Common Parasite Research Articles

Prevalence of intestinal parasites and associated factors among food handlers in food establishments in the Lideta subcity of Addis Ababa, Ethiopia: an institution-based, cross-sectional study

ObjectiveThis study was conducted to assess the prevalence of intestinal parasites and the associated factors among food handlers in the Lideta subcity of Addis Ababa, Ethiopia.DesignAn institution-based, cross-sectional study design...

First Report ofBlastocystisspp. Infection in Pet Birds in Henan Province, Central China

Blastocystis spp. are common intestinal parasites found in humans and many kinds of animals. Blastocystis spp. infection is associated with a variety of symptoms, including diarrhea, abdominal pain, and chronic urticaria, among which asymptomatic infection is the most common. Among the 11 potentially zoonotic subtypes of Blastocystis spp., 9 subtypes have been reported in bird species. The purpose of this study was to detect the infection rate and gene subtype distribution of Blastocystis spp. in pet birds in Henan Province, Central China, to provide a foundation for preventing and controlling Blastocystis spp. in pet birds. Fecal DNA was extracted from 382 fresh fecal samples of pet birds collected from five areas in Henan Province, Central China. Twenty-three species of pet birds from four orders, from local pet trading markets, parks, and individuals, were sampled. All DNA samples were investigated by PCR, and positive samples were sequenced to analyze the gene subtypes based on the small ribosomal subunit (SSU rRNA) gene. Blastocystis spp. was detected in 0.8% of the samples. Further DNA sequencing and phylogenetic analyses resulted in the identification of two known zoonotic subtypes, ST1 (n = 2) and ST7 (n = 1). As far as we know, this is the first time that ST1 subtype has been reported in Chinese birds. It is found that pet birds may be the hosts of zoonotic Blastocystis spp. subtypes, and the role of birds in transmitting Blastocystis spp. to humans needs to be further studied.

Examining Gongylonema Neoplasticum From Rats in Tabriz City (Northwest of Iran): A Case Report

Aims Different species of gongylonema are common parasites of rats that can be accidentally transmitted to humans and cause disease. This study aims to identify and investigate the morphology of Gongylonema neoplasticum and its zoonotic significance in Tabriz rats. Methods & Materials In this study, 100 rats (29 Rattus rattus and 71 Rattus norvegicus) were caught from different parts of Tabriz City in northwestern Iran using live traps. In the study areas, edible beetles are abundant and in almost all trapping areas local people complained about the presence of beetles. These beetles host the mediator of gongylonema parasites and easily infect animals, such as mice, rabbits, cats, cattle, and accidentally humans. Findings In this study, the esophagus and stomach of rats were carefully examined for infection with gongylonema and only one of the following species was isolated from them, Gongylonema neoplasticum. Conclusion Due to the high abundance of beetles, high levels of Gongylonema neoplasticum were not reported, which can be considered in terms of human infections. More parasitological studies should be done in different geographical regions of Iran and other countries.

Incidence and Socioeconomic Impact of Intestinal Parasitic Infections among School Going Children of Private and Public Sectors Schools

Background: Parasitic infection is one of the most common infections in school age children because of poor quality of water, deprived sanitation system and lack of enough health care facilities in underdeveloped countries. Parasitic infections lead to anemia, growth retardation, weight loss, and other physical and mental health problems in children. Current study is designed to evaluate frequency of different intestinal parasitic infections and possible associated risk factors among school students in of District Buner Pakistan. Material and method: This Descriptive cross-sectional study was conducted at Riaz Clinical Laboratory District Buner. All asymptomatic school going children between 5 to 15 years’ age of both genders were included in the study. Those students who had present with symptoms of gastrointestinal infection were excluded from the study. A total of 440 samples were collected from different public and private school’s children. Out of total 240 samples were collected from public sector schools and 200 samples from private sector school’s children. A pretested structured questionnaire was used to gather data on socio-demographic and associated risk factors. The adequate stool specimens were collected in sterile, screw caped disposable plastic container. All samples were examined under microscope using a direct wet mount and formal ether concentration technique. Data was analyzed through SPSS-22 and presented in the form of tables, Pie chart and bar graphs. Results: Out of 440 samples, 23.63% (104/440) were positive for an ova and cysts of different parasites. The parasite positivity ratio is greater in public sector school children (30%) compare to private sector school children (16%). Taenia saginata were most common parasite (8.4%) in school age children followed by Hymenolepis nana (5.68%), Ascaris lumbricoides (5.45%), Enterobius vermicularis 1.13%, and Strongyloides stecoralis (0.68%) were least common parasite in District Buner, Khyber Pukhtoonkhwa. Conclusion: Major contributor for the high prevalence of parasitic infections in public school children were found to be poor personal and environmental hygiene, lack of proper sanitation, contaminated food and water supply, personal habits of the children like nail biting and finger sucking, illiterate mother and low socio-economic status of the individuals. Keywords: Intestinal parasites, Worm infestation, School going children, Socioeconomic impact

