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.

Virulent potential of methicillin-resistant and methicillin-susceptible Staphylococcus pseudintermedius in dogs.

Staphylococcus pseudintermedius is a zoonotic pathogen responsible for several infectious diseases in pet animals, yet its pathogenic potential is not fully understood. Thus, this study aims to unravel the virulence profile of S. pseudintermedius from canine origin. Methicillin-resistant (MRSP) and methicillin-susceptible (MSSP) strains were isolated from different infection sites and their genotypic and phenotypic features were compared to determine the clinical implications of MRSP and MSSP strains. Bacterial identification was performed using MALDI-TOF and 16S-rDNA sequencing. In addition, we used multilocus sequence typing (MLST) for strains' sequence type (ST) determination and phylogenetic relationship. The strains were screened for toxin genes, including cytotoxins (lukS, lukF), exfoliative toxin (siet), enterotoxins (sea, seb, sec, secCanine, sel, sem, and seq) and toxic shock syndrome toxin (tst-1). In vitro phenotypic analyses assessing antimicrobial susceptibility profile, biofilm formation ability, and expression of extracellular matrix components were performed. The investigated S. pseudintermedius strains belong to 17 unique ST, most of which were classified as ST71. MSSP and MRSP strains shared siet, lukS, and lukF virulence markers. Our findings showed that some MSSP strains also harbored sel, seq, and sem enterotoxin genes, suggesting a more diverse virulence profile. All MRSP strains and 77% of MSSP strains were classified as multidrug resistant (MDR). Moreover, all investigated S. pseudintermedius strains showed strong biofilm formation ability. In summary, our findings highlight the wide spread of highly virulent and drug-resistant zoonotic S. pseudintermedius strains, being a potential concern for One Health issues.

First report of Staphylococcus pseudintermedius ST71-SCCmec III and ST45-ΨSCCmec57395 from canine pyoderma in Argentina.

Staphylococcus pseudintermedius is an opportunistic pathogen commonly associated with skin infections in dogs. Twenty-three methicillin-resistant S. pseudintermedius (MRSP) isolated in Argentina from dogs with pyoderma were analyzed using whole genome sequencing (WGS) and classified into sequence types (ST) by multilocus sequence typing (MLST) and staphylococcal chromosome cassette mec (SCCmec) types.Based on the WGS analysis, MLST, and SCCmec type results, we report for the first time in Argentina two MRSP strains, one each, belonging to ST71-SCCmec III and ST45-ΨSCCmec57395 from dogs with pyoderma. We also identified seven isolates with ST339, which had been previously reported in only two isolates in Argentina. Additionally, we identified ten MRSP isolates harboring variants of the SCCmec V found in S. aureus, seven SCCmec V (5C2&5) with two ccrC1 recombinases, and three SCCmec V (5C2) with one ccrC1 recombinase.Our findings provide important insights into the evolution and geographic spread of these hypervirulent dominant clones that threaten the health of our companion animals and represent a significant risk for zoonotic infections.

Inhibition potential of Caryocar brasiliense on methicillin-resistant Staphylococcus pseudintermedius isolated from the ocular surface of dogs with ophthalmopathies / Potencial de inibição do Caryocar brasiliense sobre Staphylococcus pseudintermedius resistente à meticilina isolado da superfície ocular de cães com oftalmopatias

The indiscriminate use of antibiotics has contributed to the emergence of multiresistant bacteria. Faced with this, the search for antibiotics from plants has proven to be a promising alternative. The objective of this work was to isolate and identify Staphylococcus sp. resistant to methicillin of the ocular surface of dogs with ophthalmopathies and to evaluate its susceptibility to alcoholic extract of the bark and hexane extract of the pulp of Caryocar brasiliense. Biological material was collected from the ocular surface of 21 dogs presenting ophthalmopathies. We isolated 64 S. pseudintermedius, among these, 4 isolates were identified as methicillin-resistant S. pseudintermedius (MRSP). The alcoholic extract of C. brasiliense peel was able to inhibit the bacterial growth of MRSP isolates at a concentration of 2.2%. Thus, the extract from the C. brasiliense peel has antimicrobial potential and represents an alternative in the control of MRSP.

O uso indiscriminado de antibióticos tem contribuído para o surgimento de bactérias multirresistentes. Diante disso, a busca por antibióticos a partir de plantas tem se mostrado uma alternativa promissora. O objetivo deste trabalho foi isolar e identificar Staphylococcus sp. resistente à meticilina da superfície ocular de cães com oftalmopatias e avaliar sua susceptibilidade ao extrato alcoólico da casca e ao extrato hexânico da polpa de Caryocar brasiliense. O material biológico foi coletado da superficie ocular de 21 cães com oftalmopatia. Isolaram-se 64 S. pseudintermedius; entre esses, quatro isolados foram identificados como S. pseudintermedius resistente à meticilina (MRSP). O extrato alcoólico da casca de C. brasiliense foi capaz de inibir o crescimento bacteriano dos isolados de MRSP na concentração de 2,2%. Dessa forma, o extrato da casca de C. brasiliense possui potencial antimicrobiano e representa uma alternativa no controle de MRSP.

