Detection of Cutibacterium acnes in Tissue Samples from Clean Primary Shoulder Surgeries - Part II / Detecção de Cutibacterium acnes em amostras de tecidos de cirurgias limpas primárias do ombro - Parte II

Abstract Objective Research and identification of Cutibacterium acnes (C. acnes) and other microorganisms in deeptissue samples collected in clean shoulder surgeries of patients who did not undergo any previous invasive joint procedure and who had no clinical history of infection. Methods We analyzed the results of cultures of intraoperative deep tissue samples from 84 patients submitted to primary clean shoulder surgery. Tubes containing culture medium were used for storage and transport of anaerobic agents, prolonged incubation time, and mass spectrometer for diagnosis of bacterial agents. Results Bacteria growth was evidenced in 34 patients (40.4%) of the 84 included in the study. Of these, 23 had growth of C. acnes in at least one sample of deep tissue collected, corresponding to 27.3% of the total patients. The second most common agent was Staphylococcus epidermidis, present in 7.2% of the total individuals included. We showed a higher relationship between sample positivity and males, a lower mean age, absence of diabetes mellitus, ASA I score, and antibiotic prophylaxis in anesthetic induction with cefuroxime. Conclusions A high percentage of isolates of different bacteria was found in shoulder tissue samples of patients undergoing clean and primary surgeries, who had no history of previous infection. Identification of C. acnes was high (27.6%), and Staphylococcus epidermidis was the second most frequent agent (7.2%).

Resumo Objetivo Pesquisa e identificação de Cutibacterium acnes (C. acnes) e de outros microrganismos em amostras de tecidos profundos coletados em cirurgias limpas de ombro em pacientes que não foram submetidos a nenhum procedimento invasivo articular prévio e que não possuíam antecedentes clínicos de infecção. Métodos Foram analisados os resultados das culturas de amostras de tecidos profundos intraoperatórias de 84 pacientes submetidos à cirurgia limpa primária do ombro. Foram utilizados tubos contendo meio de cultivo para armazenamento e transporte de agentes anaeróbicos, tempo prolongado de incubação e espectrômetro de massa para diagnósticos de agentes bacterianos. Resultados Foi evidenciado o crescimento de bactérias em 34 pacientes (40,4%) dos 84 incluídos no estudo. Desses, 23 apresentavam crescimento de C. acnes em pelo menos uma amostra de tecido profundo coletada, correspondendo a 27,3% do total de pacientes. O segundo agente mais encontrado foi o Staphylococcus epidermidis, presente em 7,2% do total de indivíduos incluídos. Evidenciamos maior relação da positividade de amostras com o gênero masculino, uma média de idade inferior, a ausência de diabetes mellitus, o escore ASA I e a profilaxia antibiótica na indução anestésica com cefuroxima. Conclusões Verificou-se um elevado percentual de isolados de diferentes bactérias em amostras de tecidos de ombros de pacientes submetidos a cirurgias limpas e primárias e sem histórico de infecção anterior. A identificação de C. acnes foi elevada (27,6%) e o Staphylococcus epidermidis foi o segundo agente mais frequente (7,2%).

Inhibitory effects of simeprevir on Staphylococcusepidermidis and itsbiofilm in vitro / 中南大学学报(医学版)

OBJECTIVES@#Staphylococcus epidermidis (S. epidermidis) is a Gram-positive opportunistic pathogen that often causes hospital infections. With the abuse of antibiotics, the resistance of S. epidermidis gradually increases, and drug repurposing has become a research hotspot in the treating of refractory drug-resistant bacterial infections. This study aims to study the antimicrobial and antibiofilm effects of simeprevir, an antiviral hepatitis drug, on S. epidermidis in vitro.@*METHODS@#The micro-dilution assay was used to determine the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of simeprevir against S. epidermidis. Crystal violet staining assay was used to detect the biofilm inhibitory effect of simeprevir. The antimicrobial activity of simeprevir against S. epidermidis and its biofilm were explored by SYTO9/PI fluorescent staining. The combined effect between simeprevir and gentamycin was assessed by checkerboard assay and was confirmed by time-inhibition assay.@*RESULTS@#Simeprevir showed significant antimicrobial effects against S. epidermidis type strains and clinical isolates with the MIC and MBC at 2-16 μg/mL and 4-32 μg/mL, respectively. The antimicrobial effects of simeprevir were confirmed by SYTO9/PI staining. Simeprevir at MIC could significantly inhibit and break the biofilm on cover slides. Similarly, simeprevir also significantly inhibit the biofilm formation on the surface of urine catheters either in TSB [from (0.700±0.020) to (0.050±0.004)] (t=54.03, P<0.001), or horse serum [from (1.00±0.02) to (0.13±0.01)] (t=82.78, P<0.001). Synergistic antimicrobial effect was found between simeprevir and gentamycin against S. epidermidis with the fractional inhibitory concentration index of 0.5.@*CONCLUSIONS@#Simeprevir shows antimicrobial effect and anti-biofilm activities against S. epidermidis.

Staphylococcus epidermidis productor de biofilm como causa de uretritis en el sexo masculino

Introducción: La emergencia de Staphylococcus epidermidis como patógeno oportunista está relacionada a su capacidad de formación de biofilm. Objetivo: Identificar Staphylococcus epidermidis productor de biofilm como causa de uretritis en el sexo masculino, en el laboratorio de Microbiología del Centro Provincial de Higiene, Epidemiología y Microbiología Guantánamo durante el año 2019. Método: Se realizó una investigación observacional, descriptiva y transversal en el laboratorio antes mencionado, con un universo de estudio conformado por 48 pacientes ambulatorios del sexo masculino con diagnóstico clínico de uretritis realizado por al médico de familia y que acudieron al laboratorio de Microbiología de dicho centro con indicación de exudado uretral con cultivo. Las variables estudiadas fueron: producción de las enzimas coagulasa, catalasa y oxidasa, crecimiento en agar manitol salado, sensibilidad de la novobiocina, producción de biofilm y resistencia a los antimicrobianos. Los resultados de las muestras fueron vaciados en una base de datos y fueron procesados con el programa SPSS versión 11.5. Resultados: Se identificó Staphylococcus epidermidis productor de biofilm como causa de uretritis en los 48 pacientes del sexo masculino estudiados. Este microorganismo mostró resistencia nula o disminuida frente a ciprofloxacina, norfloxacina, amikacina, gentamicina, amoxicilina con sulbactam, cotrimoxazol y tetraciclina. Conclusiones: Staphylococcus epidermidis emerge como patógeno oportunista frecuente en pacientes del sexo masculino con diagnóstico clínico de uretritis, con significativa resistencia a los antibióticos betalactámicos no combinados con inhibidores de la betalactamasa.

