shedders, preventing them from unnecessary anthelmintic exposure is critical for tackling resistance. There are various fecal egg count (FEC) techniques with many modifications and variations in use, but none is identified as a gold standard. The hypothesis of the study was that the diagnostic performance of 12 commonly used quantitation methodologies (three techniques with four variants) differs. In this regard, method comparison studies were performed using polystyrene beads as proxy for intestinal strongyle eggs. Mini-FLOTAC-based variants had the lowest coefficient of variation (CV%) in bead recovery, whereas McMaster variants had the highest. All four variants of Mini-FLOTAC and the NaNO₃ 1.33 specific gravity variant of modified Wisconsin followed a linear fit with R² > 0.95. In contrast, the bead standard replicates for modified McMaster variants dispersed from the regression curve, causing a lower R². The Mini-FLOTAC method seems less influenced by the choice of floatation solution and has better repeatability parameters and linearity for bead standard recovery. For FEC tests with high R² (>0.95) but that underestimated the true bead count, a correction factor (CF) was determined to estimate the true count. Finally, the validity of CF was analyzed for 5 tests with R² > 0.95 to accurately quantify intestinal strongyle eggs from 40 different horses. Overall, this study identified FEC methodologies with the highest diagnostic performance. The limitations in standardizing routine FEC tests are highlighted, and the importance of equalization of FEC results is emphasized for promoting uniformity in the implementation of parasite control guidelines. Full article

(This article belongs to the Special Issue Veterinary Parasitic Diseases: Advancements in Diagnostics, Therapeutics, and Vaccines)

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22 pages, 8689 KiB

Open AccessArticle

Curcumin and Its Supramolecular Complex with Disodium Glycyrrhizinate as Potential Drugs for the Liver Fluke Infection Caused by Opisthorchis felineus

by Maria N. Lvova, Denis V. Ponomarev, Alena A. Tarasenko, Anna V. Kovner, Galina A. Minkova, Michail A. Tsyganov, Meijun Li, Yan Lou, Veronica I. Evseenko, Alexander V. Dushkin, Irina V. Sorokina, Tatiana G. Tolstikova, Viatcheslav A. Mordvinov and Damira F. Avgustinovich

Pathogens 2023, 12(6), 819; https://doi.org/10.3390/pathogens12060819 - 09 Jun 2023

Viewed by 3109

Abstract

Opisthorchiosis is a parasitic liver disease found in mammals that is widespread throughout the world and causes systemic inflammation. Praziquantel remains the drug of choice for the treatment of opisthorchiosis, despite its many adverse effects. An anthelmintic effect is attributed to the main [...] Read more.

Opisthorchiosis is a parasitic liver disease found in mammals that is widespread throughout the world and causes systemic inflammation. Praziquantel remains the drug of choice for the treatment of opisthorchiosis, despite its many adverse effects. An anthelmintic effect is attributed to the main curcuminoid of Curcuma longa L. roots—curcumin (Cur)—along with many other therapeutic properties. To overcome the poor solubility of curcumin in water, a micellar complex of curcumin with the disodium salt of glycyrrhizic acid (Cur:Na₂GA, molar ratio 1:1) was prepared via solid-phase mechanical processing. In vitro experiments revealed a noticeable immobilizing effect of curcumin and of Cur:Na₂GA on mature and juvenile Opisthorchis felineus individuals. In vivo experiments showed that curcumin (50 mg/kg) had an anthelmintic effect after 30 days of administration to O. felineus-infected hamsters, but the effect was weaker than that of a single administration of praziquantel (400 mg/kg). Cur:Na₂GA (50 mg/kg, 30 days), which contains less free curcumin, did not exert this action. The complex, just as free curcumin or better, activated the expression of bile acid synthesis genes (Cyp7A1, Fxr, and Rxra), which was suppressed by O. felineus infection and by praziquantel. Curcumin reduced the rate of inflammatory infiltration, whereas Cur:Na₂GA reduced periductal fibrosis. Immunohistochemically, a decrease in liver inflammation markers was found, which is determined by calculating the numbers of tumor-necrosis-factor-positive cells during the curcumin treatment and of kynurenine-3-monooxygenase-positive cells during the Cur:Na₂GA treatment. A biochemical blood test revealed a normalizing effect of Cur:Na₂GA (comparable to that of curcumin) on lipid metabolism. We believe that the further development and investigation of therapeutics based on curcuminoids in relation Opisthorchis felineus and other trematode infections will be useful for clinical practice and veterinary medicine. Full article

