Showing papers in "Parasitology Research in 2018"
TL;DR: A current review on conventional acaricide and macrocyclic lactone resistance for better understanding and control of resistant ticks with particular emphasis on R. microplus on cattle is presented.
Abstract: Infestations with the cattle tick, Rhipicephalus microplus, constitute the most important ectoparasite problem for cattle production in tropical and subtropical regions worldwide, resulting in major economic losses. The control of R. microplus is mostly based on the use of conventional acaricides and macrocyclic lactones. However, the intensive use of such compounds has resulted in tick populations that exhibit resistance to all major acaricide chemical classes. Consequently, there is a need for the development of alternative approaches, possibly including the use of animal husbandry practices, synergized pesticides, rotation of acaricides, pesticide mixture formulations, manual removal of ticks, selection for host resistance, nutritional management, release of sterile male hybrids, environmental management, plant species that are unfavourable to ticks, pasture management, plant extracts, essential oils and vaccination. Integrated tick management consists of the systematic combination of at least two control technologies aiming to reduce selection pressure in favour of acaricide-resistant individuals, while maintaining adequate levels of animal production. The purpose of this paper is to present a current review on conventional acaricide and macrocyclic lactone resistance for better understanding and control of resistant ticks with particular emphasis on R. microplus on cattle.
164 citations
TL;DR: The results showed that bark extract-derived AgNPs have extremely high larvicidal potential compared to other organic solvents as well as aqueous bark extract alone and can be used safely for the control of dengue and filarial vectors that cause severe human health hazards.
Abstract: The present study was carried out to evaluate the larvicidal potential of methanol, hexane, acetone, chloroform, and aqueous bark extracts of Holarrhena antidysenterica (L.) Wall. and silver nanoparticles (AgNPs) synthesized using aqueous bark extract against the third instar larvae of Aedes aegypti L. and Culex quinquefasciatus Say. AgNPs were prepared by adding 10 ml of aqueous bark extract in 90 ml of 1 mM silver nitrate (AgNO3) solution. After 5 min of mixing, a change in color from yellow to dark brown occurred indicating the synthesis of AgNPs. Their further characterization was done through ultraviolet-visible spectroscopy (UV–Vis), X-ray diffraction analysis (XRD), field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR). UV–Vis spectrum of synthesized AgNPs showed a maximum absorption peak at 420 nm wavelength. Crystalline nature of AgNPs was confirmed by the presence of characteristic Bragg reflection peaks in XRD pattern. TEM images have shown that most of the AgNPs were spherical in shape with an average size of 32 nm. FT-IR spectrum of AgNPs showed prominent absorbance peaks at 1012.2 (C–O) and 3439.44 cm−1 (O–H) which represent the major constituents of phenolics, terpenoids, and flavonoids compounds. LC-MS analysis of the bark extract confirmed the presence of carbonyl and hydroxyl functional groups which were directly correlated with FT-IR results. These AgNPs were assayed against different mosquito vectors, and the maximum mortality was recorded against the larvae of A. aegypti with LC50 and LC90 values being 5.53 and 12.01 ppm, respectively. For C. quinquefasciatus, LC50 and LC90 values were 9.3 and 19.24 ppm, respectively, after 72 h of exposure. Bark extracts prepared in different solvents such as methanol, chloroform, hexane, acetone, and water showed moderate larvicidal activity against A. aegypti their respective LC50 values being 71.74, 94.25, 102.25, 618.82, and 353.65 ppm and LC90 values being 217.36, 222.24, 277.82, 1056.36, and 609.37 ppm. For C. quinquefasciatus, their LC50 values were 69.43, 112.39, 73.73, 597.74, and 334.75 ppm and LC90 values of 170.58, 299.76, 227.48, 1576.98, and 861.45 ppm, respectively, after 72 h of treatment. AgNPs proved to be nontoxic against the non-target aquatic organism, Mesocyclops thermocyclopoides Harada when exposed for 24, 48, and 72 h. The results showed that bark extract-derived AgNPs have extremely high larvicidal potential compared to other organic solvents as well as aqueous bark extract alone. These AgNPs, therefore, can be used safely for the control of dengue and filarial vectors that cause severe human health hazards.
68 citations
TL;DR: The most effective EOs and terpenes that were identified through the current laboratory bioassays could be used as alternative agents to control larvae and repel adults of Ae.
Abstract: In the current laboratory study, 14 essential oils (EOs) derived from 12 Lamiaceae plant species and their major components were screened for their larvicidal and repellent properties against Aedes albopictus, an invasive mosquito species of great medical importance. The results of toxicity bioassays revealed that the EOs from Thymus vulgaris, Ocimum basilicum, Origanum dictamnus, Origanum majorana, and Origanum vulgare, as well as their major components (terpenes), namely thymol, carvacrol, p-cymene, and γ-terpinene exerted the highest larvicidal effect. Essential oils from Mellisa officinalis, Origanum dictamus, Mentha spicata (chem. piperitenone epoxide), Origanum majorana, and Satureja thymbra were the most potent repellents, with the last two assigned as the best ones. Among the terpenes tested, piperitenone epoxide, carvacrol, thymol, and piperitenone provided the highest level of protection against Ae. albopictus adults. Chemical analysis revealed the presence of a high number of terpenes in the EOs, while in most cases, the biological action of the tested EOs and their major components was in consistency. The most effective EOs and terpenes that were identified through the current laboratory bioassays could be used as alternative agents to control larvae and repel adults of Ae. albopictus.
62 citations
TL;DR: The development of a new formulation of more effective antiamoebic agents based on AgNPs coated with drugs that hold promise for future applications is presented.
