Antibacterial activity of plant-derived compounds and cream formulations against canine skin bacteria.

An urgent need to find alternative antimicrobial compounds effective in the prevention and treatment of skin infections led us to study the inhibitory activity of eight plant-derived bioactive compounds (betulin, curcumin, glycyrrhizic acid, guaiazulene, piperine, quercetin, quinine, tannic acid) against 14 canine skin isolates (11 Gram-positive and three Gram-negative bacteria) selected based on antibiotic resistance and virulence features. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined using the broth microdilution method. In detail, the results for the eight different plant compounds showed their inhibitory activity in the concentration range from 0.04 to more than 16 mg/ml (MIC) and from 0.25 to more than 16 mg/ml (MBC). The most potent compounds appear to be tannic acid, followed by quinine and curcumin (MIC 0.04-16.0 mg/ml). The most susceptible strain to the tested agents in general was Bacillus cereus AE13, while Enterococcus faecium AA14 was the most resistant strain (the highest MICs) among the tested bacteria. The two most potent plant-derived compounds (tannic acid and quinine) were tested in mixture in different ratios (1:1, 1:2, 2:1). The lowest MIC and MBC values were observed for the 1:2 ratio, which was used for preparation of creams with different cream bases. One of the cream formulations (cream F) was effective up to 63.0 mg/ml (MIC) with a microbial inactivation time of 1-6 h according to the tested strain. This study provides evidence that some plant-derived compounds could have an antimicrobial effect against canine skin bacteria, the strength of which is bacterial strain dependent.

Systemic Bacterial Infection in a Captive Agouti (Dasyprocta leporina Linnaeus, 1758).

The agouti (Dasyprocta leporina) is a neotropical rodent which has the potential to be domesticated. As such, some research studies have been done on the biology of this animal. Recently, these animals are being kept in captivity as a source of animal protein. Animals which are kept in captivity may present diseases that would not have been reported in the wild due to lack of observation or the lack of occurrence. The aim of this short communication is to report a case of systemic bacterial infection that affected the lungs and liver of a captive agouti. Bacterial analysis revealed that the infection was caused by Escherichia coli. Bacterial infections have been reported in the mammary tissue as well as the skin of the agouti, but to the authors' knowledge, this is the first report of systemic infection in the agouti affecting several organs. This case was seen in a nine-month-old male agouti that was being housed at the University of the West Indies Field Station (UWI, UFS). The animal showed no apparent sign of disease except for lethargy and subsequently died before any treatment was administered. These findings showed that the agouti may have been under some stress (nutritional or environmental) which predisposed this animal to this infection. Future work has to address the nutritional requirements for the growing agouti as well as some treatment options for managements of similar cases in the future.

Positive effects of hyperbaric oxygen therapy in a cat with cutaneous nocardiosis.

Hyperbaric oxygen therapy (HBOT) has been beneficial in treating people with nocardiosis. This report describes Nocardia spp. affecting a cat, with lesions confined to the skin. To the best of the authors' knowledge, this is the first report of HBOT, combined with amikacin, used to successfully treat feline cutaneous nocardiosis.

Le traitement à l'oxygène hyperbar (HBOT) a été bénéfique pour le traitement de la nocardiose chez l'homme. Cet article décrit un chat atteint par Nocardia spp. avec des lésions cantonnées à la peau. A la connaissance des auteurs, ceci est la première description de HBOT, combinée à l'amikacine, utilisée pour traiter avec succès une nocardiose féline.

La terapia con oxígeno hiperbárico (HBOT) ha sido beneficiosa para el tratamiento de personas con nocardiosis. Este informe describe un caso de infección cutánea con Nocardia spp. que afectaba a un gato, con lesiones limitadas a la piel. A entender de los autores, este es el primer informe de HBOT, combinado con amikacina, utilizado para tratar con éxito la nocardiosis cutánea felina.

