Antimicrobial Peptide Reduces Cytotoxicity and Inflammation in Canine Epidermal Keratinocyte Progenitor Cells Induced by Pseudomonas aeruginosa Infection.

The direct effects and antimicrobial activity of synthetic antimicrobial peptides (AMPs) obtained from dogs, including cBD, cBD103, and cCath, against P. aeruginosa wild-type strain PAO1 and canine keratinocytes were analyzed. Antibacterial effects on planktonic bacteria were assessed by determining the minimum bactericidal concentrations (MBCs) of AMPs and by a time-kill assay. Antibiofilm effects were assessed using the microtiter plate assay. We also evaluated the effects of AMPs on cell cytotoxicity and host immune response induced by stimulating canine epidermal keratinocyte progenitor (CPEK) cells with PAO1 and its LPS. cBD, cBD103, and cCath all exhibited dose-dependent antimicrobial and antibiofilm effects. In particular, 25 µg/mL cBD103 showed rapid bactericidal activity within 60 min and inhibited biofilm formation. In addition, pretreatment with cBD103 (25 µg/mL) and cCath (50 µg/mL) 1 h before stimulation significantly reduced the cytotoxicity of the CPEK cells by PAO1 and LPS-induced IL-6 and TNF-a expressions. cBD had little effect on the response to PAO1 and LPS in the cells. These results indicate the therapeutic potential of AMPs in P. aeruginosa skin infections. However, further studies on the mechanism of action of AMPs in keratinocytes and clinical trials are needed.

Optimal microneedle length for hair regrowth in hair cycle arrest (alopecia X) in six dogs.

BACKGROUND: Hair cycle arrest (HCA) is a chronic alopecic disorder in dogs. Clinical responses vary and are often insufficient. Microneedling (MN) has been used as a successful treatment for HCA in dogs; ideal protocols have not yet been established. OBJECTIVES: The objective of the study was to compare the efficacy and safety of three needle lengths for MN in dogs with HCA. ANIMALS: Six unrelated client-owned dogs, including five Pomeranians and one mixed-breed dog, diagnosed with HCA. MATERIALS AND METHODS: Individual alopecic sites were divided into three sections. For each section, different lengths of needles (1, 2 and 3 mm) were used. Efficacy and safety were evaluated at 1, 3 and 6 months. Treated sections were monitored for 20 months. RESULTS: Three months after treatment with 3 mm needles, all sections showed hair regrowth. There was no hair regrowth in two of six sections treated with 2 mm needles, and four of six sections did not show a response to treatment with 1 mm needles. Two dogs developed transient pruritus. Five of six dogs had recurrent hair loss between 5 and 16 months of follow-up. CONCLUSION AND CLINICAL RELEVANCE: Microneedling using longer needles stimulated better hair regrowth in dogs with HCA. Alopecia relapsed in most dogs and minor pruritus occurred in some dogs.

CoVSense: Ultrasensitive Nucleocapsid Antigen Immunosensor for Rapid Clinical Detection of Wildtype and Variant SARS-CoV-2.

The widespread accessibility of commercial/clinically-viable electrochemical diagnostic systems for rapid quantification of viral proteins demands translational/preclinical investigations. Here, Covid-Sense (CoVSense) antigen testing platform; an all-in-one electrochemical nano-immunosensor for sample-to-result, self-validated, and accurate quantification of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid (N)-proteins in clinical examinations is developed. The platform's sensing strips benefit from a highly-sensitive, nanostructured surface, created through the incorporation of carboxyl-functionalized graphene nanosheets, and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) conductive polymers, enhancing the overall conductivity of the system. The nanoengineered surface chemistry allows for compatible direct assembly of bioreceptor molecules. CoVSense offers an inexpensive (<$2 kit) and fast/digital response (<10 min), measured using a customized hand-held reader (<$25), enabling data-driven outbreak management. The sensor shows 95% clinical sensitivity and 100% specificity (Ct<25), and overall sensitivity of 91% for combined symptomatic/asymptomatic cohort with wildtype SARS-CoV-2 or B.1.1.7 variant (N = 105, nasal/throat samples). The sensor correlates the N-protein levels to viral load, detecting high Ct values of ≈35, with no sample preparation steps, while outperforming the commercial rapid antigen tests. The current translational technology fills the gap in the workflow of rapid, point-of-care, and accurate diagnosis of COVID-19.

