WorldWideScience

Sample records for aureus clone st228

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

    Directory of Open Access Journals (Sweden)

    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.

  2. Molecular characterization of resistance to Rifampicin in an emerging hospital-associated Methicillin-resistant Staphylococcus aureus clone ST228, Spain

    Directory of Open Access Journals (Sweden)

    Liñares Josefina

    2010-03-01

    Full Text Available Abstract Background Methicillin-resistant S. aureus (MRSA has been endemic in Hospital Universitari de Bellvitge, Barcelona, since 1990. During the 1990-95 period the Iberian clone (ST-247; SCCmec-I was dominant. Isolates of clonal complex 5 (ST-125; SCCmec-IV gradually replaced the Iberian clone from 1996 to 2003. A new multiresistant MRSA phenotype showing rifampicin resistance emerged in 2004 and rapidly increased from 25% in 2004 to 45% in 2006. The aims of this study were i the molecular characterisation of rifampicin resistant MRSA isolates, ii the study of the rifampicin resistance expression by disk diffusion, microdilution and E-test, and iii the analysis of the rpoB gene mutations involved in rifampicin resistance. Results A sample of representative 108 rifampicin-resistant MRSA isolates belonged to a single PFGE genotype, ST-228, SCCmec type I and spa type t041. Of 108 isolates, 104 (96% had a low-level rifampicin resistance (MICs, 2 to 4 mg/L and 4 a high-level rifampicin resistance (MICs, 128 - ≥ 256 mg/L. Disk diffusion and E-test methods failed to identify a low-level rifampicin resistance in 20 and 12 isolates, respectively. A low-level rifampicin resistance was associated with amino acid substitution 481His/Asn in the beta-subunit of RNA polymerase. Isolates with a high-level rifampicin resistance carried additional mutations in the rpoB gene. Conclusions The emergence of MRSA clone ST228-SCCmecI, related to the Southern Germany clone, involved a therapeutical challenge for treating serious MRSA infections. Decreased susceptibility to rifampicin in MRSA strains of ST228-SCCmecI was associated with one or two specific mutations in the rpoB gene. One fifth of isolates with low-level rifampicin-resistance were missed by the diffusion methods.

  3. 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...

  4. 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...

  5. Missense mutations in PBP2A Affecting ceftaroline susceptibility detected in epidemic hospital-acquired methicillin-resistant Staphylococcus aureus clonotypes ST228 and ST247 in Western Switzerland archived since 1998.

    Science.gov (United States)

    Kelley, William L; Jousselin, Ambre; Barras, Christine; Lelong, Emmanuelle; Renzoni, Adriana

    2015-04-01

    The development and maintenance of an arsenal of antibiotics is a major health care challenge. Ceftaroline is a new cephalosporin with activity against methicillin-resistant Staphylococcus aureus (MRSA); however, no reports concerning MRSA ceftaroline susceptibility have been reported in Switzerland. We tested the in vitro activity of ceftaroline against an archived set of 60 MRSA strains from the University Hospital of Geneva collected from 1994 to 2003. Our results surprisingly revealed ceftaroline-resistant strains (MIC, >1 μg/ml in 40/60 strains; EUCAST breakpoints, susceptible [S], ≤1 μg/ml; resistant [R], >1 μg/ml) were present from 1998 to 2003. The detected resistant strains predominantly belonged to sequence type 228 (ST228) (South German clonotype) but also to ST247 (Iberian clonotype). A sequence analysis of these strains revealed missense mutations in the penicillin-binding protein 2A (PBP2A) allosteric domain (N146K or E239K and N146K-E150K-G246E). The majority of our ST228 PBP2A mutations (N146K or E150K) were distinct from ST228 PBP2A allosteric domain mutations (primarily E239K) recently described for MRSA strains collected in Thailand and Spain during the 2010 Assessing Worldwide Antimicrobial Resistance Evaluation (AWARE) global surveillance program. We also found that similar allosteric domain PBP2A mutations (N146K) correlated with ceftaroline resistance in an independent external ST228 MRSA set obtained from the nearby University Hospital of Lausanne, Lausanne, Switzerland, collected from 2003 to 2008. Thus, ceftaroline resistance was observed in our archived strains (including two examples of an MIC of 4 µg/ml for the Iberian ST247 clonotype with the triple mutation N146K/E150K/G246E), at least as far back as 1998, considerably predating the commercial introduction of ceftaroline. Our results reinforce the notion that unknown parameters can potentially exert selective pressure on PBP2A that can subsequently modulate ceftaroline

  6. Missense mutations in PBP2A Affecting ceftaroline susceptibility detected in epidemic hospital-acquired methicillin-resistant Staphylococcus aureus clonotypes ST228 and ST247 in Western Switzerland archived since 1998

    OpenAIRE

    Kelley, William; Jousselin, Ambre; Barras, Christine; Lelong, Emmanuelle; Renzoni, Adriana Maria

    2015-01-01

    The development and maintenance of an arsenal of antibiotics is a major health care challenge. Ceftaroline is a new cephalosporin with activity against methicillin-resistant Staphylococcus aureus (MRSA); however, no reports concerning MRSA ceftaroline susceptibility have been reported in Switzerland. We tested the in vitro activity of ceftaroline against an archived set of 60 MRSA strains from the University Hospital of Geneva collected from 1994 to 2003. Our results surprisingly revealed cef...

  7. Factors contributing to epidemic MRSA clones replacement in a hospital setting.

    Directory of Open Access Journals (Sweden)

    Rossella Baldan

    Full Text Available The mechanisms governing the epidemiology dynamics and success determinants of a specific healthcare-associated methicillin-resistant S. aureus (HA-MRSA clone in hospital settings are still unclear. Important epidemiological changes have occurred in Europe since 2000 that have been related to the appearance of the ST22-IV clone. Between 2006 and 2010, we observed the establishment of the ST22-IV clone displacing the predominant Italian clone, ST228-I, in a large Italian university hospital. To investigate the factors associated with a successful spread of epidemic MRSA clones we studied the biofilm production, the competitive behavior in co-culture, the capacity of invasion of the A549 cells, and the susceptibility to infection in a murine model of acute pneumonia of the two major HA-MRSA clones, ST22-IV and ST228-I. We showed that persistence of ST22-IV is associated with its increased biofilm production and capacity to inhibit the growth of ST228-I in co-culture. Compared to ST228-I, ST22-IV had a significantly higher capacity to invade the A549 cells and a higher virulence in a murine model of acute lung infection causing severe inflammation and determining death in all the mice within 60 hours. On the contrary, ST228-I was associated with mice survival and clearance of the infection. ST22-IV, compared with ST228-I, caused a higher number of persistent, long lasting bacteremia. These data suggest that ST22-IV could have exploited its capacity to i increase its biofilm production over time, ii maintain its growth kinetics in the presence of a competitor and iii be particularly invasive and virulent both in vitro and in vivo, to replace other well-established MRSA clones, becoming the predominant European clone.

  8. 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

  9. Insights into Alpha-Hemolysin (Hla) Evolution and Expression among Staphylococcus aureus Clones with Hospital and Community Origin

    DEFF Research Database (Denmark)

    Tavares, Ana; Nielsen, Jesper B; Boye, Kit;

    2014-01-01

    is not known. We evaluated nucleotide sequence variation and gene expression profiles of hla among representatives of hospital (HA) and community-associated (CA) S. aureus clones. METHODS: 51 methicillin-resistant S. aureus and 22 methicillin-susceptible S. aureus were characterized by PFGE, spa typing, MLST...

  10. Prevalence of Adhesion and Regulation of Biofilm-Related Genes in Different Clones of Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Salman Sahab Atshan

    2012-01-01

    Full Text Available Clinical information about genotypically different clones of biofilm-producing Staphylococcus aureus is largely unknown. We examined whether different clones of methicillin-sensitive and methicillin-resistant S. aureus (MSSA and MRSA differ with respect to staphylococcal microbial surface components recognizing adhesive matrix molecules (MSCRAMMs in biofilm formation. The study used 60 different types of spa and determined the phenotypes, the prevalence of the 13 MSCRAMM, and biofilm genes for each clone. The current investigation was carried out using a modified Congo red agar (MCRA, a microtiter plate assay (MPA, polymerase chain reaction (PCR, and reverse transcriptase polymerase chain reaction (RT-PCR. Clones belonging to the same spa type were found to have similar properties in adheringto thepolystyrene microtiter plate surface. However, their ability to produce slime on MCRA medium was different. PCR experiments showed that 60 clones of MSSA and MRSA were positive for 5 genes (out of 9 MSCRAMM genes. icaADBC genes were found to be present in all the 60 clones tested indicating a high prevalence, and these genes were equally distributed among the clones associated with MSSA and those with MRSA. The prevalence of other MSCRAMM genes among MSSA and MRSA clones was found to be variable. MRSA and MSSA gene expression (MSCRAMM and icaADBC was confirmed by RT-PCR.

  11. Phylogeographic variation in recombination rates within a global clone of Methicillin-Resistant Staphylococcus aureus (MRSA)

    DEFF Research Database (Denmark)

    Castillo-Ramirez, Santiago; Corander, Jukka; Marttinen, Pekka;

    2012-01-01

    by employing a recently developed Bayesian approach, BRATNextGen, for detecting recombination on an expanded NGS dataset of the globally disseminated methicillin-resistant Staphylococcus aureus (MRSA) clone ST239. RESULTS: The data confirm strong geographical clustering at continental, national and city scales...

  12. Cloning, expression, and mutagenesis of phosphatidylinositol-specific phospholipase C from Staphylococcus aureus: a potential staphylococcal virulence factor.

    OpenAIRE

    Daugherty, S; Low, M G

    1993-01-01

    Staphylococcus aureus secretes a phosphatidylinositol (PI)-specific phospholipase C (PI-PLC) which is able to hydrolyze the membrane lipid PI and membrane protein anchors containing glycosyl-PI. The gene for PI-PLC (plc) was cloned from S. aureus into Escherichia coli. Oligonucleotide probes based on partial protein sequence and polyclonal antibodies raised against the purified protein were used to identify positive clones. E. coli transformed with a plasmid containing the plc gene expressed ...

  13. Livestock Origin for a Human Pandemic Clone of Community-Associated Methicillin-Resistant Staphylococcus aureus

    DEFF Research Database (Denmark)

    Spoor, Laura E.; McAdam, Paul R.; Weinert, Lucy A.;

    2013-01-01

    humans, but an understanding of the different evolutionary origins of CA-MRSA clones and the basis for their recent expansion is lacking. Here, using a high-resolution phylogenetic approach, we report the discovery of two emergent clones of human epidemic CA-MRSA which resulted from independent livestock-to-human...... at the human-livestock interface. IMPORTANCE Animals are the major source of new pathogens affecting humans. However, the potential for pathogenic bacteria that originally were found in animals to switch hosts and become widely established in human populations is not clear. Here, we report the discovery...... of emergent clones of methicillin-resistant Staphylococcus aureus (MRSA) that originated in livestock and switched to humans, followed by host-adaptive evolution and epidemic spread in global human populations. Our findings demonstrate that livestock can act as a reservoir for the emergence of new human...

  14. Cloning, expression and characterization of glucokinase gene involved in the glucose-6- phosphate formation in Staphylococcus aureus

    OpenAIRE

    Lakshmi, Hanumanthu Prasanna; Yeswanth, Sthanikam; Prasad, Uppu Venkateswara; Vasu, Dudipeta; Swarupa, Vimjam; Kumar, Pasupuleti Santhosh; Narasu, Mangamoori Lakshmi; Krishna Sarma, Potukuchi Venkata Gurunadha

    2013-01-01

    Glucose-6-phosphate (G-6-P) formation in Staphylococcus aureus is catalysed by glucokinase (glkA) gene under high glucose concentration leading to upregulation of various pathogenic factors; therefore the present study is aimed in the cloning and characterization of glk A gene from S. aureus ATCC12600. The glk A gene was cloned in the Sma I site of pQE 30, sequenced (Accession number: JN645812) and expressed in E. coli DH5α. The recombinant glk A expressed from the resultant glk A 1 clone was...

  15. Severe invasive methicillin-resistant S. aureus (USA300 clone infection in an Italian adolescent

    Directory of Open Access Journals (Sweden)

    Piero Valentini

    2009-12-01

    Full Text Available This report describes an uncommon presentation of invasive community-acquired methicillin-resistant S. aureus (CA-MRSA infection in an immunocompetent adolescent without any other risk factor, characterized by septicaemia, meningitis, necrotising pneumonia and deep venous thrombosis (DVT. Successful treatment was performed with linezolid, rifampicin and low-molecular-weight heparin (LMWH. MRSA molecular typing revealed the presence of Panton-Valentine leukocidin (PVL gene, and a genetic background identical to USA300 clone, an emerging aggressive CA-MRSA strain in USA and Europe.

  16. Cloning, expression and crystallization of dihydrodipicolinate reductase from methicillin-resistant Staphylococcus aureus

    International Nuclear Information System (INIS)

    Given the recent rise in antimicrobial resistance, there is an urgent need to identify and characterize new antibiotic drug targets. One such target is dihydrodipicolinate reductase (DHDPR), which is an essential bacterial enzyme that catalyzes the second step in the lysine-biosynthesis pathway. In this paper, the cloning, expression, purification and crystallization of DHDPR from methicillin-resistant S. aureus are presented. Dihydrodipicolinate reductase (DHDPR; EC 1.3.1.26) catalyzes the nucleotide (NADH/NADPH) dependent second step of the lysine-biosynthesis pathway in bacteria and plants. Here, the cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of DHDPR from methicillin-resistant Staphylococcus aureus (MRSA-DHDPR) are presented. The enzyme was crystallized in a number of forms, predominantly with ammonium sulfate as a precipitant, with the best crystal form diffracting to beyond 3.65 Å resolution. Crystal structures of the apo form as well as of cofactor (NADPH) bound and inhibitor (2,6-pyridinedicarboxylate) bound forms of MRSA-DHDPR will provide insight into the structure and function of this essential enzyme and valid drug target

  17. A new lipase as a pharmaceutical target for battling infections caused by Staphylococcus aureus: Gene cloning and biochemical characterization.

    Science.gov (United States)

    Ünlü, Aişe; Tanriseven, Aziz; Sezen, I Yavuz; Çelik, Ayhan

    2015-01-01

    Staphylococcus aureus lipases along with other cell-wall-associated proteins and enzymes (i.e., catalase, coagulase, protease, hyaluronidase, and β-lactamase) play important roles in the pathogenesis of S. aureus and are important subject of drug targeting. The appearance of antibiotic-resistant types of pathogenic S. aureus (e.g., methicillin-resistant S. aureus, MRSA) is a worldwide medical problem. In the present work, a novel lipase from a newly isolated MRSA strain from a cow with subclinical mastitis was cloned and biochemically characterized. The mature part of the lipase was expressed in Escherichia coli and purified by nickel affinity chromatography. It displays a high lipase activity at pH 8.0 and 25 °C using p-nitrophenyl palmitate and has a preference for medium-long-chain substrates of p-nitrophenyl esters (pNPC10-C16). Furthermore, in search of inhibitors, the effect of farnesol on the growth of S. aureus and the lipase activity was also studied. Farnesol inhibits the growth of S. aureus and is a mixed-type inhibitor with Ki and Ki (') values of 0.2 and 1.2 mmol L(-1), respectively. A lipase with known properties could not only serve as a template for developing inhibitors for S. aureus but also a valuable addition to enzyme toolbox of biocatalysis. The discovery of this lipase can be potentially important and could provide a new target for pharmaceutical intervention against S. aureus infection. PMID:25385356

  18. Tracking methicillin-resistant Staphylococcus aureus clones in Colombian hospitals over 7 years (1996-2003): emergence of a new dominant clone.

    Science.gov (United States)

    Cruz, César; Moreno, Jaime; Renzoni, Adriana; Hidalgo, Marilyn; Reyes, Jinnethe; Schrenzel, Jacques; Lew, Daniel; Castañeda, Elizabeth; Arias, César A

    2005-12-01

    Worldwide dissemination of methicillin-resistant Staphylococcus aureus (MRSA) clones is a well-characterised phenomenon. Two hundred isolates of MRSA recovered from 17 Colombian hospitals collected between 2001 and 2003 were characterised by pulsed-field gel electrophoresis (PFGE). A new dominant electrophoretic pattern unrelated to previously characterised clones in Colombia was detected in 137 (68.5%) of these isolates. Only 40 (20%) isolates still showed a pattern closely related to a previously described dominant clone. The new electrophoretic pattern was indistinguishable from a cluster of isolates recovered in Chile between 1996 and 1998. Isolates from this clonal cluster exhibited multidrug resistance but were susceptible to linezolid and glycopeptides. The results indicate a shift in the population genetics of Colombian MRSA and confirm dissemination of the Chilean clone for the first time. PMID:16278073

  19. A field guide to pandemic, epidemic and sporadic clones of methicillin-resistant Staphylococcus aureus.

    LENUS (Irish Health Repository)

    Monecke, Stefan

    2011-04-01

    In recent years, methicillin-resistant Staphylococcus aureus (MRSA) have become a truly global challenge. In addition to the long-known healthcare-associated clones, novel strains have also emerged outside of the hospital settings, in the community as well as in livestock. The emergence and spread of virulent clones expressing Panton-Valentine leukocidin (PVL) is an additional cause for concern. In order to provide an overview of pandemic, epidemic and sporadic strains, more than 3,000 clinical and veterinary isolates of MRSA mainly from Germany, the United Kingdom, Ireland, France, Malta, Abu Dhabi, Hong Kong, Australia, Trinidad & Tobago as well as some reference strains from the United States have been genotyped by DNA microarray analysis. This technique allowed the assignment of the MRSA isolates to 34 distinct lineages which can be clearly defined based on non-mobile genes. The results were in accordance with data from multilocus sequence typing. More than 100 different strains were distinguished based on affiliation to these lineages, SCCmec type and the presence or absence of PVL. These strains are described here mainly with regard to clinically relevant antimicrobial resistance- and virulence-associated markers, but also in relation to epidemiology and geographic distribution. The findings of the study show a high level of biodiversity among MRSA, especially among strains harbouring SCCmec IV and V elements. The data also indicate a high rate of genetic recombination in MRSA involving SCC elements, bacteriophages or other mobile genetic elements and large-scale chromosomal replacements.

  20. A variant of the Southern German clone of methicillin-resistant Staphylococcus aureus is predominant in Croatia.

    Science.gov (United States)

    Budimir, A; Deurenberg, R H; Bosnjak, Z; Stobberingh, E E; Cetkovic, H; Kalenic, S

    2010-08-01

    The aim of the present study was to investigate the antibiotic susceptibility patterns and molecular epidemiology of clinical methicillin-resistant Staphylococcus aureus (MRSA) isolates recovered in 24 hospitals in 20 cities in Croatia from October to December 2004. A total of 1815 consecutive S. aureus isolates were recovered, 248 of which were MRSA. The MRSA isolates were analysed using spa typing, multilocus sequence typing and SCCmec typing. Furthermore, the presence of Panton-Valentine leukocidin (PVL) genes was determined as a genetic marker for community-associated MRSA. The MRSA prevalence was 14%. Ninety-six per cent of the MRSA isolates were resistant to ciprofloxacin, 95% to clindamycin and azithromycin, 94% to gentamicin, and 93% to erythromycin. The majority of the MRSA isolates (78%) was associated with the ST111-MRSA-I clone. In addition, various other endemic MRSA clones were observed, such as the ST247-MRSA-I (4%), the ST45-MRSA-IV (2%), the ST5-MRSA-I (2%), the ST239-MRSA-III (2%), the ST5-MRSA-II (1%), the ST8-MRSA-IV (1%) and the ST5-MRSA-IV (<1%) clones. Furthermore, we observed one PVL-negative ST80-MRSA-IV isolate. Four PVL-positive MRSA isolates were found, associated with ST8-MRSA-IV, ST80-MRSA-IV and ST80-MRSA-I. The ST111-MRSA-I clone was predominant in Croatia. Future surveillance studies of MRSA are important to elucidate whether changes in the clonal distribution of MRSA will occur, and if the minor endemic MRSA clones observed in the present study will replace the ST111-MRSA-I clone on a large scale. PMID:19732087

  1. Heteroresistance to glycopeptides in Italian meticillin-resistant Staphylococcus aureus (MRSA) isolates.

    Science.gov (United States)

    Campanile, Floriana; Borbone, Sonia; Perez, Marianna; Bongiorno, Dafne; Cafiso, Viviana; Bertuccio, Taschia; Purrello, Simona; Nicolosi, Daria; Scuderi, Cristina; Stefani, Stefania

    2010-11-01

    The prevalence and molecular characterisation of heteroresistant vancomycin-intermediate Staphylococcus aureus (hVISA) strains were determined in a large group of Italian strains isolated between 2005 and mid 2007. Amongst the 1284 strains isolated from documented infections in hospitalised patients (bloodstream infection, pneumonia, and skin and skin-structure infections), 139 S. aureus with vancomycin minimum inhibitory concentrations (MICs) between 1 mg/L and 2 mg/L were screened for the presence of hVISA using three different methods and were confirmed by population analysis profile (PAP). Thirty-six hVISA strains (25.9%) were detected. Amongst the three screening methods used, the macro Etest (MET) demonstrated 100% specificity and 75% sensitivity. hVISA strains were accessory gene regulator (agr) types I and II and belonged to the major nosocomial clones circulating in Italy (ST8, ST239, ST247 and ST228). All strains were susceptible to quinupristin/dalfopristin, linezolid, daptomycin, tigecycline and dalbavancin. In conclusion, we have demonstrated that hVISA isolates are common amongst MRSA isolates with MICs between 1 mg/L and 2 mg/L in Italy. MET, with its high sensitivity and specificity, should be used for early detection of hVISA, especially in patients with serious or prolonged infections sustained by MRSA. Finally, the most recent anti-Gram-positive drugs maintained their full spectrum of in vitro activity against these strains. PMID:20727722

  2. Diversity of staphylococcal cassette chromosome mec elements in predominant methicillin-resistant Staphylococcus aureus clones in a small geographic area.

    Science.gov (United States)

    Basset, Patrick; Senn, Laurence; Vogel, Valérie; Zanetti, Giorgio; Blanc, Dominique S

    2010-11-01

    Recent population genetic studies suggest that staphylococcal cassette chromosome mec (SCCmec) was acquired much more frequently than previously thought. In the present study, we aimed to investigate the diversity of SCCmec elements in a local methicillin-resistant Staphylococcus aureus (MRSA) population. Each MRSA isolate (one per patient) recovered in the Vaud canton of Switzerland from January 2005 to December 2008 was analyzed by the double-locus sequence typing (DLST) method and SCCmec typing. DLST analysis indicated that 1,884/2,036 isolates (92.5%) belong to four predominant clones. As expected from the local spread of a clone, most isolates within clones harbored an identical SCCmec type. However, three to seven SCCmec types have been recovered in every predominant DLST clone, suggesting that some of these elements might have been acquired locally. This pattern could also be explained by distinct importations of related isolates into the study region. The addition of a third highly variable locus to further increase the discriminatory power of typing as well as epidemiological data suggested that most ambiguous situations were explained by the second hypothesis. In conclusion, our study showed that even if the acquisition of new SCCmec elements at a local level likely occurs, it does not explain all the diversity observed in the study region. PMID:20713672

  3. Clearance of an epidemic clone of methicillin-resistant Staphylococcus aureus in a drug-use network: A follow-up study in Switzerland

    OpenAIRE

    Colombo, Carlo; Senn, Gabriela; Bürgel, Anne; Ruef, Christian

    2012-01-01

    Background: A single clone of methicillin-resistant Staphylococcus aureus (MRSA) was observed in a drug-use network starting in 1994, and was found to persist throughout 2001, with up to 19% MRSA colonization of intravenous drug users (IDUs). Recent clinical observations have shown low prevalences of this endemic drug clone among MRSA isolates. The goal of this study was to assess the evolution of MRSA carriage among IDUs. Methods: The survey took place from November 2008 to September 2009. T...

  4. Dissemination of a single clone of methicillin-resistant Staphylococcus aureus among Turkish hospitals

    NARCIS (Netherlands)

    A.F. van Belkum (Alex); R.P.A.J. Verkooyen (Roel); S.C. Sacilik; C. Cokmus; H.A. Verbrugh (Henri); W.B. van Leeuwen (Willem)

    1997-01-01

    textabstractA collection of 39 methicillin-resistant Staphylococcus aureus (MRSA) stains derived from six different hospitals in Ankara and one hospital in Barsa, Turkey, were analyzed by multiple genotyping. In agreement with the other genotyping assays, pulsed-field g

  5. Isolation of Asian endemic and livestock associated clones of methicillin resistant Staphylococcus aureus from ocular samples in Northeastern Iran.

    Directory of Open Access Journals (Sweden)

    Seyed Asghar Havaei

    2013-09-01

    Full Text Available Methicillin Resistant Staphylococcus aureus (MRSA strains are divided into Community Associated (CA- and Hospital Associated (HA- MRSA. These strains vary in antimicrobial resistance and pathogenicity. S. aureus is one of the most common microorganisms in ocular infections. This study was aimed to determine antimicrobial resistance patterns and genetic characteristics of MRSA strains isolated from ocular infections in Iran.Out of 171 S. aureus strains isolated from various clinical samples during September-December 2011 at Mashhad Emam Reza Hospital, 3 were cultured from eye discharge samples. Antimicrobial resistance tests were performed with MIC and disk diffusion methods and also genetic evaluation was done with Staphylococcal Cassette Chromosome mec (SCCmec, Accessory Gene Regulator (agr and Staphylococcal Protein A (spa typing, Multi Locus Sequence Typing (MLST and determination of toxin gene profile.All strains were MRSA and showed resistance to tetracycline, gentamicin and clindamycin too. Vancomycin, minocyclin and trimethoprim/sulfamethoxazole were effective on all ocular isolates. All isolates belonged to SCCmec IV type. MRSA1 belonged to ST239, CC8, Spa type t7688 and agrIII and had tst1 and hla toxin genes. MRSA2 belonged to ST239, CC8, Spa type t037 and agrI and had the hla toxin gene. Finally, MRSA3 belonged to ST291, CC398, Spa type t304, and agrI and had pvl and hla toxin genes.Phenotypic and genotypic evaluation of the isolated MRSA strains revealed that these strains belong to endemic Asian and livestock related clones that could reach from other body sites or environment to the eye of patients and developed ocular infection.

  6. Staphylococcus aureus eye infections in two Indian hospitals: emergence of ST772 as a major clone

    Directory of Open Access Journals (Sweden)

    Nadig S

    2012-01-01

    Full Text Available Savitha Nadig1, Nithya Velusamy2, Prajna Lalitha2, Sarita Kar3, Savitri Sharma3, Gayathri Arakere11Society for Innovation and Development, Indian Institute of Science, Bengaluru, Karnataka, 2Aravind Eye Hospital, Madurai, Tamil Nadu, 3LV Prasad Eye Institute, Bhubaneswar, Odisha, IndiaPurpose: The purpose of this study was to perform molecular characterization of Staphylococcus aureus isolates causing a variety of eye infections from two major eye care hospitals in India.Methods: Twenty-four isolates from Aravind Eye Hospital, Madurai, India, and nine isolates from LV Prasad Eye Institute, Bhubaneswar, India, representing severe to nonsevere eye infections like microbial keratitis to lacrimal sac abscess, were characterized. Staphylococcal cassette chromosome mec typing, multilocus sequence typing, accessory gene regulator typing, staphylococcal protein A typing, and pulsed field gel electrophoresis were used, along with determination of the presence of Panton–Valentine leucocidin toxin and endotoxin gene cluster among each sequence type.Results: The majority of eye infections, both severe and nonsevere, were caused by sequence type (ST772, positive for the Panton–Valentine leucocidin gene, and carrying methicillin-resistant staphylococcal cassette chromosome mec type V cassette (22/33, 67%. Some of the other sequence types that caused severe eye infections were ST1 (9%, 5 (3%, 72 (6%, 88 (3%, 121 (3%, and 672 (3%. This is the first report of the presence of ST1 and 88 in India.Conclusion: Although the number of isolates included in this study was small, most of the eye infections were caused by community-associated S. aureus where patients had no history of hospitalization or treatment in the past year. In the case of six severe infections, patients were admitted for surgeries and there is probability of hospital infection. In addition, only methicillin-resistant S. aureus isolates carrying staphylococcal cassette chromosome mec type V were

  7. A timescale for evolution, population expansion, and spatial spread of an emerging clone of methicillin-resistant Staphylococcus aureus.

    Directory of Open Access Journals (Sweden)

    Ulrich Nübel

    2010-04-01

    Full Text Available Due to the lack of fossil evidence, the timescales of bacterial evolution are largely unknown. The speed with which genetic change accumulates in populations of pathogenic bacteria, however, is a key parameter that is crucial for understanding the emergence of traits such as increased virulence or antibiotic resistance, together with the forces driving pathogen spread. Methicillin-resistant Staphylococcus aureus (MRSA is a common cause of hospital-acquired infections. We have investigated an MRSA strain (ST225 that is highly prevalent in hospitals in Central Europe. By using mutation discovery at 269 genetic loci (118,804 basepairs within an international isolate collection, we ascertained extremely low diversity among European ST225 isolates, indicating that a recent population bottleneck had preceded the expansion of this clone. In contrast, US isolates were more divergent, suggesting they represent the ancestral population. While diversity was low, however, our results demonstrate that the short-term evolutionary rate in this natural population of MRSA resulted in the accumulation of measurable DNA sequence variation within two decades, which we could exploit to reconstruct its recent demographic history and the spatiotemporal dynamics of spread. By applying Bayesian coalescent methods on DNA sequences serially sampled through time, we estimated that ST225 had diverged since approximately 1990 (1987 to 1994, and that expansion of the European clade began in 1995 (1991 to 1999, several years before the new clone was recognized. Demographic analysis based on DNA sequence variation indicated a sharp increase of bacterial population size from 2001 to 2004, which is concordant with the reported prevalence of this strain in several European countries. A detailed ancestry-based reconstruction of the spatiotemporal dispersal dynamics suggested a pattern of frequent transmission of the ST225 clone among hospitals within Central Europe. In addition

  8. 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

  9. Complete genome sequence of Staphylococcus aureus strain M1, a unique t024-ST8-IVa Danish methicillin-resistant S. aureus clone

    DEFF Research Database (Denmark)

    Larner-Svensson, Hanna; Worning, Peder; Bartels, Mette;

    2013-01-01

    We report the genome sequence, in five contigs, of a methicillin-resistant Staphylococcus aureus isolate designated M1. This clinical isolate was from the index patient of a methicillin-resistant Staphylococcus aureus (MRSA) outbreak in Copenhagen, Denmark, that started in 2003. This strain is se...... is sequence type 8 (ST8), spa type t024, and staphylococcal cassette chromosome mec element (SCCmec) type IVa....

  10. Cloning

    Science.gov (United States)

    ... copies of whole animals Therapeutic cloning, which creates embryonic stem cells. Researchers hope to use these cells to grow healthy tissue to replace injured or diseased tissues in the human body. NIH: National Human Genome Research Institute

  11. The dissemination of ST80-SCCmec-IV community-associated methicillin resistant Staphylococcus aureus clone in Kuwait hospitals

    Directory of Open Access Journals (Sweden)

    Sarkhoo Eiman

    2010-11-01

    Full Text Available Abstract Background Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA is a global healthcare problem. The purpose of this study was to characterize CA-MRSA clones and their distribution in Kuwait hospitals. Methods In total, 135 CA-MRSA isolates, carrying the SCCmec IV or V genetic elements, isolated in eight hospitals were characterized using antibiogram, pulsed-field gel electrophoresis, multilocus sequence typing, and carriage of genes for Panton-Valentine Leukocidin (PVL, capsular polysaccharides types (cap 5 and 8, accessory genes regulators (agr, Staphylococcal enterotoxins (SE and toxic shock syndrome toxin 1 (tst. Results They were susceptible to vancomycin, teicoplanin and linezolid but resistant to kanamycin (62%, fusidic acid (42.2%, tetracycline (39.3%, erythromycin and clindamycin (21.5%, gentamicin (5.9%, streptomycin (6.7%, trimethoprim (5.9%, mupirocin (6.6% and cadmium acetate (82.2%. They consisted of 10 pulsotypes with the majority belonging to PFGE type I (51.1%, type II (22.2%, type IV (13.3% and type III (3.7%. They belonged to 10 sequence types (ST comprising ST80 (51.1%, ST30 (22.2%, ST5 (14.1%, ST1 (4.45, ST6 (3.7%, ST88 (1.5%, ST834 (1.5%, ST8 (0.7%, ST46 (0.7% and ST950 (0.7%. Genes for PVL, cap 8, cap 5 and agr III, agr I and agr II were detected in 61.5%, 77.3%, 20.7% and 62.2%, 17% and 8.1% of the isolates respectively. Nine (6.7% isolates contained tst while 103 isolates were positive for SE genes with sei (63.0%, seg (41.5% and sed (29.6% as the common SE genes. Conclusions ST80-SCCmecIV was the most common CA-MRSA clone in Kuwait hospitals presenting new challenges for infection control.

  12. Genomic insights into the emergence and spread of international clones of healthcare-, community- and livestock-associated meticillin-resistant Staphylococcus aureus: Blurring of the traditional definitions.

    Science.gov (United States)

    Bal, A M; Coombs, G W; Holden, M T G; Lindsay, J A; Nimmo, G R; Tattevin, P; Skov, R L

    2016-09-01

    The evolution of meticillin-resistant Staphylococcus aureus (MRSA) from meticillin-susceptible S. aureus has been a result of the accumulation of genetic elements under selection pressure from antibiotics. The traditional classification of MRSA into healthcare-associated MRSA (HA-MRSA) and community-associated MRSA (CA-MRSA) is no longer relevant as there is significant overlap of identical clones between these groups, with an increasing recognition of human infection caused by livestock-associated MRSA (LA-MRSA). Genomic studies have enabled us to model the epidemiology of MRSA along these lines. In this review, we discuss the clinical relevance of genomic studies, particularly whole-genome sequencing, in the investigation of outbreaks. We also discuss the blurring of each of the three epidemiological groups (HA-MRSA, CA-MRSA and LA-MRSA), demonstrating the limited relevance of this classification. PMID:27530849

  13. Detection of ST772 Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus (Bengal Bay clone and ST22 S. aureus isolates with a genetic variant of elastin binding protein in Nepal

    Directory of Open Access Journals (Sweden)

    R.H. Pokhrel

    2016-05-01

    Full Text Available Genetic characteristics were analysed for recent clinical isolates of methicillin-resistant and -susceptible Staphylococcus aureus (MRSA and MSSA respectively in Kathmandu, Nepal. MRSA isolates harbouring Panton-Valentine leukocidin (PVL genes were classified into ST1, ST22 and ST88 with SCCmec-IV and ST772 with SCCmec-V (Bengal Bay clone, while PVL-positive MSSA into ST22, ST30 and ST772. ST22 isolates (PVL-positive MRSA and MSSA, PVL-negative MRSA possessed a variant of elastin binding protein gene (ebpS with an internal deletion of 180 bp, which was similar to that reported for ST121 S. aureus previously outside Nepal. Phylogenetic analysis indicated that the ebpS variant in ST22 might have occurred independently of ST121 strains. This is the first report of ST772 PVL-positive MRSA in Nepal and detection of the deletion variant of ebpS in ST22 S. aureus.

  14. Lack of association between genotypes and haematogenous seeding infections in a large cohort of patients with methicillin-resistant Staphylococcus aureus bacteraemia from 21 Spanish hospitals.

    Science.gov (United States)

    Gasch, O; Camoez, M; Dominguez, M A; Padilla, B; Pintado, V; Almirante, B; Martín-Gandul, C; López-Medrano, F; de Gopegui, E Ruiz; Ramón Blanco, J; García-Pardo, G; Calbo, E; Horcajada, J P; Granados, A; Jover-Sáenz, A; Dueñas, C; Pujol, M

    2014-04-01

    There is increasing concern regarding the association between certain methicillin-resistant Staphylococcus aureus (MRSA) genotypes and poor clinical outcome. To assess this issue, a large cohort of 579 subjects with MRSA bacteraemia was prospectively followed from June 2008 to December 2009, in 21 hospitals in Spain. Epidemiology, clinical data, therapy, and outcome were recorded. All MRSA strains were analysed in a central laboratory. Presence of a haematogenous seeding infection was the dependent variable in an adjusted logistic regression model. Of the 579 patients included in the study, 84 (15%) had haematogenous seeding infections. Microdilution vancomycin median MIC (IQR) was 0.73 (0.38-3) mg/L. Most MRSA isolates (n = 371; 67%) belonged to Clonal Complex 5 (CC5) and carried an SCCmec element type IV and agr type 2. Isolates belonging to ST8-agr1-SCCmecIV, ST22-agr1-SCCmecIV and ST228-agr2-SCCmecI--a single locus variant of ST5--accounted for 8%, 9% and 9% of the isolates, respectively. After adjusting by clinical variables, any of the clones was associated with increased risk of haematogenous seeding infections. Higher vancomycin MIC was not identified as an independent risk factor, either. In contrast, persistent bacteraemia (OR 4.2; 2.3-7.8) and non-nosocomial acquisition (3.0; 1.7-5.6) were associated with increased risk.

  15. Molecular Characterization of Methicillin Resistant Staphylococcus aureus Strains Isolated from Intensive Care Units in Iran: ST22-SCCmec IV/t790 Emerges as the Major Clone.

    Directory of Open Access Journals (Sweden)

    Mehdi Goudarzi

    Full Text Available The emergence of methicillin-resistant Staphylococcus aureus (MRSA in different patient populations is a major public health concern. This study determined the prevalence and distribution of circulating molecular types of MRSA in hospitalized patients in ICU of hospitals in Tehran.A total of 70 MRSA isolates were collected from patients in eight hospitals. Antimicrobial resistance patterns were determined using the disk diffusion method. The presence of toxin encoding genes and the vancomycin resistance gene were determined by PCR. The MRSA isolates were further analyzed using multi-locus sequence, spa, SCCmec, and agr typing.The MRSA prevalence was 93.3%. Antimicrobial susceptibility testing revealed a high resistance rate (97.1% to ampicillin and penicillin. The rate of resistance to the majority of antibiotics tested was 30% to 71.4%. Two isolates belonging to the ST22-SCCmec IV/t790 clone (MIC ≥ 8 μg/ml had intermediate resistance to vancomycin. The majority of MRSA isolates (24.3% were associated with the ST22-SCCmec IV/t790 clone; the other MRSA clones were ST859-SCCmec IV/t969 (18.6%, ST239-SCCmec III/t037 (17.1%, and ST291-SCCmec IV/t030 (8.6%.The circulating MRSA strains in Iranian hospitals were genetically diverse with a relatively high prevalence of the ST22-SCCmec IV/t790 clone. These findings support the need for future surveillance studies on MRSA to better elucidate the distribution of existing MRSA clones and detect emergence of new MRSA clones.

  16. Isolation, biochemical characterization, and cloning of a bacteriocin from the poultry-associated Staphylococcus aureus strain CH-91

    OpenAIRE

    Wladyka, Benedykt; Wielebska, Katarzyna; Wloka, Marcin; Bochenska, Oliwia; Dubin, Grzegorz; Dubin, Adam; Mak, Pawel

    2012-01-01

    Staphylococcus aureus strain CH-91, isolated from a broiler chicken with atopic dermatitis, has a highly proteolytic phenotype that is correlated with the disease. We describe the isolation and biochemical and molecular characterization of the AI-type lantibiotic BacCH91 from S. aureus CH-91 culture medium. The bacteriocin was purified using a three-stage procedure comprising precipitation with ammonium sulfate, extraction with organic solvents, and reversed-phase HPLC. The BacCH91 peptide is...

