Short-Term Prognostic Index for Breast Cancer: NPI or Lpi

Axillary lymph node involvement is an important prognostic factor for breast cancer survival but is confounded by the number of nodes examined. We compare the performance of the log odds prognostic index (Lpi), using a ratio of the positive versus negative lymph nodes, with the Nottingham Prognostic Index (NPI) for short-term breast cancer specific disease free survival. A total of 1818 operable breast cancer patients treated in the University Hospital of Leuven between 2000 and 2005 were included. The performance of the NPI and Lpi were compared on two levels: calibration and discrimination. The latter was evaluated using the concordance index (cindex), the number of patients in the extreme groups, and difference in event rates between these. The NPI had a significant higher cindex, but a significant lower percentage of patients in the extreme risk groups. After updating both indices, no significant differences between NPI and Lpi were noted

Poststaphylococcal coagulase negative reactive arthritis: a case report

We report a case of a 49-year-old patient who developed poststaphylococcal coagulase negative reactive arthritis. The woman presented with constitutional symptoms, arthritis, urinary infection and conjunctivitis. The blood culture was positive for the staphylococcal coagulase negative infection. Erythrocyte sedimentation rate and C-reactive protein were elevated, whereas the rheumatoid factor was negative. Radiographic findings confirmed diagnosis of pleuropneumonia, and one year later of chronic asymmetric sacroileitis. Physicians should be aware of possible reactive arthritis after staphylococcal coagulase negative bacteremia

Confocal laser scanning microscopy analysis of S. epidermidis biofilms exposed to farnesol, vancomycin and rifampicin

Staphylococcus epidermidis is the major bacterial species found in biofilm-related infections on indwelling medical devices. Microbial biofilms are communities of bacteria adhered to a surface and surrounded by an extracellular polymeric matrix. Biofilms have been associated with increased antibiotic tolerance to the immune system. This increased resistance to conventional antibiotic therapy has lead to the search for new antimicrobial therapeutical agents. Farnesol, a quorum-sensing molecule in Candida albicans, has been described as impairing growth of several different microorganisms and we have previously shown its potential as an adjuvant in antimicrobial therapy against S. epidermidis. However, its mechanism of action in S. epidermidis is not fully known. In this work we better elucidate the role of farnesol against S: epidermidis biofilms using confocal laser scanning microscopy (CLSM). Findings 24 h biofilms were exposed to farnesol, vancomycin or rifampicin and were analysed by CLSM, after stained with a Live/Dead stain, a known indicator of cell viability, related with cell membrane integrity. Biofilms were also disrupted by sonication and viable and cultivable cells were quantified by colony forming units (CFU) plating. Farnesol showed a similar effect as vancomycin, both causing little reduction of cell viability but at the same time inducing significant changes in the biofilm structure. On the other hand, rifampicin showed a distinct action in S. epidermidis biofilms, by killing a significant proportion of biofilm bacteria. Conclusions While farnesol is not very efficient at killing biofilm bacteria, it damages cell membrane, as determined by the live/dead staining, in a similar way as vancomycin.. Furthermore, farnesol might induce biofilm detachment, as determined by the reduced biofilm biomass, which can partially explain the previous findings regarding its role as a possible chemotherapy adjuvant.(undefined

The Possible Role of Staphylococcus epidermidis LPxTG Surface Protein SesC in Biofilm Formation

Staphylococcus epidermidis is the most common cause of device-associated infections. It has been shown that active and passive immunization in an animal model against protein SesC significantly reduces S. epidermidis biofilm-associated infections. In order to elucidate its role, knock-out of sesC or isolation of S. epidermidis sesC-negative mutants were attempted, however, without success. As an alternative strategy, sesC was introduced into Staphylococcus aureus 8325-4 and its isogenic icaADBC and srtA mutants, into the clinical methicillin-sensitive S. aureus isolate MSSA4 and the MRSA S. aureus isolate BH1CC, which all lack sesC. Transformation of these strains with sesC i) changed the biofilm phenotype of strains 8325-4 and MSSA4 from PIA-dependent to proteinaceous even though PIA synthesis was not affected, ii) converted the non-biofilm-forming strain 8325-4 ica::tet to a proteinaceous biofilm-forming strain, iii) impaired PIA-dependent biofilm formation by 8325-4 srtA::tet, iv) had no impact on protein-mediated biofilm formation of BH1CC and v) increased in vivo catheter and organ colonization by strain 8325-4. Furthermore, treatment with anti-SesC antibodies significantly reduced in vitro biofilm formation and in vivo colonization by these transformants expressing sesC. These findings strongly suggest that SesC is involved in S. epidermidis attachment to and subsequent biofilm formation on a substrate