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Sample records for environmental meticillin-resistant staphylococcus

  1. Meticillin-resistant Staphylococcus aureus (MRSA): screening and decolonisation.

    PubMed

    Cookson, Barry; Bonten, Marc J M; Mackenzie, Fiona M; Skov, Robert L; Verbrugh, Henri A; Tacconelli, Evelina

    2011-03-01

    Meticillin-resistant Staphylococcus aureus (MRSA) infections are of increasing importance to clinicians, public health agencies and governments. Prevention and control strategies must address sources in healthcare settings, the community and livestock. This document presents the conclusions of a European Consensus Conference on the role of screening and decolonisation in the control of MRSA infection. The conference was held in Rome on 5-6 March 2010 and was organised jointly by the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) and the International Society of Chemotherapy (ISC). In an environment where MRSA is endemic, universal or targeted screening of patients to detect colonisation was considered to be an essential pillar of any MRSA control programme, along with the option of decolonising carriers dependent on relative risk of infection, either to self or others, in a specific setting. Staff screening may be useful but is problematic as it needs to distinguish between transient carriage and longer-term colonisation. The consequences of identification of MRSA-positive staff may have important effects on morale and the ability to maintain staffing levels. The role of environmental contamination in MRSA infection is unclear, but screening may be helpful as an audit of hygiene procedures. In all situations, screening procedures and decolonisation carry a significant cost burden, the clinical value of which requires careful evaluation. European initiatives designed to provide further information on the cost/benefit value of particular strategies in the control of infection, including those involving MRSA, are in progress. PMID:21163631

  2. Meticillin-resistant Staphylococcus aureus isolated from Iranian hospitals: virulence factors and antibiotic resistance properties

    PubMed Central

    Momtaz, Hassan; Hafezi, Laleh

    2014-01-01

    Staphylococcus aureus is an important opportunistic pathogen responsible for a variety of diseases. Indiscriminate prescription of antibiotics caused severe antibiotic resistance especially against commonly used drugs. The present investigation was carried out to study the distribution of Panton-Valentine Leukocidin gene, SCCmec types and antibiotic resistance properties of meticillin-resistant Staphylococcus aureus isolated from Iranian hospitals. A total of 132 clinical specimens were collected from two major Iranian hospitals. Samples were cultured and their positive results were subjected to several PCR methods. The patterns of antibiotic resistance were studied using the disk diffusion method. We found that 66 out of 132 samples (50%) were positive for Staphylococcus aureus. The most commonly infected samples were superficial and surgical wounds (66.12%). The incidence of mecA, tetK, ermA, ermC, tetM, aacA-D, linA, msrA, vatA, vatC and vatB antibiotic resistance genes were 80.30%, 34.84%, 30.30%, 25.75%, 24.24%, 19.69%, 7.57%, 7.57%, 6.06%, 3.03% and 1.51%, respectively. Totally, 40.90% of isolates harbored the Panton-Valentine Leukocidin gene. Of 53 mec positive strains, the distribution of SCCmec V, SCCmec III, SCCmec IVa, SCCmec IVc and SCCmec IVb were 28 (52.83%), 13 (24.52%), 6 (11.32%), 4 (7.54%) and 2 (3.77%), respectively. All isolates were resistant to penicillin, cephalothin, cefazoline and ceftriaxone. The high levels of Staphylococcus aureus resistance against commonly used antibiotics as well as high presence of SCCmec types of meticillin-resistant virulent strains of Staphylococcus aureus suggest that infections with these strains require more advanced hospital care with emerging demand for novel antibiotics. PMID:25428674

  3. Emergence and resurgence of meticillin-resistant Staphylococcus aureus as a public-health threat.

    PubMed

    Grundmann, Hajo; Aires-de-Sousa, Marta; Boyce, John; Tiemersma, Edine

    2006-09-01

    Staphylococcus aureus is a gram-positive bacterium that colonises the skin and is present in the anterior nares in about 25-30% of healthy people. Dependent on its intrinsic virulence or the ability of the host to contain its opportunistic behaviour, S aureus can cause a range of diseases in man. The bacterium readily acquires resistance against all classes of antibiotics by one of two distinct mechanisms: mutation of an existing bacterial gene or horizontal transfer of a resistance gene from another bacterium. Several mobile genetic elements carrying exogenous antibiotic resistance genes might mediate resistance acquisition. Of all the resistance traits S aureus has acquired since the introduction of antimicrobial chemotherapy in the 1930s, meticillin resistance is clinically the most important, since a single genetic element confers resistance to the most commonly prescribed class of antimicrobials--the beta-lactam antibiotics, which include penicillins, cephalosporins, and carbapenems. PMID:16950365

  4. Higher prevalence of meticillin-resistant Staphylococcus aureus among dental students.

    PubMed

    Martínez-Ruíz, F J; Carrillo-Espíndola, T Y; Bustos-Martínez, J; Hamdan-Partida, A; Sánchez-Pérez, L; Acosta-Gío, A E

    2014-03-01

    In order to test the hypothesis that more dental students are meticillin-resistant Staphylococcus aureus (MRSA) carriers than non-dental students, 100 dental students with five to six years of exposure to patients and 81 non-dental students were tested for nasal and pharyngeal MRSA carriage by polymerase chain reaction. All 181 students were clinically healthy and none had taken antibiotics. Significantly more dental students (20/100) carried MRSA than non-dental students (5/81) (odds ratio: 4.04; 95% confidence interval: 1.6-12.6; P = 0.0033). Also, more dental students' mobile phones (8/100) carried MRSA. All MRSA isolates were distinguished by pulsed-field gel electrophoresis from epidemiologically significant strains. The results suggest that dental students are occupationally exposed to MRSA. PMID:24548405

  5. Isolation of meticillin-resistant Staphylococcus aureus (MRSA) from swine in Japan.

    PubMed

    Baba, Kotaro; Ishihara, Kanako; Ozawa, Manao; Tamura, Yutaka; Asai, Tetsuo

    2010-10-01

    Meticillin-resistant Staphylococcus aureus (MRSA) sequence type (ST) 398 is widely prevalent in swine in Europe and North America. To determine the prevalence of MRSA, and specifically ST398, in Japanese swine, a total of 115 nasal swabs and 115 faecal samples from swine reared at 23 farms located in eastern Japan were investigated. MRSA was isolated from a nasal sample (0.9%) but not from any faecal samples. The strain of MRSA was classified as ST221 by multilocus sequence typing and as t002 by spa typing. The MRSA isolate exhibited resistance to ampicillin, meticillin and dihydrostreptomycin. Interestingly, it remained susceptible to cefazolin, ceftiofur, imipenem, gentamicin, kanamycin, chloramphenicol, oxytetracycline, erythromycin, azithromycin, tylosin, vancomycin, enrofloxacin and trimethoprim. The prevalence of MRSA amongst swine was low and MRSA ST398 was not recovered in the present study. PMID:20692816

  6. Current concepts on the virulence mechanisms of meticillin-resistant Staphylococcus aureus

    PubMed Central

    David, Michael Z.; Salata, Robert A.

    2012-01-01

    Meticillin-resistant Staphylococcus aureus (MRSA) strains are prevalent bacterial pathogens that cause both health care and community-associated infections. Increasing resistance to commonly prescribed antibiotics has made MRSA a serious threat to public health throughout the world. The USA300 strain of MRSA has been responsible for an epidemic of community-associated infections in the US, mostly involving skin and soft tissue but also more serious invasive syndromes such as pneumonia, severe sepsis and endocarditis. MRSA strains are particularly serious and potentially lethal pathogens that possess virulence mechanisms including toxins, adhesins, enzymes and immunomodulators. One of these is Panton–Valentine leukocidin (PVL), a toxin associated with abscess formation and severe necrotizing pneumonia. Earlier studies suggested that PVL was a major virulence factor in community-associated MRSA infections. However, some recent data have not supported this association while others have, leading to controversy. Therefore, investigators continue to search for additional mechanisms of pathogenesis. In this review, we summarize the current understanding of the biological basis of MRSA virulence and explore future directions for research, including potential vaccines and antivirulence therapies under development that might allow clinicians to more successfully treat and prevent MRSA infections. PMID:22745137

  7. [Endocarditis due to meticillin-resistant Staphylococcus aureus originating from pigs].

    PubMed

    Ekkelenkamp, M B; Sekkat, M; Carpaij, N; Troelstra, A; Bonten, M J M

    2006-11-01

    A 63-year-old woman with a kidney transplant was admitted with endocarditis caused by meticillin-resistant Staphylococcus aureus (MRSA). Once her antibiotic therapy had been adjusted to the sensitivity-pattern of the bacterial strain she recovered, without the need for surgical intervention. The isolated S. aureus was typed by multi-locus sequence typing as sequence type 398, a MRSA-strain that has recently been isolated from a high percentage of Dutch pigs. This is the first report of a life-threatening infection with this pig MRSA. This strain is genetically different from the globally dispersed nosocomial MRSA-strains, and also from the strains that have been epidemic for several years in the USA as the causative agent ofcommunity-acquired skin infections. The Dutch Working Group on Infection Prevention (WIP) has recently adjusted its guidelines to halt further spread of this strain, and advises that the population at risk (pig breeders, slaughterhouse personnel and veterinarians) be held in isolation when hospitalised until MRSA colonisation has been excluded. The patient described here, however, did not belong to this population at risk. PMID:17131705

  8. Combination therapy with thioridazine and dicloxacillin combats meticillin-resistant Staphylococcus aureus infection in Caenorhabditis elegans.

    PubMed

    Poulsen, Marianne Ø; Schøler, Lone; Nielsen, Anette; Skov, Marianne N; Kolmos, Hans Jørn; Kallipolitis, Birgitte H; Olsen, Anders; Klitgaard, Janne K

    2014-09-01

    The shortage of drugs active against meticillin-resistant Staphylococcus aureus (MRSA) is a growing clinical problem. In vitro studies indicate that the phenothiazine thioridazine (TZ) might enhance the activity of the β-lactam antibiotic dicloxacillin (DCX) to a level where MRSA is killed, but experiments in simple animal models have not been performed. In the present study, we introduced Caenorhabditis elegans infected by S. aureus as an in vivo model to test the effect of TZ as a helper drug in combination with DCX. Because TZ is an anthelmintic, initial experiments were carried out to define the thresholds of toxicity, determined by larval development, and induction of stress-response markers. No measurable effects were seen at concentrations of less than 64 mg TZ l(-1). Seven different MRSA strains were tested for pathogenicity against C. elegans, and the most virulent strain (ATCC 33591) was selected for further analyses. In a final experiment, full-grown C. elegans were exposed to the test strain for 3 days and subsequently treated with 8 mg DCX l(-1) and 8 mg TZ l(-1) for 2 days. This resulted in a 14-fold reduction in the intestinal MRSA load as compared with untreated controls. Each drug alone resulted in a two- to threefold reduction in MRSA load. In conclusion, C. elegans can be used as a simple model to test synergy between DCX and TZ against MRSA. The previously demonstrated in vitro synergy can be reproduced in vivo. PMID:24913562

  9. Current concepts on the virulence mechanisms of meticillin-resistant Staphylococcus aureus.

    PubMed

    Watkins, Richard R; David, Michael Z; Salata, Robert A

    2012-09-01

    Meticillin-resistant Staphylococcus aureus (MRSA) strains are prevalent bacterial pathogens that cause both health care and community-associated infections. Increasing resistance to commonly prescribed antibiotics has made MRSA a serious threat to public health throughout the world. The USA300 strain of MRSA has been responsible for an epidemic of community-associated infections in the US, mostly involving skin and soft tissue but also more serious invasive syndromes such as pneumonia, severe sepsis and endocarditis. MRSA strains are particularly serious and potentially lethal pathogens that possess virulence mechanisms including toxins, adhesins, enzymes and immunomodulators. One of these is Panton-Valentine leukocidin (PVL), a toxin associated with abscess formation and severe necrotizing pneumonia. Earlier studies suggested that PVL was a major virulence factor in community-associated MRSA infections. However, some recent data have not supported this association while others have, leading to controversy. Therefore, investigators continue to search for additional mechanisms of pathogenesis. In this review, we summarize the current understanding of the biological basis of MRSA virulence and explore future directions for research, including potential vaccines and antivirulence therapies under development that might allow clinicians to more successfully treat and prevent MRSA infections. PMID:22745137

  10. Antimicrobial treatment of nosocomial meticillin-resistant Staphylococcus aureus (MRSA) pneumonia: current and future options.

    PubMed

    Welte, Tobias; Pletz, Mathias W

    2010-11-01

    Meticillin-resistant Staphylococcus aureus (MRSA) is a frequent cause of nosocomial pneumonia. Inadequate or inappropriate antimicrobial therapy, often caused by antimicrobial resistance, is associated with increased mortality for these infections. Agents currently recommended for the treatment of MRSA pneumonia include vancomycin and linezolid in the USA, and vancomycin, linezolid, teicoplanin and quinupristin/dalfopristin in Europe. Antimicrobials such as tigecycline and daptomycin, although approved for the treatment of some MRSA infections, have not demonstrated efficacy equivalent to the approved agents for MRSA pneumonia. Further agents lack data from randomised controlled trials (e.g. fosfomycin, fusidic acid or rifampicin in combination with vancomycin). Antimicrobial agents that have recently been approved or are being investigated as treatments for MRSA infections include the lipoglycopeptides telavancin (approved for the treatment of complicated skin and skin-structure infections in the USA and Canada), dalbavancin and oritavancin, the cephalosporins ceftobiprole and ceftaroline, and the dihydrofolate reductase inhibitor iclaprim. To be an effective treatment for MRSA pneumonia, antimicrobial agents must have activity against antimicrobial-resistant S. aureus, penetrate well into the lung, have a low potential for resistance development and have a good safety profile. Here, the available data for current and potential future MRSA pneumonia antimicrobials are reviewed and discussed. PMID:20724119

  11. Meticillin-resistant Staphylococcus aureus colonisation and infection in Thoroughbred racehorses and veterinarians in Japan.

    PubMed

    Kuroda, T; Kinoshita, Y; Niwa, H; Shinzaki, Y; Tamura, N; Hobo, S; Kuwano, A

    2016-05-01

    Meticillin-resistant Staphylococcus aureus (MRSA) infections have been confirmed in hospitalised Thoroughbred racehorses at the hospitals of two training centres in Japan since 2009. To investigate the source of infection, the authors examined the rate of nasal MRSA colonisation in 600 healthy Thoroughbred racehorses, 53 veterinarians and 16 office staff at the racehorse hospitals of the two training centres. MRSA was not isolated from healthy Thoroughbred racehorses or hospital office staff. However, MRSA was isolated from 16 veterinarians (30.1 per cent), and the colonisation rate was significantly higher in veterinarians than in the office staff of the same hospitals. Also, 10 of the 16 MRSA strains (62.5 per cent) isolated from veterinarians were classified as type II by staphylococcal cassette chromosome mec (SCCmec) typing and ST5 by multilocus sequence typing. Pulsed-field gel electrophoresis analysis demonstrated that these 10 MRSA strains of SCCmec type II and ST5 were genetically identical or very similar to 9 MRSA strains isolated from infected horses hospitalised at these hospitals between 2009 and 2013. These results indicate that SCCmec type II and ST5 MRSA strains were probably transmitted between veterinarians and infected horses. PMID:27114407

  12. Molecular characterization of a new efficiently transducing bacteriophage identified in meticillin-resistant Staphylococcus aureus.

    PubMed

    Varga, Marian; Pantůček, Roman; Růžičková, Vladislava; Doškař, Jirˇí

    2016-01-01

    In Staphylococcus aureus, generalized transduction mediated by temperate bacteriophages represents a highly efficient way of transferring antibiotic resistance genes between strains. In the present study, we identified and characterized in detail a new efficiently transducing bacteriophage of the family Siphoviridae, designated ϕJB, which resides as a prophage in the meticillin-resistant S. aureus (MRSA) strain Jevons B. Whole-genome sequencing followed by detailed in silico analysis uncovered a linear dsDNA genome consisting of 43 ,12 bp and comprising 70 ORFs, of which ∼40 encoded proteins with unknown function. A global genome alignment of ϕJB and other efficiently transducing phages ϕ11, ϕ53, ϕ80, ϕ80α and ϕNM4 showed a high degree of homology with ϕNM4 and substantial differences with regard to other phages. Using a model transduction system with a well-defined donor and recipient, ϕJB transferred the tetracycline resistance plasmid pT181 and a penicillinase plasmid with outstanding frequencies, beating most of the above-mentioned phages by an order of magnitude. Moreover, ϕJB demonstrated high frequencies of transferring antibiotic resistance plasmids even upon induction from a lysogenic donor strain. Considering such transducing potential, ϕJB and related bacteriophages may serve as a suitable tool for elucidating the nature of transduction and its contribution to the spread of antibiotic resistance genes in naturally occurring MRSA populations. PMID:26537974

  13. Newspaper reporting of meticillin-resistant Staphylococcus aureus and 'the dirty hospital'.

    PubMed

    Chan, P; Dipper, A; Kelsey, P; Harrison, J

    2010-08-01

    A distinctive tone is apparent in UK press coverage of meticillin-resistant Staphylococcus aureus (MRSA), dominated by the metaphor of 'the dirty hospital', which emphasises defects in hospital cleanliness and failures of government and National Health Service management. We found no primary evidence for a linkage between hospital cleanliness and MRSA incidence in publicly available data. We therefore sought the sources of this type of reporting. A textual analysis of all articles (2000-2007) about MRSA in the UK national press was performed to detect a bias towards reporting MRSA in terms of hospital cleanliness over other accepted risk factors for MRSA. This was supplemented by interviews with eight journalists and a detailed chronology of newspaper and other media releases in February 2000, seeking reasons why hospital cleanliness and MRSA have been linked. There is a strong bias in newspaper coverage of MRSA to link this infection with hospital cleanliness. The events around reporting of a National Audit Office publication in February 2000 appear to be particularly important in defining the cause of MRSA as dirty hospitals. The metaphor of 'the dirty hospital' was derived from, and was a distortion of, official reports from government departments. It had a certain evocative power, with public acceptance, and so became used by journalists, on the one side, and by politicians, government officials and ministers on the other, in a cycle of mutual reinforcement. PMID:20576321

  14. Improving the timeliness of meticillin-resistant Staphylococcus aureus antimicrobial decolonization therapy administration: a descriptive account☆

    PubMed Central

    Brooks, H.L.; Hodson, J.; Richardson, S.J.; Stezhka, L.; Gill, M.J.; Coleman, J.J.

    2014-01-01

    Summary Background It is important to ensure that the timely administration of appropriate antimicrobial decolonization therapy occurs when patients are identified as meticillin-resistant Staphylococcus aureus (MRSA)-colonized. Computerized Provider Order Entry (CPOE) with embedded Clinical Decision Support (CDS) may help to facilitate this. Aim To investigate changes in the average time from patient admission to administration of MRSA decolonization antimicrobial therapy in the context of various national and local infection control interventions, including the use of CPOE. Methods Data concerning the time of admission and of administration of patients' first MRSA decolonization antimicrobials were extracted from a locally developed CPOE system (Prescribing Investigation and Communications System: PICS) which was introduced at a large university teaching hospital in the UK in 1998. Data were extracted retrospectively from January 2006 to March 2012. Findings A variety of relevant local and national interventions occurred from 2006 to 2012. Notably, the automatic charting of MRSA decolonization antimicrobial therapy was introduced in December 2007. There was a significant decline of 15.0% per year (95% confidence interval: 11.1–18.7%; P < 0.001) in the time taken from admission to administration of MRSA decolonization antimicrobial therapy during the study period. Conclusions Numerous factors may have contributed to the observed reductions in the time from admission to administration of MRSA decolonization antimicrobials, including the implementation of specific features within a CPOE system. By rapidly attending to positive MRSA colonizations there is decreased potential for MRSA to spread, which may help to reduce the prevalence of MRSA colonizations within hospitals and improve patient outcomes. PMID:24560977

  15. Epidemiological and molecular characteristics of meticillin-resistant Staphylococcus aureus in Turkey: A multicentre study.

    PubMed

    Dündar, Devrim; Willke, Ayse; Sayan, Murat; Koc, Meliha Meric; Akan, Ozay Arıkan; Sumerkan, Bulent; Saltoglu, Nese; Yaman, Akgun; Ayaz, Celal; Koksal, Iftihar

    2016-09-01

    The aim of this study was to investigate the epidemiological and molecular features of clinical meticillin-resistant Staphylococcus aureus (MRSA) isolates in Turkey. MRSA isolates were collected from six regions of Turkey. The mecA and nuc genes were detected by PCR. Antimicrobial susceptibilities were determined by the disk diffusion method. Staphylococcal cassette chromosome mec (SCCmec) and staphylococcal protein A (spa) typing were performed by the sequencing method for 270 randomly selected MRSA isolates. The US Centers for Disease Control and Prevention (CDC) definition was used for epidemiological diagnosis of community-associated MRSA (CA-MRSA). Resistance rates of MRSA to ciprofloxacin, gentamicin, clindamycin, erythromycin, rifampicin, trimethoprim/sulfamethoxazole and tetracycline were 93.4%, 81.2%, 38.5%, 57.8%, 93.9%, 1.1% and 93.1%, respectively. The most frequent SCCmec type was SCCmec III (91.1%). SCCmec type IV was found in 5.2% of the isolates. The most frequent spa type was t030 (81.1%). Five isolates were CA-MRSA if only the epidemiological definition was used (5/725; 0.7%). Two isolates were defined as CA-MRSA both by epidemiological features and SCCmec typing (2/270; 0.7%). Of 14 SCCmec type IV isolates, 12 were not defined as CA-MRSA by epidemiological features. In conclusion, this is the most comprehensive multicentre study in Turkey investigating MRSA using both epidemiological and genotypic features. The CA-MRSA rate is low in Turkey. Combined use of epidemiological and genotypic methods is the most accurate approach for the diagnosis of CA-MRSA. PMID:27530838

  16. Epidemiological typing of meticillin-resistant Staphylococcus aureus isolates from Pakistan and India.

    PubMed

    Shabir, Sahida; Hardy, Katherine J; Abbasi, Waseem S; McMurray, Claire L; Malik, Salman A; Wattal, Chand; Hawkey, Peter M

    2010-03-01

    The levels of meticillin-resistant Staphylococcus aureus (MRSA) in Pakistan and India are known to be high, but few studies have described the epidemiology of the different MRSA clones present. In order to gain an understanding of the epidemiology of MRSA within this region, 60 MRSA isolates from Pakistan (49) and India (11) were genotyped. All isolates were typed using PFGE, staphylococcal interspersed repeat units (SIRUs), a restriction-modification method and staphylococcal cassette chromosome mec (SCCmec) typing. A subset of isolates that were distinct by PFGE and SIRUs were typed using multilocus sequence typing (MLST). Clonal complex (CC) 8 was the dominant clonal complex (57/60) and was present in both Pakistan and India. Within CC8, there were 10 SIRU profiles and 24 PFGE profiles. Two SIRU profiles were present in isolates from both India and Pakistan, whilst seven were distinct for Pakistan and one for India. All PFGE profiles were distinct for each of the two countries. Thirty-four of the 57 isolates carried SCCmec type III/IIIa and the remainder carried type IV SCCmec. MLST analysis of 14 CC8 isolates with diverse SIRU and PFGE profiles showed that all were single-locus variants, with nine belonging to sequence type (ST) 239, three to ST8 and two to ST113. From a single hospital in Pakistan, three isolates belonged to CC30 and all were indistinguishable by PFGE and SIRUs and carried the Panton-Valentine leukocidin gene. Thus, epidemiological typing of strains from three distinct locations in India and Pakistan revealed the predominance of one clonal complex and highly related STs. The ability of SIRUs and PFGE to differentiate within ST239 demonstrates their utility in defining local epidemiology in these countries. PMID:19926728

  17. Incidence of invasive meticillin-resistant Staphylococcus aureus infections in Germany, 2010 to 2014.

    PubMed

    Walter, Jan; Haller, Sebastian; Blank, Hans-Peter; Eckmanns, Tim; Abu Sin, Muna; Hermes, Julia

    2015-01-01

    Voluntary surveillance systems in Germany suggest a recent decline in the incidence of infections (subsequent to at least 2010) with meticillin-resistant Staphylococcus aureus (MRSA) from various types of specimens and settings. We asked whether this decline is reflected by data from the mandatory national surveillance system for invasive MRSA infections. Our analysis is based on the population in Germany in 2010 to 2014. Cases were identified from passive reporting by microbiological laboratories of the diagnosis of MRSA from blood culture or cerebrospinal fluid. Respective clinical data were subsequently added to the notification. We calculated risk ratios (RR) between consecutive years, stratifying cases by sex, age and federal state of residence. The national incidence increased from 4.6 episodes per 100,000 persons in 2010 to 5.6 in 2012 (2011 vs 2010: RR: 1.13, 95% confidence interval (CI): 1.08-1.18; 2012 vs 2011: RR: 1.08, 95% CI: 1.04-1.13). It stagnated at 5.4 per 100,000 in 2013 (RR: 0.97, 95% CI: 0.93-1.01) before declining to 4.8 in 2014 (RR: 0.88, 95% CI: 0.84-0.91). This trend was observed in most, but not all federal states and strata of sex and age groups. Only 204 of 20,679 (1%) episodes of infection were notified as belonging to an outbreak. Our analysis corroborates previous findings that the incidence of invasive MRSA infections in Germany may be declining. PMID:26607355

  18. Detection of livestock-associated meticillin-resistant Staphylococcus aureus CC398 in retail pork, United Kingdom, February 2015

    PubMed Central

    Hadjirin, N F; Lay, E M; Paterson, G K; Harrison, E M; Peacock, S J; Parkhill, J; Zadoks, R N

    2016-01-01

    Livestock-associated meticillin-resistant Staphylococcus aureus belonging to clonal complex 398 (LA-MRSA CC398) is an important cause of zoonotic infections in many countries. Here, we describe the isolation of LA-MRSA CC398 from retail meat samples of United Kingdom (UK) farm origin. Our findings indicate that this lineage is probably established in UK pig farms and demonstrate a potential pathway for the transmission of LA-MRSA CC398 from livestock to humans in the UK. PMID:26111237

  19. Disinfection of meticillin-resistant Staphylococcus aureus and Staphylococcus epidermidis biofilms using a remote non-thermal gas plasma.

    PubMed

    Cotter, J J; Maguire, P; Soberon, F; Daniels, S; O'Gara, J P; Casey, E

    2011-07-01

    The effective disinfection of hospital surfaces is recognised as an important factor in preventing hospital-acquired infections. The purpose of this study was to quantify the disinfection rate of a novel gas plasma system on clinically relevant biofilms. Clinical isolates of Staphylococcus epidermidis and meticillin-resistant Staphylococcus aureus (MRSA) were grown as biofilms on glass surfaces and tested in a disinfection container remote from the plasma source. The strains used in this study were known to produce substantial quantities of biofilm and average log₁₀ counts were 9.0 and 9.1 cfu/cm(2) for S. epidermidis and MRSA respectively. Counts were reduced by between 4 and 4.5 log₁₀ after 1h of exposure for MRSA and S. epidermidis respectively. More prolonged treatment in the case of MRSA biofilms resulted in a 5.5 log₁₀ reduction after 90 min. Biofilm samples were also placed in medical device packaging bags and similar rates of disinfection were observed. PMID:21601949

  20. An FDA-Drug Library Screen for Compounds with Bioactivities against Meticillin-Resistant Staphylococcus aureus (MRSA)

    PubMed Central

    Lau, Qiu Ying; Tan, Yoke Yan Fion; Goh, Vanessa Chai Yin; Lee, David Jing Qin; Ng, Fui Mee; Ong, Esther H. Q.; Hill, Jeffrey; Chia, Cheng San Brian

    2015-01-01

    The lack of new antibacterial drugs entering the market and their misuse have resulted in the emergence of drug-resistant bacteria, posing a major health crisis worldwide. In particular, meticillin-resistant Staphylococcus aureus (MRSA), a pathogen responsible for numerous human infections, has become endemic in hospitals worldwide. Drug repurposing, the finding of new therapeutic indications for approved drugs, is deemed a plausible solution to accelerate drug discovery and development in this area. Towards this end, we screened 1163 drugs approved by the Food and Drug Administration (FDA) for bioactivities against MRSA in a 10 μM single-point assay. After excluding known antibiotics and antiseptics, six compounds were identified and their MICs were determined against a panel of clinical MRSA strains. A toxicity assay using human keratinocytes was also conducted to gauge their potential for repurposing as topical agents for treating MRSA skin infections. PMID:27025633

  1. Polyhexamethylene guanidine hydrochloride-based disinfectant: a novel tool to fight meticillin-resistant Staphylococcus aureus and nosocomial infections.

    PubMed

    Oulé, Mathias K; Azinwi, Richard; Bernier, Anne-Marie; Kablan, Tano; Maupertuis, Anne-Marie; Mauler, Stephanie; Nevry, Rose K; Dembélé, Korami; Forbes, Lorraine; Diop, Lamine

    2008-12-01

    Polyhexamethylene guanidine hydrochloride (PHMGH), an antimicrobial biocide of the guanidine family, was tested for efficacy against quality-control strains of Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella choleraesuis, meticillin-resistant S. aureus (MRSA) and Escherichia coli. Bactericidal activity against S. aureus, P. aeruginosa and Salmonella choleraesuis was determined using the official methods of analysis of the Association of Official Analytical Chemists, with modifications as recommended by the Canadian General Standards Board. For MRSA and E. coli, the MIC and minimal bactericidal concentration were determined using the broth dilution technique. The experiments were carried out at 20 degrees C under a range of conditions including varying PHMGH concentration (0.001-0.1 %), contact time (0.5-10 min) and water type (distilled, tap and hard water). The phenol coefficient values determined with S. aureus, Salmonella choleraesuis and P. aeruginosa were 7.5, 6.1 and 5, respectively. No matter what type of water was used to make the dilutions, PHMGH killed MRSA and E. coli at concentrations as low as 0.04 and 0.005 % (w/v), respectively, within 1.5 min. The mode of action of PHMGH was elucidated by transmission electron microscopy: the cell envelope was broken, resulting in cell content leakage into the medium. The ultimate aim of this study was to show that PHMGH can be used as an odourless, colourless, non-corrosive and harmless disinfectant for hospital and household facilities. PMID:19018024

  2. Database screening and in vivo efficacy of antimicrobial peptides against meticillin-resistant Staphylococcus aureus USA300

    PubMed Central

    Menousek, Joseph; Mishra, Biswajit; Hanke, Mark L.; Heim, Cortney E.; Kielian, Tammy; Wang, Guangshun

    2012-01-01

    Natural antimicrobial peptides (AMPs) are promising candidates for developing a generation of new antimicrobials to meet the challenge of antibiotic-resistant pathogens such as meticillin-resistant Staphylococcus aureus (MRSA). To facilitate the search for new candidates, we have utilised the Antimicrobial Peptide Database (APD), which contains natural AMPs from bacteria, fungi, plants and animals. This study demonstrates the identification of novel templates against MRSA by screening 30 peptides selected from the APD. These peptides are short (<25 residues), cysteine-free, cationic and represent candidates from different biological sources such as bacteria, insects, arachnids, tunicates, amphibians, fish and mammals. Six peptides, including ascaphin-8, database-screened antimicrobial peptide 1 (DASamP1), DASamP2, lycotoxin I, maculatin 1.3 and piscidin 1, were found to exert potent antimicrobial activity against an MRSA USA300 isolate. Although five of the six peptides showed broad-spectrum antibacterial activity, DASamP1 displayed killing of MRSA in vitro but not of Escherichia coli, Bacillus subtilis or Pseudomonas aeruginosa. In addition, DASamP1 suppressed early biofilm formation in a mouse model of catheter-associated MRSA infection. DASamP1 is a novel, short and potent peptide that will be a useful starting template for further developing novel anti-MRSA peptides. PMID:22445495

  3. Emergent and evolving antimicrobial resistance cassettes in community-associated fusidic acid and meticillin-resistant Staphylococcus aureus.

    PubMed

    Ellington, Matthew J; Reuter, Sandra; Harris, Simon R; Holden, Matthew T G; Cartwright, Edward J; Greaves, Daniel; Gerver, Sarah M; Hope, Russell; Brown, Nicholas M; Török, M Estee; Parkhill, Julian; Köser, Claudio U; Peacock, Sharon J

    2015-05-01

    Fusidic acid is a topical and systemic antimicrobial used for the treatment of staphylococcal infections in hospitals and the community. Sales of fusidic acid and resistance rates among meticillin-resistant Staphylococcus aureus (MRSA) doubled between 1990 and 2001. For the following decade, fusidic acid resistance rates among isolates from Addenbrooke's Hospital (Cambridge, UK) were compared with national resistance rates from MRSA bacteraemia surveillance data and with antimicrobial sales data. Sales of fusidic acid remained relatively constant between 2002 and 2012, whilst fusidic acid resistance increased two- and four-fold in MRSA bacteraemias nationally and in MRSA isolates from Cambridge, respectively. A subgroup of MRSA resistant only to fusidic acid increased after 2006 by 5-fold amongst bacteraemias nationally and 17-fold (to 7.7% in 2012) amongst Cambridge MRSA isolates. All of the available local isolates from 2011 to 2012 (n=23) were acquired in the community, were not related epidemiologically and belonged to multilocus sequence typing (MLST) groups ST1, 5, 8, 45 or 149 as revealed from analysis of whole-genome sequence data. All harboured the fusC gene on one of six distinct staphylococcal cassette chromosome (SCC) elements, four of which were dual-resistance chimeras that encoded β-lactam and fusidic acid resistance. In summary, fusidic acid-resistant MRSA increased in prevalence during the 2000s with notable rises after 2006. The development of chimeric cassettes that confer dual resistance to β-lactams and fusidic acid demonstrates that the genetics underpinning resistance in community-associated MRSA are evolving. PMID:25769787

  4. Emergent and evolving antimicrobial resistance cassettes in community-associated fusidic acid and meticillin-resistant Staphylococcus aureus

    PubMed Central

    Ellington, Matthew J.; Reuter, Sandra; Harris, Simon R.; Holden, Matthew T.G.; Cartwright, Edward J.; Greaves, Daniel; Gerver, Sarah M.; Hope, Russell; Brown, Nicholas M.; Török, M. Estee; Parkhill, Julian; Köser, Claudio U.; Peacock, Sharon J.

    2015-01-01

    Fusidic acid is a topical and systemic antimicrobial used for the treatment of staphylococcal infections in hospitals and the community. Sales of fusidic acid and resistance rates among meticillin-resistant Staphylococcus aureus (MRSA) doubled between 1990 and 2001. For the following decade, fusidic acid resistance rates among isolates from Addenbrooke's Hospital (Cambridge, UK) were compared with national resistance rates from MRSA bacteraemia surveillance data and with antimicrobial sales data. Sales of fusidic acid remained relatively constant between 2002 and 2012, whilst fusidic acid resistance increased two- and four-fold in MRSA bacteraemias nationally and in MRSA isolates from Cambridge, respectively. A subgroup of MRSA resistant only to fusidic acid increased after 2006 by 5-fold amongst bacteraemias nationally and 17-fold (to 7.7% in 2012) amongst Cambridge MRSA isolates. All of the available local isolates from 2011 to 2012 (n = 23) were acquired in the community, were not related epidemiologically and belonged to multilocus sequence typing (MLST) groups ST1, 5, 8, 45 or 149 as revealed from analysis of whole-genome sequence data. All harboured the fusC gene on one of six distinct staphylococcal cassette chromosome (SCC) elements, four of which were dual-resistance chimeras that encoded β-lactam and fusidic acid resistance. In summary, fusidic acid-resistant MRSA increased in prevalence during the 2000s with notable rises after 2006. The development of chimeric cassettes that confer dual resistance to β-lactams and fusidic acid demonstrates that the genetics underpinning resistance in community-associated MRSA are evolving. PMID:25769787

  5. Use of ceftaroline after glycopeptide failure to eradicate meticillin-resistant Staphylococcus aureus bacteraemia with elevated vancomycin minimum inhibitory concentrations.

    PubMed

    Paladino, Joseph A; Jacobs, David M; Shields, Ryan K; Taylor, Jerusha; Bader, Justin; Adelman, Martin H; Wilton, Greg J; Crane, John K; Schentag, Jerome J

    2014-12-01

    Elevated minimum inhibitory concentrations (MICs) of vancomycin against meticillin-resistant Staphylococcus aureus (MRSA) and the emergence of heteroresistant S. aureus strains have led to increased use of anti-MRSA antibiotics other than vancomycin. Ceftaroline fosamil is a novel cephalosporin with activity against MRSA, but there are limited clinical data on its use for MRSA bacteraemia (MRSAB) and against strains exhibiting high vancomycin MICs (2-4 μg/mL). This multicentre, retrospective, case-control study compared the microbiological and clinical effectiveness of ceftaroline used after vancomycin failure with that of vancomycin-treated controls for the treatment of MRSA with vancomycin MICs ≥ 2 μg/mL. In total, 32 patients were matched 1:1 with respect to vancomycin MIC, age and origin of bacteraemia. In the ceftaroline group, patients received prior MRSA therapy for a median of 5 days [interquartile range (IQR), 3-15.8 days] prior to switching to ceftaroline. Median time to eradication of MRSA was significantly less after treatment with ceftaroline compared with vancomycin [4 days (IQR, 3-7.5 days) vs. 8 days (IQR, 5.8-19.5 days); P=0.02]. Both clinical success at the end of treatment and recurrence of MRSA at Day 7 were trending towards being inferior in the vancomycin group, although the results did not attain statistical significance [81% vs. 44% (P=0.06) and 6% vs. 38% (P=0.08), respectively]. Ceftaroline added at the point of vancomycin failure resolves MRSAB more rapidly and with a higher rate of clinical success, therefore ceftaroline should be considered as an alternative for these difficult-to-treat infections. PMID:25282169

  6. Characterization of meticillin-resistant and meticillin-susceptible isolates of Staphylococcus pseudintermedius from cases of canine pyoderma in Australia.