Detection of the international lineage ST71 of methicillin-resistant Staphylococcus pseudintermedius in two cities in Rio de Janeiro State.

Staphylococcus pseudintermedius is the main coagulase-positive staphylococci associated with canine skin/soft tissue infections (SSTI), otitis externa, and surgical site infections. The international spread of an epidemic and multiresistant lineage of methicillin-resistant Staphylococcus pseudintermedius (MRSP), the so-called European clone-displaying sequence type (ST) 71-requires attention. The first isolation of an MRSP ST71 isolate in South America was reported in Rio de Janeiro city, in 2010; however, a limited number of canine isolates were analyzed. Thus, to have a better panel of the MRSP spread in this city, we were stimulated to continue this study and search for the presence of MRSP in 282 colonized or infected dogs in the city of Rio de Janeiro. Among the MRSP isolates collected (N = 17; 6.1%), the pulsed-field gel electrophoresis (PFGE) patterns were similar to those of European clone. All 17 isolates were classified as ST71 by multilocus sequence typing (MLST). In order to assess whether isolates of MRSP ST71 may have also spread to the Rio de Janeiro state countryside, we collected samples from 124 infected dogs in the city of Campos dos Goytacazes (232 km away from Rio de Janeiro city). Our data showed the presence of ST71 lineage in one isolate among three MRSP detected. S. pseudintermedius was isolated from 40.6% of the clinical samples (N = 165/406). A relatively high incidence of methicillin resistance, detected by a PCR-based method, was found in 12.1% of the S. pseudintermedius recovered from animals (N = 20/165). The resistance profile of these isolates was similar to that described for the international ST71 strains whose genomes are publicly available in the GenBank. The prospect of ST71 isolates being resistant to virtually all antimicrobials used in veterinary medicine is alarming and should be considered a central issue considering that MRSP ST71 spreads over large geographic distances and its transmission from animals to humans.

Characterizing biofilm formation of Staphylococcus pseudintermedius in different suture materials.

Staphylococcus pseudintermedius is the primary cause of pyoderma and surgical site infection (SSI) in dogs, and biofilm formation is the main reason for persistent SSI. The presence of biofilm in medical devices can directly impact treatment. Methicillin-resistant S. pseudintermedius (MRSP) emerged rapidly in companion animals, limiting treatment options. MRSP is a public health problem since zoonotic transmission can occur. The study seeks to evaluate biofilm formation capacity via Staphylococcus pseudintermedius collected from dogs affected by topical infections, in suture materials commonly used in companion animal surgery. We tested segments of four types of sutures. Biofilm production was measured by staining with safranin and colorimetric absorbance measurement. We calculated colony-forming units (CFUs) for each type of sutures and visualized biofilm via Scanning Electron Microscopy (SEM) images. The genes associated with biofilm formation (icaA and icaD) were identified using PCR. The colorimetric tests showed that the biofilm is most abundantly formed on the cotton sutures and polyglactin 910. The ability to form biofilm on polypropylene and nylon sutures has also been demonstrated, although at varying intensities. PCR revealed the presence of the two genes (icaA and icaD) in all the isolates. We used a positive control using a reference strain and negative control without bacteria for comparisons. Suture material allowing biofilm formation makes it difficult to prevent and treat surgical site infections. Therefore, it is important to know which suture thread is more susceptible to biofilm formation by bacteria to prevent possible secondary infections at surgical sites.

Staphylococcus pseudintermedius's PBP4 Is Directly Associated with the Dissociated Oxacillin and Cefoxitin Phenotype.

Staphylococcus pseudintermedius is an important pathogen responsible for infections in dogs and in humans. The emergence and dissemination of methicillin-resistant S. pseudintermedius (MRSP) and the multidrug resistance frequently seen in this species make difficult the treatment of these pathogens. The cefoxitin disk is widely used as a marker of methicillin resistance mediated by the mecA gene in Staphylococcus aureus and other staphylococcal species; however, it is not useful to detect ß-lactam resistance of MRSP in clinical microbiology laboratories. The purpose of this study was to elucidate the molecular bases of the dissociated phenotype between oxacillin and cefoxitin antibiotics. By using a combinatorial approach that included the Penicillin-Binding Proteins' (PBP) profile, their affinity for different ß-lactam antibiotics and the analyses of PBPs' sequence, we provide evidence that PBP4 showed still affinity for its target cefoxitin, impairing its phenotypic resistant detection in MRSP. Together, these findings provide evidence that S. pseudintermedius PBP4 is directly associated with the dissociated oxacillin and cefoxitin phenotype.

Characterization of the First mecA-Positive Multidrug-Resistant Staphylococcus pseudintermedius Isolated from an Argentinian Patient.

