Publications

studies on in vitro antioxidant and antistaphylococcal activities of some important medicinal plants.	oxidative stress is initiated by free radicals, which seek stability through electron pairing with biological macromolecules in healthy human cells and cause protein and dna damage along with lipid peroxidation. many phytochemicals have been found to play as potential antioxidants and antimicrobials. in the present study antioxidant and antistaphylococcal activities of bauhinia variegata, tinospora cardifolia and piper longum have been determined. total phenolic contents in plant extracts were e ...	2011	21366958
improved proteolytic stability of chicken cathelicidin-2 derived peptides by d-amino acid substitutions and cyclization.	a truncated version of host defense peptide chicken cathelicidin-2, c1-15, possesses potent, broad spectrum antibacterial activity. a variant of this peptide, f(2,5,12)w, which contains 3 phenylalanine to tryptophan substitutions, possesses improved antibacterial activity and lipopolysaccharide (lps) neutralizing activity compared to c1-15. in order to improve the proteolytic resistance of both peptides we engineered novel chicken cathelicidin-2 analogs by substitution of l- with d-amino acids a ...	2011	21376095
screening for methicillin-resistant staphylococci in dogs admitted to a veterinary teaching hospital.	this study investigated the nasal carriage of methicillin-resistant staphylococci (mrs) in dogs (n=177) prior to medical examination or surgery in a veterinary teaching hospital. nasal swab samples were collected after induction of anaesthesia and incubated overnight in salt enriched trypticase-soy broth. cultures were analysed on two different agar media containing cefoxitin. suspected mrs isolates were genotypically identified and characterised by antimicrobial susceptibility testing and staph ...	2011	21726884
inhibitory effects of lipoteichoic acid from staphylococcus aureus on platelet function and platelet-monocyte aggregation.	objective: lipoteichoic acid (lta) from staphylococcus aureus has been demonstrated to inhibit agonist-stimulated platelet aggregation. however, its effects on platelet inflammatory mediator release and platelet-monocyte aggregation are still unclear. in the present study, lta is examined for its anti-inflammatory properties and effects on platelet-monocyte aggregation. methods: blood samples were obtained from 5 healthy volunteers who had taken no medicine in the previous 2 weeks. washed platel ...	2011	21503720
activity of simulated serum concentrations of daptomycin versus vancomycin during the first 24h of treatment in the presence of physiological albumin concentrations against vancomycin-susceptible, -tolerant or -intermediate-resistant staphylococcus aureus.	in order to determine whether reduced susceptibility or tolerance to vancomycin in staphylococcus aureus influences the activity of daptomycin by simulating serum concentrations in the first 24h of treatment in the presence of physiological concentrations of human albumin, a computerised pharmacodynamic simulation was performed using mueller-hinton broth with 4 g/dl human albumin concentrations. for daptomycin, the media was adjusted to physiological ionised calcium concentrations by adding 100 ...	2011	21388792
bactericidal activity and in vitro cytotoxicity assessment of hydroxyapatite containing gold nanoparticles.	hydroxyapatite (ha) containing gold (au) nanoparticles was synthesized for the biomedical applications. the morphology, structure and thermal properties of the ha containing au nanoparticles were characterized by field emission scanning electron microscopy (fe-sem), transmission electron microscopy (tem), energy dispersive x-ray (edx) spectroscopy, x-ray diffraction (xrd), fouriertransform infrared spectroscopy (ft-ir) and thermogravimetry (tga). xrd patterns clearly revealed the formation of ha ...	2011	21830474
differences in toll-like receptor expression and cytokine production after stimulation with heat-killed gram-positive and gram-negative bacteria.	innate immune surveillance in the blood is executed mostly by circulating monocytes, which recognize conserved bacterial molecules such as peptidoglycan and lipopolysaccharide. toll-like receptors (tlr) play a central role in microbe-associated molecular pattern detection. the aim of this study was to compare the differences in tlr expression and cytokine production after stimulation of peripheral blood cells with heat-killed gram-negative and gram-positive human pathogens: neisseria meningitidi ...	2011	21399944
fat embolism syndrome after femur fracture with intramedullary nailing: case report.	fat embolism syndrome is a life-threatening condition that can develop after orthopedic injury and surgery. this syndrome developed in a 19-year-old man after a traumatic femoral fracture that was surgically repaired with intramedullary nailing. the complications experienced by the patient highlight the importance of prevention and early detection of fat embolism syndrome. although minimization of the syndrome focuses primarily on prehospital care and early stabilization of a patient's condition ...	2011	21532048