Abstract: Infectious diseases are the leading cause of morbidity and mortality, killing more than 15 million people worldwide. This is despite our advances in antimicrobial chemotherapy and supportive care. Nanoparticles offer a promising technology to enhance drug efficacy and formation of effective vehicles for drug delivery. Here, we conjugated amphotericin B, nystatin (macrocyclic polyenes), and fluconazole (azole) with silver nanoparticles. Silver-conjugated drugs were synthesized successfully and characterized by ultraviolet-visible spectrophotometry, Fourier transform infrared spectroscopy, and atomic force microscopy. Conjugated and unconjugated drugs were tested against Acanthamoeba castellanii belonging to the T4 genotype using amoebicidal assay and host cell cytotoxicity assay. Viability assays revealed that silver nanoparticles conjugated with amphotericin B (Amp-AgNPs) and nystatin (Nys-AgNPs) exhibited significant antiamoebic properties compared with drugs alone or AgNPs alone (P < 0.05) as determined by Trypan blue exclusion assay. In contrast, conjugation of fluconazole with AgNPs had limited effect on its antiamoebic properties. Notably, AgNP-coated drugs inhibited amoebae-mediated host cell cytotoxicity as determined by measuring lactate dehydrogenase release. Overall, here we present the development of a new formulation of more effective antiamoebic agents based on AgNPs coated with drugs that hold promise for future applications.
52 citations
TL;DR: The high dissemination and transmission rates for WNV under a realistic temperature regime in Ae.
Abstract: West Nile virus (WNV) is continuously spreading in Eastern and Southern Europe. However, the extent of vector competence of Aedes japonicus (Theobald, 1901) is controversial. In this work, we elucidated the dynamics of virus growth in this invasive mosquito species. Females of Ae. japonicus were reared from eggs collected in the field in Switzerland and fed on bovine blood spiked with two WNV lineage 1 strains (FIN, Italy; NY99, USA). Fully engorged females were incubated for 14 days under a fluctuating temperature regime of 24 ± 7 °C (average 24 °C), 45-90% relative humidity, which is realistic for a Central European mid-summer day. Infection, dissemination, and transmission rates were assessed from individual mosquitoes by analyzing the abdomen, legs and wings, and saliva for the presence of viral RNA. Saliva was also investigated for the presence of infectious virus particles. Overall, 302 females were exposed to WNV strain FIN and 293 to strain NY99. A higher infection rate was observed for NY99 (57.4%) compared to FIN (30.4%) (p = 0.003). There was no statistical evidence that the dissemination rate (viral RNA in legs and wings) was different between females infected with FIN (57.1%) compared to NY99 (35.5%) (p = 0.16). Viral RNA load of FIN compared to NY99 was significantly higher in the hemocoel (p = 0.031) of exposed females but not at other sites (legs and wings, saliva). This is the first study describing the vector competence parameters for two WNV strains in a European population of Ae. japonicus. The high dissemination and transmission rates for WNV under a realistic temperature regime in Ae. japonicus together with recent findings on its opportunistic feeding behavior (mammals and birds) indicate its potential role in WNV transmission in Central Europe where it is highly abundant.
45 citations
TL;DR: O. compactum essential oil, carvacrol and thymol inhibited the enzyme, confirming that this could be one of the mechanisms involved in the anthelmintic activity, and demonstrated a dose-dependent larvicidal activity against A. simplex L3 larvae.
Abstract: Anisakiasis is a fish-borne parasitic disease caused by the consumption of raw or undercooked fish, as well as cephalopods, contaminated by third instar larvae (L3) of species belonging to the genus Anisakis (Anisakidae). Origanum compactum is a small herbaceous aromatic plant endemic to Spain and Morocco. In Morocco, the plant is used under infusion to treat heart diseases and intestinal pains or as preservative for foodstuffs. This is the first time that the O. compactum essential oil is tested against the parasitic nematode Anisakis simplex. The phytochemical analysis by GC-MS revealed carvacrol (50.3%) and thymol (14.8%) as the major oil constituents. The essential oil and its major constituents carvacrol and thymol were tested against A. simplex L3 larvae isolated from blue whiting fish (Micromesistius poutassou). A. simplex mortality (%) after 24 and 48 h of treatment at 1 μl/ml was 100%, with a low LD50 compared with other essential oils and extracts, and the penetration in the agar assay was also reduced, if compared with control wells. The oil, as well as its major constituents, demonstrated a dose-dependent larvicidal activity. Inhibition of the enzyme acetylcholinesterase through a colorimetric assay in 96-well plates was used to elucidate the pharmacological mechanism as this enzyme plays a key role in nematodes neuromuscular function. Interestingly, O. compactum essential oil, carvacrol and thymol inhibited the enzyme, confirming that this could be one of the mechanisms involved in the anthelmintic activity. To the best of our knowledge, this is the first time that O. compactum essential oil is reported as a larvicidal agent against A. simplex L3 larvae.
40 citations
TL;DR: The methods that are currently being used for the detection of Cryptosporidium oocysts in food material and all of the other available published methods are discussed in this review.
Abstract: Cryptosporidium is one of the most important parasitic protozoa of concern within the food production industry, worldwide. This review describes the evolution and its development, and it monitors the methodology that has been used for Cryptosporidium in food material since 1984, when the first publication appeared regarding the detection of Cryptosporidium parvum in food materials. The methods that are currently being used for the detection of Cryptosporidium oocysts in food material (mainly vegetables) and all of the other available published methods are discussed in this review. Generating more consistent and reliable data should lead to a better understanding of the occurrence, transport and fate of the oocysts in food material. Improvements in monitoring and developing effective methodology, along with food security, offer more practical possibilities for both the developed and developing worlds.
39 citations
TL;DR: Significantly higher seroprevalence was found in domestic ruminants, particularly in sheep, compared to the wild species tested, indicating widespread exposure to T. gondii among domestic and wild ungulates in Southern Spain, with significant differences among species sharing the same ecosystem.