(This article belongs to the Special Issue Veterinary Parasitic Diseases: Advancements in Diagnostics, Therapeutics, and Vaccines)

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14 pages, 1441 KiB

Open AccessArticle

Old Methods, New Insights: Reviewing Concepts on the Ecology of Trypanosomatids and Bodo sp. by Improving Conventional Diagnostic Tools

by Fernanda Moreira Alves, Cristiane Varella Lisboa, Maria Augusta Dario, Roberto Leonan Morim Novaes, Liliani Marilia Tiepolo, Ricardo Moratelli and Ana Maria Jansen

Pathogens 2023, 12(1), 71; https://doi.org/10.3390/pathogens12010071 - 02 Jan 2023

Cited by 2 | Viewed by 1722

Abstract

Mixed infections by different Trypanosoma species or genotypes are a common and puzzling phenomenon. Therefore, it is critical to refine the diagnostic techniques and to understand to what extent these methods detect trypanosomes. We aimed to develop an accessible strategy to enhance the [...] Read more.

Mixed infections by different Trypanosoma species or genotypes are a common and puzzling phenomenon. Therefore, it is critical to refine the diagnostic techniques and to understand to what extent these methods detect trypanosomes. We aimed to develop an accessible strategy to enhance the sensitivity of the hemoculture, as well as to understand the limitations of the hemoculture and the blood clot as a source of parasitic DNA. We investigated trypanosomatid infections in 472 bats by molecular characterization (18S rDNA gene) of the DNA obtained from the blood clot and, innovatively, from three hemoculture sample types: the amplified flagellates (“isolate”), the pellet of the culture harvested in its very initial growth stage (“first aliquot”), and the pellet of non-grown cultures with failure of amplification (“sediment”). We compared (a) the characterization of the flagellates obtained by first aliquots and isolates; and (b) the performance of the hemoculture and blood clot for trypanosomatid detection. We observed: (i) a putative new species of Bodo in Artibeus lituratus; (ii) the potential of Trypanosoma cruzi selection in the hemoculture; (iii) that the first aliquots and sediments overcome the selective pressure of the hemoculture; and (iv) that the blood clot technique performs better than the hemoculture. However, combining these methods enhances the detection of single and mixed infections. Full article

(This article belongs to the Special Issue Veterinary Parasitic Diseases: Advancements in Diagnostics, Therapeutics, and Vaccines)

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13 pages, 1252 KiB

Open AccessArticle

Acaricidal Activity of Tea Tree and Lemon Oil Nanoemulsions against Rhipicephalus annulatus

by Samar M. Ibrahium, Ahmed A. Wahba, Ahmed A. Farghali, Abdel-Azeem S. Abdel-Baki, Shaimaa A. A. Mohamed, Saleh Al-Quraishy, Ahmed O. Hassan and Shawky M. Aboelhadid

Pathogens 2022, 11(12), 1506; https://doi.org/10.3390/pathogens11121506 - 09 Dec 2022

Cited by 6 | Viewed by 1401

Abstract

Tick infestation is a serious problem in many countries since it has an impact on the health of animals used for food production and pets, and frequently affects humans. Therefore, the present study aimed to investigate the acaricidal effects of nanoemulsions of essential [...] Read more.

Tick infestation is a serious problem in many countries since it has an impact on the health of animals used for food production and pets, and frequently affects humans. Therefore, the present study aimed to investigate the acaricidal effects of nanoemulsions of essential oils of Melaleuca alternifolia (tea tree, TT) and Citrus limon (lemon oil, CL) against the different stages (adult, eggs, and larvae) of deltamethrin-resistant Rhipicephalus annulatus ticks. Three forms of these oils were tested: pure oils, nanoemulsions, and a binary combination. Tea tree and lemon oil nanoemulsions were prepared, and their properties were assessed using a zeta droplet size measurement and a UV-Vis spectrophotometer. The results showed that TT and CL exhibited higher adulticidal effects in their pure forms than in their nanoemulsion forms, as demonstrated by the lower concentrations required to achieve LC₅₀ (2.05 and 1.26%, vs. 12.8 and 11.4%, respectively) and LC₉₀ (4.01% and 2.62%, vs. 20.8 and 19.9%, respectively). Significant larvicidal activity was induced by the TTCL combination, and LC₅₀ was reached at a lower concentration (0.79%) than that required for the pure and nanoemulsion forms. The use of pure CL oil was found to have the most effective ovicidal effects. In conclusion, pure TT and CL have potent acaricidal effects against phenotypically resistant R. annulatus isolates. It is interesting that the activity levels of TT and CL EOs’ binary and nanoemulsion forms were lower than those of their individual pure forms. Full article