  17. The dominant Australian community-acquired methicillin-resistant Staphylococcus aureus clone ST93-IV [2B] is highly virulent and genetically distinct.

    Directory of Open Access Journals (Sweden)

    Kyra Y L Chua

    Full Text Available Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA USA300 has spread rapidly across North America, and CA-MRSA is also increasing in Australia. However, the dominant Australian CA-MRSA strain, ST93-IV [2B] appears distantly related to USA300 despite strikingly similar clinical and epidemiological profiles. Here, we compared the virulence of a recent Australian ST93 isolate (JKD6159 to other MRSA, including USA300, and found that JKD6159 was the most virulent in a mouse skin infection model. We fully sequenced the genome of JKD6159 and confirmed that JKD6159 is a distinct clone with 7616 single nucleotide polymorphisms (SNPs distinguishing this strain from all other S. aureus genomes. Despite its high virulence there were surprisingly few virulence determinants. However, genes encoding α-hemolysin, Panton-Valentine leukocidin (PVL and α-type phenol soluble modulins were present. Genome comparisons revealed 32 additional CDS in JKD6159 but none appeared to encode new virulence factors, suggesting that this clone's enhanced pathogenicity could lie within subtler genome changes, such as SNPs within regulatory genes. To investigate the role of accessory genome elements in CA-MRSA epidemiology, we next sequenced three additional Australian non-ST93 CA-MRSA strains and compared them with JKD6159, 19 completed S. aureus genomes and 59 additional S. aureus genomes for which unassembled genome sequence data was publicly available (82 genomes in total. These comparisons showed that despite its distinctive genotype, JKD6159 and other CA-MRSA clones (including USA300 share a conserved repertoire of three notable accessory elements (SSCmecIV, PVL prophage, and pMW2. This study demonstrates that the genetically distinct ST93 CA-MRSA from Australia is highly virulent. Our comparisons of geographically and genetically diverse CA-MRSA genomes suggest that apparent convergent evolution in CA-MRSA may be better explained by the rapid

  18. Methicillin-resistant Staphylococcus aureus in hospitals in Tbilisi, the Republic of Georgia, are variants of the Brazilian clone

    DEFF Research Database (Denmark)

    Bartels, M.D.; Nanuashvili, A.; Boye, K.;

    2008-01-01

    The purpose of this study was to characterise methicillin-resistant Staphylococcus aureus (MRSA) isolates from the Republic of Georgia, part of the former Soviet Union. Thirty-two non-duplicate MRSA isolates were collected in the period from May 2006 to February 2007. The patient data were analysed...

  19. Two distinct clones of methicillin-resistant Staphylococcus aureus (MRSA) with the same USA300 pulsed-field gel electrophoresis profile: a potential pitfall for identification of USA300 community-associated MRSA

    DEFF Research Database (Denmark)

    Larsen, Anders Rhod; Goering, Richard; Stegger, Marc;

    2009-01-01

    Analysis of methicillin-resistant Staphylococcus aureus (MRSA) characterized as USA300 by pulsed-field gel electrophoresis identified two distinct clones. One was similar to community-associated USA300 MRSA (ST8-IVa, t008, and Panton-Valentine leukocidin positive). The second (ST8-IVa, t024, and...

  20. 金黄色葡萄球菌FnBP配体结合区基因的克隆及其原核表达%Cloning and Prokaryotic Expression of FnBP Ligand Binding Gene of Staphylococcus aureus

    Institute of Scientific and Technical Information of China (English)

    尹荣兰; 杨正涛; 张艳晶; 刘辉; 刘珊; 杨琦; 曹永国; 张乃生

    2008-01-01

    [Objective] The study aimed to clone the FnBP ligand binding gene of Staphylococcus aureus and run prokaryotic expression by constructing a prokaryotic expression vector. [Method] The gene encoding FnBP ligand binding gene was amplified from S.aureus chromosomal DNA by PCR technique. After T-A cloning, plasmid pMD18- FnBP was constructed. pMD18- FnBP and pET28a(+)were digested by BamH Ⅰ and EcoR Ⅰ double enzymes, then the purified FnBP ligand binding gene was subcloned into the expression vector pET28a(+), and the prokaryotic expression vector pET28a-FnBP was thus constructed. The constructed plasmid pET28a-FnBP was transformed into Escherichia coli BL21(DE3) competent cells. The bacterium was induced by IPTG and the expressed products were analyzed by SDS-PAGE and Western blot. [Result] The gene fragment with the length of 370 bp was amplified by PCR approach. One approximately 30 kD exogenous protein was observed in SDS-PAGE analysis. Western blot analysis indicates the protein has antigenicity of S.aureus. [Conclusion] The FnBP ligand binding gene of S.aureus was successfully cloned and expressed in prokaryotic cells.

  1. Poultry-Like pA+ Biotype of Staphylococcus aureus CC346/084 Clone in Human Population.

    Science.gov (United States)

    Piechowicz, Lidia; Garbacz, Katarzyna

    2016-07-01

    The aim of the study was (1) to analyse the prevalence of P-like pA+ biotype of S. aureus in material from healthy and diseased individuals, not employed at slaughterhouses or meat processing plants, and (2) to analyse the relatedness of these strains and their genetic variability. The study included 344 strains of Staphylococcus aureus isolated from hospitalized patients with staphylococcal infections and from healthy carriers. The biotypes of S. aureus were determined on the basis of fibrinolysin and β-haemolysin production, coagulation of bovine plasma, and type of growth on crystal violet agar. Additionally, the strains were tested for the synthesis of protein A in order to distinguish between P-like pA+ and poultry biotypes. Fibrinolysin gene (sak) and methicillin resistance (mecA) were detected by means of PCR. The clonal structure of studied strains was analysed using pulsed field gel electrophoresis and sequencing of spa gene. Finally, the strains were typed with a basic set of 23 bacteriophages. The strains belonging to P-like pA+ biotype corresponded to nearly 20 % of all the studied strains. In contrast to the human biotype, they formed one clonal complex, spa-CC346/084. The P-like pA+ biotype strains did not synthesize fibrinolysin, lacked the sak gene, and showed susceptibility to methicillin. In contrast to the human biotype strains, they belonged mostly to phage group II. The P-like pA+ biotype strains, previously described solely in meat products and meat industry workers, can be also present in hospitalized patients and extra-hospital carriers. These strains form a single, fibrinolysin-negative, clonal complex t084/CC346. PMID:27061586

  2. A timescale for evolution, population expansion, and spatial spread of an emerging clone of methicillin-resistant Staphylococcus aureus

    DEFF Research Database (Denmark)

    Nübel, Ulrich; Dordel, Janina; Kurt, Kevin;

    2010-01-01

    or antibiotic resistance, together with the forces driving pathogen spread. Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of hospital-acquired infections. We have investigated an MRSA strain (ST225) that is highly prevalent in hospitals in Central Europe. By using mutation discovery...... they represent the ancestral population. While diversity was low, however, our results demonstrate that the short-term evolutionary rate in this natural population of MRSA resulted in the accumulation of measurable DNA sequence variation within two decades, which we could exploit to reconstruct its recent...... demographic history and the spatiotemporal dynamics of spread. By applying Bayesian coalescent methods on DNA sequences serially sampled through time, we estimated that ST225 had diverged since approximately 1990 (1987 to 1994), and that expansion of the European clade began in 1995 (1991 to 1999), several...

  3. 金黄色葡萄球菌甲氧西林耐药辅助基因femB的克隆和原核表达%Cloning and Prokaryotic Expression of femB Gene of Staphylococcus aureus

    Institute of Scientific and Technical Information of China (English)

    邹明祥; 武文君; 李军; 邬国军; 张宁洁; 刘文恩; 范学工

    2012-01-01

    FemB gene is closely related with high level of methicillin resistance of Staphylococcus aureus(S. aureus) and is a potential new target for antibiotics against MRSA. Genomic DNA from S. aureus was used as template for PCR amplification of femB gene. The obtained femB gene fragment was cloned into pGM-T vector and then transformed into the competent E. coli DH5a. The positively clone was identified by PCR, restriction endonuclease analysis and DNA sequencing. The identified fragment was cloned into expression vector pGEX-4T-l and transformed into E. coli BL21, and then induced by IPTG to express GST/FemB fusion protein. The expressed protein was identified by SDS-PAGE and Western blot. Results showed that femB gene was cloned and recombinant plasmid was constructed successfully. The recombinant protein with a relative molecular mass 75 kD, which specifically combined with the anti-GST-tag antibody, was highly expressed in E.coli. A prokaryotic expression system of femB gene has been constructed successfully, which laid foundations for investigation on its biological functions.%金黄色葡萄球菌femB基因与甲氧西林高水平耐药密切相关,可能成为开发抗MRSA药物的新靶位,以金葡菌基因组DNA为模板.PCR扩增emB全长基因,所得片段与pGM-T载体连接并转化感受态大肠杆菌DH5α,阳性克隆以PCR、双酶切及测序鉴定.将鉴定正确的目的片段定向克隆到pGEX--4T-1表达载体中,转化至大肠杆菌BL21后经IPTG诱导表达GST/FemB融合蛋白;采用SDS-PAGE及Western blot对融合蛋白进行鉴定.结果显示,重组质粒在宿主菌中获得了高效表达,融合蛋白相对分子质量为75 kD,该融合蛋白可与抗GST-tag抗体特异结合;表明femB基因的原核表迭系统构建成功,为进一步研究其生物学功能奠定了基础.

  4. 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....

  5. Cloning and sequencing of SEB gene of Staphylococcus aureus from mastitis cows%牛乳腺炎金黄葡萄球菌肠毒素B基因的克隆及序列分析

    Institute of Scientific and Technical Information of China (English)

    薛晓阳; 布日额; 吴金花; 刘洋

    2011-01-01

    Objective Cloning and sequencing of bovine mastitis Staphylococcus aureus SEB gene. Methods A pair of primers were designed by biological software of primer 5. 0 and Oligo 6. 0 according to SEB gene sequences of bovine mastitis S. aureus published on GenBank. SEB gene fragment of clinical isolated strain was amplified by PCR. Results Sequencing result showed that SEB gene sequences had 466 bp in length. SEB gene sequences of clinical isolated strain had 100% of homology with the standard strain(CMCC26074) in gene sequences, and had 99. 93% of homology with the SEB gene sequences of standard S. aureus strain (AB479118. 1) published on GenBank. Conclusion The bovine mastitis S. aureus SEB gene had been cloned. This result had laied a foundation for further established of a rapid detection method for SEB gene in dairy milk.%目的 克隆牛乳腺炎金黄葡萄球菌B(SEB)基因,并进行序列分析. 方法 根据Genlank公布的金黄葡萄球菌基因的全序列,利用生物学软件Primer5.0和Olig0 6.0设计1对特异性引物,扩增临床分离菌株的SEB基因片段.结果 扩增的基因片序列长度为466 bp,与标准菌株(CMCC26074)的SEB基因片段序列相似性为100%,与GenBank公布的金黄葡萄球菌菌株(AB479118.1)SEB基因序列相似性为99.93%. 结论 成功克隆出牛乳腺炎金黄葡萄球菌SEB基因,为建立相应的PCR快速检测牛乳SEB基因方法奠定了基础.

  6. Cloning and Occurrence of czrC, a Gene Conferring Cadmium and Zinc Resistance in Methicillin-Resistant Staphylococcus aureus CC398 Isolates

    NARCIS (Netherlands)

    Cavaco, L. M.; Hasman, H.; Stegger, M.; Andersen, P. S.; Skov, R.; Fluit, A. C.; Ito, T.; Aarestrup, F. M.

    2010-01-01

    We recently reported a phenotypic association between reduced susceptibility to zinc and methicillin resistance in Staphylococcus aureus CC398 isolates from Danish swine (F. M. Aarestrup, L. M. Cavaco, and H. Hasman, Vet. Microbiol. 142: 455-457, 2009). The aim of this study was to identify the gene

  7. Cloning and Expression of the Gene of Staphylococcus aureus GapC%金黄色葡萄球菌GapC基因的克隆和表达

    Institute of Scientific and Technical Information of China (English)

    张晶; 朱洪伟; 崔玉东

    2008-01-01

    为研究金黄色葡萄球菌(Staphylococcus aureus,S.aureus)GapC蛋白,应用PCR方法扩增出S. aureus菌株BMSM855/23-1的gapC基因,随后将其克隆到pMD18-T载体上.重组克隆pMD-T/gapC经测序后,与GenBank上已发表的序列进行对比分析.然后,将gapC基因插入到pQE-30质粒,构建重组质粒pQE30/gapC.重组质粒转化大肠杆菌E.coli M15(pREP4),IPTG诱导后,SDS-PAGE鉴定GapC融合蛋白的表达.结果表明成功扩增并克隆了S.aureus gapC,该菌株的gapC基因与GenBank上S. aureus BM10株的核苷酸序列一致性为99.3%,推导氨基酸序列一致性为99.4%.SDS-PAGE结果表明,GapC蛋白在E. coli M15(pREP4)中获得表达.

  8. 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...

  9. Emergence of Panton-Valentine leucocidin-positive ST8-methicillin-resistant Staphylococcus aureus (USA300 clone) in Korea causing healthcare-associated and hospital-acquired bacteraemia.

    Science.gov (United States)

    Jung, J; Song, E H; Park, S Y; Lee, S-R; Park, S-J; Sung, H; Kim, M-N; Kim, S-H; Lee, S-O; Choi, S-H; Woo, J H; Kim, Y S; Chong, Y P

    2016-08-01

    Panton-Valentine leucocidin (PVL)-positive sequence type (ST)8-MRSA-SCCmec IVa (USA300) is the epidemic strain of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in North America. USA300 is extremely rare in South Korea, and PVL-negative ST72 SCCmec type IVc is the predominant CA-MRSA clone. In a multicentre, prospective cohort study of S. aureus bacteraemia, we identified PVL-positive ST8-MRSA isolates by performing multilocus sequence typing and PCR for PVL. We analyzed the clinical characteristics of patients with PVL-positive ST8-MRSA bacteraemia, and performed SCCmec, spa, and agr typing, PCR for arginine catabolic mobile element (ACME), virulence gene profiling, and pulsed-field gel electrophoresis (PFGE). Among a total of 818 MRSA isolates, we identified ten isolates of PVL-positive ST8-MRSA (USA300) (3 from Hospital D, 4 from Hospital G, and 3 from Hospital A), all of which involved exclusively healthcare-associated (5 isolates) and hospital-acquired bacteraemia (5 isolates). This strain accounted for 8~10 % of the hospital-acquired MRSA bacteraemia in Hospitals D and G. Bacteraemia of unknown origin was the most common type of infection followed by pneumonia. All the isolates were SCCmec type IVa, spa type t008, and agr group I. Eight of the isolates harboured ACME. In a PFGE analysis, four isolates were identical to the USA300 control strain, five differed by a single band, and the remaining one differed by two bands. All the isolates were pulsed-field type USA300. This is the first report of healthcare-associated and hospital-acquired bacteraemia caused by USA300 in South Korea. USA300 seems to be an emerging hospital clone in this country. PMID:27209287

  10. Cloning and Occurrence of czrC, a Gene Conferring Cadmium and Zinc Resistance in Methicillin-Resistant Staphylococcus aureus CC398 Isolates

    OpenAIRE

    Cavaco, L.M.; Hasman, H.; Stegger, M.; Andersen, P S; Skov, R.; Fluit, A. C.; Ito, T.; Aarestrup, F. M.

    2010-01-01

    We recently reported a phenotypic association between reduced susceptibility to zinc and methicillin resistance in Staphylococcus aureus CC398 isolates from Danish swine (F. M. Aarestrup, L. M. Cavaco, and H. Hasman, Vet. Microbiol. 142:455-457, 2009). The aim of this study was to identify the genetic determinant causing zinc resistance in CC398 and examine its prevalence in isolates of animal and human origin. Based on the sequence of the staphylococcal cassette chromosome mec (SCCmec) eleme...

  11. Diversity of Staphylococcal Cassette Chromosome mec Elements in Predominant Methicillin-Resistant Staphylococcus aureus Clones in a Small Geographic Area ▿

    OpenAIRE

    Basset, Patrick; Senn, Laurence; Vogel, Valérie; Zanetti, Giorgio; Blanc, Dominique S.

    2010-01-01

    Recent population genetic studies suggest that staphylococcal cassette chromosome mec (SCCmec) was acquired much more frequently than previously thought. In the present study, we aimed to investigate the diversity of SCCmec elements in a local methicillin-resistant Staphylococcus aureus (MRSA) population. Each MRSA isolate (one per patient) recovered in the Vaud canton of Switzerland from January 2005 to December 2008 was analyzed by the double-locus sequence typing (DLST) method and SCCmec t...

  12. Nasal carriage of a single clone of community-acquired methicillin-resistant Staphylococcus aureus among kindergarten attendees in northern Taiwan

    Directory of Open Access Journals (Sweden)

    Lee Shih-Yi

    2007-06-01

    Full Text Available Abstract Background: To evaluate the prevalence and microbiological characterization of community-acquired (CA methicillin-resistant Staphylococcus aureus (MRSA nasal carriage in a kindergarten. Methods: Point prevalence study. Nasal swabs were collected from healthy children younger than 7 years of age who were attending a kindergarten in Taipei, Taiwan. A parent questionnaire regarding MRSA risk factors was administered simultaneously. All CA-MRSA colonization isolates were archived for subsequent antimicrobial susceptibility and molecular typing. Results: Of the 68 children who participated in the study, 17 (25% had S. aureus isolated from nasal swabs. Nine (13.2% of the 68 children had CA-MRSA carriage, and none of them had any identified risk factors. Antimicrobial susceptibility testing revealed all of the 9 CA-MRSA colonization isolates had uniformly high resistance (100% to both clindamycin and erythromycin, the macrolide-lincosamide-streptogramin-constitutive phenotype and the ermB gene. Pulsed-field gel electrophoresis revealed 8 (88.9% of 9 CA-MRSA colonization isolates were genetically related and multilocus sequence typing revealed all isolates had sequence type 59. All of the colonization isolates carried the staphylococcal cassette chromosome mec type IV, but none were positive for the Panton-Valentine leukocidin genes. Conclusion: The results of this study suggest that a single predominant CA-MRSA colonization strain featuring high clindamycin resistance circulated in this kindergarten. Additionally, due to the established transmissibility of colonization isolates, the high prevalence of nasal carriage of CA-MRSA among healthy attendees in kindergartens may indicate the accelerated spread of CA-MRSA in the community.

  13. Cloning and gene construction analysis of β-actin in Oreochromis aureus%奥利亚罗非鱼β-actin基因的克隆与结构分析

    Institute of Scientific and Technical Information of China (English)

    胡海彦; 贾永义; 唐永凯

    2011-01-01

    β-actin在真核细胞的生理过程中起着重要作用,其序列具有高度保守性,是一种管家基因.通过RT-PCR方法克隆出奥利亚罗非鱼(Oreochromis aureus)β-actin的部分cDNA序列,其长度为424 bp,翻译成138个氨基酸,计算的蛋白质分子量为15.5 ku.氨基酸同源性分析显示,奥利亚罗非鱼β-actin与真鲷(Pagrus major)、斑马鱼(Danio rerio)、青鳝(Oryzias latipes)、龙溪鳝(Rivulus marmoratus)的相似性最高,为99.3%;与鲫(Carassius auratus)、红鳍东方鲍(Takifugu rubripes)等其它鱼的相似性也较高,为97.8%~98.6%.此外,还克隆出了奥利亚罗非鱼β-actin相应的DNA序列,共619 bp.cDNA和DNA的序列比对显示克隆出的奥利亚罗非鱼β-actin含有2个内含子,这为将来设计β-actin荧光定量PCR引物以及测定其在不同组织中的表达量变化打下基础.%Eukaryotic β-actin gene plays an important role in physiological process and its sequence is highly conservative as a housekeeping gene. The partial cDNA encoding β-actin in Oreochromis aureus was isolated using RT-PCR. The cDNA isolated was 424 bp encoding 138 amino acids with a calculated molecular weight of 15.5 ku. The comparison analysis of the deduced amino acid sequence of β-actin in O. aureus showed high similarity of 99.3% with those of Pagrus major, Danio rerio, Oryzias latipes, Rivulus marmoratus, and 97.8% ~ 98.6% homology with those of other fishes, such as Carassius auratus, Takifugu rubripes. The corresponding DNA sequence of O. aureus β-actin in size of 619 bp was also cloned. By comparing the sequences of cDNA and DNA, it was found that β-actin gene in O. aureus consisted of two introns. The present study provided some useful information in designing the β-actin primers for real time RT-PCR and evaluating the β-actin expression level for different tissues.

  14. Molecular epidemiology of methicillin-resistant Staphylococcus aureus in Switzerland: sampling only invasive isolates does not allow a representative description of the local diversity of clones.

    Science.gov (United States)

    Senn, L; Basset, P; Greub, G; Prod'hom, G; Frei, R; Zbinden, R; Gaia, V; Balmelli, C; Pfyffer, G E; Mühlemann, K; Zanetti, G; Blanc, D S

    2013-07-01

    We conducted a molecular study of MRSA isolated in Swiss hospitals, including the first five consecutive isolates recovered from blood cultures and the first ten isolates recovered from other sites in newly identified carriers. Among 73 MRSA isolates, 44 different double locus sequence typing (DLST) types and 32 spa types were observed. Most isolates belonged to the NewYork/Japan, the UK-EMRSA-15, the South German and the Berlin clones. In a country with a low to moderate MRSA incidence, inclusion of non-invasive isolates allowed a more accurate description of the diversity. PMID:23458418

  15. 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...

  16. Evidence for a purifying selection acting on the β-lactamase locus in epidemic clones of methicillin-resistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    de Lencastre Hermínia

    2011-04-01

    Full Text Available Abstract Background The β-lactamase (bla locus, which confers resistance to penicillins only, may control the transcription of mecA, the central element of methicillin resistance, which is embedded in a polymorphic heterelogous chromosomal cassette (the SCCmec element. In order to assess the eventual correlation between bla allotypes and genetic lineages, SCCmec types and/or β-lactam resistance phenotypes, the allelic variation on the bla locus was evaluated in a representative collection of 54 international epidemic methicillin-resistant Staphylococcus aureus (MRSA clinical strains and, for comparative purposes, also in 24 diverse methicillin-susceptible S. aureus (MSSA strains. Results Internal fragments of blaZ (the β-lactamase structural gene were sequenced for all strains. A subset of strains, representative of blaZ allotypes, was further characterized by sequencing of internal fragments of the blaZ transcriptional regulators, blaI and blaR1. Thirteen allotypes for blaZ, nine for blaI and 12 for blaR1 were found. In a total of 121 unique single-nucleotide polymorphisms (SNP detected, no frameshift mutations were identified and only one nonsense mutation within blaZ was found in a MRSA strain. On average, blaZ alleles were more polymorphic among MSSA than in MRSA (14.7 vs 11.4 SNP/allele. Overall, blaR1 was the most polymorphic gene with an average of 24.8 SNP/allele. No correlation could be established between bla allotypes and genetic lineages, SCCmec types and/or β-lactam resistance phenotypes. In order to estimate the selection pressure acting on the bla locus, the average dN/dS values were computed. In the three genes and in both collections dN/dS ratios were significantly below 1. Conclusions The data strongly suggests the existence of a purifying selection to maintain the bla locus fully functional even on MRSA strains. Although, this is in agreement with the notion that in most clinical MRSA strains mecA gene is under the control

  17. Genotyping of methicillin-resistant Staphylococcus aureus in the Sultan Qaboos University Hospital, Oman reveals the dominance of Panton–Valentine leucocidin-negative ST6-IV/t304 clone

    Directory of Open Access Journals (Sweden)

    E.E. Udo

    2014-07-01

    Full Text Available The objective of this study was to determine the prevalence and distribution of methicillin-resistant Staphylococcus aureus (MRSA genotypes circulating at a tertiary hospital in the Sultanate of Oman. A total of 79 MRSA isolates were obtained from different clinical samples and investigated using antibiogram, pulsed-field gel electrophoresis (PFGE, staphylococcal chromosome cassette mec (SCCmec, Spa typing and multilocus sequence typing (MLST. The isolates were susceptible to linezolid, vancomycin, teicoplanin, tigecycline and mupirocin but were resistant to tetracycline (30.4%, erythromycin (26.6%, clindamycin (24.1%, trimethoprim (19.0%, ciprofloxacin (17.7%, fusidic acid (15.2% and gentamicin (12.7%. Molecular typing revealed 19 PFGE patterns, 26 Spa types and 21 sequence types. SCCmec-IV (86.0% was the dominant SCCmec type, followed by SCCmec-V (10.1%. SCCmec-III (2.5% and SCCmec-II (1.3% were less common. ST6-IV/t304 (n = 30 and ST1295-IV/t690 (n = 12 were the dominant genotypes followed by ST772-V/t657 (n = 5, ST30-IV/t019/t021 (n = 5, ST22-IV/t852 (n = 4, ST80-IV/t044 (n = 3 and 18 single genotypes that were isolated sporadically. On the basis of SCCmec typing and MLST, 91.2% of the isolates were classified as community-associated MRSA and 8.8% of the isolates (consisting of four ST22-IV/t852, one ST239-III/t632, one ST5-III/t311 and one ST5-II/t003 were classified as healthcare-associated MRSA. The study has revealed the dominance of a Panton–Valentine leucocidin-negative ST6-IV/t304 clone and provided insights into the distribution of antibiotic resistance in MRSA at the tertiary hospital in Oman. It also highlights the importance of surveillance in detecting the emergence of new MRSA clones in a healthcare facility.

  18. Molecular cloning and analysis of enterotoxin gene from wild-type Staphylococcus aureus%野生型金黄色葡萄球菌肠毒素A基因的克隆与分析

    Institute of Scientific and Technical Information of China (English)

    邵奉公; 傅磊; 高晗; 杨滔; 郭焜鹏; 佘宇佳; 张海韵; 陈鸿鹏

    2012-01-01

    根据A、B、C和D肠毒素基因的序列设计特异引物,采用聚合酶链式反应(PCR)方法对食品中的金黄色葡萄球菌进行检测和鉴定肠毒素基因型,并进一步克隆肠毒素基因.结果表明,待检食品中的金黄色葡萄球菌的肠毒素基因为A型,序列长为774 bp,编码257个氨基酸残基,同其他肠毒素A高度相似,等电点为8.85,是一种膜结合蛋白,功能结构域和三位结构预测分析发现此蛋白含有肠毒素家族结构域和肠毒素C家族结构域.%A gene from food sample was identified and cloned by PCR method with special primers for A,B,C and D enterotoxin genes in the study. The results of bioinformaiics analysis suggested that the gene was a member of A enterotoxin gene family and was 774 bp in length,encoding 257 ammo acids,the deduced protein shared high homology with other enterotoxins from Genbanki the pi was 8. 85, and anchored in the membrane after secreted from the cell. The second structure and 3D prediction analysis indicated that the deduced protein contained Stap-Strp-toxin superfamily and Stap-Strp-tox C superiamily which composed the function domains of Stapkytococcus aureus.

  19. Why Clone?

    Science.gov (United States)

    ... How might cloning be used in medicine? Cloning animal models of disease Much of what researchers learn ... the first place, such as habitat destruction and hunting. But cloning may be one more tool that ...

  20. High Level Expression and Purification of Atl, the Major Autolytic Protein of Staphylococcus aureus

    OpenAIRE

    Singh, Vineet K.

    2014-01-01

    Staphylococcus aureus is a major human and animal pathogen. Autolysins regulate the growth, turnover, cell lysis, biofilm formation, and the pathogenicity of S. aureus. Atl is the major autolysin in S. aureus. The biochemical and structural studies of staphylococcal Atl have been limited due to difficulty in cloning, high level overexpression, and purification of this protein. This study describes successful cloning, high level over-expression, and purification of two forms of fully functiona...

  1. Molecular Epidemiology of Staphylococcus aureus among Patients with Skin and Soft Tissue Infections in Two Chinese Hospitals

    Directory of Open Access Journals (Sweden)

    Fei-Fei Gu

    2016-01-01

    Conclusions: The livestock ST398 was the most common clone among patients with S. aureus SSTIs in Jiangsu Province, China. Surveillance and further studies on the important livestock ST398 clone in human infections are necessarily requested.

  2. 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.

  3. Reproductive cloning : can cloning harm the clone?

    OpenAIRE

    Pattinson, S.D.

    2002-01-01

    Since the creation of Dolly the sheep was reported in February 1997, the possibility of a cloned child has elicited powerful declarations of condemnation. A widely held view is that cloning a human being would be immoral and ought to be prohibited by legislation. This paper outlines the regulatory approaches taken in the EU countries (with particular reference to the UK), Canada and the US, before examining the claim that creating a clone would be a wrong to the resultant clone. It is argued ...

  4. 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 ...

  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. 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.

  8. Application of molecular techniques in the study of Staphylococcus aureus clonal evolution - A Review

    Directory of Open Access Journals (Sweden)

    Adriana Marcos Vivoni

    2005-11-01

    Full Text Available Staphylococcus aureus is an important agent of healthcare-associated and community-acquired infections. A major characteristic of this microorganism is the ability to develop resistance to antimicrobial agents. Several molecular techniques have been applied for the characterization of S. aureus in epidemiological studies. In the present review, we discuss the application of molecular techniques for typing S. aureus strains and describe the nomenclature and evolution of epidemic clones of this important pathogen.

  9. First report of the predominance of clonal complex 398 Staphylococcus aureus strains in osteomyelitis complicating diabetic foot ulcers: a national French study.

    Science.gov (United States)

    Senneville, E; Brière, M; Neut, C; Messad, N; Lina, G; Richard, J-L; Sotto, A; Lavigne, J-P

    2014-04-01

    Staphylococcus aureus is the most common pathogen cultured from diabetic foot infection including diabetic foot osteomyelitis. This French multicentre study determined the genetic content of S. aureus isolated from 157 consecutive cases admitted to 12 diabetic foot centres between 2008 and 2011. We describe for the first time the emergence of the CC398 methicillin-susceptible S. aureus clone, the main clone in diabetic foot osteomyelitis, and its tropism for bone. This clone spreads to humans from an animal source through its intrinsic virulence. This adaptation of S. aureus isolates looks to be a worrisome problem and should be carefully monitored.

  10. Cloning and sequencing of SEA gene of Staphylococcus aureus from bovine milk%牛乳腺炎金黄色葡萄球菌肠毒素A基因的克隆及序列分析

    Institute of Scientific and Technical Information of China (English)

    田莉莉

    2012-01-01

    A pair of primers were designed by biological software primer 5.0 and oligo 6.0 and synthesized according to SEA gene sequences of bovine mastitis Staphylococcus aureus published on Genbank. SEA gene fragment was amplified by PCR.Sequencing result showed that SEA gene had 101 bp in length. Isolated strain from Jinzhou and the standard strain had 100% of homology in genes sequence. The SEA Gene sequence of the two strains and published Staphylococcus aureus strain (EF520720.1) on Genbank were homology reach 99.14%. The result of a high degree of homology had laid a consult and experimental basis for further research and established Molecular Diagnostic Techniques.%根据Genbank上公布的金黄色葡萄球菌肠毒素A的全序列,利用生物学软件Primer 5.0和oligo 6.0设计了一对特异性引物来扩增靶序列片段,经克隆预测序,结果表明扩增片段长度为101 bp,锦州分离株与标准菌株的基因片段序列相似性为100%,与Genbank上公布的金黄色葡萄球菌菌株(EF520720.1)SEA基因相似性达到99.14%.高度相似性结果为进一步研究建立分子检测技术奠定了实验基础.

  11. Clone and Sequence Analysis of ClfA Gene of Staphylococcus aureus Isolated from Bovine Milk in Xinjiang Area%新疆地区牛乳源金黄色葡萄球菌粘附因子ClfA基因的克隆与序列分析

    Institute of Scientific and Technical Information of China (English)

    邵俊高; 苏艳

    2013-01-01

    Staphylococcus aureus which caused subclinical mastitis in bovine was isolated from Xinjiang bovine milk and identified.According to the ClfA gene sequences published by GenBank,a pair of specific primers were designed.ClfA gene was amplified by PCR with genomic DNA and the ClfA gene fragment was 1560 bp.This gene fragment was cloned and gene was analyzed by sequencing.Our result showed that the amino acid homology of ClfA protein for 3 regions in Xinjiang area was 91.5%-100%,compared with other countris the amino acid homology of ClfA protein was 91.9%-100%.These data indicated that the ClfA gene was conserved during the bacterial evolution and prevalence and provided experiment foundation for using ClfA to prevent infection caused by S.aureus in future.%采集新疆奶牛隐性乳腺炎乳样,对分离鉴定的致病性金黄色葡萄球菌,提取分离菌株的基因组DNA,参考GenBank中发表的ClfA(Clumping Factor A of Staphylococcus aureus)基因序列,设计特异性引物经PCR扩增得到1 560 bp的ClfA基因.对新疆3个地区分离的9株金黄色葡萄球菌分别进行ClfA基因的克隆和序列分析,对ClfA蛋白的氨基酸序列分析结果表明,新疆3个地区ClfA蛋白氨基酸的同源性为91.5%~100%,与国外其他分离菌株的同源性为91.9%~100%,差异性较小,该结果表明ClfA基因在该菌进化和流行过程中是保守的.

  12. 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.

  13. Clones above the unary clone

    OpenAIRE

    Goldstern, Martin; Sági, Gábor; Shelah, Saharon

    2011-01-01

    Let c be the cardinality of the continuum. We give a family of pairwise incomparable clones (on a countable base set) 2^c members, all with the same unary fragment, namely the set of all unary operations. We also give, for each n, a family of 2^c clones all with the same n-ary fragment, and all containing the set of all unary operations.

  14. 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...

  15. Reproductive Cloning

    OpenAIRE

    Neves, D.

    2010-01-01

    ABSTRACT Man desires to perpetuate himself and thereby will cross ethical barriers in the attempt to preserve his genetic heritage and thus to immortalize himself. To create a being in one’s own image has been a dream of man since the dawn of civilization and since the advent of the cloned sheep Dolly (05/07/1996) it now seems possible. The great challenge now is too reconcile human knowledge and scientific knowledge in the search for happiness, as the fron...

  16. Characterization of Staphylococcus aureus from Humans and a Comparison with Isolates of Animal Origin, in North Dakota, United States.

    Directory of Open Access Journals (Sweden)

    Valeria Velasco

    Full Text Available Different clones of methicillin-susceptible (MSSA and methicillin-resistant (MRSA Staphylococcus aureus have been found in humans as well as in animals and retail meat. However, more information about the genetic characteristics and similarities between strains is needed. The aim of this study was to identify and characterize Staphylococcus aureus from humans, and to compare their characteristics with isolates of animal origin. A total of 550 nasal swabs were taken from healthy humans, and S. aureus was isolated and identified. Positive S. aureus isolates were subjected to molecular typing and susceptibility testing. In addition, 108 MRSA isolates recovered from clinical patients in the state of North Dakota and 133 S. aureus isolates from animals and meat previously analyzed were included. The nasal carriage of S. aureus in healthy people was 7.6% and, in general, clones were genetically diverse. None of the S. aureus strains obtained from healthy people were mecA- or PVL-positive. A total of 105 (97.2% MRSA isolates from clinical cases harbored the mecA gene and 11 (10.2% isolated from blood stream infections harbored the PVL gene. The most common resistance profile among S. aureus from healthy people was penicillin, and from clinical cases were erythromycin-penicillin-ciprofloxacin. The rate of multidrug resistance (MDR was 70% in humans. Most of the S. aureus harboring mecA and PVL genes were identified as ST5 and ST8, and exhibited MDR. However, S. aureus isolates of animal origin used for comparison exhibited a lower rate of MDR. The most common resistance profiles in isolates of animal origin were penicillin-tetracycline and penicillin-tetracycline-erythromycin, in animals and raw meat, respectively. The ST5 was also found in animals and meat, with ST9 and ST398 being the major clones. The genetic similarity between clones from humans and meat suggests the risk of spread of S. aureus in the food chain.

  17. High Nasal Carriage Rate of Staphylococcus aureus Containing Panton-Valentine leukocidin- and EDIN-Encoding Genes in Community and Hospital Settings in Burkina Faso

    Science.gov (United States)

    Ouedraogo, Abdoul-Salam; Dunyach-Remy, Catherine; Kissou, Aimée; Sanou, Soufiane; Poda, Armel; Kyelem, Carole G.; Solassol, Jérôme; Bañuls, Anne-Laure; Van De Perre, Philippe; Ouédraogo, Rasmata; Jean-Pierre, Hélène; Lavigne, Jean-Philippe; Godreuil, Sylvain

    2016-01-01

    The objectives of the present study were to investigate the rate of S.aureus nasal carriage and molecular characteristics in hospital and community settings in Bobo Dioulasso, Burkina Faso. Nasal samples (n = 219) were collected from 116 healthy volunteers and 103 hospitalized patients in July and August 2014. Samples were first screened using CHROMagar Staph aureus chromogenic agar plates, and S. aureus strains were identified by mass spectrometry. Antibiotic susceptibility was tested using the disk diffusion method on Müller-Hinton agar. All S. aureus isolates were genotyped using DNA microarray. Overall, the rate of S. aureus nasal carriage was 32.9% (72/219) with 29% in healthy volunteers and 37% in hospital patients. Among the S. aureus isolates, only four methicillin-resistant S. aureus (MRSA) strains were identified and all in hospital patients (3.9%). The 72 S. aureus isolates from nasal samples belonged to 16 different clonal complexes, particularly to CC 152-MSSA (22 clones) and CC1-MSSA (nine clones). Two clones were significantly associated with community settings: CC1-MSSA and CC45-MSSA. The MRSA strains belonged to the ST88-MRSA-IV or the CC8-MRSA-V complex. A very high prevalence of toxinogenic strains 52.2% (36/69), containing Panton-Valentine leucocidin- and EDIN-encoding genes, was identified among the S. aureus isolates in community and hospital settings. This study provides the first characterization of S. aureus clones and their genetic characteristics in Burkina Faso. Altogether, it highlights the low prevalence of antimicrobial resistance, high diversity of methicillin-sensitive S. aureus clones and high frequency of toxinogenic S. aureus strains. PMID:27679613

  18. High Nasal Carriage Rate of Staphylococcus aureus Containing Panton-Valentine leukocidin- and EDIN-Encoding Genes in Community and Hospital Settings in Burkina Faso.

