Common superficial and deep cutaneous bacterial infections in domestic animals: A review

The skin covers the external surface of animals, and it is constantly exposed to and inhabited by different microorganisms, including bacteria. Alterations in the skin barrier allow commensal and/or pathogenic bacteria to proliferate and penetrate deep into the lower layers of the skin. Being the first barrier to the external environment, the skin is prone to injuries, allowing the penetration of microorganisms that may lead to severe deep infections. Companion animals, especially dogs, are prone to bacterial infections, often secondary to allergic dermatitis. When environmental conditions are unfavorable, horses, cattle, sheep, and goats can develop superficial infections, such as those caused by Dermatophilus congolensis. Deep inflammation is commonly caused by Mycobacterium spp., which results in granulomatous to pyogranulomatous dermatitis and panniculitis. Likewise, bacteria such as Nocardia spp. and Actinomyces spp. can cause deep pyogranulomatous inflammation. Bacteria that lead to deep necrotizing lesions (eg, necrotizing fasciitis/flesh-eating bacteria) can be severe and even result in death. This review includes an overview of the most common cutaneous bacterial infections of domestic animals, highlighting the main features and histologic morphology of the bacteria, cutaneous structures involved, and the type of inflammatory infiltrates.

Canine Models of Inflammatory Skin Diseases and Their Application in Pharmacological Research

The purpose of this article is to provide an overview of existing pharmacological models of canine dermatitis. Canine models of dermatitis have contributed significantly to our current understanding of the pathology of dermatitis and to the development of corresponding pharmacological interventions. Specifically, canine atopic dermatitis (AD) is reviewed here, as it is one of the most common inflammatory skin diseases in dogs. Canine AD also shares clinicopathological features with human AD, making the dog a natural and optimal model for human disease. Thus, pharmacological models of canine AD may be uniquely applicable to human pharmacological research. In this article, particular attention is dedicated to relevant in vivo, in vitro, and ex vivo models of canine AD, skin barrier defect models, pruritus models, and skin immunology models. Additionally, models of superficial pyoderma and food allergy are also discussed. With understanding of findings from canine models, researchers can select the most salient features for future pharmacological drug development. © 2023 Wiley Periodicals LLC.

Personalized Medicine in Kidney Disease

The Special Issue "Personalized Medicine in Kidney Disease" is focused on the importance of customized medicine in nephrology as it represents one of the main characteristics of successful therapeutic results [...].

Comparison of the quantity and antimicrobial activity of host defence peptides in ear canals between healthy and atopic dogs: A preliminary study

BACKGROUND

Host defence peptides (HDPs) are involved in cutaneous immune defence. The secretion of HDPs in the ears of healthy normal and noninfected atopic dogs has not been measured.

HYPOTHESES/OBJECTIVES

The aim of this study was to quantify the concentrations of β-defensins (cBD3)-like and cathelicidin (cCath) HDPs in ears of healthy and atopic dogs without infectious otitis, additionally to evaluate the antimicrobial effect of the HDPs obtained.

ANIMALS

Ten healthy and 20 atopic dogs with mild inflammatory, noninfectious otitis were included.

MATERIALS AND METHODS

Absence of infection was determined by cytological evaluation, and the severity of clinical signs, if present, was assessed by a previously validated score (Otitis Externa Scoring System for Clinical Study, OTIS-3). The left ear canal of each dog was rinsed with 2 mL of sodium phosphate buffer. The solution obtained was analysed by enzyme-linked immunosorbent assay to quantify HDPs. Additionally, aural secretions were incubated with two concentrations (5 × 105 and 5 × 104 colony-forming units/mL) of Staphylococcus pseudintermedius and the bacterial density measured after 24 h of incubation. Data were statistically analysed. Significance was set as p ≤ 0.05.

RESULTS

There was a significantly lower concentration of HDPs from atopic ears when compared with those from normal healthy dogs (cBD3-like: p = 0.0007; cCath: p = 0.049). There was minimal to variable antimicrobial activity in the aural secretions of both groups.

