Serological and molecular identification of Reticuloendotheliosis virus (REV) in chickens in Sudan.

BACKGROUND: Reticuloendotheliosis virus (REV) is a gammaretrovirus that belongs to the family of Retroviridae. The infection can result in immunosuppression, runting syndrome, high mortality, acute reticular cell neoplasia or T- and/ or B-cell lymphoma, in a variety of domestic and wild birds. The disease is widespread around the world. No related data have been reported in Sudan about the disease. The present study was conducted to determine the prevalence of REV antibodies and DNA in local and commercial breeds of chickens older than 20 weeks from June 2014 to February, 2017. METHODS: A total of 460 sera samples and 150 (50 liver and 100 spleen) tissue samples were collected from local and commercial breeds of chickens older than 20 weeks and screened for anti-REV antibodies in four states of Sudan using a commercial REV antibody ELISA test kit (IDEXX). Polymerase chain reaction (PCR) was performed to detect REV DNA in tissue samples in Khartoum State. RESULTS: The results revealed that the overall seroprevalence of REV was 74.6% among local and commercial chicken breeds, but in commercial it was 79.5% (190/239) and 69.2% in local breeds (153/221). One hundred and fifty tissue samples of chickens (50 liver, 100 spleen) were tested using PCR for detection of REV using primer sets of the conserved region in envelope glycoprotein (env) gene with a band length of 850 bp. Five out of 50 (10%) liver samples were RE provirus DNA positive detected by PCR, whereas 15 out of 100 (15%) spleen samples were PCR positive. Univariate analysis revealed there was a difference (p ≤ 0.05) between locality and breed of chickens and seropositivity to REV. CONCLUSIONS: The prevalence of the disease was high in Sudan and more studies are needed to evaluate the epidemiology and pathogenesis of the virus.

Theileria lestoquardi in Sudan is highly diverse and genetically distinct from that in Oman.

Malignant ovine theileriosis is a severe tick-borne protozoan disease of sheep and other small ruminants which is widespread in sub-Saharan Africa and the Middle East. The disease is of considerable economic importance in Sudan as the export of livestock provides a major contribution to the gross domestic product of this country. Molecular surveys have demonstrated a high prevalence of sub-clinical infections of Theileria lestoquardi, the causative agent, among small ruminants. No information is currently available on the extent of genetic diversity and genetic exchange among parasites in different areas of the country. The present study used a panel of T. lestoquardi specific micro- and mini-satellite genetic markers to assess diversity of parasites in Sudan (Africa) and compared it to that of the parasite population in Oman (Asia). A moderate level of genetic diversity was observed among parasites in Sudan, similar to that previously documented among parasites in Oman. However, a higher level of mixed-genotype infection was identified in Sudanese animals compared to Omani animals, consistent with a higher rate of tick transmission. In addition, the T. lestoquardi genotypes detected in these two countries form genetically distinct groups. The results of this work highlight the need for analysis of T. lestoquardi populations in other endemic areas in the region to inform on novel approaches for controlling malignant theileriosis.

An accessory extensor pollicis longus tendon: a case report of rare anatomical variant / Tendón accesorio del músculo extensor largo del pulgar: reporte de caso de una rara variación anatómica

SUMMARY: Variation in the morphology of the extensor pollicis longus muscle is very rare. The muscle is considered as one of the deep group of dorsal forearm muscles. It passes through the dorsal radiocarpal ligament in a detached compartment. It inserts at the base of the distal phalanx of the thumb. The muscle might have double tendons where they run either in one, or in separate compartments. In this study, we report an extremely rare condition for a 38-year-old male where some of the tendon fibers split at the base of the proximal phalanx and the two tendons insert at the sides of the base of the distal phalanx. We also noticed a high range of hyperextension where the action was painless and showed no sign of discomfort. We believe that the way the tendons get inserted might have a role in this wide range of extension.