Staphylococcus pseudintermedius is commonly associated with colonization or infection in dogs, and was identified as a novel species within the genus Staphylococcus in 2006. Methicillin resistance emerged in S. pseudintermedius during the last decade. We describe here a genomic characterization of the first methicillin-resistant S. pseudintermedius (MRSP) recovered from a human patient in Argentina. The strain was phenotypically identified as MRSP 8510 by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and antimicrobial susceptibility testing. We assessed genetic characterization by mecA PCR, SCCmec (staphylococcal chromosomal cassette) typing, and whole-genome sequencing. MRSP 8510 was phenotypically resistant to six classes of antimicrobial agents, consistent with the genes found in its genome. We concluded that MRSP 8510 was a multidrug-resistant ST1412 isolate. This study highlights the importance of the detection and characterization of pathogens with potential risks of zoonotic transmission to humans, as they may constitute a reservoir of genes associated with antimicrobial resistance.

Identification and molecular epidemiology of methicillin resistant Staphylococcus pseudintermedius strains isolated from canine clinical samples in Argentina.

BACKGROUND: Staphylococcus pseudintermedius is the leading cause of pyoderma in dogs and the frequent use of antimicrobial treatment is associated to the development of resistance to nearly all classes of antibiotics. Despite S. pseudintermedius significance, our understanding of the molecular mechanism of ß-lactam resistance and its genetic diversity remains limited. We aimed to: i) determine the phenotypic resistance profile of methicillin resistant Staphylococcus pseudintermedius (MRSP) isolated from infected dogs in three different veterinary hospitals in Buenos Aires, Argentina; ii) identify the SCCmec elements and resistance genes; and iii) analyze the clonal relationship between isolates and in regard of dominant lineages found in the world. RESULTS: In addition to the differential levels of ß-lactam resistance, MRSP isolates (n = 10) showed resistance to 5-6 families of antibiotics, and were therefore categorized as multidrug-resistant. All the isolates were variant of SCCmec V homologous to S. aureus; additional SCCmecFinder analysis classified five of the genomes as SCCmec type V (5C2&5) with mecA (encodes for PBP2a), mecRI and mecI and all the genes closely related to the reference SCCmec type V S. aureus TSGH17 strain. In the remaining five strains, mecA was present, although other genes associated with SCCmec V including mecR1 and mecI were missing. PBP2a was inducible in low level resistance strains (MRSP 8151), and constitutively expressed in MRSP 8150, suggesting different mecA regulatory mechanisms. MRSP isolates showed significant genetic diversity: eight PFGE clonal types and six multilocus-sequence typing (MLST) sequence types (STs) (339, 649, 919, 920, 921 and 922), including four new STs genetically distinct from STs reported in other geographic areas. Comparative genomics and phylogenetic analyses of the MRSP showed a correlation between the genetic content and the phenotypes, and established the genetic relationship between the isolates. CONCLUSIONS: MRSP could be a threat to animal health due to it concerning level of antimicrobial resistance. Our study highlights genetic and epidemiological aspects of multidrug-resistant MRSP strains from Argentina showing high degree of correlation between the resistance genes and the phenotype of the isolates and, furthermore, they appeared evolutionary closer to major worldwide reported ST68 and ST71.

Ceftaroline resistance in Staphylococcus pseudintermedius gene mecA carriers / Resistência à ceftarolina em Staphylococcus pseudintermedius portadores do gene mecA

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) being a constant concern, ceftaroline fosamil has been recently approved as a new cephalosporin, active against MRSA, for use in humans; only rare cases of resistance have been reported till date. There is no report of resistance to ceftaroline in Staphylococcus pseudintermedius, which is the main bacterium causing dermatitis and otitis in dogs. To evaluate staphylococcal resistance to ceftaroline, 35 isolates of methicillin-resistant S. pseudintermedius (MRSP), carrying the mecA gene, from 26 dogs with folliculitis and nine dogs with external otitis, underwent disk diffusion test with cefoxitin, oxacillin, and ceftaroline. Tests with cefoxitin and oxacillin showed > 90% sensitivity in methicillin resistance detection. In the disk diffusion test, 97.14% (34/35) were resistant to cefoxitin, 94.29% (33/35) to oxacillin, and 31.43% (11/35) to ceftaroline. Of the ceftaroline-resistant strains, 27.27% (3/11) were obtained from the ears of dogs while the rest (8/11) were from the skin. The current report is the first description of MRSP resistance to ceftaroline.(AU)

