scholarly journals Hepatozoon caimani in Caiman crocodilus yacare (Crocodylia, Alligatoridae) from North Pantanal, Brazil

2017 ◽  
Vol 26 (3) ◽  
pp. 352-358 ◽  
Author(s):  
Andréa Bouer ◽  
Marcos Rogério André ◽  
Luiz Ricardo Gonçalves ◽  
Mayara de Cássia Luzzi ◽  
Juliana Paula de Oliveira ◽  
...  

Abstract Hepatozoon species are the most common intracellular hemoparasite found in reptiles. Hepatozoon caimani, whose vectors are Culex mosquitoes, has been detected in a high prevalence among caimans in Brazil by blood smears examinations. The present work aimed to detect and characterize the Hepatozoon spp. found in 33 caimans (24 free-ranging and 9 captive; 28 males and 5 females) (Caiman crocodilus yacare) sampled at Poconé, North Pantanal, state of Mato Grosso, Brazil, using blood smears examinations and molecular techniques. Hepatozoon spp.-gametocytes were found in 70.8% (17/24) and 88.8% (8/9) of blood smears from free-ranging and captive caimans, respectively. Hepatozoon spp. 18S rRNA DNA was found in 79.2% (19/24) and 88.8% (8/9) of free-ranging and captive caimans, respectively. Comparative analysis of parasitized and non-parasitized erythrocytes showed that all analyzed features were significantly different (P<0.05) for both linear and area dimensions. Phylogenetic analysis based on 18S rRNA sequences grouped the Hepatozoon spp. sequences detected in the present study together with H. caimani, recently detected in caimans in southern Pantanal.

1994 ◽  
Vol 346 (1318) ◽  
pp. 387-397 ◽  

Thraustochytrids are a neglected group of non-photosynthetic marine protists characterized by the presence of a sagenogenetosome, an ectoplasmic net and a cell wall composed of non-cellulosic scales. Though originally classified as fungi, they are ultrastructurally closest to the labyrinthulids, which have often been treated as protozoa, but are now usually considered to be more closely related to the heterokont algae. In order to clarify their controversial taxonomic position and evolutionary relationships, we have cloned and sequenced the 18s rRNA genes of the thraustochytrids Thraustochytrium kinnei and Ulkenia profunda . Phylogenetic analysis by several methods confirms earlier suggestions based on ultrastructure that thraustochytrids constitute a deeply divergent branch of the phylum Heterokonta, which is currently classified in the kingdom Chromista. The phylum Heterokonta also includes numerous chromophyte algae (e.g. brown algae and diatoms) as well as the oomycetes. Heterokont 18s rRNA sequences can be distinguished from those of all other eukaryotes by having an AU not a UA base pair at the very base of helix 47 in the V9 region. We also tabulate signature sequences that can be used to characterize 18s rRNA sequences from each of the major heterokont taxa.


Pathogens ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 53
Author(s):  
Vivek Khanal ◽  
Harrington Wells ◽  
Akhtar Ali

Field information about viruses infecting crops is fundamental for understanding the severity of the effects they cause in plants. To determine the status of cucurbit viruses, surveys were conducted for three consecutive years (2016–2018) in different agricultural districts of Oklahoma. A total of 1331 leaf samples from >90 fields were randomly collected from both symptomatic and asymptomatic cucurbit plants across 11 counties. All samples were tested with the dot-immunobinding assay (DIBA) against the antisera of 10 known viruses. Samples infected with papaya ringspot virus (PRSV-W), watermelon mosaic virus (WMV), zucchini yellow mosaic virus (ZYMV), and cucurbit aphid-borne-yellows virus (CABYV) were also tested by RT-PCR. Of the 10 viruses, PRSV-W was the most widespread, with an overall prevalence of 59.1%, present in all 11 counties, followed by ZYMV (27.6%), in 10 counties, and WMV (20.7%), in seven counties, while the remaining viruses were present sporadically with low incidence. Approximately 42% of the infected samples were positive, with more than one virus indicating a high proportion of mixed infections. CABYV was detected for the first time in Oklahoma, and the phylogenetic analysis of the first complete genome sequence of a CABYV isolate (BL-4) from the US showed a close relationship with Asian isolates.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Claire Y. T. Wang ◽  
Emma L. Ballard ◽  
Zuleima Pava ◽  
Louise Marquart ◽  
Jane Gaydon ◽  
...  

