Staphylococcus Pseudintermedius Research Articles

Prevalence of multidrug-resistant coagulase-positive staphylococci in canine and feline dermatological patients over a 10-year period: a retrospective study.

Coagulase-positive staphylococci (CPS) are common cutaneous pathogens often requiring multiple courses of antibiotics, which may facilitate selection for methicillin-resistant (MR) and/or multidrug-resistant (MDR) strains. To determine the prevalence of canine and feline MR/MDR CPS associated with skin diseases, medical records were retrospectively searched from April 2010 to April 2020. Pets with at least one positive culture for CPS were selected. Age, sex, antimicrobial sensitivity, previous history of antimicrobial/immunomodulatory medications and methicillin resistance/multidrug resistance status were recorded. Staphylococcus pseudintermedius (SP) (575/748) and Staphylococcus schleiferi (SS) (159/748) in dogs, and Staphylococcus aureus (12/22) in cats, were the most common CPS isolated. Three hundred and twenty-three out of 575 isolates were MR-SP (56.2 %), 304/575 were MDR-SP (52.8 %), 100/159 were MR-SS (62.9 %) and 71/159 were MDR-SS (44.6 %). A trend analysis showed a significant increase of resistance to oxacillin and chloramphenicol for S. pseudintermedius (r=0.86, 0.8; P=0.0007, 0.0034, respectively). Major risk factors for MDR-SP included oxacillin resistance (OR: 3; 95 % CI: 1.4-6.5; P=0.0044), positivity for PBP2a (OR: 2.3; 95 % CI: 1-5; P=0.031) and use of antibiotics in the previous year (OR: 2.8; 95 % CI: 1.3-5.8; P=0.0071). Oxacillin resistance was identified as a major risk factor for MDR-SS (OR: 8.8; 95 % CI: 3.6-21.1; P<0.0001). These results confirmed the widespread presence of MR/MDR CPS in referred dermatological patients. Judicious antibiotic use, surveillance for MR/MDR infections and consideration of alternative therapies are crucial in mitigating the development of resistant strains.

Antibiotic resistance, biofilm formation, and virulence factors of isolates of staphylococcus pseudintermedius from healthy dogs and dogs with keratitis.

Canine bacterial keratitis is a common infection that can potentially threaten vision. Staphylococcus pseudintermedius (S. pseudintermedius) is an opportunistic pathogen that has been isolated from the canine conjunctival sac but there are only a few reports on the role of this bacterium in canine keratitis. This study focused on the distribution rate of S. pseudintermedius in the canine conjunctival sac, and the antibiotic resistance, biofilm-producing ability, and dissemination of virulence factors in strains of S. pseudintermedius isolated from healthy dogs and dogs with keratitis. The study included 35 healthy dogs and 40 dogs with keratitis. Bacterial species were confirmed by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI–TOF MS). Strains of S. pseudintermedius were screened for resistance against nine different antibiotics by the Kirby–Bauer assay. The ability to produce biofilm was investigated by microtiter plate assay (MtP) and amplification of icaA and icaD genes. Virulence factors in the strains were also evaluated. A total of 132 aerobic bacteria were isolated from the 119 samples in the study. Among them, 67 bacterial strains were isolated from 70 eyes of healthy dogs, and 65 bacterial strains were isolated from 49 eyes of dogs with keratitis. The prevalence of S. pseudintermedius, which was the most frequent bacterial isolate in both the groups, was 20.9% in the healthy group and 23.08% in the keratitis group. Most of the isolates of S. pseudintermedius were sensitive to rifampin (96.6%), oxacillin (100%), and neomycin (96.6%), and resistant to tetracycline (96.6%). Virulence factors such as lip (96.6%), hlgB (96.6%), and hlgA (96.6%) were found in most of the isolates, and 89.66% of isolates were classed as biofilm producers. In conclusion, S. pseudintermedius was the common bacterium in the conjunctivital sac of the healthy dogs and dogs with keratitis in Yangzhou, China, and the presence of virulence factors and biofilm-formation ability were high in the strains isolated from the dogs with keratitis.

In vitro susceptibility of canine corneal bacterial pathogens to three cross-linking protocols.