Infecções causadas por Staphylococcus aureus resistente à meticilina (MRSA) são uma preocupação médica constante. A ceftarolina fosamila é uma nova cefalosporina ativa contra Staphylococcus aureus resistente à meticilina recentemente aprovada para uso em humanos e raros casos de resistência relatados até agora. Não há relatos de resistência à ceftarolina em Staphylococcus pseudintermedius, principal bactéria causadora de dermatite e otite em cães. Com o objetivo de avaliar a resistência estafilocócica à ceftarolina, 35 amostras de S. pseudintermedius resistentes à meticilina (MRSP), portadoras do gene mecA, provenientes de 26 cães com foliculite e 9 com otite externa foram submetidos ao teste de disco-difusão com cefoxitina, oxacilina e ceftarolina. Os testes realizados com cefoxitina e oxacilina mostraram mais de 90% de sensibilidade na detecção da resistência à meticilina em ambas. No teste da disco-difusão, 97,14% (1/35) foram resistentes à cefoxitina, 94,29% (3/35) à oxacilina e 31,43% (11/35) à ceftarolina. Das cepas resistentes às ceftarolina, 27,27 (3/11) foram provenientes de ouvido de cães e as demais (8/11), provenientes da pele, sendo essa primeira descrição de resistência de MRSP à ceftarolina na literatura atual.(AU)

Ceftaroline resistance in Staphylococcus pseudintermedius gene mecA carriers / Resistência à ceftarolina em Staphylococcus pseudintermedius portadores do gene mecA

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) being a constant concern, ceftaroline fosamil has been recently approved as a new cephalosporin, active against MRSA, for use in humans; only rare cases of resistance have been reported till date. There is no report of resistance to ceftaroline in Staphylococcus pseudintermedius, which is the main bacterium causing dermatitis and otitis in dogs. To evaluate staphylococcal resistance to ceftaroline, 35 isolates of methicillin-resistant S. pseudintermedius (MRSP), carrying the mecA gene, from 26 dogs with folliculitis and nine dogs with external otitis, underwent disk diffusion test with cefoxitin, oxacillin, and ceftaroline. Tests with cefoxitin and oxacillin showed > 90% sensitivity in methicillin resistance detection. In the disk diffusion test, 97.14% (34/35) were resistant to cefoxitin, 94.29% (33/35) to oxacillin, and 31.43% (11/35) to ceftaroline. Of the ceftaroline-resistant strains, 27.27% (3/11) were obtained from the ears of dogs while the rest (8/11) were from the skin. The current report is the first description of MRSP resistance to ceftaroline.(AU)

Infecções causadas por Staphylococcus aureus resistente à meticilina (MRSA) são uma preocupação médica constante. A ceftarolina fosamila é uma nova cefalosporina ativa contra Staphylococcus aureus resistente à meticilina recentemente aprovada para uso em humanos e raros casos de resistência relatados até agora. Não há relatos de resistência à ceftarolina em Staphylococcus pseudintermedius, principal bactéria causadora de dermatite e otite em cães. Com o objetivo de avaliar a resistência estafilocócica à ceftarolina, 35 amostras de S. pseudintermedius resistentes à meticilina (MRSP), portadoras do gene mecA, provenientes de 26 cães com foliculite e 9 com otite externa foram submetidos ao teste de disco-difusão com cefoxitina, oxacilina e ceftarolina. Os testes realizados com cefoxitina e oxacilina mostraram mais de 90% de sensibilidade na detecção da resistência à meticilina em ambas. No teste da disco-difusão, 97,14% (1/35) foram resistentes à cefoxitina, 94,29% (3/35) à oxacilina e 31,43% (11/35) à ceftarolina. Das cepas resistentes às ceftarolina, 27,27 (3/11) foram provenientes de ouvido de cães e as demais (8/11), provenientes da pele, sendo essa primeira descrição de resistência de MRSP à ceftarolina na literatura atual.(AU)

Frequency and antimicrobial susceptibility of Staphylococcus pseudintermedius in dogs with otitis externa / Frequência e sensibilidade antimicrobiana de Staphylococcus pseudintermedius isolados de cães com otite externa

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.(AU)

Infecções por Staphyloccocus pseudintermedius (SP) na pele de cães tem sido objeto de estudos, uma vez que esses microrganismos geralmente apresentam resistência múltipla à antibióticos. Este estudo teve como objetivo identificar e avaliar a susceptibilidade antimicrobiana das cepas de SP isoladas de cães com otite. Amostras de ambas orelhas de 52 cães com otite (n=104) foram incluídas. As bactérias foram cultivadas em ágar Muller-Hinton suplementado com 5% de sangue equino e incubadas a 37ºC por 24 a 48h. Todas as colônias foram submetidas à avaliação bioquímica para identificação de estafilococos. A identificação das colônias como SP foi confirmada pela reação em cadeia da polimerase. A susceptibilidade antimicrobiana das cepas SP foi avaliada pela técnica de difusão em disco. A presença do gene mecA foi avaliada em todos os isolados de SP por PCR. 44 estirpes de SP foram isoladas de 31 cães (31/52, 59,6%). 75% das cepas foram suscetíveis a cefalexina e 93,2% à amoxicilina mais ácido clavulânico. Menos de 23% das estirpes eram suscetíveis à penicilina. Para antimicrobianos não beta-lactâmicos, 63,6% apresentaram resistência ao sulfametoxazol-trimetoprim, 61,4% à tetraciclina e 38,64% à enrofloxacina. A frequência de resistência a aminoglicosídeos foi de 27,3% para gentamicina. A resistência a oxacilina in vitro foi detectada em 13 das 44 estirpes (29,55%). Um total de 12 amostras (27,3%) foram positivas para mecA, cinco das quais foram suscetíveis à oxacilina na difusão em disco. 26 amostras (59,1%) foram resistentes a três ou mais classes de antimicrobianos e classificadas como multirresistentes. Nossos resultados mostram elevada frequência de isolados SP e multiresistentes para os antimicrobianos comumente usados em veterinária.(AU)

Frequency and antimicrobial susceptibility of Staphylococcus pseudintermedius in dogs with otitis externa / Frequência e sensibilidade antimicrobiana de Staphylococcus pseudintermedius isolados de cães com otite externa

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.