A oxigenoterapia hiperbárica (OHB) tem sido benéfica no tratamento de pessoas com nocardiose. Este relatório descreve um caso Nocardia spp. afetando um gato, com lesões limitadas à pele. De acordo com o conhecimento dos autores, este é o primeiro relato do uso de OHB, combinado com amicacina, para tratar com sucesso a nocardiose cutânea felina.

Erythema multiforme complicated by bacterial folliculitis in a 3-year-old Nubian goat.

Erythema multiforme is a rare hypersensitivity reaction that is reported in several domestic animal species, and not in goats. This case report describes the clinical and histopathological features of erythema multiforme and secondary bacterial skin infection in a goat.

Un érythème polymorphe est une réaction d 'hypersensibilité rare décrite chez plusieurs espèces d'animaux domestiques mais pas chez la chèvre. Cet article décrit les données cliniques et histopathologiques d'un érythème polymorphe et d'une infection bactérienne secondaire chez une chèvre.

El eritema multiforme es una reacción de hipersensibilidad rara que se ha descrito en diversas especies de animales domésticos, pero no en cabras. Este artículo describe las características clínicas e histopatológicas de eritema multiforme e infección cutánea bacteriana secundaria en una cabra.

O eritema multiforme é uma reação de hipersensibilidade rara relatada em várias espécies de animais domésticos, e não em cabras. Este relato de caso descreve as características clínicas e histopatológicas de eritema multiforme e infecção bacteriana secundária da pele em uma cabra.

Translocation of intestinal bacteria as a cause of subcutaneous abscesses of the neck and head in American mink (Neovison vison) - a case report.

BACKGROUND: The problem of transmission of intestinal microorganisms to tissues occurs when intestinal epithelial cells do not adhere tightly (tight junction), which is caused by improper nutrition, usually associated with poor mucosal status. The impact on maintaining its proper condition in the case of animals also depends on the proper preparation and fragmentation of the ingredients of the feed. Intestinal microbiota disorders are increasingly indicated as one of the causes of many autoimmune, neurodevelopmental and metabolic diseases. However, there are no studies indicating damage to the intestinal barrier of animals resulting in the penetration of microorganisms from the gastrointestinal tract directly into the bloodstream which may result in the development of chronic inflammation. CASE PRESENTATION: On a mink (Neovison vison) farm with a foundation stock of 4,000 females, abscesses were observed in the head, followed by progressive deaths. Antibiotic treatment with amoxicillin and clavulanic acid added to the animals' feed was not successful. Macroscopic and microscopic changes indicated local suppurative inflammation of the skin and subcutaneous tissue with the presence of purulent fistulas. Microbiological analysis showed a significant increase in Escherichia coli in all samples taken from the abscesses. The results indicate the migration of intestinal bacteria through disturbance of the permeability of the intestinal barrier and their transfer to the blood. Symptoms were alleviated in all animals following changes in the feed components and in feed particle size. CONCLUSIONS: It is necessary to take into account the possibility of transmission of intestinal bacteria in the etiology of inflammatory diseases in animals. Conducting more research in this field will improve the understanding of the relationship between intestinal microbes and the health of the body as a whole.

Alterations in the epidermis of the carp, Labeo rohita (Cyprinidae: Cypriniformes), infected by the bacteria, Aeromonas hydrophila: A scanning electron microscopic, histopathological and immunohistochemical investigation.

This study was carried out to comprehend the pathogenicity of the bacteria in the epidermis of Labeo rohita inoculated with Aeromonas hydrophila. Alterations in the histopathology of the epidermis were examined using scanning electron microscopy, light microscopy and the localization of iNOS and caspase 3 + ve cells by means of immunohistochemical methods. Skin samples obtained from infected fish at different intervals 2, 4, 6, 8 and 10 days showed significant changes in the cellular components of the epidermis. Epithelial cells often appeared hypertrophied with fragmented and loosely arranged microridges, and in the process of exfoliation. Mucous goblet cells increased significantly in density. Club cells showed degenerative changes, often with simultaneous confluence of adjacent cells and release of their contents. Increase in density of iNOS and caspase 3 + ve cells indicates inflammatory response and apoptosis. This study could provide valuable information on the pathogenesis of the disease, and disease outbreaks in farmed fish. Further, it could provide useful guidelines for fish farmers to take preventive measures for the control of the disease.