The number of mitochondrial DNA mutations as a genetic feature for hair cycle arrest (alopecia X) in Pomeranian dogs.

BACKGROUND: Hair cycle arrest (HCA) is a noninflammatory alopecic disease affecting various dog breeds, particularly Pomeranian dogs. This disease is probably a hereditary disorder considering the strong breed predisposition. Despite efforts to identify the pathogenesis of this disease, an underlying specific cause is unknown. OBJECTIVE: To identify candidate gene mutations for HCA in Pomeranian dogs. ANIMALS: Four Pomeranian dogs diagnosed with HCA and four unaffected Pomeranian dogs. MATERIALS AND METHODS: Whole blood was used for DNA extraction. Whole-genome sequencing (WGS) was performed, and variants were analysed using a Genome Analysis Toolkit (GATK) and SnpEff. All reads were aligned to the reference genome, Dog10K_Boxer_Tasha. Sanger sequencing was performed to define the complex mutations. RESULTS: A total of 113 variants of mitochondrial DNA were found to be effective gene mutations in the eight dogs. The affected dogs showed significantly increased effective mutations (average 57 variants) compared with unaffected dogs (average eight variants; p < 0.05). There was no significant difference in the number of chromosomal DNA mutations between the two groups. CONCLUSION AND CLINICAL IMPORTANCE: We suggest that an increased number of mitochondrial gene mutations are features for HCA in Pomeranian dogs.

A compact, low-cost, and binary sensing (BiSense) platform for noise-free and self-validated impedimetric detection of COVID-19 infected patients.

Electrochemical immuno-biosensors are one of the most promising approaches for accurate, rapid, and quantitative detection of protein biomarkers. The two-working electrode strip is employed for creating a self-supporting system, as a tool for self-validating the acquired results for added reliability. However, the realization of multiplex electrochemical point-of-care testing (ME-POCT) requires advancement in portable, rapid reading, easy-to-use, and low-cost multichannel potentiostat readers. The combined multiplex biosensor strips and multichannel readers allow for suppressing the possible complex matrix effect or ultra-sensitive detection of different protein biomarkers. Herein, a handheld binary-sensing (BiSense) bi-potentiostat was developed to perform electrochemical impedance spectroscopy (EIS)-based signal acquisition from a custom-designed dual-working-electrode immuno-biosensor. BiSense employs a commercially available microcontroller and out-of-shelf components, offering the cheapest yet accurate and reliable time-domain impedance analyzer. A specific electrical board design was developed and customized for impedance signal analysis of SARS-CoV-2 nucleocapsid (N)-protein biosensor in spiked samples and alpha variant clinical nasopharyngeal (NP) swab samples. BiSense showed limit-of-detection (LoD) down to 56 fg/mL for working electrode 1 (WE1) and 68 fg/mL for WE2 and reported with a dynamic detection range of 1 pg/mL to 10 ng/mL for detection of N-protein in spiked samples. The dual biosensing of N-protein in this work was used as a self-validation of the biosensor. The low-cost (∼USD$40) BiSense bi-potentiostat combined with the immuno-biosensors successfully detected COVID-19 infected patients in less than 10 min, with the BiSense reading period shorter than 1.5 min, demonstrating its potential for the realization of ME-POCTs for rapid and hand-held diagnosis of infections.

Sterile Neutrophilic Dermatosis (Sweet's Syndrome) Associated With Systemic Inflammatory Response Syndrome in a Maltese Dog: A Case Report.

We report a rare case of sterile neutrophilic dermatosis (Sweet's syndrome) accompanied by systemic inflammatory response syndrome. A 5-year-old, neutered male Maltese dog presented with extensive crusts on the whole-body surface and multifocal erosions and plaques on the four limbs. The lesions had been present for two months and did not respond to antibiotics before the presentation. In addition, the dog was lethargic, anorexic, and febrile, with joint swelling. A clinicopathologic analysis revealed neutrophilic leukocytosis with left shift and increased C-reactive protein level. Furthermore, a histopathological examination showed moderate to severe inflammatory infiltrates consisting predominantly of neutrophils from the superficial to the deep dermis. There was no evidence of bacterial or fungal infections, and autoimmune diseases, such as pemphigus, systemic lupus erythematosus, and erythema multiforme, were excluded. Sweet's syndrome, a rare skin disorder, associated with systemic inflammation was diagnosed, and the cutaneous lesions and systemic inflammation disappeared after prolonged steroid administration.