To assess in vitro antibacterial efficacy of three cross-linking (XL) protocols on bacteria associated with canine ulcerative keratitis. Three XL protocols: UVA 3mW/cm2 for 60 min, UVA 3mW/cm2 for 30 min, and UVA 30 mW/cm2 for 3min with and without application of riboflavin and a riboflavin-only protocol were performed in vitro on the four most common bacterial genera isolated from cases of canine ulcerative keratitis treated at Dick White Referrals, UK. Zones of bacterial growth inhibition (GIZ) associated with treatment were measured and compared. The four most common isolates were Pseudomonas aeruginosa (PA) (48/140, 34.3%), Streptococcus spp. (32/140, 22.9%), Staphylococcus spp. (24/140, 17.1%) and Escherichia coli (EC) (11/140, 7.9%). PA, EC, Streptococcus canis (SC), and Staphylococcus pseudintermedius (SP), isolated from canine corneas, were selected for testing. EC and SC demonstrated growth inhibition following all UVA/riboflavin protocols. PA and SP only displayed growth inhibition following the 60 min UVA/riboflavin protocol. GIZ areas for 60 min UVA/riboflavin protocols were significantly greater than 30 and 3min UVA/riboflavin protocols (p < .01) and there was no significant difference between 30 and 3min UVA/riboflavin protocols. In respect to GIZ areas, EC was significantly more susceptible to XL than SP (p=<.01). All UVA/riboflavin XL protocols caused growth inhibition of EC and SC in vitro. PA and SP did not show clear growth inhibition in vitro following exposure to XL protocol settings of UVA 3mW/cm2 for 30 min and UVA 30 mW/cm2 for 3min.

Prevalence of methicillin resistance in Staphylococcus pseudintermedius isolates from dogs with skin and ear infections in South Africa

Staphylococcus pseudintermedius (SP) is an important opportunistic pathogen, frequently associated with pyoderma and otitis in dogs. The emergence and rapid expansion of methicillin-resistant Staphylococcus pseudintermedius (MRSP) is problematic due to multidrug resistance and reduced treatment options. The aim of this study was to determine i) the prevalence of MRSP in dogs with pyoderma or otitis externa, ii) the antimicrobial resistance patterns of MRSP from South African isolates, and iii) the risk factors for MRSP-associated pyoderma or otitis externa in dogs in South Africa (RSA). Sixty-eight presumptive clinical SP isolates (collected from 65 dogs) from five geographically dispersed laboratories in RSA were collected over 2 years. Possible MRSP isolates were flagged when resistance to oxacillin was observed. Thereafter, all isolates were confirmed as SP by polymerase chain reaction (PCR) and further genotyped for the mecA gene. Fifty-seven of 68 isolates were confirmed to be SP (83.8%), while 49/57 (85.9%) carried mecA. Our findings showed that preliminary phenotypic methods supplemented by genotypic methods increased the accuracy of correctly identifying SP. All isolates were resistant to at least one antimicrobial drug. There was a high incidence of amoxicillin (70.1%) and enrofloxacin (65%) resistance. Important risk factors for mecA positive carriage were previous hospital admission, pruritus, and previous antibacterial failure. This study demonstrates a high prevalence of mecA positive carriage (85.9% of samples) in MRSP pyoderma and otitis in dogs in RSA. There is an urgent need for better laboratory diagnosis of MRSP and surveillance of dogs presenting with pyoderma and otitis in South Africa.

Effect of Nanosulfur Against Multidrug-Resistant Staphylococcus pseudintermedius and Pseudomonas aeruginosa.