Abstract: Toxoplasma gondii is a zoonotic protozoan of worldwide distribution. The present study provides information on risk factors affecting T. gondii infection in domestic and free-ranging wild ungulates sharing habitats in Mediterranean ecosystems in Spain. Serum samples from 482 extensively reared domestic ruminants and 2351 wild ungulates were tested for T. gondii antibodies using the modified agglutination test (MAT, cut-off 1:25). Toxoplasma gondii seroprevalence was 41.2% of 194 sheep, 18.6% of 199 cattle and 5.6% of 89 goats. The main risk factors associated with infection in livestock were the presence of cats, feeding on the ground and at stubble fields. In wild ungulates, T. gondii antibodies were detected in 10.5% of 1063 red deer, 15.6% of 294 fallow deer, 5.6% of 216 European mouflon, 5.6% of 90 Spanish ibex, 13.6% of 22 roe deer and 18.6% of 666 wild boars. The risk factors affecting T. gondii infection in wildlife were species, age and hunting season. Significantly higher seroprevalence was found in domestic ruminants, particularly in sheep, compared to the wild species tested. The present study indicates widespread exposure to T. gondii among domestic and wild ungulates in Southern Spain, with significant differences among species sharing the same ecosystem. The high seroprevalence observed in domestic ruminants, particularly in sheep, reinforces the need for farm management practices to control the risk factors associated with T. gondii infection in extensively reared livestock. Consumption of raw and undercooked food products from domestic and wildlife species may have important implications for public health.
38 citations
TL;DR: Interestingly, IBS is usually associated with gut dysbiosis, while the most prevalent parasite in the authors' IBS patients was Blastocystis sp.
Abstract: Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disease presenting clinically by abdominal pain with alteration of bowel habits. Although IBS has uncertain etiology, chronic gut inflammation due to persistent exposure to an infectious agent including Blastocystis sp. was proposed. The aim of this study was to detect the prevalence of Blastocystis sp. subtype (ST) isolated from stool of IBS patients and to assess Blastocystis sp. and H. pylori co-infection in IBS patients from Beni-Suef Governorate, Egypt. Stool samples were collected from 115 IBS patients, following Rome III criteria. All stool samples were microscopically examined by wet mount and permanent trichrome stain, cultured on Jones' medium with further sequencing of positive Blastocystis isolates and screened for detection of H. pylori coproantigen. Blastocystis sp. was the predominant parasite in IBS patients; it had statistical significant association with both rural residence (OR = 10) and flatulence (OR = 8.2). There was a predominance of Blastocystis sp. ST3 (81%) followed by ST1 (19%). Blastocystis culture results (19.1%) were superior than microscopy (16.5%). The majority of Blastocystis-positive IBS patients (72.7%) were co-infected with H. pylori with statistical significance; however, H. pylori was higher in Blastocystis-negative IBS patients (47/64) than in Blastocystis-positive IBS patients (17/64). Interestingly, IBS is usually associated with gut dysbiosis, while the most prevalent parasite in our IBS patients was Blastocystis sp., which is frequently found in asymptomatic individuals. Whether Blastocystis sp. is a cause or a consequence of IBS still needs further investigation, with a particular focus on correlation of IBS with different Blastocystis sp. subtypes and gut microbiomes.
37 citations
TL;DR: Results suggest that New Zealand may have high levels of coastal contamination with T. gondii, particularly in summer months, and that naturally exposed mussels can ingest and retain sporulated oocysts, further establishing shellfish consumption as a health concern.
Abstract: Pollution of marine ecosystems with the protozoan parasites Toxoplasma gondii, Cryptosporidium spp. and Giardia duodenalis can be studied using bivalve shellfish as biosentinels. Although evidence suggests that these parasites are present in New Zealand coastal waters, the extent of protozoal pollution has not been investigated. This study used optimised molecular methods to detect the presence of Cryptosporidium spp., G. duodenalis and T. gondii in commercially sourced green-lipped mussel (Perna canaliculus), an endemic species found throughout coastal New Zealand. A nested polymerase chain reaction was validated for detection of T. gondii DNA and applied to 104 commercially sourced mussels. Thirteen mussels were positive for T. gondii DNA with an estimated true prevalence of 16.4% using Bayesian statistics, and the presence of T. gondii in mussels was significantly associated with collection during the summer compared with that in the winter (P = 0.003). Consumption of contaminated shellfish may also pose a health risk for humans and marine wildlife. As only sporulated T. gondii oocysts can be infectious, a reverse transcriptase-polymerase chain reaction was used to confirm presence of a sporozoite-specific marker (SporoSAG), detected in four mussels. G. duodenalis assemblage B, known to be pathogenic in humans, was also discovered in 1% mussels, tested by polymerase chain reaction (n = 90). Cryptosporidium spp. was not detected in the sampled mussel haemolymph. Results suggest that New Zealand may have high levels of coastal contamination with T. gondii, particularly in summer months, and that naturally exposed mussels can ingest and retain sporulated oocysts, further establishing shellfish consumption as a health concern.
36 citations
TL;DR: Results reveal that a significant percentage of suckling calves are carriers of zoonotic subtypes of C. parvum, and both healthy and diarrhoeic calves younger than 1 month may represent a risk for the transmission of cryptosporidiosis in humans and animals.
Abstract: To provide up-to-date information on the occurrence of Cryptosporidium in pre-weaned calves from Sardinia (Italy), the species implicated and their zoonotic potential, 147 faecal samples from 22 cattle herds were microscopically examined for Cryptosporidium oocysts; positive isolates were molecularly characterised. A questionnaire was developed to identify risk factors for Cryptosporidium infection. Overall, the percentage of positive calves and farms was 38.8 and 68.2%, respectively. The SSU rRNA-based PCR identified two Cryptosporidium species, Cryptosporidium parvum (95.8%) and C. bovis (4.2%). Sequence analyses of the glycoprotein (gp60) gene revealed that all C. parvum isolates belonged to the subtype family IIa (IIaA15G2R1 and IIaA16G3R1), with the exception of three isolates that belonged to the subtype family IId (IIdA20G1b and IIdA20). Mixed logistic regression results indicated that calves aged 15–21 days were more likely to be Cryptosporidium-positive. The risk of being positive was also significantly higher in herds from Central Sardinia and in farms using non-slatted flooring. In addition, the application of disinfectants and milk replacers was significantly associated with higher Cryptosporidium prevalence. In contrast, the risk of being positive was significantly reduced in halofuginone-treated calves. Our results reveal that a significant percentage of suckling calves are carriers of zoonotic subtypes of C. parvum. Thus, both healthy and diarrhoeic calves younger than 1 month may represent a risk for the transmission of cryptosporidiosis in humans and animals.
