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Sample records for aureus isolates mrsa

  1. Molecular typing of MRSA and of clinical Staphylococcus aureus isolates from Iaşi, Romania.

    PubMed

    Monecke, Stefan; Müller, Elke; Dorneanu, Olivia Simona; Vremeră, Teodora; Ehricht, Ralf

    2014-01-01

    Romania is one of the countries with the highest prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in the world. To obtain data on affiliation of MRSA to strains and clonal complexes and on the population of methicillin susceptible S. aureus (MSSA), clinical isolates from bloodstream infections, skin and soft tissue infections as well as from screening swabs were collected at hospitals in Ia?i, a city in the North-Eastern part of Romania. Isolates were characterised by microarray hybridisation. Nearly half of all isolates (47%), and about one third (34%) of bloodstream isolates were MRSA. The prevalence of the Panton-Valentine leukocidin (PVL) was also high (31% among MRSA, 14% among MSSA). The most common MRSA strain was a PVL-negative CC1-MRSA-IV that might have emerged locally, as a related MSSA was also common. PVL-positive CC8-MRSA-IV ("USA300") and PVL-negative ST239-like MRSA-III were also frequently found while other MRSA strains were only sporadically detected. Among MSSA, PVL-positive CC121 as well as PVL-negative CC1, CC22 and CC45 predominated. Although this study provides only a snapshot of S. aureus/MRSA epidemiology in Romania, it confirms the high burden of MRSA and PVL on Romanian healthcare settings.

  2. Prevalence of MRSA strains among Staphylococcus aureus isolated from outpatients, 2006.

    PubMed

    Coombs, Geoffrey W; Nimmo, Graeme R; Pearson, Julie C; Christiansen, Keryn J; Bell, Jan M; Collignon, Peter J; McLaws, Mary-Louise

    2009-03-01

    Biennial community-based Staphylococcus aureus antimicrobial surveillance programs have been performed by the Australian Group for Antimicrobial Resistance (AGAR) since 2000. Over this time the percentage of S. aureus identified as methicillin resistant has increased significantly from 10.3% in 2000 to 16% in 2006. This increase has occurred throughout Australia and has been due to the emergence of community-associated MRSA (CA-MRSA) clones. However, healthcare associated MRSA were still predominant in New South Wales/Australian Capital Territory and Victoria/Tasmania. In the 2006 survey CA-MRSA accounted for 8.8% of community-onset S. aureus infections. Although multiple CA-MRSA clones were characterised, the predominate clone identified was Queensland (Qld) MRSA (ST93-MRSA-IV) a Panton-Valentine leukocidin (PVL) positive MRSA that was first reported in Queensland and northern New South Wales in 2003 but has now spread throughout Australia. Several international PVL-positive CA-MRSA clones were also identified including USA300 MRSA (ST8-MRSA-IV). In addition, PVL was detected in an EMRSA-15 (ST22-MRSA-IV) isolate; a hospital associated MRSA clone that is known to be highly transmissible in the healthcare setting. With the introduction of the international clones and the transmission of Qld MRSA throughout the country, over 50% of CA-MRSA in Australia are now PVL positive. This change in the epidemiology of CA-MRSA in the Australian community will potentially result in an increase in skin and soft tissue infections in young Australians. As infections caused by these strains frequently results in hospitalisation their emergence is a major health concern.

  3. Identification of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from burn patients by multiplex PCR.

    PubMed

    Montazeri, Effat Abbasi; Khosravi, Azar Dokht; Jolodar, Abbas; Ghaderpanah, Mozhgan; Azarpira, Samireh

    2015-05-01

    Methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative staphylococci (MRCoNS) as important human pathogens are causes of nosocomial infections worldwide. Burn patients are at a higher risk of local and systemic infections with these microorganisms. A screening method for MRSA by using a multiplex polymerase chain reaction (PCR) targeting the 16S ribosomal RNA (rRNA), mecA, and nuc genes was developed. The aim of the present study was to investigate the potential of this PCR assay for the detection of MRSA strains in samples from burn patients. During an 11-month period, 230 isolates (53.11%) of Staphylococcus spp. were collected from burn patients. The isolates were identified as S. aureus by using standard culture and biochemical tests. DNA was extracted from bacterial colonies and multiplex PCR was used to detect MRSA and MRCoNS strains. Of the staphylococci isolates, 149 (64.9%) were identified as S. aureus and 81 (35.21%) were described as CoNS. Among the latter, 51 (62.97%) were reported to be MRCoNS. From the total S. aureus isolates, 132 (88.6%) were detected as MRSA and 17 (11.4%) were methicillin-susceptible S. aureus (MSSA). The presence of the mecA gene in all isolates was confirmed by using multiplex PCR as a gold standard method. This study presented a high MRSA rate in the region under investigation. The 16S rRNA-mecA-nuc multiplex PCR is a good tool for the rapid characterization of MRSA strains. This paper emphasizes the need for preventive measures and choosing effective antimicrobials against MRSA and MRCoNS infections in the burn units. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  4. Antibiotic susceptibilities and prevalence of Methicillin resistant Staphylococcus aureus (MRSA) isolated from bovine milk in Pakistan.

    PubMed

    Aqib, Amjad Islam; Ijaz, Muhammad; Anjum, Aftab Ahmad; Malik, Muhammad Abdul Rauf; Mehmood, Khalid; Farooqi, Shahid Hussain; Hussain, Kashif

    2017-08-07

    The study was designed to investigate bovine milk for prevalence of an emerging zoonotic pathogen Methicillin resistant Staphylococcus aureus (MRSA), and in-vitro therapeutic response of various antibiotics against MRSA. Nine hundred (900) milk samples were collected (half from cattle and half from buffalo) from private and public farms located in various tehsils of district Faisalabad, using the convenient sampling method. Milk samples were put to biochemical identification of Staphylococcus aureus and later oxacilline disk sensitivity testing for confirmation of MRSA. The MRSA isolates were confirmed by PCR targeting mecA gene in Staphylococcus aureus. The study found 34% prevalence of MRSA in overall bovine milk from district Faisalabad with 30% and 38% prevalence in cattle and buffalo, respectively. Tehsil Samundari presented comparatively higher MRSA prevalence followed by tehsil Jaranwala and tehsil Faisalabad. However, there was non-significant difference of MRSA prevalence between cattle and buffalo, and among different tehsils. All assumed risk factors except specie were significantly associated with mastitis spread. The in-vitro drug trial against MRSA from buffalo milk presented 100% efficacy of Ciprofloxcin, Moxifloxacin, Linezolid, and Trimethoprim plus Sulphamethoxazole combination, followed by Gentamicin and Levofloxacin presenting 90%, and Amikacin becoming 80% efficacious against MRSA from buffalo milk. The MRSA isolates of cattle milk presented similar pattern with some variations of higher susceptibility against Oxytetracycline, and Fusidic acid. The conclusion of the study states uniform prevalence of MRSA in cattle and buffalo milk in study area having assumed risk factors positively associated with disease spread, while Ciprofloxcin, Moxifloxacin, Linezolid, and Trimethoprim plus Sulphamethoxazole drugs showed the highest efficacy to combat this pathogen. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. [Methicillin-sensitive Staphylococcus aureus isolates related to USA300 clone: Origin of community-genotype MRSA in Colombia?].

    PubMed

    Escobar-Pérez, Javier Antonio; Castro, Betsy Esperanza; Márquez-Ortiz, Ricaurte Alejandro; Gaines, Sebastián; Chavarro, Bibiana; Moreno, Jaime; Leal, Aura Lucía; Vanegas, Natasha

    2014-04-01

    USA300 is a genetic lineage found both in methicillin-resistant (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) isolates. In Colombia, hospital and community MRSA infections are caused by a USA300-related community genotype MRSA (CG-MRSA) clone. The genetic origin of this clone is unknown yet. To identify and characterize methicillin-resistant (MRSA) and methicillin-sensitive S. aureus (MSSA) isolates in order to improve the information about the origin of the CG-MRSA isolates in Colombia. USA300-related MSSA isolates were detected and characterized from a study of 184 S. aureus isolates (90 MRSA and 94 MSSA) recovered from infections. The genetic relatedness of the isolates was established by means of pulsed field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and protein A gene typification ( spa typing). Among 184 isolates, 27 (14.7%) showed molecular characteristics and genetic relationship with the USA300 clone, of which 18 were MRSA and nine were MSSA. All USA300-related MRSA harbored Staphylococcal cassette chromosome mec (SCC mec ) IVc (3.1.2). In the MSSA isolates, SCC mec remnants or att B duplicate sites were not detected. In Colombia, the CG-MRSA isolates probably originated in the dissemination of an USA300-related MSSA clone which later acquired SCC mec IVc.

  6. Frequent isolation of methicillin resistant Staphylococcus aureus (MRSA) ST398 among healthy pigs in Portugal.

    PubMed

    Conceição, Teresa; de Lencastre, Hermínia; Aires-de-Sousa, Marta

    2017-01-01

    Although livestock-associated ST398 methicillin-resistant Staphylococcus aureus (MRSA) has been widely reported in different geographic regions, MRSA carriage studies among healthy pigs in Portugal are very limited. In total, 101 swine nasal samples from two Portuguese farms were screened for MRSA. In addition five swine workers (including one veterinary and one engineer) and four household members were nasally screened. The isolates were characterized by spa typing, SCCmec typing and MLST. All isolates were tested for antimicrobial susceptibility, presence of mecA and mecC genes, and virulence determinants. MRSA prevalence in swine was 99% (100/101), 80% (4/5) in swine workers and 25% (1/4) in household members. All isolates belonged to ST398 distributed over two spa types-t011 (57%) and t108 (42%). SCCmec type V was present in most of the isolates (n = 95; 82%) while 21 isolates amplified the mecA gene only and were classified as nontypeable. The majority of the isolates were resistant to tetracycline (100%), clindamycin (97%), erythromycin (96%), chloramphenicol (84%) and gentamycin (69%). Notably, 12% showed resistance to quinupristin-dalfopristin (MICs 3-8 μg/mL). Beta-hemolysin (81%) and gamma-hemolysin (74%) were the unique virulence determinants detected. None of the isolates harboured PVL or mecC gene. This study showed a massive occurrence of ST398-MRSA in two independent swine farms, highlighting its establishment among healthy pigs in Portugal.

  7. Twenty-Five Year Epidemiology of Invasive Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates Recovered at a Burn Center

    DTIC Science & Technology

    2009-01-01

    Twenty-five year epidemiology of invasive methicillin- resistant Staphylococcus aureus (MRSA) isolates recovered at a burn center§ Clinton K. Murray...history: Accepted 12 February 2009 Keywords: Burn center Epidemiology Methicillin-resistant Staphylococcus aureus Antimicrobial susceptibility a b s t r...invasive MRSA isolates over 25 years at a single burn unit. Isolates were tested by pulsed-field gel electrophoresis (PFGE), broth microdilution

  8. Descriptive Analysis of Antibiotic-Resistant Patterns of Methicillin-Resistant Staphylococcus aureus (MRSA) st398 Isolated from Healthy Swine

    PubMed Central

    Morcillo, Ana; Castro, Beatriz; Rodríguez-Álvarez, Cristobalina; Abreu, Rossana; Aguirre-Jaime, Armando; Arias, Angeles

    2015-01-01

    Background: Livestock-associated methicillin-resistant Staphylococcus aureus (MRSA) such as the MRSA ST398 strain has spread all over the World and the most worrying aspect of this fact appears to be its capacity to easily spread to humans. The excessive use of antibiotics has made swine a reservoir of MRSA. The aim of the present study was to determine the antibiotic resistance profile of MRSA samples isolated from healthy swine of the island of Tenerife (Spain). Methods: A total of 256 MRSA isolates from swine samples and five MRSA isolates from pig worker samples were investigated for MRSA antibiotic resistant patterns. Results: Analysis of the susceptibility status of MRSA pig isolates revealed that 39 isolates were resistant to one antibiotic, 71 isolates were resistant to two antibiotics and 96 isolates were resistant to three or more antibiotics. SCCmec typing revealed the presence of types IV and V. Isolates having SCCmec IV had an increased resistance to the antimicrobial agents tested than those having SCCmec V. We observed significant differences when comparing the most common resistance patterns and SCCmec type. Conclusions: MRSA isolated from humans showed similar resistance to those isolated from pigs, excepting erythromycin, since all the workers’ isolates were sensitive to this antibiotic. The evolution of new MRSA clones has emphasized the need for infection control practices in animals and humans in close contact. PMID:25588155

  9. Genotypic and phenotypic characteristics of Methicillin-resistant Staphylococcus aureus (MRSA) strains, isolated on three different geography locations

    PubMed Central

    Ostojić, Maja; Hukić, Mirsada

    2015-01-01

    Staphylococcus aureus is a major cause of hospital-acquired infections worldwide. Increased frequency of methicillin-resistant Staphylococcus aureus (MRSA) in hospitalized patients and possibility of vancomycin resistance requires rapid and reliable characterization of isolates and control of MRSA spread in hospitals. Typing of isolates helps to understand the route of a hospital pathogen spread. The aim of this study was to investigate and compare genotypic and phenotypic characteristics of MRSA samples on three different geography locations. In addition, our aim was to evaluate three different methods of MRSA typing: spa-typing, agr-typing and GenoType MRSA. We included 104 samples of MRSA, isolated in 3 different geographical locations in clinical hospitals in Zagreb, Mostar, and Heidelberg, during the period of six months. Genotyping and phenotyping were done by spa-typing, agr-typing and dipstick assay GenoType MRSA. We failed to type all our samples by spa-typing. The most common spa-type in clinical hospital Zagreb was t041, in Mostar t001, and in Heidelberg t003. We analyzed 102/104 of our samples by agr-typing method. We did not find any agr-type IV in our locations. We analyzed all our samples by the dipstick assay GenoType MRSA. All isolates in our study were MRSA strains. In Zagreb there were no positive strains to PVL gene. In Mostar we have found 5/25 positive strains to PVL gene, in Heidelberg there was 1/49. PVL positive isolates were associated with spa-type t008 and agr-type I, thus, genetically, they were community-associated MRSA (CA-MRSA). Dipstick assay GenoType MRSA has demonstrated sufficient specificity, sensibility, simple performance and low cost, so we could introduce it to work in smaller laboratories. Using this method may expedite MRSA screening, thus preventing its spread in hospitals. PMID:26295294

  10. Genotypic and phenotypic characteristics of Methicillin-resistant Staphylococcus aureus (MRSA) strains, isolated on three different geography locations.

    PubMed

    Ostojić, Maja; Hukić, Mirsada

    2015-08-04

    Staphylococcus aureus is a major cause of hospital-acquired infections worldwide. Increased frequency of methicillin-resistant Staphylococcus aureus (MRSA) in hospitalized patients and possibility of vancomycin resistance requires rapid and reliable characterization of isolates and control of MRSA spread in hospitals. Typing of isolates helps to understand the route of a hospital pathogen spread. The aim of this study was to investigate and compare genotypic and phenotypic characteristics of MRSA samples on three different geography locations. In addition, our aim was to evaluate three different methods of MRSA typing: spa-typing, agr-typing and GenoType MRSA.  We included 104 samples of MRSA, isolated in 3 different geographical locations in clinical hospitals in Zagreb, Mostar, and Heidelberg, during the period of six months. Genotyping and phenotyping were done by spa-typing, agr-typing and dipstick assay GenoType MRSA. We failed to type all our samples by spa-typing.  The most common spa-type in clinical hospital Zagreb was t041, in Mostar t001, and in Heidelberg t003.We analyzed 102/104 of our samples by agr-typing method. We did not find any agr-type IV in our locations. We analyzed all our samples by the dipstick assay GenoType MRSA. All isolates in our study were MRSA strains. In Zagreb there were no positive strains to PVL gene. In Mostar we have found 5/25 positive strains to PVL gene, in Heidelberg there was 1/49. PVL positive isolates were associated with spa-type t008 and agr-type I, thus, genetically, they were community-associated MRSA (CA-MRSA). Dipstick assay GenoType MRSA has demonstrated sufficient specificity, sensibility, simple performance and low cost, so we could introduce it to work in smaller laboratories. Using this method may expedite MRSA screening, thus preventing its spread in hospitals.

  11. Methicillin-resistant Staphylococcus aureus (MRSA)

    MedlinePlus

    Methicillin-resistant Staphylococcus aureus; Hospital-acquired MRSA (HA-MRSA); Staph - MRSA; Staphylococcal - MRSA ... Que YA, Moreillon P. Staphylococcus aureus (including ... MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice ...

  12. Linezolid minimum inhibitory concentration (MIC) creep in methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates at a single Japanese center.

    PubMed

    Miyazaki, Motoyasu; Nagata, Nobuhiko; Miyazaki, Hiroyuki; Matsuo, Koichi; Takata, Tohru; Tanihara, Shinichi; Kamimura, Hidetoshi

    2014-01-01

    The aim of this study was to evaluate whether linezolid minimum inhibitory concentration (MIC) creep occurred in Staphylococcus aureus clinical isolates, including methicillin-resistant S. aureus (MRSA), over a recent 5-year period at a single Japanese center. A total of 453 MRSA and 195 methicillin-susceptible S. aureus (MSSA) isolates recovered from inpatients from April 1, 2008 to March 31, 2013 were analyzed. The MIC of linezolid was determined by automated Vitek-2 system. The modal MIC, MIC range, MIC50 and MIC90 (MICs required to inhibit the growth of 50% and 90% of organisms, respectively), geometric mean MIC and percentages of susceptible and resistant isolates were evaluated for each fiscal year. None of the S. aureus isolates were resistant to linezolid. Isolates with an MIC of >1 µg/mL were more common in the MSSA samples than in the MRSA samples (91.3% versus 38.2%, p<0.001). The linezolid geometric mean MIC increased by 0.403 µg/mL (from 1.178 in 2008 to 1.582 in 2012) in the MRSA isolates (p=0.006, r(2)=0.945 according to a linear regression analysis) over the 5-year period; however, no increase was observed in the MSSA isolates. The frequency of MRSA isolates with an MIC of 1 µg/mL decreased (from 76.3% in 2008 to 35.4% in 2012) and the isolates with MICs of >1 µg/mL increased over time (from 23.7% in 2008 to 64.6% in 2012). This report demonstrates the occurrence of linezolid MIC creep, as determined using the geometric mean MIC, in MRSA clinical isolates at a single Japanese center.

  13. Chlorhexidine and Mupirocin Susceptibility of Methicillin-Resistant Staphylococcus aureus Isolates in the REDUCE-MRSA Trial.

    PubMed

    Hayden, Mary K; Lolans, Karen; Haffenreffer, Katherine; Avery, Taliser R; Kleinman, Ken; Li, Haiying; Kaganov, Rebecca E; Lankiewicz, Julie; Moody, Julia; Septimus, Edward; Weinstein, Robert A; Hickok, Jason; Jernigan, John; Perlin, Jonathan B; Platt, Richard; Huang, Susan S

    2016-11-01

    Whether targeted or universal decolonization strategies for the control of methicillin-resistant Staphylococcus aureus (MRSA) select for resistance to decolonizing agents is unresolved. The REDUCE-MRSA trial (ClinicalTrials registration no. NCT00980980) provided an opportunity to investigate this question. REDUCE-MRSA was a 3-arm, cluster-randomized trial of either screening and isolation without decolonization, targeted decolonization with chlorhexidine and mupirocin, or universal decolonization without screening to prevent MRSA infection in intensive-care unit (ICU) patients. Isolates from the baseline and intervention periods were collected and tested for susceptibility to chlorhexidine gluconate (CHG) by microtiter dilution; mupirocin susceptibility was tested by Etest. The presence of the qacA or qacB gene was determined by PCR and DNA sequence analysis. A total of 3,173 isolates were analyzed; 2 were nonsusceptible to CHG (MICs, 8 μg/ml), and 5/814 (0.6%) carried qacA or qacB At baseline, 7.1% of MRSA isolates expressed low-level mupirocin resistance, and 7.5% expressed high-level mupirocin resistance. In a mixed-effects generalized logistic regression model, the odds of mupirocin resistance among clinical MRSA isolates or MRSA isolates acquired in an ICU in intervention versus baseline periods did not differ across arms, although estimates were imprecise due to small numbers. Reduced susceptibility to chlorhexidine and carriage of qacA or qacB were rare among MRSA isolates in the REDUCE-MRSA trial. The odds of mupirocin resistance were no different in the intervention versus baseline periods across arms, but the confidence limits were broad, and the results should be interpreted with caution. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  14. Antibiotic resistance patterns of methicillin-resistant Staphylococcus aureus (MRSA) isolated from livestock and associated farmers in Anuradhapura, Sri Lanka.

    PubMed

    Jayaweera, Jayaweera Arachchige Asela Sampath; Kumbukgolla, Wikum Widuranga

    2017-09-01

    The animal husbandry comes to play an important role according to new economic reforms of the rural economy in South Asia including Sri Lanka, and the rural farming community has a poor knowledge about hygienic issues of animal husbandry, which can lead to spread of pathogenic bacterial strains from animals to humans. Our study was conducted to evaluate methicillin susceptible Staphylococcus aureus (MRSA) colonization and its antimicrobial resistance pattern among livestock (n=188) and related farmers (n=94) in Anuradhapura District, Sri Lanka. S. aureus isolates were identified using mannitol salt agar, coagulase test and DNAase test. The agar plate dilution method was conducted to determine the minimum inhibitory concentration (MIC) of oxacillin against S. aureus. Antimicrobial susceptibility testing for other antibiotics was performed against MRSA isolates using antibiotic containing discs. To assess the MRSA transmission from livestock to humans, we have grouped MRSA strains according to antimicrobial susceptibility patterns against the tested antibiotics. Among MRSA isolates, 14 different groups with similar MIC and antibiotic susceptibility patterns were identified. Of those, 2 groups amongst pigs and pig farmers showed a significant relationship (p=0.031). The other groups did not show any significant relationship between animals and the farmers. The percentages of MRSA prevalence in pigs and pig farmers were 26.6% each, in poultry and poultry farmers 8.3% and 13.3% respectively, in cattle and cattle farmers 8.3% and 3%. Compared to human MRSA isolates, animal isolates were significantly more resistant to ciprofloxacin (p=0.031), gentamicin (p=0.010) and clindamycin (p=0.011). Similarly, animal methicillin susceptible Staphylococcus aureus (MSSA) isolates were significantly more resistant to ciprofloxacin (p=0.022) and doxycycline (p=0.012). Pig farming showed a higher prevalence and 2.4 times higher risk (OR=2.4, CI95%: 1.2-4.8) of likely transmission of

  15. Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) isolates of swine origin form robust biofilms.

    PubMed

    Nicholson, Tracy L; Shore, Sarah M; Smith, Tara C; Frana, Timothy S; Fraena, Timothy S

    2013-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) colonization of livestock animals is common and prevalence rates for pigs have been reported to be as high as 49%. Mechanisms contributing to the persistent carriage and high prevalence rates of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) strains in swine herds and production facilities have not been investigated. One explanation for the high prevalence of MRSA in swine herds is the ability of these organisms to exist as biofilms. In this report, the ability of swine LA-MRSA strains, including ST398, ST9, and ST5, to form biofilms was quantified and compared to several swine and human isolates. The contribution of known biofilm matrix components, polysaccharides, proteins and extracellular DNA (eDNA), was tested in all strains as well. All MRSA swine isolates formed robust biofilms similar to human clinical isolates. The addition of Dispersin B had no inhibitory effect on swine MRSA isolates when added at the initiation of biofilm growth or after pre-established mature biofilms formed. In contrast, the addition of proteinase K inhibited biofilm formation in all strains when added at the initiation of biofilm growth and was able to disperse pre-established mature biofilms. Of the LA-MRSA strains tested, we found ST398 strains to be the most sensitive to both inhibition of biofilm formation and dispersal of pre-formed biofilms by DNaseI. Collectively, these findings provide a critical first step in designing strategies to control or eliminate MRSA in swine herds.

  16. Livestock-Associated Methicillin-Resistant Staphylococcus aureus (LA-MRSA) Isolates of Swine Origin Form Robust Biofilms

    PubMed Central

    Nicholson, Tracy L.; Shore, Sarah M.; Smith, Tara C.; Fraena, Timothy S.

    2013-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) colonization of livestock animals is common and prevalence rates for pigs have been reported to be as high as 49%. Mechanisms contributing to the persistent carriage and high prevalence rates of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) strains in swine herds and production facilities have not been investigated. One explanation for the high prevalence of MRSA in swine herds is the ability of these organisms to exist as biofilms. In this report, the ability of swine LA-MRSA strains, including ST398, ST9, and ST5, to form biofilms was quantified and compared to several swine and human isolates. The contribution of known biofilm matrix components, polysaccharides, proteins and extracellular DNA (eDNA), was tested in all strains as well. All MRSA swine isolates formed robust biofilms similar to human clinical isolates. The addition of Dispersin B had no inhibitory effect on swine MRSA isolates when added at the initiation of biofilm growth or after pre-established mature biofilms formed. In contrast, the addition of proteinase K inhibited biofilm formation in all strains when added at the initiation of biofilm growth and was able to disperse pre-established mature biofilms. Of the LA-MRSA strains tested, we found ST398 strains to be the most sensitive to both inhibition of biofilm formation and dispersal of pre-formed biofilms by DNaseI. Collectively, these findings provide a critical first step in designing strategies to control or eliminate MRSA in swine herds. PMID:23951352

  17. Isolation, Virulence, and Antimicrobial Resistance of Methicillin-Resistant Staphylococcus aureus (MRSA) and Methicillin Sensitive Staphylococcus aureus (MSSA) Strains from Oklahoma Retail Poultry Meats.

    PubMed

    Abdalrahman, Lubna S; Stanley, Adriana; Wells, Harrington; Fakhr, Mohamed K

    2015-05-29

    Staphylococcus aureus is one the top five pathogens causing domestically acquired foodborne illness in the U.S. Only a few studies are available related to the prevalence of S. aureus and MRSA in the U.S. retail poultry industry. The objectives of this study were to determine the prevalence of S. aureus (MSSA and MRSA) in retail chicken and turkey meats sold in Tulsa, Oklahoma and to characterize the recovered strains for their antimicrobial resistance and possession of toxin genes. A total of 167 (114 chicken and 53 turkey) retail poultry samples were used in this study. The chicken samples included 61 organic samples while the rest of the poultry samples were conventional. The overall prevalence of S. aureus was 57/106 (53.8%) in the conventional poultry samples and 25/61 (41%) in the organic ones. Prevalence in the turkey samples (64.2%) was higher than in the chicken ones (42.1%). Prevalence of S. aureus did not vary much between conventional (43.4%) and organic chicken samples (41%). Two chicken samples 2/114 (1.8%) were positive for MRSA. PFGE identified the two MRSA isolates as belonging to PFGE type USA300 (from conventional chicken) and USA 500 (from organic chicken) which are community acquired CA-MRSA suggesting a human based source of contamination. MLST and spa typing also supported this conclusion. A total of 168 Staphylococcus aureus isolates (101 chicken isolates and 67 turkey isolates) were screened for their antimicrobial susceptibility against 16 antimicrobials and their possession of 18 different toxin genes. Multidrug resistance was higher in the turkey isolates compared to the chicken ones and the percentage of resistance to most of the antimicrobials tested was also higher among the turkey isolates. The hemolysin hla and hld genes, enterotoxins seg and sei, and leucocidins lukE-lukD were more prevalent in the chicken isolates. The PVL gene lukS-lukF was detected only in chicken isolates including the MRSA ones. In conclusion, S. aureus is

  18. Genotypic and phenotypic characterization of methicillin-resistant Staphylococcus aureus (MRSA) isolated from milk of bovine mastitis.

    PubMed

    Bardiau, M; Yamazaki, K; Duprez, J-N; Taminiau, B; Mainil, J G; Ote, I

    2013-09-01

    The aim of this study was to evaluate the presence of methicillin-resistant Staphylococcus aureus (MRSA) among a (S. aureus) collection (n = 430) isolated from milk of cows suffering from mastitis in Belgium and to compare their genotypic as well as phenotypic characteristics. Pulsed field gel electrophoresis (PFGE) and PCR-based typing techniques (MLST, spa, SCCmec, and agr typing) have been applied and supplemented by capsule serotyping, biofilm production quantification and antimicrobial susceptibility testing. Nineteen MRSA were isolated. Seven distinct ApaI PFGE patterns were observed. All isolates, except one, were identified as ST398 strains. Three spa types (t011, t567 and t108) and two SCCmec types (IV and V) were identified. All isolates belonged to agr type I and capsule type 5 and were Panton-Valentine leukocidin (PVL) negative. All isolates produced biofilm in TSBglc , whereas the majority did not in milk serum. Twelve resistance patterns were observed, with almost two-thirds of the isolates being resistant to at least six antibiotics, including penicillin and tetracycline. Our study confirms that the emerging ST398 LA-MRSA clone has attained Belgian cattle. With regard to genotypic and phenotypic typing, the 19 MRSA isolated in this study form a homogenous group and do not differ much from one another, neither from what has been previously described.

  19. Complete Genome Sequence of Staphylococcus aureus XN108, an ST239-MRSA-SCCmec III Strain with Intermediate Vancomycin Resistance Isolated in Mainland China

    PubMed Central

    Zhang, Xia; Xu, Xiaomeng; Yuan, Wenchang; Hu, Qiwen; Shang, Weilong; Hu, Xiaomei

    2014-01-01

    ST239-MRSA-SCCmec III (ST239, sequence type 239; MRSA, methicillin-resistant Staphylococcus aureus; SCCmec III, staphylococcal cassette chromosome mec type III) is the most predominant clone of hospital-acquired methicillin-resistant S. aureus in mainland China. We report here the complete genome sequence of XN108, the first vancomycin-intermediate S. aureus strain isolated from a steam-burned patient with a wound infection. PMID:25059856

  20. Molecular characterisation of methicillin-resistant Staphylococcus aureus (MRSA) isolated at a large referral hospital in Zambia.

    PubMed

    Samutela, Mulemba Tillika; Kalonda, Annie; Mwansa, James; Lukwesa-Musyani, Chileshe; Mwaba, John; Mumbula, Enoch Mulowa; Mwenya, Darlington; Simulundu, Edgar; Kwenda, Geoffrey

    2017-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is globally recognized as an important public health problem. Whereas comprehensive molecular typing data of MRSA strains is available, particularly in Europe, North America and Australia, similar information is very limited in sub-Saharan Africa including Zambia. In this study, thirty two clinical isolates of Staphylococcus aureus, collected at a large referral hospital in Lusaka, Zambia between June 2009 and December 2012 were analysed by Staphylococcal cassette chromosome mec (SCCmec), Staphylococcus protein A gene typing (spa) and detection of the Panton-Valentine Leukocidin genes (pvl). Three SCCmec types were identified namely SCCmec type IV (65.6%), SCCmec type III (21.9%), SCCmec type I (3.1%). Nine point four percent (9.4%) of the isolates were untypable. Five spa types, which included a novel type, were detected and the most prevalent spa type was t064 (40.6%). Other spa types included spa types t2104 (31.3%), t355 (3.1%) and t1257 (21.9%). The pvl genes were detected in 3 out of 32 isolates. These molecular typing data indicated that the MRSA strains collected in Lusaka were diverse. Although the source of these MRSA was not established, these results stress the need for assessing infection prevention and control procedures at this health-care facility in order to curtail possible nosocomial infections. Furthermore, country-wide surveillance of MRSA in both the community and health-care facilities is recommended for infection prevention and control. To our knowledge, this represents the first study to characterise MRSA using molecular tools in Zambia.

  1. Isolation And Partial Characterization Of Bacteria Activity Associated With Gorgonian Euplexaura sp. Against Methicillin-Resistant Staphylococcus aureus (MRSA)

    NASA Astrophysics Data System (ADS)

    Kristiana, R.; Ayuningrum, D.; Asagabaldan, M. A.; Nuryadi, H.; Sabdono, A.; Radjasa, O. K.; Trianto, A.

    2017-02-01

    Methicillin-resistant Staphylococcus aureus (MRSA) infection has emerged in around the world and has been resistance to ciprofloxacin, erythromycin, clindamycin. The aims of this study were to isolate, to investigate and to characterize bacterial symbionts gorgonian having activity against MRSA. Euplexaura sp. was collected from Panjang Island, Jepara, Indonesia by snorkling 2-5 m in depth. Bacterias were isolated by using spesific media with dilution method. Bacterias were conducted by using the streak method. Antibacterial activity was investigated by overlay method. The potent bacteria was identified by using molecular identification (DNA extraction, electrophoresis, PCR and phylogenetic analysis using 16S rDNA genes with actinobacteria-spesific primers) and bio-chemical test (among 5 isolated bacteria from gorgonian showed activity against MRSA). The strain PG-344 was the best candidat that has an inhibition zone against MRSA. The result of sequencing bacteria is 100% closely related with Virgibacillus salarius. This becomes a potential new bioactive compounds to against MRSA that can be a new drug discovery.

  2. Genotyping of methicillin-resistant Staphylococcus aureus (MRSA) isolated from milk and dairy products in South Italy.

    PubMed

    Basanisi, M G; La Bella, G; Nobili, G; Franconieri, I; La Salandra, G

    2017-04-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen emerging in hospitals as well as community and livestock. MRSA is a significant and costly public health concern because it may enter the human food chain and contaminate milk and dairy products causing foodborne illness. This study aimed to determine the occurrence and the characteristics of MRSA isolated from 3760 samples of milk and dairy products in a previous survey conducted in southern Italy during 2008-2014. Overall out of 484 S. aureus strains isolated, 40 (8.3%) were MRSA and were characterized by spa-typing, Multi-Locus Sequence Typing, SCCmec typing, Staphylococcal enterotoxins (SEs) genes, Panton-Valentine Leukocidin (PVL) genes and ability to form biofilm. The most frequently recovered STs were ST152 (t355-67.5%), followed by ST398 (t899, t108-25%), ST1 (t127-5%) and ST5 (t688-2.5%). All isolates harboured the SCCmec type V (92.5%) or IVa (25%). In one isolate (2.5%), ST398/t899, the SCCmec resulted not detected. Three isolates (7.5%) carried one or more enterotoxin encoding genes (one strain had seg, sei, sem, sen and seo genes; two strains had seh gene). The 50% of isolated strains harboured PVL-encoding genes. Molecular analysis for icaA and icaD genes showed: 72.5% icaA and icaD positive, 25% only icaD gene and one icaA and icaD negative. The detection of MRSA in food of animal origin is a potential health hazard, thus it is necessary monitoring of food-producing animals and improving hygiene standards in food practices in order to reduce the microbiological risk to minimum.

  3. Characterization of PVL/ACME-positive methicillin-resistant Staphylococcus aureus (genotypes ST8-MRSA-IV and ST5-MRSA-II) isolated from a university hospital in Japan.

    PubMed

    Kawaguchiya, Mitsuyo; Urushibara, Noriko; Yamamoto, Dai; Yamashita, Toshiharu; Shinagawa, Masaaki; Watanabe, Naoki; Kobayashi, Nobumichi

    2013-02-01

    The ST8 methicillin-resistant Staphylococcus aureus (MRSA) with Staphylococcal cassette chromosome mec (SCCmec) type IVa, known as USA300, is a prevalent community-acquired MRSA (CA-MRSA) clone in the United States and has been spreading worldwide. The USA300 characteristically harbors Panton-Valentine Leukocidin (PVL) genes and the arginine catabolic mobile element (ACME, type I). Prevalence and molecular characteristics of PVL(+) and/or ACME(+) S. aureus were investigated in a university hospital located in northern Japan, for 1,366 S. aureus isolates, including 601 MRSA strains derived from clinical specimens collected from 2008 to 2010. The PVL gene was identified in three MRSA strains with SCCmec IV, which belonged to ST8, spa type t008, coagulase type III, and agr type I. Two PVL-positive MRSA strains had also type I ACME, and were isolated from skin abscess of outpatients who have not travelled abroad recently. One of these PVL(+)/ACME(+) strains carried tet(K), msrA, and aph(3')-IIIa, showing resistance to kanamycin, tetracycline, erythromycin, and ciprofloxacin, suggesting acquisition of more resistance than ST8 CA-MRSA reported in Japan previously. In contrast, another PVL(+)/ACME(+) strain and a PVL(+)/ACME(-) strain were susceptible to more antimicrobials and had less virulence factors than PVL(-)/ACME(+) MRSA strains. Besides the two PVL(+) MRSA strains, ACME (type-ΔII) was identified into seven MRSA strains with SCCmec II belonging to ST5, one of the three spa types (t002, t067, and t071), coagulase type II, and agr type II. These PVL(-)/ACME(+) MRSA strains showed multiple drug resistance and harbored various toxin genes as observed for ST5 PVL(-)/ACME(-) MRSA-II. The present study suggested the spread of ST8-MRSA-IV in northern Japan, and a potential significance of ACME-positive ST5-MRSA-II as an emerging MRSA clone in a hospital.

  4. Incidence of Staphylococcus aureus isolated from patients treated at the Clinical Center of Skopje, Macedonia, with special attention to MRSA.

    PubMed

    Cekovska, Zaklina; Panovski, Nikola; Petrovska, Milena; Kristóf, Katalin; Rozgonyi, F

    2005-01-01

    The distribution of 3497 Staphylococcus aureus strains according to methicillin resistance, specimens, departmental profession and antibiotic resistance patterns was analysed. The strains were cultured from the patients of the Clinical Center of Skopje, Macedonia, between 1 January 2002 and 31 December 2004. The majority of the isolates was obtained from suppurated wounds (28.5%), nares (21%), intratracheal tubes (13%) and blood cultures (11.8%). Overall 1100 (31.4%) of the isolates was methicillin-resistant with 1 microg oxacillin disc. Of these 35.5%, 30.5% and 10.4% were cultured from wounds, intratracheal tubes and blood samples, respectively. The prevalence of MRSA strains was 78.6%, 75%, 44.2% and 37.3% in specimens of ICU, Coma Center, General Surgery and Haematology patients. There were extremely big differences in the frequency of MRSA between departments with particular specialisation. The 2397 MSSA isolates belonged to practically one antibiotic resistance pattern characterised with penicillin resistance and susceptibility to other antistaphylococcal drugs. The 1100 MRSA isolates distributed to four antibiotic resistance patterns on the basis of their resistance to oxacillin, penicillin, amoxicillin+clavulanic acid, azithromycin, clindamycin, amikacin, gentamicin, ciprofloxacin, trimethoprim+sulphamethoxasole, vancomycin and teicoplanin. All the MRSA isolates were multidrug resistant but sensitive to glycopeptides.

  5. Detection of mecA- and mecC-Positive Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates by the New Xpert MRSA Gen 3 PCR Assay.

    PubMed

    Becker, Karsten; Denis, Olivier; Roisin, Sandrine; Mellmann, Alexander; Idelevich, Evgeny A; Knaack, Dennis; van Alen, Sarah; Kriegeskorte, André; Köck, Robin; Schaumburg, Frieder; Peters, Georg; Ballhausen, Britta

    2016-01-01

    An advanced methicillin-resistant Staphylococcus aureus (MRSA) detection PCR approach targeting SCCmec-orfX along with mecA and mecC was evaluated for S. aureus and coagulase-negative staphylococci. The possession of mecA and/or mecC was correctly confirmed in all cases. All methicillin-susceptible S. aureus strains (n = 98; including staphylococcal cassette chromosome mec element [SCCmec] remnants) and 98.1% of the MRSA strains (n = 160, including 10 mecC-positive MRSA) were accurately categorized.

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

    PubMed Central

    Hedin, Göran; Fang, Hong

    2005-01-01

    Thirty-nine methicillin-resistant Staphylococcus aureus (MRSA) isolates with diverse genetic backgrounds and two reference strains were correctly identified as S. aureus on CHROMagar MRSA and S. aureus ID media. Growth inhibition on CHROMagar MRSA was noted. A combination of cefoxitin disk and S. aureus ID was found suitable for rapid MRSA screening. PMID:16081989

  7. Drug Resistance Reversal Potential of Isoliquiritigenin and Liquiritigenin Isolated from Glycyrrhiza glabra Against Methicillin-Resistant Staphylococcus aureus (MRSA).

    PubMed

    Gaur, Rashmi; Gupta, Vivek Kumar; Singh, Pooja; Pal, Anirban; Darokar, Mahendra Padurang; Bhakuni, Rajendra Singh

    2016-10-01

    Isoliquiritigenin (ISL) and liquiritigenin (LTG) are structurally related flavonoids found in a variety of plants. Discovery of novel antimicrobial combinations for combating methicillin-resistant Staphylococcus aureus (MRSA) infections is of vital importance in the post-antibiotic era. The present study was taken to explore the in vitro and in vivo combination effect of LTG and ISL with β-lactam antibiotics (penicillin, ampicillin and oxacillin) against mec A-containing strains of MRSA. Minimum inhibitory concentration (MIC) of both LTG and ISL exhibited significant anti-MRSA activity (50-100 µg/mL) against clinical isolates of MRSA. The result of in vitro combination study showed that ISL significantly reduced MIC of β-lactam antibiotics up to 16-folds [∑ fractional inhibitory concentration (FIC) 0.312-0.5], while LTG reduced up to 8-folds (∑FIC 0.372-0.5). Time kill kinetics at graded MIC combinations (ISL/LTG + β-lactam) indicated 3.27-9.79-fold and 2.59-3.48-fold reduction in the growth of clinical isolates of S. aureus respectively. In S. aureus-infected Swiss albino mice model, combination of ISL with oxacillin significantly (p < 0.05, p < 0.01, p < 0.001) lowered the systemic microbial burden in blood, liver, kidney, lung and spleen tissues in comparison with ISL, oxacillin alone as well as untreated control. Considering its synergistic antibacterial effect, we suggest both ISL and LTG as promising compounds for the development of novel antistaphylococcal combinations. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  8. Oxacillin-susceptible methicillin-resistant Staphylococcus aureus (OS-MRSA), a hidden resistant mechanism among clinically significant isolates in the Wessex region/UK.

    PubMed

    Saeed, K; Ahmad, N; Dryden, M; Cortes, N; Marsh, P; Sitjar, A; Wyllie, S; Bourne, S; Hemming, J; Jeppesen, C; Green, S

    2014-10-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is defined as S. aureus genetically having the mecA or mecC genes or phenotypically showing minimum inhibitory concentration (MIC) of oxacillin higher than 2 mg/L. However, recently, cefoxitin/oxacillin-susceptible mecA-positive S. aureus (OS-MRSA) has been reported worldwide. Little is known about the prevalence and virulence of these strains among clinically significant isolates in the UK. The aims were to (1) investigate the prevalence of OS-MRSA in seven major hospitals in the Wessex region/UK from a cohort of 500 clinically significant phenotypically identified MSSA isolates, (2) genetically characterise OS-MRSA strains by pulsed-field gel electrophoresis (PFGE) and compare these to common UK epidemic strains; and (3) to determine Panton-Valentine leukocidin (PVL; lukFS) gene carriage rates among these isolates. OS-MRSA was found in six isolates (1.2 %) of phenotypically identified and reported MSSA isolates by conventional methods. PFGE showed OS-MRSA strains to be genetically diverse and distinct from the common UK epidemic strains EMRSA-15 and EMRSA-16. None of these OS-MRSA stains carried the genes encoding PVL; however, overall positivity rate for PVL was 4.4 %, much higher than the nationally reported rates of 2 % in the UK. There are still many unknowns regarding phenotypic and/or genetic characterization of the emerging OS-MRSA isolates in the UK and worldwide. Data regarding their epidemiology and optimal therapy for infection are limited and need further investigation not only in the UK, but also worldwide, as it is likely to have an impact on the empirical treatment of S. aureus infections.

  9. Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) isolates of swine origin form robust biofilms

    USDA-ARS?s Scientific Manuscript database

    Methicillin-resistant Staphylococcus aureus (MRSA) colonization of livestock animals is common and prevalence rates for pigs have been reported to be as high as 49%. One hypothesis to explain the high prevalence of MRSA in swine herds is the ability of these organisms to exist as biofilms. To invest...

  10. Determining the prevalence of SCCmec polymorphism, virulence and antibiotic resistance genes among methicillin-resistant Staphylococcus aureus (MRSA) isolates collected from selected hospitals in west of Iran.

    PubMed

    Taherikalani, Morovat; Mohammadzad, Mohammad Reza; Soroush, Setareh; Maleki, Mohammad Hossein; Azizi-Jalilian, Farid; Pakzad, Iraj; Sadeghifard, Nourkhoda; Asadollahi, Parisa; Emaneini, Mohammad; Monjezi, Aazam; Alikhani, Mohammad Yousef

    2016-04-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most important pathogens worldwide and compared to other staphylococcal species that are associated with higher mortality rate. A total of 500 Staphylococcus spp. was collected from selected hospitals in Ilam, Kermanshah, Khorram Abad and Hamadan cities and, via phenotypic and genotypic methods, was assessed to find MRSA. The presence or absence of prevalent antibiotic resistance genes and virulence genes was evaluated among MRSA isolates, using polymerase chain reaction (PCR) method, and then the SCCmec typing of these isolates was assayed by multiplex PCR. A total of 372 (74.4%) Stapylococcus spp. isolates were identified as S. aureus, among which 200 (53.8%) possessed the mecA gene and were distinguished as MRSA. All of MRSA isolates contained blaZ gene. The frequency of ermA and ermC genes among erythromycin-resistant MRSA isolates was 21.6% and 66.7%, respectively. The frequency of the virulence genes eta, hla and sea among MRSA isolates was 10%, 80.5% and 100%, respectively. SCCmec type IV accounted for 30.6% of the MRSA isolates and SCCmec type III, SCCmec type II and SCCmec type I accounted for 30%, 22% and 17.5% of the isolates, respectively. The antibiotic resistance genes and the virulence genes of blaZ, hla, sea, eta and ermC had high frequencies among the MRSA isolates. This study showed that the antibiotic resistance genes had higher frequencies among SCCmec types I and IV, which confirms the previous reports in this field.

  11. Three-Way Comparison of BBL CHROMagar MRSA II, MRSASelect, and Spectra MRSA for Detection of Methicillin-Resistant Staphylococcus aureus Isolates in Nasal Surveillance Cultures

    PubMed Central

    Renzi, Pamela B.; Koch, Kim M.; Wissel, Carol M.

    2013-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of hospital-acquired and life-threatening infections. Active surveillance programs for MRSA utilize either molecular or culture-based methods. A prospective study was performed to compare the performance of selective and differential chromogenic media, BBL CHROMagar MRSA II (CMRSA II; BD Diagnostics, Sparks, MD), MRSASelect (Bio-Rad Laboratories, Redmond, WA), and Spectra MRSA (Remel, Lenexa, KS), for the detection of MRSA in nasal swab specimens. A total of 515 compliant remnant nasal swab specimens were sequentially used to inoculate BBL Trypticase soy agar with 5% sheep blood (TSA II) and each chromogenic medium. After 24 h of incubation, colony color reactions and morphology on chromogenic media were compared to suspicious colonies on nonselective TSA II. MRSA on TSA II was confirmed by Gram staining, a coagulase test, and a cefoxitin disk test. The overall prevalence of MRSA and methicillin-susceptible S. aureus (MSSA) on TSA II was 12.4% (64/515) and 9.7% (50/515), respectively. When each chromogenic medium was compared to the standard culture method, the sensitivity and specificity, respectively, were as follows: CMRSA II, 87.7% and 98.6%; MRSASelect, 89.0% and 93.4%; and Spectra MRSA, 83.6% and 92.1%. The positive predictive values were highest for CMRSA II (91.4%), followed by MRSASelect (69.1%) and Spectra MRSA (63.5%). False-positive results on chromogenic media were mainly due to color interpretation. The negative predictive values for all three media were greater than 97%. In conclusion, CMRSA II gave the best overall results for detecting MRSA from nasal specimens. PMID:23135930

  12. Community-associated methicillin-resistant Staphylococcus aureus clonal complex 80 type IV (CC80-MRSA-IV) isolated from the Middle East: a heterogeneous expanding clonal lineage.

    PubMed

    Harastani, Houda H; Tokajian, Sima T

    2014-01-01

    The emergence of community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) has caused a change in MRSA epidemiology worldwide. In the Middle East, the persistent spread of CA-MRSA isolates that were associated with multilocus sequence type (MLST) clonal complex 80 and with staphylococcal cassette chromosome mec (SCCmec) type IV (CC80-MRSA-IV), calls for novel approaches for infection control that would limit its spread. In this study, the epidemiology of CC80-MRSA-IV was investigated in Jordan and Lebanon retrospectively covering the period from 2000 to 2011. Ninety-four S. aureus isolates, 63 (67%) collected from Lebanon and 31 (33%) collected from Jordan were included in this study. More than half of the isolates (56%) were associated with skin and soft tissue infections (SSTIs), and 73 (78%) were Panton-Valentine Leukocidin (PVL) positive. Majority of the isolates (84%) carried the gene for exofoliative toxin d (etd), 19% had the Toxic Shock Syndrome Toxin-1 gene (tst), and seven isolates from Jordan had a rare combination being positive for both tst and PVL genes. spa typing showed the prevalence of type t044 (85%) and pulsed-field gel electrophoresis (PFGE) recognized 21 different patterns. Antimicrobial susceptibility testing showed the prevalence (36%) of a unique resistant profile, which included resistance to streptomycin, kanamycin, and fusidic acid (SKF profile). The genetic diversity among the CC80 isolates observed in this study poses an additional challenge to infection control of CA-MRSA epidemics. CA-MRSA related to ST80 in the Middle East was distinguished in this study from the ones described in other countries. Genetic diversity observed, which may be due to mutations and differences in the antibiotic regimens between countries may have led to the development of heterogeneous strains. Hence, it is difficult to maintain "the European CA-MRSA clone" as a uniform clone and it is better to designate as CC80-MRSA-IV isolates.

  13. Molecular typing of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) isolated from animals and retail meat in North Dakota, United States.

    PubMed

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

    2013-07-01

    The objective of this study was to determine the prevalence and molecular typing of methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) in food-producing animals and retail meat in Fargo, North Dakota. A two-step enrichment followed by culture methods were used to isolate S. aureus from 167 nasal swabs from animals, 145 samples of retail raw meat, and 46 samples of deli meat. Positive isolates were subjected to multiplex polymerase chain reaction in order to identify the genes 16S rRNA, mecA, and Panton-Valentine Leukocidin. Pulsed-field gel electrophoresis and multilocus sequence typing were used for molecular typing of S. aureus strains. Antimicrobial susceptibility testing was carried out using the broth microdilution method. The overall prevalence of S. aureus was 37.2% (n=133), with 34.7% (n=58) of the animals positive for the organism, and the highest prevalence observed in pigs (50.0%) and sheep (40.6%) (p<0.05); 47.6% (n=69) of raw meat samples were positive, with the highest prevalence in chicken (67.6%) and pork (49.3%) (p<0.05); and 13.0% (n=6) of deli meat was positive. Five pork samples (7.0%) were positive for MRSA, of which three were ST398 and two were ST5. All exhibited penicillin resistance and four were multidrug resistant (MDR). The Panton-Valentine Leukocidin gene was not detected in any sample by multiplex polymerase chain reaction. The most common clones in sheep were ST398 and ST133, in pigs and pork both ST398 and ST9, and in chicken ST5. Most susceptible S. aureus strains were ST5 isolated from chicken. The MDR isolates were found in pigs, pork, and sheep. The presence of MRSA, MDR, and the subtype ST398 in the meat production chain and the genetic similarity between strains of porcine origin (meat and animals) suggest the possible contamination of meat during slaughtering and its potential transmission to humans.

  14. Livestock-Associated Methicillin Resistant Staphylococcus aureus (LA-MRSA) Clonal Complex (CC) 398 Isolated from UK Animals belong to European Lineages

    PubMed Central

    Sharma, Meenaxi; Nunez-Garcia, Javier; Kearns, Angela M.; Doumith, Michel; Butaye, Patrick R.; Argudín, M. Angeles; Lahuerta-Marin, Angela; Pichon, Bruno; AbuOun, Manal; Rogers, Jon; Ellis, Richard J.; Teale, Christopher; Anjum, Muna F.

    2016-01-01

    In recent years, there has been an increase in the number of livestock-associated methicillin resistant Staphylococcus aureus (LA-MRSA) clonal complex (CC) 398 recovered from S. aureus isolated animals in the UK. To determine possible origins of 12 LA-MRSA CC398 isolates collected after screening more than a thousand S. aureus animal isolates from the UK between 2013 and 2015, whole genome sequences (WGS) of CC398 European, including UK, and non-European isolates from diverse animal hosts were compared. Phylogenetic reconstruction applied to WGS data to assess genetic relatedness of all 89 isolates, clustered the 12 UK CC398 LA-MRSA within the European sub-lineages, although on different nodes; implicating multiple independent incursions into the UK, as opposed to a single introduction followed by clonal expansion. Three UK isolates from healthy pigs and one from turkey clustered within the cassette chromosome recombinases ccr C S. aureus protein A (spa)-type t011 European sub-lineage and three UK isolates from horses within the ccrA2B2 t011 European sub-lineage. The remaining UK isolates, mostly from pigs, clustered within the t034 European lineage. Presence of virulence, antimicrobial (AMR), heavy metal (HMR), and disinfectant (DR) resistance genes were determined using an in-house pipeline. Most, including UK isolates, harbored resistance genes to ≥3 antimicrobial classes in addition to β-lactams. HMR genes were detected in most European ccrC positive isolates, with >80% harboring czrC, encoding zinc and cadmium resistance; in contrast ~60% ccrC isolates within non-European lineages and 6% ccrA2B2 isolates showed this characteristic. The UK turkey MRSA isolate did not harbor φAVβ avian prophage genes (SAAV_2008 and SAAV_2009) present in US MSSA isolates from turkey and pigs. Absence of some of the major human-associated MRSA toxigenic and virulence genes in the UK LA-MRSA animal isolates was not unexpected. Therefore, we can conclude that the 12 UK LA-MRSA

  15. Livestock-Associated Methicillin Resistant Staphylococcus aureus (LA-MRSA) Clonal Complex (CC) 398 Isolated from UK Animals belong to European Lineages.

    PubMed

    Sharma, Meenaxi; Nunez-Garcia, Javier; Kearns, Angela M; Doumith, Michel; Butaye, Patrick R; Argudín, M Angeles; Lahuerta-Marin, Angela; Pichon, Bruno; AbuOun, Manal; Rogers, Jon; Ellis, Richard J; Teale, Christopher; Anjum, Muna F

    2016-01-01

    In recent years, there has been an increase in the number of livestock-associated methicillin resistant Staphylococcus aureus (LA-MRSA) clonal complex (CC) 398 recovered from S. aureus isolated animals in the UK. To determine possible origins of 12 LA-MRSA CC398 isolates collected after screening more than a thousand S. aureus animal isolates from the UK between 2013 and 2015, whole genome sequences (WGS) of CC398 European, including UK, and non-European isolates from diverse animal hosts were compared. Phylogenetic reconstruction applied to WGS data to assess genetic relatedness of all 89 isolates, clustered the 12 UK CC398 LA-MRSA within the European sub-lineages, although on different nodes; implicating multiple independent incursions into the UK, as opposed to a single introduction followed by clonal expansion. Three UK isolates from healthy pigs and one from turkey clustered within the cassette chromosome recombinases ccr C S. aureus protein A (spa)-type t011 European sub-lineage and three UK isolates from horses within the ccrA2B2 t011 European sub-lineage. The remaining UK isolates, mostly from pigs, clustered within the t034 European lineage. Presence of virulence, antimicrobial (AMR), heavy metal (HMR), and disinfectant (DR) resistance genes were determined using an in-house pipeline. Most, including UK isolates, harbored resistance genes to ≥3 antimicrobial classes in addition to β-lactams. HMR genes were detected in most European ccrC positive isolates, with >80% harboring czrC, encoding zinc and cadmium resistance; in contrast ~60% ccrC isolates within non-European lineages and 6% ccrA2B2 isolates showed this characteristic. The UK turkey MRSA isolate did not harbor φAVβ avian prophage genes (SAAV_2008 and SAAV_2009) present in US MSSA isolates from turkey and pigs. Absence of some of the major human-associated MRSA toxigenic and virulence genes in the UK LA-MRSA animal isolates was not unexpected. Therefore, we can conclude that the 12 UK LA-MRSA

  16. Methicillin-resistant Staphylococcus aureus (MRSA) is associated with low within-herd prevalence of intra-mammary infections in dairy cows: Genotyping of isolates.

    PubMed

    Luini, M; Cremonesi, P; Magro, G; Bianchini, V; Minozzi, G; Castiglioni, B; Piccinini, R

    2015-08-05

    Staphylococcus aureus is one of the most common mastitis-causing pathogens worldwide. In the last decade, livestock-associated methicillin-resistant S. aureus (LA-MRSA) infections have been described in several species, included the bovines. Hence, this paper investigates the diffusion of MRSA within Italian dairy herds; the strains were further characterized using a DNA microarray, which detects 330 different sequences, including the methicillin-resistance genes mecA and mecC and SCCmec typing. The analysis of overall patterns allows the assignment to Clonal Complexes (CC). Overall 163 S. aureus isolates, collected from quarter milk samples in 61 herds, were tested. MRSA strains were further processed using spa typing. Fifteen strains (9.2%), isolated in 9 herds (14.75%), carried mecA, but none harboured mecC. MRSA detection was significantly associated (P<0.011) with a within-herd prevalence of S. aureus intra-mammary infections (IMI) ≤5%. Ten MRSA strains were assigned to CC398, the remaining ones to CC97 (n=2), CC1 (n=2) or CC8 (n=1). In 3 herds, MRSA and MSSA co-existed: CC97-MRSA with CC398-MSSA, CC1-MRSA with CC8-MSSA and CC398-MRSA with CC126-MSSA. The results of spa typing showed an overall similar profile of the strains belonging to the same CC: t127-CC1, t1730-CC97, t899 in 8 out of 10 CC398. In the remaining 2 isolates a new spa type, t14644, was identified. The single CC8 was a t3092. The SCCmec cassettes were classified as type IV, type V or type IV/V composite. All or most strains harboured the genes encoding the β-lactamase operon and the tetracycline resistance. Streptogramin resistance gene was related to CC398. Enterotoxin and leukocidin genes were carried only by CC1, CC8 and CC97-MRSA. The persistence of MRSA clones characterized by broader host range, in epidemiologically unrelated areas and in dairy herds with low prevalence of S. aureus IMI, might enhance the risk for adaptation to human species.

  17. Diversity of Methicillin-Resistant Staphylococcus aureus (MRSA) Strains Isolated from Inpatients of 30 Hospitals in Orange County, California

    PubMed Central

    Hudson, Lyndsey O.; Murphy, Courtney R.; Spratt, Brian G.; Enright, Mark C.; Elkins, Kristen; Nguyen, Christopher; Terpstra, Leah; Gombosev, Adrijana; Kim, Diane; Hannah, Paul; Mikhail, Lydia; Alexander, Richard; Moore, Douglas F.; Huang, Susan S.

    2013-01-01

    There is a need for a regional assessment of the frequency and diversity of MRSA to determine major circulating clones and the extent to which community and healthcare MRSA reservoirs have mixed. We conducted a prospective cohort study of inpatients in Orange County, California, systematically collecting clinical MRSA isolates from 30 hospitals, to assess MRSA diversity and distribution. All isolates were characterized by spa typing, with selective PFGE and MLST to relate spa types with major MRSA clones. We collected 2,246 MRSA isolates from hospital inpatients. This translated to 91/10,000 inpatients with MRSA and an Orange County population estimate of MRSA inpatient clinical cultures of 86/100,000 people. spa type genetic diversity was heterogeneous between hospitals, and relatively high overall (72%). USA300 (t008/ST8), USA100 (t002/ST5) and a previously reported USA100 variant (t242/ST5) were the dominant clones across all Orange County hospitals, representing 83% of isolates. Fifteen hospitals isolated more t008 (USA300) isolates than t002/242 (USA100) isolates, and 12 hospitals isolated more t242 isolates than t002 isolates. The majority of isolates were imported into hospitals. Community-based infection control strategies may still be helpful in stemming the influx of traditionally community-associated strains, particularly USA300, into the healthcare setting. PMID:23637976

  18. Clonal diversity and epidemiological characteristics of Staphylococcus aureus: high prevalence of oxacillin-susceptible mecA-positive Staphylococcus aureus (OS-MRSA) associated with clinical isolates in Brazil.

    PubMed

    Andrade-Figueiredo, Mariana; Leal-Balbino, Tereza Cristina

    2016-06-21

    Staphylococcus aureus is the major cause of global and nosocomial infections with a significant impact in hospitals worldwide. Our objective was to investigate clinical and molecular characteristics of S. aureus isolates causing infections in patients admitted to hospitals from Recife city, Brazil, and investigate the prevalence of oxacillin-susceptible mecA-positive S. aureus (OS-MRSA) in the region, as well as genetically characterize the isolates and compare with epidemic clones. We characterized 89 isolates in total, 31 clinical methicillin-resistant S. aureus (MRSA) and 58 methicillin-sensitive (MSSA) isolates by PFGE, MLST, spa typing and SCCmec genotyping. Isolates belonging to international MRSA clones were present: Brazilian epidemic clone (BEC) (61 % of MRSA isolates), Paediatric (36 %), New York/Japan (3 %). Some MSSA isolates were related to MRSA clones: USA400-related (10 % of MSSA isolates), Berlin clone (2 %), Paediatric (14 %), New York/Japan (2 %) and Southwest Pacific clone (17 %). MLST revealed new sequence types (ST's): ST2381, ST2382, and ST2383 and new spa types: 10548 and 10550. Among isolates phenotypically identified as MSSA by antimicrobial susceptibility assays, we verified 30 oxacillin-susceptible isolates, which exhibited the mecA gene, without mec complex amplification and were thus classified as OS-MRSA. We observed clonal spread of MRSA and MSSA, including OS-MRSA, within several areas of the main hospital investigated and closely related isolates between hospitals analyzed. The results of this study suggest a possible spread of the strains in hospital environment that could be responsible for nosocomial infections. We documented the presence of several MRSA clones, as well as new MLST and spa types, that were responsible for severe infections in hospitalized patients. The finding of OS-MRSA isolates could have implications for therapy, because testing for mecA and PBP2a is not a routine procedure performed by clinical

  19. High frequency of occupied attB regions in Norwegian Staphylococcus aureus isolates supports a two-step MRSA screening algorithm.

    PubMed

    Tunsjø, H S; Kalyanasundaram, S; Worren, M M; Leegaard, T M; Moen, A E F

    2017-01-01

    Rapid nucleic acid amplification tests for methicillin-resistant Staphylococcus aureus (MRSA) diagnostics commonly target the mec resistance gene, genes specific for S. aureus, and the integration site for the SCCmec resistance cassette, orfX. Due to poor specificity when these target genes are used individually, additional culture is required to verify positive results. The combination of these targets is useful, but the optimal algorithm may depend on the presence of the genetic markers in S. aureus isolates, as well as the prevalence of MRSA in a population. The aim of the present study was to identify a rapid, low-cost, and functional screening algorithm in order to reduce the response time for MRSA diagnostics. An in-house orfX-SCCmec polymerase chain reaction (PCR) assay was established and evaluated. The results were compared with an existing mec/nuc PCR assay and traditional culture. Methicillin-sensitive S. aureus (MSSA) that tested false-positive in the orfX-SCCmec PCR assay were further investigated with full genome sequencing using the Ion PGM™ System to verify results and causality. Based on these data, a two-step screening algorithm with initial mec/nuc PCR followed by orfX-SCCmec PCR on positive samples was suggested and tested on 1443 patient samples. 22.5 % of MSSA isolates tested false-positive with the orfX-SCCmec PCR. Full genome sequencing of these isolates identified genetic variation in the attB region of S. aureus, including empty cassette variants and non-mec SCC. The suggested two-step MRSA screening algorithm allowed us to report MRSA results for 95.6 % of all samples and 99 % of MRSA-negative samples after one day.

  20. A 5-year survey of antimicrobial susceptibility profiles of methicillin-resistant Staphylococcus aureus (MRSA) isolated from patients with bloodstream infections in Northeast Italy.

    PubMed

    Cojutti, Piergiorgio; Scarparo, Claudio; Sartor, Assunta; Coato, Paola; Rigoli, Roberto; Pea, Federico

    2015-01-01

    A 5-year survey (2009-2013) of antimicrobial susceptibility of methicillin-resistant Staphylococcus aureus (MRSA) isolated from patients with bloodstream infections was carried out in Northeast Italy. No upward creep of glycopeptides MICs was documented among 582 nonduplicate MRSA blood isolates, which were tested in accordance with broth microdilution and interpreted in accordance with EUCAST recommendations. Teicoplanin showed stably a lower MIC50 in comparison with vancomycin (0.25-0.5 versus 1 mg/L). The activities of newer anti-MRSA antibacterials stratified by glycopeptides MICs showed similar trends in MICs of either vancomycin or teicoplanin with those of daptomycin, linezolid, and tigecycline. We hypothesize that in centers with different distribution of glycopeptides MICs, downward for teicoplanin and upward for vancomycin, teicoplanin could be a more effective alternative to vancomycin for empirical treatment of MRSA-related bacteremia.

  1. Phenotypic and genotypic characterization of methicillin-resistant Staphylococcus aureus (MRSA) isolated from dogs and cats at University Veterinary Hospital, Universiti Putra Malaysia.

    PubMed

    Aklilu, E; Zunita, Z; Hassan, L; Chen, H C

    2010-12-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is known to cause nosocomial infections and is now becoming an emerging problem in veterinary medicine. The objective of the study was to determine the presence of MRSA in 100 cats and dogs sampled between November 2007 and April 2008 at the University Veterinary Hospital, Universiti Putra Malaysia. MRSA was detected in 8% of pets sampled. Ten percent (5/50) and 6% (3/50) of the isolates were from dogs and cats, respectively. All MRSA isolates possessed the mecA gene and were found to be resistant to at least three antimicrobials with a minimum of Oxacillin MIC of 8 μg/mL. One isolate (CT04) had an extremely high MIC of >256 μg/mL. The MLST type ST59 found in this study have been reported earlier from Singapore and other countries as a strain from animal and community-associated MRSA respectively. Pulsed-field gel electrophoresis revealed five pulsotypes. Two isolates from cats (CT27 and CT33) and three isolates from dogs (DG16, DG20, and DG49) were respectively assigned to pulsotypes B and D. The study suggests that cats and dogs in Malaysia are potential reservoirs for MRSA.

  2. Zinc resistance within swine associated methicillin resistant Staphylococcus aureus (MRSA) isolates in the USA is associated with MLST lineage

    USDA-ARS?s Scientific Manuscript database

    Zinc resistance in livestock-associated methicillin resistant Staphylococcus aureus (LA-MRSA) is mediated by the czrC gene co-located with the mecA gene, encoding methicillin resistance, on the type V SCCmec element. Since the czrC gene and the mecA gene are co-located on the SCCmec element, it has ...

  3. Community-Associated Methicillin-Resistant Staphylococcus aureus Clonal Complex 80 Type IV (CC80-MRSA-IV) Isolated from the Middle East: A Heterogeneous Expanding Clonal Lineage

    PubMed Central

    Harastani, Houda H.; Tokajian, Sima T.

    2014-01-01

    Background The emergence of community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) has caused a change in MRSA epidemiology worldwide. In the Middle East, the persistent spread of CA-MRSA isolates that were associated with multilocus sequence type (MLST) clonal complex 80 and with staphylococcal cassette chromosome mec (SCCmec) type IV (CC80-MRSA-IV), calls for novel approaches for infection control that would limit its spread. Methodology/Principal Findings In this study, the epidemiology of CC80-MRSA-IV was investigated in Jordan and Lebanon retrospectively covering the period from 2000 to 2011. Ninety-four S. aureus isolates, 63 (67%) collected from Lebanon and 31 (33%) collected from Jordan were included in this study. More than half of the isolates (56%) were associated with skin and soft tissue infections (SSTIs), and 73 (78%) were Panton-Valentine Leukocidin (PVL) positive. Majority of the isolates (84%) carried the gene for exofoliative toxin d (etd), 19% had the Toxic Shock Syndrome Toxin-1 gene (tst), and seven isolates from Jordan had a rare combination being positive for both tst and PVL genes. spa typing showed the prevalence of type t044 (85%) and pulsed-field gel electrophoresis (PFGE) recognized 21 different patterns. Antimicrobial susceptibility testing showed the prevalence (36%) of a unique resistant profile, which included resistance to streptomycin, kanamycin, and fusidic acid (SKF profile). Conclusions The genetic diversity among the CC80 isolates observed in this study poses an additional challenge to infection control of CA-MRSA epidemics. CA-MRSA related to ST80 in the Middle East was distinguished in this study from the ones described in other countries. Genetic diversity observed, which may be due to mutations and differences in the antibiotic regimens between countries may have led to the development of heterogeneous strains. Hence, it is difficult to maintain “the European CA-MRSA clone” as a uniform clone and it

  4. Mycelium of fungi isolated from mouldy foods inhibits Staphylococcus aureus including MRSA – A rationale for the re-introduction of mycotherapy?

    PubMed Central

    Alnaimat, Sulaiman; Alharbi, Naiyf S.; Alharbi, Sulaiman Ali; Salmen, Saleh H.; Chinnathambi, Arunachalam; Al-Johny, Bassam O.; Wainwright, M.

    2015-01-01

    Fungal mycelium capable of producing antibacterial agents was isolated from samples of apple, beetroot, lemon and orange; the mycelium of all isolates produced penicillin, while the apple and beetroot samples also produced the antibacterial mycotoxin patulin. The known penicillin-producing fungi were shown to produce penicillin, but not patulin. The mycelial discs of all of fruit and vegetable isolates, as well as the two known penicillin producing fungi, inhibited Staphylococcus aureus, and mycelium of all isolates inhibited MRSA, in contrast, only one of the two known penicillin-producers did so. The results are discussed in relation to the possibility of using the mycelium of Penicillium species in mycotherapy. PMID:26288565

  5. Performance of CHROMagar MRSA Medium for Detection of Methicillin-Resistant Staphylococcus aureus

    PubMed Central

    Diederen, Bram; van Duijn, Inge; van Belkum, Alex; Willemse, Piet; van Keulen, Peter; Kluytmans, Jan

    2005-01-01

    CHROMagar MRSA was evaluated for its ability to identify methicillin-resistant Staphylococcus aureus (MRSA). A well-defined collection consisting of 216 MRSA strains and 241 methicillin-susceptible Staphylococcus aureus isolates was used. The sensitivity of CHROMagar MRSA after 24 h of incubation was 95.4%, increasing to 100% after 48 h. The specificity was already 100% after 24 h. PMID:15815020

  6. Antimicrobial activity of ceftaroline against methicillin-resistant Staphylococcus aureus (MRSA) isolates collected in 2013-2014 at the Geneva University Hospitals.