Introduction: Staphylococcus epidermidis as an opportunistic pathogen and its ability to form biofilm has become an emergency situation. Objective: To identify biofilm-producing Staphylococcus epidermidis as a cause of urethritis in males. Study performed throughout 2019 in the Microbiología Lab of the Centro Provincial de Higiene, Epidemiología y Microbiología Lab in Guantánamo. Method: An observational, descriptive and cross-sectional study was carried out at the aforementioned lab, envolving a total of 48 male outpatients with a clinical diagnosis of urethritis certified by the family physician, attended in the Microbiology laboratory with their respective urethral discharge culture indication. The variables studied were as follow: coagulase, catalase and oxidase enzyme production test, growth of mannitol salt agar, novobiocin sensitivity, biofilm production and antimicrobial resistance. The sampling results were introduced in a database and processed with the software SPSS version 11.5. Results: Biofilm-producing Staphylococcus epidermidis was identified as the cause of urethritis in the 48 male patients involved in the study. This microorganism showed cero or low resistance to ciprofloxacin, norfloxacin, amikacin, gentamicin, amoxicillin-sulbactam combination, cotrimoxazole and tetracycline. Conclusions: Staphylococcus epidermidis emerges as a common opportunistic pathogen in male patients with a clinical diagnosis of urethritis, with significant resistance to beta-lactam antibiotics not combined with beta-lactamase inhibitors.

Introdução: O surgimento do Staphylococcus epidermidis como patógeno oportunista está relacionado à sua capacidade de formação de biofilme. Objetivo: Identificar Staphylococcus epidermidis, produtor de biofilme como causador de uretrite em homens, no laboratório de Microbiologia do Centro Provincial de Higiene, Epidemiología y Microbiología Guantánamo durante o ano de 2019. Método: Investigação observacional, descritiva e transversal. realizado no referido laboratório, tendo como universo de estudo 48 doentes ambulatórios do sexo masculino com diagnóstico clínico de uretrite feito pelo médico de família e que compareceram ao laboratório de Microbiologia do referido centro com indicação de exsudato uretral com cultura. As variáveis estudadas foram: produção das enzimas coagulase, catalase e oxidase, crescimento em ágar manitol salgado, sensibilidade à novobiocina, produção de biofilme e resistência a antimicrobianos. Os resultados das amostras foram digitados em um banco de dados e processados no programa SPSS versão 11.5. Resultados: O Staphylococcus epidermidis produtor de biofilme foi identificado como a causa da uretrite nos 48 pacientes masculinos estudados. Este microrganismo não apresentou ou apresentou resistência reduzida contra ciprofloxacino, norfloxacino, amicacina, gentamicina, amoxicilina com sulbactam, cotrimoxazol e tetraciclina. Conclusões: Staphylococcus epidermidis surge como um patógeno oportunista frequente em pacientes do sexo masculino com diagnóstico clínico de uretrite, com resistência significativa a antibióticos beta-lactâmicos não combinados com inibidores de beta-lactamase.

Symbiotic homeostasis of Staphylococcus epidermidis is associated with common skin disorders / 中华皮肤科杂志

Staphylococcus epidermidis can exhibit both protective and opportunistic pathogenic effects on the skin: on the one hand, it suppresses pathogenic bacteria and inflammation, assists the innate immune system of the skin, and maintains homeostasis of skin microenvironment; on the other hand, it exhibits pathogenic potential. How Staphylococcus epidermidis affects human skin conditions depends not only on itself, but also on the communication among it, the host immune system, other microorganisms and environment factors. The balance of this interaction is the symbiotic homeostasis of Staphylococcus epidermidis, and when the homeostasis is disrupted, a variety of skin diseases such as acne vulgaris, atopic dermatitis, rosacea and melanoma can occur. Factors affecting the symbiotic homeostasis of Staphylococcus epidermidis include environmental conditions such as temperature, oxygen content and nutrition, antibiotics, the number of other microorganisms, microecological diversity, etc. This review summarizes recent research progress in symbiotic homeostasis of Staphylococcus epidermidis.

Programa de Segurança do Paciente Focado nas Estratégias do Stewardship de Antimicrobianos para Staphylococcus Spp / Patient safety program focused on antimicrobial stewardship strategies for Staphylococcus spp

Introdução: A sedimentação do Programa de Stewardship de Antimicrobianos (ATMs), além de reduzir a indução da resistência bacteriana, assegura maior segurança aos pacientes. Este estudo teve por objetivo descrever o perfil de sensibilidade do Staphylococcus aureus e Staphylococcus coagulase negativo (S. CON) nas unidades de internação adulta do hospital para instrumentalizar as equipes e realizar o gerenciamento de ATMs. Métodos: Este estudo retrospectivo foi realizado através de busca em prontuário eletrônico de culturas laboratoriais com S. aureus e S. CON, independentemente do foco, dos anos de 2017, 2018 e 2019, das unidades de internação adultas não críticas e UTI adulto. Para análise, foi realizado o cálculo de coeficiente de sensibilidade absoluto e de médias. As variáveis qualitativas foram apresentadas em relação ao agente etiológico, antibiótico e local de isolamento, com posterior identificação de variabilidade e possibilidades terapêuticas disponíveis. Resultados: Apesar de ocorrer similaridade na distribuição das cepas de Staphylococcus spp. nos locais analisados do hospital, observou-se divergência entre os perfis de sensibilidade do S. aureus e S. CON. Existe superioridade no perfil de sensibilidade do S. aureus em comparação com o S. CON em relação a todos ATMs. A sensibilidade do S. aureus à oxacilina, ainda, possibilita tratamento com ß-lactâmicos; entretanto, a escolha de outras classes de ATMs torna-se necessária em casos de infecções complexas e graves. Conclusão: A análise periódica do perfil de sensibilidade aos ATMs é uma estratégia a ser alcançada para um eficaz programa de gerenciamento de ATMs, com fundamentação de protocolos e melhor assistência dos pacientes.

