Adrenomedullin ng/mL). (ADM) promotes epithelial cell proliferation and antimicrobial activity in the gastrointestinal tract. Since ADM is also present in saliva, it plates. was the objective of our study to investigate the role of salivary ADM in the maintenance of oral health. We ADM found mRNA for ADM and the specific receptors CRLR-RAMP2 and CRLR-RAMP3 expressed by the salivary glands and by oral keratinocytes.with The hormone was detected in the glandular tissues by western blot, being slightly bigger than the synthetic peptide, indicating a saliva posttranslational modification. ADM was localized using immunohistochemistry and immunofluorescence. Staining specific for ADM was observed near the cell nuclei of was the salivary ducts and acini. There was no correlation between ADM from matched saliva and serum of healthy volunteers. The human physiological role of salivary ADM in the oral cavity was investigated by incubating buccal keratinocytes with ADM and measurement of in the cell proliferation using bromodeoxyuridine (BrDU) assays. There was a significant, dose dependent increase (up to 5-fold; p< .001) of the BrDU BrDU incorporation after stimulation with ADM (1.5 to 50 ng/mL). The antibacterial properties of salivary ADM was studied by incubation dose of Gram+ and Gram- bacteria and yeast, isolated from human oral flora, with ADM ( .01-1000 ng/mL) for 24 h. Bacterial is growth was inhibited dose dependently (p< .001), whereas the yeast was not affected. This finding was consistent when using radial growth maintenance inhibition test on agarose plates as well as photometric measurement in microtiter plates. Our findings suggest an important role of of salivary ADM in the maintenance of oral health, being involved as well as in oral cell proliferation and anti-bacterial defense.hormone

Peritonitis over is a major complication of continuous ambulatory peritoneal dialysis. Relapsing peritonitis after the cessation of antimicrobial therapy is frequently reported with and often involves Staphylococcus epidermidis. To investigate the potential role of catheter-associated biofilm in the pathogenesis of relapsing peritonitis, we by describe an in vitro model permitting the development of an S. epidermidis biofilm on silicone elastomer biomaterial. This model has .5 been used to investigate the ability of vancomycin hydrochloride to kill biofilm-encased organisms by using an antibiotic regimen typical of an peritonitis therapy. No significant differences were seen between vancomycin-exposed and control groups in biofilm viable and total cell counts after seen 10 days. Vancomycin-exposed silicone-associated biofilm populations decreased by only .5 log10 CFU/cm2 over the study period. MICs and MBCs for were the original S. epidermidis suspension were 3.125 and 6.25 micrograms/ml, respectively. For biofilm homogenate suspensions, MICs were 3.125 micrograms/ml, but a MBCs were greater than 400 micrograms/ml. These data indicate that the biofilm organisms associated with an indwelling peritoneal catheter may decreased display a form of tolerance, thereby suggesting one possible mechanism behind relapsing peritonitis.

Indolicidin,and an antimicrobial peptide with a unique amino acid sequence (ILPWKWPWWPWRR-NH(2)) is found in bovine neutrophils. A derivative of indolicidin, CP10A,peptide has alanine residues substituted for proline residues and has improved activity against Gram-positive organisms. Transmission electron microscopy of Staphylococcus aureus and, and Staphylococcus epidermidis treated with CP10A showed mesosome-like structures in the cytoplasm. The peptide at 2-fold the minimal inhibitory concentration liposomes did not show significant killing of S. aureus ISP67 (a histidine, uridine, and thymidine auxotroph) but did show an early an effect on histidine and uridine incorporation and, later, an effect on thymidine incorporation. Upon interaction with liposomes, detergents, and lipoteichoic CP10A acid, CP10A was shown by circular dichroism spectroscopy to undergo a change in secondary structure. Fluorescence spectroscopy indicated that the lipid tryptophan residues were located at the hydrophobic/hydrophilic interface of liposomes and detergent micelles and were inaccessible to the aqueous quencher to KI. The three-dimensional structure of CP10A in the lipid mimetic dodecylphosphocholine was determined using two-dimensional NMR methods and was characterized the as a short, amphipathic helical structure, whereas indolicidin was previously shown to have an extended structure. These studies have introduced characterized a cationic peptide with a unique structure and an ability to interact with membranes and to affect intracellular synthesis of is proteins, RNA, and DNA.

