First molecular subtyping and zoonotic significance of Blastocystis sp. in Dromedary (C. dromedarius) and Bactrian (C. bactrianus) camels in Iran: A molecular epidemiology and review of available literature

BACKGROUND

Blastocystis sp. is a zoonotic protozoan parasite, and there is limited information about its molecular prevalence and subtypes (STs) distribution in camels globally, especially in Iran.

OBJECTIVES

This study aimed to examine the prevalence, STs distribution, and zoonotic potential of Blastocystis sp. in one-humped and two-humped camels in Ardabil province, northwestern Iran.

METHODS

A PCR-sequencing tool using the SSU rRNA gene was employed to examine the occurrence and genetic variation of Blastocystis sp. in 150 faecal samples from Bactrian (Camelus bactrianus, 50 samples) and Dromedary (Camelus dromedarius, 100 samples) camels in Ardabil province.

RESULTS

The overall prevalence of Blastocystis sp. in camels was determined to be 12% (18/150) through microscopy and PCR analyses. Phylogenetically, this study identified three distinct zoonotic STs: ST7, ST10, and ST14. ST10 was the most prevalent, comprising 50% (9/18) of the isolated STs from camels. ST14 closely followed with 38.9% (7/18), while ST7 made up 11.1% (2/18) of the total STs. In brief, ST10, ST14, and ST7 represented 50% (7/14), 35.7% (5/14), and 14.3% (2/14) of the Blastocystis-positive cases in one-humped camels, respectively. Further, each of the ST10 and ST14 accounted for 50% (2/4) of the Blastocystis-positive samples in two-humped camels. An analysis of the available data reveals that out of the 37-44 identified Blastocystis STs, 15 (ST1-ST7, ST10, ST14, ST15, ST21, ST24, ST25, ST26, and ST30) have been reported in camels. The predominant STs observed are ST10 and ST14. Furthermore, among the 15 zoonotic STs (ST1-ST10, ST12-ST14, ST16, and ST23) of Blastocystis reported thus far, nine zoonotic STs (ST1-ST7, ST10, and ST14) have been found in camels.

CONCLUSIONS

These findings indicate that camels serve as a proper reservoir for a diverse array of Blastocystis STs and thereby can play a significant role in the transmission of this protozoan infection to humans, animals, and water reservoirs.

Development of New PCR Protocols to Detect Genetic Diversity in the Metronidazole Metabolism Genes in Susceptible and Refractory Clinical Samples of Giardia duodenalis

PURPOSE

Investigating the genetic variation in thioredoxin reductase (TrxR) and nitroreductase (NR) genes in both treatment-resistant and -sensitive Giardia duodenalis isolates can provide valuable information in identifying potential markers of resistance to metronidazole. The rapid increase in metronidazole treatment failures suggests the presence of genetic resistance mechanisms. By analyzing these genes, researchers can gain insights into the efficacy of metronidazole against G. duodenalis and potentially develop alternative treatment strategies. In this regard, four G. duodenalis isolates (two clinically sensitive and two clinically resistant to metronidazole) were collected from various hospitals of Shiraz, southwestern Iran.

METHODS

Parasitological methods including sucrose flotation and microscopy were employed for the primary confirmation of G. duodenalis cysts in stool samples. Microscopy-positive samples were approved by SSU-PCR amplification of the parasite DNA. All four positive G. duodenalis specimens at SSU-PCR were afterward analyzed utilizing designed primers based on important metronidazole metabolism genes including TrxR, NR1, and NR2.

RESULTS

Unlike TrxR gene, the results of NR1 and NR2 genes showed that there are non-synonymous variations between sequences of treatment-sensitive and -resistant samples compared to reference sequences. Furthermore, the outcomes of molecular docking revealed that there is an interaction between the protein sequence and spatial shape of treatment-resistant samples and metronidazole in the position of serine amino acid based on the NR1 gene.

CONCLUSION

This issue can be one of the possible factors involved in the resistance of Giardia parasites to metronidazole. To reach more accurate results, a large sample size along with simulation and advanced molecular dynamics investigations are needed.