Infecções por Staphyloccocus pseudintermedius (SP) na pele de cães tem sido objeto de estudos, uma vez que esses microrganismos geralmente apresentam resistência múltipla à antibióticos. Este estudo teve como objetivo identificar e avaliar a susceptibilidade antimicrobiana das cepas de SP isoladas de cães com otite. Amostras de ambas orelhas de 52 cães com otite (n=104) foram incluídas. As bactérias foram cultivadas em ágar Muller-Hinton suplementado com 5% de sangue equino e incubadas a 37ºC por 24 a 48h. Todas as colônias foram submetidas à avaliação bioquímica para identificação de estafilococos. A identificação das colônias como SP foi confirmada pela reação em cadeia da polimerase. A susceptibilidade antimicrobiana das cepas SP foi avaliada pela técnica de difusão em disco. A presença do gene mecA foi avaliada em todos os isolados de SP por PCR. 44 estirpes de SP foram isoladas de 31 cães (31/52, 59,6%). 75% das cepas foram suscetíveis a cefalexina e 93,2% à amoxicilina mais ácido clavulânico. Menos de 23% das estirpes eram suscetíveis à penicilina. Para antimicrobianos não beta-lactâmicos, 63,6% apresentaram resistência ao sulfametoxazol-trimetoprim, 61,4% à tetraciclina e 38,64% à enrofloxacina. A frequência de resistência a aminoglicosídeos foi de 27,3% para gentamicina. A resistência a oxacilina in vitro foi detectada em 13 das 44 estirpes (29,55%). Um total de 12 amostras (27,3%) foram positivas para mecA, cinco das quais foram suscetíveis à oxacilina na difusão em disco. 26 amostras (59,1%) foram resistentes a três ou mais classes de antimicrobianos e classificadas como multirresistentes. Nossos resultados mostram elevada frequência de isolados SP e multiresistentes para os antimicrobianos comumente usados em veterinária.

Frequency and antimicrobial susceptibility of Staphylococcus pseudintermedius in dogs with otitis externa / Frequência e sensibilidade antimicrobiana de Staphylococcus pseudintermedius isolados de cães com otite 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.

RESUMO: Infecções por Staphyloccocus pseudintermedius (SP) na pele de cães tem sido objeto de estudos, uma vez que esses microrganismos geralmente apresentam resistência múltipla à antibióticos. Este estudo teve como objetivo identificar e avaliar a susceptibilidade antimicrobiana das cepas de SP isoladas de cães com otite. Amostras de ambas orelhas de 52 cães com otite (n=104) foram incluídas. As bactérias foram cultivadas em ágar Muller-Hinton suplementado com 5% de sangue equino e incubadas a 37ºC por 24 a 48h. Todas as colônias foram submetidas à avaliação bioquímica para identificação de estafilococos. A identificação das colônias como SP foi confirmada pela reação em cadeia da polimerase. A susceptibilidade antimicrobiana das cepas SP foi avaliada pela técnica de difusão em disco. A presença do gene mecA foi avaliada em todos os isolados de SP por PCR. 44 estirpes de SP foram isoladas de 31 cães (31/52, 59,6%). 75% das cepas foram suscetíveis a cefalexina e 93,2% à amoxicilina mais ácido clavulânico. Menos de 23% das estirpes eram suscetíveis à penicilina. Para antimicrobianos não beta-lactâmicos, 63,6% apresentaram resistência ao sulfametoxazol-trimetoprim, 61,4% à tetraciclina e 38,64% à enrofloxacina. A frequência de resistência a aminoglicosídeos foi de 27,3% para gentamicina. A resistência a oxacilina in vitro foi detectada em 13 das 44 estirpes (29,55%). Um total de 12 amostras (27,3%) foram positivas para mecA, cinco das quais foram suscetíveis à oxacilina na difusão em disco. 26 amostras (59,1%) foram resistentes a três ou mais classes de antimicrobianos e classificadas como multirresistentes. Nossos resultados mostram elevada frequência de isolados SP e multiresistentes para os antimicrobianos comumente usados em veterinária.