Bi-ECDAQ: An electrochemical dual-immuno-biosensor accompanied by a customized bi-potentiostat for clinical detection of SARS-CoV-2 Nucleocapsid proteins.

Multiplex electrochemical biosensors have been used for eliminating the matrix effect in complex bodily fluids or enabling the detection of two or more bioanalytes, overall resulting in more sensitive assays and accurate diagnostics. Many electrochemical biosensors lack reliable and low-cost multiplexing to meet the requirements of point-of-care detection due to either limited functional biosensors for multi-electrode detection or incompatible readout systems. We developed a new dual electrochemical biosensing unit accompanied by a customized potentiostat to address the unmet need for point-of-care multi-electrode electrochemical biosensing. The two-working electrode system was developed using screen-printing of a carboxyl-rich nanomaterial containing ink, with both working electrodes offering active sites for recognition of bioanalytes. The low-cost bi-potentiostat system (∼$80) was developed and customized specifically to the bi-electrode design and used for rapid, repeatable, and accurate measurement of electrochemical impedance spectroscopy signals from the dual biosensor. This binary electrochemical data acquisition (Bi-ECDAQ) system accurately and selectively detected SARS-CoV-2 Nucleocapsid protein (N-protein) in both spiked samples and clinical nasopharyngeal swab samples of COVID-19 patients within 30 min. The two working electrodes offered the limit of detection of 116 fg/mL and 150 fg/mL, respectively, with the dynamic detection range of 1-10,000 pg/mL and the sensitivity range of 2744-2936 Ω mL/pg.mm2 for the detection of N-protein. The potentiostat performed comparable or better than commercial Autolab potentiostats while it is significantly lower cost. The open-source Bi-ECDAQ presents a customizable and flexible approach towards addressing the need for rapid and accurate point-of-care electrochemical biosensors for the rapid detection of various diseases.

In vitro antifungal activity of cold atmospheric microwave plasma and synergistic activity against Malassezia pachydermatis when combined with chlorhexidine gluconate.

BACKGROUND: The antifungal efficacy of cold atmospheric microwave plasma (CAMP) against Malassezia pachydermatis has not been to be evaluated. OBJECTIVE: To examine the antifungal effects of CAMP against M. pachydermatis and its synergistic effects with chlorhexidine gluconate (CHX). METHODS: A M. pachydermatis isolate was collected from a dog with otitis externa and Malassezia dermatitis at the Seoul National University Veterinary Medical Teaching Hospital. The antifungal effect was determined by applying CAMP to a M. pachydermatis isolate that was incubated for 3 days at 37°C. After 1, 2, 3 and 5 min of application, the efficacy of the plasma treatment was determined according to the number of colony forming units (CFUs). A mixture consisting of inoculum and CHX was applied to evaluate the synergistic effect of the plasma treatment in the same way. RESULTS: The application of CAMP showed significant antifungal effects against M. pachydermatis. The antifungal effect of CAMP was enhanced by an increased exposure time and output power. The application of CAMP with 0.02% and 0.2% CHX resulted in lower survival rates against M. pachydermatis when compared with its sole application at 1 or 2 min. CONCLUSIONS: The study findings demonstrate that CAMP has a potential as a new antifungal option for M. pachydermatis and has synergistic antifungal effects with CHX in vitro. Clinical applications for CAMP are necessary to assess the antifungal efficacy for patients.

In vitro antibacterial and antibiofilm effects of cold atmospheric microwave plasma against Pseudomonas aeruginosa causing canine skin and ear infections.

BACKGROUND: Pseudomonas aeruginosa is an opportunist pathogen that causes purulent inflammation in the skin and in the ears of dogs. Among the various virulence factors of P. aeruginosa, biofilms have been reported to result in antibiotic resistance, leading to therapeutic limitations. Cold atmospheric microwave plasma (CAMP) is known to have a high antimicrobial effect, which causes physical cell wall rupture and DNA damage. HYPOTHESIS/OBJECTIVES: The objective of this study was to evaluate the antibacterial and antibiofilm effects of CAMP against planktonic bacteria and the biofilm of P. aeruginosa. METHODS AND MATERIALS: The antibacterial effect of CAMP against P. aeruginosa ATCC10145 and clinical isolates (n = 30) was evaluated using the colony count method. We also assessed the effect of CAMP on biofilm of P. aeruginosa ATCC strain by the colony count method, water-soluble tetrazolium salt (WST) assay and confocal laser scanning microscopy (CLSM). RESULTS: The complete eradication of P. aeruginosa (ATCC strain and clinical isolates) was achieved within 120 s at 50 W, and clinical isolates required 60 s shorter than the ATCC strain for complete eradication at 50 W. We also confirmed the time-dependent bactericidal effect of CAMP at 50 W against ATCC strain biofilm. CONCLUSIONS AND CLINICAL IMPORTANCE: CAMP was effective against both planktonic bacteria and biofilm formation of P. aeruginosa. However, further studies on in vivo efficacy and safety in canine skin and ears are necessary to fully validate its clinical application.