Clinicopathological and radiographic features in 40 cats diagnosed with pulmonary and cutaneous Rhodococcus equi infection (2012-2018).

OBJECTIVES: This retrospective study aimed to describe clinical manifestations, diagnostic options, radiological features, therapeutic plans and outcomes for cats infected with Rhodococcus equi. METHODS: Forty cats aged between 2 months and 11 years old (median 6 months) that were definitively diagnosed with rhodococcosis between 2012 and 2018 were recruited in this study. Medical records were reviewed for information on signalment, history, clinical presentation, diagnostic testing, treatment plans and clinical outcomes. RESULTS: Of the 40 cats, 36 showed the pulmonary form of the disease, with 35 (87.5%) presenting with dyspnoea, while four cats presented with only cutaneous lesions. Mean body temperature was 38.7 ± 0.2°C. Dyspnoea was noted in 87.5% of the cats. Leukocytosis (58.3%) with band neutrophilia (83.3%), monocytosis (58.3%) and thrombocytopenia (55.5%) were prominent findings in the haematology reports. Hyperproteinaemia (61.1%) with hypoalbuminaemia (22.2%) and hyperglobulinaemia (63.8%) with a low albumin:globulin ratio (38.9%) were prominent features of blood biochemistry reports. An alveolar-interstitial pattern was noted in 75% of pre-thoracocentesis radiographs. Pleural effusion, hepatomegaly, thoracic lymphadenopathy and atelectasis of any lung lobe were seen in 88.9%, 75%, 41.7% and 36.1% of cats, respectively. Overall, the mortality rate was 67.5% in both forms. CONCLUSIONS AND RELEVANCE: Clinicians should be aware that feline rhodococcosis manifests as a pulmonary disease at a much higher rate than previously reported. Further studies are required to address the epidemiology, pathophysiology, disease management and prognosis of feline rhodococcosis. The role of immunosuppression as a predisposing factor in feline rhodococcosis requires further investigation.

Impact of co-infection with Lepeophtheirus salmonis and Moritella viscosa on inflammatory and immune responses of Atlantic salmon (Salmo salar).

This study was conducted to determine the effects of a co-infection with Moritella viscosa at different exposure levels of sea lice Lepeophtheirus salmonis in Atlantic salmon (Salmo salar). M. viscosa (1.14 × 106  cfu/ml) was introduced to all experimental tanks at 10 days post-lice infection (dpLs). Mean lice counts decreased over time in both the medium lice co-infection (31.5 ± 19.0 at 7 dpLs; 16.9 ± 9.3 at 46 dpLs) and high lice co-infection (62.0 ± 10.8 at 7 dpLs; 37.6 ± 11.3 at 46 dpLs). There were significantly higher mortalities and more severe skin lesions in the high lice co-infected group compared to medium lice co-infected group or M. viscosa-only infection. Quantitative gene expression analysis detected a significant upregulation of genes in skin from the high lice co-infection group consistent with severe inflammation (il-8, mmp-9, hep, saa). Skin lesions retrieved throughout the study were positive for M. viscosa growth, but these were rarely located in regions associated with lice. These results suggest that while M. viscosa infection itself may induce skin lesion development in salmon, co-infection with high numbers of lice can enhance this impact and significantly reduce the ability of these lesions to resolve, resulting in increased mortality.

Pinpointing the role of Aeromonas salmonicida in the development of skin ulcerations in common dab (Limanda limanda).