TL;DR: Fecal specimens collected in Qinghai, China, supported the occurrence of host adaptation among E. bieneusi by PCR-sequence analysis of the ribosomal internal transcribed spacer.
Abstract: Few studies have been conducted on the distribution of Enterocytozoon bieneusi genotypes in Tibetan sheep and yaks, which live outdoors in extreme climate with high altitude. In this study, fecal specimens from 312 Tibetan sheep and 554 yaks in Qinghai, China, were collected and examined for E. bieneusi by PCR-sequence analysis of the ribosomal internal transcribed spacer. Among them, 73 (23.4%) specimens from Tibetan sheep and 40 (7.2%) from yaks were positive for E. bieneusi. There were eight E. bieneusi genotypes in Tibetan sheep, including three known ones (BEB6, COS-I, and NESH5) and five novel ones (named as CHS13-CHS17). Similarly, seven E. bieneusi genotypes were found in yaks, including five known ones (J, BEB4, BEB6, COS-I, and NESH5) and two novel ones (named as CHN13 and CHN14). Most of the E. bieneusi genotypes and all frequent ones identified in the study belonged to group 2. One new subgroup of genotypes was identified within group 1. The distribution of E. bieneusi genotypes was different between Tibetan sheep and yaks, with BEB6 as the dominant one (42.5%) in Tibetan sheep and J as the dominant one (47.5%) in yaks. These data support the occurrence of host adaptation among E. bieneusi genotypes within group 2.
TL;DR: Investigation of fish imported from Singapore, Malaysia, Thailand, or Sri Lanka to Australia for monogenean ectoparasites shows that pre-export health requirements, which include chemical treatment of goldfish, and inspection of all ornamental fish species did not prevent infection by monogeneans.
Abstract: The ornamental fish trade provides a pathway for the global translocation of aquatic parasites. We examined a total of 1020 fish imported from Singapore, Malaysia, Thailand, or Sri Lanka to Australia (including freshwater and marine fish species) for monogenean ectoparasites. Fish were received following veterinary certification that they showed no clinical signs of pests and diseases from the exporting country and visual inspection at Australian border control. Australian import conditions require mandatory treatment for goldfish with parasiticides (e.g. trichlorfon, formaldehyde, sodium chloride) for the presence of gill flukes (Dactylogyrus vastator Nybelin, 1924 and Dactylogyrus extensus Mueller and Van Cleave, 1932) prior to export. Over 950 individual parasites were detected in five imported fish species, representing 14 monogenean species. Seven Dactylogyrus spp. including D. vastator and three Gyrodactylus spp. infected goldfish, Carassius auratus Linnaeus, 1758, from Malaysia, Singapore, and Thailand. Dactylogyrus ostraviensis Řehulka, 1988, infected rosy barb, Pethia conchonius Hamilton, 1822, from Singapore, Sri Lanka, and Thailand while two Trianchoratus spp. infected three spot gourami, Trichopodus trichopterus Pallas, 1970 and pearl gourami Trichopodus leerii Bleeker, 1852, from Sri Lanka. Urocleidoides reticulatus Mizelle & Price, 1964, infected guppy, Poecilia reticulata Peters, 1859, from Sri Lanka. The discovery of D. vastator in goldfish, as well as 13 other monogenean species, shows that pre-export health requirements, which include chemical treatment of goldfish, and inspection of all ornamental fish species did not prevent infection by monogeneans. Inspection prior to exportation and at border control must account for the highly cryptic nature of monogenean parasites and consider alternatives to current pre-export conditions and visual inspection at border control.
TL;DR: There are very few studies on this subject, which present some limitations for inference and conclusions: most were cross-sectional studies, with a small sample size and in similar populations.
Abstract: Studies suggest that the protozoan Toxoplasma gondii can disturb human behavior. This study aimed to systematically review the scientific literature on the possible associations between Toxoplasma gondii infection and neurobehavioral abnormalities in humans. We reviewed and summarized the studies published since 1990. The descriptors used were related to T. gondii infection and behavioral outcomes in humans; the main databases of the medical literature were accessed. The results of eight original articles published between 1994 and 2016 were evaluated and described. The most common serological method was the enzyme immunoassay. Most of the researchers used validated instruments for behavioral evaluation. Seven studies reported some association between the prevalence of anti-T. gondii antibodies and some altered behavioral aspects in adult humans; these studies focused on adult population in Europe and the USA. The most reported behavioral deviations are related to greater impulsivity and aggressiveness. There are very few studies on this subject, which present some limitations for inference and conclusions: most were cross-sectional studies, with a small sample size and in similar populations. Investigations with a larger sample size of different population groups should be performed to evaluate multiple factors.
TL;DR: The present study confirmed the role of wild boars as a source of parasitic zoonotic diseases and thus the risk derived for humans posed by the consumption of game meat and underline the importance of monitoring and surveillance ofZoonotic parasites in Italian wild boar populations.