CONCLUSIONS AND CLINICAL RELEVANCE

This study showed, for the first time, that the ear canals of atopic dogs with mild noninfectious otitis contain a lower concentration of cBD3-like and cCath HDPs than those of healthy dogs with normal ears. A consistent antimicrobial activity was not present in the aural secretions from either group.

Autoimmunity and Infection in Glomerular Disease

The ongoing glomerular damage of infections is not limited to the most widely known form of post-streptococcal glomerulonephritis, which is today less common in the Western world; other forms of glomerulonephritis are associated with several bacterial, viral and parasitic pathogens. The mechanisms responsible range from the direct damage of glomerular cells to the formation and deposition of immunocomplexes to molecular mimicry to the secretion of superantigens. Similarly, in the course of glomerular disease, infections are more frequent than in the general population due to the loss of immunoglobulins in urine and the immunosuppressive agents used to treat the autoimmune disease that decrease the activity of the immune system. Recognizing this two-way link, understanding its pathogenetic mechanism, and identifying the most appropriate therapeutic choice are essential for the personalized management of patients. In this continuously developing field, this short review summarizes the current state of the art as support for physicians, who are increasingly involved in managing patients with glomerular disease and infections.

Biofilm Models: Different Ways of Biofilm Characterization and Drug Discovery

The ability of bacteria to develop biofilms and its added effect on antimicrobial resistance have been a concern for both animal and human medicine. The need to understand biofilm biology has been addressed with the help of three biofilm models, i.e., in vitro, ex vivo, and in vivo. Due to the implications of animal welfare involved in in vivo models, this article is mainly focused on in vitro and ex vivo study models to analyze biofilm biology. In in vitro biofilm models, the microtiter plate and Calgary biofilm device are the most commonly used techniques for biofilm analysis. Quantification of the biofilm biomass generated by these two techniques can be assessed with the help of a crystal violet assay. Although in vitro biofilm models help advance understanding of the biology of biofilm and are easy to perform, they fail to address certain important questions, such as the importance of the substrate on which biofilm grows and the interaction between the organisms and the substrate. To address this concern, an ex vivo model can be utilized to characterize the behavior and characteristics of biofilms on different substrates. Ex vivo biofilm models are considered a bridge between the in vitro and in vivo biofilm models. Although neither of the currently available biofilm assessment models is considered the gold standard, they have significantly increased understanding of biofilm behavior. Further studies are warranted to develop more refined biofilm models. © 2023 Wiley Periodicals LLC. Basic Protocol 1: In vitro biofilm models for microtiter plate/crystal violet assay for biofilm growth assessment Basic Protocol 2: Crystal violet assay/tissue culture plate method for testing of antibiofilm agents Alternate Protocol: Calgary biofilm device to determine biofilm susceptibility to antimicrobial agents Basic Protocol 3: Ex vivo biofilm skin models: canine/porcine skin explants.

Progress in pharmacotherapy for the treatment of hyperphosphatemia in renal failure

INTRODUCTION

Among the clinical and metabolic complications of progressive chronic kidney disease (CKD), CKD-mineral bone disorder (CKD-MBD) significantly contributes to morbidity and mortality. While overt and persistent hyperphosphatemia is typical of advanced CKD and requires treatment, other abnormalities of calcium/phosphate metabolism begin to occur since the early stages of the disease.

AREAS COVERED

We searched on the PubMed database, without restrictions for language or time range, for randomized clinical trials and meta-analyses investigating phosphate-lowering therapies. The various phosphate binders show different safety profiles and diverse effects on calcium/phosphate metabolism and vascular calcification. The in-depth knowledge of the characteristics of these drugs is crucial to ensure adequate treatment to CKD patients.