    PubMed

    Andrey, D O; François, P; Manzano, C; Bonetti, E J; Harbarth, S; Schrenzel, J; Kelley, W L; Renzoni, A

    2017-02-01

    Ceftaroline is a broad-spectrum antibiotic with activity against methicillin-resistant Staphylococcus aureus (MRSA) strains. Ceftaroline susceptibility of an MRSA set archived between 1994 and 2003 in the Geneva University Hospitals detected a high percentage (66 %) of ceftaroline resistance in clonotypes ST228 and ST247 and correlated with mutations in PBP2a. The ceftaroline mechanism of action is based on the inhibition of PBP2a; thus, the identification of PBP2a mutations of recently circulating clonotypes in our institution was investigated. We analyzed ceftaroline susceptibility in MRSA isolates (2013 and 2014) and established that resistant strains correlated with PBP2a mutations and specific clonotypes. Ninety-six MRSA strains were analyzed from independent patients and were isolated from blood cultures (23 %), deep infections (38.5 %), and superficial (skin or wound) infections (38.5 %). This sample showed a ceftaroline minimum inhibitory concentration (MIC) range between 0.25 and 2 μg/ml and disk diameters ranging from 10 to 30 mm, with a majority of strains showing diameters ≥20 mm. Based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints, 76 % (73/96) of isolates showed susceptibility to ceftaroline. Nevertheless, we still observed 24 % (23/96) of resistant isolates (MIC = 2 μg/ml). All resistant isolates were assigned to clonotype ST228 and carried the N146K mutation in PBP2a. Only two ST228 isolates showed ceftaroline susceptibility. The decreasing percentage of ceftaroline-resistant isolates in our hospital can be explained by the decline of ST228 clonotype circulating in our hospital since 2008. We present evidence that ceftaroline is active against recent MRSA strains from our hospital; however, the presence of PBP2a variants in particular clonotypes may affect ceftaroline efficacy.

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

    PubMed Central

    Vitko, Nicholas P.; Richardson, Anthony R.

    2014-01-01

    Staphylococcus aureus is an important bacterial pathogen in the hospital and community settings, especially Staphylococcus aureus clones that exhibit methicillin-resistance (MRSA). Many strains of S. aureus are utilized in the laboratory, underscoring the genetic differences inherent in clinical isolates. S. aureus grows quickly at 37°C with aeration in rich media (e.g. BHI) and exhibits a preference for glycolytic carbon sources. Furthermore, S. aureus has a gold pigmentation, exhibits β-hemolysis, and is catalase and coagulase positive. The four basic laboratory protocols presented in this unit describe how to culture S. aureus on liquid and solid media, how to identify S. aureus strains as methicillin resistant, and how to generate a freezer stock of S. aureus for long-term storage. PMID:23408135

  8. Laboratory maintenance of methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Vitko, Nicholas P; Richardson, Anthony R

    2013-02-01

    Staphylococcus aureus is an important bacterial pathogen in the hospital and community settings, especially Staphylococcus aureus clones that exhibit methicillin-resistance (MRSA). Many strains of S. aureus are utilized in the laboratory, underscoring the genetic differences inherent in clinical isolates. S. aureus grows quickly at 37°C with aeration in rich media (e.g., BHI) and exhibits a preference for glycolytic carbon sources. Furthermore, S. aureus has a gold pigmentation, exhibits β-hemolysis, and is catalase and coagulase positive. The four basic laboratory protocols presented in this unit describe how to culture S. aureus on liquid and solid media, how to identify S. aureus strains as methicillin resistant, and how to generate a freezer stock of S. aureus for long-term storage. © 2013 by John Wiley & Sons, Inc.

  9. Characteristics of Community-Associated Methicillin-Resistant Staphylococcus aureus (CA-MRSA) Strains Isolated from Skin and Soft-Tissue Infections in Uruguay

    PubMed Central

    Pardo, Lorena; Machado, Virginia; Mollerach, Marta; Mota, María Inés; Tuchscherr, Lorena P. N.; Gadea, Pilar; Gardella, Noella; Sordelli, Daniel O.; Vola, Magdalena; Schelotto, Felipe; Varela, Gustavo

    2009-01-01

    We analyzed 90 nonduplicates community-associated methicillin-resistant S. aureus (CA-MRSA) strains isolated from skin and soft-tissue infections. All strains were mecA positive. Twenty-four of the 90 strains showed inducible macrolide-lincosamide-streptogramin B resistance. All strains produced α-toxin; 96% and 100% of them displayed positive results for lukS-F and cna genes, respectively. Eigthy-five strains expressed capsular polysaccharide serotype 8. Six different pulsotypes were discriminated by pulsed-field gel electrophoresis (PFGE) and three predominant groups of CA-MRSA strains (1, 2, and 4) were identified, in agreement with phenotypic and genotypic characteristics. Strains of group 1 (pulsotype A, CP8+, and Panton-Valentine leukocidin (PVL)+) were the most frequently recovered and exhibited a PFGE band pattern identical to other CA-MRSA strains previously isolated in Uruguay and Brazil. Three years after the first local CA-MRSA report, these strains are still producing skin and soft-tissue infections demonstrating the stability over time of this community-associated emerging pathogen. PMID:20016669

  10. Potent in vitro synergism of fusidic acid (FA) and berberine chloride (BBR) against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Liang, Rong-mei; Yong, Xiao-lan; Duan, Yu-qin; Tan, Yong-hong; Zeng, Ping; Zhou, Zi-ying; Jiang, Yan; Wang, Shi-hua; Jiang, Yun-ping; Huang, Xiao-chun; Dong, Zhao-hui; Hu, Ting-ting; Shi, Hui-qing; Li, Nan

    2014-11-01

    It was found in the present study that combined use of fusidic acid (FA) and berberine chloride (BBR) offered an in vitro synergistic action against 7 of the 30 clinical methicillin-resistant Staphylococcus aureus (MRSA) strains, with a fractional inhibitory concentration (FIC) index ranging from 0.5 to 0.19. This synergistic effect was most pronounced on MRSA 4806, an FA-resistant isolate, with a minimum inhibitory concentration (MIC) value of 1,024 μg/ml. The time-kill curve experiment showed that FA plus BBR yielded a 4.2 log10 c.f.u./ml reduction in the number of MRSA 4806 bacteria after 24-h incubation as compared with BBR alone. Viable count analysis showed that FA plus BBR produced a 3.0 log10 c.f.u./ml decrease in biofilm formation and a 1.5 log10 c.f.u./ml decrease in mature biofilm in viable cell density as compared with BBR alone. In addition, phase contrast micrographs confirmed that biofilm formation was significantly inhibited and mature biofilm was obviously destructed when FA was used in combination with BBR. These results provide evidence that combined use of FA and BBR may prove to be a promising clinical therapeutic strategy against MRSA.

  11. In vitro synergism of magnolol and honokiol in combination with antibacterial agents against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Zuo, Guo-Ying; Zhang, Xin-Juan; Han, Jun; Li, Yu-Qing; Wang, Gen-Chun

    2015-12-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a problematic pathogen posing a serious therapeutic challenge in the clinic. It is often multidrug-resistant (MDR) to conventional classes of antibacterial agents and there is an urgent need to develop new agents or strategies for treatment. Magnolol (ML) and honokiol (HL) are two naturally occurring diallylbiphenols which have been reported to show inhibition of MRSA. In this study their synergistic effects with antibacterial agents were further evaluated via checkerboard and time-kill assays. The susceptibility spectrum of clinical MRSA strains was tested by the disk diffusion method. The minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) of ML and HL were assayed by broth microdilution. The synergy was evaluated through checkerboard microdilution and time-killing experiments. ML and HL showed similar activity against both MSSA and MRSA with MIC/MBC at 16 ~ 64 mg/L, with potency similar to amikacin (AMK) and gentamicin (GEN). When they were used in combination with conventional antibacterial agents, they showed bacteriostatic synergy with FICIs between 0.25 ~ 0.5, leading to the combined MICs decreasing to as low as 1 ~ 2 and 1 ~ 16 mg/L for ML (HL) and the agents, respectively. MIC50 of the combinations decreased from 16 mg/L to 1 ~ 4 mg/L for ML (HL) and 8 ~ 128 mg/L to 2 ~ 64 mg/L for the antibacterial agents, which exhibited a broad spectrum of synergistic action with aminoglycosides (AMK, etilmicin (ETM) and GEN), floroquinolones (levofloxacin (LEV), ciprofloxacin and norfloxacin), fosfomycin (FOS) and piperacillin. The times of dilution (TOD, the extent of decreasing in MIC value) were determined up to 16 for the combined MIC. A more significant synergy after combining was determined as ML (HL) with AMK, ETM, GEN and FOS. ML (HL) combined with antibacterial agents did not show antagonistic effects on any of the ten MRSA strains. Reversal effects of MRSA resistance to

  12. Lack of upward creep of glycopeptide MICs for methicillin-resistant Staphylococcus aureus (MRSA) isolated in the UK and Ireland 2001-07.

    PubMed

    Reynolds, R; Hope, R; Warner, M; MacGowan, A P; Livermore, D M; Ellington, M J

    2012-12-01

    There have been several reports of upward creep in vancomycin MICs for Staphylococcus aureus [predominantly methicillin-resistant S. aureus (MRSA)] over recent years, but only in single centres or using contemporaneous results. We aimed to test the hypothesis of MIC creep in a multicentre study, testing all the isolates concurrently. Nineteen laboratories in the UK and Ireland contributed isolates from blood to the BSAC Bacteraemia Resistance Surveillance Programme every year between 2001 and 2007. MICs for 271 MRSA from these sites were re-measured at a single central laboratory during a single week by the BSAC agar dilution method, but with √2-fold instead of conventional 2-fold dilutions. Re-test results were compared with the original results obtained each year at the same central laboratory. The re-test results were much less variable than the original results and avoided the confounding of experimental variation with year of collection. They demonstrated statistically significant but very slow downward trends in MICs of vancomycin and teicoplanin, at 0.027 and 0.055 doubling dilutions/year, respectively. The original results had suggested more rapid trends in MICs, upward for vancomycin and downward for teicoplanin. The proportion of EMRSA-16 fell from 21% to 9% over the study period, while EMRSA-15 rose from 76% to 85%. Historical data can give a misleading impression of trends in MIC values because of experimental variation between tests conducted at different times. There was no upward creep in glycopeptide MICs for MRSA in the UK and Ireland between 2001 and 2007.

  13. Rapid Identification of Methicillin-Resistant Staphylococcus aureus (MRSA) by the Vitek MS Saramis system.

    PubMed

    Shan, Weiguang; Li, Jiaping; Fang, Ying; Wang, Xuan; Gu, Danxia; Zhang, Rong

    2016-01-01

    A rapid, sensitive, and accurate Vitek MS assay was developed to distinguish clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) from clinical isolates of methicillin-sensitive Staphylococcus aureus (MSSA) by developing an in-house knowledgebase of SuperSpectra. Three unique peaks, including peaks at 2305.6 and 3007.3 Da specific to MRSA, and 6816.7 Da specific to MSSA, were selected for differentiating MRSA and MSSA. This assay accurately identified 84 and 91% of clinical MRSA and MSSA strains out of the total 142 clinically acquired S. aureus strains that were tested. This method will greatly improve the efficiency of single clinical sample identification of MRSA, thereby facilitating a reduction in the transmission of MRSA in clinical settings.

  14. Molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from patients with bacteremia based on MLST, SCCmec, spa, and agr locus types analysis.

    PubMed

    Goudarzi, Mehdi; Seyedjavadi, Sima Sadat; Nasiri, Mohammad Javad; Goudarzi, Hossein; Sajadi Nia, Raheleh; Dabiri, Hossein

    2017-03-01

    The widespread emergence of methicillin resistant Staphylococcus aureus, as a common cause of nosocomial infections, is becoming a serious concern in global public health. The objective of the present study was to investigate antimicrobial susceptibility pattern, frequency of virulence genes and molecular characteristics of methicillin-resistant Staphylococcus aureus strains isolated from patients with bacteremia. A total of 128 methicillin-resistant Staphylococcus aureus isolates were collected during February 2015 to January 2016. In vitro antimicrobial susceptibility of the isolates was assessed using the disk diffusion method. Conventional PCR was performed for the detection of adhesion (can, bbp, ebp, fnbB, fnbA, clfB, clfA) and toxin (etb, eta, pvl, tst) encoding genes, determining the agr type, SCCmec, MLST and spa typing of the isolates. All the methicillin-resistant Staphylococcus aureus isolates were found to be sensitive to linezolid, teicoplanin, and vancomycin. Resistance to the tested antibiotics varied from 97.7% for penicillin to 24.2% for mupirocin. The rate of multi drug resistance (MDR) in the present study was 97.7%. The most commonly detected toxin and adhesion genes were tst (58.6%), and clfB (100%), respectively. The majority of SCCmec III isolates were found in agr group I while SCCmec IV and II isolates were distributed among agr group III. Multilocus Sequence Typing (MLST) of the MRSA isolates showed five different sequence types: ST239 (43%), ST22 (39.8%), ST585 (10.9%), ST45 (3.9%) and ST240 (2.3%). All of the pvl positive strains belonged to ST22-SCCmec IV/t790 clone and were MDR. Among different 7 spa types, the most common were t790 (27.3%), t037 (21.9%), and t030 (14.1%). spa types t016, t924 and spa type t383 were reported for the first time from Asia and Iran, respectively. It was shown that spa types circulating in the studied hospitals varied which support the need to perform future surveillance studies in order to understand

  15. Use of BBL CHROMagar MRSA Medium for Identification of Methicillin-Resistant Staphylococcus aureus Directly from Blood Cultures

    PubMed Central

    Pape, John; Wadlin, Jill; Nachamkin, Irving

    2006-01-01

    We evaluated the ability of BBL CHROMagar MRSA medium (Becton Dickinson, Sparks, MD) to identify methicillin-resistant Staphylococcus aureus (MRSA) directly upon subculture from positive blood culture bottles. There were 124 MRSA isolates recovered from blood cultures in the study. BBL CHROMagar MRSA medium was highly sensitive (97.6% [121/124] at 18 to 24 h of incubation and 100% [124/124] at 48 h) and 99.9% specific for identifying MRSA from positive blood cultures. PMID:16825383

  16. Methicillin-resistant Staphylococcus aureus (mrsa) in a Malaysian hospital.

    PubMed

    Cheong, I; Tan, S C; Wong, Y H; Zainudin, B M; Rahman, M Z

    1994-03-01

    Between August 1990 to November 1991, 905 of 2583 (35.4%) isolates of Staphylococcus aureus were found to be methicillin-resistant in a general hospital in Malaysia. A detailed study of 539 of these isolates showed a high prevalence of methicillin resistant Staphylococcus aureus (MRSA) in the surgical/orthopaedic wards, paediatric wards and the special care unit. The yield of MRSA was highest from wounds/ulcers/skin swabs accounting for 64.2 per cent followed by 6.9 per cent in blood cultures. Vancomycin remains the drug of choice with no resistance detected. The resistance to ciprofloxacin was 6.7 per cent, rifampicin 4.5 per cent and fusidic acid 2.0 per cent. Most isolates were resistant to aminoglycosides. In view of the high prevalence of MRSA in this hospital, the authorities must introduce more effective measures to control its spread as a nosocomial pathogen. Otherwise it may seriously disrupt the efficient delivery of health care services in the country.

  17. Short communication: Outbreak of methicillin-resistant Staphylococcus aureus (MRSA)-associated mastitis in a closed dairy herd.

    PubMed

    Guimarães, F F; Manzi, M P; Joaquim, S F; Richini-Pereira, V B; Langoni, H

    2017-01-01

    Cows are probably the main source of contamination of raw milk with Staphylococcus aureus. Mammary glands with subclinical mastitis can shed large numbers of Staph. aureus in milk. Because of the risk of this pathogen to human health as well as animal health, the aim of this paper was to describe an outbreak of mastitis caused by methicillin-resistant Staph. aureus (MRSA), oxacillin-susceptible mecA-positive Staph. aureus (OS-MRSA), and methicillin-susceptible Staph. aureus (MSSA) on a dairy farm. Milk samples were obtained from all quarters, showing an elevated somatic cell count by the California Mastitis Test. The isolates were identified by phenotypic and genotypic methods. Staphylococcus spp. were isolated from 53% (61/115) of the milk samples, with 60 isolates identified as Staph. aureus (98.4%) and 1 isolate identified as Staphylococcus epidermidis (1.6%). The presence of the mecA gene was verified in 48.3% of Staph. aureus isolates. Of the Staph. aureus isolates, 23.3% were MRSA and 25.0% were OS-MRSA. The total of mastitis cases infected with MRSA was 12.2%. The detection of this large percentage of mastitis cases caused by MRSA and OS-MRSA is of great concern for the animals' health, because β-lactams are still the most important antimicrobials used to treat mastitis. In addition, Staph. aureus isolates causing bovine mastitis represent a public health risk.

  18. Clinical characteristics and epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in children with cystic fibrosis from a center with a high MRSA prevalence.

    PubMed

    Harik, Nada S; Com, Gulnur; Tang, Xinyu; Melguizo Castro, Maria; Stemper, Mary E; Carroll, John L

    2016-04-01

    We describe the clinical characteristics and epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in children with cystic fibrosis (CF) from the U.S. CF center with the highest MRSA prevalence. Medical records of children with CF were retrospectively reviewed from 1997-2009. MRSA clinical isolates from 2007-2009 were analyzed by polymerase chain reaction and pulsed field gel electrophoresis. The prevalence of MRSA was 1% in 1997 and 49% in 2009. Fifty-five children (26%) had persistent MRSA infection. Sixty-eight percent of MRSA isolates were hospital-associated (HA) MRSA, of which 52% were pulsed-field type USA 100. Ninety-three percent of HA MRSA isolates were clindamycin resistant. Twelve children acquired MRSA before 1 year of age, 83% of whom were hospitalized prior to acquisition of MRSA. Ten of 11 sibling pairs carried indistinguishable MRSA strains. Children with persistent MRSA were hospitalized more often (P = .01), required inhaled medications more frequently (P = .01), and had higher rates of Pseudomonas aeruginosa coinfection (P < .001). MRSA prevalence in children with CF is increasing, and most children are infected with HA MRSA. Exposure to health care facilities and gastrointestinal surgeries may facilitate early acquisition of MRSA. Siblings carry indistinguishable MRSA strains, indicating household transmission of MRSA. Children with persistent MRSA had worse pulmonary morbidity. Coinfection with MRSA and P aeruginosa is likely associated with further increased pulmonary morbidity. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  19. Potential for pet animals to harbor methicillin-resistant Staphylococcus aureus (MRSA) when residing with human MRSA patients

    PubMed Central

    Morris, Daniel O.; Lautenbach, Ebbing; Zaoutis, Theoklis; Leckerman, Kateri; Edelstein, Paul H.; Rankin, Shelley C.

    2011-01-01

    Summary Colonization by methicillin-resistant Staphylococcus aureus (MRSA) may be persistent in people, and is horizontally transmissible. The scientific literature suggests that domestic pets may also participate in cross-transmission of MRSA within households. The objectives of this study were to evaluate the prevalence of and risk factors for MRSA carriage by pets residing in households with an MRSA-infected person. From 66 households in which an MRSA infected patient resided, we screened 47 dogs and 52 cats using a swab protocol. Isolates from pets and humans were genotyped using two techniques, and compared for concordance. Human participants completed a 22-question survey of demographic and epidemiologic data relevant to staphylococcal transmission. Eleven of 99 pets (11.5%) representing 9 (13.6%) of households were MRSA-positive, but in only 6 of these households were the human and animal-source strains genetically concordant. Human infection by strain USA 100 was significantly associated with pet carriage [OR = 11.4 (95% C.I. 1.7, 76.9); p=0.013]. Yet, for each day of delay in sampling the pet after the person’s MRSA diagnosis, the odds of isolating any type of MRSA from the pet decreased by 13.9% [(95% C.I. 2.6%, 23.8%); p=0.017)]. It may be concluded that pets can harbor pandemic strains of MRSA while residing in a household with an infected person. However, the source of MRSA to the pet cannot always be attributed to the human patient. Moreover, the rapid attrition of the odds of obtaining a positive culture from pets over time suggests that MRSA carriage may be fleeting. PMID:22233337

  20. Comparative analysis of the virulence characteristics of epidemic methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from Chinese children: ST59 MRSA highly expresses core gene-encoded toxin.

    PubMed

    Li, Shipeng; Sun, Jing; Zhang, Jianzhong; Li, Xiangmei; Tao, Xiaoxia; Wang, Lijuan; Sun, Mingjiao; Liu, Yingchao; Li, Juan; Qiao, Yanhong; Yu, Sangjie; Yao, Kaihu; Yang, Yonghong; Shen, Xuzhuang

    2014-02-01

    This study aims to investigate the prevalence of a novel cell wall-anchored protein gene, sasX, and to obtain information on the genetic basis for the pathogenic potential of the MRSA strains isolated from Chinese children. The molecular and virulence characteristics of the clinical strains were analyzed. Twenty-two sequence types (STs) were obtained, with six epidemic clones ST59, ST239, ST1, ST910, ST88, and ST338 accounting for 35.8, 22, 6.6, 6.6, 5.3, and 4.1% respectively. The expression levels of hla, psmα, and RNAIII were higher in ST59 than in other STs (p < 0.05). The sasX gene was detected in 26 (10.7%) MRSA isolates. ST239-MRSA-SCCmecIII-t037 (61.5%) was the predominant sasX-positive MRSA clone. The expressions of PSMα and RNAIII were higher in sasX-positive ST239 isolates than in sasX-negative ST239 ones (p < 0.01). Notably, the percentage of invasive infection in infections caused by sasX-positive ST239 MRSA was higher than that by sasX-negative ST239 MRSA (p = 0.008). This study indicated that ST59 was the predominant clone in the MRSA isolates obtained from Chinese children and might have stronger pathogenic potential. The prevalence of the sasX gene in the MRSA isolates from children was relatively low. Furthermore, the sasX gene might be related to the expressions of PSMα and RNAIII and infection invasiveness.

  1. Comparison of Methicillin Resistant Staphylococcus Aureus in Healthy Community Hospital Visitors [CA-MRSA] and Hospital Staff [HA-MRSA

    PubMed Central

    Pathare, Nirmal A; Tejani, Sara; Asogan, Harshini; Al Mahruqi, Gaitha; Al Fakhri, Salma; Zafarulla, Roshna; Pathare, Anil V.

    2015-01-01

    Background The prevalence of community-associated methicillin-resistant Staphylococcus aureus [CA-MRSA] is unknown in Oman. Methods Nasal and cell phones swabs were collected from hospital visitors and health-care workers on sterile polyester swabs and directly inoculated onto a mannitol salt agar containing oxacillin, allowing growth of methicillin-resistant microorganisms. Antibiotic susceptibility tests were performed using Kirby Bauer’s disc diffusion method on the isolates. Minimum inhibitory concentration (MIC) was determined for vancomycin and teicoplanin against the resistant isolates of MRSA by the Epsilometer [E] test. A brief survey questionnaire was requested be filled to ascertain the exposure to known risk factors for CA-MRSA carriage. Results Overall, nasal colonization with CA-MRSA was seen in 34 individuals (18%, 95% confidence interval [CI] =12.5%–23.5%), whereas, CA-MRSA was additionally isolated from the cell phone surface in 12 participants (6.3%, 95% CI =5.6%–6.98%). Nasal colonization prevalence with hospital-acquired [HA] MRSA was seen in 16 individuals (13.8%, 95% confidence interval [CI] =7.5%–20.06%), whereas, HA-MRSA was additionally isolated from the cell phone surface in 3 participants (2.6%, 95% CI =1.7–4.54). Antibiotic sensitivity was 100% to linezolid and rifampicin in the CA-MRSA isolates. Antibiotic resistance to vancomycin and clindamycin varied between 9–11 % in the CA-MRSA isolates. Mean MIC for vancomycin amongst CA- and HA-MRSA were 6.3 and 9.3 μg/ml, whereas for teicoplanin they were 13 and 14 μg/ml respectively by the E-test. There was no statistically significant correlation between CA-MRSA nasal carriage and the risk factors (P>0.05, Chi-square test). Conclusions The prevalence of CA-MRSA in the healthy community hospital visitors was 18 % (95% CI, 12.5% to 23.5%) as compared to 13.8% HA-MRSA in the hospital health-care staff. Despite a significant prevalence of CA-MRSA, these strains were mostly sensitive

  2. Multidrug and mupirocin resistance in environmental methicillin-resistant Staphylococcus aureus (MRSA) collected from the homes of people diagnosed with a community-onset (CO-) MRSA infection.

    PubMed

    Shahbazian, J H; Hahn, P D; Ludwig, S; Ferguson, J; Baron, P; Christ, A; Spicer, K; Tolomeo, P; Torrie, A M; Bilker, W B; Cluzet, V C; Hu, B; Julian, K; Nachamkin, I; Rankin, S C; Morris, D O; Lautenbach, E; Davis, M F

    2017-09-22

    Patients with community-onset methicillin-resistant Staphylococcus aureus (CO-MRSA) infections contribute to MRSA contamination of the home environment, and may be re-exposed to MRSA strains from this reservoir. This study evaluates One Health risk factors that focus on the relationship between humans, animals and the environment for increased prevalence of multiple antimicrobial resistant MRSA in the home environment. During a trial of patients with CO-MRSA infection, MRSA was isolated from the household environment at baseline and three months later, following randomization of patients and household members to mupirocin-based decolonization therapy or education control. Up to two environmental MRSA isolates per visit were tested. MRSA isolates were identified in 68% (65/95) of homes at baseline (n=104 isolates) and 51% (33/65) of homes three months later (n=56 isolates). Rates of MDR were 61% at baseline and 55% at the three-month visit. At baseline, 100% (14/14) of MRSA isolates from rural homes were MDR. While antimicrobial use in humans or pets was associated with an increased risk for the isolation of MDR MRSA from the environment, clindamycin use was not associated risk for isolation of MDR MRSA. Two (5%) of 39 homes that were randomized to mupirocin treatment, but none of the control families, had incident low-level mupirocin resistant MRSA isolated at three months. Among patients recently treated for a CO-MRSA infection, MRSA and MDR MRSA were common contaminants in the home environment. This study contributes to evidence that occupant use of antimicrobial drugs--except clindamycin--is associated with MDR MRSA in the home environmental reservoir.Importance: MRSA is a common bacterial agent implicated in skin and soft tissue infections (SSTIs) in both community and healthcare settings. Patients with CO-MRSA infections contribute to MRSA contamination and may be re-exposed to MRSA strains from these reservoirs. People interact with natural and built

  3. Swine MRSA isolates form robust biofilms

    USDA-ARS?s Scientific Manuscript database

    Methicillin-resistant Staphylococcus aureus (MRSA) colonization of livestock animals is common and prevalence rates for pigs have been reported to be as high as 49%. Measures to prevent, control, or eliminate MRSA in swine is of considerable public health concern. Bacterial colonization of both biol...

  4. Swine MRSA isolates form robust biofilms

    USDA-ARS?s Scientific Manuscript database

    Background: Methicillin-resistant Staphylococcus aureus (MRSA) colonization of livestock animals is common and prevalence rates for pigs have been reported to be as high as 49%. Measures to prevent, control, or eliminate MRSA in swine is of considerable public health concern. Bacterial colonization ...

  5. Assessment of the efficacy of polyclonal intravenous immunoglobulin G (IVIG) against the infectivity of clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) in vitro and in vivo.

    PubMed

    Farag, N; Mahran, L; Abou-Aisha, K; El-Azizi, M

    2013-09-01

    The response to treatment of severe methicillin-resistant Staphylococcus aureus (MRSA) infections with the traditional antibiotics is sometimes unsatisfactory and multiple antibiotic resistance is common. Adjuvant therapy such as intravenous immunoglobulin G (IVIG) could possibly be helpful in the treatment of such infections. The effect of IVIG on the capacity of human neutrophils to phagocytose and kill MRSA was investigated in vitro using the MTT assay and measuring the production of reactive oxygen species (ROS) and nitric oxide (NO). The efficiency of IVIG in neutralizing α-hemolysin and coagulase of MRSA was also assessed. The capability of IVIG in the treatment and prevention of MRSA infections was also evaluated in a murine peritonitis model. IVIG significantly enhanced (p < 0.01) the killing of MRSA by neutrophils at all concentrations tested (0.1-5 mg/ml) by 30-80 % of control values. It significantly (p < 0.01) increased the level of NO production in a dose-dependent manner, giving up to 60 μM at 5 mg/ml. The ROS level significantly increased (p < 0.01) in the presence of IVIG. In addition, IVIG significantly reduced the hemolytic activity of MRSA 10-fold and its coagulation capabilities by 50 %. When tested in vivo, groups receiving IVIG via tail vein infusion showed no significant improvement in their survival. Only when delivered to the same site of infection did IVIG show an improvement in the survival of mice (n = 80). These results could pave the way for a better understanding of the mechanism of action of IVIG and suggest its clinical potential as an adjuvant preventive and therapeutic agent against life-threatening infections caused by MRSA and other bacteria.

  6. In vitro susceptibility of Staphylococcus aureus including MRSA to four disinfectants.

    PubMed

    Suzuki, J; Komatsuzawa, H; Kozai, K; Nagasaka, N

    1997-01-01

    The spread of nosocomial infections caused by pathogenic organisms such as methicillin-resistant S. aureus (MRSA) has prompted the dental community to focus more attention on certain control strategies. In the present study, we tested the abilities of the four skin disinfectants (povidone iodine, benzalkonium chloride, chlorhexidine gluconate, and ethanol) to prevent horizontal transmission of MRSA in the dental office. The bactericidal activities of the disinfectants were evaluated by the decrement over time of viable cell numbers of four clinical isolated strains of S. aureus: two MRSA strains and two methicillin-sensitive S. aureus (MSSA) strains. The most effective disinfectant was 70 percent ethanol, which eradicated both MRSA and MSSA in less than three minutes. The 0.1 percent chlorhexidine gluconate proved the least effective of four disinfectants. More than 10(2) bacteria survived despite exposure to it for thirty minutes.

  7. Prevalence of qacA/B Genes and Mupirocin Resistance Among Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates in the Setting of Chlorhexidine Bathing Without Mupirocin.

    PubMed

    Warren, David K; Prager, Martin; Munigala, Satish; Wallace, Meghan A; Kennedy, Colleen R; Bommarito, Kerry M; Mazuski, John E; Burnham, Carey-Ann D

    2016-05-01

    We aimed to determine the frequency of qacA/B chlorhexidine tolerance genes and high-level mupirocin resistance among MRSA isolates before and after the introduction of a chlorhexidine (CHG) daily bathing intervention in a surgical intensive care unit (SICU). Retrospective cohort study (2005-2012) SETTING: A large tertiary-care center Patients admitted to SICU who had MRSA surveillance cultures of the anterior nares A random sample of banked MRSA anterior nares isolates recovered during (2005) and after (2006-2012) implementation of a daily CHG bathing protocol was examined for qacA/B genes and high-level mupirocin resistance. Staphylococcal cassette chromosome mec (SCCmec) typing was also performed. Of the 504 randomly selected isolates (63 per year), 36 (7.1%) were qacA/B positive (+) and 35 (6.9%) were mupirocin resistant. Of these, 184 (36.5%) isolates were SCCmec type IV. There was a significant trend for increasing qacA/B (P=.02; highest prevalence, 16.9% in 2009 and 2010) and SCCmec type IV (P<.001; highest prevalence, 52.4% in 2012) during the study period. qacA/B(+) MRSA isolates were more likely to be mupirocin resistant (9 of 36 [25%] qacA/B(+) vs 26 of 468 [5.6%] qacA/B(-); P=.003). A long-term, daily CHG bathing protocol was associated with a change in the frequency of qacA/B genes in MRSA isolates recovered from the anterior nares over an 8-year period. This change in the frequency of qacA/B genes is most likely due to patients in those years being exposed in prior admissions. Future studies need to further evaluate the implications of universal CHG daily bathing on MRSA qacA/B genes among hospitalized patients.

  8. MRSA

    MedlinePlus

    MRSA stands for methicillin-resistant Staphylococcus aureus. It causes a staph infection (pronounced "staff infection") that is resistant to several common antibiotics. There are two types of infection. ...

  9. Misidentification of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals in Tripoli, Libya

    PubMed Central

    Ahmed, Mohamed O.; Abuzweda, Abdulbaset R.; Alghazali, Mohamed H.; Elramalli, Asma K.; Amri, Samira G.; Aghila, Ezzeddin Sh.; Abouzeed, Yousef M.

    2010-01-01

    Background Methicillin-resistant Staphylococcus aureus (MRSA) is a nosocomial (hospital-acquired) pathogen of exceptional concern. It is responsible for life-threatening infections in both the hospital and the community. Aims To determine the frequency of MRSA misidentification in hospitals in Tripoli, Libya using current testing methods. Methods One hundred and seventy S. aureus isolates previously identified as MRSA were obtained from three hospitals in Tripoli. All isolates were reidentified by culturing on mannitol salt agar, API 20 Staph System and retested for resistance to methicillin using the cefoxitin disk diffusion susceptibility test and PBP2a. D-tests and vancomycin E-tests (Van-E-tests) were also performed for vancomycin-resistant isolates. Results Of the 170 isolates examined, 86 (51%) were confirmed as MRSA (i.e. 49% were misidentified as MRSA). Fifteen (17%) of the confirmed MRSA strains exhibited inducible clindamycin resistance. Of the 86 confirmed MRSA isolates, 13 (15%) were resistant to mupirocin, 53 (62%) were resistant to ciprofloxacin, 41 (48%) were resistant to trimethoprim-sulfamethoxazole, and none were resistant to linezolid. Although disc-diffusion testing indicated that 23 (27%) of the isolates were resistant to vancomycin, none of the isolates were vancomycin-resistant by Van-E-test. Conclusions Misidentification of nosocomial S. aureus as MRSA is a serious problem in Libyan hospitals. There is an urgent need for the proper training of microbiology laboratory technicians in standard antimicrobial susceptibility procedures and the implementation of quality control programs in microbiology laboratories of Libyan hospitals. PMID:21483574

  10. Methicillin-resistant Staphylococcus aureus (MRSA) in a tertiary surgical and trauma hospital in Benghazi, Libya.

    PubMed

    Buzaid, Najat; Elzouki, Abdel-Naser; Taher, Ibrahim; Ghenghesh, Khalifa Sifaw

    2011-10-13

    Methicillin resistant Staphylococcus aureus (MRSA) is a multidrug resistant organism that threatens the continued effectiveness of antibiotics worldwide and causes a threat almost exclusively in hospitals and long-term care settings. This study investigated the prevalence of MRSA strains and their sensitivity patterns against various antibiotics used for treating hospitalized patients in a major tertiary surgical hospital in Benghazi, Libya. We investigated 200 non-duplicate S. aureus strains isolated from different clinical specimens submitted to the Microbiology Laboratory at Aljala Surgical and Trauma Hospital, Benghazi, Libya from April to July 2007. Isolates were tested for methicillin resistance by the oxacillin disc-diffusion assay according to Clinical and Laboratory Standards Institute guidelines. MRSA strains were tested for antimicrobial resistance (i.e., vancomycin, ciprofloxacin, erythromycin, chloramphenicol and fusidic acid) using commercial discs. Information on patient demographics and clinical disease was also collected. Of the isolates examined 31% (62/200) were MRSA. No significant differences were observed in the prevalence of MRSA among S. aureus from females or males or from different age groups. Most MRSA were isolated from burns and surgical wound infections. Antibiotic resistance patterns of 62 patients with MRSA to vancomycin, ciprofloxacin, fusidic acid, chloramphenicol and erythromycin were 17.7%, 33.9%, 41.9%, 38.7% and 46.8% of cases, respectively. MRSA prevalence in our hospital was high and this may be the case for other hospitals in Libya. A sound surveillance program of nosocomial infections is urgently needed to reduce the incidence of infections due to MRSA and other antimicrobial-resistant pathogens in Libyan hospitals.

  11. MRSA and multidrug-resistant Staphylococcus aureus in U.S. retail meats, 2010-2011.

    PubMed

    Ge, Beilei; Mukherjee, Sampa; Hsu, Chih-Hao; Davis, Johnnie A; Tran, Thu Thuy T; Yang, Qianru; Abbott, Jason W; Ayers, Sherry L; Young, Shenia R; Crarey, Emily T; Womack, Niketta A; Zhao, Shaohua; McDermott, Patrick F

    2017-04-01

    Methicillin-resistant Staphylococcus aureus (MRSA) has been detected in retail meats, although large-scale studies are scarce. We conducted a one-year survey in 2010-2011 within the framework of the National Antimicrobial Resistance Monitoring System. Among 3520 retail meats collected from eight U.S. states, 982 (27.9%) contained S. aureus and 66 (1.9%) were positive for MRSA. Approximately 10.4% (107/1032) of S. aureus isolates, including 37.2% (29/78) of MRSA, were multidrug-resistant (MDRSA). Turkey had the highest MRSA prevalence (3.5%), followed by pork (1.9%), beef (1.7%), and chicken (0.3%). Whole-genome sequencing was performed for all 66 non-redundant MRSA. Among five multilocus sequence types identified, ST8 (72.7%) and ST5 (22.7%) were most common and livestock-associated MRSA ST398 was assigned to one pork isolate. Eleven spa types were represented, predominately t008 (43.9%) and t2031 (22.7%). All four types of meats harbored t008, whereas t2031 was recovered from turkey only. The majority of MRSA (84.8%) possessed SCCmec IV and 62.1% harbored Panton-Valentine leukocidin. Pulsed-field gel electrophoresis showed that all ST8 MRSA belonged to the predominant human epidemic clone USA300, and others included USA100 and USA200. We conclude that a diverse MRSA population was present in U.S. retail meats, albeit at low prevalence. Published by Elsevier Ltd.

  12. Evaluation of the TPX MRSA assay for the detection of methicillin-resistant Staphylococcus aureus.

    PubMed

    Stenholm, T; Hakanen, A J; Salmenlinna, S; Pihlasalo, S; Härmä, H; Hänninen, P E; Huovinen, P; Vuopio, J; Kotilainen, P

    2011-10-01

    The aim of this study was to evaluate a new type of assay for the phenotypic detection of methicillin-resistant Staphylococcus aureus (MRSA). The assay is based on a point-of-care compatible two-photon excitation fluorescence detection technology (TPX). A collection of 243 epidemic MRSA isolates was tested in addition to 138 sporadic MRSA and 101 negative control strains. The assay proved to be both sensitive (97.9%) and specific (94.1%) in the identification of MRSA, with adequate positive (98.4%) and negative (92.2%) predictive values. The time required for obtaining a positive test result was less than 14 h for 99.0% of the MRSA true-positive samples. After a test run, the selectively enriched reaction mixtures may be recovered and further studied by molecular or standard phenotypic methods. The main benefits of the TPX methodology include a simple assay procedure, low reagent consumption, and a high-throughput capacity.

  13. [Treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections in Latin America].

    PubMed

    Luna, Carlos M; Rodríguez-Noriega, Eduardo; Bavestrello, Luis; Gotuzzo, Eduardo

    2010-08-01

    The global spread of MRSA means it is now a pathogen of worldwide public health concern. Within Latin America, MRSA is highly prevalent, with the proportion of S. aureus isolates that are methicillin-resistant on the rise, yet resources for managing the infection are limited. While several guidelines exist for the treatment of MRSA infections, many are written for the North American or European setting and need adaptation for use in Latin America. In this article, we aim to emphasize the importance of appropriate treatment of MRSA in the healthcare and community settings of Latin America. We present a summary of the available guidelines and antibiotics, and discuss particular considerations for clinicians treating MRSA in Latin America.

  14. Performance of CHROMagar Staph aureus and CHROMagar MRSA for detection of Staphylococcus aureus in seawater and beach sand--comparison of culture, agglutination, and molecular analyses.

    PubMed

    Goodwin, K D; Pobuda, M

    2009-11-01

    Beach seawater and sand were analyzed for Staphylococcus aureus and methicillin resistant S. aureus (MRSA) for samples collected from Avalon, and Doheny Beach, CA. Membrane filtration followed by incubation on CHROMagar Staph aureus (SCA) and CHROMagar MRSA (C-MRSA) was used to enumerate S. aureus and MRSA, respectively. Media performance was evaluated by comparing identification via colony morphology and latex agglutination tests to PCR (clfA, 16S, and mecA genes). Due to background color and crowding, picking colonies from membrane filters and streaking for isolation were sometimes necessary. The specificity of SCA and C-MRSA was improved if colony isolates were identified by the presence of a matte halo in addition to mauve color; however routine agglutination testing of isolates did not appear warranted. Using the appearance of a colony on the membrane filter in conjunction with isolate appearance, the positive % agreement, the negative % agreement, and the % positive predictive accuracy for SCA was 84%, 95%, and 99% respectively, and for C-MRSA it was 85%, 98%, and 92%, respectively. Sensitivity and specificity of SCA and C-MRSA with membrane-filtered beach samples were optimized through identification experience, control of filter volume and incubation time, and isolation of colonies needing further identification. With optimization, SCA and C-MRSA could be used for enumeration of S. aureus and MRSA from samples of beach water and sand. For the sites studied here, the frequency of detection of S. aureus ranged from 60 to 76% and 53 to 79% for samples of beach seawater and sand, respectively. The frequency of detection of MRSA ranged from 2 to 9% and 0 to 12% for samples of seawater and sand, respectively.

  15. New patterns of methicillin-resistant Staphylococcus aureus (MRSA) clones, community-associated MRSA genotypes behave like healthcare-associated MRSA genotypes within hospitals, Argentina.

    PubMed

    Egea, Ana L; Gagetti, Paula; Lamberghini, Ricardo; Faccone, Diego; Lucero, Celeste; Vindel, Ana; Tosoroni, Dario; Garnero, Analía; Saka, Hector A; Galas, Marcelo; Bocco, José L; Corso, Alejandra; Sola, Claudia

    2014-11-01

    Methicillin-resistant Staphylococcus aureus (MRSA) burden is increasing worldwide in hospitals [healthcare-associated (HA)-MRSA] and in communities [community-associated (CA)-MRSA]. However, the impact of CA-MRSA within hospitals remains limited, particularly in Latin America. A countrywide representative survey of S. aureus infections was performed in Argentina by analyzing 591 clinical isolates from 66 hospitals in a prospective cross-sectional, multicenter study (Nov-2009). This work involved healthcare-onset infections-(HAHO, >48 hospitalization hours) and community-onset (CO) infections [including both, infections (HACO) in patients with healthcare-associated risk-factors (HRFs) and infections (CACO) in those without HRFs]. MRSA strains were genetically typed as CA-MRSA and HA-MRSA genotypes (CA-MRSAG and HA-MRSAG) by SCCmec- and spa-typing, PFGE, MLST and virulence genes profile by PCR. Considering all isolates, 63% were from CO-infections and 55% were MRSA [39% CA-MRSAG and 16% HA-MRSAG]. A significantly higher MRSA proportion among CO- than HAHO-S. aureus infections was detected (58% vs 49%); mainly in children (62% vs 43%). The CA-MRSAG/HA-MRSAG have accounted for 16%/33% of HAHO-, 39%/13% of HACO- and 60.5%/0% of CACO-infections. Regarding the epidemiological associations identified in multivariate models for patients with healthcare-onset CA-MRSAG infections, CA-MRSAG behave like HA-MRSAG within hospitals but children were the highest risk group for healthcare-onset CA-MRSAG infections. Most CA-MRSAG belonged to two major clones: PFGE-type N-ST30-SCCmecIVc-t019-PVL(+) and PFGE-type I-ST5-IV-SCCmecIVa-t311-PVL(+) (45% each). The ST5-IV-PVL(+)/ST30-IV-PVL(+) clones have caused 31%/33% of all infections, 20%/4% of HAHO-, 43%/23% of HACO- and 35%/60% of CACO- infections, with significant differences by age groups (children/adults) and geographical regions. Importantly, an isolate belonging to USA300-0114-(ST8-SCCmecIVa-spat008-PVL(+)-ACME(+)) was detected

  16. Risk of Skin and Soft Tissue Infections among Children Found to be Staphylococcus aureus MRSA USA300 Carriers

    PubMed Central

    Immergluck, Lilly Cheng; Jain, Shabnam; Ray, Susan M.; Mayberry, Robert; Satola, Sarah; Parker, Trisha Chan; Yuan, Keming; Mohammed, Anaam; Jerris, Robert C.

    2017-01-01

    Introduction The purpose of this study was to examine community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) carriage and infections and determine risk factors associated specifically with MRSA USA300. Methods We conducted a case control study in a pediatric emergency department. Nasal and axillary swabs were collected, and participants were interviewed for risk factors. The primary outcome was the proportion of S. aureus carriers among those presenting with and without a skin and soft tissue infection (SSTI). We further categorized S. aureus carriers into MRSA USA300 carriers or non-MRSA USA300 carriers. Results We found the MRSA USA300 carriage rate was higher in children less than two years of age, those with an SSTI, children with recent antibiotic use, and those with a family history of SSTI. MRSA USA300 carriers were also more likely to have lower income compared to non-MRSA USA300 carriers and no S. aureus carriers. Rates of Panton-Valentine leukocidin (PVL) genes were higher in MRSA carriage isolates with an SSTI, compared to MRSA carriage isolates of patients without an SSTI. There was an association between MRSA USA300 carriage and presence of PVL in those diagnosed with an abscess. Conclusion Children younger than two years were at highest risk for MRSA USA300 carriage. Lower income, recent antibiotic use, and previous or family history of SSTI were risk factors for MRSA USA300 carriage. There is a high association between MRSA USA300 nasal/axillary carriage and presence of PVL in those with abscesses. PMID:28210352

  17. Association of Panton Valentine Leukocidin (PVL) genes with methicillin resistant Staphylococcus aureus (MRSA) in Western Nepal: a matter of concern for community infections (a hospital based prospective study).

    PubMed

    Bhatta, Dharm R; Cavaco, Lina M; Nath, Gopal; Kumar, Kush; Gaur, Abhishek; Gokhale, Shishir; Bhatta, Dwij R

    2016-05-15

    Methicillin resistant Staphylococcus aureus (MRSA) is a major human pathogen associated with nosocomial and community infections. Panton Valentine leukocidin (PVL) is considered one of the important virulence factors of S. aureus responsible for destruction of white blood cells, necrosis and apoptosis and as a marker of community acquired MRSA. This study was aimed to determine the prevalence of PVL genes among MRSA isolates and to check the reliability of PVL as marker of community acquired MRSA isolates from Western Nepal. A total of 400 strains of S. aureus were collected from clinical specimens and various units (Operation Theater, Intensive Care Units) of the hospital and 139 of these had been confirmed as MRSA by previous study. Multiplex PCR was used to detect mecA and PVL genes. Clinical data as well as antimicrobial susceptibility data was analyzed and compared among PVL positive and negative MRSA isolates. Out of 139 MRSA isolates, 79 (56.8 %) were PVL positive. The majority of the community acquired MRSA (90.4 %) were PVL positive (Positive predictive value: 94.9 % and negative predictive value: 86.6 %), while PVL was detected only in 4 (7.1 %) hospital associated MRSA strains. None of the MRSA isolates from hospital environment was found positive for the PVL genes. The majority of the PVL positive strains (75.5 %) were isolated from pus samples. Antibiotic resistance among PVL negative MRSA isolates was found higher as compared to PVL positive MRSA. Our study showed high prevalence of PVL among community acquired MRSA isolates. Absence of PVL among MRSA isolates from hospital environment indicates its poor association with hospital acquired MRSA and therefore, PVL may be used a marker for community acquired MRSA. This is first study from Nepal, to test PVL among MRSA isolates from hospital environment.

  18. First description of PVL-positive methicillin-resistant Staphylococcus aureus (MRSA) in wild boar meat.

    PubMed

    Kraushaar, Britta; Fetsch, Alexandra

    2014-09-01

    Staphylococcus aureus is an important food-borne pathogen due to the ability of enterotoxigenic strains to produce staphylococcal enterotoxins (SEs) in food. Methicillin-resistant S. aureus (MRSA) is also an important pathogen for humans, causing severe and hard to treat diseases in hospitals and in the community due to its multiresistance against antimicrobials. In particular, strains harbouring genes encoding for the Panton-Valentine leukocidin (PVL) toxin are of concern from a public health perspective as they are usually capable of causing severe skin and soft tissue infections (sSSTIs) and occasionally necrotizing pneumonia which is associated with high mortality. This is the first report on the detection of MRSA with genes encoding for PVL in wild boar meat. Among the 28 MRSA isolated from wild boar meat in the course of a national monitoring programme in Germany, seven harboured PVL-encoding genes. Six of the isolates were identical according to the results of spa-, MLST-, microarray- and PFGE-typing. They could be assigned to the epidemic MRSA clone USA300. Epidemiological investigations revealed that people handling the food were the most likely common source of contamination with these MRSA. These findings call again for suitable hygienic measures at all processing steps of the food production chain. The results of the study underline that monitoring along the food chain is essential to closely characterise the total burden of MRSA for public health.

  19. Subcutaneous Infection of Methicillin Resistant Staphylococcus Aureus (MRSA)

    PubMed Central

    Tseng, Ching Wen; Sanchez-Martinez, Marisel; Arruda, Andrea; Liu, George Y.

    2011-01-01

    MRSA is a worldwide threat to public health, and MRSA skin and soft-tissue infections now account for more than half of all soft-tissue infections in the United States. Among soft-tissue infections, myositis, pyomyositis, and necrotizing fasciitis have been increasingly reported in association with MRSA arising from the community. To understand the interplay between MRSA and host immunity leading to more severe infection, the availability of animal models is critical, permitting the study of host and bacterial factors. Several infection models have been introduced to assess the pathogenesis of S. aureus during superficial skin infection. Here, we describe a subcutaneous infection model that examines the skin, subcutaneous, and muscle pathologies. PMID:21339727

  20. Molecular-Characterization of Methicillin-Resistance Staphylococcus aureus (MRSA) from Different Tertiary Care Hospitals in Bangladesh.

    PubMed

    Roy, S; Barman, T K; Hossain, M A; Paul, S K; Haque, N; Ahmed, S; Nasreen, S A; Hossain, M S; Sarkar, S R; Kubayashi, N; Laskar, N

    2017-01-01

    Infections caused by Staphylococcus aureus were treated by methicillin, but about 95% of S. aureus has been resistance to methicillin, both in the community and hospitals and are increasing day by day. MRSA produces altered penicillin binding protein, PBP2a, due to the expression of mecA gene. Some strains of both the MRSA and MSSA carry PVL gene. This cross sectional observational study was conducted to detect the molecular-characterization of methicillin resistant Staphylococcus aureus (MRSA) and carried out in the Department of Microbiology, Mymensingh Medical College from July 2014 to December 2015. Clinical samples for this study were wound swab, pus, exudates from diabetic ulcer and burn ulcer, aural swab, blood and urine which were collected from three tertiary care hospitals such as from MMCH, BIRDEM hospital and SSMCH. Standard microbiological procedure & biochemical tests were carried out to detect S. aureus. Oxacillin disk diffusion method (ODDM) was done by Kirby-Bauer disk diffusion method. Out of a total 109 culture positive samples 69 isolates of S. aureus were selected for the study. Among the 69 isolates 33, 27 and 09 were from MMCH, BIRDEM hospital and SSMCH respectively. Among the 69 isolates, 17(24.6%) and 52(75.3%) were distinguished as MRSA and MSSA respectively by ODDM. In contrast, detection of presence and absence of mecA gene by PCR identified 20(28.9%) and 49(71.01%) isolates as MRSA and MSSA respectively. Multiplex PCR was performed by standard protocol with specific primers for detection of 16S rRNA gene for Staphylococcus, nuc gene for Staphylococcus aureus, mecA gene for MRSA, PVL gene as a virulence factor and ACME-arc gene for worldwide spreading USA 300 MRSA clone. The PVL gene were detected in 3 out of 20 MRSA (15%) and 19 out of 49 MSSA (38.7%) and the ACME- arc gene was not found in any isolates. All of the S. aureus (MRSA and MSSA) isolates were sensitive to Vancomycin and Gentamicin. All MRSA isolates (100%) showed resistance

  1. Methicillin-resistant Staphylococcus aureus (MRSA) in slaughtered pigs and abattoir workers in Italy.

    PubMed

    Normanno, Giovanni; Dambrosio, Angela; Lorusso, Vanessa; Samoilis, Georgios; Di Taranto, Pietro; Parisi, Antonio

    2015-10-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen present in the hospital environment (HA-MRSA), in the community (CA-MRSA) and in livestock, including pigs (LA-MRSA). MRSA may enter the human food chain during slaughtering and may infect humans coming into direct contact with pigs or pork products. This study aimed to determine the prevalence and characteristics of MRSA isolated from pigs and workers at industrial abattoirs in southern Italy. A total of 215 pig nasal swabs were screened for the presence of MRSA using PCR. An MRSA isolate was detected from each mecA/nuc PCR-positive sample and characterized by spa-typing, Multi-Locus Sequence Typing, SCC-mec and Panton-Valentine Leukocidin (PVL), and also tested for the production of staphylococcal enterotoxins (SEs). Eighty-one MRSA isolates (37.6%) were obtained from the 215 pig nasal swabs; 37 of these isolates were further characterized, and showed 18 different spa-types and 8 different STs. The most frequently recovered STs were ST398 (CC398-t034, t011, t899, t1939 - 43.2%) followed by ST8 (CC8-t008, t064, t2953, t5270 - 24.3%) and ST1 (CC1-t127, t174, t2207 - 10.8%). Nine MRSA isolates were obtained from the 113 human swabs; the isolates showed 5 different spa-types and 5 different STs, including the novel ST2794 (t159). The most representative STs recovered were ST1 (CC1-t127) and ST398 (CC398-t034) (33.3%). None of the MRSA isolates showed the ability to produce SEs and PVL and all resulted resistant to two or more classes of antimicrobials. This study shows the great genetic diversity of MRSA strains in slaughtered pigs and in abattoir employees in Italy, and clearly demonstrates the need for improved hygiene standards to reduce the risk of occupational and food-borne infection linked to the handling/consumption of raw pork containing MRSA.

  2. Characteristics of SCCmec IV and V Methicillin-Resistant Staphylococcus aureus (MRSA) in Israel.

    PubMed

    Shitrit, Pnina; Openhaim, Michal; Reisfeld, Sharon; Paitan, Yossi; Regev-Yochay, Gili; Carmeli, Yehuda; Chowers, Michal

    2015-08-01

    Isolation of methicillin-resistant Staphylococcus aureus (MRSA) in healthy individuals is not common in Israel. In our hospital, about 30% of MRSA isolates were SCCmec types IV and V. To identify the demographic and clinical characteristics of patients carrying MRSA SCCmec type IV or V, and to compare them with each other and with those of patients with SCCmec types I-III. We conducted a case-control study that included 501 patients from whom MRSA was isolated: 254 with SCCmec type I, II, or III, and 243 isolates from SCCmec types IV or V. MRSA was isolated from surveillance cultures in 75% of patients and from a clinical site in 25%. The majority of our study population was elderly, from nursing homes, and with extensive exposure to health care. First, we compared characteristics of patients identified through screening. Statistically significant predictors of SCCmec V vs. IV were Arab ethnicity (OR 7.44, 95% CI 1.5-37.9) and hospitalization in the year prior to study inclusion (OR 5.7, 95% CI 1.9-16.9). No differences were found between patients with SCCmec types I-III and patients with SCCmec type IV or V. Analysis of the subset of patients who had clinical cultures yielded similar results. SCCmec types IV and V were common in the hospital setting although rare in the community. It seems that in Israel, SCCmec IV and V are predominantly health care-associated MRSA.

  3. Evaluation of BacLite Rapid MRSA, a rapid culture based screening test for the detection of ciprofloxacin and methicillin resistant S. aureus (MRSA) from screening swabs

    PubMed Central

    Johnson, Gemma; Millar, Michael R; Matthews, Stuart; Skyrme, Margaret; Marsh, Peter; Barringer, Emma; O'Hara, Stephen; Wilks, Mark

    2006-01-01

    Background Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen worldwide. The need for accurate and rapid screening methods to detect MRSA carriers has been clearly established. The performance of a novel assay, BacLite Rapid MRSA (Acolyte Biomedica, UK) for the rapid detection (5 h) and identification of hospital associated ciprofloxacin resistant strains of MRSA directly from nasal swab specimens was compared to that obtained by culture on Mannitol salt agar containing Oxacillin (MSAO) after 48 h incubation. Results A total of 1382 nasal screening swabs were tested by multiple operators. The BacLite Rapid MRSA test detected 142 out of the 157 confirmed MRSA that were detected on MSAO giving a diagnostic sensitivity of 90.4, diagnostic specificity of 95.7% and a negative predictive value of 98.7%. Of the 15 false negatives obtained by the BacLite Rapid MRSA test, seven grew small amounts (< 10 colonies of MRSA) on the MSAO culture plate and five isolates were ciprofloxacin sensitive. However there were 13 confirmed BacLite MRSA positive samples, which were negative by the direct culture method, probably due to overgrowth on the MSAO plate. There were 53 false positive results obtained by the BacLite Rapid MRSA test at 5 h and 115 cases where MRSA colonies were tentatively identified on the MSAO plate when read at 48 h, and which subsequently proved not to be MRSA. Conclusion The Baclite MRSA test is easy to use and provides a similar level of sensitivity to conventional culture for the detection of nasal carriage of MRSA with the advantage that the results are obtained much more rapidly. PMID:17010192

  4. Methicillin resistant Staphylococcus aureus (MRSA) carriage in different free-living wild animal species in Spain.

    PubMed

    Porrero, M Concepción; Mentaberre, Gregorio; Sánchez, Sergio; Fernández-Llario, Pedro; Gómez-Barrero, Susana; Navarro-Gonzalez, Nora; Serrano, Emmanuel; Casas-Díaz, Encarna; Marco, Ignasi; Fernández-Garayzabal, José-Francisco; Mateos, Ana; Vidal, Dolors; Lavín, Santiago; Domínguez, Lucas

    2013-10-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a life-threatening pathogen in humans and its presence in animals is a public health concern. The aim of this study was to measure the prevalence of MRSA in free-living wild animals. Samples from red deer (n=273), Iberian ibex (n=212), Eurasian Griffon vulture (n=40) and wild boar (n=817) taken from different areas in Spain between June 2008 and November 2011 were analyzed. Characterization of the isolates was performed by spa typing, multi-locus sequence typing (MLST) and antimicrobial susceptibility testing. A low prevalence of MRSA was found with 13 isolates obtained from 12 animals (0.89%; 95% CI: 0.46-1.56). All MRSA sequence types belonged to ST398 (t011 and t1451) and ST1 (t127). Genotypes and antimicrobial susceptibility patterns (tetracycline resistance in ST398 and clindamycin-erythromycin-tetracycline resistance in ST1) suggest that the MRSA found probably originated in livestock (ST398) or humans (ST1). This is the first report of MRSA carriers in free-living wild animals in Europe. Although our data showed that MRSA prevalence is currently low, free-living wild animals might act as reservoir and represent a potential risk for human health.

  5. Prevalence and molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) in organic pig herds in The Netherlands.

    PubMed

    van de Vijver, L P L; Tulinski, P; Bondt, N; Mevius, D; Verwer, C

    2014-08-01

    The prevalence of the methicillin-resistant Staphylococcus aureus (MRSA) among conventional pig herds in the Netherlands is high (around 71%). Nevertheless, information about the prevalence of MRSA among organic pig herds is lacking. Here, we report a study on 24 of the 49 organic pig herds in the Netherlands. The prevalence of MRSA positive herds showed to be 21%. The genetic characteristics of the MRSA isolates were similar to MRSA CC398 described in conventional pigs except one exceptional HA-MRSA CC30 found in one herd, which was presumably caused by human to animal transmission. This resulted in a prevalence of MRSA CC398 in the organic herds of 16.7%.

  6. Selective Methicillin-Resistant Staphylococcus Aureus (MRSA) screening of a high risk population does not adequately detect MRSA carriers within a country with low MRSA prevalence.

    PubMed

    de Wouters, Solange; Daxhelet, Jérémy; Kaminski, Ludovic; Thienpont, Emmanuel; Cornu, Olivier; Yombi, Jean Cyr

    2015-12-01

    Methicillin-Resistant Staphylococcus Aureus (MRSA) has been widely recognized as a serious problem in hospital settings. The purpose of this study is to evaluate the predictive value of MRSA colonization factors in the detection of MRSA carriers in an orthopedic ward. A systematic MRSA detection strategy was set up to assess the predictive value of MRSA colonization factors among 554 patients undergoing elective knee arthroplasty. In total 116 patients were found positive for Staphylococcus Aureus; among those 110/116 patients were found positive for Methicillin-Sensitive Staphylococcus Aureus (MSSA) and 6/116 for MRSA. Only one patient out of six presented two risk factors according to MRSA risk factors. In this study, no correlation was found between the remaining conventional risk factors, according to Belgian guidelines, defined to target high-risk populations and to identify MRSA carriers. Established criteria for selective MRSA screening do not allow detecting MRSA carriers. The objective of detecting MRSA carriers is not correctly met by the actual applied criteria (Belgian consensus) for a selective screening policy. Future studies should aim at identifying the right risk factors, depending of the country's prevalence of MRSA, to improve the ability to predict the risk of MRSA carriage at hospital admission.

  7. Dissemination of Methicillin-Resistant Staphylococcus aureus (MRSA), USA300 Sequence Type 8 Lineage in Latin-America

    PubMed Central

    Reyes, Jinnethe; Rincón, Sandra; Díaz, Lorena; Panesso, Diana; Contreras, Germán A.; Zurita, Jeannete; Carrillo, Carlos; Rizzi, Adele; Guzmán, Manuel; Adachi, Javier; Chowdhury, Shahreen; Murray, Barbara E.; Arias, Cesar A.

    2009-01-01

    Background Methicillin-resistant Staphylococus aureus (MRSA) is an important nosocomial and community-associated (CA) pathogen. Recently, a variant of the MRSA USA300 clone emerged and disseminated in South-America causing important clinical problems. Methods S. aureus isolates were prospectively collected (2006 to 2008) from 32 tertiary hospitals in Colombia, Ecuador, Peru, and Venezuela. MRSA isolates were subjected to antimicrobial susceptibility testing, pulsed field gel electrophoresis (PFGE), and categorized as healthcare-associated (HA)-like or CA-like clones based on genotypic characteristics and detection of genes encoding the Panton-Valentine leukocidin (PVL) and staphylococcal cassette mec (SCCmec) IV. Additionally, MLST of representative isolates of each major CA-MRSA pulsotype, and detection of USA300-associated toxins and the arcA gene were performed in all isolates categorized as CA-MRSA. Results A total of 1570 S. aureus were included; 651 were MRSA (41%), with the highest rates of MRSA isolation in Peru (62%), and lowest in Venezuela (26%) and 71%, 27%, and 2% were classified as HA-like, CA-like, and non-CA/HA-like clones, respectively. Only 9 MRSA isolates were confirmed to have reduced susceptibility to glycopeptides (GISA phenotype). The most common pulsotype (designated ComA) amongst the CA-like MRSA strains was found in 96% of isolates with the majority (81%) having ≤6 bands difference with the USA300-0114 strain. Representative isolates of this clone were ST8 but, unlike the USA300-0114 strain, they harbored a different SCCmec IV subtype and lacked arcA (an indicator of the arginine catabolic mobile element (ACME)). Conclusion A variant CA-MRSA USA300 clone has now become established in South America and, in some countries, is endemic in hospital settings. PMID:19911971

  8. 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.

  9. Prevalence of methicillin resistant Staphylococcus aureus [MRSA] colonization or carriage among health-care workers.

    PubMed

    Pathare, Nirmal A; Asogan, Harshini; Tejani, Sara; Al Mahruqi, Gaitha; Al Fakhri, Salma; Zafarulla, Roshna; Pathare, Anil V

    2016-01-01

    In Oman, the prevalence of health care associated methicillin resistant Staphylococcus aureus [HA-MRSA] is unknown. Therefore, to estimate the prevalence of HA-MRSA, we collected nasal swabs and swabs from cell phones on sterile polyester swabs and immediately inoculated on the mannitol salt agar containing oxacillin from medical students and hospital health care providers. Antibiotic susceptibility testing of the isolates was then performed using the Kirby Bauer's disc diffusion method. Additionally, a brief survey questionnaire was used to acquire demographic data. Amongst the 311 participants enrolled, nasal colonization with HA-MRSA was found in 47 individuals (15.1%, 95% confidence interval [CI]=11.1%, 19.1%). HA-MRSA was also isolated from the cell phone surfaces in 28 participants (9.0%, 95% CI=8.6%, 9.3%). 5 participants (1.6%) showed positive results both from their nasal swabs and from their cell phones. Antibiotic resistance to erythromycin [48%] and clindamycin [29%] was relatively high. 9.3% HA-MRSA isolates were vancomycin resistant [6.6% nasal carriage]. There was no statistically significant correlation between HA-MRSA isolates and the demographic characteristics or the risk factors namely gender, underlying co-morbidities like diabetes, hypertension, skin/soft tissue infections, skin ulcers/wounds, recent exposure to antibiotics, or hospital visits (p>0.05, Chi-square test). Copyright © 2015 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  10. Prevalence of and risk factors for methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization in HIV-infected ambulatory patients.

    PubMed

    Cenizal, Mary Jo; Hardy, Robert D; Anderson, Marc; Katz, Kathy; Skiest, Daniel J

    2008-08-15

    Estimates of the prevalence of colonization with methicillin-resistant Staphylococcus aureus (MRSA) vary in HIV-infected patients. HIV clinic patients were prospectively cultured. Bilateral nasal and axillary swabs were plated on BBL CHROMagar MRSA media. Molecular typing was done by pulse-field gel electrophoresis, and staphylococcal cassette chromosomemec typing was determined. A patient questionnaire was conducted to ascertain potential MRSA risk factors; medical records were reviewed. Fifteen of 146 (10.3%) patients had MRSA nasal colonization; 1 also had axillary colonization. Twelve of 15 isolates were staphylococcal cassette chromosomemec type IV, and 8 of 14 were USA300 or USA400 genotype. MRSA colonization was associated with lower CD4 cell count, not receiving current or recent antibiotics, history of prior MRSA or methicillin-susceptible Staphylococcus aureus infection (P < 0.05 for all), and a trend toward history of hospitalization or emergency department visit in the past year (P = 0.064). Current use of trimethoprim-sulfamethoxazole was protective for colonization: 0 of 29 trimethoprim-sulfamethoxazole recipients were colonized versus 15 of 117 nonrecipients, P = 0.04. In a multivariate logistic regression model, prior infection with either methicillin-susceptible S. aureus (odds ratio = 32.4, 95% confidence interval 3.04 to 345.42) or MRSA (odds ratio = 9.71, 95% confidence interval 2.20 to 43.01), not receiving current or recent antibiotics (odds ratio = 0.026, 95% confidence interval 0.002 to 0.412), and lower CD4 count (odds ratio 0.996, 95% confidence interval 0.992 to 0.999) were associated with MRSA colonization. The prevalence of MRSA nasal colonization was relatively high compared with prior studies; axillary colonization was rare. Prior staphylococcal infection (methicillin-susceptible S. aureus or MRSA), not receiving antibiotics, and lower CD4 count were associated with MRSA nasal colonization. Trimethoprim-sulfamethoxazole seemed to be

  11. Comparison of BD GeneOhm Methicillin-Resistant Staphylococcus aureus (MRSA) PCR versus the CHROMagar MRSA Assay for Screening Patients for the Presence of MRSA Strains▿

    PubMed Central

    Boyce, John M.; Havill, Nancy L.

    2008-01-01

    We compared the BD GeneOhm methicillin-resistant Staphylococcus aureus (MRSA) real-time PCR assay with the CHROMagar MRSA assay for the detection of MRSA in 286 nasal surveillance specimens. Compared with the CHROMagar MRSA assay, PCR had sensitivity, specificity, positive predictive value, and negative predictive values of 100%, 98.6%, 95.8%, and 100%, respectively. The mean PCR turnaround time was 14.5 h. PMID:18032616

  12. Antibacterial activity of honey against community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA).

    PubMed

    Maeda, Yasunori; Loughrey, Anne; Earle, J A Philip; Millar, B Cherie; Rao, Juluri R; Kearns, Angela; McConville, Ogie; Goldsmith, Colin E; Rooney, Paul J; Dooley, James S G; Lowery, Colm J; Snelling, William J; McMahon, Ann; McDowell, David; Moore, John E

    2008-05-01

    Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has now been described globally, as a clinically significant pathogen, particularly associated with skin and soft tissue infections, including abscesses, cellulitis and furunculosis. The recent emergence of CA-MRSA combined with its predominant presentation associated with skin and soft tissue infection, the previous literature indicating honey as an effective treatment of healthcare-associated HA-MRSA-related wound infection, as well as honey's ease of topical application, make the current study timely and of interest to healthcare practitioners involved with wound management. Although previous studies have examined the antimicrobial activity of honey against HA-MRSA, such data are limited regarding the activity of honey against this emerging type of MRSA. CA-MRSA (n=6 isolates), was examined for its susceptibility to natural honey (n=3 honey produced from bees in Northern Ireland and one commercial French honey). Results demonstrated that all honey was able to reduce the cultural count of all CA-MRSA from approximately 10(6) colony-forming units (cfus) (mean = 6.46 log10 cfu/g) to none detectable within 24h of co-culture of separate CA-MRSA organisms individually with all four-honey types examined. Subsequent non-selective enrichment of honey demonstrated that inoculated honey remained positive for CA-MRSA until 72h postinoculation, after which point no culturable organisms could be detected. This study demonstrated that, in vitro, these natural products had an antimicrobial activity against the CA-MRSA organisms tested. Further studies are now required to demonstrate if this antimicrobial activity has any clinical application.

  13. 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.