Abstract: Wild boar is a source of human infections with zoonotic pathogens, including food-borne parasites. With the aim of a characterization of the human exposure risk, a survey on wild boars intended for human consumption was planned, selecting three pathogens, Toxoplasma gondii, Alaria alata, and Trichinella spp., as markers of meat infection. Diaphragm muscle samples from 100 wild boars hunted in Piedmont region (Northern Italy) in two hunting seasons (2015-2016) were collected. Concerning T. gondii, a combined approach of antibody detection and molecular techniques with genotyping was performed. For the detection of A. alata and Trichinella spp., the larva migration technique and the magnetic stirrer method were employed, respectively; in addition, molecular confirmation of the morphological identification of the recovered specimen was performed. Anti-T. gondii antibodies were found in meat juice samples (43.3%) and T. gondii DNA (type II) was detected in three animals (7.1%) out of 42 seropositive examined. In none of the sampled wild boars (0%), Trichinella spp. larvae were found, whereas one animal (1%) scored positive to A. alata mesocercariae. The molecular diagnosis proved the morphological identification of the trematode. This is the first finding of A. alata in Italian wild boar population. The present study confirmed the role of wild boars as a source of parasitic zoonotic diseases and thus the risk derived for humans posed by the consumption of game meat. Considering the zoonotic implications, the results underline the importance of monitoring and surveillance of zoonotic parasites in Italian wild boar populations.
TL;DR: Compound 32, endochin-like quinolones, miltefosine, and guanabenz can be used as effective antiparasitic with the unique ability to reduce brain tissue cysts in chronically infected mice, and these antimicrobial agents are significant criteria for drug candidates.
Abstract: Currently, there is no approved therapy that can eradicate Toxoplasma gondii tissue cysts, which are responsible for chronic infection. This systematic review was performed to assess drugs or compounds that can be used as anti-T. gondii tissue cysts in vitro and in vivo. English electronic databases (i.e., PubMed, Science Direct, Scopus, Google Scholar, and Web of Science) were systematically searched for articles published up to 2017. A total of 55 papers published from 1987 to 2017 were eligible for inclusion in this systematic review. Among the drugs, atovaquone and azithromycin were found effective after long-term inoculation into mice; however, clinical cases of resistance to these drugs have been reported. Also, FR235222, QUI-11, tanshinone IIA, and hydroxyzine were shown to be effective against Toxoplasma cysts, but their effectiveness in vivo remains unknown. Additionally, compound 32, endochin-like quinolones, miltefosine, and guanabenz can be used as effective antiparasitic with the unique ability to reduce brain tissue cysts in chronically infected mice. Importantly, these antimicrobial agents are significant criteria for drug candidates. Future studies should focus on the biology and drug susceptibility of the cyst form of T. gondii in chronic toxoplasmosis patients to find more effective strategies that have sterilizing activity for eliminating T. gondii tissue cysts from the host, preventing disease relapse and potentially shortening the required duration of drug administration. Graphical abstract.
TL;DR: The expression of AmPpo might be a suitable biomarker for hemocyte counts as part of cellular defenses against injection of buffer or mite compounds and V. destructor parasitism and perhaps other conditions involving healing and immunity.
Abstract: Circulating hemocytes are responsible for defensive and healing mechanisms in the honey bee, Apis mellifera. Parasitism by the mite Varroa destructor and injection of V. destructor homogenate in buffer, but not buffer injection, showed similar reductions in total hemocyte concentrations in both Africanized and European adult honey bees. This indicated that compounds in V. destructor homogenate can have similar effects as V. destructor parasitism and that the response is not solely due to wounding. Samples from honey bees with different hemocyte concentrations were compared for the expression patterns of hemolectin (AmHml), prophenol oxidase (AmPpo), and class C scavenger receptor (AmSRC-C). Of the genes tested, only the expression of AmPpo correlated well with hemocyte counts for all the treatments, indicating that melanization is associated with those responses. Thus, the expression of AmPpo might be a suitable biomarker for hemocyte counts as part of cellular defenses against injection of buffer or mite compounds and V. destructor parasitism and perhaps other conditions involving healing and immunity.
TL;DR: Seasonal variation in the chemical composition of the O. gratissimum essential oil influences its acaricidal activity, and can represent an important strategy for the control of R. microplus larvae.
Abstract: The tick Rhipicephalus microplus affects cattle health, with production loss in tropical and subtropical regions. Moreover, the use of commercial acaricides has been reduced due to the resistance of this parasite. Although alternatives such as plant bioactive molecules have been sought, essential oils present variations in their chemical constituents due to environmental factors, which can interfere with their acaricidal activity. The objective of the present study was to evaluate the seasonal influence of the essential oil of Ocimum gratissimum and its major constituents on acaricidal activity against R. microplus larvae. A high-yield essential oil of O. gratissimum and its major constituents were used, and a plant with a thymol-type oil was selected for seasonal analysis and acaricidal activity against R. microplus. Gas chromatography (GC) and GC-mass spectrometry (MS) were employed to identify 31 oil constituents (average yield of 6.26%). The main compounds were found to be thymol (33.4 to 47.9%), γ-terpinene (26.2 to 36.8%), and p-cymene (4.3 to 17.0%). Concerning acaricidal activity, the December (LC50 0.84 mg/mL) and September (LC50 1.58 mg/mL) oils obtained in the dry season were the most active, and assays performed with commercial standards revealed LC50 values of p-cymene, thymol, and γ-terpinene of 1.41, 1.81, and 3.08 mg/mL, respectively. Overall, lower acaricidal activities were found for oils produced from plants harvested in the rainy season. The results showed that seasonal variation in the chemical composition of the O. gratissimum essential oil influences its acaricidal activity. The seasonal variations in the thymol-type essential oil of O. gratissimum can represent an important strategy for the control of R. microplus.
TL;DR: Investigation of the effect of water quality on parasite assemblages infecting Oreochromis niloticus in selected fish farms within Nakuru County indicated that certain water quality parameters, such as dissolved oxygen, were significantly different for all the six fish farms (one-way ANOVA, p < 0.05).
