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.

Evaluation of antibacterial oxygen/ozone mixture in vitro activity on bacteria isolated from cervico-vaginal mucus of cows with acute metritis.

Ozone is an oxidating gas showing a strong microbicidal activity on bacteria, fungi, viruses and protozoa. The aim of this study was to test the in vitro bacteriocidal action of an Ozone/Oxygen gas mixture on bacteria isolated from the cervico-vaginal mucus of cows affected by acute metritis. A pilot study was initially carried out on reference strains (Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923 and Mycoplasma bovigenitalium ATCC 19852) that were tested with three different treatments: a control positive baseline group (B-group) was incubated without gas treatment, a control positive oxygen group (O2-group) was treated with pure oxygen 100%, and the treated group (T-group) was exposed to a gaseous constant flow of an Ozone/Oxygen mixture, at 50, 35, 20 µg Ozone/ml and for 5, 3 and 1 min for every different Ozone concentration. In both positive control groups, the number of colony forming units (CFU) per ml was higher than 300 CFU/ml (E. coli and S. aureus) and higher than 30 CFU/ml for M. bovigenitalium, after incubation. The T-groups showed a minimal bacterial growth equal to or lower than 1 CFU/ml per plate. Based on the results of the pilot study, a second phase was performed on bacteria isolated from the cervico-vaginal mucus (Klebsiella pneumoniae, Enterobacter agglomerans, E. coli, Proteus mirabilis and M. bovigenitalium) using the lower concentration of 20 µg/ml of Ozone for the minimum exposure time of 1 min. The E. coli and S. aureus reference strains and the clinical isolates (K. pneumoniae, E. agglomerans, E. coli, P. mirabilis) were incubated at 37 °C for 48 h and the colonies were manually counted at 24 h and 48 h following inoculation. The cultures of M. bovigenitalium (both ATCC and clinical isolate) were incubated in a jar with modified atmosphere conditions with 5% CO2 at 37 °C for 4-7 days and colony counting was performed. The second phase showed a low number of CFUs (equal to or less than 7 CFU/ml) for the clinical isolates K. pneumoniae, E. agglomerans, E. coli and P. mirabilis, and, of note, for M. bovigenitalium, both ATCC and clinical isolate, the growth was completely inhibited. Ozone was demonstrated to have a bacteriocidal activity. This study encourages further research of in vivo application of low doses of gaseous Ozone for the treatment of metritis in cows by using minimal exposure times.

Scopolamine administration in repeat breeder cows on the day of heat.

Scopolamine is a parasympatholytic drug that can modulate uterine contractile activity. Based on the hypothesis that deficiency in uterine contractility is a cause of Repeat Breeder (RB) syndrome in cows, this study aimed to evaluate the efficacy of scopolamine administration in RB cows, on the day of heat, in increasing conception rates. Forty RB cows were randomly divided into treated group [T; 20 cows treated with scopolamine butylbromide 40 mg/100 kg of body weight (BW) by the intramuscular (IM) route after clinical confirmation of heat (T0)] and the control group [C; 20 cows treated with 2 mL/100 kg of BW of saline solution, IM, at T0]. Twelve hours later (T1), all of the cows were artificially inseminated (AI). Blood plasma-progesterone (P4), hydroxyproline, and prostaglandin F2α metabolite (PGFM), concentrations were assessed at T0 and T1. Additionally, the uterine tone was evaluated by transrectal palpation. Conception rates were recorded. Drug administration increased the conception rates in group T to 80% unlike group C (25%) (P < 0.0001). Higher PGFM concentration levels were registered in the treated group than in the control group. The higher PGF2α secretion in pregnant cows of the T group may have reduced the P4 levels, making conception possible. Scopolamine administration at the time of heat can improve uterine contractility. This makes it more suitable for promoting conception in RB cows, where hormonal alterations and contractile and biochemical deficits are responsible for the syndrome.

Kisspeptin-10 and gonadotropin inhibiting hormone during pregnancy in dairy cows.

