Canine Pyoderma Research Articles

Lesionally enriched skin microbiota transplantation by activated charcoal nose pore strips for ‘treat to target’ in canine pyoderma

Amaçlar: Birçok bakteri, farklı karbon kaynaklarının bir kombinasyonu arasındaki substratları seçici olarak kullanabilir. Aktif karbon, temel ilaçlar için bir konum sergiler ve gastrointestinal ve ermatolojik sorunlarla mücadelede rol oynar. Toksinlerin deriden uzaklaştırılması yoluyla probiyotik veya patojenik bakterilere karşı farklı etki mekanizmasını bildiren bir çalışma bulunmamaktadır. Yüksek adsorpsiyon kapasitesi, kimyasal stabilitesi ve mekanik sağlamlığı nedeniyle, aktif kömür burun gözenek şeritleri kullanılarak lezyonel olarak zenginleştirilmiş cilt mikrobiyota transplantasyonunun (Le-smt) köpeklerde piyodermaya karşı savaşabileceğini varsaydık. Metodoloji: Daha önce herhangi bir ilaç reçetesi olmayan, klinik ve laboratuvar muayenelerine tabi tutulan ve yüzeysel piyoderma tanısı alan toplam 16 köpek kaydedildi ve haftada 3 kez Le-smt aktif kömür burun gözenek şeritleri ile tedavi edildi. Köpekler arasında piyoderma için önceden belirlenmiş puanlama, Le-smt öncesinde (10 ila 61 arasında değişen) ve sonrasında (0 ila 22) benimsenmiştir. Bulgular: Haftada 3 seans sonunda 16 köpeğin tamamı herhangi bir ilaç reçetesi olmadan iyileştirildi. Le-smt ortalama yüzeysel piyoderma skorlamasına göre tedavi öncesinde ve tedavi sonrasında sırasıyla 37,10 ve 9,81 (p<0,001) olmuştur. Sonuç: Bu yeni teknik, eski moda tedavi protokolünü polifarmasi ile değiştirmeli ve muhtemelen onun yerine geçmelidir.

Canine pyoderma histopathology: Insights and findings

Canine pyoderma histopathology: Insights and findings

Molecular detection of major coagulase positive Staphylococcus isolates from the canine pyoderma cases

Molecular detection of major coagulase positive Staphylococcus isolates from the canine pyoderma cases

Comparison of selected cytomorphological features of canine pemphigus foliaceus and superficial pyoderma.

Cytological detection of acantholytic keratinocytes (acantholytic cells [AC]) helps to identify canine pemphigus foliaceus (cPF) yet AC also occurs in superficial pyoderma (SP), the main differential diagnosis. To compare selected cytomorphological features of cPF and SP and to establish cytological diagnostic criteria that could differentiate cPF from SP. 40 and 51 client-owned dogs with PF and SP, respectively. Impression smears from cPF (64), impetigo (40) and exfoliative superficial pyoderma (ESP) (17) samples were stained with Romanowsky stain, randomised, blinded and evaluated by two investigators independently. The entire sample was screened (×500 or ×1000 magnification) for round (AC1), boat (AC2) and raft AC, eosinophils and bacteria. Interobserver agreements were calculated. The average number of the 10 highest ×500 fields for AC1 and AC2 was significantly higher in PF than SP (p < 0.0001; Kruskal-Wallis test). Rafts and eosinophils were more common in PF than SP (p < 0.0001; chi-square test), while bacteria were rare in PF (5%; p < 0.0001; chi-square test). Observations between the experienced and novice investigators were highly correlated. An ROC analysis identified five AC1/×500-magnification field as a suitable cut-off value for predicting PF diagnosis. This cut-off value was tested by two additional investigators, who identified sensitivity of 84%-100%, specificity of 95%-97% and accuracy of 95%-96% for the diagnosis of cPF. Criterion-based impression smear cytological evaluation can provide strong evidence to support the clinical diagnosis. Acantholytic cell morphology varies in cPF and SP, and experience can improve accuracy in cytological differentiation.