EXPERT OPINION

A proper control of serum phosphate can be achieved using phosphate binders. These medications may induce side effects. Moreover, data on their impact on clinical outcomes are partly controversial or scarce, especially for the new generation drugs. Hyperphosphatemia favors cardiovascular disease and increases the risk for CKD progression. These effects are partially mediated by fibroblast growth factor 23 (FGF23), a phosphaturic hormone that raises to maintain normal serum phosphate. Since there are no data supporting the use of phosphate-lowering agents when phosphataemia is normal, a key role is played by reducing dietary phosphate intake with the aim to control serum phosphate and the compensatory FGF23 and parathyroid hormone (PTH) increase.

Dose-Response Behavior of Pathogens and Surrogate Microorganisms across the Ultraviolet-C Spectrum: Inactivation Efficiencies, Action Spectra, and Mechanisms

The dose-response behavior of pathogens and inactivation mechanisms by UV-LEDs and excimer lamps remains unclear. This study used low-pressure (LP) UV lamps, UV-LEDs with different peak wavelengths, and a 222 nm krypton chlorine (KrCl) excimer lamp to inactivate six microorganisms and to investigate their UV sensitivities and electrical energy efficiencies. The 265 nm UV-LED had the highest inactivation rates (0.47-0.61 cm2/mJ) for all tested bacteria. The bacterial sensitivity strongly fitted the absorption curve of nucleic acids at wavelengths of 200-300 nm; however, indirect damage induced by reactive oxygen species (ROS) was the leading cause of bacterial inactivation under 222 nm UV irradiation. In addition, the guanine and cytosine (GC) content and cell wall constituents of bacteria affect inactivation efficiency. The inactivation rate constant of Phi6 (0.13 ± 0.002 cm2/mJ) at 222 nm due to lipid envelope damage was significantly higher than other UVC (0.006-0.035 cm2/mJ). To achieve 2log reduction, the LP UV lamp had the best electrical energy efficiency (required less energy, average 0.02 kWh/m3) followed by 222 nm KrCl excimer lamp (0.14 kWh/m3) and 285 nm UV-LED (0.49 kWh/m3).

Phosphate Control in Peritoneal Dialysis Patients: Issues, Solutions, and Open Questions

Hyperphosphatemia is a common complication in advanced chronic kidney disease and contributes to cardiovascular morbidity and mortality. The present narrative review focuses on the management of phosphatemia in uremic patients receiving peritoneal dialysis. These patients frequently develop hyperphosphatemia since phosphate anion behaves as a middle-size molecule despite its low molecular weight. Accordingly, patient transporter characteristics and peritoneal dialysis modalities and prescriptions remarkably influence serum phosphate control. Given that phosphate peritoneal removal is often insufficient, especially in lower transporters, patients are often prescribed phosphate binders whose use in peritoneal dialysis is primarily based on clinical trials conducted in hemodialysis because very few studies have been performed solely in peritoneal dialysis populations. A crucial role in phosphate control among peritoneal dialysis patients is played by diet, which must help in reducing phosphorous intake while preventing malnutrition. Moreover, residual renal function, which is preserved in most peritoneal dialysis patients, significantly contributes to maintaining phosphate balance. The inadequate serum phosphate control observed in many patients on peritoneal dialysis highlights the need for large and well-designed clinical trials including exclusively peritoneal dialysis patients to evaluate the effects of a multiple therapeutic approach on serum phosphate control and on hard clinical outcomes in this high-risk population.

Genome-wide association analyses define pathogenic signaling pathways and prioritize drug targets for IgA nephropathy

IgA nephropathy (IgAN) is a progressive form of kidney disease defined by glomerular deposition of IgA. Here we performed a genome-wide association study of 10,146 kidney-biopsy-diagnosed IgAN cases and 28,751 controls across 17 international cohorts. We defined 30 genome-wide significant risk loci explaining 11% of disease risk. A total of 16 loci were new, including TNFSF4/TNFSF18, REL, CD28, PF4V1, LY86, LYN, ANXA3, TNFSF8/TNFSF15, REEP3, ZMIZ1, OVOL1/RELA, ETS1, IGH, IRF8, TNFRSF13B and FCAR. The risk loci were enriched in gene orthologs causing abnormal IgA levels when genetically manipulated in mice. We also observed a positive genetic correlation between IgAN and serum IgA levels. High polygenic score for IgAN was associated with earlier onset of kidney failure. In a comprehensive functional annotation analysis of candidate causal genes, we observed convergence of biological candidates on a common set of inflammatory signaling pathways and cytokine ligand-receptor pairs, prioritizing potential new drug targets.