Bacteriophage Effectiveness for Biocontrol of Foodborne Pathogens Evaluated via High-Throughput Settings.

Bacterial pathogens continually challenge food safety systems worldwide. With increasing concerns about the emergence of heat- and sanitizer-resistant bacteria, novel antibacterial agents, are urgently needed. A bacteriophage-based biocontrol strategy is the therapeutic use of phages to control bacterial pathogens in agricultural settings. Phage biocontrol is increasingly accepted as a sustainable technology, effective at decontaminating foodborne pathogens. To ensure effective biocontrol outcomes, systematic screening of phage combinations against targeted bacteria under required environmental conditions is crucial. Antibacterial efficacy of phage cocktails may be affected by phage genera and combination, targeted bacterial strains, the multiplicity of infection, temperature, and time. To formulate a phage cocktail with superior efficacy, the proposed method was to systematically evaluate the effectiveness of individual phages and phage cocktails in killing foodborne bacterial pathogens under targeted conditions. Bacterial killing efficacy was monitored by measuring optical density at desired temperatures and durations. Superior phage efficacy was determined by complete inhibition of bacterial growth. The proposed method is a robust, evidence-based approach to facilitate formulating phage cocktails with superior antibacterial efficacy.

In vitro antimicrobial activity of cold atmospheric microwave plasma against bacteria causing canine skin and ear infections.

BACKGROUND: Cold atmospheric plasma (CAP) is a new generation medical therapeutic option for bacterial infections. CAP causes physical cell wall rupture and DNA damage, therefore making it highly useful in the treatment of various conditions such as skin infections. HYPOTHESIS/OBJECTIVES: The antimicrobial activity of cold atmospheric microwave plasma (CAMP) against major strains in canine skin infections was tested and the difference in antimicrobial activity between the antibiotic-resistant and antibiotic-susceptible strains of Staphylococcus pseudintermedius was evaluated. METHODS AND MATERIALS: American Type Culture Collection (ATCC) strains (Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli) and clinical isolates identified as methicillin-resistant S. pseudintermedius (n = 27) and methicillin-susceptible S. pseudintermedius (n = 13) were exposed to CAMP for 10 s, 30 s and 60 s. Afterwards, the bacterial survival rate was confirmed. RESULTS: Gram-negative bacteria (P. aeruginosa and E. coli) were more susceptible than Gram-positive bacteria (S. aureus and S. pseudintermedius) for the same duration of CAMP exposure. Only the Gram-negative bacteria were completely killed after 60 s exposure. In S. pseudintermedius isolates, CAMP exposure had similar antibacterial effects regardless of antibiotic resistance. CONCLUSIONS AND CLINICAL IMPORTANCE: CAMP has sufficient antimicrobial activity against major bacterial strains that cause pyoderma and otitis externa in dogs, and may be an alternative therapeutic option for S. pseudintermedius skin infections, for which antibiotics often are ineffective because of antimicrobial resistance in clinical veterinary medicine.

Small Bowel Obstruction Induced by Concurrent Postoperative Intra-Abdominal Adhesions and Small Bowel Fecal Materials in a Young Dog.

A 7-month-old neutered male poodle dog presented with general deterioration and gastrointestinal symptoms after two separate operations: a jejunotomy for small-intestinal foreign body removal and an exploratory laparotomy for diagnosis and treatment of the gastrointestinal symptoms that occurred 1 month after the first surgery. The dog was diagnosed as having small-bowel obstruction (SBO) due to intra-abdominal adhesions and small-bowel fecal material (SBFM) by using abdominal radiography, ultrasonography, computed tomography, and laparotomy. We removed the obstructive adhesive lesion and SBFM through enterotomies and applied an autologous peritoneal graft to the released jejunum to prevent re-adhesion. After the surgical intervention, the dog recovered quickly and was healthy at 1 year after the surgery without gastrointestinal signs. To our knowledge, this study is the first report of a successful treatment of SBO induced by postoperative intra-abdominal adhesions and SBFM after laparotomies in a dog.