Haematological, biochemical, histopathological studies and isolation of bacteriological agents from canine pyoderma cases in Karnataka

Haematological, biochemical, histopathological studies and isolation of bacteriological agents from canine pyoderma cases in Karnataka

Ciclosporin‐responsive pyoderma in dogs: A comparison to human pyoderma gangrenosum

AbstractWe describe 20 cases of canine pyoderma responsive to immunosuppressive treatments and resembling human pyoderma gangrenosum. All dogs presented with a rapidly evolving, focal to multifocal, painful ulcerative dermatitis, non‐responsive to multiple antibiotic and anti‐inflammatory therapies. Elevations of C‐reactive protein (100%), neutrophilia (75%) and fever (25%) were also present. Histopathology showed a severe, ulcerative, superficial to deep, predominantly neutrophilic dermatitis. Bacterial infection was the most challenging differential diagnosis. Resolution of the lesions was obtained within 4–8 weeks in 83% of dogs treated with ciclosporin. Maintenance treatment was required in the majority of the dogs.

A LAMP point-of-care test to guide antimicrobial choice for treatment of Staphylococcus pseudintermedius pyoderma in dogs

Staphylococcus pseudintermedius is the most common cause of pyoderma in dogs. We validated a point-of-care (PoC) test based on colorimetric loop-mediated isothermal amplification (LAMP) for rapid S. pseudintermedius identification and susceptibility testing for first line antimicrobials for systemic treatment of canine pyoderma, i.e., lincosamides, first generation cephalosporins and amoxicillin clavulanate. Newly designed LAMP primers targeting clinically relevant resistance genes were combined with a previously validated set of primers targeting spsL for species identification. After laboratory validation on 110 clinical isolates, we assessed the performance of the test on 101 clinical specimens using routine culture and susceptibility testing as a reference standard. The average hands-on and turnaround times for the PoC test were 30 and 90 min, respectively. The assay showed sensitivity and specificity near 100% for both species identification and susceptibility testing when performed on bacterial cultures or clinical specimens in the laboratory. However, the PoC test yielded less accurate results when performed on-site by clinical staff (92% sensitivity and 64% specificity for species identification, 67% sensitivity and 96% specificity for β-lactam susceptibility, and 83% sensitivity and 71% specificity for lincosamide susceptibility). These results indicate that the PoC test should be adapted to a user-friendly technology to facilitate performance and interpretation of results by clinical staff. If properly developed, the test would allow veterinarians to gain rapid information on antimicrobial choice, limiting the risk of treatment failure and facilitating adherence to antimicrobial use guidelines in small animal veterinary dermatology.

Longitudinal antimicrobial susceptibility trends of canine Staphylococcus pseudintermedius

Antimicrobial resistance within Staphylococcus pseudintermedius poses a significant risk for the treatment of canine pyoderma and as a reservoir for resistance and potential zoonoses, but few studies examine long-term temporal trends of resistance. This study assesses the antimicrobial resistance prevalence and minimum inhibitory concentration (MIC) trends in S. pseudintermedius (n=1804) isolated from canine skin samples at the Cornell University Animal Health Diagnostic Center (AHDC) between 2007 and 2020. Not susceptible (NS) prevalence, Cochran-Armitage tests, logrank tests, MIC50 and MIC90 quantiles, and survival analysis models were used to evaluate resistance prevalence and temporal trends to 23 antimicrobials. We use splines as predictors in accelerated failure time (AFT) models to model non-linear temporal trends in MICs. Multidrug resistance was common among isolates (47%), and isolates had moderate to high NS prevalence to the beta-lactams, chloramphenicol, the fluoroquinolones, gentamicin, the macrolides/lincosamides, the tetracyclines, and trimethoprim-sulfamethoxazole. However, low levels of NS to amikacin, rifampin, and vancomycin were observed. Around one third of isolates (38%) were found to be methicillin resistant S. pseudintermedius (MRSP), and these isolates had a higher prevalence of NS to all tested antimicrobials than methicillin susceptible isolates. Amongst the MRSP isolates, one phenotypically vancomycin resistant isolate (MIC >16 µg/mL) was identified, but genomic sequence data was unavailable. AFT models showed increasing MICs across time to the beta-lactams, chloramphenicol, the fluoroquinolones, gentamicin, and the macrolides/lincosamides, and decreasing temporal resistance (decreasing MICs) to doxycycline was observed amongst isolates. Notably, ATF modeling showed changes in MIC distributions that were not identified using Cochran-Armitage tests on prevalence, MIC quantiles, and logrank tests. Increasing resistance amongst these S. pseudintermedius isolates highlights the need for rational, empirical prescribing practices and increased antimicrobial resistance (AMR) surveillance to maintain the efficacy of current therapeutic agents. AFT models with non-linear predictors may be a useful, breakpoint-independent, surveillance tool alongside other modeling methods and antibiograms.

