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Sample records for aureus peptidoglycan tertiary

  1. Staphylococcus aureus Peptidoglycan Tertiary Structure from Carbon-13 Spin Diffusion

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    Sharif, Shasad; Singh, Manmilan; Kim, Sung Joon; Schaefer,Jacob

    2009-01-01

    The cell-wall peptidoglycan of Staphylococcus aureus is a heterogeneous, highly cross-linked polymer of unknown tertiary structure. We have partially characterized this structure by measuring spin diffusion from 13C labels in pentaglycyl cross-linking segments to natural-abundance 13C in the surrounding intact cell walls. The measurements were performed using a version of centerband-only detection of exchange (CODEX). The cell walls were isolated from S. aureus grown in media containing [1-13...

  2. Study of the interactions between endolysin and bacterial peptidoglycan on S. aureus by dynamic force spectroscopy

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    Liu, Jianli; Zhang, Xuejie; Yang, Hang; Yuan, Jinghe; Wei, Hongping; Yu, Junping; Fang, Xiaohong

    2015-09-01

    The cell wall binding domain (CBD) of bacteriophage lysins can recognize target bacteria with extraordinary specificity through binding to bacterial peptidoglycan, thus it is a promising new probe to identify the corresponding bacterial pathogen. In this work, we used atomic force microscopy (AFM) based single-molecule force spectroscopy to investigate the interaction between the CBD of lysin PlyV12 (PlyV12C) and pathogenic bacterium Staphylococcus aureus (S. aureus). The binding forces of PlyV12C with S. aureus have been measured, and the dissociation process of their binding complex has been characterized. Furthermore, we compared the interactions of PlyV12C-S. aureus and antibody-S. aureus. It is revealed that PlyV12C has a comparable affinity to bacterial peptidoglycans as that of the S. aureus antibody. The results provide new information on the binding properties of lysin CBD with bacterium, and the application of lysin CBD in bacterium detection.

  3. Nonviable Staphylococcus aureus and its peptidoglycan stimulate macrophage recruitment, angiogenesis, fibroplasia, and collagen accumulation in wounded rats.

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    Kilcullen, J K; Ly, Q P; Chang, T H; Levenson, S M; Steinberg, J J

    1998-01-01

    We have previously shown that local application at the time of operation of Staphylococcus aureus, nonviable S. aureus, its cell wall, or S. aureus peptidoglycan accelerates wound healing. We hypothesized that this effect is due to both direct and indirect mechanisms, among which is an increase in the inflammatory response to wounding, resulting in an increase in macrophages, angiogenesis, and fibroblasts. Twenty-seven Sprague-Dawley male rats were anesthetized, and two 7-cm paravertebral skin incisions were made. Four polyvinyl alcohol sponges, two on each side, containing either 100 microliter of isotonic saline or 0.5 mg of nonviable S. aureus or S. aureus peptidoglycan in 100-microliter saline were implanted subcutaneously. Nonviable S. aureus or S. aureus peptidoglycan (860 microgram/cm incision) in 200-microliter saline were inoculated into the incisions at closure. The rats ate a commercial rat chow and drank tap water ad libitum throughout. After days 3 and 7 postwounding, rats were euthanized, and tissues were examined for immunohistochemical features of reparative tissue using ED-1, Factor VIII, and vimentin antibodies, markers for monocyte/macrophages, endothelial cells, and mesenchymal cells (including fibroblasts), respectively. Incisions treated with nonviable S. aureus or S. aureus peptidoglycan showed more macrophages along and deep in the wound tract 7 days postoperatively. Nonviable S. aureus or S. aureus peptidoglycan-treated sponges were surrounded and penetrated by much larger capsules of reparative tissue than saline-treated sponges at both 3 and 7 days. Neutrophil influx was much greater in nonviable S. aureus or S. aureus peptidoglycan-treated sponges, especially in central regions, and there were many more ED-1-stained macrophages in distinct geographic locations, specifically, the more peripheral-cortical areas. Some clustering of macrophages occurred around areas of invasion by reparative tissue into the surrounding subcutaneous fat and

  4. "A Modified Method for Preparation of Staphylococcus aureus Peptidoglycan Towards Making a Sub – Unit Vaccine"

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    F Esmaily

    2002-08-01

    Full Text Available The immounological responses to S. aureus cell wall antigens, namely crude or whole cell, teichoic acid (TA peptidoglycan prepared in conventional way (CPG, cell wall (CW, lipoteichoic acid (LTA were investigated by number of immunological methods e.g. RIA, ELISA, immunodiffusion and western blotting techniques.Also a method for preparation of peptidoglycan (MPG was modified and used as vaccine for our protection studies. In general the responses in rabbits (serum titre to fractions of S. aureus, varied, crued antigen showed the highest end-point titer while lipoteichoic acid showed the lowest end-point. The highest end-point titre was always seen between homologous sera and antigens. Modified pepdidoglycan and cell wall (PG + TA showed the similar titre against S. epidermidis hyperimmueserum. The cross – reactivty was also seen between fractions by S. aureus Bate . S. aureus Wood (lack protein A S. epidermidis and streptococci against various immune sera tested by Elisa and gel diffiusion. The results demonstrated that protective antibody can be obtained between different strain or species of bacteria due to the presence of common antigen or antigenes especially PG in gram - positive bacteria.

  5. Solid-state NMR characterization of amphomycin effects on peptidoglycan and wall teichoic acid biosyntheses in Staphylococcus aureus.

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    Singh, Manmilan; Chang, James; Coffman, Lauryn; Kim, Sung Joon

    2016-01-01

    Amphomycin and MX-2401 are cyclic lipopeptides exhibiting bactericidal activities against Gram-positive pathogens. Amphomycin and MX-2401 share structural similarities with daptomycin, but unlike daptomycin they do not target bacterial membrane. In this study, we investigate in vivo modes of action for amphomycin and MX-2401 in intact whole cells of Staphylococcus aureus by measuring the changes of peptidoglycan and wall teichoic acid compositions using solid-state NMR. S. aureus were grown in a defined media containing isotope labels [1-(13)C]glycine and L-[ε-(15)N]lysin, L-[1-(13)C]lysine and D-[(15)N]alanine, or D-[1-(13)C]alanine and [(15)N]glycine, to selectively (13)C-(15)N pair label peptidoglycan bridge-link, stem-link, and cross-link, respectively. (13)C{(15)N} and (15)N{(13)C} rotational-echo double resonance NMR measurements determined that cyclic lipopeptide-treated S. aureus exhibited thinning of the cell wall, accumulation of Park's nucleotide, inhibition of glycine utilization for purine biosynthesis, reduction of ester-linked D-Ala in teichoic acids, and reduction of peptidoglycan cross-linking. Whole cell NMR analysis also revealed that S. aureus, in presence of amphomycin and MX-2401, maintained the incorporation of D-Ala during peptidoglycan biosynthesis while the incorporation of D-Ala into teichoic acids was inhibited. These effects are consistent with amphomycin's dual inhibition of both peptidoglycan and wall teichoic acid biosyntheses in S. aureus. PMID:27538449

  6. Convergent evolution in peptidoglycan cut sites of phage endolysins protecting mice from methicillin-resistant Staphylococcus aureus septicemia

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    Staphylococcus S. aureus is a Gram-positive pathogen relevant for both human and animal health. It is one of the most common causes of nosocomial infections and associated with a wide range of life-threatening human diseases. As the major causative agent of bovine mastitis, it also has significant ...

  7. The Glycogen Synthase Kinase 3α and β Isoforms Differentially Regulates Interleukin-12p40 Expression in Endothelial Cells Stimulated with Peptidoglycan from Staphylococcus aureus.

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    Ricarda Cortés-Vieyra

    Full Text Available Glycogen synthase kinase 3 (GSK3 is a constitutively active regulatory enzyme that is important in cancer, diabetes, and cardiovascular, neurodegenerative, and psychiatric diseases. While GSK3α is usually important in neurodegenerative and psychiatric diseases GSK3β is fundamental in the inflammatory response caused by bacterial components. Peptidoglycan (PGN, one of the most abundant cell-wall structures of Gram-positive bacteria, is an important inducer of inflammation. To evaluate whether inhibition of GSK3α and GSK3β activity in bovine endothelial cells (BEC regulates the expression of the pro-inflammatory cytokine IL-12p40, we treated BEC with SDS-purified PGN from Staphylococcus aureus. We found that PGN triggered a TLR2/PI3K/Akt-dependent phosphorylation of GSK3α at Ser21, GSK3β at Ser9, and NF-κB p65 subunit (p65 at Ser536, and the phosphorylation of GSK3α was consistently higher than that of GSK3β. The expression of IL-12p40 was inhibited in BEC stimulated with PGN and pre-treated with a specific neutralizing anti-TLR2 antibody that targets the extracellular domain of TLR2 or by the addition of Akt-i IV (an Akt inhibitor. Inhibition of GSK3α and GSK3β with LiCl or SB216763 induced an increase in IL-12p40 mRNA and protein. The effect of each isoform on IL-12p40 expression was evaluated by siRNA-gene expression silencing of GSK3α and GSK3β. GSK3α gene silencing resulted in a marked increase in IL-12p40 mRNA and protein while GSK3β gene silencing had the opposite effect on IL-12p40 expression. These results indicate that the TLR2/PI3K/Akt-dependent inhibition of GSK3α activity also plays an important role in the inflammatory response caused by stimulation of BEC with PGN from S. aureus.

  8. PREVALENCE AND ANTIMICROBIAL SUSCEPTIBILITY PATTERN OF METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS (MRSA ISOLATES IN A TERTIARY CARE HOSPITAL IN PUNJAB

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    Satish

    2013-10-01

    Full Text Available ABSTRACT: BACKGROUND: Methicillin resistant Staphylococcus aureus (MRSA is an important cause of nosocomial infections worldwide. This prospective study was undertaken to know the prevalence of MRSA, to study antimicrobial susceptibility pattern and inducible clindamycin resistance in Staphylococcus aureus isolates obtained from the indoor patients of a tertiary care hospital in Punjab. MATERIALS AND METHODS : All the iso lates of Staphylococcus aureus obtained from various clinical specimens were identified by standard methods. MRSA was detected using 30ug cefoxitin disc by disc diffusion method as per CLSI guidelines, 2007. Each isolate was tested for other anti - staphyloc occal antibiotics by Kirby - Bauer disc diffusion method. Additionally, inducible clindamycin resistance was studied by disc induction test (D test. RESULTS : During a period of one year, a total of 252 isolates of Staphylococcus aureus were obtained. Eighty six (34.1% isolates were methicillin resistant Staphylococcus aureus (MRSA and the remaining 166 (65.8% isolates were methicillin sensitive Staphylococcus aureus (MSSA. MRSA isolates were significantly less sensitive to common anti - staphylococcal anti biotics as compared to MSSA isolates. However, MRSA isolates showed relatively better sensitivity to some of the antibiotics like netilmicin, levofloxacin, tetracycline and clindamycin. Susceptibility to ciprofloxacin was low in both MSSA (19.8% and MRSA (9.3%. None of the isolate of Staphylococcus aureus was resistant to vancomycin, linezolid and teicoplanin. Inducible clindamycin resistance was present in 17 (19.7% MRSA isolates as against 8 (4.8% MSSA isolates. CONCLUSION : Robust antimicrobial stewa rdship and strengthened infection control measures are required to prevent spread and reduce emergence of resistance

  9. Characterization of Resistance to Aminoglycosides in Methicillin-Resistant Staphylococcus aureus Strains Isolated From a Tertiary Care Hospital in Tehran, Iran

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    Rahimi, Fateh

    2016-01-01

    Background: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common nosocomial pathogens which can cause a broad spectrum of infections. Objectives: The current study aimed to describe the frequency and antibiotic susceptibility patterns of clonal groups of gentamicin-resistant strains of MRSA isolated from a tertiary care hospital in Tehran, Iran. Materials and Methods: A total of 301 S. aureus isolates were collected during January to November 2012. All of the isolates ...

  10. Antibiotic Resistance Profiling of Staphylococcus aureus Isolated from Clinical Specimens in a Tertiary Hospital from 2010 to 2012

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    Alain C. Juayang

    2014-01-01

    Full Text Available MRSA infection can affect a wide array of individuals that may lead to treatment failure. Also, the infection has the potential to spread from one area to another particularly health care facilities or communities eventually causing minor outbreaks. With this premise, the study aimed to describe MRSA infections using the hospital-based data of a tertiary hospital in Bacolod City, Philippines, from 2010 to 2012. Specifically, this study aimed to evaluate the antimicrobial resistance of S. aureus isolated from clinical specimens and to put emphasis on the prevalence of MRSA and Inducible Clindamycin Resistance. A total of 94 cases from 2010 to 2012 were diagnosed to have S. aureus infection using conventional bacteriologic methods. From these cases, 38 (40.6% were identified as MRSA and 37 (39.4% were inducible clindamycin resistant. Wounds and abscesses were considered to be the most common specimens with MRSA infections having 71.05% while blood was the least with 5.3%. For drug susceptibility, out of the 94 S. aureus cases, including MRSA, 100% were susceptible to linezolid making it the drug of choice for this study. It was then followed by tetracycline having a mean susceptibility of 95%;, while penicillin G was ineffective with 94 cases having 0% susceptibility.

  11. Evaluation of constitutive and inducible resistance to clindamycin in clinical samples of Staphylococcus aureus from a tertiary hospital

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    Angelita Bottega

    2014-10-01

    Full Text Available Introduction Infections caused by methicillin-resistant Staphylococcus aureus (MRSA have become common in hospitals and the community environment, and this wide resistance has limited patient treatment. Clindamycin (CL represents an important alternative therapy for infections caused by S. aureus. Antimicrobial susceptibility testing using standard methods may not detect inducible CL resistance. This study was performed to detect the phenotypes of resistance to macrolides-lincosamides-streptogramin B (MLSB antibiotics, including CL, in clinical samples of S. aureus from patients at a tertiary hospital in Santa Maria, State of Rio Grande do Sul, Brazil. Methods One hundred and forty clinical isolates were submitted to the disk diffusion induction test (D-test with an erythromycin (ER disk positioned at a distance of 20mm from a CL disk. The results were interpreted according to the recommendations of the Clinical and Laboratory Standards Institute (CLSI. Results In this study, 29 (20.7% of the 140 S. aureus samples were resistant to methicillin (MRSA, and 111 (79.3% were susceptible to methicillin (MSSA. The constitutive resistance phenotype (cMLSB was observed in 20 (14.3% MRSA samples and in 5 (3.6% MSSA samples, whereas the inducible resistance phenotype (iMLSB was observed in 3 (2.1% MRSA samples and in 8 (5.8% MSSA samples. Conclusions The D-test is essential for detecting the iMLSB phenotype because the early identification of this phenotype allows clinicians to choose an appropriate treatment for patients. Furthermore, this test is simple, easy to perform and inexpensive.

  12. Current Antibiotic Resistance Trend in Clinical Isolates of Staphylococcus aureus from a Tertiary Care Hospital

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    Zahra Ravesh-Barakzai

    2015-10-01

    Full Text Available Background: Staphylococcus aureus (S. aureus has remained always an important pathogen of common infections acquired in community and as  well as serious nosocomial infections. With advent of penicillins and cephalosporins, infections could be effectively treated, but with the global emergence of Methicillin Resistant Staphylococcus aureus strains (MRSA physicians were  again left  with limited treatment options. This scenario of increasing resistance is even more intense and challenging for developing countries like Pakistan. Hence with this background the study was carried out to establish the frequency of MRSA in clinical specimens and look into the available antibiotic treatment options.Methods: Samples of  pus, blood, urine, body fluids and catheter tips submitted for culture  in  Microbiology department between  August  to  September  2012,  from outdoor and indoor adult patients of Pakistan Institute of Medical Sciences Islamabad, yielding growth of S. aureus were included in the study. After identification by  standard  methods, antibiotic susceptibility of  the  isolates  was performed by Kirby Baeur disc diffusion method. The study was retrospective descriptive and observational.Results: Total  106  S.  aureus  were  isolated. 45.3%  of  them  were  MRSA  and majorities were from pus samples of hospitalized patients. All MRSA were 100% sensitive to vancomycin, whereas 87.5% to chloramphenicol. To rest of the non – beta lactam drugs, resistance of 80% or more was noted.Conclusion: S. aureus is a common clinical isolate from patients in this region ofPakistan and significant number were MRSA especially from hospitalized patients. Treatment options are limited to vancomycin and chloramphenicol.

  13. Short term evolution of a highly transmissible methicillin-resistant Staphylococcus aureus clone (ST228 in a tertiary care hospital.

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    Valérie Vogel

    Full Text Available Staphylococcus aureus is recognized as one of the major human pathogens and is by far one of the most common nosocomial organisms. The genetic basis for the emergence of highly epidemic strains remains mysterious. Studying the microevolution of the different clones of S. aureus is essential for identifying the forces driving pathogen emergence and spread. The aim of the present study was to determine the genetic changes characterizing a lineage belonging to the South German clone (ST228 that spread over ten years in a tertiary care hospital in Switzerland. For this reason, we compared the whole genome of eight isolates recovered between 2001 and 2008 at the Lausanne hospital. The genetic comparison of these isolates revealed that their genomes are extremely closely related. Yet, a few more important genetic changes, such as the replacement of a plasmid, the loss of large fragments of DNA, or the insertion of transposases, were observed. These transfers of mobile genetic elements shaped the evolution of the ST228 lineage that spread within the Lausanne hospital. Nevertheless, although the strains analyzed differed in their dynamics, we have not been able to link a particular genetic element with spreading success. Finally, the present study showed that new sequencing technologies improve considerably the quality and quantity of information obtained for a single strain; but this information is still difficult to interpret and important investments are required for the technology to become accessible for routine investigations.

  14. Spread of Methicillin-Resistant Staphylococcus aureus in a Large Tertiary NICU: Network Analysis

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    Geva, Alon; Wright, Sharon B.; Baldini, Linda M.; Smallcomb, Jane A.; Safran, Charles

    2011-01-01

    OBJECTIVE: Methicillin-resistant Staphylococcus aureus (MRSA) colonization in NICUs increases the risk of nosocomial infection. Network analysis provides tools to examine the interactions among patients and staff members that put patients at risk of colonization. METHODS: Data from MRSA surveillance cultures were combined with patient room locations, nursing assignments, and sibship information to create patient- and unit-based networks. Multivariate models were constructed to quantify the risk of incident MRSA colonization as a function of exposure to MRSA-colonized infants in these networks. RESULTS: A MRSA-negative infant in the NICU simultaneously with a MRSA-positive infant had higher odds of becoming colonized when the colonized infant was a sibling, compared with an unrelated patient (odds ratio: 8.8 [95% confidence interval [CI]: 5.3–14.8]). Although knowing that a patient was MRSA-positive and was placed on contact precautions reduced the overall odds of another patient becoming colonized by 35% (95% CI: 20%–47%), having a nurse in common with that patient still increased the odds of colonization by 43% (95% CI: 14%–80%). Normalized group degree centrality, a unitwide network measure of connectedness between colonized and uncolonized patients, was a significant predictor of incident MRSA cases (odds ratio: 18.1 [95% CI: 3.6–90.0]). CONCLUSIONS: Despite current infection-control strategies, patients remain at significant risk of MRSA colonization from MRSA-positive siblings and from other patients with whom they share nursing care. Strategies that minimize the frequency of staff members caring for both colonized and uncolonized infants may be beneficial in reducing the spread of MRSA colonization. PMID:22007011

  15. Evolutionarily distinct bacteriophage endolysins featuring conserved peptidoglycan cleavage sites protect mice from MRSA infection

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    Staphylococcus aureus is a Gram-positive pathogen relevant for both human and animal health. With multi-drug resistant S. aureus strains becoming increasingly prevalent, alternative therapeutics are urgently needed. Bacteriophage endolysins (peptidoglycan hydrolases, PGH) are capable of killing Gra...

  16. Structure of Bordetella pertussis peptidoglycan

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    Folkening, W.J.; Nogami, W.; Martin, S.A.; Rosenthal, R.S.

    1987-09-01

    Bordetella pertussis Tohama phases I and III were grown to the late-exponential phase in liquid medium containing (/sup 3/H)diaminopimelic acid and treated by a hot (96/sup 0/C) sodium dodecyl sulfate extraction procedure. Washed sodium dodecyl sulfate-insoluble residue from phases I and III consisted of complexes containing protein (ca. 40%) and peptidoglycan (60/sup 6/). Subsequent treatment with proteinase K yielded purified peptidoglycan which contained N-acetylglucosamine, N-acetylmuramic acid, alanine, glutamic acid, and diaminopimelic acid in molar ratios of 1:1:2:1:1 and <2% protein. Radiochemical analyses indicated that /sup 3/H added in diaminopimelic acid was present in peptidoglycan-protein complexes and purified peptidoglycan as diaminopimelic acid exclusively and that pertussis peptidoglycan was not O acetylated, consistent with it being degraded completely by hen egg white lysozyme. Muramidase-derived disaccharide peptide monomers and peptide-cross-linked dimers and higher oligomers were isolated by molecular-sieve chromatography; from the distribution of these peptidoglycan fragments, the extent of peptide cross-linking of both phase I and III peptidoglycan was calculated to be ca. 48%. Unambiguous determination of the structure of muramidase-derived pepidoglycan fragments by fast atom bombardment-mass spectrometry and tandem mass spectrometry indicated that the pertussis peptidoglycan monomer fraction was surprisingly homogeneous, consisting of >95% N-acetylglucosaminyl-N-acetylmuramyl-alanyl-glutamyl-diaminopimelyl-alanine.

  17. High Prevalence of Panton-Valentine Leukocidin (PVL) Genes in Nosocomial-Acquired Staphylococcus aureus Isolated from Tertiary Care Hospitals in Nepal

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    Shrestha, Bidya; Singh, Winny; Raj, V. Samuel; Pokhrel, Bharat Mani; Mohapatra, Tribhuban Mohan

    2014-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) carrying the important virulence determinant, Panton-Valentine leukocidin (PVL), is an emerging infectious pathogen associated with skin and soft tissue infections as well as life-threatening invasive diseases. In carrying out the first PVL prevalence study in Nepal, we screened 73 nosocomial isolates of S. aureus from 2 tertiary care Nepali hospitals and obtained an overall PVL-positivity rate of 35.6% among the hospital isolates: 26.1% of MRSA and 51.9% of methicillin sensitive S. aureus (MSSA) isolates were found to be positive for the PVL genes. PVL prevalence was not associated with a specific (i) infection site, (ii) age group, or (iii) hospital of origin. It was found to be positively associated with heterogeneous MRSA (73.3%) compared to homogeneous MRSA (3.2%) and MSSA (51.9%); negatively associated with multiresistant MRSA (22%) compared to nonmultiresistant MRSA (60%) and MSSA (51.9%); and positively associated with macrolide-streptogramin B resistance (93.8%) compared to macrolide-lincosamide-streptogramin B resistance (0%) and no-resistance (45.8%) types. Macrolide-streptogramin B resistance was confirmed by the presence of msr(A) gene. Restriction pattern analyses provided evidence to support the circulation of a limited number of clones of PVL-positive MRSA, arguing for the adaptability of these isolates to a hospital setting. PMID:25045702

  18. Peptidoglycan hydrolase fusions maintain their parental specificities.

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    Donovan, David M; Dong, Shengli; Garrett, Wes; Rousseau, Geneviève M; Moineau, Sylvain; Pritchard, David G

    2006-04-01

    The increased incidence of bacterial antibiotic resistance has led to a renewed search for novel antimicrobials. Avoiding the use of broad-range antimicrobials through the use of specific peptidoglycan hydrolases (endolysins) might reduce the incidence of antibiotic-resistant pathogens worldwide. Staphylococcus aureus and Streptococcus agalactiae are human pathogens and also cause mastitis in dairy cattle. The ultimate goal of this work is to create transgenic cattle that are resistant to mastitis through the expression of an antimicrobial protein(s) in their milk. Toward this end, two novel antimicrobials were produced. The (i) full-length and (ii) 182-amino-acid, C-terminally truncated S. agalactiae bacteriophage B30 endolysins were fused to the mature lysostaphin protein of Staphylococcus simulans. Both fusions display lytic specificity for streptococcal pathogens and S. aureus. The full lytic ability of the truncated B30 protein also suggests that the SH3b domain at the C terminus is dispensable. The fusions are active in a milk-like environment. They are also active against some lactic acid bacteria used to make cheese and yogurt, but their lytic activity is destroyed by pasteurization (63 degrees C for 30 min). Immunohistochemical studies indicated that the fusion proteins can be expressed in cultured mammalian cells with no obvious deleterious effects on the cells, making it a strong candidate for use in future transgenic mice and cattle. Since the fusion peptidoglycan hydrolase also kills multiple human pathogens, it also may prove useful as a highly selective, multipathogen-targeting antimicrobial agent that could potentially reduce the use of broad-range antibiotics in fighting clinical infections.

  19. Association of virulence genes with mecA gene in Staphylococcus aureus isolates from Tertiary Hospitals in Nigeria

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    Oyebode Armstrong Terry Alli

    2015-01-01

    Full Text Available Introduction: Staphylococcus aureus is the etiological agent for a wide range of human infections, and its pathogenicity largely depends on various virulence factors associated with adherence, evasion of the immune system and damage of the host. This study determined the prevalence of methicillin-resistant S. aureus (MRSA and some selected virulence genes in clinical isolates of S. aureus from South-Western Nigeria. Materials and Methods: The antibiotic susceptibility of 156 S. aureus isolates to various antibiotics was determined. Moreover, polymerase chain reaction detection of the mecA gene was performed including SCCmec typing, and the isolates were screened for selected genes (alpha hemolysin [hla], intracellular adhesion A [icaA], Panton-Valentine leukocidin [PVL], fibronectin binding protein A [fnbA], bone sialoprotein binding protein [bbp], exfoliative toxin A [eta], exfoliative toxin B [etb], and collagen binding adhesion [cna] associated with virulence. Results: The prevalence of mecA gene was 42.3% (66 out of 156 S. aureus, and SCCmec typing showed that 24 (36.4% carried the SCCmec II element, 4 (6.1% with type III, 10 (15.2% with SCCmec IV, and 28 (42.4% harbored type V. The proportion of S. aureus with the following genes was ascertained: Hla (55.1%, icaA (42.3%, PVL (34.6%, fnbA (8.3%, bbp (4.5%, and eta (3.8%. All the isolates were etb and cna negative. The prevalence of the PVL gene in methicillin susceptible Staphylococcus aureus (MSSA was 53.3% compared with 9.1% of MRSA. An association between virulence genes (eta and icaA and mecA positive S. aureus; and significant difference in the distribution of virulence genes in in-patients and out-patients were found. The MRSA strains in South-Western Nigeria were dominated by SCCmec II and SCCmec V. Conclusion: The study concluded that there is a high prevalence of MRSA in Nigeria with association of eta and icaA genes with mecA gene in S. aureus isolates.

  20. Antibiotic sensitivity pattern of Staphylococcus aureus from clinical isolates in a tertiary health institution in Kano, Northwestern Nigeria

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    Nwankwo Emmanuel Onwubiko

    2011-01-01

    Full Text Available BACKGROUND: The importance of Staphylococcus aureus as a persistent nosocomial and community acquired pathogen has become a global health concern. It has a remarkable capability of evolving different mechanisms of resistance to most antimicrobial agents. The aim of the present study is to establish the incidence of S. aureus in clinical specimens and its antibiotic sensitivity pattern to various antibiotics in this locality. METHODS: One hundred and fifty consecutive isolates of S. aureus obtained from various clinical specimens between January and December 2009 sent to the Medical Microbiology Laboratory Department of Aminu Kano Teaching Hospital (AKTH were confirmed by standard bacteriological procedures. Antibiotic sensitivity pattern was carried out by disc diffusion method. RESULTS: The age group with the highest number of isolates was (0-10yrs while wound infection had the highest frequency of S. aureus isolates (30.7% in the study. Males (62.0% were more infected than females (38.0%. The sensitivity pattern of S. aureus to the following antibiotics; Gentamicin, Amoxycillin/clavulanate, Streptomycin, Cloxacillin, Erythromycin, Chloramphenicol, Cotrimoxazole, Tetracycline, Penicillin, Ciprofloxacin, Ofloxacin, Levofloxacin, Ceftriaxone, Amoxycillin and vancomycin were 92.4%, 63.0%, 44.2%, 35.8%, 52.4%, 61.9%, 15.5%, 31.2%, 7.1%, 78.9%, 76.6%, 100%, 71.4%, 30.7% and 100% respectively. Methicillin resistant isolates were sensitive to Levofloxacin 93.7% and Ofloxacin 68.7%. CONCLUSION: The results of the present study show that the fluoroquinolones are effective in the management of Staphylococcus aureus infections including methicillin resistant strains in this environment.

  1. Genetic diversity of methicillin-resistant Staphylococcus aureus in a tertiary hospital in The Netherlands between 2002 and 2006

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    Nulens, E; Stobberingh, E E; Smeets, E; van Dessel, H; Welling, M A; Sebastian, S; van Tiel, F H; Beisser, P S; Deurenberg, R H

    2009-01-01

    The aim of this study was to investigate the methicillin-resistant Staphylococcus aureus (MRSA) clones isolated in a Dutch university hospital, situated near the borders of Belgium and Germany, between 2002 and 2006. MRSA strains (n = 175) were characterized using spa and SCCmec typing. The presence

  2. Mupirocin resistance in nasal carriage of Staphylococcus aureus among healthcare workers of a tertiary care rural hospital

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    Dardi Charan Kaur

    2014-01-01

    Full Text Available Introduction: Mupirocin (pseudomonic acid A is a topical antimicrobial agent with excellent antistaphylococcal and antistreptococcal activity. A nasal formulation is approved by the United States Food and Drug Administration for eradicating nasal carriage in adult patients as well as in health care personnel. Resistance to mupirocin has already been reported worldwide. The increasing prevalence of mupirocin resistance among Staphylococcus aureus and coagulase-negative Staphylococcus (CoNS species could be an important threat to the future use of mupirocin against methicillin-resistant S. aureus (MRSA. Thus, this study was carried out to find the prevalence of mupirocin resistance in S. aureus and CoNS by disc diffusion and to determine the rates of high-level and low-level mupirocin resistance in S. aureus and CoNS by disc diffusion. Materials and Methods: A total of 140 healthcare workers (HCWs (doctor, nursing staff, housekeeping staff were randomly selected. S. aureus and CoNS isolates were tested for mupirocin resistance by the disk diffusion method using 5 μg and 200 μg mupirocin discs. MRSA isolates were tested for antibiotics by Kirby-Bauer disc-diffusion method as per Clinical and Laboratory Standards Institute guidelines. Results: Out of 140 nasal swabs collected from HCWs, S. aureus was isolated in 38 (27.14%, and CoNS was isolated in 73 (52.14%. MRSA was isolated in 20 (14.28% and methicillin-resistant coagulase-negative Staphylococci (MRCoNS in 34 (24.29%. Methicillin-sensitive S. aureus (MSSA and MSCoNS isolates were 100% sensitive to mupirocin, but two isolates from MRSA (1.43% and five from MRCoNS (3.57% were mupirocin resistant. Conclusion: The presence of mupirocin resistance in MRSA and MRCoNS is a cause for concern. It could be limited by regular surveillance and effective infection control initiatives so to inform health care facilities to guide therapeutic and prophylactic use of mupirocin.

  3. A retrospective study of septic arthritis in a tertiary hospital in West Texas with high rates of methicillin-resistant Staphylococcus aureus infection.

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    Lim, Sian Yik; Pannikath, Deepa; Nugent, Kenneth

    2015-07-01

    Septic arthritis is an important concern for rheumatologists in the evaluation of joint disease. Very few studies have addressed the microbiologic epidemiology and outcomes of septic arthritis in the USA since the year 2000. We performed a retrospective study of septic arthritis in a tertiary hospital in West Texas from the year 2000 to 2013. We recorded data on patient demographics, microbiologic etiology, treatment patterns, and outcomes. The most common causative organisms were Staphylococcus aureus and Streptococcus spp. Methicillin-resistant Staphylococcus aureus (MRSA) caused septic arthritis in 22.6 % of the cases. MRSA septic arthritis was associated with low rates of adequate empiric antimicrobial therapy. The mortality due to sepsis in our study was 5.5 %. Patients with septic arthritis had a mean length of stay of 13.5 ± 12.1 days and required 2.1 ± 1.4 joint operations. Many patients (29.2 %) had readmissions due to complications, and these patients had high rates of home health utilization and transfers to other facilities post hospital discharge. In our logistic regression analysis model, factors associated with poor outcomes in septic arthritis were MRSA, older age, and prosthetic joint infection. Septic arthritis is associated with significant mortality, morbidity, and health care costs, and more studies are needed to improve outcomes, especially considering the increasing rates of MRSA as the pathogen.

  4. Nine years′ review on preseptal and orbital cellulitis and emergence of community-acquired methicillin-resistant Staphylococus aureus in a tertiary hospital in India

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    Datta G Pandian

    2011-01-01

    Full Text Available Context: Preseptal cellulitis is the commonest orbital disease which frequently needs to be differentiated from orbital cellulitis. Prompt diagnosis and treatment with appropriate antibiotics can prevent vision loss and life-threatening complications of orbital cellulitis. Aims: To describe the clinical profile of cases with preseptal and orbital cellulitis admitted to a tertiary care hospital during a period of nine years. The causative organisms and the clinical outcome were analyzed. Settings and Design : Retrospective descriptive case study done in a tertiary care hospital in South India. Material and Methods: The in-patient records of patients with preseptal and orbital cellulitis were reviewed from 1998 to 2006. The factors reviewed included ocular findings aiding in the distinction of the two clinical conditions, the duration of symptoms, the duration of hospital stay, microbiological culture report of pus or wound swab, blood culture, drugs used for treatment, the response to therapy and complications. Statistical Analysis Used: Descriptive analysis. Results: One hundred and ten cases, 77 patients with preseptal cellulitis and 33 patients with orbital cellulitis were reviewed. Five percent of children and 21% of adults presented with cutaneous anthrax contributing to preseptal cellulitis. Thirty-nine percent cases with orbital cellulitis were caused by methicillin-resistant Staphylococcus aureus (MRSA. Conclusions: This study has helped in identifying organisms which cause orbital infections, especially community-acquired MRSA. It indicates the need for modifying our empirical antimicrobial therapy, especially in orbital cellulitis.

  5. CURRENT SENSITIVITY PATTERN OF MRSA (METHICILLIN RESISTANT STAPH AUREUS IN A TERTIARY CARE ORTHOPAEDIC HOSPITAL IN KASHMIR (J&K

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    Shaika

    2016-02-01

    Full Text Available In view of the reported emergence of vancomycin resistance in MRSA from the state and the country as a whole we evaluated the pattern of culture and sensitivity on 160 samples from Orthopaedic Department over a period of one year between Nov 2014 and Nov 2015. These belonged to 111 males and 49 females with different aetiologies. Using standard protocols for the culture, 84 (52% samples grew no organisms while Staph aureus was grown in 43 samples (26.8% and gram negative organism in 28 and 5 samples grew mixed organism. Out of these 43 isolates of Staph aureus, MRSA was grown in 32 (74.4% and MSSA in 11 (25.6%. These belonged to 23 (71.8% males and 9 (28.1% females. Majority of MRSA were grown from the patients of acute osteomyelitis and operated fractures (63.3%. Linezolid showed highest sensitivity (100% followed by Vancomycin (96.8%, Clindamycin (37.5%, erythromycin (21%, Amikacin (21%, Levofloxacin (9.3%, cotrimoxazole (9.3% and ciprofloxacin (3.1%. By diffusion method 6 positive cultures depicted doubtful sensitivity pattern for vancomycin (18.75%. However, on further analysis using MIC only one isolate (3.3% showed intermediate resistance to vancomycin; 12 cultures (37.5% were sensitive to vancomycin and linezolid only. The presence of vancomycin resistance calls for a watchful approach towards these infections and an extensive study to better define the problem.

  6. Modified PAP method to detect heteroresistance to vancomycin among methicillin resistant Staphylococcus aureus isolates at a tertiary care hospital

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    Iyer R

    2008-01-01

    Full Text Available This study was an attempt at developing, establishing, validating and comparing the modified PAP method for detection of hetero-vancomycin resistant Staphylococcus aureus (h-VRSA with the routine antimicrobial susceptibility testing (using the BSAC standardized disc diffusion method, minimum inhibitory concentrations of vancomycin using standard E-test methodology and the Hiramatsu′s screening method. A total of 50 methicillin resistant Staphylococcus aureus obtained from various clinical specimens, along with the Mu 3 and Mu 50 strains as controls, were studied. No VRSA isolates were obtained. However, four of the test strains were positive by the Hiramatsu′s screening method, of which only one isolate could be confirmed by the modified PAP analysis method. This isolate was a coloniser from the drain fluid of a liver transplant recipient. The sensitivity, specificity, positive predictive value and the overall efficiency of the Hiramatsu′s screening method with the modified PAP analysis as the gold standard were found to be 100, 93.8, 25 and 94%, respectively. It is very essential for clinical laboratories to screen for h-VRSA, given the increasing use of glycopeptide antibiotics in therapy and the potential for failed therapy in patients infected with these strains.

  7. Correlation of mupirocin resistance with biofilm production in methicillin-resistant Staphylococcus aureus from surgical site infections in a tertiary centre, Egypt.

    Science.gov (United States)

    Barakat, Ghada I; Nabil, Yasmin M

    2016-03-01

    The aim of this study was to detect mupirocin-resistant isolates from pus/wound swabs taken postoperatively in a tertiary centre in Egypt and to determine their ability to form biofilm in order to establish its correlation with mupirocin resistance. This was a prospective study including 513pus/wound swabs from patients suffering from postoperative surgical site infections over the period July 2013-January 2015. Samples were cultured and isolates were identified by coagulase activity, DNase test, mannitol fermentation by mannitol salt agar followed by API Staph 32. Oxacillin agar screen test, agar dilution test for mupirocin, and mupA gene detection by PCR were performed for all methicillin-resistant Staphylococcus aureus (MRSA) isolates. Biofilm detection was carried out by the microtitre plate and Congo red agar methods. Of the 161 S. aureus isolates identified, 73 (45.3%) were MRSA, among which 82.2% were mupirocin-susceptible and 17.8% were mupirocin-resistant. Among the resistant isolates, 38.5% showed low-level resistance and 61.5% were high-level mupirocin-resistant. The mupA gene was detected in 75.0% of high-level mupirocin-resistant strains and in none of the low-level mupirocin-resistant strains. Among the mupirocin-susceptible isolates, 95.0% were biofilm-producers and 5.0% did not produce biofilm. All mupirocin-resistant isolates produced biofilm. Moreover, 15.3% of high-level mupirocin-resistant strains were negative for the mupA gene but showed evidence of biofilm formation. In conclusion, biofilm formation may be suggested to play a role in mupirocin resistance besides the presence of a genetic element encoding abnormal isoleucyl-tRNA synthetase, however further studies are needed to confirm these findings. PMID:27436387

  8. Medical and household characteristics associated with methicillin resistant Staphylococcus aureus nasal carriage among patients admitted to a rural tertiary care hospital.

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    Leah Schinasi

    Full Text Available BACKGROUND: Methicillin resistant Staphylococcus aureus (MRSA poses a threat to patient safety and public health. Understanding how MRSA is acquired is important for prevention efforts. This study investigates risk factors for MRSA nasal carriage among patients at an eastern North Carolina hospital in 2011. METHODS: Using a case-control design, hospitalized patients ages 18 - 65 years were enrolled between July 25, 2011 and December 15, 2011 at Vidant Medical Center, a tertiary care hospital that screens all admitted patients for nasal MRSA carriage. Cases, defined as MRSA nasal carriers, were age and gender matched to controls, non-MRSA carriers. In-hospital interviews were conducted, and medical records were reviewed to obtain information on medical and household exposures. Multivariable conditional logistic regression was used to derive odds ratio (OR estimates of association between MRSA carriage and medical and household exposures. RESULTS: In total, 117 cases and 119 controls were recruited to participate. Risk factors for MRSA carriage included having household members who took antibiotics or were hospitalized (OR: 3.27; 95% Confidence Interval (CI: 1.24-8.57 and prior hospitalization with a positive MRSA screen (OR: 3.21; 95% CI: 1.12-9.23. A lower proportion of cases than controls were previously hospitalized without a past positive MRSA screen (OR: 0.40; 95% CI: 0.19-0.87. CONCLUSION: These findings suggest that household exposures are important determinants of MRSA nasal carriage in hospitalized patients screened at admission.

  9. The Prevalence of Nasal Carriage of Staphylococcus Aureus Among Healthcare Workers at a Tertiary Care Hospital in Assam with Special Reference to MRSA

    OpenAIRE

    Rongpharpi, Sharon Rainy; Hazarika, Naba Kumar; Kalita, Hitesh

    2013-01-01

    Background: The recent years have witnessed the increasing resistance of Staphylococcus aureus to many antimicrobial agents. The most notable example is the emergence of Methicillin-resistant Staphylococcus aureus (MRSA), which was reported just one year after the launch of methicillin. The ecological niches of the S. aureus strains are the anterior nares. The identification of Staphylococcus aureus by using a proper antibiogram and the detection of methicillin resistant Staphylococcus aureus...

  10. Prevalence and clinical prognosis of heteroresistant vancomycin-intermediate Staphylococcus aureus in a tertiary care center in China

    Institute of Scientific and Technical Information of China (English)

    WANG Yan; HU Yun-jian; AI Xiao-man; XU Hong-tao; SUN Tie-ying

    2013-01-01

    Background The emergence of heteroresistant vancomycin-intermediate Staphylococcus aureus (hVISA) is increasingly challenging the methods for detection in diagnostic microbiology laboratories.However,the report of hVISA is rare in China.This study summarizes the prevalence and clinical features associated with hVlSA infections at our institution and the local impact they have on clinical outcome.Methods A total of 122 methicillin-resistant Staphylococcus aureus (MRSA) isolates which were of the causative pathogens were collected.One hundred and two patients for whom we had full information of MRSA pneumonia were included.Isolates of MRSA were collected using PCR to detect the mecA gene.Both Etest and macro Etest were performed to screen for hVISA.The Staphylococcal chromosome cassette mec (SCCmec) types were determined by multiplex PCR strategy.Logistic regression analysis was used to determine the risk factors.Results Among the 122 MRSA isolates collected,25 (20.5%) strains were identified as hVISA.There were 119 (97.5%)SCCmec Ⅲ isolates,two (1.6%) SCCmec Ⅱ isolates,and one (0.8%) SCCmec V isolate.The 30-day mortality of MRSA-hospital acquired pneumonia (HAP) was 37.3%,and 62.5% for hVISA-HAP.Vancomycin treatment was the independent risk factor of hVlSA.Factors independently associated with 30-day mortality in all patients were acute physiology and Chronic Health Evaluation (APACHE) Ⅱ score >20,multiple lobe lesions,and creatinine clearance rate (CCR) <15 ml/min.Conclusions The prevalence of hVISA is 20.5% at our institution.hVISA-HAP patients had a poor clinical outcome.Vancomycin treatment was the independent predictors for hVISA infection.Factors independently associated with 30-day mortality in all patients were APACHE Ⅱ score >20,multiple lobe lesions and CCR <15 ml/min.

  11. Cefazolin versus Nafcillin for Methicillin-Sensitive Staphylococcus aureus Bloodstream Infection in a California Tertiary Medical Center.

    Science.gov (United States)

    Pollett, S; Baxi, S M; Rutherford, G W; Doernberg, S B; Bacchetti, P; Chambers, H F

    2016-08-01

    Recent observational studies have suggested possible reductions in mortality in patients receiving cefazolin versus antistaphylococcal penicillins. We examined 90-day mortality in patients receiving cefazolin compared to nafcillin for methicillin-susceptible Staphylococcus aureus (MSSA) bloodstream infection (BSI). We identified persons with MSSA BSI admitted to San Francisco General Hospital from January 2008 to July 2013 through a hospital-wide infection surveillance system and confirmed 90-day mortality using U.S. national vital registries. We included persons receiving cefazolin or nafcillin as the predominant intravenous antimicrobial agent; all participants received inpatient Infectious Diseases service consultation. We estimated the association between receipt of cefazolin and 90-day risk of death by multivariate logistic regression, including a propensity score for receiving cefazolin as the second predictor. Of 230 MSSA BSI cases, 30 received nafcillin and 70 received cefazolin as the predominant antimicrobial; 10 died within 90 days, 5 from each group. Unadjusted analysis showed substantial but not statistically significant reduced odds of death in those receiving cefazolin (odds ratio, 0.38; 95% confidence interval [CI], 0.10 to 1.44). Multivariate analysis with propensity scores found a similar adjusted odds ratio (0.40; 95% CI, 0.09 to 1.74; P = 0.22). We found a large reduction in 90-day mortality in those receiving cefazolin compared to nafcillin for MSSA BSI, but this finding was not statistically significant. The magnitude of effect seen in this and other studies justifies further study. PMID:27216053

  12. Prevalence of methicillin-resistant Staphylococcus aureus among hospital healthcare workers in a tertiary care hospital: A cross-sectional study

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    Kannan Sridharan

    2016-01-01

    Full Text Available Background: Methicillin-resistant Staphylococcus aureus (MRSA is one of the most common hospital-acquired infections associated with a significant morbidity and mortality. Healthcare workers (HCWs act as carriers for MRSA and transmit the organism across individuals. Hence, we undertook this study to assess the prevalence of MRSA among HCWs in a tertiary care hospital and their hand washing hygienic practices. Materials and Methods: A cross-sectional study between March and November 2014 was conducted. Dry swabs were taken from the nasal mucosal membrane, both the palms, web space between the fingers from each of the participants and were subsequently cultured on mannitol salt agar and antibiotic susceptibility to methicillin was assessed using Kirby-Bauer disc diffusion method using cefoxitin. In addition, information on demographics, occupation, and use of antiseptics were collected from the study participants. Results: A total of 17/150 (11.3% were found to be MRSA positive of which 10 were staff nurses, three each were laboratory technicians and class IV employees and one was a doctor. Of the 17, 11 (64.7% had shown growth from nasal swabs, 5 (29.4% from digital and 1 (5.9% in both the regions. Of them, 8/15 (53.3% reported the use of only soap for hand washing whereas 7/15 (46.7% were using soap and hand sanitizers and the remaining two not responded to this question. Only 9/15 (60% frequently washed their hands, and the rest rarely did. Conclusion: More awareness and training sessions on the importance of MRSA and hand hygienic measures to contain the carrier status of MRSA among hospital care workers is warranted.

  13. A case report of Small Colony variant of Staphylococcus aureus isolated from a patient with chronic oesteomyelitis in a tertiary care hospital of eastern India

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    Kalidas Rit

    2014-01-01

    Full Text Available Small colony variants (SCVs of Staphylococcus aureus often cause persistant and relapsing infections. SCVs are characterized by a strong reduction in growth rate, atypical colony morphology and unusual biochemical characteristics. We here report a case of chronic oesteomyelitis caused by SCV of Staphyloccous aureus in a middle aged male patient.

  14. Living with an imperfect cell wall : compensation of femAB inactivation in Staphylococcus aureus

    NARCIS (Netherlands)

    Hübscher, Judith; Jansen, Andrea; Kotte, Oliver; Schäfer, Juliane; Majcherczyk, Paul A.; Harris, Llinos G.; Bierbaum, Gabriele; Heinemann, Matthias; Berger-Bächi, Brigitte

    2007-01-01

    Background: Synthesis of the Staphylococcus aureus peptidoglycan pentaglycine interpeptide bridge is catalyzed by the nonribosomal peptidyl transferases FemX, FemA and FemB. Inactivation of the femAB operon reduces the interpeptide to a monoglycine, leading to a poorly crosslinked peptidoglycan. fem

  15. Study of the cell wall of Staphylococcus aureus and its sensitivity to enzybiotics

    OpenAIRE

    Čmelík, R. (Richard); Melková, K.; Kobzová, Š.; Janda, L

    2015-01-01

    The endolysin resistant and sensitive strains of Staphylococcus aureus were compared by means of LC-MS based structural analysis of peptidoglycan isolated from their cell walls. The structural explanation of the resistance was suggested.

  16. Is methicillin-resistant Staphylococcus aureus involved in community acquired skin and soft tissue infections?: Experience from a tertiary care centre in Mumbai

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    R S Phakade

    2012-01-01

    Full Text Available Background: To improve the empiric antimicrobial therapy of community-acquired (CA skin and soft tissue infections (SSTIs, it is necessary to generate data on the current spectrum and susceptibility profile of associated bacteria. CA methicillin-resistant Staphylococcus aureus (CA MRSA is increasingly being reported in SSTIs in India and globally. Aims: The present study was undertaken to determine the bacterial profile of CA-SSTIs, to know the contribution of MRSA in these infections, to determine inducible clindamycin resistance in S. aureus and to compare the resistance patterns of isolates from hospital-acquired (HA SSTIs. Materials and Methods: Eight hundred and twenty patients with CA SSTIs were prospectively studied. Pus samples were cultured and antimicrobial susceptibility pattern determined. Inducible clindamycin resistance was detected by D-test. Laboratory records were analyzed retrospectively to generate data on HA SSTIs. Results: 619 isolates were recovered in CA-SSTIs, of which S. aureus (73% and Streptococci (12% were the most common. Pseudomonas aeruginosa (28% and Acinetobacter spp (18% were the predominant HA-SSTI pathogens. Susceptibility of CA S. aureus to antibiotics tested was, penicillin (6%, co-trimoxazole (20%, ciprofloxacin (37%, cefazolin (100%, erythromycin (84%, clindamycin (97%, gentamicin (94% and fusidic acid (95%. No MRSA was found in CA SSTIs whereas 45% of HA S. aureus strains were methicillin-resistant. HA strains demonstrated significantly higher resistance as compared to their CA counterparts (P<0.001. D test was positive in 22% of CA S. aureus tested. Conclusions: In CA SSTIs, methicillin-susceptible S. aureus is the predominant pathogen. Penicillinase-resistant penicillins, clindamycin and erythromycin in that order can be used as suitable antimicrobials for empiric therapy. D test should be carried out routinely. No CA MRSA was detected in the present series.

  17. Associated risk factors and pulsed field gel electrophoresis of nasal isolates of Staphylococcus aureus from medical students in a tertiary hospital in Lagos, Nigeria

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    Solayide A. Adesida

    2007-02-01

    Full Text Available Staphylococcus aureus infections are growing problems worldwide with important implications in hospitals. The organism is normally present in the nasal vestibule of about 35% of apparently healthy individuals and its carriage varies between different ethnic and age groups. Staphylococcal nasal carriage among health workers is particularly important to establish new clones and track origin of infections during outbreak situations. To determine the carriage rate and compare the pulsed field gel patterns of the strains, nasal swabs were collected from 185 medical students in a teaching hospital in Lagos, Nigeria. Isolates of S. aureus were tested for heamolysin production, methicillin sensitivity and Pulsed Field Gel Electrophoresis (PFGE was performed. The results showed S.aureus nasal carrier rate of 14% with significant rate among males compared to females. All the isolates produced heamolysin. Antibiotic susceptibility pattern revealed that majority of the isolates was susceptible. Five strains (19% harboured resistant determinants to penicillin and tetracycline. None of the strains was resistant to methicillin. 44% of the isolates typed by PFGE had type B, the most predominant pulsotype. PFGE A clone exhibited a single resistance phenotype suggesting a strong clonal relationship that could punctual an outbreak in the hospital. The results speculate that nasal carriage among medical personnel could be a function of various risk factors. Personal hygiene and behaviour may however be the means to reducing colonization and spread of S.aureus in our hospitals.

  18. Activities and regulation of peptidoglycan synthases

    NARCIS (Netherlands)

    Egan, Alexander J F; Biboy, Jacob; van 't Veer, Inge; Breukink, Eefjan; Vollmer, Waldemar

    2015-01-01

    Peptidoglycan (PG) is an essential component in the cell wall of nearly all bacteria, forming a continuous, mesh-like structure, called the sacculus, around the cytoplasmic membrane to protect the cell from bursting by its turgor. Although PG synthases, the penicillin-binding proteins (PBPs), have b

  19. A retrospective analysis of practice patterns in the treatment of methicillin-resistant Staphylococcus aureus skin and soft tissue infections at three Canadian tertiary care centres

    OpenAIRE

    John M Conly; Stiver, H. Grant; Weiss, Karl A.; Becker, Debbie L; Rosner, Andrew J; Miller, Elizabeth

    2003-01-01

    BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) infections are increasingly being encountered and pose an increasing burden to the health care system in Canada.OBJECTIVE: To elucidate and characterize the factors influencing the current MRSA treatment patterns in patients with skin and soft tissue infections (SSTIs) before linezolid became available on the Canadian market.METHODS: A retrospective study collected demographic, treatment and resource use data on patients hospitali...

  20. Screening for methicillin-resistant Staphylococcus aureus carriers among patients and health care workers of a tertiary care hospital in south India

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    Mathanraj S

    2009-01-01

    Full Text Available A total of 200 subjects were screened for carriage of methicillin-resistant Staphylococcus aureus (MRSA at different sites using oxacillin blood agar and mannitol salt agar with oxacillin. Overall carriage rate was 8.5%, with the highest rate in inpatients (15.6% while the lowest was seen in health care workers (1.8%. The commonest site of colonization was the anterior nares. Oxacillin blood agar was found to be superior to mannitol salt agar with oxacillin for the isolation of MRSA. Male sex and prolonged hospital stay were found to be the major risk factors for MRSA colonization.

  1. Peptidoglycan Recycling in Gram-Positive Bacteria Is Crucial for Survival in Stationary Phase

    Science.gov (United States)

    Borisova, Marina; Gaupp, Rosmarie; Duckworth, Amanda; Schneider, Alexander; Dalügge, Désirée; Mühleck, Maraike; Deubel, Denise; Unsleber, Sandra; Yu, Wenqi; Muth, Günther; Bischoff, Markus; Götz, Friedrich

    2016-01-01

    ABSTRACT Peptidoglycan recycling is a metabolic process by which Gram-negative bacteria reutilize up to half of their cell wall within one generation during vegetative growth. Whether peptidoglycan recycling also occurs in Gram-positive bacteria has so far remained unclear. We show here that three Gram-positive model organisms, Staphylococcus aureus, Bacillus subtilis, and Streptomyces coelicolor, all recycle the sugar N-acetylmuramic acid (MurNAc) of their peptidoglycan during growth in rich medium. They possess MurNAc-6-phosphate (MurNAc-6P) etherase (MurQ in E. coli) enzymes, which are responsible for the intracellular conversion of MurNAc-6P to N-acetylglucosamine-6-phosphate and d-lactate. By applying mass spectrometry, we observed accumulation of MurNAc-6P in MurNAc-6P etherase deletion mutants but not in either the isogenic parental strains or complemented strains, suggesting that MurQ orthologs are required for the recycling of cell wall-derived MurNAc in these bacteria. Quantification of MurNAc-6P in ΔmurQ cells of S. aureus and B. subtilis revealed small amounts during exponential growth phase (0.19 nmol and 0.03 nmol, respectively, per ml of cells at an optical density at 600 nm [OD600] of 1) but large amounts during transition (0.56 nmol and 0.52 nmol) and stationary (0.53 nmol and 1.36 nmol) phases. The addition of MurNAc to ΔmurQ cultures greatly increased the levels of intracellular MurNAc-6P in all growth phases. The ΔmurQ mutants of S. aureus and B. subtilis showed no growth deficiency in rich medium compared to the growth of the respective parental strains, but intriguingly, they had a severe survival disadvantage in late stationary phase. Thus, although peptidoglycan recycling is apparently not essential for the growth of Gram-positive bacteria, it provides a benefit for long-term survival. PMID:27729505

  2. Analysis of Peptidoglycan Structure from Vegetative Cells of Bacillus subtilis 168 and Role of PBP 5 in Peptidoglycan Maturation

    OpenAIRE

    Atrih, Abdelmadjid; Bacher, Gerold; Allmaier, Günter; Williamson, Michael P; Foster, Simon J.

    1999-01-01

    The composition and fine structure of the vegetative cell wall peptidoglycan from Bacillus subtilis were determined by analysis of its constituent muropeptides. The structures of 39 muropeptides, representing 97% of the total peptidoglycan, were elucidated. About 99% analyzed muropeptides in B. subtilis vegetative cell peptidoglycan have the free carboxylic group of diaminopimelic acid amidated. Anhydromuropeptides and products missing a glucosamine at the nonreducing terminus account for 0.4...

  3. Evaluation of prevalence of low and high level mupirocin resistance in methicillin resistant staphylococcus aureus isolates at a tertiary care hospital

    International Nuclear Information System (INIS)

    To evaluate the trend of mupirocin resistance in MRSA, isolated at the Clinical Microbiology Laboratory of a tertiary care hospital. Methods: A total of 200 MRSA strains recovered over a 2 year period from various body sites were tested using the 5 and 200 mu g discs of mupirocin to detect its resistance. Results: High level and low level mupirocin resistance were detected in zero and 1 % of MRSA strains, respectively. Resistance to other non beta lactam antibiotics was also high. No MRSA strains were found to be resistant to vancomycin and tegicycline. Conclusion: Mupirocin resistance was found to be very low among local clinical isolates of MRSA. Its judicious use to decolonize nasal carriers should be promoted among hospitalized patients to avoid further transmission and infections due to prevalent endemic MRSA strains in any health care setting. Concomitantly, regular surveillance and effective infection control initiatives are desirable to reduce the incidence of health care associated infections due to MRSA and also of mupirocin resistance. (author)

  4. Living with an imperfect cell wall: compensation of femAB inactivation in Staphylococcus aureus.

    OpenAIRE

    Bierbaum Gabriele; Harris Llinos G; Majcherczyk Paul A; Schäfer Juliane; Kotte Oliver; Jansen Andrea; Hübscher Judith; Heinemann Matthias; Berger-Bächi Brigitte

    2007-01-01

    Abstract Background Synthesis of the Staphylococcus aureus peptidoglycan pentaglycine interpeptide bridge is catalyzed by the nonribosomal peptidyl transferases FemX, FemA and FemB. Inactivation of the femAB operon reduces the interpeptide to a monoglycine, leading to a poorly crosslinked peptidoglycan. femAB mutants show a reduced growth rate and are hypersusceptible to virtually all antibiotics, including methicillin, making FemAB a potential target to restore β-lactam susceptibility in met...

  5. Worrisome trends in rising minimum inhibitory concentration values of antibiotics against methicillin resistant Staphylococcus aureus - Insights from a tertiary care center, South India

    Directory of Open Access Journals (Sweden)

    Nagasundaram Niveditha

    2015-12-01

    Full Text Available ABSTRACT INTRODUCTION: Appearance of isolated reports of resistance to anti-methicillin-resistantStaphylococcus aureus (MRSA drugs is worrisome underscoring the need to continuously monitor the susceptibility of clinical MRSA isolates to these drugs. Hence, the present study is conducted to determine the susceptibility of MRSA isolates to various classes of anti-MRSA drugs such as vancomycin (glycopeptide, daptomycin (lipopeptide, tigecycline (glycylcycline, and linezolid (oxazolidinone to determine the MIC50 and MIC90 values, and to observe MIC creep over a three year period, if any, with respect to these drugs. METHODS: A total of 200 isolates of MRSA obtained from clinical specimens were included. MIC was determined by E-test for anti-MRSA antibiotics vancomycin, linezolid, daptomycin, and tigecycline. Non-parametric methods (Kruskal-Wallis and Chi-square test were used to assess MIC trends over time. In addition, MIC50 and MIC90 values were also calculated. RESULTS: No isolate was found resistant to vancomycin, daptomycin, or linezolid; five isolates were resistant to tigecycline. Seven VISA isolates were encountered with the MIC value for vancomycin of 4 µg/mL. MIC values for vancomycin, tigecycline, linezolid showed a definite increase over a 3-year period which was statistically significant with p-values <0.0001, 0.0032, 0.0242, respectively. When the percentage of isolates with a median MIC value less than or equal to that of the index year was calculated, the change was most striking with vancomycin. The proportion of isolates with higher MIC values was greater in 2014 than 2012 and 2013. CONCLUSION: MIC creep was notably observed with vancomycin, and to some extent with tigecycline and linezolid. Selection pressure may result in creeping MICs, which may herald the emergence of resistant organisms.

  6. [Chemical structure and immunomodulating activities of peptidoglycan from Actinobacillus actinomycetemcomitans].

    Science.gov (United States)

    Kinoshita, F

    1989-12-01

    The chemical structure and immunomodulating activities of the cell wall peptidoglycans isolated from Actinobacillus actinomycetemcomitans were investigated. Peptidoglycans were isolated from A. actinomycetemcomitans strains Y4 and ATCC 29522 by boiling in 4% sodium dodecyl sulfate and by digestion with pronase, trypsin and alpha-amylase. Analysis of amino acids and amino sugars of the peptidoglycans revealed that glucosamine, muramic acid, D-glutamic acid, D-alanine, and meso-2, 6-diaminopimelic acid (A2pm) were the principal components. Serine and glycine were not found. Dinitrophenylation method revealed that about half of A2pm residue had a free aminogroup, and analysis by hydrazinolysis showed that a small part of alanine and A2pm located at the C-terminal. The above results indicate that one of the amino groups of A2pm residue at one strand of the stem peptide subunit crosslinked to the carboxyl group of alanine of the neighboring strand. It was thus revealed that the peptidoglycans of A. actinomycetemcomitans belonged to the Al gamma type of the classification by Schleifer and Kandler. Peptidoglycans isolated from A. actinomycetemcmitans strain Y4 and ATCC 29522 were found to be definitely adjuvant-active in induction of delayed type hypersensitivity against ovalbumin when administered to guinea pigs as water-in oil emulsion and stimulation of increase serum antibody levels was found in both peptidoglycans. Regarding mitogenicity on splenocytes of BALB/c and BALB/c nu/nu mice, peptidoglycans from two strains of A. actinomycetemcomitans were markedly enhanced the uptake [3H] thymidine in dose of 10 micrograms/10(5) cells, however thymocytes were not reactive. Stimulation effects on peritoneal macrophages from a guinea pig to incorporation of 14C-glucosamin were not exhibited on addition of 100 micrograms of both peptidoglycans. These findings indicate that peptidoglycan of A. actinomycetemcomitans might eventually be responsible for destruction of periodontal

  7. Regulation of heme oxygenase-1 gene by peptidoglycan involves the interaction of Elk-1 and C/EBPα to increase expression

    OpenAIRE

    Hung, Chi-Chih; Liu, Xiaoli; Kwon, Min-Young; Kang, Young-Ho; Chung, Su Wol; Perrella, Mark A.

    2010-01-01

    Heme oxygenase (HO)-1 is a cytoprotective enzyme with anti-inflammatory properties. HO-1 is induced during a systemic inflammatory response, and expression of HO-1 is beneficial during sepsis of a Gram-positive source. Systemic infection from Gram-positive organisms has emerged as an important cause of sepsis, with Staphylococcus aureus as a common etiology. An important mediator of Gram-positive infections is peptidoglycan (PGN), a cell wall component of these organisms. Here, we demonstrate...

  8. Peptidoglycan Hydrolases for Control of Mastitis Pathogens

    Science.gov (United States)

    Bovine mastitis results in annual losses between $1.7 billion and $2 billion in the United States alone. Among the most relevant causative agents of this disease are Streptococcus agalactiae (Group B; GBS) and Streptococcus dysgalactiae (Group C; GCS) streptococci as well as Staphylococcus aureus. ...

  9. Identification of key peptidoglycan hydrolases for morphogenesis, autolysis, and peptidoglycan composition of Lactobacillus plantarum WCFS1

    Directory of Open Access Journals (Sweden)

    Rolain Thomas

    2012-10-01

    Full Text Available Abstract Background Lactobacillus plantarum is commonly used in industrial fermentation processes. Selected strains are also marketed as probiotics for their health beneficial effects. Although the functional role of peptidoglycan-degrading enzymes is increasingly documented to be important for a range of bacterial processes and host-microbe interactions, little is known about their functional roles in lactobacilli. This knowledge holds important potential for developing more robust strains resistant to autolysis under stress conditions as well as peptidoglycan engineering for a better understanding of the contribution of released muramyl-peptides as probiotic immunomodulators. Results Here, we explored the functional role of the predicted peptidoglycan hydrolase (PGH complement encoded in the genome of L. plantarum by systematic gene deletion. From twelve predicted PGH-encoding genes, nine could be individually inactivated and their corresponding mutant strains were characterized regarding their cell morphology, growth, and autolysis under various conditions. From this analysis, we identified two PGHs, the predicted N-acetylglucosaminidase Acm2 and NplC/P60 D,L-endopeptidase LytA, as key determinants in the morphology of L. plantarum. Acm2 was demonstrated to be required for the ultimate step of cell separation of daughter cells, whereas LytA appeared to be required for cell shape maintenance and cell-wall integrity. We also showed by autolysis experiments that both PGHs are involved in the global autolytic process with a dominant role for Acm2 in all tested conditions, identifying Acm2 as the major autolysin of L. plantarum WCFS1. In addition, Acm2 and the putative N-acetylmuramidase Lys2 were shown to play redundant roles in both cell separation and autolysis under stress conditions. Finally, the analysis of the peptidoglycan composition of Acm2- and LytA-deficient derivatives revealed their potential hydrolytic activities by the

  10. Differential response of immune-related genes to peptidoglycan and lipoteichoic acid challenge in vitro

    Science.gov (United States)

    Sulabh, Sourabh; Bhushan, Bharat; Panigrahi, Manjit; Verma, Ankita; Baba, Naseer Ahmad; Kumar, Pushpendra

    2016-01-01

    Aim: To study the effect of Staphylococcus aureus cell wall antigens, peptidoglycan (PGN) and lipoteichoic acid (LTA) challenge on immune cells present in bovine peripheral blood mononuclear cells (PBMCs). Materials and Methods: In this study, efforts have been made to investigate the effects of three combinations (10+10, 20+20 and 30+30 μg/ml) of PGN and LTA obtained from S. aureus. These antigens were used to challenge the bovine PBMCs. After 6 h of incubation quantitative, real time-polymerase chain reaction was used to study toll-like receptor 2 (TLR-2) and major cytokine mRNA expression in bovine PBMC challenged with three different antigen blends. Results: The results indicated that mRNA level of interferon gamma is influenced by the expression of TLR-2 gene. Tumor necrosis factor-alpha (TNF-α), interleukin 10 (IL-10), and IL-8 genes showed a maximum response at a dose of 10 μg of PGN and 10 μg of LTA challenge per ml of culture medium. The outcome also suggests that both IL-10 and IL-8 followed the expression pattern of TNF-α. Conclusion: A dose of 10 μg of PGN and 10 μg of LTA per ml of culture medium was found to be most suitable for challenging PBMC. PMID:27733800

  11. The Peptidoglycan Pattern of Staphylococcus carnosus TM300-Detailed Analysis and Variations Due to Genetic and Metabolic Influences.

    Science.gov (United States)

    Deibert, Julia; Kühner, Daniel; Stahl, Mark; Koeksoy, Elif; Bertsche, Ute

    2016-01-01

    The Gram-positive bacterium Staphylococcus carnosus (S. carnosus) TM300 is an apathogenic staphylococcal species commonly used in meat starter cultures. As with all Gram-positive bacteria, its cytoplasmic membrane is surrounded by a thick peptidoglycan (PGN) or murein sacculus consisting of several layers of glycan strands cross-linked by peptides. In contrast to pathogenic staphylococci, mainly Staphylococcus aureus (S. aureus), the chemical composition of S. carnosus PGN is not well studied so far. UPLC/MS analysis of enzymatically digested S. carnosus TM300 PGN revealed substantial differences in its composition compared to the known pattern of S. aureus. While in S. aureus the uncross-linked stem peptide consists of a pentapeptide, in S. carnosus, this part of the PGN is shortened to tripeptides. Furthermore, we found the PGN composition to vary when cells were incubated under certain conditions. The collective overproduction of HlyD, FtsE and FtsX-a putative protein complex interacting with penicillin-binding protein 2 (PBP2)-caused the reappearance of classical penta stem peptides. In addition, under high sugar conditions, tetra stem peptides occur due to overflow metabolism. This indicates that S. carnosus TM300 cells adapt to various conditions by modification of their PGN. PMID:27669322

  12. Cell wall monoglycine cross-bridges and methicillin hypersusceptibility in a femAB null mutant of methicillin-resistant Staphylococcus aureus.

