Comparison of Four Parasitological Techniques for Laboratory Diagnosis of Eggs from Spirometra spp. in Wild Mammal Fecal Samples

Evaluation of the detection method by a flotation method using a wire loop for gastrointestinal parasites

Infections by gastrointestinal parasites are found in a variety of animals worldwide. For the diagnosis of such infections, the flotation method is commonly used to detect parasitic microorganisms, such as oocysts or eggs, in feces. Instead of adding a flotation solution after the final centrifugation step and using a cover slip to collect the parasites, the method using a wire loop for the recovery of the organisms has been reported as one of alternative methods. However, the recovery rates of microorganisms from the flotation method have not been analysed. In the present study, the utility of a flotation method with the use of a wire loop of 8 mm in diameter (the loop method) was evaluated using different numbers of E. tenella oocysts and Heterakis gallinarum eggs, and chicken fecal samples collected at the farms. Consequently, we found that the oocysts and eggs in tubes could be collected at a ratio of 2.00 to 3.08. Thus, our results indicate that the loop method is a simple and time saving method, implicating the application for the estimated OPG/ EPG (Oocysts/Eggs per gram) of the samples.

Molecular, morphological and histopathological evidence of Spirometra mansoni in wild and domestic animals from Costa Rica

Spirometra mansoni is a diphyllobothroid cestode and one of the causing agents of sparganosis, a zoonotic foodborne and waterborne infection in humans. This parasite has an indirect life cycle with domestic and wild canids or felids as definitive hosts. The last report of S. mansoni in Costa Rica was done in 2004 by morphological assessment of worms, whereas molecular evidence of this species was obtained recently in the Americas. Herein, we present seven cases of spirometrosis in four dogs, three cats and a coyote from different regions of Costa Rica occurring in a time span of a year. Dog cases presented vomiting, hyporexia, lethargy and diarrhea, whereas cats were mostly asymptomatic. Moreover, the coyote was found with Spirometra sp. proglottids incidentally. Cytochrome oxidase subunit 1 (cox1) sequences of eggs or proglottids derived from all cases were analyzed with a Bayesian Inference phylogenetic tree and a haplotype network. These analyses showed the clustering of S. mansoni from Costa Rica with other sequences derived from Asia and America. Moreover, cox1 sequences clustered in two separate haplotypes, suggesting the high genetic diversity of the species. The present cases represent the first molecular evidence of the parasite in Central America; thus, extending its known range in the American continent.

Prevalence of gastrointestinal parasites in domestic cats (Felis catus) diagnosed by different coproparasitological techniques in the municipality of Seropédica, Rio de Janeiro

The objectives of this work were to investigate the occurrence of parasites in feces of cats, compare different coproparasitological techniques for their diagnosis and determine associations with parasitism. The samples were processed using three different coproparasitological techniques: centrifugal flotation in sucrose, centrifugal flotation in ZnSO4 and simple sedimentation. The parasitic association between parasitism and variables such as age, sex and fecal consistency was performed using the chi-square test or the G test with a significance level of 5%. A total of 237 samples were analyzed, of which 93 (39.2%) were positive, being Ancylostoma spp. (17.3%), Giardia intestinalis (12.2%), Platynosomum illiciens (8.0%), Cystoisospora spp. (6.3%), Toxoplasma gondii/ Hammondia hammondi (3.4%), Diphyllobothriidae (2.1%), Toxocara spp. (1.7%), Dipylidium caninum (1.3%) and Mesocestoides spp. (0.8%). In the parasitism association analysis, it was possible to verify a statistical difference in the age category for Cystoisospora spp. (p=0.001) observing a strong relationship between parasitism and young animals, the association with sex proved to be important for P. illiciens (p<0.001) with a higher frequency of parasitized females and fecal consistency revealed to be related to the parasites G. intestinalis (p=0.007) and P. illiciens (p=0.033) showing a higher number of positive animals for these parasites with normal fecal consistency. In conclusion, we observed a higher occurrence of Ancylostoma spp. and G. intestinalis in fecal samples from domestic cats received in routine diagnoses and the presence of other parasites with zoonotic potential, as well as the relationship of these diagnosed parasites with the categories sex, age and fecal consistency.

Comparison between five coprological methods for the diagnosis of Balantidium coli cysts in fecal samples from pigs

Background and Aim:

Balantidium coli is a protozoan that can infect humans and non-human primates, being the domestic pigs the animals most affected by this parasite. This study aimed to compare the performance of five coprological methods for diagnosis of Balantidium coli cysts in fecal samples from pigs.

Materials and Methods:

From September to December 2019, 558 fecal samples were collected from the rectum of backyard pigs in the Bucaramanga metropolitan area, Colombia. The average age of the sampled animals was 3-4 months. Fecal samples collected were tested using the following coprological techniques: Direct examination with Lugol’s iodine solution, buffered saline, centrifugation/flotation and McMaster techniques, and Ziehl–Neelsen method.

Results:

The results indicate that B. coli cysts were diagnosed most frequently through direct examination with Lugol’s iodine solution (52.7% of the samples) followed by direct examination with a buffered saline solution (37.6%). Moderate concordance (k=0.41; p<0.05) was determined between direct method with Lugol’s iodine and buffered saline solution, McMaster and buffered saline (k=0.35; p<0.05), and centrifugation/flotation and buffered saline (k=0.28; p<0.05) showed a fair degree of concordance. The rest of the comparisons were classified as poor. The flotation techniques (centrifugation/flotation and McMaster) did not show good recovery of cysts.

Conclusion:

It is concluded that the most efficient method for diagnosing this parasitosis was to an association between direct examination with Lugol’s iodine solution and buffered saline.