In vitro and in vivo antibacterial studies of volatile oil from Atractylodis Rhizoma against Staphylococcus pseudintermedius and multidrug resistant Staphylococcus pseudintermedius strains from canine pyoderma.

ETHNOPHARMACOLOGICAL RELEVANCE: Atractylodis Rhizoma is extensively employed in Traditional Chinese Medicine for the treatment of skin and gastrointestinal ailments. Its active components have been proven to demonstrate numerous beneficial properties, including antibacterial, antiviral, anti-inflammatory, anti-tumor, and anti-ulcer activities. Furthermore, the volatile oil from Atractylodis Rhizoma (VOAR) has been reported to effectively inhibit and eradicate pathogens such as Staphylococcus aureus, Escherichia coli and Candida albicans. Of particular concern is Staphylococcus pseudintermedius, the predominant pathogen responsible for canine pyoderma, whose increasing antimicrobial resistance poses a serious public health threat. VOAR merits further investigation regarding its antibacterial potential against Staphylococcus pseudintermedius. AIM OF THE STUDY: The study aims to verify the in vitro antibacterial activity of VOAR against Staphylococcus pseudintermedius. And a superficial skin infection model in mice was established to assess the in vivo therapeutic effect of VOAR. MATERIALS AND METHODS: Thirty strains of S. pseudintermedius were isolated from dogs with pyoderma, and the drug resistance was analyzed by disc diffusion method. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of VOAR were determined through the broth dilution method. The growth curve of bacteria in a culture medium containing VOAR was monitored using a UV spectrophotometer. Scanning electron microscopy was employed to observe the effects of VOAR on the microstructure of S. pseudintermedius. The impact of VOAR on the antibiotic resistance of S. pseudintermedius was assessed using the disc diffusion method. Twenty mice were randomly divided into four groups: the control group, the physiological saline group, the VOAR group, and the amikacin group. With the exception of the control group, the skin barrier of mice was disrupted by tap stripping, and the mice were subsequently inoculated with S. pseudintermedius to establish a superficial skin infection model. The modeled mice were treated with normal saline, VOAR, and amikacin for 5 days. Following the treatment period, the therapeutic effect of each group was evaluated based on the measures of body weight, skin symptoms, tissue bacterial load, tissue IL-6 content, and histopathological changes. RESULTS: The MIC and MBC of VOAR against 30 clinical isolates of S. pseudintermedius were found to be 0.005425% and 0.016875%, respectively. VOAR could exhibit the ability to delay the entry of bacteria into the logarithmic growth phase, disrupt the bacterial structure, and enhance the antibacterial zone in conjunction with antibiotic drugs. In the superficial skin infection model mice, VOAR significantly reduced the scores for skin redness (P < 0.0001), scab formation (P < 0.0001), and wrinkles (P < 0.0001). Moreover, VOAR markedly reduced the bacterial load (P < 0.001) and IL-6 content (P < 0.0001) in the skin tissues of mice. Histopathological observations revealed that the full-layer skin structure in the VOAR group was more complete, with clearer skin layers, and showed significant improvement in inflammatory cell infiltration and fibroblast proliferation compared to other groups. CONCLUSION: The results demonstrate that VOAR effectively inhibits and eradicates Staphylococcus pseudintermedius in vitro while also enhancing the pathogen's sensitivity to antibiotics. Moreover, VOAR exhibits a pronounced therapeutic effect in the superficial skin infection model mice.

Efficacy study of a topical treatment with a plant extract with antibiofilm activities using an in vivo model of canine superficial pyoderma.