Identification of Blastocystis spp. in Urban Rodents of Different Districts in Southwestern Iran: Subtype Distribution and Possible Zoonotic Potential

PURPOSE

Rodents are one of the most abundant and diverse species of mammals and have recently been identified as carriers of numerous human pathogens. The current study was conducted to assess the prevalence, subtype (STs) distribution, and zoonotic potential of Blastocystis spp. in various species of rodents in Shiraz, southwestern Iran.

METHODS

For this aim, a total of 120 fresh fecal samples were collected from Mus musculus (n = 40), Rattus norvegicus (n = 40), and Rattus rattus (n = 40) in various municipality districts of Shiraz (6 out of 10 districts) between February and November 2020. Upon detecting parasites using light microscopy, a DNA fragment of the Blastocystis SSU rDNA gene was amplified using conventional PCR.

RESULTS

By employing direct wet mount examination, 8 out of 120 fecal samples (6.7%; 2 from house mice, 3 from black rats, and 3 from brown rats) tested positive. Similarly, 5% (2/40) of house mice, 7.5% (3/40) of black rats, and 7.5% (3/40) of brown rats tested positive using the molecular method. Phylogenetic analysis revealed that the Blastocystis infecting different rodent species in Shiraz belonged to two potentially zoonotic STs (ST1 and ST4). Accordingly, rodents should not be overlooked as potential reservoirs of zoonotic Blastocystis infections. Different sampled urban districts and their statistical association with reported prevalence rates were analyzed separately.

CONCLUSION

 Overall, the issue of the frequency and ST distribution of Blastocystis in urban rodents of Iran is still open to question and for a proper understanding, wider and more comprehensive studies are needed.

Comparative molecular epidemiology, subtype distribution, and zoonotic potential of Blastocystis sp. in Equus animals (horses, donkeys, and mules) in northwestern Iran

A total of 500 fecal samples were collected from Equus animals in six different cities (Ardabil, Namin, Nir, Meshginshahr, Germi, and Khalkhal) of Ardabil Province, northwestern Iran, with 200 samples from horses, 200 from donkeys, and 100 from mules. Of the horse samples, 100 were from racing horses under special monitoring and care, while the remaining 100 were from non-racing horses, including those used for herding or in rural areas. All fecal samples were examined for the presence of Blastocystis sp. using PCR amplification of the SSU rRNA gene's barcode region after DNA extraction. The molecular prevalence of Blastocystis infection in Equus animals was 7.6% (38/500). Blastocystis was more common in horses [11.5% (23/200)] than in donkeys [5.5% (11/200)] and mules [4% (4/100)] (P > 0.05). Compared to racing horses [3% (3/100)], non-racing/rural horses [20% (20/100)] exhibited a substantially higher prevalence of Blastocystis (P < 0.05). The prevalence of Blastocystis in diarrheal samples and younger animals was remarkably higher than in formed samples and older animals, respectively (P < 0.05). No significant difference in Blastocystis infection prevalence was found between the genders of examined animals (P > 0.05). In Equus animals, 38 Blastocystis isolates included eight STs: ST10 [31.6% (12/38)], ST1 [21.1% (8/38)], ST2 [15.8% (6/38)], ST3 [10.5% (4/38)], ST4 [7.9% (3/38)], ST7 [5.2% (2/38)], ST14 [5.2% (2/38)], and ST6 [2.6% (1/38)]. These results suggest that Equus animals act as a proper reservoir for numerous Blastocystis STs, consequently playing a crucial part in the spread of this protozoan infection to humans, animals, and water reservoirs.

First molecular characterization of Blastocystis subtypes from domestic animals (sheep and cattle) and their animal-keepers in Ilam, western Iran: A zoonotic concern

