Cases Of Canine Pyoderma Research Articles

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

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

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.

Diverse Populations of Staphylococcus pseudintermedius Colonize the Skin of Healthy Dogs.

Staphylococcus pseudintermedius is a commensal bacterium of the canine skin but is also a key opportunistic pathogen that is responsible for most cases of pyoderma in dogs. The current paradigm indicates that infection arises when predisposing factors alter the healthy skin barrier. Despite their importance, the characteristics of the S. pseudintermedius populations colonizing the skin of healthy dogs are yet largely unknown. Here, we retrieved 67 complete circular genomes and 19 associated plasmids from S. pseudintermedius isolated from the skin of 9 healthy dogs via long-reads Nanopore sequencing. Within the S. pseudintermedius populations isolated from healthy skin, multilocus sequence typing (MLST) detected 10 different STs, distributed mainly by the host. 39% of the 18 representative genomes isolated herein were methicillin-resistant S. pseudintermedius (MRSP), and they showed, on average, a higher number of antibiotic resistance genes and prophages than did the methicillin-sensitive (MSSP). In summary, our results revealed that the S. pseudintermedius populations inhabiting the skin of healthy dogs are relatively diverse and heterogeneous in terms of MLST and methicillin resistance. In this study, all of the 67 commensal S. pseudintermedius populations that were isolated from healthy dogs contained antibiotic resistance genes, indicating the extent and severity of the problem of antimicrobial resistance in staphylococci with zoonotic potential. IMPORTANCE Staphylococcus pseudintermedius is a commensal canine bacterium that can become an opportunistic pathogen and is responsible for most cases of canine pyoderma. It can also cause occasional zoonotic infections. Infections caused by antibiotic-resistant Staphylococcus are a global concern. Skin commensal Staphylococcus pseudintermedius is understudied. To provide insight into the commensal strains circulating in healthy dogs, we performed whole-genome sequencing of 67 S. pseudintermedius isolates from different skin sites in 9 healthy dogs. Through the bioinformatic analysis of these genomes, we identified a genomic diversity that is more complete than those afforded by traditional molecular typing strategies. We identified 7 new STs. All of the isolates harbored genes associated with antibiotic resistance, and 39% of the representative genomes were methicillin-resistant. Our data provide critical insights for future skin infection control and antibiotic surveillance within veterinary medicine.

In Vitro Efficiency of Antimicrobial Peptides against Staphylococcal Pathogens Associated with Canine Pyoderma.

Simple SummaryCoagulase-positive staphylococci (CoPS) are predominant pathogens in canine pyoderma, especially S. pseudintermedius and S. aureus. The antimicrobial resistance of CoPS has a key role in the management of canine skin infections. The vast majority of those diseases have a chronic character with a tendency to recur, which is reflected by recurrent systemic antibiotic therapy, associated with an alarming increase in the proportion of antibiotic-resistant staphylococci. Antimicrobial peptides (AMPs) seem to be a promising alternative to conventional antibiotics. The aim of this in vitro study was to evaluate the antimicrobial activity of selected AMPs against pathogenic staphylococcal strains, including multidrug- and methicillin-resistant strains isolated from canine pyoderma cases. The tested AMPs were shown to be equally efficient antimicrobial agents against resistant- and susceptible pathogenic staphylococcal strains associated with canine pyoderma. AMPs were more efficient against S. pseudintermedius than against S. aureus strains. Our findings seem to be particularly interesting from a clinical perspective, as a starting point from which to perform in vivo experiments to estimate the usefulness of these peptides as topical drug molecules for the treatment of canine pyoderma.The emergence of staphylococcal canine pathogens resistant to multiple antimicrobial agents is a growing and urgent problem in veterinary practice. Antimicrobial peptides (AMPs) seem to be a promising alternative to conventional antibiotics. The aim of this in vitro study was to evaluate the antimicrobial activity of selected AMPs against pathogenic staphylococcal strains, including multidrug- and methicillin-resistant strains isolated from canine pyoderma cases. Seven antimicrobial peptides (aurein 1.2, CAMEL, citropin 1.1, protegrin-1, pexiganan, temporin A and uperin 3.6) synthesized by the 9-fluorenylmethoxycarbonyl (Fmoc) solid-phase method were tested. The minimal inhibitory and minimal bactericidal concentrations (MIC and MBC) were determined by the broth microdilution method. The study showed that analyzed AMPs exerted an extensive effect against canine pathogens, with the most active peptide being uperin 3.6. The tested AMPs were equally efficient against both resistant- and susceptible staphylococcal strains and were more efficient against Staphylococcus pseudintermedius than against Staphylococcus aureus strains. Our findings are particularly interesting from a clinical perspective, as they point to AMPs as potential therapeutic topical agents in canine pyoderma cases associated with antimicrobial resistance of staphylococci.