    Science.gov (United States)

    Ouedraogo, Abdoul-Salam; Dunyach-Remy, Catherine; Kissou, Aimée; Sanou, Soufiane; Poda, Armel; Kyelem, Carole G; Solassol, Jérôme; Bañuls, Anne-Laure; Van De Perre, Philippe; Ouédraogo, Rasmata; Jean-Pierre, Hélène; Lavigne, Jean-Philippe; Godreuil, Sylvain

    2016-01-01

    The objectives of the present study were to investigate the rate of S.aureus nasal carriage and molecular characteristics in hospital and community settings in Bobo Dioulasso, Burkina Faso. Nasal samples (n = 219) were collected from 116 healthy volunteers and 103 hospitalized patients in July and August 2014. Samples were first screened using CHROMagar Staph aureus chromogenic agar plates, and S. aureus strains were identified by mass spectrometry. Antibiotic susceptibility was tested using the disk diffusion method on Müller-Hinton agar. All S. aureus isolates were genotyped using DNA microarray. Overall, the rate of S. aureus nasal carriage was 32.9% (72/219) with 29% in healthy volunteers and 37% in hospital patients. Among the S. aureus isolates, only four methicillin-resistant S. aureus (MRSA) strains were identified and all in hospital patients (3.9%). The 72 S. aureus isolates from nasal samples belonged to 16 different clonal complexes, particularly to CC 152-MSSA (22 clones) and CC1-MSSA (nine clones). Two clones were significantly associated with community settings: CC1-MSSA and CC45-MSSA. The MRSA strains belonged to the ST88-MRSA-IV or the CC8-MRSA-V complex. A very high prevalence of toxinogenic strains 52.2% (36/69), containing Panton-Valentine leucocidin- and EDIN-encoding genes, was identified among the S. aureus isolates in community and hospital settings. This study provides the first characterization of S. aureus clones and their genetic characteristics in Burkina Faso. Altogether, it highlights the low prevalence of antimicrobial resistance, high diversity of methicillin-sensitive S. aureus clones and high frequency of toxinogenic S. aureus strains.

  19. Staphylococcus aureus clonal dynamics and virulence factors in children with atopic dermatitis

    DEFF Research Database (Denmark)

    Lomholt, Hans Bredsted; Andersen, KE; Kilian, Mogens

    2005-01-01

    A prospective cohort study was undertaken to determine the clonal dynamics of Staphylococcus aureus colonization and infection during 1 y in children with atopic dermatitis, and to correlate specific clones, accessory gene regulator (agr) groups, and production of virulence factors with eczema......, toxins, and were assigned to agr groups. S. aureus colonization patterns ranged from rare colonization over transient colonization to persistent colonization by a single clone or a dynamic exchange of up to five clones. Production of no single virulence factor including superantigens and toxins...... activity. Eleven children were examined every 6 wk with swaps taken from active eczema, anterior nose, axillae and perineum, and scoring of eczema activity by severity scoring of atopic dermatitis (SCORAD). Individual S. aureus clonal types were identified and examined for production of superantigens...

  20. Staphylococcus aureus clonal dynamics and virulence factors in children with atopic dermatitis

    DEFF Research Database (Denmark)

    Lomholt, Hans; Andersen, Klaus Ejner; Kilian, Mogens

    2005-01-01

    A prospective cohort study was undertaken to determine the clonal dynamics of Staphylococcus aureus colonization and infection during 1 y in children with atopic dermatitis, and to correlate specific clones, accessory gene regulator (agr) groups, and production of virulence factors with eczema...... activity. Eleven children were examined every 6 wk with swaps taken from active eczema, anterior nose, axillae and perineum, and scoring of eczema activity by severity scoring of atopic dermatitis (SCORAD). Individual S. aureus clonal types were identified and examined for production of superantigens......, toxins, and were assigned to agr groups. S. aureus colonization patterns ranged from rare colonization over transient colonization to persistent colonization by a single clone or a dynamic exchange of up to five clones. Production of no single virulence factor including superantigens and toxins...

  1. Nasal Carriage as a Source of agr-Defective Staphylococcus aureus Bacteremia

    OpenAIRE

    Smyth, Davida S.; Kafer, Jared M.; Wasserman, Gregory A.; Velickovic, Lili; Mathema, Barun; Robert S Holzman; Knipe, Tiffany A.; Becker, Karsten; von Eiff, Christof; Peters, Georg; Chen, Liang; Kreiswirth, Barry N.; Novick, Richard P.; Shopsin, Bo

    2012-01-01

    Inactivating mutations in the Staphylococcus aureus virulence regulator agr are associated with worse outcomes in bacteremic patients. However, whether agr dysfunction is primarily a cause or a consequence of early bacteremia is unknown. Analysis of 158 paired S. aureus clones from blood and nasal carriage sites in individual patients revealed that recovery of an agr-defective mutant from blood was usually predicted by the agr functionality of carriage isolates. Many agr-positive blood isolat...

  2. 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...

  3. Peptide Deformylase in Staphylococcus aureus: Resistance to Inhibition Is Mediated by Mutations in the Formyltransferase Gene

    OpenAIRE

    Margolis, Peter S.; Hackbarth, Corinne J.; Young, Dennis C.; Wang, Wen; Chen, Dawn; Yuan, Zhengyu; White, Richard; Trias, Joaquim

    2000-01-01

    Peptide deformylase, a bacterial enzyme, represents a novel target for antibiotic discovery. Two deformylase homologs, defA and defB, were identified in Staphylococcus aureus. The defA homolog, located upstream of the transformylase gene, was identified by genomic analysis and was cloned from chromosomal DNA by PCR. A distinct homolog, defB, was cloned from an S. aureus genomic library by complementation of the arabinose-dependent phenotype of a PBAD-def Escherichia coli strain grown under ar...

  4. Community-onset Staphylococcus aureus Surveillance Programme annual report, 2012.

    Science.gov (United States)

    Coombs, Geoffrey W; Daly, Denise A; Pearson, Julie C; Nimmo, Graeme R; Collignon, Peter J; McLaws, Mary-Louise; Robinson, James O; Turnidge, John D

    2014-03-01

    In 2012, the Australian Group on Antimicrobial Resistance (AGAR) conducted a community-onset period-prevalence survey of clinical Staphylococcus aureus isolated from hospital outpatients and general practice patients including nursing homes, long term care facilities and hospice patients. Day surgery and dialysis patients were excluded. Twenty-nine medical microbiology laboratories from all state and mainland territories participated. Isolates were tested by Vitek2® (AST-P612 card). Results were compared with previous AGAR community surveys. Nationally, the proportion of S. aureus that were methicillin-resistant S. aureus (MRSA) increased significantly from 11.5% in 2000 to 17.9% in 2012 (P<0.0001). Resistance to the non-ß-lactam antimicrobials varied between regions. No resistance was detected to vancomycin, teicoplanin or linezolid. Resistance in methicillin susceptible S. aureus was rare apart from erythromycin (12.8%) and was absent for vancomycin, teicoplanin, linezolid and daptomycin. The proportion of S. aureus characterised as health care-associated MRSA (HA-MRSA) was 5.1%. Three HA-MRSA clones were characterised, with 72.9% and 26.4% of HA-MRSA classified as ST22-IV [2B] (EMRSA-15) and ST239-III [3A] (Aus-2/3 EMRSA) respectively. Multi-clonal community-associated MRSA (CA-MRSA) accounted for 12.5% of all S. aureus. Regional variation in resistance in MRSA was primarily due to the differential distribution of the 2 major HA-MRSA clones; ST239-III [3A] (Aus-2/3 EMRSA), which is resistant to multiple non-ß-lactam antimicrobials, and ST22-IV [2B] (EMRSA-15), which is resistant to ciprofloxacin and typically erythromycin. Although the majority of CA-MRSA were non-multi-resistant, a significant expansion of Panton-Valentine leukocidin (PVL) positive CA-MRSA clones has occurred nationally. The mean age of patients (31.7 years, 95% CI 28.9-34.5) with a PVL positive CA-MRSA infection was significantly lower (P<0.0001), than the mean age of patients with a PVL

  5. Quantum cloning

    International Nuclear Information System (INIS)

    It is impossible to make perfect copies or 'clones' of unknown quantum states, but approximate copies could still have many uses in quantum computing. A computer is a physical device that consists of components that are all subject to the laws of physics. Since computers deal exclusively in information, there is a close connection between information and physical systems. But what happens if the components inside the computer become so small that they must be described by quantum mechanics rather than classical physics? The seemingly unstoppable decrease in the size of transistors and other components will force the computer industry to confront this question in the near future. However, a small band of far-sighted physicists has been thinking about these problems for almost two decades. Starting with the work of Paul Benioff, Richard Feynman, David Deutsch and Charles Bennett in the mid-1980s, the field of 'quantum information' has grown to become one of the most exciting areas of modern physics. These early pioneers realized that the representation of information by quantum systems, such as single electrons or photons, was an opportunity rather than a problem. (U.K.)

  6. The Clone Factory

    Science.gov (United States)

    Stoddard, Beryl

    2005-01-01

    Have humans been cloned? Is it possible? Immediate interest is sparked when students are asked these questions. In response to their curiosity, the clone factory activity was developed to help them understand the process of cloning. In this activity, students reenact the cloning process, in a very simplified simulation. After completing the…

  7. Evolutionary dynamics of methicillin-resistant Staphylococcus aureus within a healthcare system

    NARCIS (Netherlands)

    Hsu, Li-Yang; Harris, Simon R.; Chlebowicz, Monika A.; Lindsay, Jodi A.; Koh, Tse-Hsien; Krishnan, Prabha; Tan, Thean-Yen; Hon, Pei-Yun; Grubb, Warren B.; Bentley, Stephen D.; Parkhill, Julian; Peacock, Sharon J.; Holden, Matthew T. G.

    2015-01-01

    Background: In the past decade, several countries have seen gradual replacement of endemic multi-resistant healthcare-associated methicillin-resistant Staphylococcus aureus (MRSA) with clones that are more susceptible to antibiotic treatment. One example is Singapore, where MRSA ST239, the dominant

  8. Comparison of Genetic Backgrounds of Methicillin-Resistant and -Susceptible Staphylococcus aureus Isolates from Portuguese Hospitals and the Community

    OpenAIRE

    de Sousa, M. Aires; Conceição, T.; Simas, C.; de Lencastre, H.

    2005-01-01

    In order to understand the origins of the dominant methicillin-resistant Staphylococcus aureus (MRSA) clones in Portuguese hospitals, we compared the genetic backgrounds of nosocomial MRSA with methicillin-susceptible S. aureus (MSSA) isolates from the same hospitals (n = 155) and from the community (n = 157) where they were located. Pulsed-field gel electrophoresis, spa typing, multilocus sequence typing, and agr type analysis revealed that the genetic backgrounds correspondent to the domina...

  9. Phylogenetic Analysis of Staphylococcus aureus CC398 Reveals a Sub-Lineage Epidemiologically Associated with Infections in Horses

    DEFF Research Database (Denmark)

    Abdelbary, Mohamed M. H.; Wittenberg, Anne; Cuny, Christiane;

    2014-01-01

    -allelic polymorphisms, and phylogenetic analyses revealed that an epidemic sub-clone within CC398 (dubbed 'clade (C)') has spread within and between equine hospitals, where it causes nosocomial infections in horses and colonises the personnel. While clade (C) was strongly associated with S. aureus from horses...... in veterinary-care settings (p = 2x10(-7)), it remained extremely rare among S. aureus isolates from human infections....

  10. Clonal Complex 398 Methicillin Susceptible Staphylococcus aureus: A Frequent Unspecialized Human Pathogen with Specific Phenotypic and Genotypic Characteristics

    OpenAIRE

    Tomasz Chroboczek; Sandrine Boisset; Jean-Philippe Rasigade; Anne Tristan; Michele Bes; Helene Meugnier; François Vandenesch; Jerome Etienne; Frederic Laurent

    2013-01-01

    Clonal complex 398 livestok-associated-MRSA (CC398 LA-MRSA) clone is described as a major animal pathogen that can also colonize and infect humans. CC398 methicillin susceptible Staphylococcus aureus (CC398 MSSA) is less described. We identified 126 CC398 MSSA strains of human origin within 6380 S. aureus isolates gathered between 2009 and 2011, from the French National Reference Centre for Staphylococci. They were characterized using antimicrobial susceptibility testing, spa typing, DNA micr...

  11. Draft Genome Sequences of Staphylococcus aureus AMRF1 (ST22) and AMRF2 (ST672), Ocular Methicillin-Resistant Isolates

    KAUST Repository

    Velusamy, Nithya

    2014-03-20

    Sequence type 22 (ST22) and ST672 are the two major emerging clones of community-acquired methicillin-resistant Staphylococcus aureus in India. ST672 strains were found to cause severe ocular infections. We report the draft genome sequences of two emerging strains of methicillin-resistant S. aureus, AMRF1 (ST22) and AMRF2 (ST672), isolated from patients with ocular infections.

  12. Molecular Characterization of Resistance to Mupirocin in Methicillin-Susceptible and -Resistant Isolates of Staphylococcus aureus from Nasal Samples

    OpenAIRE

    Chaves, Fernando; García-Martínez, Jesus; Miguel, Sonia; Otero, Joaquín R.

    2004-01-01

    A total of 15 of 101 (14.8%) nasal methicillin-resistant Staphylococcus aureus (MRSA) isolates exhibited mupirocin resistance (Mupr) compared with 1 of 154 (0.6%) methicillin-susceptible Staphylococcus aureus isolates. A total of 14 (93%) isolates exhibiting high-level Mupr belonged to a single clone. Horizontal plasmid transfer and transmission of Mupr strains contribute to a high incidence of Mupr MRSA at our institution.

  13. 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.

  14. Ethical issues in cloning.

    Science.gov (United States)

    Satris, S

    2000-01-01

    There is great public concern with the ethics of human cloning. This paper briefly examines some of what I identify as pseudo-problems or myths associated with cloning, and some of the more substantial ethical concerns.

  15. Clones on regular cardinals

    OpenAIRE

    Goldstern, Martin; Shelah, Saharon

    2000-01-01

    We investigate the structure of the lattice of clones on an infinite set X. We first observe that ultrafilters naturally induce clones; this yields a simple proof of Rosenberg's theorem: "there are 2^2^kappa many maximal (=precomplete) clones on a set of size kappa." The clones we construct here do not contain all unary functions. We then investigate clones that do contain all unary functions. Using a strong negative partition theorem we show that for many cardinals kappa there are 2^2^kappa ...

  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. 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.

  18. Clonal profile, virulence and resistance of Staphylococcus aureus isolated from sheep milk.

    Science.gov (United States)

    Martins, Katheryne Benini; Faccioli-Martins, Patricia Yoshida; Riboli, Danilo Flávio Moraes; Pereira, Valéria Cataneli; Fernandes, Simone; Oliveira, Aline A; Dantas, Ariane; Zafalon, Luiz Francisco; da Cunha, Maria de Lourdes Ribeiro de Souza

    2015-06-01

    The objective of this study was to characterize the clonal profile, virulence factors and antimicrobial resistance, particularly oxacillin resistance, of Staphylococcus aureus isolated from sheep milk. Milk samples were collected from all teats for the California Mastitis Test (CMT), somatic cell count, identification of S. aureus, investigation in these strains of genes encoding toxins (sea, seb, sec, sed, tst), biofilm (icaA, icaC, icaD, bap), leukocidin (luk-PV) oxacillin resistance by mecA gene detection and susceptibility testing (12 antibiotics). Messenger RNA expression was evaluated by RT-PCR in isolates carrying toxin and biofilm genes. Biofilm formation was also evaluated phenotypically by adherence to polystyrene plates. The clonal profile of S. aureus was investigated by pulsed-field gel electrophoresis. A total of 473 milk samples were collected from 242 animals on three farms and 20 S. aureus strains were isolated and none carried the mecA gene. The two sec gene-positive isolates and the isolates carrying the tst and luk-PV genes were positive by RT-PCR. Staphylococcus aureus isolated from the three flocks studied showed high susceptibility to the drugs tested and none was biofilm producer, indicating that biofilm formation was not a virulence factor causing infection by these strains. The typing of 17 S. aureus isolates revealed the presence of a common clone on the three farms studied, and the presence and expression of the sec and tst genes in one strain of this clone suggest the possible acquisition of virulence genes by this clone, a fact that is important for animal health and food hygiene.

  19. Clonal profile, virulence and resistance of Staphylococcus aureus isolated from sheep milk

    Directory of Open Access Journals (Sweden)

    Katheryne Benini Martins

    2015-06-01

    Full Text Available The objective of this study was to characterize the clonal profile, virulence factors and antimicrobial resistance, particularly oxacillin resistance, of Staphylococcus aureus isolated from sheep milk. Milk samples were collected from all teats for the California Mastitis Test (CMT, somatic cell count, identification of S. aureus, investigation in these strains of genes encoding toxins (sea, seb, sec, sed, tst, biofilm (icaA, icaC, icaD, bap, leukocidin (luk-PV oxacillin resistance by mecA gene detection and susceptibility testing (12 antibiotics. Messenger RNA expression was evaluated by RT-PCR in isolates carrying toxin and biofilm genes. Biofilm formation was also evaluated phenotypically by adherence to polystyrene plates. The clonal profile of S. aureus was investigated by pulsed-field gel electrophoresis. A total of 473 milk samples were collected from 242 animals on three farms and 20 S. aureus strains were isolated and none carried the mecA gene. The two sec gene-positive isolates and the isolates carrying the tst and luk-PV genes were positive by RT-PCR. Staphylococcus aureus isolated from the three flocks studied showed high susceptibility to the drugs tested and none was biofilm producer, indicating that biofilm formation was not a virulence factor causing infection by these strains. The typing of 17 S. aureus isolates revealed the presence of a common clone on the three farms studied, and the presence and expression of the sec and tst genes in one strain of this clone suggest the possible acquisition of virulence genes by this clone, a fact that is important for animal health and food hygiene.

  20. Clonal profile, virulence and resistance of Staphylococcus aureus isolated from sheep milk.

    Science.gov (United States)

    Martins, Katheryne Benini; Faccioli-Martins, Patricia Yoshida; Riboli, Danilo Flávio Moraes; Pereira, Valéria Cataneli; Fernandes, Simone; Oliveira, Aline A; Dantas, Ariane; Zafalon, Luiz Francisco; da Cunha, Maria de Lourdes Ribeiro de Souza

    2015-06-01

    The objective of this study was to characterize the clonal profile, virulence factors and antimicrobial resistance, particularly oxacillin resistance, of Staphylococcus aureus isolated from sheep milk. Milk samples were collected from all teats for the California Mastitis Test (CMT), somatic cell count, identification of S. aureus, investigation in these strains of genes encoding toxins (sea, seb, sec, sed, tst), biofilm (icaA, icaC, icaD, bap), leukocidin (luk-PV) oxacillin resistance by mecA gene detection and susceptibility testing (12 antibiotics). Messenger RNA expression was evaluated by RT-PCR in isolates carrying toxin and biofilm genes. Biofilm formation was also evaluated phenotypically by adherence to polystyrene plates. The clonal profile of S. aureus was investigated by pulsed-field gel electrophoresis. A total of 473 milk samples were collected from 242 animals on three farms and 20 S. aureus strains were isolated and none carried the mecA gene. The two sec gene-positive isolates and the isolates carrying the tst and luk-PV genes were positive by RT-PCR. Staphylococcus aureus isolated from the three flocks studied showed high susceptibility to the drugs tested and none was biofilm producer, indicating that biofilm formation was not a virulence factor causing infection by these strains. The typing of 17 S. aureus isolates revealed the presence of a common clone on the three farms studied, and the presence and expression of the sec and tst genes in one strain of this clone suggest the possible acquisition of virulence genes by this clone, a fact that is important for animal health and food hygiene. PMID:26273271

  1. Molecular epidemiology of heteroresistant vancomycin-intermediate Staphylococcus aureus in Brazil

    Directory of Open Access Journals (Sweden)

    Alessandro Conrado de Oliveira Silveira

    2015-10-01

    Full Text Available ABSTRACTTo determine the epidemiological and molecular characteristics of 12 Staphylococcus aureus isolates presenting heteroresistance to vancomycin in laboratories of two cities in Santa Catarina, southern Brazil. Epidemiological data, including the city of isolation, health institution, and date of isolation were considered, as well as the associated clinical specimen. For molecular characterization, we analyzed the staphylococcal cassette chromosome types, the erm gene presence, and the genomic diversity of isolates using pulsed-field gel electrophoresis. The 12 isolates of S. aureus were previously confirmed as heteroresistance to vancomycin using the population analysis profile-area under curve. Regarding genetic variability, two clones were detected: the main one (clone A composed of four isolates and the clones B, with two isolates. For clone A, two isolates presented identical band patterns and were related to the same hospital, with an interval of 57 days between their isolation. The other isolates of this clone showed no epidemiological link between them because they were isolated in different hospitals and had no temporal relationship. The other clone showed no detectable epidemiological relationship. The heteroresistance to vancomycin recovered in Santa Catarina State from 2009 to 2012 had, in general, heterogeneous genomic patterns based on pulsed-field gel electrophoresis results, which is in accordance with the fact that these isolates had little or no epidemiological relationship among them. Due to the characteristic phenotypic instability and often prolonged vancomycin therapy for selection, clonal spread is not as common as for other resistance mechanisms disseminated through horizontal gene transfer.

  2. Molecular Epidemiology of Staphylococcus aureus among Patients with Skin and Soft Tissue Infections in Two Chinese Hospitals

    Science.gov (United States)

    Gu, Fei-Fei; Chen, Ye; Dong, De-Ping; Song, Zhen; Guo, Xiao-Kui; Ni, Yu-Xing; Han, Li-Zhong

    2016-01-01

    Background: Staphylococcus aureus is one of the predominant causes of skin and soft tissue infections (SSTIs), but limited data were available regarding the characterization of S. aureus from SSTIs patients in Jiangsu Province in China. We aimed to investigate the molecular epidemiology of S. aureus among SSTIs patients in two hospitals of Jiangsu Province. Methods: Sixty-two patients with SSTIs from two Chinese hospitals in Jiangsu Province were enrolled in this study, and 62 S. aureus isolates were collected from February 2014 to January 2015. S. aureus isolates were characterized by antimicrobial susceptibility testing, toxin gene detection, and molecular typing with sequence type, Staphylococcus protein A gene type, accessory gene regulator (agr) group, and Staphylococcal cassette chromosome mec type. Results: Sixteen (25.8%) methicillin-resistant S. aureus (MRSA) isolates were detected, and there was no isolate found resistant to vancomycin, teicoplanin, sulfamethoxazole-trimethoprim, and linezolid. The sei was the toxin gene most frequently found, and no lukS/F-PV-positive isolates were detected among the SSTIs’ patients. Molecular analysis revealed that ST398 (10/62, 16.1%; 2 MRSA and 8 methicillin-susceptible S. aureus) to be the dominant clone, followed by ST5 (8/62, 12.9%) and ST7 (8/62, 12.9%). Conclusions: The livestock ST398 was the most common clone among patients with S. aureus SSTIs in Jiangsu Province, China. Surveillance and further studies on the important livestock ST398 clone in human infections are necessarily requested. PMID:27647191

  3. Differential Analysis of the Nasal Microbiome of Pig Carriers or Non-Carriers of Staphylococcus aureus.

    Science.gov (United States)

    Espinosa-Gongora, Carmen; Larsen, Niels; Schønning, Kristian; Fredholm, Merete; Guardabassi, Luca

    2016-01-01

    Staphylococcus aureus is presently regarded as an emerging zoonotic agent due to the spread of specific methicillin-resistant S. aureus (MRSA) clones in pig farms. Studying the microbiota can be useful for the identification of bacteria that antagonize such opportunistic veterinary and zoonotic pathogen in animal carriers. The aim of this study was to determine whether the nasal microbiome of pig S. aureus carriers differs from that of non-carriers. The V3-V5 region of the 16S rRNA gene was sequenced from nasal swabs of 44 S. aureus carriers and 56 non-carriers using the 454 GS FLX titanium system. Carriers and non-carriers were selected on the basis of quantitative longitudinal data on S. aureus carriage in 600 pigs sampled at 20 Danish herds included in two previous studies in Denmark. Raw sequences were analysed with the BION meta package and the resulting abundance matrix was analysed using the DESeq2 package in R to identify operational taxonomic units (OTUs) with differential abundance between S. aureus carriers and non-carriers. Twenty OTUs were significantly associated to non-carriers, including species with known probiotic potential and antimicrobial effect such as lactic acid-producing isolates described among Leuconostoc spp. and some members of the Lachnospiraceae family, which is known for butyrate production. Further 5 OTUs were significantly associated to carriage, including known pathogenic bacteria such as Pasteurella multocida and Klebsiella spp. Our results show that the nasal microbiome of pigs that are not colonized with S. aureus harbours several species/taxa that are significantly less abundant in pig carriers, suggesting that the nasal microbiota may play a role in the individual predisposition to S. aureus nasal carriage in pigs. Further research is warranted to isolate these bacteria and assess their possible antagonistic effect on S. aureus for the pursuit of new strategies to control MRSA in pig farming. PMID:27509169

  4. Differential Analysis of the Nasal Microbiome of Pig Carriers or Non-Carriers of Staphylococcus aureus

    Science.gov (United States)

    Espinosa-Gongora, Carmen; Larsen, Niels; Schønning, Kristian; Fredholm, Merete; Guardabassi, Luca

    2016-01-01

    Staphylococcus aureus is presently regarded as an emerging zoonotic agent due to the spread of specific methicillin-resistant S. aureus (MRSA) clones in pig farms. Studying the microbiota can be useful for the identification of bacteria that antagonize such opportunistic veterinary and zoonotic pathogen in animal carriers. The aim of this study was to determine whether the nasal microbiome of pig S. aureus carriers differs from that of non-carriers. The V3-V5 region of the 16S rRNA gene was sequenced from nasal swabs of 44 S. aureus carriers and 56 non-carriers using the 454 GS FLX titanium system. Carriers and non-carriers were selected on the basis of quantitative longitudinal data on S. aureus carriage in 600 pigs sampled at 20 Danish herds included in two previous studies in Denmark. Raw sequences were analysed with the BION meta package and the resulting abundance matrix was analysed using the DESeq2 package in R to identify operational taxonomic units (OTUs) with differential abundance between S. aureus carriers and non-carriers. Twenty OTUs were significantly associated to non-carriers, including species with known probiotic potential and antimicrobial effect such as lactic acid-producing isolates described among Leuconostoc spp. and some members of the Lachnospiraceae family, which is known for butyrate production. Further 5 OTUs were significantly associated to carriage, including known pathogenic bacteria such as Pasteurella multocida and Klebsiella spp. Our results show that the nasal microbiome of pigs that are not colonized with S. aureus harbours several species/taxa that are significantly less abundant in pig carriers, suggesting that the nasal microbiota may play a role in the individual predisposition to S. aureus nasal carriage in pigs. Further research is warranted to isolate these bacteria and assess their possible antagonistic effect on S. aureus for the pursuit of new strategies to control MRSA in pig farming. PMID:27509169

  5. 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...

  6. Staphylococcus aureus Bacteraemia

    Directory of Open Access Journals (Sweden)

    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.

  7. Statement on Human Cloning

    Science.gov (United States)

    ... as our understanding of this technology advances. Support Stem Cell Research (including Research Cloning) AAAS supports stem cell research, including the use of nuclear transplantation techniques (also ...

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

    NARCIS (Netherlands)

    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

  9. Introduction of plasmid DNA into an ST398 livestock-associated methicillin-resistant Staphylococcus aureus strain

    Science.gov (United States)

    MRS926 is a livestock-associated methicillin-resistant Staphylococcus aureus (MRSA) strain of sequence type (ST) 398. In order to facilitate in vitro and in vivo studies of this strain, we sought to tag it with a fluorescent marker. We cloned a codon-optimized gene for TurboGFP into a shuttle vector...

  10. Cloning-free CRISPR

    NARCIS (Netherlands)

    Arbab, Mandana; Srinivasan, Sharanya; Hashimoto, Tatsunori; Geijsen, Niels; Sherwood, Richard I.

    2015-01-01

    We present self-cloning CRISPR/Cas9 (scCRISPR), a technology that allows for CRISPR/Cas9-mediated genomic mutation and site-specific knockin transgene creation within several hours by circumventing the need to clone a site-specific single-guide RNA (sgRNA) or knockin homology construct for each targ

  11. Characterization of Staphylococcus aureus from Humans and a Comparison with İsolates of Animal Origin, in North Dakota, United States

    OpenAIRE

    Valeria Velasco; Esra Buyukcangaz; Sherwood, Julie S.; Ryan M Stepan; Koslofsky, Ryan J.; Logue, Catherine M

    2015-01-01

    Different clones of methicillin-susceptible (MSSA) and methicillin-resistant (MRSA) Staphylococcus aureus have been found in humans as well as in animals and retail meat. However, more information about the genetic characteristics and similarities between strains is needed. The aim of this study was to identify and characterize Staphylococcus aureus from humans, and to compare their characteristics with isolates of animal origin. A total of 550 nasal swabs were taken from healthy humans, and ...

  12. Single- and Multistep Resistance Selection Studies on the Activity of Retapamulin Compared to Other Agents against Staphylococcus aureus and Streptococcus pyogenes

    OpenAIRE

    Kosowska-Shick, Klaudia; Clark, Catherine; Credito, Kim; McGhee, Pamela; Dewasse, Bonifacio; Bogdanovich, Tatiana; Appelbaum, Peter C.

    2006-01-01

    Retapamulin had the lowest rate of spontaneous mutations by single-step passaging and the lowest parent and selected mutant MICs by multistep passaging among all drugs tested for all Staphylococcus aureus strains and three Streptococcus pyogenes strains which yielded resistant clones. Retapamulin has a low potential for resistance selection in S. pyogenes, with a slow and gradual propensity for resistance development in S. aureus.

  13. 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

  14. Molecular characterization and antimicrobial susceptibility of nasal Staphylococcus aureus isolates from a Chinese medical college campus.

    Science.gov (United States)

    Du, Jimei; Chen, Chun; Ding, Baixing; Tu, Jinjing; Qin, Zhiqiang; Parsons, Chris; Salgado, Cassandra; Cai, Qiangjun; Song, Yulong; Bao, Qiyu; Zhang, Liming; Pan, Jingye; Wang, Liangxing; Yu, Fangyou

    2011-01-01

    Staphylococcus aureus colonization and infection occur more commonly among persons living or working in crowded conditions, but characterization of S. aureus colonization within medical communities in China is lacking. A total of 144 (15.4%, 144/935) S. aureus isolates, including 28 (3.0%, 28/935) MRSA isolates, were recovered from the nares of 935 healthy human volunteers residing on a Chinese medical college campus. All S. aureus isolates were susceptible to vancomycin, quinupristin/dalfopristin and linezolid but the majority were resistant to penicillin (96.5%), ampicillin/sulbactam (83.3%) and trimethoprim/sulfamethoxazole (93.1%). 82%, (23/28) of the MRSA isolates and 66% (77/116) of the MSSA isolates were resistant to multiple antibiotics, and 3 MRSA isolates were resistant to mupirocin--an agent commonly used for nasal decolonization. 16 different sequence types (STs), as well as SCCmec genes II, III, IVd, and V, were represented among MRSA isolates. We also identified, for the first time, two novel STs (ST1778 and ST1779) and 5 novel spa types for MRSA. MRSA isolates were distributed in different sporadic clones, and ST59-MRSA-VId- t437 was found within 3 MRSA isolates. Moreover, one isolate with multidrug resistance belonging to ST398-MRSA-V- t571 associated with animal infections was identified, and 3 isolates distributed in three different clones harbored PVL genes. Collectively, these data indicate a high prevalence of nasal MRSA carriage and molecular heterogeneity of S. aureus isolates among persons residing on a Chinese medical college campus. Identification of epidemic MRSA clones associated with community infection supports the need for more effective infection control measures to reduce nasal carriage and prevent dissemination of MRSA to hospitalized patients and health care workers in this community. PMID:22114670

  15. Molecular characterization and antimicrobial susceptibility of nasal Staphylococcus aureus isolates from a Chinese medical college campus.

    Directory of Open Access Journals (Sweden)

    Jimei Du

    Full Text Available Staphylococcus aureus colonization and infection occur more commonly among persons living or working in crowded conditions, but characterization of S. aureus colonization within medical communities in China is lacking. A total of 144 (15.4%, 144/935 S. aureus isolates, including 28 (3.0%, 28/935 MRSA isolates, were recovered from the nares of 935 healthy human volunteers residing on a Chinese medical college campus. All S. aureus isolates were susceptible to vancomycin, quinupristin/dalfopristin and linezolid but the majority were resistant to penicillin (96.5%, ampicillin/sulbactam (83.3% and trimethoprim/sulfamethoxazole (93.1%. 82%, (23/28 of the MRSA isolates and 66% (77/116 of the MSSA isolates were resistant to multiple antibiotics, and 3 MRSA isolates were resistant to mupirocin--an agent commonly used for nasal decolonization. 16 different sequence types (STs, as well as SCCmec genes II, III, IVd, and V, were represented among MRSA isolates. We also identified, for the first time, two novel STs (ST1778 and ST1779 and 5 novel spa types for MRSA. MRSA isolates were distributed in different sporadic clones, and ST59-MRSA-VId- t437 was found within 3 MRSA isolates. Moreover, one isolate with multidrug resistance belonging to ST398-MRSA-V- t571 associated with animal infections was identified, and 3 isolates distributed in three different clones harbored PVL genes. Collectively, these data indicate a high prevalence of nasal MRSA carriage and molecular heterogeneity of S. aureus isolates among persons residing on a Chinese medical college campus. Identification of epidemic MRSA clones associated with community infection supports the need for more effective infection control measures to reduce nasal carriage and prevent dissemination of MRSA to hospitalized patients and health care workers in this community.

  16. 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 ...

  17. [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.

  18. Multiplex PCR for Rapid Detection of Staphylococcus aureus Isolates Suspected to Represent Community-Acquired Strains▿

    OpenAIRE

    Strommenger, B.; Braulke, C.; Pasemann, B.; Schmidt, C.; Witte, W.

    2007-01-01

    The continuous spread of community-acquired methicillin-resistant Staphylococcus aureus (caMRSA) and the introduction of these highly virulent isolates into hospitals represent increasing threats. The timely recognition of caMRSA strains is crucial for infection control purposes. Thus, we developed a PCR-based assay for the easy and rapid determination of those caMRSA clones that currently are the most prevalent in Germany and Central Europe. This assay was able to correctly identify the majo...

  19. FabH Mutations Confer Resistance to FabF-Directed Antibiotics in Staphylococcus aureus

    OpenAIRE

    Parsons, Joshua B.; Yao, Jiangwei; Frank, Matthew W.; Rock, Charles O.

    2014-01-01

    Delineating the mechanisms for genetically acquired antibiotic resistance is a robust approach to target validation and anticipates the evolution of clinical drug resistance. This study defines a spectrum of mutations in fabH that render Staphylococcus aureus resistant to multiple natural products known to inhibit the elongation condensing enzyme (FabF) of bacterial type II fatty acid synthesis. Twenty independently isolated clones resistant to platensimycin, platencin, or thiolactomycin were...

  20. Cross-Border Dissemination of Methicillin-Resistant Staphylococcus aureus, Euregio Meuse-Rhin Region

    OpenAIRE

    Deurenberg, Ruud H.; Nulens, Eric; Valvatne, Havard; Sebastian, Silvie; Driessen, Christel; Craeghs, Jos; De Brauwer, Els; Heising, Bernhard; Kraat, Yvette J.; Riebe, Joachim; Stals, Frans S.; Trienekens, Thera A.; Scheres, Jacques; Friedrich, Alexander W.; van Tiel, Frank H.

    2009-01-01

    Because the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) differs among the 3 countries forming the Euregio Meuse-Rhin (EMR) region (Belgium, Germany, and the Netherlands), cross-border healthcare requires information about the spread of MRSA in the EMR. We investigated the emergence, dissemination, and diversity of MRSA clones in the EMR by using several typing methods. MRSA associated with clonal complexes 5, 8, 30, and 45 was disseminated throughout the EMR. Dutch isolat...

  1. 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.

  2. Prevalence and Molecular Epidemiology of Staphylococcus aureus among Residents of Seven Nursing Homes in Shanghai.

    Directory of Open Access Journals (Sweden)

    Ji Zhang

    Full Text Available Residents in nursing homes (NHs always represent potential reservoirs for Staphylococcus aureus and methicillin-resistant S. aureus (MRSA. To our knowledge, there is no epidemiological information up till now that describes the prevalence and molecular characteristics of S. aureus in nursing home residents in Shanghai, China.Four hundred and ninety-one unique residents from 7 NHs were enrolled in this study. Specimens were collected among these residents including 491 nasal swabs, 487 axillary swabs and 119 skin swabs. S. aureus isolated and identified from the swabs was characterized according to antimicrobial susceptibility profiling, toxin gene prevalence, and multilocus sequence typing (MLST, spa and SCCmec typing.Among the 491 residents screened, S. aureus was isolated in 109 residents from 90 nasal swabs (90/491, 18.3%, 29 axillary swabs (29/487, 6.0%, and 22 skin swabs (22/119, 18.5%. Sixty-eight MRSA isolates were detected in 52 residents from 41 nasal carriers, 15 axillary carriers and 12 skin carriers. The overall prevalence rate of S. aureus and MRSA colonization was 22.2% and 10.6% respectively. Ten residents presented S. aureus in all three sample types and 12 residents presented S. aureus in two of the three sample types collected. Molecular analysis revealed CC1 (29.1% to be the dominant clone in this study, followed by CC398 (19.9%, CC188 (13.5% and CC5 (12.8%. The most common spa type was t127 (22.0%, followed by t14383 (12.8% and t002 (10.6%.A high prevalence of S. aureus and MRSA colonization was revealed in nursing home residents in Shanghai. CC1 was the most common clonal complex and t127 was the most common spa type among NH residents. The data provides an important baseline for future surveillance of S. aureus in NHs in Shanghai and other highly urbanized regions in China. Implementation of infection control strategies must be given high priority in NHs to fight such high prevalence of both MRSA and methicillin

  3. Enzyme free cloning for high throughput gene cloning and expression

    NARCIS (Netherlands)

    de Jong, R.N.; Daniëls, M.; Kaptein, R.; Folkers, G.E.

    2006-01-01

    Structural and functional genomics initiatives significantly improved cloning methods over the past few years. Although recombinational cloning is highly efficient, its costs urged us to search for an alternative high throughput (HTP) cloning method. We implemented a modified Enzyme Free Cloning (EF

  4. 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...

  5. Main: Clone Detail [KOME

    Lifescience Database Archive (English)

    Full Text Available Clone Detail Mapping Pseudomolecule data detail Detail information Mapping to the TIGR japonica Pseudomolecu...les kome_mapping_pseudomolecule_data_detail.zip kome_mapping_pseudomolecule_data_detail ...

  6. Placentation in cloned cattle

    DEFF Research Database (Denmark)

    Miglino, M A; Pereira, F T V; Visintin, J A;

    2007-01-01

    To elucidate the morphological differences between placentas from normal and cloned cattle pregnancies reaching term, the umbilical cord, placentomes and interplacentomal region of the fetal membranes were examined macroscopically as well as by light and scanning electron microscopy. In pregnancies...

  7. Do Managers Clone Themselves?

    Science.gov (United States)

    Baron, Alma S.