The Role of Inhabited Animals With People in Human Transmission of Blastocystis sp.

Blastocystis sp. is a common intestinal parasite worldwide that can cause infection in humans and animals. Blastocystis sp. has a high genetic diversity with 17 different subtypes (ST) identified to date. Since nine of these subtypes are common in both humans and animals, it has been proposed that animals may have a role in the transmission of Blastocystis sp. to human.
 The aim of this study is to investigate the epidemiological effect of animals on the human transmission of Blastocystis species by molecular methods for in our country.
 A total of 420 faecal samples were collected from the cattle, sheep, dogs, horses and chickens. Samples were stained with trichrome staining and cultivated by Jones's medium culture method. Blastocystis was detected in 53(12.6%) of 420. The samples were examined by Polymerase Chain Reaction (PCR) to identify nine common human subtypes.
 Subtypes were not detected in 33(62.3) of the 53 Blastocystis positive samples. Subtypes were detected in 20(37.7%) samples. The detected subtypes were as follows: ST5 in 4(7.5%) sheep, ST6 in 6(11.3%) chickens, ST7 in 11(20.7%) chickens, both ST6-ST7 were detected in one chicken).
 ST1, ST2, ST3 and ST4 - common subtypes in our country- were not detected in any animal. Sheep and chickens may be the source of human transmission of ST5, ST6 and ST7, the rare subtypes in our country. 
 As a result, humans rather than animals, seem to be the source of the human transmission of Blastocystis sp. in our country.

Drug resistance in plasmodium, future malaria management strategies and importance of medicinal plants

Malaria, the most common and destructive parasite disease in humans, take the lives of 1-2 million people every year. With the exception of artemisinin, resistance to most of the existing antimalarial agent classes has arisen, resulting in a new spike in malaria-related mortality, particularly in Africa. Southeast Asia has been a focal point for the development of drug resistance in Plasmodium falciparum since the late 1950s, when the first example of chloroquine resistance was discovered along the Thai-Combodian border. Despite the fact that the first incidence of quinine resistance had been documented far earlier in South America, the emergence of chloroquine resistance in Southeast Asia signalled the beginning of a new era in malaria history. Following the development of chloroquine resistance, Thailand and African countries shifted to a sulphadoxine-pyrimethamine combination as their first-line medication (SP). SP was subsequently superseded by mefloquine. Because of the quick development of resistance to this new medicine, artemisinin was introduced as a combination drug in the mid-1990s. Artimisinin resistance has been identified in several parts of the world, and if it continues, malaria control initiatives could be jeopardised, as there is now no substitute antimalarial medicine available. The purpose of this review is to summarise the current state of knowledge about drug-resistant malaria and to sketch out the evolving trends of resistance to antibiotics, such as its causal factors, current situation in various geographical areas, molecular markers, consequences for preventing the emergence and spread of drugresistant malaria, and the role of medicinal plants in the discovery of novel antimalarials.

Dysbiosis of fish gut microbiota is associated with helminths parasitism rather than exposure to PAHs at environmentally relevant concentrations

Although parasite infection and pollution are common threats facing wild populations, the response of the gut microbiota to the joint impact of these stressors remains largely understudied. Here, we experimentally investigated the effects of exposure to Polycyclic Aromatic Hydrocarbons (PAHs) and infection by a common acanthocephalan intestinal parasite (Pomphorhynchus sp.) on the gut microbial flora of a freshwater fish, the European chub (Squalius cephalus). Naturally infected or uninfected individuals were exposed to PAHs at environmentally realistic concentrations over a five-week period. Characterization of the gut bacterial community through 16S rRNA gene amplicon sequencing revealed that parasitic infection was a more structuring factor of bacterial diversity and composition than PAH exposure. Specifically, chub infected by Pomphorhynchus sp. harbored significantly less evenly represented gut bacterial communities than the uninfected ones. In addition, substantial changes in sequence abundance were observed within the main bacterial phyla, including the Firmicutes, Fusobacteriota, Actinobacteriota, and Proteobacteria. Again, these compositional changes correlated with host infection with Pomphorhynchus sp., confirming its pivotal role in gut microbial assemblage. Overall, these results highlight the importance of defining the parasitic status of individuals when conducting microbial ecotoxicological analyses at the digestive tract level, as this should lead to better understanding of microbiota modulations and help to identify microbial markers specifically associated with chemicals.