sortase a as a tool for high-yield histatin cyclization.	cyclic peptides are highly valued tools in biomedical research. in many cases, they show higher receptor affinity, enhanced biological activity, and improved serum stability. technical difficulties in producing cyclic peptides, especially larger ones, in appreciable yields have precluded a prolific use in biomedical research. here, we describe a novel and efficient cyclization method that uses the peptidyl-transferase activity of the staphylococcus aureus enzyme sortase a to cyclize linear synth ...	2011	21525488
composite electrospun nanomembranes of fish scale collagen peptides/chito-oligosaccharides: antibacterial properties and potential for wound dressing.	the objective of the present investigation was to evaluate the antibacterial properties and the biocompatibility of composite electrospun nanofibrous membranes (nfms) with low-molecular-weight fish scale collagen peptides (fscp) and chito-oligosaccharide (cos), to determine their potential for use as wound dressings.	2011	21556341
expression of matrix metalloproteinase-9 and -12 in porcine lung infections.	matrix metalloproteinases (mmps) play a variety of roles during organogenesis, in the immune response and during acute and chronic diseases as well as in tissue remodelling. during the last decade, the pig has become used increasingly as a model for human diseases; however, studies on the expression of porcine mmps are limited. in the present study species-specific antibodies were produced to investigate the expression of mmp-9 and mmp-12 immunohistochemically in lungs from pigs infected with ac ...	2011	21737093
congenital alterations of nemo glutamic acid 223 result in hypohidrotic ectodermal dysplasia and immunodeficiency with normal serum igg levels.	hypomorphic mutations in the nuclear factor-+¦b (nf-+¦b) essential modulator (nemo) gene result in a variable syndrome of somatic and immunologic abnormalities. clinically relevant genotype-phenotype associations are essential to understanding this complex disease.	2011	21704885
adhesion mechanisms of staphylococci.	staphylococcal adherence to an either biotic or abiotic surface is the critical first event in the establishment of an infection with these serious pathogens. especially staphylococcus aureus harbours a variety of proteinaceous and non-proteinaceous adhesins that mediate attachment to a multitude of host factors, such as extracellular matrix and plasma proteins and human host cells, or intercellular adhesion, which is essential for biofilm accumulation. proteinaceous adhesins may be classified i ...	2011	21557060
porphyromonas gingivalis enzymes enhance infection with human metapneumovirus in vitro.	relatively recently discovered, the human metapneumovirus (hmpv) is a human pathogen with worldwide prevalence, accounting for a substantial percentage of respiratory tract diseases. concurrent viral and bacterial infections enable intricate mechanisms of cooperation between pathogens, which complicate the symptoms and outcome of the disease. such bilateral interactions are based on the modulation of bacterial growth on epithelium pathologically altered during viral illness and the modulation of ...	2011	21715599
management of dental unit waterline biofilms in the 21st century.	dental chair units (dcus) use water to cool and irrigate dcu-supplied instruments and tooth surfaces, and provide rinsewater during dental treatment. a complex network of interconnected plastic dental unit waterlines (duwls) supply water to these instruments. duwls are universally prone to microbial biofilm contamination seeded predominantly from microorganisms in supply water. consequently, duwl output water invariably becomes contaminated by high densities of microorganisms, principally gram-n ...	2011	22004039
influence of the recombinant human 70-kda heat-shock protein on simulation of gram-positive sepsis in rats.		2011	21562946
nsars is a cell-envelope-stress sensing two-component system of staphylococcus aureus.	s. aureus possesses 16 two-component systems (tcs), two of which (grars & nsars) belong to the intramembrane-sensing histidine kinase (im-hk) family, conserved within the firmicutes. nsars has recently been documented as being important for nisin-resistance in s. aureus. in this study we present a characterization of nsars and reveal that, as with other im-hk tcs, it responds to disruptions in the cell-envelope. analysis using a lacz reporter-gene fusion demonstrated that nsars expression is upr ...	2011	21565927
natural and synthetic cathelicidin peptides with anti-microbial and anti-biofilm activity against staphylococcus aureus.	abstract: background: chronic infected wounds typically contain multiple genera of bacteria, including staphylococcus aureus, many of which are strong biofilm formers. bacterial biofilms are thought to be a direct impediment to wound healing. new therapies that focus on a biofilm approach may improve the recovery and healing rate for infected wounds. in this study, cathelicidins and related short, synthetic peptides were tested for their anti-microbial effectiveness as well as their ability to i ...	2011	21605457