A total of 360 fecal samples were randomly collected from 150 cattle, 150 sheep, and 60 humans (30 people with close animal contact and 30 individuals without close animal contact) at 10 farms in Ilam, western Iran from June 2022 to August 2023. All samples were directly examined for Blastocystis by zinc sulfate flotation, followed by microscopic observation. Positive samples were further subtyped using conventional PCR and sequencing methods. A mean prevalence of 5.3% (16/300) was estimated for Blastocystis infection among examined animals, with 6% and 4.7% for cattle and sheep, respectively. Among the people who had close and non-close animal contact, 16.7% (5/30) and 3.3% (1/30) were infected with Blastocystis, respectively (p < 0.05). All 22 positive samples were successfully sequenced at the SSU rRNA locus. Accordingly, Blastocystis isolates infecting domestic animals in Ilam belonged to the four STs (ST1-ST3, and ST10). Of the 16 animal isolates, nine sequences (four ST10, three ST3, and two ST1) were related to cattle, and seven sequences (three ST10, two ST3, and two ST2) were isolated from sheep. Among the six human isolates, ST3 was the most predominant ST, followed by STs 1, 2, 6, and 7 (one case each). Of note, ST1-ST3 were isolated in various farms both from animals and their breeders, which indicates the possible circulation of these STs between animal and human populations.

First Molecular Identification and Subtyping of Blastocystis sp. in the Most Consumed Edible Marine Fish of Iran: A Foodborne Concern

PURPOSE

The presence of Blastocystis sp. is commonly observed in humans and different animals, displaying a wide range of genetic variations with the discovery of multiple subtypes (STs). However, the prevalence and distribution of these STs in edible marine fish and marine mammals remain uncertain. This study marks the first survey conducted in Iran and the second global molecular investigation to examine the occurrence and STs distribution of Blastocystis in various species of edible marine fish.

METHODS

This study screened 200 fresh intestinal contents from 10 well-known fish species (Narrow-barred mackerel, Indo-pacific king mackerel, Tigertooth croaker, Silver pomfret, Black pomfret, Longtail tuna, John's snapper, Blackspotted croaker, Four-finger threadfin, and Javelin grunter) in southern Iran, caught in the Persian Gulf. All collected samples were evaluated by microscopy and SSU-PCR methods.

RESULTS

Based on both microscopy and PCR, the overall prevalence of Blastocystis sp. in evaluated fish species was 2% (4/200). In brief, Blastocystis sp. was reported from Narrow-barred mackerel [10% (2/20)], Silver pomfret [5% (1/20)], and Tigertooth croaker [5% (1/20)]. Interestingly, among infected fish species three zoonotic STs (ST1, ST2, and ST7) were identified. ST2 was the most predominant ST [50% (2/4)], followed by ST1 and ST7, one sample each [5% (1/20)].

CONCLUSION

Overall, the prevalence and STs distribution of Blastocystis in edible marine fish along with the possibility of its zoonotic transmission are still open to question and require extensive and more detailed studies.

Global molecular prevalence of Giardia duodenalis in pigs (Sus domesticus): A systematic review and meta-analysis

Giardia duodenalis is one of the common intestinal parasites causing diarrhea in humans and livestock, including pigs. Thus, a healthy livestock would result in a clean environment, which benefits humans. In the present study, the global molecular prevalence of G. duodenalis infection was determined in pig populations, through systematic exploration of 4 international databases (MEDLINE/PubMed, Scopus, Web of Science, and Google Scholar) until March 4th, 2022. A random-effects meta-analysis model was used to estimate the overall and subgroup-based pooled prevalence of G. duodenalis, and I ² index was used for the evaluation of the heterogeneity. Altogether, 42 datasets from 18 papers examined 7272 pigs across 12 nations, showing a 9.1% (95% CI: 5.6-14.3%) pooled molecular prevalence. Sensitivity analysis demonstrated no remarkable variation in the reported total prevalence upon removing individual studies. It was found that 6 Giardia assemblages (A-F) are capable to infect pigs around the world, including assemblage E [16 datasets, 41.1% (95% CI: 24.8-59.6%)], B [8 datasets, 28.2% (95% CI: 12.2-52.6%)], D [3 datasets, 16.2% (95% CI: 10.6-24.1%)], C [3 datasets, 11.6% (95% CI: 7.3-17.9%)], and A [11 datasets, 9.9% (95% CI: 5.6-16.9%)]. Of note, assemblage F was only reported in one study. Meta-regression analysis showed that publication year was not significantly associated with the Giardia prevalence in swine population, in contrast to the sample size. Substantially, animals in weaner and fattener stages were more prone to giardiasis. Assemblages A and B are of utmost zoonotic significance for humans, while assemblages C, D and F have, also, been found in dogs and cats. Still, little is known on the prevalence and distribution of Giardia assemblages in pigs and requires more extensive and detailed studies.