    1981-01-01

    A recent questionnaire survey provides statistics on male managers' views of female managers. The author recommends that male managers break out of their cloning behavior and that the goal ought to be a plurality in management. (Author/WD)

  8. Asymmetric quantum cloning machines

    International Nuclear Information System (INIS)

    A family of asymmetric cloning machines for quantum bits and N-dimensional quantum states is introduced. These machines produce two approximate copies of a single quantum state that emerge from two distinct channels. In particular, an asymmetric Pauli cloning machine is defined that makes two imperfect copies of a quantum bit, while the overall input-to-output operation for each copy is a Pauli channel. A no-cloning inequality is derived, characterizing the impossibility of copying imposed by quantum mechanics. If p and p' are the probabilities of the depolarizing channels associated with the two outputs, the domain in (√p,√p')-space located inside a particular ellipse representing close-to-perfect cloning is forbidden. This ellipse tends to a circle when copying an N-dimensional state with N→∞, which has a simple semi-classical interpretation. The symmetric Pauli cloning machines are then used to provide an upper bound on the quantum capacity of the Pauli channel of probabilities px, py and pz. The capacity is proven to be vanishing if (√px, √py, √pz) lies outside an ellipsoid whose pole coincides with the depolarizing channel that underlies the universal cloning machine. Finally, the tradeoff between the quality of the two copies is shown to result from a complementarity akin to Heisenberg uncertainty principle. (author)

  9. 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...

  10. 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.

  11. [Advances in Molecular Cloning].

    Science.gov (United States)

    Ashwini, M; Murugan, S B; Balamurugan, S; Sathishkumar, R

    2016-01-01

    "Molecular cloning" meaning creation of recombinant DNA molecules has impelled advancement throughout life sciences. DNA manipulation has become easy due to powerful tools showing exponential growth in applications and sophistication of recombinant DNA technology. Cloning genes has become simple what led to an explosion in the understanding of gene function by seamlessly stitching together multiple DNA fragments or by the use of swappable gene cassettes, maximizing swiftness and litheness. A novel archetype might materialize in the near future with synthetic biology techniques that will facilitate quicker assembly and iteration of DNA clones, accelerating the progress of gene therapy vectors, recombinant protein production processes and new vaccines by in vitro chemical synthesis of any in silico-specified DNA construct. The advent of innovative cloning techniques has opened the door to more refined applications such as identification and mapping of epigenetic modifications and high-throughput assembly of combinatorial libraries. In this review, we will examine the major breakthroughs in cloning techniques and their applications in various areas of biological research that have evolved mainly due to easy construction of novel expression systems. PMID:27028806

  12. Preliminary treatment of bovine mastitis caused by Staphylococcus aureus, with trx-SA1, recombinant endolysin of S. aureus bacteriophage IME-SA1.

    Science.gov (United States)

    Fan, Jindai; Zeng, Zhiliang; Mai, Kaijie; Yang, Yu; Feng, Jiaqi; Bai, Yang; Sun, Baoli; Xie, Qingmei; Tong, Yigang; Ma, Jingyun

    2016-08-15

    Methicillin-resistant Staphylococcus aureus (MRSA) has become a great threat to human and animal health and there is an urgent need to develop novel antibacterial agents to control this pathogen. The objective of this study was to obtain an active recombinant endolysin from the novel bacteriophage (IME-SA1), and conduct an efficacy trial of its effectiveness against bovine mastitis. We isolated a phage that was virulent and specific for S. aureus with an optimal multiplicity of infection of 0.01. Electron microscopy revealed that IME-SA1 was a member of the family Myoviridae, with an isometric head (98nm) and a long contractile tail (200nm). Experimental lysis experiments indicated the phage had an incubation period of 20min with a burst size of 80. When host bacteria were in early exponential growth stages, a multiplicity of infection of 0.01 resulted in a complete bacterial lysis after 9h. The endolysin gene (804bp) was cloned into the pET-32a bacterial expression vector and recombinant endolysin Trx-SA1 was successfully obtained with molecular size of about 47kDa. Preliminary results of therapeutic trials in cow udders showed that Trx-SA1 could effectively control mild clinical mastitis caused by S. aureus. The endolysin Trx-SA1 might be an alternative treatment strategy for infections caused by S. aureus, including MRSA. PMID:27374909

  13. Cloning of an agr homologue of Staphylococcus saprophyticus.

    Science.gov (United States)

    Sakinc, Türkan; Kulczak, Pawel; Henne, Karsten; Gatermann, Sören G

    2004-08-01

    An agr homologue of Staphylococcus saprophyticus was identified, cloned and sequenced. The gene locus shows homologies to other staphylococcal agr systems, especially to those of S. epidermidis and S. lugdunensis. A putative RNAIII was identified and found to be differentially expressed during the growth phases. In contrast to the RNAIII molecules of S. epidermidis and S. aureus it does not contain an open reading frame that codes for a protein with homologies to the delta-toxin. Using PCR, the agr was found to be present in clinical isolates of S. saprophyticus.

  14. Antimicrobial resistance and molecular analysis of methicillin-resistant Staphylococcus aureus collected in a Spanish hospital.

    Science.gov (United States)

    Hernández-Porto, Miriam; Lecuona, María; Aguirre-Jaime, Armando; Castro, Beatriz; Delgado, Teresa; Cuervo, Milagros; Pedroso, Yanet; Arias, Ángeles

    2015-04-01

    Clonal distribution of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals may differ according to the geographic location and time period. Knowledge of MRSA clonal epidemiology in hospital settings involves much more than the study of healthcare-associated MRSA (HA-MRSA) clones. In recent years, investigators have documented the introduction of both community-associated MRSA (CA-MRSA) and livestock-associated MRSA (LA-MRSA) clones, the emergence of clones carrying Staphylococcal cassette chromosome mec (SCCmec) XI, and the genetic diversity among sporadic MRSA isolates. The allocation of certain antibiotypes to dominant MRSA clones in an institution allows their use as phenotypic markers for a preliminary search for new clones, early detection of clonal shift, and as a guide for better empirical therapy, infection control, and treatment within a particular institution. For these reasons, we identified 938 strains detected in a System of Universal Active Surveillance of MRSA in clinical samples during the period 2009-2010, obtaining the clonal distribution of MRSA at the Hospital Universitario de Canarias (Tenerife, Spain) and the relationship between antimicrobial susceptibility and three major clones present. The antibiotypes that best defined the ST5-MRSA-IV (Pediatric) clone showed resistance to tobramycin and susceptibility to clindamycin, erythromycin, gentamicin, rifampin, trimethoprim-sulfamethoxazole, vancomycin, quinupristin/dalfopristin, and linezolid, whereas the ST22-MRSA-IV clone (EMRSA-15) showed susceptibility to these antibiotics, and finally, the ST36-MRSA-II clone (EMRSA-16) was resistant to clindamycin, erythromycin, and tobramycin and susceptible to the remaining antimicrobials. Similar observations would allow the early detection of changes in clonal epidemiology by analysis of antimicrobial susceptibility of the isolates within a single institution. PMID:25365597

  15. Cloning-free CRISPR

    OpenAIRE

    Mandana Arbab; Sharanya Srinivasan; Tatsunori Hashimoto; Niels Geijsen; Richard I. Sherwood

    2015-01-01

    Summary We present self-cloning CRISPR/Cas9 (scCRISPR), a technology that allows for CRISPR/Cas9-mediated genomic mutation and site-specific knockin transgene creation within several hours by circumventing the need to clone a site-specific single-guide RNA (sgRNA) or knockin homology construct for each target locus. We introduce a self-cleaving palindromic sgRNA plasmid and a short double-stranded DNA sequence encoding the desired locus-specific sgRNA into target cells, allowing them to produ...

  16. Molecular epidemiology of hospital-onset methicillin-resistant Staphylococcus aureus infections in Southern Chile.

    Science.gov (United States)

    Medina, G; Egea, A L; Otth, C; Otth, L; Fernández, H; Bocco, J L; Wilson, M; Sola, C

    2013-12-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen of public health importance. In Chile, the Cordobes/Chilean clone was the predominant healthcare-associated MRSA (HA-MRSA) clone in 1998. Since then, the molecular epidemiological surveillance of MRSA has not been performed in Southern Chile. We aimed to investigate the molecular epidemiology of HA-MRSA infections in Southern Chile to identify the MRSA clones involved, and their evolutionary relationships with epidemic international MRSA lineages. A total of 303 single inpatient isolates of S. aureus were collected in the Valdivia County Hospital (2007-2008), revealing 33% (100 MRSA/303) prevalence for HA-MRSA infections. The SCCmec types I and IV were identified in 97% and 3% of HA-MRSA, respectively. All isolates lacked the pvl genes. A random sample (n = 29) of all MRSA was studied by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), SCCmec subtyping, agr and spa typing, and virulence genes profiling. PFGE analysis revealed the predominance (89%, 26/29) of pulsotype A and three additional pulsotypes, designated H1, I33, and G1. Pulsotype A (ST5-SCCmecI-spa-t149) is clonally related to the Cordobes/Chilean clone. Pulsotype H1 (ST5-SCCmecIVNT-spa-t002) is genetically related to the Pediatric clone (ST5-SCCmecIV). Pulsotype I33 (ST5-SCCmecIVc-spa-t002) is clonally related by PFGE to the community-associated MRSA (CA-MRSA) clone spread in Argentina, I-ST5-IVa-PVL(+). The G1 pulsotype (ST8-SCCmecIVc-spa-t024) is clonally related to the epidemic USA300 CA-MRSA. Here, we demonstrate the stability of the Cordobes/Chilean clone over time as the major HA-MRSA clone in Southern Chile. The identification of two CA-MRSA clones might suggest that these clones have entered into the healthcare setting from the community. These results emphasize the importance of the local surveillance of MRSA infections in the community and hospital settings.

  17. 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...

  18. 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

  19. Expression of Four Methionine Sulfoxide Reductases in Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Kuldeep Singh

    2012-01-01

    Full Text Available Staphylococcus aureus possesses three MsrA enzymes (MsrA1, MsrA2, MsrA3 that reduce the S-epimer of methionine sulfoxide (MetO and an MsrB enzyme that reduces R-MetO. The four msr genes are expressed from three different promoters. The msrA1/msrB genes are coexpressed. To determine the expression pattern of msr genes, three independent reporter strains were constructed where msr promoter was cloned in front of a promoterless lacZ and the resulting construct was integrated in the chromosome. Using these strains, it was determined that the msrA1/B expression is significantly higher in S. aureus compared to msrA2 or msrA3. Expression of msrA1/B was highest during stationary phase growth, but the expression of msrA2 and msrA3 was highest during the early to midexponential growth phase. Expression of msrA1/B was induced by oxacillin and the expression of msrA3 was upregulated by salt. Expression of msrA2 remained unchanged under all tested conditions.

  20. A Seminar on Human Cloning: Cloning in Reproductive Medicine

    OpenAIRE

    Illmensee, Karl

    2001-01-01

    This review article summarizes the historical development of mammalian cloning, presents current advances and presumed risk factors in the field of reproductive cloning, discusses possible clinical applications of therapeutic and diagnostic cloning and outlines prospective commercial trends in pharmacytical cloning. Predictable progress in biotechnology and stem cell engineering should prove to be advantageous for patients' health and for novel benefits in reproductive and regenerative medicine.

  1. 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.

  2. 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...

  3. 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 ...

  4. 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 ...

  5. 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.

  6. Levels of alpha-toxin correlate with distinct phenotypic response profiles of blood mononuclear cells and with agr background of community-associated Staphylococcus aureus isolates

    NARCIS (Netherlands)

    S.M. Shambat (Srikanth Mairpady); A. Haggar (Axana); F. Vandenesch (Francois); G. Lina (Gérard); W.J.B. van Wamel (Willem); G. Arakere (Gayathri); M. Svensson (Mattias); A. Norrby-Teglund (Anna)

    2014-01-01

    textabstractEpidemiological studies of Staphylococcus aureus have shown a relation between certain clones and the presence of specific virulence genes, but how this translates into virulence-associated functional responses is not fully elucidated. Here we addressed this issue by analyses of communit

  7. Secure the Clones

    Science.gov (United States)

    Jensen, Thomas; Kirchner, Florent; Pichardie, David

    Exchanging mutable data objects with untrusted code is a delicate matter because of the risk of creating a data space that is accessible by an attacker. Consequently, secure programming guidelines for Java stress the importance of using defensive copying before accepting or handing out references to an internal mutable object. However, implementation of a copy method (like clone()) is entirely left to the programmer. It may not provide a sufficiently deep copy of an object and is subject to overriding by a malicious sub-class. Currently no language-based mechanism supports secure object cloning. This paper proposes a type-based annotation system for defining modular copy policies for class-based object-oriented programs. A copy policy specifies the maximally allowed sharing between an object and its clone. We present a static enforcement mechanism that will guarantee that all classes fulfill their copy policy, even in the presence of overriding of copy methods, and establish the semantic correctness of the overall approach in Coq. The mechanism has been implemented and experimentally evaluated on clone methods from several Java libraries.

  8. Clip, Connect, Clone

    DEFF Research Database (Denmark)

    Fujima, Jun; Lunzer, Aran; Hornbæk, Kasper Anders Søren;

    2010-01-01

    using three mechanisms: clipping of input and result elements from existing applications to form cells on a spreadsheet; connecting these cells using formulas, thus enabling result transfer between applications; and cloning cells so that multiple requests can be handled side by side. We demonstrate...

  9. Asian Yellow Goat Cloned

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ It was released on August 24,2005 by Prof. CHEN Dayuan (Da-Yuan Chen) from the CAS Institute of Zoology that the first success in cloning the Asian Yellow Goat by nuclear transfer had recently been achieved in east China's Shandong Province.

  10. 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

  11. Animal Cloning and Food Safety

    Science.gov (United States)

    ... Products For Consumers Home For Consumers Consumer Updates Animal Cloning and Food Safety Share Tweet Linkedin Pin it ... This conclusion stems from an extensive study of animal cloning and related food safety, culminating in the release ...

  12. The First Human Cloned Embryo.

    Science.gov (United States)

    Cibelli, Jose B.; Lanza, Robert P.; West, Michael D.; Ezzell, Carol

    2002-01-01

    Describes a process known as parthenogenesis which produces cloned, early-stage embryos and human embryos generated only from eggs. Speculates that this technology puts therapeutic cloning within reach. (DDR)

  13. Adhesive polypeptides of Staphylococcus aureus identified using a novel secretion library technique in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Holm Liisa

    2011-05-01

    Full Text Available Abstract Background Bacterial adhesive proteins, called adhesins, are frequently the decisive factor in initiation of a bacterial infection. Characterization of such molecules is crucial for the understanding of bacterial pathogenesis, design of vaccines and development of antibacterial drugs. Because adhesins are frequently difficult to express, their characterization has often been hampered. Alternative expression methods developed for the analysis of adhesins, e.g. surface display techniques, suffer from various drawbacks and reports on high-level extracellular secretion of heterologous proteins in Gram-negative bacteria are scarce. These expression techniques are currently a field of active research. The purpose of the current study was to construct a convenient, new technique for identification of unknown bacterial adhesive polypeptides directly from the growth medium of the Escherichia coli host and to identify novel proteinaceous adhesins of the model organism Staphylococcus aureus. Results Randomly fragmented chromosomal DNA of S. aureus was cloned into a unique restriction site of our expression vector, which facilitates secretion of foreign FLAG-tagged polypeptides into the growth medium of E. coli ΔfliCΔfliD, to generate a library of 1663 clones expressing FLAG-tagged polypeptides. Sequence and bioinformatics analyses showed that in our example, the library covered approximately 32% of the S. aureus proteome. Polypeptides from the growth medium of the library clones were screened for binding to a selection of S. aureus target molecules and adhesive fragments of known staphylococcal adhesins (e.g coagulase and fibronectin-binding protein A as well as polypeptides of novel function (e.g. a universal stress protein and phosphoribosylamino-imidazole carboxylase ATPase subunit were detected. The results were further validated using purified His-tagged recombinant proteins of the corresponding fragments in enzyme-linked immunoassay and

  14. Surgimiento y diseminación de Staphylococcus aureus meticilinorresistente Staphylococcus aureus methicillin-resistant: emergence and dissemination

    Directory of Open Access Journals (Sweden)

    Maria Elena Velázquez-Meza

    2005-10-01

    Full Text Available Las infecciones nosocomiales ocasionadas por cepas de Staphylococcus aureus meticilinorresistentes (SAMR son un problema de salud importante en todo el mundo. Este microorganismo produce una gran variedad de infecciones incluyendo osteomielitis, endocarditis invasora, artritis séptica y septicemia. La multirresistencia es un factor que influye en la persistencia de los SAMR dentro del ámbito hospitalario. La introducción de técnicas de tipificación molecular dentro de las investigaciones epidemiológicas ha provisto nuevas herramientas para conocer el origen y las vías de diseminación de este microorganismo. Una de las conclusiones importantes que han surgido de este tipo de estudios es que un número pequeño de clonas son las responsables de las infecciones estafilocócicas en todo el mundo.Nosocomial infections due to methicillin-resistant Staphylococcus aureus (MRSA is an important health problem worldwide. This microorganism causes a variety of clinical infections, including osteomyelitis, invasive endocarditis, septic arthritis and septicemia. Antimicrobial resistance is a factor that influences the persistence of MRSA in the hospital environment. The introduction of molecular typing techniques in epidemiological investigations has provided new tools for identifying the microorganism's origin and routes of dissemination. One of the most important conclusions that have resulted from these types of studies is that a small number of clones are responsible for most of the staphylococcal infections throughout the world.

  15. Sequential cloning of chromosomes

    Energy Technology Data Exchange (ETDEWEB)

    Lacks, S.A.

    1991-12-31

    A method for sequential cloning of chromosomal DNA and chromosomal DNA cloned by this method are disclosed. The method includes the selection of a target organism having a segment of chromosomal DNA to be sequentially cloned. A first DNA segment, having a first restriction enzyme site on either side. homologous to the chromosomal DNA to be sequentially cloned is isolated. A first vector product is formed by ligating the homologous segment into a suitably designed vector. The first vector product is circularly integrated into the target organism`s chromosomal DNA. The resulting integrated chromosomal DNA segment includes the homologous DNA segment at either end of the integrated vector segment. The integrated chromosomal DNA is cleaved with a second restriction enzyme and ligated to form a vector-containing plasmid, which is replicated in a host organism. The replicated plasmid is then cleaved with the first restriction enzyme. Next, a DNA segment containing the vector and a segment of DNA homologous to a distal portion of the previously isolated DNA segment is isolated. This segment is then ligated to form a plasmid which is replicated within a suitable host. This plasmid is then circularly integrated into the target chromosomal DNA. The chromosomal DNA containing the circularly integrated vector is treated with a third, retrorestriction enzyme. The cleaved DNA is ligated to give a plasmid that is used to transform a host permissive for replication of its vector. The sequential cloning process continues by repeated cycles of circular integration and excision. The excision is carried out alternately with the second and third enzymes.

  16. HUMAN CLONING AND FDA REGULATION

    OpenAIRE

    Vosk, Ted

    1998-01-01

    In the February 27, 1997 issue of the journal Nature scientists from Scotland's Roslin Institute reported their successful efforts to clone an adult sheep using differentiated somatic cells from the animal. The clone, named Dolly, was the first instance of the successful cloning of an adult mammal. The shock waves created by the possible ramifications of this development were immediately felt around the world. For the first time, the cloning of an adult human being was no longer being conside...

  17. Probabilistic Cloning and Quantum Computation

    Institute of Scientific and Technical Information of China (English)

    GAO Ting; YAN Feng-Li; WANG Zhi-Xi

    2004-01-01

    @@ We discuss the usefulness of quantum cloning and present examples of quantum computation tasks for which the cloning offers an advantage which cannot be matched by any approach that does not resort to quantum cloning.In these quantum computations, we need to distribute quantum information contained in the states about which we have some partial information. To perform quantum computations, we use a state-dependent probabilistic quantum cloning procedure to distribute quantum information in the middle of a quantum computation.

  18. Rise and subsequent decline of community-associated methicillin resistant Staphylococcus aureus ST30-IVc in Copenhagen, Denmark through an effective search and destroy policy

    DEFF Research Database (Denmark)

    Bartels, M D; Kristoffersen, K; Boye, K;

    2010-01-01

    The number of patients with community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has increased rapidly in Copenhagen, Denmark since 2003. Patients with the typical Panton-Valentine leukocidin-positive CA-MRSA clone ST30-IVc were contacted with the aim of treating MRSA carrie....... Treatment of MRSA carriers was difficult and required many resources, but the clone was eventually successfully eliminated. The import of ST30-IVc to Denmark will continue, but the spread of the clone in Denmark can be kept to a minimum by direct intervention in the affected families....

  19. Recent emergence of Staphylococcus aureus clonal complex 398 in human blood cultures.

    Directory of Open Access Journals (Sweden)

    Erwin Verkade

    Full Text Available BACKGROUND: Recently, a clone of MRSA with clonal complex 398 (CC398 has emerged that is related to an extensive reservoir in animals, especially pigs and veal calves. It has been reported previously that methicillin-susceptible variants of CC398 circulate among humans at low frequency, and these have been isolated in a few cases of bloodstream infections (BSI. The purpose of this study was to determine the prevalence of S. aureus CC398 in blood cultures taken from patients in a geographic area with a high density of pigs. METHODOLOGY/PRINCIPAL FINDINGS: In total, 612 consecutive episodes of S. aureus BSI diagnosed before and during the emergence of CC398 were included. Three strains (2 MSSA and 1 MRSA that were isolated from bacteremic patients between 2010-2011 were positive in a CC398 specific PCR. There was a marked increase in prevalence of S. aureus CC398 BSI isolated between 2010-2011 compared to the combined collections that were isolated between 1996-1998 and 2002-2005 (3/157, 1.9% vs. 0/455, 0.0%; p = 0.017. CONCLUSIONS/SIGNIFICANCE: In conclusion, in an area with a relative high density of pigs, S. aureus CC398 was found as a cause of BSI in humans only recently. This indicates that S. aureus CC398 is able to cause invasive infections in humans and that the prevalence is rising. Careful monitoring of the evolution and epidemiology of S. aureus CC398 in animals and humans is therefore important.

  20. 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.

  1. Unique inclusions of maximal C-clones in maximal clones

    OpenAIRE

    Behrisch, Mike; Vargas-García, Edith

    2014-01-01

    $\\mathit{C}$-clones are polymorphism sets of so-called clausal relations, a special type of relations on a finite domain, which first appeared in connection with constraint satisfaction problems in [Creignou et al. 2008]. We completely describe the relationship w.r.t. set inclusion between maximal $\\mathit{C}$-clones and maximal clones. As a main result we obtain that for every maximal $\\mathit{C}$-clone there exists exactly one maximal clone in which it is contained. A precise description of...

  2. Evaluation of the Staphylococcus aureus Class C Nonspecific Acid Phosphatase (SapS) as a Reporter for Gene Expression and Protein Secretion in Gram-Negative and Gram-Positive Bacteria▿

    OpenAIRE

    Du Plessis, Erika; Theron, Jacques; Berger, Eldie; Louw, Maureen

    2007-01-01

    A phosphatase secreted by Staphylococcus aureus strain 154 has previously been characterized and classified as a new member of the bacterial class C family of nonspecific acid phosphatases. As the acid phosphatase activity can be easily detected with a cost-effective plate screen assay, quantitatively measured by a simple enzyme assay, and detected by zymography, its potential use as a reporter system was investigated. The S. aureus acid phosphatase (sapS) gene has been cloned and expressed f...

  3. 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

  4. 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

  5. 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

  6. Subpopulations of Staphylococcus aureus clonal complex 121 are associated with distinct clinical entities.

    Directory of Open Access Journals (Sweden)

    Kevin Kurt

    Full Text Available We investigated the population structure of Staphylococcus aureus clonal complex CC121 by mutation discovery at 115 genetic housekeeping loci from each of 154 isolates, sampled on five continents between 1953 and 2009. In addition, we pyro-sequenced the genomes from ten representative isolates. The genome-wide SNPs that were ascertained revealed the evolutionary history of CC121, indicating at least six major clades (A to F within the clonal complex and dating its most recent common ancestor to the pre-antibiotic era. The toxin gene complement of CC121 isolates was correlated with their SNP-based phylogeny. Moreover, we found a highly significant association of clinical phenotypes with phylogenetic affiliations, which is unusual for S. aureus. All isolates evidently sampled from superficial infections (including staphylococcal scalded skin syndrome, bullous impetigo, exfoliative dermatitis, conjunctivitis clustered in clade F, which included the European epidemic fusidic-acid resistant impetigo clone (EEFIC. In comparison, isolates from deep-seated infections (abscess, furuncle, pyomyositis, necrotizing pneumonia were disseminated in several clades, but not in clade F. Our results demonstrate that phylogenetic lineages with distinct clinical properties exist within an S. aureus clonal complex, and that SNPs serve as powerful discriminatory markers, able to identify these lineages. All CC121 genomes harboured a 41-kilobase prophage that was dissimilar to S. aureus phages sequenced previously. Community-associated MRSA and MSSA from Cambodia were extremely closely related, suggesting this MRSA arose in the region.

  7. Overlap extension PCR cloning.

    Science.gov (United States)

    Bryksin, Anton; Matsumura, Ichiro

    2013-01-01

    Rising demand for recombinant proteins has motivated the development of efficient and reliable cloning methods. Here we show how a beginner can clone virtually any DNA insert into a plasmid of choice without the use of restriction endonucleases or T4 DNA ligase. Chimeric primers encoding plasmid sequence at the 5' ends and insert sequence at the 3' ends are designed and synthesized. Phusion(®) DNA polymerase is utilized to amplify the desired insert by PCR. The double-stranded product is subsequently employed as a pair of mega-primers in a PCR-like reaction with circular plasmids. The original plasmids are then destroyed in restriction digests with Dpn I. The product of the overlap extension PCR is used to transform competent Escherichia coli cells. Phusion(®) DNA polymerase is used for both the amplification and fusion reactions, so both steps can be monitored and optimized in the same way. PMID:23996437

  8. Ethical issues in livestock cloning.

    Science.gov (United States)

    Thompson, P B

    1999-01-01

    Although cloning may eventually become an important technology for livestock production, four ethical issues must be addressed before the practice becomes widespread. First, researchers must establish that the procedure is not detrimental to the health or well-being of affected animals. Second, animal research institutions should evaluate the net social benefits to livestock producers by weighing the benefits to producers against the opportunity cost of research capacity lost to biomedical projects. Third, scientists should consider the indirect effects of cloning research on the larger ethical issues surrounding human cloning. Finally, the market structure for products of cloned animals should protect individual choice, and should recognize that many individuals find the prospect of cloning (or consuming cloned animals) repugnant. Analysis of these four issues is complicated by spurious arguments alleging that cloning will have a negative impact on environment and genetic diversity.

  9. 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

  10. Cloning-free CRISPR

    Science.gov (United States)

    Arbab, Mandana; Srinivasan, Sharanya; Hashimoto, Tatsunori; Geijsen, Niels; Sherwood, Richard I.

    2015-01-01

    Summary We present self-cloning CRISPR/Cas9 (scCRISPR), a technology that allows for CRISPR/Cas9-mediated genomic mutation and site-specific knockin transgene creation within several hours by circumventing the need to clone a site-specific single-guide RNA (sgRNA) or knockin homology construct for each target locus. We introduce a self-cleaving palindromic sgRNA plasmid and a short double-stranded DNA sequence encoding the desired locus-specific sgRNA into target cells, allowing them to produce a locus-specific sgRNA plasmid through homologous recombination. scCRISPR enables efficient generation of gene knockouts (∼88% mutation rate) at approximately one-sixth the cost of plasmid-based sgRNA construction with only 2 hr of preparation for each targeted site. Additionally, we demonstrate efficient site-specific knockin of GFP transgenes without any plasmid cloning or genome-integrated selection cassette in mouse and human embryonic stem cells (2%–4% knockin rate) through PCR-based addition of short homology arms. scCRISPR substantially lowers the bar on mouse and human transgenesis. PMID:26527385

  11. Biodiversity versus cloning

    International Nuclear Information System (INIS)

    The announcement has been made on the cloning of mice in these days and he doesn't stop to miss, because the world lives a stage where conscience of the protection is creating that should be given to the biodiversity. It is known that alone we won't subsist and the protection of the means and all that contains that environment is of vital importance for the man. But it is also known that the vegetables and animal transgenic that they come to multiply the species have appeared that we prepare. The transgenic has been altered genetically, for substitution of one or more genes of other species, inclusive human genes. This represents an improvement compared with the investigations that gave origin to the cloning animal. But it is necessary to notice that to it you arrived through the cloning. This year 28 million hectares have been sowed in cultivations of transgenic seeds and there is around 700 bovine transgenic whose milk contains a necessary protein in the treatment of the man's illnesses

  12. Cloning-free CRISPR

    Directory of Open Access Journals (Sweden)

    Mandana Arbab

    2015-11-01

    Full Text Available We present self-cloning CRISPR/Cas9 (scCRISPR, a technology that allows for CRISPR/Cas9-mediated genomic mutation and site-specific knockin transgene creation within several hours by circumventing the need to clone a site-specific single-guide RNA (sgRNA or knockin homology construct for each target locus. We introduce a self-cleaving palindromic sgRNA plasmid and a short double-stranded DNA sequence encoding the desired locus-specific sgRNA into target cells, allowing them to produce a locus-specific sgRNA plasmid through homologous recombination. scCRISPR enables efficient generation of gene knockouts (∼88% mutation rate at approximately one-sixth the cost of plasmid-based sgRNA construction with only 2 hr of preparation for each targeted site. Additionally, we demonstrate efficient site-specific knockin of GFP transgenes without any plasmid cloning or genome-integrated selection cassette in mouse and human embryonic stem cells (2%–4% knockin rate through PCR-based addition of short homology arms. scCRISPR substantially lowers the bar on mouse and human transgenesis.

  13. Clonal expansion during Staphylococcus aureus infection dynamics reveals the effect of antibiotic intervention.

    Directory of Open Access Journals (Sweden)

    Gareth McVicker

    2014-02-01

    Full Text Available To slow the inexorable rise of antibiotic resistance we must understand how drugs impact on pathogenesis and influence the selection of resistant clones. Staphylococcus aureus is an important human pathogen with populations of antibiotic-resistant bacteria in hospitals and the community. Host phagocytes play a crucial role in controlling S. aureus infection, which can lead to a population "bottleneck" whereby clonal expansion of a small fraction of the initial inoculum founds a systemic infection. Such population dynamics may have important consequences on the effect of antibiotic intervention. Low doses of antibiotics have been shown to affect in vitro growth and the generation of resistant mutants over the long term, however whether this has any in vivo relevance is unknown. In this work, the population dynamics of S. aureus pathogenesis were studied in vivo using antibiotic-resistant strains constructed in an isogenic background, coupled with systemic models of infection in both the mouse and zebrafish embryo. Murine experiments revealed unexpected and complex bacterial population kinetics arising from clonal expansion during infection in particular organs. We subsequently elucidated the effect of antibiotic intervention within the host using mixed inocula of resistant and sensitive bacteria. Sub-curative tetracycline doses support the preferential expansion of resistant microorganisms, importantly unrelated to effects on growth rate or de novo resistance acquisition. This novel phenomenon is generic, occurring with methicillin-resistant S. aureus (MRSA in the presence of β-lactams and with the unrelated human pathogen Pseudomonas aeruginosa. The selection of resistant clones at low antibiotic levels can result in a rapid increase in their prevalence under conditions that would previously not be thought to favor them. Our results have key implications for the design of effective treatment regimes to limit the spread of antimicrobial

  14. Ethical issues in animal cloning.

    Science.gov (United States)

    Fiester, Autumn

    2005-01-01

    The issue of human reproductive cloning has recently received a great deal attention in public discourse. Bioethicists, policy makers, and the media have been quick to identify the key ethical issues involved in human reproductive cloning and to argue, almost unanimously, for an international ban on such attempts. Meanwhile, scientists have proceeded with extensive research agendas in the cloning of animals. Despite this research, there has been little public discussion of the ethical issues raised by animal cloning projects. Polling data show that the public is decidedly against the cloning of animals. To understand the public's reaction and fill the void of reasoned debate about the issue, we need to review the possible objections to animal cloning and assess the merits of the anti-animal cloning stance. Some objections to animal cloning (e.g., the impact of cloning on the population of unwanted animals) can be easily addressed, while others (e.g., the health of cloned animals) require more serious attention by the public and policy makers.

  15. 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

  16. High genetic diversity among community-associated Staphylococcus aureus in Europe: results from a multicenter study.

    Directory of Open Access Journals (Sweden)

    Joana Rolo

    Full Text Available BACKGROUND: Several studies have addressed the epidemiology of community-associated Staphylococcus aureus (CA-SA in Europe; nonetheless, a comprehensive perspective remains unclear. In this study, we aimed to describe the population structure of CA-SA and to shed light on the origin of methicillin-resistant S. aureus (MRSA in this continent. METHODS AND FINDINGS: A total of 568 colonization and infection isolates, comprising both MRSA and methicillin-susceptible S. aureus (MSSA, were recovered in 16 European countries, from community and community-onset infections. The genetic background of isolates was characterized by molecular typing techniques (spa typing, pulsed-field gel electrophoresis and multilocus sequence typing and the presence of PVL and ACME was tested by PCR. MRSA were further characterized by SCCmec typing. We found that 59% of all isolates were associated with community-associated clones. Most MRSA were related with USA300 (ST8-IVa and variants (40%, followed by the European clone (ST80-IVc and derivatives (28% and the Taiwan clone (ST59-IVa and related clonal types (15%. A total of 83% of MRSA carried Panton-Valentine leukocidin (PVL and 14% carried the arginine catabolic mobile element (ACME. Surprisingly, we found a high genetic diversity among MRSA clonal types (ST-SCCmec, Simpson's index of diversity = 0.852 (0.788-0.916. Specifically, about half of the isolates carried novel associations between genetic background and SCCmec. Analysis by BURP showed that some CA-MSSA and CA-MRSA isolates were highly related, suggesting a probable local acquisition/loss of SCCmec. CONCLUSIONS: Our results imply that CA-MRSA origin, epidemiology and population structure in Europe is very dissimilar from that of USA.

  17. 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...

  18. 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.

  19. [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

  20. 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...

  1. DETECTION OF CROSS-PROJECT BENEFICIAL CLONES

    OpenAIRE

    Ms.Kavitha Esther Rajakumari; Dr.T.Jebarajan

    2014-01-01

    Duplicate codes are also known as code clones. They are considered as one of the main factors that deteriorate the quality of software. They are usually discarded by using automatic clone detection tools. In this paper the clones are detected using a data mining approach. The clones are well analyzed and the beneficial code clones are retained. These clones are maintained separately and are used in software maintenance. The beneficial clones will definitely help in reducing the overall time s...

  2. A note on clones with nullary operations

    OpenAIRE

    Behrisch, Mike

    2013-01-01

    This report discusses clones with nullary operations and the corresponding relational clones, both defined on arbitrary non-empty sets. The relationship between such clones and clones in the usual sense, i.e. without nullary operations, is investigated, and in particular the latter type of clones is located in the lattice of all clones. By means of two pairs of kernel and closure operators, a framework is developed that allows to transfer statements about usual clones to statements about clon...

  3. Status Report from the Scientific Panel on Antibiotic Use in Dermatology of the American Acne and Rosacea Society: Part 3: Current Perspectives on Skin and Soft Tissue Infections with Emphasis on Methicillin-resistant Staphylococcus aureus, Commonly Encountered Scenarios when Antibiotic Use May Not Be Needed, and Concluding Remarks on Rational Use of Antibiotics in Dermatology.

    Science.gov (United States)

    Del Rosso, James Q; Rosen, Ted; Thiboutot, Diane; Webster, Guy F; Gallo, Richard L; Leyden, James J; Walker, Clay; Zhanel, George; Eichenfield, Lawrence

    2016-06-01

    In this third article of the three-part series, management of skin and soft tissue infections is reviewed with emphasis on new information on methicillin-resistant Staphylococcus aureus. Due to changes in the evolution of methicillin-resistant Staphylococcus aureus clones, previous distinctions between healthcare-acquired methicillin-resistant Staphylococcus aureus and community-acquired methicillin-resistant Staphylococcus aureus are currently much less clinically relevant. Many nosocomial cases of methicillin-resistant Staphylococcus aureus infection are now caused by community-acquired methicillin-resistant Staphylococcus aureus, with changing patterns of antibiotic susceptibility and resistance. Also reviewed are clinical scenarios where antibiotics may not be needed and suggestions for optimal use of antibiotic therapy for dermatologie conditions, including recommendations on perioperative antibiotic use. PMID:27386047

  4. Cloning and occurrence of czrC, a gene conferring cadmium and zinc resistance in MRSA CC398 Isolates

    DEFF Research Database (Denmark)

    Cavaco, Lina; Hasman, Henrik; Stegger, Marc;

    2010-01-01

    determinant, czrC, by PCR. The cloning of czrC confirmed that the zinc chloride and cadmium acetate MICs for isogenic constructs carrying this gene were increased compared to those for S. aureus RN4220. No difference in susceptibility to sodium arsenate, copper sulfate, or silver nitrate was observed. Seventy......C is encoding zinc and cadmium resistance in CC398 MRSA isolates, and that it is widespread both in humans and animals. Thus, resistance to heavy metals such as zinc and cadmium may play a role in the coselection of methicillin resistance in S. aureus....

  5. Therapeutic cloning in the mouse

    OpenAIRE

    Mombaerts, Peter

    2003-01-01

    Nuclear transfer technology can be applied to produce autologous differentiated cells for therapeutic purposes, a concept termed therapeutic cloning. Countless articles have been published on the ethics and politics of human therapeutic cloning, reflecting the high expectations from this new opportunity for rejuvenation of the aging or diseased body. Yet the research literature on therapeutic cloning, strictly speaking, is comprised of only four articles, all in the mouse. The efficiency of d...

  6. Therapeutic cloning: The ethical limits

    International Nuclear Information System (INIS)

    A brief outline of stem cells, stem cell therapy and therapeutic cloning is given. The position of therapeutic cloning with regard to other embryonic manipulations - IVF-based reproduction, embryonic stem formation from IVF embryos and reproductive cloning - is indicated. The main ethically challenging stages in therapeutic cloning are considered to be the nuclear transfer process including the source of eggs for this and the destruction of an embryo to provide stem cells for therapeutic use. The extremely polarised nature of the debate regarding the status of an early human embryo is noted, and some potential alternative strategies for preparing immunocompatible pluripotent stem cells are indicated

  7. 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...

  8. Antimicrobial Resistance and Molecular Characteristics of Nasal Staphylococcus aureus Isolates From Newly Admitted Inpatients.