Introduction: The sedimentation of the antimicrobial stewardship program (ASP) reduces the induction of bacterial resistance and ensures greater patient safety. This study aimed to describe the sensitivity profile of Staphylococcus aureus and negative-coagulase Staphylococcus (CoNS) in adult inpatient units of the hospital to instrumentalize the teams and perform ASP management. Methods: This retrospective study was conducted by searching electronic medical records for laboratory cultures with S. aureus and CoNS, regardless of the focus, from 2017, 2018, and 2019, from the adult non-critical inpatient units and adult ICU. For the analysis, the study calculated the absolute sensitivity coefficient and means. Qualitative variables were related to the etiologic agent, antibiotic, and isolation site, with subsequent identification of variability and available therapeutic possibilities. Results: Although similarity occurred in the distribution of Staphylococcus spp. strains in the analyzed hospital sites, divergence was observed between the sensitivity profiles of S. aureus and CoNS. There is superiority in the sensitivity profile of S. aureus over CoNS concerning all ASP. The sensitivity of S. aureus to oxacillin still allows treatment with ß-lactams. However, the choice of other classes of ASP becomes necessary in cases of complex and severe infections. Conclusion: Periodic analysis of the ASP sensitivity profile is a strategy to achieve an effective ASP management program to support protocols and better patient care.

A novel approach to Cestrum intermedium (mata-boi): anatomical and physical-chemical characterization, in vitro biological activities, and metabolites of a Brazilian native species

Abstract The Brazilian native species Cestrum intermedium, known as mata-boi, induces hepatotoxicity and death when ingested by cattle. While most studies on this species focus on toxicological features, our study is the first to describe the anatomy and in vitro biological activities of Cestrum intermedium. We investigated adult leaves and stems by histochemistry, described their anatomy, performed physical-chemical analysis, determined in vitro antioxidant and antimicrobial activities, and identified secondary metabolites. A few noteworthy anatomical features were the anomocytic stomata on the abaxial surface and the absence of trichomes, in addition to the circular shaped petiole with two projections on the adaxial surface. Histochemical analysis showed chemical markers such as alkaloids, usually reported as toxic, and terpenoids. Potassium nitrate (ATR-FTIR) and lupeol palmitate (NMR) were detected on the crude stem extract. Thermogravimetric and physical-chemical analysis provided fingerprint parameters for the species. Minimal Inhibitory Concentration (MIC) assay revealed that Staphylococcus aureus, Staphylococcus epidermidis, and Candida albicans were weakly inhibited by extract samples. Chloroform and ethyl acetate fractions presented high phenolic content, which resulted in in vitro antioxidant activity. These novel features expand the knowledge about this species, considering that previous studies mainly focused on its toxicity. Our study also provided characteristics that may help in avoiding misidentification between Cestrum members, especially when taxonomic keys cannot be employed, as in the absence of flowers and fruits.

Coagulase-negative staphylococci isolates from blood cultures of newborns in a tertiary hospital in southern Brazil

Abstract Neonatal sepsis continues to be a major cause of morbidity and mortality worldwide. Coagulase-negative staphylococci (CoNS), commonly found on the skin, being the main agents isolated. The aim of this study was to evaluate CoNS isolated from blood cultures of newborn (NB) infants. The study took place between 2014 and 2016/2017 in a tertiary hospital in southern Brazil. Using the VITEK 2 system (bioMérieux, Marcy l'Etoile, France), the microorganisms were identified and had their sensitivity profiles determined. The minimum inhibitory concentrations of linezolid, tigecycline, and vancomycin were also determined. The clinical parameters and mortality rates of NBs were evaluated. From January to December 2014, 176 CoNS isolates were obtained from 131 patients and from June 2016 to July 2017, 120 CoNS isolates were obtained from 79 patients. Staphylococcus epidermidis was most prevalent in both periods. Resistance rates increased between 2014 and 2016/2017, especially against ciprofloxacin (52.27% and 73.11%, p = 0.0004), erythromycin (51.40% and 68.07%, p = 0.0054), gentamicin (50.59% and 67.23%, p = 0.0052), and penicillin (71.3% and 99.17%, p = 0.0001), respectively. With 100% susceptibility to linezolid, tigecycline, and vancomycin in both periods and methodologies tested. In 2014, 53.44% of the NBs received antibiotic therapy, and of these, 77.14% used a catheter; in 2016/2017, these were 78.48% and 95.16%, respectively. Regarding laboratory tests, a hemogram was ineffective, since patients with sepsis presented normal reference values. In 2014 and 2016/17, 15.71% and 17.74% of the NBs died, respectively. S. epidermidis was the predominant microorganism, related to catheter use in most cases. The resistance rates have increased over time, demonstrating the importance of adopting control and prevention measures in this hospital. CoNS are responsible for a significant neonatal sepsis mortality rate in infants.

Infection of expanded polytetrafluoroethylene and Dacron-coated stents with Staphylococcus epidermidis: an experimental study in pigs / Infecção de stents revestidos com politetrafluoretileno expandido e Dacron com Staphylococcus epidermidis: estudo experimental em porcos

Abstract Background Diagnosis of the etiologic agent of endoprosthesis infections is essential to enable treatment, since these infections constitute important complications of endovascular procedures. Sonication of explanted tissue and materials is a technique that can be used to facilitate detection of biofilm-producing bacteria. Objectives To evaluate infection of pigs' aortas after implantation of nitinol stents coated with polytetrafluoroethylene (ePTFE) or Dacron, previously infected with biofilm-producing Staphylococcus epidermidis. Intimal thickening and the inflammatory response in the aortic wall were also evaluated. Methods 11 ePTFE-coated nitinol stents and 10 Dacron stents infected with S. epidermidis strains were implanted in the infrarenal aorta of 21 8-week-old pigs. After 2 weeks, the aorta containing the stents was removed. A vortex mixer and ultrasound were used to homogenize the samples and remove the biofilm. Subsequently, the number of colony-forming units was counted. Results There were no significant differences between the two groups in terms of the number of colony-forming units or of inflammation in the arterial wall. With the exception of one specimen from the Dacron group, all aortic stent cultures were positive for S. epidermidis. Conclusions There were no significant differences in the inflammatory response or infection rate between ePTFE and Dacron-coated stents actively infected with biofilm-producing S. epidermidis. Intimal thickening and the inflammatory response to infection of endoprostheses were similar. These results suggest that the two most widely used stent lining materials have a similar infection rate.