Multidrug resistance (MDR) has significantly increased in the past decades and the use of nanotechnology has opened new venues for novel treatments. Nanosulfur is a potent antimicrobial agent and a cheaper alternative to other nanomaterials. However, very few studies have been published on its activity against MDR organisms. Therefore, the goal of this in vitro study was to assess cytotoxicity, antimicrobial, and anti-biofilm activity of nanosulfur (47nm, orthorhombic) against clinical isolates of MDR Staphylococcus pseudintermedius (SP) and Pseudomonas aeruginosa (PA) in planktonic and biofilm state using canine skin explants. Nanosilver (50nm, spherical) was tested as a comparative control. Concentrations between 1866.7 and 0.11μg/mL of both nanoparticles were tested. The ultrastructure of nanosulfur was assessed via electron microscopy. Both types of nanoparticles showed no direct cytotoxicity on a canine keratinocyte cell line. In the planktonic phase, nanosulfur was able to inhibit or kill (6-log10 reduction of CFU) 7 of 10 MDR-SP isolates at 233.3μg/mL, whereas, when in biofilm state, 6 of 10 isolates were killed at different concentrations (233.33 to 1866.7μg/mL). Nanosilver did not show any antimicrobial or anti-biofilm activity at any concentrations tested. Both types of nanoparticles were ineffective against MDR-PA in either state. Ultrastructurally, nanosulfur was present in individual nanoparticles as well as forming larger nanoclusters. This is the first study showing an antimicrobial and anti-biofilm activity of nanosulfur for MDR-SP in absence of cytotoxicity. Nanosulfur has the potential to be used in veterinary and human medicine as effective, safe, and cheap alternative to antimicrobials and anti-biofilm agents currently available. KEY POINTS: • Nanosulfur is a better alternative than nanosilver to treat MDR-Staphylococci. • Nanosulfur is an effective agent against MDR-Staphyloccocal biofilm. • Canine skin explant model is reliable for testing anti-biofilm agents.

Characterization of Staphylococcus pseudintermedius Isolates from Skin Infections of Dogs

Background: Staphylococcus pseudintermedius is a part of the canine skin microflora and an opportunistic pathogen. It plays a central role in canine pyoderma, otitis and surgical wound infections. These conditions correlate with virulence genes distributed in the bacterial genome. These genes determine strain variability on typing, in turn aiding epidemiological surveillance. The aim of this study was to isolate, identify and characterize Staphylococcus pseudintermedius (SP) and Methicillin resistant Staphylococcus pseudintermedius (MRSP) from dogs with skin infections in Chennai, India. Methods: SP and MRSP positive isolates were identified by multiplex PCR for nuc and mecA genes respectively. Characterization of the isolates for virulence genes responsible for biofilm formation (icaA, icaD), cell wall adherence (SpsO, SpsK, SpsP, SpsQ, SpsF), toxins (ExpA, ExpB, SIET, Sel, Se-int, LukS, LukF) and gene regulation (Agr, SarA) was performed. Result: Out of 275 samples, 120 SP and 8 MRSP positive isolates were identified. Only one isolate could be typed as SCCmec Type V whereas other MRSP isolates were non typeable. Agr typing of MRSP isolates revealed type II in 7 isolates and type III in one isolate. Our study revealed that there was no significant difference in the detection of virulence genes between MSSP and MRSP.

Immunofluorescence Targeting PBP2a Protein: A New Potential Methicillin Resistance Screening Test.

The indiscriminate use of first-line drugs contributed to the spread of resistant bacteria, a major concern for both human and veterinary medicine. Methicillin resistance is acquired through the mecA gene, which encodes for the PBP2a protein and lends the resistance to β-lactams. Verifying the correspondence between gene harboring and protein expression and accelerating methicillin resistance diagnosis is critical to improve the management of antimicrobial administration and to reduce the spread of drug resistances. We tested the applicability of immunofluorescence targeting PBP2a protein to identify a new potential methicillin resistance screening test, ancillary to conventional culture methods. We collected 26 clinical Staphylococcus pseudintermedius (SP) isolates: 25 from canine pyoderma and 1 from dermatitis in a dog owner. SP is one of the most important etiological agents in canine pyoderma and can harbor the mecA gene. We performed PCR for mecA gene detection, broth microdilution (BMD) for phenotypic methicillin resistance, and immunofluorescence targeting PBP2a protein. Compared to the PCR as the gold standard, immunofluorescence showed an apparent prevalence of 34.6% vs. a true prevalence of 53.8%, with 100% specificity, 64.3% sensitivity, and 80.8% diagnostic accuracy. PBP2a expression showed isolate-dependent variability: in some isolates, most of the bacterial cells showed an intense and clearly membranous pattern, while in others only a few of them could be detected. Performing the assay in duplicate improved the diagnostic accuracy. Since the mecA gene is shared among the members of the Staphylococcus genus, the test can be applied to identify methicillin resistance independently from the staphylococcal species, both in human and animal samples. Being a rapid and easy method and providing the unique possibility to study the expression of PBP2a by directly visualizing the morphology, it could represent a new interesting tool for both research and diagnostics. To accelerate methicillin resistance diagnosis, it would be worth further testing of its performance on cytological samples.

Clinical efficacy of artificially carbonated water bathing on superficial bacterial folliculitis in dogs.