Abstract: Aquaculture has been documented as the fastest developing food industry in Kenya with increased production since the Government initiated the Economic Stimulus Programme (ESP) in 2009 However, the production has not yet reached the maximum level (20,000 metric tons per year) anticipated in the country This is due to a number of challenges, top of which is poor water quality resulting from the uncontrolled addition of inputs (fish feeds, inorganic fertilizers, and organic fertilizers) into the ponds These deteriorate water quality, cause increased incidences of parasite infections, and impede fish production Therefore, this study investigated the effect of water quality on parasite assemblages infecting Oreochromis niloticus (Linnaeus 1758) in selected fish farms within Nakuru County from November 2016 to February 2017 Selected physico-chemical parameters namely: dissolved oxygen, temperature, pH, conductivity, and turbidity were measured in situ using appropriate meters Water samples from each fish farm were analyzed for nutrient concentrations using standard methods A total of 300 fish were examined for parasites Parasites were counted, preserved, and identified using identification keys and parasitological parameters determined The results indicated that certain water quality parameters, such as dissolved oxygen, were significantly different for all the six fish farms (one-way ANOVA, p < 005) A total of 15 species of parasites were recovered Trichodina sp and Cichlidogyrus halli were found in all the studied fish farms Correspondence analysis revealed that some parasites’ occurrences were highly correlated (positively) with certain water quality parameters Therefore, regular monitoring and control of water quality in fish ponds are recommended to reduce levels of parasite infestations
TL;DR: This is the first molecular characterisation of Trichostrongylus spp.
Abstract: To identify the gastrointestinal helminths of veterinary, zoonotic and public health importance in farmers and their ruminant livestock in Ghana, faecal samples were collected from 95 farmers and their livestock (cattle = 328, sheep = 285 and goats = 217) and examined by microscopy and/or molecular techniques. Overall, 21 farmers tested positive for at least one gastrointestinal helminth, 80.9% of which were single infections and 19.0% co-infections. The parasites identified in the farmers consisted of hookworms (n = 13) (9 were Necator americanus and the other 4 could not be amplified by PCR), Trichostrongylus spp. (n = 9), Schistosoma mansoni (n = 1), Schistosoma haematobium (n = 1) and Diphyllobothrium latum (n = 1). In livestock, strongylid nematodes were dominant (56.6%), followed by Paramphistomum spp. (16.9%), Dicrocoelium spp. (7.1%), Thysaniezia spp. (5.8%), Trichuris spp. (3.3%), Moniezia spp. (3.1%), Fasciola spp. (2.8%), Toxocara spp. (1.1%) and Schistosoma spp. (0.2%). Genotyping of Trichostrongylus spp. in the farmer’s stools identified six T. colubriformis similar to T. colubriformis detected in cattle, sheep and goats in the study, two Trichostrongylus spp. with 98.3% and 99.2% genetic similarity to T. probolurus respectively and one Trichostrongylus spp. which showed 96.6% similarity to both T. probolurus and T. rugatus. Trichostrongylus axei was also identified in cattle, sheep and goats. This is the first molecular characterisation of Trichostrongylus spp. in Ghana and the species identified in the present study suggests zoonotic transmission from cattle, sheep and goats. Further studies involving larger numbers of farmers and their household members are essential to understand the transmission dynamics and impact of these parasites on farming communities in Ghana.
TL;DR: The study at hand indicates that protozoan parasitic infections are rare among immunodeficient patients in Poland, and adults were positive mainly for Blastocystis and microsporidia, while children were more often infected with the Cryptosporidium species.
Abstract: Intestinal opportunistic infections are often caused by unicellular parasites. Individuals with decreased immunity are particularly susceptible to infection by said microorganisms, and when they are infected, diarrhea can be the main clinical manifestation. However, intestinal parasites have rarely been taken into account in intestinal disorders. In our study, an investigation was conducted to determine the prevalence of intestinal micro-pathogens, such as Cryptosporidium, Giardia, Blastocystis, and microsporidia, in hospitalized patients with different immunological statuses. The study at hand indicates that protozoan parasitic infections are rare among immunodeficient patients in Poland. The overall prevalence of micro-pathogens among participants was 4.6%; it was three times higher in adults (12.5%) than in children (2.3%). Cryptosporidium and Cyclospora species (Apicomplexa) were diagnosed as the main cause of heavy diarrhea. Accordingly, adult patients were positive mainly for Blastocystis and microsporidia, while children were more often infected with the Cryptosporidium species.
TL;DR: The invasion history of Ae.
Abstract: Aedes (Stegomyia) albopictus (Skuse, 1895) (Diptera: Culicidae), commonly known as the Asian tiger mosquito, is an invasive mosquito species of public health significance, well established in many countries worldwide. In Greece, it was first recorded in Corfu and Thesprotia between 2003 and 2004. In the following years, further distribution and establishment of Ae. albopictus in Greece have been confirmed in many Regional Units of the country. In the current study, we report the invasion history of Ae. albopictus in Greece, until 2016. The results from the entomological investigation following imported virus cases in 2014, 2015, and 2016 are also included. Moreover, its presence in Greece is demonstrated in a thematic map based on (a) information provided by pest control companies and/or citizens, (b) the official samples sent to Benaki Phytopathological Institute (BPI) and the National School of Public Health (NSPH), and (c) the entomological surveillance conducted by the BPI.
TL;DR: The present survey outcomes confirm the spread of T. gondii infection in pig farms in an area of intensive swine production, and the decrease in the biosecurity level enhanced the risk of infection within a farm.