Recently, two different molecules have been discovered to play an important role in reproduction: kisspeptin (Kp) and gonadotropin inhibiting hormone (GnIH). The aim of this study was to establish the trend of kisspeptin 10 (Kp­10) and GnIH concentrations, during all phases of pregnancy in cattle, in order to understand their possible role in the physiology of pregnancy. To examine the correlation between these hormones and steroid hormones, cortisol and oestradiol 17ß (E2) were also analyzed. Eighty pregnant cows were enrolled and the pregnancy was divided into 8 periods of 30 days each (from 30­60 days to 240­270 days). Blood samples were collected from all cows, once only for cow. Kp­10, GnIH, cortisol and E2 were measured in sera. After an initial plateau, Kp­10 concentrations increased at 90­120 days and then decreased until 180­210 days, undergoing a further increase until 240­270 days. GnIH concentrations decreased until 90­120 days, then increased until the end of gestation. These trends were opposing until 180­210 days, whereat concentrations of both increased until the end of gestation. Cortisol concentrations were homogenous at all times, except at the final period, in which they were higher. E2 showed two peaks, at 90­120 days and 240­270 days. The trends in Kp­10 and GnIH concentrations suggest that these two hormones might act to maintain the delicate endocrine equilibrium of pregnancy.

The Use of Abdominal Ultrasound to Improve the Cryptorchidectomy of Pigs.

This study aimed to describe a technique to locate retained testes in pigs by means of ultrasound examination and thereafter proceed with cryptorchidectomy. Fifty-two monolateral cryptorchid pigs were enrolled. After anaesthesia, 42 pigs (Group U) underwent ultrasound examination before cryptorchidectomy, and 10 pigs (Group C) were used as control group without ultrasonography. The total duration of anaesthesia, ultrasound examination, and surgery was evaluated. In 10 pigs of Group U and 10 pigs of Group C, the heart rate (HR), respiratory rate (RR), and body temperature (T) were monitored to assess intraoperative pain response. An operator used the Piglet Grimace Scale (PGS) to assess postoperative pain. In Group U, the total time required for anaesthesia and surgery was less than Group C. No intra- or postoperative complications were reported in both groups. For HR, RR, and T, no statistically significant differences were observed. During the postoperative pain assessment, the highest pain scores were recorded at T6 (6 h after surgery). Ultrasound examination was found to be a valid technique for locating the retained testis in the abdomen in cryptorchid pigs and to reduce the duration of the surgery.

Histopathologic and MR Imaging Appearance of Spontaneous and Radiation-Induced Necrosis in Uveal Melanomas: Initial Results.

Necrosis in uveal melanomas can be spontaneous or induced by radiotherapy. The purpose of our study was to compare the histopathologic and MRI findings of radiation-induced necrosis of a group of proton beam-irradiated uveal melanomas with those of spontaneous necrosis of a control group of patients undergoing primary enucleation. 11 uveal melanomas who had undergone proton beam radiotherapy, MRI and secondary enucleation, and a control group of 15 untreated uveal melanomas who had undergone MRI and primary enucleation were retrospectively identified. Within the irradiated and nonirradiated group, 7 and 6 eyes with histological evidence of necrosis respectively, were furtherly selected for the final analysis; the appearance of necrosis was assessed at histopathologic examination and MRI. Irradiated melanomas showed a higher degree of necrosis as compared with nonirradiated tumors. Irradiated and nonirradiated lesions differed based on the appearance and distribution of necrosis. Irradiated tumors showed large necrotic foci, sharply demarcated from the viable neoplastic tissue; nonirradiated tumors demonstrated small, distinct foci of necrosis. Radiation-induced necrosis, more pigmented than surrounding viable tumor, displayed high signal intensity on T1-weighted and low signal intensity on T2-weighted images. The hemorrhagic/coagulative necrosis, more prevalent in nonirradiated tumors (4 out of 6 vs. 1 out of 7 cases), appeared hyperintense on T2-weighted and hypointense on T1-weighted images. Our study boosts the capability to recognize radiation-induced alterations in uveal melanomas at MRI and may improve the accuracy of radiologists in the evaluation of follow-up MR examination after radiotherapy.