Hirstiella spp. Infestation in A Client-Owned Iguana (Iguana Iguana) Associated With Skin Lesions on its Owner

A green iguana (Iguana iguana) was presented for severe pruritus, dysecdysis, reduced appetite, lethargy, and the presence of dark red spots on the entire body. A pruritic dermatitis was present on the owner's arms as well. Parasitological examination (light microscopy) performed on the affected iguana, via skin scraping and acetate tape test, revealed numerous Hirstiella spp. mites. Resolution of clinical signs occurred 3 weeks after daily water bath and 3 weekly applications of a 0.25% fipronil solution (sprayed on a glove and then rubbed on the skin of the lizard) along with application of diluted fipronil (1:5 in water). This is the first case report of potential Hirstiella spp. dermatitis in an adult human. Although uncommon, Hirstiella spp. infestation should be considered as a possible differential in pruritic pet lizards specifically in cases in which the owner presents a papular dermatitis.

The Use of Mefenoxam to Treat Cutaneous and Gastrointestinal Pythiosis in Dogs: A Retrospective Study

Pythium insidiosum, an aquatic oomycete with pathogenic potential in mammals, causes gastrointestinal and cutaneous disease in dogs. Mefenoxam, an agricultural anti-oomycotic compound, has a demonstrated the ability to inhibit P. insidiosum growth in vitro and has been associated with efficacy in treating gastrointestinal pythiosis in several case reports. Electronic medical records of dogs seen at University of Florida Small Animal Hospital and treated with mefenoxam between 2013 and 2020 were searched. Dogs were included in this study upon previous definitive diagnosis with either organism identification using culture, PCR, or antibody ELISA, or a combination of these tests with or without supportive histopathological analysis. Since 2013, mefenoxam had been administered to 25 dogs with cutaneous pythiosis and 16 dogs with gastrointestinal pythiosis. In both gastrointestinal and cutaneous pythiosis groups, the administration of mefenoxam was associated with a survivability rate of approximately 51%. There was a statistically significant difference in the time to death between cutaneous (245 days (52-530)) and gastrointestinal (90 days (21-203)) groups; dogs infected with cutaneous pythiosis survived significantly longer after being diagnosed with the disease (p = 0.035). The dogs in this study experienced increased survival rates and time to death, in the absence of side effects due to mefenoxam, compared with previously published literature. The results of this retrospective study, with some limitations, are promising and should prompt further investigation into the use of mefenoxam in the treatment of both gastrointestinal and cutaneous pythiosis.

Topical therapy for canine pyoderma: what is new?

Antimicrobial-resistant cutaneous infections are increasing in veterinary medicine. The use of systemic antibiotics should be limited to severe cases of pyoderma to decrease the microbial pressure and selection for multidrug-resistant bacteria. Topical antimicrobials with a low-resistance profile, such as chlorhexidine, benzoyl peroxide, and ethyl lactate have been used for decades in veterinary dermatology. However, new alternatives have been explored in the past decade. The goal of this review is to summarize the current knowledge on the antibacterial efficacy and clinical use, when reported, of "classic" and new treatment options for topically treating canine pyoderma. This review is intended to fill the gap from previous systematic reviews published in veterinary dermatology a decade ago. The studies reported in this review emphasize the need and desire for alternatives to the classic topical antimicrobials used in veterinary medicine to significantly reduce the use of systemic antibiotics in the spirit of appropriate antimicrobial stewardship.