The effect of compliance to Hand hygiene during COVID-19 on intestinal parasitic infection and intensity of soil transmitted helminthes, among patients attending general hospital, southern Ethiopia: Observational study.

BackgroundIntestinal parasitic infection (IPIs) is one of the major health problems in Sub -Saharan Africa where water, sanitation and hygiene practices are inadequate. Taking into account the national level implementation of intensive hand hygiene against COVID-19 pandemic and general protective effect this study assessed its effect on intestinal parasite.ObjectiveThis study aim to investigate the effect of compliance to hand hygiene practice on the prevalence of intestinal parasitic infection (IPIs) and intensity of Soil transmitted helminthes (STH) among patients attending tertiary care hospital in southern Ethiopia.MethodsObservational study was conducted from June to September 2021. Data on socio demographic, hand hygiene practice and intestinal parasite (prevalence and intensity of helminthic infection) was collected from randomly selected and consented patients. Compliance to hand hygiene practice was assessed using pre-tested questionnaire. Fresh stool sample from each participant was examined by direct wet mount, concentration and Ziehl-Neelson (ZN) staining technique to detect intestinal parasite. Intensity of STH measurements was done through direct egg-count per gram using Kato Katz methods. Data analysis was done using SPSS version 25. Odds ratio with 95% confidence interval was used to measure association and p-value <0.05 was considered as statistically significant.ResultsThe study population (N = 264) consisted of 139(52.65%) male and 125 (47.34%) female with the mean ages of 36 ±16.12(±SD). The proportion of good compliance to hand hygiene during COVID-19 to was 43.93% (95%CI: 37% to 47) and prevalence of intestinal parasite was 26.14% (95%CI:21.2% to 31.75) comprising 23.48% intestinal protozoa and 6.43% of soil transmitted helminthic infection. Gardia lamblia, Entamoeba histolytica/dispar, Ascaris lumbricoides were the common parasite in the study area with prevalence of 15.53%, 6.44%, and 1.52% respectively. Prevalence of intestinal parasite among participants with good compliance to hand hygiene group and poor compliance to hand hygiene were (14.65% vs. 35.13%)(AOR: 0.48,95%CI:0.13 to 0.68) (p = 0.002) implying that good compliance to hand hygiene can reduce the risk of IPIs by 52%. Moreover significantly lower odds of intestinal protozoa among good compliance to hand hygiene group than the control (OR:0.38; (95%CI: 0.20 to 0.71);P = 0.001. However, no significant difference in the odds of intensity of STH infection in good compliance hand hygiene and poor compliance group. The result of this study also confirmed the association between intestinal parasitic infections and younger /adolescent age, education status, habit of eating raw vegetable and figure nail status.ConclusionGood hand hygiene compliance during COVID-19 significantly associated with reduction of intestinal parasitic infection. This finding highlights the secondary protective effect of improved hand hygiene against IPIs and suggest it can used in augmenting the existing parasitic control strategies in the study setting.

Prevalence of intestinal parasitic infection among school children in Kirtipur Municipality, Kathmandu

Intestinal parasitic infections are a major cause of morbidity in developing countries including Nepal. Most common intestinal parasites reported in Nepal are Ascaris lumbricoides, Hymenolepis nana, Hookworm, Trichuris trichiura, Giardia lamblia and Entamoeba histolytica. This study aimed to find out the prevalence of various intestinal parasitic infections among school children in Kirtipur Municipality, Kathmandu. A cross-sectional observational study was carried out with prepared questionnaire and stool examination between October to November, 2021. Altogether, 409 stool samples were randomly collected from different schools and examined by direct smear method. Out of 409 stool samples, 73 (17.8%) were positive and 336 (82.1%) were negative. Among positive cases, helminthic infection was seen in 45 (11.0%) and protozoan infection was found in 28 (6.8%). Altogether eight species of intestinal parasites were detected, the most common was A. lumbricoides (34.2%), followed by protozoa G. lamblia (23.3%), E. histolytica (15.1%), T. trichiura (10.96%), Hookworm (6.8%), Enterobius vermicularis (4.11%), Taenia solium (4.11%) and H. nana (1.37%) respectively. Study showed that, there was 63 (86.30%) single infections, 9 (12.33%) double infections and 1 (1.37%) multiple infection. The present study reveals that intestinal parasites are abundant among students of Kirtipur Municipality, Kathmandu. The situation strongly calls for the use of control measures including treatment of infected individuals, improvement of health status of infected students by health education, public health awareness and also develop the health care facilities and aware the people for the utilization of health services.

