Use of Mini-FLOTAC and Fill-FLOTAC for rapidly diagnosing parasitic infections in zoo mammals

Wild Animals in Captivity: An Analysis of Parasite Biodiversity and Transmission among Animals at Two Zoological Institutions with Different Typologies

We have conducted a 10-year-long coprological study of the animals housed in two zoological institutions (ZooAquarium and Faunia, Madrid, Spain) to assess the parasite biodiversity, prevalence, and their relation with host class, diet, and enclosure type (soil type and level of isolation from wild fauna). A total of 4476 faecal samples from 132 mammal species and 951 samples from 86 avian species were examined. The results indicated that only 12.8% of avian species had parasites at least once during the study period, whereas 62.1% of mammal species tested positive. Predominantly, protists (Entamoeba, flagellates, and ciliates) and nematodes (mainly Trichuris) were identified in the findings. Carnivorous species were primarily infected by nematodes, while herbivorous and omnivorous species were mainly infected by protists. The number of infected herbivorous and omnivorous species was significantly greater than carnivorous species. Differences were observed based on soil type (artificial, natural, mixed) and isolation level (isolated/accessible), but these differences were not statistically significant. Several parasites (Entamoeba spp., Giardia spp., Balantidoides coli, Trichuris spp.) could potentially be transmitted between humans and some mammals and birds. Regular animal analyses and a personnel health program in the institutions would minimise transmission risks between zoo animals, wildlife, and humans.

Prevalence of Gastrointestinal Parasites in Zoo Animals and Phylogenetic Characterization of Toxascaris leonina (Linstow, 1902) and Baylisascaris transfuga (Rudolphi, 1819) in Jiangsu Province, Eastern China

The burden of gastrointestinal parasites in zoo animals has serious implications for their welfare and the health of veterinarians and visitors. Zhuyuwan Zoo is located in the eastern suburb of Yangzhou city in eastern China, in which over 40 species of zoo animals are kept. In order to understand the infection status of GI parasites in Zhuyuwan Zoo, a total of 104 fresh fecal samples collected randomly from birds (n = 19), primates (n = 19), and non-primate mammals (n = 66) were analyzed using the saturated saline flotation technique and nylon sifter elutriation and sieving method for eggs/oocysts, respectively. Two Ascaris species were molecularly characterized. The results showed that the overall prevalence of parasitic infection was 42.3% (44/104). The parasitic infection rate in birds, primates, and non-primate mammals were 26.3% (5/19), 31.6% (6/19), and 50.0% (33/66), respectively. A total of 11 species of parasites were identified, namely, Trichostrongylidae, Capillaria sp., Trichuris spp., Strongyloides spp., Amidostomum sp., Toxascaris leonina, Baylisascaris transfuga, Parascaris equorum, Paramphistomum spp., Fasciola spp., and Eimeria spp. Paramphistomum spp. eggs were first detected from the captive Père David's deer, and Fasciola spp. eggs were first reported from sika deer in zoo in China. A sequence analysis of ITS-2 and cox1 showed that the eggs isolated from the African lion (Panthera leo Linnaeus, 1758) were T. leonina, and the eggs from the brown bear (Ursus arctos Linnaeus, 1758) were B. transfuga. The public health threat posed by these potential zoonotic parasitic agents requires attention. These results lay a theoretical foundation for prevention and control of wild animal parasitic diseases at zoos in China.

Comparison of McMaster and Mini-FLOTAC techniques for the diagnosis of internal parasites in pigs

Abstract This purpose of this study was to compare the efficiency of the McMaster and Mini-FLOTAC quantitative techniques in the investigation of helminths in feces of pigs. An analysis was made of 74 fecal samples from pigs raised on family farms located in Rio de Janeiro, Brazil. These were analyzed by the Mini-FLOTAC and McMaster techniques in a solution of 1,200g/mL NaCl. This investigation revealed a superiority in the frequency of all helminths detected by Mini-FLOTAC, including Ascaris suum, Trichuris suis, strongyles and Strongyloides ransomi. The Kappa index revealed substantial agreement in all comparisons made in relation to the frequency of positive samples. However, significant statistical differences in the comparison of EPGs between McMaster and Mini-FLOTAC were observed for all nematodes (p ≤0.05). Higher values of Pearson’s linear correlation coefficient (r), between the techniques in relation to EPG were observed for A. suum and T. suis, differently from what was observed for strongyles and S. ransomi. Mini-FLOTAC proved to be a more satisfactory and reliable technique both for the diagnosis of parasites and for the determination of EPG in pig feces due to the larger size of its counting chambers, thus increasing the helminth egg recovery rates.