An investigation of methicillin-resistant Staphylococcus pseudintermedius (MRSP) in domestic and shelter dogs in Montenegro (RS-Brazil) / Pesquisa de “Staphylococcus pseudintermedius” resistente à meticilina (MRSP) em cães domésticos e de abrigo em Montenegro (RS-Brasil)

The interaction established between man and their pets has been increasing progressively. The diagnosis of animals carrying methicillin-resistant Staphylococcus pseudintermedius (MRSP) becomes important since positive results for this opportunistic bacteria has been found in humans. The aim of this study was to investigate methicillin-resistant Staphylococcus pseudintermedius (MRSP) in domestic dogs attended in a veterinary clinic and shelter dogs. Anal and nasal swabs from 53 domestic dogs and 46 shelter dogs were collected between the months of August and October of 2015, resulting in 198 samples, which were sent for routine laboratory analysis and subsequently used for this study. Phenotypic tests for bacteria identification and susceptibility to oxacillin were performed for the investigation of MRSP. A total of 23 samples (11.6%) from 21 dogs were positive for S. pseudintermedius, however none of the isolates were MRSP. Nasal and anal swabs had similar positivity and two dogs were carriers of the bacteria in both analyzed sites (anal and nasal). Our results showed a higher positivity for S. pseudintermedius in domestic dogs compared to shelter dogs, as well as indicating the importance of collecting more than one colonization site. This is the first study to perform a comparison among different animal creating sites in Brazil.(AU)

O convívio estabelecido entre o homem e seus animais de estimação vem se intensificando progressivamente. O diagnóstico de animais portadores de Staphylococcus pseudintermedius resistente à meticilina (MRSP) se torna importante uma vez que já foram obtidos resultados positivos para esta bactéria oportunista em humanos. O objetivo do estudo foi pesquisar Staphylococcus pseudintermedius resistente à meticilina (MRSP) em cães domésticos atendidos numa clínica veterinária e em cães de abrigo. Entre os meses de Agosto e Outubro de 2015 foram coletados swabs anais e nasais de 53 cães domésticos e de 46 cães de abrigo, resultando em um total de 198 amostras, as quais foram enviadas para análise de rotina laboratorial na Universidade Feevale e, posteriormente, utilizadas para este estudo. Foram realizados testes fenotípicos de identificação da bactéria e de suscetibilidade à oxacilina para a pesquisa de MRSP. Um total de 23 amostras (11.6%) oriundas de 21 cães foi positivo para S. pseudintermedius, porém nenhum isolado era MRSP. Os swabs nasais e anais tiveram positividade semelhante, sendo dois cães portadores da bactéria em ambos os sítios (anal e nasal). Nossos resultados indicaram uma maior positividade para S. pseudintermedius em cães domésticos em comparação aos cães de abrigo, além de sinalizar sobre a importância de coletas em mais de um sítio de colonização. Este é o primeiro estudo que realizou uma comparação entre os diferentes locais de criação dos animais no Brasil.(AU)

An investigation of methicillin-resistant Staphylococcus pseudintermedius (MRSP) in domestic and shelter dogs in Montenegro (RS-Brazil) / Pesquisa de “Staphylococcus pseudintermedius” resistente à meticilina (MRSP) em cães domésticos e de abrigo em Montenegro (RS-Brasil)

The interaction established between man and their pets has been increasing progressively. The diagnosis of animals carrying methicillin-resistant Staphylococcus pseudintermedius (MRSP) becomes important since positive results for this opportunistic bacteria has been found in humans. The aim of this study was to investigate methicillin-resistant Staphylococcus pseudintermedius (MRSP) in domestic dogs attended in a veterinary clinic and shelter dogs. Anal and nasal swabs from 53 domestic dogs and 46 shelter dogs were collected between the months of August and October of 2015, resulting in 198 samples, which were sent for routine laboratory analysis and subsequently used for this study. Phenotypic tests for bacteria identification and susceptibility to oxacillin were performed for the investigation of MRSP. A total of 23 samples (11.6%) from 21 dogs were positive for S. pseudintermedius, however none of the isolates were MRSP. Nasal and anal swabs had similar positivity and two dogs were carriers of the bacteria in both analyzed sites (anal and nasal). Our results showed a higher positivity for S. pseudintermedius in domestic dogs compared to shelter dogs, as well as indicating the importance of collecting more than one colonization site. This is the first study to perform a comparison among different animal creating sites in Brazil.

O convívio estabelecido entre o homem e seus animais de estimação vem se intensificando progressivamente. O diagnóstico de animais portadores de Staphylococcus pseudintermedius resistente à meticilina (MRSP) se torna importante uma vez que já foram obtidos resultados positivos para esta bactéria oportunista em humanos. O objetivo do estudo foi pesquisar Staphylococcus pseudintermedius resistente à meticilina (MRSP) em cães domésticos atendidos numa clínica veterinária e em cães de abrigo. Entre os meses de Agosto e Outubro de 2015 foram coletados swabs anais e nasais de 53 cães domésticos e de 46 cães de abrigo, resultando em um total de 198 amostras, as quais foram enviadas para análise de rotina laboratorial na Universidade Feevale e, posteriormente, utilizadas para este estudo. Foram realizados testes fenotípicos de identificação da bactéria e de suscetibilidade à oxacilina para a pesquisa de MRSP. Um total de 23 amostras (11.6%) oriundas de 21 cães foi positivo para S. pseudintermedius, porém nenhum isolado era MRSP. Os swabs nasais e anais tiveram positividade semelhante, sendo dois cães portadores da bactéria em ambos os sítios (anal e nasal). Nossos resultados indicaram uma maior positividade para S. pseudintermedius em cães domésticos em comparação aos cães de abrigo, além de sinalizar sobre a importância de coletas em mais de um sítio de colonização. Este é o primeiro estudo que realizou uma comparação entre os diferentes locais de criação dos animais no Brasil.