RESUMEN: La variación en la morfología del músculo extensor largo del pulgar es muy rara. Es considerado perteneciente al grupo profundo de los músculos del dorso del antebrazo. Su tendón pasa a través del ligamento radiocarpiano dorsal en un compartimiento separado. Se inserta en la base de la falange distal del pulgar. El músculo puede tener tendones dobles que pasan a través de un solo compartimiento, o en compartimentos separados, del ligamento radiocarpiano dorsal. En este estudio se reporta una variación extremadamente rara en un hombre de 38 años de edad, donde algunas de las fibras del tendón se dividen en la base de la falange proximal y los dos tendones se insertaban a los lados de la base de la falange distal del pulgar. También observamos un alto grado de hiperextensión siendo la acción indolora y no mostrando ningún signo de malestar. Creemos que la forma en que los tendones se insertan podrían tener un papel en este amplio rango de extensión.

The pulmonary involvement in Theileria lestoquardi naturally infected sheep.

Malignant Ovine Theileriosis (MOT) caused by Theileria lestoquardi is considered a major constraint for sheep production in many areas of the world including Sudan. Pulmonary oedema is thought to be the main cause of animal death, but the mechanism, the cell types involved and/or the probable cause of this pneumonia has yet to be defined. The present study was carried out to investigate the pulmonary involvement post T. lestoquardi infection and to identify the cell types involved in pneumonia. Apparently healthy sheep were exposed to ticks challenge in T. lestoquardi endemic area. Lungs impression smears and tissue sections for histopathology were processed. At necropsy, fifteen infected sheep revealed severe pneumonia associated with oedema and accumulation of creamy-grayish frothy exudates. The microscopic findings of examined lungs showed emphysema, congestion, collapse and proliferation of immense amount of different kinds of cells. The current study indicates that T. lestoquardi infections are accompanied with remarkable pulmonary involvements and may lead to respiratory failure and death.

Attenuation of Theileria lestoquardi infected cells and immunization of sheep against malignant ovine theileriosis.

Malignant ovine theileriosis caused by Theileria lestoquardi is an economically important disease infecting small ruminants in the Sudan. The disease causes massive losses among sheep in many regions of Northern Sudan. The present studies were done to isolate lymphoblastoid cells infected with malignant ovine theileriosis and attenuate them by passage using culture media to develop and produce schizonts candidate vaccine, then test its efficacy and safety by exposing immunized lambs to field challenge in an area endemic with T. lestoquardi. In the present experiments we isolated and established an in vitro culture of T. lestoquardi infected lymphoblast cell line. Long-term culture of T. lestoquardi infected lymphoplastoid cells was shown to result in attenuation of their virulence and lambs inoculated with different doses of such cells at passage 105 exhibited very mild reactions with fever that lasted for 1-5 days and parasitaemia of <0.2%. The experimental lambs immunized with this candidate vaccine were immune and protected when exposed to field challenge in an area endemic of ovine theileriosis, while morbidity and mortality among non-immunized animals reached 76.9% and 46.15%, respectively, and they exhibited the clinical signs of malignant ovine theileriosis that included, high fever, loss of appetite, enlargement of lymph nodes, jaundice, loss of weight and death. The present study demonstrates the efficacy and the safety of this attenuated cell line as a live attenuated candidate vaccine.

First confirmed report of outbreak of malignant ovine theileriosis among goats in Sudan.

An outbreak of malignant ovine theileriosis among goats was confirmed and documented. In this outbreak, 16 out of 22 (72.7%) goats died within 4 days showing clinical signs of malignant ovine theileriosis as well as in the postmortem findings. The goats were reared in a mixed flock with sheep in Atbara Town, Northern Sudan. The infection was detected microscopically and confirmed serologically by IFA test and molecularly by PCR technique using specific primer for Theileria lestoquardi. Hyalomma anatolicum was the most prevalent (dominant) tick species found in the farm. It is recommended to undertake future research on the role of goats on the epidemiology of malignant ovine theileriosis.

Experimental transmission of Theileria lestoquardi by developmental stages of Hyalomma anatolicum ticks.

Theileria-free Hyalomma anatolicum larvae were fed on a naturally infected sheep with Theileria lestoquardi. Resulting flat nymphs of the tick were able to transmit T. lestoquardi infection upon feeding to 3/3 susceptible sheep. Adults emerging from the same batch of larvae were also infective to 3/3 susceptible sheep when they had the infection during their larval feeding. Transmission of T. lestoquardi to sheep was confirmed through clinical monitoring, examination of blood and lymph node biopsy smears, serology using indirect immunoflourescent test, and molecular using polymerase chain reaction technique.