Horseshoe Kidney: 500 Years From the First Report in the Literature

Horseshoe kidney or ren arcuatus is the most common renal fusion anomaly, with an incidence of 1:500 in the normal population and a male predominance of 2:1. In >90% of cases, the fusion occurs along the inferior pole. It may vary in location, orientation, and arterial and venous anatomy. In 1522, Berengario da Carpi described this renal malformation for the first time in his masterpiece "Isagogae breves" (Introduction to Anatomy). He reported the results of a postmortem examination in the public autopsy room of the University of Bologna, describing "kidneys that are continuous as if they were a kidney, with two emulsifying veins, two emulsifying arteries, two ureteral outlets." In 1564, Leonardo Botallo described and illustrated the features of this atypical anatomical representation, and later, in 1602, Leonard Doldius added further details by examining this anatomical feature during an autopsy. In 1761, Giovanni Battista Morgagni discussed this condition not only as a rare anatomical curiosity found only in necroscopy but also discussed its physiological aspect. In the nineteenth century, with the advent of renal surgery, the horseshoe kidney played a more important role in urological diagnosis and treatment, and its identification became more frequent. With the advent of pyelography, imaging reports of the horseshoe kidney allowed a more accurate representation of the anatomical variants, which was particularly useful in preoperative assessment and outcomes. Berengario da Carpi laid the foundation for a better knowledge of this anatomical anomaly. Five hundred years after the first report in the literature, relevant advances have been made in the management of complications associated with horseshoe kidney and in diagnosis, confirming the need to monitor individuals with this condition who are at higher risk of developing chronic kidney disease.

The Mysterious Life of Jeronimus Ruscelli and His Contribution to Nephrology (1504-1566)

Jeronimo Ruscelli was a mysterious humanist of great fame. He was born in Viterbo between 1504 and 1518 and died in Venice in 1566. Very little is known about Ruscelli's life, but based on his extensive literary output we can assume that he was endowed with remarkable intellectual abilities and a propensity for varied interests. At a young age, he developed a strong interest in classical studies and attended the court of Cardinal Marini Grimani in Utini. After completing his studies at the University of Padua, he participated in the founding of a humanist academy, the Accademia degli Sdegnati (the Scornful Academy). After his fruitful experience in Rome, he moved to the Neapolitan residence of Marquis Alfonso D'Avalos. Here, Ruscelli founded an "Academy of Secrets", composed of a group of humanists and nobles who had an extensive culture and had different experiences but similar interests. During these productive years, under the pseudonym Alexius Pedemontanus, he wrote one of his masterpieces, The Secreti, an important historical documentary manual of great value. In this book, the author proposes therapies for a wide variety of diseases, claiming in most cases that they have been experimentally and successfully tested in the presence of witnesses in at least 3 clinical cases. Ruscelli composed an extensive version of The Secreti, the Secreti Novi. In this book he reported more than a thousand recipes, the substances used were of a great variety and sometimes curious. According to Ruscelli, the recipes in this updated version of the book were "easy for anyone to make, of little effort, and useful for all kinds of people." The topics of this masterpiece range from general medical suggestions to more specific indications, with a wide variety of recipes and treatments of nephrological and urological interest.

Franz Volhard: 150th Birth Anniversary of a Father of Nephrology and Hypertension

Franz Volhard (May 2, 1872, to May 24, 1950) was a German clinician and researcher who made outstanding contributions to the field of nephrology and hyper-tension. His studies led to important developments in knowledge about the pathophysiology of the kidney and its relationship to cardiovascular disease. He contributed to a better understanding of the mechanisms underlying renovascular hypertension by explaining the crucial relationship between the decrease in renal blood flow and the increase in blood pressure. He also introduced a precise classification of the different types of hypertension and the associated renal involvement. In collaboration with Karl Theodor Fahr (1877-1945), he developed a new classification of Bright's disease (nephritis), which was published in the book Die Brightsche Nierenkrankheit. Klinik, Pathologie und Atlas, and revolutionized the concepts behind the mechanisms of glomerulonephritis. During his distinguished career, Volhard headed departments of internal medicine at the Luisenhospital in Dortmund (1905-1910) and in Mannheim (1910-1918). In 1918, he became chairman of the Department of Internal Medicine at the University of Halle, his alma mater, until 1928, the same year he became chairman of the Department of Internal Medicine at the University of Frankfurt until 1938. Volhard continued his successful career until 1950, when he died of complications from a car accident. The worldwide medical com-munity greatly appreciated Franz Volhard's scientific contribution. The International Society of Hypertension posthumously presented him with the "Franz Volhard Award." The aim of this article is to commemorate the importance of this giant of nephrology 150 years after his birth.

