Multi drug resistance in strong biofilm forming clinical isolates of Staphylococcus epidermidis

Staphylococcus epidermidis which exists in healthy human skin as a commensal inhabitant is also an important pathogen forming biofilms on many surfaces and recently, increased resistance traits were suggested to be acquired in biofilm environments. In this study; clinical Prevalences, antibiotic resistances and biofilm formations of S. epidermidis strains were determined and comparison of all these findings with each other was carried out in order to take precautions against them and figure out if high biofilm forming S. epidermidis strains display multi drug resistance. According to our results; samples of wound and blood were the most S. epidermidis isolated clinical materials (40%; 35%) and cardiothoracic surgery was the most S. epidermidis observed service unit. All of these strains were sensitive to vancomycin, however 65% of them showed resistance to all β-lactam antibiotics (Penicillin, Oxacillin, Amoxicilin / Clavulonic acid), used in this study and 60% of all S. epidermidis strains were found as multi drug resistant. When the results of strong biofilm forming S. epidermidis strains are examined; they were isolated from sample of blood and service unit of cardiovascular surgery in highest frequency and 80% of them were β-lactam resistant whereas 100% of them were multi drug resistant. One of these multi drug resistant strains which was resistant to maximum amount of different antimicrobial classes, was also observed as maximum biofilm forming strain among all the other S. epidermidis isolates. Multi drug resistance in strong biofilm forming strains shows that; biofilms play a role in antimicrobial resistance traits of S. epidermidis.

Histological study on acute inflammatory reaction to polyurethane-coated silicone implants in rats / Estudo histológico da reação inflamatória aguda ao implante de silicone revestido com poliuretano em ratos

PURPOSE: Evaluating histologically the silicone peri-implant coated by polyurethane inflammation associated to the use of anti-microbial and bacterial contamination. METHODS: It was used 35 Wistar rats. The animals were divided in seven groups: I - Control; II - implant cavity contamination with10 bacteria/ml; III - implant cavity contamination with 10 bacteria/ml; IV - implant cavity contamination with 10 bacteria/ml; V - identical contamination to group II and implant immersions in anti-microbial solution; VI - identical contamination in group III and implant immersions in the anti-microbial solution; VII - identical contamination of group IV and implant immersions in anti-microbial solution. It was evaluated morphometrically the peri-implant capsules after 30 days of introduction. RESULTS: The factors with more discriminating power were the giants cells of a strange body and the mononuclear. There was no correlation between the bacterial concentrations and the histological alterations. CONCLUSION: 1) The histological standard of the inflammatory reaction around the silicone implant coated with polyurethan is chronic granulomatosis type of a strange body; 2) There isnït correlation between concentration of Staphylococcus epidermidis and histological changes; 3) The use of anti-microbial solution decreased the mononuclear cell reactions, with the increase of giant cells in a strange body.(AU)

OBJETIVO: Avaliar, histologicamente, a reação inflamatória aos implantes de silicone revestidos por poliuretano, com contaminação bacteriana, associada ou não ao uso de antimicrobianos. MÉTODOS: Utilizou-se 35 ratos Wistar. Os animais foram divididos em 7 grupos: I- Controle, II- contaminação da cavidade do implante com 10Õ bactérias/ml, III- contaminação da cavidade do implante com 10³ bactérias/ml, IV- contaminação da cavidade do implante com 10(5) bactérias/ml, V- contaminação idêntica ao grupo II e imersão dos implantes em solução antimicrobiana, VI- contaminação idêntica do grupo III e imersão dos implantes em solução antimicrobiana, VII- contaminação idêntica do grupo IV e imersão dos implantes em solução antimicrobiana. Avaliou-se morfometricamente as cápsulas peri-implantes após 30 dias da introdução. RESULTADOS: Os fatores com maior poder discriminante foram as células gigantes de corpo estranho e os mononucleares. Não houve correlação entre as concentrações bacterianas e as alterações histológicas. CONCLUSÕES: 1) O padrão histológico da reação inflamatória ao redor dos implantes de silicone revestidos com poliuretano é do tipo crônica granulomatosa de corpo estranho; 2) Não há correlação entre a concentração de bactérias Staphylococcus epidermidis e as alterações morfométricas; 3) O uso de solução antimicrobiana diminui a reação de células mononucleares, com aumento de células gigantes de corpo estranho.(AU)