Diagnostic methods and therapeutic options of uveal melanoma with emphasis on MR imaging-Part I: MR imaging with pathologic correlation and technical considerations.

Uveal melanoma is a malignant neoplasm that derives from pigmented melanocytes of the uvea and involves, in order of decreasing prevalence, the choroid, ciliary body and iris. Its prognosis is related to histopathologic and genetic features, tumor size and location, extraocular extension. The diagnosis is fundamentally based on clinical evaluation (ophthalmoscopy, biomicroscopy) and ultrasonography. MRI is useful in case of untransparent lens or subretinal effusion. Moreover, MRI has a significant role to confirm the diagnosis, in the evaluation of the local extent of the disease with implications for treatment planning, and in the follow-up after radiotherapy treatment. Uveal melanoma can show different morphologic features (lentiform, dome or mushroom shape) and often determines retinal detachment. MR appearance of uveal melanoma mainly depends on the melanin content. Uveal melanoma typically displays high signal intensity on T1-weighted images and low signal intensity on T2-weighted images. Nevertheless, imaging appearance may be variable based on the degree of pigmentation and the presence of areas of necrosis or cavitation. Differential diagnosis includes other uveal lesions. The radiologists and in particular MRI play a significant role in the clinical management of uveal melanoma. The purpose of this pictorial review is to provide the radiologists with awareness about diagnostic methods and therapeutic options of uveal melanoma. In the present first section we summarize the MR anatomy of the eye and describe ophthalmological and radiological imaging techniques to diagnose uveal melanomas, with emphasis on the role of MR imaging. Additionally, we review MR imaging appearance of uveal melanomas.

Diagnostic methods and therapeutic options of uveal melanoma with emphasis on MR imaging-Part II: treatment indications and complications.

Therapy of uveal melanoma aims to preserve the eye and its function and to avoid metastatic dissemination. The treatment choice is difficult and must keep into account several factors; the therapeutic strategy of uveal melanoma should therefore be personalized, sometimes requiring to combine different treatment techniques. Nowadays globe-sparing radiotherapy techniques are often preferred to enucleation. Plaque brachytherapy, the most commonly used eye-preserving therapy, is suitable for small- and medium-sized uveal melanomas. Proton beam radiotherapy is indicated for tumours with noticeable size, challenging shape and location, but is more expensive and less available than brachytherapy. Enucleation is currently restricted to advanced tumours, uveal melanomas with orbital or optic nerve involvement, blind and painful eyes because of treatment-related complications (neovascular glaucoma, chronic inflammatory processes). The effect of proton beam therapy on neoplastic tissue is related to direct cytotoxic action of the radiations, impairment of neoplastic vascular supply and immunologic response. Complications after radiotherapy are frequent and numerous and mainly related to tumour thickness, radiation dose and distance between the tumour and optic nerve. The purpose of this pictorial review is to provide the radiologists with awareness about diagnostic methods and therapeutic options of uveal melanoma. In the present second section, we discuss the therapeutic management of uveal melanoma, describing the main ocular-conserving radiotherapic techniques. We subsequently present an overview of the effects of radiations on neoplastic tissue. Lastly, we review ocular complications following radiotherapy that should be evaluated by radiologists during follow-up MRI examinations.

Kisspeptin in the early post-partum of the dairy cow.

Recently, a new molecule, kisspeptin (Kp), and in particular Kisspeptin 10 (Kp10), was implicated in stimulating the hypothalamic-pituitary-gonadal axis. The aim of this study was to evaluate circulating Kp10 levels in the early post-partum period of the dairy cow. Blood samples were collected from 40 dairy cows, at 10 (T10), 12 (T12), 14 (T14) and 16 (T16) days after calving. Progesterone (P4) levels were evaluated using ELISA, and levels of oestrogens (E2) and Kp were evaluated using a radio-immunologic method. After an initial plateau, Kp10 significantly increased at T14 and decreased at T16. The P4 and E2 mean serum values remained in the physiological range. It is likely that Kp10 enhanced hypothalamic GnRH release as well as pituitary gonadotropin secretion, thus promoting follicular growth and the increase in E2 levels, which might have further enhanced Kp10 release through a positive feedback loop. To our best knowledge, this is the first report on the range of Kp10 blood concentration during the early post-partum period in the dairy cow. The results of our study will increase our current understanding of the complex neuro-endocrine crosstalk underlying the resumption of ovarian cyclicity in the dairy cow.