Blastocystis sp. in Small Ruminants: A Universal Systematic Review and Meta-analysis

PURPOSE

The present review was done to evaluate the prevalence and subtype distribution of Blastocystis infection among small ruminants, at a global perspective.

METHODS

Systematic search was performed in PubMed, Scopus, Google Scholar, and Web of Science until 30th January 2022 and total estimates along with 95% confidence intervals (CIs) were computed using a random-effects model.

RESULTS

Ultimately, the required data were extracted from 25 papers including 19 datasets for each animal. Among 3125 sheep, the Blastocystis prevalence was 25.3% (95% CI 16.1-37.4%) (10 countries), being lower in comparison to that in 2869 examined goats [20.5% (95% CI 11-35.1%)] (12 countries). Regarding STs distribution, fourteen genetically diverse STs of Blastocystis (ST1-ST5, ST7, ST10, ST12, ST14, ST15, ST21, ST23, ST24, ST26) have been reported in sheep, and the highest pooled prevalence was related to ST10 [11 datasets, 57.8% (95% CI 43.7-70.8%)], followed by ST14 [8 datasets, 28.4% (95% CI 20.2-38.4%)], and ST7 [2 datasets, 21.1% (95% CI 4.5-60.3%)]. Compared to sheep, more STs (ST1, ST3-ST7, ST10, ST12, ST14, ST21, ST23-ST26, and ST32) were reported from goats, and the highest weighted frequency was related to ST10 [6 datasets, 45.1% (95% CI: 25.6-66.2%)], followed by ST7 [2 datasets, 40.4% (95% CI 30-51.7%)], and ST14 [4 datasets, 29% (95% CI 15.5-47.7%)]. Out of ten known zoonotic STs reported for Blastocystis (ST1-ST9, and ST12), 7 were isolated from sheep (ST1-ST5, ST7, and ST12) and 7 were reported from goats (ST1, ST3-ST7, ST12).

CONCLUSIONS

Overall, Blastocystis epidemiology in sheep and goats is yet to be elucidated and demands more comprehensive studies.

Current global status, subtype distribution and zoonotic significance of Blastocystis in dogs and cats: a systematic review and meta-analysis

Background

Blastocystis is a common intestinal protozoa found in animal and human fecal samples, with over 1 billion individuals infected worldwide. Since domestication, dogs and cats have had a close bond with humans. However, their close proximity poses a potential health risk since they may harbor several zoonotic agents. A global estimate of Blastocystis infection and subtype (ST) distribution in dogs and cats would therefore be of great health importance to humans.

Methods

We performed a comprehensive systematic search of four English-language databases (PubMed, Scopus, Google Scholar, Web of Science) for relevant articles up to 8 November 2021. The random-effects model was used to make pooled estimates with confidence intervals (CIs).

Results

In total, we identified 49 publications that met our inclusion criteria and subsequently analyzed the 65 datasets in these articles, of which 23 and 42 datasets were on cats and dogs, respectively. Among the 2934 cats included in the 23 datasets, which involved 16 countries, the prevalence rate of Blastocystis infection was 9.3% (95% CI 5.3–15.9%). The prevalence of Blastocystis infection was slightly lower [7%, 95% CI 4.7–10.4%) among the 7946 dogs included in the 42 datasets, involving 23 countries. The sensitivity analysis showed that no remarkable variation in the estimates upon the stepwise removal of each dataset. Higher ST diversity was found among the examined dogs (ST1-8, ST10, ST23, ST24) than among cats (ST1-4, ST10, ST14). Among dogs, ST3 was the most frequent ST (41.3%), followed by ST2 (39.3%), ST1 (30.9%), ST4 (13.4%), ST8 (12.7%), ST10 (11%) and ST5 (8.1%). Also among dogs, each of ST6, ST7, ST23 and ST24 was observed in only one study. Of the ST found in the cats examined, ST4 (29.5%), followed by ST10 (22.5%), ST1 (19.8%) and ST3 (17.6%) were the most common. A single study also reported the presence of both ST2 and ST14 in cats. With respect to zoonotic Blastocystis STs (ST1–ST9 and ST12), eight were reported from dogs (ST1-ST8) and four were isolated from cats (ST1–ST4), showing the implication of dog and cats in zoonotic transmission.