(This article belongs to the Special Issue Veterinary Parasitic Diseases: Advancements in Diagnostics, Therapeutics, and Vaccines)

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9 pages, 920 KiB

Open AccessArticle

Detection of Anti-Neospora caninum IgG in Blood Serum and Colostrum Samples in Naturally Infected Sheep and in Their Newborn Offspring

by Roberto Alves Bezerra, Brendo Andrade Lima, Felipe Boniedj Ventura Alvares, Gabriel Augusto Marques Rossi, Fabio Ribeiro Braga, Renata Pimentel Bandeira de Melo, Rinaldo Aparecido Mota, Vinícius Longo Ribeiro Vilela and Thais Ferreira Feitosa

Pathogens 2022, 11(11), 1263; https://doi.org/10.3390/pathogens11111263 - 29 Oct 2022

Cited by 3 | Viewed by 1243

Abstract

The aim was to detect correlations of IgG antibodies against N. caninum in serum and colostrum samples from ewes, through the IFAT, and to evaluate the presence of this immunoglobulin in the serum of newborn lambs after colostrum ingestion. Blood samples from 162 [...] Read more.

The aim was to detect correlations of IgG antibodies against N. caninum in serum and colostrum samples from ewes, through the IFAT, and to evaluate the presence of this immunoglobulin in the serum of newborn lambs after colostrum ingestion. Blood samples from 162 ewes that did not show any disease in the general physical examination and from their newborn lambs, not more than five days postpartum, along with 162 colostrum samples and 182 blood samples from the neonates, were analyzed. In total, 27.8% (45/162) of the mothers were positive for anti-N. caninum IgG, among which antibodies were detected in the colostrum in 46.7% (21/45). All the ewes with positive colostrum had reactive offspring. The kappa agreement for the correlation between the serological tests on the ewes and the colostrum results was 0.558. This correlation increased as the antibody titers of the mothers increased, and reached 1.000 from the titer of 1:400 from the mothers. Comparison of the antibody detection results between the offspring’s serum and colostrum showed a kappa agreement of 1.000. In conclusion, there was a good agreement regarding the detection of anti-N. caninum IgG between the colostrum samples and the lambs’ serum; the use of colostrum forms a noninvasive alternative for diagnosing N. caninum in sheep herds. Full article

(This article belongs to the Special Issue Veterinary Parasitic Diseases: Advancements in Diagnostics, Therapeutics, and Vaccines)

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15 pages, 2720 KiB

Open AccessArticle

A Serodiagnostic IgM ELISA to Detect Acute Cytauxzoonosis

by Yun-Fan Kao, Rebecca Spainhour, Shannon R. Cowan, Laura Nafe, Adam Birkenheuer, Mason V. Reichard and Craig A. Miller

Pathogens 2022, 11(10), 1183; https://doi.org/10.3390/pathogens11101183 - 14 Oct 2022

Cited by 2 | Viewed by 1652

Abstract

Cytauxzoonosis is a tick-borne infectious disease affecting domestic cats with high mortality and limited treatment modalities. Because early diagnosis and therapeutic intervention are crucial to survival of infected cats, the objective of this study was to develop an ELISA capable of detecting cytauxzoonosis [...] Read more.

