In 1989, we reported the immunologic identification of a prognostic molecule in the tumor cells of breast cancer patients with a poor prognosis for recurrence and death due to their disease (1). This prognostic factor was statistically independent ofimportant clinical parameters including tumor size, lymph node involvement, and assessment of estrogen and progesterone receptors; subsequent studies also showed it to be independent of other prognostic molecules including c-erb-B2 and cathepsin D (2). Tumors marked by this prognostic molecule were nearly 4 times more likely to recur and metastasize than tumors not so marked, representing a prognostic power as strong as the presence of cancer in the axillary lymph nodes ofpatients with T1 or T2 primaries (1-3).We

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Riboflavin/UVA was effective against SA, SE, PA, MRSA, MDRPA, and DRSP, but was ineffective on CA and has the potential for use in treatment of microbial keratitis in the future.

We report a case of a surgical site infection caused by clindamycin-susceptible, erythromycin-resistant methicillin-resistant Staphylococcus aureus (MRSA) that did not respond to treatment with clindamycin. The MRSA isolate obtained after treatment was resistant to clindamycin but was found to be identical by pulsed-field gel electrophoresis to the clindamycin-susceptible isolate obtained before treatment. A post hoc erythromycin-induction test (D test) confirmed the presence of in vitro inducible macrolide-lincosamide-streptogramin B resistance (iMLS) in the pretreatment isolate. Erythromycin induction testing confirmed in vitro iMLS in 90 (56%) of 161 erythromycin-resistant, clindamycin-susceptible clinical S. aureus isolates overall and in a significantly higher proportion (78%) of methicillin-susceptible S. aureus isolates from pediatric patients. Our clinical laboratory currently tests all S. aureus isolates for iMLS before reporting clindamycin susceptibility.

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Vancomycin resistance has been reported in clinical isolates of both coagulase-negative staphylococci and Staphylococcus aureus. The emerging threat of widespread vancomycin resistance poses a serious public health concern given the fact that vancomycin has long been the preferred treatment of antibiotic-resistant gram-positive organisms. Though major efforts are now being focused on improving our understanding of vancomycin resistance, there is much that remains unknown at this time. This article reviews the major epidemiologic, microbiologic, and clinical characteristics of vancomycin resistance in both coagulase-negative staphylococci and S. aureus. The review begins with a discussion of issues common to both coagulase-negative staphylococci and S. aureus, such as definitions, laboratory detection of vancomycin resistance, and infection control issues related to vancomycin-resistant staphylococci. The rest of the article is then devoted to a discussion of issues unique to each organism, including epidemiology, risk factors for infection, mechanisms of resistance, and management options

We describe a novel adaptation of the TaqMan PCR assay which potentially allows for highly sensitive detection of any eubacterial species with simultaneous species identification. Our system relies on a unique multiprobe design in which a single set of highly conserved sequences encoded by the 16S rRNA gene serves as the primer pair and is used in combination with both an internal highly conserved sequence, the universal probe, and an internal variable region, the species-specific probe. A pre-PCR ultrafiltration step effectively decontaminates or removes background DNA. The TaqMan system described reliabAly detected 14 common bacterial species with a detection limit of 50 fg. Further, highly sensitive and specific pathogen detection was demonstrated with a prototype species-specific probe designed to detect Staphylococcus aureus. This assay has broad potential in the clinical arena for rapid and specific diagnosis of infectious diseases.Currently, the standard method for diagnosing the presence of bacterial pathogens in clinical samples relies on culture techniques. However, active research is under way using new molecular methods to decrease detection time and increase assay sensitivity. PCR has emerged as the molecular method of choice in achieving these objectives. The utility of PCR and other molecular methods is evidenced by the recent guidelines issued by the NCCLS in 1999 encouraging the use of such methods in clinical laboratories performing bacterial identification assays (11).To detect the presence of any bacterial pathogen in a clinical sample, primers annealing to regions of DNA conserved across a wide range of bacterial genomes have been employed. The design of such universal primers has often focused on the 16S rRNA gene (17). The presence of multiple copies of this gene within the bacterial genome facilitates its amplification by PCR. Further, sufficient sequence variability allows phylogenetic information to be attained for the purposes of microbial identification. However, up to the present, assays which provide for both universal detection and species identification require a second post-PCR processing step, which can be technically cumbersome and slow the time to reporting of results (9, 14).Universal PCR-based bacterial detection systems have also been hampered by contamination issues. High sequence conservation of the DNA region chosen for PCR primer annealing coupled with the immense amplification power of PCR results in the amplification of exceedingly minor bacterial contaminants, leading to false positives. Attempts to decontaminate PCR materials have involved nearly all known methods to destroy DNA, including UV irradiation, 8-MOP treatment, and incubation with various enzymes, such as DNase, restriction enzymes, or both in combination (2, 4). Thus far, none of these methods has been shown to be entirely effective or reproducible.Assessment of bacterial contamination can most reliably be made using real-time detection methods to characterize PCR amplification. Briefly, real-time PCR am...

Most prostates from men undergoing prostatectomy (87%) contain bacterial DNA from one or more species. However, the majority of individual tissue core samples were negative, suggesting regional heterogeneity in the presence of bacteria and a lack of a generalized or ubiquitous prostatic flora. Culture results suggest either the "unculturable" nature of species present in the prostate or that 16S rDNA sequences were derived from non-viable bacteria.