scholarly journals Penetration of antibiotics through Staphylococcus aureus and Staphylococcus epidermidis biofilms

2010 ◽  
Vol 65 (9) ◽  
pp. 1955-1958 ◽  
Author(s):  
R. Singh ◽  
P. Ray ◽  
A. Das ◽  
M. Sharma
2004 ◽  
Vol 32 (02) ◽  
pp. 88-91
Author(s):  
Susanne Kloß ◽  
A. Wehrend ◽  
Astrid König ◽  
H. Bostedt

Zusammenfassung: Gegenstand und Ziel: Im Gegensatz zur Hündin liegen bei der Katze bisher wenige Studien über die genitale Keimflora geschlechtsgesunder Tiere vor. Ziel der Untersuchung war daher, physiologische Daten über die aerobe Vaginalflora bei dieser Spezies zu gewinnen. Material und Methoden: Für die vorliegende Studie standen 26 gesunde, anöstrische Katzen zur Verfügung, die zu einer Ovariohysterektomie vorgestellt wurden. Nach einer klinischen Untersuchung wurden von allen Probanden unter sterilen Bedingungen Vaginaltupfer entnommen. Ergebnisse: In allen Proben konnte ein Bakterienwachstum mit durchschnittlich zwei verschiedenen Bakterienspezies nachgewiesen werden. Die Gesamtkeimgehalte wurden bei 50% der Vaginaltupferproben als gering-, bei 15% als mittel- und bei 35% als hochgradig beurteilt. Vorherrschend waren Mischkulturen aus zwei bis vier verschiedenen Keimarten. Monokulturen wurden aus 38% der Tupferproben isoliert. Am häufigsten gelang der Nachweis von E. coli variatio haemolytica (E. coli var. haem.) (58%) und Staphylococcus epidermidis (42%). Als weitere Spezies wurden E. coli, α-, β-hämolysierende Streptokokken, anhämolysierende Streptokokken, aerobe Bazillen, Staphylococcus aureus, Staphylococcus intermedius, Pasteurella multocida sowie Klebsiellen isoliert. Auffällig ist die hohe Nachweisrate von E. coli var. haem. mit 35% in Mischkulturen und 23% in Reinkultur. Schlussfolgerungen: Die physiologische Mikroflora der felinen Vaginalschleimhaut differiert deutlich von der der anöstrischen Hündin. Besonders die Dominanz von E. coli var. haem. in 38% der Mischkulturen und 23% der Monokulturen bei der Katze ist hervorzuheben. Klinische Relevanz: Die vorliegenden Ergebnisse geben eine erste Grundlage für die Interpretation mikrobiologischer Befunde feliner Vaginaltupfer.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christiane Schwerdt ◽  
Eric Röhner ◽  
Sabrina Böhle ◽  
Benjamin Jacob ◽  
Georg Matziolis

AbstractOne of the most challenging complications of total knee arthroplasty (TKA) is periprosthetic joint infection (PJI). There is growing evidence of a good anti-infective effect of intrawound vancomycin powder in total joint arthroplasty. At the same time, various different locally applied substances have become popular in total joint arthroplasty. The objective of this study was therefore to investigate a possible inhibition of the bactericidal effect of vancomycin by tranexamic acid, adrenalin, lidocaine, or dexamethasone. The bactericidal effect of vancomycin was quantified using the established method of the agar diffusion test. The plates were incubated with Staphylococcus aureus or Staphylococcus epidermidis and four wells were stamped out. The wells were filled with vancomycin alone, the tested substance alone or a mixture of the two. The fourth well remained empty as a control. The plates were incubated overnight at 37 °C and the zone of inhibition in each field was measured on the next day. All tests were run three times for each pathogen and mean values and standard deviations of the measurements were calculated. Differences between the substances were tested using the t-test at a level of significance of 0.05. The bacterial growth was homogeneous on all plates. The baseline value for the zone of inhibition of vancomycin was on average 6.2 ± 0.4 mm for Staphylococcus aureus and 12 ± 0.3 mm for Staphylococcus epidermidis. In all other substances, no inhibition was detected around the well. The combination of vancomycin and each other substance did not show any different result compared to vancomycin alone. The bactericidal effect of vancomycin on staphylococci is not altered by tranexamic acid, adrenalin, dexamethasone, or lidocaine in vitro.


2001 ◽  
Vol 69 (3) ◽  
pp. 1957-1960 ◽  
Author(s):  
Michael Otto ◽  
Hartmut Echner ◽  
Wolfgang Voelter ◽  
Friedrich Götz

ABSTRACT Cross-inhibition by quorum-sensing pheromones betweenStaphylococcus aureus and Staphylococcus epidermidis was investigated using all known S. aureus agr pheromone subgroups. All S. aureus subgroups were sensitive towards the S. epidermidis pheromone, with the exception of the recently identified subgroup 4. The subgroup 4 pheromone was also the only S. aureus pheromone able to inhibit the S. epidermidis agr response. The close relation of subgroup 4 to subgroup 1 suggests that subgroup 4 might have evolved from subgroup 1 by mutation under the selective pressure of competition with S. epidermidis. The competition between S. aureus and S. epidermidis by means of quorum-sensing cross talk seems to be generally in favor of S. epidermidis, which might explain the predominance of S. epidermidis on the skin and in infections on indwelling medical devices.


2001 ◽  
Vol 69 (6) ◽  
pp. 4079-4085 ◽  
Author(s):  
Sarah E. Cramton ◽  
Martina Ulrich ◽  
Friedrich Götz ◽  
Gerd Döring

ABSTRACT Products of the intercellular adhesion (ica) operon in Staphylococcus aureus and Staphylococcus epidermidis synthesize a linear β-1,6-linked glucosaminylglycan. This extracellular polysaccharide mediates bacterial cell-cell adhesion and is required for biofilm formation, which is thought to increase the virulence of both pathogens in association with prosthetic biomedical implants. The environmental signal(s) that triggers ica gene product and polysaccharide expression is unknown. Here we demonstrate that anaerobic in vitro growth conditions lead to increased polysaccharide expression in both S. aureus and S. epidermidis, although the regulation is less stringent inS. epidermidis. Anaerobiosis also dramatically stimulates ica-specific mRNA expression inica- and polysaccharide-positive strains of both S. aureus and S. epidermidis.These data suggest a mechanism whereby ica gene expression and polysaccharide production may act as a virulence factor in an anaerobic environment in vivo.


2021 ◽  
Vol 70 (9) ◽  
Author(s):  
Vidula Iyer ◽  
Janhavi Raut ◽  
Anindya Dasgupta

The pH of skin is critical for skin health and resilience and plays a key role in controlling the skin microbiome. It has been well reported that under dysbiotic conditions such as atopic dermatitis (AD), eczema, etc. there are significant aberrations of skin pH, along with a higher level of Staphylococcus aureus compared to the commensal Staphylococcus epidermidis on skin. To understand the effect of pH on the relative growth of S. epidermidis and S. aureus , we carried out simple in vitro growth kinetic studies of the individual microbes under varying pH conditions. We demonstrated that the growth kinetics of S. epidermidis is relatively insensitive to pH within the range of 5–7, while S. aureus shows a stronger pH dependence in that range. Gompertz’s model was used to fit the pH dependence of the growth kinetics of the two bacteria and showed that the equilibrium bacterial count of S. aureus was the more sensitive parameter. The switch in growth rate happens at a pH of 6.5–7. Our studies are in line with the general hypothesis that keeping the skin pH within an acidic range is advantageous in terms of keeping the skin microbiome in balance and maintaining healthy skin.


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