BACKGROUND: Canine pyoderma is a common skin infection caused predominantly by staphylococcal bacteria. Because of increasing rates of antimicrobial resistance in bacterial isolates, there is an urgent need for alternative or supplementary treatment options. W16P576, a Water Extract of Complex Mix of Edible Plants (WECMEP), has shown in vitro activity against a variety of bacteria, including Staphylococcus pseudintermedius. A canine model of pyoderma was developed which allows in vivo testing of antimicrobial agents in a controlled environment. OBJECTIVE: To evaluate the antibacterial efficacy of topical application of W16P576 in a model of canine pyoderma. ANIMALS: Nine laboratory housed beagle dogs. METHODS AND MATERIALS: In an evaluator-blinded cross-over study with an eight week washout period, dogs were treated topically twice daily with W16P576 WECMEP or its vehicle, starting three days before bacterial challenge. On the day of challenge, each dog was treated with two concentrations of a clinical S. pseudintermedius strain on opposite sides of the body. Topical treatment was continued for 11 days and lesions of pyoderma were evaluated and scored for 14 days. RESULTS: All dogs developed lesions consistent with bacterial pyoderma. Lesion scores were generally higher on the side inoculated with a higher concentration of bacteria. Treatment with W16P576 significantly reduced lesion development and hastened resolution of lesions, compared to placebo. CONCLUSION: Topical application of W16P576 markedly reduced lesion development in this proof of principle study. Clinical trials are warranted to estimate benefits for dogs with naturally occurring pyoderma under field conditions.

Russian traditional medicine in dermatology.

The use of herbal remedies for various medical issues is becoming increasingly commonplace in all fields of medicine, and dermatology is no exception. This review focuses on traditional dermatologic herbal remedies, commonly used in Russia, as the rich array of 11 different plant zones has resulted in a great variety of medicinal plants. Herbal remedies warrant deeper investigation and research, especially due to their active substance content, which may interfere with or reinforce the effect of modern medications, something that medical professionals should be aware of when prescribing treatments. Although there are a great number of traditional herbal treatments in Russia, only the most commonly used and known treatments and applications will be described as an introduction to the field, which has had many books of varying quality written about it. The preparation and application of treatments for vitiligo, pyodermas, parasitic and infectious skin diseases, acne, dermatitides, rosacea, hyperpigmentation, rhytides, psoriasis, and hyperhidrosis are discussed.

In vitro efficacy of a honey-based gel against canine clinical isolates of Staphylococcus pseudintermedius and Malassezia pachydermatis.

BACKGROUND: Staphylococcus pseudintermedius and Malassezia pachydermatis are important agents in canine pyoderma and otitis. HYPOTHESIS/OBJECTIVES: Determine the in vitro efficacy of a honey-based gel (HBO) against meticillin-susceptible S. pseudintermedius (MSSP), meticillin-resistant S. pseudintermedius (MRSP) and M. pachydermatis, by minimum bactericidal concentration (MBC), minimum fungicidal concentration (MFC) and time-kill assay (TKA). Efficacy of the product's honey component (HO) also was evaluated. METHODS: Sixty S. pseudintermedius and 10 M. pachydermatis canine isolates were selected. All isolates were tested against serial dilutions of an HBO containing 40% HO (40%, 20%, 10%, 5% and 2.5% w/v) and HO alone (undiluted, 40%, 20%, 10%, 5% and 2.5% w/v). Microbroth assay followed by subculture was used to determine MBC and MFC. The same protocol was applied after product exposure to catalase. A well-diffusion assay for S. pseudintermedius was used to generate inhibition zones. A TKA for 10 isolates of S. pseudintermedius and 10 isolates of M. pachydermatis was performed. RESULTS: MBC was 20% w/v (5-20% w/v) for HBO and HO. HBO had lower MBC values when compared to HO (P = 0.003). No statistical difference was observed between MSSP/MRSP isolates (HBO P = 0.757, HO P = 0.743). Only HO was affected by catalase (P = 0.015). MFC for HBO was 10% w/v (5-10% w/v) and 40% w/v for HO (20-≥40% w/v). All isolates were killed after 4 h of exposure. CONCLUSIONS AND CLINICAL IMPORTANCE: Staphylococcus pseudintermedius and M. pachydermatis are susceptible to the HBO and these results can be used for future clinical trials.

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.

Effectiveness of topical green tea against multidrug-resistant Staphylococcus aureus in cases of primary pyoderma: An open controlled trial.