    PubMed

    Siak, Meng; Burrows, Amanda K; Coombs, Geoffrey W; Khazandi, Manouchehr; Abraham, Sam; Norris, Jacqueline M; Weese, J Scott; Trott, Darren J

    2014-09-01

    Meticillin-resistant Staphylococcus pseudintermedius (MRSP) has recently emerged as a worldwide cause of canine pyoderma. In this study, we characterized 22 S. pseudintermedius isolates cultured from 19 dogs with pyoderma that attended a veterinary dermatology referral clinic in Australia in 2011 and 2012. Twelve isolates were identified as MRSP by mecA real-time PCR and phenotypic resistance to oxacillin. In addition to β-lactam resistance, MRSP isolates were resistant to erythromycin (91.6 %), gentamicin (83.3 %), ciprofloxacin (83.3 %), chloramphenicol (75 %), clindamycin (66 %), oxytetracycline (66 %) and tetracycline (50 %), as shown by disc-diffusion susceptibility testing. Meticillin-susceptible S. pseudintermedius isolates only showed resistance to penicillin/ampicillin (90 %) and tetracycline (10 %). PFGE using the SmaI restriction enzyme was unable to type nine of the 12 MRSP isolates. However the nine isolates provided the same PFGE pulsotype using the Cfr91 restriction enzyme. Application of the mec-associated direct repeat unit (dru) typing method identified the nine SmaI PFGE-untypable isolates as dt11cb, a dru type that has only previously been associated with MRSP sequence type (ST)45 isolates that possess a unique SCCmec element. The dt11cb isolates shared a similar multidrug-resistant antibiogram phenotype profile, whereas the other MRSP isolates, dt11a, dt11af (dt11a-associated) and dt10h, were resistant to fewer antibiotic classes and had distinct PFGE profiles. This is the first report of MRSP causing pyoderma in dogs from Australia. The rapid intercontinental emergence and spread of multidrug-resistant MRSP strains confirms the urgent need for new treatment modalities for recurrent canine pyoderma in veterinary practice. PMID:24994658

  7. Molecular characterization and clonal diversity of meticillin-resistant Staphylococcus aureus isolated from the community in Spain: emergence of clone sequence type 72.

    PubMed

    Potel, C; Rey, S; Otero, S; Rubio, J; Álvarez, M

    2016-08-01

    Sequence type 72 meticillin-resistant Staphylococcus aureus (ST72 MRSA) was recently detected in our hospital. Although in Europe this clone is rarely isolated, it is the leading cause of community-associated MRSA infections in Korea, spreading also into hospitals, where it has also emerged as the main MRSA clone recovered from raw meat. We studied MRSA isolated from outpatients in Spain during a nine-year period. More than 70% of the isolates belonged to predominant clones found in hospitals. There was a significant increase in the ST72 prevalence. It appears that boundaries of dominance among MRSA clones have become blurred, demanding continuous surveillance. PMID:27112049

  8. Irish-1 and Irish-2: UK epidemic meticillin-resistant Staphylococcus aureus strains associated with Northern Ireland.

    PubMed

    Aucken, H M; O'Neill, G; Ganner, M; Dinerstein, N; Ali, M; Murchan, S

    2006-06-01

    Since 1998, an increasing number of meticillin-resistant Staphylococcus aureus (MRSA) isolates with one of two characteristic phage patterns have been referred to the authors' laboratory from Northern Ireland. These strains were designated 'Irish-1' and 'Irish-2'. Analysis of 956 submitted isolates classified as Irish-1 or Irish-2 showed that 97% of the former and 95% of the latter were from Northern Ireland. Only 0.2% and 3%, respectively, were from England. Eleven Irish-2 isolates had been referred from Western Australia as representatives of an epidemic strain originally isolated there in 1994. Ninety isolates with the Irish-1 phage pattern and 91 isolates with the Irish-2 phage pattern, from numerous hospitals, were characterized by SmaI pulsed-field gel electrophoresis (PFGE), toxin gene carriage and antibiotic susceptibility. PFGE showed that, within each collection, a few isolates represented unrelated strains, but the majority were within six band differences of the most common profiles. Half of the Irish-1 isolates were homogeneous, with 22 DNA profiles among the remainder. Irish-2 isolates had two common profiles, D1 and D2, equally divided between one-third of the isolates and differing from each other by two bands; the remaining isolates shared 31 DNA profiles. Cluster analysis showed some overlap in DNA profiles between the Irish-1 and Irish-2 strains, but clear separation from other epidemic MRSA strains. There was no obvious correlation between PFGE profile and either antibiotic resistance pattern or toxin gene possession. All but three Irish-1 isolates possessed only the staphylococcal enterotoxin A (sea) gene, whereas almost all Irish-2 isolates were negative for all 12 enterotoxin genes. Sixty-nine percent of Irish-2 isolates were resistant to ciprofloxacin, erythromycin, kanamycin, neomycin and streptomycin, while 90% of Irish-1 isolates were resistant to all these plus gentamicin and mupirocin. All isolates were sensitive to quinupristin

  9. Economic and clinical impact of nosocomial meticillin-resistant Staphylococcus aureus infections in Singapore: a matched case-control study.

    PubMed

    Pada, S K; Ding, Y; Ling, M L; Hsu, L-Y; Earnest, A; Lee, T-E; Yong, H-C; Jureen, R; Fisher, D

    2011-05-01

    We performed a prospective matched case-control study, with six-month follow-up for discharged subjects, to evaluate the direct clinical and financial impact of nosocomial meticillin-resistant Staphylococcus aureus (MRSA) infections in Singaporean hospitals. Consecutive nosocomial MRSA-infected cases at both tertiary public sector hospitals in Singapore were matched for age, specialty service, major surgical procedure (if applicable) and Charlson comorbidity index with up to two non-infected controls each. Chart reviews and subject interviews were performed during hospitalisation and also upon six months post-discharge for survivors. The outcomes analysed were: mortality, length of hospitalisation (LOS), healthcare-associated financial costs, and health-related quality of life. The last was evaluated via an interviewer-administered EuroQol-5D questionnaire on discharge, with conversion to a single health state summary index. Attributable outcomes were ascertained by conditional logistic and linear regression. There were 181 cases and 351 controls. MRSA infection was independently associated with in-hospital death [14.4% vs 1.4%; odds ratio (OR): 5.54; 95% confidence interval (CI): 1.63-18.79, P=0.006], longer LOS (median of 32 days vs 7 days; coefficient: 1.21; 95% CI: 1.02-1.40, P<0.001), higher hospitalisation costs (median of US$18,129.89 vs US$4,490.47; coefficient: 1.14; 95% CI: 0.93-1.35; P<0.001), higher post-discharge healthcare-associated financial costs (median of US$337.24 vs US$259.29; coefficient: 0.39; 95% CI: 0.06-0.72; P=0.021), and poorer health-related quality of life (coefficient: -0.14; 95% CI: -0.21 to -0.08; P<0.001). Outcomes were not significantly different between both hospitals. The attributable individual, institutional and societal impact of MRSA infections is considerable in Singapore. Preventing such infections will result in substantial improvements in patient outcomes and healthcare delivery. PMID:21269733

  10. Trimethoprim-sulfamethoxazole versus vancomycin for severe infections caused by meticillin resistant Staphylococcus aureus: randomised controlled trial

    PubMed Central

    Bishara, Jihad; Yahav, Dafna; Goldberg, Elad; Neuberger, Ami; Ghanem-Zoubi, Nesrin; Dickstein, Yaakov; Nseir, William; Dan, Michael; Leibovici, Leonard

    2015-01-01

    Objective To show non-inferiority of trimethoprim-sulfamethoxazole compared with vancomycin for the treatment of severe infections due to meticillin resistant Staphylococcus aureus (MRSA). Design Parallel, open label, randomised controlled trial. Setting Four acute care hospitals in Israel. Participants Adults with severe infections caused by MRSA susceptible to trimethoprim-sulfamethoxazole and vancomycin. Patients with left sided endocarditis, meningitis, chronic haemodialysis, and prolonged neutropenia were excluded. Interventions Trimethoprim-sulfamethoxazole 320 mg/1600 mg twice daily versus vancomycin 1 g twice daily for a minimum of seven days and then by indication. Main outcome measures The primary efficacy outcome was treatment failure assessed at day 7, consisting of death, persistence of haemodynamic instability or fever, stable or worsening Sequential Organ Failure Assessment score, and persistence of bacteraemia. The primary safety outcome was all cause mortality at day 30. Non-inferiority was defined by a difference of less than 15% for treatment failure. Results 252 patients were included in the trial, of whom 91 (36%) had bacteraemia. No significant difference in treatment failure was seen for trimethoprim-sulfamethoxazole (51/135, 38%) versus vancomycin (32/117, 27%)—risk ratio 1.38 (95% confidence interval 0.96 to 1.99). However, trimethoprim-sulfamethoxazole did not meet the non-inferiority criterion—absolute difference 10.4% (95% confidence interval −1.2% to 21.5%). For patients with bacteraemia, the risk ratio was 1.40 (0.91 to 2.16). In a multivariable logistic regression analysis, trimethoprim-sulfamethoxazole was significantly associated with treatment failure (adjusted odds ratio 2.00, 1.09 to 3.65). The 30 day mortality rate was 32/252 (13%), with no significant difference between arms. Among patients with bacteraemia, 14/41 (34%) treated with trimethoprim-sulfamethoxazole and 9/50 (18%) with vancomycin died (risk ratio 1.90, 0

  11. Screening, isolation, and decolonisation strategies in the control of meticillin resistant Staphylococcus aureus in intensive care units: cost effectiveness evaluation

    PubMed Central

    Graves, Nicholas; Cookson, Barry D; Barnett, Adrian G; Wilson, Jennie A; Edgeworth, Jonathan D; Batra, Rahul; Cuthbertson, Brian H; Cooper, Ben S

    2011-01-01

    Objective To assess the cost effectiveness of screening, isolation, and decolonisation strategies in the control of meticillin resistant Staphylococcus aureus (MRSA) in intensive care units. Design Economic evaluation based on a dynamic transmission model. Setting England and Wales. Population Theoretical population of patients on an intensive care unit. Main outcome measures Infections, deaths, costs, quality adjusted life years (QALYs), incremental cost effectiveness ratios for alternative strategies, and net monetary benefits. Results All decolonisation strategies improved health outcomes and reduced costs. Although universal decolonisation (regardless of MRSA status) was the most cost effective in the short term, strategies using screening to target MRSA carriers may be preferred owing to the reduced risk of selecting for resistance. Among such targeted strategies, universal admission and weekly screening with polymerase chain reaction coupled with decolonisation using nasal mupirocin was the most cost effective. This finding was robust to the size of intensive care units, prevalence of MRSA on admission, proportion of patients classified as high risk, and precise value of willingness to pay for health benefits. All strategies using isolation but not decolonisation improved health outcomes but costs were increased. When the prevalence of MRSA on admission to the intensive care unit was 5% and the willingness to pay per QALY gained was between £20 000 (€23 000; $32 000) and £30 000, the best such strategy was to isolate only those patients at high risk of carrying MRSA (either pre-emptively or after identification by admission and weekly screening for MRSA using chromogenic agar). Universal admission and weekly screening using polymerase chain reaction based detection of MRSA coupled with isolation was unlikely to be cost effective unless prevalence was high (10% of patients colonised with MRSA on admission). Conclusions MRSA control strategies that

  12. Comparison of strategies to reduce meticillin-resistant Staphylococcus aureus rates in surgical patients: a controlled multicentre intervention trial

    PubMed Central

    Lee, Andie S; Cooper, Ben S; Malhotra-Kumar, Surbhi; Chalfine, Annie; Daikos, George L; Fankhauser, Carolina; Carevic, Biljana; Lemmen, Sebastian; Martínez, José Antonio; Masuet-Aumatell, Cristina; Pan, Angelo; Phillips, Gabby; Rubinovitch, Bina; Goossens, Herman; Brun-Buisson, Christian; Harbarth, Stephan

    2013-01-01

    Objective To compare the effect of two strategies (enhanced hand hygiene vs meticillin-resistant Staphylococcus aureus (MRSA) screening and decolonisation) alone and in combination on MRSA rates in surgical wards. Design Prospective, controlled, interventional cohort study, with 6-month baseline, 12-month intervention and 6-month washout phases. Setting 33 surgical wards of 10 hospitals in nine countries in Europe and Israel. Participants All patients admitted to the enrolled wards for more than 24 h. Interventions The two strategies compared were (1) enhanced hand hygiene promotion and (2) universal MRSA screening with contact precautions and decolonisation (intranasal mupirocin and chlorhexidine bathing) of MRSA carriers. Four hospitals were assigned to each intervention and two hospitals combined both strategies, using targeted MRSA screening. Outcome measures Monthly rates of MRSA clinical cultures per 100 susceptible patients (primary outcome) and MRSA infections per 100 admissions (secondary outcome). Planned subgroup analysis for clean surgery wards was performed. Results After adjusting for clustering and potential confounders, neither strategy when used alone was associated with significant changes in MRSA rates. Combining both strategies was associated with a reduction in the rate of MRSA clinical cultures of 12% per month (adjusted incidence rate ratios (aIRR) 0.88, 95% CI 0.79 to 0.98). In clean surgery wards, strategy 2 (MRSA screening, contact precautions and decolonisation) was associated with decreasing rates of MRSA clinical cultures (15% monthly decrease, aIRR 0.85, 95% CI 0.74 to 0.97) and MRSA infections (17% monthly decrease, aIRR 0.83, 95% CI 0.69 to 0.99). Conclusions In surgical wards with relatively low MRSA prevalence, a combination of enhanced standard and MRSA-specific infection control approaches was required to reduce MRSA rates. Implementation of single interventions was not effective, except in clean surgery wards where MRSA

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

    PubMed

    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

  14. Whole-genome sequencing as standard practice for the analysis of clonality in outbreaks of meticillin-resistant Staphylococcus aureus in a paediatric setting.

    PubMed

    Ugolotti, E; Larghero, P; Vanni, I; Bandettini, R; Tripodi, G; Melioli, G; Di Marco, E; Raso, A; Biassoni, R

    2016-08-01

    Meticillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of hospital-associated infections. This study investigated the potential use of whole-genome sequencing (WGS) for surveillance purposes by re-examining MRSA strains related to past outbreaks among hospitalized paediatric patients. WGS data ameliorated the genotypic profile previously obtained with Sanger sequencing and pulsed-field gel electrophoresis typing, and discriminated between strains that were related and unrelated to the outbreaks. This allowed strain clonality to be defined with a higher level of resolution than achieved previously. This study demonstrates the potential of WGS to trace hospital outbreaks, which may lead to WGS becoming standard practice in outbreak investigations. PMID:27184087

  15. 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.

    PubMed

    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

  16. Sequence type 72 community-associated meticillin-resistant Staphylococcus aureus emerged as a predominant clone of nasal colonization in newly admitted patients.

    PubMed

    Park, S Y; Chung, D R; Yoo, J R; Baek, J Y; Kim, S H; Ha, Y E; Kang, C-I; Peck, K R; Lee, N Y; Song, J-H

    2016-08-01

    Current knowledge of community-associated (CA) meticillin-resistant Staphylococcus aureus (MRSA) carriage in hospitalized patients is incomplete. Genotypic characteristics of 637 nasal MRSA isolates from newly admitted patients in South Korea were investigated. Sequence type (ST) 72 accounted for 52.1%, 46.3%, and 52.8% of the isolates during the periods of 2007-2008, 2009-2010, and 2013-2014, respectively. Instead of classic MRSA clones responsible for healthcare-associated infections, including ST5 and ST239, MRSA with community genotype ST72 was the predominant strain in newly admitted patients regardless of age and home province of the patients. Active strategies are needed to prevent healthcare-associated infection by CA-MRSA. PMID:26874934

  17. Meticillin-resistant Staphylococcus aureus with a novel mecA homologue in human and bovine populations in the UK and Denmark: a descriptive study

    PubMed Central

    García-Álvarez, Laura; Holden, Matthew TG; Lindsay, Heather; Webb, Cerian R; Brown, Derek FJ; Curran, Martin D; Walpole, Enid; Brooks, Karen; Pickard, Derek J; Teale, Christopher; Parkhill, Julian; Bentley, Stephen D; Edwards, Giles F; Girvan, E Kirsty; Kearns, Angela M; Pichon, Bruno; Hill, Robert LR; Larsen, Anders Rhod; Skov, Robert L; Peacock, Sharon J; Maskell, Duncan J; Holmes, Mark A

    2011-01-01

    Summary Background Animals can act as a reservoir and source for the emergence of novel meticillin-resistant Staphylococcus aureus (MRSA) clones in human beings. Here, we report the discovery of a strain of S aureus (LGA251) isolated from bulk milk that was phenotypically resistant to meticillin but tested negative for the mecA gene and a preliminary investigation of the extent to which such strains are present in bovine and human populations. Methods Isolates of bovine MRSA were obtained from the Veterinary Laboratories Agency in the UK, and isolates of human MRSA were obtained from diagnostic or reference laboratories (two in the UK and one in Denmark). From these collections, we searched for mecA PCR-negative bovine and human S aureus isolates showing phenotypic meticillin resistance. We used whole-genome sequencing to establish the genetic basis for the observed antibiotic resistance. Findings A divergent mecA homologue (mecALGA251) was discovered in the LGA251 genome located in a novel staphylococcal cassette chromosome mec element, designated type-XI SCCmec. The mecALGA251 was 70% identical to S aureus mecA homologues and was initially detected in 15 S aureus isolates from dairy cattle in England. These isolates were from three different multilocus sequence type lineages (CC130, CC705, and ST425); spa type t843 (associated with CC130) was identified in 60% of bovine isolates. When human mecA-negative MRSA isolates were tested, the mecALGA251 homologue was identified in 12 of 16 isolates from Scotland, 15 of 26 from England, and 24 of 32 from Denmark. As in cows, t843 was the most common spa type detected in human beings. Interpretation Although routine culture and antimicrobial susceptibility testing will identify S aureus isolates with this novel mecA homologue as meticillin resistant, present confirmatory methods will not identify them as MRSA. New diagnostic guidelines for the detection of MRSA should consider the inclusion of tests for mecALGA251. Funding

  18. Investigation into the potential of sub-lethal photodynamic antimicrobial chemotherapy (PACT) to reduce susceptibility of meticillin-resistant Staphylococcus aureus (MRSA) to antibiotics

    NASA Astrophysics Data System (ADS)

    Cassidy, C. M.; Donnelly, R. F.; Tunney, M. M.

    2009-06-01

    In PACT, a combination of a sensitising drug and visible light cause the selective destruction of microbial cells via singlet oxygen production. As singlet oxygen is a non-specific oxidizing agent and is only present during illumination, development of resistance to this treatment is thought to be unlikely. However, in response to oxidative stress, bacteria can up-regulate oxidative stress genes and associated antibiotic resistance genes. The up-regulation of these genes and potential transfer of genetic material may result in a resistant bacterial population. This study determined whether treatment of clinically isolated meticillin resistant Staphylococcus aureus (MRSA) strains with sub-lethal doses of methylene blue (MB) and meso-tetra (N-methyl-4-pyridyl) porphine tetra tosylate (TMP)-PACT resulted in reduced susceptibility to antibiotics and previously lethal PACT. Exposure of strains to sub-lethal doses of photosensitizer in combination with light had no effect on susceptibility to previously lethal photosensitization. Furthermore, exposure to sub-lethal concentrations of both photosensitizers caused no significant changes in the minimum inhibitory concentration (MIC) for each strain tested. Any differences in susceptibility were not significant as they did not cross breakpoints between resistant and susceptible for any organism or antibiotic tested. Therefore, PACT remains an attractive alternative option for treatment of MRSA infections.

  19. Efficacy of topical and systemic antibiotic treatment of meticillin-resistant Staphylococcus aureus in a murine superficial skin wound infection model.

    PubMed

    Vingsbo Lundberg, Carina; Frimodt-Møller, Niels

    2013-09-01

    Meticillin-resistant Staphylococcus aureus (MRSA) is a rapidly spreading pathogen associated predominantly with skin infections. The lack of clinical evidence indicating the best treatment strategy to combat MRSA skin infections prompted us to investigate the efficacy of available treatment options in an experimental skin wound infection model in mice. Mice were treated either topically with retapamulin (1%), fusidic acid (2%) or mupirocin (2%) or systemically with linezolid (50-100 mg/kg/day) or vancomycin (50-200 mg/kg/day) twice daily for 3 days or 6 days and the total bacterial loads in the skin lesions were determined. Retapamulin, fusidic acid and mupirocin treatment for 3 days reduced the bacterial loads by 2.5, 2.9 and 2.0 log(10) CFU, respectively, and treatment for 6 days by 5.0, 4.2 and 5.1 log(10) CFU, respectively, compared with non-treated controls (P < 0.001). Systemic treatment with linezolid for 6 days reduced the bacterial loads by 1.6 log(10) CFU compared with non-treated mice (P < 0.001), whereas vancomycin treatment showed no effect on reducing the bacterial loads in infected skin lesions. These findings suggest that topical treatment with retapamulin and mupirocin is significantly more effective than systemic treatment with linezolid and vancomycin in eradicating MRSA in skin wounds. Retapamulin and mupirocin may provide an alternative to fusidic acid treatment of MRSA in skin wounds when resistance to fusidic acid is suspected. PMID:23837927

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

    PubMed

    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

  1. Prevalence and characteristics of meticillin-resistant Staphylococcus aureus in humans in contact with farm animals, in livestock, and in food of animal origin, Switzerland, 2009.

    PubMed

    Huber, H; Koller, S; Giezendanner, N; Stephan, R; Zweifel, C

    2010-04-22

    A total of 2,662 samples, collected from March to September 2009 in Switzerland, were tested for the presence of meticillin-resistant Staphylococcus aureus (MRSA). The collection comprised nasal swabs from 148 pig farmers, 133 veterinarians, 179 slaughterhouse employees, 800 pigs, 300 calves, 400 cattle, 100 pooled neck skin swabs from chicken carcasses, and 460 food samples of animal origin. Moreover, 142 S. aureus strains, isolated from bovine mastitis milk, were included in the study. Twenty samples (< 1%; four veterinarians, 10 pigs, three calves, one young bull, and two mastitis milk samples) tested positive for MRSA. Genotyping of the MRSA strains was performed by multilocus sequence typing, spa- and SCCmec-typing, and revealed ST398 (n=18), ST8 (n=1), ST 1 (n=1), spa types t011 (n=7), t034 (n=11), t064 (n=1), t127 (n=1), and SCCmec types IV (n=4) and V (n=16). The 20 MRSA strains were subjected to antibiotic susceptibility testing and pulsed-field gel electrophoresis using the restriction enzyme EagI. Supplementary PCR reactions were performed to investigate the presence of Panton-Valentine leukocidin and staphylococcal enterotoxins A to D. PMID:20430001

  2. Changing characteristics of livestock-associated meticillin-resistant Staphylococcus aureus isolated from humans - emergence of a subclade transmitted without livestock exposure, the Netherlands, 2003 to 2014.

    PubMed

    Bosch, Thijs; van Luit, Martijn; Pluister, Gerlinde N; Frentz, Dineke; Haenen, Anja; Landman, Fabian; Witteveen, Sandra; van Marm-Wattimena, Naomi; van der Heide, Han G; Schouls, Leo M

    2016-05-26

    Since 2007, livestock-associated meticillin-resistant Staphylococcus aureus (LA-MRSA) has become the predominant MRSA clade isolated from humans in the Netherlands. To assess possible temporal changes, we molecularly characterised over 9,000 LA-MRSA isolates submitted from 2003 to 2014 to the Dutch MRSA surveillance. After an initial rapid increase with a peak in 2009 (n = 1,368), the total number of submitted LA-MRSA isolates has been slowly decreasing to 968 in 2014 and over 80% of LA-MRSA belonged to one of three predominant MLVA/spa-types. Next generation sequencing (n=118) showed that MT569/t034 isolates were genetically more diverse than MT398/t011 and MT572/t108. Concurrent with the decrease in LA-MRSA, fewer people reported having contact with livestock and this was most prominent for people carrying MT569/t034 LA-MRSA. The proportion of LA-MRSA isolated from infection-related materials increased from 6% in 2009, to 13% in 2014 and most of these isolates originated from patients older than 50 years of age. Remarkably, 83% of these patients reported not having contact with livestock. The results reveal an ongoing change in the genotypic and epidemiological characteristics of Dutch LA-MRSA isolated from humans with the emergence of a LA-MRSA subclade independent of livestock exposure, suggesting LA-MRSA starts to resemble non-LA-MRSA in terms of transmissibility and pathogenicity. PMID:27254022

  3. What are the drivers of the UK media coverage of meticillin-resistant Staphylococcus aureus, the inter-relationships and relative influences?

    PubMed

    Boyce, T; Murray, E; Holmes, A

    2009-12-01

    Meticillin-resistant Staphylococcus aureus (MRSA) infection in the UK receives intense media attention. The nature of coverage, political responses and solutions offered has been questioned and the relationship between health professionals, the media and government policy needs greater understanding. We identified 2880 articles on MRSA published in 12 UK newspapers between 1994 and 2005, compared with 21 articles in six major US newspapers. To investigate the relative influences and relationships further, 68 weeks of coverage from 1990 to 2004 were analysed. The dates were selected based on publication dates of the ten most frequently cited articles on MRSA according the ISI Web of Science portal of Department of Health press releases on MRSA since 1997. Within this period, 351 news articles were published with members of the public and politicians representing 60% of sources quoted. Scientific articles, even those with the highest number of citations, have negligible influence on newspaper coverage. Simple solutions quoted in the newspaper articles focused almost exclusively on cleaning. The UK press exhibits a high interest in MRSA compared with that of the USA. Healthcare workers, experts and professional bodies have criticised the nature of media reporting, but have had little influence or involvement in the press. This may facilitate journalists, celebrities, the public and politicians to drive these stories unchecked and allow politics to address only the simplistic solutions generated. PMID:19699009

  4. A multicentre study of meticillin-resistant Staphylococcus aureus in acute bacterial skin and skin-structure infections in China: susceptibility to ceftaroline and molecular epidemiology.

    PubMed

    Zhang, Hui; Xiao, Meng; Kong, Fanrong; O'Sullivan, Matthew V N; Mao, Lei-Li; Zhao, Hao-Ran; Zhao, Ying; Wang, He; Xu, Ying-Chun

    2015-04-01

    Ceftaroline is a novel cephalosporin with activity against Gram-positive organisms, including meticillin-resistant Staphylococcus aureus (MRSA). The objective of this study was to investigate the susceptibility to ceftaroline of hospital-associated MRSA (HA-MRSA) isolates causing acute bacterial skin and skin-structure infections (ABSSSIs) in China and to examine their relationship by genotyping. A total of 251 HA-MRSA isolates causing ABSSSIs were collected from a multicentre study involving 56 hospitals in 38 large cities across 26 provinces in mainland China. All isolates were characterised by multilocus sequence typing (MLST), staphylococcal cassette chromosome mec (SCCmec) typing, spa typing and detection of the Panton-Valentine leukocidin locus (lukS-PV and lukF-PV). Minimum inhibitory concentrations (MICs) of 14 antimicrobial agents, including ceftaroline, were determined by broth microdilution and were interpreted using Clinical and Laboratory Standards Institute breakpoints. The ceftaroline MIC50 and MIC90 values (MICs that inhibit 50% and 90% of the isolates, respectively) were 1 μg/mL and 2 μg/mL, respectively; 33.5% (n=84) of the isolates studied were ceftaroline-non-susceptible, with MICs of 2 μg/mL, but no isolate exhibited ceftaroline resistance (MIC>2 μg/mL). All of the ceftaroline-non-susceptible isolates belonged to the predominant HA-MRSA clones: 95.2% (n=80) from MLST clonal complex 8 (CC8), with the remaining 4.8% (n=4) from CC5. The high rate of non-susceptibility to ceftaroline amongst HA-MRSA causing ABSSSIs in China is concerning. PMID:25649348

  5. Natural and ion-exchanged illite clays reduce bacterial burden and inflammation in cutaneous meticillin-resistant Staphylococcus aureus infections in mice.

    PubMed

    Otto, Caitlin C; Kilbourne, Jacquelyn; Haydel, Shelley E

    2016-01-01

    Discoveries associated with antibacterial activity of hydrated clays necessitate assessments of in vivo efficacy, practical use and safety. Surface properties of clays can lead to variations in the composition and abundance of bound compounds or ions, thus affecting antibacterial activity. Since exchangeable metal ions released from the clay surface are responsible for in vitro antibacterial activity, we evaluated the in vivo antibacterial efficacy of four natural clays (one illite clay, two montmorillonite clays and one kaolinite clay) and three ion-exchanged, antibacterial clays against superficial, cutaneous meticillin-resistant Staphylococcus aureus (MRSA) infections in mice. Superficial, cutaneous wounds on the back of SKH1-Elite mice were generated and subsequently infected with MRSA. Following twice daily applications of a hydrated clay poultice to infected wounds for 7  days, we observed significant differences in the in vivo antibacterial efficacy between different types of clays. The natural and ion-exchanged illite clays performed best, as measured by bacterial load, inflammatory response and gross wound morphology with significant decreases in bacterial viability and dermatitis. Topical application of kaolinite clay was the least effective, resulting in the lowest decrease in bacterial load and exhibiting severe dermatitis. These data suggest that specific types of clays may offer a complementary and integrative strategy for topically treating MRSA and other cutaneous infections. However, since natural clays exhibit in vitro antibacterial variability and vary vastly in surface chemistries, adsorptive/absorptive characteristics and structural composition, the properties and characteristics of illite clays could aid in the development of standardized and customized aluminosilicates for topical infections. PMID:26508716

  6. Increase in SCCmec type IV strains affects trends in antibiograms of meticillin-resistant Staphylococcus aureus at a tertiary-care hospital.

    PubMed

    Ito, Ayumu; Nakaminami, Hidemasa; Fujii, Takeshi; Utsumi, Kenta; Noguchi, Norihisa

    2015-07-01

    The prevalence of community-acquired meticillin-resistant Staphylococcus aureus (CA-MRSA) strains has become a serious problem worldwide. The aim of this study was to investigate the annual transitions of MRSA strains with the CA-MRSA feature, which were identified as SCCmec type IV or V, in a hospital setting in Japan. Between 2005 and 2012, MRSA strains were collected from a tertiary-care hospital in Tokyo, Japan, and SCCmec typing, detection of the virulence factors and antimicrobial susceptibility testing were conducted. The rate of detection of type II SCCmec, which is found mainly in healthcare-associated MRSA, significantly decreased from 90.0 (2005-2006) to 74.3 % (2011-2012) (P < 0.01). In contrast, the rate of detection of type IV SCCmec, which is mainly found in CA-MRSA, significantly increased from 5.8 (2005-2006) to 16.3 % (2011-2012) (P < 0.01). The rate of detection of the toxic shock syndrome toxin-1 gene significantly decreased from 66.7 (2005-2006) to 51.6 % (2011-2012) (P < 0.01), whilst that of the Panton-Valentine leukocidin gene significantly increased from 0.1 (2005-2006) to 2.1 % (2011-2012) (P < 0.01). The resistance rates of cefotaxime, levofloxacin, clarithromycin and minocycline decreased every year. The resistance rates of these antimicrobial agents for the SCCmec type IV or V strains were significantly lower than those for the SCCmec type I or II strains (P < 0.01, respectively). Therefore, these results suggest that the annual transitions of the virulence factors and antibiograms in MRSA are closely related to the increase of SCCmec type IV/V strains. PMID:25934550

  7. A network meta-analysis of antibiotics for treatment of hospitalised patients with suspected or proven meticillin-resistant Staphylococcus aureus infection.

    PubMed

    Bally, Michèle; Dendukuri, Nandini; Sinclair, Alison; Ahern, Stéphane P; Poisson, Michel; Brophy, James

    2012-12-01

    Infections due to meticillin-resistant Staphylococcus aureus (MRSA) pose a serious health risk. Novel methods for assessing comparative effectiveness and safety may provide valuable insights into therapeutic choices. We did a systematic review searching electronic databases including the archives of FDA/CDER and performed a Bayesian network meta-analysis to compare parenteral antibiotics used for treating hospitalised adults with complicated skin and soft-tissue infections (cSSTIs) or hospital-acquired or ventilator-associated pneumonia (HAP/VAP). Models were adjusted for clinical heterogeneity due to between-arm differences in the proportion of patients with diabetes (for cSSTI) and in those requiring mechanical ventilation (for pneumonia). Treatments were ranked on efficacy, defined as clinical success in the modified intention-to-treat population (MITT) and in the MITT population with MRSA at baseline (MRSA m-MITT), on all-cause mortality (in pneumonia only), and on serious adverse events and withdrawals due to adverse events. We identified 24 randomised controlled trials (17 for cSSTI and 10 for HAP/VAP) comparing one of six antibiotics with vancomycin. The network meta-analysis indicated that vancomycin ranked third (of six antibiotics) in cSSTI and second (of four) in pneumonia on both efficacy and safety. However, direct pairwise meta-analyses remained inconclusive as evidenced by the adjusted median odds ratios (ORs) and their 95% credible intervals. In cSSTI, linezolid and ceftaroline were non-significantly more effective than vancomycin. Linezolid ORs were 1.15 (0.74-1.71) and 1.01 (0.42-2.14) and ceftaroline ORs were 1.12 (0.78-1.64) and 1.59 (0.68-3.74) in the MITT and MRSA m-MITT populations, respectively. For HAP/VAP, linezolid was non-significantly better than vancomycin, with ORs of 1.05 (0.72-1.57) and 1.32 (0.71-2.48) in the MITT and MRSA m-MITT populations, respectively. We suspect performance and detection bias in cSSTI trials involving

  8. Hospital-wide infection control practice and Meticillin-resistant Staphylococcus aureus (MRSA) in the intensive care unit (ICU): an observational study

    PubMed Central

    Workman, Rella

    2014-01-01

    Summary Objectives To estimate trends in infection/colonisation with meticillin-resistant Staphylococcus aureus (MRSA) in an intensive care unit (ICU). Design Observational study of results of ICU admission and weekly screens for MRSA. Setting and Participants All ICU admissions in 2001–2012. Interventions ICU admissions were screened for MRSA throughout. In late 2006, screening was extended to the whole hospital and extra measures taken in ICU. Main outcome measures Prevalence of MRSA in ICU admissions and number acquiring MRSA therein. Results In all, 366 of 6565 admissions to ICU were MRSA positive, including 270 of 4466 coming from within the hospital in which prevalence increased with time prior to transfer to ICU. Prevalence in this group was 9.4% (8.2–10.6) in 2001–2006, decreasing to 3.4% (2.3–4.5) in 2007–2009 and 1.3% (0.6–2.0) in 2010–2012, p < 0.001, due to decreased prevalence in those spending >5 days on wards before ICU admission: 18.9% (15.6–22.2) in 2001–2006, 7.1% (4.0–10.2) in 2007–2009 and 1.6% (0.1–3.1) in 2010–2012, p < 0.001. In addition, 201 patients acquired MRSA within ICU, the relative risk being greater when known positives present: 4.34 (3.98–4.70), p < 0.001. Acquisition rate/1000 bed days decreased from 13.3 (11.2–15.4) in 2001–2006 to 3.6 (2.6–4.6) in 2007–2012, p < 0.0001. Of 41 ICU-acquired MRSA bacteraemias, 38 were in 2001–2006. The risk of bacteraemia in those acquiring MRSA decreased from 25% (18.1–31.9) in 2001–2006 to 6.1% (0–12.8) thereafter, p = 0.022. Conclusions Following better hospital-wide infection control, fewer MRSA-positive patients were admitted to ICU with a parallel decrease in acquisition therein. Better practice there reduced the risk of bacteraemia. PMID:25383196

  9. Results of a multicentre randomised controlled trial of statistical process control charts and structured diagnostic tools to reduce ward-acquired meticillin-resistant Staphylococcus aureus: the CHART Project.

    PubMed

    Curran, E; Harper, P; Loveday, H; Gilmour, H; Jones, S; Benneyan, J; Hood, J; Pratt, R

    2008-10-01

    Statistical process control (SPC) charts have previously been advocated for infection control quality improvement. To determine their effectiveness, a multicentre randomised controlled trial was undertaken to explore whether monthly SPC feedback from infection control nurses (ICNs) to healthcare workers of ward-acquired meticillin-resistant Staphylococcus aureus (WA-MRSA) colonisation or infection rates would produce any reductions in incidence. Seventy-five wards in 24 hospitals in the UK were randomised into three arms: (1) wards receiving SPC chart feedback; (2) wards receiving SPC chart feedback in conjunction with structured diagnostic tools; and (3) control wards receiving neither type of feedback. Twenty-five months of pre-intervention WA-MRSA data were compared with 24 months of post-intervention data. Statistically significant and sustained decreases in WA-MRSA rates were identified in all three arms (P<0.001; P=0.015; P<0.001). The mean percentage reduction was 32.3% for wards receiving SPC feedback, 19.6% for wards receiving SPC and diagnostic feedback, and 23.1% for control wards, but with no significant difference between the control and intervention arms (P=0.23). There were significantly more post-intervention 'out-of-control' episodes (P=0.021) in the control arm (averages of 0.60, 0.28, and 0.28 for Control, SPC and SPC+Tools wards, respectively). Participants identified SPC charts as an effective communication tool and valuable for disseminating WA-MRSA data. PMID:18723251

  10. Approaching zero: temporal effects of a restrictive antibiotic policy on hospital-acquired Clostridium difficile, extended-spectrum β-lactamase-producing coliforms and meticillin-resistant Staphylococcus aureus.