Conclusions

Taken together, our results show that elucidation of the true epidemiology and ST distribution of Blastocystis in dogs and cats demands more comprehensive studies, particularly in the negelected regions of the world.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05351-2.

Occurrence, genetic characterization, and zoonotic importance of Giardia duodenalis in various species of rodents (Mus musculus, Rattus norvegicus, and Rattus rattus)

Giardia duodenalis is a well-known flagellated parasite and the causative agent of protozoal diarrhea in animals and humans worldwide. Current study was aimed at determination of G. duodenalis prevalence, genetic variation and zoonotic significance in various species of rodents in Shiraz, southwestern Iran. In brief, 120 fecal specimens were collected from rodents (Rattus rattus, Rattus norvegicus, and Mus musculus) during May up to November 2021 and microscopically examined for Giardia cysts. Further molecular characterization of positive samples was done by nested-PCR, followed by nucleotide sequencing of the triose phosphate isomerase (tpi) gene. A total prevalence of 3.3% (4/120) was observed in rodents, with highest rate in black rats [5% (2/40)]. Regarding brown rats and house mice, only one sample was found to be positive, showing 2.5% and 2.5% prevalence, respectively. It is noteworthy that Giardia B and G assemblages were found in black rats (one case/genotype), whereas the only positive samples from brown rats and house mice were characterized as assemblage G. The major findings of the present study were the presence of both zoonotic and non-zoonotic Giardia assemblages in examined rats in Shiraz and the potential of black rats to harbor Giardia infection to humans. These concerns should be taken seriously in terms of public health. Nevertheless, the true epidemiology and assemblage distribution of Giardia is still open to question.

Molecular Epidemiology, Species Distribution, and Zoonotic Importance of the Neglected Meat-Borne Pathogen Sarcocystis spp. in Cattle (Bos taurus): A Global Systematic Review and Meta-analysis

BACKGROUND

Sarcocystis species are diverse apicomplexan parasites, though only two zoonotic species (S. hominis and S. heydorni) circulate between cattle and humans. Due to the importance of cattle in the human food chain and to prevent the consequences of parasitosis in humans, the first global systematic review and meta-analysis on molecular epidemiology, species distribution, and zoonotic significance of Sarcocystis infection in cattle was performed.

METHODS

For this aim, four international English databases (PubMed, Scopus, Google Scholar, and Web of Science) were systematically searched till 20th September 2021, and random-effect models were drawn to calculate total estimates and their 95% confidence intervals (CIs).

RESULTS

Finally, 44 papers from 21 countries were qualified for this review which examined 8526 cattle regarding Sarcocystis infection, rendering a total prevalence of 62.7% (95% CI 53-71.5%). Globally, 12 Sarcocystis spp. have been reported from cattle, including S. cruzi, S. hominis, S. hirsuta, S. rommeli, S. heydorni, S. bovifelis, S. bovini, S. sinensis, S. gigantea, S. fusiformis, S. hjorti and S. tenella. Among them, S. cruzi (37 studies), S. hominis (22 studies) and S. hirsuta (19 studies) were the 3 most common species, with 76.4% (95% CI 64.8-85%), 30.2% (95% CI 19.3-44%) and 8.7% (95% CI 3.8-18.6%), respectively. However, molecular identification was not performed in 48.4% (95% CI 27.3-70.1%) of the positive samples.

CONCLUSION

Despite the zoonotic significance of Sarcocystis spp., particularly S. hominis, the epidemiology and distribution of Sarcocystis infection in cattle remains unclear and demands more extensive researches around the world.