Erythritol alters phosphotransferase gene expression and inhibits the in vitro growth of Staphylococcus coagulans isolated from canines with pyoderma.

Staphylococcus coagulans (SC) belongs to a group of coagulase-positive staphylococci occasionally isolated from the skin lesions of dogs with pyoderma. We recently revealed that erythritol, a sugar alcohol, inhibited the growth of SC strain JCM7470. This study investigated the molecular mechanisms involved in this growth inhibition of JCM7470 by erythritol, and determine whether erythritol inhibits the growth of SC isolated from the skin of dogs with pyoderma. Comprehensive analysis of the gene expression of JCM7470 in the presence of erythritol revealed that erythritol upregulated the expression of glcB and ptsG genes, both of which encode phosphotransferase system (PTS) glucoside- and glucose-specific permease C, B, and A domains (EIICBA), respectively, associated with sugar uptake. Moreover, erythritol suppressed in vitro growth of all 27 SC strains isolated from the skin lesions of canine pyoderma, including 13 mecA gene-positive and 14 mecA gene-negative strains. Finally, the growth inhibition of the SC clinical isolates by erythritol was restored by the addition of glucose. In summary, we revealed that erythritol promotes PTS gene expression and suppresses the in vitro growth of SC clinical isolates from dogs with pyoderma. Restoration of the erythritol-induced growth inhibition by glucose suggested that glucose starvation may contribute to the growth inhibition of SC.

In vitro evaluation of bactericidal effects of fluorescent light energy on Staphylococcus pseudintermedius and S. aureus.

Staphylococcus pseudintermedius and S. aureus are bacterial species of importance in veterinary medicine. The increasing incidence of antibiotic resistance necessitates the implementation of novel treatment modalities. Fluorescent light energy (FLE) is used as an adjunctive and primary treatment for canine pyoderma. However, no invitro studies exist investigating its bactericidal effects against S. pseudintermedius or S. aureus. To determine the bactericidal effects of FLE on S. pseudintermedius and S. aureus isolates. Two meticillin-susceptible S. pseudintermedius (MSSP) isolates, three meticillin-resistant S. pseudintermedius (MRSP) isolates and one meticillin-resistant S. aureus (MRSA) isolate were studied. Acommercially available blue light-emitting diode (bLED) lamp and photoconverting hydrogel FLE system was used. All bacteria were exposed to five conditions following inoculation: (i) no treatment (control); (ii) blue light (bLED) once; (iii) bLED twice consecutively; (iv) FLE (bLED and photoconverting hydrogel) once; and (v) FLE (bLED and photoconverting hydrogel) twice consecutively. Each individual exposure was 2 min long. No statistically significant differences (p < 0.05) were found for any treatment group when each bacterial isolate was evaluated individually, MSSP isolates were grouped, MRSP isolates were grouped, when all S. pseudintermedius isolates were combined, or when all isolates of both Staphylococcus species were combined. While clinical success is reported when using FLE to treat Staphylococcus infections in animals, no invitro antibacterial efficacy was identified for S. pseudintermedius or S. aureus under experimental conditions. The clinical success observed with FLE may be the result of a more complex invivo response.