Ever-increasing emergence of multi-drug resistant Staphylococcus pseudintermedius in the dog and its zoonotic potentials

Methicillin-resistant Staphylococcus pseudintermedius (MRSP) has emerged as an important pathogen in the dog over the past 10 years with an ever increasing incidence worldwide. This review focuses mainly on the epidemiology and detection of MRSP, emphasizing on the interpretation and pitfalls of screening laboratory tests and antimicrobial susceptibility tests. Risk factors for colonization and infection with MRSP and molecular analysis of the dominant clonal lineages are also described. The zoonotic potential and worldwide epidemiology of multidrug resistant Staphylococcus pseudintermedius (MDRSP) are presented. Finally, control options for the colonization of healthy dogs as well as infection by MRSP and MDRSP are described emphasizing on the indications for bacterial culture and susceptibility testing and the principles of topical therapy which may prove to be the sole effective treatment in several canine pyoderma cases.

Organisms Recovered from Cases of Canine Pyoderma and their Antibiogram Pattern

Canine pyoderma is one of the most common causes of dermatitis with worldwide occurrence in small animal practice. The condition is diagnosed on the basis of clinical manifestations, isolation and identification of causative organisms by bacteriological cultural examination. A study on 130 clinical cases of canine pyoderma was conducted at the Teaching Veterinary Clinical Complex (TVCC), Veterinary College, Anand during July, 2016 to April, 2017. In the study undertaken, bacteriological culture examination of 116 pus swabs resulted in the recovery of 165 bacterial isolates. Exudate/pus samples were collected and subjected to bacteriological cultural isolation, identification and subsequently in vitro antibiotic sensitivity testing. On culture, staphylococci were the most predominantly isolated organisms. Amongst staphylococci, Staphylococcus pseudintermedius (49.69%, n=82), a coagulase-positive staphylococci (CPS), was the most predominantly isolated organism, followed by Staphylococcus aureus (18.18%, n=30). Moreover, coagulase-negative staphylococci (CNS), Staphylococcus epidermidis (3.03%, n=5) and S. saprophyticus (0.60%, n=1) were also recovered. The methicillin-resistant staphylococci accounted for 40.07% of the total isolates. Gram negative organisms like Pseudomonas aeruginosa (15.15%, n=25), Klebsiella pneumoniae (12.12%, n=20) and Escherichia coli (0.60%, n=1); and a lone isolate of Streptococcus spp. (0.60%) were also isolated majorly in the form of mixed infections. When subjected to in vitro antibiotic sensitivity testing the isolates showed highest sensitivity to linezolid followed by enrofloxacin, cephadroxil, clindamycin and amoxicillin-clavulanic acid whereas resistance was exhibited against erythromycin, methicillin and oxacillin.

Isolation and Characterisation of Multi-Drug Resistant Coagulase Negative S.schleiferiSubsp Schleferi from a Case of Recurrent Pyoderma in Canine

Recurrent pyoderma is a chronic-relapsing clinical condition which is mostly associated with inappropriate use of antibiotics. Methicillin-resistant staphylococci are most frequent microorganisms associated with canine pyoderma and other soft tissue infections. Prevalence of methicillin-resistant staphylococci has shown an increasing trend as a cause of canine pyoderma in recent years. Coagulase positive staphylococci were predominantly reported in canine pyoderma cases until recent times. The present study describes the isolation and characterisation of multi-drug resistant coagulase negative Staphylococcus from a case of recurrent pyoderma in canine. The isolate was confirmed by the growth on selective media and other biochemical tests. Antibiotic sensitivity assay confirmed the isolate to be multidrug resistant with multiple antibiotic resistance index (MARI) of >0.9. The molecular methods based on 16s rRNA, coagulase, Nuc and MecA genes further confirmed phenotypic observations. The multidrug resistance, including antibiotics, which are not commonly used in animal practice in this region, suggests the event of either new host adoption or acquiring antibiotic resistance through lateral transfer from human isolates.