    PubMed

    Dancer, S J; Kirkpatrick, P; Corcoran, D S; Christison, F; Farmer, D; Robertson, C

    2013-02-01

    A restrictive antibiotic policy banning routine use of ceftriaxone and ciprofloxacin was implemented in a 450-bed district general hospital following an educational campaign. Monthly consumption of nine antibiotics was monitored in defined daily doses (DDDs) per 1000 patient-occupied bed-days (1000 pt-bds) 9 months before until 16 months after policy introduction. Hospital-acquired Clostridium difficile, meticillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum β-lactamase (ESBL)-producing coliform cases per month/1000 pt-bds were identified and reviewed throughout the hospital. Between the first and final 6 months of the study, average monthly consumption of ceftriaxone reduced by 95% (from 46.213 to 2.129 DDDs/1000 pt-bds) and that for ciprofloxacin by 72.5% (109.804 to 30.205 DDDs/1000 pt-bds). Over the same periods, hospital-acquisition rates for C. difficile reduced by 77% (2.398 to 0.549 cases/1000 pt-bds), for MRSA by 25% (1.187 to 0.894 cases/1000 pt-bds) and for ESBL-producing coliforms by 17% (1.480 to 1.224 cases/1000 pt-bds). Time-lag modelling confirmed significant associations between ceftriaxone and C. difficile cases at 1 month (correlation 0.83; P<0.005), and between ciprofloxacin and ESBL-producing coliform cases at 2 months (correlation 0.649; P=0.002). An audit performed 3 years after the policy showed sustained reduction in C. difficile rates (0.259 cases/1000 pt-bds), with additional decreases for MRSA (0.409 cases/1000 pt-bds) and ESBL-producing coliforms (0.809 cases/1000 pt-bds). In conclusion, banning two antibiotics resulted in an immediate and profound reduction in hospital-acquired C. difficile, with possible longer-term effects on MRSA and ESBL-producing coliform rates. Antibiotic stewardship is fundamental in the control of major hospital pathogens. PMID:23276500

  11. First report in South America of companion animal colonization by the USA1100 clone of community-acquired meticillin-resistant Staphylococcus aureus (ST30) and by the European clone of methicillin-resistant Staphylococcus pseudintermedius (ST71)

    PubMed Central

    2013-01-01

    Background Methicillin-resistant staphylococci can colonize and cause diseases in companion animals. Unfortunately, few molecular studies have been carried out in Brazil and other countries with the aim of characterizing these isolates. Consequently, little is known about the potential role of companion animals in transmitting these resistant bacteria to humans. In this work we searched for mecA gene among Staphylococcus isolates obtained from nasal microbiota of 130 healthy dogs and cats attended in a veterinary clinic located in the west region of Rio de Janeiro. The isolates recovered were identified to the species level and characterized using molecular tools. Results A community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) isolate related to USA1100 (Southwest Pacific clone) and susceptible to all non-β-lactams was detected in a cat (1.7%, 1/60). Another coagulase-positive isolate harboring mecA was recovered from a dog (1.4%, 1/70) and identified as Staphylococcus pseudintermedius (MRSP) related to the European clone (ST71). The two isolates of Staphylococcus conhii subsp. urealyticus (1.4%, 1/70 dogs and 1.7%, 1/60 cats), similarly to the MRSP isolate, also presented high-level multiresistance. The majority of the methicillin-resistant coagulase-negative staphylococci recovered were Staphylococcus saprophyticus (5.7%, 4/70 dogs and 6.7%, 4/60 cats) and all clustered into the same PFGE type. Conclusions This work demonstrates that mecA-harboring Staphylococcus isolates are common members of the nasal microbiota of the healthy companion animals studied (9.2%, 12/130 animals), including some high-level multiresistant isolates of S. pseudintermedius and S. conhii subsp. urealyticus. The detection, for the first time in South America, of USA1100-related CA-MRSA and of ST71 MRSP (European clone), colonizing companion animals, is of concern. Both S. pseudintermedius and S. aureus are important agents of infections for animals. The USA1100 CA

  12. Expression of multidrug resistance efflux pump genes in clinical and environmental isolates of Staphylococcus aureus.

    PubMed

    Kosmidis, Christos; Schindler, Bryan D; Jacinto, Pauline L; Patel, Diixa; Bains, Karanpreet; Seo, Susan M; Kaatz, Glenn W

    2012-09-01

    Increased expression of multidrug resistance efflux pump (MDR-EP) genes in clinical isolates of Staphylococcus aureus occurs frequently, but its temporal and geographic variability is unknown. Such strains may contaminate the hospital environment, posing an infection control problem. Nearly 700 clinical isolates from different geographic locales as well as 91 environmental isolates recovered from two Detroit hospitals were studied. Ethidium bromide (EtBr) minimum inhibitory concentration (MIC), quantitative expression of all characterised chromosomal MDR-EP genes, and the presence of qacA/B and smr were determined for all strains. In addition, for norA- and/or mepA-overexpressing strains, the spa type was established. MDR-EP gene overexpression varied temporally and geographically, and overexpressing strains were present in the hospital environment. Increased expression of norA was associated with meticillin resistance and spa type t002, a rare type among control strains, consistent with widespread dissemination of a norA-overexpressing, meticillin-resistant S. aureus (MRSA) clone. Clonal spread also played a role for spa type t008, mepA-overexpressing, meticillin-susceptible strains. An EtBr MIC of ≤12.5 μg/mL was highly specific (>90%) in identifying strains lacking MDR-EP gene overexpression. PMID:22766161

  13. Rapid systemic and local treatments with the antibacterial peptide dimer A3-APO and its monomeric metabolite eliminate bacteria and reduce inflammation in intradermal lesions infected with Propionibacterium acnes and meticillin-resistant Staphylococcus aureus.

    PubMed

    Ostorhazi, Eszter; Voros, Elvira; Nemes-Nikodem, Eva; Pinter, Dora; Sillo, Palma; Mayer, Balazs; Wade, John D; Otvos, Laszlo

    2013-12-01

    When administered intramuscularly, the designer antibacterial peptide dimer A3-APO is highly efficacious in mouse models of Acinetobacter baumannii and Staphylococcus aureus burn infections. Here we compared the efficacy of A3-APO and its monomeric metabolite in mouse models of S. aureus and Propionibacterium acnes intradermal infections following administration as intramuscular (i.m.) or topical treatments. In the animal models, either (i) the ears of CD-1 mice were infected with P. acnes or (ii) S. aureus was injected into burn wounds inflicted to the back. A3-APO or the monomer were injected intramuscularly at 5 mg/kg one to three times or were applied three times as 1% local treatment in phosphate-buffered saline or Vaseline(®). Despite being inactive against the strains in vitro, in vivo the skin conditions of the mice were dramatically improved upon peptide treatment regardless of dosing frequency, administration mode or drug valency. In the P. acnes study, A3-APO statistically significantly reduced ear thickness and ear bacterial counts. The amount of ear connective tissue and epithelial macrophages correlated with therapeutic success. Bacterial load in the lesions was more representative of physical improvement than ear dimensions. In the S. aureus model, both peptides eliminated wound bacteria from >10(7) CFU/mg to almost background levels, with monomer treatment being somewhat more successful. In conclusion, A3-APO and its monomeric metabolite very efficiently ameliorate resistant aerobic and anaerobic intradermal infections, but the protection is apparently not due to direct bacterial killing. Immunostimulatory and anti-inflammatory actions are likely involved. Nevertheless, topical and i.m. administrations are equally effective. PMID:24074727

  14. The National One Week Prevalence Audit of Universal Meticillin-Resistant Staphylococcus aureus (MRSA) Admission Screening 2012

    PubMed Central

    Fuller, Christopher; Robotham, Julie; Savage, Joanne; Hopkins, Susan; Deeny, Sarah R.; Stone, Sheldon; Cookson, Barry

    2013-01-01

    Introduction The English Department of Health introduced universal MRSA screening of admissions to English hospitals in 2010. It commissioned a national audit to review implementation, impact on patient management, admission prevalence and extra yield of MRSA identified compared to “high-risk” specialty or “checklist-activated” screening (CLAS) of patients with MRSA risk factors. Methods National audit May 2011. Questionnaires to infection control teams in all English NHS acute trusts, requesting number patients admitted and screened, new or previously known MRSA; MRSA point prevalence; screening and isolation policies; individual risk factors and patient management for all new MRSA patients and random sample of negatives. Results 144/167 (86.2%) trusts responded. Individual patient data for 760 new MRSA patients and 951 negatives. 61% of emergency admissions (median 67.3%), 81% (median 59.4%) electives and 47% (median 41.4%) day-cases were screened. MRSA admission prevalence: 1% (median 0.9%) emergencies, 0.6% (median 0.4%) electives, 0.4% (median 0%) day-cases. Approximately 50% all MRSA identified was new. Inpatient MRSA point prevalence: 3.3% (median 2.9%). 104 (77%) trusts pre-emptively isolated patients with previous MRSA, 63 (35%) pre-emptively isolated admissions to “high-risk” specialties; 7 (5%) used PCR routinely. Mean time to MRSA positive result: 2.87 days (±1.33); 37% (219/596) newly identified MRSA patients discharged before result available; 55% remainder (205/376) isolated post-result. In an average trust, CLAS would reduce screening by 50%, identifying 81% of all MRSA. “High risk” specialty screening would reduce screening by 89%, identifying 9% of MRSA. Conclusions Implementation of universal screening was poor. Admission prevalence (new cases) was low. CLAS reduced screening effort for minor decreases in identification, but implementation may prove difficult. Cost effectiveness of this and other policies, awaits evaluation by transmission dynamic economic modelling, using data from this audit. Until then trusts should seek to improve implementation of current policy and use of isolation facilities. PMID:24069282

  15. The First Vancomycin-Intermediate Staphylococcus aureus Strains Isolated from Patients in Thailand▿

    PubMed Central

    Lulitanond, Aroonlug; Engchanil, Chulapan; Chaimanee, Prajuab; Vorachit, Malai; Ito, Teruyo; Hiramatsu, Keiichi

    2009-01-01

    We screened 533 and 361 methicillin (meticillin)-resistant Staphylococcus aureus strains isolated in a university hospital in 2002 and 2003 and in 2006 and 2007, respectively, and identified 4 (0.8%) of the strains in the first group and 8 (2.2%) of the strains in second group as heterogeneous vancomycin-resistant S. aureus (heterogeneous VISA) strains and 3 (0.8%) of the strains in the second group as VISA strains. This is the first report of VISA strains isolated from patients in Thailand. PMID:19403764

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

    PubMed

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

    2016-01-15

    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. PMID:26711039

  17. Novel ABC Transporter Gene, vga(C), Located on a Multiresistance Plasmid from a Porcine Methicillin-Resistant Staphylococcus aureus ST398 Strain ▿

    PubMed Central

    Kadlec, Kristina; Schwarz, Stefan

    2009-01-01

    A novel ABC transporter gene, vga(C), was identified on the 14,365-bp multiresistance plasmid pKKS825 in a porcine methicillin (meticillin)-resistant Staphylococcus aureus isolate of sequence type 398. The vga(C) gene encodes a 523-amino-acid protein which confers resistance not only to streptogramin A antibiotics but also to lincosamides and pleuromutilins. Plasmid pKKS825 also carries the resistance genes aadD, tet(L), and dfrK, which may enable the coselection of vga(C) under selective pressure by kanamycin/neomycin, tetracyclines, and trimethoprim. PMID:19470508

  18. High prevalence of Staphylococcus haemolyticus and Staphylococcus saprophyticus in environmental samples of a Tunisian hospital.

    PubMed

    Dziri, Raoudha; Klibi, Naouel; Lozano, Carmen; Ben Said, Leila; Bellaaj, Ridha; Tenorio, Carmen; Boudabous, Abdellatif; Ben Slama, Karim; Torres, Carmen

    2016-06-01

    The purpose of this study was to evaluate the rate of detection of coagulase negative staphylococci (CoNS) in environmental samples of 17 services in a Tunisian hospital, determining the antimicrobial resistance phenotypes and genotypes of recovered isolates. To our knowledge, this is the first study that determines the prevalence of CoNS with correlation of antibiotic resistance in the hospital environment in Tunisia. CoNS were obtained from 83 of the 200 tested samples (41.5%). Staphylococcus haemolyticus was the most prevalent species (45.8%), followed by S. saprophyticus (36.1%). The remaining CoNS species detected were S. epidermidis, S. cohnii, S. warneri, S. sciuri, S. simulans, S. pasteuri, S. arlettae, and S. xilosus. Methicillin-resistant CoNS were detected in 20 of the 200 tested samples (10%), and the mecA gene was demonstrated in 18 S. haemolyticus, one S. epidermidis and one S. saprophyticus isolates. Methicillin susceptible isolates were detected in 63 samples (31.5%). Antimicrobial resistance genes detected were as follows (number of isolates): erythromycin [msr(A) (n = 32); erm(C) (n = 8)], tetracycline [tet(K) and/or tet(M) (n = 21)], gentamicin [aac(6')-Ie-aph(2″)-Ia (n = 16)], kanamycin [(aph(3')-IIIa (n = 19)], tobramycin [ant(4')-Ia (n = 14)], and streptomycin [ant(6')-Ia (n = 3)]. The high frequency of detection of multi-drug-resistant CoNS in the hospital environment, especially S. haemolyticus and S. saprophyticus, is of relevance and could be due to cross-transmission between patients, staff, and environment. PMID:27133307

  19. Detection of methicillin resistant Staphylococcus aureus (MRSA) from recreational beach using the mecA gene

    NASA Astrophysics Data System (ADS)

    Zulkifli, Aisya; Ahmad, Asmat

    2015-09-01

    Water samples were collected in triplicates from three different locations choosen from the recreational beach of Teluk Kemang, Port Dickson as sampling station including main area of recreation activity for the public. Bacteria were isolated from the water and cultured. Out of 286 presumptive Staphylococcus aureus enumerated by using culture method, only 4 (1.4 %) confirmed as Meticillin Resistant S. aureus (MRSA) based on PCR detection of mecA gene. Interestingly, all of MRSA detections were found at the main area of recreational activity. Our results suggested that public beaches may be reservoir for transmission of MRSA to beach visitors and PCR using the mecA gene is the fastest way to detect this pathogenic bacteria.

  20. Activity of telavancin and comparator antimicrobial agents tested against Staphylococcus spp. isolated from hospitalised patients in Europe (2007-2008).

    PubMed

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

    2010-10-01

    The activity of telavancin was evaluated against Staphylococcus spp. collected from European hospitals as part of an international surveillance study (2007-2008). A total of 7534 staphylococcal clinical isolates [5726 Staphylococcus aureus and 1808 coagulase-negative staphylococci (CoNS)] were included. Isolates were tested for susceptibility according to reference methods and minimum inhibitory concentration (MIC) values were interpreted based on Clinical and Laboratory Standards Institute (CLSI) 2010 and European Committee on Antimicrobial Susceptibility Testing (EUCAST) 2009 criteria. Telavancin breakpoints approved by the US Food and Drug Administration (FDA) were applied. Telavancin activity was evaluated against meticillin-resistant S. aureus (MRSA) displaying several antibiogram resistance patterns, including multidrug-resistant isolates. Telavancin was active against S. aureus [MIC(50/90) values (MICs for 50% and 90% of the isolates, respectively)=0.12/0.25mg/L; 100.0% susceptible] and CoNS (MIC(50/90)=0.12/0.25mg/L), inhibiting all isolates at < or =0.5mg/L. Similar results were observed when S. aureus were stratified by year or country of origin (MIC(50/90)=0.12/0.25mg/L). When MRSA isolates were clustered according to 48 different resistance patterns, telavancin showed consistent MIC(90) values (0.25mg/L) regardless of multidrug resistance. Amongst CoNS, telavancin was slightly more active against Staphylococcus capitis, Staphylococcus epidermidis, Staphylococcus hominis, Staphylococcus lugdunensis and Staphylococcus xylosus (MIC(50)=0.12 mg/L) compared with Staphylococcus haemolyticus, Staphylococcus saprophyticus and Staphylococcus warneri (MIC(50)=0.25mg/L). Overall, telavancin exhibited MIC(90) results two- to eight-fold lower than comparators (daptomycin, quinupristin/dalfopristin, vancomycin and linezolid). Based upon MIC(90) values, telavancin demonstrated potent in vitro activity against a contemporary (2007-2008) collection of Staphylococcus spp

  1. Staphylococcus aureus ST121: a globally disseminated hypervirulent clone.

    PubMed

    Rao, Qing; Shang, Weilong; Hu, Xiaomei; Rao, Xiancai

    2015-12-01

    Staphylococcus aureus is a leading cause of bacterial infections in hospitals and communities worldwide. With the development of typing methods, several pandemic clones have been well characterized, including the extensively spreading hospital-associated meticillin-resistant S. aureus (HA-MRSA) clone ST239 and the emerging hypervirulent community-associated (CA) MRSA clone USA300. The multilocus sequence typing method was set up based on seven housekeeping genes; S. aureus groups were defined by the sharing of alleles at ≥ 5 of the seven loci. In many cases, the predicted founder of a group would also be the most prevalent ST within the group. As a predicted founder of major S. aureus groups, approximately 90 % of ST121 strains was meticillin-susceptible S. aureus (MSSA). The majority of ST121 strains carry accessory gene regulator type IV, whereas staphylococcal protein A gene types for ST121 are exceptionally diverse. More than 90 % of S. aureus ST121 strains have Panton-Valentine leukocidin; other enterotoxins, haemolysins, leukocidins and exfoliative toxins also contribute to the high virulence of ST121 strains. Patients suffering from S. aureus ST121 infections often need longer hospitalization and prolonged antimicrobial therapy. In this review, we tried to summarize the epidemiology of the S. aureus clone ST121 and focused on the molecular types, toxin carriage and disease spectrum of this globally disseminated clone. PMID:26445995

  2. Role of Environmental and Antibiotic Stress on Staphylococcus epidermidis Biofilm Microstructure

    PubMed Central

    Stewart, Elizabeth J.; Satorius, Ashley E.; Younger, John G.; Solomon, Michael J.

    2014-01-01

    Cellular clustering and separation of Staphylococcus epidermidis surface adherent biofilms were found to depend significantly on both antibiotic and environmental stress present during growth under steady flow. Image analysis techniques common to colloidal science were applied to image volumes acquired with high-resolution confocal laser scanning microscopy to extract spatial positions of individual bacteria in volumes of size ~30 × 30 × 15 μm3. The local number density, cluster distribution, and radial distribution function were determined at each condition by analyzing the statistics of the bacterial spatial positions. Environmental stressors of high osmotic pressure (776 mM NaCl) and sublethal antibiotic dose (1.9 μg/mL vancomycin) decreased the average bacterial local number density 10-fold. Device-associated bacterial biofilms are frequently exposed to these environmental and antibiotic stressors while undergoing flow in the bloodstream. Characteristic density phenotypes associated with low, medium, and high local number densities were identified in unstressed S. epidermidis biofilms, while stressed biofilms contained medium- and low-density phenotypes. All biofilms exhibited clustering at length scales commensurate with cell division (~1.0 μm). However, density phenotypes differed in cellular connectivity at the scale of ~6 μm. On this scale, nearly all cells in the high- and medium-density phenotypes were connected into a single cluster with a structure characteristic of a densely packed disordered fluid. However, in the low-density phenotype, the number of clusters was greater, equal to 4% of the total number of cells, and structures were fractal in nature with df =1.7 ± 0.1. The work advances the understanding of biofilm growth, informs the development of predictive models of transport and mechanical properties of biofilms, and provides a method for quantifying the kinetics of bacterial surface colonization as well as biofilm fracture and

  3. Contamination of environmental surfaces by Staphylococcus aureus in a dermatological ward and its preventive measures.

    PubMed

    Oie, Shigeharu; Yanagi, Chikashige; Matsui, Hiroto; Nishida, Tomoko; Tomita, Masaaki; Kamiya, Akira

    2005-01-01

    We investigated contamination of environmental surfaces by Staphylococcus aureus from April 1 to the end of June in 2002 in the dermatological ward (37 beds) of a university hospital. For surfaces contaminated by high levels of S. aureus, disinfection methods were evaluated. 100-10(5) colony forming units (cfu) of methicillin-resistant S. aureus (MRSA) or methicillin-sensitive S. aureus (MSSA) were detected on items such as an immersion bathtub (examined area, about 900 cm2), foot washbowl, stretcher for an immersion bath, and chair for the shower. After disinfection, no S. aureus was detected on smooth surfaces such as the immersion bathtub and foot washbowl; however, S. aureus was detected even after disinfection on porous surfaces made of sponge-like materials (polyethylene foam) such as the stretcher for the immersion bath and the shower chair. Scanning electron microscopy of the porous surfaces showed formation of a large amount of coccus and bacillus biofilms on the walls of pores in the multi-pore structure. Material that is porous should not be used in patient care settings because it is not possible to disinfect it properly. PMID:15635175

  4. mec-A-mediated Resistance in Staphylococcus aureus in a Referral Hospital, Tehran, Iran

    PubMed Central

    Rajabiani, Afsaneh; Kamrani, Fatemeh; Boroumand, Mohammad Ali; Saffar, Hiva

    2014-01-01

    Background: The emerge of rapid and accurate detection of Meticillin-Resistant Staphylococcus aureus (MRSA) has been highlighted. Objectives: The current study evaluated the prevalence of mec-A gene in biological specimens of various medical wards, in order to determine any possible relationship. Patients and Methods: Using traditional culture methods, 250 isolates were detected. The prevalence of mec-A mediated resistance was evaluated by PCR method. Results: Among 98 isolates (39.2%) with resistant inhibition zones, 92 isolates carried mec-A gene and were considered as MRSA. Significantly higher rate of MRSA was observed in the specimens from emergency department and intensive care unit (P value < 0.001). Although, the prevalence of MRSA was higher in patients with history of previous hospital admission within the past three months (P = 0.006), but only one case with the same history was hospitalized in the emergency ward that was among the wards with the highest rate of MRSA. Conclusions: The study findings show that, although there is higher rate of MRSA infection in patients with history of hospitalization, but even in cases without any history of medical admission, more detailed questions emphasizing on receiving any recent health care should be asked in a referral hospital, in order to determine the true community-acquired MRSA. PMID:25147695

  5. Prevalence, antibiotic resistance and molecular characterisation of Staphylococcus aureus in pigs at agricultural fairs in the USA.

    PubMed

    Dressler, A E; Scheibel, R P; Wardyn, S; Harper, A L; Hanson, B M; Kroeger, J S; Diekema, D J; Bender, J B; Gray, G C; Smith, T C

    2012-05-12

    Fairs and petting zoos have been associated with outbreaks of zoonotic disease. Previously, the presence of meticillin-resistant Staphylococcus aureus (MRSA) was documented in commercial pigs; therefore, it was hypothesised that antibiotic-resistant S aureus may also occur in pigs exhibited at agricultural fairs. To test this hypothesis, 157 pigs were swabbed at two state fairs in 2008 to 2009. Both nares were sampled and cultures were grown in enrichment broth, then plated onto selective MRSA plates and blood plates. S aureus was confirmed using phenotypic and molecular methods, and was analysed using spa typing, gene-specific polymerase chain reaction and antibiotic susceptibility testing. The presence of S aureus was confirmed in samples collected from pigs exhibited at USA pig shows. Twenty-five of 157 (15.9 per cent) samples were positive for S aureus. Two isolates (8 per cent) were resistant to meticillin; 23/25 (92 per cent), 14/25 (56 per cent) and 15/25 (60 per cent) were resistant to tetracycline, erythromycin and clindamycin, respectively. spa typing revealed multiple isolates of spa type t034 (9/25, 36 per cent) and t337 (7/25, 28 per cent) and singletons of t002, t209, t526, t1236, t1334, t1683, t3075, t5784 and t5883. These results verify the presence of antibiotic-resistant S aureus in pigs exhibited at USA fairs, suggesting that pigs are a potential reservoir for S aureus within this environment. PMID:22505242

  6. Characterisation of a Staphylococcus aureus strain with progressive loss of susceptibility to vancomycin and daptomycin during therapy.

    PubMed

    Tenover, Fred C; Sinner, Scott W; Segal, Robert E; Huang, Vanthida; Alexandre, Shandline S; McGowan, John E; Weinstein, Melvin P

    2009-06-01

    Following an initial response to vancomycin therapy, a patient with meticillin-resistant Staphylococcus aureus (MRSA) bacteraemia developed endocarditis, failed a second course of vancomycin and then failed daptomycin therapy. An increase in the vancomycin minimum inhibitory concentrations of four consecutive MRSA blood isolates from 2 microg/mL to 8 microg/mL was shown by Etest. Population analysis of four successive blood culture isolates recovered over the 10-week period showed that the MRSA strain became progressively less susceptible to both vancomycin and daptomycin. Retrospectively, the macro Etest method using teicoplanin indicated a decrease in vancomycin susceptibility in the second blood isolate. The patient improved after treatment with various courses of trimethoprim/sulfamethoxazole, quinupristin/dalfopristin and linezolid. Early detection of vancomycin-heteroresistant S. aureus isolates, which appeared to have clinical significance in this case, continues to be a challenge for the clinical laboratory. Development of suitable practical methods for this should be given priority. Concurrent development of resistance to vancomycin and daptomycin, whilst rare, must be considered in a patient who is unresponsive to daptomycin following vancomycin therapy. PMID:19233622

  7. Photodynamic antibacterial and antibiofilm activity of RLP068/Cl against Staphylococcus aureus and Pseudomonas aeruginosa forming biofilms on prosthetic material.

    PubMed

    Vassena, Christian; Fenu, Simone; Giuliani, Francesco; Fantetti, Lia; Roncucci, Gabrio; Simonutti, Giulio; Romanò, Carlo Luca; De Francesco, Raffaele; Drago, Lorenzo

    2014-07-01

    Prosthetic joint infections (PJIs) are becoming a growing public health concern in developed countries as more people undergo arthroplasty for bone fixation or joint replacement. Because a wide range of bacterial strains responsible for PJIs can produce biofilms on prosthetic implants and because the biofilm structure confers elevated bacterial resistance to antibiotic therapy, new drugs and therapies are needed to improve the clinical outcome of treatment of PJIs. Antimicrobial photodynamic therapy (APDT), a non-antibiotic broad-spectrum antimicrobial treatment, is also active against multidrug-resistant micro-organisms such as meticillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. APDT uses a photosensitiser that targets bacterial cells following exposure to visible light. APDT with RLP068/Cl, a novel photosensitiser, was studied by confocal laser scanning microscopy (CLSM) to evaluate the disruption of MRSA and P. aeruginosa biofilms on prosthetic material. Quantitative CLSM studies showed a reduction in biofilm biomass (biofilm disruption) and a decrease in viable cell numbers, as determined by standard plate counting, in the S. aureus and P. aeruginosa biofilms exposed to APDT with the photosensitiser RLP068/Cl. APDT with RLP068/Cl may be a useful approach to the treatment of PJI-associated biofilms. PMID:24933446

  8. Utility of a single nasal polymerase chain reaction assay in predicting absence of skin and environmental contamination in hospitalized patients with past methicillin-resistant Staphylococcus aureus.

    PubMed

    Guerrero, Dubert M; Wagner, Matthew; Carson, Grace; Hanish, Christine; Thompson, Jody; Orr, Megan; Roth, Felix; Carson, Paul J

    2016-06-01

    We evaluated hospitalized patients with a history of methicillin-resistant Staphylococcus aureus (MRSA) for persistent colonization and need for contact precautions. Up to 3 daily cultures of nares, skin, and any present wounds were compared with a single nasal polymerase chain reaction (PCR) assay. Most patients (76.2%) were no longer colonized with MRSA. A single PCR assay was sufficient to exclude persistent colonization and environmental contamination and remove the contact precautions. PMID:26874408

  9. The development of a new three-step protocol to determine the efficacy of disinfectant wipes on surfaces contaminated with Staphylococcus aureus.

    PubMed

    Williams, G J; Denyer, S P; Hosein, I K; Hill, D W; Maillard, J-Y

    2007-12-01

    We developed a three-step protocol to quantify the efficacy of disinfectant wipes, their ability to remove and prevent microbial transfer from surfaces and their overall antimicrobial activity. Meticillin-resistant (MRSA) or -susceptible (MSSA) Staphylococcus aureus (6-7 log(10)cfu) were inoculated onto stainless steel discs with or without organic load and dried. Grapefruit extract-containing test wipes and unmedicated control wipes were used. In step 1, wipes were mechanically rotated against surfaces for 10s at 60rpm, exerting a weight of 100+/-5g. Bacterial removal was assessed by transferring the steel discs to neutraliser, resuspending and counting remaining bacteria. In step 2, bacterial transfer from wipes was assessed by eight consecutive mechanical adpression transfers to agar/neutraliser plates. Step 3 was the measurement of antimicrobial activity by direct inoculation of the wipes for 10s followed by neutralisation and enumeration. Test wipes achieved a significantly higher bacterial cell removal than control wipes on all surfaces (P<0.05). The low bactericidal activity of the wipes (<1 log(10) reduction when directly inoculated) and the subsequent survival of bacteria on the wipes, however, led to repeated microbial transfer when initially high contamination levels were present. There were no differences between MRSA and MSSA in removal, transfer or antimicrobial activity. The three-step method is a useful tool for developing future guidelines to assess the ability of wipes to disinfect surfaces. PMID:17945392

  10. Increasing antimicrobial resistance in clinical isolates of Staphylococcus intermedius group bacteria and emergence of MRSP in the UK.

    PubMed

    Beever, L; Bond, R; Graham, P A; Jackson, B; Lloyd, D H; Loeffler, A

    2015-02-14

    Frequencies of antimicrobial resistance were determined amongst 14,555 clinical Staphylococcus intermedius group (SIG) isolates from UK dogs and cats to estimate resistance trends and quantify the occurrence of meticillin-resistant Staphylococcus pseudintermedius (MRSP). Reports from two diagnostic laboratories (13,313 general submissions, 1242 referral centre only submissions) were analysed retrospectively (2003/2006-2012). MRSP were defined by phenotypic resistance to meticillin and concurrent broad β-lactam resistance; a subset was confirmed genetically (SIG-specific nuc and mecA). Trends were analysed by Cochran-Armitage test. Resistance remained below 10 per cent for cefalexin, amoxicillin-clavulanic acid and the fluoroquinolones. Increasing resistance trends were seen in both laboratories for ampicillin/amoxicillin (both P<0.001), cefovecin (both P<0.046) and enrofloxacin (both P<0.02). Resistance to cefalexin increased over time in referral hospital isolates (P<0.001) to clindamycin (P=0.01) and trimethoprim-sulfamethoxazole (P=0.001) amongst general laboratory submissions. Overall, 106 MRSP were isolated (0.7 per cent of submissions) including 32 (2.6 per cent of submissions, all genetically confirmed) from the referral centre population (inter-laboratory difference P<0.001). Against a background of widely susceptible SIG isolates, a new trend of increasing resistance to important antimicrobials was identified overtime and the emergence of MRSP from UK clinical cases was confirmed. Attention to responsible use of antibacterial therapy in small animal practice is urgently needed. PMID:25376505

  11. Multidrug-resistant Staphylococcus haemolyticus isolates from infected eyes and healthy conjunctivae in India.

    PubMed

    Panda, Sasmita; Kar, Sarita; Sharma, Savitri; Singh, Durg V

    2016-09-01

    This study aimed to determine the presence of antibiotic resistance genes (ARGs), SCCmec elements and genetic relatedness among Staphylococcus haemolyticus isolated from patients with a variety of eye infections (n=11) and from healthy conjunctiva (n=7). Minimum inhibitory concentrations were determined for 14 antimicrobials according to BSAC guidelines. PCR was used to identify the presence of mecA, mecC, SCCmec type and ARGs. Sequencing was used to determine mutations in gyrA, gyrB, topoisomerase IVA and IVB genes. Genetic relatedness was determined by PFGE. Of the 18 isolates, 17 showed resistance to at least one antibiotic, but none showed resistance to vancomycin or rifampicin. Ten isolates were oxacillin-resistant and carried the mecA gene, eight of which belonged to SCCmec type V. The presence of non-mec SCC elements in two meticillin-susceptible isolates and untypeable SCC elements in meticillin-resistant isolates suggests the involvement of S. haemolyticus in the diversification of SCC elements. Sequence analysis revealed point mutations in gyrA (Ser-84→Leu) and topoisomerase IVA genes (Ser-80→Leu) in 13 isolates, and additional variation in the QRDR (Asp-84→Asn) of two isolates, showing good correlation between mutations in gyrA and topoisomerase IV genes and the level of resistance to fluoroquinolones. PFGE analysis showed distinct pulsotypes forming two major clusters, indicating the existence of diversity among isolates, irrespective of the source of isolation. This study suggests that S. haemolyticus isolates from infected eyes and healthy conjunctivae invariably carried ARGs and SCCmec elements and showed diversity in their genomic content, irrespective of the source of isolation. PMID:27530859

  12. Clonal relatedness is a predictor of spontaneous multidrug efflux pump gene overexpression in Staphylococcus aureus.

    PubMed

    Schindler, Bryan D; Jacinto, Pauline L; Buensalido, Joseph Adrian L; Seo, Susan M; Kaatz, Glenn W

    2015-05-01

    Increased expression of genes encoding multidrug resistance efflux pumps (MDR-EPs) contributes to antimicrobial agent and biocide resistance in Staphylococcus aureus. Previously identified associations between norA overexpression and spa type t002 meticillin-resistant S. aureus (MRSA), and a similar yet weaker association between mepA overexpression and type t008 meticillin-susceptible S. aureus (MSSA), in clinical isolates are suggestive of clonal dissemination. It is also possible that related strains are prone to mutations resulting in overexpression of specific MDR-EP genes. Exposure of non-MDR-EP-overexpressing clinical isolates to biocides and dyes can select for MDR-EP-overexpressing mutants. spa types t002 and t008 isolates are predominated by multilocus sequencing typing sequence types (STs) 5 and 8, respectively. In this study, non-MDR-EP gene-overexpressing clinical isolates (MRSA and MSSA) representing ST5 and ST8 were subjected to single exposures of ethidium bromide (EtBr) to select for EtBr-resistant mutants. Measurements of active EtBr transport among mutants were used to demonstrate an efflux-proficient phenotype. Using quantitative reverse-transcription PCR, it was found that EtBr-resistant mutants of ST5 and ST8 parental strains predominantly overexpressed mepA (100%) and mdeA (83%), respectively, regardless of meticillin sensitivity. Associations between clonal lineage and MDR-EP gene overexpression differed from those previously observed and suggest the latter is due to clonal spread of efflux-proficient strains. The predilection of in vitro-selected mutants of related strains to overexpress the same MDR-EP gene indicates the presence of a consistent mutational process. PMID:25548027

  13. Insights and clinical perspectives of daptomycin resistance in Staphylococcus aureus: A review of the available evidence.

    PubMed

    Stefani, Stefania; Campanile, Floriana; Santagati, Maria; Mezzatesta, Maria Lina; Cafiso, Viviana; Pacini, Giovanni

    2015-09-01

    The emergence of glycopeptide reduced susceptibility and resistance in Staphylococcus aureus strains is a growing clinical problem that poses significant clinical challenges in treatment. Its development is a complex and novel process involving many subtle physiological changes in the micro-organism. Daptomycin is the first cyclic lipopeptide approved for clinical use. Unlike most other antimicrobials, a trend towards increased daptomycin resistance has not been reported, although several cases of daptomycin non-susceptibility have been reported. The present review will present the available evidence on daptomycin resistance of S. aureus, with particular attention to its development. In addition to a literature overview, we have compiled the reported cases of daptomycin non-susceptibility to shed light on possible clinical mechanisms of resistance. In the 36 reports describing 62 clinical cases, infections caused by meticillin-resistant S. aureus (MRSA) strains with a vancomycin minimum inhibitory concentration (MIC) between 1mg/L and 2mg/L often led to vancomycin treatment failure, which may be associated with the development of non-susceptibility to daptomycin. Additional evidence suggests that underdosage of daptomycin is an important clinical aspect that merits further study. The current analysis highlights the importance of determining the MIC when using vancomycin to treat patients with severe S. aureus infections and that when failure is suspected, testing for heterogeneous vancomycin-intermediate S. aureus (hVISA) may also be necessary. Whilst further investigation is needed, it can be hypothesised that MRSA strains become hVISA during prolonged bacteraemia, which may predispose to the development of daptomycin resistance. PMID:26143590

  14. Genomics of Staphylococcus

    NASA Astrophysics Data System (ADS)

    Lindsay, Jodi A.

    The staphylococci are Gram-positive cocci that divide to form clusters that look like grapes. By 16S ribosomal sequencing, they are most closely related to the Gram-positive, low G+C content Bacillus-Lactobacillus-Staphylococcus genera (Woese, 1987). There are over 30 species of staphylococci identified, and they are typically found on the skin and mucous membranes of mammals. About a dozen species are frequently carried on humans, including Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus capitis, Staphylococcus hominis, Staphylococcus cohnii, Staphylococcus lugdunensis, Staphylococcus schleiferi, Staphylococcus saprophyticus, Staphylococcus simulans, Staphylococcus warneri and Staphylococcus xylosus.

  15. Daptomycin combinations as alternative therapies in experimental foreign-body infection caused by meticillin-susceptible Staphylococcus aureus.

    PubMed

    El Haj, Cristina; Murillo, Oscar; Ribera, Alba; Vivas, Mireia; Garcia-Somoza, Dolors; Tubau, Fe; Cabellos, Carmen; Cabo, Javier; Ariza, Javier

    2015-08-01

    Whilst levofloxacin (LVX) in combination with rifampicin (RIF) is considered the optimal treatment for prosthetic joint infection (PJI) caused by meticillin-susceptible Staphylococcus aureus (MSSA), no therapeutic alternatives have been accurately evaluated. Based on the high effectiveness of the combination of daptomycin (DAP) plus RIF against meticillin-resistant S. aureus (MRSA) in this setting, in this study the efficacy of DAP+RIF and DAP+LVX combinations was tested as alternative therapies for foreign-body infections (FBIs) caused by MSSA. A tissue-cage infection model was performed using an MSSA strain. Male Wistar rats were treated for 7 days with LVX, DAP, RIF or the combinations LVX+RIF, DAP+RIF and DAP+LVX. Antibiotic efficacy was evaluated by bacterial counts from tissue cage fluid (TCF) and the cure rate was determined from adhered bacteria. Resistance was screened. Monotherapies were less effective than combinations (P<0.05), and resistance to DAP and RIF emerged. DAP+RIF (decrease in bacterial counts in TCF, -4.9logCFU/mL; cure rate, 92%) was the most effective therapy (P<0.05). There were no differences between LVX+RIF (-3.4logCFU/mL; 11%) and DAP+LVX (-3.3logCFU/mL; 47%). No resistant strains appeared with combined therapies. In conclusion, the combinations DAP+RIF and DAP+LVX showed good efficacy and prevented resistance. DAP+RIF provided higher efficacy than LVX+RIF. These DAP combinations were efficacious alternatives therapies for MSSA FBI. Further studies should confirm whether DAP+RIF may be useful as a first-line therapy in the setting of PJI caused by MSSA. PMID:26051988

  16. Contamination of environmental surfaces by methicillin-resistant Staphylococcus aureus (MRSA) in rooms of inpatients with MRSA-positive body sites.