    Science.gov (United States)

    Chen, Xu; Sun, Kangde; Dong, Danfeng; Luo, Qingqiong; Peng, Yibing; Chen, Fuxiang

    2016-05-01

    Staphylococcus aureus, or methicillin-resistant S. aureus (MRSA), is a significant pathogen in both nosocomial and community infections. Community-associated MRSA (CA-MRSA) strains tend to be multi-drug resistant and to invade hospital settings. This study aimed to assess the antimicrobial resistance and molecular characteristicsof nasal S. aureus among newlyadmitted inpatients.In the present study, 66 S. aureus isolates, including 10 healthcare-associated MRSA (HA-MRSA), 8 CA-MRSA, and 48 methicillin-sensitive S. aureus (MSSA) strains, were found in the nasal cavities of 62 patients by screening 292 newlyadmitted patients. Antimicrobial resistance and molecular characteristics of these isolates, including spa-type, sequence type (ST) and SCCmec type, were investigated. All isolates were sensitive to linezolid, teicoplanin, and quinupristin/dalfopristin, but high levels of resistance to penicillin and erythromycin were detected. According to D-test and erm gene detection results, the cMLS(B) and iMLS(B) phenotypes were detected in 24 and 16 isolates, respectively. All 10 HA-MRSA strains displayed the cMLS(B) phenotypemediated by ermA or ermA/ermC, while the cMLS(B) CA-MRSA and MSSA strains carried the ermB gene. Molecular characterization revealedall 10 HA-MRSA strains were derived from the ST239-SCCmec III clone, and four out of eight CA-MRSA strains were t437-ST59-SCCmec V. The results suggest that patients play an indispensable role in transmitting epidemic CA-MRSA and HA-MRSA strains. PMID:26915614

  9. Characterization of inosine monophosphate dehydrogenase from Staphylococcus aureus ATCC12600 and its involvement in biofilm formation

    Directory of Open Access Journals (Sweden)

    S. Yeswanth

    2013-10-01

    Full Text Available Background: In Staphylococcus aureus purine metabolism plays a crucial role in the formation of biofilm which is a key pathogenic factor. The present study is aimed in the characterization of inosine monophosphate dehydrogenase (IMPDH from Staphylococcus aureus ATCC 12600. Methods: IMPDH gene was amplified using primers designed from IMPDH gene sequence of S. aureus reported in the database. Then polymerase chain reaction (PCR product was cloned in the Sma I site of M13mp18 and expressed in Escherichia coli JM109. The recombinant IMPDH (rIMPDH was overexpressed with 1 mM isopropyl beta-D-1- thiogalactopyranoside (IPTG; Michaelis constant (Km, maximum enzyme velocity (Vmax and catalytic constant (Kcat of expressed IMPDH were determined. Results: The enzyme kinetics of IMPDH grown under aerobic conditions showed a Km of 43.71±1.56 µM, Vmax of 0.247±0.84/µM/mg/min and Kcat of 2.74±0.015/min while in anaerobic conditions the kinetics showed Km of 42.81±3.154/ µM, Vmax of 0.378±0.036 µM/mg/min and Kcat of 4.78±0.021 /min, indicating elevated levels of IMPDH activity under anaerobic conditions. Three-folds increased activity in the presence of 1 mM adenosine triphosphate (ATP correlated with biofilm formation. The kinetics of pure rIMPDH were close to the native IMPDH of S. aureus ATCC12600 and the enzyme showed single band in sodium dodecyl sulphate polyacrylamide gel electrophoresis with a molecular weight of 53 KDa. Conclusions: Elevated activity of IMPDH was observed in S. aureus grown under anaerobic conditions and this was correlated with the biofilm formation indicating the linkage between purine metabolism and pathogenesis.

  10. Self-Cloning CRISPR.

    Science.gov (United States)

    Arbab, Mandana; Sherwood, Richard I

    2016-01-01

    CRISPR/Cas9-gene editing has emerged as a revolutionary technology to easily modify specific genomic loci by designing complementary sgRNA sequences and introducing these into cells along with Cas9. Self-cloning CRISPR/Cas9 (scCRISPR) uses a self-cleaving palindromic sgRNA plasmid (sgPal) that recombines with short PCR-amplified site-specific sgRNA sequences within the target cell by homologous recombination to circumvent the process of sgRNA plasmid construction. Through this mechanism, scCRISPR enables gene editing within 2 hr once sgRNA oligos are available, with high efficiency equivalent to conventional sgRNA targeting: >90% gene knockout in both mouse and human embryonic stem cells and cancer cell lines. Furthermore, using PCR-based addition of short homology arms, we achieve efficient site-specific knock-in of transgenes such as GFP without traditional plasmid cloning or genome-integrated selection cassette (2% to 4% knock-in rate). The methods in this paper describe the most rapid and efficient means of CRISPR gene editing. © 2016 by John Wiley & Sons, Inc. PMID:27532819

  11. 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...

  12. 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.

  13. First report of lukM-positive livestock-associated methicillin-resistant Staphylococcus aureus CC30 from fattening pigs in Northern Ireland.

    Science.gov (United States)

    Lahuerta-Marin, Angela; Guelbenzu-Gonzalo, Maria; Pichon, Bruno; Allen, Adrian; Doumith, Michel; Lavery, John F; Watson, Conrad; Teale, Christopher J; Kearns, Angela M

    2016-01-01

    The increasing number of reports of livestock-associated meticillin-resistant Staphylococcus aureus (LA-MRSA) world-wide attests to the public health concern surrounding this pathogen in animal husbandry and in-contact humans. In Europe, LA-MRSA CC398 is predominant and generally regarded as being of low virulence for animals. Herein we report the recovery of a lineage of LA-MRSA, belonging to CC30, from three pigs in Northern Ireland and which encodes a marker of virulence (lukM and lukF-P83) restricted to animal-associated clones of S. aureus.

  14. CATO: The Clone Alignment Tool.

    Directory of Open Access Journals (Sweden)

    Peter V Henstock

    Full Text Available High-throughput cloning efforts produce large numbers of sequences that need to be aligned, edited, compared with reference sequences, and organized as files and selected clones. Different pieces of software are typically required to perform each of these tasks. We have designed a single piece of software, CATO, the Clone Alignment Tool, that allows a user to align, evaluate, edit, and select clone sequences based on comparisons to reference sequences. The input and output are designed to be compatible with standard data formats, and thus suitable for integration into a clone processing pipeline. CATO provides both sequence alignment and visualizations to facilitate the analysis of cloning experiments. The alignment algorithm matches each of the relevant candidate sequences against each reference sequence. The visualization portion displays three levels of matching: 1 a top-level summary of the top candidate sequences aligned to each reference sequence, 2 a focused alignment view with the nucleotides of matched sequences displayed against one reference sequence, and 3 a pair-wise alignment of a single reference and candidate sequence pair. Users can select the minimum matching criteria for valid clones, edit or swap reference sequences, and export the results to a summary file as part of the high-throughput cloning workflow.

  15. [The discrete horror of cloning].

    Science.gov (United States)

    Guibourg, Ricardo A

    2009-01-01

    The author raises the topic of cloning after the decision of the Argentine government, which concerned for the "dignity of the human person", passed a decree of need and urgency, No. 200/97 (Annex), prohibiting cloning experiments with human beings. Therefore, considering that the topic is so terribly urgent and necessary, the author feels it is timely to consider it.

  16. Quantum probabilistically cloning and computation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this article we make a review on the usefulness of probabilistically cloning and present examples of quantum computation tasks for which quantum cloning offers an advantage which cannot be matched by any approach that does not resort to it.In these quantum computations,one needs to distribute quantum information contained in states about which we have some partial information.To perform quantum computations,one uses state-dependent probabilistic quantum cloning procedure to distribute quantum information in the middle of a quantum computation.And we discuss the achievable efficiencies and the efficient quantum logic network for probabilistic cloning the quantum states used in implementing quantum computation tasks for which cloning provides enhancement in performance.

  17. 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

  18. 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

  19. 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.

  20. 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

  1. Clone Networks, Clone Extensions and Biregularizations of Varieties of Algebras

    Institute of Scientific and Technical Information of China (English)

    J. Plonka

    2001-01-01

    We consider algebras of type τ- without nullary operations. An identity ψ≈ψ of type τ is clone compatible if ψ and ψ are the same variable or the sets of fundamental operation symbols in ψ and ψ are non-empty and identical. For a variety V, we denote by Vc the variety defined by all clone compatible identities from Id(V). In this paper, we give a construction of algebras called a clone network. Under some assumptions, we describe algebras from Vc by means of this construction. We find some properties of Vc and applications.

  2. Rapid bench identification of methicillin-sensitive and methicillin-resistant Staphylococcus aureus: A multicenter comparative evaluation of Alere PBP2a Culture Colony Test (Alere) Versus Slidex MRSA detection (bioMérieux).

    Science.gov (United States)

    Tasse, Jason; Dupieux, Céline; Caillon, Jocelyne; Lanotte, Philippe; Lamy, Brigitte; Aissa, Nejla; Bemer, Pascale; Mereghetti, Laurent; Michon, Anne-Laure; Lozniewski, Alain; Bes, Michèle; Trouillet-Assant, Sophie; Laurent, Frédéric

    2016-08-01

    Using 30 clinical isolates of Staphylococcus aureus representative of the most prevalent clones circulating in France, the performance of the Alere™ PBP2a Culture Colony Test (CCT) and the Slidex(®) MRSA detection kit (SMD) were compared in 5 different labs. CCT demonstrated better performance and was easier to conduct in routine.

  3. A common variant of staphylococcal cassette chromosome mec type IVa in isolates from Copenhagen, Denmark, is not detected by the BD GeneOhm methicillin-resistant Staphylococcus aureus assay

    DEFF Research Database (Denmark)

    Bartels, Mette Damkjaer; Boye, Kit; Rohde, Susanne Mie;

    2009-01-01

    -susceptible Staphylococcus aureus isolates were included as negative controls. Forty-four MRSA isolates were undetectable; of these, 95% harbored SCCmec type IVa, and these included the most-common clone in Copenhagen, spa t024-sequence type 8-IVa. The false-negative MRSA isolates were tested with new primers (analyte...

  4. Rapid bench identification of methicillin-sensitive and methicillin-resistant Staphylococcus aureus: A multicenter comparative evaluation of Alere PBP2a Culture Colony Test (Alere) Versus Slidex MRSA detection (bioMérieux).

    Science.gov (United States)

    Tasse, Jason; Dupieux, Céline; Caillon, Jocelyne; Lanotte, Philippe; Lamy, Brigitte; Aissa, Nejla; Bemer, Pascale; Mereghetti, Laurent; Michon, Anne-Laure; Lozniewski, Alain; Bes, Michèle; Trouillet-Assant, Sophie; Laurent, Frédéric

    2016-08-01

    Using 30 clinical isolates of Staphylococcus aureus representative of the most prevalent clones circulating in France, the performance of the Alere™ PBP2a Culture Colony Test (CCT) and the Slidex(®) MRSA detection kit (SMD) were compared in 5 different labs. CCT demonstrated better performance and was easier to conduct in routine. PMID:27216499

  5. Clonal diversity of Staphylococcus aureus originating from the small ruminants goats and sheep.

    Science.gov (United States)

    Porrero, M Concepción; Hasman, Henrik; Vela, Ana I; Fernández-Garayzábal, Jose F; Domínguez, Lucas; Aarestrup, Frank M

    2012-04-23

    Staphylococcus aureus is an important pathogen in humans and many animal species. The prevalence of different clonal types in animal species remains largely unknown. We analyzed 267 S. aureus from intramammary infections in goats (47) and sheep (220) by spa typing, multi-locus sequence typing (MLST) and antimicrobial susceptibility. The most frequent spa types in goats were t337 (N=9), t759 (N=6) and t1534 (N=5). Sheep isolates mainly belonged to spa types t1534 (N=72), t2678 (N=29) and t3576 (N=20). Eighteen novel spa-types were observed; two from goat strains, 13 from sheep and three in both species. The majority of the goat strains grouped in MLST CC133 (N=10) and ST522 (N=10), followed by CC9 (N=9), while the majority of the sheep strains were of ST522 (N=108) followed by CC133 (N=86) and CC130 (N=11). Nine new MLST types were detected; three in goat and sheep isolates (ST1739, ST1758 and ST1780), two identified in goats only (ST1740 and ST2061) and four in sheep only (ST1742, ST1743, ST1781 and ST2011). Strains showed resistance below 20% against penicillin and tetracycline; a strong association between CC-types and penicillin resistance was observed. No resistance was detected to cefoxitin, quinupristin-dalfopristin, rifampicin and vancomycin. This study suggests that ST522 is the most common S. aureus clone associated with small ruminants followed by CC133.

  6. A single copy integration vector that integrates at an engineered site on the Staphylococcus aureus chromosome

    Directory of Open Access Journals (Sweden)

    Lei Mei G

    2012-01-01

    Full Text Available Abstract Background Single-copy integration vectors based upon the site-specific recombination systems of bacteriophage are invaluable tools in the study of bacterial pathogenesis. The utility of such vectors is often limited, however, by the fact that integration often results in the inactivation of bacterial genes or has undesirable effects on gene transcription. The aim of this study is to develop an integration vector that does not have a detectable effect on gene transcription upon integration. Findings We have developed a single-copy integration system that enables the cloning vector to integrate at a specific engineered site, within an untranscribed intergenic region, in the chromosome of Staphylococcus aureus. This system is based on the lysogenic phage L54a site-specific recombination system in which the L54a phage (attP and chromosome (attB attachment sites, which share an 18-bp identical core sequence, were modified with identical mutations. The integration vector, pLL102, was constructed to contain the modified L54a attP site (attP2 that was altered at 5 nucleotide positions within the core sequence. In the recipient strain, the similarly modified attB site (attB2 was inserted in an intergenic region devoid of detectable transcription read-through. Integration of the vector, which is unable to replicate in S. aureus extrachromosomally, was achieved by providing the L54a integrase gene in a plasmid in the recipient. We showed that pLL102 integrated specifically at the engineered site rather than at the native L54a attB site and that integration did not have a significant effect on transcription of genes immediately upstream or downstream of the integration site. Conclusions In this work, we describe an E. coli-S. aureus shuttle vector that can be used to introduce any cloned gene into the S. aureus chromosome at a select site without affecting gene expression. The vector should be useful for genetic manipulation of S. aureus and for

  7. Molecular typing and phenotype characterization of methicillin-resistant Staphylococcus aureus isolates from blood in Taiwan.

    Directory of Open Access Journals (Sweden)

    Wei-Yao Wang

    Full Text Available BACKGROUND: Staphylococcus aureus causes a variety of severe infections such as bacteremia and sepsis. At present, 60-80% of S. aureus isolates from Taiwan are methicillin resistant (MRSA. It has been shown that certain MRSA clones circulate worldwide. The goals of this study were to identify MRSA clones in Taiwan and to correlate the molecular types of isolates with their phenotypes. METHODS: A total of 157 MRSA isolates from bacteremic patients were collected from nine medical centers. They were typed based on polymorphisms in agr, SCCmec, MLST, spa, and dru. Phenotypes characterized included Panton-Valentine leucocidin (pvl, inducible macrolide-lincosamide-streptogramin B resistance (MLSBi, vancomycin (VA and daptomycin (DAP minimal inhibitory concentrations (MIC, and superantigenic toxin gene profiles. Difference between two consecutive samples was determined by Mann-Whitney-U test, and difference between two categorical variables was determined by Fisher's exact test. RESULTS: Four major MRSA clone complexes CC1, CC5, CC8, and CC59 were found, including 4 CC1, 9 CC5, 111 CC8, and 28 CC59 isolates. These clones had the following molecular types: CC1: SCCmecIV and ST573; CC5: SCCmecII and ST5; CC8: SCCmecIII, ST239, and ST241, and CC59: SCCmecIV, SCCmecV(T, ST59, and ST338. The toxin gene profiles of these clones were CC1: sec-seg-(sei-sell-selm-(seln-selo; CC5: sec-seg-sei-sell-selm-(seln-selp-tst1; CC8: sea-selk-selq, and CC59: seb-selk-selq. Most isolates with SCCmecV(T, ST59, spat437, and dru11 types were pvl(+ (13 isolates, while multidrug resistance (≥4 antimicrobials were associated with SCCmecIII, ST239, spa t037, agrI, and dru14 (119 isolates (p<0.001. One hundred and twenty four isolates with the following molecular types had higher VA MIC: SCCmecII and SCCmecIII; ST5, ST239, and ST241; spa t002, t037, and t421; dru4, dru10, dru12, dru13, and dru14 (p<0.05. No particular molecular types were found to be associated with MLSBi

  8. Biomimetic Cloning of Quantum Observables

    CERN Document Server

    Alvarez-Rodriguez, U; Lamata, L; Solano, E

    2013-01-01

    We propose a bio-inspired sequential quantum protocol for the cloning and preservation of the statistics associated to quantum observables of a given system. It combines the cloning of a set of commuting observables, permitted by the no-cloning and no-broadcasting theorems, with a controllable propagation of the initial state coherences to the subsequent generations. The protocol mimics the scenario in which an individual in an unknown quantum state copies and propagates its quantum information into an environment of blank qubits. Finally, we propose a realistic experimental implementation of this protocol in trapped ions.

  9. Cloning: revisiting an old debate.

    Science.gov (United States)

    Verhey, Allen D

    1994-09-01

    The debate about cloning that took place 25 years ago, although directed toward a different sort of cloning, elucidates fundamental issues currently at stake in reproductive technologies and research. Paul Ramsey and Joseph Fletcher were participants in this early debate. The differences between Ramsey and Fletcher about the meaning and sufficiency of freedom, the understanding and weighing of good and evil, the connection between embodiment and personhood, the relationship of humans with nature, and the meaning of parenthood suggest both a broader agenda for the debate about cloning and a cautious move forward in the development of embryo-splitting.

  10. Geographic distribution of Staphylococcus aureus causing invasive infections in Europe: a molecular-epidemiological analysis.

    Directory of Open Access Journals (Sweden)

    Hajo Grundmann

    2010-01-01

    Full Text Available BACKGROUND: Staphylococcus aureus is one of the most important human pathogens and methicillin-resistant variants (MRSAs are a major cause of hospital and community-acquired infection. We aimed to map the geographic distribution of the dominant clones that cause invasive infections in Europe. METHODS AND FINDINGS: In each country, staphylococcal reference laboratories secured the participation of a sufficient number of hospital laboratories to achieve national geo-demographic representation. Participating laboratories collected successive methicillin-susceptible (MSSA and MRSA isolates from patients with invasive S. aureus infection using an agreed protocol. All isolates were sent to the respective national reference laboratories and characterised by quality-controlled sequence typing of the variable region of the staphylococcal spa gene (spa typing, and data were uploaded to a central database. Relevant genetic and phenotypic information was assembled for interactive interrogation by a purpose-built Web-based mapping application. Between September 2006 and February 2007, 357 laboratories serving 450 hospitals in 26 countries collected 2,890 MSSA and MRSA isolates from patients with invasive S. aureus infection. A wide geographical distribution of spa types was found with some prevalent in all European countries. MSSA were more diverse than MRSA. Genetic diversity of MRSA differed considerably between countries with dominant MRSA spa types forming distinctive geographical clusters. We provide evidence that a network approach consisting of decentralised typing and visualisation of aggregated data using an interactive mapping tool can provide important information on the dynamics of MRSA populations such as early signalling of emerging strains, cross border spread, and importation by travel. CONCLUSIONS: In contrast to MSSA, MRSA spa types have a predominantly regional distribution in Europe. This finding is indicative of the selection and spread

  11. 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 ...

  12. 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.

  13. 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...

  14. 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)

  15. A Clone of Your Own.

    Science.gov (United States)

    Bilodeau, Kirsten

    1997-01-01

    Describes an activity used at the Washington Park Arboretum that helps students understand cloning through plant propagation. Students also learn how to make a pot from recycled newspapers and how to make soil that is appropriate for the plants. (DDR)

  16. Human cloning and 'posthuman' society.

    Science.gov (United States)

    Blackford, Russell

    2005-01-01

    Since early 1997, when the creation of Dolly the sheep by somatic cell nuclear transfer was announced in Nature, numerous government reports, essays, articles and books have considered the ethical problems and policy issues surrounding human reproductive cloning. In this article, I consider what response a modern liberal society should give to the prospect of human cloning, if it became safe and practical. Some opponents of human cloning have argued that permitting it would place us on a slippery slope to a repugnant future society, comparable to that portrayed in Aldous Huxley's novel, Brave New World. I conclude that, leaving aside concerns about safety, none of the psychological or social considerations discussed in this article provides an adequate policy justification for invoking the state's coercive powers to prevent human cloning.

  17. 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.

  18. Artificial cloning of domestic animals

    OpenAIRE

    Keefer, Carol L.

    2015-01-01

    Domestic animals can be cloned using techniques such as embryo splitting and nuclear transfer to produce genetically identical individuals. Although embryo splitting is limited to the production of only a few identical individuals, nuclear transfer of donor nuclei into recipient oocytes, whose own nuclear DNA has been removed, can result in large numbers of identical individuals. Moreover, clones can be produced using donor cells from sterile animals, such as steers and geldings, and, unlike ...

  19. Animal cloning: advances and prospects

    OpenAIRE

    Chuaire Lilian; Sánchez Magda Carolina; Franco María Liliana

    2004-01-01

    Few recent advances have revolutionized the developmental biology as the animal cloning has. Since the birth of Dolly, the sheep, in 1996, which was the first derived clone of a mature animal, a new scientific era began. It has been characterized by growing demystification that differentiated cells are unalterable entities in its nuclear organization and chromatin structure, and by a better understanding of the mechanisms that regulate the development. Throughout this paper, we will review ...

  20. Therapeutic cloning: promises and issues

    OpenAIRE

    Kfoury, Charlotte

    2007-01-01

    Advances in biotechnology necessitate both an understanding of scientific principles and ethical implications to be clinically applicable in medicine. In this regard, therapeutic cloning offers significant potential in regenerative medicine by circumventing immunorejection, and in the cure of genetic disorders when used in conjunction with gene therapy. Therapeutic cloning in the context of cell replacement therapy holds a huge potential for de novo organogenesis and the permanent treatment o...

  1. 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...

  2. Artificial cloning of domestic animals.

    Science.gov (United States)

    Keefer, Carol L

    2015-07-21

    Domestic animals can be cloned using techniques such as embryo splitting and nuclear transfer to produce genetically identical individuals. Although embryo splitting is limited to the production of only a few identical individuals, nuclear transfer of donor nuclei into recipient oocytes, whose own nuclear DNA has been removed, can result in large numbers of identical individuals. Moreover, clones can be produced using donor cells from sterile animals, such as steers and geldings, and, unlike their genetic source, these clones are fertile. In reality, due to low efficiencies and the high costs of cloning domestic species, only a limited number of identical individuals are generally produced, and these clones are primarily used as breed stock. In addition to providing a means of rescuing and propagating valuable genetics, somatic cell nuclear transfer (SCNT) research has contributed knowledge that has led to the direct reprogramming of cells (e.g., to induce pluripotent stem cells) and a better understanding of epigenetic regulation during embryonic development. In this review, I provide a broad overview of the historical development of cloning in domestic animals, of its application to the propagation of livestock and transgenic animal production, and of its scientific promise for advancing basic research.

  3. Towards Clone Detection in UML Domain Models

    DEFF Research Database (Denmark)

    Störrle, Harald

    2010-01-01

    , we discuss how model clones arise by analyzing several practical scenarios. We propose a formal definition of models and clones, that allows us to specify a generic clone detection algorithm. Through a thorough analysis of the detail structure of sample UML domain models, recommendations for clone...

  4. Structured Review of Code Clone Literature

    NARCIS (Netherlands)

    Hordijk, Wiebe; Ponisio, María Laura; Wieringa, Roel

    2008-01-01

    This report presents the results of a structured review of code clone literature. The aim of the review is to assemble a conceptual model of clone-related concepts which helps us to reason about clones. This conceptual model unifies clone concepts from a wide range of literature, so that findings ab

  5. Sequence diversity in the A domain of Staphylococcus aureus fibronectin-binding protein A

    Directory of Open Access Journals (Sweden)

    Speziale Pietro

    2008-05-01

    Full Text Available Abstract Background Fibronectin-binding protein A (FnBPA mediates adhesion of Staphylococcus aureus to fibronectin, fibrinogen and elastin. We previously reported that S. aureus strain P1 encodes an FnBPA protein where the fibrinogen/elastin-binding domain (A domain is substantially divergent in amino acid sequence from the archetypal FnBPA of S. aureus NCTC8325, and that these variations created differences in antigenicity. In this study strains from multilocus sequence types (MLST that spanned the genetic diversity of S.aureus were examined to determine the extent of FnBPA A domain variation within the S. aureus population and its effect on ligand binding and immuno-crossreactivity. Results Seven different isotype forms (I – VII of the FnBPA A domain were identified which were between 66 to 76% identical in amino acid sequence in any pair-wise alignment. The fnbA allelic variants in strains of different multilocus sequence type were identified by DNA hybridization using probes specific for sequences encoding the highly divergent N3 sub-domain of different isotypes. Several isotypes were not restricted to specific clones or clonal complexes but were more widely distributed. It is highly likely that certain fnbA genes have been transferred horizontally. Residues lining the putative ligand-binding trench were conserved, which is consistent with the ability of each A domain isotype to bind immobilized fibrinogen and elastin by the dock-latch-lock mechanism. Variant amino acid residues were mapped on a three-dimensional model of the FnBPA A domain and were predicted to be surface-exposed. Polyclonal antibodies raised against the recombinant isotype I A domain bound that protein with a 4 – 7 fold higher apparent affinity compared to the A domains of isotypes II – VII, while some monoclonal antibodies generated against the isotype I A domain showed reduced or no binding to the other isotypes. Conclusion The FnBPA A domain occurs in at least 7

  6. 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...

  7. 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....

  8. 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.

  9. Characterization of community acquired Staphylococcus aureus associated with skin and soft tissue infection in Beijing: high prevalence of PVL+ ST398.

    Directory of Open Access Journals (Sweden)

    Chunjiang Zhao

    Full Text Available Adult community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA and methicillin-susceptible S. aureus (CA-MSSA skin and soft tissue infection (SSTI in China is not well described. A prospective cohort of adults with SSTI was established between January 2009 and August 2010 at 4 hospitals in Beijing. Susceptibility testing and molecular typing, including multilocus sequence typing, spa, agr typing, and toxin detection were assessed for all S. aureus isolates. Overall, 501 SSTI patients were enrolled. Cutaneous abscess (40.7% was the most common infection, followed by impetigo (6.8% and cellulitis (4.8%. S. aureus accounted for 32.7% (164/501 of SSTIs. Five isolates (5/164, 3.0% were CA-MRSA. The most dominant ST in CA-MSSA was ST398 (17.6%. The prevalence of Panton-Valentine Leukocidin (pvl gene was 41.5% (66/159 in MSSA. Female, younger patients and infections requiring incision or drainage were more commonly associated with pvl-positive S. aureus (P<0.03; sec gene was more often identified in CC5 (P<0.03; seh gene was more prevalent in CC1 (P = 0.001. Importantly, ST59 isolates showed more resistance to erythromycin, clindamycin and tetracycline, and needed more surgical intervention. In conclusion, CA-MRSA infections were rare among adult SSTI patients in Beijing. Six major MSSA clones were identified and associated with unique antimicrobial susceptibility, toxin profiles, and agr types. A high prevalence of livestock ST398 clone (17.1% of all S. aureus infections was found with no apparent association to animal contact.

  10. Usefulness of double locus sequence typing (DLST) for regional and international epidemiological surveillance of methicilin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Basset, P; Senn, L; Prod'hom, G; Bille, J; Francioli, P; Zanetti, G; Blanc, D S

    2010-08-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of nosocomial infections worldwide. To differentiate reliably among S. aureus isolates, we recently developed double locus sequence typing (DLST) based on the analysis of partial sequences of clfB and spa genes. In the present study, we evaluated the usefulness of DLST for epidemiological investigations of MRSA by routinely typing 1242 strains isolated in Western Switzerland. Additionally, particular local and international collections were typed by pulsed field gel electrophoresis (PFGE) and DLST to check the compatibility of DLST with the results obtained by PFGE, and for international comparisons. Using DLST, we identified the major MRSA clones of Western Switzerland, and demonstrated the close relationship between local and international clones. The congruence of 88% between the major PFGE and DLST clones indicated that our results obtained by DLST were compatible with earlier results obtained by PFGE. DLST could thus easily be incorporated in a routine surveillance procedure. In addition, the unambiguous definition of DLST types makes this method more suitable than PFGE for long-term epidemiological surveillance. Finally, the comparison of the results obtained by DLST, multilocus sequence typing, PFGE, Staphylococcal cassette chromosome mec typing and the detection of Panton-Valentine leukocidin genes indicated that no typing scheme should be used on its own. It is only the combination of data from different methods that gives the best chance of describing precisely the epidemiology and phylogeny of MRSA. PMID:19832717

  11. Methicillin/Oxacillin-resistant Staphylococcus aureus as a hospital and public health threat in Brazil

    Directory of Open Access Journals (Sweden)

    Karinne Spirandelli Carvalho

    2010-02-01

    Full Text Available Methicillin-resistant Staphylococcus aureus is an established nosocomial pathogen (HA-MRSA, hospital acquired MRSA, but has recently begun to appear in the community (CA-MRSA, community acquired MRSA. The cause of resistance to methicillin and all other β-lactam antibiotics is the mecA gene, which is situated on a mobile genetic element, the Staphylococcal Cassette Chromosome mec (SCCmec. Seven major variants of SCCmec, type I to VII are distinguished. HA-MRSA disseminated worldwide and causes the majority of S. aureus nosocomial infections with a limited number of clones disseminated including the Brazilian Epidemic Clone (BEC, ST239-MRSA-III. CA-MRSA isolates are susceptible to non-β-lactam antibiotics, usually isolated from healthy individuals which do not possess any unknown risk factors for MRSA infection and are associated with a larger clonal diversity compared with HA-MRSA. However, during recent years distinction between HA-MRSA and CA-MRSA is beginning to fade. Actually, knowledge about MRSA disseminating clones is required to implement any strategies to control the transmission of MRSA either within hospitals or in community. For this reason, rapid identification of strains is an important issue. The rate of HA-MRSA can be reduced substantially through the implementation of interventions strategies, even in settings where MRSA is endemic as in most Brazilian hospitals. However, these policies could be quite complicated in the light of an increasing CA-MRSA prevalence in healthcare facilities, considering that distinction between HA-MRSA and CA-MRSA has started to disappear.

  12. Molecular characterization of Staphylococcus aureus isolates from skin and soft tissue infections samples and healthy carriers in the Central Slovenia region.

    Science.gov (United States)

    Svent-Kucina, Natasa; Pirs, Mateja; Kofol, Romina; Blagus, Rok; Smrke, Dragica Maja; Bilban, Marjan; Seme, Katja

    2016-04-01

    Staphylococcus aureus is among the most important human pathogens. It is associated with different infections and is a major cause of skin and soft tissue infections (SSTIs). The aim of our study was to compare S. aureus isolates associated with SSTIs with isolates obtained from healthy carriers in the Central Slovenia region in terms of antimicrobial susceptibility, genetic diversity by clonal complex (CC)/sequence type, spa type, and by toxin gene profiling. In total, 274 S. aureus isolates were collected prospectively by culturing wound samples from 461 SSTI patients and nasal samples from 451 healthy carriers. We have demonstrated high heterogeneity in terms of CCs and spa type in both groups of isolates. The main clone among SSTI strains was Panton-Valentine leukocidin gene (pvl) positive CC121, whereas the main clone among carrier strains was CC45 carrying a large range of toxin genes. The main spa type in both groups was t091. Pvl was more frequently present in SSTI strains (31.2% SSTI vs 3.6% carrier strains) and staphylococcal enterotoxin C was more frequently present in carrier strains (1.6% SSTI vs 17.0% carrier strains). We have also demonstrated that methicillin-resistant S. aureus was a rare cause (2.8%) of SSTIs in our region.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Caracterización molecular de Staphylococcus aureus de origen nosocomial por Electroforesis de Enzimas Multilocus (MLEE

    Directory of Open Access Journals (Sweden)

    Suárez Zulma

    2002-12-01

    Full Text Available Se caracterizaron 41 aislamientos se Staphylococcus aureus tomados a pacientes y personal de la unidad de cuidados intensivos (UCI del Hospital San Juan de Dios, en el periodo comprendido entre septiembre de 1998 y septiembre de 1999 por medio del método de caracterización de Electroforesis de Enzimas Multilocus(MLEE. Se establecieron las relaciones genéticas entre los individuos, así como influencia del perfil de resistencia, el biotipo y el periodo de recolección. La evidencia experimental sugirió que la estructura de la población analizada encaja en el modelo clonal descrito previamente para las poblaciones de Staphylococcus aureus, coincidiendo con la prevalencia de un pequeño número de clones durante el periodo de recolección. 

  15. 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

  16. 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...

  17. 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.

  18. 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...

  19. 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

  20. 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

  1. 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.

  2. Multiplex PCR for rapid detection of Staphylococcus aureus isolates suspected to represent community-acquired strains.

    Science.gov (United States)

    Strommenger, B; Braulke, C; Pasemann, B; Schmidt, C; Witte, W

    2008-02-01

    The continuous spread of community-acquired methicillin-resistant Staphylococcus aureus (caMRSA) and the introduction of these highly virulent isolates into hospitals represent increasing threats. The timely recognition of caMRSA strains is crucial for infection control purposes. Thus, we developed a PCR-based assay for the easy and rapid determination of those caMRSA clones that currently are the most prevalent in Germany and Central Europe. This assay was able to correctly identify the majority of the isolates as caMRSA of sequence type 80 (ST80), clonal complex 1 (USA400), and ST8 (USA300). In combination with spa typing-BURP (based upon repeat pattern) analysis and resistance typing, it provides a means for the extensive characterization of suspicious isolates. Thus, this assay represents a reliable tool for monitoring the emergence and spread of different caMRSA clones. The resulting information, in combination with careful interpretation of the epidemiological records, might help to prevent the further spread of those highly virulent caMRSA clones. PMID:18032620

  3. Quantum superposition of multiple clones and the novel cloning machine

    OpenAIRE

    Pati, Arun Kumar

    1999-01-01

    we envisage a novel quantum cloning machine, which takes an input state and produces an output state whose success branch can exist in a linear superposition of multiple copies of the input state and the failure branch exist in a superposition of composite state independent of the input state. We prove that unknown non-orthogonal states chosen from a set $\\cal S$ can evolve into a linear superposition of multiple clones by a unitary process if and only if the states are linearly independent. ...

  4. 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...

  5. 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.

  6. 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

  7. A genomic portrait of the emergence, evolution, and global spread of a methicillin-resistant Staphylococcus aureus pandemic

    DEFF Research Database (Denmark)

    Holden, Matthew T G; Hsu, Li-Yang; Kurt, Kevin;

    2013-01-01

    The widespread use of antibiotics in association with high-density clinical care has driven the emergence of drug-resistant bacteria that are adapted to thrive in hospitalized patients. Of particular concern are globally disseminated methicillin-resistant Staphylococcus aureus (MRSA) clones......-associated methicillin-sensitive population. The emergence of fluoroquinolone resistance in this EMRSA-15 subclone in the English Midlands during the mid-1980s appears to have played a key role in triggering pandemic spread, and occurred shortly after the first clinical trials of this drug. Genome-based coalescence...

  8. Animal cloning: advances and prospects

    Directory of Open Access Journals (Sweden)

    Chuaire Lilian

    2004-05-01

    Full Text Available Few recent advances have revolutionized the developmental biology as the animal cloning has. Since the birth of Dolly, the sheep, in 1996, which was the first derived clone of a mature animal, a new scientific era began. It has been characterized by growing demystification that differentiated cells are unalterable entities in its nuclear organization and chromatin structure, and by a better understanding of the mechanisms that regulate the development. Throughout this paper, we will review some of the achievements and limitations of the techniques used, both in therapeutic and in the reproductive cloning, as well as the perspectives that its application allows to glimpse within a close future. At the same time, we will point out some considerations regarding the ethical debate that surrounds such a controversial issue.

  9. Public perceptions of animal cloning

    DEFF Research Database (Denmark)

    Jelsøe, Erling; Vincentsen, Ulla; Andersen, Ida-Elisabeth;

    What was from the outset meant to be a survey testing predefined categories of ethical positions related to new biotechnologies with animal cloning as an example was subsequently developed into a process of broader involvement of groups of citizens in the issue. The survey was conducted at meetings...... in four different cities in Denmark. The participants were introduced to animal cloning and after that they filled out the questionnaire. Finally, the issue was discussed in focus groups. The process as a whole was run in a dialogue oriented way. Through the information they received in combination...... with reflecting on the survey questions the participants were well prepared for discussions in the focus groups. This approach made it possible, on the one hand to get a measure of the citizen's perceptions of the ethical aspects of animal cloning, but also to go deeper into their own thoughts of the issue...

  10. Public perceptions of animal cloning

    DEFF Research Database (Denmark)

    Jelsøe, Erling; Vincentsen, Ulla; Andersen, Ida-Elisabeth;

    What was from the outset meant to be a survey testing predefined categories of ethical positions related to new biotechnologies with animal cloning as an example was subsequently developed into a process of broader involvement of groups of citizens in the issue. The survey was conducted at meetings...... in four different cities in Denmark. The participants were introduced to animal cloning and after that they filled out the questionnaire. Finally, the issue was discussed in focus groups. The process as a whole was run in a dialogue oriented way. Through the information they received in combination...... with reflecting on the survey questions the participants were well prepared for discussions in the focus groups. This approach made it possible, on the one hand to get a measure of the citizen's perceptions of the ethical aspects of animal cloning, but also to go deeper into their own thoughts of the...

  11. 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.

  12. 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

  13. Toward an understanding of the evolution of Staphylococcus aureus strain USA300 during colonization in community households.

    Science.gov (United States)

    Uhlemann, Anne-Catrin; Kennedy, Adam D; Martens, Craig; Porcella, Stephen F; Deleo, Frank R; Lowy, Franklin D

    2012-01-01

    Staphylococcus aureus is a frequent cause of serious infections and also a human commensal. The emergence of community-associated methicillin-resistant S. aureus led to a dramatic increase in skin and soft tissue infections worldwide. This epidemic has been driven by a limited number of clones, such as USA300 in the United States. To better understand the extent of USA300 evolution and diversification within communities, we performed comparative whole-genome sequencing of three clinical and five colonizing USA300 isolates collected longitudinally from three unrelated households over a 15-month period. Phylogenetic analysis that incorporated additional geographically diverse USA300 isolates indicated that all but one likely arose from a common recent ancestor. Although limited genetic adaptation occurred over the study period, the greatest genetic heterogeneity occurred between isolates from different households and within one heavily colonized household. This diversity allowed for a more accurate tracking of interpersonal USA300 transmission. Sequencing of persisting USA300 isolates revealed mutations in genes involved in major aspects of S. aureus function: adhesion, cell wall biosynthesis, virulence, and carbohydrate metabolism. Genetic variations also included accumulation of multiple polymorphisms within select genes of two multigene operons, suggestive of small genome rearrangements rather than de novo single point mutations. Such rearrangements have been underappreciated in S. aureus and may represent novel means of strain variation. Subtle genetic changes may contribute to USA300 fitness and persistence. Elucidation of small genome rearrangements reveals a potentially new and intriguing mechanism of directed S. aureus genome diversification in environmental niches and during pathogen-host interactions.

  14. Toward an understanding of the evolution of Staphylococcus aureus strain USA300 during colonization in community households.

    Science.gov (United States)

    Uhlemann, Anne-Catrin; Kennedy, Adam D; Martens, Craig; Porcella, Stephen F; Deleo, Frank R; Lowy, Franklin D

    2012-01-01

    Staphylococcus aureus is a frequent cause of serious infections and also a human commensal. The emergence of community-associated methicillin-resistant S. aureus led to a dramatic increase in skin and soft tissue infections worldwide. This epidemic has been driven by a limited number of clones, such as USA300 in the United States. To better understand the extent of USA300 evolution and diversification within communities, we performed comparative whole-genome sequencing of three clinical and five colonizing USA300 isolates collected longitudinally from three unrelated households over a 15-month period. Phylogenetic analysis that incorporated additional geographically diverse USA300 isolates indicated that all but one likely arose from a common recent ancestor. Although limited genetic adaptation occurred over the study period, the greatest genetic heterogeneity occurred between isolates from different households and within one heavily colonized household. This diversity allowed for a more accurate tracking of interpersonal USA300 transmission. Sequencing of persisting USA300 isolates revealed mutations in genes involved in major aspects of S. aureus function: adhesion, cell wall biosynthesis, virulence, and carbohydrate metabolism. Genetic variations also included accumulation of multiple polymorphisms within select genes of two multigene operons, suggestive of small genome rearrangements rather than de novo single point mutations. Such rearrangements have been underappreciated in S. aureus and may represent novel means of strain variation. Subtle genetic changes may contribute to USA300 fitness and persistence. Elucidation of small genome rearrangements reveals a potentially new and intriguing mechanism of directed S. aureus genome diversification in environmental niches and during pathogen-host interactions. PMID:23104992

  15. Foods from black market at EU border as a neglected route of potential methicillin-resistant Staphylococcus aureus transmission.