Resumo Contexto O diagnóstico do agente etiológico é essencial para o tratamento das infecções de endoprótese, pois representam uma importante complicação do tratamento endovascular. A sonificação dos tecidos pode ser uma técnica usada para auxiliar na detecção de bactérias produtoras de biofilme. Objetivos Avaliar a infecção da aorta dos porcos após o implante de stents de nitinol revestidos com politetrafluoretileno (ePTFE) ou Dacron, infectados com Staphylococcus epidermidis, produtor de biofilme. O espessamento intimal e a resposta inflamatória na parede aórtica também foram avaliados. Métodos Onze stents de nitinol revestidos com ePTFE e 10 stents de Dacron infectados com cepas de S. epidermidis foram implantados na aorta infrarrenal de 21 porcos com 8 semanas de idade. Após duas semanas, a aorta contendo os stents foi removida. Um misturador de vórtice e ultrassom foram utilizados para homogeneizar as amostras e remover o biofilme. Posteriormente, o número de unidades formadoras de colônias foi contado. Resultados Não houve diferenças significativas no número de unidades formadoras de colônias ou inflamação na parede arterial entre os dois grupos. Todas as culturas de stent aórtico foram positivas para S. epidermidis, exceto uma no grupo Dacron. Conclusões Não houve diferenças significativas na resposta inflamatória ou na taxa de infecção entre os stents revestidos de ePTFE e Dacron, infectados ativamente pelo S. epidermidis produtor de biofilme. O espessamento intimal e a resposta inflamatória à infecção das endopróteses foram semelhantes. Esses resultados sugerem que os dois materiais de revestimento de stent mais amplamente utilizados têm uma taxa de infecção semelhante.

Migration and spread of Bacillus cereus in mice with endophthalmitis and influence on inflammation / 中华微生物学和免疫学杂志

Objective:To investigate the causes of strong pathogenicity of Bacillus cereus ( B. cereus) in a mouse model of B. cereus endophthalmitis and the factors that might be related to the prognosis of the disease. Methods:C57BL/6J mice aged 6-8 weeks were injected with 1 μl PBS solution containing 100 CFU B. cereus into the vitreous cavity to construct traumatic endophthalmitis model, and a control group was set up by injecting the contralateral eyeball with 1 μl sterile PBS. A mouse model of Staphylococcus epidermidis ( S. epidermidis) endophthalmitis was constructed in the same way as disease control group. Real-time fluorescent quantitative polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) were used to detect the levels of inflammatory cytokines at different time points. Histology, electroretinogram and transmission electron microscopy were used to detect the progression of endophthalmitis and retinal function at different time points. Results:B. cereus grew significantly faster than S. epidermidis in the eyes of C57BL/6 mice and gradually moved to the cornea 12 h after infection. The results of transmission electron microscopy showed that many more B. cereus were found in the iris with sparse pigment particles, while S. epidermidis could not be detected in the anterior segment after infection. The electroretinogram results showed that the amplitude of A wave and B wave of mice with B. cereus endophthalmitis decreased significantly 6 h after infection, and the B wave could not be detected 12 h after infection. Moreover, the amplitude reduction at different time points was significantly larger than that in the S. epidermidis endophthalmitis group. Histological examination found that compared with the S. epidermidis endophthalmitis group, the mice with B. cereus endophthalmitis had significantly increased inflammatory cells in the anterior chamber and vitreous cavity with a higher degree of infiltration, which was more destructive to the tissue structure. ELISA results showed that the activity of myeloperoxidase (MPO) was significantly stronger in the B. cereus endophthalmitis group than in the S. epidermidis endophthalmitis group, suggesting that a much more severe inflammation was induced. The expression of IL-6, TNF-α and IL-1β at the transcription and protein levels in the mouse model of B. cereus endophthalmitis were significantly higher than those in the mice with S. epidermidis endophthalmitis. Conclusions:B. cereus could induce severe endophthalmitis and tissue destruction in the eye due to its rapid growth and migration ability, which was an important factor leading to vision loss.

Application of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry in the analysis of the pollution homology of clean room in workshop / 公共卫生与预防医学

Objective To investigate the source of microbial contamination in the clean room of the workshop. Methods Microbiological sampling was carried out from the air, environment and personnel of the workshop. The samples were cultivated, the microorganisms were detected by MALDI-TOF-MS, and homology analysis was performed with the microbial identification system of the instrument. Results A total of 14 species and 41 strains of bacteria were detected. Nine strains of Staphylococcus epidermidis were selected for homology analysis, and the Staphylococcus epidermidis from personnel gloves and headgear had 94% homology. There was 83% homology among the staphylococcus epidermidis derived from the sedimentation bacteria, the ground environment and personnel, which was higher than the 71% of the standard strain. Conclusion The homology analysis demonstrates that the pollution in the clean room of the workshop mainly comes from personnel, and secondly comes from the environment outside the workshop. Enterprises need to strengthen management to prevent the occurrence of microbial contamination. MALDI-TOF-MS can be used for rapid detection of complex environmental bacteria and for homology analysis.

In vitro effectiveness of an aqueous extract of neem (azadirachta indicaa. juss) leaves on bacteria causing healthcare associated infection in Valledupar / Efectividad in vitrodel extracto de hojas de neem (azadirachta indicaa. juss) sobre bacterias causantes de infecciónes asociadas a la atención sanitaria en Valledupar

Background: Globally,the need to address strategies for preventing infections associated with health care has increased worldwide. In the city of Valledupar, Colombia, reports of bacteria resistant to chemical or enzymatic biocides in hospital environments and surfaces are increasingly frequent, evidencing the importance of conducting studies aimed at identifying alternative active ingredients for disinfectant products. Objective: Evaluate the in vitro effectiveness of Neem leaves extract over bacteria strains isolated from different areas and surfaces of a health institution in Valledupar, compared to disinfectants for hospital use, an enzymatic detergent, and a commercial chemical disinfectant. Methods: Biocidal activities on bacteria isolated from hospital surfaces, such as Acinetobacter baumanni, Bacillus subtilis, Enterobacter aerogenes, Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus sp, and Stenotrophomonas maltophilia were analyzed. The Neem leaves extract was evaluated at concentrations of 3, 4, and 5 % for each bacterium during 15-minute contact time, incubated at 37 °C for 18 hours. We compared two antimicrobial chemicals, a disinfectant (based on formaldehyde, cetrimide, and glutaraldehyde), and an enzymatic detergent (based on protease, lipase, and amylase). Results: The aqueous Neem extract did not show significant differences with the other treatments with 99.48 to 100% inhibition against bacteria of the species Acinetobacter baumanni, Enterobacter aerogenes, Staphylococcus aureus,and Micrococcus sp.; Bacillus subtilis, and Stenotrophomonas maltophilia strains were the most resistant strains inhibited by enzymatic detergent and disinfectant, respectively. None of the products evaluated were effective against all in vitro strains. Conclusions: These data show Neem's bacteriostatic properties, its potential in in-hospital products and the need to combine different active ingredients in a disinfection plan.