  14. Clinical outcomes and treatment approach for community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections in Israel.

    PubMed

    Berla-Kerzhner, E; Biber, A; Parizade, M; Taran, D; Rahav, G; Regev-Yochay, G; Glikman, D

    2017-01-01

    Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections are increasingly documented worldwide. We recently identified two major CA-MRSA clones in Israel: USA300 and t991. Here, we assessed clinical outcomes by CA-MRSA clones and the physicians' treatment approach to CA-MRSA infections. All community-onset, clinical MRSA isolates detected during 2011-2013 by Maccabi Healthcare Services were collected and characterized phenotypically and genotypically; data were collected retrospectively from electronic medical records. Of 309 patients with MRSA infections, 64 were identified as CA-MRSA (21 %). Of the CA-MRSA infections, 72 % had skin and soft tissue infections (SSTIs), 38 % were Panton-Valentine leukocidin (PVL)+, the major clone being USA300 (n = 13, 54 %). Of PVL- isolates (n = 40, 62 %), t991 was the major clone. Age was the only predictor for PVL+ CA-MRSA infection (p < 0.001). Patients with PVL+ CA-MRSA had higher incidence of SSTI recurrences (1.061 vs. 0.647 events per patient/per year, p < 0.0001) and were more likely to have the SSTI drained (64 % vs. 21 %, p = 0.003) when compared to PVL- CA-MRSA. USA300 was more common among adults, while t991 was more common among children (p = 0.002). The physician's referral to culture results and susceptibility were the only predictors of appropriate antibiotic therapy (p < 0.001). However, only a minority of physicians referred to culture results, regardless of subspecialties. PVL+ CA-MRSA isolates caused significantly more recurrences of SSTIs and increased the need for drainage compared with PVL- isolates. Physicians' awareness of CA-MRSA as a cause of SSTIs in the community was suboptimal. Culturing of pus-producing SSTIs is crucial for providing adequate antimicrobials and elucidating MRSA epidemiology.

  15. New insights into meticillin-resistant Staphylococcus aureus (MRSA) pathogenesis, treatment and resistance.

    PubMed

    Gould, Ian M; David, Michael Z; Esposito, Silvano; Garau, Javier; Lina, Gerard; Mazzei, Teresita; Peters, Georg

    2012-02-01

    Meticillin-resistant Staphylococcus aureus (MRSA) remains one of the principal multiply resistant bacterial pathogens causing serious healthcare-associated and community-onset infections. This paper reviews recent studies that have elucidated the virulence strategies employed by MRSA, key clinical trials of agents used to treat serious MRSA infections, and accumulating data regarding the implications of antibacterial resistance in MRSA for clinical success during therapy. Recent pre-clinical data support a species-specific role for Panton-Valentine leukocidin in the development of acute severe S. aureus infections and have elucidated other virulence mechanisms, including novel modes of internalisation, varying post-invasion strategies (featuring both upregulation and downregulation of virulence factors) and phenotypic switching. Recent double-blind, randomised, phase III/IV clinical trials have demonstrated the efficacy of linezolid and telavancin in hospital-acquired pneumonia (HAP) and complicated skin and skin-structure infections (cSSSIs) caused by MRSA. Tigecycline was non-inferior to imipenem/cilastatin in non-ventilator-associated HAP but was inferior in ventilator-associated pneumonia and has shown a higher rate of death than comparators on meta-analysis. Ceftaroline was clinically and microbiologically non-inferior to vancomycin/aztreonam in the treatment of MRSA cSSSI. Key resistance issues include a rise in vancomycin minimum inhibitory concentrations in MRSA, reports of clonal isolates with linezolid resistance mediated by acquisition of the chloramphenicol/florfenicol resistance gene, and case reports of daptomycin resistance resulting in clinical failure. Novel antimicrobial targets must be identified with some regularity or we will face the risk of untreatable S. aureus infections. Copyright © 2011 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  16. Methicillin-resistant Staphylococcus aureus (MRSA) in three dairy herds in southwest Germany.

    PubMed

    Spohr, M; Rau, J; Friedrich, A; Klittich, G; Fetsch, A; Guerra, B; Hammerl, J A; Tenhagen, B-A

    2011-06-01

    The objective of this study was to analyse the occurrence of methicillin-resistant Staphylococcus aureus (MRSA) in three dairy herds in the southwest of Germany that had experienced individual cases of clinical and subclinical mastitis associated with MRSA. The herds were identified by the detection of MRSA during routine resistance testing of mastitis pathogens. All quarters of all cows in the herds that were positive on California Mastitis Test were sampled for bacteriological analysis on two occasions. Bulk tank milk samples were also tested. Furthermore, nasal swabs were collected from people working on the farms and from cattle. Environmental samples were collected from associated pig holdings. Isolates were characterized using spa-typing and testing for antimicrobial resistance. Our results revealed a substantial spread of MRSA in the three dairy herds. In the first of the two investigations carried out on all cows in the three herds, milk samples of 5.1-16.7% of dairy cows were found positive for MRSA. The respective proportions in the second herd level investigation were 1.4-10.0%. Quarters harbouring MRSA had higher somatic cell counts than quarters that were negative on culture. Methicillin-resistant Staphylococcus aureus were also detected in nasal swabs of staff (7/9), cows (7/15) and calves (4/7), bulk tank milk samples (3/3) and environmental samples from pig premises (4/5) on the farm. Herds B and C had no contact to herd A. However, in all three herds MRSA of spa-type t011 were detected in milk samples. Results show that MRSA of spa-type t011 is a problem in dairy farms that needs urgent attention. © 2010 Blackwell Verlag GmbH.

  17. Multicenter evaluation of the LightCycler methicillin-resistant Staphylococcus aureus (MRSA) advanced test as a rapid method for detection of MRSA in nasal surveillance swabs.

    PubMed

    Peterson, Lance R; Liesenfeld, Oliver; Woods, Christopher W; Allen, Stephen D; Pombo, David; Patel, Parul A; Mehta, Maitry S; Nicholson, Bradly; Fuller, DeAnna; Onderdonk, Andrew

    2010-05-01

    The rate of methicillin-resistant Staphylococcus aureus (MRSA) infection continues to rise in many health care settings. Rapid detection of MRSA colonization followed by appropriate isolation can reduce transmission and infection. We compared the performance of the new Roche LightCycler MRSA advanced test to that of the BD GeneOhm MRSA test and culture. Double-headed swabs were used to collect anterior nasal specimens from each subject. For both tests, DNA was extracted and real-time PCR was performed according to manufacturer's instructions. For culture, one swab of the pair was plated directly to CHROMagar MRSA. The swab paired with the BD GeneOhm MRSA test was also placed into an enrichment broth and then plated to CHROMagar MRSA. Colonies resembling staphylococci were confirmed as S. aureus by standard methods. Discrepant specimens had further testing with additional attempts to grow MRSA as well as sample amplicon sequencing. Agreement between results for the two swabs was 99.3% for those with valid results. A total of 1,402 specimens were tested using direct culture detection of MRSA as the gold standard; 187 were culture positive for MRSA. The LightCycler MRSA advanced test had relative sensitivity and specificity of 95.2% (95% confidence interval [CI]: 91.1% to 97.8%) and 96.4% (95% CI: 95.2% to 97.4%), respectively. The BD GeneOhm assay had relative sensitivity and specificity of 95.7% (95% CI: 91.7% to 98.1%) and 91.7% (95% CI: 90.0% to 93.2%), respectively. Following discrepancy analysis, the relative sensitivities of the LightCycler MRSA advanced test and the BD GeneOhm MRSA assay were 92.2 and 93.2%, respectively; relative specificities were 98.9 and 94.2%, respectively. Specificity was significantly better (P<0.001) with the LightCycler MRSA advanced test. The sensitivity of direct culture was 80.4%. The LightCycler MRSA advanced test is a useful tool for sensitive and rapid detection of MRSA nasal colonization.

  18. Evaluation of the LightCycler methicillin-resistant Staphylococcus aureus (MRSA) advanced test for detection of MRSA nasal colonization.

    PubMed

    Yam, W C; Siu, Gilman K H; Ho, P L; Ng, T K; Que, T L; Yip, K T; Fok, Cathie P K; Chen, Jonathan H K; Cheng, Vincent C C; Yuen, K Y

    2013-09-01

    Rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization is crucial for the prevention and control of MRSA infections in health care settings. The LightCycler MRSA Advanced Test (Roche Diagnostics) is a commercially available real-time PCR assay for direct detection of MRSA nasal colonization by targeting of the staphylococcal cassette chromosome mec (SCCmec)-orfX junction. The diagnostic performance of the assay was compared with that of ChromID MRSA agar (bioMérieux) culture and an in-house duplex real-time PCR assay. Among 1,246 nasal swab specimens collected from 2 general hospitals in Hong Kong, 174 (14%) were considered true positive for MRSA. Chromogenic culture and the in-house real-time PCR assay identified 147 (84.5%) and 133 (76.4%) true-positive cases with specificities of 100% and 98.6%, respectively. Based on the target melting temperature (Tm) values (57.0 to 62.0 °C) defined by the manufacturer, the LightCycler MRSA Advanced Test identified only 85 (48.9%) true-positive specimens. Interestingly, an additional 60 (34.5%) true-positive specimens were detected despite atypical Tm values of 55 °C, providing overall sensitivity and specificity values of 83.3% and 99%, respectively. Among isolates with Tm values of 55 °C, most were typed as clonal complex 45 (CC45). By sequence analysis of the SCCmec-orfX junction, characteristic single-nucleotide polymorphisms (SNPs) were identified only in isolates with Tm values of 55°C and not in those with typical Tm values. It is conceivable that those SNPs were located inside the target region of the proprietary hybridization probes, which resulted in a Tm shift in the melting curve analysis. Our study highlights the importance of a global evaluation of commercial kits so that the interpretation algorithm covers different lineages of MRSA clones prevalent in various geographical regions.

  19. Antibacterial activity of extracellular compounds produced by a Pseudomonas strain against methicillin-resistant Staphylococcus aureus (MRSA) strains

    PubMed Central

    2013-01-01

    Background The emergence of multidrug-resistant bacteria is a world health problem. Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA) strains, is one of the most important human pathogens associated with hospital and community-acquired infections. The aim of this work was to evaluate the antibacterial activity of a Pseudomonas aeruginosa-derived compound against MRSA strains. Methods Thirty clinical MRSA strains were isolated, and three standard MRSA strains were evaluated. The extracellular compounds were purified by vacuum liquid chromatography. Evaluation of antibacterial activity was performed by agar diffusion technique, determination of the minimal inhibitory concentration, curve of growth and viability and scanning electron microscopy. Interaction of an extracellular compound with silver nanoparticle was studied to evaluate antibacterial effect. Results The F3 (ethyl acetate) and F3d (dichloromethane- ethyl acetate) fractions demonstrated antibacterial activity against the MRSA strains. Phenazine-1-carboxamide was identified and purified from the F3d fraction and demonstrated slight antibacterial activity against MRSA, and synergic effect when combined with silver nanoparticles produced by Fusarium oxysporum. Organohalogen compound was purified from this fraction showing high antibacterial effect. Using scanning electron microscopy, we show that the F3d fraction caused morphological changes to the cell wall of the MRSA strains. Conclusions These results suggest that P. aeruginosa-produced compounds such as phenazines have inhibitory effects against MRSA and may be a good alternative treatment to control infections caused by MRSA. PMID:23773484

  20. Long-term control of endemic hospital-wide methicillin-resistant Staphylococcus aureus (MRSA): the impact of targeted active surveillance for MRSA in patients and healthcare workers.

    PubMed

    Rodríguez-Baño, Jesús; García, Lola; Ramírez, Encarnación; Lupión, Carmen; Muniain, Miguel A; Velasco, Carmen; Gálvez, Juan; del Toro, M Dolores; Millán, Antonio B; López-Cerero, Lorena; Pascual, Alvaro

    2010-08-01

    To evaluate the long-term impact of successive interventions on rates of methicillin-resistant Staphylococcus aureus (MRSA) colonization or infection and MRSA bacteremia in an endemic hospital-wide situation. Quasi-experimental, interrupted time-series analysis. The impact of the interventions was analyzed by use of segmented regression. Representative MRSA isolates were typed by use of pulsed-field gel electrophoresis. A 950-bed teaching hospital in Seville, Spain. All patients admitted to the hospital during the period from 1995 through 2008. Three successive interventions were studied: (1) contact precautions, with no active surveillance for MRSA; (2) targeted active surveillance for MRSA in patients and healthcare workers in specific wards, prioritized according to clinical epidemiology data; and (3) targeted active surveillance for MRSA in patients admitted from other medical centers. Neither the preintervention rate of MRSA colonization or infection (0.56 cases per 1,000 patient-days [95% confidence interval {CI}, 0.49-0.62 cases per 1,000 patient-days]) nor the slope for the rate of MRSA colonization or infection changed significantly after the first intervention. The rate decreased significantly to 0.28 cases per 1,000 patient-days (95% CI, 0.17-0.40 cases per 1,000 patient-days) after the second intervention and to 0.07 cases per 1,000 patient-days (95% CI, 0.06-0.08 cases per 1,000 patient-days) after the third intervention, and the rate remained at a similar level for 8 years. The MRSA bacteremia rate decreased by 80%, whereas the rate of bacteremia due to methicillin-susceptible S. aureus did not change. Eighty-three percent of the MRSA isolates identified were clonally related. All MRSA isolates obtained from healthcare workers were clonally related to those recovered from patients who were in their care. Our data indicate that long-term control of endemic MRSA is feasible in tertiary care centers. The use of targeted active surveillance for MRSA in

  1. Blue Light Phototherapy Kills Methycillin Resistant Staphylococcus Aureus (MRSA)

    NASA Astrophysics Data System (ADS)

    Enwemeka, Chukuka S.; Williams, Debora; Enwemeka, Sombiri K.; Hollosi, Steve; Yens, David

    2010-05-01

    Background: Methycillin resistant staphylococcus aureus (MRSA) bacteria continue to defy most available antibiotics. As a result infections with MRSA remain a growing public health concern. As a paradigm shift and a significant departure from the on-going trend to develop stronger drug-based therapies, we studied the effect of 405 nm and 470 nm wavelengths of blue light on two strains of MRSA—US-300 strain of CA-MRSA and the IS853 strain of HA-MRSA—in vitro. Methods: We cultured and plated each strain, following which bacteria colonies were irradiated with 0, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 25, 30, 35, 40, 45, 50, 55, or 60 Jcm-2 energy densities—just once. Specimens were incubated at 35° C for 24 h. Then, digital images obtained were quantified to obtain colony counts and the aggregate area occupied by bacteria colonies. Results: Each wavelength produced a statistically significant dose-dependent reduction in both the number and the aggregate area of colonies formed by each bacteria strain (P<0.001). Maximum eradication of the US-300 (92.1%) and the IS-853 colonies (93.5%) was achieved within 10 minutes of irradiation with each wavelength. The longer the irradiation the more bacteria were eradicated. However, the effect was non-linear as increases of energy densities between 1.0 and 15 J cm-2 resulted in more bacteria death than similar increases between 15 J cm-2 and 60 J cm-2. Conclusion: At low doses, blue light photo-destroys HA-MRSA and CA-MRSA in vitro; raising the prospect that phototherapy may be an effective clinical tool in the on-going effort to stem MRSA infections.

  2. SCC mec typing and antimicrobial resistance of methicillin-resistant Staphylococcus aureus (MRSA) from pigs of Northeast India.

    PubMed

    Rajkhowa, S; Sarma, D K; Pegu, S R

    2016-12-01

    Staphylococcus aureus is one of the most important pathogens of both humans and animal. Methicillin-resistant Staphylococcus aureus (MRSA) is an important human pathogen that causes serious infections both in hospitals and communities due to its multidrug resistance tendency. This study was undertaken to characterize the MRSA isolates from pigs and to determine the antimicrobial resistance of these isolates. Forty nine MRSA strains (one strain per positive pig) isolated from pigs of Northeast India were characterized by SCCmec typing and antimicrobial resistance. The overall prevalence of MRSA was 7.02 % with the highest prevalence recorded in pigs aged 1-3 months (P = 0.001) and in nasal samples (P = 0.005). Two SCC mec types (type III and V) were found in Indian pigs with predominance of type V. All isolates were resistant to penicillin. Seventeen resistance groups were observed where 87.75 % isolates showed multidrug resistance (showed resistance to three or more classes of antimicrobials). The most predominant resistance pattern observed was Oxytetracycline + Penicillin + Sulfadiazine + Tetracycline accounting 12.24 % of the isolates. The present study contributes to the understanding of characteristics and antimicrobial resistance of porcine MRSA isolates which in turn will help in devising strategy for the control of this pathogen. Findings of the study also throw light on multidrug resistance MRSA and emphasize the need for judicious use of antimicrobials in animal practice.

  3. Alarming Proportions of Methicillin-Resistant Staphylococcus aureus (MRSA) in Wound Samples from Companion Animals, Germany 2010–2012

    PubMed Central

    Vincze, Szilvia; Stamm, Ivonne; Kopp, Peter A.; Hermes, Julia; Adlhoch, Cornelia; Semmler, Torsten; Wieler, Lothar H.; Lübke-Becker, Antina; Walther, Birgit

    2014-01-01

    Staphylococcus (S.) aureus is an important cause of wound infections in companion animals, and infections with methicillin-resistant S. aureus (MRSA) are of particular concern due to limited treatment options and their zoonotic potential. However, comparable epidemiological data on MRSA infections in dogs, cats and horses is scarce, also limiting the knowledge about possible links to MRSA isolates from human populations. To gain more knowledge about the occurrence and genotypic variation of MRSA among wound swabs of companion animal origin in Germany we performed a survey (2010–2012) including 5,229 samples from 1,170 veterinary practices. S. aureus was identified in 201 (5.8%) canine, 140 (12.2%) feline and 138 (22.8%) equine swabs from a total of 3,479 canine, 1,146 feline and 604 equine wounds, respectively. High MRSA rates were identified with 62.7%, 46.4% and 41.3% in S. aureus of canine, feline and equine origin, respectively. Further genotyping including spa typing and multilocus sequence typing (MLST) revealed a comparable distribution of spa types among canine and feline MRSA with CC22 (47.6%; 49.2%) and CC5 (30.2%; 29.2%) as predominant lineages followed by CC398 (13.5%; 7.7%) and CC8 (4.0%; 9.2%). In contrast, the majority of equine MRSA belonged to CC398 (87.7%). Our data highlight the importance of S. aureus and MRSA as a cause of wound infections, particularly in cats and horses in Germany. While “human-associated” MRSA lineages were most common in dogs and cats, a remarkable number of CC398-MRSA was detected in horses, indicating a replacement of CC8-MRSA as the predominant lineage within horses in Germany. These data enforce further longitudinal epidemiological approaches to examine the diversity and temporal relatedness of MRSA populations in humans and animals to assess probable sources of MRSA infections. This would enable a sound risk assessment and establishment of intervention strategies to limit the additional spread of MRSA. PMID

  4. Alarming proportions of methicillin-resistant Staphylococcus aureus (MRSA) in wound samples from companion animals, Germany 2010-2012.

    PubMed

    Vincze, Szilvia; Stamm, Ivonne; Kopp, Peter A; Hermes, Julia; Adlhoch, Cornelia; Semmler, Torsten; Wieler, Lothar H; Lübke-Becker, Antina; Walther, Birgit

    2014-01-01

    Staphylococcus (S.) aureus is an important cause of wound infections in companion animals, and infections with methicillin-resistant S. aureus (MRSA) are of particular concern due to limited treatment options and their zoonotic potential. However, comparable epidemiological data on MRSA infections in dogs, cats and horses is scarce, also limiting the knowledge about possible links to MRSA isolates from human populations. To gain more knowledge about the occurrence and genotypic variation of MRSA among wound swabs of companion animal origin in Germany we performed a survey (2010-2012) including 5,229 samples from 1,170 veterinary practices. S. aureus was identified in 201 (5.8%) canine, 140 (12.2%) feline and 138 (22.8%) equine swabs from a total of 3,479 canine, 1,146 feline and 604 equine wounds, respectively. High MRSA rates were identified with 62.7%, 46.4% and 41.3% in S. aureus of canine, feline and equine origin, respectively. Further genotyping including spa typing and multilocus sequence typing (MLST) revealed a comparable distribution of spa types among canine and feline MRSA with CC22 (47.6%; 49.2%) and CC5 (30.2%; 29.2%) as predominant lineages followed by CC398 (13.5%; 7.7%) and CC8 (4.0%; 9.2%). In contrast, the majority of equine MRSA belonged to CC398 (87.7%). Our data highlight the importance of S. aureus and MRSA as a cause of wound infections, particularly in cats and horses in Germany. While "human-associated" MRSA lineages were most common in dogs and cats, a remarkable number of CC398-MRSA was detected in horses, indicating a replacement of CC8-MRSA as the predominant lineage within horses in Germany. These data enforce further longitudinal epidemiological approaches to examine the diversity and temporal relatedness of MRSA populations in humans and animals to assess probable sources of MRSA infections. This would enable a sound risk assessment and establishment of intervention strategies to limit the additional spread of MRSA.

  5. Genotypic and phenotypic characterization of methicillin-resistant Staphylococcus aureus (MRSA) clones with high-level mupirocin resistance.

    PubMed

    González-Domínguez, María; Seral, Cristina; Potel, Carmen; Sáenz, Yolanda; Álvarez, Maximiliano; Torres, Carmen; Castillo, Francisco Javier

    2016-06-01

    A high proportion of methicillin-resistant Staphylococcus aureus isolates recovered in one year period showed high-level mupirocin-resistance (HLMUPR-MRSA) in our environment (27.2%). HLMUPR-MRSA isolates were mainly collected from skin and soft tissue samples, and diabetes was the main related comorbidity condition. These isolates were more frequently found in vascular surgery. HLMUPR-MRSA was more resistant to aminoglycosides than mupirocin-susceptible MRSA, linked to the presence of bifunctional and/or nucleotidyltransferase enzymes with/without macrolide resistance associated with the msr(A) gene. Most of HLMUPR-MRSA isolates belonged to ST125/t067. Nine IS257-ileS2 amplification patterns (p3 was the most frequent) were observed in HLMUPR-MRSA isolates, suggesting the presence of several mupirocin-resistance-carrying plasmids in our environment and promoting the emergence of mupirocin resistance. The presence of the same IS257-ileS2 amplification pattern p3 in 65% of HLMUPR-MRSA, all of them ST125/t067, suggests a clonal spread in our hospital and community environment which could explain the high prevalence of HLMUPR-MRSA during the study period. An outbreak situation or an increase in mupirocin consumption was not observed.

  6. Synergism between Medihoney and Rifampicin against Methicillin-Resistant Staphylococcus aureus (MRSA)

    PubMed Central

    Müller, Patrick; Alber, Dagmar G.; Turnbull, Lynne; Schlothauer, Ralf C.; Carter, Dee A.; Whitchurch, Cynthia B.; Harry, Elizabeth J.

    2013-01-01

    Skin and chronic wound infections caused by highly antibiotic resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) are an increasing and urgent health problem worldwide, particularly with sharp increases in obesity and diabetes. New Zealand manuka honey has potent broad-spectrum antimicrobial activity, has been shown to inhibit the growth of MRSA strains, and bacteria resistant to this honey have not been obtainable in the laboratory. Combinational treatment of chronic wounds with manuka honey and common antibiotics may offer a wide range of advantages including synergistic enhancement of the antibacterial activity, reduction of the effective dose of the antibiotic, and reduction of the risk of antibiotic resistance. The aim of this study was to investigate the effect of Medihoney in combination with the widely used antibiotic rifampicin on S. aureus. Using checkerboard microdilution assays, time-kill curve experiments and agar diffusion assays, we show a synergism between Medihoney and rifampicin against MRSA and clinical isolates of S. aureus. Furthermore, the Medihoney/rifampicin combination stopped the appearance of rifampicin-resistant S. aureus in vitro. Methylglyoxal (MGO), believed to be the major antibacterial compound in manuka honey, did not act synergistically with rifampicin and is therefore not the sole factor responsible for the synergistic effect of manuka honey with rifampicin. Our findings support the idea that a combination of honey and antibiotics may be an effective new antimicrobial therapy for chronic wound infections. PMID:23469049

  7. Risk and outcomes of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia among patients admitted with and without MRSA nares colonization.

    PubMed

    Marzec, Natalie S; Bessesen, Mary T

    2016-04-01

    The risk of nosocomial methicillin-sensitive Staphylococcus aureus bacteremia in patients with nasal colonization on admission is 3-fold higher than in patients who are not colonized. Limited data on this question have been reported for methicillin-resistant S aureus (MRSA). This is an observational cohort study of patients admitted to a tertiary care medical center from October 1, 2007-September 30, 2013, who underwent active screening for nasal colonization with MRSA. There were 29,371 patients who underwent screening for nasal MRSA colonization; 3,262 (11%) were colonized with MRSA. There were 32 cases of MRSA bacteremia among colonized patients, for an incidence of 1%. Thirteen cases of bacteremia occurred in non-MRSA-colonized patients, for an incidence of 0.05%. The odds of developing MRSA bacteremia for patients who were nasally colonized with MRSA compared with those who were not colonized were 19.89. There was no difference between colonized and noncolonized subjects with bacteremia in all-cause mortality at 30 days or 1 year. In a setting with active screening for MRSA, the risk of MRSA bacteremia is 19.89-fold higher among colonized than noncolonized patients. Published by Elsevier Inc.

  8. [Methicillin resistance detection in Staphylococcus aureus: comparison between conventional methods and MRSA-Screen latex agglutination technique].

    PubMed

    Soloaga, R; Corso, A; Gagetti, P; Faccone, D; Galas, M

    2004-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a significant pathogen that has emerged over the last four decades, causing both nosocomial and community-acquired infections. Rapid and accurate detection of methicillin resistance in S. aureus is important for the use of appropriate antimicrobial therapy and for the control of nosocomial spread of MRSA strains. We evaluated the efficiency of conventional methods for detection of methicillin resistance such as the disk diffusion, agar dilution, oxacillin agar screen test, and the latex agglutination test MRSA-Screen latex, in 100 isolates of S. aureus, 79 mecA positive and 21 mecA negative. The MRSA-Screen latex (Denka Seiken, Niigata, Japón), is a latex agglutination method that detects the presence of PLP-2a, product of mecA gene in S. aureus. The PCR of the mecA gene was used as the "gold standard" for the evaluation of the different methods tested. The percentages of sensitivity and specificity were as follows: disk difusión 97 and 100%, agar dilution 97 and 95%, oxacillin agar screen test 100 and 100%, and MRSA-Screen latex, 100 and 100 %. All methods presented high sensitivity and specificity, but MRSA-Screen latex had the advantage of giving a reliable result, equivalent to PCR, in only 15 minutes.

  9. Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) at ambient freshwater beaches.

    PubMed

    Fogarty, Lisa R; Haack, Sheridan K; Johnson, Heather E; Brennan, Angela K; Isaacs, Natasha M; Spencer, Chelsea

    2015-09-01

    Methicillin-resistant Staphylococcus aureus (MRSA) are a threat to human health worldwide, and although detected at marine beaches, they have been largely unstudied at freshwater beaches. Genes indicating S. aureus (SA; femA) and methicillin resistance (mecA) were detected at 11 and 12 of 13 US Great Lakes beaches and in 18% or 27% of 287 recreational water samples, respectively. Eight beaches had mecA+femA (potential MRSA) detections. During an intensive study, higher bather numbers, staphylococci concentrations, and femA detections were found in samples collected after noon than before noon. Local population density, beach cloud cover, and beach wave height were significantly correlated with SA or MRSA detection frequency. The Panton-Valentine leukocidin gene, associated with community-acquired MRSA, was detected in 12 out of 27 potential MRSA samples. The femA gene was detected less frequently at beaches that met US enterococci criteria or EU enterococci 'excellent' recreational water quality, but was not related to Escherichia coli-defined criteria. Escherichia coli is often the only indicator used to determine water quality at US beaches, given the economic and healthcare burden that can be associated with infections caused by SA and MRSA, monitoring of recreational waters for non-fecal bacteria such as staphylococci and/or SA may be warranted.

  10. Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) at ambient freshwater beaches

    USGS Publications Warehouse

    Fogarty, Lisa R.; Haack, Sheridan K.; Johnson, Heather E.; Brennan, Angela K.; Isaacs, Natasha M.; Spencer, Chelsea

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) are a threat to human health worldwide, and although detected at marine beaches, they have been largely unstudied at freshwater beaches. Genes indicating S. aureus (SA; femA) and methicillin resistance (mecA) were detected at 11 and 12 of 13 US Great Lakes beaches and in 18% or 27% of 287 recreational water samples, respectively. Eight beaches had mecA + femA (potential MRSA) detections. During an intensive study, higher bather numbers, staphylococci concentrations, and femA detections were found in samples collected after noon than before noon. Local population density, beach cloud cover, and beach wave height were significantly correlated with SA or MRSA detection frequency. The Panton-Valentine leukocidin gene, associated with community-acquired MRSA, was detected in 12 out of 27 potential MRSA samples. The femA gene was detected less frequently at beaches that met US enterococci criteria or EU enterococci ‘excellent’ recreational water quality, but was not related to Escherichia coli-defined criteria. Escherichia coli is often the only indicator used to determine water quality at US beaches, given the economic and healthcare burden that can be associated with infections caused by SA and MRSA, monitoring of recreational waters for non-fecal bacteria such as staphylococci and/or SA may be warranted.

  11. Prevalence of Staphylococcus aureus and methicillin resistant Staphylococcus aureus (MRSA) in the oral cavity.

    PubMed

    Koukos, Georgios; Sakellari, Dimitra; Arsenakis, Minas; Tsalikis, Lazaros; Slini, Theodora; Konstantinidis, Antonios

    2015-09-01

    To assess the prevalence of Staphylococcus aureus and methicillin resistant Staphylococcus aureus (MRSA) in plaque and tongue samples from systemically healthy subjects with periodontal health, gingivitis or chronic periodontitis. After screening 720 potentially eligible subjects, 154 systemically healthy participants were ultimately enrolled in the current study. Subgingival samples were taken from the first molars and the tongue and analyzed for the presence of S. aureus and MRSA by polymerase chain reaction (PCR), using primers and conditions previously described in the literature. In addition, samples were taken from deep periodontal pockets of chronic periodontitis patients. Statistical analysis was performed by applying non-parametric tests (Kruskal-Wallis for clinical parameters, and z-test with Bonferroni corrections for distributions of assessed parameters). All comparisons were set at the 0.05 significance level. S. aureus was detected in 18% of all participants and in 10% of the samples tested. No significant differences were found in its distribution among the three investigated groups (z-test for proportions with Bonferroni corrections, p>0.05). The mecA gene was not present in any of the S. aureus found. S. aureus can be found in the oral environment regardless of the periodontal conditions and therefore should be considered as a member of the transient flora not participating in periodontal pathology. Subgingival sites and tongue surfaces seem to be an unusual habitat of MRSA. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Predominance of Three Closely Related Methicillin-Resistant Staphylococcus aureus Clones Carrying a Unique ccrC-Positive SCCmec type III and the Emergence of spa t304 and t690 SCCmec type IV pvl(+) MRSA Isolates in Kinta Valley, Malaysia.

    PubMed

    Ho, Wai-Yew; Choo, Quok-Cheong; Chew, Choy-Hoong

    2017-03-01

    We investigated the epidemiology and clonality of 175 nonrepetitive methicillin-resistant Staphylococcus aureus (MRSA) isolates from clinical specimens collected between 2011 and 2012 in Kinta Valley in Malaysia. Molecular tools such as polymerase chain reaction, pulsed-field gel electrophoresis, and staphylococcal protein A (spa) typing were used. Our study revealed the predominance of three closely related ermA(+) SCCmec type III pulsotypes belonging to spa type t037 (Brazilian-Hungarian clone), which were deficient in the locus F, but positive for the ccrC gene in majority (65.7%) of the MRSA infections in this region. The first evidence of SCCmec type II MRSA in the country, belonging to spa type t2460, was also noted. Although the carriage of pvl gene was uncommon (8.6%) and mostly confined to either SCCmec type IV or SCCmec type V isolates, most of these isolates belonged to spa types t345 or t657, which are associated with the Bengal-Bay CA-MRSA clone. Interestingly, spa t304 and t690 SCCmec type IV pvl(+) were also detected among the MRSA isolates. Data from this study show the rise of uncommon clones among MRSA isolates in Malaysia.

  13. Methicillin-resistant Staphylococcus aureus (MRSA) on the skin of long-term hospitalised horses.

    PubMed

    Van den Eede, A; Hermans, K; Van den Abeele, A; Floré, K; Dewulf, J; Vanderhaeghen, W; Crombé, F; Butaye, P; Gasthuys, F; Haesebrouck, F; Martens, A

    2012-08-01

    Given the significance of methicillin-resistant Staphylococcus aureus (MRSA) infections for both horses and staff in equine veterinary hospitals, protocols are required to minimise the risk of nosocomial transmission, including the screening of the skin and nasal chambers of equine patients for evidence of infection. The objective of this study was to clarify the potential existence and extent of MRSA on the skin of horses requiring long-term hospitalisation (≥ 6 months). Thirty such horses were sampled at eight different locations on their skin and from their nasal chambers. MRSA was isolated from 12 animals (40%), with all sample sites testing positive on at least one occasion. Organisms were most frequently detected in the nasal chambers (relative sensitivity, 83.3%; 34.5% positive horses; isolation rate 33.3%). Skin presence was found in 30% of animals with the highest isolation rates found at the carpus (16.7%), neck, withers and croup (13.3% each). To achieve a relative screening sensitivity of >90%, at least one skin site was required in addition to nasal sampling. This evidence of skin as well as nasal reservoirs of MRSA in long-term hospitalised horses should facilitate the design of effective screening and containment protocols.

  14. Identification and characterization of methicillin-resistant Staphylococcus aureus (MRSA) from Austrian companion animals and horses.

    PubMed

    Loncaric, Igor; Künzel, Frank; Licka, Theresia; Simhofer, Hubert; Spergser, Joachim; Rosengarten, Renate

    2014-01-31

    The aim of this study was to investigate the antimicrobial resistance, resistance gene patterns and genetic relatedness of a collection of Austrian methicillin-resistant Staphylococcus aureus (MRSA) isolates from companion animals and horses. A total of 89 non-repetitive MRSA isolates collected during routine veterinary microbiological examinations from April 2004 to the end of 2012, and one isolate from 2013 were used for this study. The presence of mecA and other resistance genes was confirmed by PCR. Isolates were genotyped by spa typing, two multiple-locus variable-number tandem repeat analyses (MLVA) analyses, SCCmec typing and multilocus sequence typing (MLST). PCR targeting Panton-Valentine leukocidin (PVL) and detection of staphylococcal enterotoxins (SE), toxic shock syndrome toxin (TSST) was performed using PCR assays. Antimicrobial susceptibility testing was performed. Five sequence types (STs-ST398, ST254, ST22, ST5 and ST1), SCCmec types II, IVa, V, and non-type-abele, 8 spa-types (t003, t011, t036, t127, t386, t1348, and t4450), and two isolates could not be assigned, 21 MLVA-14Orsay types Multiplex-PCR MLVA (mMLVA) displayed 17 different MLVA types. The present study is the most comprehensive dealing with MRSA from Austrian companion animals and horses. The results confirm that MRSA ST398 is present in a wide range of animal species and is predominant especially in horses. In other companion animals it is unclear whether the infections with the different MRSA isolates investigated in the present study truly represents a rare phenomenon or may be an emerging problem in companion animals.

  15. Anti-methicillin-resistant Staphylococcus aureus (MRSA) activity of Rubiaceae, Fabaceae and Poaceae plants: A search for new sources of useful alternative antibacterials against MRSA infections.

    PubMed

    Sharifi-Rad, M; Iriti, M; Sharifi-Rad, M; Gibbons, S; Sharifi-Rad, J

    2016-08-29

    In this study, we evaluated the effects of the extracts of the leaves of species from the Rubiaceae (Galium aparine L. and Asperula arvensis L.), Fabaceae (Lathyrus aphaca L. and Vicia narbonensis L.) and Poaceae (Digitaria sanguinalis (L.) Scop. and Hordeum murinum L.) plant families on a wide and extensive panel of isolated methicillin-resistant Staphylococcus aureus strains (MRSA). The effects of the methanolic leaf extracts of Rubiaceae, Fabaceae and Poaceae plants on MRSA were evaluated by the disc diffusion assay and the broth dilution method. Among a total of 177 S. aureus isolates, 92 (51.97%) were found to be methicillin-resistant in an antibiogram and this was confirmed by the presence of the mecA gene in polymerase chain reaction method. All MRSA isolates were sensitive to all extracts. There were dose-dependent inhibitions on tested microorganisms for all plant extracts which showed maximum inhibition zones at a concentration of 300 mg/L. L. aphaca, G. aparine and H. murinum exhibited the highest antibacterial activity on the MRSA strains compared to the positive control (P < 0.05), as well as higher total polyphenol and flavonoid contents than other plant extracts. Minimum inhibitory concentrations on MRSA isolates ranged from 388.4 ± 0.2 mg/L, in D. sanguinalis, to 5.5 ± 0.1 mg/L, in L. aphaca. The methanolic extracts of L. aphaca (Fabaceae), G. aparine (Rubiaceae), and H. murinum (Poaceae) proved to have high antibacterial activity on MRSA isolates, thus representing promising antimicrobial agents in clinical settings.

  16. Methicillin-resistant Staphylococcus aureus (MRSA) pediatric tympanostomy tube otorrhea.

    PubMed

    Cheng, Jeffrey; Javia, Luv

    2012-12-01

    To describe our experience and clinical outcomes with the management of pediatric tympanostomy tube otorrhea secondary to methicillin-resistant Staphylococcus aureus (MRSA). Retrospective review of pediatric patients (age <18) diagnosed with culture-positive MRSA tympanostomy tube otorrhea. MRSA positive ear cultures in the presence of tympanostomy tubes were identified in 41 patients (6.3%). The average age was 2.9 years old. In all cases, culture results indicated sensitivity to trimethoprim/sulfamethoxazole and gentamicin; resistance to fluoroquinolones and clindamycin occurred in 87.8% and 61.0% of cases, respectively. Fluoroquinolone and sulfacetamide ototopical medications were found to be associated with successful otorrhea resolution (p=0.005 and 0.009, respectively). Adjunctive therapy with oral antibiotics, bactrim and clindamycin (p=0.172 and 0.877, respectively), did not improve resolution rates with medical treatment. Tympanostomy tube removal was more successful than medical therapy alone (p<0.0001). Appropriately treated recurrent or recalcitrant tympanostomy tube-related otorrhea should raise the suspicion for MRSA-related tympanostomy tube otorrhea. Fluoroquinolone ototopical medication should be considered for initial therapy. Sulfacetamide ototopical medication can be considered for failures. The adjunctive use of oral antibiotics, bactrim and clindamycin, and aminoglycoside ototopical medications did not improve clinical outcomes for medical therapy alone. We believe that some consideration be given to removal of the tympanostomy tube with or without replacement, after an initial treatment period with fluoroquinolone and/or sulfacetamide otopical medications. Our findings seem to suggest an improved rate with tympanostomy tube removal over medical therapy alone (p<0.0001). No standard management guidelines currently exist. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  17. Salicylanilide carbamates: Promising antibacterial agents with high in vitro activity against methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Zadrazilova, Iveta; Pospisilova, Sarka; Masarikova, Martina; Imramovsky, Ales; Ferriz, Juana Monreal; Vinsova, Jarmila; Cizek, Alois; Jampilek, Josef

    2015-09-18

    A series of twenty-one salicylanilide N-alkylcarbamates was assessed for novel antibacterial characteristics against three clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and S. aureus ATCC 29213 as the reference and quality control strain. The minimum inhibitory concentration was determined by the broth dilution micro-method with subsequent subcultivation of aliquots to assess minimum bactericidal concentration. The bactericidal kinetics was established by time-kill assay. Ampicillin, ciprofloxacin and vancomycin were used as reference antibacterial drugs. All the tested compounds exhibited highly potent anti-MRSA activity (⩽ 0.008-4 μg/mL) comparable or up to 250× higher than that of vancomycin, the standard in the treatment of serious MRSA infections. 4-Chloro-2-(3,4-dichlorophenylcarbamoyl)phenyl butylcarbamate and 4-chloro-2-(3,4-dichlorophenylcarbamoyl)phenyl ethylcarbamate were the most active compounds. In most cases, compounds provided reliable bacteriostatic activity, except for 4-chloro-2-(4-chlorophenylcarbamoyl)phenyl decylcarbamate exhibiting bactericidal effect at 8h (for clinical isolate of MRSA 63718) and at 24h (for clinical isolates of MRSA SA 630 and MRSA SA 3202) at 4× MIC. Structure-activity relationships are discussed.

  18. Identification of a PVL-negative SCCmec-IVa sublineage of the methicillin-resistant Staphylococcus aureus CC80 lineage: understanding the clonal origin of CA-MRSA.

    PubMed

    Edslev, S M; Westh, H; Andersen, P S; Skov, R; Kobayashi, N; Bartels, M D; Vandenesch, F; Petersen, A; Worning, P; Larsen, A R; Stegger, M

    2017-06-29

    Community-acquired (CA) methicillin-resistant Staphylococcus aureus (MRSA) isolates belonging to clonal complex 80 (CC80) are recognized as the European CA-MRSA. The prevailing European CA-MRSA clone carries a type IVc staphylococcal cassette chromosome mec (SCCmec) and expresses Panton-Valentine leukocidin (PVL). Recently, a significant increase of PVL-negative CC80 MRSA has been observed in Denmark. The aim of this study was to examine their genetics and epidemiology, and to compare them to the European CA-MRSA clone in order to understand the emergence of PVL-negative CC80 MRSA. Phylogenetic analysis of the CC80 S. aureus lineage was conducted from whole-genome sequences of 217 isolates (23 methicillin-susceptible S. aureus and 194 MRSA) from 22 countries. All isolates were further genetically characterized in regard to resistance determinants and PVL carriage, and epidemiologic data were obtained for selected isolates. Phylogenetic analysis revealed the existence of three distinct clades of the CC80 lineage: (a) an methicillin-susceptible S. aureus clade encompassing Sub-Saharan African isolates (n = 13); (b) a derived clade encompassing the European CA-MRSA SCCmec-IVc clone (n = 185); and (c) a novel and genetically distinct clade encompassing MRSA SCCmec-IVa isolates (n = 19). All isolates in the novel clade were PVL negative, but carried remnant parts (8-12 kb) of the PVL-encoding prophage ΦSa2 and were susceptible to fusidic acid and kanamycin/amikacin. Geospatial mapping could link these isolates to regions in the Middle East, Asia and South Pacific. This study reports the emergence of a novel CC80 CA-MRSA sublineage, showing that the CC80 lineage is more diverse than previously assumed. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  19. Potential for pet animals to harbour methicillin-resistant Staphylococcus aureus when residing with human MRSA patients.

    PubMed

    Morris, D O; Lautenbach, E; Zaoutis, T; Leckerman, K; Edelstein, P H; Rankin, S C

    2012-06-01

    Colonization by methicillin-resistant Staphylococcus aureus (MRSA) may be persistent in people and is horizontally transmissible. The scientific literature suggests that domestic pets may also participate in cross-transmission of MRSA within households. The objectives of this study were to evaluate the prevalence of and risk factors for MRSA carriage by pets residing in households with an MRSA-infected person. From 66 households in which an MRSA-infected patient resided, we screened 47 dogs and 52 cats using a swab protocol. Isolates from pets and humans were genotyped using two techniques and compared for concordance. Human participants completed a 22-question survey of demographic and epidemiologic data relevant to staphylococcal transmission. Eleven of 99 pets (11.5%) representing 9 (13.6%) of households were MRSA-positive, but in only six of these households were the human and animal-source strains genetically concordant. Human infection by strain USA 100 was significantly associated with pet carriage [OR = 11.4 (95% CI 1.7, 76.9); P = 0.013]. Yet, for each day of delay in sampling the pet after the person's MRSA diagnosis, the odds of isolating any type of MRSA from the pet decreased by 13.9% [(95% CI 2.6, 23.8); P = 0.017)]. It may be concluded that pets can harbour pandemic strains of MRSA while residing in a household with an infected person. However, the source of MRSA to the pet cannot always be attributed to the human patient. Moreover, the rapid attrition of the odds of obtaining a positive culture from pets over time suggests that MRSA carriage may be fleeting. © 2012 Blackwell Verlag GmbH.

  20. Prevalence and characterization of Methicillin-resistant Staphylococcus aureus isolates from retail meat and humans in Georgia

    USDA-ARS?s Scientific Manuscript database

    There is increasing interest in the presence of Staphylococcus aureus, specifically methicillin-resistant S. aureus (MRSA), on retail meat products. In this study, staphylococci were isolated from retail pork and retail beef in Georgia and MRSA from the products were compared to human MRSA from the...

  1. Prevalence and antibiotic susceptibility pattern of methicillin-resistant Staphylococcus aureus (MRSA) among primary school children and prisoners in Jimma Town, Southwest Ethiopia

    PubMed Central

    2013-01-01

    Background Staphylococcus aureus infections are increasingly reported from both health institutions and communities around the world. In particular, infections due to methicillin-resistant Staphylococcus aureus (MRSA) strains have been detected worldwide. If MRSA becomes the most common form of S. aureus in a community, it makes the treatment of common infections much more difficult. But, report on the current status of community acquired MRSA in the study area is scanty. Methods Community-based cross sectional study was conducted to evaluate the current prevalence and antibiotic susceptibility pattern of MRSA among primary school children and prisoners in Jimma town. MRSA was detected using Cefoxitin (30μg) disc; and epidemiologic risk factors were assessed using pre-designed questionnaires distributed to the children’s parents and prisoners. A total of 354 nasal swabs were collected from primary school children and prisoners from December 2010 to March 2011 following standards microbiological methods. Results A total of 169 S. aureus isolates were recovered. The overall prevalence of MRSA among the study population was 23.08 % (39/169). Specifically, the prevalence of MRSA among primary school children and prisoners were 18.8% (27/144) and 48% (12/25), respectively. The isolated S. aureus and MRSA displayed multiple drug resistance (MDR) to 2 to 10 antibiotics. The most frequent MDR was Amp/Bac/Ery/Pen/Fox (resistance to Ampicillin, Bacitracin, Erythromycin, Penicillin, and Cefoxitin). Conclusion The present study revealed that MRSA could be prevalent in the healthy community, transmitted from hospital to the community. The high distribution of MRSA could be favored by potential risk factors. Thus, for comprehensive evaluation of the current prevalence of MRSA and design control measures, consideration need to be given to the healthy community besides data coming from health institutions. PMID:23731679

  2. Prevalence of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) in food samples associated with foodborne illness in Alberta, Canada from 2007 to 2010.

    PubMed

    Crago, B; Ferrato, C; Drews, S J; Svenson, L W; Tyrrell, G; Louie, M

    2012-10-01

    Consumption of foods containing Staphylococcus aureus can cause severe gastro-intestinal illness. Given the fact that over the past decade, Canada has seen increasing rates of methicillin-resistant S. aureus (MRSA) carriage and infection, the objective of this study was to investigate the impact of methicillin-susceptible S. aureus (MSSA) and MRSA on foodborne illness in Alberta, Canada. Between January 2007 and December 2010, there were 693 food samples associated with foodborne investigations submitted to the Alberta Provincial Laboratory for Public Health (ProvLab). These foods were screened for: Bacillus cereus, Clostridium perfringens, S. aureus, Aeromonas spp., Campylobacter spp., Escherichia coli O157:H7, Salmonella, Shigella spp., and Yersinia spp. S. aureus was identified in 10.5% (73/693) of samples, and of these, 59% (43/73) were co-contaminated with at least one other organism on the screening panel. The S. aureus positive samples included 29 meat, 20 prepared foods containing meat, 11 prepared foods not containing meat, 10 dairy, and three produce. Methicillin-resistance was not detected in any isolates tested. These findings indicate that the presence of S. aureus in food associated with foodborne investigations is a cause for concern, and although MRSA was not found, the potential for outbreaks exists, and ongoing surveillance should be sustained. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  3. Multicenter Evaluation of BBL CHROMagar MRSA Medium for Direct Detection of Methicillin-Resistant Staphylococcus aureus from Surveillance Cultures of the Anterior Nares

    PubMed Central

    Flayhart, Diane; Hindler, Janet F.; Bruckner, David A.; Hall, Geraldine; Shrestha, Rabin K.; Vogel, Sherilynn A.; Richter, Sandra S.; Howard, Wanita; Walther, Rhonda; Carroll, Karen C.

    2005-01-01

    Active surveillance for methicillin-resistant Staphylococcus aureus (MRSA) is among the strategies recommended by the Society for Healthcare Epidemiology of America for control of nosocomial MRSA infections. Infection control and laboratory personnel desire rapid, sensitive, and inexpensive methods to enhance surveillance activities. A multicenter study was performed to evaluate a new selective and differential chromogenic medium, BBL CHROMagar MRSA (C-MRSA) medium (BD Diagnostics, Sparks, MD), which enables recovery and concomitant identification of MRSA strains directly from nasal swab specimens taken from the anterior nares. Specimens were inoculated to C-MRSA and Trypticase soy agar with 5% sheep blood agar (TSA II, BD Diagnostics). Mauve colonies on C-MRSA at 24 h and 48 h and suspicious colonies on TSA II were confirmed as Staphylococcus aureus by Gram stain morphology and a coagulase test. In addition, the results of C-MRSA were compared to results of susceptibility testing (five different methods) of S. aureus strains isolated on TSA II. A total of 2,015 specimens were inoculated to C-MRSA and TSA II. Three hundred fifty-four S. aureus isolates were recovered; 208 (59%) were oxacillin (methicillin) susceptible and 146 (41%) were oxacillin resistant (MRSA). On C-MRSA, 139/146 or 95.2% of MRSA isolates were recovered, whereas recovery on TSA II was 86.9% (127/146) (P = 0.0027). The overall specificity of C-MRSA was 99.7%. When C-MRSA was compared to each susceptibility testing method, the sensitivity and specificity, respectively, were as follows: oxacillin MIC by broth microdilution, 94.4% and 96.7%; oxacillin screen agar, 94.3% and 96.7%; PBP2′ latex agglutination, 93.7% and 98.5%; cefoxitin disk diffusion, 95.0% and 98.1%; and mecA PCR, 95.1% and 98.1%. In this study, C-MRSA was superior to TSA II for recovery of MRSA from surveillance specimens obtained from the anterior nares and was comparable to conventional, rapid, and molecular susceptibility

  4. Methicillin-Resistant Staphylococcus aureus (MRSA) Detection: Comparison of Two Molecular Methods (IDI-MRSA PCR Assay and GenoType MRSA Direct PCR Assay) with Three Selective MRSA Agars (MRSA ID, MRSASelect, and CHROMagar MRSA) for Use with Infection-Control Swabs▿

    PubMed Central

    van Hal, S. J.; Stark, D.; Lockwood, B.; Marriott, D.; Harkness, J.

    2007-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is an increasing problem. Rapid detection of MRSA-colonized patients has the potential to limit spread of the organism. We evaluated the sensitivities and specificities of MRSA detection by two molecular methods (IDI-MRSA PCR assay and GenoType MRSA Direct PCR assay) and three selective MRSA agars (MRSA ID, MRSASelect, and CHROMagar MRSA), using 205 (101 nasal, 52 groin, and 52 axillary samples) samples from consecutive known MRSA-infected and/or -colonized patients. All detection methods had higher MRSA detection rates for nasal swabs than for axillary and groin swabs. Detection of MRSA by IDI-MRSA was the most sensitive method, independent of the site (94% for nasal samples, 80% for nonnasal samples, and 90% overall). The sensitivities of the GenoType MRSA Direct assay and the MRSA ID, MRSASelect, and CHROMagar MRSA agars with nasal swabs were 70%, 72%, 68%, and 75%, respectively. All detection methods had high specificities (95 to 99%), independent of the swab site. Extended incubation for a further 24 h with selective MRSA agars increased the detection of MRSA, with a corresponding decline in specificity secondary to a significant increase in false-positive results. There was a noticeable difference in test performance of the GenoType MRSA Direct assay in detection of MRSA (28/38 samples [74%]) compared with detection of nonmultiresistant MRSA (17/31 samples [55%]) (susceptible to two or more non-β-lactam antibiotics). This was not observed with selective MRSA agar plates or IDI-MRSA. Although it is more expensive, in addition to rapid turnaround times of 2 to 4 h, IDI-MRSA offers greater detection of MRSA colonization, independent of the swab site, than do conventional selective agars and GenoType MRSA Direct. PMID:17537949

  5. Clonality and Antimicrobial Susceptibility of Staphylococcus aureus and Methicillin-Resistant S. aureus Isolates from Food Animals and Other Animals

    PubMed Central

    Chow, Kin-Hung; Lai, Eileen L.; Law, Pierra Y. T.; Chan, Pui-Ying; Ho, Alex Y. M.; Ng, Tak-Keung; Yam, Wing-Cheong

    2012-01-01

    Out of 3,081 animals studied, 24.9% of pigs, 4.7% of chickens, 6.3% of dogs, 10.5% of cats, and 7.1% of rodents were Staphylococcus aureus positive. Prevalence of methicillin-resistant S. aureus (MRSA) was high in pigs (animals, 21.3%; batches, 46.5%), with all MRSA isolates and most methicillin-sensitive S. aureus isolates belonging to clonal complex 9 (CC9) and being multidrug resistant. The predominant S. aureus CCs among dog and cat isolates were similar. Among rodent isolates, CC398 predominated, with spa t034 the most frequent spa type detected. PMID:22895044

  6. Clonality and antimicrobial susceptibility of Staphylococcus aureus and methicillin-resistant S. aureus isolates from food animals and other animals.

    PubMed

    Ho, Pak-Leung; Chow, Kin-Hung; Lai, Eileen L; Law, Pierra Y T; Chan, Pui-Ying; Ho, Alex Y M; Ng, Tak-Keung; Yam, Wing-Cheong

    2012-11-01

    Out of 3,081 animals studied, 24.9% of pigs, 4.7% of chickens, 6.3% of dogs, 10.5% of cats, and 7.1% of rodents were Staphylococcus aureus positive. Prevalence of methicillin-resistant S. aureus (MRSA) was high in pigs (animals, 21.3%; batches, 46.5%), with all MRSA isolates and most methicillin-sensitive S. aureus isolates belonging to clonal complex 9 (CC9) and being multidrug resistant. The predominant S. aureus CCs among dog and cat isolates were similar. Among rodent isolates, CC398 predominated, with spa t034 the most frequent spa type detected.

  7. THE FREQUENCY OF COMMUNITY-ACQUIRED METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS (CA-MRSA) AMONG SAMPLES IN INSTITUTE FOR PUBLIC HEALTH IN CANTON SARAJEVO

    PubMed Central

    Bektas, Sabaheta; Obradovic, Amina; Aljicevic, Mufida; Numanovic, Fatima; Hodzic, Dunja; Sporisevic, Lutvo

    2016-01-01

    Background: The increase in the incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections lacking risk factors for exposure to the health care system has been associated with the recognition of new MRSA clones known as community-associated MRSA (CA-MRSA). These strains have been distinguished from health care-associated MRSA (HA-MRSA) strains by epidemiological, molecular and genetic means as well as by antibiotic susceptibility profile, tissue tropism and virulence traits. Objective: To assess prevalence and antibiotic susceptibility profile of CA-MRSA in Canton Sarajevo, Bosnia and Herzegovina. Results: Out of 1.905 positive Staphylococcus aureus isolates from various samples of outpatients collected during six months, 279 (14,64%) were MRSA isolates. Out of 279 MRSA samples, 133 (47,67%) were found in nasal swabs, from which 48 (36,09%) were in the age group <1 year and 39 (29,32 %) are in the age 1-5 year. Rate of the positive skin swabs was highest among the subject of age group <1 year (46 or 54,12 %) and 1-5 year (18 or 21,18 %). Predominantly antibiotic types among MRSA strains are resistant to penicillin and cefoxitin (36,90 %) and to penicillin, cefoxitin and erythromycin (61,35 %). Conclusion: Continued monitoring of epidemiology and emerging drug resistance data is critical for the effective management of these infections. PMID:27047271

  8. Plasmid-mediated resistance and virulence mechanisms in the private health sector in KwaZulu-Natal, South Africa: An investigation of methicillin resistant Staphylococcus aureus (MRSA) clinical isolates collected during a three month period.

    PubMed

    Amoako, Daniel G; Bester, Linda A; Somboro, Anou M; Baijnath, Sooraj; Govind, Chetna N; Essack, Sabiha Y

    2016-05-01

    Due to the lack of information on the plasmid content of MRSA strains in South Africa (SA), this study investigated the resistance and virulence mechanisms of 27 clinical isolates from the private health care sector over a period of 3 months. Plasmids were extracted and the presence of MRSA confirmed by the presence of mecA. The isolates were subjected to antimicrobial susceptibility testing and molecular characterization of common resistance encoding genes and frequently encountered virulence factors by PCR using plasmid DNA as the template. The genetic relatedness between the isolates was determined by pulsed field gel electrophoresis (PFGE). All isolates were plasmid positive, and displayed ampillicin, ciprofloxacin, gentamicin, rifampicin, tetracycline, erythromycin, and clindamycin resistance. They were all fully susceptible to daptomycin, linezolid, vancomycin, tigecycline and fusidic acid. Multidrug resistance (MDR) was found in 74.1% (20/27) of the MRSA isolates. The frequency of the resistance and virulence genes ranged from 100% to 0%. PFGE analysis revealed 10 pulsotypes, designated A-J, which showed correlation with resistance profile of the isolates in each group. Of note, 85.2% (23/27) of the isolates clustered into six major PFGE types giving an indication of similar circulating MRSA clones. This study highlights the genetic diversity and resistance mechanisms in MRSA strains from the private health sector in SA hence the need for implementing effective infection control programs. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Current methodologies on genotyping for nosocomial pathogen methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Miao, Jian; Chen, Lequn; Wang, Jingwen; Wang, Wenxin; Chen, Dingqiang; Li, Lin; Li, Bing; Deng, Yang; Xu, Zhenbo

    2017-03-08

    Methicillin-resistant Staphylococcus aureus (MRSA) is a common pathogen in hospitals and the community. As the rapid spread and wide distribution of antimicrobial resistance (such as MRSA), treatment for infectious diseases caused by microorganisms has become a vital threat. Thus, early identification and genotyping are essential for further therapeutic treatment and the control of rapid expansion of MRSA. In combination with applications and data feedbacks, this review focused on the currently available molecular-based assays on their utility and performance for rapid typing of MRSA, especially on effective molecular-based methods. Besides, a common mobile element SCCmec and prevalence of HA-MRSA, LA-MRSA and CA-MRSA were introduced in this review in order to provide a more complete profile of MRSA.

  10. Proposal for common Nordic epidemiological terms and definitions for methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Skov, Robert; Gudlaugsson, Olafur; Hardardottir, Hjordis; Harthug, Stig; Jakobsen, Trond; Kolmos, Hans Jørn; Olsson-Liljequist, Barbro; Peltonen, Reijo; Tveten, Yngvar; Vuopio-Varkila, Jaana; Ahrén, Christina

    2008-01-01

    The recent increase in the incidence of methicillin-resistant Staphylococcus aureus in all the Nordic countries prompted the Scandinavian Society for Antimicrobial Chemotherapy (SSAC) to create the 'SSAC Working Party on MRSA' with the objective to identify methods to keep the invasive MRSA infections in the Nordic countries below 1%. The lack of common definitions was recognized as a major obstacle for a joint Nordic effort to combat MRSA. The aim of this publication is to present proposals for epidemiological definitions of individual cases, for how to report MRSA frequency per country, and for communication of MRSA strain characteristics between the countries.

  11. Characterization of the staphylococcal cassette chromosome mec insertion site in 108 isolates lacking the mecA gene and identified as methicillin-resistant Staphylococcus aureus by the Xpert MRSA assay.

    PubMed

    Stojanov, M; Blanc, D S

    2014-11-01

    During a 3-year period, 848 patients were detected as carriers of methicillin-resistant Staphylococcus aureus (MRSA) by the Xpert MRSA assay (Cepheid). Among them, 108 patients (12.7 %) were colonized with strains showing methicillin-susceptible phenotypes and absence of the mecA gene, despite being positive with the rapid polymerase chain reaction (PCR) assay. DNA sequences of the staphylococcal cassette chromosome mec (SCCmec) insertion site of these "false-positive" strains was determined by direct sequencing of the genomic DNA. More than half (53.7 %) of the strains had DNA sequences unrelated to either SCC or SCCmec and one-third had DNA sequences related to non-mec SCC. Only 10.2 % of the strains carried sequences related to SCCmec, suggesting that a sequence containing the mecA gene was lost from an SCCmec. These findings differ from the general idea that all methicillin-susceptible S. aureus having positive Xpert MRSA assay results are essentially MRSA that lost the mecA gene.

  12. Interaction Between Methicillin-Resistant Staphylococcus aureus (MRSA) and Acanthamoeba polyphaga.

    PubMed

    de Souza, Thamires Klein; Soares, Scheila Silva; Benitez, Lisianne Brittes; Rott, Marilise Brittes

    2017-05-01

    The interactions that occur between bacteria and amoebae can give through mutual relations, where both organisms benefit from the association or parasitic in which one organism benefits at the expense of the other. When these organisms share the same environment, it can result in some changes in the growth of organisms, in adaptation patterns, in morphology, development or even in their ability to synthesize proteins and other substances. In this study, the interaction between Acanthamoeba polyphaga and Staphylococcus aureus (MRSA) was evaluated using a co-culture model at different incubation times. The results showed that 89% of amoebic cells remained viable after contact with the bacteria. The bacterial isolate was visualized inside the amoeba through confocal microscopy and fluorescence for up to 216 h of co-cultivation. The lysate of amoebic culture increased the growth of S. aureus (MRSA), and the effect of supernatant of culture inhibited bacterial growth over the incubation times, suggesting that A. polyphaga produced some metabolite, that inhibited the growth of bacteria. Moreover, the encystment of the A. polyphaga was increased by the bacteria presence. The results show that A. polyphaga and S. aureus interaction may have an important influence on survival of both, and specially indicate a possible effect on the metabolics characteristics each other.

  13. Evaluation of rep-PCR/DiversiLab versus PFGE and spa typing in genotyping methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Aguadero, V; González Velasco, C; Vindel, A; Gonzalez Velasco, M; Moreno, J J

    2015-01-01

    Pulsed-field gel electrophoresis (PFGE) is the 'gold standard' for genotyping of methicillin-resistant Staphylococcus aureus (MRSA); however, the DiversiLab (DL) system, based on rep-PCR, is faster, simpler and could be better adapted to daily routine hospital work. We genotyped 100 MRSA isolates using PFGE, DL, and spa typing, and evaluated the discriminatory power of each technique and the correlation between them by Simpson's index(SI) and adjusted Rand coefficient (ARI), respectively. The isolates were from clinical samples from eight hospitals in Extremadura (Spain) during 2010. DL separated the 100 MRSA into 18 patterns, with 69% of the isolates grouped into four predominant patterns. spa typing reported 17 spa types, classifying 69% of MRSA into two major types (t067 and t002). PFGE revealed the existence of 27 patterns, gathering 54% of MRSA into three pulse types (E8a, E7a and E7b). SI values were 0.819, 0.726, 0.887 and 0.460 for DL, spa typing, PFGE and CC-BURP, respectively. ARI values of DL over PFGE, spa typing and CC-BURP were 0.151, 0.321 and 0.071, respectively. DL has less discriminatory power than PFGE but more than spa typing. The concordance of DL with PFGE is low, primarily because DL does not discriminate between the three predominant MRSA pulse types in our environment.

  14. Molecular epidemiology of clinical and carrier strains of methicillin resistant Staphylococcus aureus (MRSA) in the hospital settings of north India

    PubMed Central

    Dar, Javid A; Thoker, Manzoor A; Khan, Jamal A; Ali, Asif; Khan, Mohammed A; Rizwan, Mohammed; Bhat, Khalid H; Dar, Mohammad J; Ahmed, Niyaz; Ahmad, Shamim

    2006-01-01

    Background The study was conducted between 2000 and 2003 on 750 human subjects, yielding 850 strains of staphylococci from clinical specimens (575), nasal cultures of hospitalized patients (100) and eye & nasal sources of hospital workers (50 & 125 respectively) in order to determine their epidemiology, acquisition and dissemination of resistance genes. Methods Organisms from clinical samples were isolated, cultured and identified as per the standard routine procedures. Susceptibility was measured by the agar diffusion method, as recommended by the Nat ional Committee for Clinical Laboratory Standards (NCCLS). The modified method of Birnboin and Takahashi was used for isolation of plasmids from staphylococci. Pulsed-field gel electrophoresis (PFGE) typing of clinical and carrier Methicillin resistant Staphylococcus aureus (MRSA) strains isolated during our study was performed as described previously. Results It was shown that 35.1% of Staphylococcus aureus and 22.5% of coagulase-negative staphylococcal isolates were resistant to methicillin. Highest percentage of MRSA (35.5%) was found in pus specimens (n = 151). The multiple drug resistance of all MRSA (n = 180) and Methicillin resistant Coagulase-negative Staphylococcus aureus (MRCNS) (n = 76) isolates was detected. In case of both methicillin-resistant as well as methicillin-sensitive Saphylococcal isolates zero resistance was found to vancomycin where as highest resistance was found to penicillin G followed by ampicillin. It was shown that the major reservoir of methicillin resistant staphylococci in hospitals are colonized/infected inpatients and colonized hospital workers, with carriers at risk for developing endogenous infection or transmitting infection to health care workers and patients. The results were confirmed by molecular typing using PFGE by SmaI-digestion. It was shown that the resistant markers G and T got transferred from clinical S. aureus (JS-105) to carrier S. aureus (JN-49) and the

  15. Knowing prior methicillin-resistant Staphylococcus aureus (MRSA) infection or colonization status increases the empirical use of glycopeptides in MRSA bacteraemia and may decrease mortality.

    PubMed

    Robinson, J O; Phillips, M; Christiansen, K J; Pearson, J C; Coombs, G W; Murray, R J

    2014-06-01

    To compare the management and outcome of methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia in patients known to be MRSA-colonized/infected (C-patients) with the management and outcome in those not known to be colonized/infected (NC-patients), we conducted a 10-year retrospective review of MRSA bacteraemia in an adult tertiary hospital. Clinical data were obtained by chart review, and mortality data from linked databases. Prior MRSA colonization/infection status was available to treating clinicians at the time of the bacteraemia as a 'Micro-Alert' tag on the patient's labels, in medical charts, and in electronic information systems. C-patients accounted for 35.4% of all MRSA bacteraemia episodes. C-patients were more likely to be indigenous, to be diabetic, or to have a history of previous S. aureus infection. Markers of illness severity (Simplified Acute Physiology Score (SAPS)-II, need for admission to the intensive-care unit, length of stay, and metastatic seeding) were similar in both groups. Empirical therapy included a glycopeptide in 49.3% of C-patients vs. 18.9% of NC-patients (p <0.01), and contained an antibiotic to which the MRSA isolate tested susceptible in vitro in 56.7% of C-patients vs. 45.1% of NC-patients (p 0.13). All-cause 7-day and 30-day mortality were 7.5% vs. 18.9% (p 0.04), and 22.4% vs. 31.1% (p 0.20), in the C-patient and NC-patient groups, respectively. Knowing MRSA colonization status was significantly associated with lower 30-day mortality in Cox regression analysis (p <0.01). These data suggest that mortality from MRSA bacteraemia is lower in C-patients, which may reflect the earlier use of glycopeptides. The low use of empirical glycopeptides in septic patients known to be previously MRSA-colonized/infected may represent a missed opportunity for infection control to positively impact on clinical management.

  16. A cross sectional study of animal and human colonization with Methicillin-Resistant Staphylococcus aureus (MRSA) in an Aboriginal community.

    PubMed

    Daley, Peter; Bajgai, Janak; Penney, Carla; Williams, Karen; Whitney, Hugh; Golding, George R; Weese, Scott

    2016-07-19

    Methicillin-resistant Staphylococcus aureus (MRSA) infections are common among humans in Aboriginal communities in Canada, for unknown reasons. Cross sectional study of humans and dogs in an Aboriginal community of approximately 1200 persons. Our objectives were to measure community-based prevalence of nasal MRSA colonization among humans, use multivariable logistic regression to analyze risk factors for MRSA colonization, and perform molecular typing of Staphylococci isolated to investigate interspecies transmission. 461 humans were approached for consent and 442 provided complete data. 109/442 (24.7 %, 95 % C.I. = 20.7-28.7 %) of humans were colonized with MRSA. 169/442 (38.2 %) of humans had received antibiotics in the last 12 months. Only number of rooms in the house (OR 0.86, p = 0.023) and recreational dog use (OR 7.7, p = 0.002) were significant risk factors for MRSA colonization. 95/109 (87.1 %) of MRSA strains from humans were of the same spa type (CMRSA10/USA300). 8/157 (5.1 %, 95 % C.I. = 1.7-8.5 %) of dogs were colonized with methicillin-susceptible S. aureus, and no dogs were colonized with MRSA. Human MRSA colonization in this community is very common, and a single clone is predominant, suggesting local transmission. Antibiotic use is also very common. Crowding may partially explain high colonization, but most considered risk factors including animal exposure were not predictive. Very few dogs carried human Staphylococcal strains.

  17. Detection of Small Colony Variants Among Methicillin-Resistant Staphylococcus aureus Blood Isolates.

    PubMed

    Yagci, Server; Sancak, Banu; Hascelik, Gulsen

    2016-12-01

    Staphylococcus aureus small colony variants (SCVs) are associated with chronic and persistent infections. Methicillin-resistant S. aureus (MRSA) SCVs cause more severe infections and mortality rates are higher in comparison with infections caused by MRSA. Our objective was to document the prevalence and phenotypical characteristics of SCVs among MRSA blood isolates. MRSA strains isolated from blood during 1999-2009 were evaluated retrospectively. Among 299 MRSA isolates, suspected colonies were inoculated onto Columbia blood agar and Schaedler agar. Columbia blood agar was incubated in normal atmosphere and Schaedler agar in 5-10% CO2, both at 35°C. If the small, nonpigmented, nonhemolytic colonies on Columbia blood agar were seen as normal-sized, hemolytic, and pigmented colonies on Schaedler agar, they were considered as MRSA SCVs. Six MRSA SCVs were detected. When subcultures were made, four of them reversed to phenotypically normal S. aureus, but two isolates were stable as SCV phenotype. The prevalence of SCVs among MRSA blood isolates was found as 6/299 (2%) with 2 (0.67%) stable. The detection of SCVs among MRSA blood isolates was reported from Turkey for the first time in this study. As the clinical significance of MRSA infections is well documented, evaluation of MRSA SCVs in clinical samples, especially from intensive care patients and those who have chronic and persistent infections are important to consider.