Bathing with artificially carbonated water is reported to be a valuable therapeutic option for various human skin disorders. To evaluate the clinical efficacy of artificially carbonated water bathing on superficial bacterial folliculitis (SBF) caused by Staphylococcus pseudintermedius (SP) in dogs. Nineteen dogs with SBF from whom SP was isolated from skin lesions were enrolled. Dogs with SBF were allocated randomly to either the artificially carbonated water bathing group or the control group bathed with tap water. The dogs were bathed with the designated water type on day (D)0, D7 and D14. Clinical scores and skin surface pH were evaluated on D0 and D21. Colony forming unit (cfu) assays were performed in vitro to investigate whether the artificially carbonated water affected growth of clinical SP isolates. The mean rate of improvement in the clinical scores was significantly higher in the carbonated water group than in the control group. Dogs bathed with carbonated water exhibited significant decreases in their skin surface pH after bathing; dogs bathed with tap water did not. No dogs experienced significant adverse events. The cfus of SP incubated in vitro with artificially carbonated water did not significantly differ from those incubated with tap water. Bathing with artificially carbonated water might be an effective and safe adjunctive therapy for canine SP-induced SBF.

Longitudinal environmental Staphylococcus contamination in a new small animal veterinary hospital and utility of cleaning checklists.

Staphylococci are inhabitants of skin and mucous membranes with Staphylococcus pseudintermedius (SP) and Staphylococcus aureus (SA) serving as important pathogens for animals and people, respectively. Previous research has identified the environment as potentially important in hospital-associated infections and zoonotic transmission in veterinary settings. The objective of this pilot study was to determine the longitudinal prevalence over repeated samplings of environmental coagulase-positive Staphylococcus (CPS) in a new veterinary hospital and evaluate associations between contamination and environmental and clinical (caseload, cleaning checklists and staff numbers) factors. Cleaning and disinfection compliance, based on staff-completed checklists, were reviewed for the three shifts immediately prior to sampling. We hypothesized that over time, environmental contamination would increase as the clinic developed and caseload increased and compliance to cleaning checklists would decrease with increasing caseload. Over 18months, 351 environmental samples were collected at five sampling times (sampling occurred before opening the hospital and every 3 to 6months thereafter). Overall contamination with CPS was 30.8% (108/351), with SA (16.8%) and SP (13.1%) identified from the contaminated surfaces. Overall, methicillin-resistant strains (MRSA and MRSP) were infrequently recovered (combined n=3; <1%). Point prevalence of CPS contamination was relatively stable over the study period (22.5%-28.4%), with the exception of an increase at the fourth sampling (52.9%). Cleaning compliance varied over the study period (57.9%-100%); the lowest reported cleaning coincided with the highest proportion of CPS contamination. The most commonly contaminated surfaces were chairs (7/15; 46.7%), examination tables (19/47; 40.4%) and computers (12/35; 34.3%); these items were infrequently included on cleaning lists. Surfaces not included in the checklist were 2.3 times more likely to be contaminated by CPS than those that were included (OR: 2.3, CI 95%: 1.02 -5.35, p-value=.04). MRSA and MRSP were rarely isolated from the environment in the newly opened hospital, indicating it may take time for resistant strains to enter the environment and persist on surfaces. This study identified the possible utility of cleaning checklists for directing cleaning practices and reducing the environmental contamination.

Influence of hospital size on antimicrobial resistance and advantages of restricting antimicrobial use based on cumulative antibiograms in dogs with Staphylococcus pseudintermedius infections in Japan.