Antecedentes: A nivel mundial ha aumentado la necesidad de abordar estrategias para la prevención de infecciones asociadas a la atención de salud. En la ciudad de Valledupar, Colombia, cada vez son más frecuentes los reportes de bacterias resistentes a biocidas químicos o enzimáticos, en ambientes y superficies hospitalarias, lo cual evidencia la importancia de realizar estudios orientados a la identificación de principios activos alternativos para productos desinfectantes. Objetivo: Evaluar la efectividad in vitrodel extracto de hojas de Neem en cepas de bacterias aisladas en diferentes áreas y superficies de una institución de salud en Valledupar, en comparación con desinfectantes de uso hospitalario, un detergente enzimático y un desinfectante químico comercial. Métodos: Se analizó la actividad biocida sobre las bacterias aisladas de superficies hospitalarias Acinetobacter baumanni, Bacillus subtilis, Enterobacter aerogenes, Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus sp, y Stenotrophomonas maltophilia. El extracto de hojas de Neem se evaluó a concentraciones de 3, 4 y 5% para cada bacteria durante un tiempo de contacto de 15 minutos, incubados a 37 ° C durante 18 horas. Se comparó dos productos químicos antimicrobianos, un desinfectante (a base de formaldehído, cetrimide y glutaraldehído), y un detergente enzimático (a base de Proteasa, Lipasa y amilasa). Resultados: El extracto acuoso de Neem no presentó diferencias significativas con los demás tratamientos con inhibición del 99,48 al 100%, sobre bacterias de las especies Acinetobacter baumanni, Enterobacter aerogenes, Staphylococcus aureus y Micrococcus sp; las cepas Bacillus subtilisy Stenotrophomonas maltophilia fueron las más resistentes a ser inhibidas por el detergente enzimático y el desinfectante, respectivamente. Ninguno de los productos evaluados fue efectivo contra todas las cepas in vitro. Conclusiones: Estos datos evidencian las propiedades bacteriostáticas del Neem, su potencial en productos de uso intrahospitalario y la necesidad de combinar diferentes principios activos en un plan de desinfección.

Total alkaloids of Sophora alopecuroides- and matrine-induced reactive oxygen species impair biofilm formation of Staphylococcus epidermidis and increase bacterial susceptibility to ciprofloxacin / 中草药·英文版

Objective: To investigate the mechanism by which total alkaloids of Sophora alopecuroides (TASA) and matrine (MT) impair biofilm to increase the susceptibility of Staphylococcus epidermidis (S. epidermidis) to ciprofloxacin. Methods: The minimum biofilm inhibitory concentration (mBIC) was determined using a 2-fold dilution method. Structure of biofilm of S. epidermidis was examined by Confocal Laser Scanning Microscope (CLSM). The cellular reactive oxygen species (ROS) was determined using a DCFH-DA assay. The key factors related to the regulation of ROS were accessed using respective kits. Results: TASA and MT were more beneficial to impair biofilm of S. epidermidis than ciprofloxacin (CIP) (P < 0.05). TASA and MT were not easily developed resistance to biofilm-producing S. epidermidis. The mBIC of CIP decreased by 2–6-fold following the treatment of sub-biofilm inhibitory concentration (sub-BIC) TASA and MT, whereas the mBIC of CIP increased by 2-fold following a treatment of sub-BIC CIP from the first to sixth generations. TASA and MT can improve the production of ROS in biofilm-producing S. epidermidis. The ROS content was decreased 23%−33% following the treatment of sub-mBIC CIP, whereas ROS content increased 7%−24% following treatment with TASA + CIP and MT + CIP combination from the first to sixth generations. Nitric oxide (NO) as a ROS, which was consistent with the previously confirmed relationship between ROS and drug resistance. Related regulatory factors-superoxide dismutase (SOD) and glutathione peroxidase (GSH) could synergistically maintain the redox balance in vivo. Conclusion: TASA and MT enhanced reactive oxygen species to restore the susceptibility of S. epidermidis to ciprofloxacin.

Antimicrobial resistance trends in methicillin-resistant and methicillin-susceptible Staphylococcus aureus and Staphylococcus epidermidis isolates obtained from patients admitted to intensive care units. 2010-2015 / Tendencias de resistencia antimicrobiana en Staphylococcus aureus y Staphylococcus epidermidis resistentes y susceptibles a meticilina aislados, obtenidos en unidades de cuidados intensivos, 2010-2015

Absctract Introduction: The emergence and spread of antimicrobial-resistant strains in hospitals, mainly in intensive care units (ICU), has become a serious public health problem. Objective: To analyze the temporal trends of bacterial resistance phenotypes of methicillin-resistant and methicillin-susceptible Staphylococcus aureus and Staphylococcus epidermidis isolates obtained from ICU patients of a tertiary hospital in Cartagena, Colombia, between 2010 and 2015. Methods: A cross-sectional study was carried out between January 2010 and December 2015. Methicillin-resistant and Methicillin-susceptible S. aureus and S. epidermidis isolates (MRSA, MSSA, MRSE and MSSE) were used. Culture medium microdilution technique was used to detect minimal inhibitory concentration (MIC). Results: 313 Staphylococcus spp. isolates were identified, and most of them were methicillin-resistant (63.6%). Methicillin-resistant S. aureus (MRSA) and methicillin-resistant S. epidermidis (MRSE) strains represented 13.7% and 27.8%, respectively, of the total sample. The highest antibiotic resistance values in MRSA and MRSE isolates were observed for the following antibiotics: erythromycin (57.6% and 81.2%, respectively), clindamycin (54.6% and 71.0%), ciprofloxacin (48.4% and 36.4%) and trimethoprim-sulfametoxazole (36.4% and 51.4%). Conclusions: The results reported here suggest the need to rethink the control strategies designed to minimize antibiotic resistance in the hospital in which the study was conducted.