Dosimetric changes with computed tomography automatic tube-current modulation techniques.

The study is aimed at a verification of dose changes for a computed tomography automatic tube-current modulation (ATCM) technique. For this purpose, anthropomorphic phantom and Gafchromic® XR-QA2 films were used. Radiochromic films were cut according to the shape of two thorax regions. The ATCM algorithm is based on noise index (NI) and three exam protocols with different NI were chosen, of which one was a reference. Results were compared with dose values displayed by the console and with Poisson statistics. The information obtained with radiochromic films has been normalized with respect to the NI reference value to compare dose percentage variations. Results showed that, on average, the information reported by the CT console and calculated values coincide with measurements. The study allowed verification of the dose information reported by the CT console for an ATCM technique. Although this evaluation represents an estimate, the method can be a starting point for further studies.

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.

Corrigendum: Clinical and Research Activities at the CATANA Facility of INFN-LNS: From the Conventional Hadrontherapy to the Laser-Driven Approach.

[This corrects the article on p. 223 in vol. 7, PMID: 28971066.].

Clinical and Research Activities at the CATANA Facility of INFN-LNS: From the Conventional Hadrontherapy to the Laser-Driven Approach.

The CATANA proton therapy center was the first Italian clinical facility making use of energetic (62 MeV) proton beams for the radioactive treatment of solid tumors. Since the date of the first patient treatment in 2002, 294 patients have been successful treated whose majority was affected by choroidal and iris melanomas. In this paper, we report on the current clinical and physical status of the CATANA facility describing the last dosimetric studies and reporting on the last patient follow-up results. The last part of the paper is dedicated to the description of the INFN-LNS ongoing activities on the realization of a beamline for the transport of laser-accelerated ion beams for future applications. The ELIMED (ELI-Beamlines MEDical and multidisciplinary applications) project is introduced and the main scientific aspects will be described.

Uveal melanoma: quantitative evaluation of diffusion-weighted MR imaging in the response assessment after proton-beam therapy, long-term follow-up.

PURPOSE: The purpose of this prospective study was to investigate the proton-beam-induced changes in apparent diffusion coefficient (ADC) values of ocular melanoma treated with proton-beam therapy (PBT) in patients undergoing long-term magnetic resonance imaging (MRI) follow-up and to assess whether variations in ADC constitute a reliable biomarker for predicting and detecting the response of ocular melanoma to PBT. METHODS: Seventeen patients with ocular melanoma treated with PBT were enrolled. All patients underwent conventional MRI and diffusion-weighted imaging (DWI) at baseline and 1, 3, 6, and 18 months after the beginning of therapy. Tumor volumes and ADC values of ocular lesions were measured at each examination. Tumor volumes and mean ADC measurements of the five examination series were compared; correlation of ADC values and tumor regression was estimated. RESULTS: Mean ADC values of ocular melanomas significantly increased already 1 month after therapy whereas tumor volume significantly decreased only 6 months after therapy. Pretreatment ADC value of ocular melanomas and early change in ADC value 1 month after therapy significantly correlated with tumor regression. CONCLUSIONS: In ocular melanoma treated with PBT, ADC variations precede volume changes. Both pretreatment ADC and early change in ADC value may predict treatment response, thus expanding the role of DWI from diagnostic to prognostic.

Intensity-modulated radiotherapy for relapsed malignant pleural mesothelioma.

The use of novel radiotherapy techniques is widely increasing, allowing clinicians to treat diseases that were previously difficult to treat with radiation therapy. Malignant pleural mesothelioma is a clear example of this clinical challenge. We describe our first experience with intensity-modulated radiotherapy technique which was used to treat a 73-year-old patient with multiple relapsing malignant pleural mesothelioma. Intensity-modulated radiation therapy has allowed to respect the QUANTEC (quantitative analyses of normal tissue effects in the clinic) dose constraints, patient has experienced a 14 months progression-free time, without relevant subacute or late lung toxicity.