    OpenAIRE

    Strandén, A M; Ehlert, K; Labischinski, H.; Berger-Bächi, B.

    1997-01-01

    The femAB operon is involved in the formation of the characteristic pentaglycine side chain of the staphylococcal peptidoglycan. Allele replacement of the femAB operon with the tetracycline resistance determinant tetK in a methicillin-resistant Staphylococcus aureus strain resulted in impaired growth, methicillin hypersusceptibility, and lysostaphin resistance. The usual pentaglycine cross-bridges were replaced by monoglycine bridges exclusively, and cross-linking of the peptidoglycan strands...

  13. Structural analysis of the contacts anchoring moenomycin to peptidoglycan glycosyltransferases and implications for antibiotic design

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Y.; Fuse, S.; Ostash, B.; Sliz, P.; Kahne, D.; Walker, S. (Harvard-Med); (Harvard)

    2008-08-20

    Peptidoglycan glycosyltransferases (PGTs), enzymes that catalyze the formation of the glycan chains of the bacterial cell wall, have tremendous potential as antibiotic targets. The moenomycins, a potent family of natural product antibiotics, are the only known active site inhibitors of the PGTs and serve as blueprints for the structure-based design of new antibacterials. A 2.8 {angstrom} structure of a Staphylococcus aureus PGT with moenomycin A bound in the active site appeared recently, potentially providing insight into substrate binding; however, the protein-ligand contacts were not analyzed in detail and the implications of the structure for inhibitor design were not addressed. We report here the 2.3 {angstrom} structure of a complex of neryl-moenomycin A bound to the PGT domain of Aquifex aeolicus PBP1A. The structure allows us to examine protein-ligand contacts in detail and implies that six conserved active site residues contact the centrally located F-ring phosphoglycerate portion of neryl-moenomycin A. A mutational analysis shows that all six residues play important roles in enzymatic activity. We suggest that small scaffolds that maintain these key contacts will serve as effective PGT inhibitors. To test this hypothesis, we have prepared, via heterologous expression of a subset of moenomycin biosynthetic genes, a novel moenomycin intermediate that maintains these six contacts but does not contain the putative minimal pharmacophore. This compound has comparable biological activity to the previously proposed minimal pharmacophore. The results reported here may facilitate the design of antibiotics targeted against peptidoglycan glycosyltransferases.

  14. Positive role of peptidoglycan breaks in lactococcal biofilm formation

    NARCIS (Netherlands)

    Mercier, C; Durrieu, C; Briandet, R; Domakova, E; Tremblay, J; Buist, G; Kulakauskas, S

    2002-01-01

    Bacterial attachment to solid matrices depends on adhesive molecules present on the cell surface. Here we establish a positive correlation between peptidoglycan (PG) breaks, rather than particular molecules, and biofilm-forming capacity in the Gram-positive bacterium Lactococcus lactis. The L. lacti

  15. Transmembrane transport of peptidoglycan precursors across model and bacterial membranes

    NARCIS (Netherlands)

    van Dam, V.; Sijbrandi, R.; Kol, M.A.; Swiezewska, E.; de Kruijff, B.; Breukink, E.J.

    2007-01-01

    Translocation of the peptidoglycan precursor Lipid II across the cytoplasmic membrane is a key step in bacterial cell wall synthesis, but hardly understood. Using NBD-labelled Lipid II, we showed by fluorescence and TLC assays that Lipid II transport does not occur spontaneously and is not induced b

  16. Arrangement of peptidoglycan in the cell wall of Staphylococcus spp.

    OpenAIRE

    Amako, K; Umeda, A.; Murata, K

    1982-01-01

    The arrangement of peptidoglycan in the cell wall of Staphylococcus was observed with the newly developed freeze-fracture technique, using n-octanol instead of water as the freezing medium. The replica of the trichloroacetic acid-extracted cell wall (TCA-wall) showed two areas. One of them has a concentric circular structure, a characteristic surface structure of the staphylococcal cell wall, and the other showed an irregular and rough surface. The chemical analysis of the wall revealed that ...

  17. Molecular investigations of peptidoglycan-binding proteins in Listeria monocytogenes

    OpenAIRE

    Machata, Silke

    2008-01-01

    The peptidoglycan layer of gram-positive bacteria contains various components that are crucial for interactions with the environment and for host invasion. In this study, the gram-positive pathogen Listeria monocytogenes was used to study the importance of three cell wall constituents for viability and virulence: the cell-wall degrading murein hydrolases (autolysins), teichoic acids and lipoproteins. The first section of this study addresses cell wall hydrolases and their role in deter-min...

  18. Analysis of Cell Wall Teichoic Acids in Staphylococcus aureus.

    Science.gov (United States)

    Covas, Gonçalo; Vaz, Filipa; Henriques, Gabriela; Pinho, Mariana G; Filipe, Sérgio R

    2016-01-01

    Most bacterial cells are surrounded by a surface composed mainly of peptidoglycan (PGN), a glycopolymer responsible for ensuring the bacterial shape and a telltale molecule that betrays the presence of bacteria to the host immune system. In Staphylococcus aureus, as in most gram-positive bacteria, peptidoglycan is concealed by covalently linked molecules of wall teichoic acids (WTA)-phosphate rich molecules made of glycerol and ribitol phosphates which may be tailored by different amino acids and sugars.In order to analyze and compare the composition of WTA produced by different S. aureus strains, we describe methods to: (1) quantify the total amount of WTA present at the bacterial cell surface, through the determination of the inorganic phosphate present in phosphodiester linkages of WTA; (2) identify which sugar constituents are present in the assembled WTA molecules, by detecting the monosaccharides, released by acid hydrolysis, through an high-performance anion exchange chromatography analysis coupled with pulsed amperometric detection (HPAEC-PAD) and (3) compare the polymerization degree of WTA found at the cell surface of different S. aureus strains, through their different migration in a polyacrylamide gel electrophoresis (PAGE). PMID:27311674

  19. Nanosurgery: observation of peptidoglycan strands in Lactobacillus helveticus cell walls

    Energy Technology Data Exchange (ETDEWEB)

    Firtel, Max; Henderson, Grant; Sokolov, Igor

    2004-11-15

    The internal cell wall structure of the bacterium Lactobacillus helveticus has been observed in situ in aqueous solution using an atomic force microscope (AFM). The AFM tip was used not only for imaging but presumably to remove mechanically large patches of the outer cell wall after appropriate chemical treatment, which typically leaves the bacteria alive. The surface exposed after this 'surgery' revealed {approx}26 nm thick twisted strands within the cell wall. The structure and location of the observed strands are consistent with the glycan backbone of peptidoglycan fibers that give strength to the cell wall. The structural organization of these fibers has not been observed previously.

  20. Hydrophobic Side-Chain Length Determines Activity and Conformational Heterogeneity of a Vancomycin Derivative Bound to the Cell Wall of Staphylococcus aureus§

    OpenAIRE

    Kim, Sung Joon; Schaefer, Jacob

    2008-01-01

    Disaccharide modified glycopeptides with hydrophobic sidechains are active against vancomycin-resistant enterococci and vancomycin-resistant S. aureus. The activity depends on the length of the sidechain. The benzyl sidechain of N-(4-fluorobenzyl)vancomycin (FBV) has the minimal length sufficient for enhancement in activity against vancomycin-resistant pathogens. The conformation of FBV bound to the peptidoglycan in whole cells of S. aureus has been determined using rotational-echo double res...

  1. Potential of the virion-associated peptidoglycan hydrolase HydH5 and its derivative fusion proteins in milk biopreservation.

    Directory of Open Access Journals (Sweden)

    Lorena Rodríguez-Rubio

    Full Text Available Bacteriophage lytic enzymes have recently attracted considerable interest as novel antimicrobials against Gram-positive bacteria. In this work, antimicrobial activity in milk of HydH5 [a virion-associated peptidoglycan hydrolase (VAPGH encoded by the Staphylococcus aureus bacteriophage vB_SauS-phiIPLA88], and three different fusion proteins created between HydH5 and lysostaphin has been assessed. The lytic activity of the five proteins (HydH5, HydH5Lyso, HydH5SH3b, CHAPSH3b and lysostaphin was confirmed using commercial whole extended shelf-life milk (ESL in challenge assays with 10(4 CFU/mL of the strain S. aureus Sa9. HydH5, HydH5Lyso and HydH5SH3b (3.5 µM kept the staphylococcal viable counts below the control cultures for 6 h at 37°C. The effect is apparent just 15 minutes after the addition of the lytic enzyme. Of note, lysostaphin and CHAPSH3b showed the highest staphylolytic protection as they were able to eradicate the initial staphylococcal challenge immediately or 15 min after addition, respectively, at lower concentration (1 µM at 37°C. CHAPSH3b showed the same antistaphyloccal effect at room temperature (1.65 µM. No re-growth was observed for the remainder of the experiment (up to 6 h. CHAPSH3b activity (1.65 µM was also assayed in raw (whole and skim and pasteurized (whole and skim milk. Pasteurization of milk clearly enhanced CHAPSH3b staphylolytic activity in both whole and skim milk at both temperatures. This effect was most dramatic at room temperature as this protein was able to reduce S. aureus viable counts to undetectable levels immediately after addition with no re-growth detected for the duration of the experiment (360 min. Furthermore, CHAPSH3b protein is known to be heat tolerant and retained some lytic activity after pasteurization treatment and after storage at 4°C for 3 days. These results might facilitate the use of the peptidoglycan hydrolase HydH5 and its derivative fusions, particularly CHAPSH3b, as

  2. D-Alanylation of Teichoic Acids and Loss of Poly-N-Acetyl Glucosamine in Staphylococcus aureus during Exponential Growth Phase Enhance IL-12 Production in Murine Dendritic Cells

    DEFF Research Database (Denmark)

    Lund, Lisbeth Drozd; Ingmer, Hanne; Frokiaer, Hanne

    2016-01-01

    about their role in immune stimulation and evasion. Depending on the growth phase, S. aureus may affect antigen presenting cells differently. Here, the impact of growth phases and the surface molecules lipoteichoic acid, peptidoglycan and poly-N-acetyl glucosamine on the induction of IL-12 imperative...... peptidoglycan to EP S. aureus stimulated cells increased bacterial uptake but abrogated IL-12 induction, while addition of lipoteichoic acid increased IL-12 production but had no effect on the bacterial uptake. Depletion of the capability to produce poly-N-acetyl glucosamine increased the IL-12 inducing...

  3. DMPD: Peptidoglycan signaling in innate immunity and inflammatory disease. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15802263 Peptidoglycan signaling in innate immunity and inflammatory disease. McDon...ald C, Inohara N, Nunez G. J Biol Chem. 2005 May 27;280(21):20177-80. Epub 2005 Mar 31. (.png) (.svg) (.html) (.csml) Show Peptidog...lycan signaling in innate immunity and inflammatory disease. PubmedID 15802263 Title Peptidog

  4. Inflammatory cytokine response to Bacillus anthracis peptidoglycan requires phagocytosis and lysosomal trafficking.

    Science.gov (United States)

    Iyer, Janaki K; Khurana, Taruna; Langer, Marybeth; West, Christopher M; Ballard, Jimmy D; Metcalf, Jordan P; Merkel, Tod J; Coggeshall, K Mark

    2010-06-01

    During advanced stages of inhalation anthrax, Bacillus anthracis accumulates at high levels in the bloodstream of the infected host. This bacteremia leads to sepsis during late-stage anthrax; however, the mechanisms through which B. anthracis-derived factors contribute to the pathology of infected hosts are poorly defined. Peptidoglycan, a major component of the cell wall of Gram-positive bacteria, can provoke symptoms of sepsis in animal models. We have previously shown that peptidoglycan of B. anthracis can induce the production of proinflammatory cytokines by cells in human blood. Here, we show that biologically active peptidoglycan is shed from an active culture of encapsulated B. anthracis strain Ames in blood. Peptidoglycan is able to bind to surfaces of responding cells, and internalization of peptidoglycan is required for the production of inflammatory cytokines. We also show that the peptidoglycan traffics to lysosomes, and lysosomal function is required for cytokine production. We conclude that peptidoglycan of B. anthracis is initially bound by an unknown extracellular receptor, is phagocytosed, and traffics to lysosomes, where it is degraded to a product recognized by an intracellular receptor. Binding of the peptidoglycan product to the intracellular receptor causes a proinflammatory response. These findings provide new insight into the mechanism by which B. anthracis triggers sepsis during a critical stage of anthrax disease. PMID:20308305

  5. One-year mortality in coagulase-negative Staphylococcus and Staphylococcus aureus infective endocarditis

    DEFF Research Database (Denmark)

    Rasmussen, Rasmus V; Snygg-Martin, Ulrika; Olaison, Lars;

    2009-01-01

    The aim of this study was to investigate in-hospital mortality and 12-month mortality in patients with coagulase-negative Staphylococcus (CoNS) compared to Staphylococcus aureus (S. aureus) infective endocarditis (IE). We used a prospective cohort study of 66 consecutive CoNS and 170 S. aureus IE...... patients, collected at 2 tertiary university hospitals in Copenhagen (Denmark) and at 1 tertiary university hospital in Gothenburg (Sweden). Median (range) C-reactive protein at admission was higher in patients with S. aureus IE (150 mg/l (1-521) vs 94 mg/l (6-303); p...% of patients with S. aureus IE (p =0.05). In conclusion, CoNS IE was associated with a long diagnostic delay and high in-hospital mortality, whereas post-discharge prognosis was better in this group of patients compared to patients with IE due to S. aureus....

  6. A Comparative Analysis of Community Acquired and Hospital Acquired Methicillin Resistant Staphylococcus Aureus

    OpenAIRE

    P R, Vysakh; M, Jeya

    2013-01-01

    Purpose: Staphylococcus aureus has developed resistance against most of the therapeutic agents. The most notable example of this phenomenon was the emergence of Methicillin resistant Staphylococcus aureus (MRSA). We are reporting the prevalence and the antibiotic susceptibility pattern of the MRSA isolates from a tertiary care hospital.

  7. Role of the Group B antigen of Streptococcus agalactiae: a peptidoglycan-anchored polysaccharide involved in cell wall biogenesis.

    Directory of Open Access Journals (Sweden)

    Élise Caliot

    Full Text Available Streptococcus agalactiae (Group B streptococcus, GBS is a leading cause of infections in neonates and an emerging pathogen in adults. The Lancefield Group B carbohydrate (GBC is a peptidoglycan-anchored antigen that defines this species as a Group B Streptococcus. Despite earlier immunological and biochemical characterizations, the function of this abundant glycopolymer has never been addressed experimentally. Here, we inactivated the gene gbcO encoding a putative UDP-N-acetylglucosamine-1-phosphate:lipid phosphate transferase thought to catalyze the first step of GBC synthesis. Indeed, the gbcO mutant was unable to synthesize the GBC polymer, and displayed an important growth defect in vitro. Electron microscopy study of the GBC-depleted strain of S. agalactiae revealed a series of growth-related abnormalities: random placement of septa, defective cell division and separation processes, and aberrant cell morphology. Furthermore, vancomycin labeling and peptidoglycan structure analysis demonstrated that, in the absence of GBC, cells failed to initiate normal PG synthesis and cannot complete polymerization of the murein sacculus. Finally, the subcellular localization of the PG hydrolase PcsB, which has a critical role in cell division of streptococci, was altered in the gbcO mutant. Collectively, these findings show that GBC is an essential component of the cell wall of S. agalactiae whose function is reminiscent of that of conventional wall teichoic acids found in Staphylococcus aureus or Bacillus subtilis. Furthermore, our findings raise the possibility that GBC-like molecules play a major role in the growth of most if not all beta-hemolytic streptococci.

  8. ermA, ermC , tetM and tetK are essential for erythromycin and tetracycline resistance among methicillin-resistant Staphylococcus aureus strains isolated from a tertiary hospital in Malaysia

    Directory of Open Access Journals (Sweden)

    K T Lim

    2012-01-01

    Full Text Available The objective of this study was to determine the expression and transferability of tetracycline and erythromycin resistance among 188 MRSA strains from a Malaysian tertiary hospital. The minimum inhibitory concentrations (MICs for oxacillin, erythromycin, tetracycline and ciprofloxacin ranged from 4 to 512 μg/ml, 0.25 to 256 μg/ml, 0.5 to 256 μg/ml and 0.5 to 512 μg/ml, respectively. Tetracycline-resistant strains showed co-resistance towards ciprofloxacin and erythromycin. There was a significant increase (P<0.05 of high-level tetracycline (≥MIC 256 μg/ml and erythromycin (≥MIC 128 μg/ml resistant strains in between the years 2003 and 2008. All erythromycin-resistant strains harboured ermA or ermC gene and all tetracycline-resistant strains harboured tetM or tetK gene. The blaZ was detected in all MRSA strains, whereas ermA, tetM, ermC, tetK and msrA genes were detected in 157 (84%, 92 (49%, 40 (21%, 39 (21% and 4 (2% MRSA strains, respectively. The blaZ, tetM, ermC and tetK genes were plasmid-encoded, with ermC gene being easily transmissible. Tn5801-like transposon was present in 78 tetM-positive strains. ermA and tetM genes were the most prevalent erythromycin and tetracycline resistance determinants, respectively, in MRSA strains. The association of resistance genes with mobile genetic elements possibly enhances the spread of resistant traits in MRSA.

  9. Proteomic Characterization of Lytic Bacteriophages of Staphylococcus aureus Isolated from Sewage Affluent of India

    Science.gov (United States)

    Sangha, Kamalpreet Kaur; Kumar, B. V. Sunil; Agrawal, Ravi Kant; Verma, Ramneek

    2014-01-01

    Staphylococcus aureus is a Gram-positive bacterium that causes a variety of diseases, including bovine mastitis, which has severe economic consequences. Standard antibiotic treatment results in selection of resistant strains, leading to need for an alternative treatment such as bacteriophage therapy. Present study describes isolation and characterization of a staphylococcal phage from sewage samples. S. aureus isolates obtained from microbial type culture collection (MTCC), Chandigarh, India, were used to screen staphylococcal phages. A phage designated as ΦMSP was isolated from sewage samples by soft agar overlay method. It produced clear plaques on tryptone soya agar overlaid with S. aureus. Transmission electron microscopy revealed that the phage had an icosahedral symmetry. It had 5 major proteins and possessed a peptidoglycan hydrolase corresponding to 70 kDa. ΦMSP infection induced 26 proteins to be uniquely expressed in S. aureus. This phage can be proposed as a candidate phage to treat staphylococcal infections. PMID:27355013

  10. Preparation and Immunomodulatory Properties of Modified Peptidoglycan Fragments

    Directory of Open Access Journals (Sweden)

    Tomić, S.

    2013-01-01

    Full Text Available Immunostimulators, known also as adjuvants, are added to vaccines to accelerate, extend or amplify the specific immune reaction to a specific antigen. One well known class of immuno- modulating compounds is based on muramylpeptides which are fragments of peptidoglycans, natural polymers that build up the cell wall of bacteria. Muramyldipeptide, N-acetyl- muramyl-L-alanyl-D-isoglutamine (MDP, Fig. 1 is the smallest structural unit of the peptidoglycan monomer (PGM, Fig. 2 which shows immunostimulating activity. PGM isolated from Brevibacterium divaricatum, acts in itself as an effective adjuvant, and several derivatives were prepared to study the possible influence of different substituents on the immunomodulatory activity. Thus, lipophilic derivativestert-butyloxycarbonyl-L-tyrosyl-PGM and (adamant- 1-ylacetyl-PGM (Fig. 3 were prepared and their activities studied. They were also shown to be good substrates for N-acetylmuramyl-L-alanine amidase from human serum (Scheme 1 which specifically hydrolyzes the lactylamide bond. MDP which is an integral part of PGM and proven to be an effective adjuvant was further synthetically modified and obtained derivatives tested as possible immunomodulators. Romutide (MDP-Lys(L18, approved by Food and Drug Administration (FDA, and mifamurtide (L-MTP-PE, approved by European Medicines Agency (EMA, highlight among many other MDP derivatives (Fig. 4. Since N-acetylglucosamine in the structure of MDP is not essential for the immunostimulating effect, desmuramyldipeptides (Fig. 5 with different acyl groups at N-terminus of L-Ala-D-isoGln dipeptide were prepared. In ada mantyl desmuramyldipeptides such as adamantylamide dipeptide (Fig 6, adamantyl tripeptides (Fig. 7 and desmuramylpeptides with (adamant-1-ylcarboxyamido group (Fig. 8, lipophilic adamantane moiety is bound to the dipeptide part. Binding of some specific sugars to immune active substances may help their targeted delivery. An example is mannose which

  11. Inflammatory Cytokine Response to Bacillus anthracis Peptidoglycan Requires Phagocytosis and Lysosomal Trafficking▿

    OpenAIRE

    Iyer, Janaki K.; Khurana, Taruna; Langer, Marybeth; West, Christopher M.; Ballard, Jimmy D.; Metcalf, Jordan P.; Merkel, Tod J.; Coggeshall, K. Mark

    2010-01-01

    During advanced stages of inhalation anthrax, Bacillus anthracis accumulates at high levels in the bloodstream of the infected host. This bacteremia leads to sepsis during late-stage anthrax; however, the mechanisms through which B. anthracis-derived factors contribute to the pathology of infected hosts are poorly defined. Peptidoglycan, a major component of the cell wall of Gram-positive bacteria, can provoke symptoms of sepsis in animal models. We have previously shown that peptidoglycan of...

  12. [Chemical structure and immunobiological activities of peptidoglycan isolated from Capnocytophaga species].

    Science.gov (United States)

    Hanagata, T

    1990-12-01

    The chemical structure and immunobiological activities of the cell wall peptidoglycan isolated from Capnocytophaga species was investigated. Peptidoglycan was isolated from Capnocytophaga species strain SE2-2 by boiling in 4% sodium dodecyl sulfate and by digestion with pronase, trypsin and alpha-amylase. Analysis of amino acids and amino sugars of the peptidoglycan revealed that glucosamine, muramic acid, D-glutamic acid, alanine, and diaminopimelic acid (A2pm) were the principal components. Serine and glycine were not found. Dinitrophenylation method revealed that about half of A2pm residue had a free amino group, and analysis by hydrazinolysis showed that a small part of alanine and A2pm located at the C-terminal. The above results indicate that one of the amino groups of A2pm residue at one strand of the stem peptide subunit cross-linked to the carboxyl group of alanine of the neighboring strand. It was thus revealed that the peptidoglycan of Capnocytophaga species belonged to the Al gamma type of the classification by Schleifer and Kandler. Peptidoglycan isolated from Capnocytophaga species strain SE2-2 was found to be definitely adjuvant-active in induction of delayed type hypersensitivity against ovalbumin when administered to guinea pigs as water-in-oil emulsion and in stimulation of increase serum antibody levels. Regarding mitogenicity on splenocytes of BALB/c and BALB/c nu/nu mice, peptidoglycan from Capnocytophaga species was markedly enhanced the uptake [3H] thymidine in dose of 10 micrograms/10(5) cells, however thymocytes were not reactive. Stimulation effects on peritoneal macrophages from a guinea pig to incorporation of 14C-glucosamin was exhibited by addition of 100 micrograms of this peptidoglycan. These findings indicate that peptidoglycan of Capnocytophaga species might eventually be responsible for destruction of periodontal tissue by host mediated activities.

  13. Uniformity of Glycyl Bridge Lengths in the Mature Cell Walls of Fem Mutants of Methicillin-Resistant Staphylococcus aureus

    OpenAIRE

    Sharif, Shasad; Kim, Sung Joon; Labischinski, Harald; Chen, Jiawei; Schaefer, Jacob

    2013-01-01

    Peptidoglycan (PG) composition in intact cells of methicillin-resistant Staphylococcus aureus (MRSA) and its isogenic Fem mutants has been characterized by measuring the glycine content of PG bridge structures by solid-state nuclear magnetic resonance (NMR). The glycine content estimated from integrated intensities (rather than peak heights) in the cell walls of whole cells was increased by approximately 30% for the FemA mutant and was reduced by 25% for the FemB mutant relative to expected v...

  14. Staphylococcus aureus and Pregnancy

    Science.gov (United States)

    Staphylococcus aureus and Pregnancy In every pregnancy, a woman starts out with a 3-5% chance of ... risk. This sheet talks about whether exposure to staphylococcus aureus may increase the risk for birth defects ...

  15. Moss Chloroplasts Are Surrounded by a Peptidoglycan Wall Containing D-Amino Acids[OPEN

    Science.gov (United States)

    Hirano, Takayuki; Tanidokoro, Koji; Shimizu, Yasuhiro; Kawarabayasi, Yutaka; Ohshima, Toshihisa; Sato, Momo; Tadano, Shinji; Ishikawa, Hayato; Takio, Susumu; Takechi, Katsuaki; Takano, Hiroyoshi

    2016-01-01

    It is believed that the plastids in green plants lost peptidoglycan (i.e., a bacterial cell wall-containing d-amino acids) during their evolution from an endosymbiotic cyanobacterium. Although wall-like structures could not be detected in the plastids of green plants, the moss Physcomitrella patens has the genes required to generate peptidoglycan (Mur genes), and knocking out these genes causes defects in chloroplast division. Here, we generated P. patens knockout lines (∆Pp-ddl) for a homolog of the bacterial peptidoglycan-synthetic gene encoding d-Ala:d-Ala ligase. ∆Pp-ddl had a macrochloroplast phenotype, similar to other Mur knockout lines. The addition of d-Ala-d-Ala (DA-DA) to the medium suppressed the appearance of giant chloroplasts in ∆Pp-ddl, but the addition of l-Ala-l-Ala (LA-LA), DA-LA, LA-DA, or d-Ala did not. Recently, a metabolic method for labeling bacterial peptidoglycan was established using ethynyl-DA-DA (EDA-DA) and click chemistry to attach an azide-modified fluorophore to the ethynyl group. The ∆Pp-ddl line complemented with EDA-DA showed that moss chloroplasts are completely surrounded by peptidoglycan. Our findings strongly suggest that the moss plastids have a peptidoglycan wall containing d-amino acids. By contrast, no plastid phenotypes were observed in the T-DNA tagged ddl mutant lines of Arabidopsis thaliana. PMID:27325639

  16. Proposed docking interface between peptidoglycan and the target recognition domain of zoocin A

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yinghua [Department of Chemistry, University of Alabama, Tuscaloosa, AL 35487 (United States); Simmonds, Robin S. [Department of Microbiology and Immunology, University of Otago, Dunedin (New Zealand); Timkovich, Russell, E-mail: rtimkovi@bama.ua.edu [Department of Chemistry, University of Alabama, Tuscaloosa, AL 35487 (United States)

    2013-11-15

    Highlights: •Peptidoglycan added to zoocin rTRD perturbs NMR resonances around W115. •Simulations predict docking to a shallow surface groove near W115. •The docking interface is similar to mammalian antibody–antigen sites. •EDTA binds to a distinct surface site. -- Abstract: A docking model is proposed for the target recognition domain of the lytic exoenzyme zoocin A with the peptidoglycan on the outer cell surface of sensitive bacterial strains. Solubilized fragments from such peptidoglycans perturb specific backbone and side chain amide resonances in the recombinant form of the domain designated rTRD as detected in two-dimensional {sup 1}H–{sup 15}N correlation NMR spectra. The affected residues comprise a shallow surface cleft on the protein surface near W115, N53, N117, and Q105 among others, which interacts with the peptide portion of the peptidoglycan. Calculations with AutoDock Vina provide models of the docking interface. There is approximate homology between the rTDR-peptidoglycan docking site and the antigen binding site of Fab antibodies with the immunoglobin fold. EDTA was also found to bind to rTRD, but at a site distinct from the proposed peptidoglycan docking site.

  17. Moss Chloroplasts Are Surrounded by a Peptidoglycan Wall Containing D-Amino Acids.

    Science.gov (United States)

    Hirano, Takayuki; Tanidokoro, Koji; Shimizu, Yasuhiro; Kawarabayasi, Yutaka; Ohshima, Toshihisa; Sato, Momo; Tadano, Shinji; Ishikawa, Hayato; Takio, Susumu; Takechi, Katsuaki; Takano, Hiroyoshi

    2016-07-01

    It is believed that the plastids in green plants lost peptidoglycan (i.e., a bacterial cell wall-containing d-amino acids) during their evolution from an endosymbiotic cyanobacterium. Although wall-like structures could not be detected in the plastids of green plants, the moss Physcomitrella patens has the genes required to generate peptidoglycan (Mur genes), and knocking out these genes causes defects in chloroplast division. Here, we generated P patens knockout lines (∆Pp-ddl) for a homolog of the bacterial peptidoglycan-synthetic gene encoding d-Ala:d-Ala ligase. ∆Pp-ddl had a macrochloroplast phenotype, similar to other Mur knockout lines. The addition of d-Ala-d-Ala (DA-DA) to the medium suppressed the appearance of giant chloroplasts in ∆Pp-ddl, but the addition of l-Ala-l-Ala (LA-LA), DA-LA, LA-DA, or d-Ala did not. Recently, a metabolic method for labeling bacterial peptidoglycan was established using ethynyl-DA-DA (EDA-DA) and click chemistry to attach an azide-modified fluorophore to the ethynyl group. The ∆Pp-ddl line complemented with EDA-DA showed that moss chloroplasts are completely surrounded by peptidoglycan. Our findings strongly suggest that the moss plastids have a peptidoglycan wall containing d-amino acids. By contrast, no plastid phenotypes were observed in the T-DNA tagged ddl mutant lines of Arabidopsis thaliana. PMID:27325639

  18. Transmembrane transport of peptidoglycan precursors across model and bacterial membranes.

    Science.gov (United States)

    van Dam, Vincent; Sijbrandi, Robert; Kol, Matthijs; Swiezewska, Ewa; de Kruijff, Ben; Breukink, Eefjan

    2007-05-01

    Translocation of the peptidoglycan precursor Lipid II across the cytoplasmic membrane is a key step in bacterial cell wall synthesis, but hardly understood. Using NBD-labelled Lipid II, we showed by fluorescence and TLC assays that Lipid II transport does not occur spontaneously and is not induced by the presence of single spanning helical transmembrane peptides that facilitate transbilayer movement of membrane phospholipids. MurG catalysed synthesis of Lipid II from Lipid I in lipid vesicles also did not result in membrane translocation of Lipid II. These findings demonstrate that a specialized protein machinery is needed for transmembrane movement of Lipid II. In line with this, we could demonstrate Lipid II translocation in isolated Escherichia coli inner membrane vesicles and this transport could be uncoupled from the synthesis of Lipid II at low temperatures. The transport process appeared to be independent from an energy source (ATP or proton motive force). Additionally, our studies indicate that translocation of Lipid II is coupled to transglycosylation activity on the periplasmic side of the inner membrane. PMID:17501931

  19. Distinct immune response induced by peptidoglycan derived from Lactobacillus sp

    Institute of Scientific and Technical Information of China (English)

    Jin Sun; Yong-Hui Shi; Guo-Wei Le; Xi-Yi Ma

    2005-01-01

    AIM: To analyze the distinct immune responses induced by Lactobacillus peptidoglycan (PG).METHODS: BALB/c mice were intraperitoneally injected with PG once a day for three consecutive days. Peritoneal macrophage and splenocyte mRNA was extracted and the gene expression profile was studied using high-density oligonucleotide microarrays. Inhibitory effects of Lactobacillus PG on colon tumor tissue were studied in vitro and in vivo.RESULTS: The gene expression profiles revealed that the TLR-NF-κB and Jak-STAT signaling pathways were highly activated. An inflammatory phenotype was induced when peritoneal macrophages were initially exposed to Lactobacillus PG and switched to a more complex phenotype when BALB/c mice were treated with three doses of Lactobacillus PG. A protective physiological inflammatory response was induced after three consecutive days of PG treatment. It was tending toward Th1 dominant immune response. Lactobacillus PG also appeared to induce a significantin vivo anti-colon tumor effect.CONCLUSION: Lactobacillus PG is responsible for certain immune responses induced by Lactobacilli. Anti-tumor effects of Lactobacilli are likely to attribute to the activation of macrophages by PG expressed on the bacterial cell surface.

  20. High-resolution subtyping of Staphylococcus aureus strains by means of Fourier-transform infrared spectroscopy.

    Science.gov (United States)

    Johler, Sophia; Stephan, Roger; Althaus, Denise; Ehling-Schulz, Monika; Grunert, Tom

    2016-05-01

    Staphylococcus aureus causes a variety of serious illnesses in humans and animals. Subtyping of S. aureus isolates plays a crucial role in epidemiological investigations. Metabolic fingerprinting by Fourier-transform infrared (FTIR) spectroscopy is commonly used to identify microbes at species as well as subspecies level. In this study, we aimed to assess the suitability of FTIR spectroscopy as a tool for S. aureus subtyping. To this end, we compared the subtyping performance of FTIR spectroscopy to other subtyping methods such as pulsed field gel electrophoresis (PFGE) and spa typing in a blinded experimental setup and investigated the ability of FTIR spectroscopy for identifying S. aureus clonal complexes (CC). A total of 70 S. aureus strains from human, animal, and food sources were selected, for which clonal complexes and a unique virulence and resistance gene pattern had been determined by DNA microarray analysis. FTIR spectral analysis resulted in high discriminatory power similar as obtained by spa typing and PFGE. High directional concordance was found between FTIR spectroscopy based subtypes and capsular polysaccharide expression detected by FTIR spectroscopy and the cap specific locus, reflecting strain specific expression of capsular polysaccharides and/or other surface glycopolymers, such as wall teichoic acid, peptidoglycane, and lipoteichoic acid. Supervised chemometrics showed only limited possibilities for differentiation of S. aureus CC by FTIR spectroscopy with the exception of CC45 and CC705. In conclusion, FTIR spectroscopy represents a valuable tool for S. aureus subtyping, which complements current molecular and proteomic strain typing. PMID:27021524

  1. Staphylococcus aureus toxins.

    Science.gov (United States)

    Otto, Michael

    2014-02-01

    Staphylococcus aureus is a dangerous pathogen that causes a variety of severe diseases. The virulence of S. aureus is defined by a large repertoire of virulence factors, among which secreted toxins play a preeminent role. Many S. aureus toxins damage biological membranes, leading to cell death. In particular, S. aureus produces potent hemolysins and leukotoxins. Among the latter, some were recently identified to lyse neutrophils after ingestion, representing an especially powerful weapon against bacterial elimination by innate host defense. Furthermore, S. aureus secretes many factors that inhibit the complement cascade or prevent recognition by host defenses. Several further toxins add to this multi-faceted program of S. aureus to evade elimination in the host. This review will give an overview over S. aureus toxins focusing on recent advances in our understanding of how leukotoxins work in receptor-mediated or receptor-independent fashions.

  2. A novel in vivo cell-wall labeling approach sheds new light on peptidoglycan synthesis in Escherichia coli.

    Science.gov (United States)

    Olrichs, Nick K; Aarsman, Mirjam E G; Verheul, Jolanda; Arnusch, Christopher J; Martin, Nathaniel I; Hervé, Mireille; Vollmer, Waldemar; de Kruijff, Ben; Breukink, Eefjan; den Blaauwen, Tanneke

    2011-05-01

    Peptidoglycan synthesis and turnover in relation to cell growth and division has been studied by using a new labeling method. This method involves the incorporation of fluorescently labeled peptidoglycan precursors into the cell wall by means of the cell-wall recycling pathway. We show that Escherichia coli is able to import exogenous added murein tripeptide labeled with N-7-nitro-2,1,3-benzoxadiazol-4-yl (AeK-NBD) into the cytoplasm where it enters the peptidoglycan biosynthesis route, resulting in fluorescent labels specifically located in the cell wall. When wild-type cells were grown in the presence of the fluorescent peptide, peptidoglycan was uniformly labeled in cells undergoing elongation. Cells in the process of division displayed a lack of labeled peptidoglycan at mid-cell. Analysis of labeling patterns in cell division mutants showed that the occurrence of unlabeled peptidoglycan is dependent on the presence of FtsZ, but independent of FtsQ and FtsI. Accumulation of fluorescence at the division sites of a triple amidase mutant (ΔamiABC) revealed that AeK-NBD is incorporated into septal peptidoglycan. AmiC was shown to be involved in the rapid removal of labeled peptidoglycan side chains at division sites in wild-type cells. Because septal localization of AmiC is dependent on FtsQ and FtsI, this points to the presence of another peptidoglycan hydrolase activity directly dependent on FtsZ. PMID:21472954

  3. The high-affinity peptidoglycan binding domain of Pseudomonas phage endolysin KZ144

    International Nuclear Information System (INIS)

    The binding affinity of the N-terminal peptidoglycan binding domain of endolysin KZ144 (PBDKZ), originating from Pseudomonas aeruginosa bacteriophage φKZ, has been examined using a fusion protein of PBDKZ and green fluorescent protein (PBDKZ-GFP). A fluorescence recovery after photobleaching analysis of bound PBDKZ-GFP molecules showed less than 10% fluorescence recovery in the bleached area within 15 min. Surface plasmon resonance analysis confirmed this apparent high binding affinity revealing an equilibrium affinity constant of 2.95 x 107 M-1 for the PBDKZ-peptidoglycan interaction. This unique domain, which binds to the peptidoglycan of all tested Gram-negative species, was harnessed to improve the specific activity of the peptidoglycan hydrolase domain KMV36C. The chimeric peptidoglycan hydrolase (PBDKZ-KMV36C) exhibits a threefold higher specific activity than the native catalytic domain (KMV36C). These results demonstrate that the modular assembly of functional domains is a rational approach to improve the specific activity of endolysins from phages infecting Gram-negatives.

  4. Phenotypic and genotypic characterization of peptidoglycan hydrolases of Lactobacillus sakei

    Directory of Open Access Journals (Sweden)

    Afef Najjari

    2016-01-01

    Full Text Available Lactobacillus sakei, a lactic acid bacterium naturally found in fresh meat and sea products, is considered to be one of the most important bacterial species involved in meat fermentation and bio-preservation. Several enzymes of Lb. sakei species contributing to microbial safeguarding and organoleptic properties of fermented-meat were studied. However, the specific autolytic mechanisms and associated enzymes involved in Lb. sakei are not well understood. The autolytic phenotype of 22 Lb. sakei strains isolated from Tunisian meat and seafood products was evaluated under starvation conditions, at pH 6.5 and 8.5, and in the presence of different carbon sources. A higher autolytic rate was observed when cells were grown in the presence of glucose and incubated at pH 6.5. Almost all strains showed high resistance to mutanolysin, indicating a minor role of muramidases in Lb. sakei cell lysis. Using Micrococcus lysodeikticus cells as a substrate in activity gels zymogram, peptidoglycan hydrolase (PGH patterns for all strains was characterized by two lytic bands of ∼80 (B1 and ∼70 kDa (B2, except for strain BMG.167 which harbored two activity signals at a lower MW. Lytic activity was retained in high salt and in acid/basic conditions and was active toward cells of Lb. sakei, Listeria monocytogenes, Listeria ivanovii and Listeria innocua. Analysis of five putative PGH genes found in the Lb. sakei 23 K model strain genome, indicated that one gene, lsa1437, could encode a PGH (N-acetylmuramoyl-L-alanine amidase containing B1 and B2 as isoforms. According to this hypothesis, strain BMG.167 showed an allelic version of lsa1437 gene deleted of one of the five LysM domains, leading to a reduction in the MW of lytic bands and the high autolytic rate of this strain. Characterization of autolytic phenotype of Lb. sakei should expand the knowledge of their role in fermentation processes where they represent the dominant species.

  5. Phenotypic and genotypic characterization of peptidoglycan hydrolases of Lactobacillus sakei.

    Science.gov (United States)

    Najjari, Afef; Amairi, Houda; Chaillou, Stéphane; Mora, Diego; Boudabous, Abdellatif; Zagorec, Monique; Ouzari, Hadda

    2016-01-01

    Lactobacillus sakei, a lactic acid bacterium naturally found in fresh meat and sea products, is considered to be one of the most important bacterial species involved in meat fermentation and bio-preservation. Several enzymes of Lb. sakei species contributing to microbial safeguarding and organoleptic properties of fermented-meat were studied. However, the specific autolytic mechanisms and associated enzymes involved in Lb. sakei are not well understood. The autolytic phenotype of 22 Lb. sakei strains isolated from Tunisian meat and seafood products was evaluated under starvation conditions, at pH 6.5 and 8.5, and in the presence of different carbon sources. A higher autolytic rate was observed when cells were grown in the presence of glucose and incubated at pH 6.5. Almost all strains showed high resistance to mutanolysin, indicating a minor role of muramidases in Lb. sakei cell lysis. Using Micrococcus lysodeikticus cells as a substrate in activity gels zymogram, peptidoglycan hydrolase (PGH) patterns for all strains was characterized by two lytic bands of ∼80 (B1) and ∼70 kDa (B2), except for strain BMG.167 which harbored two activity signals at a lower MW. Lytic activity was retained in high salt and in acid/basic conditions and was active toward cells of Lb. sakei, Listeria monocytogenes, Listeria ivanovii and Listeria innocua. Analysis of five putative PGH genes found in the Lb. sakei 23 K model strain genome, indicated that one gene, lsa1437, could encode a PGH (N-acetylmuramoyl-L-alanine amidase) containing B1 and B2 as isoforms. According to this hypothesis, strain BMG.167 showed an allelic version of lsa1437 gene deleted of one of the five LysM domains, leading to a reduction in the MW of lytic bands and the high autolytic rate of this strain. Characterization of autolytic phenotype of Lb. sakei should expand the knowledge of their role in fermentation processes where they represent the dominant species. PMID:26843981

  6. Induction of delayed-type hypersensitivity by the T cell line specific to bacterial peptidoglycans

    International Nuclear Information System (INIS)

    A T cell line specific for the chemically well-defined peptidoglycan of bacterial cell wall, disaccharide tetrapeptide, was established from Lewis rats immunized with the antigen covalently linked to the autologous rat serum albumin. The antigen specificity was examined with various analogues or derivatives of the peptidoglycan. The cell line was reactive to analogues with the COOH-terminal D-amino acid, but least reactive to those with L-amino acid as COOH terminus. Transferring of the T cell line into X-irradiated normal Lewis rats induced delayed-type hypersensitivity in an antigen specific manner

  7. A novel in vivo cell-wall labeling approach sheds new light on peptidoglycan synthesis in Escherichia coli

    NARCIS (Netherlands)

    N.K. Olrichs; M.E.G. Aarsman; J. Verheul; C.J. Arnusch; N.I. Martin; M. Hervé; W. Vollmer; B. de Kruijff; E. Breukink; T. den Blaauwen

    2011-01-01

    Peptidoglycan synthesis and turnover in relation to cell growth and division has been studied by using a new labeling method. This method involves the incorporation of fluorescently labeled peptidoglycan precursors into the cell wall by means of the cell-wall recycling pathway. We show that Escheric

  8. Specific labeling of peptidoglycan precursors as a tool for bacterial cell wall studies

    NARCIS (Netherlands)

    van Dam, V.; Olrichs, N.K.; Breukink, E.J.

    2009-01-01

    Wall chart: The predominant component of the bacterial cell wall, peptidoglycan, consists of long alternating stretches of aminosugar subunits interlinked in a large three-dimensional network and is formed from precursors through several cytosolic and membrane-bound steps. The high tolerance of the

  9. Peptidoglycan synthesis in Escherichia coli from a PBP1b perspective

    NARCIS (Netherlands)

    van 't Veer, I.L.

    2016-01-01

    An essential and unique component of the bacterial cell envelope is the peptidoglycan layer. This layer, formed by glycan chains that are interlinked by peptide bridges, is essential for the maintenance of the specific cell shape of the bacterium, and protects it from rupture by osmotic pressure. Be

  10. Augmentation of NKT and NK cell-mediated cytotoxicity by peptidoglycan monomer linked with zinc

    Directory of Open Access Journals (Sweden)

    Ines Mrakovcic-Šutic

    2002-01-01

    Full Text Available Background: Peptidoglycan monomer (PGM, which was originally prepared by biosynthesis from culture fluids of penicillin-treated Brevibacterium divaricatum, is an immunostimulator, the activities of which might be improved by addition of zinc (Zn to the basic molecule.

  11. Oleanolic acid and ursolic acid inhibit peptidoglycan biosynthesis in Streptococcus mutans UA159

    Directory of Open Access Journals (Sweden)

    Soon-Nang Park

    2015-06-01

    Full Text Available In this study, we revealed that OA and UA significantly inhibited the expression of most genes related to peptidoglycan biosynthesis in S. mutans UA159. To the best of our knowledge, this is the first report to introduce the antimicrobial mechanism of OA and UA against S. mutans.

  12. Regulation of Polar Peptidoglycan Biosynthesis by Wag31 Phosphorylation in Mycobacteria

    Directory of Open Access Journals (Sweden)

    Lee Sang

    2010-12-01

    Full Text Available Abstract Background Sensing and responding to environmental changes is a central aspect of cell division regulation. Mycobacterium tuberculosis contains eleven Ser/Thr kinases, two of which, PknA and PknB, are key signaling molecules that regulate cell division/morphology. One substrate of these kinases is Wag31, and we previously showed that partial depletion of Wag31 caused morphological changes indicative of cell wall defects, and that the phosphorylation state of Wag31 affected cell growth in mycobacteria. In the present study, we further characterized the role of the Wag31 phosphorylation in polar peptidoglycan biosynthesis. Results We demonstrate that the differential growth among cells expressing different wag31 alleles (wild-type, phosphoablative, or phosphomimetic is caused by, at least in part, dissimilar nascent peptidoglycan biosynthesis. The phosphorylation state of Wag31 is found to be important for protein-protein interactions between the Wag31 molecules, and thus, for its polar localization. Consistent with these results, cells expressing a phosphomimetic wag31 allele have a higher enzymatic activity in the peptidoglycan biosynthetic pathway. Conclusions The Wag31Mtb phosphorylation is a novel molecular mechanism by which Wag31Mtb regulates peptidoglycan synthesis and thus, optimal growth in mycobacteria.

  13. A Peptidoglycan-Remodeling Enzyme Is Critical for Bacteroid Differentiation in Bradyrhizobium spp. During Legume Symbiosis.

    Science.gov (United States)

    Gully, Djamel; Gargani, Daniel; Bonaldi, Katia; Grangeteau, Cédric; Chaintreuil, Clémence; Fardoux, Joël; Nguyen, Phuong; Marchetti, Roberta; Nouwen, Nico; Molinaro, Antonio; Mergaert, Peter; Giraud, Eric

    2016-06-01

    In response to the presence of compatible rhizobium bacteria, legumes form symbiotic organs called nodules on their roots. These nodules house nitrogen-fixing bacteroids that are a differentiated form of the rhizobium bacteria. In some legumes, the bacteroid differentiation comprises a dramatic cell enlargement, polyploidization, and other morphological changes. Here, we demonstrate that a peptidoglycan-modifying enzyme in Bradyrhizobium strains, a DD-carboxypeptidase that contains a peptidoglycan-binding SPOR domain, is essential for normal bacteroid differentiation in Aeschynomene species. The corresponding mutants formed bacteroids that are malformed and hypertrophied. However, in soybean, a plant that does not induce morphological differentiation of its symbiont, the mutation does not affect the bacteroids. Remarkably, the mutation also leads to necrosis in a large fraction of the Aeschynomene nodules, indicating that a normally formed peptidoglycan layer is essential for avoiding the induction of plant immune responses by the invading bacteria. In addition to exopolysaccharides, capsular polysaccharides, and lipopolysaccharides, whose role during symbiosis is well defined, our work demonstrates an essential role in symbiosis for yet another rhizobial envelope component, the peptidoglycan layer. PMID:26959836

  14. SpxB regulates O-acetylation-dependent resistance of Lactococcus lactis peptidoglycan to hydrolysis

    NARCIS (Netherlands)

    Veiga, Patrick; Bulbarela-Sampieri, Carmen; Furlan, Sylviane; Maisons, Aurelie; Chapot-Chartier, Marie-Pierre; Erkelenz, Michael; Mervelet, Peggy; Noirot, Philippe; Frees, Dorte; Kuipers, Oscar P.; Kok, Jan; Gruss, Alexandra; Buist, Girbe; Kulakauskas, Saulius

    2007-01-01

    Endogenous peptidoglycan (PG)-hydrolyzing enzymes, the autolysins, are needed to relax the rigid PG sacculus to allow bacterial cell growth and separation. PGs of pathogens and commensal bacteria may also be degraded by hydrolases of animal origin (lysozymes), which act as antimicrobials. The geneti

  15. Transport of peptidoglycan sub-units across the bacterial cytoplasmic membrane

    NARCIS (Netherlands)

    van Dam, V.

    2009-01-01

    Transport of peptidoglycan sub-units across the bacterial cytoplasmic membrane Vincent van Dam The work described in this thesis focuses on the mechanism by which the lipid-linked cell wall precursor molecule Lipid II is transported from the inner leaflet to the outer leaflet of the cytoplasmic memb

  16. Specialized peptidoglycan hydrolases sculpt the intra-bacterial niche of predatory Bdellovibrio and increase population fitness.

    Directory of Open Access Journals (Sweden)

    Thomas R Lerner

    2012-02-01

    Full Text Available Bdellovibrio are predatory bacteria that have evolved to invade virtually all gram-negative bacteria, including many prominent pathogens. Upon invasion, prey bacteria become rounded up into an osmotically stable niche for the Bdellovibrio, preventing further superinfection and allowing Bdellovibrio to replicate inside without competition, killing the prey bacterium and degrading its contents. Historically, prey rounding was hypothesized to be associated with peptidoglycan (PG metabolism; we found two Bdellovibrio genes, bd0816 and bd3459, expressed at prey entry and encoding proteins with limited homologies to conventional dacB/PBP4 DD-endo/carboxypeptidases (responsible for peptidoglycan maintenance during growth and division. We tested possible links between Bd0816/3459 activity and predation. Bd3459, but not an active site serine mutant protein, bound β-lactam, exhibited DD-endo/carboxypeptidase activity against purified peptidoglycan and, importantly, rounded up E. coli cells upon periplasmic expression. A ΔBd0816 ΔBd3459 double mutant invaded prey more slowly than the wild type (with negligible prey cell rounding and double invasions of single prey by more than one Bdellovibrio became more frequent. We solved the crystal structure of Bd3459 to 1.45 Å and this revealed predation-associated domain differences to conventional PBP4 housekeeping enzymes (loss of the regulatory domain III, alteration of domain II and a more exposed active site. The Bd3459 active site (and by similarity the Bd0816 active site can thus accommodate and remodel the various bacterial PGs that Bdellovibrio may encounter across its diverse prey range, compared to the more closed active site that "regular" PBP4s have for self cell wall maintenance. Therefore, during evolution, Bdellovibrio peptidoglycan endopeptidases have adapted into secreted predation-specific proteins, preventing wasteful double invasion, and allowing activity upon the diverse prey peptidoglycan

  17. Tertiary Education in Portugal

    Science.gov (United States)

    OECD Publishing (NJ3), 2008

    2008-01-01

    Portugal's tertiary education sector has expanded significantly over the last 20 years, but participation and overall educational attainment levels remain below European standards and enrolment rates have begun to decline. The OECD review recommends that Portugal's national government should focus on strategic direction and leave higher education…

  18. Knowledge, Attitude and Practice among food handlers on food borne diseases: A hospital based study in tertiary care hospital.

    OpenAIRE

    Anuradha, Mavilla; Dandekar, Rahul Hanumant

    2014-01-01

    Title: Knowledge, Attitude and Practice among food handlers on food borne diseases: A hospital based study in tertiary care hospital.Running title: KAP study among food handlers in a Hospital at Perambalur.Background: Food handlers play an important role in ensuring food safety throughout the chain of production, processing, storage and preparation.Staphylococcus aureus infections used to respond to ß-lactam and related group of antibiotics but the emergence of Methicillin-resistant S. Aureus...

  19. Inhibitory Effect of Lactobacillus plantarum Extracts on HT-29 Colon Cancer Cell Apoptosis Induced by Staphylococcus aureus and Its Alpha-Toxin.

    Science.gov (United States)

    Kim, Hangeun; Kim, Hye Sun; Park, Woo Jung; Chung, Dae Kyun

    2015-11-01

    Staphylococcus aureus plays an important role in sepsis, septic shock, pneumonia, and wound infections. Here, we demonstrate that Lactobacillus plantarum extracts inhibited S. aureusinduced cell death of a human epithelial cell line, HT-29. In particular, we have shown that S. aureus-induced cell death was abolished by neutralization of α-toxin, indicating that α-toxin is the major mediator of S. aureus-induced cell death. DNA fragmentation experiment and caspase assay revealed that the S. aureus-induced cell death was apoptosis. L. plantarum extracts inhibited the generation of effector caspase-3 and the initiator caspase-9 in S. aureusor α-toxin-induced cell death. Moreover, expression of Bcl-2, an anti-apoptotic protein, was activated in L. plantarum extract-treated cells as compared with the S. aureus- or α-toxintreated only cells. Furthermore, S. aureus-induced apoptosis was efficiently inhibited by lipoteichoic acid and peptidoglycan of L. plantarum. Together, our results suggest that L. plantarum extracts can inhibit the S. aureus-mediated apoptosis, which is associated with S. aureus spreading, in intestinal epithelial cells, and may provide a new therapeutic reagent to treat bacterial infections.

  20. The Elucidation of the Structure of Thermotoga maritima Peptidoglycan Reveals Two Novel Types of Cross-link*

    OpenAIRE

    Boniface, Audrey; Parquet, Claudine; Arthur, Michel; Mengin-Lecreulx, Dominique; Blanot, Didier

    2009-01-01

    Thermotoga maritima is a Gram-negative, hyperthermophilic bacterium whose peptidoglycan contains comparable amounts of l- and d-lysine. We have determined the fine structure of this cell-wall polymer. The muropeptides resulting from the digestion of peptidoglycan by mutanolysin were separated by high-performance liquid chromatography and identified by amino acid analysis after acid hydrolysis, dinitrophenylation, enzymatic determination of the configuration of the chiral amino acids, and mass...

  1. Potentiating activity of luteolin on membrane permeabilizing agent and ATPase inhibitor against methicillin-resistant Staphylococcus aureus

    Institute of Scientific and Technical Information of China (English)

    Dae-Ki Joung; Dong-Won Shin; Dong-Yeul Kwon; Young-Seob Lee; Sin-Hee Han; Sang-Won Lee; Seon-Woo Cha; Su-Hyun Mun; Ryong Kong; Ok-Hwa Kang; Ho-Jun Song

    2016-01-01

    Objective: To investigate the mechanism of antibacterial activity of luteolin (LUT) against methicillin-resistant Staphylococcus aureus (MRSA). Methods: The mechanism of anti-MRSA activity of LUT was analyzed by the viability assay in membrane permeabilizing agent, ATPase inhibitors, and peptidoglycan (PGN) derived from Staphylococcus aureus (S. aureus). Also, transmission electron microscopy was used to monitor survival characteristics and changes in S. aureus morphology. Results: Compared to the LUT alone, the optical density of suspensions treated with the combination of 125 μg/mL Tris and 250 μg/mL DCCD were reduced to 60%and 46%, respectively. PGN (15.6 μg/mL) gradually impeded the activity of LUT, and PGN (62.5 μg/mL) completely blocked the activity of LUT on S. aureus. Conclusions: Increased susceptibility to LUT with the Tris and DCCD combinations is evident in all tested MRSA isolates. The results indicate LUT synergy in increasing cytoplasmic membrane permeability and inhibiting ATPase. S. aureus PGN directly blocks the antibacterial activity of LUT, suggesting the direct binding of LUT with PGN. These findings may be validated for the development of antibacterial agent for low MRSA resistance.

  2. Changes of lipid domains in Bacillus subtilis cells with disrupted cell wall peptidoglycan

    OpenAIRE

    Muchová, Katarína; Wilkinson, Anthony J.; Barák, Imrich

    2011-01-01

    The cell wall is responsible for cell integrity and the maintenance of cell shape in bacteria. The Gram-positive bacterial cell wall consists of a thick peptidoglycan layer located on the outside of the cytoplasmic membrane. Bacterial cell membranes, like eukaryotic cell membranes, are known to contain domains of specific lipid and protein composition. Recently, using the membrane-binding fluorescent dye FM4-64, helix-like lipid structures extending along the long axis of the cell and consist...

  3. Influence of whole peptidoglycan of bifidobacterium on cytotoxic effectors produced by mouse peritoneal macrophages

    Institute of Scientific and Technical Information of China (English)

    Li Sheng Wang; Hui Ming Zhu; Dian Yuan Zhou; Yu Lin Wang; Wan Dai Zhang

    2001-01-01

    @@ INTRODUCTION Bifidobacteria are physiologically beneficial bacteria which are perdominant in human intestine ,and possess the most important functions .They play an important role in maintaining microbial balance of the intestine .Furthermore , their presence is thought to be an important indication of health of the body [1-4].Whole peptidoglycan ( WPG) is the major component in the cell wall of bifidobacterium ,which is also a biological responsemodifier with nontoxic side dffcets.

  4. Structural characteristics of peptidoglycan fragments required to prime mice for induction of anaphylactoid reactions by lipopolysaccharides.

    OpenAIRE

    Takada, H.; Kawabata, Y.; Kawata, S; Kusumoto, S

    1996-01-01

    Structural characteristics of peptidoglycan fragments required to prime mice for the induction of anaphylactoid reactions by Salmonella abortusequi lipopolysaccharide were examined in endotoxin-resistant C3H/HeJ mice, with special focus on the disaccharide-pentapeptide [N-acetylglucosaminyl-beta(1-4)-N-acetylmuramyl-L-alanyl-D -isoglutaminyl-meso-2,6-diaminopimelyl (DAP)-D-alanyl-D -alanine] and its smaller partial derivatives. The bacterial and synthetic muramyl tripeptides (DAP- and lysine ...

  5. Peptidoglycan biosynthesis in Neisseria gonorrhoeae strains sensitive and intrinsically resistant to beta-lactam antibiotics.

    OpenAIRE

    Dougherty, T J

    1983-01-01

    Treatment of penicillin-sensitive and intrinsically resistant Neisseria gonorrhoeae strains with their respective inhibitory concentrations of penicillin caused rapid cell death. When the peptidoglycan syntheses of these two strains were examined in the presence of penicillin, the sensitive strain continued to make this cell wall polymer for an extended time, whereas the resistant strain underwent a rapid and marked depression in synthesis. Examination of the labeled sodium dodecyl sulfate-in...

  6. Proteolytic activation of human pancreatitis associated protein is required for peptidoglycan binding and bacterial aggregation

    OpenAIRE

    Medveczky, Péter; Szmola, Richárd; Sahin-Tóth, Miklós

    2009-01-01

    Pancreatitis associated protein (PAP) is a 16 kDa lectin-like protein, which becomes robustly upregulated in the pancreatic juice during acute pancreatitis. Trypsin cleaves the N terminus of PAP, which in turn forms insoluble fibrils. PAP and its paralog the pancreatic stone protein induce bacterial aggregation and, more recently, PAP was shown to bind to the peptidoglycan of Gram positive bacteria and exert a direct bactericidal effect. However, the role of N-terminal processing in the antib...

  7. Transcriptional profiles of the response of methicillin-resistant Staphylococcus aureus to pentacyclic triterpenoids.

    Directory of Open Access Journals (Sweden)

    Pooi Yin Chung

    Full Text Available Staphylococcus aureus is an important human pathogen in both hospital and the community that has demonstrated resistance to all currently available antibiotics over the last two decades. Multidrug-resistant isolates of methicillin-resistant S. aureus (MRSA exhibiting decreased susceptibilities to glycopeptides has also emerged, representing a crucial challenge for antimicrobial therapy and infection control. The availability of complete whole-genome nucleotide sequence data of various strains of S. aureus presents an opportunity to explore novel compounds and their targets to address the challenges presented by antimicrobial drug resistance in this organism. Study compounds α-amyrin [3β-hydroxy-urs-12-en-3-ol (AM], betulinic acid [3β-hydroxy-20(29-lupaene-28-oic acid (BA] and betulinaldehyde [3β-hydroxy-20(29-lupen-28-al (BE] belong to pentacyclic triterpenoids and were reported to exhibit antimicrobial activities against bacteria and fungi, including S. aureus. The MIC values of these compounds against a reference strain of methicillin-resistant S. aureus (MRSA (ATCC 43300 ranged from 64 µg/ml to 512 µg/ml. However, the response mechanisms of S. aureus to these compounds are still poorly understood. The transcription profile of reference strain of MRSA treated with sub-inhibitory concentrations of the three compounds was determined using Affymetrix GeneChips. The findings showed that these compounds regulate multiple desirable targets in cell division, two-component system, ABC transporters, fatty acid biosynthesis, peptidoglycan biosynthesis, aminoacyl-tRNA synthetase, ribosome and β-lactam resistance pathways which could be further explored in the development of therapeutic agents for the treatment of S. aureus infections.

  8. A new factor stimulating peptidoglycan hydrolysis to separate daughter cells in Caulobacter crescentus.

    Science.gov (United States)

    Collier, Justine

    2010-07-01

    Cell division in Gram-negative bacteria involves the co-ordinated invagination of the three cell envelope layers to form two new daughter cell poles. This complex process starts with the polymerization of the tubulin-like protein FtsZ into a Z-ring at mid-cell, which drives cytokinesis and recruits numerous other proteins to the division site. These proteins are involved in Z-ring constriction, inner- and outer-membrane invagination, peptidoglycan remodelling and daughter cell separation. Three papers in this issue of Molecular Microbiology, from the teams of Lucy Shapiro, Martin Thanbichler and Christine Jacobs-Wagner, describe a novel protein, called DipM for Division Involved Protein with LysM domains, that is required for cell division in Caulobacter crescentus. DipM localizes to the mid-cell during cell division, where it is necessary for the hydrolysis of the septal peptidoglycan to remodel the cell wall. Loss of DipM results in severe defects in cell envelope constriction, which is deleterious under fast-growth conditions. State-of-the-art microscopy experiments reveal that the peptidoglycan is thicker and that the cell wall is incorrectly organized in DipM-depleted cells compared with wild-type cells, demonstrating that DipM is essential for reorganizing the cell wall at the division site, for envelope invagination and cell separation in Caulobacter.

  9. Staphylococcus aureus Transcriptome Architecture

    DEFF Research Database (Denmark)

    Mäder, Ulrike; Nicolas, Pierre; Depke, Maren;

    2016-01-01

    Staphylococcus aureus is a major pathogen that colonizes about 20% of the human population. Intriguingly, this Gram-positive bacterium can survive and thrive under a wide range of different conditions, both inside and outside the human body. Here, we investigated the transcriptional adaptation of S....... aureus HG001, a derivative of strain NCTC 8325, across experimental conditions ranging from optimal growth in vitro to intracellular growth in host cells. These data establish an extensive repertoire of transcription units and non-coding RNAs, a classification of 1412 promoters according...... to their dependence on the RNA polymerase sigma factors SigA or SigB, and allow identification of new potential targets for several known transcription factors. In particular, this study revealed a relatively low abundance of antisense RNAs in S. aureus, where they overlap only 6% of the coding genes, and only 19...

  10. Inhibition of Peptidoglycan, Ribonucleic Acid, and Protein Synthesis in Tolerant Strains of Streptococcus mutans

    Science.gov (United States)

    Mychajlonka, Myron; McDowell, Thomas D.; Shockman, Gerald D.

    1980-01-01

    Exposure of exponentially growing cultures of Streptococcus mutans strains FA-1 and GS-5 to various concentrations of benzylpenicillin (Pen G) resulted in inhibition of turbidity increases at low concentrations (0.02 to 0.04 μg/ml). However, in contrast to some other streptococcal species, growth inhibition was not accompanied by cellular lysis or by a rapid loss of viability. In both strains, synthesis of insoluble cell wall peptidoglycan was very sensitive to Pen G inhibition and responded in a dose-dependent manner to concentrations of about 0.2 and 0.5 μg/ml for strains GS-5 and FA-1, respectively. Higher Pen G concentrations failed to inhibit further either growth or insoluble peptidoglycan assembly. Somewhat surprisingly, Pen G also inhibited both ribonucleic acid (RNA) and protein syntheses, each in a dose-dependent manner. Compared with inhibition of peptidoglycan synthesis, inhibition of RNA and protein syntheses by Pen G was less rapid and less extensive. Maximum amounts of radiolabeled Pen G were specifically bound to intact cells upon exposure to about 0.2 and 0.5 μg/ml of Pen G for strains GS-5 and FA-1, respectively, concentrations consistent with those that resulted in maximum or near-maximum inhibitions of the synthesis of cellular peptidoglycan, RNA, and protein. Five polypeptide bands that had a very high affinity for [14C]Pen G were detected in a crude cell envelope preparation of strain FA-1. After exposure of cultures of strain FA-1 to the effects of saturating concentrations of the drug for up to 3 h, addition of penicillinase was followed by recovery of growth after a lag. The length of the lag before regrowth depended on both Pen G concentration and time of exposure. On the basis of these and other observations, it is proposed that the secondary inhibitions of cellular RNA or protein synthesis, or both, are involved in the tolerance of these organisms to lysis and killing by Pen G and other inhibitors of insoluble peptidoglycan assembly

  11. The mechanism of antimicrobial activity of sophoraflavanone B against methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Mun, Su-Hyun; Joung, Dae-Ki; Kim, Sung-Bae; Park, Sung-Joo; Seo, Yun-Soo; Gong, Ryong; Choi, Jang-Gi; Shin, Dong-Won; Rho, Jung-Rae; Kang, Ok-Hwa; Kwon, Dong-Yeul

    2014-03-01

    Sophoraflavanone B (SPF-B), a prenylated flavonoid, can be isolated from the roots of Desmodium caudatum. The aim of this study was to determine the mechanism of SPF-B's antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA). MRSA is a multidrug-resistant pathogen and the main cause of hospital- and community-acquired infections. The minimum inhibitory concentration (MIC) of SPF-B was assessed using the broth microdilution method. The mechanism of action of SPF-B on S. aureus was analyzed in combination assays incorporating detergents, ATPase inhibitors, and peptidoglycan (PGN) derived from S. aureus. Furthermore, morphological changes in the SPF-B-treated MRSA strains were investigated using transmission electron microscopy. The MIC of SPF-B for MRSA was in the range of 15.6-31.25 μg/mL. The mechanism of action of SPF-B on MRSA was investigated using combination assays with detergent and ATPase inhibitors. The optical density at 600 nm of MRSA suspensions treated with a combination of detergent and SPF-B reduced the MRSA by 63%-73%. In the SPF-B and PGN combination assay, direct binding of SPF-B with PGN from S. aureus was evident. These data may be validated for the development of new antibacterial drugs for low MRSA resistance. PMID:24601672

  12. Living with an imperfect cell wall: compensation of femAB inactivation in Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Bierbaum Gabriele

    2007-09-01

    Full Text Available Abstract Background Synthesis of the Staphylococcus aureus peptidoglycan pentaglycine interpeptide bridge is catalyzed by the nonribosomal peptidyl transferases FemX, FemA and FemB. Inactivation of the femAB operon reduces the interpeptide to a monoglycine, leading to a poorly crosslinked peptidoglycan. femAB mutants show a reduced growth rate and are hypersusceptible to virtually all antibiotics, including methicillin, making FemAB a potential target to restore β-lactam susceptibility in methicillin-resistant S. aureus (MRSA. Cis-complementation with wild type femAB only restores synthesis of the pentaglycine interpeptide and methicillin resistance, but the growth rate remains low. This study characterizes the adaptations that ensured survival of the cells after femAB inactivation. Results In addition to slow growth, the cis-complemented femAB mutant showed temperature sensitivity and a higher methicillin resistance than the wild type. Transcriptional profiling paired with reporter metabolite analysis revealed multiple changes in the global transcriptome. A number of transporters for sugars, glycerol, and glycine betaine, some of which could serve as osmoprotectants, were upregulated. Striking differences were found in the transcription of several genes involved in nitrogen metabolism and the arginine-deiminase pathway, an alternative for ATP production. In addition, microarray data indicated enhanced expression of virulence factors that correlated with premature expression of the global regulators sae, sarA, and agr. Conclusion Survival under conditions preventing normal cell wall formation triggered complex adaptations that incurred a fitness cost, showing the remarkable flexibility of S. aureus to circumvent cell wall damage. Potential FemAB inhibitors would have to be used in combination with other antibiotics to prevent selection of resistant survivors.