Resumen Introducción. La aparición y la diseminación de cepas resistentes en hospitales, principalmente en unidades de cuidado intensivo (UCI), se han convertido en un serio problema de salud pública. Objetivo. Analizar la tendencia de los fenotipos de resistencia de Staphylococcus aureus y Staphylococcus epidermidis resistentes y susceptibles a meticilina aislados en pacientes atendidos en UCI de un hospital de alta complejidad de Cartagena, Colombia, del 2010 al 2015. Materiales y métodos. Estudio analítico transversal realizado entre enero de 2010 y diciembre de 2015. Se utilizaron aislamientos de S. aureus y S. epidermidis meticilino-susceptibles y meticilino-resistentes (SARM, SASR, SERM y SESM). La técnica de susceptibilidad empleada fue el método microdilución en caldo para la detección de la concentración mínima inhibitoria. Resultados. Se identificaron 313 aislamientos de Staphylococcus spp., la mayoría resistentes a meticilina (63.6%). Las cepas SARM y SERM correspondieron al 13.7% y al 27.8% del total de aislamientos, respectivamente. Los mayores porcentajes de resistencia en SARM y SERM correspondieron a eritromicina (57.6% y 81.2%, respectivamente), clindamicina (54.6% y 71.0%), ciprofloxacina (48.4% y 36.4%) y trimetoprima-sulfametoxazol (36.4% y 51.4%). Conclusión. Los resultados encontrados sugieren el replanteamiento de las estrategias de control de la resistencia antimicrobiana en el hospital objeto de estudio.

Associação entre Staphylococcus epidermidis e o nível de ácido palmítico em pacientes com acne vulgar / The association between Staphylococcus epidermidis and palmitic acid level in patients with acne vulgaris

INTRODUÇÃO: A acne vulgar é um distúrbio inflamatório da glândula pilossebácea. O ácido palmítico é um dos principais tipos de ácidos graxos livres e pode desempenhar um papel na patogênese da acne. Além disso, estudos recentes sugeriram que o Staphylococcus epidermidis pode estar envolvido na acne. OBJETIVO: Explorar a associação entre a Staphylococcus epidermidis e o ácido palmítico na acne vulgar. MÉTODOS: 43 estudantes do ensino médio de uma área urbana do sul de Sulawesi, na Indonésia, foram incluídos. O nível de ácido palmítico foi medido utilizando cromatografia gasosa e os comedões foram cultivados para detectar o perfil do microbioma. O teste de Mann-Whitney foi utilizado para analisar a diferença do nível palmítico médio entre os grupos com diferentes graus de gravidade da acne vulgar. RESULTADOS: 14 pacientes (32,6%) apresentavam acne vulgar leve, enquanto 14 e 15 pacientes apresentavam acne vulgar moderada e grave, respectivamente. O grupo grave e moderado apresentou nível de ácido palmítico significativamente maior em comparação ao grupo leve. A análise de subgrupo de pacientes com acne vulgar moderada e grave, positiva para S. epidermidis, mostrou um nível significativamente maior de ácido palmítico comparado ao grupo leve. CONCLUSÕES: Esses resultados sugerem que S. epidermidis pode estar associado ao nível de ácido palmítico e pode contribuir na patogênese da acne.

INTRODUCTION: Acne vulgaris is an inflammatory disorder of the pilosebaceous gland. Palmitic acid is one of the major types of free fatty acid and may play a role in acne pathogenesis. In addition, recent studies suggested that Staphylococcus epidermidis might be involved in acne. OBJECTIVE: To explore the association between Staphylococcus epidermidis and palmitic acid in acne vulgaris. METHODS: Forty-three high school students at an urban area in South Sulawesi, Indonesia, were included. The palmitic acid level was measured using gas chromatography and comedone was cultured to detect the microbiota profile. Mann-Whitney test was used to analyze the median palmitic level diference between groups with different acne vulgaris severity. RESULTS: Fourteen patients (32.6%) had mild acne vulgaris, while 14 and 15 patients had moderate and severe acne vulgaris, respectively The severe and moderate group showed significantly higher palmitic acid level compared with the mild group. Subgroup analysis of patients with moderate and severe acne vulgaris positive for S. epidermidis showed a significantly higher palmitic acid level compared with the mild group. CONCLUSIONS: This result suggests that S. epidermidis may be associated with the palmitic acid level and may contribute to acne pathogenesis.

Study on mechanism of total alkaloids of Sophora flavescens against Staphylococcus epidermidis / 中草药

Objective: To detect the effect of alkaloids of Sophora flavescens on biofilm formation in Staphylococcus epidermidis in vitro, and to observe whether total alkaloids of S. flavescens can affect the tolerance of Staphylococcus epidermidis to lactic acid and hydrogen peroxide, then explore the possible anti-microbial mechanism of alkaloids in Sophora flavescens. Methods: The biofilm of Staphylococcus epidermidis was prepared in vitro. We evaluated the effect of alkaloids in S. flavescens on the biofilm-forming ability of Staphylococcus epidermidis via 96-well cell culture microtiter plates with crystal violet staining as well as Congo red experiment. The biofilm formation of Staphylococcus aureus was observed using scanning electron microscope. Then, we measured the change of tolerance to oxidative stress and sensibility to antibiotics for Staphylococcus epidermidis being treated by alkaloids in S. flavescens Ait. qRT-PCR analysis was performed to show the relative transcript level of serp2195 and gpxA-2 upon Staphylococcus epidermidis strain exposed to alkaloids in S. flavescens at different concentrations. Results: Alkaloids in S. flavescens significantly prevented biofilm formation in Staphylococcus epidermidis (P < 0.001) at the concentration of 5.0 mg/mL during crystal violet staining and Congo red experiment, and thus weakened tolerance to oxidative stress and enhanced sensibility to lactate for Staphylococcus epidermidis. Alkaloids in S. flavescens could downregulate the transcript level of serp2195 and gpxA-2. Conclusion: Alkaloids in S. flavescens has a significant inhibitory effect on biofilm formation of Staphylococcus epidermidis, which weakens the tolerance of bacteria to oxidative stress. The mechanism may be realized by downregulating the transcript level of serp2195 and gpxA-2, and alkaloids in S. flavescens could reduce Staphylococcus epidermidis tolerance to lactic acid. To sum up, Alkaloids in S. flavescens can be applied to the gynecological infection caused by biofilm-producing bacteria.

