Compounds from the Medicines for Malaria Venture Box Inhibit In Vitro Growth of Babesia divergens, a Blood-Borne Parasite of Veterinary and Zoonotic Importance

Babesiosis is an infectious disease with an empty drug pipeline. A search inside chemical libraries for novel potent antibabesial candidates may help fill such an empty drug pipeline. A total of 400 compounds (200 drug-like and 200 probe-like) from the Malaria Box were evaluated in the current study against the in vitro growth of Babesia divergens (B. divergens), a parasite of veterinary and zoonotic importance. Novel and more effective anti-B. divergens drugs than the traditionally used ones were identified. Seven compounds (four drug-like and three probe-like) revealed a highly inhibitory effect against the in vitro growth of B. divergens, with IC50s ≤ 10 nanomolar. Among these hits, MMV006913 exhibited an IC50 value of 1 nM IC50 and the highest selectivity index of 32,000. The atom pair fingerprint (APfp) analysis revealed that MMV006913 and MMV019124 showed maximum structural similarity (MSS) with atovaquone and diminazene aceturate (DA), and with DA and imidocarb dipropionate (ID), respectively. MMV665807 and MMV665850 showed MMS with each other and with ID. Of note, a high concentration (0.75 IC50) of MMV006913 caused additive inhibition of B. divergens growth when combined with DA at 0.75 or 0.50 IC50. The Medicines for Malaria Venture box is a treasure trove of anti-B. divergens candidates according to the obtained results.

Potential Role of Hepatozoon canis in a Fatal Systemic Disease in a Puppy

Canine hepatozoonosis caused by Hepatozoon canis is an emerging disease in Europe. Clinical pictures vary from subclinical to life-threatening and non-specific clinical signs are predominantly reported. A 2-month-old female puppy originating from Southern Italy was adopted and moved to Northern Italy. Then, the dog was brought to a local veterinary practice for gastrointestinal signs, migrating lameness and pruritic dermatitis, and then tested positive for Hepatozoon spp. gamonts at the blood smear. After treatment with imidocarb dipropionate and doxycycline, the dog showed an initial clinical improvement. However, gastrointestinal signs recurred, and diffuse superficial pyoderma appeared on the thoracolumbar region, along with fever, lethargy, and weight loss. Eight months from the first onset of clinical signs, the dog was referred to a veterinary clinic and subjected to complete blood count, urine and fecal analysis, along with abdominal ultrasonography, whole-body CT and gastroduodenal endoscopy. Skin biopsies and blood samples were subjected to a PCR-coupled sequencing protocol, which scored both positive for H. canis. Alterations were consistent with a pre-existing cholangiohepatitis and multiple acquired extrahepatic shunts secondary to portal hypertension. The dog was euthanatized due to a clinical worsening two months later. The potential role of H. canis in the systemic disease observed, clinic-pathological findings and epizootiological implications are discussed.

↵​Haemato-biochemical and Therapeutic Studies on Ovine Babesiosis in Kashmir

Background: The clinical study was designed to evaluate the haemato-biochemical changes in sheep affected with babesiosis and therapeutic regimes of various drugs used against babesiosis. Methods: A total of 24 clinically affected sheep with 6 animals in each group were selected for the haemato-biochemical and therapeutic study. The diagnosis was based on clinical manifestations, microscopic examination of blood smears and molecular confirmation of Babesia by PCR technique. For therapeutic study Group I, II, III and IV were treated with imidocarb dipropionate, imidocarb dipropionate+oxytetracycline, diminazene aceturate and diminazene aceturate+oxytetracycline, respectively. Result: The clinical signs recorded were high fever, pale mucous membranes, presence of ticks, inappetence, coffee-coloured urine and diarrhoea. The vectors identified were Haemaphysalis ticks. Hb, PCV, TEC, total protein, albumin, calcium, phosphorus and blood glucose were significantly (P less than 0.05) lower in the diseased group as compared to healthy animals while TLC, globulin and iron levels were significantly (P less than 0.05) higher compared to the healthy control group. The study revealed that the combination of imidocarb dipropionate and oxytetracycline was highly effective for ovine babesiosis.

Relationship between Changes in Hematological Parameters, Levels of Acute Phase Proteins and Redox Homeostasis during Acute Babesia canis Infection in Dogs

Hemolysis and systemic acute inflammation characterize canine babesiosis caused by the intraerythrocytic protozoan parasite Babesia canis. Our hypothesis was that blood redox homeostasis of patients that suffered acute B. canis infection might be disturbed even after treatment with imidocarb-dipropionate and successful clinical recovery. Eight owner dogs with acute B. canis infection were used for this study. We analyzed the complete blood count, acute phase proteins (ceruloplasmin, haptoglobin, paraoxonase-1) in the serum, antioxidant enzymes (catalase and glutathione peroxidase) in the erythrocytes, and oxidative stress markers (malondialdehyde in erythrocytes and thiol groups in serum) at presentation and 15 days after treatment. Results were evaluated by corresponding statistical tests. At presentation, anemia, low/normal leukocyte count and severe thrombocytopenia occurred together with increased ceruloplasmin, haptoglobin levels within the reference interval, decreased paraoxonase-1 and compromised antioxidant defense in the red blood cells. After treatment and successful clinical recovery, hematological values generally fitted within the reference intervals, acute phase proteins were within the physiological levels in the majority of cases and the activities of the antioxidant enzymes were increased. However, elevated malondialdehyde levels indicated increased oxidative damage of erythrocytes that remained as a deleterious sequel despite a successful clinical recovery of the dogs.