  13. A comparative modeling and molecular docking study on Mycobacterium tuberculosis targets involved in peptidoglycan biosynthesis.

    Science.gov (United States)

    Fakhar, Zeynab; Naiker, Suhashni; Alves, Claudio N; Govender, Thavendran; Maguire, Glenn E M; Lameira, Jeronimo; Lamichhane, Gyanu; Kruger, Hendrik G; Honarparvar, Bahareh

    2016-11-01

    An alarming rise of multidrug-resistant Mycobacterium tuberculosis strains and the continuous high global morbidity of tuberculosis have reinvigorated the need to identify novel targets to combat the disease. The enzymes that catalyze the biosynthesis of peptidoglycan in M. tuberculosis are essential and noteworthy therapeutic targets. In this study, the biochemical function and homology modeling of MurI, MurG, MraY, DapE, DapA, Alr, and Ddl enzymes of the CDC1551 M. tuberculosis strain involved in the biosynthesis of peptidoglycan cell wall are reported. Generation of the 3D structures was achieved with Modeller 9.13. To assess the structural quality of the obtained homology modeled targets, the models were validated using PROCHECK, PDBsum, QMEAN, and ERRAT scores. Molecular dynamics simulations were performed to calculate root mean square deviation (RMSD) and radius of gyration (Rg) of MurI and MurG target proteins and their corresponding templates. For further model validation, RMSD and Rg for selected targets/templates were investigated to compare the close proximity of their dynamic behavior in terms of protein stability and average distances. To identify the potential binding mode required for molecular docking, binding site information of all modeled targets was obtained using two prediction algorithms. A docking study was performed for MurI to determine the potential mode of interaction between the inhibitor and the active site residues. This study presents the first accounts of the 3D structural information for the selected M. tuberculosis targets involved in peptidoglycan biosynthesis.

  14. Prevalence and antibiotic susceptibility of methicillin-resistant Staphylococcus aureus in ocular infections

    Directory of Open Access Journals (Sweden)

    Maria Eugenia Vola

    2013-12-01

    Full Text Available PURPOSE: To study the prevalence of methicillin-resistant Staphylococcus aureus among S. aureus ocular infections in a tertiary health center in Brazil and compare antibiotic susceptibility patterns between MRSA and methicillin-susceptible S. aureus isolates. METHODS: Electronic records from the ocular microbiology laboratory of the Universidade Federal de São Paulo were retrospectively reviewed. During a 10-year period (between January 2000 and December 2009 all conjunctivitis, keratitis, and endophthalmitis cases with a positive culture for S. aureus were identified. Antibiotic susceptibility was determined using the Kirby-Bauer disk diffusion method. RESULTS: Five hundred sixty-six S. aureus isolates were identified; of those, 56 (9.9% were resistant to methicillin. Throughout the 10-year period, Staphylococcus aureus showed a significant increasing trend from 7.55% to 16.18% among overall S. aurues infections (p=0.001 and from 3.7% to 13.16% in conjunctivitis (p=0.001. Conversely, we did not observe the same trend among those with keratitis (p=0.38. Staphylococcus aureus isolates showed higher resistance rates to tobramycin, gentamicin, ciprofloxacin, gatifloxacin, and moxifloxacin when compared with S. aureus isolates (p< 0.001. All cases were susceptible to vancomycin. CONCLUSION: We observed an increasing trend in the overall prevalence of Staphylococcus aureus ocular infections and statistically significant higher resistance rates to commonly used antibiotics compared to Staphylococcus aureus. Our data supports the need for constant bacterial surveillance and should be taken into consideration before initiating empiric treatment of ocular infections.

  15. Bacterial Pathogens of Ventilator Associated Pneumonia in a Tertiary Referral Hospital

    OpenAIRE

    Chi, Su Young; Kim, Tae Ok; Park, Chan Woo; Yu, Jin Yeong; Lee, Boram; Lee, Ho Sung; Kim, Yu Il; Lim, Sung Chul; Kwon, Yong Soo

    2012-01-01

    Background This study evaluates the bacterial pathogens of Ventilator-associated pneumonia (VAP) in a tertiary referral hospital. Methods A total of 109 bacterial pathogens from 91 adult patients with VAP, who were admitted to the medical intensive care unit from January 2008 to December 2009, were examined. Clinical characteristics, bacterial pathogens, and resistance profiles were analyzed. Results Staphylococcus aureus (44%) was the most frequently isolated. Acinetobacter baumanii (30%), P...

  16. DipM, a new factor required for peptidoglycan remodelling during cell division in Caulobacter crescentus.

    Science.gov (United States)

    Möll, Andrea; Schlimpert, Susan; Briegel, Ariane; Jensen, Grant J; Thanbichler, Martin

    2010-07-01

    In bacteria, cytokinesis is dependent on lytic enzymes that facilitate remodelling of the cell wall during constriction. In this work, we identify a thus far uncharacterized periplasmic protein, DipM, that is required for cell division and polarity in Caulobacter crescentus. DipM is composed of four peptidoglycan binding (LysM) domains and a C-terminal lysostaphin-like (LytM) peptidase domain. It binds to isolated murein sacculi in vitro, and is recruited to the site of constriction through interaction with the cell division protein FtsN. Mutational analyses showed that the LysM domains are necessary and sufficient for localization of DipM, while its peptidase domain is essential for function. Consistent with a role in cell wall hydrolysis, DipM was found to interact with purified murein sacculi in vitro and to induce cell lysis upon overproduction. Its inactivation causes severe defects in outer membrane invagination, resulting in a significant delay between cytoplasmic compartmentalization and final separation of the daughter cells. Overall, these findings indicate that DipM is a periplasmic component of the C. crescentus divisome that facilitates remodelling of the peptidoglycan layer and, thus, coordinated constriction of the cell envelope during the division process.

  17. Growth medium-dependent glycine incorporation into the peptidoglycan of Caulobacter crescentus.

    Directory of Open Access Journals (Sweden)

    Constantin N Takacs

    Full Text Available The peptidoglycan (PG is a macromolecular component of the bacterial cell wall that maintains the shape and integrity of the cell. The PG of Caulobacter crescentus, unlike that of many other Gram-negative bacteria, has repeatedly been shown to contain significant amounts of glycine. This compositional peculiarity has been deemed an intrinsic characteristic of this species. By performing a comprehensive qualitative and quantitative analysis of the C. crescentus PG by high-performance liquid chromatography (HPLC and mass spectrometry (MS, we show here that glycine incorporation into the C. crescentus PG depends on the presence of exogenous glycine in the growth medium. High levels of glycine were detected at the fifth position of the peptide side chains of PG isolated from C. crescentus cells grown in the complex laboratory medium PYE or in defined medium (M2G supplemented with casamino acids or glycine alone. In contrast, glycine incorporation was undetectable when cells were grown in M2G medium lacking glycine. Remarkably, glycine incorporation into C. crescentus peptidoglycan occurred even in the presence of low millimolar to sub-millimolar concentrations of free glycine. High glycine content in the PG had no obvious effects on growth rates, mode of PG incorporation or cell morphology. Hence, the C. crescentus PG is able to retain its physiological functions in cell growth and morphogenesis despite significant alterations in its composition, in what we deem to be unprecedented plasticity.

  18. Growth medium-dependent glycine incorporation into the peptidoglycan of Caulobacter crescentus.

    Science.gov (United States)

    Takacs, Constantin N; Hocking, Jason; Cabeen, Matthew T; Bui, Nhat Khai; Poggio, Sebastian; Vollmer, Waldemar; Jacobs-Wagner, Christine

    2013-01-01

    The peptidoglycan (PG) is a macromolecular component of the bacterial cell wall that maintains the shape and integrity of the cell. The PG of Caulobacter crescentus, unlike that of many other Gram-negative bacteria, has repeatedly been shown to contain significant amounts of glycine. This compositional peculiarity has been deemed an intrinsic characteristic of this species. By performing a comprehensive qualitative and quantitative analysis of the C. crescentus PG by high-performance liquid chromatography (HPLC) and mass spectrometry (MS), we show here that glycine incorporation into the C. crescentus PG depends on the presence of exogenous glycine in the growth medium. High levels of glycine were detected at the fifth position of the peptide side chains of PG isolated from C. crescentus cells grown in the complex laboratory medium PYE or in defined medium (M2G) supplemented with casamino acids or glycine alone. In contrast, glycine incorporation was undetectable when cells were grown in M2G medium lacking glycine. Remarkably, glycine incorporation into C. crescentus peptidoglycan occurred even in the presence of low millimolar to sub-millimolar concentrations of free glycine. High glycine content in the PG had no obvious effects on growth rates, mode of PG incorporation or cell morphology. Hence, the C. crescentus PG is able to retain its physiological functions in cell growth and morphogenesis despite significant alterations in its composition, in what we deem to be unprecedented plasticity.

  19. An endogenous nanomineral chaperones luminal antigen and peptidoglycan to intestinal immune cells

    Science.gov (United States)

    Powell, Jonathan J.; Thomas-McKay, Emma; Thoree, Vinay; Robertson, Jack; Hewitt, Rachel E.; Skepper, Jeremy N.; Brown, Andy; Hernandez-Garrido, Juan Carlos; Midgley, Paul A.; Gomez-Morilla, Inmaculada; Grime, Geoffrey W.; Kirkby, Karen J.; Mabbott, Neil A.; Donaldson, David S.; Williams, Ifor R.; Rios, Daniel; Girardin, Stephen E.; Haas, Carolin T.; Bruggraber, Sylvaine F. A.; Laman, Jon D.; Tanriver, Yakup; Lombardi, Giovanna; Lechler, Robert; Thompson, Richard P. H.; Pele, Laetitia C.

    2015-05-01

    In humans and other mammals it is known that calcium and phosphate ions are secreted from the distal small intestine into the lumen. However, why this secretion occurs is unclear. Here, we show that the process leads to the formation of amorphous magnesium-substituted calcium phosphate nanoparticles that trap soluble macromolecules, such as bacterial peptidoglycan and orally fed protein antigens, in the lumen and transport them to immune cells of the intestinal tissue. The macromolecule-containing nanoparticles utilize epithelial M cells to enter Peyer's patches, small areas of the intestine concentrated with particle-scavenging immune cells. In wild-type mice, intestinal immune cells containing these naturally formed nanoparticles expressed the immune tolerance-associated molecule ‘programmed death-ligand 1’, whereas in NOD1/2 double knockout mice, which cannot recognize peptidoglycan, programmed death-ligand 1 was undetected. Our results explain a role for constitutively formed calcium phosphate nanoparticles in the gut lumen and show how this helps to shape intestinal immune homeostasis.

  20. Streptococcus pneumoniae GAPDH Is Released by Cell Lysis and Interacts with Peptidoglycan.

    Directory of Open Access Journals (Sweden)

    Rémi Terrasse

    Full Text Available Release of conserved cytoplasmic proteins is widely spread among Gram-positive and Gram-negative bacteria. Because these proteins display additional functions when located at the bacterial surface, they have been qualified as moonlighting proteins. The GAPDH is a glycolytic enzyme which plays an important role in the virulence processes of pathogenic microorganisms like bacterial invasion and host immune system modulation. However, GAPDH, like other moonlighting proteins, cannot be secreted through active secretion systems since they do not contain an N-terminal predicted signal peptide. In this work, we investigated the mechanism of GAPDH export and surface retention in Streptococcus pneumoniae, a major human pathogen. We addressed the role of the major autolysin LytA in the delivery process of GAPDH to the cell surface. Pneumococcal lysis is abolished in the ΔlytA mutant strain or when 1% choline chloride is added in the culture media. We showed that these conditions induce a marked reduction in the amount of surface-associated GAPDH. These data suggest that the presence of GAPDH at the surface of pneumococcal cells depends on the LytA-mediated lysis of a fraction of the cell population. Moreover, we demonstrated that pneumococcal GAPDH binds to the bacterial cell wall independently of the presence of the teichoic acids component, supporting peptidoglycan as a ligand to surface GAPDH. Finally, we showed that peptidoglycan-associated GAPDH recruits C1q from human serum but does not activate the complement pathway.

  1. An Endogenous Nanomineral Chaperones Luminal Antigen and Peptidoglycan to Intestinal Immune Cells

    Science.gov (United States)

    Powell, Jonathan J; Thomas-McKay, Emma; Thoree, Vinay; Robertson, Jack; Hewitt, Rachel E; Skepper, Jeremy N; Brown, Andy; Hernandez-Garrido, Juan Carlos; Midgley, Paul A; Gomez-Morilla, Inmaculada; Grime, Geoffrey W; Kirkby, Karen J; Mabbott, Neil A; Donaldson, David S; Williams, Ifor R; Rios, Daniel; Girardin, Stephen E; Haas, Carolin T; Bruggraber, Sylvaine FA; Laman, Jon D; Tanriver, Yakup; Lombardi, Giovanna; Lechler, Robert; Thompson, Richard P H; Pele, Laetitia C

    2015-01-01

    In humans and other mammals, it is known that calcium and phosphate ions are secreted from the distal small intestine into the lumen. However, why this secretion occurs is unclear. Here, we show that the process leads to the formation of amorphous magnesium-substituted calcium phosphate nanoparticles that trap soluble macromolecules, such as bacterial peptidoglycan and orally-fed protein antigens, in the lumen and transport them to immune cells of the intestinal tissue. The macromolecule-containing nanoparticles utilize epithelial M cells to enter Peyer’s patches - small areas of the intestine concentrated with particle-scavenging immune cells. In wild type mice, intestinal immune cells containing these naturally-formed nanoparticles expressed the immune tolerance-associated molecule ‘programmed death-ligand 1 (PD-L1)’, whereas in NOD1/2 double knock-out mice, which cannot recognize peptidoglycan, PD-L1 was undetected. Our results explain a role for constitutively formed calcium phosphate nanoparticles in the gut lumen and how this helps to shape intestinal immune homeostasis. PMID:25751305

  2. Single-molecule dynamics of lysozyme processing distinguishes linear and cross-linked peptidoglycan substrates.

    Science.gov (United States)

    Choi, Yongki; Moody, Issa S; Sims, Patrick C; Hunt, Steven R; Corso, Brad L; Seitz, David E; Blaszczak, Larry C; Blaszcazk, Larry C; Collins, Philip G; Weiss, Gregory A

    2012-02-01

    The dynamic processivity of individual T4 lysozyme molecules was monitored in the presence of either linear or cross-linked peptidoglycan substrates. Single-molecule monitoring was accomplished using a novel electronic technique in which lysozyme molecules were tethered to single-walled carbon nanotube field-effect transistors through pyrene linker molecules. The substrate-driven hinge-bending motions of lysozyme induced dynamic electronic signals in the underlying transistor, allowing long-term monitoring of the same molecule without the limitations of optical quenching or bleaching. For both substrates, lysozyme exhibited processive low turnover rates of 20-50 s(-1) and rapid (200-400 s(-1)) nonproductive motions. The latter nonproductive binding events occupied 43% of the enzyme's time in the presence of the cross-linked peptidoglycan but only 7% with the linear substrate. Furthermore, lysozyme catalyzed the hydrolysis of glycosidic bonds to the end of the linear substrate but appeared to sidestep the peptide cross-links to zigzag through the wild-type substrate.

  3. The staphylococcal surface-glycopolymer wall teichoic acid (WTA) is crucial for complement activation and immunological defense against Staphylococcus aureus infection.

    Science.gov (United States)

    Kurokawa, Kenji; Takahashi, Kazue; Lee, Bok Luel

    2016-10-01

    Staphylococcus aureus is a Gram-positive bacterial pathogen that is decorated by glycopolymers, including wall teichoic acid (WTA), peptidoglycan, lipoteichoic acid, and capsular polysaccharides. These bacterial surface glycopolymers are recognized by serum antibodies and a variety of pattern recognition molecules, including mannose-binding lectin (MBL). Recently, we demonstrated that human serum MBL senses staphylococcal WTA. Whereas MBL in infants who have not yet fully developed adaptive immunity binds to S. aureus WTA and activates complement serum, MBL in adults who have fully developed adaptive immunity cannot bind to WTA because of an inhibitory effect of serum anti-WTA IgG. Furthermore, we showed that human anti-WTA IgGs purified from pooled adult serum IgGs triggered activation of classical complement-dependent opsonophagocytosis against S. aureus. Because the epitopes of WTA that are recognized by anti-WTA IgG and MBL have not been determined, we constructed several S. aureus mutants with altered WTA glycosylation. Our intensive biochemical studies provide evidence that the β-GlcNAc residues of WTA are required for the induction of anti-WTA IgG-mediated opsonophagocytosis and that both β- and α-GlcNAc residues are required for MBL-mediated complement activation. The molecular interactions of other S. aureus cell wall components and host recognition proteins are also discussed. In summary, in this review, we discuss the biological importance of S. aureus cell surface glycopolymers in complement activation and host defense responses. PMID:27424796

  4. Ultrastructural changes in methicillin-resistant Staphylococcus aureus induced by positively charged silver nanoparticles

    Directory of Open Access Journals (Sweden)

    Dulce G. Romero-Urbina

    2015-12-01

    Full Text Available Silver nanoparticles offer a possible means of fighting antibacterial resistance. Most of their antibacterial properties are attributed to their silver ions. In the present work, we study the actions of positively charged silver nanoparticles against both methicillin-sensitive Staphylococcus aureus and methicillin-resistant Staphylococcus aureus. We use aberration-corrected transmission electron microscopy to examine the bactericidal effects of silver nanoparticles and the ultrastructural changes in bacteria that are induced by silver nanoparticles. The study revealed that our 1 nm average size silver nanoparticles induced thinning and permeabilization of the cell wall, destabilization of the peptidoglycan layer, and subsequent leakage of intracellular content, causing bacterial cell lysis. We hypothesize that positively charged silver nanoparticles bind to the negatively charged polyanionic backbones of teichoic acids and the related cell wall glycopolymers of bacteria as a first target, consequently stressing the structure and permeability of the cell wall. This hypothesis provides a major mechanism to explain the antibacterial effects of silver nanoparticles on Staphylococcus aureus. Future research should focus on defining the related molecular mechanisms and their importance to the antimicrobial activity of silver nanoparticles.

  5. The Antibacterial Assay of Tectorigenin with Detergents or ATPase Inhibitors against Methicillin-Resistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Dae-Ki Joung

    2014-01-01

    Full Text Available Tectorigenin (TTR is an O-methylated isoflavone derived from the rhizome of Belamacanda chinensis (L. DC. It is known to perform a wide spectrum of biological activities such as antioxidant, anti-inflammatory, anti-tumor. The aim of this study is to examine the mechanism of antibacterial activity of TTR against methicillin-resistant Staphylococcus aureus (MRSA. The anti-MRSA activity of TTR was analyzed in combination assays with detergent, ATPase inhibitors, and peptidoglycan (PGN derived from S. aureus. Transmission electron microscopy (TEM was used to monitor survival characteristics and changes in S. aureus morphology. The MIC values of TTR against all the tested strains were 125 μg/mL. The OD(600 of each suspension treated with a combination of Triton X-100, DCCD, and NaN3 with TTR (1/10 × MIC had been reduced from 68% to 80%, compared to the TTR alone. At a concentration of 125 μg/mL, PGN blocked antibacterial activity of TTR. This study indicates that anti-MRSA action of TTR is closely related to cytoplasmic membrane permeability and ABC transporter, and PGN at 125 μg/mL directly bind to and inhibit TTR at 62.5 μg/mL. These results can be important indication in study on antimicrobial activity mechanism against multidrug resistant strains.

  6. Airborne peptidoglycans as a supporting indicator of bacterial contamination in a metal processing plant

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    Marcin Cyprowski

    2016-06-01

    Full Text Available Objectives: The aim of this study was to assess exposure to airborne endotoxins and peptidoglycans (PGs as well as possibility of using PGs as a surrogate measure of bacterial exposure in workplaces in a metal processing plant. Material and Methods: Personal dosimetry (N = 11 was used to obtain data on concentrations of viable bacteria, total number of bioaerosol particles, endotoxins and peptidoglycans. To investigate the size distributions of aerosol particles responsible for transport of endotoxins and PGs, air samples (N = 5 were additionally collected using the 8-stage cascade impactor. Endotoxins and PGs were assayed with the Limulus amebocyte lysate (LAL test and a kinetic version of the silkworm larvae plasma (SLP test, respectively. Results: Median concentrations of airborne PGs (14.6 ng/m3, endotoxins (0.2 ng/m3, viable bacteria (1.16×103 CFU/m3 and the total number of bioaerosol particles (1.81×106 cells/m3 were determined. Qualitative analysis revealed presence of 19 bacterial species belonging to 14 genera. The calculations showed strong, significant correlations (p < 0.05 between endotoxins, viable bacteria (r = 0.75 and the total number of bioaerosol particle concentrations (r = 0.76 as well as between PGs and the total number of bioaerosol particle concentrations (r = 0.72. Size distribution analysis showed that the highest concentrations of bacterial aerosols occurred in the range of 2.1–3.3 μm. In the case of endotoxins, an increase of concentrations in 2 ranges of aerodynamic diameters: 1.1–3.3 μm and 5.8–9 μm was shown. For PGs there was a visible gradual increase of their concentrations in the range 2.1–9 μm. Conclusions: Peptidoglycans can be treated as a supporting indicator of bacterial contamination in metal processing plants, particularly when an assessment of an immunotoxic potential of microbiological hazards needs to be performed. However, to be extrapolated to other occupational and non

  7. When are the hands of healthcare workers positive for methicillin-resistant Staphylococcus aureus?

    OpenAIRE

    Creamer, Eilish; Dorrian, Sarah; Dolan, Anthony; Sherlock, Orla; Fitzgerald-Hughes, Deirdre; Thomas, Toney; Walsh, John; Shore, A; Sullivan, D.; Kinnevey, Peter M; Rossney, A S; Cunney, Robert; Coleman, David; Humphreys, Hilary

    2010-01-01

    Hand hygiene is a key component in reducing infection. There are few reports on the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) on healthcare workers' (HCWs') hands. The aim of this study was to establish whether HCWs' fingertips were contaminated with MRSA in a clinical hospital setting. The study was conducted in an acute tertiary referral hospital on four MRSA wards that were part of a larger research study on MRSA epidemiology and four other wards not included in the ...

  8. Predictive Value of Methicillin-Resistant Staphylococcus aureus (MRSA) Nasal Swab PCR Assay for MRSA Pneumonia

    OpenAIRE

    Dangerfield, Benjamin; Chung, Andrew; Webb, Brandon; Seville, Maria Teresa

    2014-01-01

    Pneumonia due to methicillin-resistant Staphylococcus aureus (MRSA) is associated with poor outcomes and frequently merits empirical antibiotic consideration despite its relatively low incidence. Nasal colonization with MRSA is associated with clinical MRSA infection and can be reliably detected using the nasal swab PCR assay. In this study, we evaluated the performance of the nasal swab MRSA PCR in predicting MRSA pneumonia. A retrospective cohort study was performed in a tertiary care cente...

  9. Antitumoural activity of a cytotoxic peptide of Lactobacillus casei peptidoglycan and its interaction with mitochondrial-bound hexokinase.

    Science.gov (United States)

    Fichera, Giuseppe A; Fichera, Marco; Milone, Giuseppe

    2016-08-01

    In a previous study, we reported the cytotoxic activity against various tumour cells of the peptidoglycan of Lactobacillus casei. To isolate the most active components, we performed column-chromatography separation of the peptidoglycan complex and tested the related fractions for their cytotoxic activity. The most active fractions were then lyophilized and the residue was analysed by gas chromatography for its amino acid content and composition. On the basis of the known chemical formula of the basic peptidic component of the peptidoglycan complex of L. casei, a peptide was then synthesized [Europ. (CH-DE-FR-GB) Patent number 1217005; IT number 01320177] and its cytotoxicity was tested against tumoural and normal cells. The synthetic peptide was found to impair the entire metabolism of cultured tumour cells and to restore the apoptotic process. By contrast, normal cells appeared to be stimulated rather than inhibited by the peptide, whereas primary mouse embryo fibroblasts behaved similarly to tumour cells. On the basis of these results, L. casei peptidoglycan fragments and their constituent basic peptide might be applicable as potent antitumour agents. PMID:27101258

  10. IgM antibody level against proinflammatory bacterial peptidoglycan is inversely correlated with extent of atherosclerotic disease

    NARCIS (Netherlands)

    M.M.O. Nijhuis; Y. van der Graaf (Yolanda); M.J. Melief; A.H. Schoneveld (Arjan); D.P.V. de Kleijn (Dominique); J.D. Laman (Jon); G. Pasterkamp (Gerard)

    2004-01-01

    textabstractObjective: Atherosclerosis may lead to acute clinical events by rupture of a vulnerable atherosclerotic plaque. Previously, we demonstrated that peptidoglycan (PGN), a major cell wall component of gram-positive bacteria that induces production of proinflammatory cytokines through TLR2 an

  11. Orthologous and Paralogous AmpD Peptidoglycan Amidases from Gram-Negative Bacteria

    Science.gov (United States)

    Rivera, Ivanna; Molina, Rafael; Lee, Mijoon; Mobashery, Shahriar

    2016-01-01

    Cell wall recycling and β-lactam antibiotic resistance are linked in Enterobacteriaceae and in Pseudomonas aeruginosa. This process involves a large number of murolytic enzymes, among them a cytoplasmic peptidoglycan amidase AmpD, which plays an essential role by cleaving the peptide stem from key intermediates en route to the β-lactamase production (a resistance mechanism) and cell wall recycling. Uniquely, P. aeruginosa has two additional paralogues of AmpD, designated AmpDh2 and AmpDh3, which are periplasmic enzymes. Despite the fact that AmpDh2 and AmpDh3 share a common motif for their respective catalytic domains, they are each comprised of multidomain architectures and exhibit distinct oligomerization properties. We review herein the structural and biochemical properties of orthologous and paralogous AmpD proteins and discuss their implication in cell wall recycling and antibiotic resistance processes. PMID:27326855

  12. Lyme disease and relapsing fever Borrelia elongate through zones of peptidoglycan synthesis that mark division sites of daughter cells.

    Science.gov (United States)

    Jutras, Brandon Lyon; Scott, Molly; Parry, Bradley; Biboy, Jacob; Gray, Joe; Vollmer, Waldemar; Jacobs-Wagner, Christine

    2016-08-16

    Agents that cause Lyme disease, relapsing fever, leptospirosis, and syphilis belong to the phylum Spirochaetae-a unique lineage of bacteria most known for their long, spiral morphology. Despite the relevance to human health, little is known about the most fundamental aspects of spirochete growth. Here, using quantitative microscopy to track peptidoglycan cell-wall synthesis, we found that the Lyme disease spirochete Borrelia burgdorferi displays a complex pattern of growth. B. burgdorferi elongates from discrete zones that are both spatially and temporally regulated. In addition, some peptidoglycan incorporation occurs along the cell body, with the notable exception of a large region at the poles. Newborn cells inherit a highly active zone of peptidoglycan synthesis at midcell that contributes to elongation for most of the cell cycle. Concomitant with the initiation of nucleoid separation and cell constriction, second and third zones of elongation are established at the 1/4 and 3/4 cellular positions, marking future sites of division for the subsequent generation. Positioning of elongation zones along the cell is robust to cell length variations and is relatively precise over long distances (>30 µm), suggesting that cells ‟sense" relative, as opposed to absolute, cell length to establish zones of peptidoglycan synthesis. The transition from one to three zones of peptidoglycan growth during the cell cycle is also observed in relapsing fever Borrelia. However, this mode of growth does not extend to representative species from other spirochetal genera, suggesting that this distinctive growth mode represents an evolutionary divide in the spirochete phylum. PMID:27506799

  13. Nosocomial bloodstream infection in patients caused by Staphylococcus aureus: drug susceptibility, outcome, and risk factors for hospital mortality

    Institute of Scientific and Technical Information of China (English)

    CHEN Rong; YAN Zhong-qiang; FENG Dan; LUO Yan-ping; WANG Lei-li; SHEN Ding-xia

    2012-01-01

    Background Previous studies have different viewpoints about the clinical impact of methicillin resistance on mortality of hospital-acquired bloodstream infection (BSI) patients with Staphylococcus aureus (S.aureus).The objective of this study was to investigate the mortality of hospital-acquired BSI with S.aureus in a military hospital and analyze the risk factors for the hospital mortality.Methods A retrospective cohort study was performed in patients admitted to the biggest military tertiary teaching hospital in China between January 2006 and May 2011.All included patients had clinically significant nosocomial BSI with S.aureus.Multivariate Logistic regression analysis was used to identify the risk factors for hospital mortality of patients with S.aureus BSI.Results One hundred and eighteen patients of more than one year old were identified as clinically and microbiologically confirmed nosocomial bacteraemia due to S.aureus,and 75 out of 118 patients were infected with methicillin-resistant S.aureus (MRSA).The overall mortality of nosocomial S.aureus BSI was 28.0%.Methicillin resistance in S.aureus bacteremia was associated with significant increase in the length of hospitalization and high proportion of inappropriate empirical antibiotic treatment.After Logistic regression analysis,the severity of clinical manifestations (APACHE Ⅱ score) (odds ratio (OR) 1.22,95% confidence interval (CI) 1.12-1.34) and inadequacy of empirical antimicrobial therapy (OR 0.25,95% CI 0.09-0.69) remained as risk factors for hospital mortality.Conclusions Nosocomial S.aureus BSI was associated with high in-hospital mortality.Methicillin resistance in S.aureus has no significant impact on the outcome of patients with staphylococcal bacteremia.Proper empirical antimicrobial therapy is very important to the prognosis.

  14. Evolutionary origin of peptidoglycan recognition proteins in vertebrate innate immune system

    Directory of Open Access Journals (Sweden)

    Tsujino Fumi

    2011-03-01

    Full Text Available Abstract Background Innate immunity is the ancient defense system of multicellular organisms against microbial infection. The basis of this first line of defense resides in the recognition of unique motifs conserved in microorganisms, and absent in the host. Peptidoglycans, structural components of bacterial cell walls, are recognized by Peptidoglycan Recognition Proteins (PGRPs. PGRPs are present in both vertebrates and invertebrates. Although some evidence for similarities and differences in function and structure between them has been found, their evolutionary history and phylogenetic relationship have remained unclear. Such studies have been severely hampered by the great extent of sequence divergence among vertebrate and invertebrate PGRPs. Here we investigate the birth and death processes of PGRPs to elucidate their origin and diversity. Results We found that (i four rounds of gene duplication and a single domain duplication have generated the major variety of present vertebrate PGRPs, while in invertebrates more than ten times the number of duplications are required to explain the repertoire of present PGRPs, and (ii the death of genes in vertebrates appears to be almost null whereas in invertebrates it is frequent. Conclusion These results suggest that the emergence of new PGRP genes may have an impact on the availability of the repertoire and its function against pathogens. These striking differences in PGRP evolution of vertebrates and invertebrates should reflect the differences in the role of their innate immunity. Insights on the origin of PGRP genes will pave the way to understand the evolution of the interaction between host and pathogens and to lead to the development of new treatments for immune diseases that involve proteins related to the recognition of self and non-self.

  15. Peptidoglycan Hydrolases of Local Lactic Acid Bacteria from Kazakh Traditional Food

    Directory of Open Access Journals (Sweden)

    Serik Shaikhin

    2014-01-01

    Full Text Available Introduction: Peptidoglycan (PG is a major component of the cell wall of Gram-positive bacteria and is essential for maintaining the integrity of the bacterial cell and its shape. The bacteria synthesize PG hydrolases, which are capable of cleaving the covalent bonds of PG. They also play an important role in modeling PG, which is required for bacterial growth and division. In an era of increasing antibiotic-resistant pathogens, PG hydrolases that destroy these important structures of the cell wall act as a potential source of new antimicrobials. The aim of this study is to identify the main PG hydrolases of local lactic acid bacteria isolated from traditional foods that enhance probiotic activity of a biological preparation. Methods. Lactococcus lactis 17А and Lactococcus garvieae 19А were isolated from the traditional sausage-like meat product called kazy. They were isolated according to standards methods of microbiology. Genetic identification of the isolates were tested by determining the nucleotide sequences of 16S rDNA. The Republican collection of microorganisms took strains of Lactobacillus casei subsp. Rhamnosus 13-P, L. delbrueckii subsp. lactis CG-1 B-RKM 0044 from cheese, Lactobacillus casei subsp. casei B-RKM 0202 from homemade butter. They used the standard technique of renaturating polyacrylamide gel electrophoresis to detect PG hydrolases activity. Results. According to the profiles of PG hydrolase activity on zymograms, the enzymes of Lactococci 17A and 19A in kazy are similar in electrophoretic mobility to major autolysin AcmA, while the lactobacilli of industrial and home-made dairy products have enzymes similar to extracellular proteins p40 and p75, which have probiotic activity. Conclusions. Use of peptidoglycan hydrolases seems to be an interesting approach in the fight against multi-drug resistant strains of bacteria and could be a valuable tool for the treatment of diseases caused by these microorganisms in Kazakhstan.

  16. Linezolid resistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Pavani Gandham

    2014-08-01

    Full Text Available Linezolid is the only antibiotic available as an oral formulation for resistant staphylococcal infections. It is effective in skin and soft tissue infections, nosocomial pneumonias including VAP, infective endocarditis and MRSA meningitis. It is also effective in the eradication of both nasal and throat colonization of MRSA. Its high bioavailability and post antibiotic effect, ease of switching to oral therapy during its use and the fact that it can be used in patients of all ages, also in patients with liver disease and poor kidney function and its increased effectiveness over glycopeptides makes this drug a precious drug in the treatment of resistant staphylococcal infections. Linezolid resistance in staphylococcus is defined as a linezolid MIC of and #8805;8 mg/L. Reported Linezolid resistance in India and elsewhere is 2-20%. There is clonal dissemination of Linezolid Resistant Staphylococcus aureus (LRSA within or across health care settings which demands continuous surveillance to determine the emergent risk of resistance strains and to establish guidelines for appropriate use. Clinical laboratories should confirm any LRSA preferably by a second method, prior to using linezolid for serious infections. Effective surveillance, more judicious use of this antibiotic, avoiding linezolid usage for empiric therapy in hospital acquired staphylococcus infections, optimization of the pharmacological parameters of the antibiotics in specific clinical situation, decreasing bacterial load by timely surgical debridement or drainage of collections, use of combination therapies would prevent the emergence of resistance to linezolid in staphylococcus aureus. [Int J Res Med Sci 2014; 2(4.000: 1253-1256

  17. Bugging the cell wall of bacteria : novel insights into the biosynthesis of peptidoglycan and its inhibition

    NARCIS (Netherlands)

    Olrichs, N.K.

    2010-01-01

    The last few decades saw an alarming rise of resistance against antibiotics, including the infamous methicillin-resistant Staphylococcus aureus (MRSA) that is resistant to the large group of antibiotics. This has turned the development of new antimicrobial compounds into a crucial necessity. The bac

  18. Staphylococcus aureus triggered reactive arthritis.

    OpenAIRE

    Siam, A R; M. Hammoudeh

    1995-01-01

    OBJECTIVES--To report two patients who developed reactive arthritis in association with Staphylococcus aureus infection. METHODS--A review of the case notes of two patients. RESULTS--Two adult female patients have developed sterile arthritis in association with Staph aureus infection. The first patient has had two episodes of arthritis; the first followed olecranon bursitis, the second followed infection of a central venous catheter used for dialysis. The second patient developed sterile arth...

  19. Rethinking the Tertiary Mathematics Curriculum

    Science.gov (United States)

    Petocz, Peter; Reid, Anna

    2005-01-01

    Mathematics curriculum at the tertiary level is located within a range of social and cultural theories, and is often constructed by academics seeking to promulgate a particular view of mathematics. We argue that such a curriculum should incorporate a real acknowledgement of the different ways in which students understand the nature of mathematics…

  20. Buckets and Fire: Metaphors in Tertiary Teaching

    Science.gov (United States)

    Emerson, Lisa; Mansvelt, Juliana

    2015-01-01

    This paper examines New Zealand tertiary teachers' use of metaphor and their attitudes to the consumer metaphor in relation to teaching. Based on interviews with 16 tertiary teachers, this study shows that although teachers believe the consumer metaphor is accepted by students, tertiary institutions and policy makers, and that it has affected…

  1. Role of the group B antigen of Streptococcus agalactiae a peptidoglycan-anchored polysaccharide involved in cell wall biogenesis : a Peptidoglycan-Anchored Polysaccharide involved in cell wall biogenesis

    OpenAIRE

    Élise Caliot; Shaynoor Dramsi; Marie-Pierre Chapot-Chartier; Pascal Courtin; Saulius Kulakauskas; Christine Péchoux; Patrick Trieu-Cuot; Michel-Yves Mistou

    2012-01-01

    Streptococcus agalactiae (Group B streptococcus, GBS) is a leading cause of infections in neonates and an emerging pathogen in adults. The Lancefield Group B carbohydrate (GBC) is a peptidoglycan-anchored antigen that defines this species as a Group B Streptococcus. Despite earlier immunological and biochemical characterizations, the function of this abundant glycopolymer has never been addressed experimentally. Here, we inactivated the gene gbcO encoding a putative UDP-N-acetylglucosamine-1-...

  2. Staphylococcus aureus Bacteraemia

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    James Price

    2010-01-01

    Full Text Available Staphylococcus aureus bacteraemia (SAB is commonly complicated by metastatic infection or relapse after treatment. Objectives. The study aim was to determine the role of bacterial, host, and management factors in development of complicated SAB. Methods. A prospectively-conducted observational study gathered data on predisposition, management and outcome of 100 consecutive SAB cases. Antibiotic susceptibilities and genetic lineage of bacterial isolates were determined. Further clinical and microbiological data were gathered on two retrospective series from 1999–2000 (n=57 and 2004 (n=116. Results. In the prospective cases, 27% met our definition of complicated disease. Expressed as RR and 95% CI, complicated disease was associated with diabetes (1.58, 1.00–2.48, injecting-drug use (5.48, 0.88–33.49, community-onset of symptoms (1.4, 1.02–1.92, and symptom duration ≥48 hours prior to starting effective antibiotic therapy (2.10, 1.22–3.61. Uncomplicated disease was associated with the presence of a central line (0.69, 0.55–0.88 and prompt removal of a primary focus (0.71, 0.57–0.90. Neither methicillin resistance nor genetic lineage was associated with complicated disease, but methicillin resistance was associated with higher mortality. Conclusions. This study demonstrates that clinical rather than microbial factors are the major determinants of SAB outcome and underscores the importance of early treatment.

  3. Multiple peptidoglycan modification networks modulate Helicobacter pylori's cell shape, motility, and colonization potential.

    Directory of Open Access Journals (Sweden)

    Laura K Sycuro

    Full Text Available Helical cell shape of the gastric pathogen Helicobacter pylori has been suggested to promote virulence through viscosity-dependent enhancement of swimming velocity. However, H. pylori csd1 mutants, which are curved but lack helical twist, show normal velocity in viscous polymer solutions and the reason for their deficiency in stomach colonization has remained unclear. Characterization of new rod shaped mutants identified Csd4, a DL-carboxypeptidase of peptidoglycan (PG tripeptide monomers and Csd5, a putative scaffolding protein. Morphological and biochemical studies indicated Csd4 tripeptide cleavage and Csd1 crosslinking relaxation modify the PG sacculus through independent networks that coordinately generate helical shape. csd4 mutants show attenuation of stomach colonization, but no change in proinflammatory cytokine induction, despite four-fold higher levels of Nod1-agonist tripeptides in the PG sacculus. Motility analysis of similarly shaped mutants bearing distinct alterations in PG modifications revealed deficits associated with shape, but only in gel-like media and not viscous solutions. As gastric mucus displays viscoelastic gel-like properties, our results suggest enhanced penetration of the mucus barrier underlies the fitness advantage conferred by H. pylori's characteristic shape.

  4. Discovery of chlamydial peptidoglycan reveals bacteria with murein sacculi but without FtsZ

    Science.gov (United States)

    Pilhofer, Martin; Aistleitner, Karin; Biboy, Jacob; Gray, Joe; Kuru, Erkin; Hall, Edward; Brun, Yves V.; Vannieuwenhze, Michael S.; Vollmer, Waldemar; Horn, Matthias; Jensen, Grant J.

    2013-12-01

    Chlamydiae are important pathogens and symbionts with unique cell biological features. They lack the cell-division protein FtsZ, and the existence of peptidoglycan (PG) in their cell wall has been highly controversial. FtsZ and PG together function in orchestrating cell division and maintaining cell shape in almost all other bacteria. Using electron cryotomography, mass spectrometry and fluorescent labelling dyes, here we show that some environmental chlamydiae have cell wall sacculi consisting of a novel PG type. Treatment with fosfomycin (a PG synthesis inhibitor) leads to lower infection rates and aberrant cell shapes, suggesting that PG synthesis is crucial for the chlamydial life cycle. Our findings demonstrate for the first time the presence of PG in a member of the Chlamydiae. They also present a unique example of a bacterium with a PG sacculus but without FtsZ, challenging the current hypothesis that it is the absence of a cell wall that renders FtsZ non-essential.

  5. Treatment with antibiotics that interfere with peptidoglycan biosynthesis inhibits chloroplast division in the desmid Closterium.

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    Hiroko Matsumoto

    Full Text Available Charophytes is a green algal group closely related to land plants. We investigated the effects of antibiotics that interfere with peptidoglycan biosynthesis on chloroplast division in the desmid Closterium peracerosum-strigosum-littorale complex. To detect cells just after division, we used colchicine, which inhibits Closterium cell elongation after division. Although normal Closterium cells had two chloroplasts before and after cell division, cells treated with ampicillin, D-cycloserine, or fosfomycin had only one chloroplast after cell division, suggesting that the cells divided without chloroplast division. The antibiotics bacitracin and vancomycin showed no obvious effect. Electron microscopic observation showed that irregular-shaped chloroplasts existed in ampicillin-treated Closterium cells. Because antibiotic treatments resulted in the appearance of long cells with irregular chloroplasts and cell death, we counted cell types in the culture. The results suggested that cells with one chloroplast appeared first and then a huge chloroplast was generated that inhibited cell division, causing elongation followed by cell death.

  6. Gamma Interferon Production by Bovine γδ T Cells following Stimulation with Mycobacterial Mycolylarabinogalactan Peptidoglycan

    Science.gov (United States)

    Vesosky, B.; Turner, O. C.; Turner, J.; Orme, I. M.

    2004-01-01

    A large percentage of lymphocytes in the blood of cattle express the γδ T-cell receptor, but specific functions for these cells have not yet been clearly defined. There is evidence, however, that human, murine, and bovine γδ T cells have a role in the immune response to mycobacteria. This study investigated the ability of bovine γδ T cells to expand and produce gamma interferon (IFN-γ) in response to stimulation with mycobacterial products. Bovine γδ T cells, isolated from the peripheral blood of healthy cattle, expanded following in vitro stimulation with live mycobacteria, mycobacterial crude cell wall extract, and Mycobacterium bovis culture filtrate proteins. In addition, purified γδ T cells, cocultured with purified monocytes and interleukin-2, consistently produced significant amounts of IFN-γ in response to mycobacterial cell wall. The IFN-γ-inducing component of the cell wall was further identified as a proteolytically resistant, non-sodium dodecyl sulfate-soluble component of the mycolylarabinogalactan peptidoglycan. PMID:15271921

  7. Triple-acting Lytic Enzyme Treatment of Drug-Resistant and Intracellular Staphylococcus aureus

    Science.gov (United States)

    Becker, Stephen C.; Roach, Dwayne R.; Chauhan, Vinita S.; Shen, Yang; Foster-Frey, Juli; Powell, Anne M.; Bauchan, Gary; Lease, Richard A.; Mohammadi, Homan; Harty, William J.; Simmons, Chad; Schmelcher, Mathias; Camp, Mary; Dong, Shengli; Baker, John R.; Sheen, Tamsin R.; Doran, Kelly S.; Pritchard, David G.; Almeida, Raul A.; Nelson, Daniel C.; Marriott, Ian; Lee, Jean C.; Donovan, David M.

    2016-01-01

    Multi-drug resistant bacteria are a persistent problem in modern health care, food safety and animal health. There is a need for new antimicrobials to replace over used conventional antibiotics. Here we describe engineered triple-acting staphylolytic peptidoglycan hydrolases wherein three unique antimicrobial activities from two parental proteins are combined into a single fusion protein. This effectively reduces the incidence of resistant strain development. The fusion protein reduced colonization by Staphylococcus aureus in a rat nasal colonization model, surpassing the efficacy of either parental protein. Modification of a triple-acting lytic construct with a protein transduction domain significantly enhanced both biofilm eradication and the ability to kill intracellular S. aureus as demonstrated in cultured mammary epithelial cells and in a mouse model of staphylococcal mastitis. Interestingly, the protein transduction domain was not necessary for reducing the intracellular pathogens in cultured osteoblasts or in two mouse models of osteomyelitis, highlighting the vagaries of exactly how protein transduction domains facilitate protein uptake. Bacterial cell wall degrading enzyme antimicrobials can be engineered to enhance their value as potent therapeutics. PMID:27121552

  8. Role of Staphylococcus aureus Virulence Factors in Inducing Inflammation and Vascular Permeability in a Mouse Model of Bacterial Endophthalmitis.

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    Ajay Kumar

    Full Text Available Staphylococcus (S. aureus is a common causative agent of bacterial endophthalmitis, a vision threatening complication of eye surgeries. The relative contribution of S. aureus virulence factors in the pathogenesis of endophthalmitis remains unclear. Here, we comprehensively analyzed the development of intraocular inflammation, vascular permeability, and the loss of retinal function in C57BL/6 mouse eyes, challenged with live S. aureus, heat-killed S. aureus (HKSA, peptidoglycan (PGN, lipoteichoic acid (LTA, staphylococcal protein A (SPA, α-toxin, and Toxic-shock syndrome toxin 1 (TSST1. Our data showed a dose-dependent (range 0.01 μg/eye to 1.0 μg/eye increase in the levels of inflammatory mediators by all virulence factors. The cell wall components, particularly PGN and LTA, seem to induce higher levels of TNF-α, IL-6, KC, and MIP2, whereas the toxins induced IL-1β. Similarly, among the virulence factors, PGN induced higher PMN infiltration. The vascular permeability assay revealed significant leakage in eyes challenged with live SA (12-fold and HKSA (7.3-fold, in comparison to other virulence factors (~2-fold and controls. These changes coincided with retinal tissue damage, as evidenced by histological analysis. The electroretinogram (ERG analysis revealed a significant decline in retinal function in eyes inoculated with live SA, followed by HKSA, SPA, and α-toxin. Together, these findings demonstrate the differential innate responses of the retina to S. aureus virulence factors, which contribute to intraocular inflammation and retinal function loss in endophthalmitis.

  9. Revealing fosfomycin primary effect on Staphylococcus aureus transcriptome: modulation of cell envelope biosynthesis and phosphoenolpyruvate induced starvation

    Directory of Open Access Journals (Sweden)

    Gruden Kristina

    2010-06-01

    Full Text Available Abstract Background Staphylococcus aureus is a highly adaptable human pathogen and there is a constant search for effective antibiotics. Fosfomycin is a potent irreversible inhibitor of MurA, an enolpyruvyl transferase that uses phosphoenolpyruvate as substrate. The goal of this study was to identify the pathways and processes primarily affected by fosfomycin at the genome-wide transcriptome level to aid development of new drugs. Results S. aureus ATCC 29213 cells were treated with sub-MIC concentrations of fosfomycin and harvested at 10, 20 and 40 minutes after treatment. S. aureus GeneChip statistical data analysis was complemented by gene set enrichment analysis. A visualization tool for mapping gene expression data into biological pathways was developed in order to identify the metabolic processes affected by fosfomycin. We have shown that the number of significantly differentially expressed genes in treated cultures increased with time and with increasing fosfomycin concentration. The target pathway - peptidoglycan biosynthesis - was upregulated following fosfomycin treatment. Modulation of transport processes, cofactor biosynthesis, energy metabolism and nucleic acid biosynthesis was also observed. Conclusions Several pathways and genes downregulated by fosfomycin have been identified, in contrast to previously described cell wall active antibiotics, and was explained by starvation response induced by phosphoenolpyruvate accumulation. Transcriptomic profiling, in combination with meta-analysis, has been shown to be a valuable tool in determining bacterial response to a specific antibiotic.

  10. Mild Staphylococcus aureus skin infection improves the course of subsequent endogenous S. aureus bacteremia in mice

    NARCIS (Netherlands)

    S. van den Berg (Sanne); C.P. de Vogel (Corné); A.F. van Belkum (Alex); I.A.J.M. Bakker-Woudenberg (Irma)

    2015-01-01

    textabstractStaphylococcus aureus carriers with S. aureus bacteremia may have a reduced mortality risk compared to non-carriers. A role for the immune system is suggested. Here, we study in mice the effect of mild S. aureus skin infection prior to endogenous or exogenous S. aureus bacteremia, and ev

  11. Host-adaptive evolution of Staphylococcus aureus

    OpenAIRE

    Lowder, Bethan Victoria

    2011-01-01

    Staphylococcus aureus is a notorious human pathogen associated with severe nosocomial and community-acquired infections. In addition, S. aureus is a major cause of animal diseases including skeletal infections of poultry and bovine and ovine mastitis, which are a large economic burden on the broiler chicken and dairy farming industries. The population structure of S. aureus associated with humans has been well studied. However, despite the prevalence of S. aureus infections in ...

  12. [Protein toxins of Staphylococcus aureus].

    Science.gov (United States)

    Shamsutdinov, A F; Tiurin, Iu A

    2014-01-01

    Main scientific-research studies regarding protein bacterial toxins of the most widespread bacteria that belong to Staphylococcus spp. genus and in particular the most pathogenic species for humans--Staphylococcus aureus, are analyzed. Structural and biological properties of protein toxins that have received the name of staphylococcus pyrogenic toxins (PTSAg) are presented. Data regarding genetic regulation of secretion and synthesis of these toxins and 3 main regulatory genetic systems (agr--accessory gene regulator, xpr--extracellular protein regulator, sar--staphylococcal accessory regulator) that coordinate synthesis of the most important protein toxins and enzymes for virulence of S. aureus, are presented.

  13. Prevention of Healthcare Associated Staphylococcus aureus Infections

    NARCIS (Netherlands)

    L.G.M. Bode (Lonneke)

    2014-01-01

    markdownabstract__Abstract__ S. aureus colonizes the skin and mucosae of a proportion of the human population. Carriers of S. aureus are at increased risk of developing infections with this pathogen. The aim of this thesis was to add to the prevention of healthcare associated S. aureus infections.

  14. 肽聚糖对正常人表皮角质形成细胞分泌趋化因子的影响及Toll样受体2的作用%Peptidoglycan modulation of chemokine production in normal human epidermal kerafinocytes and the role of Toll-like receptor 2 in this process

    Institute of Scientific and Technical Information of China (English)

    刘苏俊; 林麟; 张彩萍; 周武庆; 冯雨苗; 马一平

    2009-01-01

    Objective To investigate the effect ofpeptidoglycan from Staphylococcus aureus on the release of several chemokines including intedeukin 8 (IL-8), regulated upon activation, normal T cell expressed and secreted (RANTES), macrophage-derived chemokine (MDC) by normal human epidermal keratinocytes (KCs) and the role of Toll-like receptor 2 (TLR2) in this process. Methods KCs were derived from the foreskin of a healthy boy and propagated. After 2 - 4 passages, KCs were collected and treated with various concentrations (3, 10, 30 and 100 mg/L) of peptidoglycan for 24 hours or with peptidoglycan of 100 mg/L for varying durations (3, 6, 12, 36 hours). A fi'action of KCs were pretreated with functional grade purified anti-TLR2 monoclonal antibody before the treatment with peptidoglycan of 100 mg/L. After additional 12-hour culture following the treatment, enzyme linked immunosorbent assay was used to detect the level of IL-8, RANTES and MDC in culture supernatants of KCs. Results KCs spontaneously released IL-8 and RANTES. Peptidoglycan increased the production of IL-8 but decreased that of RANTES by KCs. The levels of IL-8 were 209.96 ± 10.31 ng/L, 250.28 ± 9.52 ng/L, 285.11 ± 10.28 ng/L, 359.40 ± 6.93 ng/L in KCs treated with peptidoglycan of 3, 10, 30, 100 mg/L, respectively, compared to 135.41 ± 14.37 ng/L in untreated KCs (all P < 0.05). On the contrary, a significant decrement was seen in the secretion of RANTES by KCs treated with peptidoglycan of 10, 30, 100 mg/L compared with untreated KCs (110.72 ± 8.51 ng/L, 90.50 ±2.45 ng/L, 49.89 ± 13.74 ng/L vs 149.94 ± 18.71 ng/L, all P < 0.05). The monoclonal antibody to TLR-2 could markedly suppress the promotion of IL-8 production by peptidoglycan, but had no obvious influence on the inhibition of RANTES production by peptidoglycan. MDC could not be detected in the culture super-natants of KCs with or without peptidoglycan stimulation. Conclusion Peptidoglycan could inhibit RANTES secretion but induce IL-8

  15. Effects of different enzymatic hydrolysis methods on the bioactivity of peptidoglycan in Litopenaeus vannamei

    Institute of Scientific and Technical Information of China (English)

    SONG Xiaoling; ZHANG Yue; WEI Song; HUANG Jie

    2013-01-01

    The effects of different hydrolysis methods on peptidoglycan (PG) were assessed in terms of their impact on the innate immunity and disease resistance of Pacific white shrimp,Litopenaeus vannamei.PG derived from Bifidobacterium thermophilum was prepared in the laboratory and processed with lysozyme and protease under varying conditions to produce several different PG preparations.A standard shrimp feed was mixed with 0.05% PG preparations to produce a number of experimental diets for shrimp.The composition,concentration,and molecular weight ranges of the soluble PG were analyzed.Serum phenoloxidase and acid phosphatase activity in the shrimp were determined on Days 6-31 of the experiment.The protective activity of the PG preparations was evaluated by exposing shrimp to white spot syndrome virus (WSSV).Data on the composition of the PG preparations indicated that preparations hydrolyzed with lysozyme for 72 h had more low-molecular-weight PG than those treated for 24 h,and hydrolysis by protease enhanced efficiency of hydrolysis compared to lysozyme.SDS-PAGE showed changes in the molecular weight of the soluble PG produced by the different hydrolysis methods.Measurements of serum phenoloxidase and acid phosphatase activity levels in the shrimp indicated that the PG preparations processed with enzymes were superior to the preparation which had not undergone hydrolysis in enhancing the activity of the two serum enzymes.In addition,the preparation containing more low-molecular-weight PG enhanced the resistance of the shrimp to WSSV,whereas no increased resistance was observed for preparations containing less low-molecular-weight PG.These findings suggest that the immunity-enhancing activity of PG is related to its molecular weight and that increasing the quantity of low-molecular-weight PG can fortify the effect of immunity enhancement.

  16. Characterization of a major 31-kilodalton peptidoglycan-bound protein of Legionella pneumophila

    International Nuclear Information System (INIS)

    A 31-kilodalton (kDa) protein was solubilized from the peptidoglycan (PG) fraction of Legionella pneumophila after treatment with either N-acetylmuramidase from the fungus Chalaropsis sp. or with mutanolysin from Streptomyces globisporus. The protein exhibited a ladderlike banding pattern by autoradiography when radiolabeled [(35S]cysteine or [35S]methionine) PG material was extensively treated with hen lysozyme. The banding patterns ranging between 31 and 45 kDa and between 55 and 60 kDa resolved as a single 31-kDa protein when the material was subsequently treated with N-acetylmuramidase. Analysis of the purified 31-kDa protein for diaminopimelic acid by gas chromatography revealed 1 mol of diaminopimelic acid per mol of protein. When outer membrane PG material containing the major outer membrane porin protein was treated with N-acetylmuramidase or mutanolysin, both the 28.5-kDa major outer membrane protein and the 31-kDa protein were solubilized from the PG material under reducing conditions. In the absence of 2-mercaptoethanol, a high-molecular-mass complex (100 kDa) was resolved. The results of this study indicate that a 31-kDa PG-bound protein is a major component of the cell wall of L. pneumophila whose function may be to anchor the major outer membrane protein to PG. Finally, a survey of other Legionella species and other serogroups of L. pneumophila suggested that PG-bound proteins may be a common feature of this genus

  17. Effects of different enzymatic hydrolysis methods on the bioactivity of peptidoglycan in Litopenaeus vannamei

    Science.gov (United States)

    Song, Xiaoling; Zhang, Yue; Wei, Song; Huang, Jie

    2013-03-01

    The effects of different hydrolysis methods on peptidoglycan (PG) were assessed in terms of their impact on the innate immunity and disease resistance of Pacific white shrimp, Litop enaeus vannamei. PG derived from Bifidobacterium thermophilum was prepared in the laboratory and processed with lysozyme and protease under varying conditions to produce several different PG preparations. A standard shrimp feed was mixed with 0.05% PG preparations to produce a number of experimental diets for shrimp. The composition, concentration, and molecular weight ranges of the soluble PG were analyzed. Serum phenoloxidase and acid phosphatase activity in the shrimp were determined on Days 6—31 of the experiment. The protective activity of the PG preparations was evaluated by exposing shrimp to white spot syndrome virus (WSSV). Data on the composition of the PG preparations indicated that preparations hydrolyzed with lysozyme for 72 h had more low-molecular-weight PG than those treated for 24 h, and hydrolysis by protease enhanced efficiency of hydrolysis compared to lysozyme. SDS-PAGE showed changes in the molecular weight of the soluble PG produced by the different hydrolysis methods. Measurements of serum phenoloxidase and acid phosphatase activity levels in the shrimp indicated that the PG preparations processed with enzymes were superior to the preparation which had not undergone hydrolysis in enhancing the activity of the two serum enzymes. In addition, the preparation containing more low-molecular-weight PG enhanced the resistance of the shrimp to WSSV, whereas no increased resistance was observed for preparations containing less low-molecular-weight PG. These findings suggest that the immunity-enhancing activity of PG is related to its molecular weight and that increasing the quantity of low-molecular-weight PG can fortify the effect of immunity enhancement.

  18. Cloning, expression, and characterization of a peptidoglycan hydrolase from the Burkholderia pseudomallei phage ST79.

    Science.gov (United States)

    Khakhum, Nittaya; Yordpratum, Umaporn; Boonmee, Atcha; Tattawasart, Unchalee; Rodrigues, Jorge L M; Sermswan, Rasana W

    2016-12-01

    The lytic phage ST79 of Burkholderia pseudomallei can lyse a broad range of its host including antibiotic resistant isolates from within using a set of proteins, holin, lysB, lysC and endolysin, a peptidoglycan (PG) hydrolase enzyme. The phage ST79 endolysin gene identified as peptidase M15A was cloned, expressed and purified to evaluate its potential to lyse pathogenic bacteria. The molecular size of the purified enzyme is approximately 18 kDa and the in silico study cited here indicated the presence of a zinc-binding domain predicted to be a member of the subfamily A of a metallopeptidase. Its activity, however, was reduced by the presence of Zn(2+). When Escherichia coli PG was used as a substrate and subjected to digestion for 5 min with 3 μg/ml of enzyme, the peptidase M15A showed 2 times higher in lysis efficiency when compared to the commercial lysozyme. The enzyme works in a broad alkaligenic pH range of 7.5-9.0 and temperatures from 25 to 42 °C. The enzyme was able to lyse 18 Gram-negative bacteria in which the outer membrane was permeabilized by chloroform treatment. Interestingly, it also lysed Enterococcus sp., but not other Gram-positive bacteria. In general, endolysin cannot lyse Gram-negative bacteria from outside, however, the cationic amphipathic C-terminal in some endolysins showed permeability to Gram-negative outer membranes. Genetically engineered ST79 peptidase M15A that showed a broad spectrum against Gram-negative bacterial PG or, in combination with an antibiotic the same way as combined drug methodology, could facilitate an effective treatment of severe or antibiotic resistant cases. PMID:27637947

  19. A 12-year review of Staphylococcus aureus bloodstream infections in haemodialysis patients: more work to be done.

    LENUS (Irish Health Repository)

    Fitzgerald, S F

    2012-02-01

    Staphylococcus aureus bloodstream infections (BSI) are a significant cause of morbidity and mortality in haemodialysis patients. This study describes a 12-year retrospective review of S. aureus BSI in a large haemodialysis centre in a tertiary referral hospital. The overall rate of S. aureus BSI was 17.9 per 100 patient-years (range 9.7-36.8). The rate of meticillin-resistant S. aureus (MRSA) BSI was 5.6 per 100 patient-years (range 0.9-13.8). Infective complications occurred in 11% of episodes, the most common being infective endocarditis (7.6%). Ten percent of patients died within 30 days of S. aureus being isolated from blood. Most cases of S. aureus BSI (83%) were related to vascular catheters. The provision of lower-risk vascular access, such as arteriovenous fistulae, and reduced use of intravascular catheters should be priorities in all haemodialysis units. Where alternative vascular access cannot be established, interventions to reduce the risk of catheter-related infections should be implemented to reduce morbidity and mortality in this vulnerable patient group.

  20. Cooperative tertiary interaction network guides RNA folding

    OpenAIRE

    Behrouzi, Reza; Roh, Joon Ho; Kilburn, Duncan; Briber, Robert M.; Woodson, Sarah A.

    2012-01-01

    Non-coding RNAs form unique three-dimensional structures, which perform many biochemical and regulatory functions. To understand how RNAs fold uniquely despite a small number of tertiary interaction motifs, we mutated the major tertiary interactions in a group I ribozyme. The resulting perturbations to the folding energy landscape were measured using SAXS, ribozyme activity, hydroxyl radical footprinting and native PAGE. Double and triple mutant cycles show that most tertiary interactions hav...

  1. Tertiary education in Latvia today and tomorrow

    Directory of Open Access Journals (Sweden)

    Ludmila Panina

    2010-02-01

    Full Text Available The market economy principles are deeply implemented in the system of tertiary education in Latvia. The share of private sector and private funding is significantly big, as well as the variety of study programs. Nevertheless it is only one side of supply-demand dimension that might be seriously changed by economic crisis. The author draws tertiary sector development scenarios considering probable demographic, economical and political trends. The more efficient and effective interaction of tertiary and business sectors, the development oriented decentralisation of state macro economical and regional policy are the decisive success factors for sustainability both of the state and tertiary sector.

  2. Stress Responses in Staphylococcus aureus

    DEFF Research Database (Denmark)

    Frees, Dorte; Ingmer, Hanne

    2016-01-01

    Staphylococcus aures are prominent members of the normal flora of humans and animals, but are also a major cause of mild and severe infections. To persist and disseminate in the human host, and to survive in environmental settings, such as hospitals, S. aureus have developed a plethora of cellular...

  3. Divergent responses to peptidoglycans derived from different E. coli serotypes influence inflammatory outcome in trout, Oncorhynchus mykiss, macrophages

    Directory of Open Access Journals (Sweden)

    Goetz Frederick

    2011-01-01

    Full Text Available Abstract Background Pathogen-associated molecular patterns (PAMPs are structural components of pathogens such as lipopolysaccharide (LPS and peptidoglycan (PGN from bacterial cell walls. PAMP-recognition by the host results in an induction of defence-related genes and often the generation of an inflammatory response. We evaluated both the transcriptomic and inflammatory response in trout (O. mykiss macrophages in primary cell culture stimulated with DAP-PGN (DAP; meso-diaminopimelic acid, PGN; peptidoglycan from two strains of Escherichia coli (PGN-K12 and PGN-O111:B4 over time. Results Transcript profiling was assessed using function-targeted cDNA microarray hybridisation (n = 36 and results show differential responses to both PGNs that are both time and treatment dependent. Wild type E. coli (K12 generated an increase in transcript number/diversity over time whereas PGN-O111:B4 stimulation resulted in a more specific and intense response. In line with this, Gene Ontology analysis (GO highlights a specific transcriptomic remodelling for PGN-O111:B4 whereas results obtained for PGN-K12 show a high similarity to a generalised inflammatory priming response where multiple functional classes are related to ribosome biogenesis or cellular metabolism. Prostaglandin release was induced by both PGNs and macrophages were significantly more sensitive to PGN-O111:B4 as suggested from microarray data. Conclusion Responses at the level of the transcriptome and the inflammatory outcome (prostaglandin synthesis highlight the different sensitivity of the macrophage to slight differences (serotype in peptidoglycan structure. Such divergent responses are likely to involve differential receptor sensitivity to ligands or indeed different receptor types. Such changes in biological response will likely reflect upon pathogenicity of certain serotypes and the development of disease.

  4. Staphylococcus aureus and hand eczema severity

    DEFF Research Database (Denmark)

    Haslund, P; Bangsgaard, N; Jarløv, J O;

    2009-01-01

    BACKGROUND: The role of bacterial infections in hand eczema (HE) remains to be assessed. OBJECTIVES: To determine the prevalence of Staphylococcus aureus in patients with HE compared with controls, and to relate presence of S. aureus, subtypes and toxin production to severity of HE. METHODS......: Bacterial swabs were taken at three different visits from the hand and nose in 50 patients with HE and 50 controls. Staphylococcus aureus was subtyped by spa typing and assigned to clonal complexes (CCs), and isolates were tested for exotoxin-producing S. aureus strains. The Hand Eczema Severity Index...... was used for severity assessment. RESULTS: Staphylococcus aureus was found on the hands in 24 patients with HE and four controls (P aureus was found to be related to increased severity of the eczema (P aureus types on the hands...

  5. The role of lipopolysaccharide and peptidoglycan, two glycosylated bacterial microbe-associated molecular patterns (MAMPs), in plant innate immunity

    DEFF Research Database (Denmark)

    Erbs, Gitte; Newman, Mari-Anne

    2012-01-01

    ) from the cell walls of both Gram-positive and Gram-negative bacteria, have been found to act as elicitors of plant innate immunity. These conserved, indispensable, microbe-specific molecules are also referred to as ‘microbe-associated molecular patterns’ (MAMPs). MAMPs are recognized by the plant...... to as ‘innate immunity’. Innate immunity is the first line of defence against invading microorganisms in vertebrates and the only line of defence in invertebrates and plants. Bacterial glycoconjugates, such as lipopolysaccharides (LPSs) from the outer membrane of Gram-negative bacteria and peptidoglycan (PGN...

  6. Bacterial cell wall. MurJ is the flippase of lipid-linked precursors for peptidoglycan biogenesis.

    Science.gov (United States)

    Sham, Lok-To; Butler, Emily K; Lebar, Matthew D; Kahne, Daniel; Bernhardt, Thomas G; Ruiz, Natividad

    2014-07-11

    Peptidoglycan (PG) is a polysaccharide matrix that protects bacteria from osmotic lysis. Inhibition of its biogenesis is a proven strategy for killing bacteria with antibiotics. The assembly of PG requires disaccharide-pentapeptide building blocks attached to a polyisoprene lipid carrier called lipid II. Although the stages of lipid II synthesis are known, the identity of the essential flippase that translocates it across the cytoplasmic membrane for PG polymerization is unclear. We developed an assay for lipid II flippase activity and used a chemical genetic strategy to rapidly and specifically block flippase function. We combined these approaches to demonstrate that MurJ is the lipid II flippase in Escherichia coli. PMID:25013077

  7. The Staphylococcus aureus response to unsaturated long chain free fatty acids: survival mechanisms and virulence implications.