evaluation of lhp-« (1% hydrogen peroxide) cream versus petrolatum and untreated controls in open wounds in healthy horses: a randomized, blinded control study.	abstract:	2011	21718487
structure-function studies of an engineered scaffold protein derived from stefin a. ii: development and applications of the sqt variant.	constrained binding peptides (peptide aptamers) may serve as tools to explore protein conformations and disrupt protein-protein interactions. the quality of the protein scaffold, by which the binding peptide is constrained and presented, is of crucial importance. sqt (stefin a quadruple mutant-tracy) is our most recent development in the stefin a-derived scaffold series. stefin a naturally uses three surfaces to interact with its targets. sqt tolerates peptide insertions at all three positions. ...	2011	21616931
a new target for staphylococcus aureus associated with keratitis.	staphylococcus aureus is a leading cause of keratitis, with an increased number of isolates exhibiting antibiotic resistance. therefore, we need to understand the present situation regarding drug-resistant s. aureus in the ocular site. it has been shown that 35% of s. aureus isolates from ocular sites are methicillin-resistant staphylococcus aureus (mrsa). mrsa isolates from ocular sites have a high rate of multiple mutations and high levels of resistance against fluoroquinolones. wall teichoic ...	2011	21912228
rhesus macaques (macaca mulatta) are natural hosts of specific staphylococcus aureus lineages.	currently, there is no animal model known that mimics natural nasal colonization by staphylococcus aureus in humans. we investigated whether rhesus macaques are natural nasal carriers of s. aureus. nasal swabs were taken from 731 macaques. s. aureus isolates were typed by pulsed-field gel electrophoresis (pfge), spa repeat sequencing and multi-locus sequence typing (mlst), and compared with human strains. furthermore, the isolates were characterized by several pcrs. thirty-nine percent of 731 ma ...	2011	22028827
colonization, pathogenicity, host susceptibility, and therapeutics for staphylococcus aureus: what is the clinical relevance?	staphylococcus aureus is a human commensal that can also cause a broad spectrum of clinical disease. factors associated with clinical disease are myriad and dynamic and include pathogen virulence, antimicrobial resistance, and host susceptibility. additionally, infection control measures aimed at the environmental niches of s. aureus and therapeutic advances continue to impact upon the incidence and outcomes of staphylococcal infections. this review article focuses on the clinical relevance of a ...	2011	22160374
the staphylococcus aureus peptidoglycan protects mice against the pathogen and eradicates experimentally induced infection.	staphylococcus aureus, in spite of antibiotics, is still a major human pathogen causing a wide range of infections. the present study describes the new vaccine a170pg, a peptidoglycan-based vaccine. in a mouse model of infection, a170pg protects mice against a lethal dose of s. aureus. protection lasts at least 40 weeks and correlates with increased survival and reduced colonization. protection extends into drug-resistant (mrsa or visa) and genetically diverse clinical strains. the vaccine is ef ...	2011	22145040
induction of contact-dependent cd8(+) regulatory t cells through stimulation with staphylococcal and streptococcal superantigens(1).	the bacterial superantigen exotoxins of staphylococcus aureus and streptococcus pyogenes are potent stimulators of polyclonal t cell proliferation. they are the causes of toxic shock syndrome but also induce cd25(+) foxp3(+) regulatory cells in the cd4 compartment. several studies have recently described different forms of antigen-induced regulatory cd8(+) t cells in the context of inflammatory diseases and chronic viral infections. in this paper we show that bacterial superantigens are potent ...	2011	22043981
3-cyano-8-methyl-2-oxo-1,4-disubstituted-1,2,5,6,7,8-hexahydroquinolines. synthesis and biological evaluation as antimicrobial and cytotoxic agents.	the synthesis, in vitro antimicrobial and cytotoxic activities of some novel hexahydroquinolines supported with various pharmacophores are described. the results revealed that 18 compounds displayed pronounced activity against staphylococcus aureus and escherichia coli bacteria beside a moderate antifungal activity. compound 25 is the most active candidate with equipotency to ampicillin against s. aureus, e. coli and pseudomonas aeruginosa, together with an obvious antifungal activity. additiona ...	2011	22136527
methicillin resistant s. aureus in human and bovine mastitis.	staphylococcus aureus is a ubiquitous organism that causes a variety of diseases including mastitis in cattle and humans. high-level resistance of s. aureus to β-lactams conferred by a meca gene encoding a modified penicillin binding protein (pbp2a) was first observed in the early 1960's. these methicillin resistant s. aureus (mrsa) have been responsible for both hospital acquired infections (ha-mrsa) and, more recently, community acquired mrsa (ca-mrsa). a small number of human mrsa mastitis ca ...	2011	21984431