PREVENTION OF PYROPLASMIDOSES OF HORSES IN GORNY ALTAI

A high incidence of pyroplasmidoses (hemosporidial infections) of horses in the farms of Gorny Altai presupposes regular preventive measures against this disease. The main preventive measure is early specific chemotherapy of horses in spring. In this connection, we carried out a study on the species identification of the pathogen and the assessment of prophylactic efficacy of an antipyroplasmid drug. The studies were carried out in the livestock farm Kurmanov Ch.A. in the Ulagansky District of the Altai Republic. The blood samples from 20 horses were tested by nested polymerase chain reaction (nested PCR) in the presence of genus-specific primers for DNA of the protozoan blood parasites Babesia spp. and Theileria spp. The species membership of the identified infectious agents was established by determining nucleotide sequences of the PCR products. When studying prophylactic efficacy, "Babezan, 12%" was administered intramuscularly to the experimental group of horses (44 animals) at the rate of 2.5 mg of active substance per 1 kg of animal weight; the control group of horses (16 animals) was not given the drug. The blood samples examined were found to contain the DNA of Theileria spp. in 17 animals (85%), which was identified as Theileria equi. Early chemotherapy of the horses with "Babezan, 12%" based on the active substance imidocarb dipropionate at 2.5 mg per 1 kg of animal weight made it possible to prevent morbidity for 41 days.

Bovine Babesioses and Control

Bovine babesiosis is considered one of the most economically important tick-borne diseases in tropical and subtropical areas. Thus, it is important to understand the disease in terms causative agent, vectors, hosts, and distribution. Babesia is the causative agent of the disease and has a life cycle both in the invertebrate and vertebrate hosts. The major bovine species are B. bovis, B. bigemina, found in the tropics and sub tropics while B. divergens and B. major are found in the temperate regions. Bovine babesiosis is transmitted by the one-host cattle ticks, formerly in the genus Boophilus and now Rhipicephalus. In endemic areas are tick management, immunization, and anti-babesia drugs or by a combination. Chemotherapy is important for controlling the disease either to treat field cases or to control artificially induced infections. Conventional drugs for treating bovine babesiosis are Imidocarb dipropionate and Diminazene aceturate. Ticks are controlled by application of acaricides, but tick resistance and environmental pollution are drawbacks.

Imidocarb Dipropionate Lacks Efficacy against Theileria haneyi and Fails to Consistently Clear Theileria equi in Horses Co-Infected with T. haneyi

Control of Theileria equi, the primary cause of equine theileriosis, is largely reliant on acaracide use and chemosterilization with imidocarb dipropionate (ID). However, it is currently unknown if ID is effective against Theileria haneyi, the recently identified second causative agent of equine theileriosis, or if the drug maintains effectiveness against T. equi in the presence of T. haneyi co-infection. The purpose of this study was to address these questions using ID treatment of the following three groups of horses: (1) five T. haneyi infected horses; (2) three T. haneyi-T. equi infected horses; and (3) three T. equi-T. haneyi infected horses. Clearance was first evaluated using nPCR for each Theileria sp. on peripheral blood samples. ID failed to clear T. haneyi in all three groups of horses, and failed to clear T. equi in two of three horses in group two. For definitive confirmation of infection status, horses in groups two and three underwent splenectomy post-treatment. The T. equi-nPCR-positive horses in group two developed severe clinical signs and were euthanized. Remaining horses exhibited moderate signs consistent with T. haneyi. Our results demonstrate that ID therapy lacks efficacy against T. haneyi, and T. haneyi-T. equi co-infection may interfere with ID clearance of T. equi.

Clinical and laboratory aspects found in canine with trypanosoma spp infection in north Mato Grosso

Trypanosoma is a hemoflagellate protozoan that infects a variety of animal species and is transmitted in different ways. It is a zoonosis and anthropozoonosis of great importance in veterinary medicine. The present work aims to describe the clinical and laboratory alterations in a free-living dog in a rural area, infected by Trypanosoma spp, treated in the municipality of Sinop, north of Mato Grosso. Blood samples were collected for blood count, alanine aminotransferase (ALT) activity, creatinine, creatine kinase concentrations. The results found were a normochromic microcytic anemia, lymphopenia, trypomastigote forms of Trypanosoma spp. ALT and creatinine measurements were normal, but the serum creatine kinase level was above normal limits. Imidocarb dipropionate at a dose of 7 mg / kg subcutaneously in a single dose was prescribed.