    Science.gov (United States)

    Oniciuc, Elena-Alexandra; Ariza-Miguel, Jaime; Bolocan, Andrei-Sorin; Diez-Valcarce, Marta; Rovira, Jordi; Hernández, Marta; Fernández-Natal, Isabel; Nicolau, Anca Ioana; Rodríguez-Lázaro, David

    2015-09-16

    The illegal entrance of foods to EU through black markets at the EU borders can constitute a neglected route of dissemination of foodborne pathogens, and in particular of methicillin-resistant Staphylococcus aureus (MRSA). In this study, we have assessed the presence of MRSA in foods sold in a black market at an EU border (the southeast part of Romania, on the border with Republic of Moldavia). We performed a search for MRSA among 200 food samples collected from 2012 to 2013. All S. aureus were studied by pulsed-field gel electrophoresis (PFGE) and antimicrobial susceptibility testing. MRSA isolates were further characterized by multilocus sequence typing (MLST) and SCCmec typing, and tested for the presence of Panton-Valentine leukocidin (PVL) virulence factors. Overall, 32 S. aureus isolates were recovered from 16 food samples (8%). One isolate detected in a pork lard sample was MRSA (0.5%). PFGE with the restriction enzyme SmaI revealed 12 genotypes among the 32 S. aureus isolates. The MRSA isolate belonged to sequence type 398, harbored SCCmec type V, tested negative for the presence of the PVL genes and was resistant to ciprofloxacin, tetracycline and cefazolin, besides all β-lactams. Among 31 methicillin-sensitive S. aureus (MSSA), 29% were resistant to penicillin, 9.7% to tetracycline and 3.2% to ciprofloxacin. In conclusion, in this study we report the presence of livestock-associated MRSA in foods sold in a black market at an EU border: ST398-MRSA-V. These results confirm the potential role of food in the dissemination of MRSA lineages among population, and the potential role of illegally introduced food to EU in the prevalence and evolution of MRSA clones in the community.

  16. Quantum cloning machines and the applications

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Heng, E-mail: hfan@iphy.ac.cn [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Collaborative Innovation Center of Quantum Matter, Beijing 100190 (China); Wang, Yi-Nan; Jing, Li [School of Physics, Peking University, Beijing 100871 (China); Yue, Jie-Dong [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Shi, Han-Duo; Zhang, Yong-Liang; Mu, Liang-Zhu [School of Physics, Peking University, Beijing 100871 (China)

    2014-11-20

    No-cloning theorem is fundamental for quantum mechanics and for quantum information science that states an unknown quantum state cannot be cloned perfectly. However, we can try to clone a quantum state approximately with the optimal fidelity, or instead, we can try to clone it perfectly with the largest probability. Thus various quantum cloning machines have been designed for different quantum information protocols. Specifically, quantum cloning machines can be designed to analyze the security of quantum key distribution protocols such as BB84 protocol, six-state protocol, B92 protocol and their generalizations. Some well-known quantum cloning machines include universal quantum cloning machine, phase-covariant cloning machine, the asymmetric quantum cloning machine and the probabilistic quantum cloning machine. In the past years, much progress has been made in studying quantum cloning machines and their applications and implementations, both theoretically and experimentally. In this review, we will give a complete description of those important developments about quantum cloning and some related topics. On the other hand, this review is self-consistent, and in particular, we try to present some detailed formulations so that further study can be taken based on those results.

  17. 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.

  18. Characterization of Staphylococcus aureus isolates from faecal samples of the Straw-Coloured Fruit Bat (Eidolon helvum in Obafemi Awolowo University (OAU, Nigeria

    Directory of Open Access Journals (Sweden)

    Akobi Babatunji

    2012-11-01

    Full Text Available Abstract Background Bats (Chiroptera are one of the most diverse groups of mammals which carry out important ecological and agricultural functions that are beneficial to humans. However, they are increasingly recognized as natural vectors for a number of zoonotic pathogens and favourable hosts for zoonotic infections. Large populations of the Straw-Coloured Fruit Bat (Eidolon helvum colonize the main campus of the Obafemi Awolowo University (OAU, Ile-Ife, Nigeria, but the public health implications of faecal contamination and pollution by these flying mammals is unknown. This study characterized S. aureus obtained from faecal samples of these migratory mammals with a view to determining the clonal types of the isolates, and to investigate the possibility of these flying animals as potential reservoir for zoonotic S. aureus infections. Results One hundred and seven (107 S. aureus isolates were recovered from 560 faecal samples in eleven roosting sites from January 2008 to February 2010. A large proportion of the isolates were susceptible to antibiotics, and molecular characterization of 70 isolates showed that 65 (92.9% were assigned in coagulase type VI, while accessory gene typing classified 69 isolates into the following: type I (12; 17.1%, type II (3; 4.3%, type III (1; 1.4% and type IV (53; 75.7%. On the whole, the isolates were grouped in five (A-E main genotypes. Of the ten representative isolates selected for multilocus sequence typing (MLST, nine isolates were assigned with new sequence types: ST1725, ST1726, ST1727, ST2463-ST2467 and ST2470. Phylogenetic analysis provided evidence that S. aureus isolates in group C were closely related with ST1822 and associated clones identified in African monkeys, and group D isolates with ST75, ST883 and ST1223. The two groups exhibited remarkable genetic diversity compared to the major S. aureus clade. Conclusions Antibiotic resistance in faecal S. aureus isolates of E. helvum is low and multiple

  19. 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

  20. Positional cloning of deafness genes

    NARCIS (Netherlands)

    Kremer, H.; Cremers, F.P.M.

    2009-01-01

    The identification of the majority of the known causative genes involved in nonsyndromic sensorineural hearing loss (NSHL) started with linkage analysis as part of a positional cloning procedure. The human and mouse genome projects in combination with technical developments on genotyping, transcript

  1. EasyClone-MarkerFree

    DEFF Research Database (Denmark)

    Fabre, Mathew Malcolm Jessop; Jakociunas, Tadas; Stovicek, Vratislav;

    2016-01-01

    Clone-MarkerFree. The integration of linearized expression cassettes into defined genomic loci is facilitated by CRISPR/Cas9. Cas9 is recruited to the chromosomal location by specific guide RNAs (gRNAs) expressed from a set of gRNA helper vectors. Using our genome engineering vector suite, single and triple insertions are obtained...

  2. Clone Poems and the Microcomputer.

    Science.gov (United States)

    Irizarry, Estelle

    1989-01-01

    Describes how students can use the computer to study and create clone poems (altering original Spanish-language poems by substituting words and expressions), and how students can gain a deeper appreciation of the original poem's poetic structure and semantics. (CB)

  3. 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 ...

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. Human cloning in film: horror, ambivalence, hope

    OpenAIRE

    O'Riordan, Kate

    2008-01-01

    Fictional filmic representations of human cloning have shifted in relation to the 1997 announcement of the birth of Dolly the cloned sheep, and since therapeutic human cloning became a scientific practice in the early twentieth century. The operation and detail of these shifts can be seen through an analysis of the films The Island (2005) and Aeon Flux (2005). These films provide a site for the examination of how these changes in human cloning from fiction to practice, and from horror to hope...

  9. ETHICAL PROBLEMS OF CLONING HUMANS (SCNT)

    OpenAIRE

    SAVVINA O.V.

    2015-01-01

    The article analyses ethical problems of cloning of human beings. Today scientists have opportunity to clone animals and human embryos by somatic cell nuclear transfer (SCNT), and the author considers this technology and ethical problems generated by it. The author maintains that we must divide two types of cloning of human beings: therapeutic and reproductive. The therapeutic cloning does not generate any new ethical problems or dilemmas, but it exacerbates the problems which have already ex...

  10. Mice cloned from embryonic stem cells

    OpenAIRE

    Wakayama, Teruhiko; Rodriguez, Ivan; Perry, Anthony C F; Yanagimachi, Ryuzo; Mombaerts, Peter

    1999-01-01

    Cloning allows the asexual reproduction of selected individuals such that the offspring have an essentially identical nuclear genome. Cloning by nuclear transfer thus far has been reported only with freshly isolated cells and cells from primary cultures. We previously reported a method of cloning mice from adult somatic cells after nuclear transfer by microinjection. Here, we apply this method to clone mice from widely available, established embryonic stem (ES) cell ...

  11. [Infections caused by multi-resistant Gram-positive bacteria (Staphylococcus aureus and Enterococcus spp.)].

    Science.gov (United States)

    Cantón, Rafael; Ruiz-Garbajosa, Patricia

    2013-10-01

    Methicillin -resistant Staphylocccus aureus (MRSA) and multirresistant entorococci are still problematic in nosocomial infections and new challenges have emerged for their containment. MRSA has increased the multiresistant profile; it has been described vancomycin and linezolid resistant isolates and isolates with decreased daptomycin susceptibility. Moreover, new clones (ST398) have emerged, initially associated with piggeries, and new mec variants (mecC) with livestock origin that escape to the detection with current molecular methods based on mecA gene have been detected. In enterococci, linzeolid resistant isolates and isolates with deceased susceptibility to daptomycin have been described. Moreover, ampicillin resistant Enterococcus faecium due to β-lactamase production has been recently found in Europe. Control of MRSA isolates and multiresistant enteroccocci should combined antibiotic stewardship strategies and epidemiological measures, including detection of colonized patients in order to reduce colonization pressure and their transmission.

  12. A General Duality Theory for Clones

    OpenAIRE

    Kerkhoff, Sebastian

    2011-01-01

    In this thesis, we generalize clones (as well as their relational counterparts and the relationship between them) to categories. Based on this framework, we introduce a general duality theory for clones and apply it to obtain new results for clones on finite sets.

  13. EVALUATION OF Eucalyptus CLONES FOR CHARCOAL PRODUCTION

    Directory of Open Access Journals (Sweden)

    Paulo Fernando Trugilho

    2001-01-01

    Full Text Available Charcoal is economically representative in the Brazilian economy, specially in Minas Gerais, the main producer, and consumer of this product. A problem related to the charcoal utilization is its heterogeneous quality, which is influenced both for the wood and the production process. This variability causes waste of material and make it difficult to handle the blast furnaces. The objective of this work was to evaluate the wood of ten clones: seven of Eucalyptus grandis and three of Eucalyptus saligna: both directed to charcoal production. Also, it was looked for to select clones with highercapacity for the establishment of a forestry improvement program. During the assessment it was considered the quantitative and qualitative characteristics of the charcoal. According to the results it was verified that there exists a large variation among the assessed clones, which is higher in Eucalyptus grandis. The production of dry mass, associated to the estimation of mass of both lignin and charcoal proportionate a classification of the clones considered as the superior (clones number five, six and two, median (clones number ten, three, one and eight and inferior (clones number nine, four and seven. Clone seven was the worsen for the charcoal production due to its low growth rate. The classification of the clones based on both the wood chemical characteristics and charcoal yield was not satisfactory. The growth rate was fundamental for the clones classification, being recommendable to incorporate it in future assessment of wood quality. Eucalyptus grandis clones were superior to Eucalyptus saligna clones.

  14. No-cloning theorem in thermofield dynamics

    CERN Document Server

    Prudencio, Thiago

    2011-01-01

    Here we apply the no-cloning theorem from quantum information in the thermofield dynamics (TFD) scenario, relating the doubling procedure of TFD to a cloning machine process. As a consequence we use the no-cloning theorem to demonstrate that the thermal vaccuum state defined in TFD is necessarilly a mixed state.

  15. 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

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. SarA positively controls bap-dependent biofilm formation in Staphylococcus aureus.

    Science.gov (United States)

    Trotonda, María Pilar; Manna, Adhar C; Cheung, Ambrose L; Lasa, Iñigo; Penadés, José R

    2005-08-01

    The biofilm-associated protein Bap is a staphylococcal surface protein involved in biofilm formation. We investigated the influence of the global regulatory locus sarA on bap expression and Bap-dependent biofilm formation in three unrelated Staphylococcus aureus strains. The results showed that Bap-dependent biofilm formation was diminished in the sarA mutants by an agr-independent mechanism. Complementation studies using a sarA clone confirmed that the defect in biofilm formation was due to the sarA mutation. As expected, the diminished capacity to form biofilms in the sarA mutants correlated with the decreased presence of Bap in the bacterial surface. Using transcriptional fusion and Northern analysis data, we demonstrated that the sarA gene product acts as an activator of bap expression. Finally, the bap promoter was characterized and the transcriptional start point was mapped by the rapid amplification of cDNA ends technique. As expected, we showed that purified SarA protein binds specifically to the bap promoter, as determined by gel shift and DNase I footprinting assays. Based on the previous studies of others as well as our work demonstrating the role for SarA in icaADBC and bap expression, we propose that SarA is an essential regulator controlling biofilm formation in S. aureus.

  1. Isolation, molecular characteristics and disinfection of methicillin-resistant Staphylococcus aureus from ICU units in Brazil.

    Science.gov (United States)

    Campos, Guilherme B; Souza, Simone G; Lob O, Tassia N; Da Silva, Danilo C C; Sousa, Daniel S; Oliveira, Pollianna S; Santos, Verena M; Amorim, Aline T; Farias, S Vio T; Cruz, Mariluze P; Yatsuda, Regiane; Marques, Lucas M

    2012-04-01

    The aim of the present study was to isolate S. aureus strains resistant to antibiotics, characterize the genotype profiles of resistance staphylococci, and evaluate the efficacy of antiseptic agents and disinfectants used in two public hospitals of Vitoria da Conquista, Bahia, Brazil. Clinical samples were obtained from ICU environments and equipment surfaces in two public hospitals in Vitoria da Conquista. Broth cultures were plated onto mannitol salt agar, and antimicrobial susceptibility testing was performed by the broth microdilution method according to CLSI. MRSA strains were submitted to PCR for detecting the mecA gene. PCR products were purified and sequenced for SCCmec type identification. Moreover, the strains were tested for efficacy of different disinfectant solutions. S. aureus were isolated from 31 and 67 sites in each hospital, respectively. Among the isolates from hospital 1, 07 (22.6%) were resistant to oxacillin while 28 (41.8%) were resistant in hospital 2. Thirty-one were positive for the mecA gene. All isolates showed SCCmec type III genotype characteristics of the Brazilian epidemic clone. In disinfectant tests, sodium hypochlorite (0.5, 1.0 and 2.0%), 2% chlorhexidine gluconate, quaternary ammonium, peracetic acid and formaldehyde were effective against the isolates tested. The strains showed higher resistance to vinegar (4% acetic acid), alcohol and glutaraldehyde. The findings of this study should assist in reducing the occurrence of nosocomial infections and therefore the morbidity, mortality and socio-economic burden caused by prolonged hospitalization.

  2. 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%.

  3. Heterogeneity of clones from a human metastatic melanoma detected by autologous cytotoxic T lymphocyte clones

    OpenAIRE

    1986-01-01

    The possibility that a single human tumor may be composed of an heterogeneous population of cells with respect to susceptibility to lysis by autologous CTL clones was investigated by testing six cytolytic clones derived by micromanipulation against the autologous metastatic melanoma, Me28, and against 31 clones derived from Me28 by cloning in soft agar. Highly significant differences in the lysis of many tumor clones were observed by three of the CTL effectors in comparison with the cytotoxic...

  4. Large intervals in the clone lattice

    OpenAIRE

    Goldstern, Martin; Shelah, Saharon

    2002-01-01

    We give three examples of large intervals in the lattice of (local) clones on an infinite set X, by exhibiting clones C_1, C_2, C_3 such that: (1) the interval [C_1, O] in the lattice of local clones is (as a lattice) isomorphic to {0,1,2, ...} under the divisibility relation, (2) the interval [C_2, O] in the lattice of local clones is isomorphic to the congruence lattice of an arbitrary semilattice, (3) the interval [C_3, O] in the lattice of all clones is isomorphic to the lattice of all fi...

  5. No-cloning theorem on quantum logics

    Science.gov (United States)

    Miyadera, Takayuki; Imai, Hideki

    2009-10-01

    This paper discusses the no-cloning theorem in a logicoalgebraic approach. In this approach, an orthoalgebra is considered as a general structure for propositions in a physical theory. We proved that an orthoalgebra admits cloning operation if and only if it is a Boolean algebra. That is, only classical theory admits the cloning of states. If unsharp propositions are to be included in the theory, then a notion of effect algebra is considered. We proved that an atomic Archimedean effect algebra admitting cloning operation is a Boolean algebra. This paper also presents a partial result, indicating a relation between the cloning on effect algebras and hidden variables.

  6. 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 ...

  7. mecA-positive methicillin-sensitive Staphylococcus aureus clinical isolates in Zenica-Doboj Canton, Bosnia and Herzegovina.

    Science.gov (United States)

    Kamberović, Farah; Ibrahimagić, Amir; Uzunović, Selma; Budimir, Ana; Rijnders, Michelle I A; Stobberingh, Ellen E

    2015-01-01

    Forty-four mecA-positive and eight mecA-negative Staphylococcus aureus isolates confirmed by PCR were further tested by disc-diffusion (DD) oxacillin and cefoxitin, oxacillin Epsilon (E)-test, and oxacillin and cefoxitin minimal inhibitory concentration (MIC) Strip methicillin-resistant phenotype in S. aureus (MRSA) tests. Among 44 mecA-positive S. aureus isolates, two (4·5%) were detected as MRSA by DD-oxacillin, 17 (38·6%) by DD-cefoxitin test, and seven (15·9%) by the E-test. In the cefoxitin MIC Strip MRSA test, 19 (43·2%) isolates were resistant. In the oxacillin MIC Strip MRSA test, 18 (40·9%) isolates were resistant and 26 (59·1%) were sensitive, i.e. oxacillin-sensitive MRSA (OS-MRSA) (MIC range 0·25-≤0·25 mg/l). Fifteen out of 26 OS-MRSA (57·7%) belonged to spa-CC 355/595, 78% of which belonged to the largest PFGE clone. Some discrepancies between the phenotypic methods for MRSA identification obtained in this study were caused by large proportion of OS-MRSA. Misidentification of OS-MRSA as MSSA might result in an appearance of highly resistant MRSA in patients treated with beta-lactam antibiotics. PMID:25112955

  8. Conotoxins Are Purified and Cloned

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ A group of CAS scientists have succeeded in purifying many conotoxins and cloning more than 100 new genes from six species of cone snails living in waters off the coast of the South China Sea, paving the way for the development of new drugs to relieve neuropathic pains. The work has been honored with a first prize from the 2005 Awards for S&T Progress in Shanghai.

  9. Rice's Salt Tolerance Gene Cloned

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ In cooperation with US colleagues, CAS researchers have made significant progress in their studies into functional genes for key agronomic traits by cloning SKC1, a salt-tolerant functional gene of rice and making clear its biological functions and mechanisms. This pioneering work,which was reported in the Oct. issue of Nature Genetics (37:1141-1146), is believed to hold promise to increase the output of the crop plant in this country.

  10. Cloning expeditions: risky but rewarding.

    Science.gov (United States)

    Lodish, Harvey

    2013-12-01

    In the 1980s, a good part of my laboratory was using the then-new recombinant DNA techniques to clone and characterize many important cell surface membrane proteins: GLUT1 (the red cell glucose transporter) and then GLUT2 and GLUT4, the red cell anion exchange protein (Band 3), asialoglycoprotein receptor subunits, sucrase-isomaltase, the erythropoietin receptor, and two of the subunits of the transforming growth factor β (TGF-β) receptor. These cloned genes opened many new fields of basic research, including membrane insertion and trafficking of transmembrane proteins, signal transduction by many members of the cytokine and TGF-β families of receptors, and the cellular physiology of glucose and anion transport. They also led to many insights into the molecular biology of several cancers, hematopoietic disorders, and diabetes. This work was done by an exceptional group of postdocs and students who took exceptionally large risks in developing and using novel cloning technologies. Unsurprisingly, all have gone on to become leaders in the fields of molecular cell biology and molecular medicine.

  11. Analysis of meticillin-susceptible and meticillin-resistant biofilm-forming Staphylococcus aureus from catheter infections isolated in a large Italian hospital.

    Science.gov (United States)

    Petrelli, Dezemona; Repetto, Antonella; D'Ercole, Stefania; Rombini, Silvia; Ripa, Sandro; Prenna, Manuela; Vitali, Luca Agostino

    2008-03-01

    Several characteristics were analysed in 37 Staphylococcus aureus isolates from nosocomial catheter infections: the PFGE profile after SmaI digestion of chromosomal DNA, the ability to form a biofilm on a polystyrene surface, antibiotic susceptibility patterns (penicillin, oxacillin, erythromycin, tetracycline, clindamycin, telithromycin, gentamicin, ciprofloxacin, quinupristin/dalfopristin, rifampicin, vancomycin and linezolid), and the presence of genetic determinants of antibiotic resistance and biofilm formation. All strains but three (92 %) were able to grow on a plastic surface as a biofilm. An almost complete association was found between phenotypes and genotypic traits of antibiotic resistance, whilst PFGE profiling showed the highly polyclonal composition of the set of strains under study. Sixteen isolates (43 %) were meticillin-resistant and were subjected to staphylococcal cassette chromosome mec (SCCmec) and cassette chromosome recombinase (ccr) complex type determination by multiplex PCR. Only a subgroup of six strains belonged to the archaic clone PFGE type and bore the SCCmec/ccrAB type I structure. Among the remaining strains some presented small rearrangements of the SCCmec/ccrAB genetic locus, whilst others could barely be traced back to a known structural type. These observations suggest that, at the local level and at a particular site of infection, S. aureus may show great genetic variability and escape the general rule of expansion of the S. aureus pandemic clones. PMID:18287301

  12. A 3-year long study of Staphylococcus aureus isolates from subclinical mastitis in three Azawak zebu herds at the Sahelian experimental farm of Toukounous, Niger.

    Science.gov (United States)

    Issa, Abdoulkarim Ibrahim; Duprez, Jean-Noël; Bada-Alambedji, Rianatou; Djika, Mamane; Mainil, Jacques Georges; Bardiau, Marjorie

    2016-02-01

    Staphylococcus (S.) aureus is one of the most important pathogens causing bovine mastitis. The aim of the present work was to follow in three herds and during the 3 years the clonality of S. aureus isolated from California Mastitis Test (CMT)-positive cows at the experimental station of Toukounous (Niger) by (i) comparing their pulsed field gel electrophoresis (PFGE) fingerprints, (ii) identifying their virulotypes by PCR amplification and (iii) assessing the production of capsule and the formation of biofilm. The 88 S. aureus isolates belonged to 14 different pulsotypes, 3 of them being predominant: A (30 %), D (27 %), B (15 %). A and B pulsotypes had the highest profile similarity coefficient (94 %), while others had similarity coefficients under 60 %. Seventy-five S. aureus isolates were further studied for their virulotypes, capsular antigens and biofilm production. Most surface factor-, leukocidin- and haemolysin-, but not the enterotoxin-encoding genes were detected in the majority (>75 %) of the isolates and were evenly distributed between the A, B and D pulsotype isolates. The majority of the 72 S. aureus positive with the cap5H or cap8H PCR produced the CP5 (82 %) or the CP8 (88 %) capsular antigen, respectively. Biofilm production by the 57 icaA-positive isolates was strong for 8 isolates, moderate for 31 isolates but weak for 18 isolates, implying that the icaA gene may not be expressed in vitro by one third of the positive isolates. Similar to other studies, those results confirm that a restricted number of S. aureus clones circulate within the three herds at Toukounous and that their specific virulence-associated properties must still be further studied. PMID:26584940

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. 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...

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Genetic diversity of community-associated methicillin-resistant Staphylococcus aureus isolated from Tenerife Island, Spain.

    Science.gov (United States)

    Rivero-Pérez, Belinda; Alcoba-Flórez, Julia; Méndez-Álvarez, Sebastián

    2012-04-01

    With the recent detection of MRSA (methicillin-resistant Staphylococcus aureus) infections in patients lacking health care-related risk factors, the term community-acquired MRSA (CA-MRSA) has been become widely recognised. Many cases of CA-MRSA spreading to the community have been described worldwide. The aim of this study was to determine the features of CA-MRSA isolates from Tenerife Island. Toward this end, one hundred MRSA isolates were collected from eight different health regions, and their molecular features were investigated. This study revealed a wide variety of MRSA clones, including an emergent ST: ST1434 (CC8) and two new spa types, t7575 (ST125) and t7678 (ST22). The PVL genes were found in only five isolates belonging to unrelated lineages, ST8, ST30 and ST22, which could indicate at least three independent introductions of PVL(+) strains to Tenerife. Moreover, we detected that hospital MRSA clones, like EMRSA-15 and EMRSA-16, had spread to the community and are now circulating in both environments. Therefore, in our study, the CDC's rules were not specific enough to distinguish CA-MRSA from HA-MRSA. Thus, we think that the current epidemiological information is not enough to discriminate between both MRSAs, and it is necessary for prevention guidelines to include the routine determination of at least the genetic background, the antimicrobial susceptibility profile, and the PVL genes of each MRSA isolate.

  7. 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...

  8. 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...

  9. 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.

  10. Cloning

    Science.gov (United States)

    ... Care Online Health Resources For Health Professionals Competency & Curricular Resources Genetics 101 Genomic Medicine and Health Care ... as bacteria , produce genetically identical offspring through a process called asexual reproduction. In asexual reproduction, a new ...

  11. Cloning

    Institute of Scientific and Technical Information of China (English)

    彭荣华

    2002-01-01

    As we come near to the 21st century, it is clear than ever that science and technology are changing the way we live and work. The breakthroughs1 in bioengineering2 science are helping to uncover the mysteries of life, holding out new hope for life-saving cures to some of our greatly terrible diseases.

  12. 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

  13. Co-colonization and clonal diversity of methicillin-sensitive and methicillin-resistant Staphylococcus aureus in sows.

    Science.gov (United States)

    Fetsch, Alexandra; Roesler, Uwe; Kraushaar, Britta; Friese, Anika

    2016-03-15

    Methicillin-susceptible Staphylococcus (S.) aureus (MSSA) and methicillin-resistant S. aureus (MRSA) are colonizers of skin and mucosa. In humans, MSSA and MRSA compete for colonization space in the anterior nares of pig farmers; however, it was also shown that MSSA/MRSA co-colonization is common and one clone can be found rather than differing types of MSSA and MRSA. We investigated the colonization and clonality of both, MSSA and MRSA in pigs over a longer time. Eighteen sows were nasally sampled three times every ten weeks. Additionally, environmental samples were taken. Samples were investigated for MSSA and MRSA, respectively. The spa type was defined from up to five MRSA and MSSA isolates found per sample and sampling time; selected isolates were further investigated by microarray. Three sows (16.7%) were completely negative for MSSA and MRSA. Twelve pigs (66.7%) were irregularly positive for both, MSSA and MRSA over the time, whereas seven out of them (38.9%) were simultaneously colonized. CC398 (t034, t011) MRSA and CC9 (t337, t1430, and t13816) MSSA associated spa types were exclusively found. In 44.4% (n=8) of sows up to two different types of MSSA were present at the same time and sample. Strains of the same clonal lineage showed a high genetic identity despite their origin. Highly identic clones were present in sows and their environment. As conclusion, MSSA/MRSA may not exclude each other in the anterior nares of pigs. Pigs may also carry different clones at the same time.

  14. Methicillin-resistant Staphylococcus aureus in Spain: molecular epidemiology and utility of different typing methods.

    Science.gov (United States)

    Vindel, Ana; Cuevas, Oscar; Cercenado, Emilia; Marcos, Carmen; Bautista, Verónica; Castellares, Carol; Trincado, Pilar; Boquete, Teresa; Pérez-Vázquez, Maria; Marín, Mercedes; Bouza, Emilio

    2009-06-01

    In a point-prevalence study performed in 145 Spanish hospitals in 2006, we collected 463 isolates of Staphylococcus aureus in a single day. Of these, 135 (29.2%) were methicillin (meticillin)-resistant S. aureus (MRSA) isolates. Susceptibility testing was performed by a microdilution method, and mecA was detected by PCR. The isolates were analyzed by pulsed-field gel electrophoresis (PFGE) after SmaI digestion, staphylococcal chromosomal cassette mec (SCCmec) typing, agr typing, spa typing with BURP (based-upon-repeat-pattern) analysis, and multilocus sequence typing (MLST). The 135 MRSA isolates showed resistance to ciprofloxacin (93.3%), tobramycin (72.6%), gentamicin (20.0%), erythromycin (66.7%), and clindamycin (39.3%). Among the isolates resistant to erythromycin, 27.4% showed the M phenotype. All of the isolates were susceptible to glycopeptides. Twelve resistance patterns were found, of which four accounted for 65% of the isolates. PFGE revealed 36 different patterns, with 13 major clones (including 2 predominant clones with various antibiotypes that accounted for 52.5% of the MRSA isolates) and 23 sporadic profiles. Two genotypes were observed for the first time in Spain. SCCmec type IV accounted for 6.7% of the isolates (70.1% were type IVa, 23.9% were type IVc, 0.9% were type IVd, and 5.1% were type IVh), and SCCmec type I and SCCmec type II accounted for 7.4% and 5.2% of the isolates, respectively. One isolate was nontypeable. Only one of the isolates produced the Panton-Valentine leukocidin. The isolates presented agr type 2 (82.2%), type 1 (14.8%), and type 3 (3.0%). spa typing revealed 32 different types, the predominant ones being t067 (48.9%) and t002 (14.8%), as well as clonal complex 067 (78%) by BURP analysis. The MRSA clone of sequence type 125 and SCCmec type IV was the most prevalent throughout Spain. In our experience, PFGE, spa typing, SCCmec typing, and MLST presented good correlations for the majority of the MRSA strains; we suggest the

  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. Effective and efficient model clone detection

    DEFF Research Database (Denmark)

    Störrle, Harald

    2015-01-01

    Code clones are a major source of software defects. Thus, it is likely that model clones (i.e., duplicate fragments of models) have a significant negative impact on model quality, and thus, on any software created based on those models, irrespective of whether the software is generated fully...... automatically (“MDD-style”) or hand-crafted following the blueprint defined by the model (“MBSD-style”). Unfortunately, however, model clones are much less well studied than code clones. In this paper, we present a clone detection algorithm for UML domain models. Our approach covers a much greater variety...... of model types than existing approaches while providing high clone detection rates at high speed....

  17. Occurrence of enterotoxin genes and macrorestriction analysis of Staphylococcus aureus isolated from bovine mastitis and bulk-tank milk samples in Italy. An epidemiological study

    Directory of Open Access Journals (Sweden)

    Roberto Rosmini

    2010-01-01

    Full Text Available The goal of the study was to genotypically compare S. aureus isolates from mastitis milk and raw milk to identify therelation between strains and to assess the enterotoxigenicity of the isolates. Eighty-three Staphylococcus aureus isolatesrecovered from cows and bulk tank milk of five farms in northern Italy were compared genotypically. The genes for theenterotoxins A, D, G and I, but not for B, C, E and H and the toxic shock syndrome toxin 1 (TSST-1, were detected byPCR amplification. Macrorestriction analysis with the restrictions enzyme SmaI revealed 14 pulsed-field gel electrophoresispatterns. These were in part different from each other only in a few fragments and thus displayed a closeclonal relation. The results of the present investigation showed that identical or closely related clones seemed to beresponsible for the cases of bovine mastitis in the farms investigated and partly responsible for contamination of bulktank milk.

  18. Shifts in the Clonal Distribution of Methicillin-Resistant Staphylococcus aureus in Kuwait Hospitals: 1992-2010

    Science.gov (United States)

    Boswihi, Samar S.; Udo, Edet E.; Al-Sweih, Noura

    2016-01-01

    Background As the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) is constantly changing globally, determining the prevailing MRSA clones in a local healthcare facility is important for better management of infections. This study investigated clonal composition and distribution of MRSA isolates in Kuwait’s hospitals using a combination of molecular typing methods. Materials and Methods In total, 400 non-repeat MRSA isolates were obtained between 1992 and 2010 in 13 public hospitals and were characterized using antibiogram, SCCmec typing, spa typing, and multilocus-sequence typing. Clonal assignment and detection of virulence factors and antibiotic resistance genes were performed by DNA microarray. Results The isolates were resistant to kanamycin (74.2%), erythromycin (69.5%), tetracycline (66.7%), gentamicin (61%), ciprofloxacin, (61%), fusidic acid (53.5%), clindamycin (41.5%), high-level mupirocin resistance (5.2%) and carried aphA3, aacA-aphD, ermA, ermC, mupA, tetK, tetM, fusC and far1. Molecular typing revealed 31 different MRSA clones consisting of ST239-MRSA-III (52.2%), ST22-MRSA-IV (9.2%), ST80-MRSA-IV (7.5%), ST5-MRSA-II/IV/V/VI (6.5%), ST30-MRSA-IV (3.5%), ST241-MRSA-III (2.7%), ST6-MRSA-IV (2.2%), ST36-MRSA-II (2%) and ST772-MRSA-V (1.75%). The isolates differed in the carriage of genes for enterotoxins, Panton–Valentine leukocidin (PVL), toxic shock syndrome toxin (tst-1), arginine catabolic mobile element (ACME) and exfoliative toxins. The number of clones increased from one (ST239-III-t037) in 1992 to 30 in 2010 including ST8-IV-t008 [PVL+] [ACME+] (USA300), ST772-V (Bengal Bay clone) and ST2816 identified for the first time in Kuwait. Conclusion The study revealed that the MRSA isolates belonged to diverse clones that changed in numbers and diversity overtime. Although ST239-MRSA-III, a healthcare-associated clone remained the dominant MRSA clone overtime, the newly emerged clones consisted mostly of community-associated. PMID

  19. 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.

  20. Prevalence and characteristics of community carriage of methicillin-resistant Staphylococcus aureus in Malta.

    Science.gov (United States)

    Scerri, Jeanesse; Monecke, Stefan; Borg, Michael A

    2013-09-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen worldwide. Malta is one of the countries with the highest MRSA prevalence in Europe, as identified from hospital blood cultures [1]. However, community prevalence of MRSA has never previously been investigated. This study aimed at establishing the prevalence of community MRSA nasal colonization in Maltese individuals and identifying the clonal characteristics of the detected isolates. Nasal swabs were collected from 329 healthy individuals who were also asked to complete a brief questionnaire about risk factors commonly associated with MRSA carriage and infection. The swabs were transported and enriched in a nutrient broth supplemented with NaCl. The presence of MRSA was then determined by culturing on MRSA Select chromogenic agar and then confirming by several assays, including catalase, coagulase and PBP2a agglutination tests. The isolates were assayed for antibiotic susceptibilities and typed by microarray analysis to determine the clonal characteristics of each strain. The prevalence of MRSA nasal colonization in the healthy Maltese population was found to be 8.81% (95% confidence interval [CI], 5.75-11.87%), much higher than that found in other studies carried out in several countries. No statistical association was found between MRSA carriage and demographics or risk factors; however, this was hindered by the small sample size. Almost all the isolates were fusidic-acid resistant. The majority were found to belong to a local endemic clone (CC5) which seems to be replacing the previously prevalent European clone UK-EMRSA-15 in the country. A new clone (CC50-MRSA-V) was also characterized. The presence of such a significant community reservoir of MRSA increases the burdens already faced by the local healthcare system to control the MRSA epidemic. Colonization of MRSA in otherwise healthy individuals may represent a risk for endogenous infection and transmission to hospitalized

  1. Growth and nutrition of willow clones.

    OpenAIRE

    ViherÀ-Aarnio, Anneli; Saarsalmi, Anna

    1994-01-01

    Growth and nutrition of 20 clones representing different species and interspecific hybrids of willows growing on an abandoned field were studied. There were highly significant differences between the clones as regards the survival, number of sprouts/stool, sprout mean height and diameter and stem biomass production/stool. The differences between the clones in the concentrations of all nutrients in both the leaves and stems were highly significant.

  2. Test of high land potato clones

    OpenAIRE

    Handayani, Tri; Kusmana

    2011-01-01

    Potatoes farming in Indonesia were still dominated by Granola variety. New varieties with high yield are still needed. The objective this study was to obtain high yield clones. The study was conducted at Ciwidey, Bandung that located at altitude of 1300 m above sea level and there conducted from February to June 2007. The study applied completely randomized block design with three replications. Treatments were 15 clones include 4 controls that are tested. Among 11 clones tes...

  3. Economic Aspects of Human Cloning and Reprogenetics

    OpenAIRE

    Saint-Paul, Gilles

    2002-01-01

    This paper analyses the economic issues associated with human cloning and new reproductive technologies. We analyze the incentives for human cloning and its implications for the long run distribution of skills and income. We analyse models of human cloning for different motives, focusing on those which tend to produce new human beings with improved ability. We thus ignore purely therapeutic applications, which may well be the most likely ones to happen in the near future, but have no first-or...

  4. Benefits and problems with cloning animals.

    OpenAIRE

    Smith, L. C.; Bordignon, V.; Babkine, M; Fecteau, G; Keefer, C.

    2000-01-01

    Animal cloning is becoming a useful technique for producing transgenic farm animals and is likely to be used to produce clones from valuable adults. Other applications will also undoubtedly be discovered in the near future, such as for preserving endangered breeds and species. Although cloning promises great advantages for commerce and research alike, its outcome is not always certain due to high pregnancy losses and high morbidity and mortality during the neonatal period. Research into the m...

  5. Meat and milk compositions of bovine clones

    OpenAIRE

    Tian, X. Cindy; Kubota, Chikara; Sakashita, Kunihito; IZAIKE, Yoshiaki; OKANO, Ryoichi; Tabara, Norio; Curchoe, Carol; Jacob, Lavina; Zhang, Yuqin; Smith, Sadie; Bormann, Charles; Xu, Jie; Sato, Masumi; Andrew, Sheila; Yang, Xiangzhong

    2005-01-01

    The technology is now available for commercial cloning of farm animals for food production, but is the food safe for consumers? Here, we provide data on >100 parameters that compare the composition of meat and milk from beef and dairy cattle derived from cloning to those of genetic- and breed-matched control animals from conventional reproduction. The cloned animals and the comparators were managed under the same conditions and received the same diet. The composition of the meat and milk from...

  6. Recombination-assisted megaprimer (RAM) cloning

    OpenAIRE

    Jacques Mathieu; Emilia Alvarez; Alvarez, Pedro J. J.

    2014-01-01

    No molecular cloning technique is considered universally reliable, and many suffer from being too laborious, complex, or expensive. Restriction-free cloning is among the simplest, most rapid, and cost-effective methods, but does not always provide successful results. We modified this method to enhance its success rate through the use of exponential amplification coupled with homologous end-joining. This new method, recombination-assisted megaprimer (RAM) cloning, significantly extends the app...