Abstract Background Volunteer infection studies have become a standard model for evaluating drug efficacy against Plasmodium infections. Molecular techniques such as qPCR are used in these studies due to their ability to provide robust and accurate estimates of parasitaemia at increased sensitivity compared to microscopy. The validity and reliability of assays need to be ensured when used to evaluate the efficacy of candidate drugs in clinical trials. Methods A previously described 18S rRNA gene qPCR assay for quantifying Plasmodium falciparum in blood samples was evaluated. Assay performance characteristics including analytical sensitivity, reportable range, precision, accuracy and specificity were assessed using experimental data and data compiled from phase 1 volunteer infection studies conducted between 2013 and 2019. Guidelines for validation of laboratory-developed molecular assays were followed. Results The reportable range was 1.50 to 6.50 log10 parasites/mL with a limit of detection of 2.045 log10 parasites/mL of whole blood based on a parasite diluted standard series over this range. The assay was highly reproducible with minimal intra-assay (SD = 0.456 quantification cycle (Cq) units [0.137 log10 parasites/mL] over 21 replicates) and inter-assay (SD = 0.604 Cq units [0.182 log10 parasites/mL] over 786 qPCR runs) variability. Through an external quality assurance program, the QIMR assay was shown to generate accurate results (quantitative bias + 0.019 log10 parasites/mL against nominal values). Specificity was 100% after assessing 164 parasite-free human blood samples. Conclusions The 18S rRNA gene qPCR assay is specific and highly reproducible and can provide reliable and accurate parasite quantification. The assay is considered fit for use in evaluating drug efficacy in malaria clinical trials.


Author(s):  
Beatriz Tomé ◽  
D. James Harris ◽  
Ana Perera ◽  
Isabel Damas-Moreira

AbstractInvasive species can carry parasites to introduced locations, which may be key to understand the success or failure of species establishment and the invasive potential of introduced species. We compared the prevalence and infection levels of haemogregarine blood parasites between two sympatric congeneric species in Lisbon, Portugal: the invasive Italian wall lizard (Podarcis siculus) and the native green Iberian wall lizard (Podarcis virescens). The two species had significant differences in their infection levels: while P. virescens had high prevalence of infection (69.0%), only one individual of P. siculus was infected (3.7%), and while P. virescens exhibited an average intensity of 1.36%, the infected P. siculus individual had an infection rate of only 0.04%. Genetic analyses of 18S rRNA identified two different haemogregarine haplotypes in P. virescens. Due to the low levels of infection, we were not able to amplify parasite DNA from the infected P. siculus individual, although it was morphologically similar to those found in P. virescens. Since other studies also reported low levels of parasites in P. siculus, we hypothesize that this general lack of parasites could be one of the factors contributing to its competitive advantage over native lizard species and introduction success.


2014 ◽  
Vol 143 (2) ◽  
pp. 316-324 ◽  
Author(s):  
C. F. MANSO ◽  
J. L. ROMALDE

SUMMARYThe high incidence of norovirus (NoV) infections seems to be related to the emergence of new variants that evolved by genetic drift of the capsid gene. In this work, that represents a first effort to describe the molecular epidemiology of NoV in the northwest of Spain, a total of eight different NoV genotypes (GII.1, GII.3, GII.4, GII.6, GII.7, GII.12, GII.13, GII.14) were detected. The major genotypes observed were GII.4 (45·42%) and GII.14 (34·9%), being detected in all age groups. In addition, and although most of GII.4 sequences belonged to 2006b (7·2%) and 2010 (50·35%) variants, the presence of new NoV variants was observed. Phylogenetic analysis revealed that a high number of GII.4 sequences (35·24%) could be assigned to the newly emerging Sydney 2012 variant, even during late 2010. The high prevalence of NoV GII.14 observed in this study may indicate the emergence of this genotype in Spain.


2011 ◽  
Vol 20 (1) ◽  
pp. 85-87 ◽  
Author(s):  
Santiago Benites de Pádua ◽  
Márcia Mayumi Ishikawa ◽  
Fabiana Satake ◽  
Gabriela Tomas Jerônimo ◽  
Fabiana Pilarski

The blood infection by Trypanosoma sp. in tuvira (Gymnotus aff. inaequilabiatus) from the Pantanal wetland was reported in this study. Ten fish from the Paraguay River in the Pantanal were evaluated for the presence of hemoflagellates. Trypomastigotes of Trypanosoma sp. were observed in blood smears from three fish (30% prevalence) and some forms were seen to be undergoing division. Using the diagnostic methods of fresh examination and blood centrifugation in hematocrit capillary tubes, the prevalence rate was 80%. This is the first report of Trypanosoma sp. in tuvira in Brazil.


Author(s):  
Gerald Zirintunda ◽  
Justine Ekou

Poverty, hunger and the need for production of pigs with meagre or zero inputs have made most farmers release their pigs to range freely, thus creating a pig-human cycle that maintains Taenia solium, the pig tapeworm and cause of porcine cysticercosis, in the ecosystem. A preliminary study was designed to establish the prevalence of porcine cysticercosis by postmortem examination of the tongue and carcass of free-range pigs from February to April 2014 in Arapai subcounty, Soroti district, eastern Uganda. The tongue of each pig was extended and examined before deep incisions were made and the cut surfaces were examined. The rest of the carcasses were examined for cysts. Out of 178 pigs examined, 32 were qualitatively positive for porcine cysticercosis, representing a prevalence of 18.0%. This high prevalence represents a marked risk to the communities in the study area of neurocysticercosis, a debilitating parasitic zoonosis. Proper human waste disposal by use of pit latrines, confinement of free-range pigs and treatment with albendazole and oxfendazole are recommended.


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