Aeromonas salmonicida was isolated from ulcerations in common dab (Limanda limanda). An experiment was performed to pinpoint its role in ulceration development, considering the importance of the skin barrier and the pigmented and non-pigmented sides. The skin of dab was treated in three zones, one where scales and epidermis were removed, one where mucus was discarded and one non-treated zone. Fish were tagged to allow individual identification and challenged with A. salmonicida. Mortality and severity of the developing lesions were recorded for 21 days post-inoculation. Starting 12 days post-inoculation, mortality occurred gradually in challenged fish; however, no direct cause could be established. Both control fish and challenged fish developed ulcerations containing A. salmonicida. Sequencing of vapA gene revealed that isolates retrieved from both groups were distinct, suggesting the presence of A. salmonicida prior to the trial. Most ulcerations developed in zones where skin was removed, suggesting that abrasion might be a predisposing factor in ulceration development. Ulcerations were also observed at the insertion site of the tag, where exposed muscle tissue might have favoured the development of ulcerations. In conclusion, A. salmonicida seems to be involved in the development of skin ulcerations in dab, although the exact pathogenesis needs to be elucidated.

OXA-181-Producing Extraintestinal Pathogenic Escherichia coli Sequence Type 410 Isolated from a Dog in Portugal.

Two multidrug-resistant and carbapenemase-producing Escherichia coli clones of sequence type 410 were isolated from fecal samples of a dog with skin infection on admission to an animal hospital in Portugal and 1 month after discharge. Whole-genome sequencing revealed a 126,409-bp Col156/IncFIA/IncFII multidrug resistance plasmid and a 51,479-bp IncX3 blaOXA-181-containing plasmid. The chromosome and plasmids carried virulence genes characteristic for uropathogenic E. coli, indicating that dogs may carry multidrug-resistant E. coli isolates related to those causing urinary tract infections in humans.

Nontuberculous mycobacterial skin disease in cat; diagnosis and treatment - Case report.

INTRODUCTION: Mycobacterial diseases of humans and animals can be caused by mycobacteria other than tuberculosis (MOTT). The transmission of the infection primarily occurs via the respiratory or oral routes, but also via a damaged skin barrier. MOTT have high resistance to external factors; therefore, infected, undiagnosed animals can pose a risk for public health. CASE REPORT: The case study describes mycobacterial skin infection in a domestic cat. The correct diagnosis was reached four months after the appearance of the first clinical signs. Those were purulent, granulomatous lesions and fistulas, which could potentially act as a source of the infection for the owners and the veterinarian who cared for the animal. CONCLUSION: Despite using advanced diagnostic techniques, establishing the final cause of the cat's illness was a lengthy process. The skin lesions could contribute to the transmission of the bacteria in the environment. Non-targeted treatments could also cause antimicrobial resistance.

Scrutinizing the triad of Vibrio tapetis, the skin barrier and pigmentation as determining factors in the development of skin ulcerations in wild common dab (Limanda limanda).

Recently, Vibrio tapetis was isolated for the first time from skin ulcerations in wild-caught common dab (Limanda limanda). To further examine its role in the development of these skin lesions, an in vivo experiment was performed. The significance of the skin barrier and in addition the difference between pigmented and non-pigmented side were investigated. Hence, the skin of common dab was treated in three different ways on both the pigmented and non-pigmented side. On a first "treatment zone", the scales and overlying epidermal tissue were removed whereas in a second zone only the mucus was discarded. The third zone served as a non-treated zone. Thereafter, fish were challenged with V. tapetis. The control group was sham treated. Mortality, clinical signs, severity and size of the developing lesions were recorded. All animals were sacrificed and sampled 21 days post-inoculation. Significantly more fish of the group challenged with V. tapetis died compared to the control group with the highest incidence occurring 4 days post-inoculation. Fish challenged with V. tapetis developed more severe skin ulcerations. In zones where scales and epidermal tissue were removed, the ulcerations were more severe compared to zones where only mucus was eliminated. Ulcerations occurred more frequently, were more severe and larger on the pigmented side. Our data represents prove of V. tapetis as causative agent of ulcerative skin lesions although prior damage of the skin seems to be a major contributing factor. Furthermore, the pigmented side seemed predisposed to the development of skin ulcerations.