Role, timing and technique of radiotherapy in pediatric pleuropulmonary synovial sarcoma.

The management of pediatric thoracic synovial sarcoma remains a matter of debate in clinical oncology, especially as regard to the local control of the disease. Surgery remains the gold standard, while the role and timing of radiotherapy is still controversial. We report a 14-year-old male, who has not received proper treatment at the time of diagnosis and initial management. Intensity-modulated irradiation was performed only at relapse, as a salvage treatment and, at 10-month follow-up, the young patient was free from relapse, without significant acute and subacute toxicity. We discuss the role and timing of radiotherapy in thoracic synovial sarcoma, a disease in which the need to increase local control should be placed in the foreground.

Locally advanced rectal cancer: Qualitative and quantitative evaluation of diffusion-weighted MR imaging in the response assessment after neoadjuvant chemo-radiotherapy.

PURPOSE: to investigate the added value of qualitative and quantitative evaluation of diffusion weighted (DW) magnetic resonance (MR) imaging in response assessment after neoadjuvant chemo-radiotherapy (CRT) in patients with locally advanced rectal cancer (LARC). METHODS: 31 patients with LARC (stage ≥ T3) were enrolled in the study. All patients underwent conventional MRI and DWI before starting therapy and after neoadjuvant CRT. All patients underwent surgery; pathologic staging represented the reference standard. For qualitative analysis, two radiologists retrospectively reviewed conventional MR images and the combined set of conventional and DW MR images and recorded their confidence level with respect to complete response (ypCR). For quantitative analysis, tumor's apparent diffusion coefficient (ADC) values were measured at each examination. ADC pre-CRT, ADC post-CRT and Δ ADC post-ADC pre of the three groups of response (ypCR, partial response ypPR, stable disease ypSD) were compared. Receiver-operating characteristics (ROC) curve analysis was employed to investigate the discriminatory capability for ypCR, responders (ypCR, ypPR) and ypSD of each measure. RESULTS: addition of DWI to conventional T2-weighted sequences improved diagnostic performance of MRI in the evaluation of ypCR. A low tumor ADC value in the pre-CRT examination, a high ADC value in the post-CRT examination, a high Δ ADC post-ADC pre [>0.3 (×10(-3) mm(2)/s)] were predictive of ypCR. CONCLUSIONS: DW sequences improve MR capability to evaluate tumor response to CRT. Nevertheless, no functional MR technique alone seems accurate enough to safely select patients with ypCR.

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.

Influence of hCG on inducible nitric oxide synthase gene expression in ram testicular arteries.

UNLABELLED: Background. Experimental evidence suggests a relationship between the vasodilatory effect of hCG and the NOS system in the testis. The influence of hCG administration on testicular vascular NOS gene expression has not been fully investigated. OBJECTIVE: This study aimed to evaluate the presence of the nitric oxide syntheses gene in ram testicular arteries and the influence of hCG administration on its expression. MATERIALS AND METHODS: Both testicular arteries of sixteen rams were extracted before and after i.v. administration of 5000 IU of hCG or placebo. The expression of the iNOS gene was investigated by real time PCR. Data were analyzed by means of Wilcoxon and Mann-Whitney tests. A p value of < 0.05 was considered statistically significant. RESULTS: PCR revealed the presence of iNOS mRNA in all basal samples but the expression of the iNOS gene was significantly reduced in all arteries obtained 24 h after the administration of either hCG or placebo. A significant reduction in the expression of iNOS gene was observed in the testicular arteries extracted after 24 h in both treated and placebo groups. On the other hand hCG stimulation did not significantly influence iNOS expression following its administration compared to a placebo. CONCLUSION: Ram testicular arteries express the iNOS gene but hCG stimulation did not significantly influence iNOS expression. A significant reduction in the expression of this gene was observed in the testicular arteries extracted after 24 h in both treated and placebo groups, suggesting that iNOS expression on the testicular artery could be influenced by the spermatic vessel ligation of the controlateral testis.