  18. Silver resistance in MRSA isolated from wound and nasal sources in humans and animals.

    PubMed

    Loh, Jia V; Percival, Steven L; Woods, Emma J; Williams, Nicola J; Cochrane, Christine A

    2009-02-01

    Methicillin-resistant Staphylococcus aureus (MRSA) colonises skin, nasal passages and dermal wounds. Methods used to manage wounds infected and colonised with MRSA often include the use of topical antiseptics such as ionic silver and iodine. The objectives of this study were to determine the prevalence of silver-resistance (sil) genes in MRSA and methicillin-resistant coagulase-negative staphylococci (MR-CNS) isolated from wounds and nasal cavities of humans and animals, and also to determine the susceptibility of sil-positive and sil-negative MRSA isolates to a silver-containing Hydrofiber (SCH) wound dressing, on planktonic silE-positive and silE-negative MRSA. Polymerase chain reaction was used to determine the presence of three silver-resistance (sil) genes, silE, silP and silS in 33 MRSA and 8 methicillin-resistant staphylococci (MR-CNS). SilP and silS genes were absent in all isolates tested; however, two MRSA strains were found to contain the silE gene, together with one isolate of MR-CNS. Phenotypic resistance of the silE-positive strains and their susceptibility to the SCH dressing was evaluated using the zone of inhibition test on Mueller Hinton agar, and confocal laser microscopy using a live/dead fluorescent stain. Results confirmed that the SCH dressing was effective in killing all MRSA strains with and without the silE gene. First, this study showed that the prevalence of sil genes was low in the isolates investigated; and secondly, that the presence of a silver-resistance gene (silE) in MRSA and MR-CNS did not afford protection to the organism in the presence of a SCH wound dressing. The use of topical antiseptics in chronic wound care should be considered before the use of antibiotics that can result in their overuse and the risk of further resistance.

  19. Nasal Methicillin-Resistant Staphylococcus aureus (MRSA) PCR Testing Reduces the Duration of MRSA-Targeted Therapy in Patients with Suspected MRSA Pneumonia.

    PubMed

    Baby, Nidhu; Faust, Andrew C; Smith, Terri; Sheperd, Lyndsay A; Knoll, Laura; Goodman, Edward L

    2017-04-01

    The objective of this study was to evaluate the impact of pharmacist-ordered methicillin-resistant Staphylococcus aureus (MRSA) PCR testing on the duration of empirical MRSA-targeted antibiotic therapy in patients with suspected pneumonia. This is a retrospective analysis of patients who received vancomycin or linezolid for suspected pneumonia before and after the implementation of a pharmacist-driven protocol for nasal MRSA PCR testing. Patients were included if they were adults of >18 years of age and initiated on vancomycin or linezolid for suspected MRSA pneumonia. The primary endpoint was the duration of vancomycin or linezolid therapy. After screening 368 patients, 57 patients met inclusion criteria (27 pre-PCR and 30 post-PCR). Baseline characteristics were similar between the two groups, with the majority of patients classified as having health care-associated pneumonia (68.4%). The use of the nasal MRSA PCR test reduced the mean duration of MRSA-targeted therapy by 46.6 h (74.0 ± 48.9 h versus 27.4 ± 18.7 h; 95% confidence interval [CI], 27.3 to 65.8 h; P < 0.0001). Fewer patients in the post-PCR group required vancomycin serum levels and dose adjustment (48.1% versus 16.7%; P = 0.02). There were no significant differences between the pre- and post-PCR groups regarding days to clinical improvement (1.78 ± 2.52 versus 2.27 ± 3.34; P = 0.54), length of hospital stay (11.04 ± 9.5 versus 8.2 ± 7.8; P = 0.22), or hospital mortality (14.8% versus 6.7%; P = 0.41). The use of nasal MRSA PCR testing in patients with suspected MRSA pneumonia reduced the duration of empirical MRSA-targeted therapy by approximately 2 days without increasing adverse clinical outcomes.

  20. First reporting of methicillin-resistant Staphylococcus aureus (MRSA) ST398 in an industrial rabbit holding and in farm-related people.

    PubMed

    Agnoletti, Fabrizio; Mazzolini, Elena; Bacchin, Cosetta; Bano, Luca; Berto, Giacomo; Rigoli, Roberto; Muffato, Giovanna; Coato, Paola; Tonon, Elena; Drigo, Ilenia

    2014-05-14

    Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) has been described in food-producing animals and farm or slaughterhouse workers involved in the primary industrial production of swine, bovine and poultry. This communication describes the first case of LA-MRSA (ST398, spa types t034 and t5210) occurring in rabbits raised intensively for meat production and involving farm workers or their family members. In 2012-2013, in a study involving 40 rabbit industrial holdings in Italy, one farm was found to have rabbits colonized or infected with MRSA. Four farm workers and one of their relatives were found to be carrying MRSA. In this case holding, rabbits, people and the holding environment were further investigated and followed up by a second sampling five months later. MRSA was found in 48% (11/23) and 25% (15/59) of the rabbits carrying S. aureus at first and second samplings, respectively. Five months after first detection, some farm workers or family members were still MRSA carriers. Surface samples (2/10) and air samples (2/3) were contaminated with MRSA. Air samples yielded MRSA counts of 5 and 15CFU/m(3). MRSA from rabbits and people collected at first sampling were spa types t034 and t5210 belonging to ST398. The MRSA isolates from rabbits and persons tested at second sampling were t034 and t5210, but spa types t1190 and t2970 were also detected in MRSA isolates from rabbits. Tracing the epidemiological pattern earlier may prevent further spread of LA-MRSA in these food producing animals.

  1. Genetic Characterization of Staphylococcus aureus Isolated from Retail Meat in Riyadh, Saudi Arabia

    PubMed Central

    Raji, Muhabat A.; Garaween, Ghada; Ehricht, Ralf; Monecke, Stefan; Shibl, Atef M.; Senok, Abiola

    2016-01-01

    Limited data exist from the Gulf Cooperation Council states on the prevalence and population dynamics of Staphylococcus aureus colonizing livestock or contaminating retail meat. This study was designed to determine the presence and genetic characteristics of Staphylococcus aureus isolated from raw retail meat sold in Riyadh, Saudi Arabia. Over a period of 9 months, different raw retail meat types were aseptically processed using the double broth enrichment technique, characteristic colonies from chromogenic and mannitol salt agar were further identified using conventional methods. Susceptibility to 9 antibiotics was determined using the disc diffusion technique. Interpretation of inhibition zone was done according to Clinical and Laboratory Standards Institute guidelines. Molecular characterization was carried out using the StaphyType DNA microarray technology. Twenty-five meat samples yielded Staphylococcus aureus isolates. Camel meat had the highest contamination rate with Methicillin resistant Staphylococcus aureus (MRSA) (20%) and Methicillin susceptible Staphylococcus aureus (28%), while poultry meat had the least contamination rate with MRSA (4%). The MRSA isolates were grouped into 4 clonal complexes (CCs) namely CC1-MRSA-IV/SCCfus (n = 2), CC15-MRSA-V/SCCfus (n = 4), CC80-MRSA-IV/PVL+ (n = 5), and CC88-MRSA-IV/PVL+ (n = 2). All CC15-MRSA-V/SCCfus isolates were obtained from camel meat. This is the first study to demonstrate the novel CC15-MRSA-V/SCCfus in retail camel meat. We recommend that surveillance studies should be incorporated in public health and food hygiene programs. PMID:27375611

  2. Genetic Characterization of Staphylococcus aureus Isolated from Retail Meat in Riyadh, Saudi Arabia.

    PubMed

    Raji, Muhabat A; Garaween, Ghada; Ehricht, Ralf; Monecke, Stefan; Shibl, Atef M; Senok, Abiola

    2016-01-01

    Limited data exist from the Gulf Cooperation Council states on the prevalence and population dynamics of Staphylococcus aureus colonizing livestock or contaminating retail meat. This study was designed to determine the presence and genetic characteristics of Staphylococcus aureus isolated from raw retail meat sold in Riyadh, Saudi Arabia. Over a period of 9 months, different raw retail meat types were aseptically processed using the double broth enrichment technique, characteristic colonies from chromogenic and mannitol salt agar were further identified using conventional methods. Susceptibility to 9 antibiotics was determined using the disc diffusion technique. Interpretation of inhibition zone was done according to Clinical and Laboratory Standards Institute guidelines. Molecular characterization was carried out using the StaphyType DNA microarray technology. Twenty-five meat samples yielded Staphylococcus aureus isolates. Camel meat had the highest contamination rate with Methicillin resistant Staphylococcus aureus (MRSA) (20%) and Methicillin susceptible Staphylococcus aureus (28%), while poultry meat had the least contamination rate with MRSA (4%). The MRSA isolates were grouped into 4 clonal complexes (CCs) namely CC1-MRSA-IV/SCCfus (n = 2), CC15-MRSA-V/SCCfus (n = 4), CC80-MRSA-IV/PVL+ (n = 5), and CC88-MRSA-IV/PVL+ (n = 2). All CC15-MRSA-V/SCCfus isolates were obtained from camel meat. This is the first study to demonstrate the novel CC15-MRSA-V/SCCfus in retail camel meat. We recommend that surveillance studies should be incorporated in public health and food hygiene programs.

  3. Methicillin-Resistant Staphylococcus aureus (MRSA) in Iran: A Systematic Review and Meta-analysis.

    PubMed

    Dadashi, Masoud; Nasiri, Mohammad Javad; Fallah, Fatemeh; Owlia, Parviz; Hajikhani, Bahareh; Emaneini, Mohammad; Mirpour, Mirsasan

    2017-09-20

    Methicillin-resistant Staphylococcus aureus (MRSA) remains one of the most prevalent multidrug-resistant organisms causing health care- infections. In Iran, limited data are available about how the prevalence of MRSA has changed over the past years. In the present study, we aimed to determine the exact prevalence of MRSA in different parts of Iran. Several databases including Medline, Embase, Web of sciences and Iranian databases were searched from Mar 2000 to Jan 2016 to identify studies addressing the prevalence of MRSA in Iran. Comprehensive meta-analysis (V2.2, Biostat) software was used to analyze the data. Of the 725 records identified from the databases, 31 studies fulfilled the eligibility criteria. The analyses showed that the prevalence of MRSA infections was 43.0% [95% confidence interval (95% CI) 36.3-50.0] among culture-positive cases of S. aureus in different parts of Iran. The further stratified analyses indicated that the prevalence of MRSA was higher in studies that were done after year 2000. Since high rates of MRSA infections was seen in our analysis, the regular surveillance of hospital associated infection, monitoring of antibiotic sensitivity pattern and formulation of definite antibiotic policy may facilitate more accurate action for prevention and control of MRSA. In particular, the introduction of MRSA screening based on rapid and reliable diagnosis during inpatient admission of patients is indispensable. Copyright © 2017. Published by Elsevier Ltd.

  4. Effectiveness of Hospital-Wide Methicillin-Resistant Staphylococcus aureus (MRSA) Infection Control Policies Differs by Ward Specialty

    PubMed Central

    Sadsad, Rosemarie; Sintchenko, Vitali; McDonnell, Geoff D.; Gilbert, Gwendolyn L.

    2013-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of preventable nosocomial infections and is endemic in hospitals worldwide. The effectiveness of infection control policies varies significantly across hospital settings. The impact of the hospital context towards the rate of nosocomial MRSA infections and the success of infection control is understudied. We conducted a modelling study to evaluate several infection control policies in surgical, intensive care, and medical ward specialties, each with distinct ward conditions and policies, of a tertiary public hospital in Sydney, Australia. We reconfirm hand hygiene as the most successful policy and find it to be necessary for the success of other policies. Active screening for MRSA, patient isolation in single-bed rooms, and additional staffing were found to be less effective. Across these ward specialties, MRSA transmission risk varied by 13% and reductions in the prevalence and nosocomial incidence rate of MRSA due to infection control policies varied by up to 45%. Different levels of infection control were required to reduce and control nosocomial MRSA infections for each ward specialty. Infection control policies and policy targets should be specific for the ward and context of the hospital. The model we developed is generic and can be calibrated to represent different ward settings and pathogens transmitted between patients indirectly through health care workers. This can aid the timely and cost effective design of synergistic and context specific infection control policies. PMID:24340085

  5. Diversity of methicillin-resistant Staphylococcus aureus CC22-MRSA-IV from Saudi Arabia and the Gulf region.

    PubMed

    Senok, Abiola; Somily, Ali; Raji, Adeola; Gawlik, Darius; Al-Shahrani, Fatimah; Baqi, Shehla; Boswihi, Samar; Skakni, Leila; Udo, Edet E; Weber, Stefan; Ehricht, Ralf; Monecke, Stefan

    2016-10-01

    CC22-MRSA-IV, UK-EMRSA-15/Barnim EMRSA, is a common and pandemic strain of methicillin-resistant Staphylococcus aureus (MRSA) that has been found mainly in Western Europe, but also in other parts of the world including some Gulf countries. One suspected case of an infection with this strain in a patient who was admitted to the surgical unit in Riyadh, Kingdom of Saudi Arabia (KSA) was investigated in order to check whether this strain has reached KSA. Besides the index isolate, 46 additional isolates of CC22-MRSA-IV from patients from KSA, Abu Dhabi, Kuwait, and Germany (patients with a history of travel in the Middle East), were characterized by microarray hybridization. The study revealed a regional presence of as many as six distinct 'strains' of CC22-MRSA-IV that could be distinguished based on carriage of SCCmec IV subtypes and virulence factors. No true UK-EMRSA-15/Barnim EMRSA was identified in Riyadh; all suspected isolates from Riyadh were assigned to other, albeit related strains. However, this strain was identified in Abu Dhabi and Kuwait. CC22-MRSA-IV from KSA could be linked to other epidemic strains from the Middle East and possibly India, rather than to the Western European UK-EMRSA-15/Barnim EMRSA. High-resolution typing methods, including SCCmec subtyping, might help to differentiate related epidemic strains and to monitor routes of transmission. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. Activities of Omadacycline and Comparator Agents against Staphylococcus aureus Isolates from a Surveillance Program Conducted in North America and Europe

    PubMed Central

    Pfaller, Michael A.; Rhomberg, Paul R.; Huband, Michael D.

    2016-01-01

    ABSTRACT Omadacycline is a new broad-spectrum aminomethylcycline in late-stage clinical development for acute bacterial skin and skin structure infections and community-acquired bacterial pneumonia as a once-daily formulation taken orally or intravenously. In this study, omadacycline and comparator agents were tested against 502 isolates of Staphylococcus aureus selected from a 2014 global surveillance program, and the results were compared with those for 7,740 isolates from a 2010 surveillance program. For the 2014 isolates, testing was completed on 252 isolates from Europe and 250 isolates from North America. Each set of isolates was composed of ∼100 hospital-acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) isolates (isolated >48 h after hospital admission), 100 community-acquired MRSA (CA-MRSA) isolates (isolated <48 h after hospital admission), and 50 methicillin-susceptible S. aureus (MSSA) isolates. The omadacycline MIC50 and MIC90 for all S. aureus collected during 2014 was 0.12 and 0.12 μg/ml, respectively. The MIC90 values were identical for MRSA, HA-MRSA, and CA-MRSA (0.12 μg/ml). The MIC90 values for isolates from 2010 for S. aureus, MRSA, and CA-MRSA were 0.25 μg/ml (0.5 μg/ml for HA-MRSA; 87.8% were at ≤0.25 μg/ml). All 2014 and 2010 MRSA isolates were susceptible to vancomycin, and ≥99.8% were susceptible to daptomycin, linezolid, and tigecycline. The activity of omadacycline was similar for North American and European isolates, including MRSA (CA-MRSA or HA-MRSA). There was no evidence for emerging resistance to omadacycline between 2010 and 2014. The potent activity of omadacycline against S. aureus indicates that omadacycline merits further study in serious infections where multidrug resistance may be a concern. PMID:27993854

  7. 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

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

    2015-10-01

    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.

  8. Methicillin-resistant Staphylococcus aureus (MRSA) pyruvate kinase as a target for bis-indole alkaloids with antibacterial activities.

    PubMed

    Zoraghi, Roya; Worrall, Liam; See, Raymond H; Strangman, Wendy; Popplewell, Wendy L; Gong, Huansheng; Samaai, Toufiek; Swayze, Richard D; Kaur, Sukhbir; Vuckovic, Marija; Finlay, B Brett; Brunham, Robert C; McMaster, William R; Davies-Coleman, Michael T; Strynadka, Natalie C; Andersen, Raymond J; Reiner, Neil E

    2011-12-30

    Novel classes of antimicrobials are needed to address the emergence of multidrug-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA). We have recently identified pyruvate kinase (PK) as a potential novel drug target based upon it being an essential hub in the MRSA interactome (Cherkasov, A., Hsing, M., Zoraghi, R., Foster, L. J., See, R. H., Stoynov, N., Jiang, J., Kaur, S., Lian, T., Jackson, L., Gong, H., Swayze, R., Amandoron, E., Hormozdiari, F., Dao, P., Sahinalp, C., Santos-Filho, O., Axerio-Cilies, P., Byler, K., McMaster, W. R., Brunham, R. C., Finlay, B. B., and Reiner, N. E. (2011) J. Proteome Res. 10, 1139-1150; Zoraghi, R., See, R. H., Axerio-Cilies, P., Kumar, N. S., Gong, H., Moreau, A., Hsing, M., Kaur, S., Swayze, R. D., Worrall, L., Amandoron, E., Lian, T., Jackson, L., Jiang, J., Thorson, L., Labriere, C., Foster, L., Brunham, R. C., McMaster, W. R., Finlay, B. B., Strynadka, N. C., Cherkasov, A., Young, R. N., and Reiner, N. E. (2011) Antimicrob. Agents Chemother. 55, 2042-2053). Screening of an extract library of marine invertebrates against MRSA PK resulted in the identification of bis-indole alkaloids of the spongotine (A), topsentin (B, D), and hamacanthin (C) classes isolated from the Topsentia pachastrelloides as novel bacterial PK inhibitors. These compounds potently and selectively inhibited both MRSA PK enzymatic activity and S. aureus growth in vitro. The most active compounds, cis-3,4-dihyrohyrohamacanthin B (C) and bromodeoxytopsentin (D), were identified as highly potent MRSA PK inhibitors (IC(50) values of 16-60 nM) with at least 166-fold selectivity over human PK isoforms. These novel anti-PK natural compounds exhibited significant antibacterial activities against S. aureus, including MRSA (minimal inhibitory concentrations (MIC) of 12.5 and 6.25 μg/ml, respectively) with selectivity indices (CC(50)/MIC) >4. We also report the discrete structural features of the MRSA PK tetramer as determined by x

  9. The distribution of pathogenic and toxigenic genes among MRSA and MSSA clinical isolates.

    PubMed

    Imani Fooladi, Abbas Ali; Ashrafi, Elnaz; Tazandareh, Shafie Gorbani; Koosha, Roohollah Zarei; Rad, Hamid Sedighian; Amin, Mohsen; Soori, Mina; Larki, Reza Abbasi; Choopani, Ali; Hosseini, Hamideh Mahmoodzadeh

    2015-04-01

    Staphylococcus aureus (S. aureus) is considered as a notorious nosocomial pathogen among hospitalized patients and community-dwelling subjects. Its increasing morbidity and mortality is believed to be due to antibiotic resistance. However, the data concerning molecular properties of infecting strains are few. In this study, a total of 192 S. aureus strains, including 88 (45.8%) meticillin-sensitive S. aureus (MSSA) and 104 (54.2%) meticillin-resistant S. aureus (MRSA) were recovered from clinical samples. The prevalence of subtypes containing staphylococcal cassette chromosome mec (SSCmec), staphylococcal enterotoxins (SEs), toxic shock syndrome toxin (TSST) and exfoliative toxin was assessed by PCR. Antibiotic susceptibility pattern and vancomycin resistance of each isolate were evaluated by disk diffusion method and micro-dilution method, respectively. 9 (2.3%) strains required MIC > 2 mg/l of vancomycin, which significantly increased among multi drug resistant (MDR), MRSA and SCCmec type III strains (p < 0.05). 171 (89%), 140 (72.91%), 7 (3.6), 78 (48.6%), 5 (2.6%), 151 (78.64%), 129 (67.18%), 178 (92.7%) and 15 (7.8%) of 192 isolates harbored mecA, entA, entB, entC, entD, entE, eta, etb and tsst-1 genes, respectively. 31 (16.14%), 5 (2.6%), 95 (49.48%) and 7 (3.64%) of 192 isolates carried SCCmec type I, II, III and IV, respectively. We found a significantly higher rate of MRSA and resistance to all tested antibiotics, except to penicillin G, kanamycin and linezolide among the SCCmec type III class (p < 0.05). According to our findings, MSSA isolates should be taken as seriously as MRSA strains due to the potential presence of broad spectrum virulence factor genes.

  10. Potentiation activity of multiple antibacterial agents by Salvianolate from the Chinese medicine Danshen against methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Liu, Qing-Qing; Han, Jun; Zuo, Guo-Ying; Wang, Gen-Chun; Tang, Hua-Shu

    2016-05-01

    Salvianolate (SAL) is a prescribed medicine from the Chinese herb Danshen (Salvia miltiorrhiza Bunge). It has been widely used in treatment of coronary and other diseases with significant effects. The in vitro antimicrobial activities of SAL against infectious pathogens were assayed and its combined effects on 10 clinical isolates of SCCmec III type methicillin-resistant Staphylococcus aureus (MRSA) with ten antibiotics were evaluated. Susceptibility to each agent alone was tested using a broth microdilution method, and the chequerboard and time-kill experiments were used for the combined activities. The results showed MIC was 128-256 mg/L for SAL used alone against MRSA. Significant synergies were observed for SAL/Ampicillin (Fosfomycin, Erythromycin, Piperacillin-tazobactam or Clindamycin) combination against over half of the isolates, with their MICs reduced by times of dilution (TOD) to 4-32 (FICIs 0.375-0.5), respectively. SAL/AMP combination showed the best combined effect of synergy on bacteriostatic and bactericidal activities, while SAL/AMK combination reversed the resistance of MRSA to AMK. The results demonstrated that SAL enhanced widely the in vitro anti-MRSA efficacy of the ten antibacterial agents, which had potential for combinatory therapy of patients infected with MRSA and warrants further investigations. Copyright © 2015 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  11. Methicillin-resistant Staphylococcus aureus isolates in a hospital of Shanghai

    PubMed Central

    Wang, Xiaoguang; Ouyang, Lin; Luo, Lingfei; Liu, Jiqian; Song, Chiping; Li, Cuizhen; Yan, Hongjing; Wang, Ping

    2017-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) strains are now common both in the health care setting and in the community. Active surveillance is critical for MRSA control and prevention. Specimens of patients (200 patients with 1119 specimens) as well as medical staff and hospital setting (1000 specimens) were randomly sampled in a level 2 hospital in Shanghai from September 2011 to August 2012. Isolation, cultivation and identification of S. aureus were performed. Totally, 67 S. aureus strains were isolated. 32 S. aureus strains were isolated from patient samples; 13 (13/32, 40.6%) of the 32 S. aureus isolates were MRSA; sputum sample and patients in the department of general internal medicine were the most frequent specimen and patient group for S. aureus strains isolation. Remaining 35 S. aureus strains were isolated from the medical staff and hospital setting; 20 (20/35, 57.1%) of the 35 S. aureus isolates were MRSA; specimens sampled from doctors and nurses’ hands and nose and hospital facilities were the most frequent samples to isolate S. aureus. Resistant and virulent genes detection showed that, all 33 MRSA strains were mecA positive which accounts for 49.3% of the 67 S. aureus strains; 38 isolates were Panton-Valentine leukocidin (PVL) gene positive which accounts for 56.7% of the 67 S. aureus strains; and 17 (17/67, 25.4%) isolates are mecA and PVL genes dual positive. Multidrug-resistant strains of MRSA and PVL positive S. aureus are common in patients, medical staff and hospital setting, the potential health threat is worthy of our attention. PMID:28030828

  12. Methicillin-resistant staphylococcus aureus isolates in a hospital of shanghai.

    PubMed

    Wang, Xiaoguang; Ouyang, Lin; Luo, Lingfei; Liu, Jiqian; Song, Chiping; Li, Cuizhen; Yan, Hongjing; Wang, Ping

    2017-01-24

    Methicillin-resistant Staphylococcus aureus (MRSA) strains are now common both in the health care setting and in the community. Active surveillance is critical for MRSA control and prevention. Specimens of patients (200 patients with 1119 specimens) as well as medical staff and hospital setting (1000 specimens) were randomly sampled in a level 2 hospital in Shanghai from September 2011 to August 2012. Isolation, cultivation and identification of S. aureus were performed. Totally, 67 S. aureus strains were isolated. 32 S. aureus strains were isolated from patient samples; 13 (13/32, 40.6%) of the 32 S. aureus isolates were MRSA; sputum sample and patients in the department of general internal medicine were the most frequent specimen and patient group for S. aureus strains isolation. Remaining 35 S. aureus strains were isolated from the medical staff and hospital setting; 20 (20/35, 57.1%) of the 35 S. aureus isolates were MRSA; specimens sampled from doctors and nurses' hands and nose and hospital facilities were the most frequent samples to isolate S. aureus. Resistant and virulent genes detection showed that, all 33 MRSA strains were mecA positive which accounts for 49.3% of the 67 S. aureus strains; 38 isolates were Panton-Valentine leukocidin (PVL) gene positive which accounts for 56.7% of the 67 S. aureus strains; and 17 (17/67, 25.4%) isolates are mecA and PVL genes dual positive. Multidrug-resistant strains of MRSA and PVL positive S. aureus are common in patients, medical staff and hospital setting, the potential health threat is worthy of our attention.

  13. Comparative genomic analysis of Staphylococcus aureus FORC_001 and S. aureus MRSA252 reveals the characteristics of antibiotic resistance and virulence factors for human infection.

    PubMed

    Lim, Sooyeon; Lee, Dong-Hoon; Kwak, Woori; Shin, Hakdong; Ku, Hye-Jin; Lee, Jong-Eun; Lee, Gun Eui; Kim, Heebal; Choi, Sang-Ho; Ryu, Sangryeol; Lee, Ju-Hoon

    2015-01-01

    Staphylococcus aureus is an important foodborne pathogen that causes diverse diseases ranging from minor infections to life-threatening conditions in humans and animals. To further understand its pathogenesis, the genome of the strain S. aureus FORC_001 was isolated from a contaminated food. Its genome consists of 2,886,017 bp double-stranded DNA with a GC content of 32.8%. It is predicted to contain 2,728 open reading frames, 57 tRNAs, and 6 rRNA operons, including 1 additional 5S rRNA gene. Comparative phylogenetic tree analysis of 40 complete S. aureus genome sequences using average nucleotide identity (ANI) revealed that strain FORC_001 belonged to Group I. The closest phylogenetic match was S. aureus MRSA252, according to a whole-genome ANI (99.87%), suggesting that they might share a common ancestor. Comparative genome analysis of FORC_001 and MRSA252 revealed two non-homologous regions: Regions I and II. The presence of various antibiotic resistance genes, including the SCCmec cluster in Region I of MRSA252, suggests that this strain might have acquired the SCCmec cluster to adapt to specific environments containing methicillin. Region II of both genomes contains prophage regions but their DNA sequence identity is very low, suggesting that the prophages might differ. This is the first report of the complete genome sequence of S. aureus isolated from a real foodborne outbreak in South Korea. This report would be helpful to extend our understanding about the genome, general characteristics, and virulence factors of S. aureus for further studies of pathogenesis, rapid detection, and epidemiological investigation in foodborne outbreak.

  14. Molecular characterization of methicillin-resistant Staphylococcus aureus nasal isolates from Turkey.

    PubMed

    Kilic, Abdullah; Mert, Gurkan; Senses, Zeynep; Bedir, Orhan; Aydogan, Hakan; Basustaoglu, A Celal; Appelbaum, Peter C

    2008-11-01

    Methicillin-resistant Staphylococcus aureus (MRSA) colonize most frequently in the anterior nares of the nose and cause serious infections all over the world. The aim of this study was to determine the nasal carriage rate of S. aureus and MRSA strains in Turkish elementary school children. We also analyzed molecular characterizations of MRSA strains by using pulse field gel electrophoresis (PFGE), multi locus sequence typing (MLST), staphylococcal chromosomal cassette mec (SCCmec) typing, and detection of the Panton-valentine leucocidin (PVL) gene. The nasal swabs were obtained from 4,050 children during a 4 month period in Ankara. In vitro antimicrobial susceptibility testing to 1 mug oxacillin and 30 mug cefoxitin was determined by a disk diffusion method. We found that the 1,001 of 4,050 (24.7%) children were colonized with S. aureus. Three S. aureus strains were resistant to oxacillin and cefoxitin. The rate of MRSA among all children was 0.07%. The MRSA strains revealed three different PFGE pattern. All MRSA isolates by harbored the SCCmec type IV element, but not the PVL gene. The two MRSA isolate belonged to sequence type (ST) 30, whereas the other one was a unique type. The results of this study demonstrated that S. aureus nasal carriage rate was consistent with previous studies. However, MRSA carriage rate was low. This study also indicated that the ST30-type IV without PVL gene MRSA clone may be expected to spread in Turkish community.

  15. Detection and molecular characterization of a gentamicin-susceptible, methicillin-resistant Staphylococcus aureus (MRSA) clone in Rio de Janeiro that resembles the New York/Japanese clone.

    PubMed

    Melo, M C N; Silva-Carvalho, M C; Ferreira, R L; Coelho, L R; Souza, R R; Gobbi, C N; Rozenbaum, R; Solari, C A; Ferreira-Carvalho, B T; Figueiredo, A M S

    2004-12-01

    Staphylococcus aureus is the leading cause of hospital-acquired infections in many countries, and multiple factors contribute to the ability of these bacteria to disseminate and spread in hospitals. In Brazil it has been demonstrated that a multiresistant methicillin-resistant S. aureus clone, the so-called Brazilian epidemic clone, is widespread geographically. This clone was first detected in 1992 in Brazil, and recently from many other countries within South America, Europe and Asia. The study describes the detection of a gentamicin-susceptible heterogeneous MRSA clone that resembles another MRSA clone widely spread in US and Japanese hospitals, and supports the premise that the detection of heterogeneous MRSA isolates by some recommended methods is a challenging task that may, occasionally, result in MRSA misidentification.

  16. Structural Insights into the Anti-methicillin-resistant Staphylococcus aureus (MRSA) Activity of Ceftobiprole*

    PubMed Central

    Lovering, Andrew L.; Gretes, Michael C.; Safadi, Susan S.; Danel, Franck; de Castro, Liza; Page, Malcolm G. P.; Strynadka, Natalie C. J.

    2012-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is an antibiotic-resistant strain of S. aureus afflicting hospitals and communities worldwide. Of greatest concern is its development of resistance to current last-line-of-defense antibiotics; new therapeutics are urgently needed to combat this pathogen. Ceftobiprole is a recently developed, latest generation cephalosporin and has been the first to show activity against MRSA by inhibiting essential peptidoglycan transpeptidases, including the β-lactam resistance determinant PBP2a, from MRSA. Here we present the structure of the complex of ceftobiprole bound to PBP2a. This structure provides the first look at the molecular details of an effective β-lactam-resistant PBP interaction, leading to new insights into the mechanism of ceftobiprole efficacy against MRSA. PMID:22815485

  17. MRSA Infection

    MedlinePlus

    ... MRSA infection By Mayo Clinic Staff Methicillin-resistant Staphylococcus aureus (MRSA) infection is caused by a type of ... a fever, see your doctor. Different varieties of Staphylococcus aureus bacteria, commonly called "staph," exist. Staph bacteria are ...

  18. Novel inhibitors of the methicillin-resistant Staphylococcus aureus (MRSA)-pyruvate kinase.

    PubMed

    El-Sayed, Mardia Telep; Zoraghi, Roya; Reiner, Neil; Suzen, Sibel; Ohlsen, Knut; Lalk, Michael; Altanlar, Nurten; Hilgeroth, Andreas

    2016-12-01

    Novel bisindolyl-cycloalkane indoles resulted from the reaction of aliphatic dialdehydes and indole. As bisindolyl-natural alkaloid compounds have recently been reported as inhibitors of the methicillin-resistant Staphylococcus aureus (MRSA)-pyruvate kinase (PK), we tested our novel compounds as MRSA PK inhibitors and now report first inhibiting activities. We discuss structure-activity relationships of structurally varied compounds. Activity influencing substituents have been characterized and relations to antibacterial activities of the most active compounds have been proved.

  19. Prevalence and properties of mecC methicillin-resistant Staphylococcus aureus (MRSA) in bovine bulk tank milk in Great Britain.

    PubMed

    Paterson, G K; Morgan, F J E; Harrison, E M; Peacock, S J; Parkhill, J; Zadoks, R N; Holmes, M A

    2014-03-01

    mecC methicillin-resistant Staphylococcus aureus (MRSA) represent a newly recognized form of MRSA, distinguished by the possession of a divergent mecA homologue, mecC. The first isolate to be identified came from bovine milk, but there are few data on the prevalence of mecC MRSA among dairy cattle. The aim of this study was to conduct a prevalence study of mecC MRSA among dairy farms in Great Britain. Test farms were randomly selected by random order generation and bulk tank samples were tested for the presence of mecC MRSA by broth enrichment and plating onto chromogenic agar. All MRSA isolated were screened by PCR for mecA and mecC, and mecC MRSA were further characterized by multilocus sequence typing, spa typing and antimicrobial susceptibility testing. mecC MRSA were detected on 10 of 465 dairy farms sampled in England and Wales (prevalence 2.15%, 95% CI 1.17%-3.91%), but not from 625 farms sampled in Scotland (95% CI of prevalence 0%-0.61%). Seven isolates belonged to sequence type (ST) 425, while the other three belonged to clonal complex 130. Resistance to non-β-lactam antibiotics was uncommon. All 10 isolates produced a negative result by slide agglutination for penicillin-binding protein 2a. mecA MRSA ST398 was detected on one farm in England. mecC MRSA is widely distributed among dairy farms in Great Britain, but this distribution is not uniform across the whole country. These results provide an important baseline dataset to monitor the epidemiology of this emerging form of MRSA.

  20. Alternative Use for Spectra MRSA Chromogenic Agar in Detection of Methicillin-Resistant Staphylococcus aureus from Positive Blood Cultures ▿

    PubMed Central

    Peterson, Jess F.; Dionisio, Alexander A.; Riebe, Katherine M.; Hall, Gerri S.; Wilson, Deborah A.; Whittier, Susan; DiPersio, Joseph R.; Ledeboer, Nathan A.

    2010-01-01

    Spectra MRSA agar (Remel, Lenexa, KS), a novel chromogenic medium originally developed to detect methicillin-resistant Staphylococcus aureus (MRSA) from nasal swabs, was evaluated in this multicenter study for the detection of MRSA from positive blood cultures exhibiting Gram-positive cocci upon initial Gram staining. PMID:20392925

  1. Epidemiology of methicillin-resistant and -susceptible Staphylococcus aureus in Luanda, Angola: first description of the spread of the MRSA ST5-IVa clone in the African continent.

    PubMed

    Conceição, Teresa; Coelho, Céline; Santos-Silva, Isabel; de Lencastre, Hermínia; Aires-de-Sousa, Marta

    2014-10-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a major human pathogen worldwide, and although surveillance studies are available in the most developed countries, data from Angola are inexistent. In June 2012, 295 inpatients and 199 healthcare workers from three hospitals in Luanda, Angola were nasal swabbed for S. aureus and MRSA carriage. A total of 117 individuals (23.7%) were S. aureus nasal carriers, out of which 68 (58.1%) were colonized with MRSA. The majority of the MRSA isolates (74%) belonged to a single clonal lineage, pulsed-field gel electrophoresis (PFGE) A-ST5-IVa associated with three spa types (spa types t105/t311/t11657), followed by PFGE C-ST88-IVa (spa types t186/t325/t786/t1951/t3869) (n=9; 12%); the other 11 MRSA isolates were representatives of 4 additional lineages. Almost half (49%) of the methicillin-susceptible S. aureus (MSSA) isolates belonged to three major clones: PFGE B-ST508 (spa types t050/t861/t1346/t1574/t2626/t12218), PFGE D-ST45 (spa types t939/t11656), and PFGE E-ST30 (spa types t1202/t9118). MSSA isolates presented a high variability of virulence factors, including Panton-Valentine leukocidine (7.9%). MRSA carriage in Luanda is considerably high, and the major clone corresponds to a worldwide epidemic lineage, so far scarcely reported in Africa. Additional infection control measures in this metropolis are mandatory for a global MRSA control.

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

    PubMed

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

    2016-05-01

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

  3. Occurrence of methicillin-resistant and -susceptible Staphylococcus aureus within a single colony contributing to MRSA mis-identification.

    PubMed

    Falcão, M H; Texeira, L A; Ferreira-Carvalho, B T; Borges-Neto, A A; Figueiredo, A M

    1999-06-01

    Many methods have been described for the detection of methicillin-resistant Staphylococcus aureus (MRSA), but the homogeneous or heterogeneous expression of methicillin resistance affects the reliability of those methods. This study demonstrates that close association between methicillin-susceptible S. aureus (MSSA) and MRSA strains in the host colonisation site can present additional problems for the detection of MRSA in clinical laboratories, which may contribute to failure in the control of MRSA infection in hospital. Worse, this association may also account for the emergence of MRSA during antibiotic therapy.

  4. Prevalence and characterization of methicillin-resistant Staphylococcus aureus isolates in food industry workers.

    PubMed

    Caggiano, G; Dambrosio, A; Ioanna, F; Balbino, S; Barbuti, G; De Giglio, O; Diella, G; Lovero, G; Rutigliano, S; Scarafile, G; Baldassarre, A; Vimercati, L; Musti, M; Montagna, M T

    2016-01-01

    Methicillin-resistant S. aureus (MRSA) is a pathogen spread not only in the hospital environment but also in the community and amongst livestock (LA-MRSA). LA-MRSA can be transmitted to humans that live in close contact with MRSA-colonized animals, and human colonization and/or infection has been reported worldwide, particularly among those involved with livestock farming. In this study the authors evaluated the prevalence of S. aureus and MRSA among healthy carriers who worked in the food industry in Apulia, Southern Italy. Nasal swabs were taken from pasta and pork industry workers. All swab samples were subjected to tests for the isolation, identification and typing of S. aureus and MRSA strains. The identification of the strains was confirmed by molecular assessment using multiplex-PCR for the amplification of the nuc and mecA genes. The strains identified as MRSA were then subjected to a PCR protocol for the characterization of sequence type ST398. In total 26.3% of examined nasal swabs were positive for S. aureus, 8.2% of them were methicillin resistant strains and 28.5% of MRSA isolates were characterized as ST398. The MRSA prevalence among pork factory workers was 3% , whereas among the pasta operators the prevalence was 11.5. The presence of S. aureus and MRSA among food workers represents a public health risk. Further, considering the dissemination of S. aureus and MRSA among non-nosocomial environments, including communities and livestock, careful surveillance and continuous monitoring of the emergence of MRSA is fundamental for safeguarding public health.

  5. Distribution and characterization of methicillin-resistant Staphylococcus aureus (MRSA) at the small animal hospital, faculty of veterinary medicine, Chiang Mai University, Thailand.

    PubMed

    Patchanee, Prapas; Tadee, Pakpoom; Ingkaninan, Pimlada; Tankaew, Pallop; Hoet, Armando E; Chupia, Vena

    2014-03-01

    Of 416 samples taken from veterinary staff (n = 30), dogs (n = 356) and various environmental sites (n = 30) at the Small Animal Hospital, Faculty of Veterinary Medicine, Chiang Mai University, Thailand, 13 samples contained methicillin-resistant Staphylococcus aureus (MRSA), of which 1 (SCCmec type II) came from veterinarian, 9 (SCCmec types I, III, IVa, V and untypeable) from dogs, and 3 (SCCmec types I, III, and IVb) from environmental samples. The MRSA isolates were 100% susceptible to vancomycin (100%), 69% to cephazolin and 62% to gentamicin, but were up to 92% resistant to tetracycline group, 69% to trimethoprim-sulfamethoxazoles and 62% to ceftriaxone. In addition, all MRSA isolates showed multidrug resistance. As the MRSA isolates from the veterinary staff and dogs were of different SCCmec types, this suggests there were no cross-infections. However, environmental contamination appears to have come from dogs, and appropriate hygienic practices should be introduced to solve this problem.

  6. Antibacterial effect of essential oils from two medicinal plants against Methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Tohidpour, A; Sattari, M; Omidbaigi, R; Yadegar, A; Nazemi, J

    2010-02-01

    Antimicrobial properties of plants essential oils (EOs) have been investigated through several observations and clinical studies which purpose them as potential tools to overcome the microbial drug resistance problem. The aim of this research is to study the antibacterial effect of two traditional plants essential oils, Thymus vulgaris and Eucalyptus globulus against clinical isolates of Methicillin resistant Staphylococcus aureus (MRSA) and other standard bacterial strains through disk diffusion and agar dilution methods. Gas Chromatography (GC) and Gas Chromatography/Mass Spectrometry (GC/MS) analysis examined the chemical composition of the oils. Results revealed both of oils to possess degrees of antibacterial activity against Gram (+) and Gram (-) bacteria. T. vulgaris EO showed better inhibitory effects than E. globulus essential oil. GC analysis of T. vulgaris resulted in thymol as the oil major compound whereas GC/MS assay exhibited eucalyptol as the most abundant constitute of E. globulus EO. These results support previous studies on these oils and suggest an additional option to treat MRSA infections. Clinical and further analytical trials of these data are necessary to confirm the obtained outcomes. Copyright 2009. Published by Elsevier GmbH.

  7. Diaryltriazenes as antibacterial agents against methicillin resistant Staphylococcus aureus (MRSA) and Mycobacterium smegmatis.

    PubMed

    Vajs, Jure; Proud, Conor; Brozovic, Anamaria; Gazvoda, Martin; Lloyd, Adrian; Roper, David I; Osmak, Maja; Košmrlj, Janez; Dowson, Christopher G

    2017-02-15

    Diaryltriazene derivatives were synthesized and evaluated for their antimicrobial properties. Initial experiments showed some of these compounds to have activity against both methicillin-resistant strains of Staphylococus aureus (MRSA) and Mycobacterium smegmatis, with MICs of 0.02 and 0.03 μg/mL respectively. Those compounds with potent anti-staphylococcal and anti-mycobacterial activity were not found to act as growth inhibitors of mammalian cell lines or yeast. Furthermore, we demonstrated that one of the most active anti-MRSA diaryltriazene derivatives was subject to very low frequencies of resistance at <10(-9). Whole genome sequencing of resistant isolates identified mutations in the enzyme that lysylates phospholipids. This could result in the modification of phospholipid metabolism and consequently the characteristics of the staphylococcal cell membrane, ultimately modifying the sensitivity of these pathogens to triazene challenge. Our work has therefore extended the potential range of triazenes, which could yield novel antimicrobials with low levels of resistance.

  8. Studying the time trend of Methicillin-resistant Staphylococcus aureus (MRSA) in Norway by use of non-stationary γ-Poisson distributions

    PubMed Central

    Moxnes, John F; Moen, Aina E Fossum; Leegaard, Truls Michael

    2015-01-01

    Objectives Study the time development of methicillin-resistant Staphylococcus aureus (MRSA) and forecast future behaviour. The major question: Is the number of MRSA isolates in Norway increasing and will it continue to increase? Design Time trend analysis using non-stationary γ-Poisson distributions. Setting Two data sets were analysed. The first data set (data set I) consists of all MRSA isolates collected in Oslo County from 1997 to 2010; the study area includes the Norwegian capital of Oslo and nearby surrounding areas, covering approximately 11% of the Norwegian population. The second data set (data set II) consists of all MRSA isolates collected in Health Region East from 2002 to 2011. Health Region East consists of Oslo County and four neighbouring counties, and is the most populated area of Norway. Participants Both data sets I and II consist of all persons in the area and time period described in the Settings, from whom MRSA have been isolated. Primary and secondary outcome measures MRSA infections have been mandatory notifiable in Norway since 1995, and MRSA colonisation since 2004. In the time period studied, all bacterial samples in Norway have been sent to a medical microbiological laboratory at the regional hospital for testing. In collaboration with the regional hospitals in five counties, we have collected all MRSA findings in the South-Eastern part of Norway over long time periods. Results On an average, a linear or exponential increase in MRSA numbers was observed in the data sets. A Poisson process with increasing intensity did not capture the dispersion of the time series, but a γ-Poisson process showed good agreement and captured the overdispersion. The numerical model showed numerical internal consistency. Conclusions In the present study, we find that the number of MRSA isolates is increasing in the most populated area of Norway during the time period studied. We also forecast a continuous increase until the year 2017. PMID:26438133

  9. The Economic Burden of Community-Associated Methicillin-Resistant Staphylococcus aureus (CA-MRSA)

    PubMed Central

    Lee, Bruce Y.; Singh, Ashima; David, Michael Z.; Bartsch, Sarah M.; Slayton, Rachel B.; Huang, Susan S.; Zimmer, Shanta M.; Potter, Margaret A.; Macal, Charles M.; Lauderdale, Diane S.; Miller, Loren G.; Daum, Robert S.

    2012-01-01

    The economic impact of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) remains unclear. We developed an economic simulation model to quantify the costs associated with CA-MRSA infection from the societal and third-party payer perspectives. A single CA-MRSA case costs third-party payers $2,277 – $3,200 and society $7,070 – $20,489, depending on patient age. In the United States (US), CA-MRSA imposes an annual burden of $478 million - 2.2 billion on third-party payers and $1.4 billion - 13.8 billion on society, depending on the CA-MRSA definitions and incidences. The US jail system and Army may be experiencing annual total costs of $7 – 11 million ($6 – 10 million direct medical costs) and $15 – 36 million ($14 – 32 million), respectively. Hospitalization rates and mortality are important cost drivers. CA-MRSA confers a substantial economic burden to third-party payers and society, with CA-MRSA-attributable productivity losses being major contributors to the total societal economic burden. Although decreasing transmission and infection incidence would decrease costs, even if transmission were to continue at present levels, early identification and appropriate treatment of CA-MRSA infections before they progress could save considerable costs. PMID:22712729

  10. Genomic information on multidrug-resistant livestock-associated methicillin-resistant Staphylococcus aureus ST398 isolated from a Brazilian patient with cystic fibrosis

    PubMed Central

    Lima, Danielle F; Cohen, Renata WF; Rocha, Géssica A; Albano, Rodolpho M; Marques, Elizabeth A; Leão, Robson S

    2017-01-01

    Alarmingly, the isolation of methicillin-resistant Staphylococcus aureus (MRSA) has been increasing among patients with cystic fibrosis (CF). During a previous molecular characterisation of MRSA isolates obtained from patients with CF from Rio de Janeiro, Brazil, one isolate was identified as the ST398 clone, a livestock-associated (LA) MRSA. In this study, we report the draft genome sequence of an LA-MRSA ST398 clone isolated from a patient with CF. PMID:28076471

  11. Genomic information on multidrug-resistant livestock-associated methicillin-resistant Staphylococcus aureus ST398 isolated from a Brazilian patient with cystic fibrosis.

    PubMed

    Lima, Danielle F; Cohen, Renata Wf; Rocha, Géssica A; Albano, Rodolpho M; Marques, Elizabeth A; Leão, Robson S

    2017-01-01

    Alarmingly, the isolation of methicillin-resistant Staphylococcus aureus (MRSA) has been increasing among patients with cystic fibrosis (CF). During a previous molecular characterisation of MRSA isolates obtained from patients with CF from Rio de Janeiro, Brazil, one isolate was identified as the ST398 clone, a livestock-associated (LA) MRSA. In this study, we report the draft genome sequence of an LA-MRSA ST398 clone isolated from a patient with CF.

  12. Differences in vancomycin MIC among MRSA isolates by agar dilution and E test method.

    PubMed

    Tandel, K; Praharaj, A K; Kumar, S

    2012-01-01

    In this study, the correlation between vancomycin minimum inhibitory concentration (MIC) obtained by the E test technique and the Clinical And Laboratory Standards Institute (CLSI) agar dilution method was evaluated. A total of 53 Methicillin Resistant Staphylococcus aureus (MRSA) strains were tested by both the methods in the present study. MICs of vancomycin obtained by the E test method were consistently higher (+0.5 to 2 log2 dilutions) than those obtained by the agar dilution method. Out of 53 MRSA isolates, 49 isolates showed higher MIC results by E test than by agar dilution method. Three isolates showed same MIC result by both methods. Since many studies have demonstrated increased clinical failure with MRSA isolates for which vancomycin MICs are increased (>1 μg/ml) but still within the susceptibility range (≤ 2 μg/ml), our findings suggest the requirement to re-look into the breakpoints for vancomycin for determining sensitivity of MRSA isolates. Guidelines should also specify the method to be used for determining the MIC.

  13. Characteristics of methicillin resistant Staphylococcus aureus isolated from chicken meat and hospitalized dogs in Korea and their epidemiological relatedness.

    PubMed

    Kwon, Nam Hoon; Park, Kun Taek; Jung, Woo Kyung; Youn, Hwa Young; Lee, Yeonhee; Kim, So Hyun; Bae, Wonki; Lim, Ji Youn; Kim, Ji Yeon; Kim, Jun Man; Hong, Soon Keun; Park, Yong Ho

    2006-10-31

    Methicillin resistant Staphylococcus aureus (MRSA) is one of the most important pathogens in human and veterinary hospitals. The isolation of MRSA from animals and foodstuffs has been reported with an increased incidence. However, methicillin (oxacillin) is not used in animal husbandry or in animal hospitals in Korea. In this study, three pre-MRSA and one silent mecA-carrying methicillin susceptible S. aureus (smMSSA) were isolated from retail chicken meat, and three MRSA were isolated from hospitalized dogs in Korea. The three pre-MRSA isolates were determined to have a staphylococcal cassette chromosome mec (SCCmec) type III, and the smMSSA isolate was not classified. The animal hospital isolates were found to contain SCCmec type II. Seven and 15 S. aureus isolated from hospitalized humans and bovine milk, respectively, were also examined in this study in order to determine the epidemiological origins of MRSA. Multilocus sequencing typing (MLST) revealed that the chicken meat and bovine milk isolates were closely related to the animal hospital isolates. The SCCmec characteristics and MLST analyses indicated the possibility of the human to animal transmission of MRSA. These results highlight the importance of identifying MRSA carriers as well as intercepting MRSA transmission because MRSA is becoming increasingly widespread without any plausible relationship with the use of methicillin (oxacillin).

  14. Annual Surveillance Summary: Methicillin Resistant Staphylococcus aureus (MRSA) Infections in the Military Health System (MHS), 2016

    DTIC Science & Technology

    2017-06-30

    Staphylococcus aureus (MRSA) incidence and prevalence among all beneficiaries seeking care within the Military Health System (MHS). This report...Comparison of community- and health care -associated methicillin-resistant Staphylococcus aureus infection. JAMA. 2003;290(22):2976-84. 10. Patel...community‐associated CHCS  Composite  Health   Care  System CO  community‐onset CTS  Contingency Tracking System CY  calendar year DMDC  Defense Manpower Data

  15. Comparative virulence studies and transcriptome analysis of Staphylococcus aureus strains isolated from animals

    PubMed Central

    Iqbal, Zahid; Seleem, Mohamed N.; Hussain, Hafiz Iftikhar; Huang, Lingli; Hao, Haihong; Yuan, Zonghui

    2016-01-01

    Several studies have been conducted to check the prevalence of methicillin-resistant strains of Staphylococcus aureus (MRSA) in animals and animal-derived food products but limited data are available regarding their virulence and associated gene expression profile. In the present study, antibiotic resistance and virulence of MRSA and methicillin-sensitive S. aureus animal isolates were determined in vitro by agar dilution, biofilm formation, adhesion, invasion and intracellular survivability assays. In addition, the pathogenicity of these isolates was examined in a murine model of S. aureus sepsis. MRSA1679a, a strain isolated from chicken, was observed to be highly virulent, in cell culture and in mouse model, and exhibited extensive resistant profile. Comparative gene expression profile of MRSA1679a and the reference human MRSA strain (ATCC 29213) was performed using Illumina-based transcriptome and RT-qPCR analyses. Several virulence elements including 22 toxin genes were detected in MRSA animal-isolate. In addition, we observed enhanced expression of crucial virulence regulators, such as sarA and KdpDE in MRSA animal-isolate compared to the human isolate. Collectively, gene expression profile including several virulence and drug-resistance factors confirmed the unique and highly virulent determinants of the MRSA strain of poultry origin which warrants further attention due to significant threat to public health. PMID:27739497

  16. Anatomical patterns of colonization of pets with staphylococcal species in homes of people with methicillin-resistant Staphylococcus aureus (MRSA) skin or soft tissue infection (SSTI).

    PubMed

    Iverson, S A; Brazil, A M; Ferguson, J M; Nelson, K; Lautenbach, E; Rankin, S C; Morris, D O; Davis, M F

    2015-03-23

    Methicillin-resistant strains of Staphylococcus aureus (MRSA), Staphylococcus pseudintermedius (MRSP), and other pathogenic staphylococci can cause infections in companion animals and humans. Identification of colonized animals is fundamental to research and practice needs, but harmonized methods have not yet been established. To establish the optimal anatomic site for the recovery of methicillin-resistant coagulase positive staphylococci (CPS), survey data and swabs were collected from 196 pets (dogs, cats, reptiles, birds, fish and pocket pets) that lived in households with an MRSA-infected person. Using broth-enrichment culture and PCR for speciation, S. aureus was identified in 27 of 179 (15%) pets sampled at baseline and 19 of 125 (15%) pets sampled at a three-month follow-up home visit. S. pseudintermedius was isolated from 33 of 179 (18%) pets sampled at baseline and 21 of 125 (17%) of pets sampled at follow-up. The baseline MRSA and MRSP prevalence was 8% and 1% respectively from 145 mammalian pets. The follow-up MRSA and MRSP prevalence was 7% and <1% respectively from 95 mammalian pets. The mouth was the most sensitive single site sampled for isolation of S. aureus and S. pseudintermedius in mammals. In a subset of pets, from which all available isolates were identified, dual carriage of S. aureus and S. pseudintermedius was 22% at baseline and 11% at follow-up. These results identify the mouth as the most sensitive site to screen for pathogenic staphylococci and suggest that it should be included in sampling protocols.

  17. Meticillin-resistant Staphylococcus aureus (MRSA) contamination of ambulance cars after short term transport of MRSA-colonised patients is restricted to the stretcher.

    PubMed

    Eibicht, S J; Vogel, U

    2011-07-01

    Cabin surfaces of ambulance cars transporting hospitalised patients are at risk of meticillin-resistant Staphylococcus aureus (MRSA) contamination. In this study ambulance cars were analysed for the presence of MRSA immediately after transport of MRSA-colonised or -infected patients (two sites at the stretcher, three sites at the interior walls). Eighty-nine of 100 transport events, which fulfilled the inclusion criterion of transport time less than 20 min, were further analysed. Eight ambulance cars (9%) were contaminated (90% confidence interval: 4-14%). Transport time of 11-20 min did not result in a higher contamination rate than shorter transport time of 1-10 min. MRSA was detected only on the stretcher, i.e. the headrest and the handles. Cabin walls were not contaminated. In conclusion, ambulance cars were contaminated with MRSA even at short transport times. Disinfection after short-term transport of MRSA-positive patients should be restricted to surfaces in close vicinity to the patient's position. Consecutive investigation of 60 transport events in the absence of MRSA notification did not reveal any MRSA, but meticillin-susceptible S. aureus was detected in 12 cars, predominantly at handles and headrests. This finding highlights the importance of disinfection of surfaces in the vicinity of patients irrespective of the MRSA status. Copyright © 2011 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  18. MRSA

    MedlinePlus

    ... Sometimes doctors prescribe antibiotics to treat more stubborn staph infections. MRSA is different from other staph bacteria because ... of the antibiotics doctors usually use to treat staph infections. (Methicillin is a type of antibiotic, which is ...

  19. Comparison of the BD GeneOhm Methicillin-Resistant Staphylococcus aureus (MRSA) PCR Assay to Culture by Use of BBL CHROMagar MRSA for Detection of MRSA in Nasal Surveillance Cultures from Intensive Care Unit Patients▿

    PubMed Central

    Snyder, James W.; Munier, Gina K.; Johnson, Charles L.

    2010-01-01

    This study compared the BD GeneOhm methicillin-resistant Staphylococcus aureus (MRSA) real-time PCR assay to culture by the use of BBL CHROMagar MRSA for the detection of MRSA in 627 nasal surveillance specimens collected from intensive care unit (ICU) patients. The PCR assay had a sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 96.7%, 70.3%, and 100%, respectively. Nine of 19 false-positive PCR specimens grew methicillin-susceptible S. aureus (MSSA) from broth enrichment culture, of which two demonstrated evidence of mecA gene dropout. Compared to culture by the use of BBL CHROMagar MRSA, the BD GeneOhm MRSA PCR assay demonstrated sensitivity and specificity above 95% for the detection of MRSA nasal colonization and provided shorter turnaround time in generating positive and negative final results. PMID:20181916

  20. Staphylococcus aureus and MRSA Growth and Biofilm Formation after Treatment with Antibiotics and SeNPs.

    PubMed

    Cihalova, Kristyna; Chudobova, Dagmar; Michalek, Petr; Moulick, Amitava; Guran, Roman; Kopel, Pavel; Adam, Vojtech; Kizek, Rene

    2015-10-16

    Methicillin-resistant Staphylococcus aureus (MRSA) is a dangerous pathogen resistant to β-lactam antibiotics. Due to its resistance, it is difficult to manage the infections caused by this strain. We examined this issue in terms of observation of the growth properties and ability to form biofilms in sensitive S. aureus and MRSA after the application of antibiotics (ATBs)-ampicillin, oxacillin and penicillin-and complexes of selenium nanoparticles (SeNPs) with these ATBs. The results suggest the strong inhibition effect of SeNPs in complexes with conventional ATBs. Using the impedance method, a higher disruption of biofilms was observed after the application of ATB complexes with SeNPs compared to the group exposed to ATBs without SeNPs. The biofilm formation was intensely inhibited (up to 99%±7% for S. aureus and up to 94%±4% for MRSA) after application of SeNPs in comparison with bacteria without antibacterial compounds whereas ATBs without SeNPs inhibited S. aureus up to 79%±5% and MRSA up to 16%±2% only. The obtained results provide a basis for the use of SeNPs as a tool for the treatment of bacterial infections, which can be complicated because of increasing resistance of bacteria to conventional ATB drugs.

  1. Staphylococcus aureus and MRSA Growth and Biofilm Formation after Treatment with Antibiotics and SeNPs

    PubMed Central

    Cihalova, Kristyna; Chudobova, Dagmar; Michalek, Petr; Moulick, Amitava; Guran, Roman; Kopel, Pavel; Adam, Vojtech; Kizek, Rene

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a dangerous pathogen resistant to β-lactam antibiotics. Due to its resistance, it is difficult to manage the infections caused by this strain. We examined this issue in terms of observation of the growth properties and ability to form biofilms in sensitive S. aureus and MRSA after the application of antibiotics (ATBs)—ampicillin, oxacillin and penicillin—and complexes of selenium nanoparticles (SeNPs) with these ATBs. The results suggest the strong inhibition effect of SeNPs in complexes with conventional ATBs. Using the impedance method, a higher disruption of biofilms was observed after the application of ATB complexes with SeNPs compared to the group exposed to ATBs without SeNPs. The biofilm formation was intensely inhibited (up to 99% ± 7% for S. aureus and up to 94% ± 4% for MRSA) after application of SeNPs in comparison with bacteria without antibacterial compounds whereas ATBs without SeNPs inhibited S. aureus up to 79% ± 5% and MRSA up to 16% ± 2% only. The obtained results provide a basis for the use of SeNPs as a tool for the treatment of bacterial infections, which can be complicated because of increasing resistance of bacteria to conventional ATB drugs. PMID:26501270

  2. Prevalence and Characterization of Methicillin-Resistant Staphylococcus aureus Isolates from Retail Meat and Humans in Georgia

    PubMed Central

    Davis, Johnnie A.; Barrett, John B.

    2013-01-01

    There is increasing interest in the presence of Staphylococcus aureus, specifically methicillin-resistant S. aureus (MRSA), on retail meat products. In this study, staphylococci were isolated from retail pork and retail beef in Georgia, and MRSA from the products was compared to human MRSA from the same geographic area using broth microdilution antimicrobial susceptibility testing, multilocus sequence typing (MLST), spa typing, SCCmec typing, and pulsed-field gel electrophoresis (PFGE). S. aureus was isolated from 45% (45/100) of pork products and 63% (63/100) of beef products; mecA was detected in S. aureus from both pork (3/100; 3%) and beef (4/100; 4%). Fifty percent (50/100) of human S. aureus also contained mecA. Multidrug resistance was detected among MRSA from all sources. All MRSA (n = 57) was SCCmec type IV, and nine different spa types were present among the isolates (t002, t008, t012, t024, t179, t337, t548, t681, and t1062). Four sequence types (ST5, ST8, ST9, and ST30) were detected using MLST; the majority of MRSA isolates belonged to ST8, followed by ST5. One retail beef MRSA isolate belonged to ST8, while the remaining three were ST5. In retail pork MRSA, ST5, ST9, and ST30 were observed. The majority of human MRSA isolates belonged to ST8. Thirty-seven MRSA isolates, one of which was a retail beef MRSA isolate, were pvl+. Using PFGE, MLST, and spa typing, three retail beef MRSA isolates were found to be identical in PFGE pattern, ST, and spa type to two human clonal MRSA isolates (USA100 and USA300). One additional retail beef MRSA isolate had a PFGE pattern similar to that of a human MRSA isolate, whereas none of the retail pork MRSA isolates had PFGE patterns similar to those of human MRSA isolates. These data suggest that the retail beef samples were contaminated by a human source, possibly during processing of the meat, and may present a source of MRSA for consumers and others who handle raw meat. PMID:23363837

  3. Prevalence and characterization of methicillin-resistant Staphylococcus aureus isolates from retail meat and humans in Georgia.

    PubMed

    Jackson, Charlene R; Davis, Johnnie A; Barrett, John B

    2013-04-01

    There is increasing interest in the presence of Staphylococcus aureus, specifically methicillin-resistant S. aureus (MRSA), on retail meat products. In this study, staphylococci were isolated from retail pork and retail beef in Georgia, and MRSA from the products was compared to human MRSA from the same geographic area using broth microdilution antimicrobial susceptibility testing, multilocus sequence typing (MLST), spa typing, SCCmec typing, and pulsed-field gel electrophoresis (PFGE). S. aureus was isolated from 45% (45/100) of pork products and 63% (63/100) of beef products; mecA was detected in S. aureus from both pork (3/100; 3%) and beef (4/100; 4%). Fifty percent (50/100) of human S. aureus also contained mecA. Multidrug resistance was detected among MRSA from all sources. All MRSA (n = 57) was SCCmec type IV, and nine different spa types were present among the isolates (t002, t008, t012, t024, t179, t337, t548, t681, and t1062). Four sequence types (ST5, ST8, ST9, and ST30) were detected using MLST; the majority of MRSA isolates belonged to ST8, followed by ST5. One retail beef MRSA isolate belonged to ST8, while the remaining three were ST5. In retail pork MRSA, ST5, ST9, and ST30 were observed. The majority of human MRSA isolates belonged to ST8. Thirty-seven MRSA isolates, one of which was a retail beef MRSA isolate, were pvl(+). Using PFGE, MLST, and spa typing, three retail beef MRSA isolates were found to be identical in PFGE pattern, ST, and spa type to two human clonal MRSA isolates (USA100 and USA300). One additional retail beef MRSA isolate had a PFGE pattern similar to that of a human MRSA isolate, whereas none of the retail pork MRSA isolates had PFGE patterns similar to those of human MRSA isolates. These data suggest that the retail beef samples were contaminated by a human source, possibly during processing of the meat, and may present a source of MRSA for consumers and others who handle raw meat.

  4. High frequency of methicillin-resistant Staphylococcus aureus (MRSA) with SCCmec type III and spa type t030 in Karaj's teaching hospitals, Iran.

    PubMed

    Bayat, Bahareh; Zade, Masoumeh Hallaj; Mansouri, Samaneh; Kalantar, Enayat; Kabir, Kourosh; Zahmatkesh, Ehsan; Sepehr, Mohammad Noori; Naseri, Mohammmad Hassan; Darban-Sarokhalil, Davood

    2017-09-01

    Methicillin-resistant Staphylococcus aureus (MRSA) has been one of the most important antibiotic-resistant pathogen in many parts of the world over the past decades. This cross-sectional study was conducted to investigate MRSA isolated between July 2013 and July 2014 in Karaj, Iran. All tested isolates were collected in teaching hospitals from personnel, patients, and surfaces and each MRSA was analyzed by SCCmec and spa typing. Antibiotic susceptibility testing was accomplished by disk diffusion method. Out of 49 MRSA isolates from the Karaj's teaching hospitals, 82%, 10%, and 6% of the isolates were SCCmec types III, II, and I, respectively. The main spa type in this study was spa t030 with frequency as high as 75.5% from intensive care unit (ICU) of the hospitals and high rate of resistance to rifampicin (53%) was found in MRSA isolates. In conclusion, high frequency of spa t030 with SCCmec type III and MRSA phenotype illustrated circulating of one of the antibiotic-resistant strains in ICU of Karaj's teaching hospitals and emphasizes the need for ongoing molecular surveillance, antibiotic susceptibility monitoring, and infection control.

  5. Characterisation of Staphylococcus aureus isolates from bloodstream infections, Democratic Republic of the Congo.

    PubMed

    Vandendriessche, S; De Boeck, H; Deplano, A; Phoba, M-F; Lunguya, O; Falay, D; Dauly, N; Verhaegen, J; Denis, O; Jacobs, J

    2017-01-23

    Staphylococcus aureus is known worldwide as an invasive pathogen, but information on S. aureus from bloodstream infections in Central Africa remains scarce. A collection of S. aureus blood culture isolates recovered from hospitals in four provinces in the Democratic Republic of the Congo (2009-2013) was assessed. A total of 27/108 isolates were methicillin-resistant S. aureus (MRSA), of which >70% were co-resistant to aminoglycosides, tetracyclines, macrolides and lincosamides. For MRSA and methicillin-susceptible S. aureus (MSSA) isolates, resistance to chloramphenicol and trimethoprim-sulphamethoxazole (TMP-SMX) was <10%. However, 66.7% (72/108) of all isolates harboured the trimethoprim resistance gene dfrG. More than three-quarters (84/108, 77.8%) of isolates belonged to CC5, CC8, CC121 or CC152. Genetic diversity was higher among MSSA (31 spa types) compared to MRSA (four spa types). Most MRSA (23/27, 85.2%) belonged to CC8-spa t1476-SCCmec V and 17/23 (73.9%) MRSA ST8 were oxacillin susceptible but cefoxitin resistant. Among MRSA and MSSA combined, 49.1% (53/108) and 19.4% (21/108) contained the genes encoding for Panton-Valentine leucocidin (lukS-lukF PV, PVL) and toxic shock syndrome toxin-1 (tst, TSST-1), respectively. PVL was mainly detected among MSSA (51/53 isolates harbouring PVL were MSSA, 96.2%) and associated with CC121, CC152, CC1 and CC5. TSST-1 was associated with CC8-spa t1476-SCCmec V. The immune evasion cluster (IEC) genes scn, sak and chp were detected in 81.5% of isolates (88/108, equally represented among MSSA and MRSA). The present study confirms the occurrence of MRSA with high levels of multidrug co-resistance and PVL-positive MSSA among invasive S. aureus isolates in Central Africa.

  6. Dalbavancin reduces biofilms of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE).

    PubMed

    Knafl, D; Tobudic, S; Cheng, S C; Bellamy, D R; Thalhammer, F

    2017-04-01

    Activity of dalbavancin against methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE) in biofilm was investigated and the microbicidal biofilm concentrations (MBC) were determined. Biofilms obtained from ten MRSA and ten MRSE bloodstream isolates, collected from patients in the General Hospital of Vienna between 2012 and 2015, were incubated with dalbavancin in trypticase soy broth (TSB) in serial dilution from 0.0625 mg/l to 256 mg/l using a microtiter plate biofilm model. The plates were incubated for 24 h at 37 ° C and 50% humidity. Biofilms were fixed with 2.5% glutaraldehyde and stained with crystal violet. Subsequently the optical density (OD620) was used to measure the MBC, defined as the concentration of dalbavancin leading to a 50% reduction of biofilm. MBC for MRSA was 1 mg/l-4 mg/l (minimal inhibitory concentrations (MIC) 0.0312 mg/l-0.064 mg/l). MBC for MRSE was 2 mg/l-16 mg/l (MIC 0.023 mg/l-0.0625 mg/l). Dalbavancin successfully reduced MRSA and MRSE in biofilms, and therefore provides a promising option for the treatment of biofilm-associated infections.

  7. Comparison of the BD GeneOhm methicillin-resistant Staphylococcus aureus (MRSA) PCR assay to culture by use of BBL CHROMagar MRSA for detection of MRSA in nasal surveillance cultures from an at-risk community population.

    PubMed

    Farley, Jason E; Stamper, Paul D; Ross, Tracy; Cai, Mian; Speser, Sharon; Carroll, Karen C

    2008-02-01

    We compared the BD GeneOhm methicillin-resistant Staphylococcus aureus (MRSA) PCR assay to culture with BBL CHROMagar MRSA for nasal surveillance among 602 arrestees from the Baltimore City Jail. The sensitivity and specificity were 88.5% and 91.0%, respectively, and after secondary analysis using enrichment broth, they were 89.0% and 91.7%, respectively. Twenty-three of 42 false-positive PCR lysates contained methicillin-susceptible S. aureus.