BackgroundAntimicrobial resistance in Staphylococcus pseudintermedius (SP) and the prevalence of meticillin‐resistant SP (MRSP) is increasing in dogs worldwide.ObjectivesTo evaluate the influence of hospital size on antimicrobial resistance of SP and whether restricted use of antimicrobials based on antibiograms could reduce the identification of antimicrobial resistance in SP from infected dogs.Methods and materialsIn Study 1, a total of 2,294 SP isolates from dogs with pyoderma (n = 1,858, 52 hospitals) or otitis externa (OE; n = 436, 44 hospitals) taken between 2017 and 2019 were analysed. Clinics were categorised into small, medium and large based on numbers of practicing veterinary surgeons. In Study 2, a cumulative antibiogram was constructed for 12 antimicrobials from one large veterinary clinic from 2017 to 2018. Referring to this antibiogram, the clinic introduced strict antimicrobial selection criteria to treat dogs with pyoderma and OE, starting in 2018.ResultsMRSP was identified in 981 dogs (42.8%). In large clinics, the isolation rate of MRSP was 51.1% (404 of 791), which was significantly higher (P < 0.01) than in small clinics with less than two veterinary practitioners (34.0%, 154 of 453). In the antibiogram study, the susceptibility rates of oxacillin (MPIPC, 61.5%), cefpodoxime (CPDX, 55.8%) and minocycline (MINO, 55.8%) were significantly higher in 2019 (n = 52) than in 2017 to 2018 (n = 54; MPIPC, 37.0%; CPDX, 33.3%; MINO, 20.4%; P < 0.05).Conclusions and clinical relevanceHospital size could affect the isolation rate of MRSP in dogs. Restricted use of antimicrobials for over a year based on cumulative antibiograms could reduce the resistance rate of multiple antimicrobials in SP isolated from dogs with pyoderma and OE.

Staphylococcus pseudintermedius y el enfoque de Una Salud

El concepto de Una Salud se basa en la interdependencia entre la salud humana y la salud animal, vinculadas al medio ambiente en el que coexisten. Staphylococcus pseudintermedius es un microorganismo que forma parte de la microbiota de la piel y las mucosas en animales, especialmente en la especie canina de la que se suele aislar como agente etiológico de diferentes enfermedades. En los últimos años fue reconocido como un agente zoonótico. Si bien en condiciones normales no coloniza al hombre, puede causarle enfermedad bajo ciertas circunstancias. S. pseudintermedius cuenta con varios factores de virulencia, tales como enzimas, proteínas de superficie y toxinas, que participan en la adherencia, formación de biopelículas y evasión de la respuesta inmune. Posee resistencia múltiple a los agentes antimicrobianos, lo que dificulta el tratamiento de las infecciones que produce y, además, constituye un reservorio de genes de resistencia que pueden transmitirse a otras especies. Finalmente, los métodos convencionales usados en el laboratorio de diagnóstico no son suficientes para su identificación, por lo que muchas veces, no es posible confirmar su participación como agente etiológico de una enfermedad. El propósito de esta revisión fue exponer las características que permiten considerar a S. pseudintermedius en el marco de Una Salud.

Evidence of new sequence types of methicillin-resistant Staphylococcus pseudintermedius in Italy.

Staphylococcus pseudintermedius (SP) and methicillin-resistant SP (MRSP) is one of the most important veterinary pathogens in the dog. Herein, from a total of 126 S. pseudintermediusstrains, 23 MRSP (18%) were identified. Multi-Locus Sequence Typing (MLST) revealed that most of MRSP strains belonged to ST71 (26%), which have been already reported in Italy and other countries. Interestingly, nine new sequence types (39%), from 1053 up to 1061, were described for the first time. Moreover, the isolated MRSP strains showed relevant antibiotic resistance profiles. This report highlights the circulation of new sequence types of MRSP in Italy and underlines the need of a global epidemiological surveillance to limit the increasing spread of multidrug-resistant MRSPstrains worldwide, since they may represent a considerable concern for dog's health.

In Vitro Efficacy of Essential Oils from Melaleuca Alternifolia and Rosmarinus Officinalis, Manuka Honey-based Gel, and Propolis as Antibacterial Agents Against Canine Staphylococcus Pseudintermedius Strains.

Essential oils (EOs) and honeybee products (e.g., honey and propolis) are natural mixtures of different volatile compounds that are frequently used in traditional medicine and for pathogen eradication. The aim of this study was to evaluate the antibacterial properties of tea tree (Melaleuca alternifolia) EO (TTEO), Rosmarinus officinalis EO (ROEO), manuka-based gel, and propolis against 23 strains of Staphylococcus pseudintermedius (SP) isolated from canine pyoderma. Antimicrobial resistance screening was assessed using a panel of nine antimicrobial agents coupled with a PCR approach. An aromatogram was done for both EOs, using the disk diffusion method. The minimum inhibitory concentration (MIC) was determined for all the compounds. Among the 23 SP strains, 14 (60.9%) were multidrug-resistant (MDR), 11 strains (47.8%) were methicillin-resistant (MRSP), and 9 (39.1%) were non-MDR. The mean diameter of the inhibition zone for Melaleuca and Rosmarinus were 24.5 ± 8.8 mm and 15.2 ± 8.9 mm, respectively, resulting as statistically different (p = 0.0006). MIC values of TTEO and ROEO were similar (7.6 ± 3.2% and 8.9 ± 2.1%, respectively) and no statistical significances were found. Honeybee products showed lower MIC compared to those of EOs, 0.22 ± 0.1% for Manuka and 0.8 ± 0.5% for propolis. These findings reveal a significant antibacterial effect for all the tested products.