Global prevalence and associated risk factors of diarrheagenic Giardia duodenalis in HIV/AIDS patients: A systematic review and meta-analysis

Giardia duodenalis is one of the leading causes of diarrhea, mostly in underdeveloped nations of Africa and Asia. The present review provides insights into the prevalence, odds ratios (ORs) and associated risk factors of giardiasis in HIV/AIDS patients. Four major English databases (Web of Science, PubMed, Scopus, and Google Scholar) were excavated for relevant literature without time limitation until 20 November 2020. Next, meta-analysis was performed using a random-effects model and 95% confidence intervals (CIs). As well, heterogeneity among studies was evaluated using Cochran's Q and the I²-statistic. Totally, 19,218 HIV/AIDS patients in 130 studies were examined, showing a 5% (95% CI: 4.2%-6%) pooled prevalence. Also, the weighted random-effects OR of G. duodenalis infection among HIV/AIDS patients in comparison with their controls in 48 case-control studies was estimated as 1.71% (95% CI: 1.1%-2.66%, p = 0.016). Based on sensitivity analysis, there was no remarkable variation in the pooled OR upon omitting individual studies. Diarrhea was a potent risk factor, since HIV/AIDS patients with diarrhea were 3.8-times (95% CI: 1.6-8.9, p = 0.002) more prone to G. duodenalis infection than those without diarrhea. Moreover, the prevalence of the parasitic infection was 1.2-times higher in patients without antiretroviral therapy (ART) than those with ART (p = 0.312). Meta-regression was employed to evaluate the possible association between G. duodenalis frequency in HIV/AIDS patients and some variables such as sample size, publication year, and HDI. Additionally, the pooled prevalence of G. duodenalis infection was estimated based on several subgroups, including publication years, WHO regions, countries, continents, country incomes, and CD4⁺ T-cell levels. Altogether, the epidemiology of giardiasis in HIV/AIDS patients and its association with various risk factors is still open to question and requires more detailed and comprehensive investigations.

Global prevalence, subtypes distribution, zoonotic potential, and associated risk factors of Blastocystis sp. in domestic pigs (Sus domesticus) and wild boars (Sus scrofa): A systematic review and meta-analysis

The intestinal parasite Blastocystis sp. is a widely distributed protist among humans and various animal hosts, with significant prevalence in developing countries. Due to the zoonotic nature of its subtypes (STs), we aimed at global estimation of the prevalence, STs distribution, zoonotic potential, and associated risk factors of Blastocystis sp. infection in domestic pigs (Sus domesticus) and wild pigs/wild boars (Sus scrofa). The study was designed and conducted in 2021 via searching articles in PubMed, Scopus, Google Scholar, and Web of Science databases, based on the PRISMA checklist, and meta-analysis was done using a random-effects model to calculate the weighted estimates and 95% confidence intervals (95% CIs). Totally, 43 papers (47 datasets) reported data on 7977 examined pigs in 24 countries with a total prevalence of 50.9% (95% CI: 42.8-59%). In details, prevalence was higher among domestic pigs [52.4% (95% CI: 43.9-60.7%)] than wild boars [31.2% (95% CI: 11.2-62%)], but is poorly statistically supported as far as the CIs largely overlap. Out of 28 reported STs, nine (ST1-ST7, ST10, and ST15) were reported from domestic pigs, while six (ST1, ST3-ST5, ST8, and ST15) had been isolated from wild boars. Among nine zoonotic STs (ST1-ST8, and ST12), all were identified in examined swine populations, except for ST12. As well, ST1 and ST5 were probably the most frequently circulating STs among these animals. In addition, male and older pigs showed higher Blastocystis sp. infection. Altogether, Blastocystis epidemiology and the distribution of its related STs in pigs is still open to question and requires more extensive studies, especially in the neglected regions of the world.