  8. Comparison of the BD GeneOhm Methicillin-Resistant Staphylococcus aureus (MRSA) PCR Assay to Culture by Use of BBL CHROMagar MRSA for Detection of MRSA in Nasal Surveillance Cultures from an At-Risk Community Population▿

    PubMed Central

    Farley, Jason E.; Stamper, Paul D.; Ross, Tracy; Cai, Mian; Speser, Sharon; Carroll, Karen C.

    2008-01-01

    We compared the BD GeneOhm methicillin-resistant Staphylococcus aureus (MRSA) PCR assay to culture with BBL CHROMagar MRSA for nasal surveillance among 602 arrestees from the Baltimore City Jail. The sensitivity and specificity were 88.5% and 91.0%, respectively, and after secondary analysis using enrichment broth, they were 89.0% and 91.7%, respectively. Twenty-three of 42 false-positive PCR lysates contained methicillin-susceptible S. aureus. PMID:18057129

  9. Future challenges and treatment of Staphylococcus aureus bacteremia with emphasis on MRSA

    PubMed Central

    Rasmussen, Rasmus V.; Fowler, Vance G.; Skov, Robert; Bruun, Niels E.

    2011-01-01

    Summary Staphylococcus aureus bacteremia (SAB) is an urgent medical problem due to its growing frequency and its poor associated outcome. As healthcare delivery increasingly involves invasive procedures and implantable devices, the number of patients at risk for SAB and its complications is likely to grow. Compounding this problem is the growing prevalence of methicillin resistant S. aureus (MRSA) and the dwindling efficacy of vancomycin, long the treatment of choice for this pathogen. Despite the recent availability of several new antibiotics for S. aureus, new strategies for treatment and prevention are required for this serious, common cause of human infection. PMID:21162635

  10. Diversity of Staphylococcus aureus Isolates in European Wildlife.

    PubMed

    Monecke, Stefan; Gavier-Widén, Dolores; Hotzel, Helmut; Peters, Martin; Guenther, Sebastian; Lazaris, Alexandros; Loncaric, Igor; Müller, Elke; Reissig, Annett; Ruppelt-Lorz, Antje; Shore, Anna C; Walter, Birgit; Coleman, David C; Ehricht, Ralf

    2016-01-01

    Staphylococcus aureus is a well-known colonizer and cause of infection among animals and it has been described from numerous domestic and wild animal species. The aim of the present study was to investigate the molecular epidemiology of S. aureus in a convenience sample of European wildlife and to review what previously has been observed in the subject field. 124 S. aureus isolates were collected from wildlife in Germany, Austria and Sweden; they were characterized by DNA microarray hybridization and, for isolates with novel hybridization patterns, by multilocus sequence typing (MLST). The isolates were assigned to 29 clonal complexes and singleton sequence types (CC1, CC5, CC6, CC7, CC8, CC9, CC12, CC15, CC22, CC25, CC30, CC49, CC59, CC88, CC97, CC130, CC133, CC398, ST425, CC599, CC692, CC707, ST890, CC1956, ST2425, CC2671, ST2691, CC2767 and ST2963), some of which (ST2425, ST2691, ST2963) were not described previously. Resistance rates in wildlife strains were rather low and mecA-MRSA isolates were rare (n = 6). mecC-MRSA (n = 8) were identified from a fox, a fallow deer, hares and hedgehogs. The common cattle-associated lineages CC479 and CC705 were not detected in wildlife in the present study while, in contrast, a third common cattle lineage, CC97, was found to be common among cervids. No Staphylococcus argenteus or Staphylococcus schweitzeri-like isolates were found. Systematic studies are required to monitor the possible transmission of human- and livestock-associated S. aureus/MRSA to wildlife and vice versa as well as the possible transmission, by unprotected contact to animals. The prevalence of S. aureus/MRSA in wildlife as well as its population structures in different wildlife host species warrants further investigation.

  11. Diversity of Staphylococcus aureus Isolates in European Wildlife

    PubMed Central

    Monecke, Stefan; Gavier-Widén, Dolores; Hotzel, Helmut; Peters, Martin; Guenther, Sebastian; Lazaris, Alexandros; Loncaric, Igor; Müller, Elke; Reissig, Annett; Ruppelt-Lorz, Antje; Shore, Anna C.; Walter, Birgit; Coleman, David C.; Ehricht, Ralf

    2016-01-01

    Staphylococcus aureus is a well-known colonizer and cause of infection among animals and it has been described from numerous domestic and wild animal species. The aim of the present study was to investigate the molecular epidemiology of S. aureus in a convenience sample of European wildlife and to review what previously has been observed in the subject field. 124 S. aureus isolates were collected from wildlife in Germany, Austria and Sweden; they were characterized by DNA microarray hybridization and, for isolates with novel hybridization patterns, by multilocus sequence typing (MLST). The isolates were assigned to 29 clonal complexes and singleton sequence types (CC1, CC5, CC6, CC7, CC8, CC9, CC12, CC15, CC22, CC25, CC30, CC49, CC59, CC88, CC97, CC130, CC133, CC398, ST425, CC599, CC692, CC707, ST890, CC1956, ST2425, CC2671, ST2691, CC2767 and ST2963), some of which (ST2425, ST2691, ST2963) were not described previously. Resistance rates in wildlife strains were rather low and mecA-MRSA isolates were rare (n = 6). mecC-MRSA (n = 8) were identified from a fox, a fallow deer, hares and hedgehogs. The common cattle-associated lineages CC479 and CC705 were not detected in wildlife in the present study while, in contrast, a third common cattle lineage, CC97, was found to be common among cervids. No Staphylococcus argenteus or Staphylococcus schweitzeri-like isolates were found. Systematic studies are required to monitor the possible transmission of human- and livestock-associated S. aureus/MRSA to wildlife and vice versa as well as the possible transmission, by unprotected contact to animals. The prevalence of S. aureus/MRSA in wildlife as well as its population structures in different wildlife host species warrants further investigation. PMID:27992523

  12. MRSA infection in lower extremity wounds.

    PubMed

    Edris, Bree; Reed, James F

    2008-03-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most frequently isolated bacteria in wound cultures. MRSA has been linked to lengthened wound healing times, an increase in adverse postoperative outcomes, and mortality. This study investigated the incidence of MRSA in lower extremity wounds and examined outcomes associated with MRSA-infected wounds versus non-MRSA-infected wounds. A retrospective study was conducted. Patients with MRSA-infected wounds were compared with those with uninfected wounds in a 1:2 ratio. Demographics, infection, and stay information were collected. Data were analyzed using SPSS 15.0. 51 patients were included (17 with MRSA and 34 without MRSA). Patients with MRSA had increased lengths of stay and a higher incidence of adverse postoperative outcomes compared with non-MRSA patients. An MRSA infection adversely affects a patient's hospital course. Preoperative screening for MRSA and postoperative surveillance should be considered to prevent and eliminate the spread of this virulent bacterium.

  13. Antibiofilm Effect of Octenidine Hydrochloride on Staphylococcus aureus, MRSA and VRSA

    PubMed Central

    Amalaradjou, Mary Anne Roshni; Venkitanarayanan, Kumar

    2014-01-01

    Millions of indwelling devices are implanted in patients every year, and staphylococci (S. aureus, MRSA and vancomycin-resistant S. aureus (VRSA)) are responsible for a majority of infections associated with these devices, thereby leading to treatment failures. Once established, staphylococcal biofilms become resistant to antimicrobial treatment and host response, thereby serving as the etiological agent for recurrent infections. This study investigated the efficacy of octenidine hydrochloride (OH) for inhibiting biofilm synthesis and inactivating fully-formed staphylococcal biofilm on different matrices in the presence and absence of serum protein. Polystyrene plates and stainless steel coupons inoculated with S. aureus, MRSA or VRSA were treated with OH (zero, 0.5, one, 2 mM) at 37 °C for the prevention of biofilm formation. Additionally, the antibiofilm effect of OH (zero, 2.5, five, 10 mM) on fully-formed staphylococcal biofilms on polystyrene plates, stainless steel coupons and urinary catheters was investigated. OH was effective in rapidly inactivating planktonic and biofilm cells of S. aureus, MRSA and VRSA on polystyrene plates, stainless steel coupons and urinary catheters in the presence and absence of serum proteins. The use of two and 10 mM OH completely inactivated S. aureus planktonic cells and biofilm (>6.0 log reduction) on all matrices tested immediately upon exposure. Further, confocal imaging revealed the presence of dead cells and loss in biofilm architecture in the OH-treated samples when compared to intact live biofilm in the control. Results suggest that OH could be applied as an effective antimicrobial to control biofilms of S. aureus, MRSA and VRSA on appropriate hospital surfaces and indwelling devices. PMID:25437807

  14. Antibiofilm Effect of Octenidine Hydrochloride on Staphylococcus aureus, MRSA and VRSA.

    PubMed

    Amalaradjou, Mary Anne Roshni; Venkitanarayanan, Kumar

    2014-05-06

    Millions of indwelling devices are implanted in patients every year, and staphylococci (S. aureus, MRSA and vancomycin-resistant S. aureus (VRSA)) are responsible for a majority of infections associated with these devices, thereby leading to treatment failures. Once established, staphylococcal biofilms become resistant to antimicrobial treatment and host response, thereby serving as the etiological agent for recurrent infections. This study investigated the efficacy of octenidine hydrochloride (OH) for inhibiting biofilm synthesis and inactivating fully-formed staphylococcal biofilm on different matrices in the presence and absence of serum protein. Polystyrene plates and stainless steel coupons inoculated with S. aureus, MRSA or VRSA were treated with OH (zero, 0.5, one, 2 mM) at 37 °C for the prevention of biofilm formation. Additionally, the antibiofilm effect of OH (zero, 2.5, five, 10 mM) on fully-formed staphylococcal biofilms on polystyrene plates, stainless steel coupons and urinary catheters was investigated. OH was effective in rapidly inactivating planktonic and biofilm cells of S. aureus, MRSA and VRSA on polystyrene plates, stainless steel coupons and urinary catheters in the presence and absence of serum proteins. The use of two and 10 mM OH completely inactivated S. aureus planktonic cells and biofilm (>6.0 log reduction) on all matrices tested immediately upon exposure. Further, confocal imaging revealed the presence of dead cells and loss in biofilm architecture in the OH-treated samples when compared to intact live biofilm in the control. Results suggest that OH could be applied as an effective antimicrobial to control biofilms of S. aureus, MRSA and VRSA on appropriate hospital surfaces and indwelling devices.

  15. Nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) among Swiss veterinary health care providers: detection of livestock- and healthcare-associated clones.

    PubMed

    Wettstein Rosenkranz, K; Rothenanger, E; Brodard, I; Collaud, A; Overesch, G; Bigler, B; Marschall, J; Perreten, V

    2014-07-01

    We screened a total of 340 veterinarians (including general practitioners, small animal practitioners, large animal practitioners, veterinarians working in different veterinary services or industry), and 29 veterinary assistants for nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus pseudintermedius (MRSP) at the 2012 Swiss veterinary annual meeting. MRSA isolates (n = 14) were detected in 3.8 % (95 % CI 2.1 - 6.3 %) of the participants whereas MRSP was not detected. Large animal practitioners were carriers of livestock-associated MRSA (LA-MRSA) ST398-t011-V (n = 2), ST398-t011-IV (n = 4), and ST398-t034-V (n = 1). On the other hand, participants working with small animals harbored human healthcare-associated MRSA (HCA-MRSA) which belonged to epidemic lineages ST225-t003-II (n = 2), ST225-t014-II (n = 1), ST5-t002-II (n = 2), ST5-t283-IV (n = 1), and ST88-t186-IV (n = 1). HCA-MRSA harbored virulence factors such as enterotoxins, β-hemolysin converting phage and leukocidins. None of the MRSA isolates carried Panton-Valentine leukocidin (PVL). In addition to the methicillin resistance gene mecA, LA-MRSA ST398 isolates generally contained additional antibiotic resistance genes conferring resistance to tetracycline [tet(M) and tet(K)], trimethoprim [dfrK, dfrG], and the aminoglycosides gentamicin and kanamycin [aac(6')-Ie - aph(2')-Ia]. On the other hand, HCA-MRSA ST5 and ST225 mainly contained genes conferring resistance to the macrolide, lincosamide and streptogramin B antibiotics [erm(A)], to spectinomycin [ant(9)-Ia], amikacin and tobramycin [ant(4')-Ia], and to fluoroquinolones [amino acid substitutions in GrlA (S84L) and GyrA (S80F and S81P)]. MRSA carriage may represent an occupational risk and veterinarians should be aware of possible MRSA colonization and potential for developing infection or for transmitting these strains. Professional exposure to animals should be reported upon hospitalization and before medical

  16. Massive dissemination of methicillin resistant Staphylococcus aureus in bloodstream infections in a high MRSA prevalence country: establishment and diversification of EMRSA-15.

    PubMed

    Faria, Nuno A; Miragaia, Maria; de Lencastre, Hermínia

    2013-12-01

    Portugal is the European country with the highest prevalence of methicillin resistant Staphylococcus aureus (MRSA), in which EMRSA-15 (ST22-IVh) has been the dominant clone since soon after its introduction in Portuguese hospitals in 2001. In this study, we intend to not only, assess the evolution of the invasive MRSA in Portuguese hospitals, but also to evaluate the invasive methicillin susceptible S. aureus (MSSA) population and the relationship between both populations. In the current study, two major MRSA clones were identified: EMRSA-15 that has been dominant for more than 10 years and accounts for 75% of the MRSA isolates, and ST105-II, a clone related with the New York/Japan clone (ST5-II). In contrast, among MSSA, several clonal backgrounds were identified. Despite of the massive predominance of EMRSA-15 in the last decade, an increase in spa diversity has been observed in the last few years, which suggests a recent and local diversification of this clone. Interestingly, MRSA and MSSA populations with related clonal backgrounds appear to have increased as a result of the dissemination of MRSA to the community environment.

  17. Effects of Subinhibitory Concentrations of Ceftaroline on Methicillin-Resistant Staphylococcus aureus (MRSA) Biofilms

    PubMed Central

    Rodríguez-Mirones, Cristina; Acosta, Felix; Icardo, Jose M.; Martínez-Martínez, Luis; Ramos-Vivas, José

    2016-01-01

    Ceftaroline (CPT) is a novel cephalosporin with in vitro activity against Staphylococcus aureus. Ceftaroline exhibits a level of binding affinity for PBPs in S. aureus including PBP2a of methicillin-resistant S. aureus (MRSA). The aims of this study were to investigate the morphological, physiological and molecular responses of MRSA clinical strains and MRSA biofilms to sub-MICs (1/4 and 1/16 MIC) of ceftaroline by using transmission, scanning and confocal microscopy. We have also used quantitative Real-Time PCR to study the effect of sub-MICs of ceftaroline on the expression of the staphylococcal icaA, agrA, sarA and sasF genes in MRSA biofilms. In one set of experiments, ceftaroline was able to inhibit biofilm formation in all strains tested at MIC, however, a strain dependent behavior in presence of sub-MICs of ceftaroline was shown. In a second set of experiments, destruction of preformed biofilms by addition of ceftaroline was evaluated. Ceftaroline was able to inhibit biofilm formation at MIC in all strains tested but not at the sub-MICs. Destruction of preformed biofilms was strain dependent because the biofilm formed by a matrix-producing strain was resistant to a challenge with ceftaroline at MIC, whereas in other strains the biofilm was sensitive. At sub-MICs, the impact of ceftaroline on expression of virulence genes was strain-dependent at 1/4 MIC and no correlation between ceftaroline-enhanced biofilm formation and gene regulation was established at 1/16 MIC. Our findings suggest that sub-MICs of ceftaroline enhance bacterial attachment and biofilm formation by some, but not all, MRSA strains and, therefore, stress the importance of maintaining effective bactericidal concentrations of ceftaroline to fight biofilm-MRSA related infections. PMID:26800524

  18. Ceftaroline: A New Cephalosporin with Activity against Methicillin-Resistant Staphylococcus aureus (MRSA)

    PubMed Central

    Duplessis, Christopher; Crum-Cianflone, Nancy F.

    2011-01-01

    Microbial resistance has reached alarming levels, threatening to outpace the ability to counter with more potent antimicrobial agents. In particular, methicillin-resistant Staphylococcus aureus (MRSA) has become a leading cause of skin and soft-tissue infections and PVL-positive strains have been associated with necrotizing pneumonia. Increasing reports of growing resistance to glycopeptides have been noted, further limiting the efficacy of standard antibiotics, such as vancomycin. Ceftaroline is a novel fifth-generation cephalosporin, which exhibits broad-spectrum activity against Gram-positive bacteria, including MRSA and extensively-resistant strains, such as vancomycin-intermediate S. aureus (VISA), heteroresistant VISA (hVISA), and vancomycin-resistant S. aureus (VRSA). In addition to being an exciting new agent in the anti-MRSA armamentarium, ceftaroline provides efficacy against many respiratory pathogens including Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Ceftaroline (600 mg intravenously every 12 hours) has been shown effective in phase III studies in the treatment of complicated skin and soft tissue infections and community-acquired pneumonia. To date, this unique antibiotic exhibits a low propensity for inducing resistance and has a good safety profile, although further post-marketing data and clinical experience are needed. In summary, ceftaroline provides an additional option for the management of complex multidrug resistant infections, including MRSA. PMID:21785568

  19. Prevalence and Characterization of Staphylococcus aureus, Including Methicillin-Resistant Staphylococcus aureus, Isolated from Bulk Tank Milk from Minnesota Dairy Farms

    PubMed Central

    Haran, K. P.; Godden, S. M.; Boxrud, D.; Jawahir, S.; Bender, J. B.

    2012-01-01

    Staphylococcus aureus is a common causative agent of bovine mastitis in dairy herds. The emergence of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals as well as the community is a significant and costly public health concern. S. aureus-related bovine mastitis is a common reason for therapeutic and/or prophylactic use of antibiotics on dairy farms. In this study, herd prevalence of S. aureus, including MRSA, was estimated from bulk tank milk (BTM) from Minnesota farms. A total of 150 pooled BTM samples from 50 farms, collected over 3 seasons (spring, summer, and fall of 2009), were assessed. Herd prevalence of methicillin-susceptible S. aureus (MSSA) was 84%, while MRSA herd prevalence was 4%. A total of 93 MSSA isolates and 2 MRSA isolates were recovered from 150 BTM samples. Antibiotic susceptibility testing of S. aureus isolates showed pansusceptibility in 54 isolates, resistance to a single antibiotic class in 21 isolates, resistance to two antibiotic classes in 13 isolates, and resistance to ≥3 antibiotics classes and thus multidrug resistance in 5 isolates. The two MRSA isolates displayed resistance to β-lactams, cephalosporins, and lincosamides and were multiresistant. Staphylococcal protein A gene (spa) typing identified spa types t529 and t034 most frequently among methicillin-susceptible isolates, while t121 was observed in MRSA isolates. Seven isolates, including the two MRSA isolates, produced staphylococcal enterotoxins B, C, D, and E on overnight culture. MRSA isolates were further genotyped using multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Of the 2 MRSA isolates, one had a composite genotype profile of MLST ST 5-PFGE USA100-unknown spa type, which has been reported among hospital-associated MRSA isolates, while the second isolate carried the MLST ST 8-PFGE USA300-spa type t121 genotype, commonly identified among community-associated MRSA isolates. These results suggest that MRSA genotypes

  20. Presence of Methicillin Resistant Staphylococcus aureus (MRSA) in sewage treatment plant.

    PubMed

    Boopathy, Raj

    2017-02-23

    The presence of antibiotic resistant bacteria and antibiotic resistance genes in rural sewage treatment plants are not well reported in the literature. The aim of the present study was to study the frequency occurrence of Methicillin Resistant Staphylococcus aureus (MRSA) in a rural sewage treatment plant. This study was conducted using raw sewage as well as treated sewage from a small town sewage treatment plant in rural southeast Louisiana of USA. Results showed the presence of MRSA consistently in both raw and treated sewage. The presence of mecA gene responsible for methicillin resistance was confirmed in the raw and treated sewage water samples.

  1. [Antibiotics for treatment of infections by methicillin-resistant Staphylococcus aureus (MRSA)].

    PubMed

    Stahlmann, R

    2014-10-01

    Over the last 50 years methicillin-resistant S. aureus (MRSA) spread globally. Vancomycin is still the most recommended antibiotic for MRSA-infections. Teicoplanin is an alternative glycopeptide with longer elimination half-life. Telavancin is a more recently developed derivative of vancomycin with similar clinical efficacy as vancomycin. It is not recommended for treatment of patients with renal insufficiency. Nephrotoxicity limits the therapeutic use of glycopeptide antibiotics. The oxazolidinone linezolid exhibits similar to superior therapeutic efficacy. Hematologic controls are necessary during treatment with this antibacterial agent. Neurotoxic effects have been observed mainly in patients who received prolonged linezolid treatment. Attention must be paid to possible interactions with concomitantly given drugs acting on the serotonergic system. New therapeutic options arise with ceftaroline, the first β-lactam antibiotic with activity against MRSA. However, controlled clinical trials with pulmonary MRSA infections have not been conducted with ceftaroline. Daptomycin, a lipopeptide, and tigecycline, a glycylcyclin are active in vitro against MRSA as well, but are also not indicated in pulmonary MRSA infections. These antibiotics show in an exemplary manner that antibacterial activity in vitro is an important prerequisite, but relevant data for a therapeutic decision should be derived from randomized controlled clinical double-blind trials.

  2. Validation of a phage-open reading frame typing kit for rapid identification of methicillin-resistant Staphylococcus aureus (MRSA) transmission in a tertiary hospital.

    PubMed

    Takahashi, Hiroki; Seki, Masafumi; Yamamoto, Norihisa; Hamaguchi, Shigeto; Ojima, Masahiro; Hirose, Tomoya; Yoshiya, Kazuhisa; Toyokawa, Masahiro; Nishi, Isao; Ogura, Hiroshi; Shimazu, Takeshi; Tomono, Kazunori

    2015-01-01

    Surveillance is very important to prevent the nosocomial spread of methicillin-resistant Staphylococcus aureus (MRSA), and infection sources and routes have historically been identified using molecular and epidemiological genotyping with pulsed-field gel electrophoresis. However, phage-open reading frame typing (POT) has recently been developed. Here, we investigated whether POT would be useful to survey MRSA outbreaks and transmission. We therefore applied POT to 91 MRSA isolates detected in cultures from inpatients at our hospital between May and October 2014. Among the 91 isolates, 12 POT types comprising 38 isolated MRSA strains were considered as overlapping. Five of them were detected in different wards, whereas the remaining seven were found in the same ward, including the emergency department. Three of seven POT number 93-155-111 strains were detected in the surgical ward, and all of four POT number 93-157-61 strains were detected in the cardiosurgical ward. These data suggested that transmission of the MRSA strains with the same POT-types from the same wards was nosocomial, and that POT accurately and rapidly identified MRSA strains, which allowed effective control of infection and transmission.

  3. Differences in Epidemiological and Molecular Characteristics of Nasal Colonization with Staphylococcus aureus (MSSA-MRSA) in Children from a University Hospital and Day Care Centers

    PubMed Central

    Rodríguez, Erika A.; Correa, Margarita M.; Ospina, Sigifredo; Atehortúa, Santiago L.; Jiménez, J. Natalia

    2014-01-01

    Background Clinical significance of Staphylococcus aureus colonization has been demonstrated in hospital settings; however, studies in the community have shown contrasting results regarding the relevance of colonization in infection by community-associated MRSA (CA-MRSA). In Colombia there are few studies on S. aureus colonization. The aim of this study was to determine the molecular and epidemiological characteristics of nasal colonization by S. aureus (MSSA-MRSA) in children from a university hospital and day care centers (DCCs) of Medellin, Colombia. Methods An observational cross-sectional study was conducted in 400 children (200 in each setting), aged 0 months to 5 years, during 2011. Samples were collected from each nostril and epidemiological information was obtained from the parents. Genotypic analysis included spa typing, PFGE, MLST, SCCmec typing, detection of genes for virulence factors and agr groups. Results Frequency of S. aureus colonization was 39.8% (n = 159) (hospital 44.5% and DCCs 35.0%) and by MRSA, 5.3% (n = 21) (hospital 7.0% and DCCs 3.5%). Most S. aureus colonized children were older than two years (p = 0.005), the majority of them boys (59.1%), shared a bedroom with a large number of people (p = 0.028), with history of β-Lactamase inhibitors usage (p = 0.020). MSSA strains presented the greatest genotypic diversity with 15 clonal complexes (CC). MRSA isolates presented 6 CC, most of them (47.6%) belonged to CC8-SCCmec IVc and were genetically related to previously reported infectious MRSA strains. Conclusion Differences in epidemiological and molecular characteristics between populations may be useful for the understanding of S. aureus nasal colonization dynamics and for the design of strategies to prevent S. aureus infection and dissemination. The finding of colonizing MRSA with similar molecular characteristics of those causing infection demonstrates the dissemination capacity of S. aureus and the risk of infection

  4. Epidemiology and outcome of pneumonia caused by methicillin-resistant Staphylococcus aureus (MRSA) in Canadian hospitals.

    PubMed

    Tadros, Manal; Williams, Victoria; Coleman, Brenda L; McGeer, Allison J; Haider, Shariq; Lee, Christine; Iacovides, Harris; Rubinstein, Ethan; John, Michael; Johnston, Lynn; McNeil, Shelly; Katz, Kevin; Laffin, Nancy; Suh, Kathryn N; Powis, Jeff; Smith, Stephanie; Taylor, Geoff; Watt, Christine; Simor, Andrew E

    2013-01-01

    MRSA remains a leading cause of hospital-acquired (HAP) and healthcare-associated pneumonia (HCAP). We describe the epidemiology and outcome of MRSA pneumonia in Canadian hospitals, and identify factors contributing to mortality. Prospective surveillance for MRSA pneumonia in adults was done for one year (2011) in 11 Canadian hospitals. Standard criteria for MRSA HAP, HCAP, ventilator-associated pneumonia (VAP), and community-acquired pneumonia (CAP) were used to identify cases. MRSA isolates underwent antimicrobial susceptibility testing, and were characterized by pulsed-field gel electrophoresis (PFGE) and Panton-Valentine leukocidin (PVL) gene detection. The primary outcome was all-cause mortality at 30 days. A multivariable analysis was done to examine the association between various host and microbial factors and mortality. A total of 161 patients with MRSA pneumonia were identified: 90 (56%) with HAP, 26 (16%) HCAP, and 45 (28%) CAP; 23 (14%) patients had VAP. The mean (± SD) incidence of MRSA HAP was 0.32 (± 0.26) per 10,000 patient-days, and of MRSA VAP was 0.30 (± 0.5) per 1,000 ventilator-days. The 30-day all-cause mortality was 28.0%. In multivariable analysis, variables associated with mortality were the presence of multiorgan failure (OR 8.1; 95% CI 2.5-26.0), and infection with an isolate with reduced susceptibility to vancomycin (OR 2.5, 95% CI 1.0-6.3). MRSA pneumonia is associated with significant mortality. Severity of disease at presentation, and infection caused by an isolate with elevated MIC to vancomcyin are associated with increased mortality. Additional studies are required to better understand the impact of host and microbial variables on outcome.

  5. Molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) among veterinary students and personnel at a veterinary hospital in Malaysia.

    PubMed

    Aklilu, E; Zunita, Z; Hassan, L; Cheng, Chen Hui

    2013-06-28

    In this study, we report the molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) among veterinary students and personnel in Malaysia. Nasal and oral swabs were collected from 103 veterinary medicine students and 28 personnel from a veterinary hospital. Antibiotic sensitivity test (AST), minimum inhibitory concentration (MIC) test, and PCR amplifications of nucA and mecA gene were performed. Molecular characterization of the isolates was conducted using multilocus sequence typing (MLST), staphylococcal protein A gene (spa) typing, and pulsed-field gel electrophoresis (PFGE). Results from MLST show the presence of the pandemic and widespread MRSA clones, ST5 and ST59. Spa gene typing revealed spa type t267 which has a wide geographical distribution. A new spa type, t5697 was found in this study. Fingerprint analysis by using PFGE show heterogeneity of the isolates. These findings affirm the importance of MRSA in veterinary settings and underscore the need for further extensive research to devise contextual control and prevention strategies. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Draft Genome Sequences of Two Clinical Methicillin-Resistant Staphylococcus aureus Strains Isolated from Healthy Children in Brazil

    PubMed Central

    de Carvalho, Suzi P.; de Almeida, Jéssica B.; de Freitas, Leandro M.; Guimaraes, Ana Marcia S.; do Nascimento, Naíla C.; dos Santos, Andrea P.; Messick, Joanne B.; Timenetsky, Jorge

    2017-01-01

    ABSTRACT We report here the draft genome sequences of two community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strains, C18 and C80, isolated from healthy children from day care centers. To our knowledge, these are the first draft genome sequences of CA-MRSA ST398/CC398/SccmecV and CA-MRSA ST5/CC5/SccmecIVa isolated from healthy children in Brazil. PMID:28408675

  7. Draft Genome Sequences of Two Clinical Methicillin-Resistant Staphylococcus aureus Strains Isolated from Healthy Children in Brazil.

    PubMed

    de Carvalho, Suzi P; de Almeida, Jéssica B; de Freitas, Leandro M; Guimaraes, Ana Marcia S; do Nascimento, Naíla C; Dos Santos, Andrea P; Messick, Joanne B; Timenetsky, Jorge; Marques, Lucas M

    2017-04-13

    We report here the draft genome sequences of two community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strains, C18 and C80, isolated from healthy children from day care centers. To our knowledge, these are the first draft genome sequences of CA-MRSA ST398/CC398/SccmecV and CA-MRSA ST5/CC5/SccmecIVa isolated from healthy children in Brazil. Copyright © 2017 de Carvalho et al.

  8. Phenotypic and genomic comparisons of highly vancomycin-resistant Staphylococcus aureus strains developed from multiple clinical MRSA strains by in vitro mutagenesis.

    PubMed

    Ishii, Kenichi; Tabuchi, Fumiaki; Matsuo, Miki; Tatsuno, Keita; Sato, Tomoaki; Okazaki, Mitsuhiro; Hamamoto, Hiroshi; Matsumoto, Yasuhiko; Kaito, Chikara; Aoyagi, Tetsuji; Hiramatsu, Keiichi; Kaku, Mitsuo; Moriya, Kyoji; Sekimizu, Kazuhisa

    2015-11-25

    The development of vancomycin (VCM) resistance in Staphylococcus aureus threatens global health. Studies of the VCM-resistance mechanism and alternative therapeutic strategies are urgently needed. We mutagenized S. aureus laboratory strains and methicillin-resistant S. aureus (MRSA) with ethyl methanesulfonate, and isolated mutants that exhibited high resistance to VCM (minimum inhibitory concentration = 32 μg/ml). These VCM-resistant strains were sensitive to linezolid and rifampicin, and partly to arbekacin and daptomycin. Beta-lactams had synergistic effects with VCM against these mutants. VCM-resistant strains exhibited a 2-fold increase in the cell wall thickness. Several genes were commonly mutated among the highly VCM-resistant mutants. These findings suggest that MRSA has a potential to develop high VCM resistance with cell wall thickening by the accumulation of mutations.

  9. USA300-related methicillin-resistant Staphylococcus aureus clone is the predominant cause of community and hospital MRSA infections in Colombian children.

    PubMed

    Márquez-Ortiz, Ricaurte Alejandro; Álvarez-Olmos, Martha I; Escobar Pérez, Javier Antonio; Leal, Aura Lucia; Castro, Betsy Esperanza; Mariño, Ana Cristina; Barrero, Esther Rocio; Mujica, Sandra Celina; Gaines, Sebastián; Vanegas, Natasha

    2014-08-01

    Community-genotype methicillin-resistant Staphylococcus aureus (CG-MRSA) isolates are known to be more virulent and clinically aggressive in children. The goal of the present study was characterize the molecular epidemiology of MRSA isolates causing infections in Colombian children. An observational and prospective study was conducted between April 2009 and June 2011 at 15 hospitals in Bogotá, Colombia. A detailed epidemiological profile was made of 162 children infected with MRSA. The isolates were subjected to antimicrobial susceptibility testing, molecular characterization including 21 virulence genes, SCCmec, spa and agr typing, multilocus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE). Among all isolates included in the study, 85.8% were obtained from patients whose infectious process was initiated in the community; of these, 69,8% occurred in patients without healthcare-associated risk factors. The molecular characterization of the isolates showed a high proportion (95.1%) containing a community-genotype profile with a high prevalence of SCCmec type IV, PVL-positives, and also related to CC8. Most CG-MRSA isolates (143, 92.9%) were genetically related to the pandemic clone USA300, differing by the presence of SCCmec IVc and the absence of the arginine catabolic mobile element (ACME). An increase in the frequency of CG-MRSA infections has been reported worldwide. In this study we found that almost all MRSA infections in our pediatric population were caused by community-genotype isolates, supporting the success of the CG-MRSA clones. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Inactivating Methicillin Resistant Staphylococcus aureus (MRSA) and Other Pathogens by Bacteriocins OR-7 and E 50-52.

    USDA-ARS?s Scientific Manuscript database

    Worldwide, reports document the increasing frequency of methicillin resistant Staphylococcus aureus (MRSA) infections. Other human pathogens are recognized as unresponsive to antibiotics of last resort. These previously treatable infections now account for increased numbers of human disease and de...

  11. Inactivating Methicillin Resistant Staphylococcus aureus (MRSA) and other Pathogens by Bacteriocins OR-7 and E 50-52.

    USDA-ARS?s Scientific Manuscript database

    Worldwide, reports document the increasing frequency of methicillin resistant Staphylococcus aureus (MRSA) infections. Other human pathogens are recognized as unresponsive to antibiotics of last resort. These previously treatable infections now account for increased numbers of human disease and de...

  12. Evaluation of a New Selective Medium, BD BBL CHROMagar MRSA II, for Detection of Methicillin-Resistant Staphylococcus aureus in Stool Specimens ▿

    PubMed Central

    Havill, Nancy L.; Boyce, John M.

    2010-01-01

    We compared the recovery of methicillin-resistant Staphylococcus aureus (MRSA) on a new selective chromogenic agar, BD BBL CHROMagar MRSA II (CMRSAII), to that on traditional culture media with 293 stool specimens. The recovery of MRSA was greater on the CMRSAII agar. Screening of stool samples can identify patients who were previously unknown carriers of MRSA. PMID:20392908

  13. Genome sequencing and molecular characterisation of Staphylococcus aureus ST772-MRSA-V, "Bengal Bay Clone".

    PubMed

    Monecke, Stefan; Baier, Vico; Coombs, Geoffrey W; Slickers, Peter; Ziegler, Albrecht; Ehricht, Ralf

    2013-12-20

    The PVL-positive ST772-MRSA-V is an emerging community-associated (CA-) MRSA clone that has been named Bengal Bay Clone since most patients have epidemiological connections to the Indian subcontinent. It is found increasingly common in other areas of the world. One isolate of ST772-MRSA-V was sequenced using the Illumina Genome Analyzer System. After initial assembling the multiple sequence contigs were analysed using different in-house annotation scripts. Results were compared to microarray hybridisation results of clinical isolates of ST772-MRSA-V, of related strains and to another ST772-MRSA-V genome sequence. According to MLST e-burst analysis, ST772-MRSA-V belongs to Clonal Complex (CC)1, differing from ST1 only in one MLST allele (pta-22). However, there are several additional differences including agr alleles (group II rather than III), capsule type (5 rather than 8), the presence of the egc enterotoxin gene cluster and of the enterotoxin homologue ORF CM14 as well as the absence of the enterotoxin H gene seh. Enterotoxin genes sec and sel are present. ST772-MRSA-V harbours the genes encoding enterotoxin A (sea) and PVL (lukS/F-PV). Both are located on the same prophage. ST772-MRSA-V may have emerged from the same lineage as globally spread CC1 and CC5 strains. It has acquired a variety of virulence factors, and for a CA-MRSA strain it has an unusually high number of genes associated with antibiotic resistance.

  14. Methicillin-Resistant Staphylococcus aureus (MRSA) Infections in the Department of Defense (DOD): Annual Summary 2013

    DTIC Science & Technology

    2015-01-06

    2005 – 2013, MRSA isolates showed decreased susceptibility to cefazolin . However, MRSA showed increased susceptibility to erythromycin and...less than 2% susceptible to amoxicillin/clavulanate and cefazolin in both the DOD and DON, and to ceftriaxone and imipenem for only the DOD. Prior to...doxycycline in both the DOD and DON. In the DOD from 2005 – 2013, cefazolin showed a significant (P = <.001) trend and decrease in susceptibility since 2005

  15. Antimicrobial susceptibility profiles of Staphylococcus aureus isolates classified according to their origin in a tertiary hospital in Korea.

    PubMed

    Moon, Hee-Won; Kim, Hyun Jung; Hur, Mina; Yun, Yeo-Min

    2014-12-01

    We performed a comprehensive analysis on 3,594 Staphylococcus aureus isolates from routine culture during the last 4 years. The antimicrobial susceptibilities of the isolates were analyzed according to their origin and were compared based on the type of specimens. The proportion of methicillin-resistant Staphylococcus aureus (MRSA) in community-associated (CA), health care-associated, community onset (HACO), and health care-associated (HA) isolates were 33.0%, 54.3%, and 73.3%, respectively. The MRSA rate differed significantly between specimens, with the highest rate from urine in the CA and HACO isolates, whereas the highest rate from the respiratory tract was in the HA isolates. The monitoring of the MRSA rate in CA, HACO, and HA S aureus isolates would be valuable for surveillance. The elevated rates of MRSA in urinary specimens from CA and HCA isolates need to be addressed for infection control.

  16. Nasal carriage of methicillin-resistant Staphylococcus aureus and the effect of tea extracts on isolates.

    PubMed

    Abaza, Amani F; Mohamed, Osama N; El-Fiky, Fathy K; Ahmed, Khaled A

    2016-09-01

    This study aimed to determine the occurrence of methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage among patients, healthcare workers (HCWs), and community individuals, as well as to test the effect of tea extracts on detected S. aureus isolates. This cross-sectional study that was followed by an experimental study included a total of 1021 nasal swab samples that were collected from 470 community cases, 191 HCWs, and 360 patients. Isolation of S. aureus and MRSA was carried out on mannitol salt agar plates. S. aureus isolates were identified according to standard microbiological methods. Methicillin resistance was determined by disc-diffusion method according to the Clinical and Laboratory Standard Institute recommendations. A total of six tea samples (black and green) were purchased from different markets in Alexandria and were extracted. The antibacterial effects of these tea extracts were tested against identified MRSA isolates using agar gel diffusion method. The overall S. aureus nasal carriage rate was 12.5%, distributed as 7.9% MRSA and 4.6% methicillin-susceptible S. aureus. The rates of MRSA nasal carriage among HCWs, patients, and community cases were 10.5, 8.1, and 6.8%, respectively. Green tea had a strong effect on more than half of the isolates (55%) and an intermediate effect on 45% of them. It had no weak effect on any of the MRSA isolates. Among all tested individuals, HCWs had the highest percentage of MRSA nasal carriage. Green tea had a significantly stronger inhibitory effect than black tea on almost all tested isolates.

  17. Genomic Characterization of USA300 Methicillin-Resistant Staphylococcus aureus (MRSA) to Evaluate Intraclass Transmission and Recurrence of Skin and Soft Tissue Infection (SSTI) Among High-Risk Military Trainees.

    PubMed

    Millar, Eugene V; Rice, Gregory K; Elassal, Emad M; Schlett, Carey D; Bennett, Jason W; Redden, Cassie L; Mor, Deepika; Law, Natasha N; Tribble, David R; Hamilton, Theron; Ellis, Michael W; Bishop-Lilly, Kimberly A

    2017-08-01

    Military trainees are at increased risk for methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infection (SSTI). Whole genome sequencing (WGS) can refine our understanding of MRSA transmission and microevolution in congregate settings. We conducted a prospective case-control study of SSTI among US Army infantry trainees at Fort Benning, Georgia, from July 2012 to December 2014. We identified clusters of USA300 MRSA SSTI within select training classes and performed WGS on clinical isolates. We then linked genomic, phylogenetic, epidemiologic, and clinical data in order to evaluate intra- and interclass disease transmission. Furthermore, among cases of recurrent MRSA SSTI, we evaluated the intrahost relatedness of infecting strains. Nine training classes with ≥5 cases of USA300 MRSA SSTI were selected. Eighty USA300 MRSA clinical isolates from 74 trainees, 6 (8.1%) of whom had recurrent infection, were subjected to WGS. We identified 2719 single nucleotide variants (SNVs). The overall median (range) SNV difference between isolates was 173 (1-339). Intraclass median SNV differences ranged from 23 to 245. Two phylogenetic clusters were suggestive of interclass MRSA transmission. One of these clusters stemmed from 2 classes that were separated by a 13-month period but housed in the same barracks. Among trainees with recurrent MRSA SSTI, the intrahost median SNV difference was 7.5 (1-48). Application of WGS revealed intra- and interclass transmission of MRSA among military trainees. An interclass cluster between 2 noncontemporaneous classes suggests a long-term reservoir for MRSA in this setting.

  18. A combination of ceftaroline and daptomycin has synergistic and bactericidal activity in vitro against daptomycin nonsusceptible methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Shafiq, Iffat; Bulman, Zackery P; Spitznogle, Sarah L; Osorio, Justin E; Reilly, Irene S; Lesse, Alan J; Parameswaran, Ganapathi I; Mergenhagen, Kari A; Tsuji, Brian T

    2017-05-01

    There is an urgent need to optimize therapeutic options in patients with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia who have failed conventional therapy. Two clinical isolates were obtained from a 68-year-old male with persistent MRSA bacteremia before and after the development of daptomycin nonsusceptibility. The pharmacodynamic activity of monotherapies and combinations of ceftaroline, daptomycin, cefoxitin, nafcillin and vancomycin were evaluated in time-kill experiments versus 10(8) CFU/mL of the pre- and post-daptomycin nonsusceptible MRSA isolates. Cefoxitin, nafcillin and vancomycin alone or in combination with ceftaroline failed to generate prolonged bactericidal activity against the post-daptomycin nonsusceptible isolate whereas a ceftaroline-daptomycin combination resulted in 6, 24 and 48 h log10(CFU/mL) reductions of 3.90, 4.40 and 6.32. Population analysis profiles revealed a daptomycin heteroresistant subpopulation of the pre-daptomycin nonsusceptible MRSA isolate that expanded by >10,000× on daptomycin agar containing 2-16 mg/L in the post-daptomycin nonsusceptible isolate. Daptomycin and ceftaroline combinations may be promising against persistent MRSA bacteremia.

  19. Virulence and resistance profiles of MRSA isolates in pre- and post-liver transplantation patients using microarray.

    PubMed

    van der Heijden, Inneke Marie; de Oliveira, Larissa Marques; Brito, Glauber Costa; Abdala, Edson; Freire, Maristela Pinheiro; Rossi, Flavia; D'Albuquerque, Luiz Augusto Carneiro; Levin, Anna Sara Shafferman; Costa, Silvia Figueiredo

    2016-10-01

    Methicillin-resistant Staphylococcus aureus (MRSA) screening plays a great role in preventing infections in surgical patients. This study aims to evaluate clonality, virulence and resistance of MRSA in pre- and post-liver transplantation (LT) patients. Nasal and groin swabs of 190 patients were collected. PCR for virulence genes and staphylococcal cassette chromosome mec (SCCmec) types, microarray, PFGE, multilocus sequence typing and MIC were performed. MRSA carriers were detected in 20.5 % (39/190) of the patients. However, only three colonized patients developed infections post-LT. Sixty-nine MRSA isolates were identified, and the most frequent SCCmec type was type II (29/69; 42.0 %). Most isolates (57/69; 82.6 %) were susceptible to trimethoprim-sulfamethoxazole (TMP/SMX) and harboured the lukD, lukE, clf and fnbA genes as determined by PCR. Five sequence types (ST) were identified among nine clones; 36.2 % (25/69) isolates belonged to a predominant clone (ST105 and SCCmec type II) that was susceptible to TMP/SMX, mupirocin and chlorhexidine, which had 87.9 % similarity with the New York/Japan clone. The array showed virulence difference in isolates of the same clone and patients and that colonized isolates (pre-LT patients) were less virulent than those post-LT and those infected. Therefore, despite the high frequency of MRSA colonization, infection due to MRSA was uncommon in our LT unit. MRSA isolates presented great diversity. Isolates of the same clone expressed different virulence factors by array. Colonizing isolates pre-LT expressed less virulent factors than post-LT and infecting isolates.

  20. Significant antibacterial activity and synergistic effects of camel lactoferrin with antibiotics against methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Redwan, Elrashdy M; El-Baky, Nawal Abd; Al-Hejin, Ahmed M; Baeshen, Mohammed N; Almehdar, Hussein A; Elsaway, Abdulrahman; Gomaa, Abu-Bakr M; Al-Masaudi, Saad Berki; Al-Fassi, Fahad A; AbuZeid, Isam Eldin; Uversky, Vladimir N

    2016-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) causes major healthcare problems in many countries, as it is present as several hospital- and community-associated strains. Hospital-associated MRSA is one of the most prevalent nosocomial pathogens throughout the world and infections caused by community-acquired MRSA are rising. This emphasizes the need for new and efficient anti-MRSA agents. We evaluated the antibacterial effects of camel lactoferrin (cLf) and human lactoferrin (hLf) alone and in combination with several antibiotics against MRSA. Antimicrobials were tested against MRSA and an S. aureus control strain by the agar disc diffusion method. The minimum inhibitory concentration (MIC) was determined for antimicrobials by the broth microdilution method. Synergy between cLf or hLf and antibiotics was examined by checkerboard and time-kill assays. The agar disc diffusion assay showed that MRSA growth was inhibited by cLf at 0.25-3 mg/ml and hLf at 1-3 mg/ml. cLf demonstrated 3 times higher inhibitory activity against MRSA than hLf in terms of MIC values (250 vs. 750 μg/ml, respectively). Biotinylated cLf was recognized by two membrane proteins of MRSA, 66-67 KDa. Combinations of cLf or hLf and oxacillin or vancomycin at sub-MIC levels enhanced in vitro antibacterial activity against MRSA compared with each agent alone.

  1. A methicillin-resistant Staphylococcus aureus (MRSA) Sequence Type 8, spa type t11469 causing infection and colonizing horses in Italy.

    PubMed

    Carfora, Virginia; Caprioli, Andrea; Grossi, Ilaria; Pepe, Marco; Alba, Patricia; Lorenzetti, Serena; Amoruso, Roberta; Sorbara, Luigi; Franco, Alessia; Battisti, Antonio

    2016-06-01

    A Methicillin-resistantStaphylococcus aureus(MRSA) was isolated in Italy from a pathological sample of a mare presenting chronic purulent sinusitis and that had undergone frontal-sinus surgery three months before. Humans, horses, dogs and environmental samples were subsequently collected at the mare's stable and at the Veterinary Hospital, where the mare was operated/hospitalized, and screened for the presence of MRSA that was detected from other horses and from the environment at both sites. All the MRSA isolates belonged to clonal complex (CC)8, ST8-t11469-SCCmec-IVa, and showed similar phenotypic and genetic multidrug resistance patterns and macrorestriction-pulsed-field gel electrophoresis profiles. The only MRSA detected from humans was a CC1, ST1-t127-SCCmec-IVa. This paper represents the first report of a clinical MRSA infection in a horse in Italy. This study also supports the opinion that improper use of antibiotics and hospitalization/surgery can represent risk factors for MRSA colonization/infection in horses, and that the environment is among important sources for exposure.

  2. Synergistic effects of baicalein with ciprofloxacin against NorA over-expressed methicillin-resistant Staphylococcus aureus (MRSA) and inhibition of MRSA pyruvate kinase.

    PubMed

    Chan, Ben C L; Ip, Margaret; Lau, Clara B S; Lui, S L; Jolivalt, Claude; Ganem-Elbaz, Carine; Litaudon, Marc; Reiner, Neil E; Gong, Huansheng; See, Raymond H; Fung, K P; Leung, P C

    2011-09-01

    Baicalein, the active constituent derived from Scutellaria baicalensis Georgi., has previously been shown to significantly restore the effectiveness of β-lactam antibiotics and tetracycline against methicillin-resistant Staphylococcus aureus (MRSA). With multiple therapeutic benefits, the antibacterial actions of baicalein may also be involved in overcoming other bacterial resistance mechanisms. The aim of the present study was to further investigate antibacterial activities of baicalein in association with various antibiotics against selected Staphylococcus aureus strains with known specific drug resistance mechanisms. A panel of clinical MRSA strains was used for further confirmation of the antibacterial activities of baicalein. The effect of baicalein on inhibiting the enzymatic activity of a newly discovered MRSA-specific pyruvate kinase (PK), which is essential for Staphylococcus aureus growth and survival was also examined. In the checkerboard dilution test and time-kill assay, baicalein at 16 μg/ml could synergistically restore the antibacterial actions of ciprofloxacin against the NorA efflux pump overexpressed SA-1199B, but not with the poor NorA substrate, pefloxacin. Moreover, synergistic effects were observed when baicalein was combined with ciprofloxacin against 12 out of 20 clinical ciprofloxacin resistant strains. For MRSA PK studies, baicalein alone could inhibit the enzymatic activity of MRSA PK in a dose-dependent manner. Our results demonstrated that baicalein could significantly reverse the ciprofloxacin resistance of MRSA possibly by inhibiting the NorA efflux pump in vitro. The inhibition of MRSA PK by baicalein could lead to a deficiency of ATP which might further contribute to the antibacterial actions of baicalein against MRSA. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  3. Performance of 3 real-time PCR assays for direct detection of Staphylococcus aureus and MRSA from clinical samples.

    PubMed

    Mehta, Maitry S; McClure, J T; Mangold, Kathy; Peterson, Lance R

    2015-11-01

    We compared 3 real-time PCR assays: off-label use of 2 commercial assays (BD-GeneOhm™ MRSA assay for methicillin-resistant Staphylococcus aureus [MRSA] detection and BD-GeneOhm StaphSR™ for MRSA and methicillin-susceptible S. aureus detection) and an in-house real-time PCR assay for detection of total S. aureus from clinical specimens. Testing was performed on 200 distinct specimens. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated using culture as the gold standard. The prevalence of S. aureus in the samples was 44.5%, and MRSA was 20%. For total S. aureus, the StaphSR-PCR and the in-house PCR assays had a sensitivity and specificity of 94.4% and 96.4% and 93.3% and 99.1%, respectively. For MRSA detection, the StaphSR and the BD GeneOhm assay had a sensitivity and specificity of 92.5% and 98.8% and 92.5% and 96.3%, respectively. This study demonstrates the potential use of tests like the StaphSR-PCR assay for rapid detection of S. aureus and MRSA directly from clinical specimens; however, culture follow-up would be needed to identify other potential pathogens in the specimen.

  4. [Simultaneous isolation of MRSA and Pseudomonas aeruginosa using a novel selective and differential PMAC agar].

    PubMed

    Taguchi, F; Okuda, S; Uchino, U; Muraoka, H; Hasegawa, M; Kobayashi, I

    1996-09-01

    PMAC agar, a novel, selective and differential medium has been developed and was subjected for evaluation of its selective and differential capability of methicillin resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa from other bacteria such as Bacillus, Micrococcus, Gram-negative bacteria and drug resistant ones. Growth of MRSA and P. aeruginosa on PMAC agar was facilitated and their colonies were easily differentiated. Colonies of MRSA after 24 approximately 48 h incubation at 35 degrees C were small (2 to 4 mm in diameter), smooth and egg-yolk reaction positive. On the other hand, P. aeruginosa with pigment production (pyocianin, fluorescin or pyomelanin) formed large (2.5 to 7.0 mm in diameter), brownish black or brown colonies with a creamy edge. PMAC agar did not allow to grow unwanted bacteria tested except certain species formerly classified to Pseudomonas such as Burkholderia and Stenotrophomonas. However multi-drug resistant strains such as Enterobacter cloacae, Serratia marcescens and Acinetobacter calcoaceticus formed extremely small colonies. PMAC agar is recommended as a novel, useful medium for isolation, differentiation and presumptive identification of MRSA and P. aeruginosa from clinical and environmental sources.

  5. Classification of Epidemic Community-Acquired Methicillin-Resistant Staphylococcus aureus by Anatomical Site of Isolation

    PubMed Central

    Roberts, Jill C.

    2014-01-01

    Methicillin-resistant Staphylococcus aureus contributes significantly to cost, morbidity, and mortality due to infectious disease. We surveyed community-associated MRSA isolates to determine which strains were present within anatomical sites of interest. The most likely sources of MRSA among anatomic sites swabbed were wounds followed by the nasal cavity. The USA 300 MRSA strain was most commonly isolated among wound infections while nasal swabs largely yielded USA 100 MRSA. The frequency of isolation of USA 100 amongst community-associated strains is clinically significant as this strain is often correlated with invasive disease, exhibits broad antibiotic resistance, and has been considered to be hospital associated. The potential of USA 100 to cause serious disease and the frequency of its isolation suggest an important reservoir for opportunistic infection. These data demonstrate that MRSA epidemic clones are widespread among the community. PMID:24895625

  6. Methicillin resistance in Staphylococcus aureus strains isolated from food and wild animal carcasses in Italy.

    PubMed

    Traversa, A; Gariano, G R; Gallina, S; Bianchi, D M; Orusa, R; Domenis, L; Cavallerio, P; Fossati, L; Serra, R; Decastelli, L

    2015-12-01

    Following the detection of methicillin-resistant Staphylococcus aureus (MRSA) ST398 in food-producing animals, both livestock and wildlife, and derived products, are considered potential sources of MRSA in humans. There is a paucity of data on MRSA in foods in Italy, and the data regarding wild animals are particularly scarce. A total of 2162 food samples collected during official monitoring activities in 2008 were analyzed for the detection of S. aureus. Also, samples from 1365 wild animals collected by the National Reference Center for Wild Animal Diseases in 2003-2009 were subjected to anatomopathological examination. S. aureus isolates were processed for phenotypic and molecular methicillin resistance determinations. S. aureus was found in 2.0% of wild animal carcasses and in 3.2% of wild boar lymph nodes: none showed methicillin resistance. The prevalence of S. aureus in food was 17.1%. Two MRSA strains, both from bulk tank milk (prevalence 0.77%) were isolated: the strains were resistant to tetracycline, had spa-type t899, and were negative for the Panton-Valentine leukocidin gene. The low prevalence of MRSA suggests that the risk of transmission to humans via food is limited. However, attention should be paid to the cattle food chain, which may be a potential route of transmission of LA-MRSA.

  7. Surveillance of methicillin-resistant Staphylococcus aureus (MRSA) and Enterobacteriaceae producing extended-spectrum beta-lactamase (ESBLE) in Northern France: a five-year multicentre incidence study.

    PubMed

    Albertini, M T; Benoit, C; Berardi, L; Berrouane, Y; Boisivon, A; Cahen, P; Cattoen, C; Costa, Y; Darchis, P; Delière, E; Demontrond, D; Eb, F; Golliot, F; Grise, G; Harel, A; Koeck, J L; Lepennec, M P; Malbrunot, C; Marcollin, M; Maugat, S; Nouvellon, M; Pangon, B; Ricouart, S; Roussel-Delvallez, M; Vachée, A; Carbonne, Anne; Marty, Lawrence; Jarlier, Vincent

    2002-10-01

    In order to measure the incidence of methicillin-resistant Staphylococcus aureus (MRSA) and of Enterobacteriaceae producing extended-spectrum beta-lactamase (ESBLE), and to evaluate the impact of the national guidelines for multidrug-resistant bacteria (MDRB) prevention in hospitals of Northern France, a multicentre study was conducted for three months every year starting in 1996, in volunteer hospital laboratories. All clinical specimens positive for MRSA and ESBLE were prospectively surveyed. During the five-year surveillance period, the overall proportion of MRSA was 38.4% in the 28,534 strains of S. aureus, and that of ESBLE was 11.4% in the 6121 strains of Klebsiella pneumoniae and 47.7% in the 2353 strains of Enterobacter aerogenes. The overall incidence rates of clinical specimens positive for MRSA, ESBL-K. pneumoniae and E. aerogenes were 0.84. 0.05 and 0.12/1000 hospital-days (HD), respectively. In the 23 hospitals that participated in the survey every year, the proportion and incidence of ESBLE decreased. Hence, despite recommendations as for isolation precautions, MRSA remains poorly controlled and requires more effective measures. Copyright 2002 The Hospital Infection Society

  8. Incidence and Characterisation of Methicillin-Resistant Staphylococcus aureus (MRSA) from Nasal Colonisation in Participants Attending a Cattle Veterinary Conference in the UK

    PubMed Central

    Paterson, Gavin K.; Harrison, Ewan M.; Craven, Emily F.; Petersen, Andreas; Larsen, Anders Rhod; Ellington, Matthew J.; Török, M. Estée; Peacock, Sharon J.; Parkhill, Julian; Zadoks, Ruth N.; Holmes, Mark A.

    2013-01-01

    We sought to determine the prevalence of nasal colonisation with methicillin-resistant Staphylococcus aureus among cattle veterinarians in the UK. There was particular interest in examining the frequency of colonisation with MRSA harbouring mecC, as strains with this mecA homologue were originally identified in bovine milk and may represent a zoonotic risk to those in contact with dairy livestock. Three hundred and seven delegates at the British Cattle Veterinarian Association (BCVA) Congress 2011 in Southport, UK were screening for nasal colonisation with MRSA. Isolates were characterised by whole genome sequencing and antimicrobial susceptibility testing. Eight out of three hundred and seven delegates (2.6%) were positive for nasal colonisation with MRSA. All strains were positive for mecA and none possessed mecC. The time since a delegate’s last visit to a farm was significantly shorter in the MRSA-positive group than in MRSA-negative counterparts. BCVA delegates have an increased risk of MRSA colonisation compared to the general population but their frequency of colonisation is lower than that reported from other types of veterinarian conference, and from that seen in human healthcare workers. The results indicate that recent visitation to a farm is a risk factor for MRSA colonisation and that mecC-MRSA are rare among BCVA delegates (<1% based on sample size). Contact with livestock, including dairy cattle, may still be a risk factor for human colonisation with mecC-MRSA but occurs at a rate below the lower limit of detection available in this study. PMID:23869220

  9. Phenotypic and genotypic characterization of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible Staphylococcus aureus (MSSA) from different sources in China.

    PubMed

    Chao, Guoxiang; Zhang, Xiaoping; Zhang, Xiaorong; Huang, Yao; Xu, Lan; Zhou, Liping; Yang, Weixia; Jiang, Yuan; Xue, Feng; Wu, Yantao

    2013-03-01

    A diverse collection of 261 Staphylococcus aureus strains from human, animal, food, and environmental sources were tested for the presence and type of SCCmec elements, antibiotic susceptibility to various antibiotics, and non-ß-lactam antibiotic resistance genes. About 18.39% (48/261) of strains were methicillin-resistant S. aureus (MRSA) including 29.75% (36/121) human strains of which 29 strains were hospital-acquired MRSA (HA-MRSA) and 7 strains were community-associated MRSA (CA-MRSA) and 19.67% (12/61) animal strains that all were CA-MRSA strains. The percentage of CA-MRSA strains from animals was significantly higher than that from human (p<0.01). Most of MRSA strains and a part of methicillin-susceptible S. aureus (MSSA) strains harbored unique combinations of non-ß-lactamase genes aac(6')/aph(2″), aph(3')-III, ant (4',4″), ermA, ermC, mrsA, tetM, and tetK. Antibiotic resistance genes were detected more frequently in HA-MRSA strains than in CA-MRSA strains (p<0.01). MRSA strains and MSSA strains had 22 and 39 antibiotic profiles to 15 tested antibiotics, respectively. The resistant proportion was higher in HA-MRSA strains than in CA-MSSA strains for various antibiotics, as well as higher in MRSA strains than in MSSA strains. Animal MRSA reservoirs (particularly pigs and cows) might represent an important source of human CA-MRSA. CA-MRSA strains might acquire more different resistance genes gradually, depending on the selective pressure of antibiotics in different regions or environments. CA-MRSA is not yet endemic in China, but could be prevalent in future, contributing to its acquiring more resistance genes and huge animal sources. Infection with multidrug-resistant MSSA strains acquired from food, animal, and human sources might also become a significant problem for human medicine, which warrants further study.

  10. Molecular Characterization of Staphylococcus aureus Isolates Transmitted between Patients with Buruli Ulcer

    PubMed Central

    Amissah, Nana Ama; Chlebowicz, Monika A.; Ablordey, Anthony; Sabat, Artur J.; Tetteh, Caitlin S.; Prah, Isaac; van der Werf, Tjip S.; Friedrich, Alex W.; van Dijl, Jan Maarten

    2015-01-01

    Background Buruli ulcer (BU) is a skin infection caused by Mycobacterium ulcerans. The wounds of most BU patients are colonized with different microorganisms, including Staphylococcus aureus. Methodology This study investigated possible patient-to-patient transmission events of S. aureus during wound care in a health care center. S. aureus isolates from different BU patients with overlapping visits to the clinic were whole-genome sequenced and analyzed by a gene-by-gene approach using SeqSphere+ software. In addition, sequence data were screened for the presence of genes that conferred antibiotic resistance. Principal Findings SeqSphere+ analysis of whole-genome sequence data confirmed transmission of methicillin resistant S. aureus (MRSA) and methicillin susceptible S. aureus among patients that took place during wound care. Interestingly, our sequence data show that the investigated MRSA isolates carry a novel allele of the fexB gene conferring chloramphenicol resistance, which had thus far not been observed in S. aureus. PMID:26360794

  11. Virulence Strategies of the Dominant USA300 Lineage of Community Associated Methicillin Resistant Staphylococcus aureus (CA-MRSA)

    PubMed Central

    Thurlow, Lance R.; Joshi, Gauri S.; Richardson, Anthony R.

    2014-01-01

    Methicillin-Resistant Staphylococcus aureus (MRSA) poses a serious threat to worldwide health. Historically, MRSA clones have strictly been associated with hospital settings and most hospital-associated MRSA (HA-MRSA) disease resulted from a limited number of virulent clones. Recently, MRSA has spread into the community causing disease in otherwise healthy people with no discernible contact with healthcare environments. These community-associated (CA-MRSA) are phylogenetically distinct from traditional HA-MRSA clones and CA-MRSA strains seem to exhibit hyper virulence and more efficient host:host transmission. Consequently, CA-MRSA clones belonging to the USA300 lineage have become dominant sources of MRSA infections in North America. The rise of this successful USA300 lineage represents an important step in the evolution of emerging pathogens and a great deal of effort has been exerted to understand how these clones evolved. Here we review much of the recent literature aimed at illuminating the source of USA300 success and broadly categorize these findings into three main categories: newly acquired virulence genes, altered expression of common virulence determinants and alterations in protein sequence that increase fitness. We argue that none of these evolutionary events alone account for the success of USA300, but rather their combination may be responsible for the rise and spread of CA-MRSA. PMID:22309135

  12. Rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible Staphylococcus aureus (MSSA) using the KeyPath MRSA/MSSA blood culture test and the BacT/ALERT system in a pediatric population.

    PubMed

    Sullivan, Kaede V; Turner, Nicole N; Roundtree, Sylvester S; McGowan, Karin L

    2013-08-01

    Timely initiation of directed antimicrobial therapy for Staphylococcus aureus bacteremia is dependent on rapid identification of S. aureus to ascertain methicillin-susceptibility status. To investigate the performance of the rapid KeyPath (MicroPhage, Inc, Longmont, Colorado) methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) blood culture test (MMBT). Positive BacT/ALERT Pediatric FAN (fastidious antibiotic neutralization) blood culture bottles (bioMérieux, Inc, Durham, North Carolina) were tested prospectively using MMBT and routine bacterial identification and antibiotic susceptibility testing procedures as the gold standard. The MMBT uses an S. aureus-specific bacteriophage cocktail that infects bacterial cells and replicates them, resulting in cellular lysis. Bacteriophage-specific antibodies detect the increase in bacteriophage concentration in an immunoassay device. Phage amplification, in both the presence and absence of cefoxitin, indicates the presence of MRSA. The sensitivity, specificity, positive predictive value, and negative predictive value of MMBT in detecting S. aureus, MSSA, and MRSA were calculated. Of 188 positive blood cultures tested, 199 (63%) had Gram-positive cocci in clusters, 46 (24%) grew S. aureus (26 MSSA [57%], 20 MRSA [43%]) with the MMBT detecting 40 of 46 (87%). The sensitivity, specificity, positive predictive value, and negative predictive value among blood cultures with Gram-positive cocci in clusters were 87%, 100%, 100%, and 92% for S. aureus; 81%, 100%, 100%, and 95% for MSSA; and 95%, 100%, 100%, and 99% for MRSA. All blood cultures without growth of S. aureus tested negative by MMBT. The MMBT detected MSSA and MRSA directly from positive BacT/ALERT PF bottles with positive predictive values of 100%, suggesting that positive results could be reported immediately, but the sensitivity of this assay limited immediate reporting of negative results.

  13. Molecular characterization of methicillin-resistant Staphylococcus aureus isolates in Algeria.

    PubMed

    Ouchenane, Z; Smati, F; Rolain, J-M; Raoult, D

    2011-12-01

    The epidemiology of Staphylococcus aureus has changed radically since 1999, in particular, methicillin-resistant S. aureus (MRSA), originally restricted to hospital, has emerged as a significant pathogen in the community, and true community-acquired MRSA (CA-MRSA) infections have been reported in patients with no clear risk factors. CA-MRSA strains frequently produce Panton-Valentine leukocidin (PVL). The objectives of this study were: (i) to monitor the prevalence of PVL and toxic shock syndrome toxin-1 (TSST-1) isolates MRSA; (ii) to identify the staphylococcal cassette chromosome (SCCmec) types of MRSA isolates. Sixty-four isolates, collected between 2005 and 2007 in Didouche Mourad hospital of Algeria. The isolates were identified by conventional methods. The antibiotic susceptibility of the isolates was performed using the disk diffusion method and automat Vitek2. The presence of gene mecA, the genes encoding SCCmec type, PVL and TSST-1 toxins were investigated by real-time PCR. All strains were gene mecA positives, 32 (50%) harboured SCCmec IV type, 28 (43.75%) harboured SCCmec V type. 19 (29.68%) have been identified positive for the leukocidin toxin (PVL), they harboured SCCmec type IV. The virulence factor TSST-1 was not present among these isolates. These results show a high prevalence of PVL-positive H-MRSA in our wards. Copyright © 2010. Published by Elsevier SAS.

  14. Detection of mecC-positive Staphylococcus aureus (CC130-MRSA-XI) in diseased European hedgehogs (Erinaceus europaeus) in Sweden.

    PubMed

    Monecke, Stefan; Gavier-Widen, Dolores; Mattsson, Roland; Rangstrup-Christensen, Lena; Lazaris, Alexandros; Coleman, David C; Shore, Anna C; Ehricht, Ralf

    2013-01-01

    Recently, a novel mec gene conferring beta-lactam resistance in Staphylococcus aureus has been discovered. This gene, mecC, is situated on a SCCmec XI element that has to date been identified in clonal complexes 49, 130, 425, 599 and 1943. Some of the currently known isolates have been identified from animals. This, and observations of mecA alleles that do not confer beta-lactam resistance, indicate that mec genes might have a reservoir in Staphylococcus species from animals. Thus it is important also to screen wildlife isolates for mec genes. Here, we describe mecC-positive Staphylococcus aureus (ST130-MRSA-XI) and the lesions related to the infection in two diseased free-ranging European hedgehogs (Erinaceus europaeus). One was found dead in 2003 in central Sweden, and suffered from S. aureus septicaemia. The other one, found on the island of Gotland in the Baltic Sea in 2011, showed a severe dermatitis and was euthanised. ST130-MRSA-XI isolates were isolated from lesions from both hedgehogs and were essentially identical to previously described isolates from humans. Both isolates carried the complete SCCmec XI element. They lacked the lukF-PV/lukS-PV and lukM/lukF-P83 genes, but harboured a gene for an exfoliative toxin homologue previously described from Staphylococcus hyicus, Staphylococcus pseudintermedius and other S. aureus of the CC130 lineage. To the best of our knowledge, these are the first reported cases of CC130-MRSA-XI in hedgehogs. Given that one of the samples was taken as early as 2003, this was the earliest detection of this strain and of mecC in Sweden. This and several other recent observations suggest that CC130 might be a zoonotic lineage of S. aureus and that SCCmec XI/mecC may have originated from animal pathogens.