BACKGROUND: Antimicrobial activity of green tea against Staphylococcus aureus both in vitro and in vivo has been reported recently. Studies on clinical efficacy and safety of green tea as antibacterial agent against S. aureus in human cases are rare. OBJECTIVES: To evaluate the clinical effectiveness and safety of topical green tea on primary pyoderma caused by S. aureus. We also attempted to determine the minimum inhibitory concentration of green tea against S. aureus and methicillin-resistant S. aureus. METHODS: Open label, prospective, placebo-controlled study included community-acquired primary pyoderma cases caused by S. aureus. Severity grading was done on a scale of 1-5. Green tea ointment 3% and placebo ointment were used. Cure was defined on the basis of negative culture and assessment of clinical improvement. Minimum inhibitory concentration was determined by agar dilution method. Data were analyzed using Statistical Package for Social Sciences (SPSS) software version 16. RESULTS: Of the 372 patients, 250 received green tea and 122 received placebo. Multidrug-resistant S. aureus was isolated in 89.1% in green tea group and 81.1% in placebo group, respectively. Methicillin-resistant S. aureus was isolated in 24 patients. Cure was seen in 86% in green tea group and 6.6% in placebo group which was statistically very significant. The number of days for comprehensive cure in green tea group was 9.2 ± 6.4 days. All patients with methicillin-resistant S. aureus infection in the green tea group were cured. Minimum inhibitory concentration of green tea against S. aureus was 0.0265 ± 0.008 µg/ml and against methicillin-resistant S. aureus was 0.0205 ± 0.003 µg/ml. LIMITATIONS OF THE STUDY: Comparative trial was not conducted in the same patient with different lesions; children less than seven years were not considered as the school authorities did not permit for younger children to be included in the study and true randomization and blinding of investigators were not done. CONCLUSIONS: Green tea has a significant antibacterial effect against multidrug-resistant S. aureus. Minimum inhibitory concentration of green tea is established and is promising in methicillin-resistant S. aureus infections.

Influence of long-term oral application of quinolones on the ECG curve in dogs.

The aim of the study was to analyse the influence of enrofloxacin and pradofloxacin administered orally for 14 days on the ECG in dogs. The ECG was performed before and after a 14 day period of quinolone administration. There was an increase in the QTc and the TpTe interval in the group treated with quinolones. QTc was prolonged by 24 ms (p=0.001). The TpTe interval was shortened, on average, by 6.55 ms (p=0.048). In the group treated with enrofloxacin, QTc was prolonged by 16.27 ms (p=0.006) and the TpTe interval was shortened by 9.64 ms (p=0.050), the TpTe/QT index was reduced by 0.034 (p=0.050) on average. In dogs treated with pradofloxacin, QTc was prolonged by 21.55 ms (p=0.012) on average. The results suggest that a prolonged administration of quinolones can increase the risk of arrhythmias. Furthermore, different generations of these drugs increase this risk to various degrees. The study proved that second generation quinolones, such as enrofloxacin, significantly change the phase of depolarization and repolarization of the ventricles, at the same time increasing the risk of ventricular arrythmia. Pradofloxacin does not change the TpTe and TpTe/QT values, so it is safer in use.

A split-body, randomized, blinded study to evaluate the efficacy of a topical spray composed of essential oils and essential fatty acids from plant extracts with antimicrobial properties.