A Comparative Study of Mini-FLOTAC With Traditional Coprological Techniques in the Analysis of Cetacean Fecal Samples

Free-ranging cetaceans are considered sentinels for the marine ecosystem's health. New and non-invasive methods have been set up for the collection of fecal samples from free-ranging big whales at sea, permitting to gain an excellent epidemiological picture of parasitic infections in wild populations. To select the best protocol to be used for copromicroscopic examination in cetaceans stool samples, we evaluated the sensitivity of two commonly used techniques, i.e., a sedimentation-floatation method and the Mini-FLOTAC through validation by helminth isolation from the digestive tract. For this aim, gastrointestinal content and fecal samples were collected during necropsy from 44 cetaceans, including bottlenose dolphins (Tursiops truncatus), striped dolphins (Stenella coeruleoalba), sperm whales (Physeter macrocephalus), Risso's dolphins (Grampus griseus), Cuvier's beaked whales (Ziphius cavirostris), pilot whale (Globicephala melas), and fin whales (Balaenoptera physalus). Helminths were recovered through washing and filtering of the gastrointestinal contents and morphologically identified. Copromicroscopic examinations were performed on formalin-preserved fecal samples, using a sodium nitrate, sodium thiosulphate, and sucrose solution (s.g. = 1.450) for both methods. Helminths belonging to 9 taxa (i.e., the trematodes Synthesium tursionis, Synthesium delamurei, Campula palliata, Braunina cordiformis, Pholeter gastrophilus, the nematode Anisakis sp., cestodes of the family Tetrabothriidae and the acanthocephalan Bolbosoma sp.) were isolated. Eggs referable to the same taxa, with the exception of cestodes, were found in copromicroscopic analyses. Sensitivity of the Mini-FLOTAC method appeared higher or equal for all taxa, proving superior to the sedimentation-flotation method for the detection of all except Anisakis sp. The concordance of the two tests indeed revealed a moderate to perfect agreement (kappa values 0.42–1). Not excluding the limitations inherent to the techniques themselves, explanations for false-negative results at copromicroscopy could be linked to parasite-related factors, including prepatent infections, low parasitic burdens, or intermittent egg shedding. Notwithstanding these limitations, this study evidenced that the Mini-FLOTAC protocol approximates more accurately the composition of the gastrointestinal helminthic community of cetaceans from copromicroscopic examination, providing at the same time a quantitative estimation.

Single and Synergistic Effects of Fenbendazole and Metronidazole Against Subclinical Infection by Giardia duodenalis in Non-Human Primates in a Zoological Garden in Southern Italy

The aim of this study was to assess the single and synergistic effects of fenbendazole (Fenb) and metronidazole (Metro) for the treatment of Giardia duodenalis infection in different species of non-human primates (NHPs) housed in a zoological garden of southern Italy. Moreover, the study also aimed to better define the circulation of G. duodenalis zoonotic assemblages in NHP and the potential occurrence of zoonotic transmission between the staff from the zoo and NHP. Briefly, six species that belonged to four families (Lemuridae, Cercopithecidae, Atelidae, and Hylobatidae) of NHP and housed in six cages (CG) were identified as Giardia positive and divided into two groups. Group F (N = 16 animals) was treated with Fenb (50 mg/kg, every 24 h for 5 consecutive days) and Group M (N = 7 animals) was treated with Metro (25 mg/kg, two times a day for 5 consecutive days). After the first round of therapy, all the animals were retreated for 5 days by inverting the drugs in each group. On each sampling day [study days (SDs) 3–24], the samples were tested for the presence of Giardia cysts using the FLOTAC technique. Multiple fecal tests for the antigen detection of Giardia, such as rapid ELISA and direct immunofluorescence (IFA), were performed at each sampling point only on samples that resulted in positive for Giardia cysts with FLOTAC. The efficacy of Fenb ranged from 30 to 67% and for Metro ranged from 82 to 96%. The results showed the synergistic effects of Metro and Fenb (98–100%) over the combination of Fenb and Metro (52–90%) against the infection by Giardia in NHPs. The overall k agreement between FLOTAC and IFA was reached 0.858 (p = 0.0001). In contrast, all the samples had a negative antigen result when using ELISA. At molecular analysis, six samples were confirmed positive for Giardia by nested PCR. Only two positive samples were successfully sequenced that showed 100% of identity with assemblage B. All the samples from the humans included in the study resulted in negative for Giardia cysts. Overall, the study emphasizes the need for regular monitoring of Giardia infections in NHP housed in zoos by traditional diagnostic tools combined with molecular characterization of the parasite.