Prevalence and in vitro susceptibility of methicillin-resistant Staphylococcus pseudintermedius (MRSP) from skin and nostrils of dogs with superficial pyoderma / Prevalência e suscetibilidade in vitro de Staphylococcus pseudintermedius resistente à meticilina (MRSP) oriundos de pele e narinas de cães com piodermite superficial

In order to assess the prevalence of Methicillin-resistant Staphylococcus pseudintermedius from skin and nostrils of dogs with pyoderma, to determine its in vitro susceptibility, and to correlate these data with the presence of the mecA gene, 43 dogs were selected. Samples were collected from secretion of their skin lesions and right nostril, cultured, and analyzed for phenotypic and genotypic characteristics of the bacteria studied. In 62 samples (91%) the microorganism was classified as S. pseudintermedius. The rate of resistance against antibiotics ranged from 7% (amikacin; 4/62) to 77% (sulfamethoxazole + trimethoprim; 48/62). Resistance against oxacillin was found in 34% of the samples (21/62). Twenty-five samples (37%) were strains that carried the mecA gene. A significant correlation (P<0.01) was found between presence of the mecA gene and oxacillin resistance. Seventeen dogs were mecA gene carriers, and 8 (47%) of them had the gene in the skin lesions and nostril. A significant correlation (P<0.01) was also observed between the presence of mecA gene in the skin lesions and nostrils. Oxacillin resistance in vitro can be safely used to indicate the presence of mecA gene in MRSP samples. The nostrils can be a reservoir of MRSP in dogs.(AU)

Para acessar a prevalência de MRSP na pele e nas narinas de cães com piodermite superficial, determinar a suscetibilidade in vitro, e correlacionar estes dados com a presença do gene mecA, foram selecionados 43 cães. Amostras de lesões de pele e narinas foram coletadas, cultivadas, e analisadas fenotipica e genotipicamente. Em 62 amostras (91%), os microrganismos foram classificados como Staphylococcus pseudintermedius. A taxa de resistência a antibióticos variou entre 7% (amicacina; 4/62) e 77% (sulfamethoxazol + trimetoprim; 48/62). Resistência a oxacilina foi observada em 34% das amostras (21/62). Vinte e cinco amostras (37%), eram cepas portadoras do gene mecA. Correlação significativa (P<0,01) foi observada entre a presença do gene mecA e a resistência à oxacilina. Considerando os cães, 17 eram portadores de cepas com gene mecA e 8(47%) delas carreavam este gene nas amostras de lesão de pele e nas narinas. Correlação significativa (P>0,01) foi observada entre a presença do gene mecA nas lesões de pele e nas narinas. Sendo assim, resistência à oxacilina in vitro pode ser aferida com segurança para indicar a presença do gene mecA em amostras de MRSP, e as narinas podem constituir em um reservatório dos microorganismos em cães.(AU)

Prevalence and in vitro susceptibility of methicillin-resistant Staphylococcus pseudintermedius (MRSP) from skin and nostrils of dogs with superficial pyoderma / Prevalência e suscetibilidade in vitro de Staphylococcus pseudintermedius resistente à meticilina (MRSP) oriundos de pele e narinas de cães com piodermite superficial

In order to assess the prevalence of Methicillin-resistant Staphylococcus pseudintermedius from skin and nostrils of dogs with pyoderma, to determine its in vitro susceptibility, and to correlate these data with the presence of the mecA gene, 43 dogs were selected. Samples were collected from secretion of their skin lesions and right nostril, cultured, and analyzed for phenotypic and genotypic characteristics of the bacteria studied. In 62 samples (91%) the microorganism was classified as S. pseudintermedius. The rate of resistance against antibiotics ranged from 7% (amikacin; 4/62) to 77% (sulfamethoxazole + trimethoprim; 48/62). Resistance against oxacillin was found in 34% of the samples (21/62). Twenty-five samples (37%) were strains that carried the mecA gene. A significant correlation (P < 0.01) was found between presence of the mecA gene and oxacillin resistance. Seventeen dogs were mecA gene carriers, and 8 (47%) of them had the gene in the skin lesions and nostril. A significant correlation (P < 0.01) was also observed between the presence of mecA gene in the skin lesions and nostrils. Oxacillin resistance in vitro can be safely used to indicate the presence of mecA gene in MRSP samples. The nostrils can be a reservoir of MRSP in dogs.(AU)

