Characterization and antimicrobial susceptibility of coagulase-positive Staphylococcus isolated in a veterinary teaching hospital in Chile / Caracterización y sensibilidad antimicrobiana de Staphylococcus coagulasa-positivos aislados en un hospital clínico veterinario en Chile

Abstract There is limited information about the prevalence and antimicrobial susceptibility of coagulase-positive Staphylococcus (CoPS) strains in veterinary settings in Chile. The aim of this observational study was to identify and characterize CoPS strains from dogs, owners, veterinary professionals and surfaces in a veterinary teaching hospital at Universidad de Chile to determine the presence of methicillin-resistant strains and evaluate the genetic relationship among the strains. Veterinarians (n = 24), surfaces (n = 10), and healthy dogs (n = 40) and their respective owners (n = 40) were sampled for CoPS. Isolates were identified by PCRand antimicrobial susceptibility was assessed by the disk diffusion method and MIC. The presence of the mecA gene was evaluated by PCR, and the genetic relationship among the strains was established by PFGE. A total of 45 CoPS strains were obtained, eight from veterinary professionals, three from hospital surfaces, eight from owners and 26 from dogs. Nine of the strains were resistant to methicillin (20%), and all of them carried the mecA gene. A high percentage of the strains was resistant to clindamycin (33.3%). Additionally, the isolated CoPS showed high genetic diversity. This study suggests that veterinarians are in high risk of harboring methicillin-resistant CoPS (25% versus 2.5% from owners) and our results provide evidence that clindamycin could not be an empiric alternative for CoPS in the analyzed hospital. This is the first report of methicillin-resistant CoPS in veterinary settings in Chile, considering humans, pets and surfaces.

Resumen Existe información limitada sobre prevalencia y sensibilidad antimicrobiana de cepas de Staphylococcus coagulasa-positivas (CoPS) en entornos veterinarios en Chile. El objetivo de este estudio observacional fue identificar y caracterizar cepas CoPS de perros, duenos, veterinarios y superficies de un hospital veterinario de la Universidad de Chile, determinar la presencia de cepas meticilino-resistentes y evaluar la relación genética entre las cepas. Se colectaron muestras de veterinarios (n = 24), de superficies hospitalarias (n = 10) y de perros sanos (n =40) y sus respectivos duenos (n = 40). Los aislamientos se identificaron mediante PCR y la sensibilidad antimicrobiana se evaluó por difusión en discos y CIM. También se empleó PCR para detectar la presencia del gen mecA; la relación genética entre las cepas se estableció mediante electroforesis de campos pulsantes (PFGE). Se obtuvo un total de 45 cepas de CoPS, 8 de veterinarios, 3 de superficies hospitalarias, 8 de duenos y 26 de perros. Nueve cepas fueron meticilino-resistentes (20%), todas portadoras del gen mecA. Un porcentaje importante de cepas fue resistente a clindamicina (33,3%). Además, las cepas aisladas mostraron una alta diversidad genética. Este estudio sugiere que los veterinarios tienen alto riesgo de portar CoPS resistentes a meticilina (25% versus 2,5% propietarios). Asimismo, nuestros resultados proporcionan evidencia de que la clindamicina podría no ser una alternativa empírica para CoPS en el hospital analizado. Este es el primer estudio de CoPS meticilino-resistentes en entornos veterinarios en Chile que considera humanos, mascotas y superficies.

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)

Antibiotic resistance profiles of Staphylococcus pseudintermedius isolated from dogs and cats

Aims: Antibiotic resistance in Staphylococcus pseudintermedius is increasing gradually towards those antibiotics that are frequently used leading to limited therapeutic options due to multidrug resistance. The objectives of the study were to investigate the antibiotic resistance profiles of S. pseudintermedius isolates from pet and stray dogs and cats in Selangor, Malaysia and to detect the resistance genes (mecA and BlaZ) within the isolates. Methodology and results: A total of 200 stray and pet dogs and cats were sampled. The samples were cultured onto Mannitol Salt agar and all the presumptive colonies were subcultured, then identified using biochemical tests and confirmed by PCR assay targeting the nuc gene. The isolates were subjected to antibiotic susceptibility test against 12 antibiotics. Twenty three isolates (11.5%) were positive to S. pseudintermedius (stray cats, 11/50; stray dogs, 9/50; pet dogs, 3/50 and pet cats, 0/50). One hundred percent (100%) of the S. pseudintermedius isolates were found to be resistant to penicillin, erythromycin and tetracycline while they showed 100% susceptible to oxacillin, amoxicillinclavulanic acid, gentamicin, chloramphenicol, vancomycin, ciprofloxacin, enrofloxacin, cephalexin and rifampicin. The blaZ gene which codes for β-lactamases production was found in all of the isolates that were resistant to penicillin but not to methicillin. Conclusion, significance and impact of study: A high number of S. pseudintermedius from dogs and cats developed antibiotic resistance which is a public health concern.