    PubMed

    Kurashige, E Jessica Ohashi; Oie, Shigeharu; Furukawa, H

    2016-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) can contaminate environmental surfaces that are frequently touched by the hands of patients with MRSA colonization/infection. There have been many studies in which the presence or absence of MRSA contamination was determined but no studies in which MRSA contamination levels were also evaluated in detail. We evaluated MRSA contamination of environmental surfaces (overbed tables, bed side rails, and curtains) in the rooms of inpatients from whom MRSA was isolated via clinical specimens. We examined the curtains within 7-14 days after they had been newly hung. The environmental surfaces were wiped using gauze (molded gauze for wiping of surface bacteria; 100% cotton, 4cm×8cm) moistened with sterile physiological saline. The MRSA contamination rate and mean counts (range) were 25.0% (6/24 samples) and 30.6 (0-255)colony-forming units (cfu)/100cm(2), respectively, for the overbed tables and 31.6% (6/19 samples) and 159.5 (0-1620)cfu/100cm(2), respectively, for the bed side rails. No MRSA was detected in 24 curtain samples. The rate of MRSA contamination of environmental surfaces was high for the overbed tables and bed side rails but low for the curtains. Therefore, at least until the 14th day of use, frequent disinfection of curtains may be not necessary. PMID:27289247

  17. Impact of an Environmental Cleaning Intervention on the Presence of Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococci on Surfaces in Intensive Care Unit Rooms

    PubMed Central

    Goodman, Eric R.; Platt, Richard; Bass, Richard; Onderdonk, Andrew B.; Yokoe, Deborah S.; Huang, Susan S.

    2009-01-01

    OBJECTIVES To evaluate the adequacy of discharge room cleaning and the impact of a cleaning intervention on the presence of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) on environmental surfaces in intensive care unit (ICU) rooms. DESIGN Prospective environmental study. SETTING AND SAMPLE Convenience sample of ICU rooms in an academic hospital. METHODS AND INTERVENTION The intervention consisted of (1) a change from the use of pour bottles to bucket immersion for applying disinfectant to cleaning cloths, (2) an educational campaign, and (3) feedback regarding adequacy of discharge cleaning. Cleaning of 15 surfaces was evaluated by inspecting for removal of a preapplied mark, visible only with an ultraviolet lamp (“black light”). Six surfaces were cultured for MRSA or VRE contamination. Outcomes of mark removal and culture positivity were evaluated by χ2 testing and generalized linear mixed models, clustering by room. RESULTS The black-light mark was removed from 44% of surfaces at baseline, compared with 71% during the intervention (P <.001). The intervention increased the likelihood of removal of black-light marks after discharge cleaning (odds ratio, 4.4; P < .001), controlling for ICU type (medical vs surgical) and type of surface. The intervention reduced the likelihood of an environmental culture positive for MRSA or VRE (proportion of cultures positive, 45% at baseline vs 27% during the intervention; adjusted odds ratio, 0.4; P = .02). Broad, flat surfaces were more likely to be cleaned than were doorknobs and sink or toilet handles. CONCLUSIONS Increasing the volume of disinfectant applied to environmental surfaces, providing education for Environmental Services staff, and instituting feedback with a black-light marker improved cleaning and reduced the frequency of MRSA and VRE contamination. PMID:18624666

  18. Identification of a Novel Transposon (Tn6072) and a Truncated Staphylococcal Cassette Chromosome mec Element in Methicillin-Resistant Staphylococcus aureus ST239▿ †

    PubMed Central

    Chen, Liang; Mediavilla, José R.; Smyth, Davida S.; Chavda, Kalyan D.; Ionescu, Ramona; Roberts, Richard B.; Robinson, D. Ashley; Kreiswirth, Barry N.

    2010-01-01

    A novel composite transposon (Tn6072) resembling staphylococcal cassette chromosome mercury (SCCHg) was identified in a collection of sequence type (ST) 239 methicillin (meticillin)-resistant Staphylococcus aureus (MRSA) isolates from Romanian hospitals. Tn6072 is homologous to the 5′ region of SCCHg found in staphylococcal cassette chromosome mec (SCCmec) type III prototype strain 85/2082 but lacks the characteristic mer operon. SCCHg has previously been reported to integrate downstream of orfX, at the same chromosomal location as SCCmec. Tn6072, by contrast, is demarcated by two IS431 elements, flanked by 8-bp direct repeats, and inserted upstream of the origin of replication, within an open reading frame homologous to SAR2700 of S. aureus strain MRSA252. Analysis of a geographically and temporally diverse collection of 111 strains from the ST239 clonal group uncovered 11 additional strains harboring Tn6072, demonstrating a lineage-specific insertion pattern. Complete sequence analysis of the SCCmec regions of two representative Romanian strains (BK16704, BK16691) revealed two additional novel structures derived from a type III SCCmec background. BK16704 possesses an SCCmec 3A.1.4 structure, with an IS256 insertion downstream of the right chromosomal junction. In contrast, the SCCmec element of BK16691 is truncated downstream of the mec gene complex, with a 24-kb deletion encompassing the right chromosomal junction and an inverted downstream IS256 element. This structure, tentatively named “ψSCCmec16691,” confers methicillin resistance but lacks most of the J1/J2 region, including the ccr gene complex. Taken together, these findings provide evidence for the continuing evolution of SCC elements, as well as the ST239 clonal group. PMID:20479198

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

    PubMed

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

    2014-11-01

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

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

    PubMed

    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

  1. The Staphylococcus aureus Alternative Sigma Factor ςB Controls the Environmental Stress Response but Not Starvation Survival or Pathogenicity in a Mouse Abscess Model

    PubMed Central

    Chan, Pan F.; Foster, Simon J.; Ingham, Eileen; Clements, Mark O.

    1998-01-01

    The role of ςB, an alternative sigma factor of Staphylococcus aureus, has been characterized in response to environmental stress, starvation-survival and recovery, and pathogenicity. ςB was mainly expressed during the stationary phase of growth and was repressed by 1 M sodium chloride. A sigB insertionally inactivated mutant was created. In stress resistance studies, ςB was shown to be involved in recovery from heat shock at 54°C and in acid and hydrogen peroxide resistance but not in resistance to ethanol or osmotic shock. Interestingly, S. aureus acquired increased acid resistance when preincubated at a sublethal pH 4 prior to exposure to a lethal pH 2. This acid-adaptive response resulting in tolerance was mediated via sigB. However, ςB was not vital for the starvation-survival or recovery mechanisms. ςB does not have a major role in the expression of the global regulator of virulence determinant biosynthesis, staphylococcal accessory regulator (sarA), the production of a number of representative virulence factors, and pathogenicity in a mouse subcutaneous abscess model. However, SarA upregulates sigB expression in a growth-phase-dependent manner. Thus, ςB expression is linked to the processes controlling virulence determinant production. The role of ςB as a major regulator of the stress response, but not of starvation-survival, is discussed. PMID:9829915

  2. The health and economic burden of bloodstream infections caused by antimicrobial-susceptible and non-susceptible Enterobacteriaceae and Staphylococcus aureus in European hospitals, 2010 and 2011: a multicentre retrospective cohort study.

    PubMed

    Stewardson, Andrew J; Allignol, Arthur; Beyersmann, Jan; Graves, Nicholas; Schumacher, Martin; Meyer, Rodolphe; Tacconelli, Evelina; De Angelis, Giulia; Farina, Claudio; Pezzoli, Fabio; Bertrand, Xavier; Gbaguidi-Haore, Houssein; Edgeworth, Jonathan; Tosas, Olga; Martinez, Jose A; Ayala-Blanco, M Pilar; Pan, Angelo; Zoncada, Alessia; Marwick, Charis A; Nathwani, Dilip; Seifert, Harald; Hos, Nina; Hagel, Stefan; Pletz, Mathias; Harbarth, Stephan

    2016-08-18

    We performed a multicentre retrospective cohort study including 606,649 acute inpatient episodes at 10 European hospitals in 2010 and 2011 to estimate the impact of antimicrobial resistance on hospital mortality, excess length of stay (LOS) and cost. Bloodstream infections (BSI) caused by third-generation cephalosporin-resistant Enterobacteriaceae (3GCRE), meticillin-susceptible (MSSA) and -resistant Staphylococcus aureus (MRSA) increased the daily risk of hospital death (adjusted hazard ratio (HR) = 1.80; 95% confidence interval (CI): 1.34-2.42, HR = 1.81; 95% CI: 1.49-2.20 and HR = 2.42; 95% CI: 1.66-3.51, respectively) and prolonged LOS (9.3 days; 95% CI: 9.2-9.4, 11.5 days; 95% CI: 11.5-11.6 and 13.3 days; 95% CI: 13.2-13.4, respectively). BSI with third-generation cephalosporin-susceptible Enterobacteriaceae (3GCSE) significantly increased LOS (5.9 days; 95% CI: 5.8-5.9) but not hazard of death (1.16; 95% CI: 0.98-1.36). 3GCRE significantly increased the hazard of death (1.63; 95% CI: 1.13-2.35), excess LOS (4.9 days; 95% CI: 1.1-8.7) and cost compared with susceptible strains, whereas meticillin resistance did not. The annual cost of 3GCRE BSI was higher than of MRSA BSI. While BSI with S. aureus had greater impact on mortality, excess LOS and cost than Enterobacteriaceae per infection, the impact of antimicrobial resistance was greater for Enterobacteriaceae. PMID:27562950

  3. Environmental contamination by dog’s faeces: a public health problem?

    PubMed

    Cinquepalmi, Vittoria; Monno, Rosa; Fumarola, Luciana; Ventrella, Gianpiero; Calia, Carla; Greco, Maria Fiorella; Vito, Danila de; Soleo, Leonardo

    2013-01-01

    The risk to public health from the large number of dog stools present on streets of urban areas is cause for concern. Dog faeces may be a serious hazard because they may contain microorganisms that are both pathogenic to humans and resistant to several classes of antibiotics. The aim of this study was to evaluate the potential for zoonotic infections and for the presence of antibiotic resistant bacteria in canine faeces which contaminates the urban environment. A total of 418 canine faecal samples were collected from streets in seven areas of Bari, Southern Italy. We have isolated multi-drug resistant Enterococci and meticillin-resistant Staphylococcus aureus from these dog faecal samples. The presence of the resistant bacteria in an urban environment may represent a public health hazard which requires control measures by competent authorities. No Salmonella, Yersinia or Campylobacter species were isolated. Giardia cysts were detected in 1.9% of the samples. The predominant Enterococcus species were E. faecium (61.6%), E. gallinarum (23.3%) and E. casseliflavus (5.5%). Other species, including E. faecalis were also isolated. These strains were resistant to clindamycin (86.3%), tetracycline (65.7%), erythromycin (60.27%) and ampicillin (47.9%). High-level aminoglycoside resistance (HLAR) was found in 65.7% of enterococci. Resistance to three or more antibiotics and six or more antibiotics were observed in 67.12% and 38.4% of Enterococcus spp., respectively. Resistance to vancomycin and teicoplanin was not detected in any of the Enterococcus spp. isolated. Methicillin-resistant Staphylococcus aureus was isolated in 0.7% of the faecal samples. Canine faeces left on the streets may represent a risk factor for transmission of microorganisms and a reservoir of multidrug- resistant bacteria thus contributing to the spread of resistance genes into an urban area. PMID:23263659

  4. In vitro activity of dalbavancin against multidrug-resistant Staphylococcus aureus and streptococci from patients with documented infections in Europe and surrounding regions (2011-2013).

    PubMed

    Huband, Michael D; Castanheira, Mariana; Farrell, David J; Flamm, Robert K; Jones, Ronald N; Sader, Helio S; Mendes, Rodrigo E

    2016-06-01

    The in vitro activity of dalbavancin was evaluated against 9303 Staphylococcus aureus and 2670 streptococci, including multidrug-resistant (MDR) isolates, collected from hospitalised patients in Europe and surrounding regions from 2011 to 2013. Dalbavancin recently received approval for the treatment of acute bacterial skin and skin-structure infections by the US Food and Drug Administration (FDA) and the European Medicines Agency. Bacterial identification was confirmed by standard microbiological methods (including MALDI-TOF), and susceptibility testing was performed by reference broth microdilution methods. Dalbavancin susceptibility interpretations followed FDA/EUCAST criteria. Meticillin-resistant S. aureus (MRSA) and streptococci exhibiting resistance to at least three other drug classes were considered as MDR. Dalbavancin was highly active (MIC50/90, 0.06/0.06 mg/L; ≥99.9% susceptible) against MDR and non-MDR MRSA isolates. Vancomycin, daptomycin and linezolid were also active (99.6-100.0% susceptible) against MDR MRSA, however MIC90 values for these drugs were 8- to 16-fold higher than dalbavancin (MIC90 values of 1, 0.5 and 1 mg/L, respectively). All viridans group streptococci (VGS) and β-haemolytic streptococci were susceptible to dalbavancin regardless of resistance phenotype (MIC50/90 values of ≤0.03 mg/L and 0.06 mg/L, respectively). Dalbavancin MIC50/90 results (MIC50/90, ≤0.03/0.06 mg/L) against MDR VGS were at least eight-fold lower than those of vancomycin (MIC50/90, 0.5/1 mg/L), daptomycin (MIC50/90, 0.5/1 mg/L) and linezolid (MIC50/90, 0.5/1 mg/L). Overall, dalbavancin exhibited potent in vitro antibacterial activity against S. aureus and streptococci, including MDR phenotypes. Dalbavancin had the lowest MIC50/90 results against the isolates tested, relative to comparator agents, regardless of resistance phenotypes. PMID:27211209

  5. Transcriptional profiling of the two-component regulatory system VraSR in Staphylococcus aureus with low-level vancomycin resistance.

    PubMed

    Chen, Hongbin; Xiong, Zhujia; Liu, Kuoyue; Li, Shuguang; Wang, Ruobing; Wang, Xiaojuan; Zhang, Yawei; Wang, Hui

    2016-05-01

    The objective of this study was to comprehensively identify the target genes regulated by the two-component regulatory system VraSR in Staphylococcus aureus and to clarify the role of VraSR in low-level vancomycin resistance. Expression of vraS was determined by real-time quantitative reverse transcriptase PCR (qRT-PCR). A clinical heterogeneous vancomycin-intermediate S. aureus (hVISA) strain B6D and a vancomycin-intermediate S. aureus (VISA) strain D7 that was induced from a meticillin-resistant S. aureus strain were selected to construct vraSR null mutants by allelic replacement. The vraSR-complemented strain B6D_c was also constructed by allelic replacement. Genes differentially expressed in the wild-type, vraSR null mutant and complemented strains were detected using RNA-Seq and were validated by qRT-PCR. Compared with vancomycin-susceptible S. aureus strains, expression of vraS was upregulated in all four isogenic hVISA strains. Vancomycin minimum inhibitory concentrations (MICs) in the vraSR null mutants B6D-ΔvraSR and D7-ΔvraSR were significantly lower than in the wild-type strains B6D and D7 and the complemented strain B6D_c. RNA-Seq and qRT-PCR data showed that expression of genes encoding FmtA protein, foldase protein PrsA, capsular polysaccharide biosynthesis glycosyltransferase, TcaA, a putative membrane protein, and six hypothetical proteins was down regulated in both vraSR-null mutants B6D-ΔvraSR and D7-ΔvraSR. Most of these differentially expressed proteins are involved in cell wall biosynthesis, which is associated with vancomycin resistance in S. aureus. In conclusion, VraSR plays an important role in S. aureus strains with low-level vancomycin resistance. PrsA, FmtA, glycosyltransferase and TcaA are regulated directly or indirectly by VraSR. PMID:27084050

  6. Staphylococcus aureus and Pregnancy

    MedlinePlus

    ... known as “methicillin resistance to staphylococcus aureus” or “MRSA”. Other medications are available for treatment in this situation. What will a staph or MRSA skin infection look like? Staph bacterial infections, including ...

  7. Detection of Airborne Methicillin-Resistant Staphylococcus aureus Inside and Downwind of a Swine Building, and in Animal Feed: Potential Occupational, Animal Health, and Environmental Implications.

    PubMed

    Ferguson, Dwight D; Smith, Tara C; Hanson, Blake M; Wardyn, Shylo E; Donham, Kelley J

    2016-01-01

    Aerosolized methicillin-resistant Staphylococcus aureus (MRSA) was sampled inside and downwind of a swine facility. Animal feed was sampled before and after entry into the swine facility. Aerosolized particles were detected using an optical particle counter for real-time measurement and with an Andersen sampler to detect viable MRSA. Molecular typing and antimicrobial susceptibility testing were performed on samples collected. Viable MRSA organisms isolated inside the swine facility were primarily associated with particles >5 µm, and those isolated downwind from the swine facility were associated with particles <5 µm. MRSA isolates included spa types t008, t034, and t5706 and were resistant to methicillin, tetracycline, clindamycin, and erythromycin. Animal feed both before and after entry into the swine facility tested positive for viable MRSA. These isolates were of similar spa types as the airborne MRSA organisms. Air samples collected after power washing with a biocide inside the swine facility resulted in no viable MRSA organisms detected. This pilot study showed that the ecology of MRSA is complex. Additional studies are warranted on the maximum distance that viable MRSA can be emitted outside the facility, and the possibility that animal feed may be a source of contamination. PMID:26808288

  8. Detection of mecC-Methicillin-resistant Staphylococcus aureus isolates in river water: a potential role for water in the environmental dissemination.

    PubMed

    Concepción Porrero, M; Harrison, Ewan M; Fernández-Garayzábal, José Francisco; Paterson, Gavin K; Díez-Guerrier, Alberto; Holmes, Mark A; Domínguez, Lucas

    2014-12-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a public health concern due to limited treatment options. The recent description of a mecA homologue, mecC in human and cattle, led to studies to detect this new variant in human and other animal species. Detection of mecC in wild boar and fallow deer in a Spanish game estate led us to further investigate the presence of mecC-MRSA at this location. Samples from cattle, wild animals, workers and river water were tested. A further three mecC-MRSA isolates were obtained from river water. Molecular characterization (multilocus sequence typing and spa typing) and antimicrobial susceptibility testing (broth microdilution) showed that isolates were similar to those detected in wild animals. Whole genome sequencing confirmed that the isolates from the river water and wild animals in the same geographic area were all closely related isolates of ST425 mecC-MRSA. The presence of mecC-MRSA in the river water highlights the potential role of water in the dissemination of mecC-MRSA. PMID:25756123

  9. A case control study of environmental and occupational exposures associated with methicillin resistant Staphylococcus aureus nasal carriage in patients admitted to a rural tertiary care hospital in a high density swine region

    PubMed Central

    2014-01-01

    Background Distinct strains of methicillin resistant Staphylococcus aureus (MRSA) have been identified on livestock and livestock workers. Industrial food animal production may be an important environmental reservoir for human carriage of these pathogenic bacteria. The objective of this study was to investigate environmental and occupational exposures associated with nasal carriage of MRSA in patients hospitalized at Vidant Medical Center, a tertiary hospital serving a region with intensive livestock production in eastern North Carolina. Methods MRSA nasal carriage was identified via nasal swabs collected within 24 hours of hospital admission. MRSA carriers (cases) were gender and age matched to non-carriers (controls). Participants were interviewed about recent environmental and occupational exposures. Home addresses were geocoded and publicly available data were used to estimate the density of swine in residential census block groups of residence. Conditional logistic regression models were used to derive odds ratio (OR) estimates and 95% confidence intervals (CI). Presence of the scn gene in MRSA isolates was assessed. In addition, multi locus sequence typing (MLST) of the MRSA isolates was performed, and the Diversilab® system was used to match the isolates to USA pulsed field gel electrophoresis types. Results From July - December 2011, 117 cases and 119 controls were enrolled. A higher proportion of controls than cases were current workforce members (41.2% vs. 31.6%) Cases had a higher odds of living in census block groups with medium densities of swine (OR: 4.76, 95% CI: 1.36-16.69) and of reporting the ability to smell odor from a farm with animals when they were home (OR: 1.51, 95% CI: 0.80-2.86). Of 49 culture positive MRSA isolates, all were scn positive. Twenty-two isolates belonged to clonal complex 5. Conclusions Absence of livestock workers in this study precluded evaluation of occupational exposures. Higher odds of MRSA in medium swine density

  10. Activities of Daptomycin and Vancomycin Alone and in Combination with Rifampin and Gentamicin against Biofilm-Forming Methicillin-Resistant Staphylococcus aureus Isolates in an Experimental Model of Endocarditis ▿

    PubMed Central

    LaPlante, Kerry L.; Woodmansee, Suzanne

    2009-01-01

    The findings of clinical and in vitro research support the theory that infective endocarditis (IE)-causing bacteria form biofilms and that biofilms negatively affect treatment outcomes. The purpose of the present study was to quantify the biofilm formation of methicillin (meticillin)-resistant Staphylococcus aureus (MRSA) isolates obtained from patients with IE and to evaluate the in vitro activities of daptomycin and vancomycin alone and in combination with rifampin (rifampicin) or gentamicin while monitoring the isolates for the development of resistance. A high-inoculum, stationary-phase infection model of IE was used to simulate the pharmacokinetics in humans of daptomycin at 6 mg/kg of body weight/day, vancomycin at 1.25 g every 12 h (q12h) alone and in combination with rifampin at 300 mg every 8 h, and gentamicin at 1.3 mg/kg q12h. Two randomly selected clinical MRSA isolates were obtained from patients with IE; both MRSA isolates quantitatively produced biofilms. The time to bactericidal activity in the presence of daptomycin was isolate dependent but was achieved by 24 h for both MRSA isolates. Vancomycin did not achieve bactericidal activity throughout the experiment. At 24, 48, and 72 h, daptomycin-containing regimens had significantly more activity (greater declines in the mean number of CFU/g) than any of the vancomycin-containing regimens (P = 0.03). Rifampin and gentamicin antagonized or delayed the bactericidal activity of daptomycin (against MRSA B346846 for rifampin and against both isolates for gentamicin) in the first 24 h. Increases in the daptomycin and vancomycin MICs were not observed. We conclude that in an IE model of biofilm-forming MRSA, daptomycin monotherapy has better in vitro activity than daptomycin in combination with rifampin or gentamicin or any vancomycin-containing regimen studied within the first 24 h. Further investigations are needed to understand the initial delay in bactericidal activity observed when gentamicin or rifampin

  11. Staphylococcus aureus biofilms

    PubMed Central

    Archer, Nathan K; Mazaitis, Mark J; Costerton, J William; Leid, Jeff G; Powers, Mary Elizabeth

    2011-01-01

    Increasing attention has been focused on understanding bacterial biofilms and this growth modality's relation to human disease. In this review we explore the genetic regulation and molecular components involved in biofilm formation and maturation in the context of the Gram-positive cocci, Staphylococcus aureus. In addition, we discuss diseases and host immune responses, along with current therapies associated with S. aureus biofilm infections and prevention strategies. PMID:21921685

  12. Exotoxins of Staphylococcus aureus

    PubMed Central

    Dinges, Martin M.; Orwin, Paul M.; Schlievert, Patrick M.

    2000-01-01

    This article reviews the literature regarding the structure and function of two types of exotoxins expressed by Staphylococcus aureus, pyrogenic toxin superantigens (PTSAgs) and hemolysins. The molecular basis of PTSAg toxicity is presented in the context of two diseases known to be caused by these exotoxins: toxic shock syndrome and staphylococcal food poisoning. The family of staphylococcal PTSAgs presently includes toxic shock syndrome toxin-1 (TSST-1) and most of the staphylococcal enterotoxins (SEs) (SEA, SEB, SEC, SED, SEE, SEG, and SEH). As the name implies, the PTSAgs are multifunctional proteins that invariably exhibit lethal activity, pyrogenicity, superantigenicity, and the capacity to induce lethal hypersensitivity to endotoxin. Other properties exhibited by one or more staphylococcal PTSAgs include emetic activity (SEs) and penetration across mucosal barriers (TSST-1). A detailed review of the molecular mechanisms underlying the toxicity of the staphylococcal hemolysins is also presented. PMID:10627489

  13. The Staphylococcus aureus proteome.

    PubMed

    Otto, Andreas; van Dijl, Jan Maarten; Hecker, Michael; Becher, Dörte

    2014-03-01

    Staphylococcus aureus is a Gram-positive commensal bacterium that is regarded as a major threat for modern health care systems. This relates both to the ability of S. aureus to overcome antibiotic therapy by developing high-level resistance against multiple antibiotics and this bacterium's extensive arsenal of virulence factors. Understanding the mechanisms of resistance and functional studies on stress and starvation responses are the main goals of proteomics in staphylococcal research. This review high-lights recent advances in gel-based and gel-free proteomics analyses of S. aureus and pinpoints the importance of location-specific proteomics studies targeting the cytosol, the membrane, the cell surface and the extracellular milieu in combination with integrated global proteome studies. Emerging hot topics in staphylococcal proteomics are discussed with special focus on in vivo proteomics, membrane vesicles, biofilm formation and the acquisition of absolute proteome data for systems biological modeling approaches. PMID:24439828

  14. [Protein toxins of Staphylococcus aureus].

    PubMed

    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. PMID:25051707

  15. Anaerobic Conditions Induce Expression of Polysaccharide Intercellular Adhesin in Staphylococcus aureus and Staphylococcus epidermidis

    PubMed Central

    Cramton, Sarah E.; Ulrich, Martina; Götz, Friedrich; Döring, Gerd

    2001-01-01

    Products of the intercellular adhesion (ica) operon in Staphylococcus aureus and Staphylococcus epidermidis synthesize a linear β-1,6-linked glucosaminylglycan. This extracellular polysaccharide mediates bacterial cell-cell adhesion and is required for biofilm formation, which is thought to increase the virulence of both pathogens in association with prosthetic biomedical implants. The environmental signal(s) that triggers ica gene product and polysaccharide expression is unknown. Here we demonstrate that anaerobic in vitro growth conditions lead to increased polysaccharide expression in both S. aureus and S. epidermidis, although the regulation is less stringent in S. epidermidis. Anaerobiosis also dramatically stimulates ica-specific mRNA expression in ica- and polysaccharide-positive strains of both S. aureus and S. epidermidis. These data suggest a mechanism whereby ica gene expression and polysaccharide production may act as a virulence factor in an anaerobic environment in vivo. PMID:11349079

  16. Cytotoxic activity of Staphylococcus hyicus.

    PubMed

    Allaker, R P; Whitlock, M; Lloyd, D H

    1991-01-01

    Culture supernatants from a number of Staphylococcus hyicus strains caused toxic effects to both murine fibroblast and porcine keratinocyte cells in culture. The extent of cytotoxicity was shown to differ between strains and may provide an indication of strain virulence. Purification of cytotoxic activity produced by S. hyicus (strain P119) using preparative isoelectric-focussing demonstrated it to be cytolytic, haemolytic and non-proteolytic. The cytotoxin demonstrates certain properties in common with the delta haemolysin of Staphylococcus aureus. PMID:2024438

  17. Neonatal Staphylococcus lugdunensis urinary tract infection.

    PubMed

    Hayakawa, Itaru; Hataya, Hiroshi; Yamanouchi, Hanako; Sakakibara, Hiroshi; Terakawa, Toshiro

    2015-08-01

    Staphylococcus lugdunensis is a known pathogen of infective endocarditis, but not of urinary tract infection. We report a previously healthy neonate without congenital anomalies of the kidney and urinary tract who developed urinary tract infection due to Staphylococcus lugdunensis, illustrating that Staphylococcus lugdunensis can cause urinary tract infection even in those with no urinary tract complications. PMID:26177232

  18. Antimicrobial Susceptibility Profiles of Staphylococcus aureus Isolates Recovered from Humans, Environmental Surfaces, and Companion Animals in Households of Children with Community-Onset Methicillin-Resistant S. aureus Infections

    PubMed Central

    Morelli, John J.; Hogan, Patrick G.; Sullivan, Melanie L.; Muenks, Carol E.; Wang, Jeffrey W.; Thompson, Ryley M.; Burnham, Carey-Ann D.

    2015-01-01

    Our objective was to determine the antibiotic susceptibility profiles of Staphylococcus aureus isolates recovered from 110 households of children with community-onset methicillin-resistant S. aureus (MRSA) infections. Cultures were obtained from household members, household objects, and dogs and cats, yielding 1,633 S. aureus isolates. The S. aureus isolates were heterogeneous, although more than half were methicillin resistant. The highest proportion of MRSA was found in bathrooms. The majority of isolates were susceptible to antibiotics prescribed in outpatient settings. PMID:26248385

  19. The Evaluation of Methicillin Resistance in Staphylococcus aboard the International Space Station

    NASA Technical Reports Server (NTRS)

    Ott, C. M.; Bassinger, V. J.; Fontenot, S. L.; Castro, V. A.; Pierson, D. L.

    2005-01-01

    The International Space Station (ISS) represents a semi-closed environment with a high level of crewmember interaction. As community-acquired methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a health concern in environments with susceptible hosts in close proximity, an evaluation of isolates of clinical and environmental Staphylococcus aureus and coagulase negative Staphylococcus was performed to determine if this trend was also present in astronauts aboard ISS or the space station itself. Rep-PCR fingerprinting analysis of archived ISS isolates confirmed our earlier studies indicating a transfer of S. aureus between crewmembers. In addition, this fingerprinting also indicated a transfer between crewmembers and their environment. While a variety of S. aureus were identified from both the crewmembers and the environment, phenotypic evaluations indicated minimal methicillin resistance. However, positive results for the Penicillin Binding Protein, indicative of the presence of the mecA gene, were detected in multiple isolates of archived Staphylococcus epidermidis and Staphylococcus haemolyticus. Phenotypic analysis of these isolates confirmed their resistance to methicillin. While MRSA has not been isolated aboard ISS, the potential exists for the transfer of the gene, mecA, from coagulase negative environmental Staphylococcus to S. aureus creating MRSA strains. This study suggests the need to expand environmental monitoring aboard long duration exploration spacecraft to include antibiotic resistance profiling.

  20. Comparative characteristics of Staphylococcus sciuri, Staphylococcus lentus and Staphylococcus gallinarum isolated from healthy and sick hosts.

    PubMed

    Adegoke, G O

    1986-02-01

    Of 136 strains of coagulase-negative staphylococci isolated from healthy and sick human beings, goats, sheep, antelope and other animals, 88 (64.7%) were Staphylococcus sciuri and 35 (25.7%) were S. lentus and the remainder Staphylococcus gallinarum. The strains of S. sciuri were isolated from humans with boils and wounds, goats with pestes des petits ruminants (PPR) and dogs with nasal discharge. One isolate of S. gallinarum came from a fowl with chronic respiratory disease and 11 others were isolated from goats. The characteristics of S. sciuri, S. lentus and S. gallinarum isolated from different sources were similar. PMID:3705446

  1. Staphylococcus aureus and Community-Associated Methicillin-Resistant Staphylococcus aureus (CA-MRSA) in and Around Therapeutic Whirlpools in College Athletic Training Rooms

    PubMed Central

    Kahanov, Leamor; Kim, Young Kyun; Eberman, Lindsey; Dannelly, Kathleen; Kaur, Haninder; Ramalinga, A.

    2015-01-01

    Context: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has become a leading cause of skin and soft tissue infection in the nonhospitalized community. Care of the athletes in athletic training rooms is specifically designed with equipment tailored to the health care needs of the athletes, yet recent studies indicate that CA-MRSA is still prevalent in athletic facilities and that cleaning methods may not be optimal. Objective: To investigate the prevalence of Staphylococcus aureus and CA-MRSA in and around whirlpools in the athletic training room. Design: Cross-sectional study. Setting: National Collegiate Athletic Association Division I university. Patients or Other Participants: Student-athletes (n = 109) consisting of 46 men (42%) and 63 women (58%) representing 6 sports. Main Outcome Measure(s): Presence of MRSA and Staphylococcus aureus in and around the whirlpool structures relative to sport and number of athletes using the whirlpools. Results: We identified Staphylococcus aureus in 22% (n = 52/240) of the samples and MRSA in 0.8% (n = 2/240). A statistically significant difference existed between the number of athletes using the whirlpool and the presence of Staphylococcus aureus in and around the whirlpools (F2,238 = 2.445, P = .007). However, Staphylococcus aureus was identified regardless of whether multiple athletes used a whirlpool or no athletes used a whirlpool. We did not identify a relationship between the number of athletes who used a whirlpool and Staphylococcus aureus or MRSA density (P = .134). Conclusions: Staphylococcus aureus and MRSA were identified in and around the whirlpools. Transmission of the bacteria can be reduced by following the cleaning and disinfecting protocols recommended by the Centers for Disease Control and Prevention. Athletic trainers should use disinfectants registered by the Environmental Protection Agency to sanitize all whirlpools between uses. PMID:25710853

  2. Experimental Staphylococcus aureus brain abscess.

    PubMed

    Enzmann, D R; Britt, R R; Obana, W G; Stuart, J; Murphy-Irwin, K

    1986-01-01

    The virulent organism Staphylococcus aureus produced brain abscesses that were quantitatively and qualitatively different from those caused by less virulent organisms. S. aureus abscesses created larger lesions, as earlier ependymitis, delayed progress toward healing, and caused areas of inflammatory escape outside the collagen capsule. Imaging tests revealed similar findings: the abscesses were larger, had more extensive central necrosis, and showed earlier evidence of ependymitis. This virulent organism also demonstrated that white matter is more susceptible than overlying gray matter to destruction by infection. The pattern of spread and other histologic findings suggest that collagen capsule formation has less of an infection "containment" function than was previously thought. PMID:3085444

  3. Erythema nodosum associated with Staphylococcus xylosus septicemia.

    PubMed

    Giordano, Nicola; Corallo, Claudio; Miracco, Clelia; Papakostas, Panagiotis; Montella, Antonio; Figura, Natale; Nuti, Ranuccio

    2016-02-01

    Staphylococcus xylosus is a coagulase-negative staphylococcus. It is a commensal bacterium associated with skin and mucous membranes and occasionally it can cause human infections. We report the first case of erythema nodosum developed in a young woman with S. xylosus septicemia and specific serum antibody response. PMID:23266237

  4. Acute Necrotizing Sinusitis Caused by Staphylococcus lugdunensis▿

    PubMed Central

    Matthews, Philippa C.; Lazarus, Rajeka; Protheroe, Andrew; Milford, Christopher; Bowler, Ian C. J. W.

    2011-01-01

    Staphylococcus lugdunensis is most commonly associated with infections arising from the inguinal region, but here we report this organism as a cause of bacterial sinusitis, highlighting its potential niche as a commensal of the upper airways. The severity of necrosis demonstrates the potential for destructive pathology mimicking Staphylococcus aureus disease. PMID:21593256

  5. Staphylococcus aureus with reduced susceptibility to vancomycin in healthcare settings.

    PubMed

    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

  6. [Vancomycin-resistant Staphylococcus aureus].

    PubMed

    Rodríguez, Carlos Andrés; Vesga, Omar

    2005-12-01

    The evolution and molecular mechanisms of vancomycin resistance in Staphylococcus aureus were reviewed. Case reports and research studies on biochemestry, electron microscopy and molecular biology of Staphylococcus aureus were selected from Medline database and summarized in the following review. After almost 40 years of successful treatment of S. aureus with vancomycin, several cases of clinical failures have been reported (since 1997). S. aureus strains have appeared with intermediate susceptibility (MIC 8-16 microg/ml), as well as strains with heterogeneous resistance (global MIC < or =4 microg/ml), but with subpopulations of intermediate susceptibility. In these cases, resistance is mediated by cell wall thickening with reduced cross linking. This traps the antibiotic before it reaches its major target, the murein monomers in the cell membrane. In 2002, a total vancomycin resistant strain (MIC > or =32 microg/ml) was reported with vanA genes from Enterococcus spp. These genes induce the change of D-Ala-D-Ala terminus for D-Ala-D-lactate in the cell wall precursors, leading to loss of affinity for glycopeptides. Vancomycin resistance in S. aureus has appeared; it is mediated by cell wall modifications that trap the antibiotic before it reaches its action site. In strains with total resistance, Enterococcus spp. genes have been acquired that lead to modification of the glycopeptide target. PMID:16433184

  7. The Staphylococcus aureus RNome and Its Commitment to Virulence

    PubMed Central

    Felden, Brice; Vandenesch, François; Bouloc, Philippe; Romby, Pascale

    2011-01-01

    Staphylococcus aureus is a major human pathogen causing a wide spectrum of nosocomial and community-associated infections with high morbidity and mortality. S. aureus generates a large number of virulence factors whose timing and expression levels are precisely tuned by regulatory proteins and RNAs. The aptitude of bacteria to use RNAs to rapidly modify gene expression, including virulence factors in response to stress or environmental changes, and to survive in a host is an evolving concept. Here, we focus on the recently inventoried S. aureus regulatory RNAs, with emphasis on those with identified functions, two of which are directly involved in pathogenicity. PMID:21423670

  8. Vitamin D sufficiency and Staphylococcus aureus infection in children.

    PubMed

    Wang, Jeffrey W; Hogan, Patrick G; Hunstad, David A; Fritz, Stephanie A

    2015-05-01

    Vitamin D promotes epithelial immunity by upregulating antimicrobial peptides, including LL-37, which have bactericidal activity against Staphylococcus aureus. We found that children with vitamin D deficiency or insufficiency [25-hydroxyvitamin D <30 ng/mL] were more likely to present with recurrent, rather than primary, S. aureus skin or soft tissue infection. Vitamin D sufficiency may be one of a myriad of host and environmental factors that can be directly impacted to reduce the frequency of S. aureus skin and soft tissue infection. PMID:25860535

  9. Evaluation of the Vitek 2 System with a Variety of Staphylococcus Species▿

    PubMed Central

    Delmas, Julien; Chacornac, Jean Paul; Robin, Frédéric; Giammarinaro, Philippe; Talon, Régine; Bonnet, Richard

    2008-01-01

    The Vitek 2 gram-positive (GP) card was compared with an oligonucleotide array approach for the identification of 190 Staphylococcus strains, including 35 species, isolated from clinical and environmental specimens. The GP card provided a rapid and reliable identification of most species, whatever their origin. PMID:17959759

  10. Evaluation of RapiDEC Staph for identification of Staphylococcus aureus, Staphylococcus epidermidis, and Staphylococcus saprophyticus.