Cytauxzoonosis is a tick-borne infectious disease affecting domestic cats with high mortality and limited treatment modalities. Because early diagnosis and therapeutic intervention are crucial to survival of infected cats, the objective of this study was to develop an ELISA capable of detecting cytauxzoonosis and differentiating acute vs. chronic infection in clinical feline blood samples. A microsphere immunoassay (MIA) was developed to evaluate the production of Cytauxzoon felis-specific IgM and IgG antibodies in serial plasma samples from cats with experimental C. felis infection by targeting a C. felis-specific transmembrane protein (c88). Recombinant c88 protein was utilized to develop indirect ELISAs to detect IgM and IgG antibodies in clinical plasma samples from: PCR-positive cats with acute C. felis infection (n = 36), C. felis-negative cats with pyrexia (n = 10), healthy C. felis-negative cats (n = 22), and chronic C. felis carriers (n = 4). Anti-c88 IgM antibodies were detectable at day 12 post-tick infestation in cats with experimental C. felis infection (within 24 hours of developing clinical signs), while anti-c88 IgG was detectable at day 15 post-tick infestation – indicating IgM could be used to detect early infection. Using a cut-off value of 19.85 percent positive, the C. felis IgM ELISA detected acute cytauxzoonosis in 94.44% (34/36) of cats presented with clinical signs of acute cytauxzoonosis with 100% specificity (indicating a “Strong Positive” result). When a lower cutoff of 8.60 percent positive was used, cytauxzoonosis was detected in the 2 remaining PCR-positive cats with 87.88% specificity (indicating of a “Weak Positive” result). One C. felis-negative, febrile cat had high IgG, and chronic carriers had variable IgM and IgG results. Combined interpretation of IgM and IgG ELISAs did not reliably differentiate acute vs. chronic infection. While further validation on assay performance is needed, the C. felis IgM ELISA is a promising test to detect acute cytauxzoonosis and can be utilized to develop a point-of-care test for clinical use. Full article

(This article belongs to the Special Issue Veterinary Parasitic Diseases: Advancements in Diagnostics, Therapeutics, and Vaccines)

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Review

Jump to: Research, Other

16 pages, 1032 KiB

Open AccessReview

The Use of Innovative Diagnostics to Inform Sustainable Control of Equine Helminth Infections

by Jacqueline B. Matthews, Natalia Peczak and Kirsty L. Lightbody

Pathogens 2023, 12(10), 1233; https://doi.org/10.3390/pathogens12101233 - 11 Oct 2023

Cited by 1 | Viewed by 2559

Abstract

Helminths are commonly found in grazing equids, with cyathostomin nematodes and the cestode Anoplocephala perfoliata being the most prevalent. Most horses harbour low burdens of these parasites and do not develop signs of infection; however, in a small number of animals, high burdens [...] Read more.

Helminths are commonly found in grazing equids, with cyathostomin nematodes and the cestode Anoplocephala perfoliata being the most prevalent. Most horses harbour low burdens of these parasites and do not develop signs of infection; however, in a small number of animals, high burdens can accumulate and cause disease. Cyathostomins are associated with a syndrome known as larval cyathostominosis. This occurs when large numbers of larvae emerge from the large intestinal wall. This disease has a case fatality rate of up to 50%. A. perfoliata infection has been associated with various types of colic, with burdens of >20 worms associated with pathogenicity. Anthelmintic resistance is a serious problem in cyathostomins and is emerging in A. perfoliata. Control methods that reduce reliance on anthelmintics now need to be applied, especially as no new dewormer compounds are on the horizon. Sustainable control methods must employ diagnostics to identify horses that require treatment. Coprological tests (faecal egg counts, FECs) have been used for several decades to inform treatment decisions to reduce helminth egg shedding. These tests cannot be used to assess host burdens as FECs do not correlate with cyathostomin or A. perfoliata burdens. In the last decade, new tests have become available that measure parasite-specific antibodies, the levels of which have been shown to correlate with parasite burden. These tests measure antigen-specific IgG(T) and are available in serum (cyathostomin, A. perfoliata) or saliva (A. perfoliata) formats. Tests for other helminths have been developed as research tools and need to be translated to support equine clinicians in practice. A key element of sustainable control strategies is that diagnostics must be used in combination with management approaches to reduce environmental transmission of helminths; this will help limit the proportion of horses harbouring parasite burdens that need to be targeted by treatment. This manuscript provides a review of the development, performance and general utility of various diagnostic methods for informing equine helminth management decisions. Full article

(This article belongs to the Special Issue Veterinary Parasitic Diseases: Advancements in Diagnostics, Therapeutics, and Vaccines)

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24 pages, 2003 KiB

Open AccessReview

Overview of Apoptosis, Autophagy, and Inflammatory Processes in Toxoplasma gondii Infected Cells

by Ehsan Ahmadpour, Farhad Babaie, Tohid Kazemi, Sirous Mehrani Moghaddam, Ata Moghimi, Ramin Hosseinzadeh, Veeranoot Nissapatorn and Abdol Sattar Pagheh

Pathogens 2023, 12(2), 253; https://doi.org/10.3390/pathogens12020253 - 04 Feb 2023

Cited by 7 | Viewed by 4965

Abstract

Toxoplasma gondii (T. gondii) is an obligate intracellular parasite. During the parasitic invasion, T. gondii creates a parasitophorous vacuole, which enables the modulation of cell functions, allowing its replication and host infection. It has effective strategies to escape the immune response [...] Read more.