Abstract: Toxoplasma gondii is a widespread protozoan affecting animals and humans. One of the major routes of human infection is through the consumption of raw or under-cooked meat, particularly of certain animal species, including pigs. Although T. gondii represents an important public health issue, its control at slaughter is not mandatory. Consequently, available information on T. gondii infection in domestic animals destined for human consumption is scarce. Thus, an epidemiologic survey was designed to update information on T. gondii infection in pigs from intensive production. Fattening pigs and sows from conventional farms were sampled. Sera were tested with a commercial ELISA for anti-T. gondii antibodies, whereas molecular analysis by 529 bp repetitive element PCR and B1 real-time PCR with subsequent genotyping was performed on heart samples. Statistical analysis was carried out to detect farm management features and sanitary procedures enhancing the risk of infection. At the farm level, 63.6% (7/11) of farms housing sows and 6.7% (1/15) housing fattening pigs scored positive, with individual prevalences of 8.6% (13/151) in sows and 0.5% (1/219) in fattening pigs. T. gondii DNA was detected in eight sows and one fattening pig, and sequencing revealed the presence of all three genotypes (types I, II, and III). Furthermore, the decrease in the biosecurity level enhanced the risk of infection within a farm. The present survey outcomes confirm the spread of T. gondii infection in pig farms in an area of intensive swine production. The application of stricter sanitary procedures may contribute to a further reduction of infection.
TL;DR: Silver nanoparticle conjugation with tannic acid may be considered as potential agent against Acanthamoeba spp.
Abstract: Free-living amoebae belonging to Acanthamoeba genus are widely distributed protozoans which are able to cause infection in humans and other animals such as keratitis and encephalitis. Acanthamoeba keratitis is a vision-threatening corneal infection with currently no available fully effective treatment. Moreover, the available therapeutic options are insufficient and are very toxic to the eye. Therefore, there is an urgent need for the development of more effective anti-amoebic agents. Nanotechnology approaches have been recently reported to be useful for the elucidation antimicrobial, antiviral, antifungal and antiprotozoal activities and thus, they could be a good approach for the development of anti-Acanthamoeba agents. Therefore, this study was aimed to explore the activity and cytotoxicity of tannic acid-modified silver nanoparticles, pure silver nanoparticles and pure gold nanoparticles against clinical strains of Acanthamoeba spp. The obtained results showed a significant anti-amoebic effect of the tannic acid-modified silver nanoparticles which also presented low cytotoxicity. Moreover, tannic acid-modified silver nanoparticles were well absorbed by the trophozoites and did not induce encystation. On the other hand, pure silver nanoparticles were only slightly active against the trophozoite stage and pure gold nanoparticles did not show any activity. In conclusion and based on the observed results, silver nanoparticle conjugation with tannic acid may be considered as potential agent against Acanthamoeba spp.
TL;DR: The phylogenetic results suggest that scavenger birds could be definitive hosts of S. frondea, and according to the summarized morphological data on Sarcocystis found in the sika deer, such host should harbor at least nine different Sarcocrystis species.
Abstract: Diaphragm muscles of 25 sika deer (Cervus nippon) farmed in Lithuania were examined for sarcocysts of Sarcocystis species. Two new Sarcocystis species, Sarcocystis frondea and Sarcocystis nipponi, were observed using light microscopy (LM) and transmission electron microscopy (TEM) and characterized by 18S ribosomal DNA (rDNA) and subunit I of cytochrome c oxidase (cox1) sequence analyses. By LM, sarcocysts of S. frondea and S. nipponi were ribbon-shaped and had finger-like sarcocyst wall protrusions, respectively. Under TEM, protrusions of S. frondea were about 9 × 1–1.5 μm, filled with clearly visible electron-dense substance and microtubules, type 39-like. Whereas, protrusions (about 9 × 0.2 μm) of S. nipponi arose from dome-shaped bases were filled with microtubules extending to the ground substance layer, type 9o-like. Moreover, three known Sarcocystis spp., Sarcocystis entzerothi, Sarcocystis ovalis, and Sarcocystis truncata previously described in other cervids as intermediate hosts, were characterized in sika deer. The cox1 was more suitable than 18S rDNA delimitating closely related Sarcocystis species from cervids. The phylogenetic results suggest that scavenger birds could be definitive hosts of S. frondea. According to the summarized morphological data on Sarcocystis found in the sika deer, such host should harbor at least nine different Sarcocystis species.
TL;DR: Information is summarized on history, validity of Eimeria species, life cycle, pathogenicity, prevalence, epidemiology, diagnosis, and control of coccidiosis in camelids.
Abstract: Camelids (llamas, alpacas, vicunas, guanacos) are important for the economy of South America and Eimeria infections are important as cause of mortality in camelids. Of the five most prevalent species of Eimeria in South American camelids, Eimeria macusaniensis, Eimeria lamae, Eimeria alpacae, Eimeria punoensis, and Eimeria ivitaensis, E. macusaniensis is considered the most pathogenic. There is considerable confusion concerning the endogenous developmental stages of Eimeria spp. in camelids. Many papers on camelid coccidiosis were published in local Peruvian journals, not easily accessible to wider audience. The objective of the present paper is to summarize information on history, validity of Eimeria species, life cycle, pathogenicity, prevalence, epidemiology, diagnosis, and control of coccidiosis in camelids.
TL;DR: Although adult nematodes in the present study were identified as Anisakis paggiae, the spicule length is shorter in the authors' specimens and falls within the range reported for Anisakid oceanicus previously reported in Pacific waters from black fish and later synonymised with An isakis physeteris.
Abstract: Anisakid nematodes are the most infamous parasites occurring in seafood with ability to infect humans. In the present study, the infective stages of five anisakid larval types, including Anisakis types I and III, Terranova types I and II and Contracaecum larval type, as well as adult Anisakis paggiae are reported from 16 host species from New Caledonian waters. The specific identity of the larval types was investigated using ITS sequence data. Anisakis larval types I and III were identified as Anisakis typica and Anisakis brevispiculata, respectively, based on identical ITS sequences. However, the specific identity of the Terranova larval types and Contracaecum larval type remains unknown until a matching ITS sequence from a well-identified adult is available. Several fish host species are reported for the first time for anisakid larval types found in this study. Considering that third-stage larvae of anisakids are known to be the infective stage of the parasite for humans and the popularity of seafood in New Caledonia, presence of these parasites in New Caledonian fish is of high importance in terms of public health and raising awareness among various stakeholders. Although adult nematodes in the present study were identified as Anisakis paggiae, the spicule length is shorter in our specimens and falls within the range reported for Anisakis oceanicus previously reported in Pacific waters from black fish (genus Globicephala) and later synonymised with Anisakis physeteris. However, our specimens are different from A. physeteris in morphology of ventriculus. Anisakis paggiae has been reported from whales in southern hemisphere and this is the first report from the Pacific regions.