Chronic kidney disease, female infertility, and medically assisted reproduction: a best practice position statement by the Kidney and Pregnancy Group of the Italian Society of Nephrology

Fertility is known to be impaired more frequently in patients with chronic kidney disease than in the general population. A significant proportion of chronic kidney disease patients may therefore need Medically Assisted Reproduction. The paucity of information about medically assisted reproduction for chronic kidney disease patients complicates counselling for both nephrologists and gynaecologists, specifically for patients with advanced chronic kidney disease and those on dialysis or with a transplanted kidney. It is in this context that the Project Group on Kidney and Pregnancy of the Italian Society of Nephrology has drawn up these best practice guidelines, merging a literature review, nephrology expertise and the experience of obstetricians and gynaecologists involved in medically assisted reproduction. Although all medically assisted reproduction techniques can be used for chronic kidney disease patients, caution is warranted. Inducing a twin pregnancy should be avoided; the risk of bleeding, thrombosis and infection should be considered, especially in some categories of patients. In most cases, controlled ovarian stimulation is needed to obtain an adequate number of oocytes for medically assisted reproduction. Women with chronic kidney disease are at high risk of kidney damage in case of severe ovarian hyperstimulation syndrome, and great caution should be exercised so that it is avoided. The higher risks associated with the hypertensive disorders of pregnancy, and the consequent risk of chronic kidney disease progression, should likewise be considered if egg donation is chosen. Oocyte cryopreservation should be considered for patients with autoimmune diseases who need cytotoxic treatment. In summary, medically assisted reproduction is an option for chronic kidney disease patients, but the study group strongly advises extensive personalised counselling with a multidisciplinary healthcare team and close monitoring during the chosen medically assisted reproduction procedure and throughout the subsequent pregnancy.

New paradigm for the management of cardio-nephro-metabolic syndrome: multidisciplinary approach and role of telemedicine

Heart failure (HF), type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD) are some of the most important health problems of this century, and these three conditions often coexist, one worsening the prognosis of the other two. No disease is more important than the others in the composition of risk, which is significantly increased by their overlap. Thus, it would be more appropriate to refer to this cluster as cardio-nephro-metabolic syndrome. The aim of this review is to promote the development of an integrated multidisciplinary approach to the treatment of HF, T2DM and CKD in a perspective of paradigm shift from an individual management among different specialists to a shared one. Nowadays, this is achievable thanks to telemedicine and optimized therapy consisting in the new drugs with pleiotropic effect available today. The need is to have technological solutions, which also include telemedicine, for the management of patients affected by all three diseases to consider their fragility, sometimes due to a wrong, partial, or incomplete treatment. Multicentric, multidisciplinary trials on cardio-nephro-metabolic syndrome and new telemedicine/telemonitoring technologies could help place the chronic and fragile patient at the center of such multidimensionally integrated care.

Rare Single Nucleotide and Copy Number Variants and the Etiology of Congenital Obstructive Uropathy: Implications for Genetic Diagnosis

SIGNIFICANCE STATEMENT

Congenital obstructive uropathy (COU) is a prevalent human developmental defect with highly heterogeneous clinical presentations and outcomes. Genetics may refine diagnosis, prognosis, and treatment, but the genomic architecture of COU is largely unknown. Comprehensive genomic screening study of 733 cases with three distinct COU subphenotypes revealed disease etiology in 10.0% of them. We detected no significant differences in the overall diagnostic yield among COU subphenotypes, with characteristic variable expressivity of several mutant genes. Our findings therefore may legitimize a genetic first diagnostic approach for COU, especially when burdening clinical and imaging characterization is not complete or available.