Multidrug-resistant Staphylococcus pseudintermedius isolated from dog: case report / Staphylococcus pseudintermedius multirresistente isolado do cão: relato de caso

The zoonotic potential of multidrug resistant (MDR) bacteria is a worldwide concern and companion animals have been implicated in the spread of resistant bacteria. Therefore, surveillance is important, as there are reports of transmission of these bacteria from dog to men, as well as from men to dog. A 5-year-old mixed-breed male dog was admitted with obstructive struvite urolithiasis relapsing for over 18 months, in Botucatu, in the state of São Paulo, Brazil. The strain, biochemically identified as Staphylococcus spp., was MDR and was treated off-label with vancomycin, which resulted in clinical cure. The strain was molecularly identified as Staphylococcus pseudintermedius and the mecA gene was identified. This is the main gene responsible for methicillin-resistant S. pseudintermedius (MRSP), which is often resistant to multiple antimicrobials. The hypotheses for this clinical case are the transmission from man to animal, since the tutor was an intensivist doctor, or the bacterium itself could be part of the animal's microbiota and due to other factors, such as stress or obstructive urinary disease, opened a doorway to infection by S. pseudintermedius. Further studies should elucidate the transmission of MDR bacteria between human and pets.(AU)

O potencial zoonótico de bactérias multirresistentes é uma preocupação global e os animais de companhia têm sido implicados na disseminação de bactérias resistentes; assim, é importante a vigilância, pois já existem relatos de transmissão destas bactérias do cão para o homem e vice-versa. Um cão, sem raça definida e de cinco anos de idade, foi atendido na cidade de Botucatu, São Paulo, Brasil, apresentando urolitíase obstrutiva de estruvita recorrente há um ano e meio. Na urocultura do animal foi isolada uma estirpe de Staphylococcus spp. multirresistente; o tratamento com vancomicina possibilitou acura clínica. A estirpe de Staphylococcus spp. isolada foi identificada molecularmente como S. pseudintermedius e nela foi identificada a presença do gene mecA, o principal responsável por S. pseuidintermedius resistente à meticilina (MRSP), e que é frequentemente resistente à múltiplos antimicrobianos. As hipóteses para este caso clínico são a transmissão do homem para o animal, pois o tutor era um médico intensivista, ou que a própria bactéria fazia parte da microbiota do animal e, devido a outros fatores como estresse e doença urinária obstrutiva, abriu-se uma porta de entrada para a infecção pelo S. pseudintermedius. Mais estudos são necessários para a elucidação da transmissão de bactérias multirresistentes entre animais de companhia e o ser humano.(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)

Description of Methicillin-resistant Staphylococcus pseudintermedius from canine pyoderma in Minas Gerais state, Brazil / Descrição de Staphylococcus pseudintermedius meticilina-resistentes de piodermite canina no estado de Minas Gerais, Brasil

Methicillin-resistant Staphylococcus pseudintermedius (MRSP) is of worldwide concern in veterinary medicine. The identification of resistant strains is necessary for proper treatment and the prevention of its propagation among animals. This study aimed to identify S. pseudintermedius isolated from canine pyoderma and evaluate their resistance profiles. Lesions from 25 dogs with pyoderma were sampled. Bacterial isolates were subjected to phenotypic and genotypic analysis for identification of the causative agent. S. pseudintermedius isolates were subjected to SmaI macrorestriction analysis and PFGE for genetic grouping, and PCR to identify the presence of the mecA gene. Their resistance profiles against 12 antimicrobials were also assessed. According to the microbiological analysis, 70 of the 75 isolates obtained were S. pseudintermedius. The isolates presented PFGE patterns, with similarity varying between 84.6 and 100%, and were grouped into 19 clusters. Despite a high frequency of mecA-positive isolates (66 out 70), only 12 presented resistances to oxacillin. Multi-resistance was identified in 29 isolates. The high frequency of MRSP isolated in this study highlights the relevance of identifying resistant strains to lead proper clinical treatment.