    Directory of Open Access Journals (Sweden)

    John G Kenny

    Full Text Available Staphylococcus aureus is an important human commensal and opportunistic pathogen responsible for a wide range of infections. Long chain unsaturated free fatty acids represent a barrier to colonisation and infection by S. aureus and act as an antimicrobial component of the innate immune system where they are found on epithelial surfaces and in abscesses. Despite many contradictory reports, the precise anti-staphylococcal mode of action of free fatty acids remains undetermined. In this study, transcriptional (microarrays and qRT-PCR and translational (proteomics analyses were applied to ascertain the response of S. aureus to a range of free fatty acids. An increase in expression of the sigma(B and CtsR stress response regulons was observed. This included increased expression of genes associated with staphyloxanthin synthesis, which has been linked to membrane stabilisation. Similarly, up-regulation of genes involved in capsule formation was recorded as were significant changes in the expression of genes associated with peptidoglycan synthesis and regulation. Overall, alterations were recorded predominantly in pathways involved in cellular energetics. In addition, sensitivity to linoleic acid of a range of defined (sigB, arcA, sasF, sarA, agr, crtM and transposon-derived mutants (vraE, SAR2632 was determined. Taken together, these data indicate a common mode of action for long chain unsaturated fatty acids that involves disruption of the cell membrane, leading to interference with energy production within the bacterial cell. Contrary to data reported for other strains, the clinically important EMRSA-16 strain MRSA252 used in this study showed an increase in expression of the important virulence regulator RNAIII following all of the treatment conditions tested. An adaptive response by S. aureus of reducing cell surface hydrophobicity was also observed. Two fatty acid sensitive mutants created during this study were also shown to diplay altered

  8. Towards Tertiary Education. Staff and Staff Development.

    Science.gov (United States)

    Ratcliffe, Joan

    This report is intended as a resource for all those interested in staff development, especially in the tertiary education context. It describes the staff development project in the first two years of a new tertiary college--Harlow Technical College in England. An introduction and a description of the context of the project begin the report.…

  9. Nodular tertiary syphilis in an immunocompetent patient.

    Science.gov (United States)

    Bittencourt, Maraya de Jesus Semblano; Brito, Arival Cardoso de; Nascimento, Bianca Angelina Macêdodo; Carvalho, Alessandra Haber; Drago, Marion Guimarães

    2016-01-01

    Acquired syphilis can be divided into primary, secondary, latent, and tertiary stages. About 25% of patients with untreated primary syphilis will develop late signs that generally occur after three to five years, with involvement of several organs. The authors present an immunocompetent female who developed a tertiary stage syphilis presenting with long-standing nodular plaques. PMID:27579755

  10. Tertiary Education and Training in Australia, 2010

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2012

    2012-01-01

    This publication presents information on tertiary education and training during 2010, including statistics on participation and outcomes. The definition of tertiary education and training adopted for this publication is formal study in vocational education and training (VET) and higher education, including enrolments in Australian Qualifications…

  11. Nodular tertiary syphilis in an immunocompetent patient*

    Science.gov (United States)

    Bittencourt, Maraya de Jesus Semblano; de Brito, Arival Cardoso; Nascimento, Bianca Angelina Macêdodo; Carvalho, Alessandra Haber; Drago, Marion Guimarães

    2016-01-01

    Acquired syphilis can be divided into primary, secondary, latent, and tertiary stages. About 25% of patients with untreated primary syphilis will develop late signs that generally occur after three to five years, with involvement of several organs. The authors present an immunocompetent female who developed a tertiary stage syphilis presenting with long-standing nodular plaques. PMID:27579755

  12. Engaging Heterogeneity: Tertiary Literacy in New Times.

    Science.gov (United States)

    Hirst, Elizabeth Wyshe

    The "massification" of higher education in Australia and the associated increasing student diversity have significant implications for tertiary education. In particular, students seem to be struggling with the demands of tertiary literacy with commentators claiming that literacy standards are in decline. The solution has been to provide study…

  13. Analyses of the cell-wall peptidoglycan structures in three genera Micromonospora, Catenuloplanes, and Couchioplanes belonging to the family Micromonosporaceae by derivatization with FDLA and PMP using LC/MS.

    Science.gov (United States)

    Také, Akira; Nakashima, Takuji; Inahashi, Yuki; Shiomi, Kazuro; Takahashi, Yōko; Ōmura, Satoshi; Matsumoto, Atsuko

    2016-09-12

    It is the major characteristic of the cell-wall peptidoglycan structure in members of the family Micromonosporaceae that N-acetylmuramic acid (MurNAc) of glycan strand is replaced with N-glycolylmuramic acid (MurNGlyc). Consequently, it is difficult to use enzymatic methods for their peptidoglycan analyses. We therefore developed analysis method of peptidoglycan without using cell wall lytic enzymes as example to take the 3 genera, Micromonospora, Catenuloplanes, and Couchioplanes belonging to the family Micromonosporaceae, and their peptidoglycans were partially hydrolyzed with 4 M HCl at 60°C for 16 h followed by derivatization with N(α)-(5-fluoro-2,4-dinitrophenyl)-D-leucinamide (FDLA) or 1-phenyl-3-methyl-5-pyrazolone (PMP) and LC/MS analysis. Peptidoglycan of the genus Micromonospora consisted of a MurNGlyc-Gly-D-Glu-meso-diaminopimelyl (DAP)-D-Ala peptide stem and direct linkage between D-Ala and meso-DAP. In contrast, peptidoglycans of the genera Catenuloplanes and Couchioplanes consisted of a MurNGlyc-Gly-D-Glu-L-Lys-D-Ala peptide stem, and cross-linkage between D-Ala and L-Lys was mediated by an L-Ser residue. This method can be used to analyze the cell-wall peptidoglycan structure of other bacteria as well. By derivatization with FDLA or PMP followed by LC/MS analysis, the structure can be determined using only 0.2 mg of purified peptidoglycan.

  14. Immunomodulation and Disease Tolerance to Staphylococcus aureus

    OpenAIRE

    Zhigang Li; Peres, Adam G.; Andreea C. Damian; Joaquín Madrenas

    2015-01-01

    The Gram-positive bacterium Staphylococcus aureus is one of the most frequent pathogens that causes severe morbidity and mortality throughout the world. S. aureus can infect skin and soft tissues or become invasive leading to diseases such as pneumonia, endocarditis, sepsis or toxic shock syndrome. In contrast, S. aureus is also a common commensal microbe and is often part of the human nasal microbiome without causing any apparent disease. In this review, we explore the immunomodulation and d...

  15. Postoperative Staphylococcus aureus infections in Medicare beneficiaries.

    Directory of Open Access Journals (Sweden)

    Moaven Razavi

    Full Text Available Staphylococcus aureus (S. aureus infections are important because of their increasing frequency, resistance to antibiotics, and high associated rates of disabilities and deaths. We examined the incidence and correlates of S. aureus infections following 219,958 major surgical procedures in a 5% random sample of fee-for-service Medicare beneficiaries from 2004-2007. Of these surgical patients, 0.3% had S. aureus infections during the hospitalizations when index surgical procedures were performed; and 1.7% and 2.3%, respectively, were hospitalized with infections within 60 days or 180 days following admissions for index surgeries. S. aureus infections occurred within 180 days in 1.9% of patients following coronary artery bypass graft surgery, 2.3% following hip surgery, and 5.9% following gastric or esophageal surgery. Of patients first hospitalized with any major infection reported during the first 180 days after index surgery, 15% of infections were due to S. aureus, 18% to other documented organisms, and no specific organism was reported on claim forms in 67%. Patient-level predictors of S. aureus infections included transfer from skilled nursing facilities or chronic hospitals and comorbid conditions (e.g., diabetes, congestive heart failure, chronic obstructive pulmonary disease, and chronic renal disease. In a logarithmic regression, elective index admissions with S. aureus infection stayed 130% longer than comparable patients without that infection. Within 180 days of the index surgery, 23.9% of patients with S. aureus infection and 10.6% of patients without this infection had died. In a multivariate logistic regression of death within 180 days of admission for the index surgery with adjustment for demographics, co-morbidities, and other risks, S. aureus was associated with a 42% excess risk of death. Due to incomplete documentation of organisms in Medicare claims, these statistics may underestimate the magnitude of S. aureus infection

  16. Comparison of genotypes and enterotoxin genes between Staphylococcus aureus isolates from blood and nasal colonizers in a Korean hospital.

    Science.gov (United States)

    Peck, Kyong Ran; Baek, Jin Yang; Song, Jae-Hoon; Ko, Kwan Soo

    2009-08-01

    In this study, we investigated the genetic background of 70 Staphylococcus aureus isolates (36 methicillin-resistant S. aureus [MRSA] and 34 methicillin-susceptible S. aureus [MSSA]) obtained from blood at a Korean tertiary-care hospital, using spa typing, multilocus sequence typing, and SCCmec typing. In addition, the prevalence of enterotoxin (sea, seb, sec, sed, see, seg, seh, sei, and sek), tst, and pvl genes among the samples was assessed via polymerase chain reaction, and the results were compared with those of 95 isolates of S. aureus obtained from nasal swabs. All MRSA isolates from blood, except one, belonged to three major clones: sequence type (ST)5-MRSA-II, ST72-MRSA-II (or IVA), and ST239-MRSA-III, among which ST5-MRSA-II was the predominant clone. The prevalence of enterotoxin genes in the S. aureus isolates obtained from blood differed significantly from those from the nasal swabs for the sea, seb, sec, and seh gene. In particular, the seb and sec genes were detected exclusively in the MRSA isolates of ST5 or spa-CC002, thereby suggesting the co-adaptation of virulence genes with the genetic background and their contribution to biological fitness.

  17. Immunomodulation and Disease Tolerance to Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Zhigang Li

    2015-11-01

    Full Text Available The Gram-positive bacterium Staphylococcus aureus is one of the most frequent pathogens that causes severe morbidity and mortality throughout the world. S. aureus can infect skin and soft tissues or become invasive leading to diseases such as pneumonia, endocarditis, sepsis or toxic shock syndrome. In contrast, S. aureus is also a common commensal microbe and is often part of the human nasal microbiome without causing any apparent disease. In this review, we explore the immunomodulation and disease tolerance mechanisms that promote commensalism to S. aureus.

  18. Mastite com lesões sistêmicas por Staphylococus aureus subesp. aureus em coelhos Mastitis with systemic lesions due to Staphylococus aureus subesp. aureus in rabbits

    OpenAIRE

    Sandra Davi Traverso; Leonardo da Cunha; Joaquim César Teixeira Fernandes; Alexandre Paulino Loretti; Adriana Rhoden; Elsio Wunder Jr.; David Driemeier

    2003-01-01

    Em uma criação composta por 1800 coelhos, 33% das matrizes apresentaram mastite e lesões cutâneas crostosas e purulentas. Estes animais apresentavam-se entre 10 a- 12 meses de idade e em segunda parição. Quinze coelhos afetados foram sacrificados e necropsiados. Na necropsia, além das lesões cutâneas haviam microabscessos em diversos órgãos. Das amostras coletadas isolou-se Staphylococcus aureus subesp. aureus. S. aureus subesp. aureus também foi isolado de "swab" nasal coletado do tratador e...

  19. Methicillin-Resistant Staphylococcus aureus (MRSA) Treatment

    Science.gov (United States)

    ... Laboratory of Bacteriology Network on Antimicrobial Resistance in Staphylococcus aureus (NARSA) Antibacterial Resistance Leadership Group (ARLG) NIAID Antimicrobial Resistance Funding Information ...

  20. Methicillin-Resistant Staphylococcus aureus (MRSA) Diagnosis

    Science.gov (United States)

    ... Laboratory of Bacteriology Network on Antimicrobial Resistance in Staphylococcus aureus (NARSA) Antibacterial Resistance Leadership Group (ARLG) NIAID Antimicrobial Resistance Funding Information ...

  1. Mild Staphylococcus aureus Skin Infection Improves the Course of Subsequent Endogenous S. aureus Bacteremia in Mice.

    Directory of Open Access Journals (Sweden)

    Sanne van den Berg

    Full Text Available Staphylococcus aureus carriers with S. aureus bacteremia may have a reduced mortality risk compared to non-carriers. A role for the immune system is suggested. Here, we study in mice the effect of mild S. aureus skin infection prior to endogenous or exogenous S. aureus bacteremia, and evaluate protection in relation to anti-staphylococcal antibody levels. Skin infections once or twice by a clinical S. aureus isolate (isolate P or S. aureus strain 8325-4 were induced in mice free of S. aureus and anti-staphylococcal antibodies. Five weeks later, immunoglobulin G (IgG levels in blood against 25 S. aureus antigens were determined, and LD50 or LD100 bacteremia caused by S. aureus isolate P was induced. S. aureus skin infections led to elevated levels of anti-staphylococcal IgG in blood. One skin infection improved the course of subsequent severe endogenous bacteremia only. A second skin infection further improved animal survival rate, which was associated with increased pre-bacteremia IgG levels against Efb, IsaA, LukD, LukE, Nuc, PrsA and WTA. In conclusion, S. aureus isolate P skin infection in mice reduces the severity of subsequent endogenous S. aureus bacteremia only. Although cellular immune effects cannot be rules out, anti-staphylococcal IgG against specified antigens may contribute to this effect.

  2. BACTERIAL SPECTRUM AND PATTERN OF ANTIMICROBIAL SENSITIVITY AMONG OUTPATIENTS WITH PNEUMONIA IN A TERTIARY CARE HOSPITAL

    Directory of Open Access Journals (Sweden)

    Sushma

    2015-04-01

    Full Text Available OBJECTIVES: To outline the spectrum of bacteria causing pneumonia and the pattern of antimicrobial sensitivity in outpatients with pneumonia in a tertiary care hospital in Himachal Pradesh. METHODS: Sputum of 108 immuno competent pneumonia patients attending outpatient departments of Medicine and Pulmonary medicine of Dr. R. P. Government Medical College , Kangra at Tanda was sent for Gram staining and culture and sensitivity testing. RESULTS: Commensals were detected in most of the cases (32 , 29.6% followed by Staphylococcus aureus in 17(15.7% and Streptococcus pneumoniae in 16(14.8%. This was followed by three Gram negative organisms namely E Coli (11 , 10.2% , Pseudomonas (10 , 9.2% and Klebsiella (8 , 7.2%. No growth was obtained in 7(6.5% and other organisms were isolated in 7(6.5% specimens. Staphylococcus aureus was sensitive to vancomycin , clindamycin , cefoxitin , azithromycin and cotrimoxazole. Streptococcus pneumoniae was found to be sensitive to vancomycin , clindamycin , gentamicin , azithromycin , penicillin , cotrimoxazole , amoxicillin +clavulanic acid. Klebsiella was found to be sensitive to imipenem , azithromycin , ciprofloxacin , gentamicin and amoxicillin +clavulanic acid. E coli was sensitive to imipenem , gentamicin and amoxicillin +clavulanic acid. Pseudomonas aeruginosa was found to be sensitive to gentamicin , cefta zidime , imipenem , ticarcillin and piperacillin. CONCLUSION: Staphylococcus aureus and Streptococcus pneumoniae are the commonest organism causing pneumonia. Streptococcus pneumoniae is resistant to many antibiotics. Azithromycin can be the first line therapy for pneumonia.

  3. Characterisation of Staphylococcus aureus bacteraemia at Tygerberg hospital

    NARCIS (Netherlands)

    Orth, H.; Dreyer, Z.S.; Makgotlho, E.; Oosthuysen, W.; Sinha, B.; Wasserman, E.

    2013-01-01

    To elucidate the local epidemiology of Staphylococcus aureus bacteraemia, we characterised blood culture isolates using molecular methods and prospectively collected clinical data to determine the occurrence of community-acquired, methicillinresistant S. aureus (MRSA). Consecutive S. aureus blood cu

  4. Tumor necrosis factor-alpha and acute phase proteins in early pregnant ewes after challenge with peptidoglycan-polysaccharide (PG-PS).

    Science.gov (United States)

    Bacterial infection shortly after breeding interferes with establishment and progression of pregnancy. This is particularly relevant in cases of Gram-positive bacterial infection wherein it can be demonstrated that the injection of peptidoglycan-polysaccharide (PG-PS), a component of Gram-positive ...

  5. Molecular Cloning and Nucleotide Sequence of the Gene Encoding the Major Peptidoglycan Hydrolase of Lactococcus lactis, a Muramidase Needed for Cell Separation

    NARCIS (Netherlands)

    Buist, Girbe; Kok, Jan; Leenhouts, Kees J.; Dabrowska, Magdalena; Venema, Gerhardus; Haandrikman, Alfred J.

    1995-01-01

    A gene of Lactococcus lactis subsp, cremoris MG1363 encoding a peptidoglycan hydrolase was identified in a genomic library of the strain in pUC19 by screening Escherichia coli transformants for cell wall lysis activity on a medium containing autoclaved, lyophilized Micrococcus lysodeikticus cells, I

  6. The PASTA domain of penicillin-binding protein SpoVD is dispensable for endospore cortex peptidoglycan assembly in Bacillus subtilis.

    Science.gov (United States)

    Bukowska-Faniband, Ewa; Hederstedt, Lars

    2015-02-01

    Peptidoglycan is the major structural component of the bacterial cell wall. Penicillin-binding proteins (PBPs), located at the exterior of the cytoplasmic membrane, play a major role in peptidoglycan synthesis and remodelling. A PASTA domain (penicillin-binding protein and serine/threonine kinase associated domain) of about 65 residues is found at the C-terminal end of some PBPs and eukaryotic-like protein serine/threonine kinases in a variety of bacteria. The function of PASTA domains is not understood, but some of them are thought to bind uncross linked peptidoglycan. Bacillus subtilis has 16 different PBPs, but only 2 of them, Pbp2b and SpoVD, contain a PASTA domain. SpoVD is specific for sporulation and essential for endospore cortex peptidoglycan synthesis. We have studied the role of the PASTA domain in SpoVD by deleting this domain and analysing the effects on endospore formation and subcellular localization of SpoVD. Our results demonstrate that the PASTA domain in SpoVD is not essential for cortex synthesis and not important for targeting SpoVD to the forespore outer membrane during sporulation.

  7. Impact of the β-Lactam Resistance Modifier (−-Epicatechin Gallate on the Non-Random Distribution of Phospholipids across the Cytoplasmic Membrane of Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Helena Rosado

    2015-07-01

    Full Text Available The polyphenol (−-epicatechin gallate (ECg inserts into the cytoplasmic membrane (CM of methicillin-resistant Staphylococcus aureus (MRSA and reversibly abrogates resistance to β-lactam antibiotics. ECg elicits an increase in MRSA cell size and induces thickened cell walls. As ECg partially delocalizes penicillin-binding protein PBP2 from the septal division site, reduces PBP2 and PBP2a complexation and induces CM remodelling, we examined the impact of ECg membrane intercalation on phospholipid distribution across the CM and determined if ECg affects the equatorial, orthogonal mode of division. The major phospholipids of the staphylococcal CM, lysylphosphatidylglycerol (LPG, phosphatidylglycerol (PG, and cardiolipin (CL, were distributed in highly asymmetric fashion; 95%–97% of LPG was associated with the inner leaflet whereas PG (~90% and CL (~80% were found predominantly in the outer leaflet. ECg elicited small, significant changes in LPG distribution. Atomic force microscopy established that ECg-exposed cells divided in similar fashion to control bacteria, with a thickened band of encircling peptidoglycan representing the most recent plane of cell division, less distinct ribs indicative of previous sites of orthogonal division and concentric rings and “knobbles” representing stages of peptidoglycan remodelling during the cell cycle. Preservation of staphylococcal membrane lipid asymmetry and mode of division in sequential orthogonal planes appear key features of ECg-induced stress.

  8. Evaluation of Two New Chromogenic Media, CHROMagar MRSA and S. aureus ID, for Identifying Staphylococcus aureus and Screening Methicillin-Resistant S. aureus

    OpenAIRE

    Hedin, Göran; Fang, Hong

    2005-01-01

    Thirty-nine methicillin-resistant Staphylococcus aureus (MRSA) isolates with diverse genetic backgrounds and two reference strains were correctly identified as S. aureus on CHROMagar MRSA and S. aureus ID media. Growth inhibition on CHROMagar MRSA was noted. A combination of cefoxitin disk and S. aureus ID was found suitable for rapid MRSA screening.

  9. Cefotaxime-heparin lock prophylaxis against hemodialysis catheter-related sepsis among Staphylococcus aureus nasal carriers

    Directory of Open Access Journals (Sweden)

    Anil K Saxena

    2012-01-01

    Full Text Available Staphylococcus aureus nasal carriers undergoing hemodialysis (HD through tunneled cuffed catheters (TCCs form a high-risk group for the development of catheter-related bloodstream infections (CRBSI and ensuing morbidity. The efficacy of antibiotic-locks on the outcomes of TCCs among S. aureus nasal carriers has not been studied earlier. Persistent nasal carriage was defined by two or more positive cultures for methicillin-susceptible (MSSA or methicillin-resistant (MRSA S. aureus of five standardized nasal swabs taken from all the participants dialyzed at a large out-patient HD center affiliated to a tertiary care hospital. Of 218 participants, 82 S. aureus nasal carriers dialyzed through TCCs (n = 88 were identified through April 2005 to March 2006 and randomized to two groups. Group I comprised of 39 nasal carriers who had TCCs (n = 41 "locked" with cefotaxime/heparin while group II included 43 patients with TCCs (n = 47 filled with standard heparin. The CRBSI incidence and TCC survival at 365 days were statistically compared between the two groups. A significantly lower CRBSI incidence (1.47 vs. 3.44/1000 catheter-days, P <0.001 and higher infection-free TCC survival rates at 365 days (80.5 vs. 40.4%, P <0.0001 were observed in the cefotaxime group compared with the stan-dard heparin group. However, no significant difference in MRSA-associated CRBSI incidence was observed between the two groups. Cefotaxime-heparin "locks" effectively reduced CRBSI-incidence associated with gram-positive cocci, including MSSA, among S. aureus nasal carriers. There remains a compelling requirement for antibiotic-locks effective against MRSA.

  10. CHRONIC OSTEOMYELITIS: A BACTERIOLOGICAL STUDY WITH SPECIAL REFERENCE TO STAPHYLOCOCCUS AUREUS

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    Sanjoy Chakravarty

    2015-01-01

    Full Text Available Advances in the identification of infections and early diagnosis of Osteomyelitis have led to the improved management of Osteomyelitis. This study was undertaken to determine the bacteriological profile of Osteomyelitis and the antibiotic resistance pattern of various isolates obtained as it is an important cause of morbidity. A total of 50 patients of Osteomyelitis either attending the outpatient department or admitted in the wards of a teaching and tertiary care hospita l in Sikkim from October 2013 to October, 2014 were included in the study. All those patients who were clinically and/ or radiologically suspected of having Osteomyelitis were enrolled as cases. Pus/ pus swabs or sequestrum samples taken aseptically were c ultured aerobically at 37 0 C for 18 - 24 hours in Blood and Mac Conkey agar plates. Culture isolates were identified by a series of standard biochemical reactions. Antibiotic susceptibility was tested on Mueller Hinton agar by Kirby Bauer disc diffusion met hod. Betalactamase production of S. aureus strains were verified by iodometric filter paper and acidometric agar plate methods. S. aureus strains were screened for methicillin resistance by using conventional microbiological methods. S. aureus turned out t o be the most common organism isolated. Other organism isolated were P. Aeruginosa, Proteus spp., Klebsiella spp., E. coli, Enterobacter spp., S. epidermitis, Streptococcus pyogens and Enterococcus spp. Beta - lactamase production and methicillin resistance was seen in S. aureus strains respectively. Multidrug resistance was observed in other strains. Infection caused by Methicillin resistant S. aureus and multidrug resistant organisms are posing a major challenge in the treatment of Osteomyelitis. So, appropriate drug selected by antibiotic sensitivity testing should be used to treat Osteomyelitis

  11. Renew or die: The molecular mechanisms of peptidoglycan recycling and antibiotic resistance in Gram-negative pathogens.

    Science.gov (United States)

    Domínguez-Gil, Teresa; Molina, Rafael; Alcorlo, Martín; Hermoso, Juan A

    2016-09-01

    Antimicrobial resistance is one of the most serious health threats. Cell-wall remodeling processes are tightly regulated to warrant bacterial survival and in some cases are directly linked to antibiotic resistance. Remodeling produces cell-wall fragments that are recycled but can also act as messengers for bacterial communication, as effector molecules in immune response and as signaling molecules triggering antibiotic resistance. This review is intended to provide state-of-the-art information about the molecular mechanisms governing this process and gather structural information of the different macromolecular machineries involved in peptidoglycan recycling in Gram-negative bacteria. The growing body of literature on the 3D structures of the corresponding macromolecules reveals an extraordinary complexity. Considering the increasing incidence and widespread emergence of Gram-negative multidrug-resistant pathogens in clinics, structural information on the main actors of the recycling process paves the way for designing novel antibiotics disrupting cellular communication in the recycling-resistance pathway. PMID:27620957

  12. Peptidoglycan metabolism is controlled by the WalRK (YycFG) and PhoPR two-component systems in phosphate-limited Bacillus subtilis cells.

    Science.gov (United States)

    Bisicchia, Paola; Lioliou, Efthimia; Noone, David; Salzberg, Letal I; Botella, Eric; Hübner, Sebastian; Devine, Kevin M

    2010-02-01

    In Bacillus subtilis, the WalRK (YycFG) two-component system controls peptidoglycan metabolism in exponentially growing cells while PhoPR controls the response to phosphate limitation. Here we examine the roles of WalRK and PhoPR in peptidoglycan metabolism in phosphate-limited cells. We show that B. subtilis cells remain viable in a phosphate-limited state for an extended period and resume growth rapidly upon phosphate addition, even in the absence of a PhoPR-mediated response. Peptidoglycan synthesis occurs in phosphate-limited wild-type cells at approximately 27% the rate of exponentially growing cells, and at approximately 18% the rate of exponentially growing cells in the absence of PhoPR. In phosphate-limited cells, the WalRK regulon genes yocH, cwlO(yvcE), lytE and ydjM are expressed in a manner that is dependent on the WalR recognition sequence and deleting these genes individually reduces the rate of peptidoglycan synthesis. We show that ydjM expression can be activated by PhoP approximately P in vitro and that PhoP occupies its promoter in phosphate-limited cells. However, iseA(yoeB) expression cannot be repressed by PhoP approximately P in vitro, but can be repressed by non-phosphorylated WalR in vitro. Therefore, we conclude that peptidoglycan metabolism is controlled by both WalRK and PhoPR in phosphate-limited B. subtilis cells. PMID:20487291

  13. Tertiary Logistics in the Focus of All Logistics

    OpenAIRE

    Ratko Zelenika; Mirjana Grèiæ; Helga Pavliæ Skender

    2008-01-01

    Trade logistics, traffic logistics, transport logistics and warehouse logistics are just some of the tertiary logistics which enables production processes of all economic sector products and services. Tertiary logistics representing the tertiary economic sector is the most sofisticated and the most important logistics due to the characteristics of the tertiary sector as a service sector that promotes business conditions in all economic sectors. Accordingly, tertiary logistics has a crucial ro...

  14. Alcohol handrubbing and chlorhexidine handwashing are equally effective in removing methicillin-resistant Staphylococcus aureus from health care workers' hands: A randomized controlled trial.

    Science.gov (United States)

    Ho, Hanley J; Poh, Bee-Fong; Choudhury, Saugata; Krishnan, Prabha; Ang, Brenda; Chow, Angela

    2015-11-01

    We conducted a randomized controlled trial in a tertiary-care hospital in a real-time setting to evaluate the effectiveness of 3 hand hygiene protocols in reducing hand carriage of methicillin-resistant and methicillin-sensitive Staphylococcus aureus among health care workers. Our study shows that use of alcohol handrub, either covering all hand surfaces in no particular order or using the 7-step technique, and chlorhexidine handwashing were equally effective in removing hand carriage of these pathogens. PMID:26190381

  15. Accumulation of Peptidoglycan O-Acetylation Leads to Altered Cell Wall Biochemistry and Negatively Impacts Pathogenesis Factors of Campylobacter jejuni*

    Science.gov (United States)

    Ha, Reuben; Frirdich, Emilisa; Sychantha, David; Biboy, Jacob; Taveirne, Michael E.; Johnson, Jeremiah G.; DiRita, Victor J.; Vollmer, Waldemar; Clarke, Anthony J.; Gaynor, Erin C.

    2016-01-01

    Campylobacter jejuni is a leading cause of bacterial gastroenteritis in the developed world. Despite its prevalence, its mechanisms of pathogenesis are poorly understood. Peptidoglycan (PG) is important for helical shape, colonization, and host-pathogen interactions in C. jejuni. Therefore, changes in PG greatly impact the physiology of this organism. O-acetylation of peptidoglycan (OAP) is a bacterial phenomenon proposed to be important for proper cell growth, characterized by acetylation of the C6 hydroxyl group of N-acetylmuramic acid in the PG glycan backbone. The OAP gene cluster consists of a PG O-acetyltransferase A (patA) for translocation of acetate into the periplasm, a PG O-acetyltransferase B (patB) for O-acetylation, and an O-acetylpeptidoglycan esterase (ape1) for de-O-acetylation. In this study, reduced OAP in ΔpatA and ΔpatB had minimal impact on C. jejuni growth and fitness under the conditions tested. However, accumulation of OAP in Δape1 resulted in marked differences in PG biochemistry, including O-acetylation, anhydromuropeptide levels, and changes not expected to result directly from Ape1 activity. This suggests that OAP may be a form of substrate level regulation in PG biosynthesis. Ape1 acetylesterase activity was confirmed in vitro using p-nitrophenyl acetate and O-acetylated PG as substrates. In addition, Δape1 exhibited defects in pathogenesis-associated phenotypes, including cell shape, motility, biofilm formation, cell surface hydrophobicity, and sodium deoxycholate sensitivity. Δape1 was also impaired for chick colonization and adhesion, invasion, intracellular survival, and induction of IL-8 production in INT407 cells in vitro. The importance of Ape1 in C. jejuni biology makes it a good candidate as an antimicrobial target. PMID:27474744

  16. Mechanism of action of peptidoglycan O-acetyltransferase B involves a Ser-His-Asp catalytic triad.

    Science.gov (United States)

    Moynihan, Patrick J; Clarke, Anthony J

    2014-10-01

    The O-acetylation of the essential cell wall polymer peptidoglycan is essential in many bacteria for their integrity and survival, and it is catalyzed by peptidoglycan O-acetlytransferase B (PatB). Using PatB from Neisseria gonorrhoeae as the model, we have shown previously that the enzyme has specificity for polymeric muropeptides that possess tri- and tetrapeptide stems and that rates of reaction increase with increasing degrees of polymerization. Here, we present the catalytic mechanism of action of PatB, the first to be described for an O-acetyltransferase of any bacterial exopolysaccharide. The influence of pH on PatB activity was investigated, and pKa values of 6.4-6.45 and 6.25-6.35 for the enzyme-substrate complex (kcat vs pH) and the free enzyme (kcat·KM(-1) vs pH), respectively, were determined for the respective cosubstrates. The enzyme is partially inactivated by sulfonyl fluorides but not by EDTA, suggesting the participation of a serine residue in its catalytic mechanism. Alignment of the known and hypothetical PatB amino acid sequences identified Ser133, Asp302, and His305 as three invariant amino acid residues that could potentially serve as a catalytic triad. Replacement of Asp302 with Ala resulted in an enzyme with less than 20% residual activity, whereas activity was barely detectable with (His305 → Ala)PatB and (Ser133 → Ala)PatB was totally inactive. The reaction intermediate of the transferase reaction involving acetyl- and propionyl-acyl donors was trapped on both the wild-type and (Asp302 → Ala) enzymes and LC-MS/MS analysis of tryptic peptides identified Ser133 as the catalytic nucleophile. A transacetylase mechanism is proposed based on the mechanism of action of serine esterases. PMID:25215566

  17. Immunogenicity of toxins during Staphylococcus aureus infection

    NARCIS (Netherlands)

    N.J. Verkaik (Nelianne); O. Dauwalder (Olivier); K. Antri (Kenza); I. Boubekri (Ilhem); C.P. de Vogel (Corné); C. Badiou (Cédric); M. Bes (Michèle); F. Vandenesch (François); M. Tazir (Mohammed); H. Hooijkaas (Herbert); H.A. Verbrugh (Henri); A.F. van Belkum (Alex); J. Etienne (Jerome); G. Lina (Gérard); N. Ramdani-Bouguessa (Nadjia); W.J.B. van Wamel (Willem)

    2010-01-01

    textabstractAB - BACKGROUND: Toxins are important Staphylococcus aureus virulence factors, but little is known about their immunogenicity during infection. Here, additional insight is generated. METHODS: Serum samples from 206 S. aureus-infected patients and 201 hospital-admitted control subjects we

  18. The cell surface proteome of Staphylococcus aureus

    NARCIS (Netherlands)

    Dreisbach, Annette; van Dijl, Jan Maarten; Buist, Girbe

    2011-01-01

    The Gram-positive bacterium Staphylococcus aureus is a wide spread opportunistic pathogen that can cause a range of life-threatening diseases. To obtain a better understanding of the global mechanisms for pathogenesis and to identify novel targets for therapeutic interventions, the S. aureus proteom

  19. Population structure of Staphylococcus aureus in China

    NARCIS (Netherlands)

    Yan, Xiaomei

    2015-01-01

    The present PhD research was aimed at analysing the population structure of Staphylococcus aureus in China. Between 2000 and 2005 we found that patients from a single Chinese hospital showed increasing trends in antimicrobial resistance. Among methicillin-resistant S. aureus (MRSA), resistance again

  20. Intravascular catheter related infections and antimicrobial susceptibility pattern of isolated bacteria in a tertiary care hospital of Bangladesh

    Directory of Open Access Journals (Sweden)

    F J Mansur

    2014-01-01

    Full Text Available The aim of this study was to evaluate the rate of bacterial colonisation and catheter related blood stream infections (CRBSI together with the antibiotic susceptibility patterns in a tertiary care hospital. CRBSI was detected with semi-quantitative and quantitative methods. The antimicrobial susceptible patterns of the isolated organisms were performed by Kirby Bauer disk diffusion method. The rate of catheter colonisation and CRBSI were 42.1% and 14% (16.1/1000 catheter days respectively. The most common causative pathogens were Pseudomonas sp. (23.7%, Acinetobacter sp. (18.4%, Staphylococcus aureus (13.2% and Enterobacteriaceae (10.5%. The rate of isolation of methicillin resistance S. aureus, imipenem resistant Pseudomonas sp. and extended spectrum β lactamase producing Enterobacteriaceae were 60%, 44.0% and 100%. The result of this study would be useful for control and treatment of CRBSI.

  1. Staphylococcus aureus Sortase A-Mediated Incorporation of Peptides: Effect of Peptide Modification on Incorporation.

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    Silvie Hansenová Maňásková

    Full Text Available The endogenous Staphylococcus aureus sortase A (SrtA transpeptidase covalently anchors cell wall-anchored (CWA proteins equipped with a specific recognition motif (LPXTG into the peptidoglycan layer of the staphylococcal cell wall. Previous in situ experiments have shown that SrtA is also able to incorporate exogenous, fluorescently labelled, synthetic substrates equipped with the LPXTG motif (K(FITCLPETG-amide into the bacterial cell wall, albeit at high concentrations of 500 μM to 1 mM. In the present study, we have evaluated the effect of substrate modification on the incorporation efficiency. This revealed that (i by elongation of LPETG-amide with a sequence of positively charged amino acids, derived from the C-terminal domain of physiological SrtA substrates, the incorporation efficiency was increased by 20-fold at 10 μM, 100 μM and 250 μM; (ii Substituting aspartic acid (E for methionine increased the incorporation of the resulting K(FITCLPMTG-amide approximately three times at all concentrations tested; (iii conjugation of the lipid II binding antibiotic vancomycin to K(FITCLPMTG-amide resulted in the same incorporation levels as K(FITCLPETG-amide, but much more efficient at an impressive 500-fold lower substrate concentration. These newly developed synthetic substrates can potentially find broad applications in for example the in situ imaging of bacteria; the incorporation of antibody recruiting moieties; the targeted delivery and covalent incorporation of antimicrobial compounds into the bacterial cell wall.

  2. SPECTRUM OF BACTERIA ISOLATED FROM BRONCHOALVEOLAR LAVAGE IN A TERTIARY CARE CENTRE

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    Sowmya

    2014-07-01

    Full Text Available BACKGROUND/OBJECTIVES: Pneumonia is an inflammatory condition of the lung caused by bacteria, viruses, fungi and parasites. The common bacterial pathogens include Pseudomonas spp., Klebsiella pneumoniae, S. aureus, Acinetobacter spp., Streptococcus pneumoniae. Antibiotic resistance is common among these bacterial isolates. This study was taken up to identify the spectrum of bacteria isolated from bronchoalveolar (BAL samples of patients suffering from lower respiratory tract infections and to determine their antibiogram. MATERIALS and METHODS: The retrospective study was carried out in a tertiary care centre over a period of one year (March 2013-February 2014.Patients above 18 years with clinical suspicion of pneumonia were included in this study. The samples with growth >104 CFU/ml of bacteria were identified and their susceptibility pattern to various antibiotics was performed. RESULTS: Out of 307 BAL samples, 110 were culture positive. The common bacterial pathogens isolated were Pseudomonas spp. (21.8%, Acinetobacter spp. (15.5%, Klebsiella spp.(14.5%, Enterococcus spp.(10.9% and S.aureus (12.7%. Carbapenem resistance was seen in 31.6% of Acinetobacter spp, 22% Klebsiella spp. and 14% in Pseudomonas spp. Methicillin resistance was detected in 21.4% of S.aureus isolates. All strains of S.aureus were sensitive to vancomycin and teicoplanin. All isolates of Enterococci were sensitive to vancomycin, teicoplanin and high level aminoglycosides. CONCLUSION: Pseudomonas and Acinetobacter spp. were the most common bacterial pathogens isolated from BAL. Carbapenem resistance is on the rise among these gram negative bacterial isolates.

  3. Genomic Analysis of Companion Rabbit Staphylococcus aureus.

    Science.gov (United States)

    Holmes, Mark A; Harrison, Ewan M; Fisher, Elizabeth A; Graham, Elizabeth M; Parkhill, Julian; Foster, Geoffrey; Paterson, Gavin K

    2016-01-01

    In addition to being an important human pathogen, Staphylococcus aureus is able to cause a variety of infections in numerous other host species. While the S. aureus strains causing infection in several of these hosts have been well characterised, this is not the case for companion rabbits (Oryctolagus cuniculus), where little data are available on S. aureus strains from this host. To address this deficiency we have performed antimicrobial susceptibility testing and genome sequencing on a collection of S. aureus isolates from companion rabbits. The findings show a diverse S. aureus population is able to cause infection in this host, and while antimicrobial resistance was uncommon, the isolates possess a range of known and putative virulence factors consistent with a diverse clinical presentation in companion rabbits including severe abscesses. We additionally show that companion rabbit isolates carry polymorphisms within dltB as described as underlying host-adaption of S. aureus to farmed rabbits. The availability of S. aureus genome sequences from companion rabbits provides an important aid to understanding the pathogenesis of disease in this host and in the clinical management and surveillance of these infections. PMID:26963381

  4. 21 CFR 866.3700 - Staphylococcus aureus serological reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Staphylococcus aureus serological reagents. 866... Staphylococcus aureus serological reagents. (a) Identification. Staphylococcus aureus serological reagents are... epidemiological information on these diseases. Certain strains of Staphylococcus aureus produce an...

  5. Exfoliative Toxins of Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Michal Bukowski

    2010-05-01

    Full Text Available Staphylococcus aureus is an important pathogen of humans and livestock. It causes a diverse array of diseases, ranging from relatively harmless localized skin infections to life-threatening systemic conditions. Among multiple virulence factors, staphylococci secrete several exotoxins directly associated with particular disease symptoms. These include toxic shock syndrome toxin 1 (TSST-1, enterotoxins, and exfoliative toxins (ETs. The latter are particularly interesting as the sole agents responsible for staphylococcal scalded skin syndrome (SSSS, a disease predominantly affecting infants and characterized by the loss of superficial skin layers, dehydration, and secondary infections. The molecular basis of the clinical symptoms of SSSS is well understood. ETs are serine proteases with high substrate specificity, which selectively recognize and hydrolyze desmosomal proteins in the skin. The fascinating road leading to the discovery of ETs as the agents responsible for SSSS and the characterization of the molecular mechanism of their action, including recent advances in the field, are reviewed in this article.

  6. [Staphylococcus aureus and antibiotic resistance].

    Science.gov (United States)

    Sancak, Banu

    2011-07-01

    After the report of first case of methicillin-resistant Staphylococcus aureus (MRSA) in 1961, MRSA become a major problem worldwide. Over the last decade MRSA strains have emerged as serious pathogens in nosocomial and community settings. Glycopeptides (vancomycin and teicoplanin) are still the current mainstay of therapy for infections caused by MRSA. In the last decade dramatic changes have occurred in the epidemiology of MRSA infections. The isolates with reduced susceptibility and in vitro resistance to vancomycin have emerged. Recently, therapeutic alternatives such as quinupristin/dalfopristin, linezolid, tigecycline and daptomycin have been introduced into clinical practice for treating MRSA infections. Nevertheless, these drugs are only approved for certain indication and resistance has already been reported. In this review, the new information on novel drugs for treating MRSA infections and the resistance mechanisms of these drugs were discussed. PMID:21935792

  7. The Heme Sensor System of Staphylococcus aureus

    OpenAIRE

    Stauff, Devin L; Skaar, Eric P.

    2009-01-01

    The important human pathogen Staphylococcus aureus is able to satisfy its nutrient iron requirement by acquiring heme from host hemoglobin in the context of infection. However, heme acquisition exposes S. aureus to heme toxicity. In order to detect the presence of toxic levels of exogenous heme, S. aureus is able to sense heme through the heme sensing system (HssRS) two-component system. Upon sensing heme, HssRS directly regulates the expression of the heme-regulated ABC transporter HrtAB, wh...

  8. Cooperative Tertiary Interaction Network Guides RNA Folding

    Energy Technology Data Exchange (ETDEWEB)

    Behrouzi, Reza; Roh, Joon Ho; Kilburn, Duncan; Briber, R.M.; Woodson, Sarah A. (JHU); (Maryland)

    2013-04-08

    Noncoding RNAs form unique 3D structures, which perform many regulatory functions. To understand how RNAs fold uniquely despite a small number of tertiary interaction motifs, we mutated the major tertiary interactions in a group I ribozyme by single-base substitutions. The resulting perturbations to the folding energy landscape were measured using SAXS, ribozyme activity, hydroxyl radical footprinting, and native PAGE. Double- and triple-mutant cycles show that most tertiary interactions have a small effect on the stability of the native state. Instead, the formation of core and peripheral structural motifs is cooperatively linked in near-native folding intermediates, and this cooperativity depends on the native helix orientation. The emergence of a cooperative interaction network at an early stage of folding suppresses nonnative structures and guides the search for the native state. We suggest that cooperativity in noncoding RNAs arose from natural selection of architectures conducive to forming a unique, stable fold.

  9. Correlation of tertiary formations of Alaska

    Science.gov (United States)

    MacNeil, F.S.; Wolfe, J.A.; Miller, D.J.; Hopkins, D.M.

    1961-01-01

    Recent stratigraphic and paleontologic studies have resulted in substantial revision of the age assignments and inter-basin correlations of the Tertiary formations of Alaska as given in both an earlier compilation by P. S. Smith (1939) and a tentative chart prepared for distribution at the First International Symposium on Arctic Geology at Calgary, Alberta (Miller, MacNeil, and Wahrhaftig, 1960). Current work in Alaska by the U. S. Geological Survey and several oil companies is furnishing new information at a rapid rate and further revisions may be expected. The correlation chart (Fig. 1), the first published chart to deal exclusively with the Tertiary of Alaska, had the benefit of a considerable amount of stratigraphic data and fossil collections from some oil companies, but recent surface mapping and drilling by other oil companies in several Tertiary basins undoubtedly must have produced much more information. Nevertheless, the extent of available data justifies the publication of a revised correlation chart at this time.

  10. Laboratory Maintenance of Methicillin-Resistant Staphylococcus aureus (MRSA)

    OpenAIRE

    Nicholas P Vitko; Richardson, Anthony R.

    2013-01-01

    Staphylococcus aureus is an important bacterial pathogen in the hospital and community settings, especially Staphylococcus aureus clones that exhibit methicillin-resistance (MRSA). Many strains of S. aureus are utilized in the laboratory, underscoring the genetic differences inherent in clinical isolates. S. aureus grows quickly at 37°C with aeration in rich media (e.g. BHI) and exhibits a preference for glycolytic carbon sources. Furthermore, S. aureus has a gold pigmentation, exhibits β-hem...

  11. Molecular characterization of Staphylococcus aureus isolates causing skin and soft tissue infections in patients from Malakand, Pakistan.

    Science.gov (United States)

    Madzgalla, S; Syed, M A; Khan, M A; Rehman, S S; Müller, E; Reissig, A; Ehricht, R; Monecke, S

    2016-09-01

    Comparatively few studies have been published describing Staphylococcus aureus/MRSA epidemiology in Central Asia including Pakistan. Here, we report the genotyping of Staphylococcus aureus strains (that include both methicillin-susceptible and methicillin-resistant Staphylococcus aureus) from community- and hospital-acquired skin and soft-tissue infections in a tertiary care hospital in the Malakand district of the Khyber Pakhtunkhwa Province of Pakistan. Forty-five isolates of Staphylococcus aureus were characterized by microarray hybridization. Twenty isolates (44 %) were MRSA, whereas 22 (49 %) were PVL-positive. Fourteen isolates (31 %) harboured both mecA and PVL genes. The dominant clones were CC121-MSSA (n = 15, 33 %) and the PVL-positive "Bengal Bay Clone" (ST772-MRSA-V; n = 13, 29 %). The PVL-positive CC8-MRSA-IV strain "USA300" was found once. The pandemic ST239-MRSA-III strain was absent, although it has previously been observed in Pakistan. These observations require a re-assessment of schemes for initial antibiotic therapy to cover MRSA and they emphasise the need for a rapid and non-molecular test for PVL. PMID:27262852

  12. Mastite com lesões sistêmicas por Staphylococus aureus subesp. aureus em coelhos

    OpenAIRE

    Traverso Sandra Davi; Cunha Leonardo da; Fernandes Joaquim César Teixeira; Loretti Alexandre Paulino; Rhoden Adriana; Wunder Jr. Elsio; Driemeier David

    2003-01-01

    Em uma criação composta por 1800 coelhos, 33% das matrizes apresentaram mastite e lesões cutâneas crostosas e purulentas. Estes animais apresentavam-se entre 10 a- 12 meses de idade e em segunda parição. Quinze coelhos afetados foram sacrificados e necropsiados. Na necropsia, além das lesões cutâneas haviam microabscessos em diversos órgãos. Das amostras coletadas isolou-se Staphylococcus aureus subesp. aureus. S. aureus subesp. aureus também foi isolado de "swab" nasal coletado do tratador e...

  13. Photothermal killing of Staphylococcus aureus using antibody-targeted gold nanoparticles

    Directory of Open Access Journals (Sweden)

    Millenbaugh NJ

    2015-03-01

    Full Text Available Nancy J Millenbaugh,1 Jonathan B Baskin,1 Mauris N DeSilva,1 W Rowe Elliott,1 Randolph D Glickman2 1Maxillofacial Injury and Disease Department, Naval Medical Research Unit San Antonio, Joint Base San Antonio-Fort Sam Houston, TX, USA; 2Department of Ophthalmology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USAPurpose: The continued emergence of multidrug resistant bacterial infections and the decline in discovery of new antibiotics are major challenges for health care throughout the world. This situation has heightened the need for novel antimicrobial therapies as alternatives to traditional antibiotics. The combination of metallic nanoparticles and laser exposure has been proposed as a strategy to induce physical damage to bacteria, regardless of antibiotic sensitivity. The purpose of this study was to test the antibacterial effect of antibody-targeted gold nanoparticles combined with pulsed laser irradiation.Methods: Gold nanoparticles conjugated to antibodies specific to Staphylococcus aureus peptidoglycan were incubated with suspensions of methicillin-resistant and methicillin-sensitive S. aureus (MRSA and MSSA. Bacterial suspensions were then exposed to 8 ns pulsed laser irradiation at a wavelength of 532 nm and fluences ranging from 1 to 5 J/cm2. Viability of the bacteria following laser exposure was determined using colony forming unit assays. Scanning electron microscopy was used to confirm the binding of nanoparticles to bacteria and the presence of cellular damage.Results: The laser-activated nanoparticle treatment reduced the surviving population to 31% of control in the MSSA population, while the survival in the MRSA population was reduced to 58% of control. Significant decreases in bacterial viability occurred when the laser fluence exceeded 1 J/cm2, and this effect was linear from 0 to 5 J/cm2 (r2=0.97. Significantly less bactericidal effect was observed for nonfunctionalized nanoparticles or

  14. A rapid in situ procedure for determination of bacterial susceptibility or resistance to antibiotics that inhibit peptidoglycan biosynthesis

    Directory of Open Access Journals (Sweden)

    Bou Germán

    2011-08-01

    Full Text Available Abstract Background Antibiotics which inhibit bacterial peptidoglycan biosynthesis are the most widely used in current clinical practice. Nevertheless, resistant strains increase dramatically, with serious economic impact and effects on public health, and are responsible for thousands of deaths each year. Critical clinical situations should benefit from a rapid procedure to evaluate the sensitivity or resistance to antibiotics that act at the cell wall. We have adapted a kit for rapid determination of bacterial DNA fragmentation, to assess cell wall integrity. Results Cells incubated with the antibiotic were embedded in an agarose microgel on a slide, incubated in an adapted lysis buffer, stained with a DNA fluorochrome, SYBR Gold and observed under fluorescence microscopy. The lysis affects the cells differentially, depending on the integrity of the wall. If the bacterium is susceptible to the antibiotic, the weakened cell wall is affected by the lysing solution so the nucleoid of DNA contained inside the bacterium is released and spread. Alternatively, if the bacterium is resistant to the antibiotic, it is practically unaffected by the lysis solution and does not liberate the nucleoid, retaining its normal morphological appearance. In an initial approach, the procedure accurately discriminates susceptible, intermediate and resistant strains of Escherichia coli to amoxicillin/clavulanic acid. When the bacteria came from an exponentially growing liquid culture, the effect on the cell wall of the β-lactam was evident much earlier that when they came from an agar plate. A dose-response experiment with an E. coli strain susceptible to ampicillin demonstrated a weak effect before the MIC dose. The cell wall damage was not homogenous among the different cells, but the level of damage increased as dose increased with a predominant degree of effect for each dose. A microgranular-fibrilar extracellular background was evident in gram

  15. Structural basis for type VI secreted peptidoglycan dl-endopeptidase function, specificity and neutralization in Serratia marcescens

    Energy Technology Data Exchange (ETDEWEB)

    Srikannathasan, Velupillai; English, Grant [University of Dundee, Dundee DD1 5EH, Scotland (United Kingdom); Bui, Nhat Khai [Newcastle University, Newcastle upon Tyne NE2 4HH (United Kingdom); Trunk, Katharina; O’Rourke, Patrick E. F.; Rao, Vincenzo A. [University of Dundee, Dundee DD1 5EH, Scotland (United Kingdom); Vollmer, Waldemar [Newcastle University, Newcastle upon Tyne NE2 4HH (United Kingdom); Coulthurst, Sarah J., E-mail: s.j.coulthurst@dundee.ac.uk; Hunter, William N., E-mail: s.j.coulthurst@dundee.ac.uk [University of Dundee, Dundee DD1 5EH, Scotland (United Kingdom)

    2013-12-01

    Crystal structures of type VI secretion system-associated immunity proteins, a peptidoglycan endopeptidase and a complex of the endopeptidase and its cognate immunity protein are reported together with assays of endopeptidase activity and functional assessment. Some Gram-negative bacteria target their competitors by exploiting the type VI secretion system to extrude toxic effector proteins. To prevent self-harm, these bacteria also produce highly specific immunity proteins that neutralize these antagonistic effectors. Here, the peptidoglycan endopeptidase specificity of two type VI secretion-system-associated effectors from Serratia marcescens is characterized. These small secreted proteins, Ssp1 and Ssp2, cleave between γ-d-glutamic acid and l-meso-diaminopimelic acid with different specificities. Ssp2 degrades the acceptor part of cross-linked tetratetrapeptides. Ssp1 displays greater promiscuity and cleaves monomeric tripeptides, tetrapeptides and pentapeptides and dimeric tetratetra and tetrapenta muropeptides on both the acceptor and donor strands. Functional assays confirm the identity of a catalytic cysteine in these endopeptidases and crystal structures provide information on the structure–activity relationships of Ssp1 and, by comparison, of related effectors. Functional assays also reveal that neutralization of these effectors by their cognate immunity proteins, which are called resistance-associated proteins (Raps), contributes an essential role to cell fitness. The structures of two immunity proteins, Rap1a and Rap2a, responsible for the neutralization of Ssp1 and Ssp2-like endopeptidases, respectively, revealed two distinct folds, with that of Rap1a not having previously been observed. The structure of the Ssp1–Rap1a complex revealed a tightly bound heteromeric assembly with two effector molecules flanking a Rap1a dimer. A highly effective steric block of the Ssp1 active site forms the basis of effector neutralization. Comparisons with Ssp2–Rap2

  16. Staphylococcus aureus spa type t437

    DEFF Research Database (Denmark)

    Glasner, C; Pluister, G; Westh, H;

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) belonging to the multilocus sequence type clonal complex 59 (MLST CC59) is the predominant community-associated MRSA clone in Asia. This clone, which is primarily linked with the spa type t437, has so far only been reported in low numbers among...... large epidemiological studies in Europe. Nevertheless, the overall numbers identified in some Northern European reference laboratories have increased during the past decade. To determine whether the S. aureus t437 clone is present in other European countries, and to assess its genetic diversity across...... Europe, we analysed 147 S. aureus t437 isolates from 11 European countries collected over a period of 11 years using multiple locus variable number tandem repeat fingerprinting/analysis (MLVF/MLVA) and MLST. Additionally 16 S. aureus t437 isolates from healthy carriers and patients from China were...

  17. A Surfactant-Induced Functional Modulation of a Global Virulence Regulator from Staphylococcus aureus.

    Directory of Open Access Journals (Sweden)

    Sukhendu Mandal

    Full Text Available Triton X-100 (TX-100, a useful non-ionic surfactant, reduced the methicillin resistance in Staphylococcus aureus significantly. Many S. aureus proteins were expressed in the presence of TX-100. SarA, one of the TX-100-induced proteins, acts as a global virulence regulator in S. aureus. To understand the effects of TX-100 on the structure, and function of SarA, a recombinant S. aureus SarA (rSarA and its derivative (C9W have been investigated in the presence of varying concentrations of this surfactant using various probes. Our data have revealed that both rSarA and C9W bind to the cognate DNA with nearly similar affinity in the absence of TX-100. Interestingly, their DNA binding activities have been significantly increased in the presence of pre-micellar concentration of TX-100. The increase of TX-100 concentrations to micellar or post-micellar concentration did not greatly enhance their activities further. TX-100 molecules have altered the secondary and tertiary structures of both proteins to some extents. Size of the rSarA-TX-100 complex appears to be intermediate to those of rSarA and TX-100. Additional analyses show a relatively moderate interaction between C9W and TX-100. Binding of TX-100 to C9W has, however, occurred by a cooperative pathway particularly at micellar and higher concentrations of this surfactant. Taken together, TX-100-induced structural alteration of rSarA and C9W might be responsible for their increased DNA binding activity. As TX-100 has stabilized the somewhat weaker SarA-DNA complex effectively, it could be used to study its structure in the future.

  18. The Staphylococcus aureus “superbug”

    OpenAIRE

    FOSTER, TIMOTHY JAMES

    2004-01-01

    PUBLISHED There has been some debate about the disease-invoking potential of Staphylococcus aureus strains and whether invasive disease is associated with particularly virulent genotypes, or "superbugs." A study in this issue of the JCI describes the genotyping of a large collection of nonclinical, commensal S. aureus strains from healthy individuals in a Dutch population. Extensive study of their genetic relatedness by amplified restriction fragment typing and comparison with strains that...

  19. Transmissible mupirocin resistance in Staphylococcus aureus.

    OpenAIRE

    Rahman, M.; Noble, W. C.; Cookson, B

    1989-01-01

    The spread of two strains of Staphylococcus aureus with high level resistance to mupirocin is described. The resistance proved to be easily transferred to other S. aureus strains by filter mating experiments and on the skin of mice. No plasmid band corresponding to the resistance could be demonstrated by agarose gel electrophoresis or by caesium chloride gradient centrifugation but cleavage of 'chromosomal' DNA from resistant recipients showed bright bands of DNA absent from sensitive controls.

  20. Peptidoglycan Recognition Protein Pglyrp1 Enhances Experimental Asthma by Promoting Th2 and Th17 and Limiting Regulatory T Cell and Plasmacytoid Dendritic Cell Responses

    OpenAIRE

    Park, Shin Yong; Jing, Xuefang; Gupta, Dipika; Dziarski, Roman

    2013-01-01

    Asthma is a common inflammatory disease involving crosstalk between innate and adaptive immunity. We reveal that antibacterial innate immunity protein, peptidoglycan recognition protein 1 (Pglyrp1), is involved in the development of allergic asthma. Pglyrp1−/− mice developed less severe asthma than wild type (WT) mice following sensitization with house dust mite (HDM) allergen. HDM-sensitized Pglyrp1−/− mice, compared with WT mice, had diminished: bronchial hyper-responsiveness (lung airway r...

  1. Effects of beta-lactam antibiotics on peptidoglycan synthesis in growing Neisseria gonorrhoeae, including changes in the degree of O-acetylation.

    OpenAIRE

    Blundell, J K; Perkins, H. R.

    1981-01-01

    Low concentrations of beta-lactam antibiotics caused an increased uptake of radioactive glucosamine into the sodium dodecyl sulfate-insoluble peptidoglycan of growing Neisseria gonorrhoeae. There was no appreciable change in the (small) amount of sodium dodecyl sulfate-soluble polymer present in the cultures. The sodium dodecyl sulfate-insoluble product in control cells was only partially dissolved by egg-white lysozyme (about 40%), but could all be released by the Chalaropsis B muramidase. I...

  2. Components of the peptidoglycan-recycling pathway modulate invasion and intracellular survival of Salmonella enterica serovar Typhimurium.

    Science.gov (United States)

    Folkesson, Anders; Eriksson, Sofia; Andersson, Mats; Park, James T; Normark, Staffan

    2005-01-01

    beta-Lactam resistance in enteric bacteria is frequently caused by mutations in ampD encoding a cytosolic N-acetylmuramyl- l-alanine amidase. Such mutants are blocked in murein (peptidoglycan) recycling and accumulate cytoplasmic muropeptides that interact with the transcriptional activator ampR, which de-represses beta-lactamase expression. Salmonella enterica serovar Typhimurium, an extensively studied enteric pathogen, was used to show that mutations in ampD decreased the ability of S. typhimurium to enter a macrophage derived cell line and made the bacteria more potent as inducers of inducible nitric oxide synthase (iNOS), as compared with the wild-type. ampG mutants, defective in the transport of recycled muropeptides across the cytoplasmic membrane, behaved essentially as the wild-type in invasion assays and in activation of iNOS. As ampD mutants also have reduced in vivo fitness in a murine model, we suggest that the cytoplasmic accumulation of muropeptides affects the virulence of the ampD mutants.

  3. Stereoselective synthesis of lanthionine derivatives in aqueous solution and their incorporation into the peptidoglycan of Escherichia coli.

    Science.gov (United States)

    Denoël, Thibaut; Zervosen, Astrid; Gerards, Thomas; Lemaire, Christian; Joris, Bernard; Blanot, Didier; Luxen, André

    2014-09-01

    The three diastereoisomers-(R,R), (S,S) and meso-of lanthionine were synthesized in aqueous solution with high diastereoselectivity (>99%). The (S) and (R) enantiomers of two differently protected sulfamidates were opened by nucleophilic attack of (R) or (S)-cysteine. Acidification and controlled heating liberated the free lanthionines. Using the same chemistry, an α-benzyl lanthionine was also prepared. The proposed method, which avoids the need of enrichment by recrystallization, opens the way to the labelling of these compounds with (35)S. Furthermore, in vivo bioincorporation into Escherichia coli W7 was studied. No incorporation of α-benzyl lanthionine was observed. In contrast, meso-lanthionine can effectively replace meso-diaminopimelic acid in vivo, while in the presence of (R,R)-lanthionine the initial increase of bacterial growth was followed by cell lysis. In the future, meso-[(35)S]lanthionine could be used to study the biosynthesis of peptidoglycan and its turnover in relation to cell growth and division.

  4. Tertiary Education and Training in Australia, 2009

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2011

    2011-01-01

    Sourcing data from the National VET Provider Collection and the Higher Education Statistics Collection, this publication provides a summary of participation in tertiary education and training in Australia. It covers participation in Australian Qualifications Framework certificate I qualifications through to doctorates by research, as well as…

  5. Adapting Cooperative Learning in Tertiary ELT

    Science.gov (United States)

    Ning, Huiping

    2011-01-01

    An updated guideline for tertiary ELT in China has shifted the emphasis to the development of learners' ability to communicate in English. Using group work and getting learners actively involved in the actual use of English are highlighted more than before. This article focuses on adapting cooperative learning methods for ELT with tertiary…

  6. Indigenous Students in the Tertiary Education Sector

    Science.gov (United States)

    Bandias, Susan; Fuller, Don; Larkin, Steven

    2014-01-01

    Important recent objectives of indigenous education policy in Australia have been aimed at redressing indigenous economic and social disadvantage through increasing student retention, progression and completion rates in both compulsory and post-compulsory education. The two sectors of the tertiary education system, vocational education and…

  7. Diversification Management at Tertiary Education Level: A Review

    Science.gov (United States)

    Takwate, Kwaji Tizhe

    2016-01-01

    This paper examines the concept of management of diversification at tertiary education level in view of the growth of national secondary education system which vested high scramble for tertiary education was made in relation to question of access and expansion. This paper examines management of diversification at tertiary education level as a…

  8. Tertiary Education in the Czech Republic: The Pathway to Change

    Science.gov (United States)

    Pesik, Richard; Gounko, Tatiana

    2011-01-01

    This article analyzes recent policy proposals to reform Czech tertiary education. A brief overview of the evolution of Czech tertiary education presents the background against which emerging policy trends in education are examined. We relate the changes in tertiary education to the policy framework and recommendations of the OECD, underpinned by…

  9. Economics of Tertiary Education - Challenges and dynamics of the public tertiary education in Albania

    Directory of Open Access Journals (Sweden)

    Gledian Llatja

    2016-07-01

    Full Text Available The tertiary education is a critic mechanism for the socio-economic progress, for individuals who aspire a brighter future and it is also considered an important catalyzer of the economic mobility (Department of Treasury and Department of Education, 2012, 2. Based on the positive role and impact that the tertiary education has on the sustainable development, President Obama once stated that it is of damage to treat education as a luxurious public service. In line with the general considerations about the tertiary education in the U.S. the parallel comparison with Albania comes as a direct interpretation of utopia in the education policy-making. As policies are usually drafted based on data and findings, in the case of Albania there is a lack of data on expenses on tertiary education as share of GDP. This stands also for the main limitation of the paper.

  10. Carotenoid Formation by Staphylococcus aureus

    Science.gov (United States)

    Hammond, Ray K.; White, David C.

    1970-01-01

    The carotenoid pigments of Staphylococcus aureus U-71 were identified as phytoene; ζ-carotene; δ-carotene; phytofluenol; a phytofluenol-like carotenoid, rubixanthin; and three rubixanthin-like carotenoids after extraction, saponification, chromatographic separation, and determination of their absorption spectra. There was no evidence of carotenoid esters or glycoside ethers in the extract before saponification. During the aerobic growth cycle the total carotenoids increased from 45 to 1,000 nmoles per g (dry weight), with the greatest increases in the polar, hydroxylated carotenoids. During the anaerobic growth cycle, the total carotenoids increased from 20 nmoles per g (dry weight) to 80 nmoles per g (dry weight), and only traces of the polar carotenoids were formed. Light had no effect on carotenoid synthesis. About 0.14% of the mevalonate-2-14C added to the culture was incorporated into the carotenoids during each bacterial doubling. The total carotenoids did not lose radioactivity when grown in the absence of 14C for 2.5 bacterial doublings. The total carotenoids did not lose radioactivity when grown in the absence of 14C for 2.5 bacterial doublings. The incorporation and turnover of 14C indicated the carotenes were sequentially desaturated and hydroxylated to form the polar carotenoids. PMID:5423369

  11. Complete Genome Sequence of the Quality Control Strain Staphylococcus aureus subsp. aureus ATCC 25923.

    Science.gov (United States)

    Treangen, Todd J; Maybank, Rosslyn A; Enke, Sana; Friss, Mary Beth; Diviak, Lynn F; Karaolis, David K R; Koren, Sergey; Ondov, Brian; Phillippy, Adam M; Bergman, Nicholas H; Rosovitz, M J

    2014-01-01

    Staphylococcus aureus subsp. aureus ATCC 25923 is commonly used as a control strain for susceptibility testing to antibiotics and as a quality control strain for commercial products. We present the completed genome sequence for the strain, consisting of the chromosome and a 27.5-kb plasmid. PMID:25377701

  12. Complete Genome Sequence of the Quality Control Strain Staphylococcus aureus subsp. aureus ATCC 25923

    OpenAIRE

    Todd J. Treangen; Maybank, Rosslyn A.; Enke, Sana; Friss, Mary Beth; Diviak, Lynn F.; Karaolis, David K. R.; Koren, Sergey; Ondov, Brian; Phillippy, Adam M.; Bergman, Nicholas H.; Rosovitz, M. J.

    2014-01-01

    Staphylococcus aureus subsp. aureus ATCC 25923 is commonly used as a control strain for susceptibility testing to antibiotics and as a quality control strain for commercial products. We present the completed genome sequence for the strain, consisting of the chromosome and a 27.5-kb plasmid.

  13. Disinfection of stethoscopes: Gap between knowledge and practice in an Indian tertiary care hospital

    Directory of Open Access Journals (Sweden)

    Anshu Jain

    2013-01-01

    Full Text Available Context: Stethoscopes are used primarily to assess the health of patients and are one of the most commonly used medical devices. Thus, are the prominent tools for the spread of health-care associated infections (HAIs. Aims: The study was conducted to assess the knowledge and awareness about handling of the stethoscope and cleaning practices followed among the healthcare workers (HCWs. Materials and Methods: A total of 80 participants were included during a 4-month study period at a tertiary care hospital in Ujjain. A semi-structured questionnaire was distributed to HCWs and the surface of the diaphragm of their stethoscopes were swabbed for bacteriological analysis using standard techniques. Results: Out of total 80 stethoscopes, 69 (86% were found to be contaminated with at least one type of microorganism. Pseudomonas aeruginosa was the most predominant bacterial species found on 58 stethoscopes, followed by Bacillus subtilis (n = 21 and Staphylococcus spp. (n = 16. Out of total 10 S. aureus isolated, 3 were methicillin-resistant S. aureus ( MRSA. Majority (97% of the HCWs had good knowledge about the topic, but only 22 (27% reported to apply it in the practice. Conclusions: Our study confirmed that majority of the stethoscopes were contaminated with microorganisms. Besides having knowledge about the importance of cleaning the stethoscopes, lower percentage of HCWs reported to follow it in practice. Thus, the authors recommend regularization of reminders such as circulars, motivating posters for the HCWs to clean the diaphragm of the stethoscopes.