magnetic drug targeting as new therapeutic option for the treatment of biomaterial infections.	implant-associated infections are a challenging problem in surgery. bacteria in biofilms are difficult to treat as they are less susceptible to antibiotics or antiseptics which require high drug concentrations at the site of infection. we present a novel strategy to concentrate high antibiotic doses systemically at the target site using newly developed antibiotic-functionalized nanoparticles directed by a magnetic drug-targeting system. the important and effective antibiotic gentamicin served as ...	2011	22182398
phagocytosis and intracellular killing of heterogeneous vancomycin-intermediate staphylococcus aureus strains.	risk factors for invasive infections by heterogeneous vancomycin-intermediate staphylococcus aureus (hvisa) may involve resistance to opsonophagocytosis and bacterial killing. hvisa strains typically have a thickened cell wall with altered peptidoglycan cross-linking. to determine whether hvisa may be endowed with an increased resistance to phagocytosis, this study assessed the characteristics of uptake and killing by granulocytes of three hvisa strains. all isolates were analysed by multilocus ...	2011	21959204
antimicrobial evaluation of huilliche plant medicine used to treat wounds.	the traditional use of 40 plant species used for treatment of wounds and associated infections by the huilliche people of chile was evaluated against bacterial and fungal human pathogens, especially including wound pathogens.	2011	21939748
molecular characterization and antimicrobial susceptibility of nasal staphylococcus aureus isolates from a chinese medical college campus.	staphylococcus aureus colonization and infection occur more commonly among persons living or working in crowded conditions, but characterization of s. aureus colonization within medical communities in china is lacking. a total of 144 (15.4%, 144/935) s. aureus isolates, including 28 (3.0%, 28/935) mrsa isolates, were recovered from the nares of 935 healthy human volunteers residing on a chinese medical college campus. all s. aureus isolates were susceptible to vancomycin, quinupristin/dalfoprist ...	2011	22114670
Novel anti-bacterial activities of ß-defensin 1 in human platelets: suppression of pathogen growth and signaling of neutrophil extracellular trap formation.	Human ß-defensins (hBD) are antimicrobial peptides that curb microbial activity. Although hBD's are primarily expressed by epithelial cells, we show that human platelets express hBD-1 that has both predicted and novel antibacterial activities. We observed that activated platelets surround Staphylococcus aureus (S. aureus), forcing the pathogens into clusters that have a reduced growth rate compared to S. aureus alone. Given the microbicidal activity of ß-defensins, we determined whether hBD fami ...	2011	22102811
chimeric anti-staphylococcal enterotoxin b antibodies and lovastatin act synergistically to provide in vivo protection against lethal doses of seb.	staphylococcal enterotoxin b (seb) is one of a family of toxins secreted by staphylococcus aureus that act as superantigens, activating a large fraction of the t-cell population and inducing production of high levels of inflammatory cytokines that can cause toxic shock syndrome (tss) and death. extracellular engagement of the tcr of t-cells and class ii mhc of antigen presenting cells by seb triggers the activation of many intracellular signaling processes. we engineered chimeric antibodies to b ...	2011	22102880
immunopathogenesis of staphylococcus aureus pulmonary infection.	staphylococcus aureus is a common human pathogen highly evolved as both a component of the commensal flora and as a major cause of invasive infection. severe respiratory infection due to staphylococci has been increasing due to the prevalence of more virulent usa300 ca-mrsa strains in the general population. the ability of s. aureus to adapt to the milieu of the respiratory tract has facilitated its emergence as a respiratory pathogen. its metabolic versatility, the ability to scavenge iron, coo ...	2011	22037948
cheminformatics-driven discovery of selective, nanomolar inhibitors for staphylococcal pyruvate kinase.	we have recently mapped the protein interaction network of methicillin-resistant staphylococcus aureus (mrsa), which revealed its scale-free organization with characteristic presence of highly connected hub proteins that are critical for bacterial survival. here we report the discovery of inhibitors that are highly potent against one such hub target, staphylococcal pyruvate kinase (pk). importantly, the developed compounds demonstrate complete selectivity for the bacterial enzyme compared to all ...	2011	22066782