Biofilm-forming ability and virulence factors of methicillin-resistant Staphylococcus pseudintermedius from canine pyoderma

Staphylococcus pseudintermedius (SP) has been associated with high antibiotic-resistance rates (e.g. methicillin) in European countries [1,3]. This condition could be also related to the ability to produce biofilm [2]. The aim of this study was to investigate the presence of methicillin-resistant SP strains and determine their ability to produce biofilm and some crucial virulence factors.Forty-two SP strains, previously determined as multi drug resistant (MDR) by the disk diffusion method using a panel of 17 antimicrobial agents, were selected from our collection and tested phenotypically for the minimum inhibitory concentration (MIC) of methicillin and genotypically for the presence of mecA and blaZ genes. The ability to produce biofilm was assessed phenotypically by two different assays: the Congo Red Agar plates (CRA) and the Microtitre Plate test (MtP) and genetically by the amplification of icaA and icaD genes. Three virulence factors genes coding for bicomponent leukocidin and enterotoxins (luk-I, seC, se-int) were searched.Twenty-three strains revealed a value of MIC for the methicillin greater than 128 µg/mL. The 83% were mecA-positive and 86% resulted blaZ-positive; all the strains positive for mecA were also positive for blaZ. All SP strains resulted biofilm-producers by MtP assay and classified as weakly producers (4.7%), moderate producers (47.6 %) and strongly producers (47.6 %). In contrast, only 35.7% of all strains were considered biofilm-producers by CRA method. The amplification of icaA and icaD gene occurred respectively in 66.6% and 97.6%; only one strain was negative for both genes. Almost all strains were positive for luk-I (95%), seC (74%) and se-int (84%).Our data reveal the pathogenicity potential of SP strains from dogs, suggesting that they could be considered zoonotic potential agents and confirming other previous studies [3-5]. Moreover could be observed a clear linkage between antibiotic-resistance and ability to produce biofilm.

Frequency and antimicrobial susceptibility of Staphylococcus pseudintermedius in dogs with otitis externa

ABSTRACT: Infections by Staphyloccocus pseudintermedius in the skin of dogs have been object of studies, since such microorganisms often present multiple resistance to antibiotics. This study aimed to identify and evaluate the antimicrobial susceptibility of Staphylococcus pseudintermedius (SP) strains isolated from dogs with otitis. Swabs from both ears of 52 dogs with otitis (n=104) were included. Bacteria were cultured using Muller-Hinton agar (supplemented with 5% equine blood and incubated at 37°C for 24 to 48 hours. All colonies underwent biochemical evaluation for identification of staphylococci. The identity of colonies as SP was confirmed by polymerase chain reaction. The antimicrobial susceptibility of SP strains was evaluated by disk diffusion. The presence of the gene mecA was evaluated in all SP isolates by PCR. Forty-four SP strains were isolated from swabs of 31 dogs (31/52, 59.6%). Seventy-five percent of the strains were susceptible to cephalexin and 93.2% to amoxicillin plus clavulanic acid. Less than 23% of the strains were susceptible to penicillin. For non-beta-lactam antimicrobials, 63.6% of the strains showed resistance to sulfamethoxazole-trimethoprim, 61.4% to tetracycline, and 38, 64% to enrofloxacin. Aminoglycoside resistance rate was 27.3% for gentamicin. Resistance to oxacillin in vitro was detected in 13 of the 44 strains (29, 55%). A total of 12 strains (27.3%) were positive for mecA gene and five of these 12 strains were susceptible to in vitro oxacillin. Twenty-six (59, 1%) strains were resistant to three or more classes of antimicrobials, and classified as multi resistant. Our results showed high frequency of SP and multi resistant isolates to antimicrobials commonly used in veterinary.

Correction: Development of a real-time PCR for detection of Staphylococcus pseudintermedius using a novel automated comparison of whole-genome sequences.