Analysis of antimicrobial resistance and staphylococcal cassette chromosome mec ( SCCmec ) in 99 Staphylococcus epidermidis strains isolated from early pregnancy cervical swabs and external environ-ment / 中华微生物学和免疫学杂志

Objective To analyze the antimicrobial resistance, distribution of resistance genes and staphylococcal cassette chromosome mec ( SCCmec) in 99 strains of mecA gene-positive Staphylococcus epi-dermidis strains isolated from early pregnancy cervical swabs and external environment in Beijing Chaoyang District from 2015 to 2016. Methods Kirby-Bauer disk diffusion method was performed to detect the sus-ceptibility of the 99 Staphylococcus epidermidis strains to cefoxitin. Microbroth dilution method was used to test their susceptibility to vancomycin, daptomycin, penicillin, erythromycin, compound sulfamethoxazole, tetracycline, ciprofloxacin, clindamycin, gentamicin and chloramphenicol. PCR was used to detect drug re-sistance genes of ermA, ermB, ermC, msrA, norA1, norA2, sul1, sul2, sul3, aac(6')/aph(2″), ant(4', 4″), ant(6) and tetM and to analyze the SCCmec types ofⅠ, Ⅱ, Ⅲ, Ⅳa, Ⅳb, Ⅳc, Ⅳd and Ⅴ. The results were compared with those of capillary electrophoresis. SPSS was used for data analysis. Results All of the 99 mecA-positive Staphylococcus epidermidis strains were sensitive to vancomycin and 93. 94％ of them were sensitive to datomycin. The resistance rates to penicillin, erythromycin, cefoxitin, compound sulfame-thoxazole, tetracycline, ciprofloxacin, clindamycin, gentamicin and chloramphenicol were 97. 98％, 85. 86％, 79. 80％, 52. 54％, 27. 27％, 43. 43％, 36. 36％, 23. 23％ and 11. 11％. The strains that car-ried the genes of norA1, norA2, ermA, ermB, ermC, msrA, sul1, sul2, sul3, aac(6')/aph(2″), ant(4', 4″), ant(6) and tetM accounted for 100％, 93. 94％, 0. 00％, 3. 03％, 17. 17％, 57. 58％, 50. 51％, 12. 12％, 4. 04％, 30. 30％, 8. 08％, 4. 04％ and 25. 26％, respectively. Among the 99 strains, 5. 05％, 0％, 43. 43％, 10. 10％, 0. 00％, 3. 03％, 3. 03％ and 19. 19％ belonged to SCCmecⅠ, Ⅱ, Ⅲ, Ⅳa,Ⅳb,Ⅳc,Ⅳd andⅤ, respectively, and 4. 04％ (4/99) were positive to two SCCmec types. The types of 12. 12％ (12/99) of the strains were unidentified. Conclusions All of the 99 strains of mecA-positive Staphylococcus epidermidis were sensitive to vancomycin. Among them, the strains carrying multidrug resist-ance genes accounted for 89. 90％. The main mechanisms of resistance to macrolides, sulfonamides and ami-noglycosides in local strains were related to the resistance genes of msrA, sul1 and aac ( 6')/aph ( 2″) . SCCmec Ⅲ was the prevalent type. There were 88. 37％ of SCCmec Ⅲ type strains and 75％ of unknown type strains carrying multiple resistance genes. Apart from that, the isolated strains of other SCCmecⅢtypes all carried multiple resistance genes.

Study of the resistance pattern and alteration in the conjunctival flora of patients exposed to repeated antibiotics / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To investigate and analyze the changes in the conjunctival flora of patients exposed to repeated antibiotic usage. In addition, determining the effects of this repeated exposure on the resistance pattern of the conjunctival flora.<p>METHODS: This study included 40 patients, admitted to the Retina Unit of the Research Institute of Ophthalmology. All chosen patients had a minimum of 4 consecutive, monthly intravitreal injections(IVI), some were extended to 6mo or 1y as required. The patients were randomly divided into 3 groups and each group received one kind of antibiotic which was either ofloxacin, moxifloxacin or ceftazidime. All bacterial isolates were tested for antibiotic susceptibility using Kirby-Bauer disc diffusion technique.<p>RESULTS: In this study the conjunctival normal flora at baseline culture varied from a predominance of <i>Staphylococcus epidermidis </i>(51.2%), followed by <i>Staphylococcus aureus</i> 14% to <i>Micrococcus</i> species 12.8% and other coagulase negative staphylococci(CONS)13%. Our results showed an increase in the percentage of <i>Staphylococcus epidermidis</i> among ceftazidime treated eyes during the four visits in comparison to baseline cultures of patients randomized to ceftazidime. In contrast, there was no noticeable increase in <i>Staphylococcus aureus</i> percentage from baseline. In fluoroquinolone treated eyes, we also observed an increase in percentage of <i>Staphylococcus epidermidis</i> from base line. In contrast to ceftazidime treated eyes, the <i>Staphylococcus aureus</i> percentage in fluoroquinolone treated eyes showed an increase from baseline. However, the pattern of the ocular flora composition changed with the exposure to the old and newer generation of fluoroquinolones. We noticed an increase of <i>Staphylococcus epidermidis</i> in moxifloxacin treated eyes than that in ofloxacin treated eyes from baseline. There was no observed difference in the pattern of <i>Staphylococcus aureus</i> regarding exposure to older and newer generations of fluoroquinolones.<p>CONCLUSION: Repeated use of ophthalmic antibiotics not only alters the composition of the normal ocular flora, but also selects for resistant strains.