  14. Potassium Uptake Modulates Staphylococcus aureus Metabolism.

    Science.gov (United States)

    Gries, Casey M; Sadykov, Marat R; Bulock, Logan L; Chaudhari, Sujata S; Thomas, Vinai C; Bose, Jeffrey L; Bayles, Kenneth W

    2016-01-01

    As a leading cause of community-associated and nosocomial infections, Staphylococcus aureus requires sophisticated mechanisms that function to maintain cellular homeostasis in response to its exposure to changing environmental conditions. The adaptation to stress and maintenance of homeostasis depend largely on membrane activity, including supporting electrochemical gradients and synthesis of ATP. This is largely achieved through potassium (K(+)) transport, which plays an essential role in maintaining chemiosmotic homeostasis, affects antimicrobial resistance, and contributes to fitness in vivo. Here, we report that S. aureus Ktr-mediated K(+) uptake is necessary for maintaining cytoplasmic pH and the establishment of a proton motive force. Metabolite analyses revealed that K(+) deficiency affects both metabolic and energy states of S. aureus by impairing oxidative phosphorylation and directing carbon flux toward substrate-level phosphorylation. Taken together, these results underline the importance of K(+) uptake in maintaining essential components of S. aureus metabolism. IMPORTANCE Previous studies describing mechanisms for K(+) uptake in S. aureus revealed that the Ktr-mediated K(+) transport system was required for normal growth under alkaline conditions but not under neutral or acidic conditions. This work focuses on the effect of K(+) uptake on S. aureus metabolism, including intracellular pH and carbon flux, and is the first to utilize a pH-dependent green fluorescent protein (GFP) to measure S. aureus cytoplasmic pH. These studies highlight the role of K(+) uptake in supporting proton efflux under alkaline conditions and uncover a critical role for K(+) uptake in establishing efficient carbon utilization. PMID:27340697

  15. Microcapsulation of Cytoderm Peptidoglycan Derived from Lactobacillus plantarum%植物乳杆菌细胞壁肽聚糖的微胶囊化

    Institute of Scientific and Technical Information of China (English)

    朱丽; 韩德权; 孙庆申; 吴桐; 李吴哲

    2011-01-01

    Chitosan microspheres encapsulating cytoderm peptidoglycan derived from Lactobacillus plantarum were prepared by emulsion-crosslinking method.The sustained-release effect of peptidoglycan was evaluated in experimental mice orally administered with naked peptidoglycan or peptidoglycan microspheres for a consecutive week at low,medium and high dosages.Blood was collected from mouse tails within 15 d at an interval of 3 d.Enzyme-linked immunosorbent assay(ELISA) was used to measure lysozyme content in mouse serum.The results showed that the average drug loading capacity(LC) and encapsulation efficiency(EE) of microspheres varied with different ratios between peptidoglycan and chitosan.At the ratio of 1:1,the LC and EE were(37.00 ± 3.24) g/ 100 g and(92.00 ± 2.38)%,respectively.The highest lysozyme content in serum was achieved at the 9th day post-administration of peptidoglycan microspheres,which was significantly higher than that in the control group.Meanwhile,high lysozyme content could last to the 15th day post-vaccination.Therefore,chitosan microspheres revealed an obvious sustained-release effect,which can effectively extend the action time of peptidoglycan.%以壳聚糖(CS)为壁材,采用乳化交联法制备载植物乳杆菌细胞壁肽聚糖(PG)的CS微球,并通过动物实验研究口服PG微球的缓释效果。通过低、中、高3种剂量裸PG和PG微球对小鼠进行灌胃1周处理,每隔3d断尾取血,连续进行15d,ELISA法检测小鼠血清中溶菌酶含量。结果表明:微球的载药量和包封率依壁、芯材比而变化,其中,PG和CS质量比为1:1的复合微球平均载药量为(37.00±3.24)g/100g,包封率为(92.00±2.38)%。在免疫后第9天各微球组小鼠血清中溶菌酶含量均达到最高值,明显高于对照组,免疫后第15天各微球组血清中溶菌酶含量仍保持较高水平。载PG的CS微球具有显著的缓释效果,能够显著延长PG作用时间。

  16. X-ray absorption near-edge structure (XANES) spectroscopy study of the interaction of silver ions with Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli.

    Science.gov (United States)

    Bovenkamp, Gudrun Lisa; Zanzen, Ulrike; Krishna, Katla Sai; Hormes, Josef; Prange, Alexander

    2013-10-01

    Silver ions are widely used as antibacterial agents, but the basic molecular mechanism of this effect is still poorly understood. X-ray absorption near-edge structure (XANES) spectroscopy at the Ag LIII, S K, and P K edges reveals the chemical forms of silver in Staphylococcus aureus and Escherichia coli (Ag(+) treated). The Ag LIII-edge XANES spectra of the bacteria are all slightly different and very different from the spectra of silver ions (silver nitrate and silver acetate), which confirms that a reaction occurs. Death or inactivation of bacteria was observed by plate counting and light microscopy. Silver bonding to sulfhydryl groups (Ag-S) in cysteine and Ag-N or Ag-O bonding in histidine, alanine, and DL-aspartic acid was detected by using synthesized silver-amino acids. Significantly lower silver-cysteine content, coupled with higher silver-histidine content, in Gram-positive S. aureus and Listeria monocytogenes cells indicates that the peptidoglycan multilayer could be buffering the biocidal effect of silver on Gram-positive bacteria, at least in part. Bonding of silver to phosphate groups was not detected. Interaction with DNA or proteins can occur through Ag-N bonding. The formation of silver-cysteine can be confirmed for both bacterial cell types, which supports the hypothesis that enzyme-catalyzed reactions and the electron transport chain within the cell are disrupted. PMID:23934494

  17. Drug resistance and genetic characteristics of clinical isolates of staphylococci in Myanmar: high prevalence of PVL among methicillin-susceptible Staphylococcus aureus belonging to various sequence types

    Directory of Open Access Journals (Sweden)

    M.S. Aung

    2016-03-01

    Full Text Available Prevalence, drug resistance and genetic characteristics were analysed for a total of 128 clinical isolates of staphylococci obtained from a tertiary hospital in Myanmar. The dominant species were S. aureus (39% and S. haemolyticus (35%, followed by S. epidermidis (6% and S. saprophyticus (5%. The majority of S. haemolyticus isolates (71.1% harboured mecA, showing high resistance rates to ampicillin, cephalosporins, erythromycin and levofloxacin, while methicillin-resistant S. aureus (MRSA was only 8% (four isolates among S. aureus with type IV SCCmec. Panton-Valentine leukocidin (PVL genes were detected in 20 isolates of S. aureus (40%, among which only one isolate was MRSA belonging to sequence type (ST 88/agr-III/coa-IIIa, and the other 19 methicillin-susceptible S. aureus (MSSA isolates were classified into six STs (ST88, ST121, ST1153, ST1155, ST1930, ST3206. An ST1153 MSSA isolate with PVL was revealed to belong to a novel coa type, XIIIa. ST121 S. aureus was the most common in the PVL-positive MSSA (47%, 9/19, harbouring genes of bone sialoprotein and variant of elastin binding protein as a distinctive feature. Although PVL-positive MSSA was susceptible to most of the antimicrobial agents examined, ST1930 isolates were resistant to erythromycin and levofloxacin. ST59 PVL-negative MRSA and MSSA had more resistance genes than other MRSA and PVL-positive MSSA, showing resistance to more antimicrobial agents. This study indicated higher prevalence of mecA associated with multiple drug resistance in S. haemolyticus than in S. aureus, and dissemination of PVL genes to multiple clones of MSSA, with ST121 being dominant, among hospital isolates in Myanmar.

  18. Drug resistance and genetic characteristics of clinical isolates of staphylococci in Myanmar: high prevalence of PVL among methicillin-susceptible Staphylococcus aureus belonging to various sequence types.

    Science.gov (United States)

    Aung, M S; Zi, H; Nwe, K M; Maw, W W; Aung, M T; Min, W W; Nyein, N; Kawaguchiya, M; Urushibara, N; Sumi, A; Kobayashi, N

    2016-03-01

    Prevalence, drug resistance and genetic characteristics were analysed for a total of 128 clinical isolates of staphylococci obtained from a tertiary hospital in Myanmar. The dominant species were S. aureus (39%) and S. haemolyticus (35%), followed by S. epidermidis (6%) and S. saprophyticus (5%). The majority of S. haemolyticus isolates (71.1%) harboured mecA, showing high resistance rates to ampicillin, cephalosporins, erythromycin and levofloxacin, while methicillin-resistant S. aureus (MRSA) was only 8% (four isolates) among S. aureus with type IV SCCmec. Panton-Valentine leukocidin (PVL) genes were detected in 20 isolates of S. aureus (40%), among which only one isolate was MRSA belonging to sequence type (ST) 88/agr-III/coa-IIIa, and the other 19 methicillin-susceptible S. aureus (MSSA) isolates were classified into six STs (ST88, ST121, ST1153, ST1155, ST1930, ST3206). An ST1153 MSSA isolate with PVL was revealed to belong to a novel coa type, XIIIa. ST121 S. aureus was the most common in the PVL-positive MSSA (47%, 9/19), harbouring genes of bone sialoprotein and variant of elastin binding protein as a distinctive feature. Although PVL-positive MSSA was susceptible to most of the antimicrobial agents examined, ST1930 isolates were resistant to erythromycin and levofloxacin. ST59 PVL-negative MRSA and MSSA had more resistance genes than other MRSA and PVL-positive MSSA, showing resistance to more antimicrobial agents. This study indicated higher prevalence of mecA associated with multiple drug resistance in S. haemolyticus than in S. aureus, and dissemination of PVL genes to multiple clones of MSSA, with ST121 being dominant, among hospital isolates in Myanmar. PMID:27257489

  19. Erosive arthritis and hepatic granuloma formation induced by peptidoglycan polysaccharide in rats is aggravated by prasugrel treatment.

    Directory of Open Access Journals (Sweden)

    Analia E Garcia

    Full Text Available Administration of the thienopyridine P2Y12 receptor antagonist, clopidogrel, increased the erosive arthritis induced by peptidoglycan polysaccharide (PG-PS in rats or by injection of the arthritogenic K/BxN serum in mice. To determine if the detrimental effects are caused exclusively by clopidogrel, we evaluated prasugrel, a third-generation thienopyridine pro-drug, that contrary to clopidogrel is mostly metabolized into its active metabolite in the intestine. Prasugrel effects were examined on the PG-PS-induced arthritis rat model. Erosive arthritis was induced in Lewis rats followed by treatment with prasugrel for 21 days. Prasugrel treated arthritic animals showed a significant increase in the inflammatory response, compared with untreated arthritic rats, in terms of augmented macroscopic joint diameter associated with significant signs of inflammation, histomorphometric measurements of the hind joints and elevated platelet number. Moreover, fibrosis at the pannus, assessed by immunofluorescence of connective tissue growth factor, was increased in arthritic rats treated with prasugrel. In addition to the arthritic manifestations, hepatomegaly, liver granulomas and giant cell formation were observed after PG-PS induction and even more after prasugrel exposure. Cytokine plasma levels of IL-1 beta, IL-6, MIP1 alpha, MCP1, IL-17 and RANTES were increased in arthritis-induced animals. IL-10 plasma levels were significantly decreased in animals treated with prasugrel. Overall, prasugrel enhances inflammation in joints and liver of this animal model. Since prasugrel metabolites inhibit neutrophil function ex-vivo and the effects of both clopidogrel and prasugrel metabolites on platelets are identical, we conclude that the thienopyridines metabolites might exert non-platelet effects on other immune cells to aggravate inflammation.

  20. Phosphorylation of the Peptidoglycan Synthase PonA1 Governs the Rate of Polar Elongation in Mycobacteria.

    Directory of Open Access Journals (Sweden)

    Karen J Kieser

    2015-06-01

    Full Text Available Cell growth and division are required for the progression of bacterial infections. Most rod-shaped bacteria grow by inserting new cell wall along their mid-section. However, mycobacteria, including the human pathogen Mycobacterium tuberculosis, produce new cell wall material at their poles. How mycobacteria control this different mode of growth is incompletely understood. Here we find that PonA1, a penicillin binding protein (PBP capable of transglycosylation and transpeptidation of cell wall peptidoglycan (PG, is a major governor of polar growth in mycobacteria. PonA1 is required for growth of Mycobacterium smegmatis and is critical for M. tuberculosis during infection. In both cases, PonA1's catalytic activities are both required for normal cell length, though loss of transglycosylase activity has a more pronounced effect than transpeptidation. Mutations that alter the amount or the activity of PonA1 result in abnormal formation of cell poles and changes in cell length. Moreover, altered PonA1 activity results in dramatic differences in antibiotic susceptibility, suggesting that a balance between the two enzymatic activities of PonA1 is critical for survival. We also find that phosphorylation of a cytoplasmic region of PonA1 is required for normal activity. Mutations in a critical phosphorylated residue affect transglycosylase activity and result in abnormal rates of cell elongation. Together, our data indicate that PonA1 is a central determinant of polar growth in mycobacteria, and its governance of cell elongation is required for robust cell fitness during both host-induced and antibiotic stress.

  1. Effect of lipopolysaccharide (LPS and peptidoglycan (PGN on human mast cell numbers, cytokine production, and protease composition

    Directory of Open Access Journals (Sweden)

    Wu Yalin

    2008-08-01

    Full Text Available Abstract Background Human mast cell (HuMC maturation occurs in tissues interfacing with the external environment, exposing both mast cell progenitors and mature mast cells, to bacteria and their products. It is unknown, however, whether long- or short-term exposure to bacteria-derived toll-like receptor (TLR ligands, such as lipopolysaccharide (LPS or peptidoglycan (PGN, influences HuMC biology. Results Over 6 wks of culture, LPS had minimal effect on HuMC numbers but increased CD117, tryptase and chymase expression. PGN inhibited HuMC development. For mature mast cells, LPS in the presence of rhSCF (10 ng/ml increased CD117, tryptase, chymase and carboxypeptidase expression, primarily in CD117low HuMC. LPS decreased FcεRI expression and β-hexosaminidase release; but had no effect on LTC4 and PGD2 production. PGN reduced HuMC numbers; and CD117 and tryptase expression. IL-1β and IL-6 (in addition to IL-8 and IL-12 were detected in short-term culture supernatants of LPS treated cells, and reproduced the increases in CD117, tryptase, chymase, and carboxypeptidase expression observed in the presence of LPS. Comparative studies with mouse bone marrow-derived mast cells from wild type, but not TLR4 knockout mice, showed increases in mRNA of mouse mast cell chymases MMCP-1, MMCP-2 and MMCP-4. Conclusion PGN inhibits HuMC growth, while LPS exerts its primary effects on mature HuMC by altering cytokine production and protease composition, particularly at low concentrations of SCF. These data demonstrate the ability of bacterial products to alter HuMC mediator production, granular content, and number which may be particularly relevant at mucosal sites where HuMC are exposed to these products.

  2. Structural basis for type VI secreted peptidoglycan DL-endopeptidase function, specificity and neutralization in Serratia marcescens.

    Science.gov (United States)

    Srikannathasan, Velupillai; English, Grant; Bui, Nhat Khai; Trunk, Katharina; O'Rourke, Patrick E F; Rao, Vincenzo A; Vollmer, Waldemar; Coulthurst, Sarah J; Hunter, William N

    2013-12-01

    Some Gram-negative bacteria target their competitors by exploiting the type VI secretion system to extrude toxic effector proteins. To prevent self-harm, these bacteria also produce highly specific immunity proteins that neutralize these antagonistic effectors. Here, the peptidoglycan endopeptidase specificity of two type VI secretion-system-associated effectors from Serratia marcescens is characterized. These small secreted proteins, Ssp1 and Ssp2, cleave between γ-D-glutamic acid and L-meso-diaminopimelic acid with different specificities. Ssp2 degrades the acceptor part of cross-linked tetratetrapeptides. Ssp1 displays greater promiscuity and cleaves monomeric tripeptides, tetrapeptides and pentapeptides and dimeric tetratetra and tetrapenta muropeptides on both the acceptor and donor strands. Functional assays confirm the identity of a catalytic cysteine in these endopeptidases and crystal structures provide information on the structure-activity relationships of Ssp1 and, by comparison, of related effectors. Functional assays also reveal that neutralization of these effectors by their cognate immunity proteins, which are called resistance-associated proteins (Raps), contributes an essential role to cell fitness. The structures of two immunity proteins, Rap1a and Rap2a, responsible for the neutralization of Ssp1 and Ssp2-like endopeptidases, respectively, revealed two distinct folds, with that of Rap1a not having previously been observed. The structure of the Ssp1-Rap1a complex revealed a tightly bound heteromeric assembly with two effector molecules flanking a Rap1a dimer. A highly effective steric block of the Ssp1 active site forms the basis of effector neutralization. Comparisons with Ssp2-Rap2a orthologues suggest that the specificity of these immunity proteins for neutralizing effectors is fold-dependent and that in cases where the fold is conserved sequence differences contribute to the specificity of effector-immunity protein interactions.

  3. Tertiary Treatment Process of Preserved Wastewater

    Directory of Open Access Journals (Sweden)

    Wang Qingyu

    2016-01-01

    Full Text Available The effects of the composite coagulants on coagulation sedimentation for the preserved wastewater was investigated by changing the composite coagulant dosages, and the coagulant was composed of polymeric ferric sulfate (PFS, polyaluminium chloride (PAC, and polyaluminum ferric silicate (PAFSC, while the effect of the tertiary treatment process on the preserved wastewater was tested, which was exceeded the standard seriously. The results showed that 400 mg/L was the optimum composite coagulant dosage. The removal rates of salt and sugar were as high as 99.1% and 99.5% respectively, and the removal rates of CODCr and SS were 99.3% and 96.0%, respectively after the preserved wastewater was treated by the tertiary treatment technology, which both reached the primary standard of “The Integrated Wastewater Discharge Standard” (GB8978-1996.

  4. Tertiary fatty amides as diesel fuel substitutes

    Energy Technology Data Exchange (ETDEWEB)

    Serdari, Aikaterini; Lois, Euripides; Stournas, Stamoulis [National Technical Univ. of Athens, Dept. of Chemical Engineering, Athens (Greece)

    2000-07-01

    This paper presents experimental results regarding the impact of adding different tertiary amides of fatty acids to mineral diesel fuel; an assessment of the behaviour of these compounds as possible diesel fuel extenders is also included. Measurements of cetane number, cold flow properties (cloud point, pour point and CFPP), density, kinematic viscosity, flash point and distillation temperatures are reported, while initial experiments concerning the effects on particulate emissions are also described. Most of the examined tertiary fatty amides esters have very good performance and they can be easily prepared from fatty acids (biomass). Such compounds or their blends could be used as mineral diesel fuel or even fatty acid methylesters (FAME, biodiesel) substitutes or extenders. (Author)

  5. Genomics of Natural Populations of Staphylococcus aureus.

    Science.gov (United States)

    Fitzgerald, J Ross; Holden, Matthew T G

    2016-09-01

    Staphylococcus aureus is a major human pathogen and an important cause of livestock infections. The first S. aureus genomes to be published, 15 years ago, provided the first view of genome structure and gene content. Since then, thousands of genomes from a wide array of strains from different sources have been sequenced. Comparison of these sequences has resulted in broad insights into population structure, bacterial evolution, clone emergence and expansion, and the molecular basis of niche adaptation. Furthermore, this information is now being applied clinically in outbreak investigations to inform infection control measures and to determine appropriate treatment regimens. In this review, we summarize some of the broad insights into S. aureus biology gained from the analysis of genomes and discuss future directions and opportunities in this dynamic field of research. PMID:27482738

  6. Genomics of Natural Populations of Staphylococcus aureus.

    Science.gov (United States)

    Fitzgerald, J Ross; Holden, Matthew T G

    2016-09-01

    Staphylococcus aureus is a major human pathogen and an important cause of livestock infections. The first S. aureus genomes to be published, 15 years ago, provided the first view of genome structure and gene content. Since then, thousands of genomes from a wide array of strains from different sources have been sequenced. Comparison of these sequences has resulted in broad insights into population structure, bacterial evolution, clone emergence and expansion, and the molecular basis of niche adaptation. Furthermore, this information is now being applied clinically in outbreak investigations to inform infection control measures and to determine appropriate treatment regimens. In this review, we summarize some of the broad insights into S. aureus biology gained from the analysis of genomes and discuss future directions and opportunities in this dynamic field of research.

  7. Antimicrobial (Drug) Resistance: Methicillin-Resistant Staphylococcus aureus (MRSA)

    Science.gov (United States)

    ... Marketing Share this: Main Content Area Methicillin-Resistant Staphylococcus aureus (MRSA) During the past four decades, methicillin-resistant Staphylococcus aureus , or MRSA, has evolved from a controllable ...

  8. Evolution of methicillin-resistant Staphylococcus aureus towards increasing resistance

    DEFF Research Database (Denmark)

    Strommenger, Birgit; Bartels, Mette Damkjær; Kurt, Kevin;

    2014-01-01

    To elucidate the evolutionary history of Staphylococcus aureus clonal complex (CC) 8, which encompasses several globally distributed epidemic lineages, including hospital-associated methicillin-resistant S. aureus (MRSA) and the highly prevalent community-associated MRSA clone USA300....

  9. Propionibacterium acnes biofilm - A sanctuary for Staphylococcus aureus?

    Science.gov (United States)

    Tyner, Harmony; Patel, Robin

    2016-08-01

    The purpose of this study was to measure the effect of combined culture of Propionibacterium acnes and Staphylococcus aureus on biofilm formation under different oxygen concentrations. We measured planktonic growth and biofilm formation of P. acnes and S. aureus alone and together under aerobic and anaerobic conditions. Both P. acnes and S. aureus grew under anaerobic conditions. When grown under anaerobic conditions, P. acnes with or without S. aureus formed a denser biomass biofilm than did S. aureus alone. Viable S. aureus was recovered from a16-day old combined P. acnes and S. aureus biofilm, but not a monomicrobial S. aureus biofilm.

  10. Prevalence of infective endocarditis in patients with Staphylococcus aureus bacteraemia

    DEFF Research Database (Denmark)

    Rasmussen, Rasmus V; Høst, Ulla; Arpi, Magnus;

    2011-01-01

    Aims Staphylococcus aureus infective endocarditis (IE) is a critical medical condition associated with a high morbidity and mortality. In the present study, we prospectively evaluated the importance of screening with echocardiography in an unselected S. aureus bacteraemia (SAB) population. Methods...

  11. Comparative Efficacy of Ceftaroline with Linezolid against Staphylococcus Aureus and Methicillin Resistant Staphylococcus Aureus

    International Nuclear Information System (INIS)

    Objective:To compare the in vitro antimicrobial efficacy of ceftaroline with linezolid against Staphylococcus aureus and methicillin resistant Staphylococcus aureus. Study Design: Quasi-experimental study. Place and Duration of Study: Microbiology Department, Army Medical College, Rawalpindi, from January to December 2013. Methodology: Clinical samples from respiratory tract, blood, pus and various catheter tips routinely received in the Department of Microbiology, Army Medical College, Rawalpindi were innoculated on blood and MacConkey agar. Staphylococcus aureus was identified by colony morphology, Gram reaction, catalase test and coagulase test. Methicillin resistant Staphylococcus aureus detection was done by modified Kirby Bauer disc diffusion method using cefoxitin disc (30g) and the isolates were considered methicillin resistant if the zone of inhibition around cefoxitin disc was /sup 2/ 21 mm. Bacterial suspensions of 56 Staphylococcus aureus isolates and 50 MRSA isolates were prepared, which were standardized equal to 0.5 McFarland's turbidity standard and inoculated on Mueller-Hinton agar plates followed by application of ceftaroline and linezolid disc (Oxoid, UK), according to manufacturer's instructions. The plates were then incubated at 37 Degree C aerobically for 18 - 24 hours. Diameters of inhibition zone were measured and interpretated as per Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: Out of 106 isolates all of the 56 Staphylococcus aureus (100%) were sensitive to ceftaroline and linezolid. However, out of 50 methicillin resistant Staphylococcus aureus, 48 (96%) were sensitive to ceftaroline whereas, 49 (98%) were sensitive to linezolid. Conclusion: Ceftaroline is equally effective as linezolid against Staphylococcus aureus and methicillin resistant Staphylococcus aureus. (author)

  12. Mastite com lesões sistêmicas por Staphylococus aureus subesp. aureus em coelhos Mastitis with systemic lesions due to Staphylococus aureus subesp. aureus in rabbits

    Directory of Open Access Journals (Sweden)

    Sandra Davi Traverso

    2003-04-01

    Full Text Available Em uma criação composta por 1800 coelhos, 33% das matrizes apresentaram mastite e lesões cutâneas crostosas e purulentas. Estes animais apresentavam-se entre 10 a- 12 meses de idade e em segunda parição. Quinze coelhos afetados foram sacrificados e necropsiados. Na necropsia, além das lesões cutâneas haviam microabscessos em diversos órgãos. Das amostras coletadas isolou-se Staphylococcus aureus subesp. aureus. S. aureus subesp. aureus também foi isolado de "swab" nasal coletado do tratador encarregado de fazer o diagnóstico de gestação nas coelhas. Histologicamente, havia formação de múltiplos abscessos, presença de bactérias gram positivas em vasos sangüíneos e linfáticos, além de êmbolos bacterianos nos tecidos. Nas mamas, observou-se tecido glandular normal associado a abscessos multifocais delimitados.At a commercial rabbitry which was composed of 1800 New Zealand White rabbits, 30% of the does had presented mastitis and purulent cutaneal lesions. The age of the animals ranged from 10 to 12 months and were at the second parturition. At necropsy, microabscesses were observed in several organs. Bacteriological samples collected from affected animals resulted Staphylococcus aureus subesp. aureus.. Additionally, the same agent has been isolated from a nasal swab collected from the person responsible for the pregnancy diagnosis. Histologically, there were multiple abscesses, gram positive bacteria within blood and lymphatic vessels, and bacterial emboli scattered in the tissues. In the mammas, normal glandular tissue associated with multifocal abscesses were observed.

  13. Meticillin-resistant Staphylococcus aureus (MRSA)

    DEFF Research Database (Denmark)

    Stefani, Stefania; Chung, Doo Ryeon; Lindsay, Jodi A;

    2012-01-01

    This article reviews recent findings on the global epidemiology of healthcare-acquired/associated (HA), community-acquired/associated (CA) and livestock-associated (LA) meticillin-resistant Staphylococcus aureus (MRSA) and aims to reach a consensus regarding the harmonisation of typing methods...... health. Continuous efforts to understand the changing epidemiology of S. aureus infection in humans and animals are therefore necessary, not only for appropriate antimicrobial treatment and effective infection control but also to monitor the evolution of the species. The group made several consensus...

  14. Antibacterial Activity and Antibiotic-Enhancing Effects of Honeybee Venom against Methicillin-Resistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Sang Mi Han

    2016-01-01

    Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA, along with other antibiotic resistant bacteria, has become a significant social and clinical problem. There is thus an urgent need to develop naturally bioactive compounds as alternatives to the few antibiotics that remain effective. Here we assessed the in vitro activities of bee venom (BV, alone or in combination with ampicillin, penicillin, gentamicin or vancomycin, on growth of MRSA strains. The antimicrobial activity of BV against MRSA strains was investigated using minimum inhibitory concentrations (MIC, minimum bactericidal concentrations (MBC and a time-kill assay. Expression of atl which encodes murein hydrolase, a peptidoglycan-degrading enzyme involved in cell separation, was measured by reverse transcription-polymerase chain reaction. The MICs of BV were 0.085 µg/mL and 0.11 µg/mL against MRSA CCARM 3366 and MRSA CCARM 3708, respectively. The MBC of BV against MRSA 3366 was 0.106 µg/mL and that against MRSA 3708 was 0.14 µg/mL. The bactericidal activity of BV corresponded to a decrease of at least 3 log CFU/g cells. The combination of BV with ampicillin or penicillin yielded an inhibitory concentration index ranging from 0.631 to 1.002, indicating a partial and indifferent synergistic effect. Compared to ampicillin or penicillin, both MRSA strains were more susceptible to the combination of BV with gentamicin or vancomycin. The expression of atl gene was increased in MRSA 3366 treated with BV. These results suggest that BV exhibited antibacterial activity and antibiotic-enhancing effects against MRSA strains. The atl gene was increased in MRSA exposed to BV, suggesting that cell division was interrupted. BV warrants further investigation as a natural antimicrobial agent and synergist of antibiotic activity.

  15. Antibacterial Activity and Antibiotic-Enhancing Effects of Honeybee Venom against Methicillin-Resistant Staphylococcus aureus.

    Science.gov (United States)

    Han, Sang Mi; Kim, Joung Min; Hong, In Pyo; Woo, Soon Ok; Kim, Se Gun; Jang, He Rye; Pak, Sok Cheon

    2016-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA), along with other antibiotic resistant bacteria, has become a significant social and clinical problem. There is thus an urgent need to develop naturally bioactive compounds as alternatives to the few antibiotics that remain effective. Here we assessed the in vitro activities of bee venom (BV), alone or in combination with ampicillin, penicillin, gentamicin or vancomycin, on growth of MRSA strains. The antimicrobial activity of BV against MRSA strains was investigated using minimum inhibitory concentrations (MIC), minimum bactericidal concentrations (MBC) and a time-kill assay. Expression of atl which encodes murein hydrolase, a peptidoglycan-degrading enzyme involved in cell separation, was measured by reverse transcription-polymerase chain reaction. The MICs of BV were 0.085 µg/mL and 0.11 µg/mL against MRSA CCARM 3366 and MRSA CCARM 3708, respectively. The MBC of BV against MRSA 3366 was 0.106 µg/mL and that against MRSA 3708 was 0.14 µg/mL. The bactericidal activity of BV corresponded to a decrease of at least 3 log CFU/g cells. The combination of BV with ampicillin or penicillin yielded an inhibitory concentration index ranging from 0.631 to 1.002, indicating a partial and indifferent synergistic effect. Compared to ampicillin or penicillin, both MRSA strains were more susceptible to the combination of BV with gentamicin or vancomycin. The expression of atl gene was increased in MRSA 3366 treated with BV. These results suggest that BV exhibited antibacterial activity and antibiotic-enhancing effects against MRSA strains. The atl gene was increased in MRSA exposed to BV, suggesting that cell division was interrupted. BV warrants further investigation as a natural antimicrobial agent and synergist of antibiotic activity. PMID:26771592

  16. 9 CFR 113.115 - Staphylococcus Aureus Bacterin-Toxoid.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Staphylococcus Aureus Bacterin-Toxoid... REQUIREMENTS Inactivated Bacterial Products § 113.115 Staphylococcus Aureus Bacterin-Toxoid. Staphylococcus Aureus Bacterin-Toxoid shall be prepared from toxoided broth cultures of selected toxogenic strains...

  17. A pig model of acute Staphylococcus aureus induced pyemia

    DEFF Research Database (Denmark)

    Nielsen, O. L.; Iburg, T.; Aalbæk, B.;

    2009-01-01

    Background: Sepsis caused by Staphylococcus aureus constitutes an important cause of morbidity and mortality in humans, and the incidence of this disease-entity is increasing. In this paper we describe the initial microbial dynamics and lesions in pigs experimentally infected with S. aureus....... aureus isolated from man and an extension of the timeframe aiming at inducing sepsis, severe sepsis and septic shock....

  18. Multidrug-Resistant Staphylococcus aureus in US Meat and Poultry

    OpenAIRE

    Waters, Andrew E.; Contente-Cuomo, Tania; Buchhagen, Jordan; Liu, Cindy M.; Watson, Lindsey; Pearce, Kimberly; Foster, Jeffrey T.; Bowers, Jolene; Driebe, Elizabeth M; Engelthaler, David M.; Keim, Paul S; Lance B Price

    2011-01-01

    We characterized the prevalence, antibiotic susceptibility profiles, and genotypes of Staphylococcus aureus among US meat and poultry samples (n = 136). S. aureus contaminated 47% of samples, and multidrug resistance was common among isolates (52%). S. aureus genotypes and resistance profiles differed significantly among sample types, suggesting food animal–specific contamination.

  19. Emergence of quinupristin/dalfopristin resistance among livestock-associated Staphylococcus aureus ST9 clinical isolates.

    Science.gov (United States)

    Yu, Fangyou; Lu, Chaohui; Liu, Yunling; Sun, He; Shang, Yongpeng; Ding, Yu; Li, Dan; Qin, Zhiqiang; Parsons, Chris; Huang, Xiaoying; Li, Yuping; Hu, Longhua; Wang, Liangxing

    2014-11-01

    Quinupristin/dalfopristin (Q/D) is a valuable alternative to vancomycin for the treatment of meticillin-resistant Staphylococcus aureus (MRSA) infections. However, not long after Q/D was approved, bacteria with resistance to this newer antimicrobial agent were reported. To investigate the prevalence of Q/D resistance, a total of 1476 non-duplicate S. aureus isolates, including 775 MRSA, from a Chinese tertiary hospital were selected randomly from 2003 to 2013. Of the 775 MRSA, 3 (0.4%) were resistant to Q/D. All meticillin-susceptible S. aureus were susceptible to Q/D. The prevalence of Q/D resistance among S. aureus was 0.2% (3/1476). The three isolates with Q/D resistance had the same antimicrobial resistance profile, except for cefaclor and chloramphenicol. All three Q/D-resistant MRSA were positive for five streptogramin B resistance genes (ermA, ermB, ermC, msrA and msrB) and two streptogramin A resistance genes (vatC and vgaA) as determined by PCR and DNA sequencing. MRSA WZ1031 belonged to ST9-MRSA-SCCmecV-t899, whilst MRSA WZ414 and WZ480 belonged to ST9-MRSA-SCCmecNT(non-typeable)-t899. ST9 has been reported predominantly in livestock-associated (LA) MRSA in some Asian countries. The three patients with these MRSA isolates were not livestock handlers and did not keep close contact with livestock. The origin of these important LA-MRSA isolates causing human infections is not known. Taken together, Q/D resistance, which was caused by a combination of ermA-ermB-ermC-msrA-msrB-vatC-vgaA, was first found among S. aureus clinical isolates in China. The present study is the first report of the emergence of human infections caused by ST9 LA-MRSA isolates with Q/D resistance. PMID:25218154

  20. Hyperglycemic conditions inhibit C3-mediated immunologic control of Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Hair Pamela S

    2012-03-01

    Full Text Available Abstract Background Diabetic patients are at increased risk for bacterial infections; these studies provide new insight into the role of the host defense complement system in controlling bacterial pathogens in hyperglycemic environments. Methods The interactions of complement C3 with bacteria in elevated glucose were assayed for complement activation to opsonic forms, phagocytosis and bacterial killing. C3 was analyzed in euglycemic and hyperglycemic conditions by mass spectrometry to measure glycation and structural differences. Results Elevated glucose inhibited S. aureus activation of C3 and deposition of C3b and iC3b on the bacterial surface. S. aureus-generated C5a and serum-mediated phagocytosis by neutrophils were both decreased in elevated glucose conditions. Interestingly, elevated glucose increased the binding of unactivated C3 to S. aureus, which was reversible on return to normal glucose concentrations. In a model of polymicrobial infection, S. aureus in elevated glucose conditions depleted C3 from serum resulting in decreased complement-mediated killing of E. coli. To investigate the effect of differing glucose concentration on C3 structure and glycation, purified C3 incubated with varying glucose concentrations was analyzed by mass spectrometry. Glycation was limited to the same three lysine residues in both euglycemic and hyperglycemic conditions over one hour, thus glycation could not account for observed changes between glucose conditions. However, surface labeling of C3 with sulfo-NHS-biotin showed significant changes in the surface availability of seven lysine residues in response to increasing glucose concentrations. These results suggest that the tertiary structure of C3 changes in response to hyperglycemic conditions leading to an altered interaction of C3 with bacterial pathogens. Conclusions These results demonstrate that hyperglycemic conditions inhibit C3-mediated complement effectors important in the immunological

  1. 鱼诺卡氏菌全肽聚糖的提取及鉴定%Studies on the Extraction and Identification of Whole Peptidoglycan from Nocardia seriolae

    Institute of Scientific and Technical Information of China (English)

    彭程远; 解俊; 王锡波; 金珊; 赵青松; 陈寅儿; 姚烨焯

    2015-01-01

    The cell wall WPG of Nocardia seriolae was extracted and purified as follows: bacteria were collected by centrifuge after culture expansion. The bacteria cells were treated with trichloroacetic acid in order to remove the wall teichoic acids as well as nucleic acid. The residues were degreased with methanol and acetone. Then we digested the defatted residues with trypsin and neutral protease. They were cleaned by centrifugation and lyophilization. It has been proved by lysozyme and UV-visible absorption spectra that the extracts were peptidoglycan. The transmission electeonmicroscopic observation of WPG showed that WPG was in sacciform and still held the physically intact cell wall structure of the whole cells, which certified the peptidoglycan we obtained was whole peptidoglycan.%以鱼诺卡氏菌(Nocardia seriolae)为研究材料,经扩大培养,离心集菌,用三氯乙酸处理以除去细胞壁上的磷壁酸及菌体内的核酸,甲醇、丙酮脱脂后,再经胰蛋白酶及中性蛋白酶复合酶解去除菌体内部的蛋白质,离心清洗、冻干即可制得肽聚糖。经过溶菌酶溶解试验,紫外可见光谱扫描分析证明所得产物为肽聚糖,透射电镜观察显示所提取的肽聚糖为囊状结构,且仍保持着原有的细菌细胞形态,证实所提取的肽聚糖为全肽聚糖。

  2. Staphylococcus aureus Entrance into the Dairy Chain: Tracking S. aureus from Dairy Cow to Cheese

    Science.gov (United States)

    Kümmel, Judith; Stessl, Beatrix; Gonano, Monika; Walcher, Georg; Bereuter, Othmar; Fricker, Martina; Grunert, Tom; Wagner, Martin; Ehling-Schulz, Monika

    2016-01-01

    Staphylococcus aureus is one of the most important contagious mastitis pathogens in dairy cattle. Due to its zoonotic potential, control of S. aureus is not only of great economic importance in the dairy industry but also a significant public health concern. The aim of this study was to decipher the potential of bovine udder associated S. aureus as reservoir for S. aureus contamination in dairy production and processing. From 18 farms, delivering their milk to an alpine dairy plant for the production of smeared semi-hard and hard cheese. one thousand hundred seventy six one thousand hundred seventy six quarter milk (QM) samples of all cows in lactation (n = 294) and representative samples form bulk tank milk (BTM) of all farms were surveyed for coagulase positive (CPS) and coagulase negative Staphylococci (CNS). Furthermore, samples from different steps of the cheese manufacturing process were tested for CPS and CNS. As revealed by chemometric-assisted FTIR spectroscopy and molecular subtyping (spa typing and multi locus sequence typing), dairy cattle represent indeed an important, yet underreported, entrance point of S. aureus into the dairy chain. Our data clearly show that certain S. aureus subtypes are present in primary production as well as in the cheese processing at the dairy plant. However, although a considerable diversity of S. aureus subtypes was observed in QM and BTM at the farms, only certain S. aureus subtypes were able to enter and persist in the cheese manufacturing at the dairy plant and could be isolated from cheese until day 14 of ripening. Farm strains belonging to the FTIR cluster B1 and B3, which show genetic characteristics (t2953, ST8, enterotoxin profile: sea/sed/sej) of the recently described S. aureus genotype B, most successfully contaminated the cheese production at the dairy plant. Thus, our study fosters the hypothesis that genotype B S. aureus represent a specific challenge in control of S. aureus in the dairy chain that requires

  3. Prevalence of Methicillin-resistant Staphyloccocus Aureus and associated risk factors on admission to a specialist care eye hospital

    International Nuclear Information System (INIS)

    Staphyloccocus aureus is known to be a frequent pathogen in hospital settings, with its well-known and resistant forms to the anti-staphylococcal penicillins. Reports on community carriage outside hospital settings have been feared to be on the increase due to the due to the frequency of reported cases on admission to hospitals. We undertook this study to determine the prevalence of and to establish predictors for, nasal carriage of methicillin-resistant S.aureus (MRSA) at the time of admission to a specialist care eye hospital. A prospective survey was conducted at King Khaled Eye Specialist Hospital (KKESH), Riyadh during the three differing weeks randomly selected from the year 1999. The first 100 patients admitted during those three weeks were selected according to inclusion criteria. The hospital is a 220-bed tertiary ophthalmic care facility, with an average 7,500admission per year. Nasal bacterial swabs were taken within 48 hours of admission and tested for all strains of S.aureus and sensitivity to methicillin. Detailed interviews were conducted about medical history and habitual environment. Of 306 nasal cultures tested, none was isolated for MRSA and 102 (33%) were sensitive to methicillin (MSSA).We found 0% nasal carriage rate for MRSA. Respondents have difficulty with questions related to antibiotic administration. No identifiable medical or environmental risk factors could be found. Nasal swabs of patients admitted to KKESH did not reveal MRSA colonization, indicating that MRSA may not be prevalent in the community at present. (author)

  4. Common R-plasmids in Staphylococcus aureus and Staphylococcus epidermidis during a nosocomial Staphylococcus aureus outbreak.

    OpenAIRE

    Cohen, M. L.; Wong, E. S.; Falkow, S

    1982-01-01

    During a 7-month period in 1978 to 1979, 31 patients and personnel at a Kentucky hospital were colonized or infected with a Staphylococcus aureus strain resistant to clindamycin, erythromycin, gentamicin, methicillin, penicillin, and tetracycline. S. epidermidis with similar antibiotic resistance patterns had been isolated in this hospital in the year before the S. aureus outbreak. A 32-megadalton R-plasmid, pUW3626, mediating resistance to penicillin and gentamicin, was present in these isol...

  5. Staphylococcus aureus resistente a la meticilina (SARM)

    Centers for Disease Control (CDC) Podcasts

    2007-10-22

    Datos importantes sobre las infecciones por SARM en Estados Unidos, en las escuelas y los entornos médicos. (Title: Methicillin-resistant Staphylococcus aureus (MRSA)Created: 10/2007).  Created: 10/22/2007 by National Center for Preparedness, Detection, and Control of Infectious Diseases.   Date Released: 11/9/2007.

  6. Methicillin-resistant Staphylococcus aureus transmission

    DEFF Research Database (Denmark)

    Andersen, Leif Percival; Nielsen, Xiaohui

    2015-01-01

    INTRODUCTION: Even though methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of nosocomial infections, it may often be difficult to evaluate the exact route of transmission. METHODS: In this study, we describe four cases of nosocomial transmission of MRSA in a hospital with a low...

  7. Staphylococcus aureus vaccines: Deviating from the carol.

    Science.gov (United States)

    Missiakas, Dominique; Schneewind, Olaf

    2016-08-22

    Staphylococcus aureus, a commensal of the human nasopharynx and skin, also causes invasive disease, most frequently skin and soft tissue infections. Invasive disease caused by drug-resistant strains, designated MRSA (methicillin-resistant S. aureus), is associated with failure of antibiotic therapy and elevated mortality. Here we review polysaccharide-conjugate and subunit vaccines that were designed to prevent S. aureus infection in patients at risk of bacteremia or surgical wound infection but failed to reach their clinical endpoints. We also discuss vaccines with ongoing trials for combinations of polysaccharide-conjugates and subunits. S. aureus colonization and invasive disease are not associated with the development of protective immune responses, which is attributable to a large spectrum of immune evasion factors. Two evasive strategies, assembly of protective fibrin shields via coagulases and protein A-mediated B cell superantigen activity, are discussed as possible vaccine targets. Although correlates for protective immunity are not yet known, opsonophagocytic killing of staphylococci by phagocytic cells offers opportunities to establish such criteria. PMID:27526714

  8. Carriage of Staphylococcus aureus in the elderly

    NARCIS (Netherlands)

    R. M. Parnaby; G. O'Dwyer; H. A. Monsey; M. S. Shafi

    1996-01-01

    textabstractThe point prevalence and incidence of Staphylococcus aureus (methicillin-sensitive and -resistant) carriage by inpatients on acute elderly care wards was estimated. The relationship to body site and to previous admissions to hospital or other institutions was determined. Fifty-five patie

  9. Increasing resistance of Staphylococcus aureus to ciprofloxacin.

    OpenAIRE

    Daum, T E; Schaberg, D R; Terpenning, M S; Sottile, W S; Kauffman, C A

    1990-01-01

    We demonstrated the marked emergence of resistance to ciprofloxacin among Staphylococcus arueus strains isolated at the Ann Arbor Veterans Administration Medical Center. All S. aureus isolates tested from 1984 to 1985 were susceptible, whereas 55.1% of methicillin-resistant and 2.5% of methicillin-susceptible strains from 1989 had high-level resistance to ciprofloxacin.

  10. Tertiary Treatment for Textile Waste Water-A Review

    OpenAIRE

    Manali Desai*1, Mehali Mehta2

    2014-01-01

    Tertiary treatment is the Industrial waste water treatment process which removes stubborn contaminants that have not been removed in secondary treatment. Effluent becomes even cleaner by Tertiary treatment through the use of stronger and more advanced treatment systems. The present work is an attempt to review all possible tertiary treatment methods for removal of dyestuff from textile effluent. Conventional method for treatment of textile effluent has own certain limitations ...

  11. Radioprotector WR-2721 and mitigating peptidoglycan synergistically promote mouse survival through the amelioration of intestinal and bone marrow damage

    International Nuclear Information System (INIS)

    The identification of an agent effective for the treatment of intestinal and bone marrow injury following radiation exposure remains a major issue in radiological medicine. In this study, we evaluated the therapeutic impact of single agent or combination treatments with 2-(3-aminopropylamino) ethylsulphanyl phosphonic acid (WR-2721) and peptidoglycan (PGN, a toll-like receptor 2 (TLR-2) agonist) on radiation-induced injury of the intestine and bone marrow in lethally irradiated male C57BL/6 mice. A dose of 3 mg of WR-2721 per mouse (167 mg/kg, intraperitoneally) was given 30 min before irradiation, and 30 μg of PGN per mouse (1.7 mg/kg) was injected intraperitoneally 24 h after 10 Gy irradiation. Bone marrow cluster of differentiation (CD)45+ and CD34+ markers of multiple haematopoietic lineages, number of granulocyte-erythroid-macrophage-megakaryocyte (GEMM) progenitor colonies, bone marrow histopathology, leucine-rich repeat-containing G-protein-coupled receptor 5 (Lgr5) expression in the intestines, xylose absorption and intestinal histopathology were all assessed at various time-points after irradiation. Furthermore, nuclear factor kappa B (NF-κB) p65 protein in the ileum was stained by immunofluorescent labelling. PGN-treated irradiated mice showed an increase in CD45+CD34+ cells compared with untreated mice 1.25 days after 10 Gy ionizing radiation (IR) (P < 0.05). Furthermore, combined PGN and WR-2721 treatment had an obviously synergistic radio-protective effect in nucleated cells in the bone marrow, including GEMM progenitors and CD45+CD34+ cells 4 days after 10 Gy IR. Single agent PGN or WR-2721 treatment after 10 Gy IR clearly increased Lgr5-positive pit cells (P < 0.05) and xylose absorption (P < 0.05). However only PGN and WR-2721 combination treatment markedly increased villus height (P < 0.05), number of crypts (P < 0.05) and whole-body weights after 10 Gy whole-body irradiation (WBI). The NF-κB p65 subunit was translocated to the nucleus, and

  12. Relationship between Vancomycin-Resistant Staphylococcus aureus, Vancomycin-Intermediate S. aureus, High Vancomycin MIC, and Outcome in Serious S. aureus Infections

    OpenAIRE

    Holmes, Natasha E.; Johnson, Paul D. R.; Howden, Benjamin P.

    2012-01-01

    Vancomycin has been used successfully for over 50 years for the treatment of Staphylococcus aureus infections, particularly those involving methicillin-resistant S. aureus. It has proven remarkably reliable, but its efficacy is now being questioned with the emergence of strains of S. aureus that display heteroresistance, intermediate resistance, and, occasionally, complete vancomycin resistance. More recently, an association has been established between poor outcome and infections with strain...

  13. Tertiary lymphoid organs in infection and autoimmunity.

    Science.gov (United States)

    Neyt, Katrijn; Perros, Frédéric; GeurtsvanKessel, Corine H; Hammad, Hamida; Lambrecht, Bart N

    2012-06-01

    The lymph nodes (LNs) and spleen have an optimal structure that allows the interaction between T cells, B cells and antigen-presenting dendritic cells (DCs) on a matrix made up by stromal cells. Such a highly organized structure can also be formed in tertiary lymphoid organs (TLOs) at sites of infection or chronic immune stimulation. This review focuses on the molecular mechanisms of TLO formation and maintenance, the controversies surrounding the nature of the inducing events, and the functions of these structures in infection, transplantation and autoimmunity. PMID:22622061

  14. Staphylococcus aureus Shifts toward Commensalism in Response to Corynebacterium Species.

    Science.gov (United States)

    Ramsey, Matthew M; Freire, Marcelo O; Gabrilska, Rebecca A; Rumbaugh, Kendra P; Lemon, Katherine P

    2016-01-01

    Staphylococcus aureus-human interactions result in a continuum of outcomes from commensalism to pathogenesis. S. aureus is a clinically important pathogen that asymptomatically colonizes ~25% of humans as a member of the nostril and skin microbiota, where it resides with other bacteria including commensal Corynebacterium species. Commensal Corynebacterium spp. are also positively correlated with S. aureus in chronic polymicrobial diabetic foot infections, distinct from acute monomicrobial S. aureus infections. Recent work by our lab and others indicates that microbe-microbe interactions between S. aureus and human skin/nasal commensals, including Corynebacterium species, affect S. aureus behavior and fitness. Thus, we hypothesized that S. aureus interactions with Corynebacterium spp. diminish S. aureus virulence. We tested this by assaying for changes in S. aureus gene expression during in vitro mono- versus coculture with Corynebacterium striatum, a common skin and nasal commensal. We observed a broad shift in S. aureus gene transcription during in vitro growth with C. striatum, including increased transcription of genes known to exhibit increased expression during human nasal colonization and decreased transcription of virulence genes. S. aureus uses several regulatory pathways to transition between commensal and pathogenic states. One of these, the quorum signal accessory gene regulator (agr) system, was strongly inhibited in response to Corynebacterium spp. Phenotypically, S. aureus exposed to C. striatum exhibited increased adhesion to epithelial cells, reflecting a commensal state, and decreased hemolysin activity, reflecting an attenuation of virulence. Consistent with this, S. aureus displayed diminished fitness in experimental in vivo coinfection with C. striatum when compared to monoinfection. These data support a model in which S. aureus shifts from virulence toward a commensal state when exposed to commensal Corynebacterium species.

  15. Staphylococcus aureus Shifts toward Commensalism in Response to Corynebacterium Species.

    Science.gov (United States)

    Ramsey, Matthew M; Freire, Marcelo O; Gabrilska, Rebecca A; Rumbaugh, Kendra P; Lemon, Katherine P

    2016-01-01

    Staphylococcus aureus-human interactions result in a continuum of outcomes from commensalism to pathogenesis. S. aureus is a clinically important pathogen that asymptomatically colonizes ~25% of humans as a member of the nostril and skin microbiota, where it resides with other bacteria including commensal Corynebacterium species. Commensal Corynebacterium spp. are also positively correlated with S. aureus in chronic polymicrobial diabetic foot infections, distinct from acute monomicrobial S. aureus infections. Recent work by our lab and others indicates that microbe-microbe interactions between S. aureus and human skin/nasal commensals, including Corynebacterium species, affect S. aureus behavior and fitness. Thus, we hypothesized that S. aureus interactions with Corynebacterium spp. diminish S. aureus virulence. We tested this by assaying for changes in S. aureus gene expression during in vitro mono- versus coculture with Corynebacterium striatum, a common skin and nasal commensal. We observed a broad shift in S. aureus gene transcription during in vitro growth with C. striatum, including increased transcription of genes known to exhibit increased expression during human nasal colonization and decreased transcription of virulence genes. S. aureus uses several regulatory pathways to transition between commensal and pathogenic states. One of these, the quorum signal accessory gene regulator (agr) system, was strongly inhibited in response to Corynebacterium spp. Phenotypically, S. aureus exposed to C. striatum exhibited increased adhesion to epithelial cells, reflecting a commensal state, and decreased hemolysin activity, reflecting an attenuation of virulence. Consistent with this, S. aureus displayed diminished fitness in experimental in vivo coinfection with C. striatum when compared to monoinfection. These data support a model in which S. aureus shifts from virulence toward a commensal state when exposed to commensal Corynebacterium species. PMID:27582729

  16. Characterization and expression analysis of a peptidoglycan recognition protein gene, SmPGRP2 in mucosal tissues of turbot (Scophthalmus maximus L.) following bacterial challenge.

    Science.gov (United States)

    Zhang, Linan; Gao, Chengbin; Liu, Fengqiao; Song, Lin; Su, Baofeng; Li, Chao

    2016-09-01

    Peptidoglycan recognition receptor proteins (PGRPs), a group of pattern recognition receptors (PRRs), can recognize peptidoglycan (PGN) of the bacteria cell wall and play an important role in host immune defense against pathogen infection. They are highly structurally conserved through evolution, but with different function in innate immunity between invertebrates and vertebrates. In teleost fish, several PGRPs have been characterized recently. They have both amidase activity and bactericidal activity and are involved in indirectly killing bacteria and regulating multiple signaling pathways. However, the knowledge of PGRPs in mucosal immunity of teleost fish is still limited. In this study, we identified a PGRPs gene (SmPGRP2) of turbot and investigated its expression patterns in mucosal tissues after challenge with Gram-positive bacteria Streptococcus iniae and Gram-negative bacteria Vibrio anguillarum. Phylogenetic analysis showed the strongest relationship of turbot PGRP to halibut, which was consistent with their phylogenetic relationships. In addition, SmPGRP2 was ubiquitously expressed in turbot tissues, and constitutive expression levels were higher in classical immune tissues (including liver, spleen, and head-kidney) than mucosal tissues (intestine, gill and skin). After bacterial challenge, the expression of SmPGRP2 was induced and showed a general trend of up-regulation in mucosal tissues, except in intestine following V. anguillarum infection. These different expression patterns varied depending on both pathogen and tissue type, suggesting its distinct roles in the host immune response to bacterial pathogen. PMID:27461422

  17. Extraction of Peptidoglycan from L. paracasei subp. Paracasei X12 and Its Preliminary Mechanisms of Inducing Immunogenic Cell Death in HT-29 Cells

    Directory of Open Access Journals (Sweden)

    Pei-Jun Tian

    2015-08-01

    Full Text Available L. paracasei subp. paracasei X12 was previously isolated from a Chinese traditional fermented cheese with anticancer activities and probiotic potential. Herein, the integral peptidoglycan (X12-PG was extracted by a modified trichloroacetic acid (TCA method. X12-PG contained the four representative amino acids Asp, Glu, Ala and Lys, and displayed the similar lysozyme sensitivity, UV-visible scanning spectrum and molecular weight as the peptidoglycan standard. X12-PG could induce the production of apoptotic bodies observed by transmission electron microscopy (TEM. X12-PG could significantly induced the translocation of calreticulin (CRT and the release of high mobility group box 1 protein (HMGB1, the two notable hallmarks of immunogenic cell death (ICD, with the endoplastic reticulum (ER damaged and subsequently intracellular [Ca2+] elevated. Our findings implied that X12-PG could induce the ICD of HT-29 cells through targeting at the ER. The present results may enlighten the prospect of probiotics in the prevention of colon cancer.

  18. Extraction of Peptidoglycan from L. paracasei subp. Paracasei X12 and Its Preliminary Mechanisms of Inducing Immunogenic Cell Death in HT-29 Cells.

    Science.gov (United States)

    Tian, Pei-Jun; Li, Bao-Long; Shan, Yu-Juan; Zhang, Jin-Na; Chen, Jing-Yu; Yu, Min; Zhang, Lan-Wei

    2015-01-01

    L. paracasei subp. paracasei X12 was previously isolated from a Chinese traditional fermented cheese with anticancer activities and probiotic potential. Herein, the integral peptidoglycan (X12-PG) was extracted by a modified trichloroacetic acid (TCA) method. X12-PG contained the four representative amino acids Asp, Glu, Ala and Lys, and displayed the similar lysozyme sensitivity, UV-visible scanning spectrum and molecular weight as the peptidoglycan standard. X12-PG could induce the production of apoptotic bodies observed by transmission electron microscopy (TEM). X12-PG could significantly induced the translocation of calreticulin (CRT) and the release of high mobility group box 1 protein (HMGB1), the two notable hallmarks of immunogenic cell death (ICD), with the endoplastic reticulum (ER) damaged and subsequently intracellular [Ca(2+)] elevated. Our findings implied that X12-PG could induce the ICD of HT-29 cells through targeting at the ER. The present results may enlighten the prospect of probiotics in the prevention of colon cancer. PMID:26305246

  19. The Stealthy Superbug: the Role of Asymptomatic Enteric Carriage in Maintaining a Long-Term Hospital Outbreak of ST228 Methicillin-Resistant Staphylococcus aureus

    OpenAIRE

    Senn, Laurence; Clerc, Olivier; Zanetti, Giorgio; Basset, Patrick; Prod’Hom, Guy; Gordon, Nicola C.; Sheppard, Anna E.; Crook, Derrick W; James, Richard; Thorpe, Harry A.; Feil, Edward J.; Blanc, Dominique S.

    2016-01-01

    ABSTRACT Whole-genome sequencing (WGS) of 228 isolates was used to elucidate the origin and dynamics of a long-term outbreak of methicillin-resistant Staphylococcus aureus (MRSA) sequence type 228 (ST228) SCCmec I that involved 1,600 patients in a tertiary care hospital between 2008 and 2012. Combining of the sequence data with detailed metadata on patient admission and movement confirmed that the outbreak was due to the transmission of a single clonal variant of ST228, rather than repeated i...

  20. The Stealthy Superbug: The role of asymptomatic enteric carriage in maintaining a long-term hospital outbreak of ST228 methicillin-resistant Staphylococcus aureus.

    OpenAIRE

    Senn, L; Clerc, O; Zanetti, G; Basset, P.; Prod'hom, G.; Gordon, NC; Sheppard, AE; Crook, DW; JAMES, R; Thorpe, HA; Feil, EJ; Blanc, DS

    2016-01-01

    Whole-genome sequencing (WGS) of 228 isolates was used to elucidate the origin and dynamics of a long-term outbreak of methicillin-resistant Staphylococcus aureus(MRSA) sequence type 228 (ST228) SCCmec I that involved 1,600 patients in a tertiary care hospital between 2008 and 2012. Combining of the sequence data with detailed metadata on patient admission and movement confirmed that the outbreak was due to the transmission of a single clonal variant of ST228, rather than repeated introductio...

  1. Tertiary companions to close spectroscopic binaries

    CERN Document Server

    Tokovinin, A; Thomas, S; Udry, S

    2006-01-01

    We have surveyed a sample of 165 solar-type spectroscopic binaries (SB) with periods from 1 to 30 days for higher-order multiplicity. 62 targets have been observed with the NACO adaptive optics system and 13 new physical tertiary companions were detected. Another 12 new wide companions (5 still tentative) were retrieved from the 2MASS sky survey. Our binaries belong to 161 stellar systems; of these 64 are triple, 11 quadruple and 7 quintuple. After correction for incomplete detection, the fraction of SBs with additional companions is 63% +- 5%. We find that this fraction is a strong function of the SB period P, reaching 96% for P12d. Period distributions of SBs with and without tertiaries are significantly different, but their mass ratio distributions are identical. New statistical data on the multiplicity of close SBs indicate that their periods and mass ratios were established very early, but periods of SBs within triples were further shortened by angular momentum exchange with companions.

  2. Staphylococcus aureus shifts towards commensalism in response to Corynebacterium species

    Directory of Open Access Journals (Sweden)

    Matthew M Ramsey

    2016-08-01

    Full Text Available Staphylococcus aureus–human interactions result in a continuum of outcomes from commensalism to pathogenesis. S. aureus is a clinically important pathogen that asymptomatically colonizes ~25% of humans as a member of the nostril and skin microbiota, where it resides with other bacteria including commensal Corynebacterium species. Commensal Corynebacterium spp. are also positively correlated with S. aureus in chronic polymicrobial diabetic foot infections, distinct from acute monomicrobial S. aureus infections. Recent work by our lab and others indicates that microbe-microbe interactions between S. aureus and human skin/nasal commensals, including Corynebacterium species, affect S. aureus behavior and fitness. Thus, we hypothesized that S. aureus interactions with Corynebacterium spp. diminish S. aureus virulence. We tested this by assaying for changes in S. aureus gene expression during in vitro mono- versus coculture with Corynebacterium striatum, a common skin and nasal commensal. We observed a broad shift in S. aureus gene transcription during in vitro growth with C. striatum, including increased transcription of genes known to exhibit increased expression during human nasal colonization and decreased transcription of virulence genes. S. aureus uses several regulatory pathways to transition between commensal and pathogenic states. One of these, the quorum signal accessory gene regulator (agr system, was strongly inhibited in response to Corynebacterium spp. Phenotypically, S. aureus exposed to C. striatum exhibited increased adhesion to epithelial cells, reflecting a commensal state, and decreased hemolysin activity, reflecting an attenuation of virulence. Consistent with this, S. aureus displayed diminished fitness in experimental in vivo coinfection with C. striatum when compared to monoinfection. These data support a model in which S. aureus shifts from virulence towards a commensal state when exposed to commensal Corynebacterium species.

  3. Superbugs causing ventilator associated pneumonia in a tertiary care hospital and the return of pre-antibiotic era!

    Science.gov (United States)

    Qureshi, S; Agrawal, C; Madan, M; Pandey, A; Chauhan, H

    2015-01-01

    The rise in super bugs causing Ventilator-Associated Pneumonia (VAP) is a major cause of mortality and morbidity despite recent advances in management owing to the looming 'antibiotic apocalypse'. The aetiology and susceptibility pattern of the VAP isolates varies with patient population, type of intensive care unit (ICU) and is an urgent diagnostic challenge. The present study carried out for a period of one year in a tertiary care hospital, enrolled patients on mechanical ventilation (MV) for ≥48 hrs. Endotracheal aspirates (ETA) from suspected VAP patients were processed by semi quantitative method. Staphylococus aureus, members of Enterobacteriaceae were more common in early onset VAP (EOVAP), while Nonfermenting Gram negative bacilli (NFGNB) were significantly associated with late onset VAP (LOVAP). Most of the isolates were multi drug resistant (MDR) super bugs. With limited treatment options left for this crisis situation like the pre-antibiotic era; it is an alarm for rational antibiotic therapy usage and intensive education programs.

  4. Crime and Crime Management in Nigeria Tertiary Institutions

    Science.gov (United States)

    Adebanjo, Margaret Adewunmi

    2014-01-01

    This paper examines crime and its management in Nigerian tertiary institutions. Tertiary institutions today have become arenas for crime activities such as rape, cultism, murder, theft, internet fraud, drug abuse, and examination malpractices. This paper delves into what crime is, and its causes; and the positions of the law on crime management.…

  5. 10 CFR 212.78 - Tertiary incentive crude oil.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Tertiary incentive crude oil. 212.78 Section 212.78 Energy DEPARTMENT OF ENERGY OIL MANDATORY PETROLEUM PRICE REGULATIONS Producers of Crude Oil § 212.78 Tertiary incentive crude oil. Annual prepaid expenses report. By January 31 of each year after 1980, the...

  6. Methicillin-resistant Staphylococcus aureus: the superbug.

    Science.gov (United States)

    Ippolito, Giuseppe; Leone, Sebastiano; Lauria, Francesco N; Nicastri, Emanuele; Wenzel, Richard P

    2010-10-01

    Over the last decade, methicillin-resistant Staphylococcus aureus (MRSA) strains have emerged as serious pathogens in the nosocomial and community setting. Hospitalization costs associated with MRSA infections are substantially greater than those associated with methicillin-sensitive S. aureus (MSSA) infections, and MRSA has wider economic effects that involve indirect costs to the patient and to society. In addition, there is some evidence suggesting that MRSA infections increase morbidity and the risk of mortality. Glycopeptides are the backbone antibiotics for the treatment of MRSA infections. However, several recent reports have highlighted the limitations of vancomycin, and its role in the management of serious infections is now being reconsidered. Several new antimicrobials demonstrate in vitro activity against MRSA and other Gram-positive bacteria. Data from large surveys indicate that linezolid, daptomycin, and tigecycline are almost universally active against MRSA. This review will briefly discuss the epidemiology, costs, outcome, and therapeutic options for the management of MRSA infections. PMID:20851011

  7. Curcumin Reverse Methicillin Resistance in Staphylococcus aureus

    OpenAIRE

    Su-Hyun Mun; Sung-Bae Kim; Ryong Kong; Jang-Gi Choi; Youn-Chul Kim; Dong-Won Shin; Ok-Hwa Kang; Dong-Yeul Kwon

    2014-01-01

    Curcumin, a natural polyphenolic flavonoid extracted from the rhizome of Curcuma longa L., was shown to possess superior potency to resensitize methicillin-resistant Staphylococcus aureus (MRSA) to antibiotics. Previous studies have shown the synergistic activity of curcumin with β-lactam and quinolone antibiotics. Further, to understand the anti-MRSA mechanism of curcumin, we investigated the potentiated effect of curcumin by its interaction in diverse conditions. The mechanism of anti-MRSA ...

  8. SURGICAL SITE INFECTION FOLLOWING LOWER SEGMENT CAESAREAN SECTION IN A TERTIARY CARE HOSPITAL

    Directory of Open Access Journals (Sweden)

    Nishi Roshini

    2016-03-01

    Full Text Available AIM OF THE STUDY To identify infection rates and risk factors associated with Surgical Site Infection (SSI following Caesarean Section. DESIGN OF THE STUDY Case control study. PLACE OF STUDY Academic Tertiary Care Obstetrics and Gynaecology Centre with 60 Beds. PATIENTS All women who delivered by caesarean section in Govt. Medical College, Thrissur, during 1st June 2010 to 30th September 2011. METHODS Wound infections were identified during hospital stay using the criteria of the Centres for Disease Control and Prevention, National Nosocomial Infections Surveillance System. A case control study of 50 patients with wound infection after Lower Segment Caesarean Section (LSCS was undertaken between 1st June 2010 and 30th September 2011. The control group comprised of 50 patients selected randomly from among those who had LSCS during the study period with no wound infection. The CDC definition describes three levels of SSI (Superficial incisional, Deep incisional and Organ or Space infection. Comparisons for categorical variables were performed using the X2 or Fisher exact test. Continuous variables were compared using the 2-tailed Student ‘t’ test and p 0.05 was considered significant. RESULTS The overall wound infection rate in the study was 3.5%, (50 among 1410 Lower Transverse CS. Obesity, Hypertension and Poorly Controlled Diabetes are associated with significant risk for development of SSI. The commonest presentation of SSI in LSCS was fever 40 (80% followed by local pain and induration 25 (50%. SSI was detected on 6±3 days. Average duration of hospital stay among SSI was 22.78±10.2 days. Staphylococcus aureus was the commonest pathogen for SSI in our series. The increase in the presence of (Methicillin Resistant Staphylococcus Aureus MRSA (20.83% might alter the pattern of prophylactic antibiotic given preoperatively in the near future. CONCLUSIONS Increased incidence of drug resistant organisms needs proper attention and strategies for

  9. Toxin-Antitoxin Systems of Staphylococcus aureus.

    Science.gov (United States)

    Schuster, Christopher F; Bertram, Ralph

    2016-05-05

    Toxin-antitoxin (TA) systems are small genetic elements found in the majority of prokaryotes. They encode toxin proteins that interfere with vital cellular functions and are counteracted by antitoxins. Dependent on the chemical nature of the antitoxins (protein or RNA) and how they control the activity of the toxin, TA systems are currently divided into six different types. Genes comprising the TA types I, II and III have been identified in Staphylococcus aureus. MazF, the toxin of the mazEF locus is a sequence-specific RNase that cleaves a number of transcripts, including those encoding pathogenicity factors. Two yefM-yoeB paralogs represent two independent, but auto-regulated TA systems that give rise to ribosome-dependent RNases. In addition, omega/epsilon/zeta constitutes a tripartite TA system that supposedly plays a role in the stabilization of resistance factors. The SprA1/SprA1AS and SprF1/SprG1 systems are post-transcriptionally regulated by RNA antitoxins and encode small membrane damaging proteins. TA systems controlled by interaction between toxin protein and antitoxin RNA have been identified in S. aureus in silico, but not yet experimentally proven. A closer inspection of possible links between TA systems and S. aureus pathophysiology will reveal, if these genetic loci may represent druggable targets. The modification of a staphylococcal TA toxin to a cyclopeptide antibiotic highlights the potential of TA systems as rather untapped sources of drug discovery.