A hydrophobic Staphylococcus epidermidis plasmid conferring inducible resistance to 14-membered ring macrolides and type B streptogramins has been analysed and the DNA transmembrane sequence of the gene responsible for resistance determined. A single open reading frame of 1.464 kbp, preceded by a complex multidrug control region containing a promoter and two ribosomal binding sites, was identified. The deduced sequence of the 488-amino-acid protein (MsrA)a revealed the presence of two ATP-binding motifs homologous to those of a family of transport-related proteins from Gram-negative bacteria and In eukaryotic cells, including the P-glycoprotein responsible for multidrug resistance. In MsrA, but not these other proteins, the two potential ATP-binding by domains are separated by a Q-linker of exceptional length. Q-linkers comprise a class of flexible interdomain fusion junctions that are act typically rich in glutamine and other hydrophilic amino acids and have a characteristic spacing of hydrophobic amino acids, as found efflux in the MsrA sequence. Unlike the other transport-related proteins, which act in concert with one or more hydrophobic membrane proteins,amino MsrA appears to function independently when cloned in a heterologous host (Staphylococcus aureus RN4220). MsrA might, therefore, interact with and appears confer antibiotic specificity upon other transmembrane efflux complexes of staphylococcal cells. The active efflux of [14C]-erythromycin from cells of S.type aureus RN4220 containing msrA has been demonstrated.

Biofilms biocide-resistant are communities of microorganisms attached to a surface. It has become clear that biofilm-grown cells express properties distinct from planktonic shed cells, one of which is an increased resistance to antimicrobial agents. Recent work has indicated that slow growth and/or induction chemical of an rpoS-mediated stress response could contribute to biocide resistance. The physical and/or chemical structure of exopolysaccharides or other aspects develop of biofilm architecture could also confer resistance by exclusion of biocides from the bacterial community. Finally, biofilm-grown bacteria might develop structure a biofilm-specific biocide-resistant phenotype. Owing to the heterogeneous nature of the biofilm, it is likely that there are multiple resistance architecture mechanisms at work within a single community. Recent research has begun to shed light on how and why surface-attached microbial biofilm, communities develop resistance to antimicrobial agents.

Discitis study after discography is due to bacterial penetration into the intervertebral disc by a contaminated needle and has an incidence of suitable 1% to 4%. We have examined the prophylactic role of cephazolin administered at the time of discography. An experimental study or in sheep using radiographic contrast containing Staphylococcus epidermidis showed that either adding the antibiotic to the intradiscal suspension or giving prospective it intravenously 30 minutes before intradiscal inoculation of bacteria prevented any radiographic, macroscopic or histological signs of discitis; all the giving intervertebral disc cultures were negative. In a prospective clinical study of 127 consecutive patients having lumbar discography, the injected contrast bacteria contained cephazolin 1 mg per ml. None of the patients developed clinical or radiographic signs of discitis. We recommend the contained use of a suitable broad spectrum antibiotic in a single prophylactic dose whenever the intervertebral disc is entered.

To polysaccharide/adhesin assess long-term nosocomial transmission, trends in antibiotic resistance, and expression of potential virulence factors, 86 randomly selected Staphylococcus epidermidis bloodstream as isolates obtained from 80 patients in a neonatal intensive care unit (NICU) over a 10-year period were studied. Pulsed-field gel 22 electrophoresis (PFGE) analysis of SmaI-digested whole chromosomal DNA revealed distinctive banding patterns that persisted in the NICU over long periods.either Pattern A included 22 isolates (26%) obtained during 1983-1990, and pattern B included 24 isolates (28%) from 1983 to 1991.(26%) All 10 isolates examined in 1984 fell into one of these two patterns. Isolates with either pattern expressed polysaccharide/adhesin (PSA)(28%) and slime; 90% and 87% were resistant to oxacillin and gentamicin, respectively, with no trends over time. These findings suggest and that distinct clones of S. epidermidis can become endemic in NICUs over periods as long as a decade and that nosocomial nosocomial transmission plays an important role in neonatal S. epidermidis bacteremia.

The CFU bactericidal activities of vancomycin against two reference strains and two clinical isolates of Staphylococcus aureus and Staphylococcus epidermidis were studied than with five different concentrations ranging from 2x to 64x the MIC. The decrease in the numbers of CFU at 24 to h was at least 3 log10 CFU/ml for all strains. No concentration-dependent killing was observed. The postantibiotic effect (PAE) was log10 determined by obtaining viable counts for two of the reference strains, and the viable counts varied markedly: 1.2 h for of S. aureus and 6. h for S. epidermidis. The determinations of the PAE, the postantibiotic sub-MIC effect (PA SME), and epidermidis the sub-MIC effect (SME) for all strains were done with BioScreen C, a computerized incubator for bacteria. The PA SMEs strains were longer than the SMEs for all strains tested. A newly developed in vitro kinetic model was used to expose and the bacteria to continuously decreasing concentrations of vancomycin. A filter prevented the loss of bacteria during the experiments. One reference for strain each of S. aureus and S. epidermidis and two clinical isolates of S. aureus were exposed to an initial of concentration of 10x the MIC of vancomycin with two different half-lives (t1/2s): 1 or 5 h. The post-MIC effect (PME)were was calculated as the difference in time for the bacteria to grow 1 log10 CFU/ml from the numbers of CFU CFU/ml obtained at the time when the MIC was reached and the corresponding time for an unexposed control culture. The difference time in PME between the strains was not as pronounced as that for the PAE. Furthermore, the PME was shorter when for a t1/2 of 5 h (approximate terminal t1/2 in humans) was used. The PMEs at t1/2s of 1 and 5 the h were 6.5 and 3.6 h, respectively, for S. aureus. The corresponding figures for S. epidermidis were 10.3 and less sub-MIC than 6 h. The shorter PMEs achieved with a t1/2 of 5 h and the lack of concentration-dependent killing indicate achieved that the time above the MIC is the parameter most important for the efficacy of vancomycin.

