First study on molecular epidemiology of caseous lymphadenitis in slaughtered sheep and goats in Duhok Province, Iraq

Background

Caseous lymphadenitis (CLA) is a chronic suppurative bacterial infection caused by Corynebacterium pseudotuberculosis (C. pseudotuberculosis) affecting superficial and internal lymph nodes and internal organs of small ruminants.

Aims

Through the use of molecular methods, this study aimed to estimate the prevalence of CLA and its contributing factors as well as the degree of genetic diversity and epidemiological relationships among C. pseudotuberculosis isolates from slaughtered sheep and goats in various districts of Duhok Province, Iraq.

Methods

A total of 18,836 carcasses (15,775 sheep and 3,061 goats) were inspected by veterinarians at slaughterhouses [Duhok-Sumel (2,453 sheep + 627 goats), Zakho (6,000 sheep), Bardarash (1,117 sheep + 379 goats), Amedi (413 sheep + 178 goats) and Akre (5,792 sheep + 1,877 goats)] in Duhok Province for detection the prevalence rate of CLA using molecular techniques.

Results

The prevalence of the disease was 0.94% and 1.93% in sheep and goats, respectively. Sheep in Duhok-Sumel and goats in Amedi were at a higher risk of infection than the animals in another location, with a prevalence rate of 4.31% and 6.18%, respectively. Sheep and goats of older age were more susceptible. Females were more susceptible than males in all districts except Duhok-Sumel where the reverse was true. ERIC-PCR analysis grouped the bacterial isolates into 11 different genotypes. The maximum likelihood phylogenetic tree of partial sequences of the 16S rRNA gene sequences of C. pseudotuberculosis revealed no divergent sequences discovered in this study.

Conclusion

A strict control program needs to be applied to reduce the entrance of pathogen from neighboring countries.

Combination therapy with immune checkpoint inhibitors (ICIs); a new frontier

Recently, immune checkpoint inhibitors (ICIs) therapy has become a promising therapeutic strategy with encouraging therapeutic outcomes due to their durable anti-tumor effects. Though, tumor inherent or acquired resistance to ICIs accompanied with treatment-related toxicities hamper their clinical utility. Overall, about 60-70% of patients (e.g., melanoma and lung cancer) who received ICIs show no objective response to intervention. The resistance to ICIs mainly caused by alterations in the tumor microenvironment (TME), which in turn, supports angiogenesis and also blocks immune cell antitumor activities, facilitating tumor cells' evasion from host immunosurveillance. Thereby, it has been supposed and also validated that combination therapy with ICIs and other therapeutic means, ranging from chemoradiotherapy to targeted therapies as well as cancer vaccines, can capably compromise tumor resistance to immune checkpoint blocked therapy. Herein, we have focused on the therapeutic benefits of ICIs as a groundbreaking approach in the context of tumor immunotherapy and also deliver an overview concerning the therapeutic influences of the addition of ICIs to other modalities to circumvent tumor resistance to ICIs.

Histopathological and Serological Analysis of Aborted Ewes and Neonatal Death with Toxoplasma gondii in Duhok City, Kurdistan-Iraq

This study was carried out on seven flocks of ewes suffered from late abortion and neonatal mortality with the prevalence rate of infection reported as 13.95%. The blood and tissue samples were collected from the aborted ewes in several flocks of Duhok province, Kurdistan Region, Iraq. Serological analysis indicated that all the aborted ewes were confirmed positive for agglutination to Toxoplasma gondii (T. gondii)antibody. The investigation of the aborted fetuses showed the blood-stained fluid in the thoracic and abdominal cavity. Most of the aborted fetuses had also enlarged, congested, and friable livers and lungs. The placenta was swollen, reddish, and friable, and its cotyledons also spotted with whitish foci. T. gondii tachyzoites were also demonstrated in the placental sections of some aborted ewes. Severe congestion, necrosis, and infiltration of multinucleated cells were the most predominant histopathological changes of the aborted fetuses, as well as presented tissue cysts, tachyzoites, and bradyzoites in the liver, brain, heart, and lung. There were also several clusters of dark purple banana-shaped T. gondii tachyzoites within the brain and heart tissues in most of the examined aborted fetuses in different flocks. T. gondii tachyzoites were also detected from the peritoneal ascites of mice inoculated experimentally 12 days following the infection. Moreover, T. gondii tissue cysts were detected from the impression smears of the mice brains 32 days after the infection. Accordingly, the demonstration of T. gondii in Giemsa-stained impression smears associated with characteristic histopathological changes of different organs is a great fundamental method for the diagnosis of T. gondii in aborted cases.