Successful Treatment of Mucocutaneous Lupus Erythematosus in a Dog with Prednisolone, Mycophenolate Mofetil and Tacrolimus.

A 6-year-old, intact male miniature Pinscher dog had erosive lesions on perilabial, peripenial and perianal mucocutaneous areas, which were exacerbated by ulcerations, crusts, with pain while defecating and urinating. The lesions were symmetrical, and no systemic signs were observed. Histopathological evaluation showed parakeratotic hyperkeratosis, ulceration and cell-rich lymphoplasmacytic interface dermatitis with basal keratinocyte apoptosis. Immunohistochemistry revealed strong reaction in the dermoepidermal junction against goat-canine IgG and mild-to-moderate reaction against goat-canine IgA, IgM and C3. Based on these findings, the dog was diagnosed with mucocutaneous lupus erythematosus (MCLE). Oral prednisolone 1 mg/kg twice daily, mycophenolate mofetil (MMF) 18.3 mg/kg twice daily and 0.1% tacrolimus ointment were prescribed as initial treatment. The lesions showed remarkable improvement within 4 weeks, but the dog exhibited polyuria, polydipsia and hepatomegaly with high dosage of prednisolone. Hence, the dosage of prednisolone was gradually tapered for 9 weeks and discontinued, but MMF and tacrolimus were continued. No new lesion or associated side effect was observed while reducing the MMF dose to 10 mg/kg twice daily and with continuous use of tacrolimus ointment after steroid discontinuation. In conclusion, this case report emphasizes the usefulness of MMF and tacrolimus as steroid-sparing agents in the treatment of dogs with MCLE. To the best of our knowledge, this is the first case report of MCLE that was successfully managed long-term with MMF and tacrolimus.

Sex-Specific Differences in the Gut Microbiome in Response to Dietary Fiber Supplementation in IL-10-Deficient Mice.

There is growing interest in studying dietary fiber to stimulate microbiome changes that might prevent or alleviate inflammatory bowel disease (IBD). However, dietary fiber effects have shown varying degrees of efficacy, for reasons that are unclear. This study examined whether the effects of isomaltodextrin on gut microbiota and IBD were dependent on dose or host sex, using an Interleukin (IL)-10 deficient murine colitis model. After 12 weeks, colonic IL-12p70 was depressed in male mice receiving high-dose isomaltodextrin supplementation compared to the control group (p = 0.04). Male mice receiving high-dose isomaltodextrin exhibited changes in microbial alpha-diversity, including enhanced richness and evenness (p = 0.01) and limited reduction in the relative abundance of Coprococcus (q = 0.08), compared to the control group. These microbial compositional changes were negatively associated with IL-12p70 levels in the male group (rs ≤ -0.51, q ≤ 0.08). In contrast, female mice receiving isomaltodextrin displayed a reduction in alpha-diversity and Coprococcus abundance and a high level of IL-12p70, as did the control group. Together, these results indicate that isomaltodextrin altered the gut microbial composition linking specific immune-regulatory cytokine responses, while the interactions among fiber, microbiota and immune response were dose dependent and largely sex specific. The results further indicate that interactions between environmental and host factors can affect microbiome manipulation in the host.

A Diversified Dietary Pattern Is Associated With a Balanced Gut Microbial Composition of Faecalibacterium and Escherichia/Shigella in Patients With Crohn's Disease in Remission.