  7. Ultra-Low Background DNA Cloning System

    OpenAIRE

    Goto, Kenta; Nagano, Yukio

    2013-01-01

    Yeast-based in vivo cloning is useful for cloning DNA fragments into plasmid vectors and is based on the ability of yeast to recombine the DNA fragments by homologous recombination. Although this method is efficient, it produces some by-products. We have developed an “ultra-low background DNA cloning system” on the basis of yeast-based in vivo cloning, by almost completely eliminating the generation of by-products and applying the method to commonly used Escherichia coli vectors, particularly...

  8. Metabolomic phenotyping of a cloned pig model

    Directory of Open Access Journals (Sweden)

    Callesen Henrik

    2011-08-01

    Full Text Available Abstract Background Pigs are widely used as models for human physiological changes in intervention studies, because of the close resemblance between human and porcine physiology and the high degree of experimental control when using an animal model. Cloned animals have, in principle, identical genotypes and possibly also phenotypes and this offer an extra level of experimental control which could possibly make them a desirable tool for intervention studies. Therefore, in the present study, we address how phenotype and phenotypic variation is affected by cloning, through comparison of cloned pigs and normal outbred pigs. Results The metabolic phenotype of cloned pigs (n = 5 was for the first time elucidated by nuclear magnetic resonance (NMR-based metabolomic analysis of multiple bio-fluids including plasma, bile and urine. The metabolic phenotype of the cloned pigs was compared with normal outbred pigs (n = 6 by multivariate data analysis, which revealed differences in the metabolic phenotypes. Plasma lactate was higher for cloned vs control pigs, while multiple metabolites were altered in the bile. However a lower inter-individual variability for cloned pigs compared with control pigs could not be established. Conclusions From the present study we conclude that cloned and normal outbred pigs are phenotypically different. However, it cannot be concluded that the use of cloned animals will reduce the inter-individual variation in intervention studies, though this is based on a limited number of animals.

  9. Cloning of spin-coherent states

    International Nuclear Information System (INIS)

    We consider optimal cloning of the spin coherent states in Hilbert spaces of different dimensionality d. We give explicit form of optimal cloning transformation for spin coherent states in the three-dimensional space, analytical results for the fidelity of the optimal cloning in d=3 and d=4 as well as numerical results for higher dimensions. In the low-dimensional case we construct the corresponding completely positive maps and exhibit their structure with the help of Jamiolkowski isomorphism. This allows us to formulate some conjectures about the form of optimal coherent cloning completely positive maps in arbitrary dimension

  10. Quantum cloning disturbed by thermal Davies environment

    Science.gov (United States)

    Dajka, Jerzy; Łuczka, Jerzy

    2016-06-01

    A network of quantum gates designed to implement universal quantum cloning machine is studied. We analyze how thermal environment coupled to auxiliary qubits, `blank paper' and `toner' required at the preparation stage of copying, modifies an output fidelity of the cloner. Thermal environment is described in terms of the Markovian Davies theory. We show that such a cloning machine is not universal any more but its output is independent of at least a part of parameters of the environment. As a case study, we consider cloning of states in a six-state cryptography's protocol. We also briefly discuss cloning of arbitrary input states.

  11. Cloning and sequence analysis of genes encoding Staphylococcus hyicus exfoliative toxin types A, B, C, and D

    DEFF Research Database (Denmark)

    Ahrens, Peter; Andresen, Lars Ole

    2004-01-01

    Exfoliative toxins produced by certain strains of Staphylococcus hyicus mediate exudative epidermitis in pigs. In this study the genes coding for four different exfoliative toxin from S. hyicus (ExhA, ExhB, ExhC, and ExhD) were cloned and sequenced. The coding sequence of the four toxin genes...... ranged from 816 to 834 bp. The amino acid sequences of these four toxins were homologous to the earlier described exfoliative toxins SHETB from S. hyicus and ETA, ETB, and ETD from Staphylococcus aureus. The homology between the S. hyicus toxins was at the same level as the homology to the exfoliative...

  12. A single-copy galK promoter cloning vector suitable for cloning strong promoters

    DEFF Research Database (Denmark)

    Dandanell, Gert; Court, Donald L.; Hammer, Karin

    1986-01-01

    We report the construction of lambda galK promoter cloning vectors for cloning and characterization of strong promoters. This phage, which contains a unique HindIII cloning site, was applied to the cloning and analysis of transcription initiations of the regulatory region of the deo-operon of...... Escherichia coli and the PL promoter of bacteriophage lambda....

  13. Alloreactive cloned T cell lines. I. Interactions between cloned amplifier and cytolytic T cell lines

    OpenAIRE

    1980-01-01

    Several T cell clones have been derived by limiting dilution of secondary mixed leukocyte culture cells stimulated by H-2- and M locus (Mls)-disparate spleen cells. When examined for the expression of cytolytic activity and the ability to proliferate, these cell clones can be classified into two major categories. One type of cell is noncytolytic; when cultured with irradiated spleen cells, such clones proliferate in response to Mls determinants. Some, but not all, of these clones express Lyt-...

  14. General View on Gateway Cloning Technology: Faster, Easier, More Accurate Cloning Method

    OpenAIRE

    Meryem JEFFERIES; Mustafa HACIÖMEROĞLU

    2010-01-01

    Gateway Cloning Technology (GCT) is developed by the scientists James Hartley, Dominic Esposito and Mike Brasch. This technology is an universal cloning method based on the site-specific recombination properties of bacteriophage lambda. The Gateway Cloning is performed in two steps. The first step, called BP recombination, the reaction between an attB-flanked DNA fragment and an attP-containing donor vector to generate an entry clone by BP clonase. The second step is called as LR Reaction. I...

  15. 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.

  16. 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

  17. 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...

  18. ES cells derived from cloned embryos in monkey - a jump toward human therapeutic cloning

    Institute of Scientific and Technical Information of China (English)

    Xiangzhong Yang; Sadie L Smith

    2007-01-01

    @@ Therapeutic cloning refers to the derivation of embryonic stem cells (ntESC) from embryos derived from somatic cell nuclear transfer (SCNT) also known as cloning. Cloning involves transplanting a differentiated cell into an oocyte that has had its nucleus (DNA) removed.

  19. 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....

  20. 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.

  1. Progress in interspecies cloning of mammals

    Institute of Scientific and Technical Information of China (English)

    WEN Duancheng; BI Chunming; CHEN Dayuan

    2004-01-01

    Interspecies mammalian cloning can be achieved by application of two key techniques, i.e.the technique of interspecies nuclear transfer and the technique of interspecies pregnancy.The general principles, problems and possible solutions, as well as the recent advances of interspecies mammalian cloning have been summarized in this review.

  2. Computerized adaptive testing with item cloning

    NARCIS (Netherlands)

    Glas, Cees A.W.; Linden, van der Wim J.

    2003-01-01

    To increase the number of items available for adaptive testing and reduce the cost of item writing, the use of techniques of item cloning has been proposed. An important consequence of item cloning is possible variability between the item parameters. To deal with this variability, a multilevel item

  3. No-cloning theorem in thermofield dynamics

    OpenAIRE

    Prudencio, Thiago

    2011-01-01

    We discuss the relation between the no-cloning theorem from quantum information and the doubling procedure used in the formalism of thermofield dynamics (TFD). We also discuss how to apply the no-cloning theorem in the context of thermofield states defined in TFD. Consequences associated to mixed states, von Neumann entropy and thermofield vacuum are also addressed.

  4. Challenges in regulating farm animal cloning

    DEFF Research Database (Denmark)

    Gunning, Jennifer; Hartlev, Mette; Gamborg, Christian

    Report from the project Cloning in Public: A specific support action within the 6th framework programme, priority 5: Food quality and safety......Report from the project Cloning in Public: A specific support action within the 6th framework programme, priority 5: Food quality and safety...

  5. 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.

  6. Coconut clones through somatic embryogenesis

    OpenAIRE

    Verdeil, Jean-Luc; Buffard-Morel, Jacqueline; Rival, Alain; Grosdemange, Frédérique; Huet, Christine; Pannetier, Catherine

    1993-01-01

    Une étape importante a été atteinte dans la maîtrise de la propagation végétative #in vitro$ du cocotier : obtention reproductible de plantules à partir de 5 clones appartenant à différents génotypes. Deux sortes de tissus prélevés sur des arbres adultes sélectinnés ont été utilisés : explants foliaires et explants inflorenscenciels. La méthode développée comprend les étapes suivantes : induction de la callogénèse sur explants primaires, induction de l'embryogénèse sur les cals obtenus, matur...

  7. Metabolomic phenotyping of af cloned pig model

    DEFF Research Database (Denmark)

    Clausen, Morten Rahr; Christensen, Kirstine Lykke; Hedemann, Mette Skou;

    2011-01-01

    Background Pigs are widely used as models for human physiological changes in intervention studies, because of the close resemblance between human and porcine physiology and the high degree of experimental control when using an animal model. Cloned animals have, in principle, identical genotypes...... and possibly also phenotypes and this offer an extra level of experimental control which could possibly make them a desirable tool for intervention studies. Therefore, in the present study, we address how phenotype and phenotypic variation is affected by cloning, through comparison of cloned pigs and normal...... outbred pigs. Results The metabolic phenotype of cloned pigs (n = 5) was for the first time elucidated by nuclear magnetic resonance (NMR)-based metabolomic analysis of multiple bio-fluids including plasma, bile and urine. The metabolic phenotype of the cloned pigs was compared with normal outbred pigs (n...

  8. Metabolomic phenotyping of a cloned pig model

    DEFF Research Database (Denmark)

    Clausen, Morten Rahr; Christensen, Kirstine Lykke; Hedemann, Mette Skou;

    2011-01-01

    Background Pigs are widely used as models for human physiological changes in intervention studies, because of the close resemblance between human and porcine physiology and the high degree of experimental control when using an animal model. Cloned animals have, in principle, identical genotypes and...... established. Conclusions From the present study we conclude that cloned and normal outbred pigs are phenotypically different. However, it cannot be concluded that the use of cloned animals will reduce the inter-individual variation in intervention studies, though this is based on a limited number of animals....... possibly also phenotypes and this offer an extra level of experimental control which could possibly make them a desirable tool for intervention studies. Therefore, in the present study, we address how phenotype and phenotypic variation is affected by cloning, through comparison of cloned pigs and normal...

  9. 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....

  10. 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

  11. 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

  12. 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.

  13. 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...

  14. 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.

  15. 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....

  16. 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....

  17. 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...

  18. 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

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

    OpenAIRE

    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...

  20. 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...

  1. 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...

  2. 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.

  3. 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...

  4. Production and applications of an N-terminally-truncated recombinant beta-haemolysin from Staphylococcus aureus.

    Science.gov (United States)

    Singh, M; Singh, A; Sharma, A

    2014-07-01

    The beta-haemolysin of Staphylococcus aureus (SA-hlb) is a secreted neutral sphingomyelinase (nSMase) implicated in the pathogenesis of infection and responsible for the characteristic in vitro 'hot-cold' haemolytic ability of the bacterium. Here, we describe the production of a biologically active N-terminally-truncated recombinant SA-hlb protein for use in in vitro assays and as a research tool. Using local isolates of S. aureus, we PCR-amplified an SA-hlb DNA sequence of 891 nucleotides, 99 nucleotides shorter than the full-length molecule, before cloning and sequencing (GenBank accession no. JN580071). The pQE.TriSystem vector (Qiagen, Germany) was used to express recombinant SA-hlb (r-SA-hlb) with a C-terminal 8xHis tag in Escherichia coli JM107 cells. Both JM107 lysate and the purified r-SA-hlb possessed hot-cold lytic activity against sheep and buffalo erythrocytes, which was abolished by incubation at ≥90 °C for 30 min or exposure to dithiothreitol, and could be neutralized by bovine immune sera. Purified r-SA-hlb was also cytotoxic to buffalo mononuclear cells and was effective as a coating antigen for indirect ELISA to screen for reactive sera. Importantly, the r-SA-hlb was suitable for use as a β-toxin in the modified CAMP test. We conclude that the r-SA-hlb protein produced was functionally active and has numerous potential applications.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. Aberrant DNA methylation in cloned ovine embryos

    Institute of Scientific and Technical Information of China (English)

    LIU Lei; HOU Jian; LEI TingHua; BAI JiaHua; GUAN Hong; AN XiaoRong

    2008-01-01

    By using the approach of immunofluorescence staining with an antibody against 5-methylcytosine (5MeC), the present study detected the DNA methylation patterns of cloned ovine embryos. The em-bryos derived from in vitro fertilization were also examined for reference purpose. The results showed that: (1) during the pre-implantation development, cloned embryos displayed a similar demethylation profile to the fertilized embryos; that is, the methylation level decreased to the lowest at 8-cell stage, and then increased again at morulae stage. However, methylation level was obviously higher in cloned embryos than in stage-matched fertilized embryos, especially at 8-cell stage and afterwards; (2) at blastocyst stage, the methylation pattern in cloned embryos was different from that in fertilized em-bryos. In cloned blastocyst, inner cell mass (ICM) exhibited a comparable level to trophectoderm cells (TE), while in in-vitro fertilized blastocyst the methylation level of ICM was lower than that of TE, which is not consistent with that reported by other authors. These results indicate that DNA methylation is abnormally reprogrammed in cloned embryos, implying that aberrant DNA methylation reprogramming may be one of the factors causing cloned embryos developmental failure.

  10. Human embryo cloning prohibited in Hong Kong.

    Science.gov (United States)

    Liu, Athena

    2005-12-01

    Since the birth of Dolly (the cloned sheep) in 1997, debates have arisen on the ethical and legal questions of cloning-for-biomedical-research (more commonly termed "therapeutic cloning") and of reproductive cloning using human gametes. Hong Kong enacted the Human Reproductive Technology Ordinance (Cap 561) in 2000. Section 15(1)(e) of this Ordinance prohibits the "replacing of the nucleus of a cell of an embryo with a nucleus taken from any other cell," i.e., nucleus substitution. Section 15(1)(f) prohibits the cloning of any embryo. The scope of the latter, therefore, is arguably the widest, prohibiting all cloning techniques such as cell nucleus replacement, embryo splitting, parthenogenesis, and cloning using stem cell lines. Although the Human Reproductive Technology Ordinance is not yet fully operative, this article examines how these prohibitions may adversely impact on basic research and the vision of the Hong Kong scientific community. It concludes that in light of recent scientific developments, it is time to review if the law offers a coherent set of policies in this area.

  11. 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.

  12. The molecular epidemiology of the highly virulent ST93 Australian community Staphylococcus aureus strain.

    Directory of Open Access Journals (Sweden)

    Geoffrey W Coombs

    Full Text Available In Australia the PVL-positive ST93-IV [2B], colloquially known as "Queensland CA-MRSA" has become the dominant CA-MRSA clone. First described in the early 2000s, ST93-IV [2B] is associated with skin and severe invasive infections including necrotizing pneumonia. A singleton by multilocus sequence typing (MLST eBURST analysis ST93 is distinct from other S. aureus clones. To determine if the increased prevalence of ST93-IV [2B] is due to the widespread transmission of a single strain of ST93-IV [2B] the genetic relatedness of 58 S. aureus ST93 isolated throughout Australia over an extended period were studied in detail using a variety of molecular methods including pulsed-field gel electrophoresis, spa typing, MLST, microarray DNA, SCCmec typing and dru typing. Identification of the phage harbouring the lukS-PV/lukF-PV Panton Valentine leucocidin genes, detection of allelic variations in lukS-PV/lukF-PV, and quantification of LukF-PV expression was also performed. Although ST93-IV [2B] is known to have an apparent enhanced clinical virulence, the isolates harboured few known virulence determinants. All PVL-positive isolates carried the PVL-encoding phage ΦSa2USA and the lukS-PV/lukF-PV genes had the same R variant SNP profile. The isolates produced similar expression levels of LukF-PV. Although multiple rearrangements of the spa sequence have occurred, the core genome in ST93 is very stable. The emergence of ST93-MRSA is due to independent acquisitions of different dru-defined type IV and type V SCCmec elements in several spa-defined ST93-MSSA backgrounds. Rearrangement of the spa sequence in ST93-MRSA has subsequently occurred in some of these strains. Although multiple ST93-MRSA strains were characterised, little genetic diversity was identified for most isolates, with PVL-positive ST93-IVa [2B]-t202-dt10 predominant across Australia. Whether ST93-IVa [2B] t202-dt10 arose from one PVL-positive ST93-MSSA-t202, or by independent acquisitions of

  13. Phenotypic and molecular characterization of Staphylococcus aureus isolates expressing low- and high-level mupirocin resistance in Nigeria and South Africa

    Directory of Open Access Journals (Sweden)

    Udo Edet E

    2009-01-01

    Full Text Available Abstract Background Mupirocin is a topical antimicrobial agent which is used for the treatment of skin and postoperative wound infections, and the prevention of nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA. However, the prevalence of mupirocin resistance in S. aureus, particularly in MRSA, has increased with the extensive and widespread use of this agent in hospital settings. This study characterized low- and high-level mupirocin-resistant S. aureus isolates obtained from Nigeria and South Africa. Methods A total of 17 mupirocin-resistant S. aureus isolates obtained from two previous studies in Nigeria and South Africa, were characterized by antibiogram, PCR-RFLP of the coagulase gene and PFGE. High-level mupirocin resistant isolates were confirmed by PCR detection of the mupA gene. The genetic location of the resistance determinants was established by curing and transfer experiments. Results All the low-level mupirocin resistant isolates were MRSA and resistant to gentamicin, tetracycline and trimethoprim. PFGE identified a major clone in two health care institutions located in Durban and a health care facility in Pietermaritzburg, Greytown and Empangeni. Curing and transfer experiments indicated that high-level mupirocin resistance was located on a 41.1 kb plasmid in the South African strain (A15. Furthermore, the transfer of high-level mupirocin resistance was demonstrated by the conjugative transfer of the 41.1 kb plasmid alone or with the co-transfer of a plasmid encoding resistance to cadmium. The size of the mupirocin-resistance encoding plasmid in the Nigerian strain (35 IBA was approximately 35 kb. Conclusion The emergence of mupirocin-resistant S. aureus isolates in Nigeria and South Africa should be of great concern to medical personnel in these countries. It is recommended that methicillin-susceptible S. aureus (MSSA and MRSA should be routinely tested for mupirocin resistance even in facilities where the agent

  14. Human embryo cloning prohibited in Hong Kong

    OpenAIRE

    Liu, Athena

    2005-01-01

    Since the birth of Dolly (the cloned sheep) in 1997, debates have arisen on the ethical and legal questions of cloning-for-biomedical-research (more commonly termed “therapeutic cloning”) and of reproductive cloning using human gametes. Hong Kong enacted the Human Reproductive Technology Ordinance (Cap 561) in 2000. Section 15(1)(e) of this Ordinance prohibits the “replacing of the nucleus of a cell of an embryo with a nucleus taken from any other cell,” i.e., nucleus substitution. Section 15...

  15. Simplified cryopreservation of porcine cloned blastocysts

    DEFF Research Database (Denmark)

    Du, Yutao; Zhang, Yunhai; Li, Juan;

    2007-01-01

    )â€"handmade cloning (HMC)â€"to establish a simplified and efficient cryopreservation system for porcine cloned embryos. In Experiment 1, zonae pellucidae of oocytes were partially digested with pronase, followed by centrifugation to polarize lipid particles. Ninety percent (173/192) oocytes were successfully......). Our results prove that porcine embryos produced from delipated oocytes by PA or HMC can be cryopreserved effectively by ultrarapid vitrification. Further experiments are required to assess the in vivo developmental competence of the cloned-vitrified embryos  ...

  16. Maximum confidence measurements via probabilistic quantum cloning

    Institute of Scientific and Technical Information of China (English)

    Zhang Wen-Hai; Yu Long-Bao; Cao Zhuo-Liang; Ye Liu

    2013-01-01

    Probabilistic quantum cloning (PQC) cannot copy a set of linearly dependent quantum states.In this paper,we show that if incorrect copies are allowed to be produced,linearly dependent quantum states may also be cloned by the PQC.By exploiting this kind of PQC to clone a special set of three linearly dependent quantum states,we derive the upper bound of the maximum confidence measure of a set.An explicit transformation of the maximum confidence measure is presented.

  17. Antimicrobial activity of tigecycline against community-acquired methicillin-resistant Staphylococcus aureus isolates recovered from North American medical centers.

    Science.gov (United States)

    Mendes, Rodrigo E; Sader, Helio S; Deshpande, Lalitagauri; Jones, Ronald N

    2008-04-01

    A total of 1989 community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) were susceptibility tested by broth microdilution. Pulsed-field gel electrophoresis, SCCmec type, and polymerase chain reaction for Panton-Valentine leukocidin (PVL) genes were also performed. The overall tigecycline susceptibility rate was 98.2%. Glycopeptides, quinupristin/dalfopristin, linezolid, and chloramphenicol were also active against this collection (< or =0.7% resistant). The vast majority (70.8%) of the CA-MRSA was SCCmec type IV, from which 88.4% belonged to the USA300-0114 clone and 94.7% were PVL positive. Tigecycline showed in vitro activity comparable with other highly active parenteral agents and represents an option for treating complicated infections caused by CA-MRSA. PMID:18068326

  18. The presence of heterogeneous vancomycin-lntermediate Staphylococcus aureus (heteroVISA) in a major Malaysian hospital.

    Science.gov (United States)

    Norazah, Ahmad; Law, Ngiik Ling; Kamel, Abd Ghani Mohamed; Salbiah, Nawi

    2012-06-01

    This study was conducted to detect the presence of heterogenous vancomycin-intermediate Staphylococcus aureus (heteroVISA) among MRSA isolates in a major hospital. Forty-three MRSA isolates with vancomycin MIC 2 microg/ml collected in 2009 was screened for heteroVISA using Etest Glycopeptide Resistance Detection (GRD) and confirmed by population analysis profile-area under curve method. The genetic relatedness of heteroVISA strains with other MRSA was examined by pulsed-field gel electrophoresis (PFGE) method. Two isolates were shown to be heteroVISA and derived from the same clone. This showed that heteroVISA strains were already present among our local strains since 2009 and were genetically related to other susceptible strains.

  19. Detecção de Staphylococcus aureus utilizando a técnica de REP-PCR no monitoramento da qualidade do leite de cabra Detection of Staphylococcus aureus using the REP-PCR technique to monitor goat milk quality

    Directory of Open Access Journals (Sweden)

    Cellyneude de Souza Olivindo

    2009-07-01

    Full Text Available Este estudo foi realizado com o objetivo de aplicar a técnica de REP-PCR no monitoramento da qualidade do leite de cabra por meio da detecção de Staphylococcus aureus em amostras de mãos de ordenhador, tetos das cabras, leite, ordenhadeira e água para estabelecimento e implantação do sistema de Análise de Perigos e Pontos Críticos de Controle (APPCC. Verificaram-se vários fingerprints de todos os isolados coletados das diferentes fontes estudadas (mãos de ordenhador, tetos das cabras, leite, ordenhadeira e água. Observaram-se comportamentos muito similares das bandas, o que indica que os isolados podem ser relatados como clones epidemiológicos. As mãos do ordenhador caracterizaram-se como ponto crítico de controle, pois se destacaram como iniciador de contaminação nas amostras Staphylococcus aureus. A técnica demonstrou ser eficiente para a análise da similaridade entre indivíduos da espécie Staphylococcus aureus e, portanto, constitui ferramenta útil para investigação de falhas no manejo e na busca de controle mais eficiente para evitar ou reduzir a disseminação de microrganismos patogênicos causadores de sérias enfermidades em humanos e animais, que muitas vezes podem ser transmitidas por produtos como o leite e seus derivados.The objective of the present study was to apply REP-PCR sequences in the monitoring goat milk quality, by detecting Staphylococcus aureus, in samples of from milker hands, goat teats, milk, milking machine and water, for the future establishment and implantation of the system of Hazard Analysis Critical Control Points (HACCP. Several fingerprints were verified of all the isolates collected from the different sources studied (milker hands, goat teats, milk, milking machine and water. Very similar band behaviors were observed that indicated that the isolates can be reported as epidemic clones. Milker´s hands were was characterized as a critical control point (CCP, because it stands out as an

  20. Molecular architecture of the regulatory Locus sae of Staphylococcus aureus and its impact on expression of virulence factors.

    Science.gov (United States)

    Steinhuber, Andrea; Goerke, Christiane; Bayer, Manfred G; Döring, Gerd; Wolz, Christiane

    2003-11-01

    We characterized the sae operon, a global regulator for virulence gene expression in Staphylococcus aureus. A Tn917 sae mutant was obtained by screening a Tn917 library of the agr mutant ISP479Mu for clones with altered hemolytic activity. Sequence analysis of the sae operon revealed two additional open reading frames (ORFs) (ORF3 and ORF4) upstream of the two-component regulatory genes saeR and saeS. Four overlapping sae-specific transcripts (T1 to T4) were detected by Northern blot analysis, and the transcriptional initiation points were mapped by primer extension analysis. The T1, T2, and T3 mRNAs are probably terminated at the same stem-loop sequence downstream of saeS. The T1 message (3.1 kb) initiates upstream of ORF4, T2 (2.4 kb) initiates upstream of ORF3, and T3 (2.0 kb) initiates in front of saeR. T4 (0.7 kb) represents a monocistronic mRNA encompassing ORF4 only. sae-specific transcripts were detectable in all of the 40 different clinical S. aureus isolates investigated. Transcript levels were at maximum during the post-exponential growth phase. The sae mutant showed a significantly reduced rate of invasion of human endothelial cells, consistent with diminished transcription and expression of fnbA. The expression of type 5 capsular polysaccharide is activated in the sae mutant of strain Newman, as shown by immunofluorescence and promoter-reporter fusion experiments. In summary, the sae operon constitutes a four-component regulator system which acts on virulence gene expression in S. aureus.

  1. Epidemiology of Emerging Methicillin-Resistant Staphylococcus aureus (MRSA) in Denmark: a Nationwide Study in a Country with Low Prevalence of MRSA Infection

    Science.gov (United States)

    Faria, Nuno A.; Oliveira, Duarte C.; Westh, Henrik; Monnet, Dominique L.; Larsen, Anders R.; Skov, Robert; de Lencastre, Hermínia

    2005-01-01

    Strict infection control measures introduced during the 1970s have kept the incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections extremely low in Denmark. Nevertheless, similarly to other countries, MRSA infections began to appear in the community in the late 1990s. A nationwide surveillance program has collected and stored all MRSA isolates since 1988 and, since 1999, clinical information has been also recorded. We used this information and isolates in a detailed epidemiological and molecular analysis of the 81 MRSA infections identified in Denmark in 2001. MRSA isolates were characterized by pulsed-field gel electrophoresis (PFGE), spa typing, multilocus sequence typing, and SCCmec typing. Comparison of the 45 community-onset MRSA (CO-MRSA) infections with the 36 hospital-acquired MRSA (HA-MRSA) infections showed several striking contrasts. Most CO-MRSA were recovered from skin and soft tissue infections caused by isolates carrying the Panton-Valentine leucocidin toxin genes, and the majority (84%) of isolates belonged to a single clonal type, ST80-IV, which has been found in the community in other European countries. Clone ST80-IV could be traced in Denmark back to 1993. ST80-IV was rarely found in HA-MRSA infections, which belonged to a large number of clonal types, including some pandemic MRSA clones. The low number of HA-MRSA infections and the diversity of MRSA clones in Danish hospitals may be the result of successful infection control measures that prevent spread of clones in hospitals. The mechanism of spread of the ST80-IV clone in the Danish community is not known, and new control measures are needed to control further spread of this and other CA-MRSA clones. PMID:15815005

  2. Molecular characterisation of methicillin-susceptible and methicillin-resistant Staphylococcus aureus in inpatients and outpatients in Bosnia and Herzegovina.

    Science.gov (United States)

    Uzunović-Kamberović, Selma; Rijnders, Michelle I A; Stobberingh, Ellen E; Ibrahimagić, Amir; Kamberović, Farah; Ille, Tatjana

    2013-01-01

    The aim of this study was to investigate the genetic background of methicillin-susceptible (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) obtained from clinical specimens of inpatients and outpatients. Methicillin resistance was confirmed by the presence of the mecA gene by PCR. The genetic characterisation was performed using spa typing and the algorithm based upon repeat pattern (BURP). Staphylococcus aureus was isolated from 68 and 79 inpatient and outpatient samples, 31 (46 %) and 14 (18 %) of which were MRSA, respectively. Among 37 inpatients and 65 outpatients with MSSA, 22 and 38 spa types were clustered into seven and eight spa-CCs, respectively. The main MSSA spa-CC of inpatients and outpatients was spa-CC015 (multilocus sequence typing (MLST) CC45). Most MRSA were associated with spa-CC355/595 (MLST CC152). MRSA-related background was found in 32 % of inpatients and 43 % of outpatients with MSSA, suggesting that MRSA did not arise from predominant MSSA clones. PMID:23053564

  3. 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.

  4. 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.

  5. 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.

  6. Cloning and characterization of new bioluminescent proteins

    Science.gov (United States)

    Szent-Gyorgyi, Christopher; Ballou, Byron T.; Dagnal, Erich; Bryan, Bruce

    1999-07-01

    Over the past two years Prolume has undertaken a comprehensive program to clone luciferases and associated 'green fluorescent proteins' (GFPs) from marine animals that use coelenterazine as the luciferin. To data we have cloned several bioluminescent proteins, including two novel copepod luciferases and two anthozoan GFPs. These four proteins have sequences that differ greatly form previously cloned analogous proteins; the sequence diversity apparently is due to independent evolutionary origins and unusual evolutionary constraints. Thus coelenterazine-based bioluminescent systems may also manifest a variety of useful properties. We discuss form this taxonomic perspective the initial biochemical and spectral characterization of our cloned proteins. Emphasis is placed on the anthozoan luciferase-GFP systems, whose efficient resonance energy transfer has elicited much current interest.

  7. A genetic system for direct selection of gene-positive clones during recombinational cloning in yeast

    OpenAIRE

    Noskov, Vladimir; Kouprina, Natalay; Leem, Sun-Hee; Koriabine, Maxim; Barrett, J. Carl; Larionov, Vladimir

    2002-01-01

    Transformation-associated recombination (TAR) is a cloning technique that allows specific chromosomal regions or genes to be isolated directly from genomic DNA without prior construction of a genomic library. This technique involves homologous recombination during spheroplast transformation between genomic DNA and a TAR vector that has 5′ and 3′ gene targeting sequences (hooks). Typically, TAR cloning produces positive YAC recombinants at a frequency of ∼0.5%; the positive clones are identifi...

  8. IVA cloning: A single-tube universal cloning system exploiting bacterial In Vivo Assembly

    OpenAIRE

    Javier García-Nafría; Watson, Jake F.; Greger, Ingo H.

    2016-01-01

    In vivo homologous recombination holds the potential for optimal molecular cloning, however, current strategies require specialised bacterial strains or laborious protocols. Here, we exploit a recA-independent recombination pathway, present in widespread laboratory E.coli strains, to develop IVA ( In Vivo Assembly) cloning. This system eliminates the need for enzymatic assembly and reduces all molecular cloning procedures to a single-tube, single-step PCR, performed in

  9. Recombinatorial Cloning Using Heterologous Lox Sites

    OpenAIRE

    Siegel, Robert W.; Velappan, Nileena; Pavlik, Peter; Chasteen, Leslie; Bradbury, Andrew

    2004-01-01

    Recombination systems based on λ and Cre/loxP have been described to facilitate gene transfer from one vector to another in a high-throughput fashion, avoiding the bottlenecks associated with traditional cloning. However, no system described to date is suitable for the cloning of affinity reagents selected from display libraries, which requires that the recombination signals flanking the affinity reagent are translated with a minimum impact on functionality. As affinity reagents will be essen...

  10. Teleportation using continuous variable quantum cloning machine

    OpenAIRE

    Adhikari, Satyabrata

    2008-01-01

    We show that an unknown quantum state in phase space can be teleported via three-mode entanglement generated by continuous variable quantum cloning machine (transformation). Further, proceeding with our teleportation protocol we are able to improve the fidelity of teleportation obtained by Loock et.al. [Phys.Rev.Lett. 84, 3482(2000)]. Also we study here the entanglement between the two output copies from cloning machine.

  11. Towards Clone Detection in UML Domain Models

    DEFF Research Database (Denmark)

    Störrle, Harald

    2013-01-01

    on the thorough analysis of practical scenarios. We propose a formal definition of model clones, specify a clone detection algorithm for UML domain models, and implement it prototypically. We investigate different similarity heuristics to be used in the algorithm, and report the performance of our approach. While...... we believe that our approach advances the state of the art significantly, it is restricted to UML models, its results leave room for improvements, and there is no validation by field studies....

  12. Is There a Constitutional Right to Clone?

    OpenAIRE

    Sunstein, Cass Robert

    2002-01-01

    Recent scientific innovations, and proposed legislation, have raised questions about the nature of the constitutional right to reproductive freedom, and in particular about whether there is a constitutional “right to clone.” This essay urges that as a matter of substantive due process, rationality review is probably appropriate, and that restrictions on both reproductive and therapeutic cloning would and should survive constitutional scrutiny. At the same time, many of the arguments for banni...

  13. Bacteriophage Lambda as a Cloning Vector

    OpenAIRE

    Chauthaiwale, V M; Therwath, A; Deshpande, V V

    1993-01-01

    Extensive research has been directed toward the development of multipurpose lambda vectors for cloning ever since the potential of using coliphage lambda as a cloning vector was recognized in the late 1970s. An understanding of the intrinsic molecular organization and of the genetic events which determine lysis or lysogeny in lambda has allowed investigators to modify it to suit the specific requirements of gene manipulations. Unwanted restriction sites have been altered and arranged together...

  14. Economical phase-covariant cloning with multiclones

    Institute of Scientific and Technical Information of China (English)

    Zhang Wen-Hai; Ye Liu

    2009-01-01

    This paper presents a very simple method to derive the explicit transformations of the optimal economical to M phase-covariant cloning. The fidelity of clones reaches the theoretic bound [D'Ariano G M and Macchiavello C 2003 Phys. Rcv. A 67 042306]. The derived transformations cover the previous contributions [Delgado Y,Lamata L et al,2007 Phys. Rev. Lett. 98 150502] in which M must be odd.

  15. Do Clones Dream of Love? Images of Clones in Popular Culture

    Directory of Open Access Journals (Sweden)

    Dragana Antonijević

    2016-02-01

    Full Text Available Fantasies about clones, cyborgs and androids have become part and parcel of the mythology of modern times – the mythologies of the biotechnological era in which the achievements of genetic engineering have inflamed fears of possible abuse of scientific knowledge and the consequences of such abuse. The paper considers the phenomenon of reproductive cloning of human beings as it is represented in popular culture, especially film as it is one of the most important sources of representations and constructions of ideas about clones. After the introductory consideration of this phenomenon in scientific, ethical and media debates which are imbued with rejection of reproductive cloning, I have analyzed the different uses of the clone motif in selected movies. I have examined the structure and content of the genre formula of "social melodrama" which is present in films about clones, and have analyzed the mythical patterns pertaining to the topic of cloning, such as the myth of immortality, the myth of twins, the myth of the uniqueness of human kind etc. Ultimately, the nature and origins of the fear of clones and disgust that clones cause have been examined, and it has been shown that they mostly boil down to the fear of the dehumanization of human beings, the fear of the loss of difference and the transgression of biological, sociocultural and metaphysical boundaries.

  16. [Community associated-methicillin-resistant Staphylococcus aureus (SAMR-AC): comunication of the first four pediatric cases in the Roberto del Rio Children's Hospital].

    Science.gov (United States)

    Acuña, Mirta; Benadof, Dona; Jadue, Carla; Hormazábal, Juan C; Alarcón, Pedro; Contreras, Julio; Torres, Ramón; Mülchi, Cristóbal; Aguayo, Carolina; Fernández, Jorge; Araya, Pamela

    2015-06-01

    Staphylococcus aureus is a known pathogen in pediatric patients that produces skin infections, cutaneous abscess, cellulitis and osteoarticular infections. Most of these infections are produced by a meticilin susceptible strain. The community associated methicillin resistant Staphylococcus aureus was published for the first time in 1993, ever since then is has been recognized as a cosmopolite pathogen. The first report in Latin America was published in 2003, and in Chile in 2008 from adult patients that have reported traveling to other countries. The following series describes four pediatric cases, all school-aged children, diagnosed since 2012 with clinical followups and molecular studies. Two cases presented as osteomyelitis of the lower extremity; and one presented as arm cellulitis. These three cases had Panton Valentine leukocidine (PV-L) negative strains from the clone complex 8. The last case presented a renal abscess, the strain was PV-L positive from the clone complex 30. This case series constitutes the first pediatric case report in Chile. PMID:26230445

  17. Antibacterial activity of defensin PaDef from avocado fruit (Persea americana var. drymifolia) expressed in endothelial cells against Escherichia coli and Staphylococcus aureus.

    Science.gov (United States)

    Guzmán-Rodríguez, Jaquelina Julia; López-Gómez, Rodolfo; Suárez-Rodríguez, Luis M; Salgado-Garciglia, Rafael; Rodríguez-Zapata, Luis C; Ochoa-Zarzosa, Alejandra; López-Meza, Joel E

    2013-01-01

    Antimicrobial therapy is a useful tool to control infectious diseases in general and rising antibiotic resistant microorganisms in particular. Alternative strategies are desirable, and antimicrobial peptides (AMP) represent attractive control agents. Mexican avocado (Persea americana var. drymifolia) is used in traditional medicine; however, the AMP production has not been reported in this plant. We obtained a cDNA library from avocado fruit and clone PaDef was identified, which has a cDNA (249 bp) encoding a protein (78 aa) homologous with plant defensins (>80%). We expressed the defensin PaDef cDNA (pBME3) in the bovine endothelial cell line BVE-E6E7. Polyclonal and clonal populations were obtained and their activity was evaluated against Escherichia coli, Staphylococcus aureus, and Candida albicans. E. coli viability was inhibited with 100 μg/mL of total protein from clones (>55%). Also, S. aureus viability was inhibited from 50 μg/mL total protein (27-38%) but was more evident at 100 μg/mL (52-65%). This inhibition was higher than the effect showed by polyclonal population (~23%). Finally, we did not detect activity against C. albicans. These results are the first report that shows antimicrobial activity of a defensin produced by avocado and suggest that this AMP could be used in the control of pathogens.

  18. Antibacterial Activity of Defensin PaDef from Avocado Fruit (Persea americana var. drymifolia Expressed in Endothelial Cells against Escherichia coli and Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Jaquelina Julia Guzmán-Rodríguez

    2013-01-01

    Full Text Available Antimicrobial therapy is a useful tool to control infectious diseases in general and rising antibiotic resistant microorganisms in particular. Alternative strategies are desirable, and antimicrobial peptides (AMP represent attractive control agents. Mexican avocado (Persea americana var. drymifolia is used in traditional medicine; however, the AMP production has not been reported in this plant. We obtained a cDNA library from avocado fruit and clone PaDef was identified, which has a cDNA (249 bp encoding a protein (78 aa homologous with plant defensins (>80%. We expressed the defensin PaDef cDNA (pBME3 in the bovine endothelial cell line BVE-E6E7. Polyclonal and clonal populations were obtained and their activity was evaluated against Escherichia coli, Staphylococcus aureus, and Candida albicans. E. coli viability was inhibited with 100 μg/mL of total protein from clones (>55%. Also, S. aureus viability was inhibited from 50 μg/mL total protein (27–38% but was more evident at 100 μg/mL (52–65%. This inhibition was higher than the effect showed by polyclonal population (~23%. Finally, we did not detect activity against C. albicans. These results are the first report that shows antimicrobial activity of a defensin produced by avocado and suggest that this AMP could be used in the control of pathogens.