Staphylococcus pseudintermedius meticilina-resistente (MRSP) é de preocupação mundial na medicina veterinária. A identificação de cepas resistentes é necessária a um tratamento adequado e à prevenção da sua propagação entre os animais. O objetivo do estudo foi identificar S. pseudintermedius isolados de piodermite canina e avaliar o perfil de resistência. Foram coletadas amostras de lesões de 25 cães com piodermite. Os isolados bacterianos foram submetidos a análises fenotípicas e genotípicas para identificação do agente causador. Isolados de S. pseudintermedius foram submetidos à análise de macrorrestrição por SmaI e PFGE para agrupamento genético e à PCR para identificar a presença do gene mecA. Seu perfil de resistência contra 12 antimicrobianos também foi avaliado. De acordo com a análise microbiológica, 70 dos 75 isolados obtidos foram identificados como S. pseudintermedius. Os isolados apresentaram padrões de PFGE com similaridade variando entre 84.6 e 100% e foram agrupados em 19 grupos genéticos. Apesar da frequência alta de isolados mecA positivos (66 em 70), apenas 12 apresentaram resistência à oxacilina. Multirresistência foi identificada em 29 isolados. A alta frequência de MRSP isolados neste estudo destaca a relevância de se identificarem cepas resistentes para se conduzir um tratamento clínico adequado.

An update on microbiological causes of canine otitis externa in Campania Region, Italy

Objective: To update the recent knowledge of the microbiological causes of canine otitis externa in Campania Region (Italy) and the antibiotic susceptibility patterns of the iso-lated strains. Methods: A total of 122 dogs were examined by otoscopy, and auricular swab samples were collected from both ears in 74 dogs presenting clinical bilateral otitis and from single ears in 48 dogs displaying clinical unilateral otitis. Cytological examination, bacteriological analysis and antimicrobial susceptibility tests were performed. Results: Thirty-one out of 122 dogs were positive for yeast species (25.4%, 95% con-fidence interval (CI): 18.2%–34.2%) with a higher prevalence of Malassezia pachy-dermatis (21/31 isolates, 67.7%, CI: 48.5%–82.7%), and a total of 91 out of 122 dogs were positive for bacterial species (74.6%;CI:65.8%–81.8%) with a higher prevalence of Staphylococcus pseudintermedius (45/143 isolates, 31.5%, CI: 24.1%–39.8%). These results are the first description of Streptococcus agalactiae-associated otitis. The yeasts isolated showed high levels of susceptibility to all antifungal agents tested; on the con-trary all the isolated bacterial strains were highly resistant to at least four out of ten antimicrobial classes. Both Gram-positive and Gram-negative bacteria showed high resistance to amoxicillin/clavulanate and kanamycin hence they are not recommended as initial empirical therapy for the otitis treatment. Conclusions: This update illustrates an increase in antibiotic resistances providing an insight into the current knowledge of the therapeutic procedures followed on canine otitis externa in Italy. It also emphasizes the importance of considering the results of the microbiological and sensitivity tests to decide on an appropriate antibiotic therapy.

An update on microbiological causes of canine otitis externa in Campania Region, Italy

Objective: To update the recent knowledge of the microbiological causes of canine otitis externa in Campania Region (Italy) and the antibiotic susceptibility patterns of the isolated strains. Methods: A total of 122 dogs were examined by otoscopy, and auricular swab samples were collected from both ears in 74 dogs presenting clinical bilateral otitis and from single ears in 48 dogs displaying clinical unilateral otitis. Cytological examination, bacteriological analysis and antimicrobial susceptibility tests were performed. Results: Thirty-one out of 122 dogs were positive for yeast species (25.4%, 95% confidence interval (CI): 18.2%-34.2%) with a higher prevalence of Malassezia pachydermatis (21/31 isolates, 67.7%, CI: 48.5%-82.7%), and a total of 91 out of 122 dogs were positive for bacterial species (74.6%; CI: 65.8%-81.8%) with a higher prevalence of Staphylococcus pseudintermedius (45/143 isolates, 31.5%, CI: 24.1%-39.8%). These results are the first description of Streptococcus agalactiae-associated otitis. The yeasts isolated showed high levels of susceptibility to all antifungal agents tested; on the contrary all the isolated bacterial strains were highly resistant to at least four out of ten antimicrobial classes. Both Gram-positive and Gram-negative bacteria showed high resistance to amoxicillin/clavulanate and kanamycin hence they are not recommended as initial empirical therapy for the otitis treatment. Conclusions: This update illustrates an increase in antibiotic resistances providing an insight into the current knowledge of the therapeutic procedures followed on canine otitis externa in Italy. It also emphasizes the importance of considering the results of the microbiological and sensitivity tests to decide on an appropriate antibiotic therapy.