Toxoplasma gondii (T. gondii) is an obligate intracellular parasite. During the parasitic invasion, T. gondii creates a parasitophorous vacuole, which enables the modulation of cell functions, allowing its replication and host infection. It has effective strategies to escape the immune response and reach privileged immune sites and remain inactive in a controlled environment in tissue cysts. This current review presents the factors that affect host cells and the parasite, as well as changes in the immune system during host cell infection. The secretory organelles of T. gondii (dense granules, micronemes, and rhoptries) are responsible for these processes. They are involved with proteins secreted by micronemes and rhoptries (MIC, AMA, and RONs) that mediate the recognition and entry into host cells. Effector proteins (ROP and GRA) that modify the STAT signal or GTPases in immune cells determine their toxicity. Interference byhost autonomous cells during parasitic infection, gene expression, and production of microbicidal molecules such as reactive oxygen species (ROS) and nitric oxide (NO), result in the regulation of cell death. The high level of complexity in host cell mechanisms prevents cell death in its various pathways. Many of these abilities play an important role in escaping host immune responses, particularly by manipulating the expression of genes involved in apoptosis, necrosis, autophagy, and inflammation. Here we present recent works that define the mechanisms by which T. gondii interacts with these processes in infected host cells. Full article

(This article belongs to the Special Issue Veterinary Parasitic Diseases: Advancements in Diagnostics, Therapeutics, and Vaccines)

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Other

Jump to: Research, Review

8 pages, 4110 KiB

Open AccessCase Report

Fulminant Pneumonia Due to Reactivation of Latent Toxoplasmosis in a Cat—A Case Report

by Simone A. Fietz, Thomas Grochow, Gereon Schares, Tanja Töpfer and Romy M. Heilmann

Pathogens 2024, 13(1), 7; https://doi.org/10.3390/pathogens13010007 - 20 Dec 2023

Viewed by 1073

Abstract

Toxoplasma (T.) gondii is an obligate intracellular parasite with felids, including domestic cats, as definitive hosts. In immunocompetent individuals, T. gondii infection is usually asymptomatic. However, under immunosuppression, it may have severe pathological impacts, which often result from the reactivation of a chronic [...] Read more.

Toxoplasma (T.) gondii is an obligate intracellular parasite with felids, including domestic cats, as definitive hosts. In immunocompetent individuals, T. gondii infection is usually asymptomatic. However, under immunosuppression, it may have severe pathological impacts, which often result from the reactivation of a chronic infection. In this case study, a 21-month-old female domestic shorthair cat—diagnosed with primary immune-mediated hemolytic anemia three months prior and treated with cyclosporine and prednisolone—presented with acute tachypnea, dyspnea, diarrhea, and anorexia. Thoracic radiography suggested severe pneumonia. Testing for Mycoplasma spp., Anaplasma spp., Ehrlichia spp., and lungworm infection was negative. Serology for T. gondii revealed seroconversion of IgG, but not of IgM, indicating previous exposure to T. gondii. The cat remained stable but tachypneic for three days, followed by an acute onset of dyspnea and clinical deterioration, after which euthanasia was elected. Numerous protozoa were present in a postmortem transtracheal bronchoalveolar lavage and fine-needle aspiration of the lung. Microsatellite typing classified the extracted DNA as T. gondii type II variant TgM-A. This case demonstrates that T. gondii reactivation, leading to fulminant pneumonia, can be a sequela of immunosuppressive treatment in cats and should, therefore, be considered as a differential diagnosis in immunosuppressed cats with acute-onset respiratory signs. Rapid diagnosis may prevent fatal consequences. Full article

(This article belongs to the Special Issue Veterinary Parasitic Diseases: Advancements in Diagnostics, Therapeutics, and Vaccines)

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