BACKGROUND: Bacterial pyoderma is a frequent presentation in dogs. Despite the widespread availability of effective systemic and topical antimicrobial products, good clinical practice currently recommends avoidance of long-term use to mitigate the development of bacterial resistance. HYPOTHESIS/OBJECTIVES: To evaluate the speed of resolution of clinical signs of bacterial pyoderma in dogs treated with a systemic antimicrobial agent with or without the use of an adjunctive spray with antimicrobial properties. ANIMALS: Twelve dogs with superficial bacterial pyoderma. METHODS: In this controlled and blinded study, all dogs were treated with oral cefalexin and a topical spray (PYOClean Spray) for 4 weeks. The spray was applied to one half of each dog's body, whereas a placebo spray was applied to the other half. RESULTS: Twelve dogs completed the study. Mean clinical scores were significantly reduced on spray-treated sites, for test product and placebo (respectively), by 47% and 34% at Week 1, 83% and 60% at Week 2, 95% and 82% at Week 3, and 100% and 96% at Week 4. Fifty percent of treated sites were considered clinically and cytologically cured at Week 2, 83% at Week 3, and 100% at Week 4 compared to 8%, 50% and 83% for the placebo sites, respectively. CONCLUSIONS AND CLINICAL IMPORTANCE: These results demonstrate that use of a topical spray which contains plant-derived essential oils and fatty acids, and compounds with antimicrobial properties (Manuka oil and N-acetyl cysteine) may help to speed resolution of pyoderma and may allow for shorter antimicrobial treatment time.

Clinico-bacteriological profile of primary pyodermas in Kashmir: a hospital-based study.

Pyodermas are a common group of infectious dermatological conditions on which few studies have been conducted. This study aimed to characterise the clinical and bacteriological profile of pyodermas, and to determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) infection in primary pyodermas in a dermatology outpatient department in Kashmir. Methods We conducted a hospital based cross-sectional study in the outpatient Department of Dermatology, Sexually Transmitted Diseases and Leprosy of Shri Maharaja Hari Singh Hospital, Srinagar, Jammu and Kashmir, India. Patients presenting with primary pyodermas were included in the study. A detailed history and complete physical and cutaneous examination was carried out along with microbiological testing to find aetiological microorganisms and their respectiveantimicrobial susceptibility patterns. Antimicrobial susceptibility testing, including that for methicillin resistance, was carried out by standard methods as outlined in the current Clinical and Laboratory Standards Institute guidelines. Results In total, 110 patients were included; the age of the study population ranged from 3 to 65 years (mean age 28 years); 62% were male. Poor personal hygiene was noted in 76 (69%). Furunculosis (56; 51%) was the most common clinical presentation. Staphylococcus aureus was isolated in 89 (81%) of cases, and MRSA formed 54/89 (61%) of Staphylococcus aureus isolates. All MRSA strains were sensitive to vancomycin. Conclusion The prevalence of MRSA was high in this sample of communityacquired primary pyodermas. It is therefore important to monitor the changing trends in bacterial infection and their antimicrobial susceptibility patterns and to formulate a definite antibiotic policy which may be helpful in decreasing the incidence of MRSA infection.

Effectiveness of a combined (4% chlorhexidine digluconate shampoo and solution) protocol in MRS and non-MRS canine superficial pyoderma: a randomized, blinded, antibiotic-controlled study.

BACKGROUND: There is a lack of studies comparing topical antiseptics to systemic antibiotics in the treatment of canine superficial pyoderma. HYPOTHESIS/OBJECTIVES: To compare the efficacy of topical chlorhexidine with systemic amoxicillin-clavulanic acid for the treatment of canine superficial pyoderma. ANIMALS: A randomized controlled trial was conducted in dogs with superficial pyoderma. Group T (n = 31) was treated topically with 4% chlorhexidine digluconate shampoo (twice weekly) and solution (once daily) for 4 weeks. Group S (n = 20) was treated orally with amoxicillin-clavulanic acid (25 mg/kg) twice daily for 4 weeks. METHODS: Bacterial culture and susceptibility testing were performed on clinical specimens collected before treatment. Severity of lesions and number of intracellular bacteria were evaluated using four-point scales to calculate a total pyoderma score for each dog. Pruritus was assessed by owners using a visual analog scale (range 0-10). Scores were analysed for statistical differences between groups T and S. RESULTS: Staphylococcus pseudintermedius was isolated from 48 dogs, including eight meticillin-resistant strains (MRSP). Although the number of dogs was small, no significant differences in pyoderma and pruritus scores were observed between groups throughout the study except for day 1, when group S had a significantly higher total score than group T (P = 0.03). Treatment with chlorhexidine products resulted in resolution of clinical signs in all dogs including those infected with MRSP. CONCLUSION AND CLINICAL IMPORTANCE: Topical therapy with chlorhexidine digluconate products may be as effective as systemic therapy with amoxicillin-clavulanic acid. This finding supports the current recommendations to use topical antiseptics alone for the management of superficial pyoderma.