[This corrects the article DOI: 10.1371/journal.pone.0183925.].

Activity In Vitro of Clotrimazole against Canine Methicillin-Resistant and Susceptible Staphylococcus pseudintermedius.

Emergence of multidrug-resistance in Staphylococcus pseudintermedius (SP) has increased interest in topical therapy as an alternative to systemic antibiotics in canine pyoderma. The antifungal imidazole, clotrimazole, is contained in numerous licensed canine ear preparations. Its in vitro activity against SP has not been evaluated, although previous studies have shown that the related imidazole, miconazole, has significant anti-staphylococcal efficacy. We therefore determined minimum inhibitory concentrations (MICs) of clotrimazole amongst 50 SP isolates (25 methicillin-resistant [MR]SP and susceptible [MS]SP) collected from dogs in Germany during 2010–2011 using an agar dilution method (CLSI VET01-A4). MICs amongst MRSP and MSSP were comparable (MIC50 and MIC90 = 1mg/L for both groups, p = 0.317); overall, 49 isolates had MIC = 1 mg/L and one had MIC = 0.5 mg/L. The relatively low MICs obtained in this study are likely to be exceeded by topical therapy and thus further clinical evaluation of clotrimazole use in canine superficial pyoderma and otitis externa caused by MRSP and MSSP is now warranted.

Staphylococcus p seudintermedius Isolated from Two Dog Cases with Ophthalmic Lesions

Two dog cases with history of recurrent bacterial conjunctivitis were submitted to Purdue University for bacterial culture and sensitivity testing. The bacterial cultures were also tested for their ability to form a biofilm. Biofilm forming Staphylococcus pseudintermedius was isolated from the two cases and identified by Vitek2 and PCR analysis. The bacterial antibiotic sensitivity testing revealed that Isolate one was susceptible to ticarcillin, ceftiofur, cefazolin, moxifloxacin, amikacin and rifampicin with MICs ranging 0.03125-4 μg/ml. Isolate two was susceptible to ceftiofur, gatifloxacin, cefazolin, moxifloxacin, tetracycline, doxycycline and rifampicin with MICs ranging <0.0625–4 μg/ml. Meanwhile, the biofilm antibiotic sensitivity testing revealed that Isolate one biofilm was resistant to all antibiotics except for ceftiofur and moxifloxacin with MICs <0.25 and 8 μg/ml respectively. Isolate two biofilm was resistant to all antibiotics except for tetracycline, amikacin, doxycycline, chloramphenicol and rifampicin with MICs ranged from <0.125 to 8 μg/ml. Case one was resolved with topical cefazolin therapy. Meanwhile case two showed complete recovery after treated with topical levofloxacin plus oral doxycycline.

The Activity of Apo-transferrin on the Growth of Staphylococcus pseudintermedius

The Activity of Apo-transferrin on the Growth of Staphylococcus pseudintermedius

Virulence Genes Detection and Antimicrobial Susceptibility of Staphylococcus pseudintermedius Isolates from Canine Skin Infection in Chennai, India

Staphylococcus pseudintermedius (SP) is the major pathogen incriminated in the skin infections of dog. Identification of SP requires molecular methods. The incidence of methicillin resistant SP (MRSP) is increasing worldwide and it is a growing concern in treating pet animals. The prevalence of SP and MRSP from skin infections of dog in India has not been studied previously. Hence, the present study was aimed to isolate SP from common skin infections of dog in Chennai, India and to characterize these isolates. A total of 53 SP organisms were isolated from 91 samples of skin infection accounting for 59 % of isolation rate. Labrador was a major breed from which isolation was made. Panton–Valentine leucotoxin (Luk-I) and S. intermedius exfoliative toxin (siet) genes were detected in all SP isolates but staphylococcal protein A homologue (spsQ) gene was detected only in 36 % of the SP isolates. Out of 53 isolates, 17 % were found to be strong and 19 % to be moderate producers of biofilm and 28 % were classified as MRSP due to possession of the mecA gene. Most isolates were sensitive to tetracycline and ciprofloxacin and least sensitive to erythromycin and trimethoprim/sulphamethaxazole. The authors first time reported the isolation of MRSP, characterization of SP isolates by detecting virulence genes, biofilm forming ability and susceptibility to antimicrobials in Chennai, India.