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Parasitic copepods are common damaging ectoparasites of cultured marine fish that induce high mortalities in fish farms. The present study aimed to identify the cause of mass mortalities of cultured gilthead sea bream (Sparus aurata) as one of the highly valuable cultured marine fish species in Egypt. Parasitological examination demonstrated Ergasilus sieboldin (E. sieboldi) adult females of (1.3 ± 0.01 mm, n = 55) mean body length and (0.53 ± 0.04 mm) body width, lodged in the gill filaments of the forty examined fish with a pair of strong clawed antennae. The detected parasite has six segmented antennules and consists of cephalosome followed by four divided thoracic segments that narrow posteriorly, five pairs of swimming legs, genital segment, abdominal segments followed by furcal rami with unequal caudal setae and two egg sacs at the end of the body. The collected E. sieboldi were confirmed by molecular characterization and phylogenetic analysis based on 28S rDNA sequencing. The obtained sequence in this study was registered in the GenBank with (OM812074) accession number as a first sequence of E. sieboldi from Egypt. Oxidative stress biomarkers in the gills of the parasitized fish were evaluated to describe the host defense mechanisms against E. sieboldi infestation. The current study demonstrated decreasing in reduced glutathione (GSH) content and activity of the anti-oxidant enzyme catalase (CAT), as well as elevation in the level of malondialdehyde (MDA) due to exposure to oxidative damage that might have a role in the tissue damage and dysfunction. [ABSTRACT FROM AUTHOR]

This study aimed to identify the mortality present in private fish farm Amyloodinium ocellatum and Cryptocaryon irritans were isolated from this outbreak affecting Liza carinata fingerlings at an earthen-based aquaculture facility in Damietta, Egypt. A total of 140 moribunds, L. carinata, were collected from the fish ponds during the mortality events. Physico-chemical analysis of water was analyzed. The skin, fins, gills, and eyes of each fish specimen were scraped gently onto slides in areas over 2 cm area. All smears were examined separately under the light microscope. Molecular identification of the parasites using analysis of ITS rDNA regions flanking both 18S and 28S rDNA genes of Amyloodinium protozoa and C. irritans. Identities of the detected parasites were confirmed by gene sequence and phylogenetic analysis. The majority of the examined fish (90%) were infected, 66.42% had a mixed infection, and 23.57% had a single infection either with A. ocellatum (10.71%) or C. irritans (12.85%).The mean intensity of A. ocellatum was 16.5 ± 2.03 in the skin and 13.18 ± 1.90 in the gills of infected fish, while that of C. irritans was 4.75 ± 1.05 in gills and 7.43 ± 1.45 in the skin, respectively. To control the emergent mortalities, affected ponds were treated using copper sulfate pentahydrate, hydrogen peroxides solutions, and amprolium hydrochloride powder in feed. Fish across the treated ponds were gradually improved with low morbidity and mortalityrates during the treatment period. The clinical disease was almost diminished at the end of the second week of treatment. Coinciding with the clinical improvement of the treated juveniles, microscopical examination of skin/gill scraps exhibited a marked decline in the number of protozoan parasites at the end of the second week of treatment. [ABSTRACT FROM AUTHOR]

Molecular diagnosis of helicobacters by PCR is simpler, more accurate, and feasible compared to other diagnostic methods. Validity and accuracy are highly dependent on the PCR primer design, diffusion time, and mutation rate of helicobacters. This study aimed to design 16srRNA -specific primers for Helicobacter spp. and H. pylori. Application of comparative statistical analysis of the diagnostic utility of the most available 16srRNA genus-specific primers. The new primers were designed using bioinformatics tools (MAFFT MSA and Gblocks command line). A comparative study was applied on nine genus-specific 16srRNA primers in comparison to the ConsH using in silico and laboratory evaluation. The results demonstrated that the best specificity and sensitivity of the primers designed for this study compared to other primers. The comparative study revealed that the heminested outer/inner primers were the worst. Although H276, 16srRNA(a), HeliS/Heli-nest, and Hcom had acceptable diagnostic utility, false positive and false negative results were obtained. Specificity testing on clinical samples indicated a surprising result; that H. pylori was not the sole enemy that we were looking for, but the Non-Helicobacter pylori Helicobacters should be considered as a real risk prognostic for gastric diseases, consequently, a specific diagnosis and treatment should be developed. This study concluded that our designed primers were the most specific and sensitive in comparison with other primers. In addition, in silico evaluation is not accurate enough for primer assessment and that the laboratory evaluation is mandatory. [ABSTRACT FROM AUTHOR]

Stomach horse bots (Gasterophilus intestinalis larvae; Diptera: Oestridae) are obligatory parasites inhabit the stomach of domestic Equidae. Colonization of Gasterophilus intestinalis larvae cause funnel-shaped stomach ulcers, sub-serosal abscess, and peritonitis. In the current research work, 3rd instar larvae of G. intestinalis were exposed to different concentrations (5, 10, 20, 40, 80 and 100 ppm) of curcumin from turmeric plant root (Curcuma longa). Survival of insect larvae, their morphological characterization, growth regulation, enzymatic assay and comet assay were assessed. Curcumin exhibited time and concentration dependent insecticidal effect on survival of 3rd instar larvae of G. intestinalis (bot flies). The aqueous extract of curcumin was highly toxic to G. intestinalis larvae with LC50 value of 16.92 ppm after 24 h. The mean comet tail length (µm) and tail moment (µm) at the highest curcumin concentration of 100 ppm were 16.03 ± 0.15 and 3.03 ± 0.09 µm, whereas DNA damage percent was 14.77 ± 0.12%. Further, remarkable inhibition of Glutathione S-transferases (GST) and Acetylcholinesterase (AChE) enzymatic activity were detected. Aqueous extract of curcumin exhibited potent lethal effects to the 3rd instar larvae of G. intestinalis, therefore, it could be used as an active and harmless natural insecticidal to control bot flies' larvae in donkeys. [ABSTRACT FROM AUTHOR]