BACKGROUND

Congenital obstructive uropathy (COU) is a common cause of developmental defects of the urinary tract, with heterogeneous clinical presentation and outcome. Genetic analysis has the potential to elucidate the underlying diagnosis and help risk stratification.

METHODS

We performed a comprehensive genomic screen of 733 independent COU cases, which consisted of individuals with ureteropelvic junction obstruction ( n =321), ureterovesical junction obstruction/congenital megaureter ( n =178), and COU not otherwise specified (COU-NOS; n =234).

RESULTS

We identified pathogenic single nucleotide variants (SNVs) in 53 (7.2%) cases and genomic disorders (GDs) in 23 (3.1%) cases. We detected no significant differences in the overall diagnostic yield between COU sub-phenotypes, and pathogenic SNVs in several genes were associated to any of the three categories. Hence, although COU may appear phenotypically heterogeneous, COU phenotypes are likely to share common molecular bases. On the other hand, mutations in TNXB were more often identified in COU-NOS cases, demonstrating the diagnostic challenge in discriminating COU from hydronephrosis secondary to vesicoureteral reflux, particularly when diagnostic imaging is incomplete. Pathogenic SNVs in only six genes were found in more than one individual, supporting high genetic heterogeneity. Finally, convergence between data on SNVs and GDs suggest MYH11 as a dosage-sensitive gene possibly correlating with severity of COU.

CONCLUSIONS

We established a genomic diagnosis in 10.0% of COU individuals. The findings underscore the urgent need to identify novel genetic susceptibility factors to COU to better define the natural history of the remaining 90% of cases without a molecular diagnosis.

Problem-Oriented Approach in Exotic Companion Mammals

Dermatologic disorders are some of the most common conditions affecting exotic companion mammals. This article provides a clinical approach of the conditions presenting with alopecia, pruritus, scaling/crusting, erosion/ulceration, and nodules in order to select and interpret the appropriate diagnostic tests to achieve a diagnosis for a successful treatment.

Modeling Antibiotic Concentrations in the Vicinity of Antibiotic-Producing Bacteria at the Micron Scale

It is generally thought that antibiotics confer upon the producing bacteria the ability to inhibit or kill neighboring microorganisms, thereby providing the producer with a significant competitive advantage. Were this to be the case, the concentrations of emitted antibiotics in the vicinity of producing bacteria might be expected to fall within the ranges of MICs that are documented for a number of bacteria. Furthermore, antibiotic concentrations that bacteria are punctually or chronically exposed to in environments harboring antibiotic-producing bacteria might fall within the range of minimum selective concentrations (MSCs) that confer a fitness advantage to bacteria carrying acquired antibiotic resistance genes. There are, to our knowledge, no available in situ measured antibiotic concentrations in the biofilm environments that bacteria typically live in. The objective of the present study was to use a modeling approach to estimate the antibiotic concentrations that might accumulate in the vicinity of bacteria that are producing an antibiotic. Fick's law was used to model antibiotic diffusion using a series of key assumptions. The concentrations of antibiotics within a few microns of single producing cells could not reach MSC (8 to 16 μg/L) or MIC (500 μg/L) values, whereas the concentrations around aggregates of a thousand cells could reach these concentrations. The model outputs suggest that single cells could not produce an antibiotic at a rate sufficient to achieve a bioactive concentration in the vicinity, whereas a group of cells, each producing the antibiotic, could do so. IMPORTANCE It is generally assumed that a natural function of antibiotics is to provide their producers with a competitive advantage. If this were the case, sensitive organisms in proximity to producers would be exposed to inhibitory concentrations. The widespread detection of antibiotic resistance genes in pristine environments suggests that bacteria are indeed exposed to inhibitory antibiotic concentrations in the natural world. Here, a model using Fick's law was used to estimate potential antibiotic concentrations in the space surrounding producing cells at the micron scale. Key assumptions were that per-cell production rates drawn from the pharmaceutical manufacturing industry are applicable in situ, that production rates were constant, and that produced antibiotics are stable. The model outputs indicate that antibiotic concentrations in proximity to aggregates of a thousand cells can indeed be in the minimum inhibitory or minimum selective concentration range.