  19. Antibacterial activity of defensin PaDef from avocado fruit (Persea americana var. drymifolia) expressed in endothelial cells against Escherichia coli and Staphylococcus aureus.

    Science.gov (United States)

    Guzmán-Rodríguez, Jaquelina Julia; López-Gómez, Rodolfo; Suárez-Rodríguez, Luis M; Salgado-Garciglia, Rafael; Rodríguez-Zapata, Luis C; Ochoa-Zarzosa, Alejandra; López-Meza, Joel E

    2013-01-01

    Antimicrobial therapy is a useful tool to control infectious diseases in general and rising antibiotic resistant microorganisms in particular. Alternative strategies are desirable, and antimicrobial peptides (AMP) represent attractive control agents. Mexican avocado (Persea americana var. drymifolia) is used in traditional medicine; however, the AMP production has not been reported in this plant. We obtained a cDNA library from avocado fruit and clone PaDef was identified, which has a cDNA (249 bp) encoding a protein (78 aa) homologous with plant defensins (>80%). We expressed the defensin PaDef cDNA (pBME3) in the bovine endothelial cell line BVE-E6E7. Polyclonal and clonal populations were obtained and their activity was evaluated against Escherichia coli, Staphylococcus aureus, and Candida albicans. E. coli viability was inhibited with 100 μg/mL of total protein from clones (>55%). Also, S. aureus viability was inhibited from 50 μg/mL total protein (27-38%) but was more evident at 100 μg/mL (52-65%). This inhibition was higher than the effect showed by polyclonal population (~23%). Finally, we did not detect activity against C. albicans. These results are the first report that shows antimicrobial activity of a defensin produced by avocado and suggest that this AMP could be used in the control of pathogens. PMID:24319695

  20. 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....

  1. Molecular typing of toxic shock syndrome toxin-1- and Enterotoxin A-producing methicillin-sensitive Staphylococcus aureus isolates from an outbreak in a neonatal intensive care unit.

    Science.gov (United States)

    Layer, Franziska; Sanchini, Andrea; Strommenger, Birgit; Cuny, Christiane; Breier, Ann-Christin; Proquitté, Hans; Bührer, Christoph; Schenkel, Karl; Bätzing-Feigenbaum, Jörg; Greutelaers, Benedikt; Nübel, Ulrich; Gastmeier, Petra; Eckmanns, Tim; Werner, Guido

    2015-10-01

    Outbreaks of Staphylococcus aureus are common in neonatal intensive care units (NICUs). Usually they are documented for methicillin-resistant strains, while reports involving methicillin-susceptible S. aureus (MSSA) strains are rare. In this study we report the epidemiological and molecular investigation of an MSSA outbreak in a NICU among preterm neonates. Infection control measures and interventions were commissioned by the Local Public Health Authority and supported by the Robert Koch Institute. To support epidemiological investigations molecular typing was done by spa-typing and Multilocus sequence typing; the relatedness of collected isolates was further elucidated by DNA SmaI-macrorestriction, microarray analysis and bacterial whole genome sequencing. A total of 213 neonates, 123 healthcare workers and 205 neonate parents were analyzed in the period November 2011 to November 2012. The outbreak strain was characterized as a MSSA spa-type t021, able to produce toxic shock syndrome toxin-1 and Enterotoxin A. We identified seventeen neonates (of which two died from toxic shock syndrome), four healthcare workers and three parents putatively involved in the outbreak. Whole-genome sequencing permitted to exclude unrelated cases from the outbreak and to discuss the role of healthcare workers as a reservoir of S. aureus on the NICU. Genome comparisons also indicated the presence of the respective clone on the ward months before the first colonized/infected neonates were detected.

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

    Science.gov (United States)

    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

  3. Cloning: Past, Present, and the Exciting Future. Breakthroughs in Bioscience.

    Science.gov (United States)

    Di Berardino, Marie A.

    This document explores the history of cloning by focusing on Dolly the Sheep, one of the first large animal clonings. The disadvantages and advantages of transgenic clones are discussed as well as the future implications of cloning from the perspective of human health. (Contains 10 resources.) (YDS)

  4. Public perceptions of farm animal cloning in Europe

    OpenAIRE

    Lassen, Jesper

    2005-01-01

    This report presents a picture of European opinion on farm animal cloning. In the report, both agricultural and biomedical applications of farm animal cloning are considered. With the arrival of Dolly, animal cloning became an integral part of the biotech debate, but this debate did not isolate animal cloning as a single issue.

  5. Assessment of genetic diversity within sour cherry clones

    DEFF Research Database (Denmark)

    Clausen, Sabine Karin; Andersen, Sven Bode; Henriksen, K.;

    2013-01-01

    Harvested yields of sour cherry (Prunus cerasus) cultivar ‘Stevnsbaer’ clones grown in Denmark have been highly variable over the years, yet some propagated derived trees selected from within the two widely grown clones of ‘Stevnsbaer’ clone ‘Birgitte’ and clone ‘Viki’ have consistently produced...

  6. Universal Quantum Cloning Machines for Two Identical Mixed Qubits

    Institute of Scientific and Technical Information of China (English)

    YANG Shuai; ZHAO Mei-Sheng; LIU Nai-Le; CHEN Zeng-Bing

    2007-01-01

    We present a series of universal quantum cloning machines for two identical mixed qubits. Every machine is optimal in the sense that it achieves the optimal bound of the single copy shrinking factor. Unlike in the case of pure state cloning, the single copy shrinking factor does not uniquely determine the cloning map in the case of mixed state cloning.

  7. Public perceptions of farm animal cloning in Europe

    DEFF Research Database (Denmark)

    Lassen, Jesper

    This report presents a picture of European opinion on farm animal cloning. In the report, both agricultural and biomedical applications of farm animal cloning are considered. With the arrival of Dolly, animal cloning became an integral part of the biotech debate, but this debate did not isolate...... animal cloning as a single issue....

  8. Typing of Panton-Valentine Leukocidin-encoding Phages and lukSF-PV Gene Sequence Variation in Staphylococcus aureus from China

    Directory of Open Access Journals (Sweden)

    Huanqiang Zhao

    2016-08-01

    Full Text Available Panton-Valentine leucocidin (PVL, encoded by lukSF-PV genes, a bi-component and pore-forming toxin, is carried by different staphylococcal bacteriophages. The prevalence of PVL in Staphylococcus aureus (S. aureus have been reported around the globe. However, the data on PVL-encoding phage types, lukSF-PV gene variation and chromosomal phage insertion sites for PVL-positive S. aureus are limited, especially in China. In order to obtain a more complete understanding of the molecular epidemiology of PVL-positive S. aureus, an integrated and modified PCR-based scheme was applied to detect the PVL-encoding phage types. Phage insertion locus and the lukSF-PV variant were determined by PCR and sequencing. Meanwhile, the genetic background was characterized by staphylococcal cassette chromosome mec (SCCmec typing, staphylococcal protein A (spa gene polymorphisms typing, pulsed-field gel electrophoresis (PFGE typing, accessory gene regulator (agr locus typing and multilocus sequence typing (MLST. Seventy eight (78/1175, 6.6% isolates possessed the lukSF-PV genes and 59.0% (46/78 of PVL-positive strains belonged to CC59 lineage. Eight known different PVL-encoding phage types were detected, and Φ7247PVL/ΦST5967PVL (n=13 and ΦPVL (n=12 were the most prevalent among them. While 25 (25/78, 32.1% isolates, belonging to ST30 and ST59 clones, were unable to be typed by the modified PCR-based scheme. Single nucleotide polymorphisms (SNPs were identified at five locations in the lukSF-PV genes, two of which were non-synonymous. Maximum-likelihood tree analysis of attachment sites sequences detected six SNP profiles for attR and eight for attL, respectively. In conclusion, the PVL-positive S. aureus mainly harbored Φ7247PVL/ΦST5967PVL and ΦPVL in the regions studied. lukSF-PV gene sequences, PVL-encoding phages and phage insertion locus generally varied with lineages. Moreover, PVL-positive clones that have emerged worldwide likely carry distinct phages.

  9. [Ethical considerations on human cloning. A psychoanalytic perspective].

    Science.gov (United States)

    Alvarez, A

    2000-01-01

    A brief review of ethical issues related to two types of human cloning is presented: cloning embryonic cells not intended to culminate in the birth of a new individual and cloning human beings. Advantages and objections related to both types of human cloning are analyzed from an ethical point of view. Repercussions on individuals born by the technique of cloning are discussed from a psychoanalytical perspective. It can be concluded that cloning embryonic cells could be admissible, while not cloning considered as a reproductive option.

  10. 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.

  11. A systematic review of animal models for Staphylococcus aureus osteomyelitis

    Directory of Open Access Journals (Sweden)

    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.

  12. 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

  13. 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

  14. Prevalence and Trends of Staphylococcus aureus Bacteraemia in Hospitalized Patients in South Africa, 2010 to 2012: Laboratory-Based Surveillance Mapping of Antimicrobial Resistance and Molecular Epidemiology.

    Directory of Open Access Journals (Sweden)

    Olga Perovic

    Full Text Available We aimed to obtain an in-depth understanding on recent antimicrobial resistance trends and molecular epidemiology trends of S. aureus bacteraemia (SAB.Thirteen academic centres in South Africa were included from June 2010 until July 2012. S. aureus susceptibility testing was performed on the MicroScan Walkaway. Real-time PCR using the LightCycler 480 II was done for mecA and nuc. SCCmec and spa-typing were finalized with conventional PCR. We selected one isolate per common spa type per province for multilocus sequence typing (MLST.S. aureus from 2709 patients were included, and 1231 (46% were resistant to methicillin, with a significant decline over the three-year period (p-value = 0.003. Geographical distribution of MRSA was significantly higher in Gauteng compared to the other provinces (P<0.001. Children <5 years were significantly associated with MRSA with higher rates compared to all other age groups (P = 0.01. The most prevalent SCCmec type was SCCmec type III (531 [41%] followed by type IV (402 [31%]. Spa-typing discovered 47 different spa-types. The five (87% most common spa-types were t037, t1257, t045, t064 and t012. Based on MLST, the commonest was ST612 clonal complex (CC8 (n = 7 followed by ST5 (CC5 (n = 4, ST36 (CC30 (n = 4 and ST239 (CC8 (n = 3.MRSA rate is high in South Africa. Majority of the isolates were classified as SCCmec type III (41% and type IV (31%, which are typically associated with hospital and community- acquired infections, respectively. Overall, this study reveals the presence of a variety of hospital-acquired MRSA clones in South Africa dominance of few clones, spa 037 and 1257. Monitoring trends in resistance and molecular typing is recommended to detect changing epidemiological trends in AMR patterns of SAB.

  15. Prevalence and Trends of Staphylococcus aureus Bacteraemia in Hospitalized Patients in South Africa, 2010 to 2012: Laboratory-Based Surveillance Mapping of Antimicrobial Resistance and Molecular Epidemiology

    Science.gov (United States)

    Perovic, Olga; Iyaloo, Samantha; Kularatne, Ranmini; Lowman, Warren; Bosman, Noma; Wadula, Jeannette; Seetharam, Sharona; Duse, Adriano; Mbelle, Nontombi; Bamford, Colleen; Dawood, Halima; Mahabeer, Yesholata; Bhola, Prathna; Abrahams, Shareef; Singh-Moodley, Ashika

    2015-01-01

    Introduction We aimed to obtain an in-depth understanding on recent antimicrobial resistance trends and molecular epidemiology trends of S. aureus bacteraemia (SAB). Methods Thirteen academic centres in South Africa were included from June 2010 until July 2012. S. aureus susceptibility testing was performed on the MicroScan Walkaway. Real-time PCR using the LightCycler 480 II was done for mecA and nuc. SCCmec and spa-typing were finalized with conventional PCR. We selected one isolate per common spa type per province for multilocus sequence typing (MLST). Results S. aureus from 2709 patients were included, and 1231 (46%) were resistant to methicillin, with a significant decline over the three-year period (p-value = 0.003). Geographical distribution of MRSA was significantly higher in Gauteng compared to the other provinces (P<0.001). Children <5 years were significantly associated with MRSA with higher rates compared to all other age groups (P = 0.01). The most prevalent SCCmec type was SCCmec type III (531 [41%]) followed by type IV (402 [31%]). Spa-typing discovered 47 different spa-types. The five (87%) most common spa-types were t037, t1257, t045, t064 and t012. Based on MLST, the commonest was ST612 clonal complex (CC8) (n = 7) followed by ST5 (CC5) (n = 4), ST36 (CC30) (n = 4) and ST239 (CC8) (n = 3). Conclusions MRSA rate is high in South Africa. Majority of the isolates were classified as SCCmec type III (41%) and type IV (31%), which are typically associated with hospital and community- acquired infections, respectively. Overall, this study reveals the presence of a variety of hospital-acquired MRSA clones in South Africa dominance of few clones, spa 037 and 1257. Monitoring trends in resistance and molecular typing is recommended to detect changing epidemiological trends in AMR patterns of SAB. PMID:26719975

  16. Nonlocal quantum cloning via quantum dots trapped in distant cavities

    Institute of Scientific and Technical Information of China (English)

    Yu Tao; Zhu Ai-Dong; Zhang Shou

    2012-01-01

    A scheme for implementing nonlocal quantum cloning via quantum dots trapped in cavities is proposed.By modulating the parameters of the system,the optimal 1 → 2 universal quantum cloning machine,1 → 2 phase-covariant cloning machine,and 1 → 3 economical phase-covariant cloning machine are constructed.The present scheme,which is attainable with current technology,saves two qubits compared with previous cloning machines.

  17. Clonal complex 398 methicillin susceptible Staphylococcus aureus: a frequent unspecialized human pathogen with specific phenotypic and genotypic characteristics.

    Directory of Open Access Journals (Sweden)

    Tomasz Chroboczek

    Full Text Available Clonal complex 398 livestok-associated-MRSA (CC398 LA-MRSA clone is described as a major animal pathogen that can also colonize and infect humans. CC398 methicillin susceptible Staphylococcus aureus (CC398 MSSA is less described. We identified 126 CC398 MSSA strains of human origin within 6380 S. aureus isolates gathered between 2009 and 2011, from the French National Reference Centre for Staphylococci. They were characterized using antimicrobial susceptibility testing, spa typing, DNA microarrays (Identibac S. aureus Genotyping ®, Alere, CC398-specific sequence PCR, ermT (encoding macrolides résistance PCR. Fifty-three CC398 LA-MRSA collected from French pigs and veal were used as comparators, and phylogenetic relations between human CC398 MSSA and animal CC398 MRSA populations were explored on the basis of spa-typing and DNA microarrays. CC398 MSSA were able to induce a large spectrum of infections (especially skin, bloodstream, and pneumonias. The prevalence rate of this clone was high in MSSA population, i.e., 24.7% in a local prospective study on nasal colonization, and 7.5% in a national prospective study on infective endocarditis. CC398 MSSA isolates were frequently (89% erythromycin resistant, due to the presence of the ermT gene, a gene not detected in erythromycin resistant CC398 LA-MRSA strains. Expression of staphylococcal complement inhibitor (scn and the chemotaxis inhibitory protein (chp, was also specific to this population. The CC398 MRSA signature included also a panel of antibiotic resistance genes, especially a type IV or V cassette mec and tetM. CC398 MSSA and CC398 LA-MRSA populations were closely related based on spa-typing and DNA microarrays, with the MRSA strains forming the most derived lineage in phylogenic trees. Both MSSA and MRSA populations may come from common ancestors, which would have evolved in the settings of different selective pressures, explaining the acquisition of ermT, chp and scn for MSSA, and

  18. Cloning and sequencing genes related to preeclampsia

    Institute of Scientific and Technical Information of China (English)

    SHI Juan-zi; LIU Yan-fang; YAO Yuan-qing; YAN Wei; ZHU Feng; ZHAO Zhong-liang

    2001-01-01

    To clone genes specifically expressed in the placenta of patients with preeclampsia, and to explain the mechanism in the etiopathology ofpreeclampsia. Methods: The placentae ofpreeclamptic and normotensive subjects with pregnancy were used as models, and the cDNA Library was constructed and 20 differentially expressed fragments were cloned after a new version of PCR-based subtractive hybridization. The false positive clones were identified by reverse dot blot analysis. With one of the obtained gene taken as the probe, the placentas of 10 normal pregnant women and 10 preeclamptic patients were studied by using dot hybridization methods. Results: Six false positive clones were identified by reverse dot blot, and the rest 14 clones were identified as preeclampsia-related genes. These clones were sequenced, and analyzed with BLAST analysis system. Eleven of 14 clones were genes already known, among which one belongs to necdin family; the rest 3 were identified as novel genes. These 3 genes were acknowledged by GenBank, with the accession numbers AF232216, AF232217, AF233648. The results of dot hybridization using necdin gene as probe were as follows: (1) There was this mRNA in the placental tissues of normal pregnancy as well as in that ofpreeclampsia.(2) The intensity of transcription of this mRNA in the placental tissues of preeclampsia increased significantly compared with that of the normal pregnancy (P<0.05). Conclusions: This study for the first time reported this group of genes, especially necdin-expressing gene, which are related to the etiopathology of preeclampsia. In addition, the overtranscription ofnecdin gene has been found in preeclampsia. It is helpful in further studies of the etiology ofpreeclampsia.

  19. 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

  20. Contribution of coagulases towards Staphylococcus aureus disease and protective immunity.

    Directory of Open Access Journals (Sweden)

    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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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

  15. 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...

  16. 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...

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. An assessment on DNA microarray and sequence-based methods for the characterization of methicillin-susceptible Staphylococcus aureus from Nigeria

    Directory of Open Access Journals (Sweden)

    Adebayo Osagie Shittu

    2015-10-01

    Full Text Available Staphylococcus aureus is an important human pathogen causing nosocomial and community-acquired infections worldwide. In the characterization of this opportunistic pathogen, DNA microarray hybridization technique is used as an alternative to sequence based genotyping to obtain a comprehensive assessment on the virulence, resistance determinants, and population structure. The objective of this study was to characterize a defined collection of S. aureus isolates from Nigeria using the microarray technique, and to assess the extent that it correlates with sequence-based genotyping methods. The clonal diversity and genomic content of 52 methicillin-susceptible Staphylococcus aureus (MSSA were investigated by spa typing, MLST and DNA microarray hybridization. More than half (55.8% of these isolates were associated with clonal complexes typically associated with methicillin-resistant S. aureus (MRSA clones i.e. CC1, CC5, CC8, CC30 and CC45. Certain genes linked with virulence (hlgA and clfA and adherence (ebpS, fnbA, sspA, sspB and sspP were detected in all isolates. A number of genes or gene clusters were associated with distinct clonal types. The enterotoxin gene cluster (egc was linked with CC5, CC25, CC30, CC45 and CC121, enterotoxin H gene (seh with CC1, exfoliative toxin D gene (etd with CC25 and CC80, and the epidermal cell differentiation inhibitor B gene (edinB with CC25, CC80 and CC152. The excellent agreement between data from DNA microarray and MLST in the delineation of Nigerian MSSA isolates indicates that the microarray technique is a useful tool to provide information on antibiotic resistance, clonal diversity and virulence factors associated with infection and disease.

  2. Pre-weaning performance and health of pigs born to cloned (fetal cell derived) swine versus non-cloned swine.

    Science.gov (United States)

    Martin, M; Adams, C; Wiseman, B

    2004-07-01

    The objective of this study was to compare the pre-weaning performance of pigs derived from cloned versus non-cloned parents. Five cloned gilts and one cloned boar were used to produce five litters of pigs. One of five cloned females and the cloned boar were derived from two genetically unmanipulated fetal fibroblast cell lines. The remaining female clones were derived from a fetal fibroblast cell line in which random insertion of a alpha-1,3-galactosyltransferase gene targeting construct had occurred. Fetal cell lines had similar genetic backgrounds and were derived from three different fetuses in three different litters. Five litters of pigs were also generated from matings between two non-cloned boars and five non-cloned gilts. The mean gestation length, mean litter size, mean birth and weaning weights for male and female pigs were similar for litters derived from cloned parents versus non-cloned parents. The proportions of pigs born live and pigs that survived to weaning were also similar for pigs born to cloned as compared to non-cloned parents. In summary, matings between cloned swine derived from fetal fibroblast cell lines yielded litters of pigs that were similar in the number born, piglet birth weight and perinatal and pre-weaning mortality to litters produced by non-cloned swine.

  3. Royana: Successful Experience in Cloning the Sheep

    Directory of Open Access Journals (Sweden)

    Saeed Kazemi Ashtiani

    2008-01-01

    Full Text Available Objective: This study describes our experiences in reproductive cloning using two differentprocedures resulting in birth of the first successfully cloned sheep in Iran and theMiddle-East, nick-named "Royana".Materials and Methods: Abattoir-derived sheep oocytes were enucleated after in vitromaturation for 18-20hrs and then reconstructed by ear-derived sheep somatic cells usingtwo different procedures of renucleation (subzonary, intracytoplasmic, embryo culture (coculture,sequential medium and embryo transfer (intra fallopian, intra uterine. Pregnancystatus and fetal development were followed regularly and elective cesarean was inductedon day 145 of pregnancy. Histopathological and genetical examinations were performedon either aborted and delivered clones for confirmation different aspects of cloning.Results: The two procedures were both efficient in producing early and/or advancedcloned embryos, establishing early and/or advanced stages of pregnancy till delivery. Fourpregnancies were detected; one were failed at early pregnancy, one aborted on day 90,one was still born and the fourth delivered to a healthy male lamb nick named "Royana".Conclusion: Many different approaches have been developed for mammalian cloningwhich all are judged by their ultimate potency for establishment of successful pregnanciesterminated to healthy/viable clones. As a preliminary study toward establishment ofthe technology, this study also successfully examined the competency of two proceduresof somatic cell nuclear transfer (SCNT. However, the overall low efficiency of SCNT indicatesthat many different aspects of the technology remain to be dissolved.

  4. Consensus maps of cloned plant cuticle genes

    Institute of Scientific and Technical Information of China (English)

    Eviatar; Nevo

    2010-01-01

    Plant cuticle,which covers the plant surface,consists of waxes and cutins,and is associated with plant drought,cold,and salt resistance.Hitherto,at least 47 genes participating in the formation of plant cuticle have been cloned from Arabidopsis thaliana,Oryza sativa,Zea mays,Ricinus communis,Brassica napus,and Medicago truncatula;and about 85% of them encode proteins sharing above 50% identities with their rice homologous sequences.These cloned cuticle genes were mapped in silico on different chromosomes of rice and Arabidopsis,respectively.The mapping results revealed that plant cuticle genes were not evenly distributed in both genomes.About 40% of the mapped cuticle genes were located on chromosome 1 in Arabidopsis,while 20% of the mapped cuticle genes were located on chromosome 2 but none on chromosome 12 in rice.Some cloned plant cuticle genes have several rice homologous sequences,which might be produced by chromosomal segment duplication.The consensus map of cloned plant cuticle genes will provide important clues for the selection of candidate genes in a positional cloning of an unknown cuticle gene in plants.

  5. Elephant grass clones for silage production

    Directory of Open Access Journals (Sweden)

    Rerisson José Cipriano dos Santos

    2013-02-01

    Full Text Available Ensiling warm-season grasses often requires wilting due to their high moisture content, and the presence of low-soluble sugars in these grasses usually demands the use of additives during the ensiling process. This study evaluated the bromatological composition of the fodder and silage from five Pennisetum sp. clones (IPA HV 241, IPA/UFRPE Taiwan A-146 2.114, IPA/UFRPE Taiwan A-146 2.37, Elephant B, and Mott. The contents of 20 Polyvinyl chloride (PVC silos, which were opened after 90 days of storage, were used for the bromatological analysis and the evaluation of the pH, nitrogen, ammonia, buffer capacity, soluble carbohydrates, and fermentation coefficients. The effluent losses, gases and dry matter recovery were also calculated. Although differences were observed among the clones (p < 0.05 for the concentrations of dry matter, insoluble nitrogen in acid detergents, insoluble nitrogen in neutral detergents, soluble carbohydrates, fermentation coefficients, and in vitro digestibility in the forage before ensiling, no differences were observed for most of these variables after ensiling. All of the clones were efficient in the fermentation process. The IPA/UFRPE TAIWAN A-146 2.37 clone, however, presented a higher dry matter concentration and the best fermentation coefficient, resulting in a better silage quality, compared to the other clones.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. High prevalence of hospital-associated methicillin-resistant Staphylococcus aureus in the community in Portugal: evidence for the blurring of community-hospital boundaries.

    Science.gov (United States)

    Tavares, A; Miragaia, M; Rolo, J; Coelho, C; de Lencastre, H

    2013-10-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of infection in the community (CA-MRSA), but in spite of its relevance, no data exist concerning its epidemiology in Portugal. In this study, we aimed to evaluate the prevalence, population structure, and origin of MRSA in the Portuguese community. A total of 527 isolates, both methicillin-susceptible S. aureus (MSSA) and MRSA, were collected from individuals with no healthcare-related risk factors attending 16 healthcare institutions in Portugal. Isolates were characterized for the presence of mecA, Panton-Valentine leukocidin (PVL), and arginine catabolic mobile element (ACME), and by staphylococcal cassette chromosome mec (SCCmec) typing, pulsed-field gel electrophoresis (PFGE), spa, and multilocus sequence typing (MLST). Susceptibility to a panel of 13 antibiotics was tested. Isolates relatedness was analyzed by goeBURST and BURP. We found a high frequency (21.6%) of MRSA in the community. However, only 11.4% of the isolates belonged to typical CA-MRSA epidemic clones (USA300, USA400, USA700, Southwest Pacific, European, and ST398). The remaining isolates, which constituted the great majority (88.6%), belonged to hospital-associated MRSA (HA-MRSA) epidemic clones, namely, to the EMRSA-15 clone (77.2%). PVL was rare and carried by 17 isolates only (five MRSA and 12 MSSA). In the whole collection, some MRSA and MSSA were highly related. The high frequency of MRSA in the community in Portugal seems to result mainly from dissemination from the hospital. They might also have emerged from an extant MSSA population, by SCCmec acquisition, or MRSA clonal introduction from abroad. PMID:23604782

  12. Prevalence and diversity of enterotoxin genes with genetic background of Staphylococcus aureus isolates from different origins in China.

    Science.gov (United States)

    Chao, Guoxiang; Bao, Guangyu; Cao, Yongzhong; Yan, Wenguang; Wang, Yan; Zhang, Xiaorong; Zhou, Liping; Wu, Yantao

    2015-10-15

    Staphylococcal enterotoxins (SE) induce toxin-mediated diseases, such as food poisoning. In the present study, 568 isolates from different sources were tested for the prevalence of 18 SE genes and performed spa typing. In addition, we characterized the relationships between the distribution of SE genes and molecular clones based on multilocus sequence typing (MLST), spa and staphylococcal cassette chromosome mec (SCCmec) typing in selected 250 isolates. Approximately 54.40% of the isolates from different sources harbored one or more SE genes forming 120 distinct gene profiles. Seven genes, sea, seb, seg, seo, sem, seq, and sel were more frequently detected. The distributions of the SE genes among the isolates from human, animals, and foodborne origins were highly different with isolates from environments (P0.05). We identified two important gene clusters, sea-sek-seq, which is closely related to hospital-acquired (HA) methicillin-resistant Staphylococcus aureus (MRSA)-III, and the egc cluster, which accounts for nearly half of all genes. Approximately 71% isolates could be typed by spa, yielding 103 spa types, of which 18 spa types were primary types. In clonal complex (CC) 239, an important Asian HA-MRSA-III clone from humans, nearly all isolates harbored complete or partial sea-sek-seq cluster; the main spa types were t030 and t037. In CC630, an important new community-associated (CA) MRSA-V CC in China, only sporadic SE genes, three main spa types, t4549, t2196, and t377 were observed. The egc cluster coexisting with other genes was present in isolates of CC5, CC9, CC1281, CC1301, CC30 and sequence type (ST) 25, but completely absent in isolates of CC239, CC59, CC7, and CC88. The results illustrate the genetic clonal diversity and the identity of S. aureus isolates from different sources with respect to SE genes and highlight a correlation between SE genes or gene clusters and CCs, spa, and MRSA clones. The foodborne and human origin isolates were the main

  13. Quantum cloning, Bell's inequality and teleportation

    International Nuclear Information System (INIS)

    We analyse the possibility of using the two-qubit output state from the Buzek-Hillery quantum copying machine (not necessarily a universal quantum cloning machine) as a teleportation channel. We show that there is a range of values of the machine parameter ξ for which the two-qubit output state is entangled and violates the Bell-CHSH inequality and for a different range it remains entangled but does not violate the Bell-CHSH inequality. Further, we observe that for certain values of the machine parameter the two-qubit mixed state can be used as a teleportation channel. The use of the output state from the Buzek-Hillery cloning machine as a teleportation channel provides an additional appeal to the cloning machine and motivation for our present work

  14. MOLECULAR CLONING OF HUMAN NEUROTROPHIN-4 GENE

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective Cloning and sequencing of the human neurotrophin-4(hNT-4) gene.Methods With the chromosomal DNA of human blood lymphocytes as template,hNT-4 coding genes were amplified by polymerase chain reaction(PCR) and recombinated into phage vector pGEM-T Easy,which were sequenced by using Sanger's single stranded DNA terminal termination method.Results The sequence of the cloned gene is completely the same as that reported in the literature(GenBank data base,M86528).Conclusion This study successfully cloning and sequenced the gene of mhNT-4,and it would be convenient for us to study the expression of mhNT-4 in eukaryote,and to continue the research on the gene therapy of Alzheimer's disease intensively.This study indicate that the hNT-4 is conservative in different races and individuals.

  15. THE CLONING OF HUMAN NEUROTROPHIN-3 GENE

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    In the present study, we have cloned the gene of human neurotrophin-3 (hNT-3) from the genomic DNA of white blood cells (WBC) by polymerase chain reaction (PCR). The amplification products were cloned into pUC19 and sequenced. Genomic sequence comparison of the cloned fragment and the reported hNT-3 (GenBank M61180) reveals 7 base differences: 1 in the signal peptide, 3 in the prepro peptide, and 3 in the mature hNT-3. Except the 2 varied bases (16th, T to G; 285th, A to C) in the signal peptide and pro-sequence resulted in the change of their encoded amino-acids (Tyr→Asp; Gln→His), the other varied bases have no influence on their respective encoded amino-acids, and all the changes have no influence on the open reading frame (ORF) of the hNT-3.

  16. Cloning for human reproduction: one American perspective.

    Science.gov (United States)

    Chester, R

    2001-09-01

    The author, an American law professor, believes that whole-body cloning of adult humans will be possible in the near future. He does not believe the procedure should be banned when used as a form of assisted reproduction, but that it should be regulated by the government to ensure proper testing and application. After raising a number of scientific, ethical, religious and legal issues, Professor Chester addresses parentage in light of both old and new concepts of the 'family.' Finally, he focuses on the problem of women as surrogate mothers of clones, arguing in the process that the surrogate, having no real genetic tie to the clone, would have less of a claim to parentage than at least some of the surrogates currently gestating foetuses.

  17. Human cloning: three mistakes and an alternative.

    Science.gov (United States)

    Baylis, Françoise

    2002-06-01

    The current debate on the ethics of cloning humans is both uninspired and uninspiring. In large measure this is because of mistakes that permeate the discourse, including the mistake of thinking that cloning technology is strictly a reproductive technology when it is used to create whole beings. As a result, the challenge this technology represents regarding our understanding of ourselves and the species to which we belong typically is inappropriately downplayed or exaggerated. This has meant that important (albeit disquieting) societal issues and species-type concerns have not been fully explored. This paper, intended as a corrective, suggests that we take an alternate view of human cloning as both an enhancement and a reproductive technology. This proposed shift in the framework for analysis counters the current narrow framing of the issues and introduces new questions about the prospect of modifying the species.

  18. Ultra-low background DNA cloning system.

    Directory of Open Access Journals (Sweden)

    Kenta Goto

    Full Text Available Yeast-based in vivo cloning is useful for cloning DNA fragments into plasmid vectors and is based on the ability of yeast to recombine the DNA fragments by homologous recombination. Although this method is efficient, it produces some by-products. We have developed an "ultra-low background DNA cloning system" on the basis of yeast-based in vivo cloning, by almost completely eliminating the generation of by-products and applying the method to commonly used Escherichia coli vectors, particularly those lacking yeast replication origins and carrying an ampicillin resistance gene (Amp(r. First, we constructed a conversion cassette containing the DNA sequences in the following order: an Amp(r 5' UTR (untranslated region and coding region, an autonomous replication sequence and a centromere sequence from yeast, a TRP1 yeast selectable marker, and an Amp(r 3' UTR. This cassette allowed conversion of the Amp(r-containing vector into the yeast/E. coli shuttle vector through use of the Amp(r sequence by homologous recombination. Furthermore, simultaneous transformation of the desired DNA fragment into yeast allowed cloning of this DNA fragment into the same vector. We rescued the plasmid vectors from all yeast transformants, and by-products containing the E. coli replication origin disappeared. Next, the rescued vectors were transformed into E. coli and the by-products containing the yeast replication origin disappeared. Thus, our method used yeast- and E. coli-specific "origins of replication" to eliminate the generation of by-products. Finally, we successfully cloned the DNA fragment into the vector with almost 100% efficiency.

  19. Photonic Programmable Tele-Cloning Network.

    Science.gov (United States)

    Li, Wei; Chen, Ming-Cheng

    2016-01-01

    The concept of quantum teleportation allows an unknown quantum states to be broadcasted and processed in a distributed quantum network. The quantum information injected into the network can be diluted to distant multi-copies by quantum cloning and processed by arbitrary quantum logic gates which were programed in advance in the network quantum state. A quantum network combines simultaneously these fundamental quantum functions could lead to new intriguing applications. Here we propose a photonic programmable telecloning network based on a four-photon interferometer. The photonic network serves as quantum gate, quantum cloning and quantum teleportation and features experimental advantage of high brightness by photon recycling. PMID:27353838

  20. Photonic Programmable Tele-Cloning Network

    Science.gov (United States)

    Li, Wei; Chen, Ming-Cheng

    2016-06-01

    The concept of quantum teleportation allows an unknown quantum states to be broadcasted and processed in a distributed quantum network. The quantum information injected into the network can be diluted to distant multi-copies by quantum cloning and processed by arbitrary quantum logic gates which were programed in advance in the network quantum state. A quantum network combines simultaneously these fundamental quantum functions could lead to new intriguing applications. Here we propose a photonic programmable telecloning network based on a four-photon interferometer. The photonic network serves as quantum gate, quantum cloning and quantum teleportation and features experimental advantage of high brightness by photon recycling.

  1. Information cloning of harmonic oscillator coherent states

    Indian Academy of Sciences (India)

    N D Hari Dass; Pradeep Ganesh

    2002-08-01

    We show that in the case of unknown harmonic oscillator coherent statesit is possible to achieve what we call perfect information cloning. By this we mean that it is still possible to make arbitrary number of copies of a state which has exactly the same information content as the original unknown coherent state. By making use of this perfect information cloning it would be possible to estimate the original state through measurements and make arbitrary number of copies of the estimator. We define the notion of a measurement fidelity and calculate it for our case as well as for the Gaussian cloners.

  2. Cloning arbuscule-related genes from mycorrhizas

    DEFF Research Database (Denmark)

    Burleigh, Stephen

    2000-01-01

    Until recently little was known about the identity of the genes expressed in the arbuscules of mycorrhizas, due in part to problems associated with cloning genes from the tissues of an obligate symbiont. However, the combination of advanced molecular techniques, innovative use of the materials...... available and fortuitous cloning has resulted in the recent identification of a number of arbuscule-related genes. This article provides a brief summary of the genes involved in arbuscule development, function and regulation, and the techniques used to study them. Molecular techniques include differential...

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. 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...

  13. 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...

  14. 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...

  15. 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…

  16. 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...

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. 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...

  2. 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

  3. 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 ...

  4. 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...

  5. 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.

  6. Quick and clean cloning: a ligation-independent cloning strategy for selective cloning of specific PCR products from non-specific mixes.

    Directory of Open Access Journals (Sweden)

    Frank Thieme

    Full Text Available We have developed an efficient strategy for cloning of PCR products that contain an unknown region flanked by a known sequence. As with ligation-independent cloning, the strategy is based on homology between sequences present in both the vector and the insert. However, in contrast to ligation-independent cloning, the cloning vector has homology with only one of the two primers used for amplification of the insert. The other side of the linearized cloning vector has homology with a sequence present in the insert, but nested and non-overlapping with the gene-specific primer used for amplification. Since only specific products contain this sequence, but none of the non-specific products, only specific products can be cloned. Cloning is performed using a one-step reaction that only requires incubation for 10 minutes at room temperature in the presence of T4 DNA polymerase to generate single-stranded extensions at the ends of the vector and insert. The reaction mix is then directly transformed into E. coli where the annealed vector-insert complex is repaired and ligated. We have tested this method, which we call quick and clean cloning (QC cloning, for cloning of the variable regions of immunoglobulins expressed in non-Hodgkin lymphoma tumor samples. This method can also be applied to identify the flanking sequence of DNA elements such as T-DNA or transposon insertions, or be used for cloning of any PCR product with high specificity.

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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...

  16. 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.

  17. China Succeeded in Somatic Cell Cloning

    Institute of Scientific and Technical Information of China (English)

    Song Jianlan

    2002-01-01

    @@ Chinese scientists have succeeded in cloning a colony of cattle from fully differentiated somatic cells. The news was announced jointly by the Chinese Academy of Sciences (CAS), National Natural Science Foundation of China (NSFC) and the government of Shandong Province at a press conference held on March 7, 2002.

  18. Genetic Crossing vs Cloning by Computer Simulation

    Science.gov (United States)

    Dasgupta, Subinay

    We perform Monte Carlo simulation using Penna's bit string model, and compare the process of asexual reproduction by cloning with that by genetic crossover. We find them to be comparable as regards survival of a species, and also if a natural disaster is simulated.

  19. Detecting Android Malware Using Clone Detection

    Institute of Scientific and Technical Information of China (English)

    陈健; Manar H. Alalfi; Member; ACM; IEEE; Thomas R. Dean; 邹颖

    2015-01-01

    Android is currently one of the most popular smartphone operating systems. However, Android has the largest share of global mobile malware and significant public attention has been brought to the security issues of Android. In this paper, we investigate the use of a clone detector to identify known Android malware. We collect a set of Android applications known to contain malware and a set of benign applications. We extract the Java source code from the binary code of the applications and use NiCad, a near-miss clone detector, to find the classes of clones in a small subset of the malicious applications. We then use these clone classes as a signature to find similar source files in the rest of the malicious applications. The benign collection is used as a control group. In our evaluation, we successfully decompile more than 1 000 malicious apps in 19 malware families. Our results show that using a small portion of malicious applications as a training set can detect 95% of previously known malware with very low false positives and high accuracy at 96.88%. Our method can effectively and reliably pinpoint malicious applications that belong to certain malware families.

  20. 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