TL;DR: An in vitro evaluation of the leishmanicidal activity of the essential oil of Tunisian chamomile showed that (−)-α-bisabolol was able to activate a programmed cell death process in the promastigote stage of the parasite.
Abstract: According to the World Health Organization, leishmaniasis is considered as a major neglected tropical disease causing an enormous impact on global public health. Available treatments were complicated due to the high resistance, toxicity, and high cost. Therefore, the search for novel sources of anti-leishmania agents is an urgent need. In the present study, an in vitro evaluation of the leishmanicidal activity of the essential oil of Tunisian chamomile (Matricaria recutita L.) was carried out. Chamomile essential oil exhibits a good activity on promastigotes forms of L. amazonensis and L. infantum with a low inhibitory concentration at 50% (IC50) (10.8 ± 1.4 and 10.4 ± 0.6 μg/mL, respectively). Bio-guided fractionation was developed and led to the identification of (−)-α-bisabolol as the most active molecule with low IC50 (16.0 ± 1.2 and 9.5 ± 0.1 μg/mL for L. amazonensis and L. infantum, respectively). This isolated sesquiterpene alcohol was studied for its activity on amastigotes forms (IC50 = 5.9 ± 1.2 and 4.8 ± 1.3 μg/mL, respectively) and its cytotoxicity (selectivity indexes (SI) were 5.4 and 6.6, respectively). The obtained results showed that (−)-α-bisabolol was able to activate a programmed cell death process in the promastigote stage of the parasite. It causes phosphatidylserine externalization and membrane damage. Moreover, it decreases the mitochondrial membrane potential and total ATP levels. These results highlight the potential use of (−)-α-bisabolol against both L. amazonensis and L. infantum, and further studies should be undertaken to establish it as novel leishmanicidal therapeutic agents.
TL;DR: The proposed in vitro protocol showed to be useful for the integral assessment of the nutraceutical potential of different plant species as it included the nutritional value and the AH activity against eggs and L3 in the selected plant species.
Abstract: Nutraceutical plants provide nutrients for the animal as well as secondary compounds that can affect the biology and survival of gastrointestinal nematodes (GIN). Current screening of nutraceutical plants is based on in vitro evidence of anthelmintic (AH) activity against different life stages of GIN, but nutritional information is omitted or scarce. This study proposes an integral in vitro screening protocol to identify the nutraceutical value of the foliage from plant species consumed by small ruminants, using Haemonchus contortus as a biological model. The leaves from Acacia collinsii, A. pennatula, Bunchosia swartziana, Gymnopodium floribundum, Havardia albicans, Leucaena leucocephala, Lysiloma latisiliquum, Mimosa bahamensis, Piscidia piscipula, and Senegalia gaumeri were evaluated for their chemical composition and in vitro digestibility. Acetone:water extracts (70:30) from leaves of each plant were evaluated using the egg hatch assay and larval exsheathment inhibition assay. Respective effective concentrations 50% (EC50) were determined for each assay. The ten plant species showed good nutritional value for ruminants, including crude protein (> 10%), metabolizable energy (> 2.9 MJ/kg DM), and varied CT content (from 1.0 to 37.6%). The best AH activity against H. contortus eggs (EC50 = 401.8 μg/mL) and L3 (EC50 = 83.1 μg/mL) was observed for S. gaumeri extract. Although all the plant species showed in vitro nutraceutical potential, the leaves of S. gaumeri had the best values. The proposed in vitro protocol showed to be useful for the integral assessment of the nutraceutical potential of different plant species as it included the nutritional value and the AH activity against eggs and L3 in the selected plant species.
TL;DR: The results suggest that each amoeba subtype is genetically distinct, and they exhibit different patterns of infectious behavior in the oral cavity.
Abstract: Advances in molecular biology have facilitated analyses of the oral microbiome; however, the parasites role is poorly understood Periodontal disease is a multifactorial process involving complex interactions among microorganisms, the host, and environmental factors At present, the precise composition of the mouth parasites microbiota is unclear Two protozoan species have been detected in the oral microbiota: Trichomonas tenax and Entamoeba gingivalis, and a new variant, E gingivalis-ST2-kamaktli, was recently identified by us In this study, both E gingivalis and the new E gingivalis-ST2-kamaktli variant were detected in the oral cavities of people with healthy periodontium, individuals undergoing orthodontic treatment, and patients with periodontal disease In the group with healthy periodontium, the prevalence of E gingivalis-ST1 was 486% and that of E gingivalis-ST2-kamaktli 295%, with a combined prevalence of 543% In patients undergoing orthodontics treatment, 812% carried both amoebas, with 475% having E gingivalis-ST1 and 738% E gingivalis-ST2-kamaktli In people with periodontal disease, the prevalence of E gingivalis-ST1 was 578%, and that of E gingivalis-ST2-kamaktli 500%, with a combined prevalence of 735%; hence, E gingivalis-ST1 and E gingivalis-ST2-kamaktli were detected in all three groups The question arises, what are E gingivalis-ST1 and E gingivalis-ST2-kamaktli doing in the oral cavity? Although, the answer remains unclear, our results suggest that each amoeba subtype is genetically distinct, and they exhibit different patterns of infectious behavior We hypothesize that E gingivalis-ST1 and E gingivalis-ST2-kamaktli may represent separate species Our data contribute to better understanding of the roles of E gingivalis-ST1 and E gingivalis-ST2-kamaktli in the oral microbiota