Physico-chemical characteristics and biodegradability of primary effluent and particulate matter removed by microscreens

In this study, the physical, chemical, and biological characteristics of raw wastewater were compared with the liquid and solid streams generated by a primary clarifier (PC), a rotating belt filter (RBF, 350 μm), and a drum filter (DF, 60 μm) and series (SER) combination of an RBF with a PC or a DF using pilot-scale primary treatment units. The RBF removed about 36% of the influent total suspended solids. The DF and PC yielded an influent total suspended solid removal of 47% to 55% in both individual (parallel) and SER configurations. The size fractionation and chemical characterizations of the liquid fractions indicated a significant change in the wastewater composition in both filter configurations with no variation in the biodegradability of liquid fractions. The solids recovered by RBF had a higher total solids (TS) concentration and a higher volatile solids (VS) content (0.92 g VS/g TS) than that of DF and PC treatments (0.58 to 0.84 g VS/g TS). DF and PC sludge demonstrated a higher biodegradability rate (k₁ ; 0.11 d^-1  < k₁  < 0.20 d^-1 ) than solids recovered by RBF (0.09 d^-1 ). The retained solids in the SER configuration demonstrated a significantly lower theoretical biochemical methane potential than the parallel configuration, likely due to the presence of smaller particles with a significantly higher ratio of particulate chemical oxygen demand over volatile suspended solids (1.86 to 2.40 g chemical oxygen demand/g volatile suspended solids). These results indicated that the physical, chemical, and biological characteristics of liquid and solids from different filter configurations are required to determine design criteria to upgrade or retrofit water resource recovery facilities using an RBF or a DF. PRACTITIONER POINTS: A rotating belt filter (RBF) removed less solids than a drum filter (DF) or a primary clarifier (PC). A series configuration of an RBF with either a DF or PC resulted in an effluent with a lower proportion of slowly biodegradable organic matter than in a parallel configuration. Solids from an RBF, a DF, or a PC had similar theoretical biochemical methane potential.

A Keynesian perspective on the health economics of kidney transplantation would strengthen the value of the whole organ donation and transplantation service

Background

In this study, the Keynesian principle “savings may be used as investments in resources” is applied to Kidney Transplantation (KT), contextualizing the whole Organs Donation and Transplantation (ODT) service as a unique healthcare entity. Our aim was to define the financial resources that may be acquired in the form of savings from the KT activity.

Methods

We analyzed registry and funding data for ODT in our region, between 2015 and 2019. Our hypotheses aimed to evaluate whether the savings would offset the Organ Donation (OD) costs, define the scope for growth, and estimate what savings could be generated by higher KT activity. To facilitate the evaluation of the resources produced by KT, we defined a coefficient generated from the combination of clinical outcomes, activity, and costs.

Results

The ODT activity reached a peak in 2017, declining through 2018–2019. The savings matured in 2019 from the KT activity exceeded €15 million while the OD costs were less than €9 million. The regional KT activity was superior to the national average but inferior to international benchmarks. The estimated higher KT activity would produce savings between €16 and 20 million.

Conclusion

The financial resources produced by KT contribute to defining a comprehensive perspective of ODT finance. The optimization of the funding process may lead to the financial self-sufficiency of the ODT service. The reproducible coefficient allows a reliable estimate of savings, subsequently enabling adequate investments and budgeting. Applying such a perspective jointly with reliable estimates would establish the basis for an in-hospital fee-for-value funding methodology for ODT.