Susceptibility in vitro of canine methicillin-resistant and -susceptible staphylococcal isolates to fusidic acid, chlorhexidine and miconazole: opportunities for topical therapy of canine superficial pyoderma.

OBJECTIVES: Increasing multidrug resistance amongst canine pathogenic staphylococci has renewed interest in topical antibacterial therapy for skin infections in the context of responsible veterinary prescribing. We therefore determined the activity in vitro of three clinically relevant topical agents and synergism between two of them against Staphylococcus pseudintermedius and Staphylococcus aureus. METHODS: The MICs of fusidic acid (n = 199), chlorhexidine (n = 198), miconazole (n = 198) and a 1:1 combination of miconazole/chlorhexidine (n = 198) were determined for canine isolates [50 MRSA and 49 methicillin-resistant S. pseudintermedius (MRSP), 50 MSSA and 50 methicillin-susceptible S. pseudintermedius (MSSP)] collected from the UK and Germany using an agar dilution method (CLSI VET01-A4). Fractional inhibitory concentration (FIC) indices were calculated to assess the interaction of miconazole with chlorhexidine. RESULTS: MICs of each drug/combination were significantly (P < 0.0005) higher for S. aureus when compared with S. pseudintermedius. Most strains (n = 172) had an MIC of fusidic acid of ≤0.03 mg/L (MIC ≥64 mg/L, n = 5 MRSA). All strains had MICs of chlorhexidine of 0.5-4 mg/L, except for one MRSA (MIC = 8 mg/L). All but four strains had MICs of miconazole of 1-4 mg/L (MIC = 16 mg/L, n = 3; MIC = 256 mg/L, n = 1). Miconazole/chlorhexidine (1:1 ratio) had a synergistic effect against 49/50 MRSA, 31/50 MSSA, 12/49 MRSP and 23/49 MSSP. CONCLUSIONS: Since the majority of these staphylococci, including methicillin-resistant isolates, had MICs that should be readily exceeded by topical skin application of these agents, their therapeutic efficacy for canine superficial pyoderma should be assessed. The synergistic interaction shown in vitro supports further clinical evaluation of miconazole/chlorhexidine combination therapy for staphylococcal infection.

Efficacy of anti-staphylococcal protein P128 for the treatment of canine pyoderma: potential applications.

In this study, we demonstrate the antibacterial activity of P128 on Staphylococcus isolates responsible for canine pyoderma. Eighty seven swabs were collected from dogs suffering from pyoderma and subjected to antibiotic sensitivity test and 46 Staphylococcus strains were isolated and characterized. In-vitro antimicrobial susceptibility testing with P128 was done by Minimum Inhibitory Concentration (MIC) method as per CLSI guidelines. All the Staphylococci isolated from the dogs with pyoderma, although showed resistance to various antibiotics tested, were lysed by P128. Clinical efficacy of P128 was examined in 17 dogs with pyoderma by application of the P128 hydrogel twice daily for 8 days and the results indicated complete healing of all the lesions of all the dogs under treatment. Under the conditions of this study, P128 was found to be a potent convenient proteinaceous drug for the treatment of staphylococcal pyoderma in dogs.

Factors associated with methicillin-resistant versus methicillin-susceptible Staphylococcus pseudintermedius infection in dogs.

