The protective effects of bacteriophages were assessed against experimental Staphylococcus aureus infection in mice. Of the S. aureus phages isolated in the study, phi MR11 was representatively used for all testing, because its host range was the most broad and it carries no genes for known toxins or antibiotic resistance. Intraperitoneal injections (8 x 10(8) cells) of S. aureus, including methicillin-resistant bacteria, caused bacteremia and eventual death in mice. In contrast, subsequent intraperitoneal administration of purified phi MR11 (MOI > or = 0.1) suppressed S. aureus-induced lethality. This lifesaving effect coincided with the rapid appearance of phi MR11 in the circulation, which remained at substantial levels until the bacteria were eradicated. Inoculation with high-dose phi MR11 alone produced no adverse effects attributable to the phage. These results uphold the efficacy of phage therapy against pernicious S. aureus infections in humans and suggest that phi MR11 may be a potential prototype for gene-modified, advanced therapeutic S. aureus phages.

Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1), a latent viral protein consistently expressed in infected proliferating cells, is essentially required in trans to maintain EBV episomes in cells. We constructed a mutant (mt) EBNA1 and examined whether it exerted dominant-negative effects on maintenance of the viral episome thereby leading to abrogation of EBV-infected tumor cell growth. Using lymphocyte and epithelial cell lines converted with neomycin-resistant recombinant EBV (rEBV) as models, adenovirus vector-mediated transduction of mtEBNA1, but not LacZ, brought about rapid and striking reductions in rEBV-derived wild-type EBNA1 levels and viral genomic loads in converted lines of three major viral latencies. This outcome was further validated at the single-cell level by cellular loss of G418 resistance and viral signals in situ. The mtEBNA1 transduction significantly impaired growth of naturally EBV-harboring Burkitt lymphoma cells in vitro and in vivo, largely in association with the eradication of viral episomes. Expression of mtEBNA1 per se caused no detectable cytotoxicity in EBV-uninfected cells. These results indicate that mtEBNA1 can act as a dominant-negative effector that efficiently impedes the EBV-dependent malignant phenotypes in cells regardless of viral latency or tissue origin. The mutant will afford an additional therapeutic strategy specifically targeting EBV-associated malignancies.

Urinary tract infections are common both in the community and hospitalized patients. Widespread use of antimicrobial agents often leads to the selection of multi-drug resistant micro-organisms. Acquired or emerging bacterial resistance to one or several antimicrobial agents is a global problem.1,2 Many micro-organisms have become resistant to antimicrobial agents.3 Some bacteria, especially Klebsiella pneumoniae, are showing increasing resistance to cephalosporins. These organisms produce extendedspectrum P-lactamases, which are coded by genes located on transferable plasmids.4 Resistance to the quinolones in strains of E. coli isolated from urine specimens of outpatients is also increasing.5As the pattern of bacterial resistance is constantly changing, monitoring of antimicrobial susceptibilities is important. It provides information on the pathogenic organisms isolated from patients, and assists in choosing the most appropriate empirical antimicrobial therapy. In addition, continuous surveys of antimicrobial resistance are crucial for monitoring changes in this resistance. In this report, we analyze the antimicrobial resistance patterns of bacteria isolated from urine specimens examined at

Makkonen and his colleagues published an article in the Journal of Virology entitled "6-O-and N-Sulfated Syndecan-1 Promotes Baculovirus Binding and Entry into Mammalian Cells" (1). Some parts of the data and conclusions seem misleading and not fully justified.Heparan sulfate (HS) alone can bind baculovirus to cells during entry and transduction. Syndecan-1 (SDC-1) contains a protein core and HS chains. Therefore, it is called heparan sulfate proteoglycan (HSPG). I have examined the ability of baculovirus to enter mammalian cells after treatment with heparinase III (EC 4.2.2.8), which specifically digests HS chains from the protein core. For HT1080 cells, heparinase III could significantly reduce baculovirus entry compared with untreated control cells (Fig. 1A). The reduced susceptibility of cells with the baculovirus vector after enzymatic removal of HS indicates that HS plays an important role in baculovirus entry. The protein core of syndecan-1 does not have any role in baculovirus binding.The pgsD-677 cell has a single mutation affecting both N-acetylglucosaminyltransferase and glucuronosyltransferase, which are necessary for polymerization of HS chains, and does not synthesize HS but does produce three times more chondroitin sulfate (CS) than the wild-type CHO-K1 cell does (2). A baculovirus vector was used to evaluate entry into the CHO-K1 cell and its mutant, pgsD-677. The lack of HS expression severely impaired the ability of baculovirus vector to enter into the mutant cell (Fig. 1B). Despite overproduction of CS in pgsD-677 cells, poor transduction in mutant cells further demonstrated the specificity of baculovirus for HS.The authors masked SDC-1 with various concentrations of anti-SDC-1 antibody and tested whether baculovirus binding could be inhibited. They showed that anti-SDC-1 antibody was able to decrease baculovirus binding and transduction of cells. The anti-SDC-1 antibody (sc-5632; Santa Cruz Biotechnology, CA) used in this study was raised against the core protein of SDC-1, but not against HS. Therefore, an explanation should be given for how blocking of SDC-1 (not HS) with its antibody can block the binding of baculovirus.The authors also showed that increasing concentrations of recombinant SDC-1 (ab83609; Abcam, Cambridge, MA) could decrease baculovirus entry and transduction in a dose-dependent manner. Abcam produces recombinant SDC-1 protein in Escherichia coli which does not efficiently glycosylate SDC-1. As a result, recombinant SDC-1 cannot compete with mammalian cell surface SDC-1. Therefore, an explanation of how recombinant SDC-1 can inhibit baculovirus entry into cells is needed.The authors further mentioned that baculovirus could bind 293T cells despite low-level expression of SDC-1. They argued that this could be due to significant differences in the disaccharide composition of HS chains of SDC-1. I found that expression of HS in 293T cells was low and resulted in poor transduction of foamy virus (3), but good transduction of baculovirus. In addition to HS, herpes simplex virus 1 ...