A systematic review and meta-analysis on the global prevalence and subtypes distribution of Blastocystis sp. infection in cattle: A zoonotic concern

Blastocystosis is an interesting parasitosis, since the parasitic infection is still seriously neglected and a considerable zoonotic evidence is emerging. Blastocystis sp. infects the intestinal lumen of humans and a wide range of animals, while there is a lack of comprehensive information on Blastocystis epidemiology in cattle worldwide. Thus, the present systematic review and meta-analysis were performed by exploring four electronic databases (PubMed, Web of Science, Scopus, and Google scholar) for relevant published papers up to 7th November 2020, utilizing a random-effects model to pool estimations and assign 95 % confidence intervals (CIs). Results of 28 studies (29 datasets) on cattle showed a 24.4 % (95 % CI: 16.9-33.9 %) prevalence for Blastocystis infection. Also, 16 out of 26 reported subtypes (STs) were isolated from cattle, with ST10 (18 datasets) as the highest-reported [32.3 % (95 % CI: 21.6-45.3)] as well as ST24 and ST25 (one study each) as the lowest-reported STs [1.4 % (95 % CI: 0.2-9.1)]. Additionally, among nine well-known zoonotic STs (ST1-ST8 and ST12), all STs except for ST8 were reported from cattle worldwide, demonstrating this animal species as a potential reservoir for human infections. Meanwhile, the overall prevalence of Blastocystis in various subgroups (publication year, WHO regions, countries, continents, and age groups) was analyzed separately. The finding of the present review article highlights the cattle as a significant source of zoonotic transmission of Blastocystis infection to humans, which must be considered for preventive measures.

Identification of ectoparasites of camels in Sabzevar City, Iran

Ectoparasite infestation can transmit pathogens. They also cause economic losses and sometimes can cause mortality and reduce growth rates. Therefore, the objective of the present study was the determination of ectoparasite infestations on camels (C. dromedarius) in Sabzevar city, Iran. This survey was conducted from April 2017 to March 2018. A total of 75 camels were examined for ectoparasite infestation. All ectoparasites were collected in vials containing ethyl alcohol (70%) and were brought to the laboratory. The results showed that 25 camels (33.33%) were infested with hard ticks. There was not any infestation by other external parasites (mite, lice, flea, myias). The whole detected ticks were 130. The hard ticks on camels were identified as follows: Hyalomma anatolicum anatolicum (37/69%), Hyalomma dromedarii (34/61%), Rhipicephalus bursa (27/69%), In conclusion, appropriate tick control programs in Sabzevar city would seem a prerequisite for progressing camel milk and meat production.

Morphologic and molecular analysis of Dicrocoelium dendriticum species from Iranian native sheep

Dicrocoeliosis is a worldwide parasitic disease of ruminants which affects the liver. In this current study, the phylogenic pattern of Dicrocoelium species in Iranian native sheep from three different geographical regions was investigated by investigating a 520 bp fragment of mitochondirial NAD1 gene. The analysis of the NAD1 oligo nucleotide sequences from 10 D. dendriticum (GenBank accession numbers: MG889399 to MG889408) revealed few non-significant differences, suggesting limited application for NAD1 gene as a biomarker for study of genetic variation in Dicrocoelium. The morphometrical study also showed a significant relationship for the several morphometric indices among the Dicrocoelium spp. isolates from different regions of Iran.

Prevalence of hydatid cyst, Fasciola spp. and Dicrocoelium dendriticum in cattle and sheep slaughtered in Sabzevar abattoir, Iran

Hydatid cyst, Dicrocoelium dendriticum, and Fasciola spp. are common parasites among ruminants. The current study was conducted to assess the prevalence of these parasites in cattle and sheep slaughtered in Sabzevar abattoir, from April 2014 to March 2016. Total of 1653 cattle and 26720 sheep were inspected for helminthic infections of liver and lung in different seasons. The prevalence rates were found to be 684 (2.55%) and 235 (14.21%) in sheep and cattle, respectively. The infection rate of liver in cattle was estimated to be 5.86%, 0.84% and 5.68% for hydatid cysts, Fasciola spp. and D. dendriticum, respectively and lung infection with hydatid cyst in cattle was 1.81%. Moreover, the liver infection rate of sheep was estimated to be 0.87%, 0.06% and 2.13% with hydatid cysts, Fasciola spp. and D. dendriticum, respectively and lung infection with hydatid cyst was 0.35%. The rate of infection with D. dendriticum was higher in the both animals than the other parasites. The results of this study indicated that the prevalence of the aforementioned parasites was high, which caused high economic losses. Therefore, sanitary and preventive measures should be taken.