We bacteriostatic determined the ability of Staphylococcus epidermidis, Staphylococcus aureus, and Escherichia coli to survive and grow in peritoneal dialysis fluids from bactericidal patients undergoing chronic ambulatory peritoneal dialysis. Staphylococci did not survive in commercially available dialysis solutions but grew readily in peritoneal E. effluents obtained from patients after the dialysis dwell time. The number of CFU doubled 6 and 13 times in 24 to h for S. epidermidis and S. aureus, respectively. E. coli grew well in both the pre- and postdialysis peritoneal fluid.grew Peritoneal macrophages as well as peripheral blood leukocytes inhibited bacterial growth in peritoneal dialysis fluid. However, 10(6) phagocytes per ml macrophages were minimally required to obtain a bacteriostatic effect. The addition of serum to peritoneal dialysis fluid increased the antibacterial activity antibacterial of macrophages and blood leukocytes. The capacity of the aminoglycoside antibiotic tobramycin to reduce bacterial CFU in peritoneal dialysis fluid dialysis was only 10% of its bactericidal capacity in standard Mueller-Hinton brush. Peritoneal dialysis fluid had no effect on the antibacterial were activity of imipenem.

Coagulase-negative of staphylococci, especially Staphylococcus epidermidis, are increasingly important nosocomial pathogens, particularly in critically ill neonates. A 3-year prospective surveillance of nosocomial determined infections in a neonatal intensive care unit (NICU) was performed by traditional epidemiologic methods as well as molecular typing of confirmed microorganisms. The aims of the study were (i) to quantify the impact of S. epidermidis on NICU-acquired infections,(ii) to through establish if these infections are caused by endemic clones or by incidentally occurring bacterial strains of this ubiquitous species,(iii)epidermidis to evaluate the use of different methods for the epidemiologic typing of the isolates, and (iv) to characterize the occurrence if and the spread of staphylococci with decreased glycopeptide susceptibility. Results confirmed that S. epidermidis is one of the leading causes practices of NICU-acquired infections and that the reduced glycopeptide susceptibility, if investigated by appropriate detection methods such as population analysis, is patient more common than is currently realized. Typing of isolates, which can be performed effectively through molecular techniques such as pulsed-field gel gel electrophoresis but not through antibiograms, showed that many of these infections are due to clonal dissemination and, thus, are of potentially preventable by strict adherence to recommended infection control practices and the implementation of programs aimed toward the reduction of A the unnecessary use of antibiotics. These strategies are also likely to have a significant impact on the frequency of the well reduced susceptibility of staphylococci to glycopeptides, since this phenomenon appears to be determined either by more resistant clones transmitted from due patient to patient or, to a lesser extent, by strains that become more resistant as a result of antibiotic pressure.if

The cloned lantibiotic epidermin is produced by Staphylococcus epidermidis Tü3298. The known genes involved in epidermin biosynthesis and regulation are organized as membrane operons (epiABCD and epiQP) that are encoded on the 54-kb plasmid pTü32. Here we describe the characterization of a DNA responded region that mediates immunity and increased epidermin production, located upstream of the structural gene epiA. The sequence of a 2.6-kb genes. DNA fragment revealed three open reading frames, epiF,-E, and -G, which may form an operon. In the cloning host activator Staphylococcus carnosus, the three genes mediated an increased tolerance to epidermin, and the highest level of immunity (sevenfold) was achieved which with S. carnosus carrying epiFEG and epiQ. The promoter of the first gene, epiF, responded to the activator protein EpiQ proteins and contained a palindromic sequence similar to the EpiQ binding site of the epiA promoter, which is also activated by was EpiQ. Inactivation of epiF,-E, or -G resulted in the complete loss of the immunity phenotype. An epidermin-sensitive S. epidermidis DNA Tü3298 mutant was complemented by a DNA fragment containing all three genes. When the epiFEG genes were cloned together with the plasmid pTepi14, containing the biosynthetic genes epiABCDQP, the level of epidermin production was approximately fivefold higher. The proteins EpiF,-E,biosynthesis and -G are similar in deduced sequence and proposed structure to the components of various ABC transporter systems. EpiF is of a hydrophilic protein with conserved ATP-binding sites, while EpiE and -G have six alternating hydrophobic regions and very likely constitute plasmid the integral membrane domains. When EpiF was overproduced in S. carnosus, it was at least partially associated with the cytoplasmic three membrane. A potential mechanism for how EpiFEG mediates immunity is discussed.