OBJECTIVE: To compare methicillin-resistant Staphylococcus pseudintermedius (MRSP) and methicillin-susceptible S pseudintermedius (MSSP) infections in dogs. DESIGN: Multicenter case-control study. ANIMALS: Dogs with MRSP infections were matched, by hospital, with 2 MSSP controls, with the infections occurring immediately before and after the case infection. PROCEDURES: Signalment, historical, clinical, treatment, and outcome data were documented. Conditional logistic regression was performed. A manual stepwise backward elimination procedure was used to build the multivariable model. RESULTS: 56 case and 112 control dogs were enrolled. Pyoderma was the most common infection type in both groups. In the final multivariable model, systemic administration of antimicrobials within 30 days prior to infection was significantly associated with an MRSP versus an MSSP infection (OR, 9.9; 95% confidence interval, 3.59 to 27.53). CONCLUSIONS AND CLINICAL RELEVANCE: The association of prior antimicrobial administration and MRSP infection indicated the potential impact of routine antimicrobial use in veterinary medicine on antimicrobial resistance and the need for prudent use of these important drugs. Mortality rate was not significantly different between MRSP and MSSP infections; the lack of a significant difference suggested that MRSP was inherently no more virulent than MSSP, provided the infection was properly diagnosed and appropriate treatment was started. Basic concepts such as prudent antimicrobial use and early diagnosis through timely submission of appropriate culture specimens therefore can be important measures to try to reduce the impact of this pathogen.

Selection of CMY-2 producing Escherichia coli in the faecal flora of dogs treated with cephalexin.

Cephalexin is a first generation cephalosporin commonly used in dogs for treatment of pyoderma. The objective of this study was to evaluate the in vivo effects of cephalexin on selection of Escherichia coli resistant to extended-spectrum cephalosporins. A cohort study was conducted on 13 dogs presenting clinical signs of pyoderma and treated with cephalexin and 22 healthy dogs that had not been treated with antibiotics during the previous six months. Selective plating of faeces on MacConkey agar plates containing cefotaxime (CTX) yielded growth of CTX-resistant E. coli for eight of the 13 treated dogs (62%), whereas no growth was observed for any of the control dogs (Fisher exact test, P<0.001). PCR and sequence analysis identified bla(CMY-2) in all eight dogs. PCR-based replicon typing and restriction fragment length polymorphism (RFLP) of E. coli transformants revealed location of bla(CMY-2) on indistinguishable IncI1 plasmids in five of the eight dogs. One representative of these five epidemiologically related IncI1 plasmids was further characterized as sequence type (ST2) by plasmid multilocus sequence typing (pMLST). E. coli from the remaining three dogs harboured bla(CMY-2) on distinct plasmids with non-typeable replicons. A single isolate was classified as an extraintestinal pathogenic E. coli (ExPEC) due to the presence of iutA, papC and sfa/foc. The results provide a strong indication that cephalexin selects for E. coli producing plasmid-borne CMY-2 ß-lactamase. The isolation of a specific IncI1 plasmid carrying bla(CMY-2) from five epidemiologically unrelated dogs suggests that cephalexin use may contribute to the spread of this plasmid lineage among Danish dogs.

Risk factors associated with the antimicrobial resistance of staphylococci in canine pyoderma.

This study reports the susceptibility to antimicrobial agents of staphylococci (n=105) isolated from dogs, and the factors associated with this resistance. The study animals were 23 healthy dogs (group A), 24 with first-time pyoderma (group B), and 27 with recurrent pyoderma that had undergone long-term antibiotic treatment (group C). Staphylococci were more commonly isolated from the pyoderma-affected than the healthy dogs (p<0.0001). Some 78% of the isolates were resistant to at least one antimicrobial agent. Resistance to amoxicillin-clavulanate, cephalosporins (OR 4.29, 95% CI [1.15, 16.3] respectively), enrofloxacin (OR 9.47, 95% CI [1.53, 58.5]) and ciprofloxacin (OR 79.7 95% CI [3.26, 1947.4]) was more common among group C isolates. Some 32% of all the isolates were multiresistant (MR) and 10.4% were methicillin-resistant (MRS). The probability of isolating MRS staphylococci in group C increased by a factor of four (95% CI [1.18, 17.9]) compared to A plus B. Multi-resistant (MR) isolates were obtained more commonly from urban than rural dogs (OR 3.79, 95% CI [1.09, 13.17]). All the MRS staphylococci encountered were obtained from urban dogs and more commonly from male dogs (p=0.07). This study shows that dogs bred in urban habitat, with a history of antibiotic therapy in the past year represents significant risk of being carriers of isolates resistant to methicillin (MRS) and other antimicrobials. These factors should be considered before applying an antimicrobial treatment in veterinary clinics.