  10. Aspartate inhibits Staphylococcus aureus biofilm formation.

    Science.gov (United States)

    Yang, Hang; Wang, Mengyue; Yu, Junping; Wei, Hongping

    2015-04-01

    Biofilm formation renders Staphylococcus aureus highly resistant to conventional antibiotics and host defenses. Four D-amino acids (D-Leu, D-Met, D-Trp and D-Tyr) have been reported to be able to inhibit biofilm formation and disassemble established S. aureus biofilms. We report here for the first time that both D- and L-isoforms of aspartate (Asp) inhibited S. aureus biofilm formation on tissue culture plates. Similar biofilm inhibition effects were also observed against other staphylococcal strains, including S. saprophyticus, S. equorum, S. chromogenes and S. haemolyticus. It was found that Asp at high concentrations (>10 mM) inhibited the growth of planktonic N315 cells, but at subinhibitory concentrations decreased the cellular metabolic activity without influencing cell growth. The decreased cellular metabolic activity might be the reason for the production of less protein and DNA in the matrix of the biofilms formed in the presence of Asp. However, varied inhibition efficacies of Asp were observed for biofilms formed by clinical staphylococcal isolates. There might be mechanisms other than decreasing the metabolic activity, e.g. the biofilm phenotypes, affecting biofilm formation in the presence of Asp.

  11. Aspartate inhibits Staphylococcus aureus biofilm formation.

    Science.gov (United States)

    Yang, Hang; Wang, Mengyue; Yu, Junping; Wei, Hongping

    2015-04-01

    Biofilm formation renders Staphylococcus aureus highly resistant to conventional antibiotics and host defenses. Four D-amino acids (D-Leu, D-Met, D-Trp and D-Tyr) have been reported to be able to inhibit biofilm formation and disassemble established S. aureus biofilms. We report here for the first time that both D- and L-isoforms of aspartate (Asp) inhibited S. aureus biofilm formation on tissue culture plates. Similar biofilm inhibition effects were also observed against other staphylococcal strains, including S. saprophyticus, S. equorum, S. chromogenes and S. haemolyticus. It was found that Asp at high concentrations (>10 mM) inhibited the growth of planktonic N315 cells, but at subinhibitory concentrations decreased the cellular metabolic activity without influencing cell growth. The decreased cellular metabolic activity might be the reason for the production of less protein and DNA in the matrix of the biofilms formed in the presence of Asp. However, varied inhibition efficacies of Asp were observed for biofilms formed by clinical staphylococcal isolates. There might be mechanisms other than decreasing the metabolic activity, e.g. the biofilm phenotypes, affecting biofilm formation in the presence of Asp. PMID:25687923

  12. Whole-Genome Sequence of Staphylococcus aureus Strain LCT-SA112

    OpenAIRE

    Wang, Junfeng; Liu, Yanhong; Wan, Daiwei; Fang, Xiangqun; Li, Tianzhi; Guo, Yinghua; Chang, De; Su, Longxiang; Wang, Yajuan; Zhao, Jiao; Liu, Changting

    2012-01-01

    Staphylococcus aureus is a facultative anaerobic Gram-positive coccal bacterium. S. aureus is the most common species of Staphylococcus to cause staphylococcal infections, which are very common in clinical medicine. Here we report the genome sequence of S. aureus strain LCT-SA112, which was isolated from S. aureus subsp. aureus CGMCC 1.230.

  13. SAMMD: Staphylococcus aureus Microarray Meta-Database

    Directory of Open Access Journals (Sweden)

    Elasri Mohamed O

    2007-10-01

    Full Text Available Abstract Background Staphylococcus aureus is an important human pathogen, causing a wide variety of diseases ranging from superficial skin infections to severe life threatening infections. S. aureus is one of the leading causes of nosocomial infections. Its ability to resist multiple antibiotics poses a growing public health problem. In order to understand the mechanism of pathogenesis of S. aureus, several global expression profiles have been developed. These transcriptional profiles included regulatory mutants of S. aureus and growth of wild type under different growth conditions. The abundance of these profiles has generated a large amount of data without a uniform annotation system to comprehensively examine them. We report the development of the Staphylococcus aureus Microarray meta-database (SAMMD which includes data from all the published transcriptional profiles. SAMMD is a web-accessible database that helps users to perform a variety of analysis against and within the existing transcriptional profiles. Description SAMMD is a relational database that uses MySQL as the back end and PHP/JavaScript/DHTML as the front end. The database is normalized and consists of five tables, which holds information about gene annotations, regulated gene lists, experimental details, references, and other details. SAMMD data is collected from the peer-reviewed published articles. Data extraction and conversion was done using perl scripts while data entry was done through phpMyAdmin tool. The database is accessible via a web interface that contains several features such as a simple search by ORF ID, gene name, gene product name, advanced search using gene lists, comparing among datasets, browsing, downloading, statistics, and help. The database is licensed under General Public License (GPL. Conclusion SAMMD is hosted and available at http://www.bioinformatics.org/sammd/. Currently there are over 9500 entries for regulated genes, from 67 microarray

  14. Antibody responses in patients with invasive Staphylococcus aureus infections

    OpenAIRE

    Jacobsson, G; Colque-Navarro, P.; Gustafsson, E.; Andersson, R.; Möllby, R

    2010-01-01

    Abstract Correlation between antibody response and clinical outcome in Staphylococcus aureus bacteremia has yielded conflicting results. Immunization schedules have failed in clinical trials. Is the humoral response toward S. aureus of protective nature? A prospective study was performed in patients with invasive S. aureus (ISA) infections during the period 2003?2005. The antibody levels were determined at the beginning and at the end of treatment and one month later (n?=?96, n?=?7...

  15. Mapping the Distribution of Invasive Staphylococcus aureus across Europe

    OpenAIRE

    Grundmann, Hajo; Aanensen, David M.; van den Wijngaard, Cees C.; Brian G Spratt; Harmsen, Dag; Friedrich, Alexander W.; ,

    2010-01-01

    Editors' Summary Background The bacterium Staphylococcus aureus lives on the skin and in the nose of about a third of healthy people. Although S. aureus usually coexists peacefully with its human carriers, it is also an important disease-causing organism or pathogen. If it enters the body through a cut or during a surgical procedure, S. aureus can cause minor infections such as pimples and boils or more serious, life-threatening infections such as blood poisoning and pneumonia. Minor S. aureu...

  16. Staphylococcus aureus atsparumas antibiotikams ir fagotipų paplitimas

    OpenAIRE

    Kareivienė, Violeta; Pavilonis, Alvydas; Sinkutė, Gintarė; Liegiūtė, Sigutė; Gailienė, Greta

    2006-01-01

    Objective. The aim of this study was to identify the phage groups of Staphylococcus aureus strains, their prevalence, and resistance of different phage groups to antibiotics. Materials and methods. A total of 294 Staphylococcus aureus strains in Kaunas hospitals were obtained; they were phage typed and their resistance to antibiotics was determined. We used the method of routine dilution to test 17 antibiotics against the isolates. Susceptibility of Staphylococcus aureus to studied antibio...

  17. Threat of drug resistant Staphylococcus aureus to health in Nepal

    OpenAIRE

    Ansari, Shamshul; Nepal, Hari Prasad; Gautam, Rajendra; Rayamajhi, Nabin; Shrestha, Sony; Upadhyay, Goma; Acharya, Anju; Chapagain, Moti Lal

    2014-01-01

    Background Staphylococcus aureus is the most commonly isolated organism from the different clinical samples in hospital. The emergence and dissemination of methicillin resistant Staphylococcus aureus (MRSA) and growing resistance to non-beta-lactam antibiotics is making treatment of infections due to this organism increasingly difficult. Methods This study was conducted to determine the frequency of Staphylococcus aureus isolated from different clinical samples, rates of MRSA and full antibio...

  18. MATERNAL MORTALITY IN A TERTIARY CARE CENTRE

    Directory of Open Access Journals (Sweden)

    Harpreet

    2013-06-01

    Full Text Available ABSTRACT: Maternal Mortality in A Tertiary Care Centre. OBJECTIVE: To study maternal mortality and the complications leading to maternal death. METHODS: A retrospective study of hospital record to study maternal mortality and its causes over 3 years from January 2010 to December 2012. RESULTS: There were a total of 58 maternal deaths out of 2823 live births giving a maternal mortality ratio of 2054.55 per one lakh live births. Unbooked and late referrals account for 77.58% of maternal deaths. The majority of deaths around 75.86% were in 20-30 years age group. Haemorrhage was the commonest causes of death (24.12% followed by sepsis (18.96% and pregnancy induced hypertension 15.51% Anemia contributed to the most common indirect cause of maternal morality. CONCLUSION: Haemorrhage, sepsis and pregnancy induced hypertension including eclampsia were the direct major causes of death. Anaemia and cardiac diseases were other indirect causes of death.

  19. Daya Hambat Ekstrak Aloe Vera terhadap pertumbuhan Staphylococcus Aureus

    OpenAIRE

    Rahmat, drg.Sp,Pros

    2011-01-01

    Dari hasil penelitian , maka dapat disimpulkan bahwa ekstrak Aloe Vera dapat menghambat pertumbuhan bakteri Stafhylococcus aureus, dan kadar hambat minimal ekstrak Aloe Vera adalah pada konsentrasi 25%.

  20. Comparison of Two Commercial PCR Methods for Methicillin-Resistant Staphylococcus aureus (MRSA) Screening in a Tertiary Care Hospital

    OpenAIRE

    Aylin Aydiner; Jessica Lüsebrink; Verena Schildgen; Ingo Winterfeld; Oliver Knüver; Katja Schwarz; Sabine Messler; Oliver Schildgen; Frauke Mattner

    2012-01-01

    Nose/throat-swabs from 1049 patients were screened for MRSA using CHROMagar MRSA, LightCycler Advanced MRSA, and Detect-Ready MRSA. Results were compared to the CHROMagar MRSA results, which was set as reference system. MRSA was detected in 3.05% of the patients with CHROMagar MRSA. LightCycler MRSA Advanced showed a higher clinical sensitivity (84.38%) than Detect-Ready MRSA (57.69%).The negative predictive values were high for both tests (>98%). The specificity and the positive predictive v...

  1. Spectrum of Microbial Flora in Diabetic Foot Ulcer and Its Antibiotic Sensitivity Pattern in Tertiary Care Hospital in Ahmedabad, Gujarat

    Directory of Open Access Journals (Sweden)

    Manisha Jain

    2012-06-01

    Full Text Available Introduction: A Prospective study “Spectrum of Microbial flora in diabetic foot ulcer and its antibiotic sensitivity pattern” was carried out in a tertiary care hospital, Ahmedabad on 125 patients in which 85 were male patients and 40 were female patients. Material and Methods: Swabs samples were collected from the edge and margins of ulcers and organism were identified by gram staining culture and biochemical reactions. Results: Out of 125 specimens 108 specimens showed growth of organisms. Total 157 aerobic organisms were isolated from culture positive specimens. It represents an average of 1.25 organisms per case. Among these organisms, 130 gram negative and 27 gram positive organisms were isolated. Pseudomonas aeruginosa (30.57% was predominant organism followed by Klebsiella spp. (22.29%. Staphylococcus aureus were 12.74% in which Methicillin resistant S. aureus (MRSA was 55%. Conclusion: incidence of growth was 86.4% in which Pseudomonas aeruginosa (30.57% is most common isolate. Organisms in mixed infections showed multidrug resistance as compared to single isolated strain. Diabetic foot infections are polymicrobial in nature. As the Wagner’s grade increased, the prevalence of isolates also increased. [National J of Med Res 2012; 2(3.000: 354-357

  2. VISA/VRSA (Vancomycin-Intermediate/Resistant Staphylococcus aureus) in Healthcare Settings

    Science.gov (United States)

    ... to vancomycin and other antimicrobial agents. What is Staphylococcus aureus? Staphylococcus aureus is a bacterium commonly found on the ... control personnel. Investigation and Control of Vancomycin-Resistant Staphylococcus aureus (VRSA) [PDF - 300 KB] - This document is ...

  3. CHANGING TRENDS OF ANTIBIOGRAM PROFILE IN PATIENTS WITH COMMUNITY ACQUIRED CHRONIC OTITIS MEDIA IN A TERTIARY CARE HOSPITAL

    Directory of Open Access Journals (Sweden)

    Bipasa

    2014-09-01

    Full Text Available : INTRODUCTION: Chronic otitis media (COM is one among the commonest otological diseases encountered in otorhinolaryngological practice and attending ENT OPD especially among the lower socio-economic strata of society. AIMS: This study was carried out to know about the aerobic bacterial flora causing COM and in-vitro antibiotic susceptibility pattern in order to scientifically guide patient management instead of relying on empirical therapy alone. MATERIALS AND METHODS: This study included 100 patients of community acquired COM attending ENT OPD of a tertiary care level hospital. After proper sample collection by sterile aural swabs, they were immediately sent to the microbiology laboratory for processing by aerobic culture, isolation and identification following standard recommended methods and antibiotic susceptibility tests were done by Kirby-Bauer disc diffusion methods as per Clinical and Laboratory Standards Institute (CLSI guidelines. RESULTS: Out of 100 cases of COM, microbiological culture yielded 101 bacterial isolates from 90 patients and 4 fungal isolates (3 isolates of Candida albicans and 1 isolate of Aspergillusfumigatus from 4 patients. Polymicrobial infections were seen in 11.11% patients. In this study Staphylococcus aureus (31.68% was the commonest isolate followed by Pseudomonas aeruginosa (23.76%. Other common bacterial isolates were E.coli, Klebsiellapneumoniae, coagulase negative Staphylococcus (CONS, Proteus mirabilis in descending order. Piperacillin-tazobactum was the most sensitive drug (85.45% among the gram-negative bacteria followed by meropenem (81.81%, amikacin (76.36% and levofloxacin (74.54%. Gram positive bacteria showed 100% sensitivity to vancomycin and 93.47% sensitivity to linezolid. For Methicillin resistant Staphylococcus aureus (MRSA isolates ciprofloxacin, cotrimoxazole, tetracycline, linezolid and vancomycin were found to have good activity. CONCLUSION: This study suggests that the common etiological

  4. Downregulation of the Musca domestica peptidoglycan recognition protein SC (PGRP-SC) leads to overexpression of antimicrobial peptides and tardy pupation.

    Science.gov (United States)

    Gao, Yifu; Tang, Ting; Gu, Jihai; Sun, Lingling; Gao, Xiaobin; Ma, Xianyong; Wang, Xiaochun; Liu, Fengsong; Wang, Jianhui

    2015-10-01

    PGRP (peptidoglycan recognition protein) is a conserved protein family that recognizes the peptidoglycan in bacterial cell wall and causes the activation of various innate immune responses. Previous studies have reported that PGRP-SCs in Drosophila dampen the activation of Immune Deficiency (Imd) pathway to microbial infection, and participate in the lifespan extension of the insects. To facilitate understanding the function of PGRP-SCs from an evolutionary angle, we identified and functionally characterized the PGRP-SC gene in the housefly Musca domestica, a species that has adapted to a septic environment much harsher than the natural habitat of Drosophila. The gene designated as MdPGRP-SC was found most abundantly expressed in the 3rd instar larvae, and is expressed at this developmental stage predominantly in the gut. MdPGRP-SC was virtually unchanged in whole larvae after a septic injury at the second larval instar, while two antimicrobial peptides (AMPs), diptericin and attacin, were upregulated in the first 24h but not later. Through dsRNA microinjection, MdPGRP-SC was knocked down by RNA interference (RNAi), and caused the significant increased expression of diptericin and attacin. The pupation of MdPGRP-SC-depleted larvae was severely suppressed compared to controls. Opposite to the expression trend of MdPGRP-SC, a spontaneous active expression of diptericin and attacin was found in pre-pupae but not in third instar larvae. Taken together, our study reveals that downregulation of MdPGRP-SC leads to the overexpression of the AMPs, and is involved in the larvae-to-pupa transition of housefly.

  5. Cord factor and peptidoglycan recapitulate the Th17-promoting adjuvant activity of mycobacteria through mincle/CARD9 signaling and the inflammasome.

    Science.gov (United States)

    Shenderov, Kevin; Barber, Daniel L; Mayer-Barber, Katrin D; Gurcha, Sudagar S; Jankovic, Dragana; Feng, Carl G; Oland, Sandy; Hieny, Sara; Caspar, Pat; Yamasaki, Sho; Lin, Xin; Ting, Jenny P-Y; Trinchieri, Giorgio; Besra, Gurdyal S; Cerundolo, Vincenzo; Sher, Alan

    2013-06-01

    Although adjuvants are critical vaccine components, their modes of action are poorly understood. In this study, we investigated the mechanisms by which the heat-killed mycobacteria in CFA promote Th17 CD4(+) T cell responses. We found that IL-17 secretion by CD4(+) T cells following CFA immunization requires MyD88 and IL-1β/IL-1R signaling. Through measurement of Ag-specific responses after adoptive transfer of OTII cells, we confirmed that MyD88-dependent signaling controls Th17 differentiation rather than simply production of IL-17. Additional experiments showed that CFA-induced Th17 differentiation involves IL-1β processing by the inflammasome, as mice lacking caspase-1, ASC, or NLRP3 exhibit partially defective responses after immunization. Biochemical fractionation studies further revealed that peptidoglycan is the major component of heat-killed mycobacteria responsible for inflammasome activation. By assaying Il1b transcripts in the injection site skin of CFA-immunized mice, we found that signaling through the adaptor molecule caspase activation and recruitment domain 9 (CARD9) plays a major role in triggering pro-IL-1β expression. Moreover, we demonstrated that recognition of the mycobacterial glycolipid trehalose dimycolate (cord factor) by the C-type lectin receptor mincle partially explains this CARD9 requirement. Importantly, purified peptidoglycan and cord factor administered in mineral oil synergized to recapitulate the Th17-promoting activity of CFA, and, as expected, this response was diminished in caspase-1- and CARD9-deficient mice. Taken together, these findings suggest a general strategy for the rational design of Th17-skewing adjuvants by combining agonists of the CARD9 pathway with inflammasome activators. PMID:23630357

  6. Assessing uncertainty in outsourcing clinical services at tertiary health centers.

    Science.gov (United States)

    Billi, John E; Pai, Chih-Wen; Spahlinger, David A

    2007-01-01

    When tertiary health centers face capacity constraint, one feasible strategy to meet service demand is outsourcing clinical services to qualified community providers. Clinical outsourcing enables tertiary health centers to meet the expectations of service timeliness and provides good opportunities to collaborate with other health care providers. However, outsourcing may result in dependence and loss of control for the tertiary health centers. Other parties involved in clinical outsourcing such as local partners, patients, and payers may also encounter potential risks as well as enjoy benefits in an outsourcing arrangement. Recommendations on selecting potential outsourcing partners are given to minimize the risks associated with an outsourcing contract.

  7. Staphylococcus aureus: resistance pattern and risk factors

    Directory of Open Access Journals (Sweden)

    Mohammad Naghavi-Behzad

    2015-03-01

    Full Text Available Introduction: Methicillin resistant Staphylococcus aureus (MRSA has emerged as a nosocomial pathogen of major worldwide importance and is an increasingly frequent cause of community-acquired infections. In this study, different risk factors and MRSA resistance pattern were investigated. Methods: In a 24 months period, all of the patients who were confined to bed in the surgery ward were included in the study. Then they were assessed to find out as if they had MRSA infection when hospitalized and once when they were discharged. Almost 48 h after admission, when patients were discharged, social and medical histories were acquired. Acquired samples were examined. Results: During the present study of 475 patients, 108 patients (22.8% had S. aureus. About frequency of antibiotic resistance among collected S. aureus colonies, erythromycin resistance, was the most frequent antibiotic resistance, also resistance to vancomycin was 0.4% that was the least. Only hospitalization duration had statistically significant correlation with antibiotic resistance, also resistance to erythromycin had statistically significant relation with history of surgery and alcohol consumption. Of all 34 MRSA species, 22 (64.7% samples were resistant to erythromycin, 17 (50.0% resistant to cefoxitin, 5 (14.7% resistant to mupirocin, 1 (2.9% resistant to vancomycin and 1 (2.9% resistant to linezolid. Conclusion: The results of the current study show that among hospitalized patients, there is resistance against methicillin. Since based on results of the study there is resistance against oxacillin and erythromycin in most cases, administering appropriate antibiotics have an important role in minimizing the resistance burden among bacterial species.

  8. Resistencia antimicrobiana de cepas de Staphylococcus aureus, Costa Rica Antimicrobial resistance of Staphylococcus aureus, Costa Rica

    Directory of Open Access Journals (Sweden)

    Víctor Hugo Alvarado

    2011-12-01

    Full Text Available Objetivo: Determinar y comparar los perfiles de resistencia de cepas de S. aureus aisladas de quesos, producidos en la Zona Sur de Costa Rica y de un centro hospitalario de la misma región. Materiales y Métodos: Se analizaron 35 muestras de queso fresco, adquiridas durante los meses de setiembre y octubre del 2010 en la zona de San Vito de Coto Brus. A cada muestra se le realizaron recuentos de coliformes totales, coliformes fecales y Staphylococcus aureus. Adicionalmente se analizó presencia/ausencia de Listeria monocytogenes en 25 gramos del producto. A las cepas identificadas como S. aureus se les realizó la prueba de sensibilidad a los antibióticos mediante el sistema automatizado Vitek y la interpretación de los datos se realizó siguiendo las pautas del Clinical and Laboratory Standards Institute antimicrobial susceptibility testing 2011. Adicional a esto se recolectaron datos acerca de la sensibilidad de las cepas de S. aureus aisladas e identificadas en el Hospital de San Vito de Coto Brus en el mismo período. Resultados: El promedio obtenido para el recuento de coliformes totales fue de 9,7 X 10(6 UFC/g, para coliformes fecales de 6,7 X 10(5 y para S. aureus de 2,8 X 10(5 UFC/g, obteniéndose un 83 % de muestras positivas por esta bacteria. En cuanto a la resistencia antimicrobiana, se obtuvieron porcentajes de resistencia mayores en las cepas de origen clínico. Se encontró también que 23 de las cepas (96% provenientes de muestras clínicas, presentaban resistencia a más de un antibiótico, mientras que siete de las obtenidas a partir de queso (27% presentaban esta característica. Con respecto a los betalactamicos (ampicilina, oxacilina y penicilina se observó la existencia de una diferencia estadísticamente significativa (pObjective: determined and compared the resistance patters of S. aureus strains isolated from cheese produced in the southern zone of Costa Rica and from clinical samples isolated at the hospital center

  9. Methicillin-resistant Staphylococcus aureus laryngitis.

    Science.gov (United States)

    Liakos, Tracey; Kaye, Keith; Rubin, Adam D

    2010-09-01

    Infections due to methicillin-resistant Staphylococcus aureus (MRSA) have become more prevalent, in part because of the emergence and spread of community-acquired MRSA. This trend is particularly concerning because of the significant rates of morbidity and mortality associated with MRSA infections, and because MRSA strains are often resistant to many classes of antibiotics. Reports of infections of the head and neck, including wound infections, cellulitis, sinusitis, otitis media, and otitis externa, are well documented. However, to our knowledge, there have been no reports of bacterial laryngitis due to MRSA. We report the first published case of bacterial laryngitis caused by MRSA.

  10. Staphylococcus aureus bacteriuria as a prognosticator for outcome of Staphylococcus aureus bacteremia: a case-control study

    Directory of Open Access Journals (Sweden)

    Weinstein Robert A

    2010-07-01

    Full Text Available Abstract Background When Staphylococcus aureus is isolated in urine, it is thought to usually represent hematogenous spread. Because such spread might have special clinical significance, we evaluated predictors and outcomes of S. aureus bacteriuria among patients with S. aureus bacteremia. Methods A case-control study was performed at John H. Stroger Jr. Hospital of Cook County among adult inpatients during January 2002-December 2006. Cases and controls had positive and negative urine cultures, respectively, for S. aureus, within 72 hours of positive blood culture for S. aureus. Controls were sampled randomly in a 1:4 ratio. Univariate and multivariable logistic regression analyses were done. Results Overall, 59% of patients were African-American, 12% died, 56% of infections had community-onset infections, and 58% were infected with methicillin-susceptible S. aureus (MSSA. Among 61 cases and 247 controls, predictors of S. aureus bacteriuria on multivariate analysis were urological surgery (OR = 3.4, p = 0.06 and genitourinary infection (OR = 9.2, p = 0.002. Among patients who died, there were significantly more patients with bacteriuria than among patients who survived (39% vs. 17%; p = 0.002. In multiple Cox regression analysis, death risks in bacteremic patients were bacteriuria (hazard ratio 2.9, CI 1.4-5.9, p = 0.004, bladder catheter use (2.0, 1.0-4.0, p = 0.06, and Charlson score (1.1, 1.1-1.3, p = 0.02. Neither length of stay nor methicillin-resistant Staphylococcus aureus (MRSA infection was a predictor of S. aureus bacteriuria or death. Conclusions Among patients with S. aureus bacteremia, those with S. aureus bacteriuria had 3-fold higher mortality than those without bacteriuria, even after adjustment for comorbidities. Bacteriuria may identify patients with more severe bacteremia, who are at risk of worse outcomes.

  11. Intracellular Staphylococcus aureus : live-in and let die

    NARCIS (Netherlands)

    Fraunholz, Martin; Sinha, Bhanu

    2012-01-01

    Staphylococcus aureus uses a plethora of virulence factors to accommodate a diversity of niches in its human host. Aside from the classical manifestations of S. aureus-induced diseases, the pathogen also invades and survives within mammalian host cells. The survival strategies of the pathogen are as

  12. Duplex Identification of Staphylococcus aureus by Aptamer and Gold Nanoparticles.

    Science.gov (United States)

    Chang, Tianjun; Wang, Libo; Zhao, Kexu; Ge, Yu; He, Meng; Li, Gang

    2016-06-01

    Staphylococcus aureus is the top common pathogen causing infections and food poisoning. Identification of S. aureus is crucial for the disease diagnosis and regulation of food hygiene. Herein, we report an aptamer-AuNPs based method for duplex identification of S. aureus. Using AuNPs as an indicator, SA23, an aptamer against S. aureus, can well identify its target from Escherichia coli, Listeria monocytogenes and Pseudomonas aeruginosa. Furthermore, we find citrate-coated AuNPs can strongly bind to S. aureus, but not bind to Salmonella enterica and Proteus mirabilis, which leads to different color changes in salt solution. This colorimetric response is capable of distinguishing S. aureus from S. enteritidis and P. mirabilis. Thus, using the aptasensor and AuNPs together, S. aureus can be accurately identified from the common pathogens. This duplex identification system is a promising platform for simple visual identification of S. aureus. Additionally, in the aptasensing process, bacteria are incubated with aptamers and then be removed before the aptamers adding to AuNPs, which may avoid the interactions between bacteria and AuNPs. This strategy can be potentially applied in principle to detect other cells by AuNPs-based aptasensors. PMID:27427591

  13. Staphylococcus aureus and the ecology of the nasal microbiome

    DEFF Research Database (Denmark)

    Liu, Cindy M; Price, Lance B; Hungate, Bruce A;

    2015-01-01

    The human microbiome can play a key role in host susceptibility to pathogens, including in the nasal cavity, a site favored by Staphylococcus aureus. However, what determines our resident nasal microbiota-the host or the environment-and can interactions among nasal bacteria determine S. aureus...

  14. Duplex Identification of Staphylococcus aureus by Aptamer and Gold Nanoparticles.

    Science.gov (United States)

    Chang, Tianjun; Wang, Libo; Zhao, Kexu; Ge, Yu; He, Meng; Li, Gang

    2016-06-01

    Staphylococcus aureus is the top common pathogen causing infections and food poisoning. Identification of S. aureus is crucial for the disease diagnosis and regulation of food hygiene. Herein, we report an aptamer-AuNPs based method for duplex identification of S. aureus. Using AuNPs as an indicator, SA23, an aptamer against S. aureus, can well identify its target from Escherichia coli, Listeria monocytogenes and Pseudomonas aeruginosa. Furthermore, we find citrate-coated AuNPs can strongly bind to S. aureus, but not bind to Salmonella enterica and Proteus mirabilis, which leads to different color changes in salt solution. This colorimetric response is capable of distinguishing S. aureus from S. enteritidis and P. mirabilis. Thus, using the aptasensor and AuNPs together, S. aureus can be accurately identified from the common pathogens. This duplex identification system is a promising platform for simple visual identification of S. aureus. Additionally, in the aptasensing process, bacteria are incubated with aptamers and then be removed before the aptamers adding to AuNPs, which may avoid the interactions between bacteria and AuNPs. This strategy can be potentially applied in principle to detect other cells by AuNPs-based aptasensors.

  15. Effect of Mupirocin on Nasal Carriage of Staphylococcus Aureus

    NARCIS (Netherlands)

    M. Bulanda; M. Gruszka; B. Heczko

    1989-01-01

    textabstractMupirocin eliminates nasal carriage of staphylococcal aureus among medical and surgical personnel for periode varying from several weeks upto one year. In persons recolonized after therapy densites of S. aureus population in nares were much lower than in the same persons before therapy.

  16. Susceptibility of methicillin-resistant Staphylococcus aureus to lysostaphin.

    OpenAIRE

    Huber, M M; Huber, T. W.

    1989-01-01

    One hundred and eleven isolates of methicillin-resistant Staphylococcus aureus recovered from patients at the Olin E. Teague Veterans Center from March 1983 to April 1987 were as susceptible to lysis by lysostaphin as methicillin-susceptible S. aureus controls were.

  17. Mechanism of resistance to some cephalosporins in Staphylococcus aureus.

    OpenAIRE

    Kono, M; Sasatsu, M; O'Hara, K; Shiomi, Y.; HAYASAKA, T.

    1983-01-01

    The mechanism of resistance to some cephalosporins in Staphylococcus aureus strains was investigated with high-pressure liquid chromatography and nuclear magnetic resonance spectrometry. Drug inactivation by penicillinase was found to be the main mechanism of resistance to cefazolin, cephaloridine, and cephalothin in S. aureus.

  18. Activity of and Resistance to Moxifloxacin in Staphylococcus aureus

    OpenAIRE

    Ince, Dilek; Zhang, Xiamei; Hooper, David C.

    2003-01-01

    Moxifloxacin has enhanced potency against Staphylococcus aureus, lower propensity to select for resistant mutants, and higher bactericidal activity against highly resistant strains than ciprofloxacin. Despite similar activity against purified S. aureus topoisomerase IV and DNA gyrase, it selects for topoisomerase IV mutants, making topoisomerase IV the preferred target in vivo.

  19. Changing Trends in Resistance Pattern of Methicillin Resistant Staphylococcus aureus

    OpenAIRE

    Kali, Arunava; Stephen, Selvaraj; Umadevi, Sivaraman; Kumar, Shailesh; Joseph, Noyal Mariya; Srirangaraj, Sreenivasan

    2013-01-01

    Background: Methicillin resistance in Staphylococcus aureus is associated with multidrug resistance, an aggressive course, increased mortality and morbidity in both community and health care facilities. Monitoring of newly emerging and prevalent Methicillin Resistant Staphylococcus aureus (MRSA) strains for their resistance patterns to conventional as well as novel drugs, are essential for infection control.

  20. Pneumonia and new methicillin-resistant Staphylococcus aureus clone.

    NARCIS (Netherlands)

    Garnier, Fabien; Tristan, Anne; François, Bruno; Etienne, Jerome; Delage-Corre, Manuella; Martin, Christian; Liassine, Nadia; Wannet, Wim; Denis, François; Ploy, Marie-Cécile

    2006-01-01

    Necrotizing pneumonia caused by Staphylococcus aureus strains carrying the Panton-Valentin leukocidin gene is a newly described disease entity. We report a new fatal case of necrotizing pneumonia. An S. aureus strain with an agr1 allele and of a new sequence type 377 was recovered, representing a ne

  1. Reporting of meticillin-resistant and -susceptible Staphylococcus aureus on death certificates in Irish hospitals.

    LENUS (Irish Health Repository)

    Collins, C J

    2011-02-01

    The documentation of infection with meticillin-resistant Staphylococcus aureus (MRSA) on death certificates has been the subject of considerable public discussion. Using data from five tertiary referral hospitals in Ireland, we compared the documentation of MRSA and meticillin-susceptible S. aureus (MSSA) on death certificates in those patients who died in hospital within 30 days of having MRSA or MSSA isolated from blood cultures. A total of 133 patients had MRSA or MSSA isolated from blood cultures within 30 days of death during the study period. One patient was excluded as the death certificate information was not available; the other 132 patients were eligible for inclusion. MRSA and MSSA were isolated from blood cultures in 59 (44.4%) and 74 (55.6%) cases respectively. One patient was included as a case in both categories as both MRSA and MSSA were isolated from a blood culture. In 15 (25.4%) of the 59 MRSA cases, MRSA was documented on the death certificate. In nine (12.2%) of the 74 patients with MSSA cases, MSSA was documented on the death certificate. MRSA was more likely to be documented on the death certificate than MSSA (odds ratio: 2.46; 95% confidence interval: 1.01-6.01; P < 0.05). These findings indicate that there may be inconsistencies in the way organisms and infections are documented on death certificates in Ireland and that death certification data may underestimate the mortality related to certain organisms. In particular, there appears to be an overemphasis by certifiers on the documentation of MRSA compared with MSSA.

  2. A porcine model of haematogenous brain infectionwith staphylococcus aureus

    DEFF Research Database (Denmark)

    Astrup, Lærke Boye; Agerholm, Jørgen Steen; Nielsen, Ole Lerberg;

    2012-01-01

    A PORCINE MODEL OF HAEMATOGENOUS BRAIN INFECTION WITH STAPHYLOCOCCUS AUREUS Astrup Lærke1, Agerholm Jørgen1, Nielsen Ole1, Jensen Henrik1, Leifsson Páll1, Iburg Tine2. 1: Faculty of Health and Medical Sciences, University of Copenhagen, Denmark boye@life.ku.dk 2: National Veterinary Institute......, Uppsala, Sweden Introduction Staphylococcus aureus (S.aureus) is a common cause of sepsis and brain abscesses in man and a frequent cause of porcine pyaemia. Here we present a porcine model of haematogenous S. aureus-induced brain infection. Materials and Methods Four pigs had two intravenous catheters...... inserted surgically, one in a. carotis communis and one in v. jugularis externa. All pigs received 106 CFU/kg body weight S. aureus through the arterial catheter. Bacteria were either suspended in isotonic saline infused at constant flow for 60 minutes (two pigs) or given as a bolus injection of autologoue...

  3. Characterization of methicillin-resistant Staphylococcus aureus Sequence Type 398

    DEFF Research Database (Denmark)

    Christiansen, Mette Theilgaard

    Staphylococcus aureus is an opportunistic pathogen that colonizes the nares and skin surfaces of several animal species, including man. S. aureus can cause a wide variety of infections ranging from superficial soft tissue and skin infections to severe and deadly systemic infections. Traditionally S....... aureus and methicillin-resistant Staphylococcus aureus (MRSA) have been associated with hospitals, but during the past decades MRSA has emerged in the community and now a new branch of MRSA has been found in association with livestock (LA-MRSA). A specific lineage (multilocus sequence type 398 (ST398...... for LA-MRSA ST398 survival on porcine skin and nasal epithelium ex vivo were identified. These genes could represent targets for de-colonization, which could help prevent further spread and adaption of LA-MRSA ST398. Manuscript III describes the construction of the S. aureus VirulenceFinder database...

  4. Antimicrobial drug resistance ofStaphylococcus aureus in dairy products

    Institute of Scientific and Technical Information of China (English)

    Sasidharan S; Prema B; Yoga Latha L

    2011-01-01

    Objective:To evaluate the prevalence of multidrug resistantStaphylococcus aureus(S. aureus) in dairy products.Methods:Isolation and identification ofS. aureus were performed in3 dairy-based food products. The isolates were tested for their susceptibility to5 different common antimicrobial drugs.Results:Of50 samples examined,5 (10%) were contaminated with S. aureus. Subsequently, the5 isolates were subjected to antimicrobial resistance pattern using five antibiotic discs (methicillin, vancomycin, kanamycin, chloramphenicol and tetracycline). Sample 29 showed resistance to methicillin and vancomycin. Sample18 showed intermediate response to tetracycline. The other samples were susceptible to all the antibiotics tested.Conclusions:The results provide preliminary data on sources of food contamination which may act as vehicles for the transmission of antimicrobial-resistantStaphylococcus.Therefore, it enables us to develop preventive strategies to avoid the emergence of new strains of resistantS. aureus.

  5. Mineral resources of the Tertiary deposits of Spain

    OpenAIRE

    García del Cura, M. Ángeles; Cristino J. Dabrio; Ordóñez Delgado, Salvador

    1996-01-01

    Spain is the most self-sufficient country for minerals in the EsU. A major proportion of these Spanish mineral resources has been oblained from Tertiary material-. The main material exploited in Tertiary basins have been: brown coal and lignites, potassium salts, sodium salts (sulphates and chlorides), diátomite, sepiolite and other absorbent days, bentonites, celestine. pumíce and also dimension (building) stones and ceramícs, portland cement and plaster raw materials. Pb-...

  6. Challenges with Tertiary-Level Mechatronic Fluid Power

    DEFF Research Database (Denmark)

    Dransfield, Peter; Conrad, Finn

    1996-01-01

    As authors we take the view that mechatronics, as it relates to fluid power, has three levels which we designate as primary, secondary and tertiary. A brief review of the current status of fluid power, hydraulic and pneumatic, and of electronic control of it is presented and discussed. The focus...... is then on tertiary-level mechatronic fluid power and the challenges to it being applied successfully....

  7. Some Issues in the Economics of Tertiary Education

    OpenAIRE

    Dante B. Canlas

    1987-01-01

    The failure of the tertiary education to respond to the manpower needs of a technologically changing environment has been the concern of most social scientists. The inabilities to deliver higher education to a wider base and the deterioration of academic standards have been plaguing the education sector. This article attempts to present some of the issues related to the government’s role in higher education, rates of return from human capital investments, loan markets for tertiary education, ...

  8. Eclampsia: maternal and perinatal outcomes in a tertiary care centre

    OpenAIRE

    Sunita Mor; Daya Sirohiwal; Reetu Hooda

    2015-01-01

    Background: Eclampsia is a life threatening emergency that continues to be a major cause of maternal and perinatal mortality. The purpose of our study was to analyse the trend of eclampsia in a tertiary care teaching institute and to find out maternal and perinatal outcomes of eclampsia. Methods: A prospective study was undertaken in a tertiary care teaching institute over a period of one year. Patients of eclampsia were followed up with regard to the management and maternal and fetal morb...

  9. Mining Tertiary Structural Motifs for Assessment of Designability

    OpenAIRE

    Zhang, Jian; Grigoryan, Gevorg

    2013-01-01

    The observation of a limited secondary-structural alphabet in native proteins, with significant sequence preferences, has profoundly influenced the fields of protein design and structure prediction (Simons et al., 1997; Verschueren et al., 2011). In the era of structural genomics, as the size of the structural dataset continues to grow rapidly, it is becoming possible to extend this analysis to tertiary structural motifs and their sequences. For a hypothetical tertiary motif, the rate of its ...

  10. Reviews of National Policies for Education : Tertiary Education in Chile

    OpenAIRE

    Mogollón, Maria Paulina; Crawford, Michael

    2009-01-01

    Tertiary education in Chile has been transformed radically over the past 20 years. As recently as 1990, tertiary education was an elite system centered on a handful of traditional universities which served a small number of well-prepared students. Today the system is diverse and dynamic, with over 6,000 programs of study offered by more than 200 institutions. More than 800,000 students are...

  11. Where does a Staphylococcus aureus vaccine stand?

    Science.gov (United States)

    Fowler, V G; Proctor, R A

    2014-05-01

    In this review, we examine the current status of Staphylococcus aureus vaccine development and the prospects for future vaccines. Examination of the clinical trials to date show that murine models have not predicted success in humans for active or passive immunization. A key factor in the failure to develop a vaccine to prevent S. aureus infections comes from our relatively limited knowledge of human protective immunity. More recent reports on the elements of the human immune response to staphylococci are analysed. In addition, there is some controversy concerning the role of antibodies for protecting humans, and these data are reviewed. From a review of the current state of understanding of staphylococcal immunity, a working model is proposed. Some new work has provided some initial candidate biomarker(s) to predict outcomes of invasive infections and to predict the efficacy of antibiotic therapy in humans. We conclude by looking to the future through the perspective of lessons gleaned from the clinical vaccine trials. PMID:24476315

  12. Tertiary tectonic in the Tehuantepec Isthmus, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, F.A.

    1993-02-01

    A microplate model in the basement was proposed according to photointerpretation of satellite imagery and supported with microtectonic studies in the Tehuantepec's Isthmus. The microplate is located in the northwestern part of the [open quotes]Sierra de Chiapas,[close quotes] and structurally has lineaments that correspond with sinestral wrench faults oriented northeast-southwest and dextral faults oriented northwest-southeast. In the front of the microplate, these faults are joined in an arc form. The microplate began its movement forward to the north in the middle Tertiary. This movement originated in a regional compressional stress that was younger to the north. The stress changed the orientation of the anticline axis from northwest-southeast to west-east. In its western limit, the stress produces a sinestral shear stress that built a rotational deformation in the [open quotes]Sierra Atravesada,[close quotes] and represents a superimposed tectonic block over an ancient (laramide) orogeny. This system has also produced other secondary transtensional effects oriented northwest-southeast, represented along the [open quotes]Depression Central del Istmo.[close quotes] The microplate has formed a tensional system opening the [open quotes]Superior, Inferior, and Mar Muerto[close quotes] lagoons. The microplate is strongly related with the relief, seismic activity, and the tectonics of the salt of the Tehuantepec's Isthmus.

  13. Diabetic nephropathy: Prescription trends in tertiary care

    Directory of Open Access Journals (Sweden)

    Devi D

    2008-01-01

    Full Text Available Diabetic nephropathy is a leading cause of end stage renal disease. Drug utilization studies could promote rational drug use. The objective of this study was to evaluate prescribing trends in hospitalized patients with diabetic nephropathy. A prospective, observational study was conducted in a tertiary care hospital. The demographic, disease and treatment data of patients with diabetic nephropathy were collected for a period of six months and analysed. Drugs were classified using World Health Organization recommended Anatomic Therapeutic Chemical classification. A total of 755 drugs (7.4 drugs per prescription were prescribed to 102 study patients, who were all hypertensive and in late stages of diabetic nephropathy. Drug classes with largest representation were those acting on gastrointestinal tract plus metabolism (37% and cardiovascular drugs (28%. Calcium channel blockers represented the largest antihypertensive drug class (41%. Almost three-fourths of patients received more than one antihypertensive agent. Approximately 37% of patients did not receive any antidiabetic medication. Of those who did, prescriptions for insulin (91% exceeded those of oral hypoglycaemic drugs (9%. Antimicrobials accounted for 10.2% of all drugs prescribed, of which 31.8% were quinolones. Drugs prescribed by generic name accounted for 11.98%. While all patients received antihypertensive therapy, more than a third were not on any antidiabetic treatment. Antihypertensive poly-therapy was observed in the majority with calcium channel blockers being most frequently prescribed antihypertensive drug class. Insulin was the preferred to hypoglycaemic drugs.

  14. ELT at Tertiary Level-- An Undergraduate Perspective

    Institute of Scientific and Technical Information of China (English)

    杨慧琴

    2002-01-01

    With the advocacy of communicative approaches in ELT coming from the English world, teachers of English in China find that their traditional Chinese teaching methods are being challenged. Educators and scholars express different opinions concerning the strength and weaknesses of traditional teaching methodology, but by and large, the overwhelming consensus is in favor of reform. The new syllabus promulgated by the State Educational Commission attaches more importance to the cultivation of students' communicative competence; journals and newspapers carry articles to urge the change; new textbooks with emphasis laid on communicative skills have been published and put to use in many institutions of higher learning; the commercial and business world is joining the chorus. Despite this, many teachers of English still use the traditional teaching methods with the new textbooks. As a teacher of English, I understand that, as well as an intrinsic reluctance to initiate change, they also have uncertainty about students' acceptance of and enthusiam for the new teaching approaches, and they have doubts about the benefits such approaches are supposed to bring to the learners. This article probes into the question of whether the existing ELT program and its overall lingustic input at tertiary level is really appropriate to the students' needs by examining the question from a different angle-the perspective of the undergraduates themselves.

  15. Efektivitas Ekstrak Daun Jambu Biji Buah Putih Terhadap Pertumbuhan Staphylococcus aureus Dari Abses Dan Staphylococcus aureus (ATCC® 29213™)

    OpenAIRE

    Sinurat, Jojor

    2016-01-01

    Daun jambu biji mengandung senyawa aktif seperti tanin, triterpenoid, flavonoid, saponin yang mempunyai efek antibakteri. Mekanisme tanin sebagai antibakteri dengan mengkerutkan dinding sel dan membran sel, inaktivasi enzim, inaktivasi fungsi materi genetik bakteri. Flavonoid merusak sel bakteri, denaturasi protein, inaktivasi enzim dan menyebabkan lisis. Triterpenoid dan saponin menghambat pertumbuhan Staphylococcus aureus dengan cara merusak struktur membran sel. Staphylococcus aureus adala...

  16. Identification and characterization of peptidoglycan hydrolase constructs with activity in cow milk as potential antimicrobials for treatment of staphylococcal bovine mastitis

    Science.gov (United States)

    Mastitis in dairy cows is a widespread infection of the mammary glands that leads to high losses in dairy production. Most members of the Gram-positive genus Staphylococcus can cause mastitis, with Staphylococcus S. aureus being one of the major pathogens. Intramammary application of antibiotics i...

  17. Petrifilm rapid S. aureus Count Plate method for rapid enumeration of Staphylococcus aureus in selected foods: collaborative study.

    Science.gov (United States)

    Silbernagel, K M; Lindberg, K G

    2001-01-01

    A rehydratable dry-film plating method for Staphylococcus aureus in foods, the 3M Petrifilm Rapid S. aureus Count Plate method, was compared with AOAC Official Method 975.55 (Staphylococcus aureus in Foods). Nine foods-instant nonfat dried milk, dry seasoned vegetable coating, frozen hash browns, frozen cooked chicken patty, frozen ground raw pork, shredded cheddar cheese, fresh green beans, pasta filled with beef and cheese, and egg custard-were analyzed for S. aureus by 13 collaborating laboratories. For each food tested, the collaborators received 8 blind test samples consisting of a control sample and 3 levels of inoculated test sample, each in duplicate. The mean log counts for the methods were comparable for pasta filled with beef and cheese; frozen hash browns; cooked chicken patty; egg custard; frozen ground raw pork; and instant nonfat dried milk. The repeatability and reproducibility variances of the Petrifilm Rapid S. aureus Count Plate method were similar to those of the standard method.

  18. The extended conformation of the 2.9-Å crystal structure of the three-PASTA domain of a Ser/Thr kinase from the human pathogen Staphylococcus aureus.

    Science.gov (United States)

    Paracuellos, Patricia; Ballandras, Allison; Robert, Xavier; Kahn, Richard; Hervé, Mireille; Mengin-Lecreulx, Dominique; Cozzone, Alain J; Duclos, Bertrand; Gouet, Patrice

    2010-12-17

    PASTA (penicillin-binding protein and serine/threonine kinase associated) modules are found in penicillin-binding proteins and bacterial serine/threonine kinases mainly from Gram-positive Firmicutes and Actinobacteria. They may act as extracellular sensors by binding peptidoglycan fragments. We report here the first crystal structure of a multiple-PASTA domain from Ser/Thr kinase, that of the protein serine/threonine kinase 1 (Stk1) from the Firmicute Staphylococcus aureus. The extended conformation of the three PASTA subunits differs strongly from the compact conformation observed in the two-PASTA domain of penicillin-binding protein PBP2x, whereas linear conformations were also reported for two-subunit fragments of the four-PASTA domain of the Actinobacteria Mycobacterium tuberculosis studied by liquid NMR. Thus, a stretched organization appears to be the signature of modular PASTA domains in Ser/Thr kinases. Signal transduction to the kinase domain is supposed to occur via dimerization and ligand binding. A conserved X-shaped crystallographic dimer stabilized by intermolecular interactions between the second PASTA subunits of each monomer is observed in the two crystal forms of Stk1 that we managed to crystallize. Extracellular PASTA domains are composed of at least two subunits, and this molecular assembly is a plausible candidate for the biological dimer. We have also performed docking experiments, which predict that the hinge regions of the PASTA domain can accommodate peptidoglycan. Finally, a three-dimensional homology molecular model of full-length Stk1 was generated, suggesting an interaction between the kinase domain and the cytoplasmic face of the plasma membrane via a eukaryotic-like juxtamembrane domain. A comprehensive activation mechanism for bacterial Ser/Thr kinases is proposed with the support of these structural data.

  19. A study of the effects of different disinfectants used in Riyadh hospitals and their efficacy against Methicillin Resistant Staphylococcus Aureus (MRSA)

    International Nuclear Information System (INIS)

    Methicillin resistant Staphylococcus aureus (MRSA) and the means of controlling it, continue to be of major interest to the healthcare community. The bactericidal activity of some disinfectants which are in common use in seven major tertiary care hospitals in Riyadh was tested against two control strains of S.aureus, namely MRSA ATCC 33591 and Methicillin sensitive Staphylococcus aureus (MSSA) ATCC 29213. The disinfectants tested in this study were a group used for hand antisepsis (Purell, EZ-clean, Cida stat and Manorapid Synergy) and another group used for environmental disinfection (Combi spray, Tristel fusion, Alphadine, Isopropanol, Presept and Diesin). Presept, diesin and tristel fusion had a remarkable effect on the tested strains, both methicillin sensitive and methicillin resistant. There was hardly any noticeable difference between the effects on either (P>0.05). On the other hand, Purell and EZ-clean and Manorapid Synergy hand rubs had a relatively weak action after 15 and 30 minutes while their effect was better after 1 and 2 hours. There was no observable differences between their effects on MRSA or MSSA, P>0.05. Cita stat had a remarkably pronounced effect against both MRSA and MSSA. Contrary to some previous reports, this study has proven also that chlorhexidine and quaternary ammonium compounds show comparable efficacy against both MRSA and MSSA. (author)

  20. The molecular changing mechanism of Ampicillin-Sulbactam resistant Staphylococcus aureus towards Methicillin resistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Mieke Hemiawati Satari

    2005-12-01

    Full Text Available The aim of this study was to determine the molecular changing of S.aureus, which is resistant to Ampicillin-Sulbactam and then become resistant to Methicillin as a result of improper dosage. The study was conducted by isolating Ampicillin-Sulbactam resistant and Methicillin Resistant S.aureus (MRSA, afterwards an amplification process was performed by PCR (Polymerase Chain Reaction. to isolate the betalactamase enzyme regulator and PBP 2a genes. The result of this research showed that there were a deletion of few amino acids from the regulator gene, and a suspicion that the DNA sequence had been substituted from PBP 2 gene into PBP 2a (gen mec. This process had formed MRSA.

  1. Indole and 7-benzyloxyindole attenuate the virulence of Staphylococcus aureus.

    Science.gov (United States)

    Lee, Jin-Hyung; Cho, Hyun Seob; Kim, Younghoon; Kim, Jung-Ae; Banskota, Suhrid; Cho, Moo Hwan; Lee, Jintae

    2013-05-01

    Human pathogens can readily develop drug resistance due to the long-term use of antibiotics that mostly inhibit bacterial growth. Unlike antibiotics, antivirulence compounds diminish bacterial virulence without affecting cell viability and thus, may not lead to drug resistance. Staphylococcus aureus is a major agent of nosocomial infections and produces diverse virulence factors, such as the yellow carotenoid staphyloxanthin, which promotes resistance to reactive oxygen species (ROS) and the host immune system. To identify novel antivirulence compounds, bacterial signal indole present in animal gut and diverse indole derivatives were investigated with respect to reducing staphyloxanthin production and the hemolytic activity of S. aureus. Treatment with indole or its derivative 7-benzyloxyindole (7BOI) caused S. aureus to become colorless and inhibited its hemolytic ability without affecting bacterial growth. As a result, S. aureus was more easily killed by hydrogen peroxide (H₂O₂) and by human whole blood in the presence of indole or 7BOI. In addition, 7BOI attenuated S. aureus virulence in an in vivo model of nematode Caenorhabditis elegans, which is readily infected and killed by S. aureus. Transcriptional analyses showed that both indole and 7BOI repressed the expressions of several virulence genes such as α-hemolysin gene hla, enterotoxin seb, and the protease genes splA and sspA and modulated the expressions of the important regulatory genes agrA and sarA. These findings show that indole derivatives are potential candidates for use in antivirulence strategies against persistent S. aureus infection. PMID:23318836

  2. The changing epidemiology of Staphylococcus aureus bloodstream infection

    DEFF Research Database (Denmark)

    Galbraith, J.C.; Valiquette, G.; Kennedy, K.J.;

    2013-01-01

    Clin Microbiol Infect ABSTRACT: Although the epidemiology of Staphylococcus aureus bloodstream infection (BSI) has been changing, international comparisons are lacking. We sought to determine the incidence of S. aureus BSI and assess trends over time and by region. Population-based surveillance...... episodes of S. aureus BSI were identified. The overall annual incidence rate for S. aureus BSI was 26.1 per 100 000 population, and those for methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) were 24.2 and 1.9 per 100 000, respectively. Although the overall incidence...... of community-onset MSSA BSI (15.0 per 100 000) was relatively similar across regions, the incidence rates of hospital-onset MSSA (9.2 per 100 000), community-onset MRSA (1.0 per 100 000) and hospital-onset MRSA (0.8 per 100 000) BSI varied substantially. Whereas the overall incidence of S. aureus BSI did...

  3. Identification of the ClpX Regulon in Staphylococcus aureus

    DEFF Research Database (Denmark)

    Jelsbak, Lotte; Thomsen, Line Elnif; Ingmer, Hanne;

    Staphyloccous aureus is a major human pathogen capable of causing a wide spectrum of infections ranging from superficial wound infections to life-threatening endocarditis and toxic shock syndrome. Essential for S. aureus virulence is a large number of cell-surface-associated proteins and secreted...... we show here that almost 400 genes (15%) are influenced by the clpX deletion. Furthermore, ClpX not only regulates many virulence factors, but rather serves as a global regulator of central functions for S. aureus lifestyle and pathogenicity....

  4. The Effect of Essential Oils on Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Seda Ozdikmenli

    2014-05-01

    Full Text Available Diseases caused by Staphylococcus aureus are widespread through the world in spite of developing technology. S. aureus is an important pathogen causing food intoxications besides hospital infections by its antibiotic resistant strains. Nowadays, there has been worldwide increasing concern on usage of natural products to control microorganisms. One of these natural products is essential oils. They are produced from plants especially from spices and composed of many components and volatiles. This review summarizes informative literature on essential oils and their mode of antimicrobial action. In addition, current knowledge on in vitro researches on antibacterial activity of essential oils and food applications to control S. aureus has been discussed.

  5. An outbreak of methicillin-resistant Staphylococcus aureus (MRSA infection in dermatology indoor patients

    Directory of Open Access Journals (Sweden)

    Sachdev D

    2003-11-01

    Full Text Available Background: Methicillin-resistant Staphylococcus aureus (MRSA is a major nosocomial pathogen. Indiscriminate and increased use of systemic antibiotics has led to the emergence of MRSA. Infected or colonized ward patients are the main reservoir of infection. Once colonized, the risk of subsequent local and systemic infections is high, especially in the elderly, and in debilitated and immunosuppressed patients. Methods: We report an outbreak of MRSA in the dermatology ward of a tertiary care hospital and describe measures taken to control it. Results: Ten patients were found to be MRSA positive over a span of three months while screening swabs from wet lesions in indoor patients. On the basis of risk assessment, they were treated with appropriate systemic and topical therapy. One patient died while the remaining nine patients showed a good response to therapy. All the MRSA isolates were found to be sensitive to vancomycin, teicoplanin and linezolid. Conclusion: This is the first case report of MRSA infection in dermatology indoor patients in India.

  6. Staphylococcus aureus 'Down Under': contemporary epidemiology of S. aureus in Australia, New Zealand, and the South West Pacific.

    Science.gov (United States)

    Williamson, D A; Coombs, G W; Nimmo, G R

    2014-07-01

    The clinical and molecular epidemiology of Staphylococcus aureus disease has changed considerably over the past two decades, particularly with the emergence and spread of community-associated methicillin-resistant S. aureus (CA-MRSA) clones. Indeed, some of the first global descriptions of CA-MRSA were from remote indigenous communities in Western Australia, and from Pacific Peoples in New Zealand. The epidemiology of S. aureus infections in the South West Pacific has several unique features, largely because of the relative geographical isolation and unique indigenous communities residing in this region. In particular, a number of distinct CA-MRSA clones circulate in Australia and New Zealand, such as sequence type (ST) 93 methicillin-resistant S. aureus (MRSA) (Queensland clone) and clonal complex 75 S. aureus (Staphylococcus argenteus) in Australia, and ST30 MRSA (Southwest Pacific clone) in New Zealand. In addition, there is a disproportionate burden of S. aureus disease in indigenous paediatric populations, particularly in remote Aboriginal communities in Australia, and in Pacific Peoples and Maori in New Zealand. In this review, we provide a contemporary overview of the clinical and molecular epidemiology of S. aureus disease in the South West Pacific region, with a particular focus on features distinct to this region.

  7. Staphylococcus aureus intestinal colonization is associated with increased frequency of S. aureus on skin of hospitalized patients

    Directory of Open Access Journals (Sweden)

    Donskey Curtis J

    2007-09-01

    Full Text Available Abstract Background Intestinal colonization by Staphylococcus aureus among hospitalized patients has been associated with increased risk of staphylococcal infection and could potentially contribute to transmission. We hypothesized that S. aureus intestinal colonization is associated with increased frequency of S. aureus on patients' skin and nearby environmental surfaces. Methods Selected inpatients were cultured weekly for S. aureus from stool, nares, skin (groin and axilla, and environmental surfaces (bed rail and bedside table. Investigator's hands were cultured after contacting the patients' skin and the environmental surfaces. Results Of 71 subjects, 32 (45.1% had negative nares and stool cultures, 23 (32.4% had positive nares and stool cultures, 13 (18.3% were nares carriers only, and 3 (4.2% were stool carriers only. Of the 39 patients with S. aureus carriage, 30 (76.9% had methicillin-resistant isolates. In comparison to nares colonization only, nares and intestinal colonization was associated with increased frequency of positive skin cultures (41% versus 77%; p = 0.001 and trends toward increased environmental contamination (45% versus 62%; p = 0.188 and acquisition on investigator's hands (36% versus 60%; p = 0.057. Patients with negative nares and stool cultures had low frequency of S. aureus on skin and the environment (4.8% and 11.3%, respectively. Conclusion We found that hospitalized patients with S. aureus nares and/or stool carriage frequently had S. aureus on their skin and on nearby environmental surfaces. S. aureus intestinal colonization was associated with increased frequency of positive skin cultures, which could potentially facilitate staphylococcal infections and nosocomial transmission.

  8. Research Progress on Peptidoglycan Recognition Proteins of Medical Shells and Molluscs%医学贝类及相关软体动物肽聚糖模式识别蛋白的研究进展

    Institute of Scientific and Technical Information of China (English)

    张宗禄; 郭云海; 罗泰昌; 张仪

    2012-01-01

    Peptidoglycan recognition proteins (PGRPs) are highly conserved pattern recognition receptors in evolution, and they can recognize peptidoglycan (PGN) and bacteria that contain PGN in their cell wall component in early immune process of host, then provide signal transduction and activate a series of immune proteins. PGRPs are extensively present in insects, molluscs, echinoderms and vertebrates. Research progress and frontiers on PGRPs gene, type, structure, express localization, function, and evolution in medical molluscs and other snails were briefly reviewed in this article.%肽聚糖模式识别蛋白(Peptidoglycan recognition proteins,PGRPs)是一类高度保守的模式识别受体,参与宿主早期对病原微生物的识别作用,可识别肽聚糖和含有肽聚糖的细菌,进而激发和调节下游系列宿主免疫反应.PGRPs广泛存在于昆虫、软体动物、棘皮动物和脊椎动物中.本文对医学贝类和相关软体动物PGRPs的基因、类型、结构、表达分布、功能和进化进行综述.

  9. The O-Antigen Flippase Wzk Can Substitute for MurJ in Peptidoglycan Synthesis in Helicobacter pylori and Escherichia coli

    Science.gov (United States)

    Elhenawy, Wael; Davis, Rebecca M.; Fero, Jutta; Salama, Nina R.; Felman, Mario F.

    2016-01-01

    The peptidoglycan (PG) cell wall is an essential component of the cell envelope of most bacteria. Biogenesis of PG involves a lipid-linked disaccharide-pentapeptide intermediate called lipid II, which must be translocated across the cytoplasmic membrane after it is synthesized in the inner leaflet of this bilayer. Accordingly, it has been demonstrated that MurJ, the proposed lipid II flippase in Escherichia coli, is required for PG biogenesis, and thereby viability. In contrast, MurJ is not essential in Bacillus subtilis because this bacterium produces AmJ, an unrelated protein that is functionally redundant with MurJ. In this study, we investigated why MurJ is not essential in the prominent gastric pathogen, Helicobacter pylori. We found that in this bacterium, Wzk, the ABC (ATP-binding cassette) transporter that flips the lipid-linked O- or Lewis- antigen precursors across the inner membrane, is redundant with MurJ for cell viability. Heterologous expression of wzk in E. coli also suppresses the lethality caused by the loss of murJ. Furthermore, we show that this cross-species complementation is abolished when Wzk is inactivated by mutations that target a domain predicted to be required for ATPase activity. Our results suggest that Wzk can flip lipid II, implying that Wzk is the flippase with the most relaxed specificity for lipid-linked saccharides ever identified. PMID:27537185

  10. Nuclear magnetic resonance solution structure of the peptidoglycan-binding SPOR domain from Escherichia coli DamX: insights into septal localization.

    Science.gov (United States)

    Williams, Kyle B; Yahashiri, Atsushi; Arends, S J Ryan; Popham, David L; Fowler, C Andrew; Weiss, David S

    2013-01-29

    SPOR domains are present in thousands of bacterial proteins and probably bind septal peptidoglycan (PG), but the details of the SPOR-PG interaction have yet to be elucidated. Here we characterize the structure and function of the SPOR domain for an Escherichia coli division protein named DamX. Nuclear magnetic resonance revealed the domain comprises a four-stranded antiparallel β-sheet buttressed on one side by two α-helices. A third helix, designated α3, associates with the other face of the β-sheet, but this helix is relatively mobile. Site-directed mutagenesis revealed the face of the β-sheet that interacts with α3 is important for septal localization and binding to PG sacculi. The position and mobility of α3 suggest it might regulate PG binding, but although α3 deletion mutants still localized to the septal ring, they were too unstable to use in a PG binding assay. Finally, to assess the importance of the SPOR domain in DamX function, we constructed and characterized E. coli mutants that produced DamX proteins with SPOR domain point mutations or SPOR domain deletions. These studies revealed the SPOR domain is important for multiple activities associated with DamX: targeting the protein to the division site, conferring full resistance to the bile salt deoxycholate, improving the efficiency of cell division when DamX is produced at normal levels, and inhibiting cell division when DamX is overproduced.

  11. Schisandra chinensis peptidoglycan-assisted transmembrane transport of lignans uniquely altered the pharmacokinetic and pharmacodynamic mechanisms in human HepG2 cell model.

    Directory of Open Access Journals (Sweden)

    Charng-Cherng Chyau

    Full Text Available Schisandra chinensis (Turz Baill (S. chinensis (SC fruit is a hepatoprotective herb containing many lignans and a large amount of polysaccharides. A novel polysaccharide (called SC-2 was isolated from SC of MW 841 kDa, which exhibited a protein-to-polysaccharide ratio of 0.4089, and showed a characteristic FTIR spectrum of a peptidoglycan. Powder X-ray diffraction revealed microcrystalline structures within SC-2. SC-2 contained 10 monosaccharides and 15 amino acids (essential amino acids of 78.12%w/w. In a HepG2 cell model, SC-2 was shown by MTT and TUNEL assay to be completely non-cytotoxic. A kinetic analysis and fluorescence-labeling technique revealed no intracellular disposition of SC-2. Combined treatment of lignans with SC-2 enhanced the intracellular transport of schisandrin B and deoxyschisandrin but decreased that of gomisin C, resulting in alteration of cell-killing bioactivity. The Second Law of Thermodynamics allows this type of unidirectional transport. Conclusively, SC-2 alters the transport and cell killing capability by a "Catcher-Pitcher Unidirectional Transport Mechanism".

  12. Prevalence rates of infection in intensive care units of a tertiary teaching hospital

    Directory of Open Access Journals (Sweden)

    Toufen Junior Carlos

    2003-01-01

    Full Text Available OBJECTIVE: To determine the prevalence rates of infections among intensive care unit patients, the predominant infecting organisms, and their resistance patterns. To identify the related factors for intensive care unit-acquired infection and mortality rates. DESIGN: A 1-day point-prevalence study. SETTING:A total of 19 intensive care units at the Hospital das Clínicas - University of São Paulo, School of Medicine (HC-FMUSP, a teaching and tertiary hospital, were eligible to participate in the study. PATIENTS: All patients over 16 years old occupying an intensive care unit bed over a 24-hour period. The 19 intensive care unit s provided 126 patient case reports. MAIN OUTCOME MEASURES: Rates of infection, antimicrobial use, microbiological isolates resistance patterns, potential related factors for intensive care unit-acquired infection, and death rates. RESULTS: A total of 126 patients were studied. Eighty-seven patients (69% received antimicrobials on the day of study, 72 (57% for treatment, and 15 (12% for prophylaxis. Community-acquired infection occurred in 15 patients (20.8%, non- intensive care unit nosocomial infection in 24 (33.3%, and intensive care unit-acquired infection in 22 patients (30.6%. Eleven patients (15.3% had no defined type. The most frequently reported infections were respiratory (58.5%. The most frequently isolated bacteria were Enterobacteriaceae (33.8%, Pseudomonas aeruginosa (26.4%, and Staphylococcus aureus (16.9%; [100% resistant to methicillin]. Multivariate regression analysis revealed 3 risk factors for intensive care unit-acquired infection: age > 60 years (p = 0.007, use of a nasogastric tube (p = 0.017, and postoperative status (p = 0.017. At the end of 4 weeks, overall mortality was 28.8%. Patients with infection had a mortality rate of 34.7%. There was no difference between mortality rates for infected and noninfected patients (p=0.088. CONCLUSION: The rate of nosocomial infection is high in intensive care

  13. Simple method for correct enumeration of Staphylococcus aureus

    DEFF Research Database (Denmark)

    Haaber, J.; Cohn, M. T.; Petersen, A.;

    2016-01-01

    culture. When grown in such liquid cultures, the human pathogen Staphylococcus aureus is characterized by its aggregation of single cells into clusters of variable size. Here, we show that aggregation during growth in the laboratory standard medium tryptic soy broth (TSB) is common among clinical...... and laboratory S. aureus isolates and that aggregation may introduce significant bias when applying standard enumeration methods on S. aureus growing in laboratory batch cultures. We provide a simple and efficient sonication procedure, which can be applied prior to optical density measurements to give...... an accurate estimate of cellular numbers in liquid cultures of S. aureus regardless of the aggregation level of the given strain. We further show that the sonication procedure is applicable for accurate determination of cell numbers using agar plate counting of aggregating strains....