Isolation and antibiogram profiling of Staphylococcus species in canine pyoderma

Isolation and antibiogram profiling of Staphylococcus species in canine pyoderma

Epidemiologic case investigation on the zoonotic transmission of Methicillin-resistant Staphylococcus pseudintermedius among dogs and their owners

Dogs often carry methicillin-resistant Staphylococci asymptomatically. These bacteria are frequently linked to conditions such as canine pyoderma and otitis. Close interaction between dogs and humans can facilitate the exchange of resistant strains, particularly Methicillin-resistant Staphylococcus pseudintermedius (MRSP). This represents a public health issue, since these strains, in addition to occasionally causing infections in humans, can also serve as a source of resistance and virulence genes for strains of greater importance in human medicine, such as Staphylococcus aureus. Furthermore, MRSP strains are often multidrug resistant, which ends up compromising the treatment of infections. This study aimed to assess the potential transmission of Staphylococcus pseudintermedius among dogs and their owners. We examined a total of one hundred canine samples collected from cases of pyoderma and otitis to detect the presence of staphylococci. Simultaneously, we conducted evaluations on all dog owners. Staphylococci strains were identified using MALDI-TOF MS and PCR targeting the nuc gene. Methicillin resistance screening was also performed by detecting the mecA gene using PCR. Among the sampled dogs, 64 carried S. pseudintermedius. Nine were identified as MRSP. In six instances, dogs and their owners exhibited S. pseudintermedius. These samples underwent genome sequencing and were screened for antimicrobial resistance genes, SCCmec typing, MLST characterization, and Single Nucleotide Polymorphisms (SNP) analyses. The results of the phylogenetic analysis revealed that in three cases, dogs and owners had closely related isolates, suggesting interspecies transmission. Two of these cases involved MRSP and one MSSP. Moreover, in the two MRSP cases, the same SCCmec type (type V) was detected. Additionally, the sequence type was consistent across all three cases involving dogs and owners (MSSP ST2277, MRSP ST2282, and ST2286). These findings strongly indicate a transmission event. Since Staphylococcus pseudintermedius is primarily isolated from canine samples, it is plausible that dogs may have acted as a potential source. In the remaining three cases, despite identifying the same species in both samples, they had notable phylogenetic differences.

Topical erythritol combined with L-ascorbyl-2-phosphate inhibits staphylococcal growth and alleviates staphylococcal overgrowth in skin lesions of canine superficial pyoderma

Topical erythritol combined with L-ascorbyl-2-phosphate inhibits staphylococcal growth and alleviates staphylococcal overgrowth in skin lesions of canine superficial pyoderma

Methicillin-resistant Staphylococci in canine pyoderma in Thailand.

Methicillin-resistant Staphylococci (MRS) seriously threatens animal and human health. Repeated antibiotic use allows the bacteria to develop resistance to several antibiotic classes and become multidrug-resistant (MDR). Canine pyoderma, a common skin condition in dogs, is mainly caused by Staphylococci, including MRS. Detecting this infection in all canine populations is crucial to develop a proper preventive plan. This study estimated the prevalence, antibiogram, and risk factors of MRS in canine patients at a referral animal hospital in Khon Kaen, Thailand. Skin swabs and relevant information were collected from 56 client-owned dogs that visited the hospital from September 2019 to September 2020. Staphylococci colonies were subjected to molecular identification and antibiotic susceptibility tests using an automated system (VITEK® 2). These colonies were also genetically identified using multiplex-polymerase chain reaction (PCR) and sequencing. The mecA gene, encoding methicillin resistance, was detected using simplex-PCR. The risk factors of MRS infection and their association with MRS infection were analyzed using logistic regression and the Chi-square test, respectively. The prevalence of MRS was found to be 35.7% (20/56 dogs). By species, methicillin-resistant Staphylococcus pseudintermedius was found in 24 of 104 isolates (23.1%), and all samples were MDR. Receiving systemic antibiotics in the past 6 months was a major risk factor associated with MRS infection (p < 0.05; odds ratio (OR) > 1). In addition to the MRS isolates, the mecA gene was also detected in methicillin-susceptible Staphylococci isolates. This might be because of the high expression of blaI, and mutations in c-di-AMP cyclase DacA, RelA, and Fem proteins. A high prevalence of MRS and MDR was observed in the studied population, which might be potentially due to improper antibiotic use by the owners and horizontal transfer of drug-resistance genes.