Changes in Gut Microbiota Composition Associated with the Presence of Enteric Protist Blastocystis in Captive Forest Musk Deer (Moschus Berezovskii).

ABSTRACTBlastocystis is a common protistan parasite inhabiting the gastrointestinal tract of a wide range of hosts including humans and domestic and wild animals. Many studies have revealed the associations between Blastocystis and gut microbiome in humans. However, only a few studies have focused on the associations between Blastocystis and gut microbiome of animals, especially in forest musk deer (Moschus berezovskii). We investigated the effects of the Blastocystis colonization on the intestinal bacterial community compositions using amplicon sequencing targeting the V4 variable region of the 16S rRNA. Two subtypes of Blastocystis (ST5 and ST10) and Blastocystis-free (control) were included in this study. We found that compared with the forest musk deer without Blastocystis, ST10-colonized forest musk deer had higher bacterial richness and diversity, while ST5-colonized forest musk deer showed a comparable bacterial diversity. Likewise, beta diversity revealed significant differences in bacterial community structure between ST10-colonized and Blastocystis-free forest musk deer. The proportion of Bacteroidetes were significantly enriched in ST10-colonized forest musk deer. Bacterial community structure between ST5-colonized and Blastocystis-free forest musk deer did not differ significantly. The present study explored the associations between Blastocystis and gut microbial community of forest musk deer for the first time, and revealed ST10 colonization, instead of ST5, is associated with higher bacterial diversity and shifted microbial structure. Our data provides valuable insights into the associations between gut microbiomes and parasites.IMPORTANCE Forest musk deer is listed as an endangered species by International Union for Conservation of Nature Red List, and the Chinese government has introduced captivity breeding measures to curb the rapid decline of the musk deer population since the 1950s. It has been suggested that Blastocystis colonization can modulate the composition of the host's intestinal microbiota, thereby affecting the host health. The present study investigated the effects of the Blastocystis colonization on the gut microbiota in the feces of forest musk deer in Sichuan Province, China. Two subtypes (ST5 and ST10) have differential effects on the bacterial diversity and community composition, suggesting that the study of Blastocystis should be distinguished at the subtype level. Because the pathogenicity of Blastocystis is controversial, pathogenic, or commensal, continuous monitoring of the impact of Blastocystis colonization on the intestinal microbiota is of great significance to assess its health effects on forest musk deer.

Presence of Blastocystis in gut microbiota is associated with cognitive traits and decreased executive function

Growing evidence implicates the gut microbiome in cognition. Blastocystis is a common gut single-cell eukaryote parasite frequently detected in humans but its potential involvement in human pathophysiology has been poorly characterized. Here we describe how the presence of Blastocystis in the gut microbiome was associated with deficits in executive function and altered gut bacterial composition in a discovery (n = 114) and replication cohorts (n = 942). We also found that Blastocystis was linked to bacterial functions related to aromatic amino acids metabolism and folate-mediated pyrimidine and one-carbon metabolism. Blastocystis-associated shifts in bacterial functionality translated into the circulating metabolome. Finally, we evaluated the effects of microbiota transplantation. Donor’s Blastocystis subtypes led to altered recipient’s mice cognitive function and prefrontal cortex gene expression. In summary, Blastocystis warrant further consideration as a novel actor in the gut microbiome-brain axis.