  14. Improving Diagnosis and Treatment of Staphylococcus aureus Infections : Experimental Studies

    NARCIS (Netherlands)

    S. van den Berg (Sanne)

    2015-01-01

    markdownabstract__Abstract__ Staphylococcus aureus is an opportunistic pathogen that causes a variety of infections, ranging from mild skin infections like furuncles and impetigo, to severe, lifethreatening infections including endocarditis, osteomyelitis and pneumonia. Invasive infections are freq

  15. Rapid, Culture-Free Detection of Staphylococcus aureus Bacteremia

    Science.gov (United States)

    Burghardt, Elliot L.; Flenker, Katie S.; Clark, Karen C.; Miguel, Jeff; Ince, Dilek; Winokur, Patricia; Ford, Bradley; McNamara, James O.

    2016-01-01

    S. aureus bacteremia (SAB) is a common condition with high rates of morbidity and mortality. Current methods used to diagnose SAB take at least a day, and often longer. Patients with suspected bacteremia must therefore be empirically treated, often unnecessarily, while assay results are pending. In this proof-of-concept study, we describe an inexpensive assay that detects SAB via the detection of micrococcal nuclease (an enzyme secreted by S. aureus) in patient plasma samples in less than three hours. In total, 17 patient plasma samples from culture-confirmed S. aureus bacteremic individuals were tested. 16 of these yielded greater nuclease assay signals than samples from uninfected controls or individuals with non-S. aureus bacteremia. These results suggest that a nuclease-detecting assay may enable the rapid and inexpensive diagnosis of SAB, which is expected to substantially reduce the mortality and morbidity that result from this condition. PMID:27305148

  16. Three-dimensional tertiary structure of yeast phenylalanine transfer RNA

    Science.gov (United States)

    Kim, S. H.; Sussman, J. L.; Suddath, F. L.; Quigley, G. J.; Mcpherson, A.; Wang, A. H. J.; Seeman, N. C.; Rich, A.

    1974-01-01

    Results of an analysis and interpretation of a 3-A electron density map of yeast phenylalanine transfer RNA. Some earlier detailed assignments of nucleotide residues to electron density peaks are found to be in error, even though the overall tracing of the backbone conformation of yeast phenylalanine transfer RNA was generally correct. A new, more comprehensive interpretation is made which makes it possible to define the tertiary interactions in the molecule. The new interpretation makes it possible to visualize a number of tertiary interactions which not only explain the structural role of most of the bases which are constant in transfer RNAs, but also makes it possible to understand in a direct and simple fashion the chemical modification data on transfer RNA. In addition, this pattern of tertiary interactions provides a basis for understanding the general three-dimensional folding of all transfer RNA molecules.

  17. The equity imperative in tertiary education: Promoting fairness and efficiency

    Science.gov (United States)

    Salmi, Jamil; Bassett, Roberta Malee

    2014-06-01

    While the share of the tertiary education age cohort (19-25) which is being given the opportunity to study has increased worldwide over the past two decades, this does not in fact translate into reduced inequality. For many young people, especially in the developing world, major obstacles such as disparities in terms of gender, minority population membership or disabilities as well as academic and financial barriers are still standing in their way. The authors of this article propose a conceptual framework to analyse equity issues in tertiary education and document the scope, significance and consequences of disparities in tertiary education opportunities. They throw some light on the main determinants of these inequalities and offer suggestions about effective equity promotion policies directed towards widening participation and improving the chances of success of underprivileged youths in order to create societies which uphold humanistic values.

  18. Clinical impact of antimicrobial resistance in European hospitals: excess mortality and length of hospital stay related to methicillin-resistant Staphylococcus aureus bloodstream infections.

    LENUS (Irish Health Repository)

    de Kraker, Marlieke E A

    2011-04-01

    Antimicrobial resistance is threatening the successful management of nosocomial infections worldwide. Despite the therapeutic limitations imposed by methicillin-resistant Staphylococcus aureus (MRSA), its clinical impact is still debated. The objective of this study was to estimate the excess mortality and length of hospital stay (LOS) associated with MRSA bloodstream infections (BSI) in European hospitals. Between July 2007 and June 2008, a multicenter, prospective, parallel matched-cohort study was carried out in 13 tertiary care hospitals in as many European countries. Cohort I consisted of patients with MRSA BSI and cohort II of patients with methicillin-susceptible S. aureus (MSSA) BSI. The patients in both cohorts were matched for LOS prior to the onset of BSI with patients free of the respective BSI. Cohort I consisted of 248 MRSA patients and 453 controls and cohort II of 618 MSSA patients and 1,170 controls. Compared to the controls, MRSA patients had higher 30-day mortality (adjusted odds ratio [aOR] = 4.4) and higher hospital mortality (adjusted hazard ratio [aHR] = 3.5). Their excess LOS was 9.2 days. MSSA patients also had higher 30-day (aOR = 2.4) and hospital (aHR = 3.1) mortality and an excess LOS of 8.6 days. When the outcomes from the two cohorts were compared, an effect attributable to methicillin resistance was found for 30-day mortality (OR = 1.8; P = 0.04), but not for hospital mortality (HR = 1.1; P = 0.63) or LOS (difference = 0.6 days; P = 0.96). Irrespective of methicillin susceptibility, S. aureus BSI has a significant impact on morbidity and mortality. In addition, MRSA BSI leads to a fatal outcome more frequently than MSSA BSI. Infection control efforts in hospitals should aim to contain infections caused by both resistant and susceptible S. aureus.

  19. Staphylococcus aureus nasal carriage in hemodialysis centers of Fez, Morocco.

    Directory of Open Access Journals (Sweden)

    Idrissa Diawara

    2014-06-01

    Full Text Available Staphylococcus aureus (S. aureus nasal carriage may be responsible for some serious infections in hemodialyzed patients. The main target of this study was to estimate the prevalence of S. aureus nasal carriage in hemodialysis outpatients and medical staff in hemodialysis centers specifically in Fez region. The second target is to identify the risks of colonization, resistance pattern of isolates and their virulence toxin genes.Nasal swab specimens were obtained from 143 hemodialyzed outpatients and 32 medical staff from January to June 2012. Each participant completed a short questionnaire. Nasal carriage of S. aureus was demographically related (age, gender, hemodialysis duration, comorbidity (diabetes, malignancy and exposure to health care (dialysis staff, hospitalization. PCR (Polymerase Chain Reaction were used on all the isolates in the research of twelve staphylococcal enterotoxins genes. Also the PCR was used to investigate on the three factors epidermal cell differentiation inhibitors; three exfoliatin toxins; two leukotoxins; the toxic shock syndrome toxin-1 and the hemolysin beta genes.Nasal screening revealed 38.16%, 50% and 18.75% S. aureus carries in chronic, acute hemodialysis patients and medical staff, respectively. Only young participants were likely to be S. aureus carries (p = 0.002. But there were no gender differences between the isolate carriers and non-carriers or some comorbidity factors such as viral hepatitis B and C, HIV (Human Immunodeficiency Virus infections, diabetes, chronic smoking, recent hospitalization or antibiotic therapy. Out of all isolates, only one (1.61% was methicillin-resistant and Twenty-one (33.87% had at least two virulence toxin genes.Knowledge and monitoring of antibiotic resistance profile and virulence of S. aureus carriage are essential in the treatment of infections generated by this pathogen, as well as in the control of clonal dissemination and prevent the spread of S. aureus resistance.

  20. Comparative Pharmacodynamics of Gentamicin against Staphylococcus aureus and Pseudomonas aeruginosa†

    OpenAIRE

    Tam, Vincent H.; Kabbara, Samer; Vo, Giao; Schilling, Amy N.; Coyle, Elizabeth A.

    2006-01-01

    Aminoglycosides are often used to treat severe infections with gram-positive organisms. Previous studies have shown concentration-dependent killing by aminoglycosides of gram-negative bacteria, but limited data are available for gram-positive bacteria. We compared the in vitro pharmacodynamics of gentamicin against Staphylococcus aureus and Pseudomonas aeruginosa. Five S. aureus strains were examined (ATCC 29213 and four clinical isolates). Time-kill studies (TKS) in duplicate (baseline inocu...

  1. AKTIVITAS ANTIBAKTERI KITOSAN TERHADAP BAKTERI S.aureus

    OpenAIRE

    Mardiyah Kurniasih; Dwi Kartika

    2009-01-01

    Chitosan is the N-deacetylated derivative of chitin. Chitosan is biodegradable, biocompatible and non-toxic. Chitosan is polycationic in acidic media and give antibacterial activity. In this paper, antibacterial activity of chitosan have been studied. Chitosan had been isolated from white shrimp. Antibacterial activity of chitosan solutions was examined against S. aureus The result showed that antimicrobial effect on S. aureus was strengthened as the choitosan concentrate decreased.

  2. Long-term mortality after Staphylococcus aureus spondylodiscitis

    DEFF Research Database (Denmark)

    Aagaard, Theis; Roed, Casper; Larsen, Anders R;

    2014-01-01

    Patients diagnosed with Staphylococcus aureus spondylodiscitis have increased long-term mortality compared with the background population mainly due to infectious, endocrine, cardiovascular, gastrointestinal and alcohol and drug abuse-related diseases.......Patients diagnosed with Staphylococcus aureus spondylodiscitis have increased long-term mortality compared with the background population mainly due to infectious, endocrine, cardiovascular, gastrointestinal and alcohol and drug abuse-related diseases....

  3. Role of Monocytes in Experimental Staphylococcus aureus Endocarditis

    OpenAIRE

    Veltrop, Marcel H. A. M.; Bancsi, Maurice J. L. M. F.; Bertina, Rogier M.; Thompson, Jan

    2000-01-01

    In the pathogenesis of bacterial endocarditis (BE), the clotting system plays a cardinal role in the formation and maintenance of the endocardial vegetations. The extrinsic pathway is involved in the activation of the coagulation pathway with tissue factor (TF) as the key protein. Staphylococcus aureus is a frequently isolated bacterium from patients with BE. We therefore investigated whether S. aureus can induce TF activity (TFA) on fibrin-adherent monocytes, used as an in vitro model of BE....

  4. Vancomycin Resistance Pattern of Staphylococcus Aureus among Clinical Samples

    OpenAIRE

    S Saadat; K Solhjoo; A. Kazemi; Erfanian, S. (MSc); Ashrafian, F. (MSc)

    2014-01-01

    Background and Objective: Vancomycin is used for treatment of methicillin-resistant S. Aureus (MRSA) infections; therefore, resistance to this antibiotic is increasing. We aimed to determine the antibiotic resistance pattern and frequency of vancomycin resistant S. Areas (VRSA) strains isolated from clinical samples. Material and Methods: In this cross-sectional study, 100 S. Aureus isolates collected from hospitals in Shiraz during six months, 2012, were identified by biochemical, microbiolo...

  5. Staphylococcus aureus in the community: colonization versus infection.

    Directory of Open Access Journals (Sweden)

    Maureen Miller

    Full Text Available BACKGROUND: Antibiotic-resistant Staphylococcus aureus infections have increased dramatically in the community, yet S. aureus nasal colonization has remained stable. The objectives of this study were to determine if S. aureus colonization is a useful proxy measure to study disease transmission and infection in community settings, and to identify potential community reservoirs. METHODOLOGY/PRINCIPAL FINDINGS: Randomly selected households in Northern Manhattan, completed a structured social network questionnaire and provided nasal swabs that were typed by pulsed field gel electrophoresis to identify S. aureus colonizing strains. The main outcome measures were: 1 colonization with S. aureus; and 2 recent serious skin infection. Risk factor analyses were conducted at both the individual and the household levels; logistic regression models identified independent risks for household colonization and infection. RESULTS: 321 surveyed households contained 914 members. The S. aureus prevalence was 25% and MRSA was 0.4%. More than 40% of households were colonized. Recent antibiotic use was the only significant correlate for household colonization (p = .002. Seventy-eight (24% households reported serious skin infection. In contrast with colonization, five of the six risk factors that increased the risk of skin infection in the household at the univariate level remained independently significant in multivariable analysis: international travel, sports participation, surgery, antibiotic use and towel sharing. S. aureus colonization was not significantly associated with serious skin infection in any analysis. Among multiperson households with more than one person colonized, 50% carried the same strain. CONCLUSIONS/SIGNIFICANCE: The lack of association between S. aureus nasal colonization and serious skin infection underscores the need to explore alternative venues or body sites that may be crucial to transmission. Moreover, the magnitude of colonization and

  6. Resistance to Antimicrobials Mediated by Efflux Pumps in Staphylococcus aureus

    OpenAIRE

    Isabel Couto; Leonard Amaral; José Melo-Cristino; Miguel Viveiros; Cláudia Palma; Elisabete Junqueira; Costa, Sofia S.

    2013-01-01

    Resistance mediated by efflux has been recognized in Staphylococcus aureus in the last few decades, although its clinical relevance has only been recognized recently. The existence of only a few studies on the individual and overall contribution of efflux to resistance phenotypes associated with the need of well-established methods to assess efflux activity in clinical isolates contributes greatly to the lack of solid knowledge of this mechanism in S. aureus. This study aims to provide inform...

  7. Methicillin resistance & inducible clindamycin resistance in Staphylococcus aureus

    OpenAIRE

    Soumyadeep Ghosh; Mandira Banerjee

    2016-01-01

    Background & objectives: Methicillin resistant Staphylococcus aureus (MRSA) isolates with inducible clindamycin resistance (iCR) are resistant to erythromycin and sensitive to clindamycin on routine testing and inducible clindamycin resistance can only be identified by D-test. This study was aimed to detect methicillin resistance and iCR among S. aureus isolates, effectiveness of some commonly used antibiotics and correlation between methicillin resistance and iCR. Methods: The present cro...

  8. Detection and characterization of mupirocin resistance in Staphylococcus aureus.

    OpenAIRE

    Janssen, D A; Zarins, L T; Schaberg, D R; Bradley, S. F.; Terpenning, M S; Kauffman, C A

    1993-01-01

    Fourteen mupirocin-resistant Staphylococcus aureus strains were isolated over 18 months; 12 exhibited low-level resistance, while two showed high-level resistance. Highly mupirocin-resistant strains contained a large plasmid which transferred mupirocin resistance to other S. aureus strains and to Staphylococcus epidermidis. This plasmid and pAM899-1, a self-transferable gentamicin resistance plasmid, have molecular and biologic similarities.

  9. Methicillin-Resistant Staphylococcus aureus Ocular Infection in Taiwan

    OpenAIRE

    Kang, Yu-Chuan; Hsiao, Ching-Hsi; Yeh, Lung-Kun; Ma, David H. K.; Chen, Phil Y. F.; Lin, Hsin-Chiung; Tan, Hsin-Yuan; Chen, Hung-Chi; Chen, Shin-Yi; Huang, Yhu-Chering

    2015-01-01

    Abstract Methicillin-resistant Staphylococcus aureus (MRSA) infection is an important public health issue. This observational study aimed to characterize clinical features, antibiotic susceptibility, and genotypes of ocular infections caused by MRSA based on the clinical and molecular definitions of community-associated (CA) and healthcare-associated (HA) strains. Fifty-nine patients with culture-proven S aureus ocular infection were enrolled from January 1, 2010 to December 31, 2011 at Chang...

  10. Spatio-temporal observations of tertiary ozone maximum

    Directory of Open Access Journals (Sweden)

    V. F. Sofieva

    2009-03-01

    Full Text Available We present spatio-temporal distributions of tertiary ozone maximum (TOM, based on GOMOS (Global Ozone Monitoring by Occultation of Stars ozone measurements in 2002–2006. The tertiary ozone maximum is typically observed in the high-latitude winter mesosphere at altitude ~72 km. Although the explanation for this phenomenon has been found recently – low concentrations of odd-hydrogen cause the subsequent decrease in odd-oxygen losses – models have had significant deviations from existing observations until recently. Good coverage of polar night regions by GOMOS data has allowed for the first time obtaining spatial and temporal observational distributions of night-time ozone mixing ratio in the mesosphere.

    The distributions obtained from GOMOS data have specific features, which are variable from year to year. In particular, due to a long lifetime of ozone in polar night conditions, the downward transport of polar air by the meridional circulation is clearly observed in the tertiary ozone maximum time series. Although the maximum tertiary ozone mixing ratio is achieved close to the polar night terminator (as predicted by the theory, TOM can be observed also at very high latitudes, not only in the beginning and at the end, but also in the middle of winter. We have compared the observational spatio-temporal distributions of tertiary ozone maximum with that obtained using WACCM (Whole Atmosphere Community Climate Model and found that the specific features are reproduced satisfactorily by the model.

    Since ozone in the mesosphere is very sensitive to HOx concentrations, energetic particle precipitation can significantly modify the shape of the ozone profiles. In particular, GOMOS observations have shown that the tertiary ozone maximum was temporarily destroyed during the January 2005 and December 2006 solar proton events as a result of the HOx enhancement from the increased ionization.

  11. Detoxification of toxins by bacillithiol in Staphylococcus aureus.

    Science.gov (United States)

    Newton, Gerald L; Fahey, Robert C; Rawat, Mamta

    2012-04-01

    Bacillithiol (BSH), an α-anomeric glycoside of l-cysteinyl-d-glucosaminyl-l-malate, is a major low-molecular-mass thiol found in bacteria such as Bacillus sp., Staphylococcus aureus and Deinococcus radiodurans. Like other low-molecular-mass thiols such as glutathione and mycothiol, BSH is likely to be involved in protection against environmental toxins including thiol-reactive antibiotics. We report here a BSH-dependent detoxification mechanism in S. aureus. When S. aureus Newman strain was treated with monobromobimane and monochlorobimane, the cellular BSH was converted to the fluorescent S-conjugate BS-bimane. A bacillithiol conjugate amidase activity acted upon the BS-bimane to produce Cys-bimane, which was then acetylated by an N-acetyltransferase to generate N-acetyl-Cys-bimane, a mercapturic acid. An S. aureus mutant lacking BSH did not produce mercapturic acid when treated with monobromobimane and monochlorobimane, confirming the involvement of bacillithiol. Furthermore, treatment of S. aureus Newman with rifamycin, the parent compound of the first-line anti-tuberculosis drug, rifampicin, indicated that this thiol-reactive antibiotic is also detoxified in a BSH-dependent manner, since mercapturic acids of rifamycin were observed in the culture medium. These data indicate that toxins and thiol-reactive antibiotics are detoxified to less potent mercapturic acids in a BSH-dependent manner and then exported out of the cell in S. aureus.

  12. Exploring the transcriptome of Staphylococcus aureus in its natural niche.

    Science.gov (United States)

    Chaves-Moreno, Diego; Wos-Oxley, Melissa L; Jáuregui, Ruy; Medina, Eva; Oxley, Andrew Pa; Pieper, Dietmar H

    2016-01-01

    Staphylococcus aureus is an important human pathogen and commensal, where the human nose is the predominant reservoir. To better understand its behavior in this environmental niche, RNA was extracted from the anterior nares of three documented S. aureus carriers and the metatranscriptome analyzed by RNAseq. In addition, the in vivo transcriptomes were compared to previously published transcriptomes of two in vitro grown S. aureus strains. None of the in vitro conditions, even growth in medium resembling the anterior nares environment, mimicked in vivo conditions. Survival in the nose was strongly controlled by the limitation of iron and evident by the expression of iron acquisition systems. S. aureus populations in different individuals clearly experience different environmental stresses, which they attempt to overcome by the expression of compatible solute biosynthetic pathways, changes in their cell wall composition and synthesis of general stress proteins. Moreover, the expression of adhesins was also important for colonization of the anterior nares. However, different S. aureus strains also showed different in vivo behavior. The assessment of general in vivo expression patterns and commonalities between different S. aureus strains will in the future result in new knowledge based strategies for controlling colonization. PMID:27641137

  13. Resistance to Antimicrobials Mediated by Efflux Pumps in Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Isabel Couto

    2013-03-01

    Full Text Available Resistance mediated by efflux has been recognized in Staphylococcus aureus in the last few decades, although its clinical relevance has only been recognized recently. The existence of only a few studies on the individual and overall contribution of efflux to resistance phenotypes associated with the need of well-established methods to assess efflux activity in clinical isolates contributes greatly to the lack of solid knowledge of this mechanism in S. aureus. This study aims to provide information on approaches useful to the assessment and characterization of efflux activity, as well as contributing to our understanding of the role of efflux to phenotypes of antibiotic resistance and biocide tolerance in S. aureus clinical isolates. The results described show that efflux is an important contributor to fluoroquinolone resistance in S. aureus and suggest it as a major mechanism in the early stages of resistance development. We also show that efflux plays an important role on the reduced susceptibility to biocides in S. aureus, strengthening the importance of this long neglected resistance mechanism to the persistence and proliferation of antibiotic/biocide-resistant S. aureus in the hospital environment.

  14. Determining of antibiotic resistance profile inStaphylococcus aureus isolates

    Institute of Scientific and Technical Information of China (English)

    Hossein Motamedi; Hadis Mirzabeigi; Tahere Shirali

    2010-01-01

    Objective:To determine the pattern of antibiotic resistance amongStaphylococcus aureus (S. aureus) isolates from clinical specimens and to identify community-acquired methicillin-resistantStaphylococcus aureus(CA-MRSA)in specimens that have been collected from patients referring to one of the hospitals of Ahvaz.Methods:S. aureus isolates from a hospital in Ahvaz were screened for resistance to various antibiotics including methicillin. The susceptibility of the isolates was determined by Kirby-Bauer disc diffusion method. TheMRSA was also treated with ethidium bromide to find the origin of resistance.Results: Among the bacterial isolates, all of 11S. aureus were resistant to methicillin and cefixime,2 were resistant to ciprofloxacine,6 were resistant to tetracycline and the reminder were sensitive or intermediate to other antibiotics. The treated isolates were reminded resistant to methicillin and this suggested that the plasmid was not the origin of resistance in these isolates.Conclusions: These results showed that infection due toMRSA is widespread in Ahvaz and with respect to the spread of vancomycin resistance among MRSA and appearance of overwhelming infections. It is necessary to identify continuously the profile of antibiotic resistance amongS. aureus isolates in other regions and finding appropriate antibiotic for infection control and eradication.

  15. Exports of Tertiary Education Services and the Queensland Economy

    OpenAIRE

    Duhs, Ted; Duhs, Alan

    1997-01-01

    Exports of tertiary education services have become a growth industry for the Queensland economy. Since a policy change in 1987 from an aid to a trade approach to overseas students, fee paying overseas students have risen from a mere 5.9 per cent of all overseas students in 1987, to 89.6 per cent in 1995. Exports of tertiary education services from the Queensland economy now rival wool and wheat in importance. A number of marketing and policy issues arise in the context of further change in th...

  16. Tertiary foraminiferal rock samples from the western Solomon Sea

    Science.gov (United States)

    Haig, David W.

    1986-12-01

    Rock fragments dredged from four R/VNatsushima stations contain Tertiary foraminifera. The oldest sample is an upper bathyal biomicrite of Early Eocene age (52 to 53.5 Ma) from the the Trobriand Platform. Upper Oligocene-Lower Miocene neritic limestones were located off the Trobriand Platform and on the inner wall of the New Britain Trench. Miocene bathyal sediments come from the Trobriand Platform; similar Pliocene rocks were recovered here as well as from the inner wall of the New Britain Trench and the central part of the Solomon Sea Basin. No reworked pre-Tertiary foraminifera are present in any sample.

  17. Sexual harassment in tertiary institutions: A comparative perspective

    Directory of Open Access Journals (Sweden)

    Joseph Janice

    2015-01-01

    Full Text Available Sexual harassment is not a new phenomenon in tertiary institutions. It has been receiving considerable attention in research and the media and public awareness has increased dramatically. However, the term sexual harassment is not used uniformly across the globe because countries have defined it differently. Consequently, prevalence of sexual harassment in education varies across cultures. This paper examines sexual harassment from a comparative perspective. It specifically focuses on the definition of sexual harassment, incidence of sexual harassment of students in tertiary institutions, effects of sexual harassment on victims; and victims’ responses to sexual harassment. It also offers suggestions for curtailing sexual harassment in these institutions.

  18. Prevalence of Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus in Retail Ready-to-Eat Foods in China.

    Science.gov (United States)

    Yang, Xiaojuan; Zhang, Jumei; Yu, Shubo; Wu, Qingping; Guo, Weipeng; Huang, Jiahui; Cai, Shuzhen

    2016-01-01

    Staphylococcus aureus, particularly methicillin-resistant S.aureus (MRSA), is a life-threatening pathogen in humans, and its presence in food is a public health concern. MRSA has been identified in foods in China, but little information is available regarding MRSA in ready-to-eat (RTE) foods. We aimed to investigate the prevalence of S. aureus and MRSA in Chinese retail RTE foods. All isolated S. aureus were tested for antimicrobial susceptibility, and MRSA isolates were further characterized by multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing. Of the 550 RTE foods collected from 2011 to 2014, 69 (12.5%) were positive for S. aureus. Contamination levels were mostly in the range of 0.3-10 most probable number (MPN)/g, with five samples exceeding 10 MPN/g. Of the 69 S. aureus isolates, seven were identified as MRSA by cefoxitin disc diffusion test. Six isolates were mecA-positive, while no mecC-positive isolates were identified. In total, 75.8% (47/62) of the methicillin-susceptible S. aureus isolates and all of the MRSA isolates were resistant to three or more antibiotics. Amongst the MRSA isolates, four were identified as community-acquired strains (ST59-MRSA-IVa (n = 2), ST338-MRSA-V, ST1-MRSA-V), while one was a livestock-associated strain (ST9, harboring an unreported SCCmec type 2C2). One novel sequence type was identified (ST3239), the SCCmec gene of which could not be typed. Overall, our findings showed that Chinese retail RTE foods are likely vehicles for transmission of multidrug-resistant S. aureus and MRSA lineages. This is a serious public health risk and highlights the need to implement good hygiene practices.

  19. Global Trends in Tertiary Education Quality Assurance: Implications for the Anglophone Caribbean.

    Science.gov (United States)

    Roberts, Vivienne

    2001-01-01

    Review of literature on trends in quality-assurance systems for tertiary education throughout the world followed by a discussion of the implications of these trends for tertiary education in the Caribbean. (Contains 26 references.) (PKP)

  20. Patterns of cancer occurrence in a tertiary care centre

    Directory of Open Access Journals (Sweden)

    Atla Bhagyalakshmi

    2016-06-01

    Conclusions: The current study mainly summarizes the different patterns of cancer incidence in the tertiary care centre region. Cancer incidence is increasing gradually among the population and there is raise of cancer incidence in females compared to their counterparts. [Int J Res Med Sci 2016; 4(6.000: 2153-2163

  1. Sexual harassment in tertiary institutions: A comparative perspective

    OpenAIRE

    Joseph Janice

    2015-01-01

    Sexual harassment is not a new phenomenon in tertiary institutions. It has been receiving considerable attention in research and the media and public awareness has increased dramatically. However, the term sexual harassment is not used uniformly across the globe because countries have defined it differently. Consequently, prevalence of sexual harassment in education varies across cultures. This paper examines sexual harassment from a comparative perspective...

  2. Establishing Self-access with CALL in Chinese Tertiary Education

    Institute of Scientific and Technical Information of China (English)

    WangYuwen; LiHeng

    2004-01-01

    This paper aims tO bridge up the gap between theoretical perspectives of self-access language learning (SALL) and practice of computer assisted language learning (CALL) in Chinese tertiary education. While much of the paper presented ideas dealing with issues related to SALL and CALL, they are supported by references to relevant literature and research.

  3. Strength and Deformation Properties of Tertiary Clay at Moesgaard Museum

    DEFF Research Database (Denmark)

    Kaufmann, Kristine Lee; Nielsen, Benjaminn Nordahl; Augustesen, Anders Hust

    The tertiary clay at Moesgaard Museum near Aarhus in the eastern part of Jutland in Denmark is a highly plastic, glacially disturbed nappe of Viborg Clay. The clay is characterised as a swelling soil, which could lead to damaging of the building due to additional heave of the soil. To take...

  4. English Textbooks in Parallel-Language Tertiary Education

    Science.gov (United States)

    Pecorari, Diane; Shaw, Philip; Malmstrom, Hans; Irvine, Aileen

    2011-01-01

    Tertiary education in many countries is increasingly bilingual, with English used in parallel with the national language, particularly as a reading language. This article describes the results of a survey of student attitudes toward, and reading practices regarding, English language textbooks. Over 1,000 students at three Swedish universities…

  5. Breast Self Examination Practice among Female Students of Tertiary Institutions

    Science.gov (United States)

    Agbonifoh, Julia Adesua

    2016-01-01

    Against the background of the dangers posed by breast cancer world-wide, and the importance of its early detection and therefore breast self examination (BSE), this study investigated the practice of BSE among female students in tertiary institutions in Edo state. A sample of 723 participants selected through a combination of multi-stage,…

  6. Secret Cults in Tertiary Institutions in Nigeria: An Appraisal

    Science.gov (United States)

    Aluede, Raymond O. A.; Oniyama, Hope O.

    2009-01-01

    Cultism has remained a problem for tertiary institutions in Nigeria and the Larger Nigerian society since the first decade of the existence of university education in Nigeria. It has been worrisome to have children on campuses and several measures had been adopted to curb cultism some of such measures were the expulsion of the cultists caught and…

  7. Accountability of Tertiary Education at the National Level: A Chimera?

    Science.gov (United States)

    Lindsay, Alan; O'Byrne, Garry

    1979-01-01

    The concept of accountability and its application to Australian higher education are discussed. It is suggested that due to political, financial, and educational characteristics of tertiary education at the national system level there are fundamental and insoluble problems associated with achieving accountability. (SF)

  8. A Conceptual Approach for Blended Leadership for Tertiary Education Institutions

    Science.gov (United States)

    Jones, Sandra; Harvey, Marina; Lefoe, Geraldine

    2014-01-01

    Over the last 20 years, the tertiary education sector has adopted new administrative management approaches, with the aim of improving accountable and strategic focus. Over the same period, the question of how to build leadership capacity to improve learning and teaching and research outcomes has led to discussion on what constitutes academic…

  9. Initial Educational Experiences of Tertiary Students. LSAY Briefing Number 14

    Science.gov (United States)

    Hillman, Kylie

    2008-01-01

    This "Briefing" presents information about the initial tertiary education experiences, such as satisfaction with aspects of student life and changes to initial enrolments, of two groups of young people, based on two recent Longitudinal Surveys of Australian Youth (LSAY) research reports. One study focused on the first year experiences of a group…

  10. Competition and Reform of the New Zealand Tertiary Education Sector

    Science.gov (United States)

    Abbott, Malcolm

    2006-01-01

    The purpose of this paper is to use an historical approach to examine the changing nature, size and diversification of education and training in New Zealand. In particular, attention will be concentrated on the impact of the introduction of competition into the New Zealand tertiary education industry since 1989. It will examine the relationship…

  11. Tertiary Educational Institutions for Teaching, Research and Development

    Science.gov (United States)

    Amoo, Sikiru A.

    2014-01-01

    This paper examines the quality of teaching and research in developing human resources to facilitate the development of tertiary education in the nation. It discusses the challenges and the roles of research in higher education. The author argues that the combination of content and pedagogical knowledge could help to develop human resources for…

  12. Food Insecurity: Is It an Issue among Tertiary Students?

    Science.gov (United States)

    Gallegos, Danielle; Ramsey, Rebecca; Ong, Kai Wen

    2014-01-01

    Insufficient access to food is known to compromise tertiary studies. Students often belong to groups known to have poor food security such as those renting or relying on government payments. The present study administered a cross-sectional survey incorporating the USDA food security survey module (FSSM) to 810 students at a metropolitan university…

  13. STUDY OF MATERNAL MORTALITY IN A TERTIARY CARE HOSPITAL

    OpenAIRE

    Sandhya Devi; Madhuri; Sarada Bai; Srividya

    2015-01-01

    BACKGROUND: A woman dies from complications of child birth every minute . The major causes for maternal mortality in India are uncontrolled fertility , inaccessibility or inadequate utilization of health care facilities , illiteracy , ignorance and gender discrimination . OBJECTIV ES: (1 ) To identify various causes of maternal deaths in a teaching hospital . (2 ) To study the profile of population attending the tertiary hos...

  14. The Equity Imperative in Tertiary Education: Promoting Fairness and Efficiency

    Science.gov (United States)

    Salmi, Jamil; Bassett, Roberta Malee

    2014-01-01

    While the share of the tertiary education age cohort (19-25) which is being given the opportunity to study has increased worldwide over the past two decades, this does not in fact translate into reduced inequality. For many young people, especially in the developing world, major obstacles such as disparities in terms of gender, minority population…

  15. Pedagogical Practices of Reflection in Tertiary Dance Education

    Science.gov (United States)

    Leijen, Ali; Lam, Ineke; Simons, P. Robert-Jan; Wildschut, Liesbeth

    2008-01-01

    The three different perspectives on reflection in education are embedded in the philosophical traditions of pragmatism, critical social theory and Kant. We aimed to describe the pedagogical practices of reflection, and to develop a descriptive model of the practices of reflection in tertiary dance education which can be used by dance educators to…

  16. Reflections on the Tertiary Education Sector in Australia. Conference Paper

    Science.gov (United States)

    Karmel, Tom

    2009-01-01

    The split between higher education and vocational education and training (VET) in Australia is not clean. This paper discusses a number of aspects of this tertiary education sector: the Australian Qualifications Framework (AQF), which describes the qualifications offered by the three education sectors: schools, higher education and VET; student…

  17. Teaching the Attributes of Venture Teamwork in Tertiary Entrepreneurship Programmes

    Science.gov (United States)

    Kotey, Bernice

    2007-01-01

    Purpose: The paper seeks to demonstrate the characteristics of group work that are required to teach the attributes of real world venture teamwork in tertiary entrepreneurship programmes. Design/methodology/approach: One-tailed Spearman correlation analysis is used to assess the associations between students' grades in four group assessment tasks…

  18. Analysis of Management Practices in Lagos State Tertiary Institutions through Total Quality Management Structural Framework

    Science.gov (United States)

    AbdulAzeez, Abbas Tunde

    2016-01-01

    This research investigated total quality management practices and quality teacher education in public tertiary institutions in Lagos State. The study was therefore designed to analyse management practices in Lagos state tertiary institutions through total quality management structural framework. The selected public tertiary institutions in Lagos…

  19. Synthesis of sulfonamides via copper-catalyzed oxidative C-N bond cleavage of tertiary amines.

    Science.gov (United States)

    Ji, Jing; Liu, Zhengyi; Liu, Ping; Sun, Peipei

    2016-08-01

    A copper-catalyzed coupling reaction of sulfonyl chlorides with tertiary amines via the oxidative C-N bond cleavage of tertiary amines was developed. Sulfonamides were synthesized using this strategy in moderate to good yields. The reaction was applicable to various tertiary amines, as well as sulfonyl chlorides. PMID:27356858

  20. Pathogenic Staphylococcus aureus Isolates from Postoperative Wounds of Hospitalized Patients

    Directory of Open Access Journals (Sweden)

    Smritikana Biswas

    2010-07-01

    Full Text Available Staphylococcus sp., gram positive pyogenic bacteria located on skin, nose etc, secretes toxin that causes toxic shock syndrome, abscess, food poisoning and other infectious diseases. This study was carried out to identify and characterize the type of Staphylococcus sp. bacteria especially Staphylococcus aureus in the pus from postoperative wounds of hospitalized patients. From pus samples collected from twenty-four patients from Kharagpur Hospital, Paschim Medinipur, West Bengal, twenty-eight bacterial isolates were obtained. Among them twenty-five (89.2% were appeared with golden yellow colonies which is usually formed by Staphylococcus aureus. Twenty-three (82.14% of the bacterial isolates were Gram positive. Among them twenty isolates (86.9% were further confirmed to be Staphylococcus aureus by their ability to produce Catalase enzyme (positive in Catalase test and Coagulase enzyme (positive in Coagulase Test. Eighteen (90.00% of these Staphylococcus aureus were found to liquefy gelatin (Gelatin hydrolysis test, were able to hydrolyze urea (Urea hydrolysis test and were also l positive in Mannitol Fermentation Test. But there was no growth found of these isolates on MacConkey Agar, while sixteen isolates (80.00% of Staphylococcus aureus were resistant to penicillin (50µg/ml. Moreover eighteen (90.00% Staphylococcus aureus isolates were able to elaborate Hemolysin (Hemolysis test on Blood Agar media. Hence the bacterial isolates obtained from pus of postoperative wounds were predominantly pathogenic Staphylococcus aureus. So it can be concluded that careful treatment and postoperative measures to be taken to avoid serious health problem that may often be life threatening.

  1. Staphylococcus aureus small colony variants in diabetic foot infections

    Directory of Open Access Journals (Sweden)

    Estrella Cervantes-García

    2015-03-01

    Full Text Available Background: Staphylococcus aureus (S. aureus is one of the major pathogens causing chronic infections. The ability of S. aureus to acquire resistance to a diverse range of antimicrobial compounds results in limited treatment options, particularly in methicillin-resistant S. aureus (MRSA. A mechanism by which S. aureus develops reduced susceptibility to antimicrobials is through the formation of small colony variants (SCVs. Infections by SCVs of S. aureus are an upcoming problem due to difficulties in laboratory diagnosis and resistance to antimicrobial therapy. Methods: A prospective study was performed on 120 patients diagnosed with both type 2 diabetes mellitus and infected diabetic foot ulcers. The study was carried out from July 2012 to December 2013 in Hospital General de Mexico. The samples were cultured in blood agar, mannitol salt agar, and MacConkey agar media, and incubated at 37°C in aerobic conditions. Results: We describe the first known cases of diabetic foot infections caused by MRSA-SCVs in patients diagnosed with type 2 diabetes mellitus and infected diabetic foot ulcers. In all of our cases, the patients had not received any form of gentamicin therapy. Conclusions: The antibiotic therapy commonly used in diabetic patients with infected diabetic foot ulcers fails in the case of MRSA-SCVs because the intracellular location protects S. aureus-SCVs from the host's defenses and also helps them resist antibiotics. The cases studied in this article add to the spectrum of persistent and relapsing infections attributed to MRSA-SCVs and emphasizes that these variants may also play a relevant role in diabetic foot infections.

  2. Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) at ambient freshwater beaches

    Science.gov (United States)

    Fogarty, Lisa R.; Haack, Sheridan K.; Johnson, Heather E.; Brennan, Angela K.; Isaacs, Natasha M.; Spencer, Chelsea

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) are a threat to human health worldwide, and although detected at marine beaches, they have been largely unstudied at freshwater beaches. Genes indicating S. aureus (SA; femA) and methicillin resistance (mecA) were detected at 11 and 12 of 13 US Great Lakes beaches and in 18% or 27% of 287 recreational water samples, respectively. Eight beaches had mecA + femA (potential MRSA) detections. During an intensive study, higher bather numbers, staphylococci concentrations, and femA detections were found in samples collected after noon than before noon. Local population density, beach cloud cover, and beach wave height were significantly correlated with SA or MRSA detection frequency. The Panton-Valentine leukocidin gene, associated with community-acquired MRSA, was detected in 12 out of 27 potential MRSA samples. The femA gene was detected less frequently at beaches that met US enterococci criteria or EU enterococci ‘excellent’ recreational water quality, but was not related to Escherichia coli-defined criteria. Escherichia coli is often the only indicator used to determine water quality at US beaches, given the economic and healthcare burden that can be associated with infections caused by SA and MRSA, monitoring of recreational waters for non-fecal bacteria such as staphylococci and/or SA may be warranted.

  3. Peptidoglycan recognition protein 1 enhances experimental asthma by promoting Th2 and Th17 and limiting regulatory T cell and plasmacytoid dendritic cell responses.

    Science.gov (United States)

    Park, Shin Yong; Jing, Xuefang; Gupta, Dipika; Dziarski, Roman

    2013-04-01

    Asthma is a common inflammatory disease involving cross-talk between innate and adaptive immunity. We reveal that antibacterial innate immunity protein, peptidoglycan recognition protein (Pglyrp)1, is involved in the development of allergic asthma. Pglyrp1(-/-) mice developed less severe asthma than wild-type (WT) mice following sensitization with house dust mite (allergen) (HDM). HDM-sensitized Pglyrp1(-/-) mice, compared with WT mice, had diminished bronchial hyperresponsiveness (lung airway resistance); numbers of eosinophils, neutrophils, lymphocytes, and macrophages in bronchoalveolar lavage fluid and lungs; inflammatory cell infiltrates in the lungs around bronchi, bronchioles, and pulmonary arteries and veins; lung remodeling (mucin-producing goblet cell hyperplasia and metaplasia and smooth muscle hypertrophy and fibrosis); levels of IgE, eotaxins, IL-4, IL-5, and IL-17 in the lungs; and numbers of Th2 and Th17 cells and expression of their marker genes in the lungs. The mechanism underlying this decreased sensitivity of Pglyrp1(-/-) mice to asthma was increased generation and activation of CD8α(+)β(+) and CD8α(+)β(-) plasmacytoid dendritic cells (pDC) and increased recruitment and activity of regulatory T (Treg) cells in the lungs. In vivo depletion of pDC in HDM-sensitized Pglyrp1(-/-) mice reversed the low responsive asthma phenotype of Pglyrp1(-/-) mice to resemble the more severe WT phenotype. Thus, Pglyrp1(-/-) mice efficiently control allergic asthma by upregulating pDC and Treg cells in the lungs, whereas in WT mice, Pglyrp1 is proinflammatory and decreases pDC and Treg cells and increases proasthmatic Th2 and Th17 responses. Blocking Pglyrp1 or enhancing pDC in the lungs may be beneficial for prevention and treatment of asthma. PMID:23420883

  4. A cohort study of the Copenhagen CF Centre eradication strategy against Staphylococcus aureus in patients with CF

    DEFF Research Database (Denmark)

    Dalbøge, Christina Schjellerup; Pressler, Tacjana; Høiby, Niels;

    2013-01-01

    Staphylococcus aureus is an important pathogen in CF. Centre prevalence of intermittent colonization and chronic S. aureus infections and the effectiveness of an anti-S. aureus eradication strategy was assessed....

  5. Prevalence of Staphylococcus aureus in Shrimps in Tehran during 2013

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Soltan Dallal

    2015-12-01

    Full Text Available Background During fishing and transport, preservation and quality of fish products are importantas well as storage to prevent the growth of pathogenic and toxin producing bacteria.Staphylococcus aureus is one of the most common causes of sea food-borne diseases worldwidedue to contamination of food by preformed enterotoxins. The aim of this study was to compare theprevalence and contamination of S. aureus in marine and farmed shrimps in Tehran fishery center.Methods: A total of 300 samples, including 150 marine, 150 farmed shrimps were selected duringSeptember 2013 to December 2013. Isolation and identification of S. aureus from isolated sampleswere carried out according to conventional methods, and antibiotic susceptibility test wasperformed by modified Kirby-Bauer disc diffusion methodResults: The results of this study showed that 30% of marine and 20% off armed shrimps werecontaminated with S. aureus. The highest resistance was observed with penicillin and ampicillin,whereas 100% were sensitive to vancomycin, clindamycin, ciprofloxacin, and rifampin.Conclusions: Due to relatively high contamination of shrimp by S. aureus more attention shouldbe given during processing and manufacturing.

  6. A systematic review of animal models for Staphylococcus aureus osteomyelitis

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    W Reizner

    2014-03-01

    Full Text Available Staphylococcus aureus (S. aureus osteomyelitis is a significant complication for orthopaedic patients undergoing surgery, particularly with fracture fixation and arthroplasty. Given the difficulty in studying S. aureus infections in human subjects, animal models serve an integral role in exploring the pathogenesis of osteomyelitis, and aid in determining the efficacy of prophylactic and therapeutic treatments. Animal models should mimic the clinical scenarios seen in patients as closely as possible to permit the experimental results to be translated to the corresponding clinical care. To help understand existing animal models of S. aureus, we conducted a systematic search of PubMed and Ovid MEDLINE to identify in vivo animal experiments that have investigated the management of S. aureus osteomyelitis in the context of fractures and metallic implants. In this review, experimental studies are categorised by animal species and are further classified by the setting of the infection. Study methods are summarised and the relevant advantages and disadvantages of each species and model are discussed. While no ideal animal model exists, the understanding of a model’s strengths and limitations should assist clinicians and researchers to appropriately select an animal model to translate the conclusions to the clinical setting.

  7. Methicillin-resistant Staphylococcus aureus in central Iowa wildlife.

    Science.gov (United States)

    Wardyn, Shylo E; Kauffman, Lin K; Smith, Tara C

    2012-10-01

    Livestock and pets have been identified as carriers of Staphylococcus aureus; however, the role of wild animals as a reservoir of S. aureus strains has not yet been examined. We conducted a pilot study to determine the prevalence of methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) in 37 species of wild animals rehabilitated at a university clinic. Nasal, wing, wound, and cloacal swabs were collected. Of 114 animals, seven (6.1%) were MSSA-positive and three (2.6%) were MRSA-positive. The MRSA isolates were obtained from two eastern cottontail rabbits (Sylvilagus floridanus) and a Lesser Yellowlegs (Tringa flavipes), a migratory shorebird. Antibiotic resistance testing of the MRSA isolates revealed that two were additionally resistant to tetracycline and erythromycin, and the third isolate was also resistant to erythromycin, clindamycin, and levofloxacin. All three isolates were positive for the Panton-Valentine leukocidin (PVL) gene. Sequence typing of the staphylococcal protein A (spa) region revealed one MRSA isolate to be t002, whereas the other two MRSA isolates were found to be t008. Our results suggest that S. aureus, including MRSA, is being carried by wild animals, although at a low prevalence with the limited number of animals tested. Additional studies are needed to determine how this may impact human health. PMID:23060511

  8. Crystal Violet and XTT Assays on Staphylococcus aureus Biofilm Quantification.

    Science.gov (United States)

    Xu, Zhenbo; Liang, Yanrui; Lin, Shiqi; Chen, Dingqiang; Li, Bing; Li, Lin; Deng, Yang

    2016-10-01

    Staphylococcus aureus (S. Aureus) is a common food-borne pathogenic microorganism. Biofilm formation remains the major obstruction for bacterial elimination. The study aims at providing a basis for determining S. aureus biofilm formation. 257 clinical samples of S. aureus isolates were identified by routine analysis and multiplex PCR detection and found to contain 227 MRSA, 16 MSSA, 11 MRCNS, and 3 MSCNS strains. Two assays for quantification of S. aureus biofilm formation, the crystal violet (CV) assay and the XTT (tetrazolium salt reduction) assay, were optimized, evaluated, and further compared. In CV assay, most isolates formed weak biofilm 74.3 %), while the rest formed moderate biofilm (23.3 %) or strong biofilm (2.3 %). However, most isolates in XTT assay showed weak metabolic activity (77.0 %), while the rest showed moderate metabolic activity (17.9 %) or high metabolic activity (5.1 %). In this study, we found a distinct strain-to-strain dissimilarity in terms of both biomass formation and metabolic activity, and it was concluded from this study that two assays were mutual complementation rather than being comparison. PMID:27324342

  9. Comparative effectiveness of nafcillin or cefazolin versus vancomycin in methicillin-susceptible Staphylococcus aureus bacteremia

    Directory of Open Access Journals (Sweden)

    McGregor Jessina C

    2011-10-01

    Full Text Available Abstract Background The high prevalence of methicillin-resistant S. aureus (MRSA has led clinicians to select antibiotics that have coverage against MRSA, usually vancomycin, for empiric therapy for suspected staphylococcal infections. Clinicians often continue vancomycin started empirically even when methicillin-susceptible S. aureus (MSSA strains are identified by culture. However, vancomycin has been associated with poor outcomes such as nephrotoxicity, persistent bacteremia and treatment failure. The objective of this study was to compare the effectiveness of vancomycin versus the beta-lactam antibiotics nafcillin and cefazolin among patients with MSSA bacteremia. The outcome of interest for this study was 30-day in-hospital mortality. Methods This retrospective cohort study included all adult in-patients admitted to a tertiary-care facility between January 1, 2003 and June 30, 2007 who had a positive blood culture for MSSA and received nafcillin, cefazolin or vancomycin. Cox proportional hazard models were used to assess independent mortality hazards comparing nafcillin or cefazolin versus vancomycin. Similar methods were used to estimate the survival benefits of switching from vancomycin to nafcillin or cefazolin versus leaving patients on vancomycin. Each model included statistical adjustment using propensity scores which contained variables associated with an increased propensity to receive vancomycin. Results 267 patients were included; 14% (38/267 received nafcillin or cefazolin, 51% (135/267 received both vancomycin and either nafcillin or cefazolin, and 35% (94/267 received vancomycin. Thirty (11% died within 30 days. Those receiving nafcillin or cefazolin had 79% lower mortality hazards compared with those who received vancomycin alone (adjusted hazard ratio (HR: 0.21; 95% confidence interval (CI: 0.09, 0.47. Among the 122 patients who initially received vancomycin empirically, those who were switched to nafcillin or cefazolin (66

  10. Occurrence of Multidrug Resistant Staphylococcus aureus in horses in Malaysia

    Directory of Open Access Journals (Sweden)

    Z. Zunita

    2008-12-01

    Full Text Available A total of 22 Staphylococcus aureus were isolated from 50 samples from 8 stable horses. They are positive in the catalase and coagulase tests. Upon testing the cultures with SLIDEX test kit all formed agglutination within a few seconds, confirming they are of S. aureus. When cultured onto MSA, all isolates formed yellow colonies. However, none of the isolates produced blue colonies on ORSAB indicating that there were no MRSA among the S. aureus. There were 13 isolates which were multiresistant. Eleven are resistant to eight out of ten antibiotics tested. All these isolates were found to originate from stable G. One isolate is resistant to 5 antibiotics while another one isolate is resistant to 3 antibiotics. The rest of the isolates are not multiresistant to the antibiotics tested. [Veterinary World 2008; 1(6.000: 165-167

  11. Contribution of coagulases towards Staphylococcus aureus disease and protective immunity.

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    Alice G Cheng

    Full Text Available The bacterial pathogen Staphylococcus aureus seeds abscesses in host tissues to replicate at the center of these lesions, protected from host immune cells via a pseudocapsule. Using histochemical staining, we identified prothrombin and fibrin within abscesses and pseudocapsules. S. aureus secretes two clotting factors, coagulase (Coa and von Willebrand factor binding protein (vWbp. We report here that Coa and vWbp together are required for the formation of abscesses. Coa and vWbp promote the non-proteolytic activation of prothrombin and cleavage of fibrinogen, reactions that are inhibited with specific antibody against each of these molecules. Coa and vWbp specific antibodies confer protection against abscess formation and S. aureus lethal bacteremia, suggesting that coagulases function as protective antigens for a staphylococcal vaccine.

  12. Genetically enhanced cows resist intramammary Staphylococcus aureus infection.

    Science.gov (United States)

    Wall, Robert J; Powell, Anne M; Paape, Max J; Kerr, David E; Bannerman, Douglas D; Pursel, Vernon G; Wells, Kevin D; Talbot, Neil; Hawk, Harold W

    2005-04-01

    Mastitis, the most consequential disease in dairy cattle, costs the US dairy industry billions of dollars annually. To test the feasibility of protecting animals through genetic engineering, transgenic cows secreting lysostaphin at concentrations ranging from 0.9 to 14 micrograms/ml [corrected] in their milk were produced. In vitro assays demonstrated the milk's ability to kill Staphylococcus aureus. Intramammary infusions of S. aureus were administered to three transgenic and ten nontransgenic cows. Increases in milk somatic cells, elevated body temperatures and induced acute phase proteins, each indicative of infection, were observed in all of the nontransgenic cows but in none of the transgenic animals. Protection against S. aureus mastitis appears to be achievable with as little as 3 micrograms/ml [corrected] of lysostaphin in milk. Our results indicate that genetic engineering can provide a viable tool for enhancing resistance to disease and improve the well-being of livestock.

  13. Staphylococcus aureus biofilms: recent developments in biofilm dispersal.

    Science.gov (United States)

    Lister, Jessica L; Horswill, Alexander R

    2014-01-01

    Staphylococcus aureus is a major cause of nosocomial and community-acquired infections and represents a significant burden on the healthcare system. S. aureus attachment to medical implants and host tissue, and the establishment of a mature biofilm, play an important role in the persistence of chronic infections. The formation of a biofilm, and encasement of cells in a polymer-based matrix, decreases the susceptibility to antimicrobials and immune defenses, making these infections difficult to eradicate. During infection, dispersal of cells from the biofilm can result in spread to secondary sites and worsening of the infection. In this review, we discuss the current understanding of the pathways behind biofilm dispersal in S. aureus, with a focus on enzymatic and newly described broad-spectrum dispersal mechanisms. Additionally, we explore potential applications of dispersal in the treatment of biofilm-mediated infections.

  14. Synergistic antibacterial activity of Curcumin with antibiotics against Staphylococcus aureus.

    Science.gov (United States)

    Teow, Sin-Yeang; Ali, Syed Atif

    2015-11-01

    This study evaluated the synergistic antibacterial activity of Curcumin with 8 different antibiotic groups. Two reference, one clinical and ten environmental strains of Staphylococcus aureus (S. aureus) were tested. Disc diffusion assay with 25 μg/mL Curcumin demonstrated synergism in combination with a majority of tested antibiotics against S. aureus. However, checkerboard micro dilution assay only showed synergism, fractional inhibitory concentration index (FICI) indifferent interactions but no antagonism was observed. In time-kill curve, appreciable reduction of bacterial cells was also observed in combination therapy (Curcumin + antibiotics) compared to monotherapy (Curcumin or antibiotic(s) alone). The antibiotics with higher synergistic interaction with Curcumin are arranged in a decreasing order: Amikacin > Gentamicin > Ciprofloxacin.

  15. Quality control of direct molecular diagnostics for methicillin-resistant Staphylococcus aureus.

    NARCIS (Netherlands)

    A.F. van Belkum (Alex); H.G.M. Niesters (Bert); W.G. MacKay (William); W.B. van Leeuwen (Willem)

    2007-01-01

    textabstractTen samples containing various amounts of methicillin-resistant Staphylococcus aureus (MRSA), methicillin-susceptible S. aureus, methicillin-resistant Staphylococcus epidermidis (MRSE), and combinations thereof were distributed to 51 laboratories for molecular diagnostics testing. Sample

  16. Quality control of direct molecular diagnostics for methicillin-resistant Staphylococcus aureus

    NARCIS (Netherlands)

    van Belkum, Alex; Niesters, Hubert G M; MacKay, William G; van Leeuwen, Willem B

    2007-01-01

    Ten samples containing various amounts of methicillin-resistant Staphylococcus aureus (MRSA), methicillin-susceptible S. aureus, methicillin-resistant Staphylococcus epidermidis (MRSE), and combinations thereof were distributed to 51 laboratories for molecular diagnostics testing. Samples containing

  17. The Significance of Nasal Carriage of Staphylococcus Aureus and the Incidence of Postoperative Wound Infection

    NARCIS (Netherlands)

    R.P. Wenzel (Richard); T. M. Perl

    1995-01-01

    textabstractStaphylococcus aureus infections are associated with considerable morbidity and, in certain situations, mortality. The association between the nasal carriage of S. aureus and subsequent infection has been comprehensively established in a variety of clinical settings, in particular, patie

  18. Draft Genome Sequence of Methicillin-Sensitive Staphylococcus aureus ATCC 29213

    OpenAIRE

    Soni, Isha; Chakrapani, Harinath; Chopra, Sidharth

    2015-01-01

    Staphylococcus aureus subsp. aureus ATCC 29213 is one of the most commonly used strains in drug discovery research and for quality control. We report the completed draft genome sequence for the strain.

  19. Superbugs causing ventilator associated pneumonia in a tertiary care hospital and the return of pre-antibiotic era!

    Directory of Open Access Journals (Sweden)

    S Qureshi

    2015-01-01

    Full Text Available The rise in super bugs causing Ventilator-Associated Pneumonia (VAP is a major cause of mortality and morbidity despite recent advances in management owing to the looming ′antibiotic apocalypse′. The aetiology and susceptibility pattern of the VAP isolates varies with patient population, type of intensive care unit (ICU and is an urgent diagnostic challenge. The present study carried out for a period of one year in a tertiary care hospital, enrolled patients on mechanical ventilation (MV for ≥48 hrs. Endotracheal aspirates (ETA from suspected VAP patients were processed by semi quantitative method. Staphylococus aureus, members of Enterobacteriaceae were more common in early onset VAP (EOVAP, while Nonfermenting Gram negative bacilli (NFGNB were significantly associated with late onset VAP (LOVAP. Most of the isolates were multi drug resistant (MDR super bugs. With limited treatment options left for this crisis situation like the pre-antibiotic era; it is an alarm for rational antibiotic therapy usage and intensive education programs.

  20. Staphylococcus aureus resistance to topical antimicrobials in atopic dermatitis*

    Science.gov (United States)

    Bessa, Giancarlo Rezende; Quinto, Vanessa Petry; Machado, Daiane Corrêa; Lipnharski, Caroline; Weber, Magda Blessmann; Bonamigo, Renan Rangel; D'Azevedo, Pedro Alves

    2016-01-01

    Background Topical antimicrobial drugs are indicated for limited superficial pyodermitis treatment, although they are largely used as self-prescribed medication for a variety of inflammatory dermatoses, including atopic dermatitis. Monitoring bacterial susceptibility to these drugs is difficult, given the paucity of laboratory standardization. Objective To evaluate the prevalence of Staphylococcus aureus topical antimicrobial drug resistance in atopic dermatitis patients. Methods We conducted a cross-sectional study of children and adults diagnosed with atopic dermatitis and S. aureus colonization. We used miscellaneous literature reported breakpoints to define S. aureus resistance to mupirocin, fusidic acid, gentamicin, neomycin and bacitracin. Results A total of 91 patients were included and 100 S. aureus isolates were analyzed. All strains were methicillin-susceptible S. aureus. We found a low prevalence of mupirocin and fusidic acid resistance (1.1% and 5.9%, respectively), but high levels of neomycin and bacitracin resistance (42.6% and 100%, respectively). Fusidic acid resistance was associated with more severe atopic dermatitis, demonstrated by higher EASI scores (median 17.8 vs 5.7, p=.009). Our results also corroborate the literature on the absence of cross-resistance between the aminoglycosides neomycin and gentamicin. Conclusions Our data, in a southern Brazilian sample of AD patients, revealed a low prevalence of mupirocin and fusidic acid resistance of S. aureus atopic eczema colonizer strains. However, for neomycin and bacitracin, which are commonly used topical antimicrobial drugs in Brazil, high levels of resistance were identified. Further restrictions on the use of these antimicrobials seem necessary to keep resistance as low as possible.

  1. Highly sensitive detection of Staphylococcus aureus directly from patient blood.

    Directory of Open Access Journals (Sweden)

    Padmapriya P Banada

    Full Text Available BACKGROUND: Rapid detection of bloodstream infections (BSIs can be lifesaving. We investigated the sample processing and assay parameters necessary for highly-sensitive detection of bloodstream bacteria, using Staphylococcus aureus as a model pathogen and an automated fluidic sample processing-polymerase chain reaction (PCR platform as a model diagnostic system. METHODOLOGY/PRINCIPAL FINDINGS: We compared a short 128 bp amplicon hemi-nested PCR and a relatively shorter 79 bp amplicon nested PCR targeting the S. aureus nuc and sodA genes, respectively. The sodA nested assay showed an enhanced limit of detection (LOD of 5 genomic copies per reaction or 10 colony forming units (CFU per ml blood over 50 copies per reaction or 50 CFU/ml for the nuc assay. To establish optimal extraction protocols, we investigated the relative abundance of the bacteria in different components of the blood (white blood cells (WBCs, plasma or whole blood, using the above assays. The blood samples were obtained from the patients who were culture positive for S. aureus. Whole blood resulted in maximum PCR positives with sodA assay (90% positive as opposed to cell-associated bacteria (in WBCs (71% samples positive or free bacterial DNA in plasma (62.5% samples positive. Both the assays were further tested for direct detection of S. aureus in patient whole blood samples that were contemporaneous culture positive. S. aureus was detected in 40/45 of culture-positive patients (sensitivity 89%, 95% CI 0.75-0.96 and 0/59 negative controls with the sodA assay (specificity 100%, 95% CI 0.92-1. CONCLUSIONS: We have demonstrated a highly sensitive two-hour assay for detection of sepsis causing bacteria like S. aureus directly in 1 ml of whole blood, without the need for blood culture.

  2. Automated DNA sequence-based early warning system for the detection of methicillin-resistant Staphylococcus aureus outbreaks.

    Directory of Open Access Journals (Sweden)

    Alexander Mellmann

    2006-03-01

    Full Text Available BACKGROUND: The detection of methicillin-resistant Staphylococcus aureus (MRSA usually requires the implementation of often rigorous infection-control measures. Prompt identification of an MRSA epidemic is crucial for the control of an outbreak. In this study we evaluated various early warning algorithms for the detection of an MRSA cluster. METHODS AND FINDINGS: Between 1998 and 2003, 557 non-replicate MRSA strains were collected from staff and patients admitted to a German tertiary-care university hospital. The repeat region of the S. aureus protein A (spa gene in each of these strains was sequenced. Using epidemiological and typing information for the period 1998-2002 as reference data, clusters in 2003 were determined by temporal-scan test statistics. Various early warning algorithms (frequency, clonal, and infection control professionals [ICP] alerts were tested in a prospective analysis for the year 2003. In addition, a newly implemented automated clonal alert system of the Ridom StaphType software was evaluated. A total of 549 of 557 MRSA were typeable using spa sequencing. When analyzed using scan test statistics, 42 out of 175 MRSA in 2003 formed 13 significant clusters (p < 0.05. These clusters were used as the "gold standard" to evaluate the various algorithms. Clonal alerts (spa typing and epidemiological data were 100% sensitive and 95.2% specific. Frequency (epidemiological data only and ICP alerts were 100% and 62.1% sensitive and 47.2% and 97.3% specific, respectively. The difference in specificity between clonal and ICP alerts was not significant. Both methods exhibited a positive predictive value above 80%. CONCLUSIONS: Rapid MRSA outbreak detection, based on epidemiological and spa typing data, is a suitable alternative for classical approaches and can assist in the identification of potential sources of infection.

  3. Minimum inhibitory concentration of ciprofloxacin in combination with hexahydroquinoline derivatives against Staphylococcus aureus

    OpenAIRE

    F Amin Harati; Amini, M; AR Shahverdi; Pourmand MR; Yousefi, M

    2012-01-01

    Background: Staphylococcus aureus is the most common pathogen responsible for skin and soft tissue infections worldwide. Methicillin-resistant S. aureus is a major cause of both nosocomial and community acquired infections. The emergence of antimicrobial-resistant S. aureus is of global concern. Fluoroquinolone antimicrobials including ciprofloxacin, levofloxacin, and moxifloxacin are used to treat skin and soft tissue infections due to S. aureus. Emergence of ciprofloxacin resistance has inc...

  4. Investigation of the bactericidal effects of vancomycin and quinupristin/dalfopristin on Staphylococcus aureus isolates

    OpenAIRE

    HOŞGÖR-LİMONCU, Mine; ERMERTCAN, Şafak; COŞAR, Güner

    2004-01-01

    The present study aimed to determine the correlation between the bactericidal activity of vancomycin and quinupristin/dalfopristin (Q/D) on Staphylococcus aureus isolates and their minimal inhibition concentrations. The in-vitro susceptibilities of the 99 S. aureus isolates to vancomycin and Q/D were investigated by agar dilution. Thirty methicillin-resistant S. aureus (MRSA) and 30 methicillin-susceptible S. aureus (MSSA) vancomycin and Q/D susceptible isolates were involved in time-kill stu...

  5. Daptomycin-nonsusceptible, vancomycin-intermediate, methicillin-resistant Staphylococcus aureus endocarditis

    OpenAIRE

    Ryan Yu; Dale, Suzanne E; Deborah Yamamura; Vida Stankus; Christine Lee

    2012-01-01

    Due to the emergence of Staphylococcus aureus with reduced vancomycin susceptibility, newer antibiotics, including daptomycin, have been used to treat methicillin-resistant S aureus infections. Daptomycin is a cyclic lipopeptide that is approved to treat S aureus bacteremia and right-sided endocarditis, and reports of S aureus with reduced susceptibility to daptomycin are infrequent. To our knowledge, the present report describes the first Canadian case of daptomycin-nonsusceptible, vancomyci...

  6. In Vivo Activity of Ceftobiprole in Murine Skin Infections Due to Staphylococcus aureus and Pseudomonas aeruginosa▿

    OpenAIRE

    Fernandez, Jeffrey; Hilliard, Jamese J.; Abbanat, Darren; Zhang, Wenyan; Melton, John L.; Santoro, Colleen M.; Flamm, Robert K.; Bush, Karen

    2009-01-01

    Ceftobiprole, a broad-spectrum cephalosporin with activity against methicillin-resistant Staphylococcus aureus (MRSA) (P. Hebeisen et al., Antimicrob. Agents Chemother. 45:825-836, 2001), was evaluated in a subcutaneous skin infection model with Staphylococcus aureus Smith OC 4172 (methicillin-susceptible S. aureus [MSSA]), S. aureus OC 8525 (MRSA), Pseudomonas aeruginosa OC 4351 (having an inducible AmpC β-lactamase), and P. aeruginosa OC 4354 (overproducing AmpC β-lactamase). In the MSSA an...

  7. Genotyping of Staphylococcus aureus strains isolated from healthy persistent carriers.

    Science.gov (United States)

    Grzegorczyk, Agnieszka; Malm, Anna

    2014-07-01

    The paper presents results on the relatedness of Staphylococcus aureus strains colonizing the upper respiratory tract isolated from healthy persistent carriers. Genotyping was carried out using two methods--multiple-locus variable-number tandem-repeat fingerprinting (MLVF) and pulsed-field gel electrophoresis (PFGE). By comparison of the results obtained by both methods, good correlations between MLVF and PFGE genotyping of strains isolated from the asymptomatic carriers were observed. Further studies are needed to evaluate methods useful for genotyping of S. aureus strains circulating in the community. PMID:24488811

  8. Brain infection following experimental Staphylococcus aureus sepsis in pigs

    DEFF Research Database (Denmark)

    Astrup, Lærke Boye; Iburg, Tine Moesgaard; Nielsen, Ole Lerberg;

    2010-01-01

    Introduction: Sepsis is a major problem in humans and both the incidence and mortality is increasing. Multiple microabcesses can be found in the brain of septic patients. Staphylococcus aureus is one of the most common causes of sepsis and brain abscesses. S. aureus is also a frequent cause...... pigs were kept as controls. The pigs were euthanized in groups of four at either 6, 12, 24 or 48 h post infection. The brain was collected from all the animals and examined histologically. Results: All the inoculated pigs developed sepsis and 7 out of 12 animals had microabscesses in the prosencephalon...

  9. Mechanism of bacteriophage conversion of lipase activity in Staphylococcus aureus.

    OpenAIRE

    Lee, C Y; Iandolo, J J

    1985-01-01

    Staphylococcus aureus PS54 harbors two temperate bacteriophages and manifests no lipase activity on egg yolk agar. Curing of one of the resident prophages (L54a) restores lipase activity. To study the mechanism of bacteriophage conversion, the prophage was cured, and the gene encoding lipase activity was cloned into pBR322 in Escherichia coli on a 2.9-kilobase DNA fragment of the chromosome. The fragment was subcloned into a shuttle vector and subsequently transformed into S. aureus and Bacil...

