A pilot study on molecular diagnosis of Hapalotrema mistroides (Digenea: Spirorchiidae) infection in blood samples of live loggerhead turtles Caretta caretta

Other Schistosomatoidea and Diplostomoidea

Trematodes of the order Diplostomida are well known as serious pathogens of man, and both farm and wild animals; members of the genus Schistosoma (Schistosomatidae) are responsible for human schistosomosis (schistosomiasis) affecting more than 200 million people in tropical and subtropical countries, and infections of mammals and birds by animal schistosomes are of great veterinary importance. The order Diplostomida is also rich in species parasitizing other major taxa of vertebrates. The "Aporocotylidae" sensu lato are pathogenic in fish, "Spirorchiidae" sensu lato in reptiles. All these flukes have two-host life cycles, with asexually reproducing larvae usually in mollusks and occasionally in annelids, and adults usually live in the blood vessels of their vertebrate hosts. Pathology is frequently associated with inflammatory reactions to eggs trapped in various tissues/organs. On the other hand, the representatives of Diplostomidae and Strigeidae have three- or four-host life cycles in which vertebrates often serve not only as definitive but also as intermediate or paratenic hosts. Pathology is usually associated with migration of metacercariae and mesocercariae within the host tissues. The impact of these trematode infections on both farm and wild animals may be significant.

Case report: Blindness associated with Learedius learedi trematode infection in a green sea turtle, Chelonia mydas, of the northern Red Sea

Spirorchiid blood flukes are widespread in sea turtles, causing disease and mortality in their populations, with high prevalence in several ocean basins. Besides being leading parasitic causes of sea turtle strandings in several parts of the world, these infectious agents can cause endocarditis, vasculitis, thrombosis, miliary egg granulomas, and aneurysms, which ultimately may compromise the survival of green sea turtles. More severe cases may also result in multifocal granulomatous meningitis or pneumonia, both of which can be fatal. Herein, we report the first case of severe trematode infection, Caused by Learedius learedi, in a green sea turtle in the northern Red Sea; this infection is associated with bilateral blindness. Necropsy revealed multiple granulomas with intralesional trematode eggs in the optic nerve, eyes, spleen, heart, and lungs. The parasite was identified as Learedius learedi through specific primers of the ribosomal genome and COI sequences obtained from GenBank. Altogether, these findings emphasize the importance of recognizing the systemic nature of this particular fluke infection to ultimately protect the lives of these marine animals and ensure the sustainability of these species in the wild.

Molecular diagnosis of three outbreaks during three successive years (2018, 2019, and 2020) of Lumpy skin disease virus in cattle in Sharkia Governorate, Egypt

Background

Lumpy skin disease (LSD) is endemic in Egypt despite the Egyptian authorities' annual mass vaccination of cattle with sheeppox vaccine (Veterinary Serum and Vaccine Research Institute, Egypt), and the LSD virus (LSDV) continues to thrive practically every summer. The disease has a huge economic impact on the trade of the animal and its by-product.

Aim

This paper study the molecular characterization of LSDV strains that have been circulating in Sharkia Governorate, Egypt, for three successive years (2018, 2019, and 2020).

Methods

A total of 61 specimens (26 skin nodules and 35 oculonasal swabs) were collected from a clinic in the hospital of veterinary medicine, Zagazig University, during the summer months (July, August, and September) of three outbreaks in 2018, 2019, and 2020. These were examined by polymerase chain reaction (PCR) based on the open reading frame 103 (ORF103) gene to confirm the suspected cases and determine the degree of homology between the three different outbreaks during three successive years between each other and between the derived sequences of GenBank.

Results

Cattle is thought to be infected with LSDV due to the presence of scattered local or diffuse circumscribed skin nodules along with fever and lymph node enlargement and sometimes leg edema. The PCR approach proved rapid, sensitive, and specific for the detection of LSDV and confirmative diagnosis of the disease. Forty-six were detected to be positive by PCR (75.4%). The seven sequenced samples were translated to amino acid and registered in GenBank under accession number MW357655-MW357661. A single nucleotide mutation and amino acid variation were observed at positions 161 C (2020)/T (2018&2019) and consequently, a change in the amino acid at position 54 P (2020)/L (2018&2019) between the outbreak in 2020 and those in 2018 and 2019, respectively. The field LSDV isolates from Egypt cattle were more closely related to other LSDV sequences from Africa (Kenya), Asia, Europe, and the United States.These findings highlight the necessity of ongoing surveillance and characterization of circulating strains and the need to improve procedures for distinguishing vaccine strains from field viruses.

Some Digenetic Trematodes Found in a Loggerhead Sea Turtle (Caretta Caretta) from Brazil

This paper reports three recovered species of digeneans from an adult loggerhead sea turtle - Caretta caretta (Testudines, Cheloniidae) in Brazil. These trematodes include Diaschistorchis pandus (Pronocephalidae), Cymatocarpus solearis (Brachycoeliidae) and Rhytidodes gelatinosus (Rhytidodidae) The first two represent new geographic records. A list of helminths reported from the Neotropical region, Gulf of Mexico and USA (Florida) is presented.

The use of echocardiography as a health assessment tool in green sea turtles (Chelonia mydas)

There are limited techniques available to assess the health of sea turtles as physical examination has little correlation to clinical findings, and blood reference intervals are broad and provide limited prognostic significance. Advances in the portability of ultrasound machines allow echocardiography to be increasingly used in the health assessments of wild animals. This study performed blood analysis and echocardiograms on 11 green sea turtles upon admission to a rehabilitation clinic and six animals before release. Significant differences were seen between groups, with admission animals having significantly smaller diameters of the cavum arteriosum at systole and diastole, smaller E-waves and an increased fractional shortening. Pre-release animals displayed significant increases in the maximum blood velocities of both the pulmonary artery and the left aorta. Significant negative correlations were seen between fractional shortening and uric acid and between the velocity time integral of the pulmonary artery and urea. The pulmonary artery velocity time integral was also significantly correlated to the E wave. Furthermore, there was asynchrony between the cavum arteriosum and the cavum pulmonale and the detection of a parasitic granuloma in the ventricular outflow tract of one animal. Overall, the results suggest that cardiac function in stranded green sea turtles is significantly impaired and that echocardiography has applications in the health assessments of green sea turtles.