Para acessar a prevalência de MRSP na pele e nas narinas de cães com piodermite superficial, determinar a suscetibilidade in vitro, e correlacionar estes dados com a presença do gene mecA, foram selecionados 43 cães. Amostras de lesões de pele e narinas foram coletadas, cultivadas, e analisadas fenotipica e genotipicamente. Em 62 amostras (91%), os microrganismos foram classificados como Staphylococcus pseudintermedius. A taxa de resistência a antibióticos variou entre 7% (amicacina; 4/62) e 77% (sulfamethoxazol + trimetoprim; 48/62). Resistência a oxacilina foi observada em 34% das amostras (21/62). Vinte e cinco amostras (37%), eram cepas portadoras do gene mecA. Correlação significativa (P < 0,01) foi observada entre a presença do gene mecA e a resistência à oxacilina. Considerando os cães, 17 eram portadores de cepas com gene mecA e 8(47%) delas carreavam este gene nas amostras de lesão de pele e nas narinas. Correlação significativa (P>0,01) foi observada entre a presença do gene mecA nas lesões de pele e nas narinas. Sendo assim, resistência à oxacilina in vitro pode ser aferida com segurança para indicar a presença do gene mecA em amostras de MRSP, e as narinas podem constituir em um reservatório dos microorganismos em cães.(AU)

Methicillin-resistant Staphylococcus pseudintermedius clonal groups isolated from canine pyoderma in Brazil

Background: Since the early reports of mecA-positive Staphylococcus (S.) pseudintermedius isolates in the United States and in Europe were published, the frequency of methicillin-resistant S. pseudintermedius (MRSP) has increased among skin disease cases in dogs in many countries. Moreover, MRSP isolates frequently present a multi-drug resistant profile, which include most drugs used for the skin disease treatment. The distribution of multi- drug resistant MRSP clonal groups in turn varies according to geographic region. Despite the large dog population in Brazil, no data on the MRSP resistance profile or clonal groups have been reported. The aim of this study was to assess the antimicrobial resistance phenotypes and clonal relationships of MRSP isolates originating from dogs affected by recurrent skin diseases.Material, Methods & Results: Twenty-one epidemiologically unrelated isolates originating from dogs inflicted with a recurrent skin disease, which were treated at the Veterinary Hospital (HCV) of the Federal University of Rio Grande do Sul (UFRGS) in Porto Alegre, were included in this study. The isolates suspected of being MRSP were subjected to PCR analysis to confirm their identity. Identifications were made using PCR analysis that targeted the mecA gene and PCRRFLP that targeted the pta gene. Isolates were further assessed by a disc diffusion test for resistance to 13 antimicrobials. Clonal groups were determined according to spa typing and SmaI fingerprinting (Pulsed-field Gel Electrophoresis-PFGE) profiles. All 21 isolates were confirmed to be MRSP and displayed a multiple resistance profile. In total, 4 different spa types were identified, and the most prevalent was a novel spa type (tyA) described in this study. SmaI-macrorestriction analysis demonstrated that the MRSP isolates presented between seven and twelve fragments and were distributed among 15 PFGE profiles.[...]

Methicillin-resistant Staphylococcus pseudintermedius clonal groups isolated from canine pyoderma in Brazil

Background: Since the early reports of mecA-positive Staphylococcus (S.) pseudintermedius isolates in the United States and in Europe were published, the frequency of methicillin-resistant S. pseudintermedius (MRSP) has increased among skin disease cases in dogs in many countries. Moreover, MRSP isolates frequently present a multi-drug resistant profile, which include most drugs used for the skin disease treatment. The distribution of multi- drug resistant MRSP clonal groups in turn varies according to geographic region. Despite the large dog population in Brazil, no data on the MRSP resistance profile or clonal groups have been reported. The aim of this study was to assess the antimicrobial resistance phenotypes and clonal relationships of MRSP isolates originating from dogs affected by recurrent skin diseases.Material, Methods & Results: Twenty-one epidemiologically unrelated isolates originating from dogs inflicted with a recurrent skin disease, which were treated at the Veterinary Hospital (HCV) of the Federal University of Rio Grande do Sul (UFRGS) in Porto Alegre, were included in this study. The isolates suspected of being MRSP were subjected to PCR analysis to confirm their identity. Identifications were made using PCR analysis that targeted the mecA gene and PCRRFLP that targeted the pta gene. Isolates were further assessed by a disc diffusion test for resistance to 13 antimicrobials. Clonal groups were determined according to spa typing and SmaI fingerprinting (Pulsed-field Gel Electrophoresis-PFGE) profiles. All 21 isolates were confirmed to be MRSP and displayed a multiple resistance profile. In total, 4 different spa types were identified, and the most prevalent was a novel spa type (tyA) described in this study. SmaI-macrorestriction analysis demonstrated that the MRSP isolates presented between seven and twelve fragments and were distributed among 15 PFGE profiles.[...](AU)