The Prophylactic Effect of Ivermectin Treatments on Nematode Infections of Mammals in a Faunistic Park (Northern Italy)

Nematode infections of mammals can spread in zoos and faunistic parks and lead to disease in humans and animals. Group treatment strategies with anthelminthic drugs are common. Still, their effectiveness should be verified by sensitive and specific copromicroscopic analyses. This study assessed longitudinal parasitological monitoring, by FLOTAC® dual technique, in mammals housed in an Italian faunistic park, in order to verify the effectiveness of the two adopted ivermectin prophylactic treatments. Twenty-one species of herbivorous mammals from ten families were treated twice per year with ivermectin in an in-feed formulation (medicated feed containing 1.7 g/ton ivermectin daily, for 30 days in March and November), while 13 species of carnivores and primates from five families were treated once a month with oral or subcutaneous administrations of ivermectin (200 μg/kg body weight (b.w.), from March to November). Fecal samples were collected in June–July and October 2019 (late spring–early summer and autumn sampling groups, respectively). All nematode infections, sustained by Nematodirus spp., Capillaria spp., Trichuris spp., Parascaris spp. and Strongylida, were detected in samples collected from herbivores, presenting prevalence rates of infection of 17.3% (9/52), 15.4% (8/52), 15.4% (8/52), 5.8% (3/52), and 3.8% (2/52), respectively. All carnivores and primates tested negative. The general linear mixed model showed that nematode eggs’ excretion in herbivores were influenced by sampling and sampling-host family interaction. Results showed that frequency and dose of prophylactic treatments in herbivores should be improved according to host and parasite taxonomic groups. The treatment adopted in carnivores and primates, together with hygienic management, was effective in nematode control.

Use of the FLOTAC technique as a new coproparasitological diagnostic method in aquatic mammals and comparison with traditional methods

The inadequate choice of a diagnostic method or the option for techniques that have low sensitivity and specificity may limit the diagnosis of parasitic agents that affect aquatic mammals. The aim of this study was to evaluate the performance of the FLOTAC technique and compare it with three traditional methods (Willis, sedimentation and centrifugation- flotation) used in the diagnosis of gastrointestinal parasites in aquatic mammals. For this, 129 fecal samples from 12 species were collected. Each sample was submitted to laboratory processing using the Willis, Hoffman techniques, Faust method and FLOTAC. Sensitivity, specificity, real prevalence, estimated prevalence, positive predictive value, negative predictive value, correct classification (accuracy) and incorrect classification were evaluated to compare the different diagnostic methods. The highest frequency of positive samples occurred using FLOTAC (46.51%), compared to Hoffman (23.25%), Faust (10.07%) and Willis techniques (6.97%). In the samples analyzed, the occurrence of Strongylidae eggs and Eimeriidae oocysts was frequently observed. The FLOTAC technique proved to be the most appropriate technique and due to its efficacy, is strongly recommended for coproparasitological evaluations in aquatic mammals.

Occurrence and molecular characterization of Cryptosporidium spp., Giardia duodenalis, Enterocytozoon bieneusi, and Blastocystis sp. in captive wild animals in zoos in Henan, China

BACKGROUND

Captive wild animals in zoos infected with Cryptosporidium spp., Giardia duodenalis, Enterocytozoon bieneusi, and Blastocystis sp. can be sources of zoonotic infections and diseases. Therefore, to investigate the distribution of these pathogens in captive wild animals of zoos in Henan, China, a total of 429 fresh fecal samples were collected from six zoos in Henan, China. The infection rates of Cryptosporidium spp., G. duodenalis, E. bieneusi, and Blastocystis sp. were determined by PCR analysis of corresponding loci. Positive results for Cryptosporidium (C. parvum and C. hominis) were subtyped based on the (gp60) gene.