Characterization of meticillin-resistant and meticillin-susceptible isolates of Staphylococcus pseudintermedius from cases of canine pyoderma in Australia

Meticillin-resistant Staphylococcus pseudintermedius (MRSP) has recently emerged as a worldwide cause of canine pyoderma. In this study, we characterized 22 S. pseudintermedius isolates cultured from 19 dogs with pyoderma that attended a veterinary dermatology referral clinic in Australia in 2011 and 2012. Twelve isolates were identified as MRSP by mecA real-time PCR and phenotypic resistance to oxacillin. In addition to β-lactam resistance, MRSP isolates were resistant to erythromycin (91.6 %), gentamicin (83.3 %), ciprofloxacin (83.3 %), chloramphenicol (75 %), clindamycin (66 %), oxytetracycline (66 %) and tetracycline (50 %), as shown by disc-diffusion susceptibility testing. Meticillin-susceptible S. pseudintermedius isolates only showed resistance to penicillin/ampicillin (90 %) and tetracycline (10 %). PFGE using the SmaI restriction enzyme was unable to type nine of the 12 MRSP isolates. However the nine isolates provided the same PFGE pulsotype using the Cfr91 restriction enzyme. Application of the mec-associated direct repeat unit (dru) typing method identified the nine SmaI PFGE-untypable isolates as dt11cb, a dru type that has only previously been associated with MRSP sequence type (ST)45 isolates that possess a unique SCCmec element. The dt11cb isolates shared a similar multidrug-resistant antibiogram phenotype profile, whereas the other MRSP isolates, dt11a, dt11af (dt11a-associated) and dt10h, were resistant to fewer antibiotic classes and had distinct PFGE profiles. This is the first report of MRSP causing pyoderma in dogs from Australia. The rapid intercontinental emergence and spread of multidrug-resistant MRSP strains confirms the urgent need for new treatment modalities for recurrent canine pyoderma in veterinary practice.

Molecular characterization of Staphylococcus intermedius carriage by healthy dogs and comparison of antimicrobial susceptibility patterns to isolates from dogs with pyoderma

We conducted an epidemiological study of Staphylococcus intermedius using arbitrarily primed PCR (AP-PCR) and antibiograms. One hundred and twenty-five S. intermedius isolates were recovered from the oral cavity and/or cranial hair coat of healthy dogs enrolled in a pet therapy program. Commensal S. intermedius was cultured from 32% of the oral cavity cultures and 13% of the cranial hair coat cultures. We characterized the colonization of the dogs as transient, intermittent, or persistent. For dogs characterized as persistently colonized, 73% of the isolates came from the oral cavity. These isolates were also genotyped by AP-PCR. A single major AP-PCR type was observed in 91% of the dogs (n=22); minor variations were frequently observed in these major types. Antibiograms of these commensal isolates were compared to antibiograms from 97 historical clinical isolates (1988-1992) obtained from cases of canine pyoderma. Resistance was most often observed to penicillin (64% and 55%) and tetracycline (38% and 38%) among the commensal and clinical isolates, respectively. The commensal isolates were significantly less resistant to erythromycin, clarithromycin, clindamycin, and trimethoprim/sulfamethoxazole. Our data suggests that differences in both genotype and antimicrobial susceptibility phenotypes exist among S. intermedius strains isolated from different anatomic sites from the same dog and supports the opportunistic nature of S. intermedius in canine infections.

Post-antibiotic effect of cephalexin against isolates of Staphylococcus intermedius obtained from cases of canine pyoderma.

The post-antibiotic effect in vitro (PAE) of cephalexin was determined according to a broth dilution method against 5 isolates of Staphylococcus intermedius obtained from cases of canine pyoderma. Two durations of exposure and 3 concentrations were tested. The PAE increased when time of exposure or concentration increased. The mean PAE ranged from 0.7 to 3.3 h. The PAE of cephalexin against Staph-ylococcus intermedius may be clinically relevant when selecting a dosage regimen to treat pyoderma in dogs.