    PubMed Central

    Janda, W M; Ristow, K; Novak, D

    1994-01-01

    RapiDEC Staph is a test for presumptive identification of the principal human staphylococcal species, Staphylococcus aureus, S. epidermidis, and S. saprophyticus. The test includes control and test cupules for fluorogenic detection of coagulase and chromogenic substrates for alkaline phosphatase and beta-galactosidase. These tests identify S. aureus, S. epidermidis, and S. saprophyticus, respectively. Positive results with both chromogenic substrates provide a presumptive identification of S. xylosus or S. intermedius (S. xylosus-S. intermedius). Test cupules are inoculated with an organism suspension, and reactions are read after a 2-h incubation. RapiDEC-Staph was evaluated with 303 clinical and stock staphylococcal strains. Identifications were compared with those obtained by the tube coagulase test, a latex slide coagulase test (StaphAUREX), another commercial identification system (Staph-TRAC), and additional conventional tests. RapiDEC-Staph correctly identified 100% of 130 S. aureus strains, 70.3% of 74 S. epidermidis strains, and 81.3% of 32 S. saprophyticus strains. Four of five S. xylosus isolates were called S. xylosus-S. intermedius. Unidentified S. epidermidis and S. saprophyticus strains were called "Staphylococcus spp." Among the 62 other coagulase-negative staphylococci, 4 were misidentified as S. epidermidis and 7 were misidentified as S. saprophyticus. While the sensitivity and specificity of the fluorogenic coagulase test for S. aureus were 100%, failure to detect alkaline phosphatase activity in several S. epidermidis isolates resulted in fewer correct identifications by the RapiDEC-Staph test for this species. PMID:7814525

  11. 9 CFR 113.115 - Staphylococcus Aureus Bacterin-Toxoid.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Staphylococcus Aureus Bacterin-Toxoid... REQUIREMENTS Inactivated Bacterial Products § 113.115 Staphylococcus Aureus Bacterin-Toxoid. Staphylococcus... Staphylococcus aureus which has been inactivated and is nontoxic. Each serial of biological product...

  12. 21 CFR 866.3700 - Staphylococcus aureus serological reagents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 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...

  13. 21 CFR 866.3700 - Staphylococcus aureus serological reagents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 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...

  14. 21 CFR 866.3700 - Staphylococcus aureus serological reagents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 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...

  15. 9 CFR 113.115 - Staphylococcus Aureus Bacterin-Toxoid.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Staphylococcus Aureus Bacterin-Toxoid... REQUIREMENTS Inactivated Bacterial Products § 113.115 Staphylococcus Aureus Bacterin-Toxoid. Staphylococcus... Staphylococcus aureus which has been inactivated and is nontoxic. Each serial of biological product...

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

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Staphylococcus Aureus Bacterin-Toxoid... REQUIREMENTS Inactivated Bacterial Products § 113.115 Staphylococcus Aureus Bacterin-Toxoid. Staphylococcus... Staphylococcus aureus which has been inactivated and is nontoxic. Each serial of biological product...

  17. 9 CFR 113.115 - Staphylococcus Aureus Bacterin-Toxoid.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Staphylococcus Aureus Bacterin-Toxoid... REQUIREMENTS Inactivated Bacterial Products § 113.115 Staphylococcus Aureus Bacterin-Toxoid. Staphylococcus... Staphylococcus aureus which has been inactivated and is nontoxic. Each serial of biological product...

  18. [Staphylococcus aureus and antibiotic resistance].

    PubMed

    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

  19. Comparative genomic analysis of the genus Staphylococcus including Staphylococcus aureus and its newly described sister species Staphylococcus simiae

    PubMed Central

    2012-01-01

    Background Staphylococcus belongs to the Gram-positive low G + C content group of the Firmicutes division of bacteria. Staphylococcus aureus is an important human and veterinary pathogen that causes a broad spectrum of diseases, and has developed important multidrug resistant forms such as methicillin-resistant S. aureus (MRSA). Staphylococcus simiae was isolated from South American squirrel monkeys in 2000, and is a coagulase-negative bacterium, closely related, and possibly the sister group, to S. aureus. Comparative genomic analyses of closely related bacteria with different phenotypes can provide information relevant to understanding adaptation to host environment and mechanisms of pathogenicity. Results We determined a Roche/454 draft genome sequence for S. simiae and included it in comparative genomic analyses with 11 other Staphylococcus species including S. aureus. A genome based phylogeny of the genus confirms that S. simiae is the sister group to S. aureus and indicates that the most basal Staphylococcus lineage is Staphylococcus pseudintermedius, followed by Staphylococcus carnosus. Given the primary niche of these two latter taxa, compared to the other species in the genus, this phylogeny suggests that human adaptation evolved after the split of S. carnosus. The two coagulase-positive species (S. aureus and S. pseudintermedius) are not phylogenetically closest but share many virulence factors exclusively, suggesting that these genes were acquired by horizontal transfer. Enrichment in genes related to mobile elements such as prophage in S. aureus relative to S. simiae suggests that pathogenesis in the S. aureus group has developed by gene gain through horizontal transfer, after the split of S. aureus and S. simiae from their common ancestor. Conclusions Comparative genomic analyses across 12 Staphylococcus species provide hypotheses about lineages in which human adaptation has taken place and contributions of horizontal transfer in pathogenesis. PMID

  20. [Psoas abscess caused by Staphylococcus lugdunensis].

    PubMed

    Tamargo Delpón, María; Demelo-Rodríguez, Pablo; Cano Ballesteros, Juan Carlos; Vela de la Cruz, Laura

    2016-01-01

    Staphylococcus lugdunensis is a coagulase-negative staphylococcus of growing importance and atypical behavior. The infections caused by this microorganism are becoming more frequent, having a broader spectrum. Psoas abscesses caused by this germ are rare, with few cases reported in the literature. In this work, we present a case of a psoas abscess caused by S. lugdunensis in a patient suffering from diabetes mellitus and rheumatoid arthritis, which was treated with intravenous cloxacillin with a good outcome. PMID:27086257

  1. Potassium Uptake Modulates Staphylococcus aureus Metabolism.

    PubMed

    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

  2. Potassium Uptake Modulates Staphylococcus aureus Metabolism

    PubMed Central

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

    2016-01-01

    ABSTRACT 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

  3. Staphylococcus chromogenes, a Coagulase-Negative Staphylococcus Species That Can Clot Plasma.

    PubMed

    Dos Santos, Danielle Cabral; Lange, Carla Christine; Avellar-Costa, Pedro; Dos Santos, Katia Regina Netto; Brito, Maria Aparecida Vasconcelos Paiva; Giambiagi-deMarval, Marcia

    2016-05-01

    Staphylococcus chromogenes is one of the main coagulase-negative staphylococci isolated from mastitis of dairy cows. We describe S. chromogenes isolates that can clot plasma. Since the main pathogen causing mastitis is coagulase-positive Staphylococcus aureus, the coagulase-positive phenotype of S. chromogenes described here can easily lead to misidentification. PMID:26912749

  4. Vaccination Against Staphylococcus aureus Pneumonia

    PubMed Central

    Spaulding, Adam R.; Salgado-Pabón, Wilmara; Merriman, Joseph A.; Stach, Christopher S.; Ji, Yinduo; Gillman, Aaron N.; Peterson, Marnie L.; Schlievert, Patrick M.

    2014-01-01

    Background. Staphylococcus aureus causes serious infections in both hospital and community settings. Attempts have been made to prevent human infection through vaccination against bacterial cell-surface antigens; thus far all have failed. Here we show that superantigens and cytolysins, when used in vaccine cocktails, provide protection from S. aureus USA100–USA400 intrapulmonary challenge. Methods. Rabbits were actively vaccinated (wild-type toxins or toxoids) or passively immunized (hyperimmune serum) against combinations of superantigens (toxic shock syndrome toxin 1, enterotoxins B and C, and enterotoxin-like X) and cytolysins (α-, β-, and γ-toxins) and challenged intrapulmonarily with multiple strains of S. aureus, both methicillin-sensitive and methicillin-resistant. Results. Active vaccination against a cocktail containing bacterial cell-surface antigens enhanced disease severity as tested by infective endocarditis. Active vaccination against secreted superantigens and cytolysins resulted in protection of 86 of 88 rabbits when challenged intrapulmonarily with 9 different S. aureus strains, compared to only 1 of 88 nonvaccinated animals. Passive immunization studies demonstrated that production of neutralizing antibodies was an important mechanism of protection. Conclusions. The data suggest that vaccination against bacterial cell-surface antigens increases disease severity, but vaccination against secreted virulence factors provides protection against S. aureus. These results advance our understanding of S. aureus pathogenesis and have important implications in disease prevention. PMID:24357631

  5. Ceftaroline-Heteroresistant Staphylococcus aureus

    PubMed Central

    Saravolatz, Stephanie N.; Martin, Hayley; Pawlak, Joan; Johnson, Leonard B.

    2014-01-01

    Heteroresistance refers to the presence, within a large population of antimicrobial-susceptible microorganisms, of subpopulations with lesser susceptibilities. Ceftaroline is a novel cephalosporin with activity against methicillin-resistant Staphylococcus aureus (MRSA). The aim of this study was to detect the prevalence of ceftaroline heteroresistance in vitro in a select group of S. aureus strains. There were 57 isolates selected for evaluation, 20 MRSA, 20 vancomycin-intermediate S. aureus (VISA), 7 daptomycin-nonsusceptible S. aureus (DNSSA), 6 linezolid-nonsusceptible S. aureus (LNSSA), and 4 heteroresistant VISA (hVISA) isolates. MICs and minimal bactericidal concentrations were determined using the broth microdilution method according to CLSI guidelines. All of the isolates were analyzed by pulsed-field gel electrophoresis. The staphylococcal cassette chromosome mec element (SCCmec) types were determined by a multiplex PCR. Population analysis profiles (PAPs) were performed to determine heteroresistance for all of the isolates using plates made by adding various amounts of ceftaroline to brain heart infusion agar. The frequencies of resistant subpopulations were 1 in 104 to 105 organisms. We determined that 12 of the 57 (21%) isolates tested were ceftaroline-heteroresistant S. aureus (CHSA). CHSA occurred among strains with reduced susceptibilities to vancomycin, daptomycin, and linezolid but occurred in none of the USA-300 isolates tested. Evaluation of the heteroresistant strains demonstrated that the phenotype was unstable. Further studies are needed to determine whether CHSA has a role in clinical failures and to determine the implications of our study findings. PMID:24637680

  6. Gaseous and air decontamination technologies for Clostridium difficile in the healthcare environment.

    PubMed

    Davies, A; Pottage, T; Bennett, A; Walker, J

    2011-03-01

    The recent data for hospital-acquired infections suggest that infection rates for meticillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile are beginning to decrease. However, while there is still pressure to maintain this trend, the resistance of C. difficile spores to standard detergents continues to present a problem for many UK hospitals trying to prevent its spread or control outbreaks. Alternative disinfection technologies such as gaseous decontamination are currently being marketed to the healthcare sector as an alternative/supplement to manual disinfection, and have been shown to be effective in reducing environmental contamination. When used correctly, they offer a complementary technology to manual cleaning that increases the probability of an effective reduction in viability and provides a comparatively uniform distribution of disinfectant. Three gaseous decontamination technologies are examined for their suitability in reducing environmental contamination with C. difficile: gaseous hydrogen peroxide, chlorine dioxide and ozone. Air decontamination and UV-based technologies are also briefly described. We conclude that while there is a role to play for these new technologies in the decontamination of ward surfaces contaminated with C. difficile, the requirement for both a preclean before use and the limited 'in vivo' evidence means that extensive field trials are necessary to determine their cost-effectiveness in a healthcare setting. PMID:21130521

  7. Personal Hygiene and Methicillin-resistant Staphylococcus aureus Infection

    PubMed Central

    Lin, Mei; Wolkoff, Barbara; Dodson, Douglas; Gladbach, Stephen; Zhu, Bao-Ping

    2006-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) infections outside the healthcare setting are an increasing concern. We conducted a case-control study to investigate an MRSA outbreak during 2002–2003 in a Missouri prison and focused on hygiene factors. Information on sociodemographic characteristics, medical history, and hygiene practices of study participants was collected by interview and medical record review. Logistic regression was used to evaluate MRSA infection in relation to hygiene factors individually and as a composite hygiene score; potential confounding factors were controlled. Selected MRSA isolates were analyzed by pulsed-field gel electrophoresis (PFGE). MRSA infection was significantly associated with a low composite hygiene score. Transmission among prison inmates appeared to be responsible for this outbreak. PFGE analysis showed that isolates were indistinguishable and associated with community-onset MRSA infections in other US prisons. Improving hygiene practices and environmental conditions may help prevent and interrupt future MRSA outbreaks in prison settings. PMID:16704779

  8. Staphylococcus pseudintermedius necrotizing fasciitis in a dog

    PubMed Central

    Weese, J. Scott; Poma, Roberta; James, Fiona; Buenviaje, Gilbert; Foster, Robert; Slavic, Durda

    2009-01-01

    Staphylococcus pseudintermedius was implicated as the cause of rapidly progressive and fatal necrotizing fasciitis in a dog. The isolate was methicillin-susceptible and did not contain genes encoding the Panton-Valentine leukocidin. While Streptococcus canis is typically considered to be the main cause of necrotizing fasciitis in dogs, staphylococci should also be considered. PMID:19721787

  9. Staphylococcus simulans osteitis in a diabetic patient.

    PubMed

    Désidéri-Vaillant, C; Nédelec, Y; Guichon, J-M; Le Louarn, S; Noyer, V; Sapin-Lory, J; Le Guen, P; Nicolas, X

    2011-12-01

    Staphylococcus simulans was identified as the aetiological agent of osteitis in a diabetic woman. Its identifying characteristics and antibiogram were confirmed. Diabetic foot frequently becomes infected and the spread of infection to bone is a major causal factor behind lower-limb amputation. Early diagnosis and appropriate treatment are essential in such cases. PMID:22074636

  10. Susceptibility of Staphylococcus species and subspecies to teicoplanin.

    PubMed Central

    Bannerman, T L; Wadiak, D L; Kloos, W E

    1991-01-01

    Twenty-four Staphylococcus species and their subspecies were examined for their susceptibilities to teicoplanin by disk diffusion (30-micrograms disk) and agar dilution for the determination of MICs. Moderately susceptible and resistant clinical strains were further tested for their susceptibilities to oxacillin and vancomycin. Teicoplanin resistance was not observed in the reference strains of the various Staphylococcus species isolated from healthy volunteers or animals. However, the novobiocin-resistant species Staphylococcus saprophyticus, Staphylococcus cohnii, Staphylococcus xylosus, Staphylococcus arlettae, Staphylococcus kloosii, and Staphylococcus gallinarum were less susceptible to teicoplanin (MIC, 2 to 8 micrograms/ml) than most of the novobiocin-susceptible species were (MIC, 0.5 to 4 micrograms/ml). Clinical isolates of coagulase-negative species were generally less susceptible to teicoplanin than were reference strains. Seven percent of the Staphylococcus epidermidis clinical strains were moderately susceptible (MIC, 16 micrograms/ml) to teicoplanin. Of these strains, 70% were oxacillin resistant. For Staphylococcus haemolyticus strains, 11% were resistant (MIC, greater than 16 micrograms/ml) and 21% were moderately susceptible to teicoplanin. Of these strains, 95% were oxacillin resistant, No strains of S. epidermidis or S. haemolyticus were intermediate or resistant to vancomycin. Teicoplanin appears to be less active in vitro against oxacillin-resistant S. haemolyticus. However, teicoplanin is an effective antimicrobial agent against many Staphylococcus species. PMID:1835340

  11. Susceptibility of Staphylococcus species and subspecies to teicoplanin.

    PubMed

    Bannerman, T L; Wadiak, D L; Kloos, W E

    1991-09-01

    Twenty-four Staphylococcus species and their subspecies were examined for their susceptibilities to teicoplanin by disk diffusion (30-micrograms disk) and agar dilution for the determination of MICs. Moderately susceptible and resistant clinical strains were further tested for their susceptibilities to oxacillin and vancomycin. Teicoplanin resistance was not observed in the reference strains of the various Staphylococcus species isolated from healthy volunteers or animals. However, the novobiocin-resistant species Staphylococcus saprophyticus, Staphylococcus cohnii, Staphylococcus xylosus, Staphylococcus arlettae, Staphylococcus kloosii, and Staphylococcus gallinarum were less susceptible to teicoplanin (MIC, 2 to 8 micrograms/ml) than most of the novobiocin-susceptible species were (MIC, 0.5 to 4 micrograms/ml). Clinical isolates of coagulase-negative species were generally less susceptible to teicoplanin than were reference strains. Seven percent of the Staphylococcus epidermidis clinical strains were moderately susceptible (MIC, 16 micrograms/ml) to teicoplanin. Of these strains, 70% were oxacillin resistant. For Staphylococcus haemolyticus strains, 11% were resistant (MIC, greater than 16 micrograms/ml) and 21% were moderately susceptible to teicoplanin. Of these strains, 95% were oxacillin resistant, No strains of S. epidermidis or S. haemolyticus were intermediate or resistant to vancomycin. Teicoplanin appears to be less active in vitro against oxacillin-resistant S. haemolyticus. However, teicoplanin is an effective antimicrobial agent against many Staphylococcus species. PMID:1835340

  12. Ward assessment of SmartIdeas Project: bringing source isolation to the patient.

    PubMed

    Moore, G; Ali, S; FitzGerald, G; Muzslay, M; Atkinson, S; Smith, S; Cryer, P; Gush, C; Wilson, A P R

    2010-10-01

    Most UK hospitals lack enough single rooms to provide source isolation for all infected patients. The aim of this study was to test prototype isolation systems on general wards together with specifically designed portable sink units and toilets. Questionnaires were offered to staff, patients and visitors covering ease of use and acceptability. A total of 53 patients were isolated, with concurrent collection of environmental samples and staff hand hygiene audit. Blocking of beds next to infected patients was avoided but patients and staff were concerned about limited space and communication. Hand hygiene compliance on entry or exit to/from an isolated bed space significantly improved [43/76 (56.6%) to 107/147 (72.8%), P<0.05]. Although popular, the toilets were mechanically unreliable. Low levels of microbial contamination (<1-3.4cfu/cm(2)) were present within all isolated bed spaces. The highest colony counts were obtained from high contact sites (e.g. remote controls). Meticillin-resistant Staphylococcus aureus (MRSA) was present at similar levels inside all systems. Although one system was designed to provide airborne as well as contact isolation, MRSA was isolated from air inside and outside the system suggesting poor efficiency of the air door. The finding was confirmed by aerobiology tests at the Health Protection Agency Laboratory, Porton Down, UK. A trial of redesigned units is required to establish efficacy (Trial Identifier: ISRCTN02681602). PMID:20561713

  13. Evidence for icaADBC-Independent Biofilm Development Mechanism in Methicillin-Resistant Staphylococcus aureus Clinical Isolates

    PubMed Central

    Fitzpatrick, Fidelma; Humphreys, Hilary; O'Gara, James P.

    2005-01-01

    Synthesis of a polysaccharide adhesin by icaADBC-encoded enzymes is currently the best-understood mechanism of staphylococcal biofilm development. In four methicillin-resistant Staphylococcus aureus isolates, environmental activation of icaADBC did not always correlate with increased biofilm production. Moreover, glucose-mediated biofilm development in these isolates was icaADBC independent. Apparently, an environmentally regulated, ica-independent mechanism(s) of biofilm development exists in S. aureus clinical isolates. PMID:15815035

  14. [Ecthyma gangrenosum caused by Staphylococcus aureus].

    PubMed

    Jaque, Alejandra; Moll-Manzur, Catherina; Dossi, María Teresa; Berroeta-Mauriziano, Daniela; Araos-Baeriswyl, Esteban; Monsalve, Ximena

    2016-06-01

    Ecthyma gangrenosum is an uncommon necrotizing vasculitis, in most cases secondary to sepsis by Pseudo-mona aeruginosa in immunocompromised patients. However, there have been several reports of ecthyma gangre-nosum caused by other infectious etiologies. We report an unusual case of ecthyma gangrenosum associated with methicillin-resistant Staphylococcus aureus infection in a patient without the classic immunological risk factors described in the literature. PMID:27598286

  15. Stability of Penicillinase Plasmids in Staphylococcus aureus

    PubMed Central

    Johnston, L. H.; Dyke, K. G. H.

    1971-01-01

    The isolation of mutants of Staphylococcus aureus that are affected in the stability of penicillinase plasmids is described. One mutation is plasmid borne and results in nonreplication of the plasmid at 42 C. A second type of mutation is host-borne and gives rise to instability of both mcrI and mcrII penicillinase plasmids but not a tetracycline-resistant plasmid. Images PMID:4105036

  16. Staphylococcus epidermidis Sets Things Right Again.

    PubMed

    Skabytska, Yuliya; Biedermann, Tilo

    2016-03-01

    Commensal cutaneous bacteria are believed to play a role in skin homeostasis, possibly by counteracting the effects of pathogenic inflammation. In this issue, Xia et al. show that Staphylococcus epidermidis is involved in the regulation of Propionibacterium acnes-induced inflammation. Staphylococcal lipoteichoic acid induces miR-143, which in turn inhibits toll-like receptor 2 mRNA to decrease toll-like receptor 2 protein and consequently suppresses P. acnes-induced proinflammatory cytokines. PMID:26902125

  17. The changing epidemiology of Staphylococcus aureus?

    PubMed Central

    Chambers, H. F.

    2001-01-01

    Strains of methicillin-resistant Staphylococcus aureus (MRSA), which had been largely confined to hospitals and long-term care facilities, are emerging in the community. The changing epidemiology of MRSA bears striking similarity to the emergence of penicillinase-mediated resistance in S. aureus decades ago. Even though the origin (hospital or the community) of the emerging MRSA strains is not known, the prevalence of these strains in the community seems likely to increase substantially. PMID:11294701

  18. Bacterial Decolorization of Textile Azo Dye Acid Orange by Staphylococcus hominis RMLRT03

    PubMed Central

    Singh, Rajat Pratap; Singh, Pradeep Kumar; Singh, Ram Lakhan

    2014-01-01

    A bacterial strain RMLRT03 with ability to decolorize textile dye Acid Orange dye was isolated from textile effluent contaminated soil of Tanda, Ambedkar Nagar, Uttar Pradesh (India). The decolorization studies were performed in Bushnell and Haas medium (BHM) amended with Acid Orange dye. The bacterial strain was identified as Staphylococcus hominis on the basis of 16S rDNA sequence. The bacterial strain exhibited good decolorization ability with glucose and yeast extract supplementation as cosubstrate in static conditions. The optimal condition for the decolorization of Acid Orange dye by Staphylococcus hominis RMLRT03 strain were at pH 7.0 and 35°C in 60 h of incubation. The bacterial strain could tolerate high concentrations of Acid Orange dye up to 600 mg l-1. The high decolorizing activity under natural environmental conditions indicates that the bacterial strain has practical application in the treatment of dye containing wastewaters. PMID:25253925

  19. A Survey of Staphylococcus sp and its Methicillin Resistance aboard the International Space Station

    NASA Technical Reports Server (NTRS)

    Bassinger, V. J.; Fontenot, S. L.; Castro, V. A.; Ott, C.; Healy, M.; Pierson, D. L.

    2004-01-01

    Background: Within the past few years, methicillin-resistant Staphylococcus aureus has emerged in environments with susceptible hosts in close proximity, such as hospitals and nursing homes. As the International Space Station (ISS) represents a semi-closed environment with a high level of crewmember interaction, an evaluation of isolates of clinical and environmental Staphylococcus aureus and coagulase negative Staphylococcus was performed to determine if this trend was also present in astronauts occupying ISS or on surfaces of the space station itself. Methods: Identification of isolates was completed using VITEK (GPI cards, BioMerieux), 16S ribosomal DNA analysis (MicroSeq 500, ABI), and Rep-PCR DNA fingerprinting (Divemilab, Bacterial Barcodes). Susceptibility tests were performed using VITEK (GPS-105 cards, BioMerieux) and resistance characteristics were evaluated by testing for the presence of the mecA gene (PBP2' MRSA test kit, Oxoid). Results: Rep-PCR analysis indicated the transfer of S. aureus between crewmembers and between crewmembers and ISS surfaces. While a variety of S. aureus were identified from both the crewmembers and environment, evaluations of the microbial population indicated minimal methicillin resistance. Results of this study indicated that within the semi-closed ISS environment, transfer of bacteria between crewmembers and their environment has been occurring, although there was no indication of a high concentration of methicillin resistant Staphylococcus species. Conclusions: While this study suggests that the spread of methicillin resistant S. aureus is not currently a concern aboard ISS, the increasing incidence of Earth-based antibiotic resistance indicates a need for continued clinical and environmental monitoring.

  20. Sterilization Efficiency of a Novel Electrochemical Disinfectant against Staphylococcus aureus.

    PubMed

    Zhang, Qian; Ma, Ruonan; Tian, Ying; Su, Bo; Wang, Kaile; Yu, Shuang; Zhang, Jue; Fang, Jing

    2016-03-15

    Disinfection of hazardous microorganisms that may challenge environmental safety is a crucial issue for economic and public health. Here, we explore the potential of a novel electrochemical disinfectant named plasma activated water (PAW), which was generated by nonthermal plasma, for inactivating Staphylococcus aureus (S. aureus). Meanwhile, the influence of bovine serum albumin (BSA) on the PAW disinfection efficacy was investigated. In the presence of BSA, PAW treatments achieved a reduction of S. aureus ranging from 2.1 to 5.5 Log, when without BSA it reached 7 Log. The sterilization efficacy depended on the PAW treatment time of S. aureus and plasma activation time for PAW generation. The results of electron spin resonance spectra showed the concentrations of hydroxyl radical (OH•) and nitric oxide radical (NO•) in water activated by plasma for 10 min (10-PAW) were higher than those in water activated by plasma for 5 min (5-PAW). Additionally, the physiological analysis of S. aureus demonstrated that the integrity of cell membrane, membrane potential, and intracellular pH homeostasis as well as DNA structure were damaged by PAW, and the molecule structure and chemical bonds of S. aureus were also altered due to PAW. Thus, PAW can be a promising chemical-free and environmentally friendly electrochemical disinfectant for application in the medical and food industries. PMID:26857097

  1. Staphylococcus aureus and Staphylococcus epidermidis Virulence Strains as Causative Agents of Persistent Infections in Breast Implants

    PubMed Central

    Chessa, Daniela; Ganau, Giulia; Spiga, Luisella; Bulla, Antonio; Mazzarello, Vittorio; Campus, Gian Vittorio; Rubino, Salvatore

    2016-01-01

    Staphylococcus epidermidis and Staphylococcus aureus are currently considered two of the most important pathogens in nosocomial infections associated with catheters and other medical implants and are also the main contaminants of medical instruments. However because these species of Staphylococcus are part of the normal bacterial flora of human skin and mucosal surfaces, it is difficult to discern when a microbial isolate is the cause of infection or is detected on samples as a consequence of contamination. Rapid identification of invasive strains of Staphylococcus infections is crucial for correctly diagnosing and treating infections. The aim of the present study was to identify specific genes to distinguish between invasive and contaminating S. epidermidis and S. aureus strains isolated on medical devices; the majority of our samples were collected from breast prostheses. As a first step, we compared the adhesion ability of these samples with their efficacy in forming biofilms; second, we explored whether it is possible to determine if isolated pathogens were more virulent compared with international controls. In addition, this work may provide additional information on these pathogens, which are traditionally considered harmful bacteria in humans, and may increase our knowledge of virulence factors for these types of infections. PMID:26811915

  2. Cutaneous Immune Defenses Against Staphylococcus aureus Infections

    PubMed Central

    Choi, Ji Hae; Seo, Ho Seong; Lim, Sang Young; Park, Kyungho

    2014-01-01

    Staphylococcus aureus (S. aureus) is a virulent bacterium that abundantly colonizes inflammatory skin diseases. Since S. aureus infections occur in an impaired skin barrier, it is important to understand the protective mechanism through cutaneous immune responses against S. aureus infections and the interaction with Staphylococcal virulence factors. In this review, we summarize not only the pathogenesis and key elements of S. aureus skin infections, but also the cutaneous immune system against its infections and colonization. The information obtained from this area may provide the groundwork for further immunomodulatory therapies or vaccination strategies to prevent S. aureus infections. PMID:26064853

  3. Neutrophil-Mediated Phagocytosis of Staphylococcus aureus

    PubMed Central

    van Kessel, Kok P. M.; Bestebroer, Jovanka; van Strijp, Jos A. G.

    2014-01-01

    Initial elimination of invading Staphylococcus aureus from the body is mediated by professional phagocytes. The neutrophil is the major phagocyte of the innate immunity and plays a key role in the host defense against staphylococcal infections. Opsonization of the bacteria with immunoglobulins and complement factors enables efficient recognition by the neutrophil that subsequently leads to intracellular compartmentalization and killing. Here, we provide a review of the key processes evolved in neutrophil-mediated phagocytosis of S. aureus and briefly describe killing. As S. aureus is not helpless against the professional phagocytes, we will also highlight its immune evasion arsenal related to phagocytosis. PMID:25309547

  4. Immunomodulation and Disease Tolerance to Staphylococcus aureus

    PubMed Central

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

    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 disease tolerance mechanisms that promote commensalism to S. aureus. PMID:26580658

  5. Epidemiology of Staphylococcus aureus during space flight

    NASA Technical Reports Server (NTRS)

    Pierson, D. L.; Chidambaram, M.; Heath, J. D.; Mallary, L.; Mishra, S. K.; Sharma, B.; Weinstock, G. M.

    1996-01-01

    Staphylococcus aureus was isolated over 2 years from Space Shuttle mission crewmembers to determine dissemination and retention of bacteria. Samples before and after each mission were from nasal, throat, urine, and feces and from air and surface sampling of the Space Shuttle. DNA fingerprinting of samples by digestion of DNA with SmaI restriction endonuclease followed by pulsed-field gel electrophoresis showed S. aureus from each crewmember had a unique fingerprint and usually only one strain was carried by an individual. There was only one instance of transfer between crewmembers. Strains from interior surfaces after flight matched those of crewmembers, suggesting microbial fingerprinting may have forensic application.

  6. Methicillin-resistant Staphylococcus aureus in obstetrics.

    PubMed

    Sheffield, Jeanne S

    2013-02-01

    Methicillin-resistant Staphylococcus aureus (MRSA) remains one of the major multiple antibiotic-resistant bacterial pathogens causing serious community-associated and health care-associated infections. It is now pervasive in the obstetric population associated with skin and soft tissue infections, mastitis, episiotomy, and cesarean wound infections and urinary tract infections. This review addresses the epidemiology, definitions, microbiology, and pathogenesis as well as common clinical presentations. A discussion of the 2011 Infectious Diseases Society of America MRSA treatment guidelines details available antibiotics, invasive and noninvasive MRSA management, and specific factors related to obstetrics. Finally, prevention strategies including decolonization are discussed. PMID:23292915

  7. Pasteurella multocida pneumonia complicated by Staphylococcus aureus.

    PubMed

    Martyn, V; Swift, D

    1984-02-01

    A 71-year-old woman presented with acute non-cardiogenic pulmonary oedema. She proved to have a Pasteurella multocida pneumonia, with blood stream invasion by the organism, and required positive pressure ventilation for 53 days. Penicillin G., the drug of choice for this infection, failed to reverse the steady decline in her arterial oxygen-tension, and it was only after treatment with chloramphenicol and prednisolone that she began to improve. Serological tests strongly indicated the presence of a Staphylococcus aureus infection and the delay in giving antibiotics appropriate to this second pathogen may have been the reason for the patient's initial downhill course. PMID:6709548

  8. Susceptibility of Staphylococcus species and subspecies to fleroxacin.

    PubMed Central

    Bannerman, T L; Wadiak, D L; Kloos, W E

    1991-01-01

    Twenty-four Staphylococcus species or subspecies were examined for their susceptibilities to the fluoroquinolone fleroxacin (Ro 23-6240) by disk diffusion (5-micrograms disk) and by agar dilution for the determination of MICs. Resistant strains were further tested for their susceptibilities to oxacillin and the fluoroquinolone ciprofloxacin. Reference strains of the novobiocin-resistant species (Staphylococcus saprophyticus, Staphylococcus cohnii, Staphylococcus xylosus, Staphylococcus arlettae, and Staphylococcus gallinarum) had an intrinsic intermediate susceptibility (MIC, 4 micrograms/ml) to fleroxacin. Fleroxacin resistance was not observed in the reference strains of the novobiocin-susceptible species (MIC, 0.5 to 2.0 micrograms/ml). Clinical isolates of coagulase-negative species were generally less susceptible to fleroxacin than were reference strains. Seven percent of the Staphylococcus epidermidis clinical strains were resistant (MIC, greater than or equal to 8 micrograms/ml) to fleroxacin. Of these strains, 77% were resistant to oxacillin and 50% were resistant to ciprofloxacin. Thirty-four percent of the Staphylococcus haemolyticus clinical strains were resistant to fleroxacin, and 9% had intermediate susceptibility. Of the resistant strains, 95% were resistant to oxacillin and 77% were resistant to ciprofloxacin, while 23% had intermediate susceptibility to ciprofloxacin. Fleroxacin is an effective antimicrobial agent against most staphylococci. PMID:1759838

  9. Survival of Staphylococcus aureus on fomites.

    PubMed

    Cuesta, Alicia; Nastri, Natalia; Bernat, Maria; Brusca, Maria; Turcot, Liliana; Nastri, Maria; Rosa, Alcira C

    2008-01-01

    The aim of this study was to evaluate duration of survival of Staphylococcus aureus on contaminated standardized fomites, such as sterilization paper (SP) and polyester previously sterilized in a steam autoclave, and to determine the potential inhibitory effects of the substrates (fabrics used to manufacture garments and special wrapping paper used in the dental setting) using the bacteriostasis test. The test was performed on two types of sterile standardized samples (T1 and T2). Sterility of the samples was validated following the protocol in use at the Department of Microbiology, after which the samples were inoculated with 50 microl of a calibrated suspension of Staphylococcus aureus (reference strain ATCC 25923) in the exponential growth phase, in a final concentration of 10(7) cfu/ml and 10(6) cfu/ml). The samples were incubated at 27 degrees C and survival and concentration of microorganisms attached to the surface of the substrates was determined at the following experimental time points: immediately post-contamination, and 3 hours, 24 hours, 3 days, and 7 days post-contamination. Recovery was determined and expressed as a percentage; the bacteriostasis test was performed and showed negative results. Our results suggest that the quantity of recovered microorganisms varies according to the type of substrate and that there is a relation between survival and incubation time of the inoculated substrate serving as an artificial niche. PMID:19177850

  10. Osteomyelitis Caused by Staphylococcus schleiferi and Evidence of Misidentification of This Staphylococcus Species by an Automated Bacterial Identification System

    PubMed Central

    Calvo, Jorge; Hernández, José L.; Fariñas, Maria C.; García-Palomo, Daniel; Agüero, Jesús

    2000-01-01

    We report a case of sternal osteomyelitis due to Staphylococcus schleiferi in a patient who underwent thoracic surgery. This constitutes the first documented case of osteomyelitis caused by this Staphylococcus species. We also relate our experience in the utilization of commercially available MicroScan panels for the identification of this microorganism. PMID:11015429

  11. Quantitative assessment of organizational culture within hospitals and its relevance to infection prevention and control strategies.

    PubMed

    Borg, M A; Waisfisz, B; Frank, U

    2015-05-01

    It has been suggested that organizational culture (OC) is an important driver of infection prevention and control (IPC) behaviour among healthcare workers. This study examined OC in seven European hospitals using a validated assessment tool based on Hofstede's model, and identified significant variations in OC scores. Hospitals with low prevalence of meticillin-resistant Staphylococcus aureus (MRSA) exhibited high scores for change facilitation and change readiness, whereas hospitals with high prevalence of MRSA exhibited low scores for these determinants. It is possible to use tools, available outside health care, to study OC within hospitals and gain better insight into IPC behaviour change strategies. PMID:25676113

  12. Staphylococcus aureus infections: transmission within households and the community

    PubMed Central

    Knox, Justin; Uhlemann, Anne-Catrin; Lowy, Franklin D.