In vitro evaluation of octenidine as an antimicrobial agent against Staphylococcus epidermidis in disinfecting the root canal system

OBJECTIVES: Irrigants are imperative in endodontic therapy for the elimination of pathogens from the infected root canal. The present study compared the antimicrobial efficacy of octenidine dihydrochloride (OCT) with chlorhexidine (CHX) and sodium hypochlorite (NaOCl) against Staphylococcus epidermidis (S. epidermidis) for root canal disinfection. MATERIALS AND METHODS: The minimum inhibitory concentration (MIC) was obtained using serial dilution method. The agar diffusion method was then used to determine the zones of inhibition for each irrigant. Lastly, forty 6-mm dentin blocks were prepared from human mandibular premolars and inoculated with S. epidermidis. Samples were randomly divided into 4 groups of 10 blocks and irrigated for 3 minutes with saline (control), 2% CHX, 3% NaOCl, or 0.1% OCT. Dentin samples were then collected immediately for microbial analysis, including an analysis of colony-forming units (CFUs). RESULTS: The MICs of each tested irrigant were 0.05% for CHX, 0.25% for NaOCl, and 0.0125% for OCT. All tested irrigants showed concentration-dependent increase in zones of inhibition, and 3% NaOCl showed the largest zone of inhibition amongst all tested irrigants (p < 0.05). There were no significant differences among the CFU measurements of 2% CHX, 3% NaOCl, and 0.1% OCT showing complete elimination of S. epidermidis in all samples. CONCLUSIONS: This study showed that OCT was comparable to or even more effective than CHX and NaOCl, demonstrating antimicrobial activity at low concentrations against S. epidermidis.

The inhibition of accessory gene regulator C specific binding peptides on biofilm formation of Staphylococcus epidermidis on the surface of polyvinyl chloride in vitro / 中国修复重建外科杂志

Objective: To investigate the effect of accessory gene regulator C (agr C) specific binding peptides (named N1) on the biofilm formation of Staphylococcus epidermidis on the surface of polyvinyl chloride (PVC) materials in vitro. Methods: Firstly, the two strains (ATCC35984, ATCC12228) were cultured with N1 at concentrations of 100, 200, 400, 800, and 1 600 μg/mL, respectively. The control group was cultured with agrC specific binding unrelated peptides (named N0) at the same concentrations and the absorbance ( A) value was measured after 24 hours to determine the optimal bacteriostatic concentration of N1. The two strains were cultured with N1 and N0 of the optimal concentration, respectively. The A values were measured at 6, 12, 18, 24, 30, and 48 hours to observe the effect of N1 on the biofilm formation ability of Staphylococcus epidermidis. On this basis, the surface structure of the biofilm on the surface of PVC material was observed by scanning electron microscopy after 6, 12, 18, 24, and 30 hours of incubation with PVC material sheet. The thickness of the biofilm was observed by laser confocal microscopy after 6, 12, 18, and 24 hours of incubation with ATCC35984 strain. Results: The optimal bacteriostatic concentration of N1 was 800 μg/mL. ATCC 12228 strain did not form obvious biofilm after being cultured with N1 and N0. When ATCC35984 strain was cultured with N1 and N0 for 12 hours, the difference in biofilm formation ability between groups N1 and N0 was statistically significant ( P0.05). Scanning electron microscopy examination showed that mature biofilm structure was observed in ATCC35984 strain and was not observed in ATCC12228 strain. Laser confocal microscopy observation showed that the number of bacteria in the group N1 was significantly lower than that in the group N0 at 12 hours, and the most of bacteria were dead bacteria. There was no significant difference in the number of bacteria at 6, 18, and 24 hours, and the most of them were live bacteria. The biofilm thickness of group N1 was significantly lower than that of group N0 at 12 and 18 hours ( P<0.05). Conclusion: The intensity of N1 inhibiting the formation of Staphylococcus epidermidis biofilm is dose-dependent. During the aggregation period, N1 can inhibit the biofilm formation by hindering the bacterial growth and aggregation. The inhibition effect on mature biofilm is not obvious.

Resistencia antimicrobiana en staphylococcus aureus y staphylococcus epidermidis: tendencia temporal (2010-2016) y fenotipos de multirresistencia, Cartagena (Colombia) / Antimicrobial resistance in staphylococcus aureus and staphylococcus epidermidis: temporal tendencies (2010-2016) and multi-drug resistance phenotypes, Cartagena (Colombia)

RESUMEN Introducción: Las especies de Staphylococcus spp. son patógenos oportunistas que causan enfermedades como osteomielitis y bacteriemias. Estas bacterias pueden adquirir resistencia a antibióticos, lo que hace que se conviertan en un problema de salud pública debido a la restricción de opciones terapéuticas. Objetivo: Evaluar la tendencia de los perfiles de resistencia antimicrobiana de S. aureus y S. epidermidis aislados en un hospital de Cartagena entre 2010 y 2016. Materiales y métodos: Estudio de corte transversal. El método de microdilución en caldo fue usado para la determinación de la concentración mínima inhibitoria de 12 agentes antimicrobianos. Se estudió el comportamiento de la resistencia antimicrobiana de acuerdo a la especie Staphylococcus, el sitio de infección y el período de tiempo. Resultados: Se aislaron 1218 cocos grampositivos, de los cuales 42,7 % fueron S. aureus y 18,9 % S. epidermidis. El 47,5 % de S. aureus fueron resistentes a meticilina y se encontraron principalmente en secreciones (43,3 %); mientras que el 68,7 % de S. epidermidis fueron meticilino resistentes y aislados principalmente en sangre (76,9 %). Conclusión: Se identificaron aislamientos clínicos de S. aureus y S. epidermidis con perfil de multirresistencia. Se observo un comportamiento constante en sus perfiles de resistencia durante el período de estudio, excepto en los dos últimos años en los que se identificó una reducción significativa de la meticilino resistencia en S. epidermidis.

ABSTRACT Introduction: Staphylococcus spp. are opportunistic pathogens that cause diseases like osteomyelitis and bacteremia. These bacteria can acquire resistance to antibiotics being a public health problem due to the restriction of therapeutic options. Objective: To evaluate the tendency of antimicrobial resistance profiles of Staphylococcus aureus and Staphylococcus epidermidis isolated in a hospital in CartagenaColombia between 2010 and 2016. Materials and methods: Cross-sectional study. The broth microdilution method was used to determine the minimum inhibitory concentration of 12 antimicrobial agents. The behavior of antimicrobial resistance was studied according to the Staphylococcus species, the site of infection and the time period. Results: A total of 1218 Gram-positive cocci were isolated of which 42.7% were S. aureus, and 18.9% belonged to S. epidermidis. Of the isolates of S. aureus, 47.5% were resistant to methicillin and were found mainly in secretions (43.3%). In the case of S. epidermidis, 68.7% were resistant to methicillin and were found mainly in the blood (76.9%). Conclusion: Clinical isolates of S. aureus and S. epidermidis with a multi-resistance profile was identified. A constant behavior in their resistance profiles was detected during the study period except in the last two years in which a significant reduction of methicillin resistance in S. epidermidis was recognized.