  15. Detection of mecC-Positive Staphylococcus aureus (CC130-MRSA-XI) in Diseased European Hedgehogs (Erinaceus europaeus) in Sweden

    PubMed Central

    Monecke, Stefan; Gavier-Widen, Dolores; Mattsson, Roland; Rangstrup-Christensen, Lena; Lazaris, Alexandros; Coleman, David C.; Shore, Anna C.; Ehricht, Ralf

    2013-01-01

    Recently, a novel mec gene conferring beta-lactam resistance in Staphylococcus aureus has been discovered. This gene, mecC, is situated on a SCCmec XI element that has to date been identified in clonal complexes 49, 130, 425, 599 and 1943. Some of the currently known isolates have been identified from animals. This, and observations of mecA alleles that do not confer beta-lactam resistance, indicate that mec genes might have a reservoir in Staphylococcus species from animals. Thus it is important also to screen wildlife isolates for mec genes. Here, we describe mecC-positive Staphylococcus aureus (ST130-MRSA-XI) and the lesions related to the infection in two diseased free-ranging European hedgehogs (Erinaceus europaeus). One was found dead in 2003 in central Sweden, and suffered from S. aureus septicaemia. The other one, found on the island of Gotland in the Baltic Sea in 2011, showed a severe dermatitis and was euthanised. ST130-MRSA-XI isolates were isolated from lesions from both hedgehogs and were essentially identical to previously described isolates from humans. Both isolates carried the complete SCCmec XI element. They lacked the lukF-PV/lukS-PV and lukM/lukF-P83 genes, but harboured a gene for an exfoliative toxin homologue previously described from Staphylococcus hyicus, Staphylococcus pseudintermedius and other S. aureus of the CC130 lineage. To the best of our knowledge, these are the first reported cases of CC130-MRSA-XI in hedgehogs. Given that one of the samples was taken as early as 2003, this was the earliest detection of this strain and of mecC in Sweden. This and several other recent observations suggest that CC130 might be a zoonotic lineage of S. aureus and that SCCmec XI/mecC may have originated from animal pathogens. PMID:23776626

  16. The Combination of Catechin and Epicatechin Gallate from Fructus Crataegi Potentiates β-Lactam Antibiotics Against Methicillin-Resistant Staphylococcus aureus (MRSA) in Vitro and in Vivo

    PubMed Central

    Qin, Rongxin; Xiao, Kangkang; Li, Bin; Jiang, Weiwei; Peng, Wei; Zheng, Jiang; Zhou, Hong

    2013-01-01

    Fructus crataegi (hawthorn) is the common name of all plant species in the genus Crataegus of the Rosaceae family. In the present study, three monomers of (+)-catechin (C), (−)-epicatechin gallate (ECg) and (−)-epigallocatechin (EGC) were isolated from the hawthorn under the guide of antibacterial sensitization activity. The bioactivity of the composite fraction in enhancing the antibacterial effect of oxacillin against methicillin-resistant Staphylococcus aureus (MRSA) was greater than that of the individual monomer of the hawthorn extract in vitro. Two-fold dilution and checkerboard methods were used to analyze antibacterial activity and screen for the combination and proportion of monomers with the best bioactivity. The result showed that C (128 mg/L) combined with ECg (16 mg/L) had the greatest effect and the combination also reduced the bacterial load in blood of septic mice challenged with a sublethal dose of MRSA, increased daunomycin accumulation within MRSA and down-regulated the mRNA expression of norA, norC and abcA, three important efflux pumps of MRSA. In summary, C and ECg enhanced the antibacterial effect of β-lactam antibiotics against MRSA in vitro and in vivo, which might be related to the increased accumulation of antibiotics within MRSA via suppression of important efflux pumps’ gene expression. PMID:23325048

  17. The combination of catechin and epicatechin callate from Fructus Crataegi potentiates beta-lactam antibiotics against methicillin-resistant staphylococcus aureus (MRSA) in vitro and in vivo.

    PubMed

    Qin, Rongxin; Xiao, Kangkang; Li, Bin; Jiang, Weiwei; Peng, Wei; Zheng, Jiang; Zhou, Hong

    2013-01-16

    Fructus crataegi (hawthorn) is the common name of all plant species in the genus Crataegus of the Rosaceae family. In the present study, three monomers of (+)-catechin (C), (-)-epicatechin gallate (ECg) and (-)-epigallocatechin (EGC) were isolated from the hawthorn under the guide of antibacterial sensitization activity. The bioactivity of the composite fraction in enhancing the antibacterial effect of oxacillin against methicillin-resistant Staphylococcus aureus (MRSA) was greater than that of the individual monomer of the hawthorn extract in vitro. Two-fold dilution and checkerboard methods were used to analyze antibacterial activity and screen for the combination and proportion of monomers with the best bioactivity. The result showed that C (128 mg/L) combined with ECg (16 mg/L) had the greatest effect and the combination also reduced the bacterial load in blood of septic mice challenged with a sublethal dose of MRSA, increased daunomycin accumulation within MRSA and down-regulated the mRNA expression of norA, norC and abcA, three important efflux pumps of MRSA. In summary, C and ECg enhanced the antibacterial effect of β-lactam antibiotics against MRSA in vitro and in vivo, which might be related to the increased accumulation of antibiotics within MRSA via suppression of important efflux pumps' gene expression.

  18. Association between antimicrobial consumption and clinical isolates of methicillin-resistant Staphylococcus aureus: a 14-year study.

    PubMed

    Nakamura, Ayako; Miyake, Kazunori; Misawa, Shigeki; Kuno, Yutaka; Horii, Takashi; Hori, Satoshi; Kondo, Shigemi; Tabe, Yoko; Ohsaka, Akimichi

    2012-02-01

    The objective of this study was to determine the relationship between clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and antimicrobial consumption in hospitalized patients over a 14-year period. The study was retrospectively conducted between January 1995 and December 2008 at Juntendo University Hospital, Tokyo, Japan, a 1,020-bed tertiary-care teaching hospital. The incidence of MRSA isolates was examined using clinical specimens presented to the microbiology laboratory in the hospital. Antimicrobial consumption through intravenous injection was calculated in terms of the number of defined daily doses per 100 bed-days. The correlation between the incidence of MRSA isolates and antimicrobial consumption was determined employing a multiple stepwise regression analysis. A total of 109,946 bacterial isolates were consecutively collected over the 14-year period, and, of these, 13,872 (64% of S. aureus strains excluding coagulase-negative staphylococci) were MRSA strains. The longitudinal observation showed that the number and rate of MRSA isolates marginally decreased. The rate of MRSA isolates among S. aureus strains in 1995 was 68.5%, whereas that in 2008 was 53.8%. Consumption of cephalosporins decreased. Among carbapenems, the rate of imipenem (IPM) consumption decreased, whereas that of meropenem increased. A multiple stepwise regression analysis revealed that the antimicrobial consumption of cefmetazole, cefotiam, and IPM was positively correlated with the incidence of MRSA isolates. The use of β-lactam antimicrobials may contribute to the development of MRSA strains.

  19. Novel quorum-quenching agents promote methicillin-resistant Staphylococcus aureus (MRSA) wound healing and sensitize MRSA to β-lactam antibiotics.

    PubMed

    Kuo, David; Yu, Guanping; Hoch, Wyatt; Gabay, Dean; Long, Lisa; Ghannoum, Mahmoud; Nagy, Nancy; Harding, Clifford V; Viswanathan, Rajesh; Shoham, Menachem

    2015-03-01

    The dwindling repertoire of antibiotics to treat methicillin-resistant Staphylococcus aureus (MRSA) calls for novel treatment options. Quorum-quenching agents offer an alternative or an adjuvant to antibiotic therapy. Three biaryl hydroxyketone compounds discovered previously (F1, F12, and F19; G. Yu, D. Kuo, M. Shoham, and R. Viswanathan, ACS Comb Sci 16:85-91, 2014) were tested for efficacy in MRSA-infected animal models. Topical therapy of compounds F1 and F12 in a MRSA murine wound infection model promotes wound healing compared to the untreated control. Compounds F1, F12, and F19 afford significant survival benefits in a MRSA insect larva model. Combination therapy of these quorum-quenching agents with cephalothin or nafcillin, antibiotics to which MRSA is resistant in monotherapy, revealed additional survival benefits. The quorum-quenching agents sensitize MRSA to the antibiotic by a synergistic mode of action that also is observed in vitro. An adjuvant of 1 μg/ml F1, F12, or F19 reduces the MIC of nafcillin and cephalothin about 50-fold to values comparable to those for vancomycin, the antibiotic often prescribed for MRSA infections. These findings suggest that it is possible to resurrect obsolete antibiotic therapies in combination with these novel quorum-quenching agents.

  20. Novel Quorum-Quenching Agents Promote Methicillin-Resistant Staphylococcus aureus (MRSA) Wound Healing and Sensitize MRSA to β-Lactam Antibiotics

    PubMed Central

    Kuo, David; Yu, Guanping; Hoch, Wyatt; Gabay, Dean; Long, Lisa; Ghannoum, Mahmoud; Nagy, Nancy; Harding, Clifford V.; Viswanathan, Rajesh

    2014-01-01

    The dwindling repertoire of antibiotics to treat methicillin-resistant Staphylococcus aureus (MRSA) calls for novel treatment options. Quorum-quenching agents offer an alternative or an adjuvant to antibiotic therapy. Three biaryl hydroxyketone compounds discovered previously (F1, F12, and F19; G. Yu, D. Kuo, M. Shoham, and R. Viswanathan, ACS Comb Sci 16:85–91, 2014) were tested for efficacy in MRSA-infected animal models. Topical therapy of compounds F1 and F12 in a MRSA murine wound infection model promotes wound healing compared to the untreated control. Compounds F1, F12, and F19 afford significant survival benefits in a MRSA insect larva model. Combination therapy of these quorum-quenching agents with cephalothin or nafcillin, antibiotics to which MRSA is resistant in monotherapy, revealed additional survival benefits. The quorum-quenching agents sensitize MRSA to the antibiotic by a synergistic mode of action that also is observed in vitro. An adjuvant of 1 μg/ml F1, F12, or F19 reduces the MIC of nafcillin and cephalothin about 50-fold to values comparable to those for vancomycin, the antibiotic often prescribed for MRSA infections. These findings suggest that it is possible to resurrect obsolete antibiotic therapies in combination with these novel quorum-quenching agents. PMID:25534736

  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. Staphylococcus aureus and community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in and around therapeutic whirlpools in college athletic training rooms.

    PubMed

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

    2015-04-01

    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. To investigate the prevalence of Staphylococcus aureus and CA-MRSA in and around whirlpools in the athletic training room. Cross-sectional study. National Collegiate Athletic Association Division I university. Student-athletes (n = 109) consisting of 46 men (42%) and 63 women (58%) representing 6 sports. Presence of MRSA and Staphylococcus aureus in and around the whirlpool structures relative to sport and number of athletes using the whirlpools. 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 (F(2,238) = 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). 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.

  3. Isolation and characterization of methicillin-resistant Staphylococcus aureus from pork farms and visiting veterinary students.

    PubMed

    Frana, Timothy S; Beahm, Aleigh R; Hanson, Blake M; Kinyon, Joann M; Layman, Lori L; Karriker, Locke A; Ramirez, Alejandro; Smith, Tara C

    2013-01-01

    In the last decade livestock-associated methicillin-resistant S. aureus (LA-MRSA) has become a public health concern in many parts of the world. Sequence type 398 (ST398) has been the most commonly reported type of LA-MRSA. While many studies have focused on long-term exposure experienced by swine workers, this study focuses on short-term exposures experienced by veterinary students conducting diagnostic investigations. The objectives were to assess the rate of MRSA acquisition and longevity of carriage in students exposed to pork farms and characterize the recovered MRSA isolates. Student nasal swabs were collected immediately before and after farm visits. Pig nasal swabs and environmental sponge samples were also collected. MRSA isolates were identified biochemically and molecularly including spa typing and antimicrobial susceptibility testing. Thirty (30) veterinary students were enrolled and 40 pork farms were visited. MRSA was detected in 30% of the pork farms and in 22% of the students following an exposure to a MRSA-positive pork farm. All students found to be MRSA-positive initially following farm visit were negative for MRSA within 24 hours post visit. Most common spa types recovered were t002 (79%), t034 (16%) and t548 (4%). Spa types found in pork farms closely matched those recovered from students with few exceptions. Resistance levels to antimicrobials varied, but resistance was most commonly seen for spectinomycin, tetracyclines and neomycin. Non-ST398 MRSA isolates were more likely to be resistant to florfenicol and neomycin as well as more likely to be multidrug resistant compared to ST398 MRSA isolates. These findings indicate that MRSA can be recovered from persons visiting contaminated farms. However, the duration of carriage was very brief and most likely represents contamination of nasal passages rather than biological colonization. The most common spa types found in this study were associated with ST5 and expands the range of livestock

  4. 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. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  5. Comparison of MRSASelect Agar, CHROMagar Methicillin-Resistant Staphylococcus aureus (MRSA) Medium, and Xpert MRSA PCR for Detection of MRSA in Nares: Diagnostic Accuracy for Surveillance Samples with Various Bacterial Densities ▿

    PubMed Central

    Wolk, D. M.; Marx, J. L.; Dominguez, L.; Driscoll, D.; Schifman, R. B.

    2009-01-01

    Rapid laboratory methods provide optimal support for active surveillance efforts to screen for methicillin-resistant Staphylococcus aureus (MRSA). Most laboratories struggle to determine the optimal use of resources, considering options to balance cost, speed, and diagnostic accuracy. To assess the performance of common methods, the first comparison of MRSASelect agar (MS) and CHROMagar MRSA (CA), with and without broth enrichment followed by a 24-h subculture to MS, was performed. Results were compared to those of the Xpert MRSA assay. For direct culture methods, the agreement between MS and CA was 98.8%. At 18 h, direct MS identified 93% of all positive samples from direct culture and 84% of those identified by the Xpert MRSA. For Trypticase soy broth-enriched MS culture, incubated overnight and then subcultured for an additional 24 h, the agreement with Xpert MRSA was 96%. The agreement between direct MS and Xpert MRSA was 100% when semiquantitative culture revealed a bacterial density of 2+ or greater; however, discrepancies between culture and Xpert MRSA arose for MRSA bacterial densities of 1+ or less, indicating low density as a common cause of false-negative culture results. Since 1+ or less was established as the most common MRSA carrier state, broth enrichment or PCR may be critical for the identification of all MRSA carriers who may be reservoirs for transmission. In this active-surveillance convenience sample, the use of broth enrichment followed by subculture to MS offered a low-cost but sensitive method for MRSA screening, with performance similar to that of Xpert MRSA PCR. PMID:19828738

  6. Comparison of MRSASelect Agar, CHROMagar Methicillin-Resistant Staphylococcus aureus (MRSA) Medium, and Xpert MRSA PCR for detection of MRSA in Nares: diagnostic accuracy for surveillance samples with various bacterial densities.

    PubMed

    Wolk, D M; Marx, J L; Dominguez, L; Driscoll, D; Schifman, R B

    2009-12-01

    Rapid laboratory methods provide optimal support for active surveillance efforts to screen for methicillin-resistant Staphylococcus aureus (MRSA). Most laboratories struggle to determine the optimal use of resources, considering options to balance cost, speed, and diagnostic accuracy. To assess the performance of common methods, the first comparison of MRSASelect agar (MS) and CHROMagar MRSA (CA), with and without broth enrichment followed by a 24-h subculture to MS, was performed. Results were compared to those of the Xpert MRSA assay. For direct culture methods, the agreement between MS and CA was 98.8%. At 18 h, direct MS identified 93% of all positive samples from direct culture and 84% of those identified by the Xpert MRSA. For Trypticase soy broth-enriched MS culture, incubated overnight and then subcultured for an additional 24 h, the agreement with Xpert MRSA was 96%. The agreement between direct MS and Xpert MRSA was 100% when semiquantitative culture revealed a bacterial density of 2+ or greater; however, discrepancies between culture and Xpert MRSA arose for MRSA bacterial densities of 1+ or less, indicating low density as a common cause of false-negative culture results. Since 1+ or less was established as the most common MRSA carrier state, broth enrichment or PCR may be critical for the identification of all MRSA carriers who may be reservoirs for transmission. In this active-surveillance convenience sample, the use of broth enrichment followed by subculture to MS offered a low-cost but sensitive method for MRSA screening, with performance similar to that of Xpert MRSA PCR.

  7. Molecular characterization of Staphylococcus aureus isolates from various healthcare institutions in Nairobi, Kenya: a cross sectional study.

    PubMed

    Omuse, Geoffrey; Van Zyl, Kristien Nel; Hoek, Kim; Abdulgader, Shima; Kariuki, Samuel; Whitelaw, Andrew; Revathi, Gunturu

    2016-09-20

    Staphylococcus aureus (S. aureus) has established itself over the years as a major cause of morbidity and mortality both within the community and in healthcare settings. Methicillin resistant S. aureus (MRSA) in particular has been a major cause of nosocomial infections resulting in significant increase in healthcare costs. In Africa, the MRSA prevalence has been shown to vary across different countries. In order to better understand the epidemiology of MRSA in a setting, it is important to define its population structure using molecular tools as different clones have been found to predominate in certain geographical locations. We carried out PFGE, MLST, SCCmec and spa typing of selected S. aureus isolates from a private and public referral hospital in Nairobi, Kenya. A total of 93 S. aureus isolates were grouped into 19 PFGE clonal complexes (A-S) and 12 singletons. From these, 55 (32 MRSA and 23 MSSA) representative isolates from each PFGE clonal complex and all singletons were spa typed. There were 18 different MRSA spa types and 22 MSSA spa types. The predominant MRSA spa type was t037 comprising 40.6 % (13/32) of all MRSA. In contrast, the MSSA were quite heterogeneous, only 2 out of 23 MSSA shared the same spa type. Two new MRSA spa types (t13149 and t13150) and 3 new MSSA spa types (t13182, t13193 and t13194) were identified. The predominant clonal complex was CC 5 which included multi-locus sequence types 1, 8 and 241. In contrast to previous studies published from Kenya, there's marked genetic diversity amongst clinical MRSA isolates in Nairobi including the presence of well-known epidemic MRSA clones. Given that these clones are resident within our referral hospitals, adherence to strict infection control measures needs to be ensured to reduce morbidity and mortality associated with hospital acquired MRSA infections.

  8. Molecular characteristics of methicillin-resistant Staphylococcus aureus blood isolates: clonal spread of staphylococcal cassette chromosome mec type IVA between the community and the hospital.

    PubMed

    Moon, Soo-Youn; Lee, Hee-Joo; Lee, Mi Suk

    2010-09-01

    Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is becoming increasingly common worldwide. The purpose of this study was to identify the prevalence and molecular characteristics of MRSA bloodstream isolates in hospitals. Clinical data from patients with MRSA bacteremia between 2003 and 2005 were collected. Isolates were classified as hospital-acquired (HA-MRSA), health care-associated (HCA-MRSA), or CA-MRSA according to the time of isolation and the risk factors for colonization. Available strains were tested for the presence of mecA, staphylococcal cassette chromosome mec (SCCmec), and by multilocus sequence test. Among 129 cases, 78 nonduplicated isolates were analyzed. The proportion of CA-MRSA, HCA-MRSA, and HA-MRSA was 2.6% (2), 23.1% (18), and 74.4% (58), respectively. According to multilocus sequence test and SCCmec, there were seven genotypes with sequence types (STs) and SCCmec types. The predominant genotype, ST5-MRSA-II, was found in 57.7% (45). All type IVA isolates was ST72 (9), and ST72-MRSA-IVA was identified in CA-MRSA (2, 100%), HCA-MRSA (1, 5.6%), and HA-MRSA (6, 10.3%), respectively. In summary, CA-MRSA bacteremia was not common in our hospital during the period.

  9. Albumin reduces the antibacterial activity of polyhexanide-biguanide-based antiseptics against Staphylococcus aureus and MRSA.

    PubMed

    Kapalschinski, N; Seipp, H M; Onderdonk, A B; Goertz, O; Daigeler, A; Lahmer, A; Lehnhardt, M; Hirsch, T

    2013-09-01

    Wound infection is one of the major complications in acute and chronic wound healing. Antiseptic solutions and wound irrigating agents are routinely used for therapy and prevention in healthcare today. Even if wound exudate contains total protein concentrations up to 9.3% and albumin concentrations up to 2.7% its influence to the antibacterial efficacy of these agents is barely investigated. This study analyzed the antibacterial effect of polyhexanide biguanide (PHMB) agents (PHMB-concentration 0.005-0.1%) against Staphylococcus aureus and methicillin-resistant-S. aureus (MRSA) after 2min incubation in presents of albumin in different concentrations (0-3%) in a standardized quantitative suspension assay. A significant decrease of the antibacterial activity against S. aureus was shown for a PHMB-concentration of 0.005% from 0.3% albumin (p<0.05), respectively highly significant from 0.75% (p<0.01) on. Thereby the loss of antimicrobial effect was presented as a linear correlation to the rising concentration of albumin. Furthermore a reduction of the antibacterial activity against MRSA in comparison to S. aureus was presented, for albumin concentrations from 3% on highly significant (p<0.01). The study showed that albumin causes a significant decrease of the antibacterial potency of PHMB-based antiseptics. Furthermore a diminished potency of the investigated substances for MRSA-contaminated wounds must be taken in consideration. If in vitro experiments show a significant decrease of antibacterial efficacy in the presence of albumin a sufficient activity of PHMB-based agents in clinical practice, especially in cases of exuding wounds or dried-up exudates, cannot be expected. Copyright © 2013 Elsevier Ltd and ISBI. All rights reserved.

  10. Solid lipid nanoparticles of clotrimazole silver complex: An efficient nano antibacterial against Staphylococcus aureus and MRSA.

    PubMed

    Kalhapure, Rahul S; Sonawane, Sandeep J; Sikwal, Dhiraj R; Jadhav, Mahantesh; Rambharose, Sanjeev; Mocktar, Chunderika; Govender, Thirumala

    2015-12-01

    New and effective strategies to transform current antimicrobials are required to address the increasing issue of microbial resistance and declining introduction of new antibiotic drugs. In this context, metal complexes of known drugs and nano delivery systems for antibiotics are proving to be promising strategies. The aim of the study was therefore to synthesize a silver complex of clotrimazole and formulate it into a nano delivery system for enhanced and sustained antibacterial activity against susceptible and resistant Staphylococcus aureus. A silver complex of clotrimazole was synthesized, characterized and further encapsulated into solid lipid nanoparticles to evaluate its antibacterial activity against S. aureus and methicillin-resistant S. aureus (MRSA). An in vitro cytotoxicity study was performed on HepG2 cell lines to assess the overall biosafety of the synthesized clotrimazole silver complex to mammalian cells, and was found to be non-toxic to mammalian cells (cell viability >80%). The minimum inhibitory concentrations (MIC) of clotrimazole and clotrimazole-silver were 31.25 and 9.76 μg/mL against S. aureus, and 31.25 and 15.62 against MRSA, respectively. Clotrimazole SLNs exhibited MIC values of 104 and 208 μg/mL against both MSSA and MRSA at the end of 18 and 36 h, respectively, but thereafter completely lost its antibacterial activity. Clotrimazole-silver SLNs had an MIC value of 52 μg/mL up to 54 h, after which the MIC value was 104 μg/mL against both strains at the end of 72 h. Thus, clotrimazole-silver SLNs was found to be an efficient nanoantibiotic. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Discovery of bisindolyl-substituted cycloalkane-anellated indoles as novel class of antibacterial agents against S. aureus and MRSA.

    PubMed

    El-Sayed, Mardia Telep; Suzen, Sibel; Altanlar, Nurten; Ohlsen, Knut; Hilgeroth, Andreas

    2016-01-01

    Antibiotic resistance is an ongoing problem in the treatment of bacterial diseases. Among the various antibacterial infections Staphylococcus aureus infections remain critical due to the increasing resistances, especially against the methicillin-resistant S. aureus (MRSA). We discovered novel antibacterial compounds with activities against both S. aureus and MRSA types. Structure-activity relationships (SAR) are discussed and show that the activity depends on the ring size of the anellated cycloalkane. Moreover, first substituent effects have been investigated for both the cycloalkane and the indole residues.

  12. The Pleiotropic Antibacterial Mechanisms of Ursolic Acid against Methicillin-Resistant Staphylococcus aureus (MRSA).

    PubMed

    Wang, Chao-Min; Jhan, Yun-Lian; Tsai, Shang-Jie; Chou, Chang-Hung

    2016-07-07

    (1) BACKGROUND: Several triterpenoids were found to act synergistically with classes of antibiotic, indicating that plant-derived chemicals have potential to be used as therapeutics to enhance the activity of antibiotics against multidrug-resistant pathogens. However, the mode of action of triterpenoids against bacterial pathogens remains unclear. The objective of this study is to evaluate the interaction between ursolic acid against methicillin-resistant Staphylococcus aureus (MRSA); (2) METHODS: The ability of ursolic acid to damage mammalian and bacterial membranes was examined. The proteomic response of methicillin-resistant S. aureus in ursolic acid treatment was investigated using two-dimensional (2D) proteomic analysis; (3) RESULTS: Ursolic acid caused the loss of staphylococcal membrane integrity without hemolytic activity. The comparison of the protein pattern of ursolic acid-treated and normal MRSA cells revealed that ursolic acid affected a variety of proteins involved in the translation process with translational accuracy, ribonuclease and chaperon subunits, glycolysis and oxidative responses; (4) CONCLUSION: The mode of action of ursolic acid appears to be the influence on the integrity of the bacterial membrane initially, followed by inhibition of protein synthesis and the metabolic pathway. These findings reflect that the pleiotropic effects of ursolic acid against MRSA make it a promising antibacterial agent in pharmaceutical research.

  13. Chlorhexidine whole-body washing of patients reduces methicillin-resistant Staphylococcus aureus and has a direct effect on the distribution of the ST5-MRSA-II (New York/Japan) clone.

    PubMed

    Velázquez-Meza, Maria Elena; Mendoza-Olazarán, Soraya; Echániz-Aviles, Gabriela; Camacho-Ortiz, Adrián; Martínez-Reséndez, Michel Fernando; Valero-Moreno, Vanessa; Garza-González, Elvira

    2017-06-01

    Methicillin-resistant Staphylococcus aureus (MRSA) colonizes the skin of hospitalized patients and is associated with high morbidity and mortality. To prevent colonization and infection by S. aureus, better disinfection practices are required. Therefore, we evaluated the effect of chlorhexidine whole-body washing on hospital-acquired S. aureus infections among intensive care unit (ICU) patients in a tertiary hospital in Mexico. The study was conducted over 18 months to evaluate the effect of 2 % chlorhexidine gluconate (CXG) whole-body washing of ICU adult patients on chlorhexidine and antibiotic resistance, biofilm production and clonal distribution of S. aureus in a tertiary care hospital. Minimum inhibitory concentrations for CXG, antibiotic susceptibility and biofilm production by S. aureus isolates were determined. Pulsed-field gel electrophoresis, multilocus sequence typing (MLST) and PCR for Panton-Valentine leucocidin (PVL) were used for molecular typing of MRSA isolates.Results/Key findings. We included 158 isolates. A reduction in antibiotic resistance in the study period was observed for clindamycin, levofloxacin, norfloxacin, oxacillin and trimethoprim/sulfamethoxazole. None of the isolates showed reduced susceptibility to CXG. Most of the isolates were non-biofilm producers (147/158). The most commonly identified clone was a descendant of the ST5-MRSA-II (New York/Japan) clone. This clone decreased during the intervention period and reappeared markedly in the post-intervention period. During the post-intervention period, two isolates were related with the clone ST8-MRSA-IV (also known as USA300). Our findings suggest that the CXG bathing favored the reduction of healthcare-associated MRSA isolates and a temporary reduction of the predominant ST5-MRSA-II (New York/Japan) clone.

  14. Characterization of Staphylococcus aureus Isolates That Colonize Medical Students in a Hospital of the City of Cali, Colombia

    PubMed Central

    Collazos Marín, Luis Fernando; Estupiñan Arciniegas, Gina; Chavez Vivas, Monica

    2015-01-01

    Introduction. Nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) represents a risk for the spread of bacteria. This study characterized the S. aureus isolated from medical students, who were in their clinical rotation at a hospital in the city of Cali. Materials and Methods. 216 students participated in the study and 63 isolates of S. aureus were evaluated for susceptibility and PCR amplification of agr and mecA genes. The origin of MRSA isolates was established by analyzing agr polymorphisms. Results. A total of 29.2% of students were colonized by S. aureus and nasal carriage rate was 23.6% and 14.3% MRSA. Three agr groups (agr II, and agr III) were identified; the agr I group was the most common, with a 35% prevalence; this group is from community origin. Conclusion. The present study demonstrates that medical students carry S. aureus strains, with the threat of spreading them both to community and hospital environments. PMID:26495001

  15. 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.

    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

  16. Report - Antibacterial activity of sea buckthorn (Hippophae rhamnoides L.) against methicillin resistant Staphylococcus aureus (MRSA).

    PubMed

    Qadir, Muhammad Imran; Abbas, Khizar; Younus, Adnan; Shaikh, Rehan Sadiq

    2016-09-01

    Objective of the present study was to investigate the antibacterial activity of Sea buckthorn (Hippophae rhamnoides L.) berries and leaves against methicillin resistant Staphylococcus aureus (MRSA) by using the standard disc diffusion method. Chloroform, n-hexane and aqueous extract of the plant parts were used. Doses of 2mg/ml, 4 mg/ml and 6mg/ml were tested against the microorganism, and the zone of inhibition was compared against the standard drug vancomycin. Results indicated that n-hexane and chloroform extracts of berries and n-hexane extract leaves showed significant (p<0.05) antibacterial activity comparable with vancomycin. It was concluded from the study that extracts berries and leaves of Hippophae rhamnoides have antibacterial activity against MRSA.

  17. The increase of methicillin-resistant Staphylococcus aureus (MRSA) and the presence of an unusual sequence type ST49 in slaughter pigs in Switzerland

    PubMed Central

    2011-01-01

    Background In years past, methicillin-resistant S. aureus (MRSA) has been frequently detected in pigs in Europe, North America and Asia. Recent, yet sporadic studies have revealed a low occurrence of MRSA in Switzerland. In 2009, a monitoring survey of the prevalence and genetic diversity of methicillin-resistant S. aureus (MRSA) in slaughter pigs in Switzerland was conducted using methods recommended by the EU guidelines, and using a sampling strategy evenly distributed throughout the year and representative of the Swiss slaughter pig population. Monitoring should determine if the overall prevalence of MRSA in the entire country is increasing over the years and if specific multi-resistant MRSA clones are spreading over the country. Results In 2009, the nasal cavities of eight out of 405 randomly selected pigs were positive for MRSA, representing a prevalence of 2.0% (95% CI 0.9-3.9). The following year, 23 out of 392 pigs were positive for MRSA [5.9% prevalence (95% CI 3.8-8.7)]. Three multilocus sequence types (ST), four spa types and two types of staphylococcal cassette chromosome mec (SCCmec) elements were detected. The most frequent genotypes were ST398 (MLST)-(spa)t034-V(SCCmec) (n = 18) and ST49-t208-V (n = 7), followed by ST398-t011-V (n = 4), ST398-t1451-V (n = 1), and ST1-t2279-IVc (n = 1). The isolates displayed resistance to ß-lactams [mecA, (31/31); blaZ, (19/31)]; tetracycline [tet(M), (31/31); tet(K), (30/31)] (n = 31); macrolides and lincosamides [erm(C) (4/31) or erm(A) (18/31)] (n = 22); tiamulin [vga(A)v (9/31) or unknown mechanism (18/31)] (n = 27); trimethoprim [dfr(G) (18/31); spectinomycin [ant(9)-Ia (19/31) or unknown mechanism (3/31)] (n = 22); streptomycin [str (19/31)]; sulphamethoxazole (7/31) and ciprofloxacin (n = 1) (mechanisms not determined). Conclusions This study is the first to describe the presence of MRSA ST49 in slaughter pigs, and to demonstrate a significant and nearly three-fold increase of MRSA prevalence in pigs within

  18. In vitro activity of retapamulin against linezolid and methicillin-resistant Staphylococcus aureus isolates.

    PubMed

    Candel, F J; Morales, G; Picazo, J J

    2011-09-01

    To determine the in vitro activity of retapamulin and other topical antibiotics (mupirocin, bacitracin, and fusidic acid) usually employed for nasal decolonization, against methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), and linezolid and methicillin-resistant S. aureus. The minimum inhibitory concentrations (MICs) were determined on Mueller-Hinton agar according to the guidelines of the Clinical and Laboratory Standards Institute and of the European Committee for Antimicrobial Susceptibility Testing. Presence of the cfr gene in linezolid and methicillin-resistant S. aureus isolates was detected using polymerase chain reaction. Retapamulin inhibited all the isolates of MSSA and MRSA at 0.125 mg/L, but the 18 linezolid-resistant-MRSA strains proved resistant, with MICs over 32 mg/L. Most MSSA isolates (9/10) were susceptible to mupirocin with MICs under 0.19 mg/L, although this value decreased to half against MRSA, and almost all linezolid-resistant MRSA (17/18) strains were resistant to mupirocin with an MIC range of between 8 mg/L and 28 mg/L. The MIC of fusidic acid increased substantially against linezolid-resistant MRSA, whereas that of bacitracin showed no differences. Retapamulin demonstrated excellent in vitro activity against MSSA and MRSA strains, but not against MRSA isolates harbouring the cfr gene. The results of this in vitro study support cut-off values for retapamulin of ≤ 0.5, 1, and ≥ 2 mg/L for susceptible, intermediate, and resistant strains, respectively.

  19. 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.

  20. Detection of methicillin-resistant Staphylococcus aureus (MRSA) using the NanoLantern Biosensor

    NASA Astrophysics Data System (ADS)

    Strohsahl, Christopher M.; Miller, Benjamin L.; Krauss, Todd D.

    2009-02-01

    Staphylococcus aureus is a leading cause of human illness, and has developed the remarkable ability to resist the bactericidal capabilities of many of the world's leading antibiotics (i.e. MRSA). In an effort to enable rapid detection and treatment of MRSA infections, we have developed a DNA detection technology termed the NanoLantern(TM). The NanoLantern(TM) biosensor technology is based on the simple immobilization of a fluorophore-terminated DNA hairpin onto a gold chip. This produces a label-free sensor that allows for a positive response to be obtained without extensive processing of the sample, saving cost and increasing accuracy. We will also discuss a newly developed method of partial gene analysis, used to develop a DNA hairpin probe that is capable of detecting the presence of the mecR gene, a gene necessary for methicillin resistance to be present in S. aureus, with 100% sequence specificity. The successful incorporation of this probe into the NanoLantern(TM) platform, along with the concomitant development of the paired PCR assay has allowed for the successful detection of methicillin-resistance directly from a culture of S. aureus. These results represent an important step forward in terms of developing the ability to rapidly and effectively detect the presence of antibiotic resistance in bacterial infections.

  1. Strict versus modified isolation for prevention of nosocomial transmission of methicillin-resistant Staphylococcus aureus.

    PubMed

    Ribner, B S; Landry, M N; Gholson, G L

    1986-06-01

    Patients colonized or infected with methicillin-resistant Staphylococcus aureus (MRSA) in a Surgical Intensive Care Unit and Surgical Intermediate Care Unit were placed either in Strict Isolation or cared for with modified isolation precautions. The assignment was determined by the unit in which they were hospitalized. Units were changed from one form of isolation to the other and served as their own controls. Over a 4-month study period, the rate of MRSA transmission did not change when the type of isolation precautions were altered. The ratio of colonized to infected patients also remained constant. Infected patients were usually first detected by clinical specimens, while colonized patients were usually detected by surveillance cultures performed under the study protocol. Following the study, all hospitalized patients with MRSA were placed in modified isolation precautions. Total new acquisitions of MRSA in the hospital have decreased over the subsequent 6-month period.

  2. Emergence of Hospital- and Community-Associated Panton-Valentine Leukocidin-Positive Methicillin-Resistant Staphylococcus aureus Genotype ST772-MRSA-V in Ireland and Detailed Investigation of an ST772-MRSA-V Cluster in a Neonatal Intensive Care Unit

    PubMed Central

    Shore, Anna C.; Corcoran, Suzanne; Tecklenborg, Sarah; Coleman, David C.; O'Connell, Brian

    2012-01-01

    Sequence type 22 (ST22) methicillin-resistant Staphylococcus aureus (MRSA) harboring staphylococcal cassette chromosome mec (SCCmec) IV (ST22-MRSA-IV) has predominated in Irish hospitals since the late 1990s. Six distinct clones of community-associated MRSA (CA-MRSA) have also been identified in Ireland. A new strain of CA-MRSA, ST772-MRSA-V, has recently emerged and become widespread in India and has spread into hospitals. In the present study, highly similar MRSA isolates were recovered from seven colonized neonates in a neonatal intensive care unit (NICU) in a maternity hospital in Ireland during 2010 and 2011, two colonized NICU staff, one of their colonized children, and a NICU environmental site. The isolates exhibited multiantibiotic resistance, spa type t657, and were assigned to ST772-MRSA-V by DNA microarray profiling. All isolates encoded resistance to macrolides [msr(A) and mpb(BM)] and aminoglycosides (aacA-aphD and aphA3) and harbored the Panton-Valentine leukocidin toxin genes (lukF-PV and lukS-PV), enterotoxin genes (sea, sec, sel, and egc), and one of the immune evasion complex genes (scn). One of the NICU staff colonized by ST772-MRSA-V was identified as the probable index case, based on recent travel to India. Seven additional hospital and CA-ST772-MRSA-V isolates recovered from skin and soft tissue infections in Ireland between 2009 and 2011 exhibiting highly similar phenotypic and genotypic characteristics to the NICU isolates were also identified. The clinical details of four of these patients revealed connections with India through ethnic background or travel. Our study indicates that hospital-acquired and CA-ST772-MRSA-V is currently emerging in Ireland and may have been imported from India on several occasions. PMID:22189119

  3. Methicillin-resistant staphylococcus aureus (MRSA) colonization among Intensive Care Unit (ICU) patients and health care workers at Muhimbili national hospital, Dar Es Salaam, Tanzania, 2012.

    PubMed

    Geofrey, Alfred; Abade, Ahmed; Aboud, Said

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) has been recognized as important nosocomial pathogens worldwide. S aureus may induce clinically manifested diseases, or the host may remain completely asymptomatic. A cross-sectional hospital-based study was conducted from October 2012 to March 2013 in two ICUs at MNH. Admitted patients and health care workers were enrolled in the study. Interviewer administered questionnaires; patient history forms, observation charts and case report forms were used to collect data. Swabs (nostrils, axillary or wounds) were collected. MRSA were screened and confirmed using cefoxitin, oxacillin discs and oxacillin screen agar. Antibiotic susceptibility was performed using Kirby-Bauer disk diffusion method. The risk factors for MRSA were determined using the logistic regression analysis and a p - value of <0.05 was considered as statistically significant. Of the 169 patients and 47 health workers who were recruited, the mean age was 43.4 years ± SD 15.3 and 37.7 years ± (SD) 11.44 respectively. Among the patients male contributed 108 (63.9%) while in health worker majority 39(83%) were females. The prevalence of MRSA colonization among patients and health care workers was 11.83% and 2.1% respectively. All (21) MRSA isolates were highly resistant to penicillin and erythromycin, and 17 (85.7%) were highly sensitive to vancomycin. Being male (AOR 6.74, 95% CI 1.31-34.76), history of sickness in past year (AOR 4.89, 95% CI 1.82- 13.12), being sick for more 3 times (AOR 8.91, 95% CI 2.32-34.20), being diabetic (AOR 4.87, 95% CI 1.55-15.36) and illicit drug use (AOR 10.18, 95%CI 1.36-76.52) were found to be independently associated with MRSA colonization. A study identified a high prevalence of MRSA colonization among patients admitted in the ICU. MRSA isolates were highly resistant to penicillin and erythromycin. History of illegal drug use was highly associated with MRSA colonization.

  4. Antibacterial and synergic effects of gallic acid-grafted-chitosan with β-lactams against methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Lee, Dae-Sung; Eom, Sung-Hwan; Kim, Young-Mog; Kim, Hye Seon; Yim, Mi-Jin; Lee, Sang-Hoon; Kim, Do-Hyung; Je, Jae-Young

    2014-10-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is spreading worldwide, emphasizing the need to search for new antibiotics. The anti-MRSA activities of gallic acid-grafted-chitosans (GA-g-chitosans) were investigated against 2 MRSA standards and 10 MRSA clinical isolates by determining the minimum inhibitory concentrations (MICs). GA-g-chitosan (I), which has the highest gallic acid content, exhibited the strongest anti-MRSA activities, with MICs of 32-64 μg/mL. A time-kill investigation revealed that GA-g-chitosan (I) exhibited a bactericidal effect at twice the MIC, also demonstrating good thermal and pH stability. Investigation of cell envelope integrity showed the release of intracellular components with an increasing absorbance value at 260 nm, indicating cell envelope damage caused by the GA-g-chitosan (I), which was further confirmed by transmission electron microscopy. When GA-g-chitosans were combined with β-lactams, including ampicillin and penicillin, synergistic effects were observed on the 2 standard MRSA strains and on the 10 clinical isolates, with fractional inhibitory indices ranging from 0.125 to 0.625. In the time-kill dynamic confirmation test, synergistic bactericidal effects were observed for the combinations of GA-g-chitosans with β-lactams, and over 4.0 log CFU/mL reductions were observed after 24 h when combination treatment was used. These results may prove GA-g-chitosans to be a potent agent when combined with ampicillin and penicillin for the elimination of MRSA.

  5. Vulvar Abscess Caused by Methicillin-resistant Staphylococcus Aureus (MRSA) in a Postmenopausal Woman

    PubMed Central

    Kim, Tae-Hee; Kim, Soo Ah; Heo, Gyeong-Eun

    2016-01-01

    Infections of the vulva can present a complex differential to the gynecologist, ranging from superficial skin infections to lifethreatening necrotizing fasciitis. Recognition and timely treatment remain universal to skin and soft-tissue infections as the subcutaneous anatomy of the vulva can facilitate rapid spread to other tissues with significant morbidity and mortality. Employing a multidisciplinary team approach to care for vulvar cellulitis and abscess can guide treatment from antibiotic therapies to more aggressive surgical debridement. In this report, we describe a case of vulvar abscess caused by Methicillin-resistant staphylococcus aureus (MRSA) in a postmenopausal woman with underlying diseases of bronchiectasis and atelectasis. PMID:27617247

  6. Vulvar Abscess Caused by Methicillin-resistant Staphylococcus Aureus (MRSA) in a Postmenopausal Woman.

    PubMed

    Kim, Tae-Hee; Seap, Bel; Kim, Soo Ah; Heo, Gyeong-Eun

    2016-08-01

    Infections of the vulva can present a complex differential to the gynecologist, ranging from superficial skin infections to lifethreatening necrotizing fasciitis. Recognition and timely treatment remain universal to skin and soft-tissue infections as the subcutaneous anatomy of the vulva can facilitate rapid spread to other tissues with significant morbidity and mortality. Employing a multidisciplinary team approach to care for vulvar cellulitis and abscess can guide treatment from antibiotic therapies to more aggressive surgical debridement. In this report, we describe a case of vulvar abscess caused by Methicillin-resistant staphylococcus aureus (MRSA) in a postmenopausal woman with underlying diseases of bronchiectasis and atelectasis.

  7. ST2249-MRSA-III: a second major recombinant methicillin-resistant Staphylococcus aureus clone causing healthcare infection in the 1970s.

    PubMed

    Nimmo, G R; Steen, J A; Monecke, S; Ehricht, R; Slickers, P; Thomas, J C; Appleton, S; Goering, R V; Robinson, D A; Coombs, G W

    2015-05-01

    Typing of healthcare-associated methicillin-resistant Staphylococcus aureus (MRSA) from Australia in the 1970s revealed a novel clone, ST2249-MRSA-III (CC45), present from 1973 to 1979. This clone was present before the Australian epidemic caused by the recombinant clone, ST239-MRSA-III. This study aimed to characterize the genome of ST2249-MRSA-III to establish its relationship to other MRSA clones. DNA microarray analysis was conducted and a draft genome sequence of ST2249 was obtained. The recombinant structure of the ST2249 genome was revealed by comparisons to publicly available ST239 and ST45 genomes. Microarray analysis of genomic DNA of 13 ST2249 isolates showed gross similarities with the ST239 chromosome in a segment around the origin of replication and with ST45 for the remainder of the chromosome. Recombination breakpoints were precisely determined by the changing pattern of nucleotide polymorphisms in the genome sequence of ST2249 isolate SK1585 compared with ST239 and ST45. One breakpoint was identified to the right of oriC, between sites 1014 and 1065 of the gene D484_00045. Another was identified to the left of oriC, between sites 1185 and 1248 of D484_01632. These results indicate that ST2249 inherited approximately 35.3% of its chromosome from an ST239-like parent and 64.7% from an ST45-like parent. ST2249-MRSA-III resulted from a major recombination between parents that resemble ST239 and ST45. Although only limited Australian archival material is available, the oldest extant isolate of ST2249 predates the oldest Australian isolate of ST239 by 3 years. It is therefore plausible that these two recombinant clones were introduced into Australia separately.

  8. Synergism of coumarins from the Chinese drug Zanthoxylum nitidum with antibacterial agents against methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Zuo, Guo-Ying; Wang, Chun-Juan; Han, Jun; Li, Yu-Qing; Wang, Gen-Chun

    2016-12-15

    Methicillin-resistant Staphylococcus aureus (MRSA) poses a serious therapeutic challenge in current clinic and new drug development. Natural coumarins have diverse bioactivities and the potential of resistance modifying effects. This study is to present in-depth evaluations of in vitro antimicrobial activities of four natural coumarins 5-geranyloxy-7-methoxycoumarin (Gm, 1), (5,7-dimethoxy-8-prenyloxycoumarin (artanin, Ar, 2)), isopimpinellin (Is, 3) and phellopterin (Ph, 4) from Zanthoxylum nitidum (Roxb.) DC. (Rutaceae) extracts, focusing on their potential restoration the activity of conventional antibacterial agents against clinical MRSA strains. Bioactivity-guided fractionation and spectral analyses were used to isolate the coumarins and identify the structures, respectively. The double broth microdilution method was used to assay the coumarins' alone activity. The classic checkerboard microdilution and dynamic time-killing methods were used to evaluate combinatory effects. The four plant coumarins Gm (1), Ar (2), Is (3) and Ph (4) were isolated and identified from Z. nitidum extracts. Coumarins 1-4 displayed promising inhibition against both MSSA and MRSA with minimal inhibitory concentrations (MICs) of 8-64µg/ml, but very weak against Gram-negative pathogen and yeast with MICs of 256 to ≥1024µg/ml. The geranyloxy and prenyloxy substitutions showed to be more active than the methoxy substitution on the coumarin skeletons. 1-4 also showing different extent of synergism with a total of eight conventional antibacterial agents, i.e. chloramphenicol (CL), gentamicin (CN), fosfomycin (FF), levofloxacin (LE), minocycline (MI), piperacillin/tazobactam (P/T), teicoplanin (TE) and vancomycin (VA) against ten clinical MRSA strains. Four to ten of the tested MRSA strains showed bacteriostatic synergy in the eleven combinations. The anti-MRSA modifying effects were related to different arrangement in the combinations with fractional inhibitory concentration indices

  9. Analysis of Invasive Community-Acquired Methicillin-Susceptible Staphylococcus aureus Infections during a Period of Declining CA-MRSA Infections at a Large Children's Hospital.

    PubMed

    Hultén, Kristina G; Mason, Edward O; Lamberth, Linda B; Forbes, Andrea R; Revell, Paula A; Kaplan, Sheldon L

    2017-08-28

    The epidemiology of community acquired (CA) Staphylococcus aureus infections is changing in the United States. We investigated the current epidemiology of S. aureus infections at Texas Children's Hospital (TCH). Patients with CA-S. aureus skin and soft tissue (SSTI) and invasive infections were retrospectively identified from 1/1/2007-12/31/2014. Invasive CA-MSSA isolates were characterized by PFGE, Spa typing, agr type and presence of lukSF-PV (pvl) genes. Medical records were reviewed. Statistical analyses included Fisher's exact, Chi-square for trend and Wilcoxon tests. CA-MRSA infections decreased by 60.4% (1461 to 578 infections) from 2007-2014 (P<0.0001), while CA-MSSA infections averaged 550 infections annually. Invasive CA-MRSA infections decreased by 67.2% from 61 to 20 infections (P<0.0001); invasive CA-MSSA averaged 44 infections annually. Among 296 invasive CA-MSSA isolates, 74 (25%) isolates were USA300 and 88 (30%) were pvl+. USA300 declined among invasive CA-MSSA over time (P<0.008). Musculoskeletal infections were most common (242/296, 82%); 52/242 (21.5%) isolates were USA300 and 62/242 (25.6%) pvl+. All 18 isolates from musculoskeletal infections with DVT and/or septic shock were pvl+ and 16/18 (88.9%) were USA300. Pneumonia isolates were mainly USA300 (8, 66.7%) and pvl+ (11, 91.7%). MSSA now cause the majority of invasive CA-S. aureus infections at our institution. Molecular analysis of invasive CA-MSSA isolates suggests strain diversity with USA300 on the decline and that disease presentations are to some extent strain specific. Changes in the CA-S. aureus epidemiology may, in part, be related to changes in immunity to the USA300 clone in the general population.

  10. [Comparing results of methicillin-resistant Staphylococcus aureus (MRSA) surveillance using the French DRG-based information system (PMSI)].

    PubMed

    Nuemi, G; Astruc, K; Aho, S; Quantin, C

    2013-10-01

    The surveillance of methicillin-resistant Staphylococcus aureus (MRSA) is a national priority. The rate of MRSA infections is one of six indicators tracked by the Department of Health. Since 2002, the French institute for public health surveillance (InVS) has monitored MRSA infections to estimate incidence density. Today, the use of the French administrative database (PMSI) could facilitate this surveillance. The aim of this study was to compare MRSA incidence density computed at a national level using PMSI databases with the results from the InVS taken as the reference. PMSI databases for the years 2006 to 2009 were used. The reference results were those published by the InVS from 2006 to 2009. MRSA density defined as the number of MRSA infections recorded per year over 1000 hospital stays was computed. It was then compared with the MRSA incidence density measured by InVS. The time course of MRSA incidence in the PMSI records was modeled using a Poisson regression. The incidence density measured by the InVS was higher than the MRSA density computed using the PMSI, but this difference appeared to decrease over time. The PMSI density/InVS MRSA incidence density ratio was 0.8% in 2006 and about 9.2% in 2009. We observed inverted trends with a growing trend in MRSA density identified by the PMSI. Furthermore, the year of study was significantly associated with incidence density (P=0.01). Using PMSI data as an additional source of information in the hospital MRSA surveillance process makes it possible to detect and analyze patient repeats at the regional and national levels with linkage facilities. Estimation of incidence density for hospitals not participating to this surveillance system will be the next step. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  11. How to reduce the negative psychological impact of MRSA isolation on patients.

    PubMed

    Jones, Donna

    MRSA is contagious and difficult to treat, and the isolation of infected patients is recommended by the Department of Health. However, isolation can have a negative psychological impact on patients and is controversial. This literature review explores the effects of isolation based on three themes: isolation environment and psychological impact; stigma of MRSA; and nursing care.

  12. Pediatric Staphylococcus aureus Isolate Genotypes and Infections from the Dawn of the Community-Associated Methicillin-Resistant S. aureus Epidemic Era in Chicago, 1994 to 1997

    PubMed Central

    Acree, Mary Ellen; Sieth, Julia J.; Boxrud, Dave J.; Dobbins, Ginette; Lynfield, Ruth; Boyle-Vavra, Susan; Daum, Robert S.

    2015-01-01

    Widespread infections with community-associated (CA) methicillin-resistant Staphylococcus aureus (MRSA) have occurred in the United States with the dissemination of the USA300 strain beginning in 2000. We examined 105 isolates obtained from children treated at the University of Chicago from 1994 to 1997 (75 methicillin-susceptible S. aureus [MSSA] and 30 MRSA isolates) in order to investigate for possible evidence of USA300 during this period. Infections were defined epidemiologically based on medical record review. The isolates underwent multilocus sequence typing (MLST), as well as assays for the Panton-Valentine leukocidin (PVL) genes, the protein A gene (spa), and arcA and opp3, proxy markers for the arginine catabolic mobile element (ACME), characteristic of USA300 MRSA. MRSA isolates also underwent staphylococcal cassette chromosome mec (SCCmec) typing and pulsed-field gel electrophoresis (PFGE) subtyping. MSSA isolates belonged to 17 sequence type (ST) groups. The 12 epidemiologically defined CA-MRSA infection isolates were either ST1 (n = 4) or ST8 (n = 8). They belonged to 3 different PFGE types: USA100 (n = 1), USA400 (n = 5), and USA500 (n = 6). Among the CA-MRSA infection isolates, 8 (67%) were PVL+. None of the MRSA or MSSA isolates contained arcA or opp3. Only one MRSA isolate was USA300 by PFGE. This was a health care-associated (HA) MRSA isolate, negative for PVL, that carried SCCmec type II. USA300 with its characteristic features was not identified in the collection from the years 1994 to 1997. PMID:26019202

  13. Pediatric Staphylococcus aureus Isolate Genotypes and Infections from the Dawn of the Community-Associated Methicillin-Resistant S. aureus Epidemic Era in Chicago, 1994 to 1997.

    PubMed

    David, Michael Z; Acree, Mary Ellen; Sieth, Julia J; Boxrud, Dave J; Dobbins, Ginette; Lynfield, Ruth; Boyle-Vavra, Susan; Daum, Robert S

    2015-08-01

    Widespread infections with community-associated (CA) methicillin-resistant Staphylococcus aureus (MRSA) have occurred in the United States with the dissemination of the USA300 strain beginning in 2000. We examined 105 isolates obtained from children treated at the University of Chicago from 1994 to 1997 (75 methicillin-susceptible S. aureus [MSSA] and 30 MRSA isolates) in order to investigate for possible evidence of USA300 during this period. Infections were defined epidemiologically based on medical record review. The isolates underwent multilocus sequence typing (MLST), as well as assays for the Panton-Valentine leukocidin (PVL) genes, the protein A gene (spa), and arcA and opp3, proxy markers for the arginine catabolic mobile element (ACME), characteristic of USA300 MRSA. MRSA isolates also underwent staphylococcal cassette chromosome mec (SCCmec) typing and pulsed-field gel electrophoresis (PFGE) subtyping. MSSA isolates belonged to 17 sequence type (ST) groups. The 12 epidemiologically defined CA-MRSA infection isolates were either ST1 (n = 4) or ST8 (n = 8). They belonged to 3 different PFGE types: USA100 (n = 1), USA400 (n = 5), and USA500 (n = 6). Among the CA-MRSA infection isolates, 8 (67%) were PVL(+). None of the MRSA or MSSA isolates contained arcA or opp3. Only one MRSA isolate was USA300 by PFGE. This was a health care-associated (HA) MRSA isolate, negative for PVL, that carried SCCmec type II. USA300 with its characteristic features was not identified in the collection from the years 1994 to 1997. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  14. Evaluation of Antimicrobial Resistance in Staphylococcus aureus Isolates by Years

    PubMed Central

    Rağbetli, Cennet; Parlak, Mehmet; Bayram, Yasemin; Guducuoglu, Huseyin; Ceylan, Nesrin

    2016-01-01

    Objective. Recently, community and hospital-acquired infections with Staphylococcus aureus have increased and raised antibiotic resistant isolates. In this study, we aimed to evaluate the antibiotic resistance profile of S. aureus isolates over several years in various clinical specimens from our hospital. Materials and Methods. S. aureus strains from 2009 to 2014 were isolated from various clinical samples at Yuzuncu Yil University, Dursun Odabas Medical Center, Microbiology Laboratory, and their antibiotic susceptibility test results were retrospectively investigated. The isolates were identified by conventional methods, and antibiotic susceptibility tests were performed by the Phoenix (Becton Dickinson, USA) automated system method according to Clinical and Laboratory Standards Institute (CLSI) standards. Results. A total of 1,116 S. aureus isolates were produced and methicillin-resistant S. aureus (MRSA) to 21% of all S. aureus isolates between 2009 and 2014. According to the results of susceptibility tests of all isolates of S. aureus, they have been identified as sensitive to vancomycin, daptomycin, linezolid, and levofloxacin. While the resistance rates to nitrofurantoin, quinupristin-dalfopristin, and trimethoprim-sulfamethoxazole were determined as 0.3%, 2.4%, and 6%, respectively, resistance rates to penicillin, erythromycin, rifampicin, gentamicin, and clindamycin were determined as 100%, 18%, 14%, 14%, and 11%, respectively. The highest percentage of methicillin resistance was determined as 30% in 2009, and the resistance was determined to have decreased in subsequent years (20%, 16%, 13%, 19%, and 21%) (p < 0.001). Conclusion. Currently, retrospective evaluations of causes of nosocomial infection should be done periodically. We think that any alteration of resistance over the years has to be identified, and all centers must determine their own resistance profiles, in order to guide empirical therapies. Reducing the rate of antibiotic resistance will

  15. Molecular characterisation of Panton-Valentine leucocidin-producing methicillin-resistant Staphylococcus aureus clones isolated from the main hospitals in Taif, KSA.

    PubMed

    Eed, E M; Ghonaim, M M; Hussein, Y M; Al-Shehri, S S; Khalifa, A S

    2016-01-01

    Panton-Valentine leucocidin (PVL) is a bicomponent pore-forming cytolytic toxin encoded by the lukF-PV and lukS-PV genes. Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) may carry the pvl genes which may be related to increased disease severity. This study aimed to characterise the PVL-producing MRSA recovered from different Taif Hospitals, Saudi Arabia. The study included 45 hospital-acquired-MRSA (HA-MRSA) and 26 CA-MRSA strains which were identified from 445 S. aureus strains isolated from different clinical samples. MRSA strains were identified by standard oxacillin salt agar screening procedure and by the detection of the mecA gene by the polymerase chain reaction (PCR). Detection of the S. aureus-specific femA, mecA and pvl genes was performed by multiplex PCR. PCR-restriction fragment length polymorphism (PCR-RFLP) analysis was done for coagulase (coa) gene. The staphylococcal cassette chromosome mec types of the 45 HA-MRSA strains were Type I (n = 24), Type II (n = 7) and Type III (n = 14) whereas the 26 CA-MRSA strains were Type IV (n = 14), Type V (n = 11) and one isolate was non-typeable. All the HA-MRSA and six CA-MRSA strains were PVL-negative PCR-RFLP analysis of coa gene showed that PVL-positive MRSA (n = 20) isolates showed six different patterns, and five patterns were shared by PVL-positive methicillin-susceptible S. aureus (MSSA). The eighth pattern was the most frequent in both MRSA and MSSA. PVL is more frequent among CA-MRSA than MSSA. All the HA-MRSA and 25% of CA-MRSA strains were negative for PVL. The pvl gene was related to the severity of infection but not related to coa gene RFLP pattern.

  16. Isolation of a potent antibiotic producer bacterium, especially against MRSA, from northern region of the Persian Gulf

    PubMed Central

    Darabpour, Esmaeil; Ardakani, Mohammad Roayaei; Motamedi, Hossein; Ronagh, Mohammad Taghi

    2012-01-01

    Nowadays, emergence and prevalence of MRSA (Methicillin Resistant Staphylococcus aureus) strain have become a great global concern in 21st century, so, it is necessary to discover new antibiotics against this pathogen. The aim of this study was isolation and evaluation marine bacteria from the Persian Gulf in order to finding antibiotic compounds against some pathogenic bacteria. For this purpose, water and sediment samples were collected from the Persian Gulf during March to October 2009. The antibacterial activity of the isolated bacteria was assessed using disc diffusion method. The Growth Curve Interference (GCI) parameter against MRSA was determined for the high potential antibiotic producing strain. The most important factors affecting fermentation conditions in antibiotic production were also optimized. Definite identification of intended isolate was confirmed by 16S rRNA sequencing. Altogether, 51 bacterial colony was isolated and among them only 3 bacterium showed antibacterial activity. Pseudoalteromonaspiscicida PG-01 isolated from a sediment sample was chosen as the best antibiotic producing strain. This strain was effective against all tested Gram-positive bacteria, had good anti-MRSA activity and also GCI value against MRSA was two times lower than MIC value. Among the optimized fermentation parameters, carbon and nitrogen sources play major role in efficacy of optimized antibiotic production. Ultrastructural study on the effect of intended antibiotic compounds on MRSA using TEM revealed that the target site for this compound is cell wall. Considering the antibacterial effect of PG-01 strain especially against MRSA, intended antibiotic compounds can gives hope for treatment of diseases caused by multi-drug resistant bacteria. PMID:22642595

  17. Epidemiology and staphylococcal cassette chromosome mec typing of methicillin-resistant Staphylococcus aureus isolates in Taiwan: A multicenter study.

    PubMed

    Pan, Sung-Ching; Wang, Jann-Tay; Lauderdale, Tsai-Ling; Ko, Wen-Chien; Chen, Yao-Shen; Liu, Jien-Wei; Lau, Yeu-Jun; Wang, Li-Hsin; Liu, Ke-Sun; Liao, Chun-Hsing; Lin, San-Yi; Hu, Bor-Shen; Chang, Shan-Chwen

    2014-07-01

    After community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) was identified, new community-onset, healthcare-associated MRSA (HA-MRSA-CO) infections have been noticed as MRSA infection in patients with community-onset infection who have underlying conditions resulting in frequent exposure to the healthcare system. However, previous studies have not thoroughly investigated whether HA-MRSA-CO has characteristics resembling those of CA-MRSA or hospital-onset, healthcare-associated MRSA (HA-MRSA-HO) infection. A multicenter, retrospective study was conducted to analyze the clinical and microbiological data of patients with clinical isolates of MRSA from nine hospitals in Taiwan. In total, 203 patients with MRSA isolates, including 27 patients with CA-MRSA (13.3%), 59 with HA-MRSA-CO (29.1%), and 117 with HA-MRSA-HO (57.6%), were studied. Compared to HA-MRSA-HO isolates, the CA-MRSA and HA-MRSA-CO isolates were associated with a higher proportion of skin and soft tissue infections (81.8% and 65.3% vs. 40.5%, p=0.001 and p=0.002) as well as lesser rate of resistance to ciprofloxacin (33.3% and 50.9% vs. 74.4%, p<0.001 and p=0.002), gentamicin (44.4% and 64.4% vs. 84.6%, p<0.001 and p=0.002), and trimethoprim/sulfamethoxazole (33.3% and 42.4% vs. 58.1%, p=0.02 and p=0.048), and a lower 30-day all-cause mortality rate (7.4% and 0% vs. 20.9%, p<0.001). Most of the CA-MRSA isolates were classified as staphylococcal cassette chromosome mec (SCCmec) type VT (11/27, 40.7%), whereas most HA-MRSA-HO isolates were classified as SCCmec type III (66/117, 56.4%). The CA-MRSA, HA-MRSA-CO, and HA-MRSA-HO clinical isolates significantly differed in their clinical presentations and molecular characteristics. Copyright © 2012. Published by Elsevier B.V.

  18. Methicillin-resistant Staphylococcus aureus isolates from surfaces and personnel at a hospital laundry facility.

    PubMed

    Michael, K E; No, D; Roberts, M C

    2016-09-01

    Examine a clinical laundry facility for the presence of methicillin-resistant Staphylococcus aureus (MRSA) on environmental surfaces and among personnel. Nasal and face samples along with surface samples were collected four times in 2015. MRSA isolates were confirmed using standardized biochemical assays and molecular characterization. MRSA was identified in 33/120 (28%) samples from the dirty and 3/120 (3%) samples from the clean environmental areas. MRSA isolates included: (dirty) ST5 SCCmec type II, ST8 SCCmec type IV, ST231 SCCmec type II, ST239 SCCmec type III, ST239 SCCmec type IV, ST256 SCCmec type IV and (clean) ST5 SCCmec type II and ST8 SCCmec type IV. Five different employees were MRSA positive, 4/8 (50%) from the dirty: and 1/15 (6·7%) from the clean, but there was a 10-fold higher MRSA carriage 6/22 (27%) dirty vs 1/38 (2·6%) clean when all 50 human samples were combined. MRSA prevalence was significantly higher (28 vs 3%) in dirty vs clean areas within the laundry facility suggesting a greater risk for personnel on the dirty side. This is the first report of isolation and characterization of MRSA from surfaces and personnel from a clinical laundry facility. © 2016 The Society for Applied Microbiology.

  19. Recovery method development of sodium chloride-susceptible methicillin-resistant Staphylococcus aureus isolates from ground pork samples.

    PubMed

    Pang, Lu; Luo, Yanping; Gu, Yihai; Xu, Xiao; Xu, Jin; Zhang, Fenglan; Cui, Shenghui

    2015-02-01

    The growth of certain methicillin-resistant Staphylococcus aureus (MRSA) isolates could be inhibited by NaCl higher than 2.5%. The objective of this study was to develop an enrichment method to recover NaCl-susceptible MRSA isolates from meat samples. The growth of 12 MRSA and 10 non-MRSA strains was measured in Mueller-Hinton (MH) broth supplemented with 2.5%, 4%, 6.5%, and 7.5% NaCl. Selective agents, including aztreonam, polymyxin B, NaCl, nalidixic acid, and NaN3, were determined for their inhibitory effect to MRSA and non-MRSA strains in MH broth. Based on these data, a two-step enrichment method was developed to recover both NaCl-susceptible and -resistant MRSA isolates in meat products. Comparing to the enrichment method that only used MH broth supplemented with 6.5% NaCl, five additional NaCl-susceptible MRSA isolates were recovered from 92 retail ground pork samples by this newly developed two-step enrichment method. To the best of our knowledge, this is the first study that considers NaCl-susceptible MRSA recovery from ground pork samples. The application of this new enrichment method might expand the diversity of MRSA isolates recovered from various samples.

  20. Methicillin-resistant Staphylococcus aureus (MRSA) catheter-related bacteraemia in haemodialysis patients.

    PubMed

    Cuervo, Guillermo; Camoez, Mariana; Shaw, Evelyn; Dominguez, María Ángeles; Gasch, Oriol; Padilla, Belén; Pintado, Vicente; Almirante, Benito; Molina, José; López-Medrano, Francisco; Ruiz de Gopegui, Enrique; Martinez, José A; Bereciartua, Elena; Rodriguez-Lopez, Fernando; Fernandez-Mazarrasa, Carlos; Goenaga, Miguel Ángel; Benito, Natividad; Rodriguez-Baño, Jesús; Espejo, Elena; Pujol, Miquel

    2015-10-30

    The aim of the study was to determine clinical and microbiological differences between patients with methicillin-resistant Staphylococcus aureus (MRSA) catheter-related bacteraemia (CRB) undergoing or not undergoing haemodialysis, and to compare outcomes. Prospective multicentre study conducted at 21 Spanish hospitals of patients with MRSA bacteraemia diagnosed between June 2008 and December 2009. Patients with MRSA-CRB were selected. Data of patients on haemodialysis (HD-CRB) and those not on haemodialysis (non-HD-CRB) were compared. Among 579 episodes of MRSA bacteraemia, 218 (37.7%) were CRB. Thirty-four (15.6%) were HD-CRB and 184 (84.4%) non-HD-CRB. All HD-CRB patients acquired the infection at dialysis centres, while in 85.3% of the non-HD-CRB group the infection was nosocomial (p < .001). There were no differences in age, gender or severity of bacteraemia (Pitt score); comorbidities (Charlson score ≥ 4) were higher in the HD-CRB group than in the non-HD-CRB group (73.5% vs. 46.2%, p = .003). Although there were no differences in VAN-MIC ≥ 1.5 mg/L according to microdilution, using the E-test a higher rate of VAN-MIC ≥ 1.5 mg/L was observed in HD-CRB than in non-HD-CRB patients (63.3% vs. 44.1%, p = .051). Vancomycin was more frequently administered in the HD-CRB group than in the non-HD-CRB group (82.3% vs. 42.4%, p = <.001) and therefore the appropriate empirical therapy was significantly higher in HD-CRB group (91.2% vs. 73.9%, p = .029). There were no differences with regard to catheter removal (79.4% vs. 84.2%, p = .555, respectively). No significant differences in mortality rate were observed between both groups (Overall mortality: 11.8% vs. 27.2%, p = .081, respectively), but there was a trend towards a higher recurrence rate in HD-CRB group (8.8% vs. 2.2%, p = .076). In our multicentre study, ambulatory patients in chronic haemodialysis represented a significant proportion of cases of MRSA catheter-related bacteraemia. Although

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

    PubMed

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

    2016-08-01

    Using 30 clinical isolates of Staphylococcus aureus representative of the most prevalent clones circulating in France, the performance of the Alere™ PBP2a Culture Colony Test (CCT) and the Slidex(®) MRSA detection kit (SMD) were compared in 5 different labs. CCT demonstrated better performance and was easier to conduct in routine. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. [Outbreak of methicillin-resistant Staphylococcus aureus (MRSA) in the Rijnmond region: the largest outbreak in the Netherlands].

    PubMed

    Melles, D C; Hendriks, W D; Ott, A; Verbrugh, H A

    2004-05-22

    EPIDEMIC: The annual number of new MRSA isolates in the Netherlands tripled in 2002 compared with previous years. This increase was in part due to a MRSA outbreak in the Rijnmond region. The outbreak occurred in two merged hospitals and is the largest ever to occur in the Netherlands. From November 2001 till June 2003 MRSA was isolated from 381 patients and 113 hospital employees. The worst affected departments were Surgery and Internal Medicine. One MRSA strain (pulsed-field gel electroforesis (PFGE) type 16) remained initially unrecognised and was therefore able to spread unnoticed. Soon two additional epidemic MRSA strains (types 37 and 38) were discovered. Multiple factors played a role in the extent and duration of the outbreak. Because of the delayed detection and rapid spread of MRSA type 16, the outbreak grew too large once recognised to be resolved within the available infrastructure. Investments were needed at various fields, including the infection-control service and the microbiology laboratory. Employees had to be informed and motivated, and a separate MRSA ward and OPD were provided. New MRSA outbreaks occurred, despite extensive MRSA (contact) screening among patients and employees. The numbers of isolates began falling as from the beginning of 2003.

  3. Decolonisation of meticillin-resistant Staphylococcus aureus (MRSA) carriage in adopted children with cleft lip and palate.

    PubMed

    Bos, Maria; Hopman, Joost; Stuiver, Martijn M; Voss, Andreas

    2016-12-01

    This study aimed to determine the percentage success and to investigate influencing factors of meticillin-resistant Staphylococcus aureus (MRSA) decolonisation treatment in children with cleft lip and/or palate (CLP) who are adopted to The Netherlands. This was a historic cohort study in nine Dutch hospitals with a CLP treatment centre of children who were adopted from abroad in 2005-2012 who had CLP and MRSA carriage upon arrival in The Netherlands. A total of 55 adopted children with CLP and MRSA carriage were eligible for the study. Most children were adopted from China and had cheilognathopalatoschisis. Fourteen children were not treated for MRSA carriage, of whom six became MRSA-negative spontaneously. Forty-one children received decolonisation treatment (either topical treatment and disinfectant body wash or these combined with oral antibiotics). Overall, eighteen children [44%; 95% confidence interval (CI) 29-59%] became MRSA-negative after treatment. Treatment success was higher (56%; 95% CI 33-77%) in the group of children treated according to the Dutch guideline for treatment of MRSA carriage (odds ratio=6.1, 95% CI 4.4-26.4; p=0.017). In conclusion, MRSA decolonisation treatment in adopted children with CLP was successful in 44% of cases and the success percentage was higher in the group of children treated in accordance with the national guideline for treatment of MRSA carriage. However, given the percentage of children who turned MRSA-negative without treatment, waiting for spontaneous clearance of MRSA carriage can be advised after careful consideration of the benefits and risks of decolonisation treatment. Copyright © 2016 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

  4. Identification of virulence genes carried by bacteriophages obtained from clinically isolated methicillin-resistant Staphylococcus aureus.