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 relevanceAtractylodis 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 studyThe 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 methodsThirty 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. ResultsThe 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. ConclusionThe 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.

Time-Kill Analysis of Canine Skin Pathogens: A Comparison of Pradofloxacin and Marbofloxacin.

Time-kill curves (TKCs) are more informative compared with the use of minimum inhibitory concentration (MIC) as they allow the capture of bacterial growth and the development of drug killing rates over time, which allows to compute key pharmacodynamic (PD) parameters. Our study aimed, using a semi-mechanistic mathematical model, to estimate the best pharmacokinetic/pharmacodynamic (PK/PD) indices (ƒAUC/MIC or %ƒT > MIC) for the prediction of clinical efficacy of veterinary FQs in Staphylococcus pseudintermedius, Staphylococcus aureus, and Escherichia coli collected from canine pyoderma cases with a focus on the comparison between marbofloxacin and pradofloxacin. Eight TCKs for each bacterial species (4 susceptible and 4 resistant) were analysed in duplicate. The best PK/PD index was ƒAUC24h/MIC in both staphylococci and E. coli. For staphylococci, values of 25-40 h were necessary to achieve a bactericidal effect, whereas the calculated values (25-35 h) for E. coli were lower than those predicting a positive clinical outcome (100-120 h) in murine models. Pradofloxacin showed a higher potency (lower EC50) in comparison with marbofloxacin. However, no difference in terms of a maximal possible pharmacological killing rate (Emax) was observed. Taking into account in vivo exposure at the recommended dosage regimen (3 and 2 mg/kg for pradofloxacin and marbofloxacin, respectively), the overall killing rates (Kdrug) computed were also similar in most instances.

Genomic Features of Antimicrobial Resistance in Staphylococcus pseudintermedius Isolated from Dogs with Pyoderma in Argentina and the United States: A Comparative Study.

Staphylococcus pseudintermedius is the most common opportunistic pathogen in dogs and methicillin resistance (MRSP) has been identified as an emerging problem in canine pyoderma. Here, we evaluated the antimicrobial resistance (AMR) features and phylogeny of S. pseudintermedius isolated from canine pyoderma cases in Argentina (n = 29) and the United States (n = 29). 62% of isolates showed multi-drug resistance. The AMR genes found: mecA, blaZ, ermB, dfrG, catA, tetM, aac(6')-aph(2″), in addition to tetK and lnuA (only found in U.S. isolates). Two point mutations were detected: grlA(S80I)-gyrA(S84L), and grlA(D84N)-gyrA(S84L) in one U.S. isolate. A mutation in rpoB (H481N) was found in two isolates from Argentina. SCCmec type III, SCCmec type V, ΨSCCmec57395 were identified in the Argentinian isolates; and SCCmec type III, SCCmec type IVg, SCCmec type V, and SCCmec type VII variant in the U.S. cohort. Sequence type (ST) ST71 belonging to a dominant clone was found in isolates from both countries, and ST45 only in Argentinian isolates. This is the first study to comparatively analyze the population structure of canine pyoderma-associated S. pseudintermedius isolates in Argentina and in the U.S. It is important to maintain surveillance on S. pseudintermedius populations to monitor AMR and gain further understanding of its evolution and dissemination.

An investigation of household dogs as the source in a case of human bacteraemia caused by Staphylococcus pseudintermedius

ABSTRACT Staphylococcus pseudintermedius is a commensal and an opportunistic pathogen in dogs, and is also an opportunistic pathogen in humans. Here we report about a case of bacteraemia with a fatal outcome in a 77-year-old co-morbid male likely caused by a S. pseudintermedius and the investigation into the possible transmission from the two dogs in the patient’s household. The two dogs carried the same S. pseudintermedius strain, but this dog strain was unrelated to the strain from the patient. In contrast to the patient strain, the dog strain showed reduced susceptibility to several antibiotics and both dogs had received antibiotic treatment prior to sampling. So, it is conceivable that these treatments can have eliminated the patient’s strain between the transmission event and the dog sampling. It is also worth noting that the patient strain was positive for the expA gene, which encodes an exfoliative toxin closely related to the S. aureus exfoliative toxin B. This toxin has been linked to canine pyoderma, but its effect on humans remains unknown. Transmission of S. pseudintermedius was confirmed in the household between the dogs. However, we could not verify that the dogs were the source for the S. pseudintermedius in the patient.