Characterization, mechanism of action and optimization of activity of a novel peptide-peptoid hybrid against bacterial pathogens involved in canine skin infections.

Integumentary infections like pyoderma represent the main reason for antimicrobial prescription in dogs. Staphylococcus pseudintermedius and Pseudomonas aeruginosa are frequently identified in these infections, and both bacteria are challenging to combat due to resistance. To avoid use of important human antibiotics for treatment of animal infections there is a pressing need for novel narrow-spectrum antimicrobial agents in veterinary medicine. Herein, we characterize the in vitro activity of the novel peptide-peptoid hybrid B1 against canine isolates of S. pseudintermedius and P. aeruginosa. B1 showed potent minimum inhibitory concentrations (MICs) against canine S. pseudintermedius and P. aeruginosa isolates as well rapid killing kinetics. B1 was found to disrupt the membrane integrity and affect cell-wall synthesis in methicillin-resistant S. pseudintermedius (MRSP). We generated 28 analogues of B1, showing comparable haemolysis and MICs against MRSP and P. aeruginosa. The most active analogues (23, 26) and B1 were tested against a collection of clinical isolates from canine, of which only B1 showed potent activity. Our best compound 26, displayed activity against P. aeruginosa and S. pseudintermedius, but not the closely related S. aureus. This work shows that design of target-specific veterinary antimicrobial agents is possible, even species within a genus, and deserves further exploration.

Mycobacterium nebraskense infection in a dog in Switzerland with disseminated skin lesions.

BACKGROUND: Cutaneous disseminated mycobacteriosis is rare in dogs. To the best of the authors' knowledge, the slowly growing mycobacterial species Mycobacterium nebraskense has not been described before in this species. OBJECTIVE: Description of clinical features, laboratory analyses and treatment regimen of this unusual case. ANIMAL: A 9-year-old female-spayed West Highland white terrier dog presented with progressive nodules and ulcerations on both sides of the thorax and the rostral aspect of the chest. METHODS AND MATERIALS: Investigations involved histopathological examination of skin biopsies (including special stains for fungi, bacteria and mycobacteria), standard and mycobacterial culture (including susceptibility testing), 16S/23S rRNA sequencing and BLAST similarity searching. RESULTS: Ziehl-Neelsen staining of decontaminated biopsy material revealed acid-fast bacteria morphologically consistent with mycobacteria. Treatment with clarithromycin and marbofloxacin achieved partial resolution. A change in the treatment regimen to pradofloxacin and azithromycin resulted in rapid deterioration of skin lesions. Final healing occurred with the addition of prednisolone at an anti-inflammatory dose. The results of mycobacterial culture and susceptibility testing were received 10 and 12 months, respectively, after the first presentation of the dog. Therapy was stopped after 16 months without recurrence of skin lesions. CONCLUSIONS AND CLINICAL IMPORTANCE: This case is noteworthy for the description of a new mycobacterial species contributing to disseminated panniculitis in a dog and for the difficulties experienced in the lengthy empirical treatment of slowly growing nontuberculous mycobacterial infections. The addition of prednisolone to induce complete healing raises the question of whether the mycobacterial infection was primary or whether it occurred secondarily to an ongoing sterile panniculitis.

Novel association of Psychrobacter and Pseudomonas with malodour in bloodhound dogs, and the effects of a topical product composed of essential oils and plant-derived essential fatty acids in a randomized, blinded, placebo-controlled study.