    PubMed

    Karasartova, Djursun; Cavusoglu, Zeynep Burcin; Turegun, Buse; Ozsan, Murat T; Şahin, Fikret

    2016-12-01

    Bacteriophages play an important role in the pathogenicity of Staphylococcus aureus (S. aureus) either by carrying accessory virulence factors or several superantigens. Despite their importance, there are not many studies showing the actual distribution of the virulence genes carried by the prophages obtained from the clinically isolated Staphylococcus. In this study, we investigated prophages obtained from methicillin-resistant S. aureus (MRSA) strains isolated from hospital- and community-associated (HA-CA) infections for the virulence factors. In the study, 43 phages isolated from 48 MRSA were investigated for carrying toxin genes including the sak, eta, lukF-PV, sea, selp, sek, seg, seq chp, and scn virulence genes using polymerase chain reaction (PCR) and Southern blot. Restriction fragment length polymorphism was used to analyze phage genomes to investigate the relationship between the phage profiles and the toxin genes' presence. MRSA strains isolated from HA infections tended to have higher prophage presence than the MRSA strains obtained from the CA infections (97% and 67%, respectively). The study showed that all the phages with the exception of one phage contained one or more virulence genes in their genomes with different combinations. The most common toxin genes found were sea (83%) followed by sek (77%) and seq (64%). The study indicates that prophages encode a significant proportion of MRSA virulence factors.

  5. Characterization of Methicillin Resistant Staphylococcus aureus isolated from human and animal samples in Egypt.

    PubMed

    Bendary, M M; Solyman, S M; Azab, M M; Mahmoud, N F; Hanora, A M

    2016-02-29

    Staphylococcus aureus (S. aureus) has been one of the most problematic pathogens. Methicillin Resistant S. aureus (MRSA) has emerged as a major concern for both human and animal. Antibiotic resistance genes dissemination might be possible between human and animal bacteria. The aim of this study is to show phenotypic and genotypic diversity of human and animal MRSA isolates. Antibiogram typing and biofilm production were used as a primary phenotypic typing tool for the characterization of (40) animal and (38) human MRSA isolates. Genetic typing based on sequencing of 16S rRNA gene and virulence gene profiles were done. Antimicrobial resistance profiles of the animal isolates showed little evidence of widespread of resistance, although this was seen in many human isolates. The biofilm production was detected in higher percentage among animal isolates. Based on the genetic typing and multiple antibiotic resistance (MAR) index, the majority of animal isolates clustered into lineages that were not found in human isolates. Animal and human MRSA isolates showed diversity in antibiotic resistance and virulence gene profiles may be due to host adaptation or chances for contamination between the two hosts were not present in our study.

  6. Spread of methicillin-resistant Staphylococcus aureus belonging to the Brazilian epidemic clone in a general hospital and emergence of heterogenous resistance to glycopeptide antibiotics among these isolates.

    PubMed

    dos Santos Soares, M J; da Silva-Carvalho, M C; Ferreira-Carvalho, B T; Figueiredo, A M

    2000-04-01

    Methicillin-resistant Staphylococcus aureus (MRSA) infections have been increasing at an alarming rate world-wide. MRSA epidemics due to the clonal spread of multi-resistant isolates have been described. In this paper we show the absolute predominance of MRSA strains from the Brazilian epidemic clone in a hospital in the Northeast region of Brazil and the emergence of a vancomycin and teicoplanin heterogeneous resistant subpopulation among these isolates.

  7. Biochemical Fingerprinting of Methicillin-Resistant Staphylococcus aureus Isolated From Sewage and Hospital in Iran

    PubMed Central

    Rahimi, Fateh; Bouzari, Majid

    2015-01-01

    Background: Methicillin-resistant Staphylococcus aureus (MRSA) is known as a common pathogen in nosocomial and community-acquired infections. Sewage acts as an environmental reservoir and may have a significant role in development and dissemination of antibiotic resistance. Objectives: This study was undertaken to determine the epidemiological relatedness between the MRSA isolated from sewage and human infections. Materials and Methods: Samples were collected from a referral hospital and also a sewage treatment plant in Tehran, Iran, during 2010. All the MRSA isolates were identified at the species level and typed using Phene plate (PhP) system and SCCmec typing. Antibiotic susceptibility tests were also performed. Results: Of the 1142 isolates, 200 MRSA strains from the sewage (n = 100) and the clinic (n = 100) were isolated. Distinct PhP types, consisting of 16 common types and 13 single types, and also 3 different staphylococcal cassette chromosome mec (SCCmec) types (III, IVa and IVc) were found amongst the MRSA isolated from the two different sources. The results of antibiotic susceptibility testing showed an increased resistance to penicillin, ciprofloxacin, erythromycin, clindamycin and tetracycline. In addition, none of the isolates showed resistance to vancomycin, quinupristin -dalfopristin and linezolid. Conclusions: The presence of common PhP types and also SCCmec type III, as an indicator for hospital strains, among the isolates, may indicate an epidemiological link between clinical and sewage MRSA isolates in Tehran. PMID:26421131

  8. Heavy metal and disinfectant resistance genes among livestock-associated methicillin-resistant Staphylococcus aureus isolates.

    PubMed

    Argudín, M Angeles; Lauzat, Birgit; Kraushaar, Britta; Alba, Patricia; Agerso, Yvonne; Cavaco, Lina; Butaye, Patrick; Porrero, M Concepción; Battisti, Antonio; Tenhagen, Bernd-Alois; Fetsch, Alexandra; Guerra, Beatriz

    2016-08-15

    Livestock associated methicillin-resistant Staphylococcus aureus (LA-MRSA) has emerged in animal production worldwide. Most LA-MRSA in Europe belong to the clonal complex (CC) 398. The reason for the LA-MRSA emergence is not fully understood. Besides antimicrobial agents used for therapy, other substances with antimicrobial activity applied in animal feed, including metal-containing compounds might contribute to their selection. Some of these genes have been found in various novel SCCmec cassettes. The aim of this study was to assess the occurrence of metal-resistance genes among a LA-S. aureus collection [n=554, including 542 MRSA and 12 methicillin-susceptible S. aureus (MSSA)] isolated from livestock and food thereof. Most LA-MRSA isolates (76%) carried at least one metal-resistance gene. Among the LA-MRSA CC398 isolates (n=456), 4.8%, 0.2%, 24.3% and 71.5% were positive for arsA (arsenic compounds), cadD (cadmium), copB (copper) and czrC (zinc/cadmium) resistance genes, respectively. In contrast, among the LA-MRSA non-CC398 isolates (n=86), 1.2%, 18.6% and 16.3% were positive for the cadD, copB and czrC genes, respectively, and none were positive for arsA. Of the LA-MRSA CC398 isolates, 72% carried one metal-resistance gene, and the remaining harboured two or more in different combinations. Differences between LA-MRSA CC398 and non-CC398 were statistically significant for arsA and czrC. The czrC gene was almost exclusively found (98%) in the presence of SCCmec V in both CC398 and non-CC398 LA-MRSA isolates from different sources. Regarding the LA-MSSA isolates (n=12), some (n=4) were also positive for metal-resistance genes. This study shows that genes potentially conferring metal-resistance are frequently present in LA-MRSA.

  9. Minimum inhibitory concentration of vancomycin to methicillin resistant Staphylococcus aureus isolated from different clinical samples at a tertiary care hospital in Nepal.

    PubMed

    Kshetry, Arjun Ojha; Pant, Narayan Dutt; Bhandari, Raju; Khatri, Sabita; Shrestha, Krishma Laxmi; Upadhaya, Shambhu Kumar; Poudel, Asia; Lekhak, Binod; Raghubanshi, Bijendra R

    2016-01-01

    Methicillin resistant Staphylococcus aureus (MRSA) has evolved as a serious threat to public health. It has capability to cause infections not only in health care settings but also in community. Due to the multidrug resistance shown by MRSA, there are limited treatment options for the infections caused by this superbug. Vancomycin is used as the drug of choice for the treatment of infections caused by MRSA. Different studies from all around the world have documented the emergence of strains of S. aureus those are intermediate sensitive or resistant to vancomycin. And recently, there have been reports of reduced susceptibility of MRSA to vancomycin, from Nepal also. So the main purpose of this study was to determine the minimum inhibitory concentration (MIC) of vancomycin to methicillin resistant S. aureus isolated from different clinical specimens. Total 125 strains of S. aureus isolated from different clinical samples at KIST Medical College and Teaching Hospital, Lalitpur, Nepal from Nov 2012 to June 2013, were subjected to MRSA detection by cefoxitin disc diffusion method. The minimum inhibitory concentrations of vancomycin to confirmed MRSA strains were determined by agar dilution method. Yellow colored colonies in mannitol salt agar, which were gram positive cocci, catalase positive and coagulase positive were confirmed to be S. aureus. Among, total 125 S. aureus strains isolated; 47(37.6%) were MRSA. Minimum inhibitory concentrations of vancomycin to the strains of MRSA ranged from 0.125 μg/ml to 1 μg/ml. From our findings we concluded that the rate of isolation of MRSA among all the strains of S. aureus isolated from clinical samples was very high. However, none of the MRSA strains were found to be vancomycin intermediate-sensitive or vancomycin-resistant.

  10. Frequency of biocide-resistant genes and susceptibility to chlorhexidine in high-level mupirocin-resistant, methicillin-resistant Staphylococcus aureus (MuH MRSA).

    PubMed

    Liu, Qingzhong; Zhao, Huanqiang; Han, Lizhong; Shu, Wen; Wu, Qiong; Ni, Yuxing

    2015-08-01

    The aim of this study was to determine the prevalence of biocide-resistant determinants and the susceptibility to chlorhexidine in high-level mupirocin-resistant, methicillin-resistant Staphylococcus aureus (MuH MRSA). Fifty-three MuH MRSA isolates were analyzed for plasmid-borne genes (qacA/B, smr, qacG, qacH, and qacJ) by polymerase chain reaction (PCR); for chromosome-mediated genes (norA, norB, norC, mepA, mdeA, sepA, and sdrM) by PCR and quantitative reverse transcription-PCR (qRT-PCR); and for susceptibility to chlorhexidine by MIC and minimum bactericidal concentration (MBC). Furthermore, disinfectant efficacy was tested in the presence of 3.0% bovine serum albumin (BSA) in MBC detection. The plasmid-borne genes qacA/B (83.0%) and smr (77.4%) and overexpressions of chromosome-mediated genes norA (49.0%) and norB (28.8%) were predominantly found in isolates studied, and 90.6% of the isolates revealed tolerance to chlorhexidine. In the presence of BSA, the average MBC of chlorhexidine for these isolates rose to 256 μg/mL. Altogether, our results suggest that surveillance of sensitivity to biocides among MuH MRSA isolates is essential for hospital infection control.

  11. Noninvasive In Vivo Imaging to Evaluate Immune Responses and Antimicrobial Therapy against Staphylococcus aureus and USA300 MRSA Skin Infections

    PubMed Central

    Cho, John S.; Zussman, Jamie; Donegan, Niles P.; Irene Ramos, Romela; Garcia, Nairy C.; Uslan, Daniel Z.; Iwakura, Yoichiro; Simon, Scott I.; Cheung, Ambrose L.; Modlin, Robert L.; Kim, Jenny; Miller, Lloyd S.

    2011-01-01

    Staphylococcus aureus skin infections represent a significant public health threat because of the emergence of antibiotic-resistant strains such as methicillin-resistant S. aureus (MRSA). As greater understanding of protective immune responses and more effective antimicrobial therapies are needed, a S. aureus skin wound infection model was developed in which full-thickness scalpel cuts on the backs of mice were infected with a bioluminescent S. aureus (methicillin sensitive) or USA300 community-acquired MRSA strain and in vivo imaging was used to noninvasively monitor the bacterial burden. In addition, the infection-induced inflammatory response was quantified using in vivo fluorescence imaging of LysEGFP mice. Using this model, we found that both IL-1α and IL-1β contributed to host defense during a wound infection, whereas IL-1β was more critical during an intradermal S. aureus infection. Furthermore, treatment of a USA300 MRSA skin infection with retapamulin ointment resulted in up to 85-fold reduction in bacterial burden and a 53% decrease in infection-induced inflammation. In contrast, mupirocin ointment had minimal clinical activity against this USA300 strain, resulting in only a 2-fold reduction in bacterial burden. Taken together, this S. aureus wound infection model provides a valuable preclinical screening method to investigate cutaneous immune responses and the efficacy of topical antimicrobial therapies. PMID:21191403

  12. Antimicrobial resistance and virulence markers in methicillin sensitive Staphylococcus aureus isolates associated with nasal colonization.

    PubMed

    Sarkar, Abdullah; Raji, Adeola; Garaween, Ghada; Soge, Olusegun; Rey-Ladino, Jose; Al-Kattan, Wael; Shibl, Atef; Senok, Abiola

    2016-04-01

    Most Staphylococcus aureus infections occur in previously colonized persons who also act as reservoirs for continued dissemination. This study aimed to investigate the carriage of antimicrobial resistance and virulence markers in S. aureus isolates associated with nasal colonization. The study was conducted from December 2013-April 2014. Nasal swabs were collected and questionnaires administered to 97 medical students in Riyadh Saudi Arabia. Bacterial culture, identification and antimicrobial susceptibility testing were performed by conventional methods and chromogenic agar was used for methicillin resistant S. aureus (MRSA) screening. Molecular characterization of isolates was carried out using the StaphyType DNA microarray. Thirty two students (43%) had S. aureus nasal carriage (MSSA = 31; MRSA = 1). Seventeen clonal complexes (CC) were identified namely: CC15-MSSA (n = 5), CC1-MSSA-SCCfus (n = 4), CC8-MSSA (n = 3), CC22-MSSA (n = 3), CC25-MSSA (n = 3), CC101-MSSA (n = 2). Other CC found as single isolates were CC5-MSSA, CC6-MSSA, CC30-MSSA, CC45-MSSA, CC96-MSSA, CC188-MSSA, CC398-MSSA, CC942-MSSA/PVL+, CC1290-MSSA, ST2482-MSSA, CC80-MRSA-IV/PVL+. The CC1-SCCfus isolates harbored the Staphylococcal cassette chromosome (SCC) with ccrA-1; ccrB-1 and ccrB-3 genes plus the putative fusidic acid resistance marker Q6GD50. One MSSA isolate was genotyped as coagulase negative Staphylococcus spp with an irregular composite SCCmec element. Majority of the isolates harbored various virulence genes including the hemolysin, enterotoxin, and exfoliative genes as well as various adhesive protein producing genes. Although there was low carriage of MRSA, the MSSA isolates harbored various resistance and virulence genes including those usually seen in MRSA isolates. The presence of isolates with incomplete SCCmec elements plus putative resistance and virulence genes is of concern.

  13. Molecular characterization of Staphylococcus aureus isolates from southwest of Iran using spa and SCCmec typing methods.

    PubMed

    Darban-Sarokhalil, Davood; Khoramrooz, Seyed Sajjad; Marashifard, Masoud; Malek Hosseini, Seyed Ali Asghar; Parhizgari, Najmeh; Yazdanpanah, Mahboobeh; Gharibpour, Farzaneh; Mirzaii, Mehdi; Sharifi, Bahman; Haeili, Mehri

    2016-09-01

    Staphylococcus aureus remains a major cause of nosocomial infection worldwide. Characterization of S. aureus isolates circulating in the southwest of Iran will contribute to understand and control the spread of the strains in this area. spa and SCCmec typing methods were used for genotyping of 125 S. aureus isolates obtained from two teaching hospitals in Ahvaz. Drug susceptibility testing was performed by using disk diffusion method. Frequency of the methicillin resistant S. aureus (MRSA) isolates was 39% (n = 34) and 27% (n = 10) in Emam Khomeini and Golestan hospitals, respectively. Except for Erythromycin, MRSA strains showed high rate of resistance to antimicrobial agents including penicillin (100%), norfloxacine (80%), azitromycin (80%), ciprofloxacin (80%), gentamycin (77%), cotrimoxazole (75%), cephotaxime. All isolates were sensitive to vancomycin. Out of 44 MRSA strains, 39 (88.5%) were SCCmec III, three (7%) were IVc and two (4.5%) of them were nontypeable. spa types t037 (26 isolates; 59%), and t1149 (25 isolates; 31%) were the most dominant types found in MRSA and methicillin sensitive S. aureus (MSSA) strains, respectively. We found SCCmec type III as the most prominent type indicating that most of the studied bacterial population had hospital origin. spa type t037, the most frequent genotype in this study were significantly (100%) associated with MRSA. For the first time we are reporting spa types t692, t706 and t018 from Iran and t342, t704, t2622, t5598, t11270 and t2864 from Asia. Moreover we are reporting types t6871 and t2684 for the second time in the world. Copyright © 2016. Published by Elsevier Ltd.

  14. Being Met as marked - patients' experiences of being infected with community-acquired methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Skyman, Eva; Lindahl, Berit; Bergbom, Ingegerd; Sjöström, Harrieth Thunberg; Åhrén, Christina

    2016-12-01

    It is known that patients who acquired methicillin-resistant Staphylococcus aureus (MRSA) in hospitals suffer and feel as plague. Moreover, the patient interaction with nurses and physicians is described as frightening. Little is known about patient experiences after having acquired CA-MRSA concerning care and everyday life. To reveal and interpret otherwise healthy patients' lived experiences of receiving care and their everyday life after having acquired community MRSA (CA-MRSA). A phenomenological hermeneutic approach guided by Ricouer was conducted. Interviews with twelve patients were transcribed verbatim into a text. The text was analysed in three phases: naive understanding, structural analysis and comprehensive understanding to reveal a possible being in the world. In this study, this referred to what it means to be infected with CA-MRSA. The findings indicate that patients who acquired MRSA experience a changed body image. They suffer from ignorant and frightened behavior from healthcare workers, social contacts, and also of being bullied by colleagues. Despite this, patients assume great responsibility for protecting others. However, knowledgeable staff alleviate suffering and bring peace of mind to the patients. Preventing patient's feelings of being a pest, an outsider living with fear, requires urgent education and understanding about resistant bacteria and how to meet an infected patient. The results describing patients, affected with MRSA, may contribute and touch the readers to better understanding of patient's changed body image and suffering and how to mitigate these feelings. © 2016 Nordic College of Caring Science.

  15. Complete genome sequence of livestock associated methicillin resistant Staphylococcus aureus ST398 isolated from swine in USA

    USDA-ARS?s Scientific Manuscript database

    Methicillin resistant Staphylococcus aureus colonizes and causes disease in many animal species. Livestock associated-MRSA isolates are represented by isolates of the sequence type 398. These isolates are considered to be livestock adapted. This report provides the complete genome of one swine assoc...

  16. Comparison of the BD MAX MRSA XT to the Cepheid™ Xpert® MRSA assay for the molecular detection of methicillin-resistant Staphylococcus aureus from nasal swabs.

    PubMed

    Mehta, Sanjay R; Estrada, Jasmine; Ybarra, Juan; Fierer, Joshua

    2017-04-01

    Variation in MRSA genotypes may affect the sensitivity of molecular assays to detect this organism. We compared 2 commonly used screening assays, the Cepheid™ Xpert® MRSA and the BD MAX™ MRSA XT on consecutively obtained nasal swabs from 479 subjects. Specimens giving discordant results were subjected to additional microbiologic and molecular testing. Six hundred forty-two (97.6%) of the 658 test results were concordant. Of the 16 discordant results from 12 subjects, additional results suggested that 9 (60%) of the 15 MRSA XT assays were likely correct, and 6 (40%) of the 15 Xpert® assays were likely correct. One discordant result could not be resolved. A mecA dropout and novel mec right-extremity junction (MREJ) sites led to false-positive and negative results by Xpert®. While both assays performed well, continued vigilance is needed to monitor for Staphylococcus aureus with novel MREJ sites, mecA dropouts, and mecC, leading to inaccurate results in screening assays. Published by Elsevier Inc.

  17. Characterization of Methicillin-Resistant Staphylococcus aureus Isolated from Healthy Turkeys and Broilers Using DNA Microarrays.

    PubMed

    El-Adawy, Hosny; Ahmed, Marwa; Hotzel, Helmut; Monecke, Stefan; Schulz, Jochen; Hartung, Joerg; Ehricht, Ralf; Neubauer, Heinrich; Hafez, Hafez M

    2016-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a major human health problem and recently, domestic animals are described as carriers and possible reservoirs. Twenty seven S. aureus isolates from five turkey farms (n = 18) and two broiler farms (n = 9) were obtained by culturing of choana and skin swabs from apparently healthy birds, identified by Taqman-based real-time duplex nuc-mecA-PCR and characterized by spa typing as well as by a DNA microarray based assay which covered, amongst others, a considerable number of antibiotic resistance genes, species controls, and virulence markers. The antimicrobial susceptibility profiles were tested by agar diffusion assays and genotypically confirmed by the microarray. Five different spa types (3 in turkeys and 2 in broilers) were detected. The majority of MRSA isolates (24/27) belonged to clonal complex 398-MRSA-V. The most frequently occurring spa types were accordingly t011, t034, and t899. A single CC5-MRSA-III isolated from turkey and CC398-MRSA with an unidentified/truncated SCCmec element in turkey and broiler were additionally detected. The phenotypic antimicrobial resistance profiles of S. aureus isolated from both turkeys and broilers against 14 different antimicrobials showed that all isolates were resistant to ampicillin, cefoxitin, oxacillin, doxycycline, and tetracycline. Moreover, all S. aureus isolated from broilers were resistant to erythromycin and azithromycin. All isolates were susceptible to gentamicin, chloramphenicol, sulphonamides, and fusidic acid. The resistance rate against ciprofloxacin was 55.6% in broiler isolates and 42.1% in turkey isolates. All tetracycline resistant isolates possessed genes tetK/M. All erythromycin-resistant broiler isolates carried ermA. Only one broiler isolate (11.1%) carried genes ermA, ermB, and ermC, while 55.6% of turkey isolates possessed ermA and ermB genes. Neither PVL genes (lukF/S-PV), animal-associated leukocidin (lukM and luk-P83) nor the gene encoding

  18. Characterization of Methicillin-Resistant Staphylococcus aureus Isolated from Healthy Turkeys and Broilers Using DNA Microarrays

    PubMed Central

    El-Adawy, Hosny; Ahmed, Marwa; Hotzel, Helmut; Monecke, Stefan; Schulz, Jochen; Hartung, Joerg; Ehricht, Ralf; Neubauer, Heinrich; Hafez, Hafez M.

    2016-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a major human health problem and recently, domestic animals are described as carriers and possible reservoirs. Twenty seven S. aureus isolates from five turkey farms (n = 18) and two broiler farms (n = 9) were obtained by culturing of choana and skin swabs from apparently healthy birds, identified by Taqman-based real-time duplex nuc-mecA-PCR and characterized by spa typing as well as by a DNA microarray based assay which covered, amongst others, a considerable number of antibiotic resistance genes, species controls, and virulence markers. The antimicrobial susceptibility profiles were tested by agar diffusion assays and genotypically confirmed by the microarray. Five different spa types (3 in turkeys and 2 in broilers) were detected. The majority of MRSA isolates (24/27) belonged to clonal complex 398-MRSA-V. The most frequently occurring spa types were accordingly t011, t034, and t899. A single CC5-MRSA-III isolated from turkey and CC398-MRSA with an unidentified/truncated SCCmec element in turkey and broiler were additionally detected. The phenotypic antimicrobial resistance profiles of S. aureus isolated from both turkeys and broilers against 14 different antimicrobials showed that all isolates were resistant to ampicillin, cefoxitin, oxacillin, doxycycline, and tetracycline. Moreover, all S. aureus isolated from broilers were resistant to erythromycin and azithromycin. All isolates were susceptible to gentamicin, chloramphenicol, sulphonamides, and fusidic acid. The resistance rate against ciprofloxacin was 55.6% in broiler isolates and 42.1% in turkey isolates. All tetracycline resistant isolates possessed genes tetK/M. All erythromycin-resistant broiler isolates carried ermA. Only one broiler isolate (11.1%) carried genes ermA, ermB, and ermC, while 55.6% of turkey isolates possessed ermA and ermB genes. Neither PVL genes (lukF/S-PV), animal-associated leukocidin (lukM and luk-P83) nor the gene encoding

  19. Characterization of methicillin-resistant Staphylococcus aureus isolated from dogs in Korea.

    PubMed

    Pak, S I; Han, H R; Shimizu, A

    1999-09-01

    Twelve strains of the methicillin-resistant Staphylococcus aureus (MRSA) recovered from hospitalized dogs were analyzed for in vitro antimicrobial susceptibility and virulence, and were genetically characterized by pulsed-field gel electrophoresis (PFGE). Antibiotic susceptibility test showed that nearly all isolates were resistant to beta-lactam antibiotics tested and all the strains were fully susceptible to glycopeptides. There were no inhibitory activities among the aminoglycosides. The 50% lethal dose (LD50) was determined by intraperitoneal injection of cell suspensions and estimated by the Spearman-Kärber method. The mouse lethality of MRSA and methicillin-susceptible S. aureus (MSSA) was not significantly different in both normal and cyclophosphamide-treated mice (p>0.05), indicating that they were equally virulent. There was a great difference in the incidence of toxin production between the MRSA and MSSA group; 83.3% (10 of 12) of the MRSA and 14.3% (1 of 7) of the MSSA were toxin producers. The predominant types produced by MRSA was B. All the MRSA strains were capsular type 5 producers, while of 7 MSSA strains, four were type 5, one for type 8, and two were nontypeable. Based on the PFGE analysis, the 12 MRSA isolates generated 9 to 11 fragments in the size range of <48.5 to 630.5 kb, and yielded 6 different patterns. The results indicated that production of toxin and capsule type do not play a role in the pathogenicity to mouse and PFGE is a valuable tool for the characterization of MRSA. This report is the first such cases in the veterinary literature in Korea and may indicate the frequent emergence of MRSA in veterinary clinic hereafter.

  20. Characterization of MLS(b) resistance among Staphylococcus aureus and Staphylococcus epidermidis isolates carrying different SCCmec types.

    PubMed

    Teodoro, Cristiane R S; Mattos, Cláudio S; Cavalcante, Fernanda S; Pereira, Eliezer M; dos Santos, Kátia R N

    2012-09-01

    This work characterizes MLS(b) resistance in 39 methicillin-resistant Staphylococcus aureus (MRSA) and 32 Staphylococcus epidermidis (MRSE) isolates. Of 21 erm(A) gene encoding MRSA isolates, 71.4% carried SCCmecIII, whereas of 12 isolates carrying the erm(C) gene, 83.3% carried SCCmecIV. Among the 25 MRSE isolates positive for the erm(C) gene, 80% had SCCmecIV or nontypeable cassettes. Isolates carrying these genes had MIC(90) ≥ 256 μg/mL to erythromycin and clindamycin. The msr(A) gene was associated with a low MIC(90) to these drugs. The erm(A) gene was associated with SCCmecIII in MRSA isolates, whereas the erm(C) gene was associated with SCCmecIV in both MRSA and MRSE isolates. © 2012 The Societies and Wiley Publishing Asia Pty Ltd.

  1. Biochemical and Molecular Analysis of Staphylococcus aureus Clinical Isolates from Hospitalized Patients

    PubMed Central

    Karmakar, Amit; Dua, Parimal; Ghosh, Chandradipa

    2016-01-01

    Staphylococcus aureus is opportunistic human as well as animal pathogen that causes a variety of diseases. A total of 100 Staphylococcus aureus isolates were obtained from clinical samples derived from hospitalized patients. The presumptive Staphylococcus aureus clinical isolates were identified phenotypically by different biochemical tests. Molecular identification was done by PCR using species specific 16S rRNA primer pairs and finally 100 isolates were found to be positive as Staphylococcus aureus. Screened isolates were further analyzed by several microbiological diagnostics tests including gelatin hydrolysis, protease, and lipase tests. It was found that 78%, 81%, and 51% isolates were positive for gelatin hydrolysis, protease, and lipase activities, respectively. Antibiogram analysis of isolated Staphylococcus aureus strains with respect to different antimicrobial agents revealed resistance pattern ranging from 57 to 96%. Our study also shows 70% strains to be MRSA, 54.3% as VRSA, and 54.3% as both MRSA and VRSA. All the identified isolates were subjected to detection of mecA, nuc, and hlb genes and 70%, 84%, and 40% were found to harbour mecA, nuc, and hlb genes, respectively. The current investigation is highly important and informative for the high level multidrug resistant Staphylococcus aureus infections inclusive also of methicillin and vancomycin. PMID:27366185

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

    PubMed

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

    2016-09-01

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

  3. Molecular Characterization and Panton-Valentine Leucocidin Typing of Community-Acquired Methicillin-Sensitive Staphylococcus aureus Clinical Isolates

    PubMed Central

    Sloan, Tim; Kearns, Angela M.; James, Richard

    2012-01-01

    Limited comprehensive molecular typing data exist currently for Panton-Valentine leucocidin (PVL)-positive, methicillin-sensitive Staphylococcus aureus (PVL-MSSA) clinical isolates. Characterization of PVL-MSSA isolates by multilocus sequence typing (MLST) and spa typing in this study showed a genetic similarity to PVL-positive, methicillin-resistant S. aureus (PVL-MRSA) strains, although three novel spa types and a novel MLST (ST1518) were detected. Furthermore, the detection of PVL phages and haplotypes in PVL-MSSA identical to those previously found in PVL-MRSA isolates highlights the role these strains may play as precursors of emerging lineages of clinical significance. PMID:22718937

  4. Inhibition of penicillin-binding protein 2a (PBP2a) in methicillin resistant Staphylococcus aureus (MRSA) by combination of ampicillin and a bioactive fraction from Duabanga grandiflora.

    PubMed

    Santiago, Carolina; Pang, Ee Leen; Lim, Kuan-Hon; Loh, Hwei-San; Ting, Kang Nee

    2015-06-10

    The inhibition of penicillin-binding protein 2a (PBP2a) is a promising solution in overcoming resistance of methicillin resistance Staphylococcus aureus (MRSA). A potential approach in achieving this is by combining natural product with currently available antibiotics to restore the activity as well as to amplify the therapeutic ability of the drugs. We studied inhibition effects of a bioactive fraction, F-10 (isolated from the leaves of Duabanga grandiflora) alone and in combination with a beta-lactam drug, ampicillin on MRSA growth and expression of PBP2a. Additionally, phytochemical analysis was conducted on F-10 to identify the classes of phytochemicals present. Fractionation of the ethyl acetate leaf extract was achieved by successive column chromatography which eventually led to isolation of an active fraction, F-10. Both extract and F-10 were analyzed for the presence of major classes of phytochemicals in addition to obtaining a high performance liquid chromatography (HPLC) profile to reveal the complexity of the fraction F-10. Broth microdilution method was employed to determine minimum inhibitory concentration (MIC) of the extract and fractions against MRSA. Evaluation of synergistic activity of the active fraction with ampicillin was determined using checkerboard methodand kinetic growth experiments. Effect of combination treatments on expression of PBP2a, a protein that confers resistance to beta-lactam antibiotics, was elucidated with the Western blot assay. MIC of F-10 against MRSA was 750 mg/L which showed an improved activity by 4-fold compared to its crude extract (MIC = 3000 mg/L). Phytochemical analysis revealed occurrence of tannins, saponin, flavonoids, sterols, and glycosides in F10 fraction. In FIC index interpretation, the most synergistic activity was achieved for combinations of 1/64 × MIC ampicillin + 1/4 × MIC F-10. The combination also evidently inhibited MRSA growth in kinetic growth curve assay. As a result of this synergistic

  5. Kocurin, the True Structure of PM181104, an Anti-Methicillin-Resistant Staphylococcus aureus (MRSA) Thiazolyl Peptide from the Marine-Derived Bacterium Kocuria palustris

    PubMed Central

    Martín, Jesús; Sousa, Thiciana da S.; Crespo, Gloria; Palomo, Sara; González, Ignacio; Tormo, José R.; de la Cruz, Mercedes; Anderson, Matthew; Hill, Russell T.; Vicente, Francisca; Genilloud, Olga; Reyes, Fernando

    2013-01-01

    A new thiazolyl peptide, kocurin (1), was isolated from culture broths of a marine-derived Kocuria palustris. Its structural elucidation was accomplished using a combination of spectroscopic and chemical methods, including HRMS, extensive 1D and 2D NMR analysis, MS/MS fragmentation, and chemical degradation and Marfey’s analysis of the resulting amino acid residues. The structure herein reported corrects that previously assigned to PM181104 (3). Kocurin displayed activity against methicillin-resistant Staphylococcus aureus (MRSA), with MIC values in the submicromolar range. PMID:23380989

  6. In Vivo Assessment of Phage and Linezolid Based Implant Coatings for Treatment of Methicillin Resistant S. aureus (MRSA) Mediated Orthopaedic Device Related Infections

    PubMed Central

    Kaur, Sandeep; Harjai, Kusum; Chhibber, Sanjay

    2016-01-01

    Staphylococcus comprises up to two-thirds of all pathogens in orthopaedic implant infections with two species respectively Staphylococcus aureus and Staphylococcus epidermidis, being the predominate etiological agents isolated. Further, with the emergence of methicillin-resistant S. aureus (MRSA), treatment of S. aureus implant infections has become more difficult, thus representing a devastating complication. Use of local delivery system consisting of S.aureus specific phage along with linezolid (incorporated in biopolymer) allowing gradual release of the two agents at the implant site represents a new, still unexplored treatment option (against orthopaedic implant infections) that has been studied in an animal model of prosthetic joint infection. Naked wire, hydroxypropyl methylcellulose (HPMC) coated wire and phage and /or linezolid coated K-wire were surgically implanted into the intra-medullary canal of mouse femur bone of respective groups followed by inoculation of S.aureus ATCC 43300(MRSA). Mice implanted with K-wire coated with both the agents i.e phage as well as linezolid (dual coated wires) showed maximum reduction in bacterial adherence, associated inflammation of the joint as well as faster resumption of locomotion and motor function of the limb. Also, all the coating treatments showed no emergence of resistant mutants. Use of dual coated implants incorporating lytic phage (capable of self-multiplication) as well as linezolid presents an attractive and aggressive early approach in preventing as well as treating implant associated infections caused by methicillin resistant S. aureus strains as assessed in a murine model of experimental joint infection. PMID:27333300

  7. Micheliolide provides protection of mice against Staphylococcus aureus and MRSA infection by down-regulating inflammatory response

    PubMed Central

    Jiang, Xinru; Wang, Yuli; Qin, Yifei; He, Weigang; Benlahrech, Adel; Zhang, Qingwen; Jiang, Xin; Lu, Zhenhui; Ji, Guang; Zheng, Yuejuan

    2017-01-01

    A major obstacle to therapy in intensive care units is sepsis caused by severe infection. In recent years gram-positive (G+) bacteria, most commonly staphylococci, are thought to be the main pathogens. Micheliolide (MCL) was demonstrated to provide a therapeutic role in rheumatoid arthritis, inflammatory intestinal disease, colitis-associated cancer, and lipopolysaccharide (LPS, the main component of G− bacterial cell wall) induced septic shock. We proved here that MCL played an anti-inflammatory role in Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA) induced peritonitis. It inhibited the expression of inflammatory cytokines and chemokines in macrophages and dendritic cells upon stimulation with peptidoglycan (PGN, the main cell wall composition of G+ bacteria). PI3K/Akt and NF-κB pathways account for the anti-inflammatory role of MCL after PGN stimulation. MCL reduced IL-6 secretion through down-regulating NF-κB activation and improved the survival status in mice challenged with a lethal dose of S. aureus. In MRSA infection mouse model, MCL down-regulated the expression of IL-6, TNF-α, MCP-1/CCL2 and IFN-γ in sera, and ameliorated the organ damage of liver and kidney. In conclusion, MCL can help maintain immune equilibrium and decrease PGN, S. aureus and MRSA-triggered inflammatory response. These provide the rationality for the potential usage of MCL in sepsis caused by G+ bacteria (e.g., S. aureus) and antibiotic-resistant bacteria (e.g., MRSA). PMID:28165033

  8. Active Surveillance and Decolonization Without Isolation Is Effective in Preventing Methicillin-Resistant Staphylococcus aureus Transmission in the Psychiatry Units

    PubMed Central

    Das, Sanchita; Harazin, Maureen; Wright, Marc Oliver; Dusich, Irene; Robicsek, Ari; Peterson, Lance R.

    2014-01-01

    Background  Control of methicillin-resistant Staphylococcus aureus (MRSA) is difficult in select populations. We used molecular typing to study the effect of universal surveillance and decolonization of carriers, without isolation, on MRSA transmission in a specialized unit. Methods  Patients admitted to the unit were screened for nasal MRSA at admission and discharge. Those who acquired MRSA during their stay were identified and linked to carriers with shared time in unit. Molecular typing of isolates was performed to identify transmission. Results  Of 3285 admissions, 82% were tested for MRSA nasal carriage; the discharge screening compliance was 64.7%. Admission prevalence was 2.3% among patients screened, and 7 (0.42%) acquired nasal MRSA during their stay. All patients who acquired MRSA shared time in the unit with a colonized patient. There were 3.9 MRSA acquisitions per 1000 at-risk days. Isolates from 5 patients that acquired MRSA during their stay as well as their potential donors (11 donor: recipient patient pairs) were available for typing. Pulsed-field gel electrophoresis matched 1 acquisition isolate to a colonized patient isolate. There were no MRSA infections during the study period. Conclusions  Despite less than perfect nasal screening compliance and exemption from traditional isolation precautions, acquisition of MRSA was 0.42% in this patient population over a course of 4.75 years, including a single case of acquisition, genetically similar to a known potential donor source. Screening for MRSA colonization and decolonizing of carriers was sufficient in reducing transmission in this vulnerable population. PMID:25734137

  9. Detection of methicillin-resistant Staphylococcus aureus (MRSA) in the microbial flora from the conjunctiva of healthy donkeys from Sicily (Italy).

    PubMed

    Foti, Maria; Fisichella, Vittorio; Giacopello, Cristina

    2013-03-01

    To describe the bacterial flora present in the normal conjunctiva of donkeys from Sicily (Italy). A total of 46 healthy donkeys housed in 3 locations within the territory of Palermo (Sicily, Italy) were studied. Donkeys ranged from 2 to 13 years of age, with a median age of 6 years. Forty-six conjunctival swabs were obtained from both eyes of each animal, and specimens were cultured for aerobic bacteria. Furthermore, the antimicrobial activity of methicillin (1 μg) and oxacillin (5 μg) on Staphylococcus spp. isolates was evaluated, and a specific PCR assay, which allows the detection of mecA gene specific for methicillin-resistant Staphylococcus aureus (MRSA) strains, was performed. Forty of 46 (86.9%) donkeys were positive for bacteria. Eighty bacterial isolates, representing 9 bacteria genera, were successfully cultured. The most frequently recovered bacterial genus was Staphylococcus (52/80 isolates; 65%). Several strains (20/80 isolates; 25%) belonging to the Enterobacteriaceae family were also isolated, among which the most frequently isolated genus was Enterobacter (eight isolates). Of the 52 Staphylococcus spp. isolates, 14 (26.9%) strains were oxacillin/methicillin resistant. The mecA gene was detected in 6/52 (11.5%) strains. This study contributes to the knowledge about normal ocular flora and MRSA occurrence in donkey farms in Sicily. © 2012 American College of Veterinary Ophthalmologists.

  10. Colonisation of dentures by Staphylococcus aureus and MRSA in out-patient and in-patient populations.

    PubMed

    Lewis, N; Parmar, N; Hussain, Z; Baker, G; Green, I; Howlett, J; Kearns, A; Cookson, B; McDonald, A; Wilson, M; Ready, D

    2015-09-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is an important human pathogen, and colonisation with this organism can result in localised or systemic infections which may be fatal. One hundred in-patients admitted to a London teaching hospital and 100 out-patients attending prosthetic dentistry clinics were recruited into this study. Of the 100 out-patients, 27 % harboured S. aureus on their dentures, compared to 33 % of in-patients. Only one out-patient had MRSA colonising their dentures whereas 12 % of the in-patients harboured MRSA. The median total bacterial count of the denture plaque samples was 6.2 × 10(7) cfu/sample and 6.9 × 10(7) cfu/sample for the out-patient and in-patient populations, respectively. In most instances, where present, S. aureus comprised less than 1 % of the total viable denture microbiota. Phage typing demonstrated that EMRSA-15 and non-typeable strains were harboured on dentures. The results of this study have revealed that dentures are a potential reservoir of MRSA and so account should be taken of these findings when planning decontamination procedures for elimination of this pathogen.

  11. Antibacterial Activity of Mulinum spinosum Extracts against Slime-Producing Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus Isolated from Nasal Carriers

    PubMed Central

    Daniela, Echenique; Alejandra, Chiaramello; Pedro, Rossomando; Claudia, Mattana; Lucía, Alcaráz; Carlos, Tonn; Analía, Laciar; Sara, Satorres

    2014-01-01

    Nasal carriers of Staphylococcus aureus are important reservoirs with risk of developing endogenous infections or transmitting infections to susceptible individuals. Methicillin-resistant S. aureus (MRSA) are associated with higher rates of treatment failure. Some strains of S. aureus produce slime which is believed to make the microorganisms more resistant to antibiotics and host defenses. The antibacterial activity of ethyl acetate : n-hexane (EtOAc : HEX) extracts of Mulinum spinosum (5 : 95% EtOAc : HEX, 50 : 50% EtOAc : HEX, 70 : 30% EtOAc : HEX and mix 20 : 80/30 : 70% EtOAc : HEX, 50 : 50/70 : 30/100 : 0% EtOAc : HEX) were assayed against 3 slime-producing S. aureus strains and 2 MRSA strains isolated from nasal carriers. S. aureus ATCC 35556 slime-producing strain and MRSA ATCC 43300 strain were used as controls. The extracts were prepared using flash chromatography. M. spinosum 5 : 95% AcOEt : HEX showed antibacterial effect against all slime-producing strains (MIC: 500 µg/mL) and the highest activity against MRSA strains (MIC: 500 to 1000 µg/mL). All M. spinosum extracts assayed were active against slime-producing S. aureus and MRSA at doses between 500 and 4000 µg/mL. Both, slime-producing S. aureus and MRSA are highly contagious and hardly eradicated by antibiotic therapies. So, there is an increasing need to find new substances with the ability to inhibit these strains. PMID:25530997

  12. Antibacterial activity of Mulinum spinosum extracts against slime-producing Staphylococcus aureus and methicillin-resistant Staphylococcus aureus isolated from nasal carriers.

    PubMed

    Daniela, Echenique; Alejandra, Chiaramello; Pedro, Rossomando; Claudia, Mattana; Lucía, Alcaráz; Carlos, Tonn; Analía, Laciar; Sara, Satorres

    2014-01-01

    Nasal carriers of Staphylococcus aureus are important reservoirs with risk of developing endogenous infections or transmitting infections to susceptible individuals. Methicillin-resistant S. aureus (MRSA) are associated with higher rates of treatment failure. Some strains of S. aureus produce slime which is believed to make the microorganisms more resistant to antibiotics and host defenses. The antibacterial activity of ethyl acetate:n-hexane (EtOAc:HEX) extracts of Mulinum spinosum (5:95% EtOAc:HEX, 50:50% EtOAc:HEX, 70:30% EtOAc:HEX and mix 20:80/30:70% EtOAc:HEX, 50:50/70:30/100:0% EtOAc:HEX) were assayed against 3 slime-producing S. aureus strains and 2 MRSA strains isolated from nasal carriers. S. aureus ATCC 35556 slime-producing strain and MRSA ATCC 43300 strain were used as controls. The extracts were prepared using flash chromatography. M. spinosum 5:95% AcOEt:HEX showed antibacterial effect against all slime-producing strains (MIC: 500 µg/mL) and the highest activity against MRSA strains (MIC: 500 to 1000 µg/mL). All M. spinosum extracts assayed were active against slime-producing S. aureus and MRSA at doses between 500 and 4000 µg/mL. Both, slime-producing S. aureus and MRSA are highly contagious and hardly eradicated by antibiotic therapies. So, there is an increasing need to find new substances with the ability to inhibit these strains.

  13. MRSA Screening

    MedlinePlus

    ... identify S. aureus and the mecA gene that confers resistance to methicillin, oxacillin, nafcillin, dicloxacillin, and other similar antibiotics. Molecular MRSA screening is becoming more widespread. Some ...

  14. Antibiotic Resistance Trends in Methicillin-resistant Staphylococcus aureus isolated in Kuwait hospitals: 2011-2015.

    PubMed

    Udo, Edet; Boswihi, Samar

    2017-10-04


    The aim of this study was to determine antibiotic resistance trends and carriage of staphylococcal cassette chromosome mec (SCCmec) genetic elements in methicillin-resistant Staphylococcus aureus (MRSA) isolated in Kuwait hospitals to ascertain whether they were healthcare-associated (HA-MRSA) or community-associated (CA-MRSA).
    Materials (Subjects) and Methods
    In total 6,922 MRSA isolates obtained from different clinical samples were tested for resistance to antibiotics, urease production and carriage of SCCmec elements.
    Results:
    All MRSA isolates were susceptible to linezolid, vancomycin and teicoplanin. However, some isolates were resistant to kanamycin (2979 ; 43%), ciprofloxacin (2955; 42.7%), erythromycin and clindamycin (2935; 42.4%), fusidic acid (2858; 41.2%), gentamicin (2665; 38.5%), tetracycline (2652; 38.3%) and trimethoprim (2324; 33.5%). Whereas the prevalence of resistance to most antibiotics showed annual variations, those of resistance to chloramphenicol and rifampicin increased from 2.6% and 0.1% to 9.6% and 1.6% respectively, and high-level mupirocin declined from 9.3% in 2011 to 3.6% in 2015. In total, 3244 (53.9%) of the isolates carried SCCmec IV followed by SCCmec III (1737 (28.8%) and SCCmec V: (890; 14.8%). SCCmec I (21; 0.3%) and II (79; 0.8%) occurred sporadically. A total of 3651 (60.7%) of the isolates belonged to CA-MRSA genotype and 2290 (38.1%) isolates were identified as HA-MRSA.
    Conclusion:
    The study demonstrated changes in antibiotic resistance patterns of MRSA overtime and reinforces the value of surveillance in detecting such changes for the benefit of infection control and patient management.
    . ©2017The Author(s). Published by S. Karger AG, Basel.

  15. A combination of silver nanoparticles and visible blue light enhances the antibacterial efficacy of ineffective antibiotics against methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Akram, Fatma Elzahraa; El-Tayeb, Tarek; Abou-Aisha, Khaled; El-Azizi, Mohamed

    2016-08-17

    Silver nanoparticles (AgNPs) are potential antimicrobials agents, which can be considered as an alternative to antibiotics for the treatment of infections caused by multi-drug resistant bacteria. The antimicrobial effects of double and triple combinations of AgNPs, visible blue light, and the conventional antibiotics amoxicillin, azithromycin, clarithromycin, linezolid, and vancomycin, against ten clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) were investigated. The antimicrobial activity of AgNPs, applied in combination with blue light, against selected isolates of MRSA was investigated at 1/2-1/128 of its minimal inhibitory concentration (MIC) in 24-well plates. The wells were exposed to blue light source at 460 nm and 250 mW for 1 h using a photon emitting diode. Samples were taken at different time intervals, and viable bacterial counts were determined. The double combinations of AgNPs and each of the antibiotics were assessed by the checkerboard method. The killing assay was used to test possible synergistic effects when blue light was further combined to AgNPs and each antibiotic at a time against selected isolates of MRSA. The bactericidal activity of AgNPs, at sub-MIC, and blue light was significantly (p < 0.001) enhanced when both agents were applied in combination compared to each agent alone. Similarly, synergistic interactions were observed when AgNPs were combined with amoxicillin, azithromycin, clarithromycin or linezolid in 30-40 % of the double combinations with no observed antagonistic interaction against the tested isolates. Combination of the AgNPs with vancomycin did not result in enhanced killing against all isolates tested. The antimicrobial activity against MRSA isolates was significantly enhanced in triple combinations of AgNPs, blue light and antibiotic, compared to treatments involving one or two agents. The bactericidal activities were highest when azithromycin or clarithromycin was included in the triple

  16. The Plasmin-Sensitive Protein Pls in Methicillin-Resistant Staphylococcus aureus (MRSA) Is a Glycoprotein

    PubMed Central

    Pohlentz, Gottfried; Xia, Guoqing; Hussain, Muzaffar; Foster, Simon; Peters, Georg

    2017-01-01

    Most bacterial glycoproteins identified to date are virulence factors of pathogenic bacteria, i.e. adhesins and invasins. However, the impact of protein glycosylation on the major human pathogen Staphylococcus aureus remains incompletely understood. To study protein glycosylation in staphylococci, we analyzed lysostaphin lysates of methicillin-resistant Staphylococcus aureus (MRSA) strains by SDS-PAGE and subsequent periodic acid-Schiff’s staining. We detected four (>300, ∼250, ∼165, and ∼120 kDa) and two (>300 and ∼175 kDa) glycosylated surface proteins with strain COL and strain 1061, respectively. The ∼250, ∼165, and ∼175 kDa proteins were identified as plasmin-sensitive protein (Pls) by mass spectrometry. Previously, Pls has been demonstrated to be a virulence factor in a mouse septic arthritis model. The pls gene is encoded by the staphylococcal cassette chromosome (SCC)mec type I in MRSA that also encodes the methicillin resistance-conferring mecA and further genes. In a search for glycosyltransferases, we identified two open reading frames encoded downstream of pls on the SCCmec element, which we termed gtfC and gtfD. Expression and deletion analysis revealed that both gtfC and gtfD mediate glycosylation of Pls. Additionally, the recently reported glycosyltransferases SdgA and SdgB are involved in Pls glycosylation. Glycosylation occurs at serine residues in the Pls SD-repeat region and modifying carbohydrates are N-acetylhexosaminyl residues. Functional characterization revealed that Pls can confer increased biofilm formation, which seems to involve two distinct mechanisms. The first mechanism depends on glycosylation of the SD-repeat region by GtfC/GtfD and probably also involves eDNA, while the second seems to be independent of glycosylation as well as eDNA and may involve the centrally located G5 domains. Other previously known Pls properties are not related to the sugar modifications. In conclusion, Pls is a glycoprotein and Pls glycosyl

  17. The Plasmin-Sensitive Protein Pls in Methicillin-Resistant Staphylococcus aureus (MRSA) Is a Glycoprotein.

    PubMed

    Bleiziffer, Isabelle; Eikmeier, Julian; Pohlentz, Gottfried; McAulay, Kathryn; Xia, Guoqing; Hussain, Muzaffar; Peschel, Andreas; Foster, Simon; Peters, Georg; Heilmann, Christine

    2017-01-01

    Most bacterial glycoproteins identified to date are virulence factors of pathogenic bacteria, i.e. adhesins and invasins. However, the impact of protein glycosylation on the major human pathogen Staphylococcus aureus remains incompletely understood. To study protein glycosylation in staphylococci, we analyzed lysostaphin lysates of methicillin-resistant Staphylococcus aureus (MRSA) strains by SDS-PAGE and subsequent periodic acid-Schiff's staining. We detected four (>300, ∼250, ∼165, and ∼120 kDa) and two (>300 and ∼175 kDa) glycosylated surface proteins with strain COL and strain 1061, respectively. The ∼250, ∼165, and ∼175 kDa proteins were identified as plasmin-sensitive protein (Pls) by mass spectrometry. Previously, Pls has been demonstrated to be a virulence factor in a mouse septic arthritis model. The pls gene is encoded by the staphylococcal cassette chromosome (SCC)mec type I in MRSA that also encodes the methicillin resistance-conferring mecA and further genes. In a search for glycosyltransferases, we identified two open reading frames encoded downstream of pls on the SCCmec element, which we termed gtfC and gtfD. Expression and deletion analysis revealed that both gtfC and gtfD mediate glycosylation of Pls. Additionally, the recently reported glycosyltransferases SdgA and SdgB are involved in Pls glycosylation. Glycosylation occurs at serine residues in the Pls SD-repeat region and modifying carbohydrates are N-acetylhexosaminyl residues. Functional characterization revealed that Pls can confer increased biofilm formation, which seems to involve two distinct mechanisms. The first mechanism depends on glycosylation of the SD-repeat region by GtfC/GtfD and probably also involves eDNA, while the second seems to be independent of glycosylation as well as eDNA and may involve the centrally located G5 domains. Other previously known Pls properties are not related to the sugar modifications. In conclusion, Pls is a glycoprotein and Pls glycosyl

  18. Detection of Methicillin Resistant Staphylococcus aureus and Determination of Minimum Inhibitory Concentration of Vancomycin for Staphylococcus aureus Isolated from Pus/Wound Swab Samples of the Patients Attending a Tertiary Care Hospital in Kathmandu, Nepal

    PubMed Central

    Adhikari, Raghabendra; Neupane, Sanjeev; Neupane, Mukesh; Bhattarai, Roshan; Bhatta, Sabita; Chaudhary, Raina; Lekhak, Binod

    2017-01-01

    The present study was conducted to evaluate the performance of cefoxitin disc diffusion method and oxacillin broth microdilution method for detection of methicillin resistant S. aureus (MRSA), taking presence of mecA gene as reference. In addition, inducible clindamycin resistance and beta-lactamase production were studied and minimum inhibitory concentration (MIC) of vancomycin for S. aureus isolates was determined. A total of 711 nonrepeated pus/wound swab samples from different anatomic locations were included in the study. The Staphylococcus aureus was identified on the basis of colony morphology, Gram's stain, and biochemical tests. A total of 110 (15.47%) S. aureus isolates were recovered, of which 39 (35.50%) isolates were identified as MRSA by cefoxitin disc diffusion method. By oxacillin broth microdilution method, 31.82% of the Staphylococcus aureus isolates were found to be MRSA. However, mecA gene was present in only 29.1% of the isolates. Further, beta-lactamase production was observed in 71.82% of the isolates, while inducible clindamycin resistance was found in 10% of S. aureus isolates. The MIC value of vancomycin for S. aureus ranged from 0.016 μg/mL to 1 μg/mL. On the basis of the absolute sensitivity (100%), both phenotypic methods could be employed for routine diagnosis of MRSA in clinical microbiology laboratory; however cefoxitin disc diffusion could be preferred over MIC method considering time and labour factor. PMID:28154581

  19. Genetic Diversity and Antibiotic Resistance Patterns of Staphylococcus Aureus Isolated from Leaf Vegetables in Korea.

    PubMed

    Hong, Jisoo; Kim, Yangkyun; Kim, Jonguk; Heu, Sunggi; Kim, Se-ri; Kim, Kwang-Pyo; Roh, Eunjung

    2015-07-01

    Staphylococcus aureus is an important foodborne pathogen on global basis. The current study investigated the genetic patterns in S. aureus isolates from leaf vegetables (n = 53). Additional isolates from livestock (n = 31) and humans (n = 27) were compared with the leaf vegetable isolates. Genes associated with toxins, antibiotic resistance, and pulsed-field gel electrophoresis (PFGE) patterns were analyzed. At least 1 enterotoxin-encoding gene (sea, seb, sec, sed, and see) was detected in 11 of 53 (20.75%) leaf vegetable isolates. When the agr (accessory gene regulator) grouping was analyzed, agr II was the major group, whereas agr IV was not present in leaf vegetable isolates. All S. aureus isolates from leaf vegetables were resistant to more than one of the antibiotics tested. Nineteen of 53 (35.85%) isolates from leaf vegetables exhibited multidrug-resistance, and 11 of these were MRSA (methicillin-resistant S. aureus). A dendrogram displaying the composite types of S. aureus isolates from 3 origins was generated based on the combination of the toxin genes, agr genes, antibiotic resistance, and PFGE patterns. The isolates could be clustered into 8 major composite types. The genetic patterns of S. aureus isolates from leaf vegetables and humans were similar, whereas those from livestock had unique patterns. This suggests some S. aureus isolates from leaf vegetables to be of human origin.

  20. Epidemiology and molecular characterization of methicillin-resistant Staphylococcus aureus nasal carriage isolates from bovines.

    PubMed

    Nemeghaire, Stéphanie; Argudín, M Angeles; Haesebrouck, Freddy; Butaye, Patrick

    2014-07-10

    Staphylococcus aureus is a common bacterium usually found on skin and mucous membranes of warm blooded animals. Resistance in S. aureus has been increasingly reported though depending on the clonal lineage. Indeed, while hospital acquired (HA)-methicillin resistant S. aureus (MRSA) are typically multi-resistant, community associated (CA)-MRSA are by large more susceptible to many antibiotics. Although S. aureus isolated from animals are often susceptible to most antibiotics, multi-resistant livestock associated (LA)-MRSA have been recovered from bovine mastitis.In this study, we investigated the prevalence and types of MRSA present in the nose of healthy bovines of different age groups and rearing practices. Since no validated methods for MRSA isolation from nasal swabs were available, we compared two isolation methods. Molecular characterization was performed by means of spa-typing, MLST, SCCmec typing and microarray analysis for the detection of antimicrobial resistance and virulence genes. MRSA between herd prevalence in bovines was estimated at 19.8%. There was a marked difference between rearing practices with 9.9%, 10.2% and 46.1% of the dairy, beef and veal calve farms respectively being MRSA positive. No significant difference was observed between both isolation methods tested. Most isolates were ST398 spa type t011 or closely related spa types. Few ST239 spa type t037 and t388 and ST8 spa type t121 were also found. SCCmec types carried by these strains were mainly type IV(2B), IV(2B&5) and type V. Type III and non-typeable SCCmec were recovered to a lesser extent. All isolates were multi-resistant to at least two antimicrobials in addition to the expected cefoxitin and penicillin resistance, with an average of resistance to 9.5 different antimicrobials. Isolates selected for microarray analysis carried a broad range of antimicrobial resistance and virulence genes. MRSA were mainly present in veal farms, compared to the lower prevalence in dairy or beef

  1. Epidemiology and molecular characterization of methicillin-resistant Staphylococcus aureus nasal carriage isolates from bovines

    PubMed Central

    2014-01-01

    Background Staphylococcus aureus is a common bacterium usually found on skin and mucous membranes of warm blooded animals. Resistance in S. aureus has been increasingly reported though depending on the clonal lineage. Indeed, while hospital acquired (HA)-methicillin resistant S. aureus (MRSA) are typically multi-resistant, community associated (CA)-MRSA are by large more susceptible to many antibiotics. Although S. aureus isolated from animals are often susceptible to most antibiotics, multi-resistant livestock associated (LA)-MRSA have been recovered from bovine mastitis. In this study, we investigated the prevalence and types of MRSA present in the nose of healthy bovines of different age groups and rearing practices. Since no validated methods for MRSA isolation from nasal swabs were available, we compared two isolation methods. Molecular characterization was performed by means of spa-typing, MLST, SCCmec typing and microarray analysis for the detection of antimicrobial resistance and virulence genes. Results MRSA between herd prevalence in bovines was estimated at 19.8%. There was a marked difference between rearing practices with 9.9%, 10.2% and 46.1% of the dairy, beef and veal calve farms respectively being MRSA positive. No significant difference was observed between both isolation methods tested. Most isolates were ST398 spa type t011 or closely related spa types. Few ST239 spa type t037 and t388 and ST8 spa type t121 were also found. SCCmec types carried by these strains were mainly type IV(2B), IV(2B&5) and type V. Type III and non-typeable SCCmec were recovered to a lesser extent. All isolates were multi-resistant to at least two antimicrobials in addition to the expected cefoxitin and penicillin resistance, with an average of resistance to 9.5 different antimicrobials. Isolates selected for microarray analysis carried a broad range of antimicrobial resistance and virulence genes. Conclusion MRSA were mainly present in veal farms, compared to the lower

  2. Bullous impetigo in children infected with methicillin-resistant Staphylococcus aureus alone or in combination with methicillin-susceptible S. aureus: analysis of genetic characteristics, including assessment of exfoliative toxin gene carriage.

    PubMed

    Shi, Da; Higuchi, Wataru; Takano, Tomomi; Saito, Kohei; Ozaki, Kyoko; Takano, Misao; Nitahara, Yoshiyuki; Yamamoto, Tatsuo

    2011-05-01

    Among bullous impetigo isolates, exfoliative toxin (ET) gene carriage was found in 61.5% of methicillin-resistant Staphylococcus aureus (MRSA) isolates versus 90.6% of methicillin-susceptible S. aureus (MSSA) isolates. MRSA-only cases were ETB or ETA positive, while MRSA/MSSA coinfection cases were ET negative for MRSA but ETA positive for MSSA. Collagen adhesin may facilitate some MRSA infections.

  3. Bullous Impetigo in Children Infected with Methicillin-Resistant Staphylococcus aureus Alone or in Combination with Methicillin-Susceptible S. aureus: Analysis of Genetic Characteristics, Including Assessment of Exfoliative Toxin Gene Carriage▿

    PubMed Central

    Shi, Da; Higuchi, Wataru; Takano, Tomomi; Saito, Kohei; Ozaki, Kyoko; Takano, Misao; Nitahara, Yoshiyuki; Yamamoto, Tatsuo

    2011-01-01

    Among bullous impetigo isolates, exfoliative toxin (ET) gene carriage was found in 61.5% of methicillin-resistant Staphylococcus aureus (MRSA) isolates versus 90.6% of methicillin-susceptible S. aureus (MSSA) isolates. MRSA-only cases were ETB or ETA positive, while MRSA/MSSA coinfection cases were ET negative for MRSA but ETA positive for MSSA. Collagen adhesin may facilitate some MRSA infections. PMID:21430094

  4. Emergence of cfr-Mediated Linezolid Resistance in a Methicillin-Resistant Staphylococcus aureus Epidemic Clone Isolated from Patients with Cystic Fibrosis

    PubMed Central

    de Dios Caballero, Juan; Pastor, María Dolores; Vindel, Ana; Máiz, Luis; Yagüe, Genoveva; Salvador, Carme; Cobo, Marta; Morosini, María-Isabel; Cantón, Rafael

    2015-01-01

    Resistance to linezolid (LZD) in methicillin-resistant Staphylococcus aureus (MRSA) isolates from patients with cystic fibrosis (CF) is due mainly to ribosomal mutations. We report on four CF patients with LZD-resistant MRSA bronchopulmonary infections by strains carrying the cfr gene. Strains from one patient also harbored the G2576U mutation (23S rRNA) and the G139R substitution (L3 protein). All strains belonged to the epidemic clone ST125 MRSA IVc. Our results support the monitoring of LZD resistance emergence in CF and non-CF MRSA isolates. PMID:26666940

  5. Emergence of cfr-Mediated Linezolid Resistance in a Methicillin-Resistant Staphylococcus aureus Epidemic Clone Isolated from Patients with Cystic Fibrosis.

    PubMed

    de Dios Caballero, Juan; Pastor, María Dolores; Vindel, Ana; Máiz, Luis; Yagüe, Genoveva; Salvador, Carme; Cobo, Marta; Morosini, María-Isabel; del Campo, Rosa; Cantón, Rafael

    2015-12-14

    Resistance to linezolid (LZD) in methicillin-resistant Staphylococcus aureus (MRSA) isolates from patients with cystic fibrosis (CF) is due mainly to ribosomal mutations. We report on four CF patients with LZD-resistant MRSA bronchopulmonary infections by strains carrying the cfr gene. Strains from one patient also harbored the G2576U mutation (23S rRNA) and the G139R substitution (L3 protein). All strains belonged to the epidemic clone ST125 MRSA IVc. Our results support the monitoring of LZD resistance emergence in CF and non-CF MRSA isolates.

  6. Surveillance of Physician-Diagnosed Skin and Soft Tissue Infections Consistent With Methicillin-Resistant "Staphylococcus aureus" (MRSA) among Nebraska High School Athletes, 2008-2012

    ERIC Educational Resources Information Center

    Buss, Bryan F.; Connolly, Susan

    2014-01-01

    Though historically confined to hospital settings, methicillin-resistant Staphylococcus aureus (MRSA) has received increasing attention in the wider community, particularly among athletes. A 2007-2008 investigation in Nebraska concluded that MRSA skin infections were an emerging problem among the state's student athletes. Statewide surveillance…

  7. Surveillance of Physician-Diagnosed Skin and Soft Tissue Infections Consistent With Methicillin-Resistant "Staphylococcus aureus" (MRSA) among Nebraska High School Athletes, 2008-2012

    ERIC Educational Resources Information Center

    Buss, Bryan F.; Connolly, Susan

    2014-01-01

    Though historically confined to hospital settings, methicillin-resistant Staphylococcus aureus (MRSA) has received increasing attention in the wider community, particularly among athletes. A 2007-2008 investigation in Nebraska concluded that MRSA skin infections were an emerging problem among the state's student athletes. Statewide surveillance…

  8. Prospective Comparison of a New Chromogenic Medium, MRSASelect, to CHROMagar MRSA and Mannitol-Salt Medium Supplemented with Oxacillin or Cefoxitin for Detection of Methicillin-Resistant Staphylococcus aureus

    PubMed Central

    Stoakes, Luba; Reyes, Romina; Daniel, Janis; Lennox, Gwen; John, Michael A.; Lannigan, Robert; Hussain, Zafar

    2006-01-01

    MRSASelect agar was compared to CHROMagar, mannitol-salt agar with oxacillin, and mannitol-salt agar with cefoxitin (MSA-CFOX) for the isolation of methicillin-resistant Staphylococcus aureus (MRSA). The sensitivities and specificities were 97.3% and 99.8%, 82.9% and 99.1%, 80.2% and 79%, and 99.1% and 84.8%, respectively. MSA-CFOX and MRSASelect had a high sensitivity. MRSASelect, however, was more specific and proved to be a more reliable and rapid medium for the detection of MRSA. PMID:16455933

  9. Antibacterial alkaloids from chelidonium majus linn (papaveraceae) against clinical isolates of methicillin-resistant Staphylococcus aureus.

    PubMed

    Zuo, Guo Ying; Meng, Fan Yan; Hao, Xiao Yan; Zhang, Yun Ling; Wang, Gen Chun; Xu, Gui Li

    2008-01-01

    This study describes the antibacterial effect of extracts and compounds isolated from the aerial part of Chelidonium majus Linn. (Papaveraceae) acting against clinical strains of methicillin-resistant Staphylococcus aureus (MRSA). The activities were evaluated by using the macrobroth dilution method and reported as the MICs/MBCs. Bioassay-guided fractionation of the most active extract from the aerial parts (EtOAc) led to the isolation of benzo[c]phenanthridine-type alkaloids 8-hydroxydihydrosanguinarine (hhS), 8-hydroxydihydrochelerythrine (hhC), which were potently active against MRSA strains. The selective antibacterial activity reported in this paper for 8-hydroxylated benzo[c]phenanthridine-type alkaloids isolated from C.majus opens the possibility that they could be helpful for the developing of new antibacterial agents for treating the infection of MRSA which has created nosocomial problem worldwide.

  10. USA300 Methicillin-Resistant Staphylococcus aureus Bacteremia and the Risk of Severe Sepsis: Is USA300 MRSA Associated with More Severe Infections?

    PubMed Central

    Kreisel, Kristen M.; Stine, O. Colin; Johnson, J. Kristie; Perencevich, Eli N.; Shardell, Michelle D.; Lesse, Alan J.; Gordin, Fred M.; Climo, Michael W.; Roghmann, Mary-Claire

    2011-01-01

    Objective USA300 methicillin-resistant Staphylococcus aureus (MRSA) is increasing as a cause of severe community-associated bacteremic infections. We assessed severe sepsis in response to infection in patients with USA300 MRSA compared to non-USA300 MRSA bacteremia. Methods A cohort study was conducted from 1997–2008 comparing sepsis in response to infection in 271 patients with MRSA bacteremia from four VA hospitals. Results Sixty-seven (25%) patients with MRSA bacteremia were USA300 MRSA; 204 (75%) were non-USA300 MRSA. The proportion of MRSA bacteremia caused by USA300 MRSA increased over time (χ2 p<0.0001). Adjusting for age and nosocomial infection, patients with USA300 MRSA bacteremia were more likely to have severe sepsis or septic shock in response to infection than patients with non-USA300 MRSA bacteremia (adjusted Relative Risk=1.82; 95% CI: 1.16–2.87; p=0.01). Conclusions This suggests that patients with USA300 MRSA are more likely to develop severe sepsis in response to their infection, which could be due to host or bacterial differences. PMID:21558047

  11. Risk factors for methicillin-resistant Staphylococcus aureus skin and soft tissue infection in MRSA-colonized patients discharged from a Veterans Affairs hospital.

    PubMed

    Cadena, J; Richardson, A M; Frei, C R

    2016-02-01

    Currently, limited studies have quantified the risk of methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTIs) for MRSA-colonized patients on discharge from hospital. Our retrospective, case-control study identified independent risk factors for the development of MRSA SSTIs among such patients detected by active MRSA nasal screening in an acute care hospital by PCR on admission, and bacteriological cultures on discharge. Cases were MRSA-colonized patients aged ⩾18 years who developed a MRSA SSTI post-discharge and controls were those who did not develop a MRSA SSTI post-discharge. Controls were matched to cases by length of follow-up (±10 days) for up to 18 months. Potential demographic and clinical risk factors for MRSA infection were identified using electronic queries and manual chart abstraction; data were compared by standard statistical tests and variables with P values ⩽0·05 in bivariable analysis were entered into a logistic regression model. Multivariable analysis demonstrated prior hospital admission within 12 months (P = 0·02), prior MRSA infection (P = 0·05), and previous myocardial infarction (P = 0·01) were independently predictive of a MRSA SSTI post-discharge. Identification of MRSA colonization upon admission and recognition of risk factors could help identify a high-risk population that could benefit from MRSA SSTI prevention strategies.