Comparative ribotyping of Staphylococcus intermedius from dogs, pigeons, horses and mink

Strains of Staphylococcus (S.) intermedius from dogs, pigeons, horses and mink were typed by comparison of rRNA gene restriction fragment length polymorphisms (ribotyping) and the resulting ribotypes examined by cluster-analysis. Digestion of whole-cell DNA with HindIII resulted in 9 ribotypes with 3 to 4 bands. Separation of isolates from different host animal species was not possible. EcoRI yielded 11 different patterns with 4 to 9 fragments. The EcoRI-ribotypes of all canine strains grouped in one cluster encompassing four closely related ribotypes. Isolates were indistinguishable with respect to their origin from cases of canine pyoderma or from healthy carriers. In contrast, pigeon and equine strains expressed a greater variety of ribotypes including some strains with patterns similar to canine isolates. However, for canine versus pigeon and equine strains the difference in distribution among ribotypes was significant ( P < 0.001). The data might suggest that pigeons and horses carry S. intermedius transiently and might be able to spread these bacteria to other animal species.

Chloramphenicol resistance in Staphylococcus intermedius from a single veterinary centre: evidence for plasmid and chromosomal location of the resistance genes

A total of seven Staphylococcus intermedius cultures isolated from cases of canine pyoderma were investigated for the genetic basis of chloramphenicol resistance (Cm r). All of these S. intermedius isolates mediated Cm r via the expression of the Cm-inactivating enzyme chloramphenicol acetyltransferase (CAT); the respective cat genes were found to be located on small multicopy plasmids of 3.1 to 4.1 kb in four of the seven cultures. The four Cm r plasmids, designated pSCS20–23, differed upon restriction endonuclease mapping. Hybridization experiments identified all of them to belong to the pC221-family of staphylococcal Cm r plasmids. The expression of all four plasmid-encoded cat genes was inducible with chloramphenicol. The remaining three S. intermedius isolates also harboured an inducible cat gene of the pC221-type which, however, was found to be located in the chromosomal DNA. These differences in the subcellular localisation and consequently in the number of cat gene copies per S. intermedius cell had no influence on the MIC values of Cm exhibited by the respective S. intermedius isolates.

Characterisation of Staphylococcus intermedius isolates from canine pyoderma and from healthy carriers by SDS-PAGE of exoproteins, immunoblotting and restriction endonuclease digest analysis

Ten Staphylococcus intermedius isolates from cases of canine pyoderma and 10 from healthy carriers were examined by SDS-PAGE of exoproteins, immunoblotting and restriction endonuclease digest analysis. Similarities between banding patterns of the isolates were calculated as Dice coefficients for all three methods. For SDS-PAGE and immunoblotting, no significant differentiation was found between the pyoderma and "healthy" groups. Analysis of DNA digested with BglII indicated that S. intermedius is genetically heterogeneous; Dice coefficients for the pyoderma group were distinct from those for the healthy group (p < 0.001), and cluster analysis confirmed that the pyoderma isolates (9) formed a group separate from the majority (6 of 9) of the normal isolates.

Proteolytic Zymograms ofStaphylococcus intermediusIsolates from Cases of Canine Pyoderma and Healthy Carriers

The extracellular proteases of Staphylococcus intermedius were separated on native polyacrylamide gels and characterised by relative mobility using zymograms showing caseinolysis. No clear differences between isolates from cases of canine pyoderma and healthy carriers were demonstrated. Keywords: Staphylococcus intermedius ; Staphylococci; Canine pyoderma; Virulence; Protease.

Proteolytic Zymograms ofStaphylococcus intermedinsIsolates from Cases of Canine Pyoderma and Healthy Carriers

Proteolytic Zymograms of<i>Staphylococcus intermedins</i>Isolates from Cases of Canine Pyoderma and Healthy Carriers

Production of 'virulence factors' byStaphylococcus intermediusisolates from cases of canine pyoderma and healthy carriers

Staphylococcus intermedius isolates from healthy dogs and dogs with pyoderma were compared for their ability to produce a range of potential virulence factors. All the isolates were coagulase positive with canine plasma. Haemolysin production, examined using solid and liquid media, demonstrated that 100 per cent and 95 per cent of isolates were beta and delta lysin positive respectively. Enterotoxin C production was a characteristic of 15 per cent of the isolates. None of the isolates produced toxic shock syndrome toxin 1 or epidermolytic toxins. Protease activity was demonstrated by 90 per cent of the isolates. No clear differences in the toxin profiles between the two groups of isolates were demonstrated. Keywords: Staphylococcus intermedius ; Staphylococci; Canine pyoderma; Virulence, Toxin.

Production of 'virulence factors' byStaphylococcus intermediusisolates from cases of canine pyoderma and healthy carriers

Production of 'virulence factors' by<i>Staphylococcus intermedius</i>isolates from cases of canine pyoderma and healthy carriers