scholarly journals Amoebic gill disease outbreak in marine fish cultured in Korea

2017 ◽  
Vol 29 (3) ◽  
pp. 357-361 ◽  
Author(s):  
Wi-Sik Kim ◽  
Kyoung-Hui Kong ◽  
Jong-Oh Kim ◽  
Sung-Ju Jung ◽  
Jeong-Ho Kim ◽  
...  

In 2015, 6.7–60% mortality was observed in black seabream ( Acanthopagrus schlegelii), rock bream ( Oplegnathus fasciatus), and gray mullet ( Mugil cephalus) farmed in the southern coast of Korea. On examination, numerous amoebae were found on the gills of these 3 fish species with detection rate of 100%. Some rock bream and gray mullet were coinfected with bacteria ( Pseudomonas anguilliseptica, Vibrio tapetis, or Vibrio anguillarum). Histologic examination revealed extensive hyperplastic epithelium and lamellar fusion in the gills. Numerous amoebae were seen between gill filaments. The amoebae collected from the 3 fish species had specific 630 bp of a partial 18S rRNA gene fragment for Neoparamoeba perurans. Phylogenetic analysis based on partial 18S rRNA gene nucleotide sequences revealed that these Korean amoeba isolates belonged to the N. perurans group. Based on our results, black seabream, rock bream, and gray mullet were added as new hosts for N. perurans.

Nematology ◽  
2016 ◽  
Vol 18 (5) ◽  
pp. 591-604 ◽  
Author(s):  
Mehrab Esmaeili ◽  
Ramin Heydari ◽  
Pablo Castillo ◽  
Mozhgan Ziaie Bidhendi ◽  
Juan E. Palomares-Rius

During a survey on pin nematodes in western Iran, two populations of Paratylenchus audriellus and Paratylenchus tenuicaudatus were collected and subsequently analysed morphologically and molecularly. Paratylenchus audriellus is characterised by the long stylet (48-61 μm) and the typical female tail with a characteristic claw-like process with sharply pointed terminus. To our knowledge, the Iranian population of P. tenuicaudatus is the first record from Iran. The molecular characterisation of P. audriellus nematodes using the D2-D3 of 28S rRNA and the partial 18S rRNA gene sequences revealed that this species is clearly separated from P. straeleni and should be considered as a valid taxon.


Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1707
Author(s):  
Dalytė Mardosaitė-Busaitienė ◽  
Jana Radzijevskaja ◽  
Linas Balčiauskas ◽  
Algimantas Paulauskas

Babesia microti (Aconoidasida: Piroplasmida) (Franca, 1910) is an emerging tick-borne parasite with rodents serving as the considered reservoir host. However, the distribution of B. microti in Europe is insufficiently characterized. Based on the sample of 1180 rodents from 19 study sites in Lithuania, the objectives of this study were: (1) to investigate the presence of Babesia parasites in eight species of rodents, (2) to determine the prevalence of Babesia parasites in rodents from different habitats, and (3) to characterize the detected Babesia strains using partial sequencing of the 18S rRNR gene. Babesia DNA was detected in 2.8% rodents. The highest prevalence of Babesia was found in Microtus oeconomus (14.5%) and Microtus agrestis (7.1%) followed by Clethrionomys glareolus (2.3%), Apodemus flavicollis (2.2%) and Micromys minutus (1.3%). In M. minutus, Babesia was identified for the first time. The prevalence of Babesia-infected rodents was higher in the meadow (5.67%) than in the ecotone (1.69%) and forest (0.31%) habitats. The sequence analysis of the partial 18S rRNA gene reveals that Babesia isolates derived from rodents were 99–100% identical to human pathogenic B. microti ‘Jena/Germany’ strain.


2018 ◽  
Vol 10 (2) ◽  
pp. 320-325
Author(s):  
Rokhmani Rokhmani ◽  
Endang Ariyani Setyawati ◽  
Daniel Joko Wahyono

Protozoa species of Trichodina spp. may be found in most hatchery centers in Banyumas, Purbalingga, and Banjarnegara. However, the determination of Trichodina spp. types is still based on its body’s morphological variations, not yet molecular. A research has been conducted to identify molekuler of the Trichodina spp. with the infecting 18S rRNA gene marking on the gourami larvae in Exs. Residence of Banyumas, Central Java. The research used a survey method with the samples of gourami. Amplification of 18S rRNA gene from Trichodina heterodentata was Performed using PCR technique. Primer used is Forward primer (5 ‘-AAC CTG GTT GAT CCT GCC ATG-3’) and Reverse primer (5 ‘-TGA TCC TTC TGC AGG TTC ACC TAC-3’) which produces a 600 pb amplicon of DNA. Molecular research can be a complementary identification of organisms morphologically. Amplification of the partial 18S rRNA gene may be used to identify Trichodina specifically. Gourami larvae taken from the hatchery centers in Banyumas, Purbalingga, and Banjarnegara. The results show that the detected percentage of Trichodina heterodentata genes with the infecting 18S rRNA gene marking on the gourami larvae in Central Java taken from the hatchery centers in Banyumas, Purbalingga and Banjarnegara are respectively 10%, 10%, and 45%. This research provides a benefit in mapping the presence of protozoa pathogen of Trichodina spp. in gourami hatcheries in the Former Exs. Residence of Banyumas, Central Java


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.


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