Antimicrobial Resistance and Current Alternatives in Veterinary Practice: A Review.

Antibiotics are commonly used to treat bacterial infections. For many years, antibiotics have been used at sub-therapeutic doses to promote animal growth and misused as prophylactics and metaphylactic on farms. The widespread and improper use of antibiotics has resulted in a serious problem, defined as antibiotic resistance by the World Health Organisation, which is a major public health threat in the 21st century. Bacteria have evolved sophisticated mechanistic strategies to avoid being killed by antibiotics. These strategies can be classified as intrinsic resistance (referring to the inherent structural or functional characteristics of a bacterial species) or acquired resistance (referring to mutations in chromosomal genes or the acquisition of external genetic determinants of resistance). In farm animals, the use of antibiotics warrants serious consideration, as their residues leach into the environment through effluents and come into contact with humans through food. Several factors have contributed to the emergence of antibiotic-resistant bacteria. This review provides an update on antibiotic resistance mechanisms, while focusing on the effects of this threat on veterinary medicine, and highlighting causal factors in clinical practice. Finally, it makes an excursus on alternative therapies, such as the use of bacteriophages, bacteriocins, antimicrobial photodynamic therapy, phytochemicals, and ozone therapy, which should be used to combat antibiotic-resistant infections. Some of these therapies, such as ozone therapy, are aimed at preventing the persistence of antibiotics in animal tissues and their contact with the final consumer of food of animal origin.

Kisspeptin and bovine follicular cysts.

The aim of this study was to investigate kisspeptin (Kp) and sexual hormone blood concentrations in healthy dairy cows (H) and in cows diagnosed with ovarian follicular cysts (FC). Forty dairy cows were enrolled in this study and divided in 2 groups of 20 subjects each. All cows underwent blood collection on the day of diagnosis and on that of heat detection, respectively. Kisspeptin 10, estradiol, and progesterone blood concentrations were assessed. All the parameters were higher in Group FC than in Group H. These results suggest that the higher steroid levels found may have determined the increase in Kp secretion in the cystic cows. This, in turn, may have directly or indirectly stimulated the sustained Luteinizing Hormone (LH) release, known to occur in dairy cystic disease.

In vivo model for mastocytosis: A comparative review.

Human mastocytosis are heterogeneous group of neoplastic diseases characterized by a different degree of uncontrolled mast cell (MC) proliferation and activation. Interestingly, human mastocytosis share several biological and clinical features with canine mast cell disorders, so called canine mast cell tumors (CMCTs). These CMCTs are the most common spontaneous cutaneous tumors found in dogs representing a valid model to study neoplastic mast cell disorders. It has been discovered that the pathological activation of c-Kit receptor (c-KitR), expressed by MCs, has been involved in the pathogenesis of neoplastic MC disorders. In this review we have focused on human mastocytosis in terms of: (i) epidemiology and classification; (ii) pathogenesis at molecular levels; (iii) clinical presentation. In addition, we have summarized animal models useful to study neoplastic MC disorders including CMCTs and murine transgenic models. Finally, we have revised therapeutic approaches mostly common in human and canine MCTs and novel tyrosine kinase inhibitors approved for CMCTs and recently translated in human clinical trials.

Fluoroquinolone and Ovariectomy in the Bitch: Physiology of the Immune System as to CD56 and CD16 Expression.

Natural killer (NK) cells are innate lymphoid cells which act against a variety of pathogens and tumours. Phenotypically they are characterized by surface markers named cluster designation (CD) antigens. CD56 and CD16 are recognized as specific NK markers in the dogs as well as in humans. Surgical interventions suppress NK cells both in rats and humans. In this direction, it has been shown that an antibiotic regimen (amoxicillin, benzylpenicillin/dihydrostreptomycin, sulfametazine/sulfamerazine/ sulfathiazole, enrofloxacin, lincomycin/spectinomycin) administered only twice is effective in preventing infections after laparatomic ovariectomy, in the bitch. On these grounds, this research will show that the administration of a fluoroquinolone (5 mg/kg of enrofloxacin, Baytril®, Bayer, Milan, Italy) one hour before and at the end of ovariectomy is able to increase CD56 and CD16 expression levels. Moreover, the antibiotic administration modifies the relative expression levels of the two CD; thus suggesting that the fluoroquinolone employed enhances the activation of a specific subset of NK cells mainly involved in body recovering during the post operative period as already observed in humans.

Immunological aspects of metritis in dairy cows: a review.

This paper reviews puerperal metritis in the cow, particularly the complex and multi-factorial pathogenesis characterized by an altered cross-talk among infectious agents, endocrine and immune systems. Uterine infections impair fertility and is one of the main causes of economic losses in dairy production. The early postpartum is a period characterized by an increased exposition to infectious agents and the disruption of the metabolic homeostasis, leading to endocrine and immunologic disorders. Dysregulation of uterine defence mechanisms results in the development of metritis. Because there is a complex interaction between infectious, endocrine and immune factors during metritis, there is need to use safer and cheaper drugs which are able to strengthen the anti-infective actions of the routine therapies.

Tyrosine kinase inhibitors (TKIs) in human and pet tumours with special reference to breast cancer: a comparative review.

Tyrosine kinase receptors (TKRs) play a key role in tumour cell proliferation and survival since they are involved in endothelial cell activation leading to tumour neoangiogenesis. In particular, vascular endothelial growth factor receptors (VEGFRs), platelet-derived growth factor receptor (PDGFR), stem cell factor receptor (c-KitR), and colony-stimulating factor 1 (CSF-1) are overexpressed or constitutively activated in human and pet malignancies. A variety of small molecule inhibitors targeting specific tyrosine kinases (known as tyrosine kinase inhibitors or TKIs) have recently been approved, or are under investigation, for the treatment of human cancer. TKI application in animal cancer is however relatively recent. This review aims to illustrate the major aspects of tyrosine kinase dysfunctions, with special regard to human and animal cancer of the mammary gland, providing an update on the background of the anti-angiogenic and anti-neoplastic properties of TKIs in human and veterinary cancer.