Comparative proteomic analyses of resistant and susceptible crucian carp to Gyrodactylus kobayashii infection

Gyrodactylid monogeneans are common parasites of teleost fishes characterized by high host specificity. Host specificity and its underlying mechanisms of monogenean have been always a fascinating issue that has attracted considerable attention from researchers. However, the molecular mechanism responsible for the host specificity of monogenean is still not yet fully understood. In this study, the susceptibility to Gyrodactylus kobayashii of different species or varieties in the genus Carassius was investigated. Furthermore, the proteome changes in the skin mucus of resistant and susceptible fish were analyzed by Tandem Mass Tags (TMT) quantitative proteomics method. The experimental results indicated that G. kobayashii was found in 12 varieties of goldfish and ChangFeng C. auratus gibelio with different degrees of infection percentage, while no G. kobayashii was found in C. auratus gibelio var. CAS Ⅴ. Population dynamics of G. kobayashii on red white common goldfish and C. auratus gibelio var. CAS Ⅴ showed distinct trends in the in vivo infection experiment. These results demonstrated C. auratus gibelio var. CAS Ⅴ is a resistant fish to G. kobayashii. Proteomic analysis revealed that 41 differentially expressed proteins (DEPs), including 25 up-regulated and 16 down-regulated proteins, were identified. Bioinformatics analysis indicated these DEPs were involved in multiple biological functions including immunity, metabolism, and signal transduction. Among them, some immune-related proteins, such as cadherin-1, serotransferrin, and glutathione transferase in the fish mucus might be potential determinants of the host susceptibility to G. kobayashii. Also, some structural and energy metabolism-related DEPs, such as small muscular protein, keratin and vitelline membrane outer layer protein served as a source of nutrition and might also affect host susceptibility. Overall, this study not only provided systematic protein information of crucian carp skin mucus but also identified some potential candidate proteins that might be related to host susceptibility to G. kobayashii.

Alteration of gut bacteria composition among individuals with asymptomatic Blastocystis infection: A case-control study

The gut microbiota consists a diverse and complex ecosystem that is involved in beneficial functions as well as potentially harmful conditions for human. Blastocystis sp. is a common parasite of the digestive tract of animals and humans; however, limited data is available concerning the association of asymptomatic Blastocystis infection and gut bacteria composition. Hence, in this cross-sectional study, the gut bacteria composition of twenty asymptomatic Blastocystis sp. positive and twenty Blastocystis sp. negative individuals was assessed with real time PCR. The case and control groups were matched for age and sex. Both groups were negative for other gastrointestinal infections and did not have any gastrointestinal symptoms. The subtype of ten Blastocystis sp. isolates was assessed based on sequencing. Sequencing of ten Blastocystis sp. isolates revealed the ST1, ST2, and ST3 subtypes in 40%, 30%, and 30% of the isolates. The relative expression of each bacteria in the case than control group revealed that the expression level of Bifidobacterium group (P < 0.033), Peptostreptococcus productus (P < 0.014), Lactobacillus/Enterococcus group (P < 0.001), and Escherichia coli (P < 0.001) were significantly upregulate in the Blastocystis sp. carriers than the control group, while the relative amounts of Bacteroides fragilis (P < 0.001) and Enterococcus sp. (P < 0.001) were significantly downregulated in the case than the control group. Taken together, the results of this study have shown that asymptomatic Blastocystis infection could alter the composition of gut bacteria in healthy individuals.

Predictors of Intestinal Parasites among Food Handlers in Goba Town, Southeast Ethiopia, 2020.

Background Globally, around 1.9 million people were dying due to food-borne diseases annually, and intestinal parasites infected one-third of the population, according to estimates and more prevalent in developing countries due to poverty. This study assessed predictors of intestinal parasites among food handlers working in Goba towns. Methods A laboratory-based cross-sectional study was conducted from October to December 2020. Clean, dry, and leak-proof stool cups were used to collect the samples. The SPSS version 20 computer software was used to enter and clean the data, code it, and analyze it. The researchers performed binary and multivariable logistic regression analyses, with a p value of 0.05 considered significant. Result A total of 98 (34%) of the 288 food workers tested positive for various intestinal parasites. Giardia lamblia was the most common parasite, with 42 (14.6%), followed by Entamoeba histolytica/dispar with 31 (10.8%), Ascaris lumbricoides with 8 (2.8%), Taenia species with 5 (1.7%), and E. vermicularis with 4 (1.4%). Six (2%) of the 98 positive food handlers had two infections. E. histolytica and G. lamblia were the most common parasites found in mixed infections. Hand washing with soap and water before handling food (AOR: 3.06, 95% CI: 1.16, 7.26) and untrimmed fingernail status (AOR: 2.3, 95% CI: 1.14, 4.34) were found to be strongly linked to intestinal parasite infection. Conclusion In this investigation, intestinal parasite species were found in 34% of stool samples. Independent predictors of intestinal parasite infection were fingernail status and hand washing with water and soap use before food handling. To control intestinal parasite infection among food handlers in the research area, personal hygiene and ambient cleanliness should be improved.