    2015-01-01

    Staphylococcus aureus , both methicillin susceptible and resistant, are now major community-based pathogens worldwide. The basis for this is multifactorial and includes the emergence of epidemic clones with enhanced virulence, antibiotic resistance, colonization potential, or transmissibility. Household reservoirs of these unique strains are crucial to their success as community-based pathogens. Staphylococci become resident in households, either as colonizers or environmental contaminants, increasing the risk for recurrent infections. Interactions of household members with others in different households or at community sites including schools and daycare facilities play a critical role in the ability of these strains to become endemic. Colonization density at these sites appears to play an important role in facilitating transmission. The integration of research tools including whole genome sequencing, mathematical modeling and social network analysis have provided additional insight into the transmission dynamics of these strains. Thus far, interventions designed to reduce recurrent infections among household members have had limited success, likely due to the multiplicity of potential sources for recolonization. The development of better strategies to reduce the number of household-based infections will depend on greater insight into the different factors that contribute to the success of these uniquely successful epidemic clones of S. aureus. PMID:25864883

  13. Staphylococcus aureus infections: transmission within households and the community.

    PubMed

    Knox, Justin; Uhlemann, Anne-Catrin; Lowy, Franklin D

    2015-07-01

    Staphylococcus aureus, both methicillin susceptible and resistant, are now major community-based pathogens worldwide. The basis for this is multifactorial and includes the emergence of epidemic clones with enhanced virulence, antibiotic resistance, colonization potential, or transmissibility. Household reservoirs of these unique strains are crucial to their success as community-based pathogens. Staphylococci become resident in households, either as colonizers or environmental contaminants, increasing the risk for recurrent infections. Interactions of household members with others in different households or at community sites, including schools and daycare facilities, have a critical role in the ability of these strains to become endemic. Colonization density at these sites appears to have an important role in facilitating transmission. The integration of research tools, including whole-genome sequencing (WGS), mathematical modeling, and social network analysis, has provided additional insight into the transmission dynamics of these strains. Thus far, interventions designed to reduce recurrent infections among household members have had limited success, likely due to the multiplicity of potential sources for recolonization. The development of better strategies to reduce the number of household-based infections will depend on greater insight into the different factors that contribute to the success of these uniquely successful epidemic clones of S. aureus. PMID:25864883

  14. Converting a Staphylococcus aureus toxin into effective cyclic pseudopeptide antibiotics.

    PubMed

    Solecki, Olivia; Mosbah, Amor; Baudy Floc'h, Michèle; Felden, Brice

    2015-03-19

    Staphylococcus aureus produces peptide toxins that it uses to respond to environmental cues. We previously characterized PepA1, a peptide toxin from S. aureus, that induces lytic cell death of both bacterial and host cells. That led us to suggest that PepA1 has an antibacterial activity. Here, we demonstrate that exogenously provided PepA1 has activity against both Gram-positive and Gram-negative bacteria. We also see that PepA1 is significantly hemolytic, thus limiting its use as an antibacterial agent. To overcome these limitations, we converted PepA1 into nonhemolytic derivatives. Our most promising derivative is a cyclic heptapseudopeptide with inconsequential toxicity to human cells, enhanced stability in human sera, and sharp antibacterial activity. Mechanistically, linear and helical PepA1 derivatives form pores at the bacterial and erythrocyte surfaces, while the cyclic peptide induces bacterial envelope reorganization, with insignificant action on the erythrocytes. Our work demonstrates that bacterial toxins might be an attractive starting point for antibacterial drug development. PMID:25728268

  15. Transmission Dynamics of Methicillin-Resistant Staphylococcus aureus in Pigs

    PubMed Central

    Crombé, Florence; Argudín, M. Angeles; Vanderhaeghen, Wannes; Hermans, Katleen; Haesebrouck, Freddy; Butaye, Patrick

    2013-01-01

    From the mid-2000s on, numerous studies have shown that methicillin-resistant Staphylococcus aureus (MRSA), renowned as human pathogen, has a reservoir in pigs and other livestock. In Europe and North America, clonal complex (CC) 398 appears to be the predominant lineage involved. Especially worrisome is its capacity to contaminate humans in close contact with affected animals. Indeed, the typical multi-resistant phenotype of MRSA CC398 and its observed ability of easily acquiring genetic material suggests that MRSA CC398 strains with an increased virulence potential may emerge, for which few therapeutic options would remain. This questions the need to implement interventions to control the presence and spread of MRSA CC398 among pigs. MRSA CC398 shows a high but not fully understood transmission potential in the pig population and is able to persist within that population. Although direct contact is probably the main route for MRSA transmission between pigs, also environmental contamination, the presence of other livestock, the herd size, and farm management are factors that may be involved in the dissemination of MRSA CC398. The current review aims at summarizing the research that has so far been done on the transmission dynamics and risk factors for introduction and persistence of MRSA CC398 in farms. PMID:23518663

  16. Measurement and Impact of Staphylococcus aureus Colonization Pressure in Households

    PubMed Central

    Rodriguez, Marcela; Hogan, Patrick G.; Krauss, Melissa; Warren, David K.; Fritz, Stephanie A.

    2013-01-01

    Background Methicillin-resistant Staphylococcus aureus (MRSA) “colonization pressure” (CP) predicts infections in hospitals. We applied the CP concept to staphylococcal transmission within households. We tested the hypothesis that children with S aureus skin and soft tissue infection (SSTI) plus colonization (“cases”) with higher baseline household CP (HHCP) would be at greater risk for persistent colonization and recurrent SSTI during study period. Methods We collected baseline colonization swabs from 92 cases and 296 of their household contacts. Cases underwent decolonization. S aureus HHCP was calculated as the proportion of colonized household contacts at baseline (excluding cases). S aureus colonization and recurrent SSTI in cases were followed for 12 months. Results Overall, median S aureus HHCP was 60% (mean = 55%). For cases colonized with MRSA, median MRSA HHCP was 11% (mean 29%); methicillin-susceptible S aureus (MSSA)–colonized cases had a median MSSA HHCP of 50% (mean = 49%). Over 1 year, MRSA HHCP was an independent risk factor for persistent MRSA colonization in cases (each 10-unit increase in HHCP associated with an adjusted odds ratio of 1.25; 95% confidence interval, 1.06–1.47). HHCP was not associated with recurrent SSTI in cases. Conclusions MRSA HHCP is associated with persistent colonization in outpatients. Further studies are needed to determine the relationship between persistent colonization of household contacts, environmental contamination, and SSTI. PMID:23717786

  17. Characterization of MazFSa, an Endoribonuclease from Staphylococcus aureus▿

    PubMed Central

    Fu, Zhibiao; Donegan, Niles P.; Memmi, Guido; Cheung, Ambrose L.

    2007-01-01

    The mazEF homologs of Staphylococcus aureus, designated mazEFsa, have been shown to cotranscribe with the sigB operon under stress conditions. In this study, we showed that MazEFSa, as with their Escherichia coli counterparts, compose a toxin-antitoxin module wherein MazFSa leads to rapid cell growth arrest and loss in viable CFU upon overexpression. MazFSa is a novel sequence-specific endoribonuclease which cleaves mRNA to inhibit protein synthesis. Using ctpA mRNA as the model substrate both in vitro and in vivo, we demonstrated that MazFSa cleaves single-strand RNA preferentially at the 5′ side of the first U or 3′ side of the second U residue within the consensus sequences VUUV′ (where V and V′ are A, C, or G and may or may not be identical). Binding studies confirmed that the antitoxin MazESa binds MazFSa to form a complex to inhibit the endoribonuclease activity of MazFSa. Contrary to the system in E. coli, exposure to selected antibiotics augmented mazEFsa transcription, akin to what one would anticipate from the environmental stress response of the sigB system. These data indicate that the mazEF system of S. aureus differs from the gram-negative counterparts with respect to mRNA cleavage specificity and antibiotic stresses. PMID:17933891

  18. Genetic effects of an air discharge plasma on Staphylococcus aureus at the gene transcription level

    NASA Astrophysics Data System (ADS)

    Xu, Zimu; Wei, Jun; Shen, Jie; Liu, Yuan; Ma, Ronghua; Zhang, Zelong; Qian, Shulou; Ma, Jie; Lan, Yan; Zhang, Hao; Zhao, Ying; Xia, Weidong; Sun, Qiang; Cheng, Cheng; Chu, Paul K.

    2015-05-01

    The dynamics of gene expression regulation (at transcription level) in Staphylococcus aureus after different doses of atmospheric-pressure room-temperature air plasma treatments are investigated by monitoring the quantitative real-time polymerase chain reaction. The plasma treatment influences the transcription of genes which are associated with several important bio-molecular processes related to the environmental stress resistance of the bacteria, including oxidative stress response, biofilm formation, antibiotics resistance, and DNA damage protection/repair. The reactive species generated by the plasma discharge in the gas phase and/or induced in the liquid phase may account for these gene expression changes.

  19. Microbial degradation of dibenzofuran, fluorene, and dibenzo-p-dioxin by staphylococcus auriculans DBF63

    SciTech Connect

    Monna, L.; Omori, Toshio; Kodama, Tohru )

    1993-01-01

    Polychlorinated derivatives of dibenzo-p-dioxin (DD) and dibezonfuran (DBF), well known for their toxicity and mutagenicity, have created serious environmental contamination problems. They are formed during combustion of dust or bleaching of pulp as well as production of halogen-containing aromatics such as herbicides. Information on the microbial degradation of these compounds is limited. This papers describes the isolation and characterization of Staphylococcus auriculans DBF63, which can be grown on either DBF or FN as the sole source of carbon and energy. The resting cell reaction of DD is also investigated, leading to proposed metabolic degradation pathways of DBF, FN, and DD. 15 refs., 3 figs.

  20. Purification and characterization of aminoglycoside-modifying enzymes from Staphylococcus aureus and Staphylococcus epidermidis.

    PubMed Central

    Ubukata, K; Yamashita, N; Gotoh, A; Konno, M

    1984-01-01

    Several strains of Staphylococcus aureus and Staphylococcus epidermidis, exhibiting characteristic resistance patterns to aminoglycoside antibiotics, were examined. The aminoglycoside-modifying enzymes from these strains were purified by DEAE-Sephadex A-50 chromatography, affinity chromatography, and Sephadex G-100 gel filtration. Three enzymes, a 3'-phosphotransferase III (molecular weight, 31,000; pI 4.1), a bifunctional enzyme having 6'-acetyltransferase and 2"-phosphotransferase (molecular weight, 56,000; pI 4.1) activity, and a 4'4"-adenylytransferase (molecular weight, 34,000; pI 4.7), were isolated from crude extracts of the resistant strains. Aminoglycoside-modifying enzymes with identical enzymatic properties derived from S. aureus and S. epidermidis were also immunologically identical. Images PMID:6331299

  1. Antimicrobial susceptibility of Staphylococcus aureus and Staphylococcus pseudintermedius isolated from various animals.

    PubMed

    Rubin, Joseph E; Ball, Katherine R; Chirino-Trejo, Manuel

    2011-02-01

    This study characterized the antimicrobial susceptibility of 221 Staphylococcus aureus isolated from various species, and 60 canine Staphylococcus pseudintermedius isolated from 1986 through 2000 at the Western College of Veterinary Medicine (WCVM). Resistance of S. aureus was most common to penicillin (31%) and tetracycline (14%); resistance of S. pseudintermedius to penicillin was present in 8% and to tetracycline in 34% of isolates. Resistance to trimethoprim/sulfamethoxazole was only seen among S. pseudintermedius, and there was no resistance to amoxicillin/clavulanate, ampicillin/sulbactam, cephalothin, amikacin, gentamicin, enrofloxacin, chloramphenicol, or rifampin among any isolate. Inducible clindamycin resistance was found in both S. aureus and S. pseudintermedius, highlighting the need for careful interpretation of culture and susceptibility test results. There were significant differences in the minimum inhibitory concentrations of penicillin, ciprofloxacin, enrofloxacin, clindamycin, erythromycin, chloramphenicol, and tetracycline between avian, bovine, equine, and porcine isolates. PMID:21532820

  2. Staphylococcus epidermidis and Staphylococcus haemolyticus: Molecular Detection of Cytotoxin and Enterotoxin Genes

    PubMed Central

    Pinheiro, Luiza; Ivo Brito, Carla; de Oliveira, Adilson; Yoshida Faccioli Martins, Patrícia; Cataneli Pereira, Valéria; Ribeiro de Souza da Cunha, Maria de Lourdes

    2015-01-01

    Although opportunistic pathogens, coagulase-negative staphylococci (CoNS), including Staphylococcus epidermidis and Staphylococcus haemolyticus, have long been regarded as avirulent organisms. The role of toxins in the development of infections caused by CoNS is still controversial. The objective of this study was to characterize the presence of enterotoxin and cytotoxin genes in S. epidermidis and S. haemolyticus isolates obtained from blood cultures. Cytotoxin genes were detected by PCR using novel species-specific primers. Among the 85 S. epidermidis and 84 S. haemolyticus isolates, 95.3% and 79.8%, respectively, carried at least one enterotoxin gene. The most frequent enterotoxin genes were sea (53.3%), seg (64.5%) and sei (67.5%). The seg gene was positively associated with S. epidermidis (p = 0.02), and this species was more toxigenic than S. haemolyticus. The hla/yidD gene was detected in 92.9% of S. epidermidis and the hla gene in 91.7% of S. haemolyticus isolates; hlb was detected in 92.9% of the S. epidermidis isolates and hld in 95.3%. Nosocomial Staphylococcus epidermidis and S. haemolyticus isolates exhibited a high toxigenic potential, mainly containing the non-classical enterotoxin genes seg and sei. The previously unreported detection of hla/yidD and hlb in S. epidermidis and S. haemolyticus using species-specific primers showed that these hemolysin genes differ between CoNS species and that they are highly frequent in blood culture isolates. PMID:26389954

  3. Longitudinal study on methicillin-resistant Staphylococcus pseudintermedius in households.

    PubMed

    Laarhoven, Laura M; de Heus, Phebe; van Luijn, Jeanine; Duim, Birgitta; Wagenaar, Jaap A; van Duijkeren, Engeline

    2011-01-01

    Methicillin-resistant Staphylococcus pseudintermedius (MRSP) is an emerging pathogen in dogs and has been found in Europe, Asia and North America. To date most studies are one-point prevalence studies and therefore little is known about the dynamics of MRSP in dogs and their surrounding. In this longitudinal study MRSP colonization in dogs and the transmission of MRSP to humans, contact animals and the environment was investigated. Sixteen dogs with a recent clinical MRSP infection were included. The index dogs, contact animals, owners and environments were sampled once a month for six months. Samples taken from the nose, perineum and infection site (if present) of the index cases and contact animals, and the nares of the owners were cultured using pre-enrichment. Index cases were found positive for prolonged periods of time, in two cases during all six samplings. In five of the 12 households that were sampled during six months, the index case was intermittently found MRSP-positive. Contact animals and the environment were also found MRSP-positive, most often in combination with a MRSP-positive index dog. In four households positive environmental samples were found while no animals or humans were MRSP-positive, indicating survival of MRSP in the environment for prolonged periods of time. Genotyping revealed that generally similar or indistinguishable MRSP isolates were found in patients, contact animals and environmental samples within the same household. Within two households, however, genetically distinct MRSP isolates were found. These results show that veterinarians should stay alert with (former) MRSP patients, even after repeated MRSP-negative cultures or after the disappearance of the clinical infection. There is a considerable risk of transmission of MRSP to animals in close contact with MRSP patients. Humans were rarely MRSP-positive and never tested MRSP-positive more than once suggesting occasional contamination or rapid elimination of colonization of

  4. PENICILLINASE PLASMID DNA FROM Staphylococcus aureus*

    PubMed Central

    Rush, Mark G.; Gordon, C. N.; Novick, Richard P.; Warner, Robert C.

    1969-01-01

    A penicillinase plasmid from Staphylococcus aureus and three of its derivatives, all previously identified as extrachromosomal genetic elements, have been isolated in high yield as circular duplex DNA molecules. The wild-type plasmid was found by contour-length measurements of electron micrographs to have a molecular weight of 18.6 × 106 daltons. Two plasmids with deletions encompassing six and eight of the eleven known plasmid cistrons had molecular weights of 16.4 × 106 and 15.3 × 106 daltons, respectively. This information was used to establish approximate physical distances for the genetic map. A high-frequency transducing element also derived from the plasmid had a molecular weight of approximately 24 × 106 daltons. Although each plasmid preparation appeared homogeneous by ultracentrifugal analysis, electron micrographs always revealed the presence of a low percentage of complex oligomeric forms, particularly circular and catenated dimers. Images PMID:5260933

  5. Selenium nanoparticles inhibit Staphylococcus aureus growth

    PubMed Central

    Tran, Phong A; Webster, Thomas J

    2011-01-01

    Staphylococcus aureus is a key bacterium commonly found in numerous infections. S. aureus infections are difficult to treat due to their biofilm formation and documented antibiotic resistance. While selenium has been used for a wide range of applications including anticancer applications, the effects of selenium nanoparticles on microorganisms remain largely unknown to date. The objective of this in vitro study was thus to examine the growth of S. aureus in the presence of selenium nanoparticles. Results of this study provided the first evidence of strongly inhibited growth of S. aureus in the presence of selenium nanoparticles after 3, 4, and 5 hours at 7.8, 15.5, and 31 μg/mL. The percentage of live bacteria also decreased in the presence of selenium nanoparticles. Therefore, this study suggests that selenium nanoparticles may be used to effectively prevent and treat S. aureus infections and thus should be further studied for such applications. PMID:21845045

  6. Acute Postoperative Endophthalmitis Caused by Staphylococcus lugdunensis▿

    PubMed Central

    Chiquet, C.; Pechinot, A.; Creuzot-Garcher, C.; Benito, Y.; Croize, J.; Boisset, S.; Romanet, J. P.; Lina, G.; Vandenesch, F.

    2007-01-01

    Acute postoperative endophthalmitis caused by Staphylococcus lugdunensis is infrequently reported in clinical studies. Five cases of acute postcataract surgery endophthalmitis caused by S. lugdunensis were taken from a multicenter prospective study conducted in four university-affiliated hospitals in France (2004 to 2005). These cases were characterized by severe ocular inflammation occurring with a mean delay of 7.6 days after cataract surgery, severe visual loss (hand motions or less in three cases), and dense infiltration of the vitreous. Each of these patients was initially treated by using a standard protocol with intravitreal (vancomycin and ceftazidime), systemic, and topical antibiotics. Given the severity of the endophthalmitis, even though bacteria were sensitive to intravitreal antibiotics, pars plana vitrectomy was needed in four cases. The final visual prognosis was complicated by severe retinal detachment in three cases. The microbiological diagnosis was reached by using conventional cultures with specific biochemical tests and eubacterial PCR amplification followed by direct sequencing. PMID:17392442

  7. Evasion of Neutrophil Killing by Staphylococcus aureus.

    PubMed

    McGuinness, Will A; Kobayashi, Scott D; DeLeo, Frank R

    2016-01-01

    Staphylococcus aureus causes many types of infections, ranging from self-resolving skin infections to severe or fatal pneumonia. Human innate immune cells, called polymorphonuclear leukocytes (PMNs or neutrophils), are essential for defense against S. aureus infections. Neutrophils are the most prominent cell type of the innate immune system and are capable of producing non-specific antimicrobial molecules that are effective at eliminating bacteria. Although significant progress has been made over the past few decades, our knowledge of S. aureus-host innate immune system interactions is incomplete. Most notably, S. aureus has the capacity to produce numerous molecules that are directed to protect the bacterium from neutrophils. Here we review in brief the role played by neutrophils in defense against S. aureus infection, and correspondingly, highlight selected S. aureus molecules that target key neutrophil functions. PMID:26999220

  8. The Heme Sensor System of Staphylococcus aureus

    PubMed Central

    Stauff, Devin L.; Skaar, Eric P.

    2016-01-01

    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, which alleviates heme toxicity. Importantly, the inability to sense or respond to heme alters the virulence of S. aureus, highlighting the importance of heme sensing and detoxification to staphylococcal pathogenesis. Furthermore, potential orthologues of the Hss and Hrt systems are found in many species of Gram-positive bacteria, a possible indication that heme stress is a challenge faced by bacteria whose habitats include host tissues rich in heme. PMID:19494582

  9. Generation of Ramoplanin-Resistant Staphylococcus aureus

    PubMed Central

    Schmidt, John W.; Greenough, Adrienne; Burns, Michelle; Luteran, Andrea E.; McCafferty, Dewey G.

    2013-01-01

    Ramoplanin is a lipoglycodepsipeptide antimicrobial active against clinically important Gram-positive bacteria including methicillin resistant Staphylococcus aureus. To proactively examine ramoplanin resistance, we subjected S. aureus NCTC 8325-4 to serial passage in the presence of increasing concentrations of ramoplanin, generating the markedly resistant strain RRSA16. Susceptibility testing of RRSA16 revealed the unanticipated acquisition of cross-resistance to vancomycin and nisin. RRSA16 displayed phenotypes, including a thickened cell wall and reduced susceptibility to Triton X-100 induced autolysis, which are associated with vancomycin intermediate resistant S. aureus strains. Passage of RRSA16 for 18 days in drug-free medium yielded strain R16-18d with restored antibiotic susceptibility. The RRSA16 isolate may be used to identify the genetic and biochemical basis for ramoplanin-resistance and further our understanding of the evolution of antibiotic cross-resistance mechanisms in S. aureus. PMID:20659164

  10. Emerging Functions for the Staphylococcus aureus RNome

    PubMed Central

    Felden, Brice

    2013-01-01

    Staphylococcus aureus is a leading pathogen for animals and humans, not only being one of the most frequently isolated bacteria in hospital-associated infections but also causing diseases in the community. To coordinate the expression of its numerous virulence genes for growth and survival, S. aureus uses various signalling pathways that include two-component regulatory systems, transcription factors, and also around 250 regulatory RNAs. Biological roles have only been determined for a handful of these sRNAs, including cis, trans, and cis-trans acting RNAs, some internally encoding small, functional peptides and others possessing dual or multiple functions. Here we put forward an inventory of these fascinating sRNAs; the proteins involved in their activities; and those involved in stress response, metabolisms, and virulence. PMID:24348246

  11. Evasion of Neutrophil Killing by Staphylococcus aureus

    PubMed Central

    McGuinness, Will A.; Kobayashi, Scott D.; DeLeo, Frank R.

    2016-01-01

    Staphylococcus aureus causes many types of infections, ranging from self-resolving skin infections to severe or fatal pneumonia. Human innate immune cells, called polymorphonuclear leukocytes (PMNs or neutrophils), are essential for defense against S. aureus infections. Neutrophils are the most prominent cell type of the innate immune system and are capable of producing non-specific antimicrobial molecules that are effective at eliminating bacteria. Although significant progress has been made over the past few decades, our knowledge of S. aureus-host innate immune system interactions is incomplete. Most notably, S. aureus has the capacity to produce numerous molecules that are directed to protect the bacterium from neutrophils. Here we review in brief the role played by neutrophils in defense against S. aureus infection, and correspondingly, highlight selected S. aureus molecules that target key neutrophil functions. PMID:26999220

  12. Methicillin-resistant Staphylococcus aureus: the superbug.

    PubMed

    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

  13. The T Cell Response to Staphylococcus aureus

    PubMed Central

    Bröker, Barbara M.; Mrochen, Daniel; Péton, Vincent

    2016-01-01

    Staphylococcus aureus (S. aureus) is a dangerous pathogen and a leading cause of both nosocomial and community acquired bacterial infection worldwide. However, on the other hand, we are all exposed to this bacterium, often within the first hours of life, and usually manage to establish equilibrium and coexist with it. What does the adaptive immune system contribute toward lifelong control of S. aureus? Will it become possible to raise or enhance protective immune memory by vaccination? While in the past the S. aureus-specific antibody response has dominated this discussion, the research community is now coming to appreciate the role that the cellular arm of adaptive immunity, the T cells, plays. There are numerous T cell subsets, each with differing functions, which together have the ability to orchestrate the immune response to S. aureus and hence to tip the balance between protection and pathology. This review summarizes the state of the art in this dynamic field of research. PMID:26999219

  14. Agglutination of Staphylococcus aureus by Rabbit Sera

    PubMed Central

    Forsgren, Arne; Forsum, Urban

    1972-01-01

    Of 137 Staphylococcus aureus strains, 87 agglutinated in normal rabbit serum. The agglutination was shown to be caused by the Fc-part of immunoglobulin G (IgG). F(ab1)2-fragments of IgG and immunoglobulin M (IgM) in corresponding concentrations were unreactive. The agglutinating strains had a high or moderate content of protein A. Strains with a low content of protein A and protein A-negative mutants did not agglutinate. The importance of the reaction between the Fc part of IgG and protein A for serotyping of S. aureus is demonstrated. Two alternative methods for serotyping S. aureus are suggested, using either F(ab1)2 fragments of IgG or intact IgM. Images PMID:4564678

  15. A Tactile Response in Staphylococcus aureus

    PubMed Central

    Lower, Steven K.; Yongsunthon, Ruchirej; Casillas-Ituarte, Nadia N.; Taylor, Eric S.; DiBartola, Alex C.; Lower, Brian H.; Beveridge, Terrance J.; Buck, Andrew W.; Fowler, Vance G.

    2010-01-01

    It is well established that bacteria are able to respond to temporal gradients (e.g., by chemotaxis). However, it is widely held that prokaryotes are too small to sense spatial gradients. This contradicts the common observation that the vast majority of bacteria live on the surface of a solid substrate (e.g., as a biofilm). Herein we report direct experimental evidence that the nonmotile bacterium Staphylococcus aureus possesses a tactile response, or primitive sense of touch, that allows it to respond to spatial gradients. Attached cells recognize their substrate interface and localize adhesins toward that region. Braille-like avidity maps reflect a cell's biochemical sensory response and reveal ultrastructural regions defined by the actual binding activity of specific proteins. PMID:21044577

  16. Staphylococcus cohnii hemolysins - isolation, purification and properties.

    PubMed

    Rózalska, M; Szewczyk, E M

    2008-01-01

    A total 355 of Staphylococcus cohnii isolates from hospital environment, patients (newborns), medical staff and from non-hospital environment were tested for hemolytic activity. Ninety-one % of S. cohnii ssp. cohnii and 74.5 % S. cohnii ssp. urealyticus strains exhibited hemolysis synergistic to S. aureus ATCC 25923 strain. Crude preparations of hemolysins of both bacterial subspecies presented delta-hemolysin, but not alpha- and beta-toxin activity. Highly pure hemolysins were obtained by semipreparative SDS-PAGE or by organic solvent extraction from the freeze-dried crude preparations. Native-PAGE and 2D-PAGE showed their high heterogeneity. Molar masses of single hemolysin units estimated by the Tris-Tricine-SDS-PAGE were calculated as 3.47 kDa for S. cohnii ssp. cohnii and 3.53 kDa for S. cohnii ssp. urealyticus. PMID:19381478

  17. Generation of ramoplanin-resistant Staphylococcus aureus.

    PubMed

    Schmidt, John W; Greenough, Adrienne; Burns, Michelle; Luteran, Andrea E; McCafferty, Dewey G

    2010-09-01

    Ramoplanin is a lipoglycodepsipeptide antimicrobial active against clinically important Gram-positive bacteria including methicillin-resistant Staphylococcus aureus. To proactively examine ramoplanin resistance, we subjected S. aureus NCTC 8325-4 to serial passage in the presence of increasing concentrations of ramoplanin, generating the markedly resistant strain RRSA16. Susceptibility testing of RRSA16 revealed the unanticipated acquisition of cross-resistance to vancomycin and nisin. RRSA16 displayed phenotypes, including a thickened cell wall and reduced susceptibility to Triton X-100-induced autolysis, which are associated with vancomycin intermediate-resistant S. aureus strains. Passage of RRSA16 for 18 days in a drug-free medium yielded strain R16-18d with restored antibiotic susceptibility. The RRSA16 isolate may be used to identify the genetic and biochemical basis for ramoplanin resistance and to further our understanding of the evolution of antibiotic cross-resistance mechanisms in S. aureus. PMID:20659164

  18. Methicillin-resistant Staphylococcus aureus, Western Australia

    PubMed Central

    Dailey, Lynne; Coombs, Geoffrey W.; O'Brien, Frances G.; Pearman, John W.; Christiansen, Keryn; Grubb, Warren B.

    2005-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) continues to be a notable cause of hospital-acquired infections. A statewide screening and control policy was implemented in Western Australia (WA) after an outbreak of epidemic MRSA in a Perth hospital in 1982. We report on statutory notifications from1998 to 2002 and review the 20-year period from 1983 to 2002. The rate of reporting of community-associated Western Australia MRSA (WAMRSA) escalated from 1998 to 2002 but may have peaked in 2001. Several outbreaks were halted, but they resulted in an increase in reports as a result of screening. A notable increase in ciprofloxacin resistance during the study period was observed as a result of more United Kingdom epidemic MRSA (EMRSA) -15 and -16. WA has seen a persistently low incidence of multidrug-resistant MRSA because of the screening and decolonization program. Non–multidrug-resistant, community-associated WAMRSA strains have not established in WA hospitals. PMID:16318700

  19. A humanized monoclonal antibody targeting Staphylococcus aureus.

    PubMed

    Patti, Joseph M

    2004-12-01

    This current presentation describes the in vitro and in vivo characterization of Aurexis (tefibazumab), a humanized monoclonal antibody that exhibits a high affinity and specificity and for the Staphylococcus aureus MSCRAMM (Microbial Surface Components Recognizing Adhesive Matrix Molecules) protein ClfA. Aurexis inhibited ClfA binding to human fibrinogen, and enhanced the opsonophagocytic uptake of ClfA-coated beads. Preclinical in vivo testing revealed that a single administration of Aurexis significantly protected against an IV challenge with a methicillin resistant S. aureus (MRSA) strain in murine septicemia and rabbit infective endocarditis (IE) models. Safety and pharmacokinetic data from a 19-patient phase I study support continued evaluation of Aurexis in phase II studies. PMID:15576200

  20. Kinin receptor expression during Staphylococcus aureus infection

    PubMed Central

    Bengtson, Sara H.; Phagoo, Stephen B.; Norrby-Teglund, Anna; Påhlman, Lisa; Mörgelin, Matthias; Zuraw, Bruce L.; Leeb-Lundberg, L. M. Fredrik; Herwald, Heiko

    2006-01-01

    An inappropriate host response to invading bacteria is a critical parameter that often aggravates the outcome of an infection. Staphylococcus aureus is a major human Gram-positive pathogen that causes a wide array of community- and hospital-acquired diseases ranging from superficial skin infections to severe conditions such as staphylococcal toxic shock. Here we find that S aureus induces inflammatory reactions by modulating the expression and response of the B1 and B2 receptors, respectively. This process is initiated by a chain of events, involving staphylococcal-induced cytokine release from monocytes, bacteria-triggered contact activation, and conversion of bradykinin to its metabolite desArg9bradykinin. The data of the present study implicate an important and previously unknown role for kinin receptor regulation in S aureus infections. PMID:16735595

  1. Triclosan promotes Staphylococcus aureus nasal colonization.

    PubMed

    Syed, Adnan K; Ghosh, Sudeshna; Love, Nancy G; Boles, Blaise R

    2014-01-01

    The biocide triclosan is used in many personal care products, including toothpastes, soaps, clothing, and medical equipment. Consequently, it is present as a contaminant in the environment and has been detected in some human fluids, including serum, urine, and milk. Staphylococcus aureus is an opportunistic pathogen that colonizes the noses and throats of approximately 30% of the population. Colonization with S. aureus is known to be a risk factor for several types of infection. Here we demonstrate that triclosan is commonly found in the nasal secretions of healthy adults and the presence of triclosan trends positively with nasal colonization by S. aureus. We demonstrate that triclosan can promote the binding of S. aureus to host proteins such as collagen, fibronectin, and keratin, as well as inanimate surfaces such as plastic and glass. Lastly, triclosan-exposed rats are more susceptible to nasal colonization with S. aureus. These data reveal a novel factor that influences the ability of S. aureus to bind surfaces and alters S. aureus nasal colonization. IMPORTANCE Triclosan has been used as a biocide for over 40 years, but the broader effects that it has on the human microbiome have not been investigated. We demonstrate that triclosan is present in nasal secretions of a large portion of a test population and its presence correlates with Staphylococcus aureus nasal colonization. Triclosan also promotes the binding of S. aureus to human proteins and increases the susceptibility of rats to nasal colonization by S. aureus. These findings are significant because S. aureus colonization is a known risk factor for the development of several types of infections. Our data demonstrate the unintended consequences of unregulated triclosan use and contribute to the growing body of research demonstrating inadvertent effects of triclosan on the environment and human health. PMID:24713325

  2. Clinical Management of Staphylococcus aureus Bacteremia

    PubMed Central

    Holland, Thomas L.; Arnold, Christopher; Fowler, Vance G.

    2014-01-01

    Importance Several management strategies may improve outcomes in patients with Staphylococcus aureus bacteremia (SAB). The strength of evidence supporting these management strategies, however, varies widely. Objective To perform a systematic review of the evidence for two unresolved questions involving management strategies for SAB: 1) is transesophageal echocardiography (TEE) necessary in all cases of SAB; and 2) what is the optimal antibiotic therapy for methicillin resistant Staphylococcus aureus (MRSA) bacteremia? Evidence acquisition A PubMed search from inception through May 2014 was performed to find studies that addressed the role of TEE in SAB. A second search of PubMed, EMBASE, and The Cochrane Library from 1/1/1990 to 5/28/2014 was performed to find studies that addressed antibiotic treatment of MRSA bacteremia. Studies that reported outcomes of systemic antibiotic therapy for MRSA bacteremia were included. All searches were augmented by review of bibliographic references from included studies. The quality of evidence was assessed using the GRADE system by consensus of independent evaluations by at least two authors. Results In 9 studies with a total of 3513 patients, use of TEE was associated with higher rates of diagnosis of endocarditis (14–25%) when compared with TTE (2–14%). Five studies proposed criteria to identify patients in whom TEE might safely be avoided. Only one high-quality trial of antibiotic therapy for MRSA bacteremia was identified from the 83 studies considered. Conclusions and relevance Most contemporary management strategies for SAB are based upon low quality evidence. TEE is indicated in most patients with SAB. It may be possible to identify a subset of SAB patients for whom TEE can be safely avoided. Vancomycin and daptomycin are the first-line antibiotic choices for MRSA bacteremia. Well-designed studies to address the management of SAB are desperately needed. PMID:25268440

  3. "Staphylococcus pettenkoferi," a novel staphylococcal species isolated from clinical specimens.

    PubMed

    Trülzsch, Konrad; Rinder, Heinz; Trcek, Janja; Bader, Lutz; Wilhelm, Ulrike; Heesemann, Jürgen

    2002-07-01

    In this report we describe a novel species of coagulase-negative novobiocin susceptible staphylococci obtained from an epidemiologically unrelated blood culture and a wound infection. These isolates significantly differed from all other validated Staphylococcus species based on phenotypic characteristics and 16S rRNA gene sequencing. Both isolates had identical 16S rRNA sequences and phylogenetic trees constructed from evolutionary distances showed that this species formed a distinct and deep subline that was most closely related to members of the Staphylococcus saprophyticus cluster group (S. kloosii, S. gallinarum, S. arlettae, S. saprophyticus, S. xylosus, S. equorum, S. succinus and S. cohnii) and Staphylococcus auricularis. Furthermore these strains could each be distinguished from all other staphylococci based on at least one phenotypic trait. Therefore we propose the designation of "Staphylococcus pettenkoferi" a novel species of coagulase-negative staphylococci. PMID:12106949

  4. Staphylococcus massiliensis sp. nov., isolated from a human brain abscess.

    PubMed

    Al Masalma, Mouhamad; Raoult, Didier; Roux, Véronique

    2010-05-01

    Gram-positive, catalase-positive, coagulase-negative, non-motile, non-fermentative and novobiocin-susceptible cocci were isolated from a human brain abscess sample (strain 5402776(T)). This novel strain was analysed by a polyphasic taxonomic approach. The respiratory quinones detected were MK-7 (93 %) and MK-6 (7 %) and the major fatty acids were C(15 : 0) iso (60.5 %), C(17 : 0) iso (8.96 %) C(15 : 0) anteiso (7.93 %) and C(19 : 0) iso (6.78 %). The peptidoglycan type was A3alpha l-Lys-Gly(2-3)-l-Ser-Gly. Based on cellular morphology and biochemical criteria, the new isolate was assigned to the genus Staphylococcus, although it did not correspond to any recognized species. The G+C content of the DNA was 36.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequence comparisons showed that the new isolate was most closely related to Staphylococcus piscifermentans, Staphylococcus condimenti, Staphylococcus carnosus subsp. carnosus, S. carnosus subsp. utilis and Staphylococcus simulans (97.7 %, 97.6 %, 97.6 %, 97.6 % and 96.5 % sequence similarity, respectively). Comparison of tuf, hsp60, rpoB, dnaJ and sodA gene sequences was also performed. In phylogenetic analysis inferred from tuf, dnaJ and rpoB gene sequence comparisons, strain 5402776(T) clustered with Staphylococcus pettenkoferi (93.7 %, 82.5 % and 89 % sequence similarity, respectively) and on phylogenetic analysis inferred from sodA gene sequence comparisons, it clustered with Staphylococcus chromogenes (82.8 %). On the basis of phenotypic and genotypic data, this isolate represents a novel species for which the name Staphylococcus massiliensis sp. nov. is proposed (type strain 5402776(T)=CCUG 55927(T)=CSUR P23(T)). PMID:19666814

  5. A proposal to unify two subspecies of Staphylococcus equorum: Staphylococcus equorum subsp. equorum and Staphylococcus equorum subsp. linens.