BACKGROUND AND AIMS: Crohn's disease [CD] is associated with alterations in gut microbial composition and function. The present controlled-intervention study investigated the relationship between patterns of dietary intake and baseline gut microbiota in CD patients in remission and examined the effects of a dietary intervention in patients consuming a non-diversified diet [NDD]. METHODS: Forty outpatients with quiescent CD were recruited in Calgary, Alberta, Canada. Based on 3-day food records, patients consuming a lower plant-based and higher red and processed meat-based diet were assigned to the NDD group [n = 15] and received a 12-week structured dietary intervention; all other patients were assigned to the diversified diet [DD] control group [n = 25] and received conventional management. Faecal microbiota composition, short chain fatty acids [SCFAs] and calprotectin were measured. RESULTS: At baseline the NDD and DD groups had a different faecal microbial beta-diversity [p = 0.003, permutational multivariate analysis of variance]. The NDD group had lower Faecalibacterium and higher Escherichia/Shigella relative abundances compared to the DD group [3.3 ±â€…5.4% vs. 8.5 ±â€…10.6%; 6.9 ±â€…12.2% vs. 1.6 ±â€…4.4%; p ≤ 0.03, analysis of covariance]. These two genera showed a strong negative correlation [rs = -0.60, q = 0.0002]. Faecal butyrate showed a positive correlation with Faecalibacterium [rs = 0.52, q = 0.002], and an inhibitory relationship with Escherichia/Shigella abundance [four-parameter sigmoidal model, R = -0.83; rs = -0.44, q = 0.01], respectively. After the 12 weeks of dietary intervention, no difference in microbial beta-diversity between the two groups was observed [p = 0.43]. The NDD group demonstrated an increase in Faecalibacterium [p < 0.05, generalized estimated equation model], and resembled the DD group at the end of the intervention [p = 0.84, t-test with permutation]. We did not find an association of diet with faecal SCFAs or calprotectin. CONCLUSIONS: Dietary patterns are associated with specific gut microbial compositions in CD patients in remission. A diet intervention in patients consuming a NDD modifies gut microbial composition to resemble that seen in patients consuming a DD. These results show that diet is important in shaping the microbial dysbiosis signature in CD towards a balanced community.

Identification of fusidic acid resistance in clinical isolates of Staphylococcus pseudintermedius from dogs in Korea.

BACKGROUND: Staphylococcus pseudintermedius is a major bacterial species associated with canine pyoderma and otitis. Fusidic acid is used to treat skin infections caused by Gram-positive bacteria. The incidence of resistance to fusidic acid in S. pseudintermedius has importance in terms of limiting treatment options for bacterial infections. HYPOTHESIS/OBJECTIVES: To evaluate the occurrence and mechanisms of fusidic acid resistance in clinical isolates of S. pseudintermedius. ANIMALS: Fifty-two S. pseudintermedius isolates were collected from dogs with pyoderma (n = 36) or otitis (n = 16). METHODS AND MATERIALS: The disk diffusion method determined that isolates <24 mm were resistant to fusidic acid. Minimum inhibitory concentrations (MICs) were measured by the E-test in those with confirmed resistance to fusidic acid by the disk diffusion method. Phenotypically fusidic acid resistant isolates were subjected to PCR to detect the presence of resistance-related genes (fusA, fusB, fusC and fusD) and fusA was further sequenced to identify point mutations. RESULTS: Fourteen of 52 (27%) S. pseudintermedius isolates were resistant to fusidic acid and all of these showed low-level resistance. Among fusidic acid resistant isolates, fusA point mutations were confirmed in 11 isolates and amino acid substitutions were found in five. fusC was detected in seven isolates, but neither fusB nor fusD was detected. CONCLUSIONS AND CLINICAL IMPORTANCE: This study demonstrates the occurrence and resistance mechanisms to fusidic acid in clinical isolates of S. pseudintermedius. Continuous monitoring for fusidic acid resistance is recommended.

In vitro antibacterial activity of the manuka essential oil from Leptospermum scoparium combined with Tris-EDTA against Gram-negative bacterial isolates from dogs with otitis externa.

BACKGROUND: The increasing prevalence of antimicrobial resistance among bacteria in dogs with otitis externa has led to a need for novel therapeutic agents. HYPOTHESIS/OBJECTIVE: To examine the antibacterial effects of manuka oil combined with ethylenediaminetetraacetic acid-tromethamine (Tris-EDTA) against Gram-negative bacteria isolates from dogs with otitis externa. METHODS AND MATERIALS: A total of 53 clinical isolates including Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae ssp. pneumoniae and Proteus mirabilis. Antimicrobial susceptibility was determined using disk diffusion; the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of manuka essential oil, with or without Tris-EDTA, were investigated. RESULTS: A total of 44 isolates were resistant to at least one antibiotic and 19 strains were multidrug-resistant, with resistance to at least one agent in three or more antimicrobial classes. The MICs and MBCs of manuka oil alone were ≥1% (v/v) and ≥2% (v/v), respectively. There was no antimicrobial effect of Tris-EDTA (1.125:0.3 mg/mL) without manuka oil. However, the combination of manuka oil with Tris-EDTA significantly decreased the MICs (ranging from 0.06% to 0.5%, v/v; P < 0.001) and MBCs (ranging from 0.06% to 1%, v/v; P < 0.001). There also was no significant difference between multidrug-resistant and nonresistant bacterial isolates in terms of the antimicrobial activity of manuka oil with Tris-EDTA. CONCLUSIONS AND CLINICAL IMPORTANCE: The study findings suggest that manuka oil, especially when combined with Tris-EDTA, may be a promising alternative therapeutic option for Gram-negative otic pathogens. Clinical studies are needed to assess potential for in vivo ototoxic effects and efficacy.