Expansion of T helper type 17 lymphocytes in patients with chronic granulomatous disease.	Hyper-immunoglobulin (Ig)E syndrome (HIES) is a primary immunodeficiency associated with mutations in STAT3 resulting in impaired development of T helper type 17 (Th17) lymphocytes. HIES patients with a reduced frequency of Th17 cells present with infections caused by Staphylococcus aureus and/or Candida strains. The same spectrum of pathogens is present in patients with chronic granulomatous disease (CGD).We analysed the characteristics of the Th17 compartment in HIES and CGD. HIES patients sho ...	2011	21910722
peptidylarginine deiminases present in the airways during tobacco smoking and inflammation can citrullinate the host defense peptide ll-37 resulting in altered activities.	bacterial colonization of the lower respiratory tract is frequently seen in copd and may cause exacerbations leading to deterioration of the disease. an important part of the innate lung immunity is antimicrobial peptides, not least the cathelicidin hcap-18/ll-37. peptidylarginine deiminases (padi) posttranslationally modifies proteins by converting cationic peptidylarginine residues to neutral peptidylcitrulline. increased presence of padi2 and citrullinated proteins has been demonstrated in th ...	2011	21960546
cluster-forming property correlated with hemolytic activity by staphylococcal γ-hemolysin transmembrane pores.	staphylococcal γ-hemolysin (hlg) is a pore-forming toxin consisting of two separate components, lukf (34kda) and hlg2 (32kda). here we show that hlg pores aggregate and form clusters on human erythrocyte membranes in association with increasing hemolytic activity. quantitative analysis using transmission electron microscopy and image processing revealed that the formation of single pores and clusters is related to the release of potassium ions and of hemoglobin from erythrocytes, respectively. t ...	2011	22001207
staphylococcus aureus survival in human blood.	methicillin-resistant staphylococcus aureus (mrsa) is abundant in hospitals and in the united states is a leading cause of mortality due to infectious agents. community-associated mrsa (ca-mrsa) strains such as usa300, which typically cause disease outside of healthcare settings, are also prevalent in the united states. although most ca-mrsa infections affect skin and soft tissue, the pathogen can enter the bloodstream and ultimately cause severe disease. in a recent paper, we used usa300-specif ...	2011	21971187
the first detection of methicillin-resistant staphylococcus aureus st398 in pigs in korea.	in order to determine the presence of methicillin-resistant staphylococcus aureus (mrsa) in pigs in korea, a total of 657 nasal swabs were collected from pigs on 66 different pig farms nationwide during february 2008-may 2009. the prevalences of mrsa positive samples in pigs and farms were 3.2% (21/657) and 22.7% (15/66), respectively. two different types were found among the 21 mrsa isolates: 17 strains of livestock-associated type (la; st398 or st541/spa t034) and 4 strains of human-associated ...	2011	21899962
Thiadiazolidinones: A new class of alanine racemase inhibitors with antimicrobial activity against methicillin-resistant Staphylococcus aureus.	Methicillin-resistant Staphylococcus aureus (MRSA) is a human pathogen and a major cause of hospital-acquired infections. New antibacterial agents that have not been compromised by bacterial resistance are needed to treat MRSA-related infections. We chose the S. aureus cell wall synthesis enzyme, alanine racemase (Alr) as the target for a high-throughput screening effort to obtain novel enzyme inhibitors, which inhibit bacterial growth. Among the 'hits' identified was a thiadiazolidinone with ch ...	2012	22146584
comparison of the effects of human β-defensin 3, vancomycin, and clindamycin on staphylococcus aureus biofilm formation.	despite improvements in surgical techniques and implant design in orthopedic surgery, implantation-associated infections are still a challenging problem for surgeons. in 2006, trace quantities of human β-defensin 3 (hbd-3) were found in human bone tissue and bone cells. human β-defensin 3 is a 45-amino-acid peptide that is considered the most promising class of defensin antimicrobial peptides and may help in the prevention and treatment of implantation-associated infections. studies of the effec ...	2012	22229614
electrospun poly(l-lactic acid)-co-poly(ɛ-caprolactone) nanofibres containing silver nanoparticles for skin-tissue engineering.	silver nanoparticles (agnps) and silver ions (ag(+)) show growth-inhibitory activity against microorganisms and have been used for decades as antibacterial agents in various fields. to fabricate a nanofibrous scaffold which is antibacterial against bacteria and non-toxic to cells, we electrospun composite poly(l-lactic acid)-co-poly(ɛ-caprolactone) nanofibres containing silver nanoparticles (pllcl-agnps) with different concentrations (0.25, 0.50 and 0.75 wt%) of silver nitrate (agno(3)) in pllcl ...	2012	22244047
expression of antimicrobial peptides in diabetic foot ulcer.	foot ulcers are one of the main diabetes complications due to its high frequency and difficulty of complete healing. there are several factors that participate in diabetic ulcers development and limited information exists about the role of antimicrobial peptides (amp) in its pathogenesis.	2012	22047630