    PubMed

    Jeong, Do-Won; Kim, Hye-Rim; Han, Seulhwa; Jeon, Che Ok; Lee, Jong-Hoon

    2013-12-01

    Twelve isolates from jeotgal, a Korean high-salt-fermented seafood, identified as Staphylococcus equorum were compared by phenotypic and genotypic methods to determine their precise taxonomic identities at the subspecies level. Four strains and three strains had complete 16S rRNA gene sequence matches with S. equorum subsp. equorum DSM 20674(T) and S. equorum subsp. linens DSM 15097(T), respectively. Five strains showed 99.9 % identity with the sequences of both type strains. In our DNA-DNA hybridization analyses among two type strains and two isolates, the similarities were over 72 % and were higher than the similarities presented at the subspecies proposal. Physiological characteristics such as sugar utilization, β-galactosidase activity, novobiocin resistance and salt tolerance, which were adopted for subspecies separation, could not be applied to assign the isolates to a taxonomic unit. Antibiotic susceptibility, hemolytic activity, biofilm formation and protein profiles did not present markers to divide the isolates into either of the subspecies. Multilocus sequence typing of the sequences of the 16S rRNA gene and five housekeeping genes did not produce any coherent relationship among the isolates and type strains. Repetitive element-PCR fingerprinting using ERIC (enterobacterial repetitive intergenic consensus) primers classified 12 isolates to three genotypes, and the genotypes of both type strains coincided with two isolates expressing different characteristics. Based on these phenotypic and genotypic analyses results, we propose to unify the present two subspecies of S. equorum into one species, S. equorum. PMID:24057981

  6. In situ rheology of Staphylococcus epidermidis bacterial biofilms

    PubMed Central

    Pavlovsky, Leonid

    2014-01-01

    We developed a method to grow Staphylococcus epidermidis bacterial biofilms and characterize their rheological properties in situ in a continuously fed bioreactor incorporated into a parallel plate rheometer. The temperature and shear rates of growth modeled bloodstream conditions, a common site of S. epidermidis infection. We measured the linear elastic (G′) and viscous moduli (G″) of the material using small-amplitude oscillatory rheology and the yield stress using non-linear creep rheology. We found that the elastic and viscous moduli of the S. epidermidis biofilm were 11 ± 3 Pa and 1.9 ± 0.5 Pa at a frequency of 1 Hz (6.283 rad per s) and that the yield stress was approximately 20 Pa. We modeled the linear creep response of the biofilm using a Jeffreys model and found that S. epidermidis has a characteristic relaxation time of approximately 750 seconds and a linear creep viscosity of 3000 Pa s. The effects on the linear viscoelastic moduli of environmental stressors, such as NaCl concentration and extremes of temperature, were also studied. We found a non-monotonic relationship between moduli and NaCl concentrations, with the stiffest material properties found at human physiological concentrations (135 mM). Temperature dependent rheology showed hysteresis in the moduli when heated and cooled between 5 °C and 60 °C. Through these experiments, we demonstrated that biofilms are rheologically complex materials that can be characterized by a combination of low modulus (~10 Pa), long relaxation time (~103 seconds), and a finite yield stress (20 Pa). This suggests that biofilms should be viewed as soft viscoelastic solids whose properties are determined in part by local environmental conditions. The in situ growth method introduced here can be adapted to a wide range of biofilm systems and applied over a broad spectrum of rheological and environmental conditions because the technique minimizes the risk of irreversible, non-linear deformation of the microbial

  7. Adherence to a metal, polymer and composite by Staphylococcus aureus and Staphylococcus epidermidis.

    PubMed

    Verheyen, C C; Dhert, W J; de Blieck-Hogervorst, J M; van der Reijden, T J; Petit, P L; de Groot, K

    1993-04-01

    Bacterial adherence on to several materials with a potential application in reconstructive surgery was studied. Polymer (poly(L-lactide)), composite (hydroxyapatite/poly(L-lactide)) and metal (316L stainless steel) were evaluated both as smooth and sandblasted specimens. All materials were incubated in phosphate-buffered saline, challenged with Staphylococcus aureus or S. epidermidis and evaluated for up to 24 h. S. aureus showed a preference for the metal and composite tested over the polymer used. For S. epidermidis no preference was found for one of the investigated materials. The influence of surface roughness on bacterial growth was demonstrated by increased colonization on the sandblasted specimens. PMID:8507783

  8. Toxin-Antitoxin Systems of Staphylococcus aureus

    PubMed Central

    Schuster, Christopher F.; Bertram, Ralph

    2016-01-01

    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. PMID:27164142

  9. Toxin-Antitoxin Systems of Staphylococcus aureus.

    PubMed

    Schuster, Christopher F; Bertram, Ralph

    2016-01-01

    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. PMID:27164142

  10. Nasal commensal Staphylococcus epidermidis counteracts influenza virus

    PubMed Central

    Chen, Hui-Wen; Liu, Pei-Feng; Liu, Yu-Tsueng; Kuo, Sherwin; Zhang, Xing-Quan; Schooley, Robert T.; Rohde, Holger; Gallo, Richard L.; Huang, Chun-Ming

    2016-01-01

    Several microbes, including Staphylococcus epidermidis (S. epidermidis), a Gram-positive bacterium, live inside the human nasal cavity as commensals. The role of these nasal commensals in host innate immunity is largely unknown, although bacterial interference in the nasal microbiome may promote ecological competition between commensal bacteria and pathogenic species. We demonstrate here that S. epidermidis culture supernatants significantly suppressed the infectivity of various influenza viruses. Using high-performance liquid chromatography together with mass spectrometry, we identified a giant extracellular matrix-binding protein (Embp) as the major component involved in the anti-influenza effect of S. epidermidis. This anti-influenza activity was abrogated when Embp was mutated, confirming that Embp is essential for S. epidermidis activity against viral infection. We also showed that both S. epidermidis bacterial particles and Embp can directly bind to influenza virus. Furthermore, the injection of a recombinant Embp fragment containing a fibronectin-binding domain into embryonated eggs increased the survival rate of virus-infected chicken embryos. For an in vivo challenge study, prior Embp intranasal inoculation in chickens suppressed the viral titres and induced the expression of antiviral cytokines in the nasal tissues. These results suggest that S. epidermidis in the nasal cavity may serve as a defence mechanism against influenza virus infection. PMID:27306590

  11. Modulation of Staphylococcus aureus spreading by water.

    PubMed

    Lin, Mei-Hui; Ke, Wan-Ju; Liu, Chao-Chin; Yang, Meng-Wei

    2016-01-01

    Staphylococcus aureus is known to spread rapidly and form giant colonies on the surface of soft agar and animal tissues by a process called colony spreading. So far, the mechanisms underlying spreading remain poorly understood. This study investigated the spreading phenomenon by culturing S. aureus and its mutant derivatives on Tryptic Soy Agarose (TSA) medium. We found that S. aureus extracts water from the medium and floats on water at 2.5 h after inoculation, which could be observed using phase contrast microscopy. The floating of the bacteria on water could be verified by confocal microscopy using an S. aureus strain that constitutively expresses green fluorescence protein. This study also found that as the density of bacterial colony increases, a quorum sensing response is triggered, resulting in the synthesis of the biosurfactants, phenolic-soluble modulins (PSMs), which weakens water surface tension, causing water to flood the medium surface to allow the bacteria to spread rapidly. This study reveals a mechanism that explains how an organism lacking a flagellar motor is capable of spreading rapidly on a medium surface, which is important to the understanding of how S. aureus spreads in human tissues to cause infections. PMID:27125382

  12. Immunopathogenesis of Staphylococcus aureus pulmonary infection

    PubMed Central

    Parker, Dane; Prince, Alice

    2013-01-01

    Staphylococcus aureus is a common human pathogen highly evolved as both a component of the commensal flora and as a major cause of invasive infection. Severe respiratory infection due to staphylococci has been increasing due to the prevalence of more virulent USA300 CA-MRSA strains in the general population. The ability of S. aureus to adapt to the milieu of the respiratory tract has facilitated its emergence as a respiratory pathogen. Its metabolic versatility, the ability to scavenge iron, coordinate gene expression, and the horizontal acquisition of useful genetic elements have all contributed to its success as a component of the respiratory flora, in hospitalized patients, as a complication of influenza and in normal hosts. The expression of surface adhesins facilitates its persistence in the airways. In addition, the highly sophisticated interactions of the multiple S. aureus virulence factors, particularly the α-hemolysin and protein A, with diverse immune effectors in the lung such as ADAM10, TNFR1, EGFR, immunoglobulin, and complement all contribute to the pathogenesis of staphylococcal pneumonia. PMID:22037948

  13. Genomic Analysis of Companion Rabbit Staphylococcus aureus.

    PubMed

    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

  14. Where does a Staphylococcus aureus vaccine stand?

    PubMed

    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

  15. Hidden Staphylococcus aureus Carriage: Overrated or Underappreciated?

    PubMed Central

    2016-01-01

    ABSTRACT Staphylococcus aureus is a persistent companion bacterial species in one-third of humankind. Reservoirs include the nasal and nasopharyngeal cavities, skin, and gastrointestinal (GI) tract. Despite earlier claims that colonization of individuals is caused by clonal organisms, next-generation sequencing (NGS) has revealed that resident type heterogeneity is not exceptional. Carriage, whether overt or hidden, is correlated with a risk of autoinfection. In a recent article in mBio, it was shown that, based on staphylococcal genome sequencing, low-level GI persistence may cause long-term nosocomial outbreaks [L. Senn et al., 7(1):e02039-15, 2016, doi:10.1128/mBio.02039-15]. Institutional endemicity with methicillin-resistant S. aureus (MRSA) sequence type 228 (ST228) is shown to originate not from high-level nasal carriage or poor compliance with infection control practice but from low-grade asymptomatic GI colonization. This shows the power of NGS in elucidating staphylococcal epidemiology and, even more important, demonstrates that (drug-resistant) microorganisms may possess stealthy means of persistence. Identifying these persistence mechanisms is key to successful infection control. PMID:26884429

  16. Antimicrobial therapy of Staphylococcus aureus bloodstream infection.

    PubMed

    Tacconelli, Evelina; Cataldo, Maria A

    2007-10-01

    Staphylococcus aureus bloodstream infection (BSI) contributes significantly to the morbidity and mortality of in-patients. The optimal therapy for methicillin-susceptible S. aureus BSI consists of penicillins. The efficacy of these drugs is well documented from several published data and supported from a long clinical experience. Methicillin-resistant S. aureus (MRSA) strains are responsible for the majority of nosocomial BSI and are recovered with increasing frequency at hospital admission. Although glycopeptides still represent the drugs of choice, there are several concerns on the treatment of MRSA BSI: reports of clinical failure with vancomycin treatment, regardless of the in vitro susceptibility; increasing reports of MRSA strains with reduced vancomycin susceptibility; difficulty in therapeutic dosage monitoring of teicoplanin; lack of evidence on the efficacy of combination therapy. Recently, new drugs have been introduced in the therapeutic arsenal for MRSA infections, but their clinical use is not yet clearly established for BSI. The review summarises evidence on present therapeutic options for the treatment of S. aureus BSI. PMID:17931086

  17. Molecular basis of Staphylococcus epidermidis infections.

    PubMed

    Otto, Michael

    2012-03-01

    Staphylococcus epidermidis is the most important member of the coagulase-negative staphylococci and one of the most abundant colonizers of human skin. While for a long time regarded as innocuous, it has been identified as the most frequent cause of device-related infections occurring in the hospital setting and is therefore now recognized as an important opportunistic pathogen. S. epidermidis produces a series of molecules that provide protection from host defenses. Specifically, many proteins and exopolymers, such as the exopolysaccharide PIA, contribute to biofilm formation and inhibit phagocytosis and the activity of human antimicrobial peptides. Furthermore, recent research has identified a family of pro-inflammatory peptides in S. epidermidis, the phenol-soluble modulins (PSMs), which have multiple functions in immune evasion and biofilm development, and may be cytolytic. However, in accordance with the relatively benign relationship that S. epidermidis has with its host, production of aggressive members of the PSM family is kept at a low level. Interestingly, in contrast to S. aureus with its large arsenal of toxins developed for causing infection in the human host, most if not all "virulence factors" of S. epidermidis appear to have original functions in the commensal lifestyle of this bacterium. PMID:22095240

  18. Destruction of Staphylococcus aureus during frankfurter processing.

    PubMed Central

    Palumbo, S A; Smith, J L; Kissinger, J C

    1977-01-01

    We studied the thermal resistance of Staphylococcus aureus during frankfurter processing in respect to whether staphylococci are killed by the heating step of the process and whether heat injury interferes with the quantitative estimation of the survivors. With S. aureus 198E, heat injury could be demonstrated only when large numbers of cells (10(8)/g) were present and at a product temperature of 140 degrees F (60 degrees C). On tryptic soy agar and tryptic soy agar plus 7% NaCl media, at temperatures less than 140 degrees F, the counts were virtually identical; above 140 degrees F, the counts converged, with the organisms dying so rapidly that heat injury was not demonstrable. Heat injury was thus judged not to interfere with the quantitative estimation of staphylococci surviving the normal commercial heating given frankfurters. By using a combination of direct plating on tryptic soy agar and a most-probable-number technique, we detected no viable cells (less than 0.3/g) of several strains of S. aureus in frankfurters heated to 160 degrees F (71.1 degrees C). This temperature is compatible with the normal final temperature to which federally inspected processors heat their frankfurters and with the temperature needed to destroy salmonellae. PMID:563701

  19. NVC-422 Inactivates Staphylococcus aureus Toxins

    PubMed Central

    Jekle, Andreas; Yoon, Jungjoo; Zuck, Meghan; Najafi, Ramin; Wang, Lu; Shiau, Timothy; Francavilla, Charles; Rani, Suriani Abdul; Eitzinger, Christian; Nagl, Markus; Anderson, Mark

    2013-01-01

    Bacterial pathogens have specific virulence factors (e.g., toxins) that contribute significantly to the virulence and infectivity of microorganisms within the human hosts. Virulence factors are molecules expressed by pathogens that enable colonization, immunoevasion, and immunosuppression, obtaining nutrients from the host or gaining entry into host cells. They can cause pathogenesis by inhibiting or stimulating certain host functions. For example, in systemic Staphylococcus aureus infections, virulence factors such as toxic shock syndrome toxin 1 (TSST-1), staphylococcal enterotoxin A (SEA), and staphylococcal enterotoxin B (SEB) cause sepsis or toxic shock by uncontrolled stimulation of T lymphocytes and by triggering a cytokine storm. In vitro, these superantigens stimulate the proliferation of human peripheral blood mononuclear cells (PBMC) and the release of many cytokines. NVC-422 (N,N-dichloro-2,2-dimethyltaurine) is a broad-spectrum, fast-acting topical anti-infective agent against microbial pathogens, including antibiotic-resistant microbes. Using mass spectrometry, we demonstrate here that NVC-422 oxidizes methionine residues of TSST-1, SEA, SEB, and exfoliative toxin A (ETA). Exposure of virulence factors to 0.1% NVC-422 for 1 h prevented TSST-1-, SEA-, SEB-, and ETA-induced cell proliferation and cytokine release. Moreover, NVC-422 also delayed and reduced the protein A- and clumping factor-associated agglutination of S. aureus cultures. These results show that, in addition to its well-described direct microbicidal activity, NVC-422 can inactivate S. aureus virulence factors through rapid oxidation of methionines. PMID:23208720

  20. Staphylococcus aureus vaccines: Deviating from the carol.

    PubMed

    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

  1. Essential Staphylococcus aureus toxin export system

    PubMed Central

    Chatterjee, Som S.; Joo, Hwang-Soo; Duong, Anthony C.; Dieringer, Thomas D.; Tan, Vee Y.; Song, Yan; Fischer, Elizabeth R.; Cheung, Gordon Y. C.; Li, Min; Otto, Michael

    2012-01-01

    Widespread antibiotic resistance among important bacterial pathogens such as Staphylococcus aureus1 calls for alternative routes of drug development. Interfering with critical virulence determinants is considered a promising novel approach to control bacterial infection2. Phenol-soluble modulins (PSMs) are peptide toxins with multiple key roles in pathogenesis3–5 and a major impact on the ability of highly virulent S. aureus to cause disease3,6. However, targeting PSMs for therapeutic intervention is hampered by their multitude and diversity. Here, we report that an ABC transporter with previously unknown function is responsible for the export of all PSM classes, thus representing a single target to interfere simultaneously with the production of all PSMs. The transporter had a strong effect on virulence phenotypes, such as neutrophil lysis, and the development of S. aureus infection, similar in extent to the sum of all PSMs. Furthermore, it proved essential for bacterial growth. Moreover, it protected the producer from the antimicrobial activity of secreted PSMs and contributed to defense against PSM-mediated bacterial interference. Our study reveals a non-canonical, dedicated secretion mechanism for an important toxin class and identifies this mechanism as a comprehensive potential target for the development of drugs efficiently inhibiting growth and virulence of pathogenic staphylococci. PMID:23396209

  2. Genomic Analysis of Companion Rabbit Staphylococcus aureus

    PubMed Central

    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

  3. Predictors of Mortality in Staphylococcus aureus Bacteremia

    PubMed Central

    Jensen, Slade O.; Vaska, Vikram L.; Espedido, Björn A.; Paterson, David L.; Gosbell, Iain B.

    2012-01-01

    Summary: Staphylococcus aureus bacteremia (SAB) is an important infection with an incidence rate ranging from 20 to 50 cases/100,000 population per year. Between 10% and 30% of these patients will die from SAB. Comparatively, this accounts for a greater number of deaths than for AIDS, tuberculosis, and viral hepatitis combined. Multiple factors influence outcomes for SAB patients. The most consistent predictor of mortality is age, with older patients being twice as likely to die. Except for the presence of comorbidities, the impacts of other host factors, including gender, ethnicity, socioeconomic status, and immune status, are unclear. Pathogen-host interactions, especially the presence of shock and the source of SAB, are strong predictors of outcomes. Although antibiotic resistance may be associated with increased mortality, questions remain as to whether this reflects pathogen-specific factors or poorer responses to antibiotic therapy, namely, vancomycin. Optimal management relies on starting appropriate antibiotics in a timely fashion, resulting in improved outcomes for certain patient subgroups. The roles of surgery and infectious disease consultations require further study. Although the rate of mortality from SAB is declining, it remains high. Future international collaborative studies are required to tease out the relative contributions of various factors to mortality, which would enable the optimization of SAB management and patient outcomes. PMID:22491776

  4. agr function in clinical Staphylococcus aureus isolates

    PubMed Central

    Traber, Katrina E.; Lee, Elsie; Benson, Sarah; Corrigan, Rebecca; Cantera, Mariela; Shopsin, Bo; Novick, Richard P.

    2016-01-01

    The accessory gene regulator (agr) of Staphylococcus aureus is a global regulator of the staphylococcal virulon, which includes secreted virulence factors and surface proteins. The agr locus is important for virulence in a variety of animal models of infection, and has been assumed by inference to have a major role in human infection. Although most human clinical S. aureus isolates are agr+, there have been several reports of agr-defective mutants isolated from infected patients. Since it is well known that the agr locus is genetically labile in vitro, we have addressed the question of whether the reported agr-defective mutants were involved in the infection or could have arisen during post-isolation handling. We obtained a series of new staphylococcal isolates from local clinical infections and handled these with special care to avoid post-isolation mutations. Among these isolates, we found a number of strains with non-haemolytic phenotypes owing to mutations in the agr locus, and others with mutations elsewhere. We have also obtained isolates in which the population was continuously heterogeneous with respect to agr functionality, with agr+ and agr− variants having otherwise indistinguishable chromosomal backgrounds. This finding suggested that the agr− variants arose by mutation during the course of the infection. Our results indicate that while most clinical isolates are haemolytic and agr+, non-haemolytic and agr− strains are found in S. aureus infections, and that agr+ and agr− variants may have a cooperative interaction in certain types of infections. PMID:18667559

  5. Modulation of Staphylococcus aureus spreading by water

    PubMed Central

    Lin, Mei-Hui; Ke, Wan-Ju; Liu, Chao-Chin; Yang, Meng-Wei

    2016-01-01

    Staphylococcus aureus is known to spread rapidly and form giant colonies on the surface of soft agar and animal tissues by a process called colony spreading. So far, the mechanisms underlying spreading remain poorly understood. This study investigated the spreading phenomenon by culturing S. aureus and its mutant derivatives on Tryptic Soy Agarose (TSA) medium. We found that S. aureus extracts water from the medium and floats on water at 2.5 h after inoculation, which could be observed using phase contrast microscopy. The floating of the bacteria on water could be verified by confocal microscopy using an S. aureus strain that constitutively expresses green fluorescence protein. This study also found that as the density of bacterial colony increases, a quorum sensing response is triggered, resulting in the synthesis of the biosurfactants, phenolic-soluble modulins (PSMs), which weakens water surface tension, causing water to flood the medium surface to allow the bacteria to spread rapidly. This study reveals a mechanism that explains how an organism lacking a flagellar motor is capable of spreading rapidly on a medium surface, which is important to the understanding of how S. aureus spreads in human tissues to cause infections. PMID:27125382

  6. Cadmium Modulates Biofilm Formation by Staphylococcus epidermidis

    PubMed Central

    Wu, Xueqing; Santos, Regiane R.; Fink-Gremmels, Johanna

    2015-01-01

    The aim of the study was to evaluate the effect of cadmium exposure on Staphylococcus epidermidis (ATCC 35984) biofilm formation. Bacteria were cultured in the absence or presence of different concentrations (0–50 µM) of cadmium. Biofilm formation and bacterial viability were assessed. Quantitative Real Time-PCR (qRT-PCR) was used to determine the mRNA expression of molecular markers of S. epidermidis biofilm formation and dispersion. S. epidermidis biofilm formation was stimulated (p < 0.001) by 1.56 and 3.13 µM cadmium. Confocal laser scanning microscopy (CLSM) analysis confirmed an increase in biofilm thickness (23 and 22 µm, versus 17.8 µm in the controls) after exposure to 1.56 or 3.13 µM cadmium, respectively. qRT-PCR was performed showing the up-regulation of atlE, embp, aap, icaA and icaB after exposure to 3.13 µM cadmium. Taken together, these findings show that cadmium at low, sub-toxic concentrations acts as inducer of S. epidermidis biofilm formation. PMID:25749322

  7. Triclosan Promotes Staphylococcus aureus Nasal Colonization

    PubMed Central

    Syed, Adnan K.; Ghosh, Sudeshna; Love, Nancy G.; Boles, Blaise R.

    2014-01-01

    ABSTRACT The biocide triclosan is used in many personal care products, including toothpastes, soaps, clothing, and medical equipment. Consequently, it is present as a contaminant in the environment and has been detected in some human fluids, including serum, urine, and milk. Staphylococcus aureus is an opportunistic pathogen that colonizes the noses and throats of approximately 30% of the population. Colonization with S. aureus is known to be a risk factor for several types of infection. Here we demonstrate that triclosan is commonly found in the nasal secretions of healthy adults and the presence of triclosan trends positively with nasal colonization by S. aureus. We demonstrate that triclosan can promote the binding of S. aureus to host proteins such as collagen, fibronectin, and keratin, as well as inanimate surfaces such as plastic and glass. Lastly, triclosan-exposed rats are more susceptible to nasal colonization with S. aureus. These data reveal a novel factor that influences the ability of S. aureus to bind surfaces and alters S. aureus nasal colonization. PMID:24713325

  8. Tryptophan biosynthetic enzymes of Staphylococcus aureus.

    PubMed

    Proctor, A R; Kloos, W E

    1973-04-01

    Tryptophan biosynthetic enzymes were assayed in various tryptophan mutants of Staphylococcus aureus strain 655 and the wild-type parent. All mutants, except trpB mutants, lacked only the activity corresponding to the particular biosynthetic block, as suggested previously by analysis of accumulated intermediates and auxonography. Tryptophan synthetase A was not detected in extracts of either trpA or trpB mutants but appeared normal in other mutants. Mutants in certain other classes exhibited partial loss of another particular tryptophan enzyme activity. Tryptophan synthetase B activity was not detected in cell extract preparations but was detected in whole cells. The original map order proposed for the S. aureus tryptophan gene cluster was clarified by the definition of trpD (phosphoribosyl transferase(-)) and trpF (phosphoribosyl anthranilate isomerase(-)) mutants. These mutants were previously unresolved and designated as trp(DF) mutants (anthranilate accumulators). Phosphoribosyl anthranilate isomerase and indole-3-glycerol phosphate synthetase enzymes were separable by molecular sieve chromatography, suggesting that these functions are coded by separate loci. Molecular sieve chromatography failed to reveal aggregates involving anthranilate synthetase, phosphoribosyl transferase, phosphoribosyl anthranilate isomerase, and indole-3-glycerol phosphate synthetase, and this procedure provided an estimate of the molecular weights of these enzymes. Tryptophan was shown to repress synthesis of all six tryptophan biosynthetic enzymes, and derepression of all six activities was incident upon tryptophan starvation. Tryptophan inhibited the activity of anthranilate synthetase, the first enzyme of the pathway. PMID:4698207

  9. Aspartate inhibits Staphylococcus aureus biofilm formation.

    PubMed

    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

  10. Ecological Overlap and Horizontal Gene Transfer in Staphylococcus aureus and Staphylococcus epidermidis

    PubMed Central

    Méric, Guillaume; Miragaia, Maria; de Been, Mark; Yahara, Koji; Pascoe, Ben; Mageiros, Leonardos; Mikhail, Jane; Harris, Llinos G.; Wilkinson, Thomas S.; Rolo, Joana; Lamble, Sarah; Bray, James E.; Jolley, Keith A.; Hanage, William P.; Bowden, Rory; Maiden, Martin C.J.; Mack, Dietrich; de Lencastre, Hermínia; Feil, Edward J.; Corander, Jukka; Sheppard, Samuel K.

    2015-01-01

    The opportunistic pathogens Staphylococcus aureus and Staphylococcus epidermidis represent major causes of severe nosocomial infection, and are associated with high levels of mortality and morbidity worldwide. These species are both common commensals on the human skin and in the nasal pharynx, but are genetically distinct, differing at 24% average nucleotide divergence in 1,478 core genes. To better understand the genome dynamics of these ecologically similar staphylococcal species, we carried out a comparative analysis of 324 S. aureus and S. epidermidis genomes, including 83 novel S. epidermidis sequences. A reference pan-genome approach and whole genome multilocus-sequence typing revealed that around half of the genome was shared between the species. Based on a BratNextGen analysis, homologous recombination was found to have impacted on 40% of the core genes in S. epidermidis, but on only 24% of the core genes in S. aureus. Homologous recombination between the species is rare, with a maximum of nine gene alleles shared between any two S. epidermidis and S. aureus isolates. In contrast, there was considerable interspecies admixture of mobile elements, in particular genes associated with the SaPIn1 pathogenicity island, metal detoxification, and the methicillin-resistance island SCCmec. Our data and analysis provide a context for considering the nature of recombinational boundaries between S. aureus and S. epidermidis and, the selective forces that influence realized recombination between these species. PMID:25888688

  11. Improving the safety of Staphylococcus aureus polyvalent phages by their production on a Staphylococcus xylosus strain.

    PubMed

    El Haddad, Lynn; Ben Abdallah, Nour; Plante, Pier-Luc; Dumaresq, Jeannot; Katsarava, Ramaz; Labrie, Steve; Corbeil, Jacques; St-Gelais, Daniel; Moineau, Sylvain

    2014-01-01

    Team1 (vB_SauM_Team1) is a polyvalent staphylococcal phage belonging to the Myoviridae family. Phage Team1 was propagated on a Staphylococcus aureus strain and a non-pathogenic Staphylococcus xylosus strain used in industrial meat fermentation. The two Team1 preparations were compared with respect to their microbiological and genomic properties. The burst sizes, latent periods, and host ranges of the two derivatives were identical as were their genome sequences. Phage Team1 has 140,903 bp of double stranded DNA encoding for 217 open reading frames and 4 tRNAs. Comparative genomic analysis revealed similarities to staphylococcal phages ISP (97%) and G1 (97%). The host range of Team1 was compared to the well-known polyvalent staphylococcal phages phi812 and K using a panel of 57 S. aureus strains collected from various sources. These bacterial strains were found to represent 18 sequence types (MLST) and 14 clonal complexes (eBURST). Altogether, the three phages propagated on S. xylosus lysed 52 out of 57 distinct strains of S. aureus. The identification of phage-insensitive strains underlines the importance of designing phage cocktails with broadly varying and overlapping host ranges. Taken altogether, our study suggests that some staphylococcal phages can be propagated on food-grade bacteria for biocontrol and safety purposes. PMID:25061757

  12. Improving the Safety of Staphylococcus aureus Polyvalent Phages by Their Production on a Staphylococcus xylosus Strain

    PubMed Central

    El Haddad, Lynn; Ben Abdallah, Nour; Plante, Pier-Luc; Dumaresq, Jeannot; Katsarava, Ramaz; Labrie, Steve; Corbeil, Jacques; St-Gelais, Daniel; Moineau, Sylvain

    2014-01-01

    Team1 (vB_SauM_Team1) is a polyvalent staphylococcal phage belonging to the Myoviridae family. Phage Team1 was propagated on a Staphylococcus aureus strain and a non-pathogenic Staphylococcus xylosus strain used in industrial meat fermentation. The two Team1 preparations were compared with respect to their microbiological and genomic properties. The burst sizes, latent periods, and host ranges of the two derivatives were identical as were their genome sequences. Phage Team1 has 140,903 bp of double stranded DNA encoding for 217 open reading frames and 4 tRNAs. Comparative genomic analysis revealed similarities to staphylococcal phages ISP (97%) and G1 (97%). The host range of Team1 was compared to the well-known polyvalent staphylococcal phages phi812 and K using a panel of 57 S. aureus strains collected from various sources. These bacterial strains were found to represent 18 sequence types (MLST) and 14 clonal complexes (eBURST). Altogether, the three phages propagated on S. xylosus lysed 52 out of 57 distinct strains of S. aureus. The identification of phage-insensitive strains underlines the importance of designing phage cocktails with broadly varying and overlapping host ranges. Taken altogether, our study suggests that some staphylococcal phages can be propagated on food-grade bacteria for biocontrol and safety purposes. PMID:25061757

  13. Response of Staphylococcus Aureus to a Spaceflight Analogue

    NASA Technical Reports Server (NTRS)

    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

  14. SRD: a Staphylococcus regulatory RNA database.

    PubMed

    Sassi, Mohamed; Augagneur, Yoann; Mauro, Tony; Ivain, Lorraine; Chabelskaya, Svetlana; Hallier, Marc; Sallou, Olivier; Felden, Brice

    2015-05-01

    An overflow of regulatory RNAs (sRNAs) was identified in a wide range of bacteria. We designed and implemented a new resource for the hundreds of sRNAs identified in Staphylococci, with primary focus on the human pathogen Staphylococcus aureus. The "Staphylococcal Regulatory RNA Database" (SRD, http://srd.genouest.org/) compiled all published data in a single interface including genetic locations, sequences and other features. SRD proposes novel and simplified identifiers for Staphylococcal regulatory RNAs (srn) based on the sRNA's genetic location in S. aureus strain N315 which served as a reference. From a set of 894 sequences and after an in-depth cleaning, SRD provides a list of 575 srn exempt of redundant sequences. For each sRNA, their experimental support(s) is provided, allowing the user to individually assess their validity and significance. RNA-seq analysis performed on strains N315, NCTC8325, and Newman allowed us to provide further details, upgrade the initial annotation, and identified 159 RNA-seq independent transcribed sRNAs. The lists of 575 and 159 sRNAs sequences were used to predict the number and location of srns in 18 S. aureus strains and 10 other Staphylococci. A comparison of the srn contents within 32 Staphylococcal genomes revealed a poor conservation between species. In addition, sRNA structure predictions obtained with MFold are accessible. A BLAST server and the intaRNA program, which is dedicated to target prediction, were implemented. SRD is the first sRNA database centered on a genus; it is a user-friendly and scalable device with the possibility to submit new sequences that should spread in the literature. PMID:25805861

  15. Global Gene Expression in Staphylococcus aureus Biofilms

    PubMed Central

    Beenken, Karen E.; Dunman, Paul M.; McAleese, Fionnuala; Macapagal, Daphne; Murphy, Ellen; Projan, Steven J.; Blevins, Jon S.; Smeltzer, Mark S.

    2004-01-01

    We previously demonstrated that mutation of the staphylococcal accessory regulator (sarA) in a clinical isolate of Staphylococcus aureus (UAMS-1) results in an impaired capacity to form a biofilm in vitro (K. E. Beenken, J. S. Blevins, and M. S. Smeltzer, Infect. Immun. 71:4206-4211, 2003). In this report, we used a murine model of catheter-based biofilm formation to demonstrate that a UAMS-1 sarA mutant also has a reduced capacity to form a biofilm in vivo. Surprisingly, mutation of the UAMS-1 ica locus had little impact on biofilm formation in vitro or in vivo. In an effort to identify additional loci that might be relevant to biofilm formation and/or the adaptive response required for persistence of S. aureus within a biofilm, we isolated total cellular RNA from UAMS-1 harvested from a biofilm grown in a flow cell and compared the transcriptional profile of this RNA to RNA isolated from both exponential- and stationary-phase planktonic cultures. Comparisons were done using a custom-made Affymetrix GeneChip representing the genomic complement of six strains of S. aureus (COL, N315, Mu50, NCTC 8325, EMRSA-16 [strain 252], and MSSA-476). The results confirm that the sessile lifestyle associated with persistence within a biofilm is distinct by comparison to the lifestyles of both the exponential and postexponential phases of planktonic culture. Indeed, we identified 48 genes in which expression was induced at least twofold in biofilms over expression under both planktonic conditions. Similarly, we identified 84 genes in which expression was repressed by a factor of at least 2 compared to expression under both planktonic conditions. A primary theme that emerged from the analysis of these genes is that persistence within a biofilm requires an adaptive response that limits the deleterious effects of the reduced pH associated with anaerobic growth conditions. PMID:15231800

  16. Antimicrobial Activity against Intraosteoblastic Staphylococcus aureus

    PubMed Central

    Trouillet-Assant, Sophie; Riffard, Natacha; Tasse, Jason; Flammier, Sacha; Rasigade, Jean-Philippe; Chidiac, Christian; Vandenesch, François; Ferry, Tristan; Laurent, Frédéric

    2015-01-01

    Although Staphylococcus aureus persistence in osteoblasts, partly as small-colony variants (SCVs), can contribute to bone and joint infection (BJI) relapses, the intracellular activity of antimicrobials is not currently considered in the choice of treatment strategies for BJI. Here, antistaphylococcal antimicrobials were evaluated for their intraosteoblastic activity and their impact on the intracellular emergence of SCVs in an ex vivo osteoblast infection model. Osteoblastic MG63 cells were infected for 2 h with HG001 S. aureus. After killing the remaining extracellular bacteria with lysostaphin, infected cells were incubated for 24 h with antimicrobials at the intraosseous concentrations reached with standard therapeutic doses. Intracellular bacteria and SCVs were then quantified by plating cell lysates. A bactericidal effect was observed with fosfomycin, linezolid, tigecycline, oxacillin, rifampin, ofloxacin, and clindamycin, with reductions in the intracellular inocula of −2.5, −3.1, −3.9, −4.2, −4.9, −4.9, and −5.2 log10 CFU/100,000 cells, respectively (P < 10−4). Conversely, a bacteriostatic effect was observed with ceftaroline and teicoplanin, whereas vancomycin and daptomycin had no significant impact on intracellular bacterial growth. Ofloxacin, daptomycin, and vancomycin significantly limited intracellular SCV emergence. Overall, ofloxacin was the only molecule to combine an excellent intracellular activity while limiting the emergence of SCVs. These data provide a basis for refining the choice of antibiotics to prioritise in the management of BJI, justifying the combination of a fluoroquinolone for its intracellular activity with an anti-biofilm molecule, such as rifampin. PMID:25605365

  17. Antibiotics, Acne, and Staphylococcus aureus Colonization

    PubMed Central

    Fanelli, Matthew; Kupperman, Eli; Lautenbach, Ebbing; Edelstein, Paul H.; Margolis, David J.