Prevalence of Helminthic Infections in the Gastrointestinal Tract of Cattle in Mazandaran Province (Northern Iran).

Ruminant parasites are found in all parts of the world, including the tropical and subtropical regions. Mazandaran province (northern Iran) is one of the areas prone to the activity of gastrointestinal parasites in ruminants. This study was performed in 2020, in order to identify common parasites of cattle gastrointestinal tract, the percentage of the infection, the effect of seasons, and livestock on the amount of infection and determine the severity of infection. In this study, seven genera of gastrointestinal parasites including Strongyloides, Haemonchus, Ostertagia, Cooperia, Trichostrongylus, Oesophagostomum, and Chabertia were identified among 240 cattle. Overall, 34.58% of cows were infected with different kinds of parasites. Based on the average percentage of livestock infected with gastrointestinal parasites across different seasons, winter had the lowest percentage (18.33%) compared to other seasons, which has a statistically significant difference (P < 0.05). Also, we observe that the female cattle's infection rate, in comparison with males, had no significant difference (P < 0.05). Moreover, 67.17% of the cattle had a moderate level of infection. Despite the fact that farmers use antiparasitic drugs, helminthic infections in cattle are still high. In conclusion, the lack of proper implementation of helminthic infection control programs as well as antiparasitic drug resistance in this area can be a key element for the high prevalence of livestock helminthic infection in these areas.

Seroprevalence of Toxoplasma gondii in students with occupational risk

Toxoplasmosis is a disease that results from infection with the Toxoplasma gondii parasite, one of the world's most common parasites. The zoonotic infection usually occurs by eating undercooked contaminated meat or by contact with contaminated cat feces. A few studies of toxoplasmosis in healthy and immuno-compromised persons were done in Chile, but investigations related to occupational risk groups, such as Veterinary Medicine students were not studied. Determine the seroprevalence for T. gondii in Veterinary Medicine students at a university located in the center-south of the country, and evaluated to association with intrinsic variables. Peripheral blood samples were taken from 74 veterinary students from a university in south-central Chile. Immunoassay with sequential chemiluminescent was used as diagnostic technique. Of the total number of students, 16 were seropositive, which is equivalent to 21.6%, the largest number of seropositive students was female (75%), they were in the age range between 24 and 26 years of age (43.7%), all consumed meat and vegetables (100%) and collected pet cat feces without protection 50 (68,7%). The results obtained show the presence of antibodies against T. gondii in Veterinary Medicine students. To the authors' knowledge, it is the first serological study for toxoplasmosis performed in university students of Veterinary Medicine in Chile.

Establishment and application of a TaqMan probe-based qPCR for the detection of Enterocytozoon hepatopenaei in shrimp Litopenaeus vannamei.

Enterocytozoon hepatopenaei (EHP) is a common parasite that invades the epithelial cytoplasm in the hepatopancreas of shrimp Litopenaeus vannamei and results in slow growth of the host shrimps to cause significant economic loss in shrimp aquaculture. In this study, a TaqMan probe-based qPCR for quantitative detection of EHP was established. A pair of specific primers and a TaqMan probe were designed based on the sequence of cysteine desulfurase gene (NFS1) of EHP. The standard curve between cycle threshold (Ct) and the logarithmic starting quantity (SQ) of the template was determined as Ct = - 3.231 lg (SQ) + 40.638, with a correlation coefficient (R2) of 0.998 and an amplification efficiency of 103.9%. The lower limit of quantification was 1.67 × 101 copies/μL for this TaqMan probe-based qPCR and 1.67 × 103 copies/μL for the conventional PCR. The TaqMan probe-based qPCR established in the research was 100 times more sensitive than the conventional PCR method. In addition, the results of clinical sample detection indicated that the present technique was efficient in detecting EHP in the hepatopancreas, feces, water, and pond bottom mud samples. Therefore, the established TaqMan probe-based qPCR is a suitable technique for detecting EHP in both shrimp and aquatic environment samples.