BACKGROUND: The pathogenesis and treatment of cutaneous malodour in dogs have not been investigated previously. Staphylococcus and Corynebacterium spp. are associated with human axillary malodour. HYPOTHESIS: Staphylococcus and Corynebacterium spp. are associated with cutaneous malodour in dogs, and treatment with a topical essential oil-based product will improve malodour and reduce the abundance of odour-causing bacteria. ANIMALS: Twenty seven bloodhound dogs from a south Texas boarding facility were enrolled in this study. METHODS AND MATERIALS: Skin swabs were taken from the axilla and dorsum of 27 dogs at initiation of the study. Mean malodour scores were used to assign dogs to control or malodour groups. The malodourous dogs were randomly assigned to a treatment or placebo group, received four weekly topical applications of the spot-on or placebo, and samples were recollected. Next-generation sequencing (NGS) and real-time quantitative PCR (qPCR) were performed on all swabs. RESULTS: Psychrobacter and Pseudomonas spp. were significantly more abundant (P < 0.001, P = 0.006; respectively), and overall bacterial diversity was reduced (P = 0.0384) on the skin of malodourous dogs. Staphylococcus and Corynebacterium spp. were not associated with malodour. The topical essential oil-based product significantly (P = 0.0078) improved malodour in the treatment group and shifted their bacterial community structure. CONCLUSIONS AND CLINICAL IMPORTANCE: A novel association of bacterial genera with malodour in bloodhound dogs, identified by NGS, highlights future targets for odour control. The topical treatment significantly reduced malodour. The interaction between the topical treatment and cutaneous microbiota should be further investigated and may be useful in other dermatological conditions involving microbiota.

Recurrent Anthrax Outbreaks in Humans, Livestock, and Wildlife in the Same Locality, Kenya, 2014-2017.

Epidemiologic data indicate a global distribution of anthrax outbreaks associated with certain ecosystems that promote survival and viability of Bacillus anthracis spores. Here, we characterized three anthrax outbreaks involving humans, livestock, and wildlife that occurred in the same locality in Kenya between 2014 and 2017. Clinical and epidemiologic data on the outbreaks were collected using active case finding and review of human, livestock, and wildlife health records. Information on temporal and spatial distribution of prior outbreaks in the area was collected using participatory epidemiology. The 2014-2017 outbreaks in Nakuru West subcounty affected 15 of 71 people who had contact with infected cattle (attack rate = 21.1%), including seven with gastrointestinal, six with cutaneous, and two with oropharyngeal forms of the disease. Two (13.3%) gastrointestinal human anthrax cases died. No human cases were associated with infected wildlife. Of the 54 cattle owned in 11 households affected, 20 died (attack rate = 37%). The 2015 outbreak resulted in death of 10.5% of the affected herbivorous wildlife at Lake Nakuru National Park, including 745 of 4,500 African buffaloes (species-specific mortality rate = 17%) and three of 18 endangered white rhinos (species-specific mortality rate = 16%). The species mortality rate ranged from 1% to 5% for the other affected wildlife species. Participatory epidemiology identified prior outbreaks between 1973 and 2011 in the same area. The frequency and severity of outbreaks in this area suggests that it is an anthrax hotspot ideal for investigating risk factors associated with long-term survival of anthrax spores and outbreak occurrence.

Superficial Chronic Ulcerative Dermatitis (SCUD) in Psittacine Birds: Review of 11 Cases (2008-2016).

We reviewed 11 cases of superficial chronic ulcerative dermatitis (SCUD) in psittacine birds that presented to an exotic animal practice over an 8-year period. African grey parrots ( Psittacus erithacus) were overrepresented, accounting for 55% of SCUD-affected birds. All affected birds were hand-reared pets and bonded strongly to their owners. In all cases, fungal culture results were negative. The most commonly cultured bacteria were Enterobacter cloacae (27%), followed by Escherichia coli, and Staphylococcus aureus (both 18%). An underlying cause of behavioral self-mutilation with secondary infection of dermatitis lesions by opportunistic bacteria was suspected in 10 of 11 cases. The axillae were the most common anatomic sites affected (45%). In two cases, more than one site was affected concurrently. Mean age of birds affected was 11.4 years. Two birds had suffered from SCUD previously, with 1 bird having suffered from 3 previous episodes and was euthanized as a result. All birds were treated with systemic antibiotics, topical antibacterial preparations, and systemic nonsteroidal anti-inflammatory drugs. A neck collar was applied in all cases. Median time to clinical resolution was 2 months (range, 1-21 months). Excluding the bird that was euthanized, all birds showed a positive response to treatment.