    2011-01-01

    Objectives To determine the frequency of Staphylococcus aureus colonization among patients with acne and to compare the susceptibility patterns between the patients who are using antibiotics and those who are not using antibiotics. Design Survey (cross-sectional) study of patients treated for acne. Setting Dermatology outpatient office practice Participants The study included 83 patients who were undergoing treatment and evaluation for acne. Main Outcome Measure Colonization of the nose or throat with S aureus. Results A total of 36 of the 83 participants (43%) were colonized with S aureus. Two of the 36 patients (6%) had methicillin-resistant S aureus; 20 (56%) had S aureus solely in their throat; 9 (25%) had S aureus solely in their nose; and 7 (19%) had S aureus in both their nose and their throat. When patients with acne who were antibiotic users were compared with nonusers, the prevalence odds ratio for the colonization of S aureus was 0.16 (95% confidence interval [CI], 0.08–1.37) after 1 to 2 months of exposure and increased to 0.52 (95% CI, 0.12–2.17) after 2 months of exposure (P =.31). Many of the S aureus isolates were resistant to treatment with clindamycin and erythromycin (40% and 44%, respectively), particularly the nasal isolates. Very few showed resistance rates (<10%) to treatment with tetracycline antibiotics. Conclusion Unlike current dogma about the long-term use of antimicrobial agents, the prolonged use of tetracycline antibiotics commonly used to treat acne lowered the prevalence of colonization by S aureus and did not increase resistance to the tetracycline antibiotics. PMID:21482860

  18. Alpha-toxin of Staphylococcus aureus.

    PubMed Central

    Bhakdi, S; Tranum-Jensen, J

    1991-01-01

    Alpha-toxin, the major cytotoxic agent elaborated by Staphylococcus aureus, was the first bacterial exotoxin to be identified as a pore former. The protein is secreted as a single-chain, water-soluble molecule of Mr 33,000. At low concentrations (less than 100 nM), the toxin binds to as yet unidentified, high-affinity acceptor sites that have been detected on a variety of cells including rabbit erythrocytes, human platelets, monocytes and endothelial cells. At high concentrations, the toxin additionally binds via nonspecific absorption to lipid bilayers; it can thus damage both cells lacking significant numbers of the acceptor and protein-free artificial lipid bilayers. Membrane damage occurs in both cases after membrane-bound toxin molecules collide via lateral diffusion to form ring-structured hexamers. The latter insert spontaneously into the lipid bilayer to form discrete transmembrane pores of effective diameter 1 to 2 nm. A hypothetical model is advanced in which the pore is lined by amphiphilic beta-sheets, one surface of which interacts with lipids whereas the other repels apolar membrane constitutents to force open an aqueous passage. The detrimental effects of alpha-toxin are due not only to the death of susceptible targets, but also to the presence of secondary cellular reactions that can be triggered via Ca2+ influx through the pores. Well-studied phenomena include the stimulation of arachidonic acid metabolism, triggering of granule exocytosis, and contractile dysfunction. Such processes cause profound long-range disturbances such as development of pulmonary edema and promotion of blood coagulation.(ABSTRACT TRUNCATED AT 250 WORDS) Images PMID:1779933

  19. SRD: a Staphylococcus regulatory RNA database

    PubMed Central

    Sassi, Mohamed; Augagneur, Yoann; Mauro, Tony; Ivain, Lorraine; Chabelskaya, Svetlana; Hallier, Marc; Sallou, Olivier; Felden, Brice

    2015-01-01

    An overflow of regulatory RNAs (sRNAs) was identified in a wide range of bacteria. We designed and implemented a new resource for the hundreds of sRNAs identified in Staphylococci, with primary focus on the human pathogen Staphylococcus aureus. The “Staphylococcal Regulatory RNA Database” (SRD, http://srd.genouest.org/) compiled all published data in a single interface including genetic locations, sequences and other features. SRD proposes novel and simplified identifiers for Staphylococcal regulatory RNAs (srn) based on the sRNA's genetic location in S. aureus strain N315 which served as a reference. From a set of 894 sequences and after an in-depth cleaning, SRD provides a list of 575 srn exempt of redundant sequences. For each sRNA, their experimental support(s) is provided, allowing the user to individually assess their validity and significance. RNA-seq analysis performed on strains N315, NCTC8325, and Newman allowed us to provide further details, upgrade the initial annotation, and identified 159 RNA-seq independent transcribed sRNAs. The lists of 575 and 159 sRNAs sequences were used to predict the number and location of srns in 18 S. aureus strains and 10 other Staphylococci. A comparison of the srn contents within 32 Staphylococcal genomes revealed a poor conservation between species. In addition, sRNA structure predictions obtained with MFold are accessible. A BLAST server and the intaRNA program, which is dedicated to target prediction, were implemented. SRD is the first sRNA database centered on a genus; it is a user-friendly and scalable device with the possibility to submit new sequences that should spread in the literature. PMID:25805861

  20. Hyaluronan Modulation Impacts Staphylococcus aureus Biofilm Infection.

    PubMed

    Ibberson, Carolyn B; Parlet, Corey P; Kwiecinski, Jakub; Crosby, Heidi A; Meyerholz, David K; Horswill, Alexander R

    2016-06-01

    Staphylococcus aureus is a leading cause of chronic biofilm infections. Hyaluronic acid (HA) is a large glycosaminoglycan abundant in mammalian tissues that has been shown to enhance biofilm formation in multiple Gram-positive pathogens. We observed that HA accumulated in an S. aureus biofilm infection using a murine implant-associated infection model and that HA levels increased in a mutant strain lacking hyaluronidase (HysA). S. aureus secretes HysA in order to cleave HA during infection. Through in vitro biofilm studies with HA, the hysA mutant was found to accumulate increased biofilm biomass compared to the wild type, and confocal microscopy showed that HA is incorporated into the biofilm matrix. Exogenous addition of purified HysA enzyme dispersed HA-containing biofilms, while catalytically inactive enzyme had no impact. Additionally, induction of hysA expression prevented biofilm formation and also dispersed an established biofilm in the presence of HA. These observations were corroborated in the implant model, where there was decreased dissemination from an hysA mutant biofilm infection compared to the S. aureus wild type. Histopathology demonstrated that infection with an hysA mutant caused significantly reduced distribution of tissue inflammation compared to wild-type infection. To extend these studies, the impact of HA and S. aureus HysA on biofilm-like aggregates found in joint infections was examined. We found that HA contributes to the formation of synovial fluid aggregates, and HysA can disrupt aggregate formation. Taken together, these studies demonstrate that HA is a relevant component of the S. aureus biofilm matrix and HysA is important for dissemination from a biofilm infection. PMID:27068096

  1. Staphopains Modulate Staphylococcus aureus Biofilm Integrity

    PubMed Central

    Mootz, Joe M.; Malone, Cheryl L.; Shaw, Lindsey N.

    2013-01-01

    Staphylococcus aureus is a known cause of chronic biofilm infections that can reside on medical implants or host tissue. Recent studies have demonstrated an important role for proteinaceous material in the biofilm structure. The S. aureus genome encodes many secreted proteases, and there is growing evidence that these enzymes have self-cleavage properties that alter biofilm integrity. However, the specific contribution of each protease and mechanism of biofilm modulation is not clear. To address this issue, we utilized a sigma factor B (ΔsigB) mutant where protease activity results in a biofilm-negative phenotype, thereby creating a condition where the protease(s) responsible for the phenotype could be identified. Using a plasma-coated microtiter assay, biofilm formation was restored to the ΔsigB mutant through the addition of the cysteine protease inhibitor E-64 or by using Staphostatin inhibitors that specifically target the extracellular cysteine proteases SspB and ScpA (called Staphopains). Through construction of gene deletion mutants, we determined that an sspB scpA double mutant restored ΔsigB biofilm formation, and this recovery could be replicated in plasma-coated flow cell biofilms. Staphopain levels were also found to be decreased under biofilm-forming conditions, possibly allowing biofilm establishment. The treatment of S. aureus biofilms with purified SspB or ScpA enzyme inhibited their formation, and ScpA was also able to disperse an established biofilm. The antibiofilm properties of ScpA were conserved across S. aureus strain lineages. These findings suggest an underappreciated role of the SspB and ScpA cysteine proteases in modulating S. aureus biofilm architecture. PMID:23798534

  2. Assessing the biological efficacy and rate of recontamination following hydrogen peroxide vapour decontamination.

    PubMed

    Otter, J A; Cummins, M; Ahmad, F; van Tonder, C; Drabu, Y J

    2007-10-01

    The inanimate hospital environment can become contaminated with nosocomial pathogens. Hydrogen peroxide vapour (HPV) decontamination has proven effective for the eradication of persistent environmental contamination. We investigated the extent of meticillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE) and gentamicin-resistant Gram-negative rod (GNR) contamination in a ward side-room occupied by a patient with a history of MRSA, VRE and GNR infection and colonisation and investigated the impact of HPV decontamination. Fifteen standardised sites in the room were sampled using a selective broth enrichment protocol to culture MRSA, VRE and GNR. Sampling was performed before cleaning, after cleaning, after HPV decontamination and at intervals over the subsequent 19 days on two separate occasions. Environmental contamination was identified before cleaning on 60, 30 and 6.7% of sites for MRSA, GNR and VRE, respectively, and 40, 10 and 6.7% of sites after cleaning. Only one site (3.3%) was contaminated with MRSA after HPV decontamination. No recontamination with VRE was identified and no recontamination with MRSA and GNR was identified during the two days following HPV decontamination. Substantial recontamination was identified approximately one week after HPV decontamination towards post-cleaning levels for GNR and towards pre-cleaning levels for MRSA. HPV is more effective than standard terminal cleaning for the eradication of nosocomial pathogens. Recontamination was not immediate for MRSA and GNR but contamination returned within a week in a room occupied by a patient colonised with MRSA and GNR. This finding has important implications for the optimal deployment of HPV decontamination in hospitals. PMID:17884250

  3. Finding a benchmark for monitoring hospital cleanliness.

    PubMed

    Mulvey, D; Redding, P; Robertson, C; Woodall, C; Kingsmore, P; Bedwell, D; Dancer, S J

    2011-01-01

    This study evaluated three methods for monitoring hospital cleanliness. The aim was to find a benchmark that could indicate risk to patients from a contaminated environment. We performed visual monitoring, ATP bioluminescence and microbiological screening of five clinical surfaces before and after detergent-based cleaning on two wards over a four-week period. Five additional sites that were not featured in the routine domestic specification were also sampled. Measurements from all three methods were integrated and compared in order to choose appropriate levels for routine monitoring. We found that visual assessment did not reflect ATP values nor environmental contamination with microbial flora including Staphylococcus aureus and meticillin-resistant S. aureus (MRSA). There was a relationship between microbial growth categories and the proportion of ATP values exceeding a chosen benchmark but neither reliably predicted the presence of S. aureus or MRSA. ATP values were occasionally diverse. Detergent-based cleaning reduced levels of organic soil by 32% (95% confidence interval: 16-44%; P<0.001) but did not necessarily eliminate indicator staphylococci, some of which survived the cleaning process. An ATP benchmark value of 100 relative light units offered the closest correlation with microbial growth levels <2.5 cfu/cm(2) (receiver operating characteristic ROC curve sensitivity: 57%; specificity: 57%). In conclusion, microbiological and ATP monitoring confirmed environmental contamination, persistence of hospital pathogens and measured the effect on the environment from current cleaning practices. This study has provided provisional benchmarks to assist with future assessment of hospital cleanliness. Further work is required to refine practical sampling strategy and choice of benchmarks. PMID:21129820

  4. In vitro antimicrobial activity of a commercial ear antiseptic containing chlorhexidine and Tris-EDTA.

    PubMed

    Guardabassi, Luca; Ghibaudo, Giovanni; Damborg, Peter

    2010-06-01

    Minimum bactericidal concentrations (MBCs) of a commercial ear antiseptic containing chlorhexidine 0.15% and Tris-EDTA (Otodine) were determined by broth microdilution for 150 isolates representing the most common pathogens associated with canine otitis. The microorganisms were classified into three groups according to their levels of susceptibility. The most susceptible group included Staphylococcus pseudintermedius, Malassezia pachydermatis, Streptococcus canis and Corynebacterium auriscanis, which were generally killed by 1 : 64 dilution of the antiseptic product (MBC = 23/0.8 microg/mL of chlorhexidine/Tris-EDTA). The most resistant organism was Proteus mirabilis, which survived up to 1 : 8 dilution of the product (MBC = 375/12 microg/mL). Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus displayed intermediate MBCs ranging between 188/6 and 47/1.5 microg/mL. Interestingly, S. pseudintermedius was more susceptible than S. aureus, and no significant difference was observed between meticillin-resistant and meticillin-susceptible isolates within each species, indicating that antiseptic use is unlikely to co-select for meticillin resistance. Although the concentrations required for killing (MBCs) varied considerably with microorganism type, the combination of chlorhexidine 0.15% and Tris-EDTA was active against all the pathogens most commonly involved in canine otitis. PMID:20030799

  5. Characterizing the in vitro biofilm phenotype of Staphylococcus epidermidis isolates from central venous catheters.

    PubMed

    Van Kerckhoven, Marian; Hotterbeekx, An; Lanckacker, Ellen; Moons, Pieter; Lammens, Christine; Kerstens, Monique; Ieven, Margareta; Delputte, Peter; Jorens, Philippe G; Malhotra-Kumar, Surbhi; Goossens, Herman; Maes, Louis; Cos, Paul

    2016-08-01

    Central venous catheter (CVC)-related infections are commonly caused by Staphylococcus epidermidis that is able to form a biofilm on the catheter surface. Many studies involving biofilm formation by Staphylococcus have been published each adopting an own in vitro model. Since the capacity to form a biofilm depends on multiple environmental factors, direct comparison of results obtained in different studies remains challenging. This study characterized the phenotype (strong versus weak biofilm-producers) of S. epidermidis from CVCs in four different in vitro biofilm models, covering differences in material type (glass versus polymer) and nutrient presentation (static versus continuous flow). A good correlation in phenotype was obtained between glass and polymeric surfaces independent of nutrient flow, with 85% correspondence under static growth conditions and 80% under dynamic conditions. A 80% correspondence between static and dynamic conditions on polymeric surfaces could be demonstrated as well. Incubation time had a significant influence on the biofilm phenotype with only 55% correspondence between the dynamic models at different incubation times (48h versus 17h). Screening for the presence of biofilm-related genes only revealed that ica A was correlated with biofilm formation under static but not under dynamic conditions. In conclusion, this study highlights that a high level of standardization is necessary to interpret and compare results of different in vitro biofilm models. PMID:27196636

  6. Low-shear modelled microgravity alters expression of virulence determinants of Staphylococcus aureus

    NASA Astrophysics Data System (ADS)

    Rosado, Helena; Doyle, Marie; Hinds, Jason; Taylor, Peter W.

    2010-02-01

    Microbiological monitoring of air and surfaces within the ISS indicate that bacteria of the genus Staphylococcus are found with high frequency. Staphylococcus aureus, an opportunistic pathogen with the capacity to cause severe debilitating infection, constitutes a significant proportion of these isolates. Experiments conducted during short-term flight suggest that growth in microgravity leads to increases in bacterial antibiotic resistance and to cell wall changes. Growth under low-shear modelled microgravity (LSMMG) indicated that a reduced gravitational field acts as an environmental signal for expression of enhanced bacterial virulence in gram-negative pathogens. We therefore examined the effect of simulated microgravity on parameters of antibiotic susceptibility and virulence in methicillin-susceptible S. aureus isolates RF1, RF6 and RF11; these strains were grown in a high aspect ratio vessel under LSMMG and compared with cells grown under normal gravity (NG). There were no significant differences in antibiotic susceptibility of staphylococci grown under LSMMG compared to NG. LSMMG-induced reductions in synthesis of the pigment staphyloxanthin and the major virulence determinant α-toxin were noted. Significant changes in global gene expression were identified by DNA microarray analysis; with isolate RF6, the expression of hla and genes of the regulatory system saeR/saeS were reduced approximately two-fold. These data provide strong evidence that growth of S. aureus under modelled microgravity leads to a reduction in expression of virulence determinants.

  7. Facing Antibiotic Resistance: Staphylococcus aureus Phages as a Medical Tool

    PubMed Central

    Kaźmierczak, Zuzanna; Górski, Andrzej; Dąbrowska, Krystyna

    2014-01-01

    Staphylococcus aureus is a common and often virulent pathogen in humans. This bacterium is widespread, being present on the skin and in the nose of healthy people. Staphylococcus aureus can cause infections with severe outcomes ranging from pustules to sepsis and death. The introduction of antibiotics led to a general belief that the problem of bacterial infections would be solved. Nonetheless, pathogens including staphylococci have evolved mechanisms of drug resistance. Among current attempts to address this problem, phage therapy offers a promising alternative to combat staphylococcal infections. Here, we present an overview of current knowledge on staphylococcal infections and bacteriophages able to kill Staphylococcus, including experimental studies and available data on their clinical use. PMID:24988520

  8. Diversity and enterotoxigenicity of Staphylococcus spp. associated with domiati cheese.

    PubMed

    El-Sharoud, Walid M; Spano, Giuseppe

    2008-12-01

    A total of 87 samples of fresh and stored Domiati cheese (an Egyptian soft cheese) were examined for the presence of Staphylococcus spp. Fifteen Staphylococcus isolates identified as S. aureus (2 isolates), S. xylosus (4), S. caprae (4), and S. chromogenes (5) were recovered from 15 cheese samples. The S. aureus isolates were resistant to penicillin G and ampicillin, and one isolate was also resistant to tetracycline. S. aureus isolates harbored classical staphylococcal enterotoxin (SE) genes (sea and seb) and recently characterized SE-like genes (selg, seli, selm, and selo). One S. aureus isolate contained a single SE gene (sea), whereas another isolate contained five SE genes (seb, selg, seli, selm, and selo). These results suggest that Domiati cheese is a source for various Staphylococcus species, including S. aureus strains that could be enterotoxigenic. PMID:19244916

  9. [Correlation between Staphylococcus carriage, specific antibody-production and AB0-blood grouping in plasma donors].

    PubMed

    Nemyrovs'ka, L M; Patoka, V V

    2002-01-01

    Interaction peculiarities of three components of the immune human homeostasis-antigens of blood groups AB0, staphylococcus antigens and antistaphylococcus antibodies have been investigated. Donors (85) of antistaphylococcus plasma immunized by staphylococcus anatoxin have been investigated. It is found that the nasal staphylococcus carriage in donors depends on the level of specific and natural antibodies and on the coincidence between the staphylococcus antigen structure and the protein substance of the specific blood group factors. PMID:12190026

  10. Lysostaphin Disrupts Staphylococcus aureus and Staphylococcus epidermidis Biofilms on Artificial Surfaces

    PubMed Central

    Wu, Julie A.; Kusuma, Caroline; Mond, James J.; Kokai-Kun, John F.

    2003-01-01

    Staphylococci often form biofilms, sessile communities of microcolonies encased in an extracellular matrix that adhere to biomedical implants or damaged tissue. Infections associated with biofilms are difficult to treat, and it is estimated that sessile bacteria in biofilms are 1,000 to 1,500 times more resistant to antibiotics than their planktonic counterparts. This antibiotic resistance of biofilms often leads to the failure of conventional antibiotic therapy and necessitates the removal of infected devices. Lysostaphin is a glycylglycine endopeptidase which specifically cleaves the pentaglycine cross bridges found in the staphylococcal peptidoglycan. Lysostaphin kills Staphylococcus aureus within minutes (MIC at which 90% of the strains are inhibited [MIC90], 0.001 to 0.064 μg/ml) and is also effective against Staphylococcus epidermidis at higher concentrations (MIC90, 12.5 to 64 μg/ml). The activity of lysostaphin against staphylococci present in biofilms compared to those of other antibiotics was, however, never explored. Surprisingly, lysostaphin not only killed S. aureus in biofilms but also disrupted the extracellular matrix of S. aureus biofilms in vitro on plastic and glass surfaces at concentrations as low as 1 μg/ml. Scanning electron microscopy confirmed that lysostaphin eradicated both the sessile cells and the extracellular matrix of the biofilm. This disruption of S. aureus biofilms was specific for lysostaphin-sensitive S. aureus, as biofilms of lysostaphin-resistant S. aureus were not affected. High concentrations of oxacillin (400 μg/ml), vancomycin (800 μg/ml), and clindamycin (800 μg/ml) had no effect on the established S. aureus biofilms in this system, even after 24 h. Higher concentrations of lysostaphin also disrupted S. epidermidis biofilms. PMID:14576095

  11. Effect of Substance P in Staphylococcus aureus and Staphylococcus epidermidis Virulence: Implication for Skin Homeostasis

    PubMed Central

    N'Diaye, Awa; Mijouin, Lily; Hillion, Mélanie; Diaz, Suraya; Konto-Ghiorghi, Yoan; Percoco, Giuseppe; Chevalier, Sylvie; Lefeuvre, Luc; Harmer, Nicholas J.; Lesouhaitier, Olivier; Feuilloley, Marc G. J.

    2016-01-01

    Staphylococcus aureus and Staphylococcus epidermidis are two major skin associated bacteria, and Substance P (SP) is a major skin neuropeptide. Since bacteria are known to sense and response to many human hormones, we investigated the effects of SP on Staphylococci virulence in reconstructed human epidermis model and HaCaT keratinocytes. We show that SP is stimulating the virulence of S. aureus and S. epidermidis in a reconstructed human epidermis model. qRT-PCR array analysis of 64 genes expressed by keratinocytes in the response to bacterial infection revealed a potential link between the action of SP on Staphylococci and skin physiopathology. qRT-PCR and direct assay of cathelicidin and human β-defensin 2 secretion also provided that demonstration that the action of SP on bacteria is independent of antimicrobial peptide expression by keratinocytes. Considering an effect of SP on S. aureus and S. epidermidis, we observed that SP increases the adhesion potential of both bacteria on keratinocytes. However, SP modulates the virulence of S. aureus and S. epidermidis through different mechanisms. The response of S. aureus is associated with an increase in Staphylococcal Enterotoxin C2 (SEC2) production and a reduction of exolipase processing whereas in S. epidermidis the effect of SP appears mediated by a rise in biofilm formation activity. The Thermo unstable ribosomal Elongation factor Ef-Tu was identified as the SP-interacting protein in S. aureus and S. epidermidis. SP appears as an inter-kingdom communication factor involved in the regulation of bacterial virulence and essential for skin microflora homeostasis. PMID:27148195

  12. Effect of Substance P in Staphylococcus aureus and Staphylococcus epidermidis Virulence: Implication for Skin Homeostasis.

    PubMed

    N'Diaye, Awa; Mijouin, Lily; Hillion, Mélanie; Diaz, Suraya; Konto-Ghiorghi, Yoan; Percoco, Giuseppe; Chevalier, Sylvie; Lefeuvre, Luc; Harmer, Nicholas J; Lesouhaitier, Olivier; Feuilloley, Marc G J

    2016-01-01

    Staphylococcus aureus and Staphylococcus epidermidis are two major skin associated bacteria, and Substance P (SP) is a major skin neuropeptide. Since bacteria are known to sense and response to many human hormones, we investigated the effects of SP on Staphylococci virulence in reconstructed human epidermis model and HaCaT keratinocytes. We show that SP is stimulating the virulence of S. aureus and S. epidermidis in a reconstructed human epidermis model. qRT-PCR array analysis of 64 genes expressed by keratinocytes in the response to bacterial infection revealed a potential link between the action of SP on Staphylococci and skin physiopathology. qRT-PCR and direct assay of cathelicidin and human β-defensin 2 secretion also provided that demonstration that the action of SP on bacteria is independent of antimicrobial peptide expression by keratinocytes. Considering an effect of SP on S. aureus and S. epidermidis, we observed that SP increases the adhesion potential of both bacteria on keratinocytes. However, SP modulates the virulence of S. aureus and S. epidermidis through different mechanisms. The response of S. aureus is associated with an increase in Staphylococcal Enterotoxin C2 (SEC2) production and a reduction of exolipase processing whereas in S. epidermidis the effect of SP appears mediated by a rise in biofilm formation activity. The Thermo unstable ribosomal Elongation factor Ef-Tu was identified as the SP-interacting protein in S. aureus and S. epidermidis. SP appears as an inter-kingdom communication factor involved in the regulation of bacterial virulence and essential for skin microflora homeostasis. PMID:27148195

  13. Staphylococcus pseudintermedius expresses surface proteins that closely resemble those from Staphylococcus aureus.

    PubMed

    Geoghegan, Joan A; Smith, Emma J; Speziale, Pietro; Foster, Timothy J

    2009-09-18

    Staphylococcus pseudintermedius is a commensal of dogs that is implicated in the pathogenesis of canine pyoderma. This study aimed to determine if S. pseudintermedius expresses surface proteins resembling those from Staphylococcus aureus and to characterise them. S. pseudintermedius strain 326 was shown to adhere strongly to purified fibrinogen, fibronectin and cytokeratin 10. It adhered to the alpha-chain of fibrinogen which, along with binding to cytokeratin 10, is the hallmark of clumping factor B of S. aureus, a surface protein that is in part responsible for colonisation of the human nares. Ligand-affinity blotting with cell-wall extracts demonstrated that S. pseudintermedius 326 expressed a cell-wall anchored fibronectin binding protein which recognised the N-terminal 29kDa fragment. The ability to bind fibronectin is an important attribute of pathogenic S. aureus and is associated with the ability of S. aureus to colonise skin of human atopic dermatitis patients. S. pseudintermedius genomic DNA was probed with labelled DNA amplified from the serine-aspartate repeat encoding region of clfA of S. aureus. This probe hybridised to a single SpeI fragment of S. pseudintermedius DNA. In the cell-wall extract of S. pseudintermedius 326, a 180kDa protein was discovered which bound to fibrinogen by ligand-affinity blotting and reacted in a Western blot with antibodies raised against the serine-aspartate repeat region of ClfA and the B-repeats of SdrD of S. aureus. It is proposed that this is an Sdr protein with B-repeats that has an A domain that binds to fibrinogen. Whether it is the same protein that binds cytokeratin 10 is not clear. PMID:19372010

  14. Evaluation of an Immunochromatographic Assay for Rapid Detection of Penicillin-Binding Protein 2a in Human and Animal Staphylococcus intermedius Group, Staphylococcus lugdunensis, and Staphylococcus schleiferi Clinical Isolates.

    PubMed

    Arnold, A R; Burnham, C-A D; Ford, B A; Lawhon, S D; McAllister, S K; Lonsway, D; Albrecht, V; Jerris, R C; Rasheed, J K; Limbago, B; Burd, E M; Westblade, L F

    2016-03-01

    The performance of a rapid penicillin-binding protein 2a (PBP2a) detection assay, the Alere PBP2a culture colony test, was evaluated for identification of PBP2a-mediated beta-lactam resistance in human and animal clinical isolates of Staphylococcus intermedius group, Staphylococcus lugdunensis, and Staphylococcus schleiferi. The assay was sensitive and specific, with all PBP2a-negative and PBP2a-positive strains testing negative and positive, respectively. PMID:26677248

  15. Staphylococcus aureus infection of the feet following fish pedicure.

    PubMed

    Veraldi, S; Nazzaro, G; Çuka, E

    2014-10-01

    We report a case of Staphylococcus aureus infection of the feet that appeared after a "fish pedicure" (immersion of the feet in a tank with the fish Garra rufa, that nibbles off dead skin). Clinical picture was characterized by maceration, purulent discharge, scales, crusts, itching and burning sensation. Bacteriological examinations were positive for Staphylococcus aureus. Mycological examinations were negative. The patient was successfully treated with ciprofloxacin. Only one case of skin foot infection after fish pedicure was reported so far. Fish pedicure can be a potentially dangerous procedure in immunocompromised or diabetic patients. PMID:24771416

  16. New MLSB Resistance Gene erm(43) in Staphylococcus lentus

    PubMed Central

    Schwendener, Sybille

    2012-01-01

    The search for a specific rRNA methylase motif led to the identification of the new macrolide, lincosamide, and streptogramin B resistance gene erm(43) in Staphylococcus lentus. An inducible resistance phenotype was demonstrated by cloning and expressing erm(43) and its regulatory region in Staphylococcus aureus. The erm(43) gene was detected in two different DNA fragments, of 6,230 bp and 1,559 bp, that were each integrated at the same location in the chromosome in several S. lentus isolates of human, dog, and chicken origin. PMID:22733067

  17. Staphylococcus cohnii septicaemia in a patient with colon cancer.

    PubMed

    Basaglia, Giancarlo; Moras, Laura; Bearz, Alessandra; Scalone, Simona; Paoli, Paolo De

    2003-01-01

    A coagulase-negative staphylococcal strain was isolated from peripheral blood and central venous catheter blood of a febrile patient with cancer. This isolate, initially classified by a commercial test as Staphylococcus kloosii, was definitively assigned to Staphylococcus cohnii by physiological and molecular tests. The strain lacked virulence factors, such as biofilm production and haemagglutination, and was sensitive to the antibiotics tested. The data suggest that rare micro-organisms with low pathogenic potential can cause severe illness in cancer patients; reference identification is required, however, to describe correctly the epidemiological characteristics and virulence factors of these clinical isolates. PMID:12488572

  18. Longitudinal Antibiotic Susceptibility Profiles of Staphylococcus aureus Cutaneous Infections in a Pediatric Outpatient Population.

    PubMed

    Slater, Nathaniel A; Gilligan, Peter H; Morrell, Dean S

    2016-09-01

    This longitudinal update on Staphylococcus aureus prevalence and antibiotic resistance patterns surveyd 291 cultures from 188 patients in a pediatric outpatient dermatology clinic with suspected skin and soft tissue infections. The prevalence of methicillin-resistant Staphylococcus aureus remained stable at 24%. Staphylococcus aureus resistance to tetracyclines modestly but demonstrably increased in the interval since 2009. PMID:27384814

  19. Identification of Staphylococcus spp. by PCR-Restriction Fragment Length Polymorphism of gap Gene

    PubMed Central

    Yugueros, Javier; Temprano, Alejandro; Sánchez, María; Luengo, José María; Naharro, Germán

    2001-01-01

    Oligonucleotide primers specific for the Staphylococcus aureus gap gene were previously designed to identify 12 Staphylococcus spp. by PCR. In the present study, AluI digestion of PCR-generated products rendered distinctive restriction fragment length polymorphism patterns that allowed 24 Staphylococcus spp. to be identified with high specificity. PMID:11574593

  20. Occurrence and Molecular Characteristics of Methicillin-Resistant Staphylococcus aureus and Methicillin-Resistant Staphylococcus pseudintermedius in an Academic Veterinary Hospital▿

    PubMed Central

    Ishihara, Kanako; Shimokubo, Natsumi; Sakagami, Akie; Ueno, Hiroshi; Muramatsu, Yasukazu; Kadosawa, Tsuyoshi; Yanagisawa, Chie; Hanaki, Hideaki; Nakajima, Chie; Suzuki, Yasuhiko; Tamura, Yutaka

    2010-01-01

    Recently, methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus pseudintermedius (MRSP) have been increasingly isolated from veterinarians and companion animals. With a view to preventing the spread of MRSA and MRSP, we evaluated the occurrence and molecular characteristics of each in a veterinary college. MRSA and MRSP were isolated from nasal samples from veterinarians, staff members, and veterinary students affiliated with a veterinary hospital. Using stepwise logistic regression, we identified two factors associated with MRSA carriage: (i) contact with an identified animal MRSA case (odds ratio [OR], 6.9; 95% confidence interval [95% CI], 2.2 to 21.6) and (ii) being an employee (OR, 6.2; 95% CI, 2.0 to 19.4). The majority of MRSA isolates obtained from individuals affiliated with the veterinary hospital and dog patients harbored spa type t002 and a type II staphylococcal cassette chromosome mec (SCCmec), similar to the hospital-acquired MRSA isolates in Japan. MRSA isolates harboring spa type t008 and a type IV SCCmec were obtained from one veterinarian on three different sampling occasions and also from dog patients. MRSA carriers can also be a source of MRSA infection in animals. The majority of MRSP isolates (85.2%) carried hybrid SCCmec type II-III, and almost all the remaining MRSP isolates (11.1%) carried SCCmec type V. MRSA and MRSP were also isolated from environmental samples collected from the veterinary hospital (5.1% and 6.4%, respectively). The application of certain disinfection procedures is important for the prevention of nosocomial infection, and MRSA and MRSP infection control strategies should be adopted in veterinary medical practice. PMID:20543040

  1. Risk of organism acquisition from prior room occupants: a systematic review and meta-analysis.

    PubMed

    Mitchell, B G; Dancer, S J; Anderson, M; Dehn, E

    2015-11-01

    A systematic review and meta-analysis was conducted to determine the risk of pathogen acquisition for patients associated with prior room occupancy. The analysis was also broadened to examine any differences in acquisition risk between Gram-positive and Gram-negative organisms. A search using Medline/PubMed, Cochrane and CINHAL yielded 2577 citations between 1984 and 2014. Reviews were assessed in accordance with the international prospective register of systematic reviews (PROSPERO). Just seven articles met the inclusion criteria, namely: (a) papers were peer reviewed, (b) pathogen acquisition prevalence rates were reported, (c) articles were written in English; and (d) had minimal or no risk of bias based on the Newcastle-Ottawa Scale (NOS). One study was an extension of a previous study and was discarded. Employing NOS provided little difference between the studies, with five studies receiving eight-star and two studies receiving seven-star ratings, respectively. Overall, pooled acquisition odds ratio for study pathogens (meticillin-resistant Staphylococcus aureus; vancomycin-resistant enterococcus; Clostridium difficile; acinetobacter; extended-spectrum β-lactamase-producing coliforms; pseudomonas) was 2.14 [95% confidence interval (CI): 1.65-2.77]. When comparing data between Gram-positive and Gram-negative organisms, the pooled acquisition odds ratio for Gram-negatives was 2.65 (95% CI: 2.02-3.47) and 1.89 (95% CI: 1.62-2.21) for Gram positives. The findings have important implications for infection control professionals, environmental cleaning services and patients, since current practices fail to adequately reduce acquisition risk. Although there may be non-preventable sources of acquisition, revised practices require collaborative work between all responsible staff in order to reduce this risk to a minimum. PMID:26365827

  2. Influence of possible disinfectant transfer on Staphylococcus aureus plate counts after agar contact sampling.

    PubMed Central

    Brummer, B

    1976-01-01

    Asbestos-vinyl tile floor panels were mopped with three types of chemical disinfectant product, as well as after contact, with the untreated control panel were prepared according to the manufacturer's label instructions. Similar floor panels were inoculated artificially with Staphylococcus aureus. RODAC (replicate organism detection and counting) surface sampling plates were pressed to the disinfectant-treated panels or to the untreated control panel and then immediately pressed to sampling sites on the artificially inoculated floor panels. Plate counts were determined after contact with panels treated with each type of disinfectant, product, as well as after contact with the untreated control panel. Results indicate that disinfectant residues on environmental surfaces do not alter the average plate counts obtained by RODAC samplings. PMID:788638

  3. RNA Degradation in Staphylococcus aureus: Diversity of Ribonucleases and Their Impact

    PubMed Central

    Bonnin, Rémy A.; Bouloc, Philippe

    2015-01-01

    The regulation of RNA decay is now widely recognized as having a central role in bacterial adaption to environmental stress. Here we present an overview on the diversity of ribonucleases (RNases) and their impact at the posttranscriptional level in the human pathogen Staphylococcus aureus. RNases in prokaryotes have been mainly studied in the two model organisms Escherichia coli and Bacillus subtilis. Based on identified RNases in these two models, putative orthologs have been identified in S. aureus. The main staphylococcal RNases involved in the processing and degradation of the bulk RNA are (i) endonucleases RNase III and RNase Y and (ii) exonucleases RNase J1/J2 and PNPase, having 5′ to 3′ and 3′ to 5′ activities, respectively. The diversity and potential roles of each RNase and of Hfq and RppH are discussed in the context of recent studies, some of which are based on next-generation sequencing technology. PMID:25977913

  4. Investigation of a pyoderma outbreak caused by methicillin-susceptible Staphylococcus aureus in a nursery for newborns.

    PubMed

    Lin, M F; Huang, M L; Lai, S H

    2004-05-01

    An outbreak of pyoderma caused by methicillin-susceptible Staphylococcus aureus occurred in a nursery for newborns over 26 days. During this period, six neonates were involved. The mother of the first case had trunk pyoderma before delivery, which was regarded as the source of the outbreak. Contamination of the environment and equipment were implicated as the reservoirs of further pathogen spread, as supported by pulsed-field gel electrophoresis (PFGE) results, which showed that some screening isolates were indistinguishable from the epidemic strain. Termination of the outbreak was achieved by the reinforcement of infection control practices and disinfection of environmental surfaces. PMID:15142714

  5. 9 CFR 113.115 - Staphylococcus Aureus Bacterin-Toxoid.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Staphylococcus Aureus Bacterin-Toxoid. 113.115 Section 113.115 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Inactivated Bacterial Products...

  6. Staphylococcus aureus subsp. anaerobius strain ST1464 genome sequence

    PubMed Central

    Elbir, Haitham; Robert, Catherine; Nguyen, Ti Thien; Gimenez, Grégory; El Sanousi, Sulieman M.; Flock, Jan-Ingmar; Raoult, Didier

    2013-01-01

    Staphylococcus aureus subsp. anaerobius is responsible for Morel's disease in animals and a cause of abscess in humans. It is characterized by a microaerophilic growth, contrary to the other strains of S. aureus. The 2,604,446-bp genome (32.7% GC content) of S. anaerobius ST1464 comprises one chromosome and no plasmids. The chromosome contains 2,660 open reading frames (ORFs), 49 tRNAs and three complete rRNAs, forming one complete operon. The size of ORFs ranges between 100 to 4,600 bp except for two ORFs of 6,417 and 7,173 bp encoding segregation ATPase and non-ribosomal peptide synthase, respectively. The chromosome harbors Staphylococcus phage 2638A genome and incomplete Staphylococcus phage genome PT1028, but no detectable CRISPRS. The antibiotic resistance gene for tetracycline was found although Staphylococcus aureus subsp. anaerobius is susceptible to tetracycline in-vitro. Intact oxygen detoxification genes encode superoxide dismutase and cytochrome quinol oxidase whereas the catalase gene is impaired by a stop codon. Based on the genome, in-silico multilocus sequence typing indicates that S. aureus subsp. anaerobius emerged as a clone separated from all other S. aureus strains, illustrating host-adaptation linked to missing functions. Availability of S. aureus subsp. anaerobius genome could prompt the development of post-genomic tools for its rapid discrimination from S. aureus. PMID:24501641

  7. Complete Genome Sequence of Staphylococcus aureus Siphovirus Phage JS01

    PubMed Central

    Jia, Hongying; Bai, Qinqin; Yang, Yongchun

    2013-01-01

    Staphylococcus aureus is the most prevalent and economically significant pathogen causing bovine mastitis. We isolated and characterized one staphylophage from the milk of mastitis-affected cattle and sequenced its genome. Transmission electron microscopy (TEM) observation shows that it belongs to the family Siphovirus. We announce here its complete genome sequence and report major findings from the genomic analysis. PMID:24233583

  8. Internet Queries and Methicillin-Resistant Staphylococcus aureus Surveillance

    PubMed Central

    Dukic, Vanja M.; David, Michael Z.

    2011-01-01

    The Internet is a common source of medical information and has created novel surveillance opportunities. We assessed the potential for Internet-based surveillance of methicillin-resistant Staphylococcus aureus and examined the extent to which it reflects trends in hospitalizations and news coverage. Google queries were a useful predictor of hospitalizations for methicillin-resistant S. aureus infections. PMID:21749772

  9. Review on Panton Valentine leukocidin toxin carriage among Staphylococcus aureus.

    PubMed

    Shrestha, B

    2013-09-01

    Panton Valentine leukocidin is a toxin making pores in the polymorphonuclear cells which is a virulence factor of some strains of Staphylococcus aureus. Initially it was produced by methicillin susceptible Staphylococcus aureus only. Later with the acquisition of mecA gene has lead it to be PVL positive methicillin resistant Staphylococcus aureus. Since MRSA are resistant to many antibiotics and further they produce a toxin the infections by PVL positive MRSA has become a challenge. PVL positive MRSA a virulent strain of drug resistant superbug MRSA that has spread around the world, has claimed many lives in UK, Europe, USA and Australia. Some strains of superbug attack the healthy young people and kill within 24 hrs. PVL positive Staphylococcus aureus has been reported to be associated with skin and soft tissue infections however they also cause invasive infections and necrotizing pneumonia. These microorganisms known to be community associated have spread to hospitals. Hospital acquired infection by such microorganisms lead to an increase in mortality hence should be controlled before they become prevalent in hospitals. PMID:24908537

  10. Agglutinating serum for distinguishing Staphylococcus aureus of human biotype.

    PubMed

    Live, I

    1975-08-01

    Antiserum to Staphylococcus aureus strain 17 was treated with S. aureus strain 61218 until the antibodies against thermostable agglutinogen were removed. The absorbed serum agglutinated phage-typable as well as phageuntypable staphylococci of human biotype, whether recovered from people or from dogs. PMID:125241