Clinical efficacy of orally administered fluralaner for treatment of scabies in six free-ranging raccoon dogs (Nyctereutes procyonoides).

BACKGROUND: Sarcoptic mange in free-ranging raccoon dogs (Nyctereutes procyonoides) caused by Sarcoptes scabiei is a widespread zoonotic disease that causes severe skin lesions with significant morbidity and mortality. Fluralaner is a member of the isoxazoline chemical class and is an acaricide and insecticide widely used in flea, tick and mite infections of dogs (Canis lupus familiaris). OBJECTIVE: To evaluate the clinical efficacy of orally administered fluralaner in free-ranging raccoon dogs naturally infected with sarcoptic mange. ANIMALS: Six raccoon dogs rescued at the Seoul Wildlife Center between November 2017 and April 2018. METHODS AND MATERIALS: Raccoon dogs were treated with a single dose of a chewable fluralaner tablet. Clinical lesion scoring and superficial skin scraping were performed weekly for three weeks to assess treatment efficacy; the general health was assessed daily to monitor response and observe any adverse drug reactions. RESULTS: Within seven days of treatment, a marked reduction in skin lesions was observed and mites were no longer present in skin scrapings. There was no evidence of re-infestation and no additional drug administration was required. CONCLUSIONS AND CLINICAL IMPORTANCE: Although this was a nonrandomized, uncontrolled study of a small number of animals, it demonstrated that fluralaner may be suitable for treating sarcoptic mange in raccoon dogs.

Identification of VIM-2 metallo-ß-lactamase-producing Pseudomonas aeruginosa isolated from dogs with pyoderma and otitis in Korea.

BACKGROUND: Pseudomonas aeruginosa is a challenging pathogen cultured from cases of acute and chronic canine otitis and sometimes in cases of deep pyoderma. The spread of antimicrobial resistance, especially carbapenem resistance, is a serious therapeutic challenge worldwide. HYPOTHESIS/OBJECTIVES: To investigate the identification and characterization of resistant P. aeruginosa clinical canine isolates. MATERIALS: Clinical isolates (n = 80) were collected from dogs with pyoderma (n = 18) and otitis (n = 62) in Korea. METHODS: Antimicrobial susceptibility was determined using agar dilution and using Clinical and Laboratory Standards Institute guidelines for recording susceptibility for human Pseudomonas isolates; genetic relatedness of isolates was investigated by multilocus sequence typing (MLST) and SpeI macrorestriction analysis. The class 1 integrons were amplified and sequenced using primer walking. RESULTS: Most isolates were susceptible to colistin (97.5%), polymyxin B (96.3%), ciprofloxacin (81.3%) and meropenem (80.0%); whereas resistance to aztreonam (80%), piperacillin (52.5%), piperacillin/tazobactam (41.3%) and cefepime (37.5%) was high; 12 carbapenem-nonsusceptible isolates (15%) were detected. MLST revealed 45 different sequence types (STs) and macrorestriction analysis detected 55 distinct pulsotypes (PTs), which were divided into 25 clonal groups. Among carbapenem-nonsusceptible isolates, 10 (83.3%) were VIM-2-producing strains. Nine VIM-2-producing isolates were identified as ST1047 and harboured the same 2.8 kb class 1 integron. One remaining isolate was ST1203 with 2.1 kb class 1 integron. CONCLUSIONS AND CLINICAL IMPORTANCE: This study demonstrated the diversity of the phenotype and genotype of clinical P. aeruginosa isolates from dogs with pyoderma and otitis. The identification of VIM-2-producing P. aeruginosa in dogs is alarming and warrants further surveillance.