Multidrug- and methicillin resistant Staphylococcus pseudintermedius as a cause of canine pyoderma: a case report.

A case of a dog with a long-term inflammatory skin disorder due to infection with methicillin-resistant Staphylococcus pseudintermedius (MRSP) is described. After initial diagnostics of MRSP, follow-up swabs of the dog (nose, skin) were taken twice after four and seven weeks. MRSP was constantly isolated from the skin and once from the nose. Since infected humans might be a source of reinfection, the owners of the dog were screened (nasal) three times during their pet's therapy. Thereby, the male owner was found to be colonized with MRSP once in the first sampling round. Comparative typing of all MRSP-isolates by pulsed-field gel electrophoresis (PFGE), SCCmec typing, multilocus sequence typing (MLST), spa typing, PCR-detection of the leukotoxin encoding operon (LukI) and the Staphylococcus intermedius-exfoliative toxin (SIET) as well as antimicrobial resistance profiling by broth microdilution revealed that all five MRSP isolates from the dog and the single isolate from the owner were indistinguishable by any of the applied methods. All isolates were assigned to a certain strain, a multidrug-resistant MRSP belonging to sequence type (ST) 71, spa type (t)05, harbouring SCCmecIII as well as the genes encoding LukI and SIET. In this case, a number of reasons might have contributed to therapy failure and re-infection, respectively (e. g. contact to other MRSP-colonized dogs, contact to MRSP-colonized humans, refusal to clip the dog's fur). In addition, MRSP-contaminated objects or surfaces in the household, which were difficult to disinfect or simply not considered as a potential source of MRSP, might have served as a source of re-infection. These results envision the possibility of a dog-to-human transmission of MRSP and the relevance of this aspect as a potential source of re-infection in cases of bacterial-supported long-term skin disorders in canine patients. First cases of MRSP infections in humans have been described only recently. However, the general pathogenic potential of multidrug resistant MRSP in humans is unknown so far and needs further investigation.

Multifocal papular deep bacterial pyoderma in a Boxer dog caused by Pseudomonas aeruginosa.

A young adult Boxer dog was presented with a papular dermatitis on the dorsal back and ventral neck that had developed while it was being treated with cyclosporine and cephalexin for atopic dermatitis and secondary superficial staphylococcal pyoderma, respectively. Histopathology demonstrated nodular to diffuse pyogranulomatous dermatitis with focal furunculosis. Numerous bacterial rods, free in the tissue and engulfed by neutrophils and macrophages, could be demonstrated on stained samples (haematoxylin-eosin; Giemsa). Bacterial culture from an aseptically collected skin biopsy punch sample yielded a pure growth of Pseudomonas aeruginosa, sensitive to a variety of antimicrobials. Successful treatment was accomplished following discontinuation of cyclosporine and an extended course of enrofloxacin. There has not been a recurrence of the pseudomonal pyoderma during the subsequent 2 years.

Efficacy of orbifloxacin tablets for the treatment of superficial and deep pyoderma due to Staphylococcus intermedius infection in dogs.

Orbifloxacin tablets were administered orally to 23 dogs with superficial and/or deep staphylococcal pyoderma. Response to therapy was excellent in 95.6% of the dogs. Duration of therapy varied from 21 to 40 days (average 29 days) for dogs having only superficial infections, and from 25 to 150 days (average 72 days) for dogs having deep infections. Relapses occurred in 18% of the dogs within a 3-month period. One dog developed a presumed adverse cutaneous drug reaction. Under the conditions of this study, orbifloxacin was an effective, safe, and convenient antibiotic for the treatment of superficial and deep staphylococcal pyoderma in dogs.