Prevalence and genetic diversity of Giardia duodenalis in pet dogs from Zhengzhou, central China and the association between gut microbiota and fecal characteristics during infection

As a common zoonotic intestinal parasite, Giardia duodenalis could infect humans and various mammals worldwide, including pet dogs, leading to giardiasis. This study detected the infection of G. duodenalis in asymptomatic pet dogs in Zhengzhou, and evaluated the possibility of zoonosis and the relationship between gut microbiota and fecal characteristics. We randomly collected 448 fresh fecal samples from Zhengzhou, and G. duodenalis was screened based on the beta-giardin (bg), glutamate dehydrogenase (gdh), and triose phosphate isomerase (tpi) genes. The difference of gut microbiota between five G. duodenalis-positive and five G. duodenalis-negative samples was investigated by 16S rRNA gene sequencing. The overall prevalence of G. duodenalis was 7.1% (32/448) based on bg, gdh, and tpi locus, two G. duodenalis assemblages (C = 13, D = 14) and five (15.6%) mixed infection (C + D) were identified. Moreover, compared with the G. duodenalis-negative group, the diversity of gut microbiota increased in G. duodenalis-positive group. The decrease of Lactobacillus spp. and considerable increase of Prevotella spp. were associated with the fecal characteristics. These results show that the transmission of zoonotic giardiasis between humans and pet dogs is rare in Zhengzhou, central China, and support the use of Lactobacillus spp. as a potential probiotic agent to improve intestinal health in dogs, or even humans, by treating G. duodenalis. Therefore, the public health significance of G. duodenalis to humans, companion animals, and the environment should be further evaluated from One Health perspective.

ROV observations reveal infection dynamics of gill parasites in midwater cephalopods

Gill parasites of coleoid cephalopods are frequently observed during remotely operated vehicle (ROV) dives in the Monterey Submarine Canyon. However, little knowledge exists on the identity of the parasite species or their effects on the cephalopod community. With the help of ROV-collected specimens and in situ footage from the past 27 years, we report on their identity, prevalence and potential infection strategy. Gill parasites were genetically and morphologically identified from collected specimens of Chiroteuthis calyx, Vampyroteuthis infernalis and Gonatus spp. In situ prevalence was estimated from video footage for C. calyx, Galiteuthis spp., Taonius spp. and Japetella diaphana, enabled by their transparent mantle tissue. The most common parasite was identified as Hochbergia cf. moroteuthensis, a protist of unresolved taxonomic ranking. We provide the first molecular data for this parasite and show a sister group relationship to the dinoflagellate genus Oodinium. Hochbergia cf. moroteuthensis was most commonly observed in adult individuals of all species and was sighted year round over the analyzed time period. In situ prevalence was highest in C. calyx (75%), followed by Galiteuthis spp. (29%), Taonius spp. (27%) and J. diaphana (7%). A second parasite, not seen on the in situ footage, but occurring within the gills of Gonatus berryi and Vampyroteuthis infernalis, could not be found in the literature or be identified through DNA barcoding. The need for further investigation is highlighted, making this study a starting point for unravelling ecological implications of the cephalopod-gill-parasite system in deep pelagic waters.

A novel use of a geometric morphometric technique to distinguish human parasite eggs of twelve different species

Copro-microscopic diagnostic methods are the most common approach for screening patients with parasitic infections. However, expertise is required to identify helminthic eggs from fecal specimens. Consequently, new methods are required to support accurate species identification. Novel technologies have recently been developed for the classification of organisms, including geometric morphometric (GM) approaches. In this study, the outline-based GM approach was used to distinguish the eggs of 12 common human parasite species, including Ascaris lumbricoides, Trichuris trichiura, Enterobius vermicularis, hookworm, Capillaria philippinensis, Opisthorchis spp., Fasciola spp., Paragonimus spp., Schistosoma mekongi, Taenia spp., Hymenolepis diminuta and Hymenolepis nana. The GM analysis revealed that the size cannot be used as the main variable in the identification of parasite species at the egg stage, producing only 30.18% overall accuracy. However, comparisons of shape based on the Mahalanobis distances between pairs of parasite species showed significant differences in all pairs (p < 0.05). The shape analysis produced 84.29% overall accuracy. This is the first time that outline-based GM has been preliminarily confirmed as a valuable approach to support copro-microscopic analysis, in order to effectively screen helminth eggs. However, further studies with a larger set of helminth eggs and artefacts should be carried out to increase confidence in the identification of parasite species in the absence of local experts.