RESULTS

The overall prevalence was 43.1% (185/429), and the prevalence of Cryptosporidium, Giardia duodenalis, Enterocytozoon bieneusi, and Blastocystis sp. were 2.8% (12/429), 0.5% (2/429), 20.8% (89/429), and 19.1% (82/429), respectively. Five Cryptosporidium species, namely, C. hominis, C. parvum, C. muris, C. andersoni, and C. macropodum, were identified in this study. Cryptosporidium parvum was further subtyped as IIdA19G1. Two Giardia duodenalis assemblages (A and E) were also identified. A total of 20 Enterocytozoon bieneusi genotypes were detected, including 18 known (BEB6, D, HND-1, CD7, SDD1, Henan-IV, KIN-1, CHK1, Peru8, Henan-V, CHG11, CHG-1, CHS9, CHG21, Type-IV, CHC9, CM5, and CHB1) and 2 novel genotypes (CHWD1 and CHPM1). A total of nine subtypes of Blastocystis sp. (ST1, ST2, ST3, ST5, ST6, ST7, ST10, ST13, and ST14) were identified in captive wild animals in zoos in the present study. Cryptosporidium andersoni, nine Enterocytozoon bieneusi genotypes, and five Blastocystis subtypes were here first identified in new hosts.

CONCLUSIONS

Our study has expanded the host ranges of these four pathogens. The data indicate that animals in zoos can commonly be infected with these four zoonotic pathogens, and animals in zoos are potential sources of zoonotic infections in humans.

Implementation of Mini-FLOTAC in Routine Diagnosis of Coccidia and Helminth Infections in Domestic and Exotic Birds

Mini-FLOTAC (MF) has recently been proposed for the fecal quantification of gastrointestinal (GI) parasites in birds due to its higher sensitivity and precision in comparison with the McMaster method. The current research aimed to test the use of MF in routine diagnosis of coccidia and helminth infections in several domestic and exotic bird collections in Portugal. Between July 2020 and April 2021, a total of 142 fecal samples from organic layers, peacocks and ratites were collected in four Portuguese bird collections and processed using MF and fecal cultures to identify and calculate GI parasite shedding and prevalence. The McMaster method was also used to compare the shedding levels obtained for both quantitative techniques. MF’s relative sensitivity and specificity were also assessed, using McMaster as the reference technique. The implementation of MF resulted in an average Eimeria spp. shedding higher in peacocks from bird collection 2 (502 OPG), followed by peacocks from collection 1 (107 OPG) and organic layers (24 OPG) and peacocks from collection 3 (9 OPG). Peacocks were also positive for Capillaria spp., Trichostrongylus tenuis and Strongyloides pavonis, whereas ostriches and emus were infected by L. douglassii. The MF protocol for exotic animals and the McMaster method did not differ significantly for each parasitic agent and bird species, and MF achieved relative sensitivities and specificities higher than 70% for Galliform Eimeria spp., peacock helminths and ratites’ L. douglassii infections. Higher L. douglassii EPG values were identified using the MF protocol for exotic species (2 g of feces/38 mL of sucrose solution), followed by McMaster 2/28, MF 5/45 and MF 2/18. The use of MF allowed for obtaining different intestinal parasitic populations in several bird species and locations, and MF 2/38 is globally proposed as the most suitable protocol for bird fecal samples as an alternative to the McMaster method in the diagnosis of avian intestinal parasitic infections.

Molecular Subtyping of Blastocystis sp. Isolated from Farmed Animals in Southern Italy

Blastocystis is a common intestinal protist distributed worldwide, infecting humans and a wide range of domestic and wild animals. It exhibits an extensive genetic diversity and, so far, 25 distinct small subunit ribosomal RNA (SSU rRNA) lineages termed subtypes (STs)) have been characterized; among them, 12 have thus far been reported in humans. The aims of the present study were to detect and genetically characterize Blastocystis sp. in synantropic animals to improve our current knowledge on the distribution and zoonotic transmission of Blastocystis STs in Italy. Samples were collected from N = 193 farmed animals and submitted to DNA extraction and PCR amplification of the SSU rRNA. Blastocystis was detected in 60 samples (31.08%) and successfully subtyped. Phylogenetic analysis evidenced that the isolates from fallow deer, goats, and pigs (N = 9) clustered within the ST5; those from pheasants (N = 2) in the ST6; those from chickens (N = 8) in the ST7; those from sheep (N = 6) in the ST10; and those from water buffaloes (N = 9) in the ST14 clade. The comparison between the present isolates from animals and those previously detected in humans in Italy suggested the animal-to-human spillover for ST6 and ST7. The present study represents the widest Blastocystis survey performed thus far in farmed animals in Italy. Further epidemiological studies using molecular approaches are required to determine the occurrence and distribution of Blastocystis STs in other potential animal reservoirs in Italy and to define the pathways of zoonotic transmission.