Comparative Susceptibility of Pathogenic Methicillin-Resistant and Methicillin-Susceptible Staphylococcus pseudintermedius to Empirical Cotrimazole for Canine Pyoderma.

The prevalence of methicillin-resistant Staphylococcus pseudintermedius (MRSP) that causes pyoderma has been gradually shifting, according to many surveillance studies, with annual changes. The empirical cotrimazole regimen remains interesting, but research on cotrimazole susceptibility to MRSP is limited. The objective of this study was to evaluate the susceptibility of cotrimazole to canine pyoderma MRSP isolates. Sixty isolates of S. pseudintermedius were identified as 16 MRSP and 44 methicillin-susceptible S. pseudintermedius (MSSP) using an oxacillin disk diffusion test and VITEK 2 system with VITEK GP card. Using the VITEK 2 system with a VITEK AST-GP81 card, the susceptibility rates of MRSP (15.00%) and MSSP (35.00%) to cotrimazole was observed. The median MIC of cotrimazole on MSSP (median, ≤10; IQR, 10-320) was lower than that of MRSP (median, ≥320; IQR, 10-320) (p = 0.5889, Mann-Whitney test). Percent attainment of PK/PD targets in MRSP (q 12 h, 43.75; q 8 h, 43.75) were lower than that of MSSP (q 12 h, 52.27; q 8 h, 52.27) (p = 0.7710). These findings show the moderately phenotypic cotrimazole susceptibilities of both MRSP and MSSP. Further study is required to develop clinical trials examining the use of cotrimazole in dogs with pyoderma.

Effects of Piper betle Extracts against Biofilm Formation by Methicillin-Resistant Staphylococcus pseudintermedius Isolated from Dogs.

Emergence of methicillin-resistant Staphylococcus pseudintermedius (MRSP) isolated from dogs with cutaneous and wound infections has significantly impacted veterinary medicine. This study aimed to isolate S. pseudintermedius from canine pyoderma and investigate the effects of ethanolic extracts of Piper betle (PB), P. sarmentosum (PS), and P. nigrum (PN) on the bacterial growth and biofilm formation of S. pseudintermedius and MRSP. Of the isolated 152 isolates, 53 were identified as S. pseudintermedius using polymerase chain reaction, and 10 isolates (6.58%) were identified as MRSP based on the presence of mecA. Based on phenotype, 90% of MRSPs were multidrug-resistant. All MRSP had moderate (10%, 1/10) and strong (90%, 9/10) biofilm production ability. PB extracts were the most effective in inhibiting planktonic cells, and the minimum inhibitory concentration at which ≥50% of the isolates were inhibited (MIC50) was 256 µg/mL (256-1024 µg/mL) for S. pseudintermedius isolates and 512 µg/mL (256-1024 µg/mL) for MRSP isolates. The MIC90 for S. pseudintermedius and MRSP was 512 µg/mL. In XTT assay, PB at 4× MIC showed an inhibition rate of 39.66-68.90% and 45.58-59.13% for S. pseudintermedius and MRSP, respectively, in inhibiting biofilm formation. For PB at 8× MIC, the inhibition rates for S. pseudintermedius and MRSP were 50.74-81.66% and 59.57-78.33%, respectively. Further, 18 compounds were identified in PB using gas chromatography-mass spectrometry, and hydroxychavicol (36.02%) was the major constituent. These results indicated that PB could inhibit bacteria growth of and biofilm formation by S. pseudintermedius and MRSP isolated from canine pyoderma in a concentration-dependent manner. Therefore, PB is a potential candidate for the treatment of MRSP infection and biofilm formation in veterinary medicine.