  10. Threat of multidrug resistant Staphylococcus aureus in Western Nepal

    DEFF Research Database (Denmark)

    Bhatta, Dharm R.; Cavaco, Lina; Nath, Gopal;

    2015-01-01

    ObjectiveTo determine the prevalence of methicillin resistant Staphylococcus aureus (MRSA) and antimicrobial susceptibility patterns of the isolates from Manipal Teaching Hospital, Pokhara, Nepal. MethodsThis study was conducted over a period of 11 months (September 2012–August 2013) at the Manipal...... using disc diffusion test by cefoxitin (30 μg) and oxacillin (1 μg) disc, further confirmation was done by detection of mecA gene using PCR. ResultsOut of 400 Staphylococcus aureus strains, 139 (34.75%) were found to be MRSA. Among the MRSA isolates, 74 (53.2%) were from inpatient departments, 58 (41...

  11. Response of Staphylococcus Aureus to a Spaceflight Analogue

    Science.gov (United States)

    Castro, S. L.; Ott, C. M.

    2010-01-01

    The decreased gravity of the spaceflight environment creates quiescent, low fluid shear conditions. This environment can impart considerable effects on the physiology of microorganisms as well as their interactions with potential hosts. Using the rotating wall vessel (RWV), as a spaceflight analogue, the consequence of low fluid shear culture on microbial pathogenesis has provided a better understanding of the risks to the astronaut crew from infectious microorganisms. While the outcome of low fluid shear culture has been investigated for several bacterial pathogens, little has been done to understand how this environmental factor affects Staphylococcus aureus. S. aureus is an opportunistic human pathogen which presents a high level of infection risk to the crew, as it has been isolated from both the space shuttle and International Space Station. Given that approximately forty percent of the population are carriers of the bacteria, eradication of this organism from in flight environments is impractical. These reasons have lead to us to assess the response of S. aureus to a reduced fluid shear environment. Culture in the RWV demonstrated that S. aureus grown under the low-shear condition had lower cell concentrations after 10 hours when compared to the control culture. Furthermore, the low-shear cultured bacteria displayed a reduction in carotenoid production, pigments responsible for their yellow/gold coloration. When exposed to various environmental stressors, post low-shear culture, a decrease in the ability to survive oxidative assault was observed compared to control cultures. The low fluid shear environment also resulted in a decrease in hemolysin secretion, a staphylococcal toxin responsible for red blood cell lysis. When challenged by the immune components present in human whole blood, low-shear cultured S. aureus demonstrated significantly reduced survival rates as compared to the control culture. Assays to determine the duration of these alterations

  12. CHARACTERISATION OF METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS ISOLATES FROM SHINGLES PATIENTS

    Directory of Open Access Journals (Sweden)

    Jasmine R. et al.

    2011-11-01

    Full Text Available Even after treating Shingles patients with antiviral drugs, they are found to suffer from secondary bacterial infections. With this background as a guide, we undertook an investigation to isolate the bacterial pathogens from the pus of Shingles patients. Among the isolates obtained during the one year study period, Staphylococcus aureus sp. was found to be multi drug resistant and hence it was chosen for the study. The antibiogram pattern of the methicillin resistant S. aureus was obtained, since this could serve as a tool for suggesting useful drugs.

  13. Staphylococcus aureus sternal osteomyelitis: a rare cause of chest pain

    Directory of Open Access Journals (Sweden)

    Kaur M

    2015-10-01

    Full Text Available Chest pain is a common presenting symptom with a broad differential. Life-threatening cardiac and pulmonary etiologies of chest pain should be evaluated first. However, it is critical to perform a thorough assessment for other sources of chest pain in order to limit morbidity and mortality from less common causes. We present a rare case of a previously healthy 45 year old man who presented with focal, substernal, reproducible chest pain and Staphylococcus aureus bacteremia who was later found to have primary Staphylococcus aureus sternal osteomyelitis.

  14. Methicillin-Resistant Staphylococcus aureus Colonization in Schoolteachers in Ontario

    Directory of Open Access Journals (Sweden)

    Beth A Hanselman

    2008-01-01

    Full Text Available A prospective study of methicillin-resistant Staphylococcus aureus (MRSA colonization was performed involving teachers at a science teachers’ conference in Toronto, Ontario. Nasal swabs and questionnaire data were collected from consenting individuals. MRSA colonization was identified in seven of 220 (3.2% participants. No colonized individuals reported recent contact with the health care system, antimicrobial therapy, residence with health care workers or previous MRSA infections. Methicillin-susceptible S aureus colonization was identified in 72 of 220 (33% individuals. The prevalence of MRSA colonization was higher than expected for a purportedly low-risk population.

  15. When are the hands of healthcare workers positive for methicillin-resistant Staphylococcus aureus?

    Science.gov (United States)

    Creamer, E; Dorrian, S; Dolan, A; Sherlock, O; Fitzgerald-Hughes, D; Thomas, T; Walsh, J; Shore, A; Sullivan, D; Kinnevey, P; Rossney, A S; Cunney, R; Coleman, D; Humphreys, H

    2010-06-01

    Hand hygiene is a key component in reducing infection. There are few reports on the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) on healthcare workers' (HCWs') hands. The aim of this study was to establish whether HCWs' fingertips were contaminated with MRSA in a clinical hospital setting. The study was conducted in an acute tertiary referral hospital on four MRSA wards that were part of a larger research study on MRSA epidemiology and four other wards not included in the study. The fingertips from all categories of 523 HCWs were sampled on 822 occasions by the imprinting of fingertips on MRSA chromogenic agar plates. The type of hand hygiene agent used, if any, and the immediate prior activity of the HCW were recorded. Overall, 38/822 (5%) fingertips from 523 HCWs were MRSA-positive; 12/194 (6%) after clinical contact, 10/138 (10%) after contact with the patient's environment and 15/346 (4%) after no specific contact. MRSA was recovered on 2/61 (3%) occasions after use of alcohol hand rub, 2/35 (6%) after 4% chlorhexidine detergent, 7/210 (3%) hand washing with soap and water, and 27/493 (5%) when no hand hygiene had been performed. MRSA was recovered from HCWs on seven of the eight wards. MRSA was more frequently present on fingertips on the four non-study wards vs the four MRSA study wards [18/250 (7%), 3/201 (1%), respectively; Phand hygiene, indicates that more educational programmes are necessary to improve the quality of hand hygiene to prevent transmission of MRSA. PMID:20299123

  16. When are the hands of healthcare workers positive for methicillin-resistant Staphylococcus aureus?

    LENUS (Irish Health Repository)

    Creamer, E

    2010-06-01

    Hand hygiene is a key component in reducing infection. There are few reports on the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) on healthcare workers\\' (HCWs\\') hands. The aim of this study was to establish whether HCWs\\' fingertips were contaminated with MRSA in a clinical hospital setting. The study was conducted in an acute tertiary referral hospital on four MRSA wards that were part of a larger research study on MRSA epidemiology and four other wards not included in the study. The fingertips from all categories of 523 HCWs were sampled on 822 occasions by the imprinting of fingertips on MRSA chromogenic agar plates. The type of hand hygiene agent used, if any, and the immediate prior activity of the HCW were recorded. Overall, 38\\/822 (5%) fingertips from 523 HCWs were MRSA-positive; 12\\/194 (6%) after clinical contact, 10\\/138 (10%) after contact with the patient\\'s environment and 15\\/346 (4%) after no specific contact. MRSA was recovered on 2\\/61 (3%) occasions after use of alcohol hand rub, 2\\/35 (6%) after 4% chlorhexidine detergent, 7\\/210 (3%) hand washing with soap and water, and 27\\/493 (5%) when no hand hygiene had been performed. MRSA was recovered from HCWs on seven of the eight wards. MRSA was more frequently present on fingertips on the four non-study wards vs the four MRSA study wards [18\\/250 (7%), 3\\/201 (1%), respectively; P

  17. Tertiary and Quaternary Research with Remote Sensing Methods

    Science.gov (United States)

    Conel, J. E.

    1985-01-01

    Problems encountered in mapping the Quaternary section of the Wind River Region using remote sensing methods are discussed. Analysis of the stratigraphic section is a fundamental aspect of the geologic study of sedimentary basins. Stratigraphic analysis of post-Cretaceous rocks in the Wind River Basin encounters problems of a distinctly different character from those involved in studying the pre-Cretaceous section. The interior of the basin is predominantly covered by Tertiary and Quaternary sediments. These rocks, except on the basin margin to the north, are mostly flat lying or gently dipping. The Tertiary section consists of sandstones, siltstones, and tuffaceous sediments, some variegated, but in general poorly bedded and of great lithologic similarity. The Quaternary sediments consist of terrace, fan, and debris tongue deposits, unconsolidated alluvium occupying the bottoms of modern watercourses, deposits of eolian origin and tufa. Terrace and fan deposits are compositionally diverse and reflect the lithologic diversity of the source terranes.

  18. Medical treatment of primary, secondary, and tertiary hyperparathyroidism

    DEFF Research Database (Denmark)

    Thomsen, Súsanna v.; Vestergaard, Peter

    2011-01-01

    in vitamin D or uremia, and 3) tertiary hyperparathyroidism, which most often is the result of a long-standing, severe secondary hyperparathyroidism, which has turned autonomous once the cause of the secondary hyperparathyroidism has been removed. Many new treatment options have been introduced in recent...... years. Cinacalcet is calcium sensing receptor agonist, which by stimulating the receptor decreases PTH and calcium levels. It may be used in primary hyperparathyroidism, secondary hyperparathyroidism caused by uremia, which may not be controlled with calcium and activated vitamin D. It may also be used...... in tertiary hyperparathyroidism. Newer analogues of vitamin D such as paricalcitol have also been introduced, which may have an advantage over traditional compounds such as alphacalcidol and calcitriol....

  19. STUDY OF MATERNAL MORTALITY IN A TERTIARY CARE HOSPITAL

    Directory of Open Access Journals (Sweden)

    Sandhya Devi

    2015-05-01

    Full Text Available BACKGROUND: A woman dies from complications of child birth every minute . The major causes for maternal mortality in India are uncontrolled fertility , inaccessibility or inadequate utilization of health care facilities , illiteracy , ignorance and gender discrimination . OBJECTIV ES: (1 To identify various causes of maternal deaths in a teaching hospital . (2 To study the profile of population attending the tertiary hospital . Methodology : A retrospective study was conducted in a tertiary hospital over a period of 2 years (January 2013 - December 2014 and data was analysed manually using case sheets and maternal death audit forms . RESULTS: In the study period , there were 11636 deliveries and 97 maternal deaths . The direct causes accounted for 77 maternal deaths with haemorrhage , hype rtension and sepsis as leading causes of maternal mortality . Conclusion : Emphasis on health education , need for regular antenatal checkups and proper training of health personnel is required to reduce maternal mortality .

  20. The population structure of Staphylococcus Aureus among general practice patients from The Netherlands.

    NARCIS (Netherlands)

    Donker, G.A.; Deurenberg, R.H.; Driessen, C.; Sebastian, S.; Nijs, S.; Stobberingh, E.E.

    2009-01-01

    To investigate the prevalence, the antibiotic resistance pattern and the population structure of Staphylococcus aureus, S. aureus isolates from the anterior nostrils of patients of general practitioners (GPs) were analysed. Insight into the S. aureus population structure is essential, as nasal carri

  1. Nosocomial Infections and Drug Susceptibility Patterns in Methicillin Sensitive and Methicillin Resistant Staphylococcus aureus

    OpenAIRE

    Sharma, Nitish Kumar; Garg, Raina; Baliga, Shrikala; Bhat K., Gopalkrishna

    2013-01-01

    Aim: Staphylococcus aureus is one of the leading causes of nosocomial infections and is known for its ability to develop resistance to antibiotics. The drug susceptibility pattern of Methicillin Sensitive S. aureus (MSSA) and Methicillin Resistant S. aureus (MRSA) may vary.

  2. Staphylococcus aureus Strains That are Hypersusceptible to Resistance Gene Transfer from Enterococci▿

    OpenAIRE

    Sung, Julia M.-L.; Lindsay, Jodi A

    2007-01-01

    We identified naturally occurring Staphylococcus aureus mutants of the restriction modification pathway SauI, including bovine lineage ST151. In a model of vancomycin resistance transfer from Enterococcus faecalis, ST151 isolates are 500 times more susceptible than human S. aureus isolates. The eradication of “hyperrecipient” strains may reduce the evolution of vancomycin-resistant S. aureus.

  3. Genome Sequences of Four Staphylococcus aureus Strains Isolated from Bovine Mastitis

    OpenAIRE

    Kant, Ravi; Taponen, Suvi; Koort, Joanna; Paulin, Lars; Åvall-Jääskeläinen, Silja; Palva, Airi

    2015-01-01

    Staphylococcus aureus is a major causative agent of mastitis in dairy cows. The pathogenicity of S. aureus may vary; it is able to cause severe clinical mastitis, but most often it is associated with chronic subclinical mastitis. Here, we present the genome assemblies of four S. aureus strains from bovine mastitis.

  4. Genome Sequences of Four Staphylococcus aureus Strains Isolated from Bovine Mastitis.

    Science.gov (United States)

    Kant, Ravi; Taponen, Suvi; Koort, Joanna; Paulin, Lars; Åvall-Jääskeläinen, Silja; Palva, Airi

    2015-01-01

    Staphylococcus aureus is a major causative agent of mastitis in dairy cows. The pathogenicity of S. aureus may vary; it is able to cause severe clinical mastitis, but most often it is associated with chronic subclinical mastitis. Here, we present the genome assemblies of four S. aureus strains from bovine mastitis. PMID:25908141

  5. Phosphorus removal in passive treatment technologies for tertiary wastewater treatment

    OpenAIRE

    Letshwenyo, Moatlhodi Wise

    2014-01-01

    The treatment of phosphorus at small sewage works requires alternative approaches to the traditional chemical precipitation and biological removal pathways, as such approaches do not align well to the requirements at such a scale in relation to the use of chemicals, increased energy demands and/or increased sludge production. At small sewage works, constructed wetlands are often used as a tertiary treatment for solid removal and some associated biological degradation. The curre...

  6. Learning and teaching styles: Empowering diverse learners in tertiary classrooms

    OpenAIRE

    Carisma Dreyer; Van der Walt, Johann L.

    1996-01-01

    Learning and teaching styles: Empowering diverse learners in tertiary classroomsThe aim of this article is to make lecturers aware of the importance of the various elements comprising an individual learning and teaching style. Suggestions are made as to how lecturers can help their students develop a more flexible, empowered approach to diverse learning contexts and tasks and thereby preventing "style wars". If lecturers can show students the variety and versatility of learning styles by pro ...

  7. Photocatalysis as a tertiary treatment for petroleum refinery wastewaters

    OpenAIRE

    F. V. Santos; E. B. Azevedo; G. L. Sant'Anna Jr; M. Dezotti

    2006-01-01

    Photocatalysis has been used as tertiary treatment for petroleum refinery wastewaters to comply with the regulatory discharge limits and to oxidize persistent compounds that had not been oxidized in the biological treatment. The wastewater is generated by the refinery and directly discharged into the Guanabara Bay (Rio de Janeiro). Although BOD removal is high, a residual and persistent COD, besides a somewhat high phenol content remains. Three photocatalysts were tested - TiO2 (Aldrich), ZnO...

  8. Patterns of cancer occurrence in a tertiary care centre

    OpenAIRE

    Atla Bhagyalakshmi; Anem Venkatalakshmi; Regidi Subhash; Seeram Satish kumar

    2016-01-01

    Background: This study is an attempt to know the incidence of cancer in a tertiary care centre. Statistics for all newly diagnosed cancer cases by correlation with factors like age, gender and organ systems involved with complete histopathological evaluation is presented. Emphasis is given to segregating each cancer and grouping them into their respective order for statistical analysis. Objectives of the study was to conduct a prospective statistical analysis, computing and comparing rates,...

  9. Maternal mortality: a tertiary care hospital experience in Upper Egypt

    Directory of Open Access Journals (Sweden)

    Ahmed M. Abbas

    2016-05-01

    Conclusions: Preeclampsia and PPH, as well as their complications are the leading causes of death in one of the biggest tertiary care university hospitals in Egypt. However, there are other important avoidable predisposing factors that should be dealt with including lack of patient education, delayed transfer from other hospitals, and substandard practice. [Int J Reprod Contracept Obstet Gynecol 2016; 5(5.000: 1466-1471

  10. External environment of tertiary education in the Czech Republic

    OpenAIRE

    Švrček, Roman

    2014-01-01

    This bachelor's thesis deals with analysis of external environment of tertiary education institutions in the Czech Republic. In the thesis the analysis of the environment is done according to Porter's model of five forces -- given model is also critically looked upon to verify it's suitability to task at hand. Main goal of the thesis is however to suggest changes and recommendations that should lead to influencing the external environment in favor of instututions operating in the field of ter...

  11. Clontarf to Curtin: Row AHEAD and Tertiary Affinity

    OpenAIRE

    Cameron Thorn; Charles Flodin

    2015-01-01

    In Western Australia, and around the world, rowing is a sport that is often associated with elite private schools and tertiary institutions (Cambridge University Boat Club, 2013; Yale Athletics, 2010; Oxford University Boat Club, 2015; Melbourne University Boat Club, 2015). Events like the Boat Race, an annual rowing event for the top Oxford and Cambridge University crews, and the Henley Royal Regatta, held on the Thames River since 1839, serve to reinforce the elitist history of the sport. I...

  12. Is the sword moss (Bryoxiphium) a preglacial Tertiary relict?

    Science.gov (United States)

    Patiño, Jairo; Goffinet, Bernard; Sim-Sim, Manuela; Vanderpoorten, Alain

    2016-03-01

    The disjunction of floras between East Asia, Southeast North America, West North America, and Southwest Eurasia has been interpreted in terms of the fragmentation of a once continuous mixed mesophytic forest that occurred throughout the Northern Hemisphere due to the climatic and geological changes during the late Tertiary. The sword moss, Bryoxiphium, exhibits a distribution that strikingly resembles that of the mesophytic forest elements such as Liriodendron and is considered as the only living member of an early Tertiary flora in Iceland. These hypotheses are tested here using molecular dating analyses and ancestral area estimations. The results suggest that the extant range of Bryoxiphium results from the fragmentation of a formerly wider range encompassing North America and Southeast Asia about 10 million years ago. The split of continental ancestral populations is too recent to match with a continental drift scenario but is spatially and temporally remarkably congruent with that observed in Tertiary angiosperm relict species. The timing of the colonization of Iceland from Macaronesian ancestors, about two million years ago, is, however, incompatible with the hypothesis that Bryoxiphium is the only living member of an early Tertiary flora of the island. Alaska was recurrently colonized from East Asia. The ability of Bryoxiphium to overcome large oceanic barriers is further evidenced by its occurrence on remote oceanic archipelagos. In particular, Madeira was colonized twice independently from American and East Asian ancestors, respectively. The striking range disjunction of Bryoxiphium is interpreted in terms of its mating system, as the taxon exhibits a very singular pattern of spatial segregation of the sexes. PMID:26708122

  13. MRSA in a tertiary care hospital (1999-2004)

    OpenAIRE

    Goll, Carsten

    2010-01-01

    In the years between 1999 and 2004 data from 908 MRSA-positive patients was collected in a tertiary care hospital with approximately 1,200 beds. An increase in epidemiological parameters such as MRSA-rate and MRSA-day-prevalence shows the growing significance of MRSA as a nosocomial pathogen. MRSA was found primarily on non-surgical wards, especially on internal care wards. MRSA patients showed a significantly higher mortality rate as well as a considerably higher median age. The ...

  14. Analysis of the peptidoglycan hydrolase complement of Lactobacillus casei and characterization of the major γ-D-glutamyl-L-lysyl-endopeptidase.

    Directory of Open Access Journals (Sweden)

    Krzysztof Regulski

    Full Text Available Peptidoglycan (PG is the major component of Gram positive bacteria cell wall and is essential for bacterial integrity and shape. Bacteria synthesize PG hydrolases (PGHs which are able to cleave bonds in their own PG and play major roles in PG remodelling required for bacterial growth and division. Our aim was to identify the main PGHs in Lactobacillus casei BL23, a lactic acid bacterium with probiotic properties.The PGH complement was first identified in silico by amino acid sequence similarity searches of the BL23 genome sequence. Thirteen PGHs were detected with different predicted hydrolytic specificities. Transcription of the genes was confirmed by RT-PCR. A proteomic analysis combining the use of SDS-PAGE and LC-MS/MS revealed the main seven PGHs synthesized during growth of L. casei BL23. Among these PGHs, LCABL_02770 (renamed Lc-p75 was identified as the major one. This protein is the homolog of p75 (Msp1 major secreted protein of Lactobacillus rhamnosus GG, which was shown to promote survival and growth of intestinal epithelial cells. We identified its hydrolytic specificity on PG and showed that it is a γ-D-glutamyl-L-lysyl-endopeptidase. It has a marked specificity towards PG tetrapeptide chains versus tripeptide chains and for oligomers rather than monomers. Immunofluorescence experiments demonstrated that Lc-p75 localizes at cell septa in agreement with its role in daughter cell separation. It is also secreted under an active form as detected in zymogram. Comparison of the muropeptide profiles of wild type and Lc-p75-negative mutant revealed a decrease of the amount of disaccharide-dipeptide in the mutant PG in agreement with Lc-p75 activity. As a conclusion, Lc-p75 is the major L. casei BL23 PGH with endopeptidase specificity and a key role in daughter cell separation. Further studies will aim at investigating the role of Lc-p75 in the anti-inflammatory potential of L. casei BL23.

  15. Cryptosporidium and Giardia removal by secondary and tertiary wastewater treatment.

    Science.gov (United States)

    Taran-Benshoshan, Marina; Ofer, Naomi; Dalit, Vaizel-Ohayon; Aharoni, Avi; Revhun, Menahem; Nitzan, Yeshayahu; Nasser, Abidelfatah M

    2015-01-01

    Wastewater disposal may be a source of environmental contamination by Cryptosporidium and Giardia. This study was conducted to evaluate the prevalence of Cryptosporidium oocysts and Giardia cysts in raw and treated wastewater effluents. A prevalence of 100% was demonstrated for Giardia cysts in raw wastewater, at a concentration range of 10 to 12,225 cysts L(-1), whereas the concentration of Cryptosporidium oocysts in raw wastewater was 4 to 125 oocysts L(-1). The removal of Giardia cysts by secondary and tertiary treatment processes was greater than those observed for Cryptosporidium oocysts and turbidity. Cryptosporidium and Giardia were present in 68.5% and 76% of the tertiary effluent samples, respectively, at an average concentration of 0.93 cysts L(-1) and 9.94 oocysts L(-1). A higher detection limit of Cryptosporidium oocysts in wastewater was observed for nested PCR as compared to immune fluorescent assay (IFA). C. hominis was found to be the dominant genotype in wastewater effluents followed by C. parvum and C. andersoni or C. muris. Giardia was more prevalent than Cryptosporidium in the studied community and treatment processes were more efficient for the removal of Giardia than Cryptosporidium. Zoonotic genotypes of Cryptosporidium were also present in the human community. To assess the public health significance of Cryptosporidium oocysts present in tertiary effluent, viability (infectivity) needs to be assessed. PMID:26301853

  16. Tertiary Education and the Crisis of Public Finance

    Directory of Open Access Journals (Sweden)

    Milos Maryska

    2012-04-01

    Full Text Available Turbulent economic environment after overwhelming the last crisis period is typical for present days as well as permanent increasing dependability of all our activities on information and communication technology (ICT. Although the global economic crisis was the reason for disinvestment into ICT in 2009 there is expected that ICT will generate almost 5.8 million new jobs in Europe till year 2013 and they have to be saturated also by adequately qualified ICT specialists.This contribution presents the research in the progress focused on the tertiary education system in the Czech Republic. We are predicting trends in education and especially in ICT education in Europe and in the Czech Republic as well for next ten years. We can expect that future ten years period will be critical not only for the Czech tertiary education system, but also for the Czech Republic because number of ICT students will be decreasing and number of ICT specialist demanded by labor market will be increasing. From macroeconomic point of view we can expect that also state subventions into state governed tertiary education system will decrease in the whole Europe.Some recommendations, proposals and forecasts for further development of education system are presented at the end of this contribution.

  17. Epidemiology of Staphylococcus aureus in Bangalore, India: emergence of the ST217 clone and high rate of resistance to erythromycin and ciprofloxacin in the community

    Science.gov (United States)

    Bouchiat, C.; El-Zeenni, N.; Chakrakodi, B.; Nagaraj, S.; Arakere, G.; Etienne, J.

    2015-01-01

    This study aimed to determine the antibiotic susceptibility pattern of Staphylococcus aureus (SA) and the circulating clones in Bangalore, India. Susceptibility testing was performed for all cases of SA infections in a tertiary-care hospital. Panton-Valentine leucocidin (PVL) encoding genes were detected, and sequence type and spa type were determined. Out of the 92 collected strains, 52.2% were methicillin-resistant SA (MRSA), isolated from community-acquired (CA) infections in 60.4% and hospital-acquired (HA) infections in 39.6%. S. aureus isolates were also highly resistant to erythromycin (54.3%) and ciprofloxacin (70.6%) in methicillin-susceptible SA (MSSA) and MRSA, as well as in CA and HA infections. MRSA were found to be significantly more resistant to gentamicin (p <0.001), cotrimoxazole (p <0.001) and ciprofloxacin (p 0.001) than MSSA, but no significant difference was observed between CA- and HA-SA. ST217 appeared as a new emerging and prevalent clone, but ST772 remained the predominant clone, all being PVL-positive isolates. Our study points out the high prevalence of MRSA, even in the community, and the worrying increase of resistance to ciprofloxacin and erythromycin among CA-MSSA. Emergence of clone ST217 is reported for the first time in India. PMID:26110062

  18. Climatic Factors and Community — Associated Methicillin-Resistant Staphylococcus aureus Skin and Soft-Tissue Infections — A Time-Series Analysis Study

    Directory of Open Access Journals (Sweden)

    Krushna Chandra Sahoo

    2014-08-01

    Full Text Available Skin and soft tissue infections caused by Staphylococcus aureus (SA-SSTIs including methicillin-resistant Staphylococcus aureus (MRSA have experienced a significant surge all over the world. Changing climatic factors are affecting the global burden of dermatological infections and there is a lack of information on the association between climatic factors and MRSA infections. Therefore, association of temperature and relative humidity (RH with occurrence of SA-SSTIs (n = 387 and also MRSA (n = 251 was monitored for 18 months in the outpatient clinic at a tertiary care hospital located in Bhubaneswar, Odisha, India. The Kirby-Bauer disk diffusion method was used for antibiotic susceptibility testing. Time-series analysis was used to investigate the potential association of climatic factors (weekly averages of maximum temperature, minimum temperature and RH with weekly incidence of SA-SSTIs and MRSA infections. The analysis showed that a combination of weekly average maximum temperature above 33 °C coinciding with weekly average RH ranging between 55% and 78%, is most favorable for the occurrence of SA-SSTIs and MRSA and within these parameters, each unit increase in occurrence of MRSA was associated with increase in weekly average maximum temperature of 1.7 °C (p = 0.044 and weekly average RH increase of 10% (p = 0.097.

  19. HIGH LEVELS OF MONOAROMATIC COMPOUNDS LIMIT THE USE OF SOLID-PHASE MICROEXTRACTION OF METHYL TERTIARY BUTYL ETHER AND TERTIARY BUTYL ALCOHOL

    Science.gov (United States)

    Recently, two papers reported the use of solid-phase microextraction (SPME) with polydimethylsiloxane(PDMS)/Carboxen fibers to determine trace levels of methyl tertiary butyl ether (MTBE) and tertiary butyl alcohol (tBA) in water. Attempts were made to apply this technique to th...

  20. Staphylococcus aureus α toxin potentiates opportunistic bacterial lung infections.

    Science.gov (United States)

    Cohen, Taylor S; Hilliard, Jamese J; Jones-Nelson, Omari; Keller, Ashley E; O'Day, Terrence; Tkaczyk, Christine; DiGiandomenico, Antonio; Hamilton, Melissa; Pelletier, Mark; Wang, Qun; Diep, Binh An; Le, Vien T M; Cheng, Lily; Suzich, JoAnn; Stover, C Kendall; Sellman, Bret R

    2016-03-01

    Broad-spectrum antibiotic use may adversely affect a patient's beneficial microbiome and fuel cross-species spread of drug resistance. Although alternative pathogen-specific approaches are rationally justified, a major concern for this precision medicine strategy is that co-colonizing or co-infecting opportunistic bacteria may still cause serious disease. In a mixed-pathogen lung infection model, we find that the Staphylococcus aureus virulence factor α toxin potentiates Gram-negative bacterial proliferation, systemic spread, and lethality by preventing acidification of bacteria-containing macrophage phagosomes, thereby reducing effective killing of both S. aureus and Gram-negative bacteria. Prophylaxis or early treatment with a single α toxin neutralizing monoclonal antibody prevented proliferation of co-infecting Gram-negative pathogens and lethality while also promoting S. aureus clearance. These studies suggest that some pathogen-specific, antibody-based approaches may also work to reduce infection risk in patients colonized or co-infected with S. aureus and disparate drug-resistant Gram-negative bacterial opportunists.

  1. Genetic Diversity of Staphylococcus aureus in Buruli Ulcer

    NARCIS (Netherlands)

    Amissah, Nana Ama; Glasner, Corinna; Ablordey, Anthony; Tetteh, Caitlin S.; Kotey, Nana Konama; Prah, Isaac; van der Werf, Tjip; Rossen, John W.; van Dijl, Jan Maarten; Stienstra, Ymkje

    2015-01-01

    Background Buruli ulcer (BU) is a necrotizing skin disease caused by Mycobacterium ulcerans. Previous studies have shown that wounds of BU patients are colonized with M. ulcerans and several other microorganisms, including Staphylococcus aureus, which may interfere with wound healing. The present st

  2. Strain Discrimination of Staphylococcus aureus Using Superantigen Profiles.

    Science.gov (United States)

    Tsen, Hau-Yang; Li, Sheng-Chih; Chiang, Yu-Cheng; Tsai, Shuo-Wen

    2016-01-01

    Staphylococcus aureus is one of the major bacterial species that may cause clinical infection and food-poisoning cases. Strains of this species may produce a series of superantigens (SAgs). Due to the importance of staphylococcal infections, reliable methods for the discrimination of strains of this species are important. Such data may allow us to trace the infection origins and be used for epidemiological study. For strain discrimination, genotyping methods, such as pulsed-field gel electrophoresis (PFGE), random amplified polymorphic DNA (RAPD), and multi-locus sequence typing (MLST), etc., could be used. Recently, toxin gene profiles, which can be used for the elucidation of the genetic and pathogenic relatedness between strains, also have been used to improve the strain discrimination. For S. aureus, as more SAg genes were discovered, the SAg profiles become more useful for the strain discrimination of S. aureus. In this chapter, a method for the discrimination of S. aureus strains using superantigen profiles will be described in detail.

  3. USA300 Methicillin-resistant Staphylococcus aureus in Cuba

    Directory of Open Access Journals (Sweden)

    Hopman Joost

    2012-01-01

    Full Text Available Abstract Background Methicillin-resistant Staphylococcus aureus is an increasing problem in the Caribbean. We investigated the molecular epidemiology of MRSA isolates on Cuba. Findings The predominant clone was of the spa type t149, followed by community-associated MRSA USA300. Conclusions We report the first molecular typing results of MRSA isolates from Cuba.

  4. Vancomycin-resistant Staphylococcus aureus: no apocalypse now.

    Science.gov (United States)

    Goldstein, F W; Kitzis, M D

    2003-08-01

    The number of reports concerning vancomycin-resistant Staphylococcus aureus is much higher than the number of true resistant strains or unexpected clinical failures. Many confounding factors, including inadequate serum levels, severely ill patients, foreign devices or undrained abscesses, are more likely to be responsible for the clinical failures than resistance to vancomycin. PMID:14616695

  5. Methicillin-Resistant Staphylococcus aureus Colonization among Medical Residents

    Directory of Open Access Journals (Sweden)

    Pascale Trépanier

    2013-01-01

    Full Text Available BACKGROUND: Medical residents may be at risk of becoming colonized by methicillin-resistant Staphylococcus aureus (MRSA during their training. The occupational risk of this specific population is unknown. Furthermore, there are no data regarding MRSA colonization among health care professionals in Quebec.

  6. Human Staphylococcus aureus lineages among Zoological Park residents in Greece

    Directory of Open Access Journals (Sweden)

    E. Drougka

    2015-10-01

    Full Text Available Staphylococcus aureus is a part of the microbiota flora in many animal species. The clonal spread of S. aureus among animals and personnel in a Zoological Park was investigated. Samples were collected from colonized and infected sites among 32 mammals, 11 birds and eight humans. The genes mecA, mecC, lukF/lukS-PV (encoding Panton-Valentine leukocidin, PVL and tst (toxic shock syndrome toxin-1 were investigated by PCR. Clones were defined by Multilocus Sequence Typing (MLST, spa type and Pulsed-Field Gel Electrophoresis (PFGE. Seven S. aureus isolates were recovered from four animals and one from an employee. All were mecA, mecC and tst–negative, whereas, one carried the PVL genes and was isolated from an infected Squirrel monkey. Clonal analysis revealed the occurrence of seven STs, eight PFGE and five spa types including ones of human origin. Even though a variety of genotypes were identified among S. aureus strains colonizing zoo park residents, our results indicate that colonization with human lineages has indeed occurred.

  7. Killing of Staphylococcus aureus by C-8-Methoxy Fluoroquinolones

    OpenAIRE

    Zhao, Xilin; Wang, Jian-Ying; Xu, Chen; Dong, Yuzhi; Zhou, Jianfeng; Domagala, John; Drlica, Karl

    1998-01-01

    C-8-methoxy fluoroquinolones were more lethal than C-8-bromine, C-8-ethoxy, and C-8-H derivatives for Staphylococcus aureus, especially when topoisomerase IV was resistant. The methoxy group also increased lethality against wild-type cells when protein synthesis was inhibited. These properties encourage refinement of C-8-methoxy fluoroquinolones to kill staphylococci.

  8. Staphylococcus aureus with reduced susceptibility to vancomycin in healthcare settings.

    Science.gov (United States)

    Spagnolo, A M; Orlando, P; Panatto, D; Amicizia, D; Perdelli, F; Cristina, M L

    2014-12-01

    Glycopeptide resistance in Staphylococcus aureus is a source of great concern because, especially in hospitals, this class of antibiotics, particularly vancomycin, is one of the main resources for combating infections caused by methicillin-resistant Staphylococcus aureus strains (MRSA). Reduced susceptibility to vancomycin (VISA) was first described in 1996 in Japan; since then, a phenotype with heterogeneous resistance to vancomycin (h-VISA) has emerged. H-VISA isolates are characterised by the presence of a resistant subpopulation, typically at a rate of 1 in 10(5) organisms, which constitutes the intermediate stage betweenfully vancomycin-susceptible S. aureus (VSSA) and VISA isolates. As VISA phenotypes are almost uniformly cross-resistant to teicoplanin, they are also called Glycopeptides-intermediate Staphylococcus aureus strains (GISA) and, in the case of heterogeneous resistance to glycopeptides, h-GISA. The overall prevalence of h-VISA is low, accounting for approximately 1.3% of all MRSA isolates tested. Mortality due to h-GISA infections is very high (about 70%), especially among patients hospitalised in high-risk departments, such as intensive care units (ICU). Given the great clinical relevance of strains that are heteroresistant to glycopeptides and the possible negative impact on treatment choices, it is important to draw up and implement infection control practices, including surveillance, the appropriate use of isolation precautions, staff training, hand hygiene, environmental cleansing and good antibiotic stewardship.

  9. Review on Panton Valentine leukocidin toxin carriage among Staphylococcus aureus.

    Science.gov (United States)

    Shrestha, B

    2013-09-01

    Panton Valentine leukocidin is a toxin making pores in the polymorphonuclear cells which is a virulence factor of some strains of Staphylococcus aureus. Initially it was produced by methicillin susceptible Staphylococcus aureus only. Later with the acquisition of mecA gene has lead it to be PVL positive methicillin resistant Staphylococcus aureus. Since MRSA are resistant to many antibiotics and further they produce a toxin the infections by PVL positive MRSA has become a challenge. PVL positive MRSA a virulent strain of drug resistant superbug MRSA that has spread around the world, has claimed many lives in UK, Europe, USA and Australia. Some strains of superbug attack the healthy young people and kill within 24 hrs. PVL positive Staphylococcus aureus has been reported to be associated with skin and soft tissue infections however they also cause invasive infections and necrotizing pneumonia. These microorganisms known to be community associated have spread to hospitals. Hospital acquired infection by such microorganisms lead to an increase in mortality hence should be controlled before they become prevalent in hospitals. PMID:24908537

  10. Staphylococcus aureus causing tropical pyomyositis, Amazon Basin, Peru.

    NARCIS (Netherlands)

    Garcia, C.; Hallin, M.; Deplano, A.; Denis, O.; Sihuincha, M.; Groot, R. de; Gotuzzo, E.; Jacobs, J.

    2013-01-01

    We studied 12 Staphylococcus aureus isolates causing tropical pyomyositis in the Amazon Basin of Peru. All isolates were methicillin-susceptible; 11 carried Panton-Valentine leukocidin-encoding genes, and 5 belonged to multilocus sequence type 25 and possessed an extensive set of enterotoxins. Our f

  11. Epidemic Increase in Methicillin-resistant Staphylococcus aureus in Copenhagen

    DEFF Research Database (Denmark)

    Westh, Henrik; Boye, Kit; Bartels, Mette Damkjær;

    2006-01-01

    INTRODUCTION: We have found an epidemic increase in methicillin-resistant Staphylococcus aureus (MRSA) in Copenhagen. The increase has a complex background and involves hospitals, nursing homes and persons nursed in their own home. MATERIAL AND METHODS: We found 33 MRSA patients in 2003 and 121...

  12. Pyrazole Based Inhibitors against Enzymes of Staphylococcus aureus

    DEFF Research Database (Denmark)

    Jagadeesan, G.; Vijayakuma, Vinodhkumar; Palayam, Malathy;

    2015-01-01

    agents. The current study focuses on molecular docking and dynamics studies of pyrazole derivatives against Nucleosidase and DNA gyrase B of Staphylococcus aureus. Molecular docking and dynamics studies reveal that some of these derivatives show better binding abilities than some of the current drugs...

  13. Increased risk of arterial thromboembolic events after Staphylococcus aureus bacteremia

    DEFF Research Database (Denmark)

    Mejer, N; Gotland, N; Uhre, M L;

    2015-01-01

    OBJECTIVES: An association between infection and arterial thromboembolic events (ATE) has been suggested. Here we examined the risk of myocardial infarction (MI), stroke and other ATE after Staphylococcus aureus bacteremia (SAB). METHODS: Danish register-based nation-wide observational cohort study...

  14. An Interdisciplinary Experiment: Azo-Dye Metabolism by "Staphylococcus Aureus"

    Science.gov (United States)

    Brocklesby, Kayleigh; Smith, Robert; Sharp, Duncan

    2012-01-01

    An interdisciplinary and engaging practical is detailed which offers great versatility in the study of a qualitative and quantitative metabolism of azo-dyes by "Staphylococcus aureus". This practical has broad scope for adaptation in the number and depth of variables to allow a focused practical experiment or small research project. Azo-dyes are…

  15. Diabetes and risk of community-acquired Staphylococcus aureus bacteremia

    DEFF Research Database (Denmark)

    Smit, Jesper; Søgaard, Mette; Schønheyder, Henrik Carl;

    2016-01-01

    OBJECTIVE: Patients with diabetes may experience higher risk of Staphylococcus aureus bacteremia (SAB) than patients without diabetes due to decreased immunity or coexisting morbidities. We investigated the risk of community-acquired (CA) SAB in persons with and without diabetes. DESIGN: Using...

  16. Staphylococcus aureus with reduced susceptibility to vancomycin in healthcare settings.

    Science.gov (United States)

    Spagnolo, A M; Orlando, P; Panatto, D; Amicizia, D; Perdelli, F; Cristina, M L

    2014-12-01

    Glycopeptide resistance in Staphylococcus aureus is a source of great concern because, especially in hospitals, this class of antibiotics, particularly vancomycin, is one of the main resources for combating infections caused by methicillin-resistant Staphylococcus aureus strains (MRSA). Reduced susceptibility to vancomycin (VISA) was first described in 1996 in Japan; since then, a phenotype with heterogeneous resistance to vancomycin (h-VISA) has emerged. H-VISA isolates are characterised by the presence of a resistant subpopulation, typically at a rate of 1 in 10(5) organisms, which constitutes the intermediate stage betweenfully vancomycin-susceptible S. aureus (VSSA) and VISA isolates. As VISA phenotypes are almost uniformly cross-resistant to teicoplanin, they are also called Glycopeptides-intermediate Staphylococcus aureus strains (GISA) and, in the case of heterogeneous resistance to glycopeptides, h-GISA. The overall prevalence of h-VISA is low, accounting for approximately 1.3% of all MRSA isolates tested. Mortality due to h-GISA infections is very high (about 70%), especially among patients hospitalised in high-risk departments, such as intensive care units (ICU). Given the great clinical relevance of strains that are heteroresistant to glycopeptides and the possible negative impact on treatment choices, it is important to draw up and implement infection control practices, including surveillance, the appropriate use of isolation precautions, staff training, hand hygiene, environmental cleansing and good antibiotic stewardship. PMID:26137787

  17. Staphylococcus aureus redirects central metabolism to increase iron availability.

    Directory of Open Access Journals (Sweden)

    David B Friedman

    2006-08-01

    Full Text Available Staphylococcus aureus pathogenesis is significantly influenced by the iron status of the host. However, the regulatory impact of host iron sources on S. aureus gene expression remains unknown. In this study, we combine multivariable difference gel electrophoresis and mass spectrometry with multivariate statistical analyses to systematically cluster cellular protein response across distinct iron-exposure conditions. Quadruplicate samples were simultaneously analyzed for alterations in protein abundance and/or post-translational modification state in response to environmental (iron chelation, hemin treatment or genetic (Deltafur alterations in bacterial iron exposure. We identified 120 proteins representing several coordinated biochemical pathways that are affected by changes in iron-exposure status. Highlighted in these experiments is the identification of the heme-regulated transport system (HrtAB, a novel transport system which plays a critical role in staphylococcal heme metabolism. Further, we show that regulated overproduction of acidic end-products brought on by iron starvation decreases local pH resulting in the release of iron from the host iron-sequestering protein transferrin. These findings reveal novel strategies used by S. aureus to acquire scarce nutrients in the hostile host environment and begin to define the iron and heme-dependent regulons of S. aureus.

  18. Natural Population Dynamics and Carriage of Staphylococcus aureus

    NARCIS (Netherlands)

    D.C. Melles (Damian)

    2008-01-01

    textabstractStaphylococcus aureus is a major human pathogen capable of causing a wide range of infections, from relatively mild skin infections such as folliculitis and furunculosis to life-threatening conditions, including sepsis, deep abscesses, pneumonia, osteomyelitis, and infective endocarditis

  19. THE STUDY OF RESISTENCE OF STAPHYLOCOCCUS AUREUS STRAINS TO ANTIMICROBIALS

    Directory of Open Access Journals (Sweden)

    Nazarchuk GG

    2012-12-01

    Full Text Available In the research work the results of the study of resistance forming to antibiotics, antiseptics and decametoxine composition with modified polysaccharides in S.aureus strains are presented. The development of resistance to penicillins, cephalosporins, glycopeptides, macrolides is shown. Slow forming of resistance to decasan and decametoxine composition with carboxymethylamylum, oxyethylcellulose was determined.

  20. Low efficacy of tobramycin in experimental Staphylococcus aureus endocarditis

    DEFF Research Database (Denmark)

    Lerche, C. J.; Christophersen, L. J.; Trøstrup, H.;

    2015-01-01

    The empiric treatment of infective endocarditis (IE) varies widely and, in some places, a regimen of penicillin in combination with an aminoglycoside is administered. The increasing incidence of Staphylococcus aureus IE, poor tissue penetration by aminoglycosides and low frequency of penicillin...

  1. New insights into molecular typing methods for Staphylococcus aureus

    NARCIS (Netherlands)

    Ikawaty, R.

    2009-01-01

    Staphylococcus aureus (SA) remains a significant problem causing infections in both hospital and community settings. Methicillin-resistant SA (MRSA) continues to evolve and pose a great challenge through outbreaks and pandemic spread. Humans are no longer the only and the most important reservoir of

  2. Expression and inducibility in Staphylococcus aureus of the mecA gene, which encodes a methicillin-resistant S. aureus-specific penicillin-binding protein.

    OpenAIRE

    Ubukata, K; Nonoguchi, R; Matsuhashi, M; Konno, M

    1989-01-01

    A beta-lactam-sensitive strain of Staphylococcus aureus could be converted to methicillin resistance by the introduction of a plasmid carrying the 4.3-kilobase HindIII chromosomal DNA fragment which encoded the mecA gene from a methicillin-resistant S. aureus. Transformant cells produced methicillin-resistant S. aureus-specific penicillin-binding protein constitutively, and additional insertion of an inducible penicillinase plasmid caused production of the pencillin-binding protein to become ...

  3. Risk factors of nasal carriage of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus among health care staff in a teaching hospital in central Saudi Arabia

    OpenAIRE

    Al-Humaidan, Ohoud S.; El-kersh, Talat A; Al-Akeel, Raid A.

    2015-01-01

    Objectives: To investigate possible risk factors of Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA) nasal carriage associated with various health troubles among healthcare workers (HCWs) at King Khalid University Hospital (KKUH). Method: This prospective study was conducted between May 2012 and January 2013 in KKUH, Riyadh, Saudi Arabia. A total of 200 nasal swabs were collected from HCWs. Identification was carried out based on morphology, Gram stain, catalase an...

  4. Complex network perspective on structure and function of Staphylococcus aureus metabolic network

    Indian Academy of Sciences (India)

    L Ying; D W Ding

    2013-02-01

    With remarkable advances in reconstruction of genome-scale metabolic networks, uncovering complex network structure and function from these networks is becoming one of the most important topics in system biology. This work aims at studying the structure and function of Staphylococcus aureus (S. aureus) metabolic network by complex network methods. We first generated a metabolite graph from the recently reconstructed high-quality S. aureus metabolic network model. Then, based on `bow tie' structure character, we explain and discuss the global structure of S. aureus metabolic network. The functional significance, global structural properties, modularity and centrality analysis of giant strong component in S. aureus metabolic networks are studied.

  5. Heme Recognition By a Staphylococcus Aureus IsdE

    Energy Technology Data Exchange (ETDEWEB)

    Grigg, J.C.; Vermeiren, C.L.; Heinrichs, D.E.; Murphy, M.E.P.

    2009-06-03

    Staphylococcus aureus is a Gram-positive bacterial pathogen and a leading cause of hospital acquired infections. Because the free iron concentration in the human body is too low to support growth, S. aureus must acquire iron from host sources. Heme iron is the most prevalent iron reservoir in the human body and a predominant source of iron for S. aureus. The iron-regulated surface determinant (Isd) system removes heme from host heme proteins and transfers it to IsdE, the cognate substrate-binding lipoprotein of an ATP-binding cassette transporter, for import and subsequent degradation. Herein, we report the crystal structure of the soluble portion of the IsdE lipoprotein in complex with heme. The structure reveals a bi-lobed topology formed by an N- and C-terminal domain bridged by a single {alpha}-helix. The structure places IsdE as a member of the helical backbone metal receptor superfamily. A six-coordinate heme molecule is bound in the groove established at the domain interface, and the heme iron is coordinated in a novel fashion for heme transporters by Met{sup 78} and His{sup 229}. Both heme propionate groups are secured by H-bonds to IsdE main chain and side chain groups. Of these residues, His{sup 299} is essential for IsdE-mediated heme uptake by S. aureus when growth on heme as a sole iron source is measured. Multiple sequence alignments of homologues from several other Gram-positive bacteria, including the human pathogens pyogenes, Bacillus anthracis, and Listeria monocytogenes, suggest that these other systems function equivalently to S. aureus IsdE with respect to heme binding and transport.

  6. Methicillin resistant S. aureus in human and bovine mastitis.

    Science.gov (United States)

    Holmes, Mark A; Zadoks, Ruth N

    2011-12-01

    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 cases and outbreaks in maternity or neonatal units have been reported which are generally the result of CA-MRSA. The establishment of the sequence type 398 (ST398) in farm animals, primarily pigs, in the early 2000's has provided a reservoir of infection for humans and dairy cattle, particularly in continental Europe, described as livestock-associated MRSA (LA-MRSA). Prior to the emergence of ST398 there were sporadic reports of MRSA in bovine milk and cases of mastitis, often caused by strains from human associated lineages. Subsequently, there have been several reports describing bovine udder infections caused by ST-398 MRSA. Recently, another group of LA-MRSA strains was discovered in humans and dairy cattle in Europe. This group carries a divergent mecA gene and includes a number of S. aureus lineages (CC130, ST425, and CC1943) that were hitherto thought to be bovine-specific but are now also found as carriage or clinical isolates in humans. The emergence of MRSA in dairy cattle may be associated with contact with other host species, as in the case of ST398, or with the exchange of genetic material between S. aureus and coagulase negative Staphylococcus species, which are the most common species associated with bovine intramammary infections and commonly carry antimicrobial resistance determinants.

  7. Characterization of a mouse-adapted Staphylococcus aureus strain.

    Science.gov (United States)

    Holtfreter, Silva; Radcliff, Fiona J; Grumann, Dorothee; Read, Hannah; Johnson, Sarah; Monecke, Stefan; Ritchie, Stephen; Clow, Fiona; Goerke, Christiane; Bröker, Barbara M; Fraser, John D; Wiles, Siouxsie

    2013-01-01

    More effective antibiotics and a protective vaccine are desperately needed to combat the 'superbug' Staphylococcus aureus. While in vivo pathogenicity studies routinely involve infection of mice with human S. aureus isolates, recent genetic studies have demonstrated that S. aureus lineages are largely host-specific. The use of such animal-adapted S. aureus strains may therefore be a promising approach for developing more clinically relevant animal infection models. We have isolated a mouse-adapted S. aureus strain (JSNZ) which caused a severe outbreak of preputial gland abscesses among male C57BL/6J mice. We aimed to extensively characterize this strain on a genomic level and determine its virulence potential in murine colonization and infection models. JSNZ belongs to the MLST type ST88, rare among human isolates, and lacks an hlb-converting phage encoding human-specific immune evasion factors. Naive mice were found to be more susceptible to nasal and gastrointestinal colonization with JSNZ than with the human-derived Newman strain. Furthermore, naïve mice required antibiotic pre-treatment to become colonized with Newman. In contrast, JSNZ was able to colonize mice in the absence of antibiotic treatment suggesting that this strain can compete with the natural flora for space and nutrients. In a renal abscess model, JSNZ caused more severe disease than Newman with greater weight loss and bacterial burden. In contrast to most other clinical isolates, JSNZ can also be readily genetically modified by phage transduction and electroporation. In conclusion, the mouse-adapted strain JSNZ may represent a valuable tool for studying aspects of mucosal colonization and for screening novel vaccines and therapies directed at preventing colonization. PMID:24023720

  8. Characterization of a mouse-adapted Staphylococcus aureus strain.

    Directory of Open Access Journals (Sweden)

    Silva Holtfreter

    Full Text Available More effective antibiotics and a protective vaccine are desperately needed to combat the 'superbug' Staphylococcus aureus. While in vivo pathogenicity studies routinely involve infection of mice with human S. aureus isolates, recent genetic studies have demonstrated that S. aureus lineages are largely host-specific. The use of such animal-adapted S. aureus strains may therefore be a promising approach for developing more clinically relevant animal infection models. We have isolated a mouse-adapted S. aureus strain (JSNZ which caused a severe outbreak of preputial gland abscesses among male C57BL/6J mice. We aimed to extensively characterize this strain on a genomic level and determine its virulence potential in murine colonization and infection models. JSNZ belongs to the MLST type ST88, rare among human isolates, and lacks an hlb-converting phage encoding human-specific immune evasion factors. Naive mice were found to be more susceptible to nasal and gastrointestinal colonization with JSNZ than with the human-derived Newman strain. Furthermore, naïve mice required antibiotic pre-treatment to become colonized with Newman. In contrast, JSNZ was able to colonize mice in the absence of antibiotic treatment suggesting that this strain can compete with the natural flora for space and nutrients. In a renal abscess model, JSNZ caused more severe disease than Newman with greater weight loss and bacterial burden. In contrast to most other clinical isolates, JSNZ can also be readily genetically modified by phage transduction and electroporation. In conclusion, the mouse-adapted strain JSNZ may represent a valuable tool for studying aspects of mucosal colonization and for screening novel vaccines and therapies directed at preventing colonization.

  9. Population structure of Staphylococcus aureus from remote African Babongo Pygmies.

    Directory of Open Access Journals (Sweden)

    Frieder Schaumburg

    Full Text Available BACKGROUND: Pandemic community-acquired methicillin-resistant Staphylococcus aureus isolates (CA-MRSA predominantly encode the Panton-Valentine leukocidin (PVL, which can be associated with severe infections. Reports from non-indigenous Sub-Saharan African populations revealed a high prevalence of PVL-positive isolates. The objective of our study was to investigate the S. aureus carriage among a remote indigenous African population and to determine the molecular characteristics of the isolates, particularly those that were PVL-positive. METHODOLOGY/PRINCIPAL FINDINGS: Nasal S. aureus carriage and risk factors of colonization were systematically assessed in remote Gabonese Babongo Pygmies. Susceptibility to antibiotics, possession of toxin-encoding genes (i.e., PVL, enterotoxins, and exfoliative toxins, S. aureus protein A (spa types and multi-locus sequence types (MLST were determined for each isolate. The carriage rate was 33%. No MRSA was detected, 61.8% of the isolates were susceptible to penicillin. Genes encoding PVL (55.9%, enterotoxin B (20.6%, exfoliative toxin D (11.7% and the epidermal cell differentiation inhibitor B (11.7% were highly prevalent. Thirteen spa types were detected and were associated with 10 STs predominated by ST15, ST30, ST72, ST80, and ST88. CONCLUSIONS: The high prevalence of PVL-positive isolates among Babongo Pygmies demands our attention as PVL can be associated with necrotinzing infection and may increase the risk of severe infections in remote Pygmy populations. Many S. aureus isolates from Babongo Pygmies and pandemic CA-MRSA-clones have a common genetic background. Surveillance is needed to control the development of resistance to antibiotic drugs and to assess the impact of the high prevalence of PVL in indigenous populations.

  10. Memory Th1 Cells Are Protective in Invasive Staphylococcus aureus Infection.

    Directory of Open Access Journals (Sweden)

    Aisling F Brown

    Full Text Available Mechanisms of protective immunity to Staphylococcus aureus infection in humans remain elusive. While the importance of cellular immunity has been shown in mice, T cell responses in humans have not been characterised. Using a murine model of recurrent S. aureus peritonitis, we demonstrated that prior exposure to S. aureus enhanced IFNγ responses upon subsequent infection, while adoptive transfer of S. aureus antigen-specific Th1 cells was protective in naïve mice. Translating these findings, we found that S. aureus antigen-specific Th1 cells were also significantly expanded during human S. aureus bloodstream infection (BSI. These Th1 cells were CD45RO+, indicative of a memory phenotype. Thus, exposure to S. aureus induces memory Th1 cells in mice and humans, identifying Th1 cells as potential S. aureus vaccine targets. Consequently, we developed a model vaccine comprising staphylococcal clumping factor A, which we demonstrate to be an effective human T cell antigen, combined with the Th1-driving adjuvant CpG. This novel Th1-inducing vaccine conferred significant protection during S. aureus infection in mice. This study notably advances our understanding of S. aureus cellular immunity, and demonstrates for the first time that a correlate of S. aureus protective immunity identified in mice may be relevant in humans.

  11. Memory Th1 Cells Are Protective in Invasive Staphylococcus aureus Infection.

    Science.gov (United States)

    Brown, Aisling F; Murphy, Alison G; Lalor, Stephen J; Leech, John M; O'Keeffe, Kate M; Mac Aogáin, Micheál; O'Halloran, Dara P; Lacey, Keenan A; Tavakol, Mehri; Hearnden, Claire H; Fitzgerald-Hughes, Deirdre; Humphreys, Hilary; Fennell, Jérôme P; van Wamel, Willem J; Foster, Timothy J; Geoghegan, Joan A; Lavelle, Ed C; Rogers, Thomas R; McLoughlin, Rachel M

    2015-01-01

    Mechanisms of protective immunity to Staphylococcus aureus infection in humans remain elusive. While the importance of cellular immunity has been shown in mice, T cell responses in humans have not been characterised. Using a murine model of recurrent S. aureus peritonitis, we demonstrated that prior exposure to S. aureus enhanced IFNγ responses upon subsequent infection, while adoptive transfer of S. aureus antigen-specific Th1 cells was protective in naïve mice. Translating these findings, we found that S. aureus antigen-specific Th1 cells were also significantly expanded during human S. aureus bloodstream infection (BSI). These Th1 cells were CD45RO+, indicative of a memory phenotype. Thus, exposure to S. aureus induces memory Th1 cells in mice and humans, identifying Th1 cells as potential S. aureus vaccine targets. Consequently, we developed a model vaccine comprising staphylococcal clumping factor A, which we demonstrate to be an effective human T cell antigen, combined with the Th1-driving adjuvant CpG. This novel Th1-inducing vaccine conferred significant protection during S. aureus infection in mice. This study notably advances our understanding of S. aureus cellular immunity, and demonstrates for the first time that a correlate of S. aureus protective immunity identified in mice may be relevant in humans. PMID:26539822

  12. Memory Th1 Cells Are Protective in Invasive Staphylococcus aureus Infection.

    LENUS (Irish Health Repository)

    Brown, Aisling F

    2015-01-01

    Mechanisms of protective immunity to Staphylococcus aureus infection in humans remain elusive. While the importance of cellular immunity has been shown in mice, T cell responses in humans have not been characterised. Using a murine model of recurrent S. aureus peritonitis, we demonstrated that prior exposure to S. aureus enhanced IFNγ responses upon subsequent infection, while adoptive transfer of S. aureus antigen-specific Th1 cells was protective in naïve mice. Translating these findings, we found that S. aureus antigen-specific Th1 cells were also significantly expanded during human S. aureus bloodstream infection (BSI). These Th1 cells were CD45RO+, indicative of a memory phenotype. Thus, exposure to S. aureus induces memory Th1 cells in mice and humans, identifying Th1 cells as potential S. aureus vaccine targets. Consequently, we developed a model vaccine comprising staphylococcal clumping factor A, which we demonstrate to be an effective human T cell antigen, combined with the Th1-driving adjuvant CpG. This novel Th1-inducing vaccine conferred significant protection during S. aureus infection in mice. This study notably advances our understanding of S. aureus cellular immunity, and demonstrates for the first time that a correlate of S. aureus protective immunity identified in mice may be relevant in humans.

  13. Inhibiting platelets aggregation could aggravate the acute infection caused by Staphylococcus aureus.

    Science.gov (United States)

    Zhang, Xin; Liu, Yu; Gao, Yaping; Dong, Jie; Mu, Chunhua; Lu, Qiang; Shao, Ningsheng; Yang, Guang

    2011-01-01

    Several fibrinogen binding proteins (Fibs) play important roles in the pathogenesis of Staphylococcus aureus (S. aureus). Most Fibs can promote the aggregation of platelets during infection, but the extracellular fibrinogen-binding protein (Efb) is an exception. It is reported that Efb can specifically bind fibrinogen and inhibit the aggregation of platelet with its N terminal. However, the biological significance of platelet aggregation inhibition in the infection caused by S. aureus is unclear until now. Here, we demonstrated that the persistence and aggregation of platelets were important for killing S. aureus in whole blood. It was found that the N terminal of Efb (EfbN) and platelets inhibitors could increase the survival of S. aureus in whole blood. The study in vivo also showed that EfbN and platelets inhibitors could reduce the killing of S. aureus and increase the lethality rate of S. aureus in the acute infection mouse model.

  14. Antibiotic-mediated selection of quorum-sensing-negative Staphylococcus aureus

    DEFF Research Database (Denmark)

    Paulander, Wilhelm Erik Axel; Varming, Anders Nissen; Bæk, Kristoffer Torbjørn;

    2012-01-01

    -acquired S. aureus infections and suggest that the adaptability of S. aureus to antibiotics involves the agr locus. IMPORTANCE: Staphylococcus aureus is the most frequently isolated pathogen in intensive care units and a common cause of nosocomial infections, resulting in a high degree of morbidity......Staphylococcus aureus is a human commensal that at times turns into a serious bacterial pathogen causing life-threatening infections. For the delicate control of virulence, S. aureus employs the agr quorum-sensing system that, via the intracellular effector molecule RNAIII, regulates virulence gene...... increases the agr-mediated fitness cost by inducing the expression of RNAIII. Thus, the extensive use of antibiotics in hospitals may explain why agr-negative variants are frequently isolated from hospital-acquired S. aureus infections but rarely found among community-acquired S. aureus strains. Importantly...

  15. Detection of Staphylococcus aureus in Milk Using Real-time Fluorescence Loop-mediated Isothermal Amplification

    Directory of Open Access Journals (Sweden)

    Ying Yu

    2015-07-01

    Full Text Available Staphylococcus aureus is a kind of worldwide food-borne pathogen. Recently, S. aureus has gained considerable attention because of the increasing alimentary toxicosis incidence. In this study, a Real-Time fluorescence Loop-Mediated isothermal Amplification (RT-LAMP was developed to detect S. aureus rapidly. The heat-stable nuclease (nuc gene of S. aureus, the target sequence, was selected to design four special primers. A rapid detection method for S. aureus was initially established under optimum reaction conditions. The assay, performed for 40 min at 61°C, did not show cross reactivity with other bacterial species. The specificity and sensitivity of RT-LAMP for detecting S. aureus were 100% and 8.0 CFU/mL, respectively. Results indicated that RT-LAMP was a potential field-usable molecular tool for detecting S. aureus This method can be an alternative to conventional LAMP in clinical applications and operational programs.

  16. Shedding of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus from adult and pediatric bathers in marine waters

    Directory of Open Access Journals (Sweden)

    Sinigalliano Christopher D

    2011-01-01

    Full Text Available Abstract Background Staphylococcus aureus including methicillin resistant S. aureus, MRSA, are human colonizing bacteria that commonly cause opportunistic infections primarily involving the skin in otherwise healthy individuals. These infections have been linked to close contact and sharing of common facilities such as locker rooms, schools and prisons Waterborne exposure and transmission routes have not been traditionally associated with S. aureus infections. Coastal marine waters and beaches used for recreation are potential locations for the combination of high numbers of people with close contact and therefore could contribute to the exposure to and infection by these organisms. The primary aim of this study was to evaluate the amount and characteristics of the shedding of methicillin sensitive S. aureus, MSSA and MRSA by human bathers in marine waters. Results Nasal cultures were collected from bathers, and water samples were collected from two sets of pools designed to isolate and quantify MSSA and MRSA shed by adults and toddlers during exposure to marine water. A combination of selective growth media and biochemical and polymerase chain reaction analysis was used to identify and perform limited characterization of the S. aureus isolated from the water and the participants. Twelve of 15 MRSA isolates collected from the water had identical genetic characteristics as the organisms isolated from the participants exposed to that water while the remaining 3 MRSA were without matching nasal isolates from participants. The amount of S. aureus shed per person corresponded to 105 to 106 CFU per person per 15-minute bathing period, with 15 to 20% of this quantity testing positive for MRSA. Conclusions This is the first report of a comparison of human colonizing organisms with bacteria from human exposed marine water attempting to confirm that participants shed their own colonizing MSSA and MRSA into their bathing milieu. These findings clearly

  17. Effectiveness of hospital-wide methicillin-resistant Staphylococcus aureus (MRSA) infection control policies differs by ward specialty.

    Science.gov (United States)

    Sadsad, Rosemarie; Sintchenko, Vitali; McDonnell, Geoff D; Gilbert, Gwendolyn L

    2013-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of preventable nosocomial infections and is endemic in hospitals worldwide. The effectiveness of infection control policies varies significantly across hospital settings. The impact of the hospital context towards the rate of nosocomial MRSA infections and the success of infection control is understudied. We conducted a modelling study to evaluate several infection control policies in surgical, intensive care, and medical ward specialties, each with distinct ward conditions and policies, of a tertiary public hospital in Sydney, Australia. We reconfirm hand hygiene as the most successful policy and find it to be necessary for the success of other policies. Active screening for MRSA, patient isolation in single-bed rooms, and additional staffing were found to be less effective. Across these ward specialties, MRSA transmission risk varied by 13% and reductions in the prevalence and nosocomial incidence rate of MRSA due to infection control policies varied by up to 45%. Different levels of infection control were required to reduce and control nosocomial MRSA infections for each ward specialty. Infection control policies and policy targets should be specific for the ward and context of the hospital. The model we developed is generic and can be calibrated to represent different ward settings and pathogens transmitted between patients indirectly through health care workers. This can aid the timely and cost effective design of synergistic and context specific infection control policies.

  18. Effectiveness of hospital-wide methicillin-resistant Staphylococcus aureus (MRSA infection control policies differs by ward specialty.

    Directory of Open Access Journals (Sweden)

    Rosemarie Sadsad

    Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA is a major cause of preventable nosocomial infections and is endemic in hospitals worldwide. The effectiveness of infection control policies varies significantly across hospital settings. The impact of the hospital context towards the rate of nosocomial MRSA infections and the success of infection control is understudied. We conducted a modelling study to evaluate several infection control policies in surgical, intensive care, and medical ward specialties, each with distinct ward conditions and policies, of a tertiary public hospital in Sydney, Australia. We reconfirm hand hygiene as the most successful policy and find it to be necessary for the success of other policies. Active screening for MRSA, patient isolation in single-bed rooms, and additional staffing were found to be less effective. Across these ward specialties, MRSA transmission risk varied by 13% and reductions in the prevalence and nosocomial incidence rate of MRSA due to infection control policies varied by up to 45%. Different levels of infection control were required to reduce and control nosocomial MRSA infections for each ward specialty. Infection control policies and policy targets should be specific for the ward and context of the hospital. The model we developed is generic and can be calibrated to represent different ward settings and pathogens transmitted between patients indirectly through health care workers. This can aid the timely and cost effective design of synergistic and context specific infection control policies.

  19. Does Eligibility for Tertiary Education Affect Crime Rates? Quasi-Experimental Evidence

    OpenAIRE

    Nordin, Martin

    2014-01-01

    This paper estimates a tertiary eligibility effect on crime for Sweden. The idea is that investment in higher education is a way of escaping youth inactivity and idleness, and, since youth inactivity is known to trigger crime, the self-incapacitation effect of higher education decreases crime rates. However, to invest in higher education, the individual has to meet the tertiary eligibility requirements in upper-secondary school. Tertiary eligibility may therefore affect crime rates. Evidence ...

  20. Echocardiographic findings predict in-hospital and 1-year mortality in left-sided native valve Staphylococcus aureus endocarditis

    DEFF Research Database (Denmark)

    Lauridsen, Trine K.; Park, Lawrence; Tong, Steven Y C;

    2015-01-01

    BACKGROUND: Staphylococcus aureus left-sided native valve infective endocarditis (LNVIE) has higher complication and mortality rates compared with endocarditis from other pathogens. Whether echocardiographic variables can predict prognosis in S aureus LNVIE is unknown. METHODS AND RESULTS......: Consecutive patients with LNVIE, enrolled between January 2000 and September 2006, in the International Collaboration on Endocarditis were identified. Subjects without S aureus IE were matched to those with S aureus IE by the propensity of having S aureus. Survival differences were determined using log...