Resistencia antimicrobiana y epidemiología molecular de aislamientos de Staphylococcus pseudintermedius de muestras clínicas de caninos / Antimicrobial resistance and molecular epidemiology of Staphylococcus pseudintermedius strains isolated from dog clinical samples

Se estudiaron 28 aislamientos obtenidos de muestras clínicas de perros e identificados por espectrometría de masas (MALDI-TOF) como Staphylococcus pseudintermedius; el objetivo fue evaluar la sensibilidad a los antimicrobianos por el método de difusión y establecer la relación clonal entre aislamientos por electroforesis en campo pulsado (PFGE). La resistencia a meticilina se evaluó mediante PCR por amplificación del gen mecA y se observó en 3/28 aislamientos (10,7 %). Quince aislamientos (53,6 %) presentaron resistencia a alguno de los antibióticos ensayados y 11 de ellos (39,3 %) presentaron resistencia múltiple (resistencia a 3 o más familias de antibióticos). Once aislamientos (39,3 %) presentaron resistencia a eritromicina, debido a la presencia de metilasa ribosomal ermB, y no se detectó resistencia inducible a clindamicina. Por PFGE se pudieron diferenciar 27 tipos clonales, lo cual demuestra gran diversidad clonal. Se destaca el hallazgo de aislamientos de S. pseudintermedius multirresistentes como una eventual problemática a considerar en el diagnóstico veterinario de laboratorio, el tratamiento de las infecciones caninas y el ámbito de la salud pública.

Twenty-eight strains isolated from dog clinical samples identified as Staphylococcus pseudintermedius by mass spectrometry (MALDI-TOF) were studied to assess antimicrobial susceptibility by the diffusion method and clonal relationship by pulsed field gel electrophoresis (PFGE). Methicillin resistance (3/28 isolates; 10,7 %) was evaluated by mecA PCR. Fifteen strains (53.6 %) were resistant to at least one of the antibiotics tested, and eleven of them (39.3 %) showed multiple resistance (3 or more antimicrobial families). Eleven isolates (39.3 %) were resistant to erythromycin due to the presence of ribosomal methylase ermB, whereas clindamycin inducible resistance was not detected. Twenty-seven (27) clonal types were differentiated by PFGE, suggesting high clonal diversity. We emphasize that the finding of multiresistant S. psedintermedius strains is an emerging problem to be considered in veterinary diagnostic laboratory treatment of canine infections and in public health settings.

Antibiotic resistance and molecular characterization of ophthalmic Staphylococcus pseudintermedius isolates from dogs

The prevalence, virulence potential, and antibiotic resistance of ophthalmic Staphylococcus pseudintermedius (SP) isolated from dogs were examined. Sixty-seven Staphylococcus species were isolated from ophthalmic samples and surveyed for species-specific sequences in the Staphylococcus intermedius group (SIG) nuclease gene (SInuc), exfoliative toxin gene for SIG (siet), and antibiotic resistance genes (blaZ and mecA). PCR-restriction fragment length polymorphism analysis of the pta gene was also performed. Fifty isolates were identified as SIG strains, all of which were found to be SP. The blaZ gene was detected in 42 of the 50 SP strains and mecA gene was observed in 18 of the 50 SP strains. The 50 SP strains were most susceptible to amoxicillin/clavulanic acid (94%) and chlorampenicol (70%), and highly resistant to tetracycline (94%) and penicillin (92%). It was also found that 16 (88.9%) mecA-positive SP strains were resistant to oxacillin, tetracycline and penicillin. All mecA-positive SP were resistant to more than four of the eight tested antibiotics and therefore considered SP with multi-drug resistance (MDR). Our results indicate a high prevalence of antibiotic resistance genes in ophthalmic SP along with a close relationship between MDR SP strains and the mecA gene. Based on our findings, judicious administration of antibiotics to companion dogs is necessary.

Determination of staphylococcal exotoxins, SCCmec types, and genetic relatedness of Staphylococcus intermedius group isolates from veterinary staff, companion animals, and hospital environments in Korea

The Staphylococcus (S.) intermedius group (SIG) has been a main research subject in recent years. S. pseudintermedius causes pyoderma and otitis in companion animals as well as foodborne diseases. To prevent SIG-associated infection and disease outbreaks, identification of both staphylococcal exotoxins and staphylococcal cassette chromosome mec (SCCmec) types among SIG isolates may be helpful. In this study, it was found that a single isolate (one out of 178 SIG isolates examined) harbored the canine enterotoxin SEC gene. However, the S. intermedius exfoliative toxin gene was found in 166 SIG isolates although the S. aureus-derived exfoliative toxin genes, such as eta, etb and etd, were not detected. SCCmec typing resulted in classifying one isolate as SCCmec type IV, 41 isolates as type V (including three S. intermedius isolates), and 10 isolates as non-classifiable. Genetic relatedness of all S. pseudintermedius isolates recovered from veterinary staff, companion animals, and hospital environments was determined by pulsed-field gel electrophoresis. Strains having the same band patterns were detected in S. pseudintermedius isolates collected at 13 and 18 months, suggesting possible colonization and/or expansion of a specific S. pseudintermedius strain in a veterinary hospital.