  12. Molecular Epidemiology of Methicillin-Resistant Staphylococcus aureus Isolated from Australian Veterinarians

    PubMed Central

    Groves, Mitchell D.; Crouch, Bethany; Coombs, Geoffrey W.; Jordan, David; Pang, Stanley; Barton, Mary D.; Giffard, Phil

    2016-01-01

    This work investigated the molecular epidemiology and antimicrobial resistance of methicillin-resistant Staphylococcus aureus (MRSA) isolated from veterinarians in Australia in 2009. The collection (n = 44) was subjected to extensive molecular typing (MLST, spa, SCCmec, dru, PFGE, virulence and antimicrobial resistance genotyping) and antimicrobial resistance phenotyping by disk diffusion. MRSA was isolated from Australian veterinarians representing various occupational emphases. The isolate collection was dominated by MRSA strains belonging to clonal complex (CC) 8 and multilocus sequence type (ST) 22. CC8 MRSA (ST8-IV [2B], spa t064; and ST612-IV [2B], spa variable,) were strongly associated with equine practice veterinarians (OR = 17.5, 95% CI = 3.3–92.5, P < 0.001) and were often resistant to gentamicin and rifampicin. ST22-IV [2B], spa variable, were strongly associated with companion animal practice veterinarians (OR = 52.5, 95% CI = 5.2–532.7, P < 0.001) and were resistant to ciprofloxacin. A single pig practice veterinarian carried ST398-V [5C2], spa t1451. Equine practice and companion animal practice veterinarians frequently carried multiresistant-CC8 and ST22 MRSA, respectively, whereas only a single swine specialist carried MRSA ST398. The presence of these strains in veterinarians may be associated with specific antimicrobial administration practices in each animal species. PMID:26735694

  13. Molecular Epidemiology of Methicillin-Resistant Staphylococcus aureus Isolated from Australian Veterinarians.

    PubMed

    Groves, Mitchell D; Crouch, Bethany; Coombs, Geoffrey W; Jordan, David; Pang, Stanley; Barton, Mary D; Giffard, Phil; Abraham, Sam; Trott, Darren J

    2016-01-01

    This work investigated the molecular epidemiology and antimicrobial resistance of methicillin-resistant Staphylococcus aureus (MRSA) isolated from veterinarians in Australia in 2009. The collection (n = 44) was subjected to extensive molecular typing (MLST, spa, SCCmec, dru, PFGE, virulence and antimicrobial resistance genotyping) and antimicrobial resistance phenotyping by disk diffusion. MRSA was isolated from Australian veterinarians representing various occupational emphases. The isolate collection was dominated by MRSA strains belonging to clonal complex (CC) 8 and multilocus sequence type (ST) 22. CC8 MRSA (ST8-IV [2B], spa t064; and ST612-IV [2B], spa variable,) were strongly associated with equine practice veterinarians (OR = 17.5, 95% CI = 3.3-92.5, P < 0.001) and were often resistant to gentamicin and rifampicin. ST22-IV [2B], spa variable, were strongly associated with companion animal practice veterinarians (OR = 52.5, 95% CI = 5.2-532.7, P < 0.001) and were resistant to ciprofloxacin. A single pig practice veterinarian carried ST398-V [5C2], spa t1451. Equine practice and companion animal practice veterinarians frequently carried multiresistant-CC8 and ST22 MRSA, respectively, whereas only a single swine specialist carried MRSA ST398. The presence of these strains in veterinarians may be associated with specific antimicrobial administration practices in each animal species.

  14. [Identification and characterization of Panton-Valentine leukocidin-positive Staphylococcus aureus isolated in Okinawa, Japan].

    PubMed

    Miyagi, Ayano; Tokashiki, Yoshino T; Nakasone, Isamu; Kisanuki, Kyoko; Nago, Tamami T; Yamane, Nobuhisa

    2010-09-01

    We experienced hospital-acquired infection in March 2008 that three nurses became infected with Panton-Valentine leukocidin (PVL)-positive methicillin-resistant Staphylococcus aureus (MRSA). Accordingly, we performed the retrospective study to determine the prevalence of PVL-positive S. aureus in Okinawa. A total of 731 clinical isolates, consisting of 600 MRSA and 131 methicillin-susceptible isolates in Okinawa, were included. Of the isolates, 16 were positive for PVL gene (lukS-PV-lukF-PV). All the PVL-positive isolates were MRSA, and the first appeared in March 2008. The isolates from the University Hospital were characterized as staphylococcal chromosomal cassette mec type IVa. Through the analysis of pulsed-field gel electrophoresis (PFGE), 16 PVL-positive MRSA isolates were divided in three groups. One isolate (the first group) from the other hospital was less similar (< 40% similarity) when compared with the remaining 15 isolates from the University Hospital. The second group consisted of two respective paired isolates from the same department wards, and those were very similar with each other, indicating possible patient-to-patient transmission. The 11 isolates were characterized as the third group with >80% similarity. The DiversiLab system (bioMérieux) based on repetitive-sequence-based PCR typing demonstrated that the isolates of the third group were similar and indistinguishable with the strains of USA300 clone. However, the first and second groups were not determinable which USA clone was the origin. With these, we could conclude that the PVL-positive MRSA close to USA300 clone first appeared in Okinawa in 2008 and is now becoming prevalent multi-focally. Also, person-to-person transmission is already likely in a hospital setting.

  15. Extensive Genetic Diversity Identified among Sporadic Methicillin-Resistant Staphylococcus aureus Isolates Recovered in Irish Hospitals between 2000 and 2012

    PubMed Central

    Kinnevey, Peter M.; Shore, Anna C.; Brennan, Grainne I.; Sullivan, Derek J.; Ehricht, Ralf; Monecke, Stefan

    2014-01-01

    Clonal replacement of predominant nosocomial methicillin-resistant Staphylococcus aureus (MRSA) strains has occurred several times in Ireland during the last 4 decades. However, little is known about sporadically occurring MRSA in Irish hospitals or in other countries. Eighty-eight representative pvl-negative sporadic MRSA isolates recovered in Irish hospitals between 2000 and 2012 were investigated. These yielded unusual pulsed-field gel electrophoresis and antibiogram-resistogram typing patterns distinct from those of the predominant nosocomial MRSA clone, ST22-MRSA-IV, during the study period. Isolates were characterized by spa typing and DNA microarray profiling for multilocus sequence type (MLST) clonal complex (CC) and/or sequence type (ST) and SCCmec type assignment, as well as for detection of virulence and antimicrobial resistance genes. Conventional PCR-based SCCmec subtyping was undertaken when necessary. Extensive diversity was detected, including 38 spa types, 13 MLST-CCs (including 18 STs among 62 isolates assigned to STs), and 25 SCCmec types (including 2 possible novel SCCmec elements and 7 possible novel SCCmec subtypes). Fifty-four MLST-spa-SCCmec type combinations were identified. Overall, 68.5% of isolates were assigned to nosocomial lineages, with ST8-t190-MRSA-IID/IIE ± SCCM1 predominating (17.4%), followed by CC779/ST779-t878-MRSA-ψSCCmec-SCC-SCCCRISPR (7.6%) and CC22/ST22-t032-MRSA-IVh (5.4%). Community-associated clones, including CC1-t127/t386/t2279-MRSA-IV, CC59-t216-MRSA-V, CC8-t008-MRSA-IVa, and CC5-t002/t242-MRSA-IV/V, and putative animal-associated clones, including CC130-t12399-MRSA-XI, ST8-t064-MRSA-IVa, ST398-t011-MRSA-IVa, and CC6-t701-MRSA-V, were also identified. In total, 53.3% and 47.8% of isolates harbored genes for resistance to two or more classes of antimicrobial agents and two or more mobile genetic element-encoded virulence-associated factors, respectively. Effective ongoing surveillance of sporadic nosocomial MRSA is

  16. Molecular epidemiology of methicillin resistant Staphylococcus aureus isolated from newborns in a hospital in Rio de Janeiro, Brazil.

    PubMed

    Loureiro, M M; de Moraes, B A; Quadra, M R; Pinheiro, G S; Suffys, P N; Asensi, M D

    2000-01-01

    Methicillin resistant Staphylococcus aureus (MRSA) is an organism that is frequently transmitted in hospitals and perinatal units. The MRSA is considered a public health problem in neonatology because of its strong potential for dissemination in the wards associated with high rates of morbidity and mortality. In this study we describe the bacteriological, epidemiological and molecular characteristics of MRSA isolated from anterior nares and blood cultures of newborns hospitalized in a public maternity hospital in the city of Rio de Janeiro, Brazil. The frequency of MRSA isolated from nasal swabs of newborns was 47.8% (43/90). The genetic analysis of MRSA strains from anterior nares, showed 8 different pulsed field gel electrophoresis patterns (PFGE). Upon analysis of PFGE patterns of the 12 MRSA strains isolated from blood cultures, 8 different patterns were observed, 9 (75%) strains were genetic related to nasal secretion isolates patterns. In conclusion, our data demonstrate the importance of screening of newborns for the presence of MRSA in Brazilian hospitals and the usefulness of genetic typing of these pathogen during epidemiologic studies. This should lead to a better knowledge on the significancy and spreading of MRSA in the hospitals.

  17. Molecular analysis and frequency of Staphylococcus aureus virulence genes isolated from bloodstream infections in a teaching hospital in Tianjin, China.

    PubMed

    Wang, L X; Hu, Z D; Hu, Y M; Tian, B; Li, Jing; Wang, F X; Yang, H; Xu, H R; Li, Y C; Li, J

    2013-03-11

    Staphylococcus aureus is an important cause of bloodstream infections worldwide. We examined the prevalence of genes that encode erythromycin ribosome methylase and bacterial toxins in S. aureus collected from bloodstream infections. Sixty different S. aureus isolates were obtained from blood cultures of patients who were admitted to a Teaching Hospital in Tianjin from January 2006 to August 2011. The susceptibility of the isolates to 16 antibiotics was tested. Methicillin-resistant S. aureus (MRSA) was identified using the disk diffusion method with cefoxitin. PCR was used to detect genes that encode the staphylococcal enterotoxins, Panton-Valentine leukocidin, toxic shock syndrome toxin 1 and erythromycin ribosome methylase. Molecular analysis of the MRSA strains was done using pulsed-field gel electrophoresis (PFGE) and staphylococcal cassette chromosome mec (SCCmec) typing. The positivity rates of mecA, ermA, ermB, and ermC in the isolates were 13/60, 10/60, 18/60, and 18/60, respectively. Among the 60 isolates, 30 harbored enterotoxin genes, with sea as the most frequent toxin gene (33%), followed by sec (15%), sed (12%), and seb (5%). The see and tst genes were not found in any of the isolates. The pvl gene was detected in four strains. Eleven MRSA isolates were of the SCCmec type III; two MRSA isolates could not be determined through SCCmec typing. PFGE analysis of the 13 MRSA isolates produced 8 distinct pulsotypes. Virulence genes and erythromycin ribosome methylase genes were highly prevalent in these isolates. The PFGE results demonstrated that the MRSA spread through cloning, mainly involving SCCmec type III.

  18. Analysis of reporting time for identification of methicillin-resistant Staphylococcus aureus carriers using ChromID MRSA.

    PubMed

    Lee, Yirang; Kim, Jae-Seok; Kim, Han-Sung; Kim, Hyun Soo; Song, Wonkeun; Lee, Kyu Man

    2014-05-01

    We assessed the reporting times for identification of nasal methicillin-resistant Staphylococcus aureus (MRSA) carriers in 2011 in a university-affiliated hospital using surveillance cultures incubated for 1 and 2 days with ChromID MRSA (bioMérieux, France). Of 2,732 nasal swabs tested, MRSA was detected in 829 (85.6%) and 140 (14.4%) swabs after 1 and 2 days of incubation, respectively, and the median reporting times for positive specimens were 33.7 hr (range, 18.2-156.9 hr) and 108.1 hr (range, 69.8-181.0 hr), respectively. Detection rate after 1-day incubation was 85%. Additional 1-day incubation improved detection rate; however, it prolonged the reporting times of positive specimens approximately up to 4 days because of the need for confirmatory tests such as species identification and susceptibility tests. Following a 2-day culture with ChromID MRSA, rapid confirmatory tests are warranted to reduce delay in identifying MRSA carriers.

  19. The bactericidal effect of 470 nm light and hyperbaric oxygen on methicillin-resistant Staphylococcus aureus (MRSA)

    PubMed Central

    Bumah, Violet Vakunseh; Whelan, Harry Thomas; Masson-Meyers, Daniela Santos; Quirk, Brendan; Buchmann, Ellen; Enwemeka, Chukuka Samuel

    2015-01-01

    It has been shown that, in vitro, hyperbaric oxygen (HBO) suppresses 28% bacterial growth, while 470 nm blue light alone suppresses up to 92% methicillin resistant Staphylococcus aureus (MRSA) in one application in vitro. Therefore, we determined if combined 470 nm light (55 J/cm2) and HBO will yield 100% bacterial suppression in experimental simulation of mild, moderate or severe MRSA infection. We cultured MRSA at 3×106, 5×106, 7×106, 8×106 or 12×106 CFU/ml and treated each concentration in four groups as follows: (1) Control (no treatment) (2) photo-irradiation only, (3) photo-irradiation then HBO, (4) HBO only, and (5) HBO then photo-irradiation. Bacteria colonies were then quantified. The results showed that at each bacterial concentration, HBO alone was significantly less effective in suppressing MRSA than photo-irradiation or combined HBO and photo-irradiation (p<0.0001). Similarly, at no bacterial concentration did combined HBO and 470 nm light treatment yield a statistically better result than 470 nm light alone (p > 0.05), neither did HBO treatment either before or after irradiation make a difference. Furthermore, at no bacterial concentration was 100% MRSA suppression achieved. Indeed, the maximum bacterial suppression attained was in the mild infection model (3×106 CFU/ml), with blue light producing 97.3±0.2% suppression and HBO +55 J/cm2 yielding 97.5±2.5% suppression. We conclude that: (1) HBO and 470 nm light individually suppress MRSA growth; (2) 470nm blue light is more effective in suppressing MRSA than HBO; and (3) HBO did not act synergistically to heighten the bactericidal effect of 470 nm light. PMID:25700768

  20. Antibacterial mode of action of violacein from Chromobacterium violaceum UTM5 against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Aruldass, Claira Arul; Masalamany, Santhana Raj Louis; Venil, Chidambaram Kulandaisamy; Ahmad, Wan Azlina

    2017-03-31

    Violacein, violet pigment produced by Chromobacterium violaceum, has attracted much attention recently due to its pharmacological properties including antibacterial activity. The present study investigated possible antibacterial mode of action of violacein from C. violaceum UTM5 against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) strains. Violet fraction was obtained by cultivating C. violaceum UTM5 in liquid pineapple waste medium, extracted, and fractionated using ethyl acetate and vacuum liquid chromatography technique. Violacein was quantified as major compound in violet fraction using HPLC analysis. Violet fraction displayed bacteriostatic activity against S. aureus ATCC 29213 and methicillin-resistant S. aureus ATCC 43300 with minimum inhibitory concentration (MIC) of 3.9 μg/mL. Fluorescence dyes for membrane damage and scanning electron microscopic analysis confirmed the inhibitory effect by disruption on membrane integrity, morphological alternations, and rupture of the cell membranes of both strains. Transmission electron microscopic analysis showed membrane damage, mesosome formation, and leakage of intracellular constituents of both bacterial strains. Mode of action of violet fraction on the cell membrane integrity of both strains was shown by release of protein, K(+), and extracellular adenosine 5'-triphosphate (ATP) with 110.5 μg/mL, 2.34 μg/mL, and 87.24 ng/μL, respectively, at 48 h of incubation. Violet fraction was toxic to human embryonic kidney (HEK293) and human fetal lung fibroblast (IMR90) cell lines with LC50 value of 0.998 ± 0.058 and 0.387 ± 0.002 μg/mL, respectively. Thus, violet fraction showed a strong antibacterial property by disrupting the membrane integrity of S. aureus and MRSA strains. This is the first report on the possible mode of antibacterial action of violet fraction from C. violaceum UTM5 on S. aureus and MRSA strains.

  1. What Is the Origin of Livestock-Associated Methicillin-Resistant Staphylococcus aureus Clonal Complex 398 Isolates from Humans without Livestock Contact? An Epidemiological and Genetic Analysis.

    PubMed

    Lekkerkerk, W S N; van Wamel, W J B; Snijders, S V; Willems, R J; van Duijkeren, E; Broens, E M; Wagenaar, J A; Lindsay, J A; Vos, M C

    2015-06-01

    Fifteen percent of all methicillin-resistant Staphylococcus aureus (MRSA) clonal complex 398 (CC398) human carriers detected in The Netherlands had not been in direct contact with pigs or veal calves. To ensure low MRSA prevalence, it is important to investigate the likely origin of this MRSA of unknown origin (MUO). Recently, it was shown that CC398 strains originating from humans and animals differ in the presence of specific mobile genetic elements (MGEs). We hypothesized that determining these specific MGEs in MUO isolates and comparing them with a set of CC398 isolates of various known origin might provide clues to their origin. MUO CC398 isolates were compared to MRSA CC398 isolates obtained from humans with known risk factors, a MRSA CC398 outbreak isolate, livestock associated (LA) MRSA CC398 isolates from pigs, horses, chickens, and veal calves, and five methicillin-susceptible Staphylococcus aureus (MSSA) CC398 isolates of known human origin. All strains were spa typed, and the presence or absence of, scn, chp, φ3 int, φ6 int, φ7 int, rep7, rep27, and cadDX was determined by PCRs. The MRSA CC398 in humans, MUO, or MRSA of known origin (MKO) resembled MRSA CC398 as found in pigs and not MSSA CC398 as found in humans. The distinct human MSSA CC398 spa type, t571, was not present among our MRSA CC398 strains; MRSA CC398 was tetracycline resistant and carried no φ3 bacteriophage with scn and chp. We showed by simple PCR means that human MUO CC398 carriers carried MRSA from livestock origin, suggestive of indirect transmission. Although the exact transmission route remains unknown, direct human-to-human transmission remains a possibility as well. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  2. Fluoroquinolone use and methicillin-resistant Staphylococcus aureus isolation rates in hospitalized patients: a quasi experimental study.

    PubMed

    Charbonneau, Pierre; Parienti, Jean-Jacques; Thibon, Pascal; Ramakers, Michel; Daubin, Cédric; du Cheyron, Damien; Lebouvier, Guy; Le Coutour, Xavier; Leclercq, Roland

    2006-03-15

    We investigated the possible association between fluoroquinolone use and the rate of methicillin-resistant Staphylococcus aureus (MRSA) recovery from consecutive hospitalized patients. We conducted a nonrandomized, prospective, controlled interventional "fluoroquinolone-free" study at 4 large teaching hospitals in northwest France, catering to a total of 5,882,600 persons. During the intervention period (January through December 2001), fluoroquinolone use was prohibited at 1 of the 4 hospitals (Caen Hospital), unless no effective alternative was available. Three university hospitals were used as controls because they had similar preintervention rates of MRSA. During the intervention period (2001), the annual rate of fluoroquinolone use decreased from 54 to 5 defined daily doses per 1000 patients per day at Caen Hospital and remained stable in the control hospitals. At the end of the intervention, the rate of MRSA isolation was significantly lower at Caen Hospital than at the control hospitals (353 [32.3%] of 1093 S. aureus isolates were MRSA, compared with 2495 [36.8%] of 6787 isolates; odds ratio, 0.82; 95% confidence interval, 0.69-0.99; P=.036), as determined on the basis of a marginal model that took into account within-hospital clustering. In a before-after time series analysis, compared with forecasted rates, there was a significant downward trend in observed monthly rates of MRSA isolation at Caen Hospital at the end of the intervention. This quasi experimental study confirms the association between fluoroquinolone use and MRSA isolation among hospitalized patients.

  3. Detection of Methicillin Resistance and Various Virulence Factors in Staphylococcus aureus Strains Isolated from Nasal Carriers

    PubMed Central

    Dağı, Hatice Türk; Fındık, Duygu; Demirel, Gamze; Arslan, Uğur

    2015-01-01

    Background: Staphylococus aureus can be found as a commensal on skin and nasal flora or it may cause local and invasive infections. S. aureus has a large number of virulence factors. Aims: To investigate the methicillin resistance and frequency of various virulence factors in S. aureus nasal isolates. Study Design: Descriptive study. Methods: Nasal samples collected from university students were cultured in media. S. aureus was identified by conventional methods and the Staphyloslide latex test (Becton Dickinson, Sparks, USA). Antibiotic susceptibility tests were conducted, and the methicillin resistance was determined. The mecA, nuc, pvl and staphylococcal toxin genes were examined by polymerase chain reaction (PCR). Results: S. aureus was isolated in 104 of 600 (17.3%) nasal samples. In total, 101 (97.1%) S. aureus isolates were methicillin-sensitive and the remaining 3 (2.9%) were methicillin-resistant. Furthermore, all but five isolates carried at least one staphylococcal enterotoxin gene, with seg being predominant. The tst and eta genes were determined in 29 (27.9%), and 3 (2.9%) isolates, respectively. None of the S. aureus isolates harbored see, etb, and pvl genes. Conclusion: A moderate rate of S. aureus carriage and low frequency of MRSA were detected in healthy students. S. aureus isolates had a high prevalence of staphylococcal enterotoxin genes and the tst gene. In this study, a large number of virulence factors were examined in S. aureus nasal isolates, and the data obtained from this study can be used for monitoring the prevalence of virulence genes in S. aureus strains isolated from nasal carriers. PMID:26167341

  4. Identification of a methicillin-resistant Staphylococcus aureus inhibitory compound isolated from Serratia marcescens

    PubMed Central

    Kadouri, Daniel E.; Shanks, Robert M.Q.

    2013-01-01

    In this study, we identified an antimicrobial compound produced by the Gram-negative bacterium Serratia marcescens. Colonies of S. marcescens inhibited the growth of nine different methicillin-resistant Staphylococcus aureus (MRSA) isolates and several other tested Gram-positive bacterial species, but not Gram-negative bacteria. Genetic analysis revealed the requirement for the swrW gene which codes for a non-ribosomal peptide synthetase that generates the cyclodepsipeptide antibiotic serratamolide, also known as serrawettin W1. This is the first report describing the anti-MRSA properties of serratamolide. PMID:23791620

  5. Prevalence, antimicrobial susceptibility and molecular typing of Methicillin-Resistant Staphylococcus aureus (MRSA) in bulk tank milk from southern Italy.

    PubMed

    Parisi, A; Caruso, M; Normanno, G; Latorre, L; Sottili, R; Miccolupo, A; Fraccalvieri, R; Santagada, G

    2016-09-01

    This paper assesses the prevalence of MRSA in bulk tank milk (BTM) samples from southern Italy, and the relationship between the Coagulase Positive Staphylococci count (CPS) and MRSA prevalence. Of 486 BTM samples tested, 12 samples (2.5%) resulted positive for the presence of MRSA. Great genetic diversity was found among the isolates: ST1/t127 and t174/IVa, ST5/t688/V, ST8/t unknown/IVa/V, ST45/t015/IVa, ST71/t524/V, ST88/t786/Iva, ST398/t011 and t899/IVa/V and ST2781/t1730/V. All isolates were pvl-negative and icaA positive. The majority of strains (58%) carried the ses (sec, seh, seg, seo, sem and sen) genes. All tested strains resulted susceptible to amikacin, cephalotin, cloramphenicol, gentamycin, trimethoprim - sulfamethoxazole, tobramycin and vancomycin, and variably resistant to ampicillin, oxacillin and tetracycline. No statistical association between the CPS count and MRSA detection was found in the MRSA-positive samples. Although some of the spa-types and STs detected in our survey are known to cause human infections, raw milk from Italian herds in the considered area is not a common source of MRSA. Nonetheless, it is necessary to assess the risk of foodborne infection and the risk related to the handling of milk. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Staphylococcal Cassette Chromosome mec and Panton-Valentine Leukocidin Characterization of Methicillin-Resistant Staphylococcus aureus Clones▿

    PubMed Central

    Moroney, Shannon M.; Heller, Loree C.; Arbuckle, Jesse; Talavera, Monica; Widen, Ray H.

    2007-01-01

    Staphylococcal cassette chromosome mec (SCCmec) types and Panton-Valentine leukocidin (PVL) gene carriage were compared among suspected community-associated methicillin-resistant Staphylococcus aureus MRSA (CA-MRSA) and health care-associated MRSA (HA-MRSA) isolates. CA-MRSA isolates carried the SCCmec type IV complex, and most were PVL positive. The HA-MRSA isolates carried the SCCmec type II complex and did not harbor the PVL genes. PMID:17192420

  7. Why tackling MRSA needs a comprehensive approach.

    PubMed

    Fairclough, Sarah J

    Methicillin-resistant Staphylococcus aureus (MRSA) causes a fifth of hospital-acquired infections and many other bacteria now show increased resistance to antibacterials. In some parts of the world, community-associated MRSA infections cause a growing number of infections (Fridkin et al, 2005). Attempts to control the spread of MRSA rely on several factors: detecting and isolating infected or colonized patients (cordon sanitaire), rational antibiotic prescribing, hand hygiene and cleanliness. Nurses are key to implementing all of these measures. This article examines the epidemiology of MRSA, as exemplifying an antibiotic-resistant bacterium, and reviews the evidence for the various interventions. A single measure alone is unlikely to eradicate MRSA from either hospitals or the community; indeed, eradicating MRSA is probably impossible. However, a comprehensive approach, including, in particular, good hand hygiene, could reduce the morbidity and mortality arising from MRSA and other hospital-acquired infections.

  8. High Rate of qacA- and qacB-Positive Methicillin-Resistant Staphylococcus aureus Isolates from Chlorhexidine-Impregnated Catheter-Related Bloodstream Infections

    PubMed Central

    Ho, Cheng-Mao; Li, Chi-Yuan; Ho, Mao-Wang; Lin, Chien-Yu; Liu, Shu-Hui

    2012-01-01

    Chlorhexidine has been widely used for infection control. Although the use of chlorhexidine-impregnated catheters has reduced catheter-related infections, chlorhexidine-resistant Staphylococcus aureus has emerged. The correlation between the existence of the chlorhexidine-resistant genes qacA and qacB (qacA/B) in methicillin-resistant Staphylococcus aureus (MRSA) isolates and the effectiveness of chlorhexidine-impregnated catheters in the prevention of MRSA infections is unknown. Sixty methicillin-sensitive Staphylococcus aureus (MSSA) and 96 MRSA isolates from the blood cultures of different patients were collected, and a case-control study was conducted to determine whether more clinical S. aureus isolates from chlorhexidine-impregnated catheter-related bloodstream infections (CRBSI) have the biocide-resistant genes (qacA/B or smr) than those from other infections. The chlorhexidine MIC50s of MSSA and MRSA isolates were 1 μg/ml and 2 μg/ml, respectively. Results of PCR analyses showed that 3.3% (n = 2) of MSSA and 43.8% (n = 42) of MRSA isolates harbored qacA/B and 5% (n = 3) of MSSA and 25% (n = 24) of MRSA isolates contained smr. With multivariate logistic regression analyses, the significant risk factors for definite CRBSI with chlorhexidine-impregnated catheters were determined to be S. aureus isolates with qacA/B and a chlorhexidine MIC of ≥2 μg/ml (odds ratios [OR], 9.264 and 8.137, respectively, in all 156 S. aureus isolates and 6.097 and 4.373, respectively, in the 96 MRSA isolates). Further prospective studies are needed to investigate the transmission of these biocide-resistant genes. PMID:22908163

  9. [Prevention strategies for methicillin-resistant Staphylococcus aureus (MRSA) infections in Latin America].

    PubMed

    Alvarez, Carlos; Labarca, Jaime; Salles, Mauro

    2010-08-01

    After the first reports of the emergence of MRSA in the 1970s, numerous measures intended to prevent its transmission were initiated in hospitals. However, in most cases, large-scale measures failed to be implemented and the transmission of MRSA has since led to a global pandemic. Presently, doubts still remain about the best approach to prevent and control MRSA and more often than not, control measures are not implemented. Therefore, we review here the current situation in Latin America with respect to existing policies for control of MRSA, and evaluate the evidence for control measures in hospitals and the community. We look at the risk factors for infection and transmission of MRSA between hospital patients and within specific populations in the community, and at the effect of antibiotic usage on the spread of MRSA in these settings. Finally, we summarize recommendations for the prevention and control of MRSA, which can be applied to the Latin American hospital environment and community setting.

  10. Emerging ST121/agr4 community-associated methicillin-resistant Staphylococcus aureus (MRSA) with strong adhesin and cytolytic activities: trigger for MRSA pneumonia and fatal aspiration pneumonia in an influenza-infected elderly.

    PubMed

    Wan, T-W; Tomita, Y; Saita, N; Konno, K; Iwao, Y; Hung, W-C; Teng, L-J; Yamamoto, T

    2016-09-01

    The pathogenesis of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) pneumonia in influenza-infected elderly individuals has not yet been elucidated in detail. In the present study, a 92-year-old man infected with influenza developed CA-MRSA pneumonia. His CA-MRSA was an emerging type, originated in ST121/agr4 S. aureus, with diversities of Panton-Valentine leucocidin (PVL)(-)/spat5110/SCCmecV(+) versus PVL(+)/spat159((etc.))/SCCmec (-), but with common virulence potentials of strong adhesin and cytolytic activities. Resistance to erythromycin/clindamycin (inducible-type) and gentamicin was detected. Pneumonia improved with the administration of levofloxacin, but with the subsequent development of fatal aspiration pneumonia. Hence, characteristic CA-MRSA with strong adhesin and cytolytic activities triggered influenza-related sequential complications.

  11. Rapid and high-resolution distinction of community-acquired and nosocomial Staphylococcus aureus isolates with identical pulsed-field gel electrophoresis patterns and spa types.

    PubMed

    Glasner, Corinna; Sabat, Artur J; Dreisbach, Annette; Larsen, Anders R; Friedrich, Alexander W; Skov, Robert L; van Dijl, Jan Maarten

    2013-03-01

    Methicillin-resistant Staphylococcus aureus (MRSA) represent a serious threat for public health worldwide. Of particular concern is the emergence of community-acquired MRSA, which is often difficult to distinguish from nosocomial MRSA due to a lack of suitable typing methods for early detection. For example, the USA300 pulsed-field gel electrophoresis (PFGE) pattern includes both the 'classical' community-acquired USA300 clone with spa type t008 and an epidemiologically unrelated nosocomial clone with spa type t024. Likewise, spa typing cannot distinguish the classic USA300 from nosocomial MRSA with the spa type t008. Since the fast and high-resolution distinction of these S. aureus types is important for infection prevention and surveillance, we investigated whether multiple-locus variable number tandem repeat fingerprinting (MLVF) can be applied to overcome these limitations. Indeed, MLVF correctly grouped 91 MRSA isolates belonging to the classic USA300 lineage, nosocomial MRSA isolates with the USA300 PFGE profile and spa type t024, and nosocomial MRSA isolates with spa type t008 into 3 distinct clusters. Importantly, several sub-clusters were also identified, reflecting epidemiological relationships between the respective isolates. We conclude that MLVF has the discriminatory power needed to rapidly distinguish very similar community-acquired and nosocomial MRSA isolates and that MLVF-based sub-clustering of isolates is highly useful for epidemiological investigations, outbreak prevention, and control. Copyright © 2012 Elsevier GmbH. All rights reserved.

  12. Bio-inspired synthesis yields a tricyclic indoline that selectively resensitizes methicillin-resistant Staphylococcus aureus (MRSA) to β-lactam antibiotics

    PubMed Central

    Podoll, Jessica D.; Liu, Yongxiang; Chang, Le; Walls, Shane; Wang, Wei; Wang, Xiang

    2013-01-01

    The continuous emergence of resistant bacteria has become a major worldwide health threat. The current development of new antibacterials has lagged far behind. To discover reagents to fight against resistant bacteria, we initiated a chemical approach by synthesizing and screening a small molecule library, reminiscent of the polycyclic indole alkaloids. Indole alkaloids are a class of structurally diverse natural products, many of which were isolated from plants that have been used as traditional medicine for millennia. Specifically, we adapted an evolutionarily conserved biosynthetic strategy and developed a concise and unified diversity synthesis pathway. Using this pathway, we synthesized 120 polycyclic indolines that contain 26 distinct skeletons and a wide variety of functional groups. A tricyclic indoline, Of1, was discovered to selectively potentiate the activity of β-lactam antibiotics in multidrug-resistant methicillin-resistant Staphylococcus aureus (MRSA), but not in methicillin-sensitive S. aureus. In addition, we found that Of1 itself does not have antiproliferative activity but can resensitize several MRSA strains to the β-lactam antibiotics that are widely used in the clinic, such as an extended-spectrum β-lactam antibiotic amoxicillin/clavulanic acid and a first-generation cephalosporin cefazolin. These data suggest that Of1 is a unique selective resistance-modifying agent for β-lactam antibiotics, and it may be further developed to fight against resistant bacteria in the clinic. PMID:24019472

  13. Clinical MRSA isolates from skin and soft tissue infections show increased in vitro production of phenol soluble modulins

    PubMed Central

    Berlon, Nicholas R.; Qi, Robert; Sharma-Kuinkel, Batu K.; Joo, Hwang-Soo; Park, Lawrence P.; George, Dennis; Thaden, Joshua T.; Messina, Julia A.; Maskarinec, Stacey A.; Mueller-Premru, Manica; Athan, Eugene; Tattevin, Pierre; Pericas, Juan M.; Woods, Christopher W.; Otto, Michael; Fowler, Vance G.

    2016-01-01

    Summary Background Phenol-soluble modulins (PSMs) are amphipathic, pro-inflammatory proteins secreted by most Staphylococcus aureus isolates. This study tested the hypothesis that in vitro PSM production levels are associated with specific clinical phenotypes. Methods 177 methicillin-resistant S. aureus (MRSA) isolates from infective endocarditis (IE), skin and soft tissue infection (SSTI), and hospital-acquired/ventilator-associated pneumonia (HAP) were matched by geographic origin, then genotyped using spa-typing. In vitro PSM production was measured by high performance liquid chromatography/mass spectrometry. Statistical analysis was performed using Chi-squared or Kruskal–Wallis tests as appropriate. Results Spa type 1 was significantly more common in SSTI isolates (62.7% SSTI; 1.7% IE; 16.9% HAP; p < 0.0001) while HAP and IE isolates were more commonly spa type 2 (0% SSTI; 37.3% IE; 40.7% HAP; p < 0.0001). USA300 isolates produced the highest levels of PSMs in vitro. SSTI isolates produced significantly higher quantities of PSMα1-4, PSMβ1, and δ-toxin than other isolates (p < 0.001). These findings persisted when USA300 isolates were excluded from analysis. PMID:26079275

  14. Natural history of colonization with methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE): a systematic review

    PubMed Central

    2014-01-01

    Background No published systematic reviews have assessed the natural history of colonization with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE). Time to clearance of colonization has important implications for patient care and infection control policy. Methods We performed parallel searches in OVID Medline for studies that reported the time to documented clearance of MRSA and VRE colonization in the absence of treatment, published between January 1990 and July 2012. Results For MRSA, we screened 982 articles, identified 16 eligible studies (13 observational studies and 3 randomized controlled trials), for a total of 1,804 non-duplicated subjects. For VRE, we screened 284 articles, identified 13 eligible studies (12 observational studies and 1 randomized controlled trial), for a total of 1,936 non-duplicated subjects. Studies reported varying definitions of clearance of colonization; no study reported time of initial colonization. Studies varied in the frequency of sampling, assays used for sampling, and follow-up period. The median duration of total follow-up was 38 weeks for MRSA and 25 weeks for VRE. Based on pooled analyses, the model-estimated median time to clearance was 88 weeks after documented colonization for MRSA-colonized patients and 26 weeks for VRE-colonized patients. In a secondary analysis, clearance rates for MRSA and VRE were compared by restricting the duration of follow-up for the MRSA studies to the maximum observed time point for VRE studies (43 weeks). With this restriction, the model-fitted median time to documented clearance for MRSA would occur at 41 weeks after documented colonization, demonstrating the sensitivity of the pooled estimate to length of study follow-up. Conclusions Few available studies report the natural history of MRSA and VRE colonization. Lack of a consistent definition of clearance, uncertainty regarding the time of initial colonization, variation in frequency of

  15. Natural history of colonization with methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE): a systematic review.

    PubMed

    Shenoy, Erica S; Paras, Molly L; Noubary, Farzad; Walensky, Rochelle P; Hooper, David C

    2014-03-31

    No published systematic reviews have assessed the natural history of colonization with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE). Time to clearance of colonization has important implications for patient care and infection control policy. We performed parallel searches in OVID Medline for studies that reported the time to documented clearance of MRSA and VRE colonization in the absence of treatment, published between January 1990 and July 2012. For MRSA, we screened 982 articles, identified 16 eligible studies (13 observational studies and 3 randomized controlled trials), for a total of 1,804 non-duplicated subjects. For VRE, we screened 284 articles, identified 13 eligible studies (12 observational studies and 1 randomized controlled trial), for a total of 1,936 non-duplicated subjects. Studies reported varying definitions of clearance of colonization; no study reported time of initial colonization. Studies varied in the frequency of sampling, assays used for sampling, and follow-up period. The median duration of total follow-up was 38 weeks for MRSA and 25 weeks for VRE. Based on pooled analyses, the model-estimated median time to clearance was 88 weeks after documented colonization for MRSA-colonized patients and 26 weeks for VRE-colonized patients. In a secondary analysis, clearance rates for MRSA and VRE were compared by restricting the duration of follow-up for the MRSA studies to the maximum observed time point for VRE studies (43 weeks). With this restriction, the model-fitted median time to documented clearance for MRSA would occur at 41 weeks after documented colonization, demonstrating the sensitivity of the pooled estimate to length of study follow-up. Few available studies report the natural history of MRSA and VRE colonization. Lack of a consistent definition of clearance, uncertainty regarding the time of initial colonization, variation in frequency of sampling for persistent colonization

  16. Identification of livestock-associated methicillin-resistant Staphylococcus aureus isolates in Korea and molecular comparison between isolates from animal carcasses and slaughterhouse workers.

    PubMed

    Moon, Dong Chan; Tamang, Migma Dorji; Nam, Hyang-Mi; Jeong, Jin-Ha; Jang, Geum-Chan; Jung, Suk-Chan; Park, Yong-Ho; Lim, Suk-Kyung

    2015-04-01

    This study was undertaken to screen methicillin-resistant Staphylococcus aureus (MRSA) in animal carcasses and slaughterhouse workers and characterize MRSA isolates identified during 2010-2012 in Korea. A total of 830 (16.4%) S. aureus and 65 (1.3%) MRSA were isolated from 9669 carcass samples. MRSA was more frequently detected in chicken carcasses (1.2%) than in cattle (0.3%) and pig carcasses (0.6%). The prevalence of MRSA in workers was 6.9% (4/58) in chicken slaughterhouse workers, but no MRSA was detected in pig and cattle slaughterhouse workers (0/41). Two different lineages of MRSA were identified (i.e., human-associated type [ST5, ST59, and ST72] and livestock-associated [LA] type [ST398, ST541, and ST692]); only LA MRSA was observed in chicken carcasses, whereas both types were found in cattle and pig carcasses and workers. All human-associated MRSA isolates carried enterotoxin and/or leukotoxin genes, whereas LA MRSA types did not carry these genes, except ST692 type. However, all LA MRSA isolates were multiresistant, whereas human-associated types were susceptible or resistant to fewer than two antimicrobials except ST5. Furthermore, one or more resistance genes were attributed for resistance to aminoglycosides (aac(6')-Ie-aph(2″), ant(4')-Ia, and aph(3')-IIIa), tetracycline [tet(K), tet(L), tet(M), and tet(S)], macrolide-lincosamide-streptogramin B (ermA, ermB, ermC, and ermT), lincosamide [lnu(B)], phenicol-lincosamide-oxazolidinone-pleuromutilin-streptogramin A (cfr), chloramphenicol (fexA), and fusidic acid [fus(C)]. To our knowledge, this is the first report of tet(S) gene in MRSA isolates and first detection of a unique (ST692) type of MRSA in occupational workers. Detection of new types of human-associated and LA MRSA with multiple resistance and virulence genes in food animal products constitutes a potential threat to public health.

  17. Antimicrobial susceptibility pattern of Staphylococcus aureus isolated from clinical specimens in Northern area of Jordan

    PubMed Central

    Al-Zoubi, Mazhar Salim; Al-Tayyar, Ibrahim Ali; Hussein, Emad; Jabali, Alla Al; Khudairat, Salih

    2015-01-01

    Background and Objectives: The global spread of methicillin resistant Staphylococcus aureus (MRSA) constitutes one of the most serious contemporary challenges to the treatment of hospital-acquired infections. We aimed to screen and assess the antibiotic susceptibility pattern of Staphylococcus aureus isolated from clinical specimens in local hospitals of Northern province in Jordan. Materials and Methods: Staphylococcus aureus was isolated and identified using standard methods from various clinical specimens of different infected body sites from 358 patients during the period from January 2008 to November 2012. Results: Our analysis showed that 31.6% of S. aureus infections were MRSA, while 31% were multidrug resistance (MDR) and 42.7% were Oxacillin-resistant (ORSA). Most of these strains were isolated from wound specimens. All isolates were susceptible to vancomycin (100%). They were also susceptible to chloramphenicol, linezolid, nitrofurantoin, rifampicin and teicoplanin (>80%), but showed resistance to erythromycin and penicillin. Conclusion: Vancomycin was the most effective antimicrobial agent against S. aureus. We recommend regular surveillance of hospital associated infections and monitoring antibiotic sensitivity pattern and strict drug policy for antibiotics used within and outside the hospital environments. PMID:26719783

  18. Antimicrobial susceptibility pattern of Staphylococcus aureus isolated from clinical specimens in Northern area of Jordan.

    PubMed

    Al-Zoubi, Mazhar Salim; Al-Tayyar, Ibrahim Ali; Hussein, Emad; Jabali, Alla Al; Khudairat, Salih

    2015-10-01

    The global spread of methicillin resistant Staphylococcus aureus (MRSA) constitutes one of the most serious contemporary challenges to the treatment of hospital-acquired infections. We aimed to screen and assess the antibiotic susceptibility pattern of Staphylococcus aureus isolated from clinical specimens in local hospitals of Northern province in Jordan. Staphylococcus aureus was isolated and identified using standard methods from various clinical specimens of different infected body sites from 358 patients during the period from January 2008 to November 2012. Our analysis showed that 31.6% of S. aureus infections were MRSA, while 31% were multidrug resistance (MDR) and 42.7% were Oxacillin-resistant (ORSA). Most of these strains were isolated from wound specimens. All isolates were susceptible to vancomycin (100%). They were also susceptible to chloramphenicol, linezolid, nitrofurantoin, rifampicin and teicoplanin (>80%), but showed resistance to erythromycin and penicillin. Vancomycin was the most effective antimicrobial agent against S. aureus. We recommend regular surveillance of hospital associated infections and monitoring antibiotic sensitivity pattern and strict drug policy for antibiotics used within and outside the hospital environments.

  19. Methicillin-resistant Staphylococcus aureus isolates with SCCmec type V and spa types t437 or t1081 associated to discordant susceptibility results between oxacillin and cefoxitin, Central Taiwan.

    PubMed

    Ho, Cheng-Mao; Lin, Chien-Yu; Ho, Mao-Wang; Lin, Hsiao-Chuan; Chen, Chao-Jung; Lin, Lee-Chung; Lu, Jang-Jih

    2016-12-01

    Staphylococcus aureus isolates with discordant susceptibility results between oxacillin and cefoxitin obtained using automated microbiology systems are infrequently observed. From April 2013 to December 2014, 1956 methicillin-resistant S. aureus (MRSA) and 1761 methicillin-susceptible S. aureus isolates were obtained from different patients. Forty isolates (1.1% and 2% in case of S. aureus and MRSA, respectively) with discordant susceptibility results (oxacillin susceptible and cefoxitin resistant) and carrying mecA gene were obtained. Except 2 SCCmec type IV isolates, 38 MRSA isolates were all SCCmec type V (VT or non-VT), which were further divided into VT (n=22) and non-VT (n=16). The most common spa type in VT and non-VT isolates were t437 (n=19) and t1081 (n=13), respectively. Only 55% of patients received effective antimicrobial agents; 2 mortalities were not attributable to MRSA infection. Using standard agar dilution, 17 MRSA isolates (0.46% and 0.87% in case of S. aureus and MRSA, respectively) had oxacillin MIC in the susceptible ranges (oxacillin-susceptible MRSA [OS-MRSA]); all carried SCCmec type V (VT, n=8; non-VT, n=9). The most common spa-MLST types of OS-MRSA in VT and non-VT were t437-ST59 (n=4) and t1081-ST45 (n=7), respectively. Concomitant testing by both cefoxitin- and oxacillin-based methods is a practical strategy for OS-MRSA detection in the clinical laboratories. Continuous monitoring of OS-MRSA isolates is necessary to elucidate their impact in clinical infectious diseases.

  20. [Optimization of cluster analysis based on drug resistance profiles of MRSA isolates].

    PubMed

    Tani, Hiroya; Kishi, Takahiko; Gotoh, Minehiro; Yamagishi, Yuka; Mikamo, Hiroshige

    2015-12-01

    We examined 402 methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from clinical specimens in our hospital between November 19, 2010 and December 27, 2011 to evaluate the similarity between cluster analysis of drug susceptibility tests and pulsed-field gel electrophoresis (PFGE). The results showed that the 402 strains tested were classified into 27 PFGE patterns (151 subtypes of patterns). Cluster analyses of drug susceptibility tests with the cut-off distance yielding a similar classification capability showed favorable results--when the MIC method was used, and minimum inhibitory concentration (MIC) values were used directly in the method, the level of agreement with PFGE was 74.2% when 15 drugs were tested. The Unweighted Pair Group Method with Arithmetic mean (UPGMA) method was effective when the cut-off distance was 16. Using the SIR method in which susceptible (S), intermediate (I), and resistant (R) were coded as 0, 2, and 3, respectively, according to the Clinical and Laboratory Standards Institute (CLSI) criteria, the level of agreement with PFGE was 75.9% when the number of drugs tested was 17, the method used for clustering was the UPGMA, and the cut-off distance was 3.6. In addition, to assess the reproducibility of the results, 10 strains were randomly sampled from the overall test and subjected to cluster analysis. This was repeated 100 times under the same conditions. The results indicated good reproducibility of the results, with the level of agreement with PFGE showing a mean of 82.0%, standard deviation of 12.1%, and mode of 90.0% for the MIC method and a mean of 80.0%, standard deviation of 13.4%, and mode of 90.0% for the SIR method. In summary, cluster analysis for drug susceptibility tests is useful for the epidemiological analysis of MRSA.

  1. Prevalence of methicillin-resistant Staphylococcus aureus (MRSA) infection and the molecular characteristics of MRSA bacteraemia over a two-year period in a tertiary teaching hospital in Malaysia.

    PubMed

    Sit, Pik San; Teh, Cindy Shuan Ju; Idris, Nuryana; Sam, I-Ching; Syed Omar, Sharifah Faridah; Sulaiman, Helmi; Thong, Kwai Lin; Kamarulzaman, Adeeba; Ponnampalavanar, Sasheela

    2017-04-13

    Methicillin-resistant Staphylococcus aureus (MRSA) is an established pathogen that causes hospital- and community-acquired infections worldwide. The prevalence rate of MRSA infections were reported to be the highest in Asia. As there is limited epidemiological study being done in Malaysia, this study aimed to determine the prevalence of MRSA infection and the molecular characteristics of MRSA bacteraemia. Two hundred and nine MRSA strains from year 2011 to 2012 were collected from a tertiary teaching hospital in Malaysia. The strains were characterized by antimicrobial susceptibility testing, staphylococcal cassette chromosome mec (SCCmec) typing, detection of Panton-Valentine leukocidin (PVL) gene, multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Patient's demographic and clinical data were collected and correlated with molecular data by statistical analysis. Male gender and patient >50 years of age (p < 0.0001) were significantly associated with the increased risk of MRSA acquisition. Fifty-nine percent of MRSA strains were HA-MRSA that carried SCCmec type II, III, IV and V while 31% were CA-MRSA strains with SCCmec III, IV and V. The prevalence of PVL gene among 2011 MRSA strains was 5.3% and no PVL gene was detected in 2012 MRSA strains. All of the strains were sensitive to vancomycin. However, vancomycin MIC creep phenomenon was demonstrated by the increased number of MRSA strains with MIC ≥1.5 μg/mL (p = 0.008) between 2011 and 2012. Skin disease (p = 0.034) and SCCmec type III (p = 0.0001) were found to be significantly associated with high vancomycin MIC. Forty-four percent of MRSA strains from blood, were further subtyped by MLST and PFGE. Most of the bacteraemia cases were primary bacteraemia and the common comorbidities were diabetes, hypertension and chronic kidney disease. The predominant pulsotype was pulsotype C exhibited by SCCmec III-ST239. This is a first study in Malaysia that reported the occurrence of

  2. Dissemination of multiple MRSA clones among community-associated methicillin-resistant Staphylococcus aureus infections from Japanese children with impetigo.

    PubMed

    Hisata, Ken; Ito, Teruyo; Matsunaga, Nobuaki; Komatsu, Mitsutaka; Jin, Jingxun; Li, Shanshuang; Watanabe, Shinya; Shimizu, Toshiaki; Hiramatsu, Keiichi

    2011-10-01

    The proportion of MRSA strains that cause skin and soft infections has recently increased. In 3 months we have characterized 17 MRSA strains isolated from children with impetigo at a Japanese hospital. Seventeen MRSA strains belonged to 7 clones defined by clonal complex (CC) in MLST genotype and type of SCCmec, which were rarely identified among healthcare-associated MRSA: CC 91-SCCmecIIb (4 strains); CC91-SCCmecIIn (2 strains); CC91-SCCmecIVa (2 strains); CC91-SCCmecV (4 strains); CC88-SCCmecIVg (3 strains); CC1-SCCmecIVc (1 strain); and CC5-SCCmecIVn (1 strain). Although one strain belonged to CC5, which has been commonly identified in healthcare-associated MRSA, it did not carry type II SCCmec, but carried type IV SCCmec. Fourteen of the 17 strains carried exfoliative toxin a or b gene, and none carried Panton-Valentine leukocidine gene. Furthermore, we determined the entire nucleotide sequences of two type V SCCmec elements carried by strains JCSC5952, a CC91 strain, and TSGH17, a Taiwanese CC59 strain. The structure of SCCmecJCSC5952 was more than 99% homologous in nucleotide identity with those of Taiwanese PVL-positive ST59 MRSA strains TSGH17 and PM1, which were designated as type V (5C2&5). Identification of multiple MRSA clones distinct from those disseminating at the hospital suggests that MRSA strains might be emerging in the community from MSSA strains by acquiring SCCmec elements on various occasions. Carriage of the similar type V(5C2&5) SCCmec element by strains of distinct genetic backgrounds, CC91 and CC59, suggested horizontal transfer of the SCCmec element.

  3. Naphthacemycins, novel circumventors of β-lactam resistance in MRSA, produced by Streptomyces sp. KB-3346-5. I. The taxonomy of the producing strain, and the fermentation, isolation and antibacterial activities.

    PubMed

    Fukumoto, Atsushi; Kim, Yong-Pil; Matsumoto, Atsuko; Takahashi, Yoko; Suzuki, Makoto; Onodera, Hideyuki; Tomoda, Hiroshi; Matsui, Hidehito; Hanaki, Hideaki; Iwatsuki, Masato; Ōmura, Satoshi; Shiomi, Kazuro

    2017-05-01

    Screening for circumventors of β-lactam resistance in methicillin-resistant Staphylococcus aureus (MRSA) led us to find 17 novel antibiotics, naphthacemycins A1-A11, B1-B4 and C1-C2. The naphthacemycins were isolated from a cultured broth of Streptomyces sp. KB-3346-5 by repeated silica gel column chromatography and HPLC. Naphthacemycins enhanced imipenem activity 100-500 times against MRSA at 0.5 μg ml(-1), and naphthacemycins A4-A11 themselves showed MIC50 values of 1-4 μg ml(-1) against 22 MRSA strains.

  4. Characterization of clinical strains of MSSA, MRSA and MRSE isolated from skin and soft tissue infections and the antibacterial activity of ZnO nanoparticles.

    PubMed

    Ansari, Mohammad Azam; Khan, Haris M; Khan, Aijaz A; Sultan, Asfia; Azam, Ameer

    2012-04-01

    Staphylococcus aureus, particularly methicillin-resistant S. aureus (MRSA), is an important cause of pyogenic skin and soft tissue infections (SSTIs). MRSA is an important pathogen in the healthcare sector that has neither been eliminated from the hospital nor community environment. In humans, S. aureus causes superficial lesions in the skin and localized abscesses, pyogenic meningitis/encephalitis, osteomyelitis, septic arthritis, invasive endocarditis, pneumonia, urinary tract infections and septicemia. Investigations focused in the search of other alternatives for the treatment of MRSA infections are in progress. Among the range of compounds whose bactericidal activity is being investigated, ZnO nanoparticles (ZnO-NPs) appears most promising new unconventional antibacterial agent that could be helpful to confront this and other drug-resistant bacteria. The aim of present study is to investigate the antibacterial potential of ZnO-NPs against Staphylococcus species isolated from the pus and wounds swab from the patients with skin and soft tissue infections in a tertiary care hospital of north India. ZnO-NPs (≈19.82 nm) synthesized by sol-gel process were characterized using scanning electron microscopy, X-ray diffraction , and Atomic force microscopy. The antibacterial potential was assessed using time-dependent growth inhibition assay, well diffusion test, MIC and MBC test and colony forming units methods. ZnO-NPs inhibited bacterial growth of methicillin-sensitive S. aureus (MSSA), MRSA and methicillin-resistant S. epidermidis (MRSE) strains and were effective bactericidal agents that were not affected by drug-resistant mechanisms of MRSA and MRSE.

  5. One-year experience with modified BD GeneOhm MRSA assay for detection of methicillin-resistant Staphylococcus aureus from pooled nasal, skin, and throat samples.

    PubMed

    Svent-Kucina, Natasa; Pirs, Mateja; Mueller-Premru, Manica; Cvitkovic-Spik, Vesna; Kofol, Romina; Seme, Katja

    2009-02-01

    We report our 1-year experience with modified GeneOhm MRSA assay (formerly IDI-MRSA) for pooled surveillance specimens in low methicillin-resistant Staphylococcus aureus (MRSA) prevalence clinical setting. We have successfully modified the GeneOhm MRSA assay protocol during the specimen preparation step by adding an extra washing step followed by pooling of up to 3 samples per patient (nose, skin, with or without throat) at the lysis step. The sensitivity of the modified assay compared with conventional cultivation was 94.3%, specificity 99.2%, negative predictive value 99.2%, and positive predictive value 94.3%. The modified test is reliable and performed well compared with conventional culture methods in our clinical setting with low-level prevalence of MRSA colonization. Our findings support the use of pooling of the patients samples as a cost-effective way of screening for MRSA colonization.

  6. Diversity of Methicillin-Resistant Staphylococcus aureus Strains Isolated from Residents of 26 Nursing Homes in Orange County, California

    PubMed Central

    Hudson, Lyndsey O.; Reynolds, Courtney; Spratt, Brian G.; Enright, Mark C.; Quan, Victor; Kim, Diane; Hannah, Paul; Mikhail, Lydia; Alexander, Richard; Moore, Douglas F.; Godoy, Daniel; Bishop, Cynthia J.

    2013-01-01

    Nursing homes represent a unique and important methicillin-resistant Staphylococcus aureus (MRSA) reservoir. Not only are strains imported from hospitals and the community, strains can be transported back into these settings from nursing homes. Since MRSA bacteria are prevalent in nursing homes and yet relatively poorly studied in this setting, a multicenter, regional assessment of the frequency and diversity of MRSA in the nursing home reservoir was carried out and compared to that of the MRSA from hospitals in the same region. The prospective study collected MRSA from nasal swabbing of residents of 26 nursing homes in Orange County, California, and characterized each isolate by spa typing. A total of 837 MRSA isolates were collected from the nursing homes. Estimates of admission prevalence and point prevalence of MRSA were 16% and 26%, respectively. The spa type genetic diversity was heterogeneous between nursing homes and significantly higher overall (77%) than the diversity in Orange County hospitals (72%). MRSA burden in nursing homes appears largely due to importation from hospitals. As seen in Orange County hospitals, USA300 (sequence type 8 [ST8]/t008), USA100 (ST5/t002), and a USA100 variant (ST5/t242) were the dominant MRSA clones in Orange County nursing homes, representing 83% of all isolates, although the USA100 variant was predominant in nursing homes, whereas USA300 was predominant in hospitals. Control strategies tailored to the complex problem of MRSA transmission and infection in nursing homes are needed in order to minimize the impact of this unique reservoir on the overall regional MRSA burden. PMID:24025901

  7. Occurrence, Virulence Factors, Antimicrobial Resistance, and Genotyping of Staphylococcus aureus Strains Isolated from Chicken Products and Humans.

    PubMed

    El Bayomi, Rasha M; Ahmed, Heba A; Awadallah, Maysa A I; Mohsen, Rasha A; Abd El-Ghafar, Abeer E; Abdelrahman, Mahmoud A

    2016-03-01

    Staphylococcus aureus in food is a consequence of inadequate hygienic handling and processing, posing a potential risk to public health. The current study aimed to characterize virulence factors, as well as antimicrobial resistance of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) isolated from retail chicken products and hand swabs from vendors in Egypt. In addition, genetic relatedness of the isolates from chicken and humans was evaluated by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using protein A as a target. A total of 110 samples were collected from chicken products (n = 80) and vendors (n = 30). Overall, 30 (37.5%) chicken products samples were positive for S. aureus, whereas hand swabs from meat handlers revealed that 18 (60%) were positive. Ten MRSA strains were characterized by the presence of the mecA gene, comprising seven isolates from chicken and three from humans. Virulence-associated factors were evaluated by PCR, revealing that 31.3% of S. aureus isolates harbored the Panton-Valentine leukocidin (PVL) gene, whereas 10.4% were positive for the sea and sed genes each, and only two isolates were positive for γ-hemolysin-associated gene. Genotyping using spa PCR-RFLP showed identical restriction banding patterns of MRSA isolates of human and chicken meat origin, indicating the genetic relatedness of the isolates. To the best of our knowledge, this is the first study to characterize PVL-positive MRSA from chicken products and to utilize spa-RFLP for evaluating the genetic relatedness between MRSA of human and chicken origin in Egypt.

  8. Susceptibility profile of methicillin-resistant Staphylococcus aureus to linezolid in clinical isolates

    PubMed Central

    Shariq, Ali; Tanvir, Syed Bilal; Zaman, Atif; Khan, Salman; Anis, Armeena; Khan, Misha Aftab; Ahmed, Sumaira

    2017-01-01

    Objective: To determine the resistance and sensitivity pattern of methicillin-resistant Staphylococcus aureus (MRSA) isolates to linezolid (LZD) along with its prevalence in a tertiary care hospital of Karachi, Pakistan. Materials and Methods: A cross-sectional study was carried out. This study lasted for about 1 year. Prevalence and sensitivity of LZD, vancomycin, and oxacillin was tested against isolates of MRSA. Results: Out of total 369 specimens 165 were found to be MRSA making the prevalence in our study 44.7%. All of the isolates which were tested positive for MRSA were susceptible to LZD and no resistance was noted when compared with previous studies performed in Europe and USA. Conclusion: Stringent implementation of infection control measures along with screening for resistance in patients on prolonged LZD therapy or who previously went under LZD therapy should be performed, coupled with judicious usage of the aforementioned antibiotic should be undertaken, as sufficient data is not available at this point for the clinical spectrum of LZD resistant S. aureus, antimicrobial resistance. PMID:28293153

  9. Molecular Characterization of Community-Associated Methicillin-Resistant Staphylococcus aureus Isolated from Skin and Pus Samples of Outpatients in Japan.

    PubMed

    Yamaguchi, Tetsuo; Okamura, Sakiko; Miura, Yuri; Koyama, Shinobu; Yanagisawa, Hideji; Matsumoto, Tetsuya

    2015-08-01

    Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is now endemic in the United States. In Japan, CA-MRSA infections and CA-MRSA surveillance have been scarcely reported. In this study, we conducted a nationwide survey of CA-MRSA in Japan. We collected MRSA strains isolated from outpatients with skin and soft-tissue infection (SSTI) at 107 medical facilities from 24 prefectures in 2010 and 2012. Among 10,385 clinical samples from SSTI patients, 3,581 S. aureus isolates (35%) were obtained and 673 of the S. aureus strains (19%) were identified as MRSA. Among 625 MRSA strains tested in this study, 266 strains (43%) and 114 strains (18%) were classified as SCCmec types IV and V, respectively. Detection of virulence genes was as follows: Panton-Valentine leukocidin (PVL) gene (57 strains, 9%), exfoliative toxin (ET) gene (179 strains, 29%), toxic shock syndrome toxin-1 (TSST-1) gene (195 strains, 31%), or none. PVL-positive strains were classified into eight sequence types (STs) (i.e., ST1, ST5, ST8, ST22, ST30, ST452, ST59, and ST154) and six clonal complexes (i.e., CC1, CC5, CC8, CC22, CC30, and CC59). Only 10 PVL-positive strains (2%) were pulsed-field type USA300 clone. There were a wide variety of CA-MRSA clones in Japan, which were different from the situation in the United States.

  10. Efficacy of Caltropis procera and Ficus sycomorus extracts in treating MRSA (methicillin-resistant Staphylococcus aureus)-keratitis in rabbit

    PubMed Central

    Sayed, Waiel F.; Salem, Wesam M. A.; Haridy, Mohie A. M.; Hassan, Ne'mat H.

    2015-01-01

    MRSA-induced keratitis in rabbit was used to evaluate the therapeutic effect of F. sycomorus leaves and C. procera latex extracts. Within the 6 rabbit groups tested, group 1 received sterilized saline, while other groups (2 to 6) received 100 μl of intrastromal injections of 1.5×103 colony forming unit (cfu) ml-1 of methicillin-resistant Staphylococcus aureus (MRSA). After 12 hours, groups 3 to 6 also received chloramphenicol, aqueous extract of C. procera latex, aqueous and alcoholic extracts of F. sycomorus leaves, respectively 3 times daily for 12 successive days. The tested extracts inhibited MRSA growth in vitro (i.e. on culture medium). Colony counts in cornea discs from groups 3 to 6 were significantly reduced (P ≤ 0.001) compared to group 2 (untreated). Clinical signs of keratitis were observed on group 2 until the end of experiment. In groups 3 to 6, gradual recovery was observed and signs disappeared by the 12th DPI (days post inoculation). Only mild symptoms persisted in group 5 (aqueous extract of leaves). In group 3 and 5, cornea, iris, ciliary body and conjunctiva showed mild leukocytic infiltration and depigmentation of melanin cells while recovery of cornea and iris was observed in groups 4 and 6. In conclusion, the used extracts have potential therapeutic effects on MRSA-induced keratitis in rabbit. PMID:26648824

  11. Antimicrobial Agent of Susceptibilities and Antiseptic Resistance Gene Distribution among Methicillin-Resistant Staphylococcus aureus Isolates from Patients with Impetigo and Staphylococcal Scalded Skin Syndrome

    PubMed Central

    Noguchi, Norihisa; Nakaminami, Hidemasa; Nishijima, Setsuko; Kurokawa, Ichiro; So, Hiromu; Sasatsu, Masanori

    2006-01-01

    The susceptibilities to antimicrobial agents of and distributions of antiseptic resistance genes in methicillin-resistant Staphylococcus aureus (MRSA) strains isolated between 1999 and 2004 in Japan were examined. The data of MRSA strains that are causative agents of impetigo and staphylococcal scalded skin syndrome (SSSS) were compared with those of MRSA strains isolated from patients with other diseases. The susceptibilities to antiseptic agents in MRSA isolates from patients with impetigo and SSSS were higher than those in MRSA isolates from patients with other diseases. The distribution of the qacA/B genes in MRSA strains isolated from patients with impetigo and SSSS (1.3%, 1/76) was remarkably lower than that in MRSA strains isolated from patients with other diseases (45.9%, 95/207). Epidemiologic typings of staphylococcal cassette chromosome mec (SCCmec) and pulsed-field gel electrophoresis (PFGE) showed that MRSA strains isolated from patients with impetigo and SSSS had type IV SCCmec (75/76), except for one strain, and 64.5% (49/76) of the strains had different PFGE types. In addition, the patterns of restriction digestion of all tested qacA/B plasmid in MRSA isolates having different PFGE types were identical. The results showed that a specific MRSA clone carrying qacA/B was not prevalent, but qacA/B was spread among health care-associated MRSA strains. Therefore, it was concluded that the lower distribution rate of qacA/B resulted in higher susceptibilities to cationic antiseptic agents in MRSA isolated from patients with impetigo and SSSS. PMID:16757607

  12. Antimicrobial agent of susceptibilities and antiseptic resistance gene distribution among methicillin-resistant Staphylococcus aureus isolates from patients with impetigo and staphylococcal scalded skin syndrome.

    PubMed

    Noguchi, Norihisa; Nakaminami, Hidemasa; Nishijima, Setsuko; Kurokawa, Ichiro; So, Hiromu; Sasatsu, Masanori

    2006-06-01

    The susceptibilities to antimicrobial agents of and distributions of antiseptic resistance genes in methicillin-resistant Staphylococcus aureus (MRSA) strains isolated between 1999 and 2004 in Japan were examined. The data of MRSA strains that are causative agents of impetigo and staphylococcal scalded skin syndrome (SSSS) were compared with those of MRSA strains isolated from patients with other diseases. The susceptibilities to antiseptic agents in MRSA isolates from patients with impetigo and SSSS were higher than those in MRSA isolates from patients with other diseases. The distribution of the qacA/B genes in MRSA strains isolated from patients with impetigo and SSSS (1.3%, 1/76) was remarkably lower than that in MRSA strains isolated from patients with other diseases (45.9%, 95/207). Epidemiologic typings of staphylococcal cassette chromosome mec (SCCmec) and pulsed-field gel electrophoresis (PFGE) showed that MRSA strains isolated from patients with impetigo and SSSS had type IV SCCmec (75/76), except for one strain, and 64.5% (49/76) of the strains had different PFGE types. In addition, the patterns of restriction digestion of all tested qacA/B plasmid in MRSA isolates having different PFGE types were identical. The results showed that a specific MRSA clone carrying qacA/B was not prevalent, but qacA/B was spread among health care-associated MRSA strains. Therefore, it was concluded that the lower distribution rate of qacA/B resulted in higher susceptibilities to cationic antiseptic agents in MRSA isolated from patients with impetigo and SSSS.

  13. Meticillin-resistant Staphylococcus aureus isolated from foot ulcers in diabetic patients in a Chinese care hospital: risk factors for infection and prevalence.

    PubMed

    Wang, Shao-Hua; Sun, Zi-Lin; Guo, Yi-Jing; Yang, Bing-Quan; Yuan, Yang; Wei, Qiong; Ye, Kuan-Ping

    2010-10-01

    A retrospective case-control study of 118 (male : female, 68 : 50) Chinese type 2 diabetic patients with foot ulcers (Wagner's grade 3-5) was conducted to determine the prevalence and risk factors for meticillin-resistant Staphylococcus aureus (MRSA) infection in relation to the original community or hospital parameters. Ulcer specimens were processed for Gram staining, aerobic culture and antimicrobial susceptibility testing. Staphylococcus species were tested for meticillin resistance using oxacillin. S. aureus was the most frequent pathogen (25.6 %) in diabetic patient specimens (160 isolates), and a high proportion of S. aureus isolates were MRSA (63.4 %). A high percentage of S. aureus isolates (65.4 %) satisfied the definition for hospital-associated MRSA (HA-MRSA) infection. The size of ulcers [adjusted odds ratio (OR) 1.61; 95 % confidence interval (CI) 1.22-2.12] and osteomyelitis (adjusted OR 18.51, 95 % CI 2.50-137.21) were independent predictors of MRSA infection. The HA-MRSA group had a significantly different distribution from the community-associated MRSA group with respect to age, history of diabetes and length of hospital stay (all P<0.001). Neuropathy, vascular disease (all P=0.049) and osteomyelitis (P=0.026) were the most common underlying conditions observed in the HA-MRSA group. This study contributes to the establishment of precautions against the emergence of MRSA including MRSA acquired from different sources among the Chinese population with diabetic foot ulcers based on their original or clinical parameters.

  14. Trends in Staphylococcus aureus bacteraemia and impacts of infection control practices including universal MRSA admission screening in a hospital in Scotland, 2006–2010: retrospective cohort study and time-series intervention analysis

    PubMed Central

    Edwards, Becky; López-Lozano, José-Maria; Gould, Ian

    2012-01-01

    Objectives To describe secular trends in Staphylococcus aureus bacteraemia (SAB) and to assess the impacts of infection control practices, including universal methicillin-resistant Staphylococcus aureus (MRSA) admission screening on associated clinical burdens. Design Retrospective cohort study and multivariate time-series analysis linking microbiology, patient management and health intelligence databases. Setting Teaching hospital in North East Scotland. Participants All patients admitted to Aberdeen Royal Infirmary between 1 January 2006 and 31 December 2010: n=420 452 admissions and 1 430 052 acute occupied bed days (AOBDs). Intervention Universal admission screening programme for MRSA (August 2008) incorporating isolation and decolonisation. Primary and secondary measures Hospital-wide prevalence density, hospital-associated incidence density and death within 30 days of MRSA or methicillin-sensitive Staphylococcus aureus (MSSA) bacteraemia. Results Between 2006 and 2010, prevalence density of all SAB declined by 41%, from 0.73 to 0.50 cases/1000 AOBDs (p=0.002 for trend), and 30-day mortality from 26% to 14% (p=0.013). Significant reductions were observed in MRSA bacteraemia only. Overnight admissions screened for MRSA rose from 43% during selective screening to >90% within 4 months of universal screening. In multivariate time-series analysis (R2 0.45 to 0.68), universal screening was associated with a 19% reduction in prevalence density of MRSA bacteraemia (−0.035, 95% CI −0.049 to −0.021/1000 AOBDs; p<0.001), a 29% fall in hospital-associated incidence density (−0.029, 95% CI −0.035 to −0.023/1000 AOBDs; p<0.001) and a 46% reduction in 30-day mortality (−15.6, 95% CI −24.1% to −7.1%; p<0.001). Positive associations with fluoroquinolone and cephalosporin use suggested that antibiotic stewardship reduced prevalence density of MRSA bacteraemia by 0.027 (95% CI 0.015 to 0.039)/1000 AOBDs. Rates of MSSA bacteraemia were not

  15. Trends in Staphylococcus aureus bacteraemia and impacts of infection control practices including universal MRSA admission screening in a hospital in Scotland, 2006-2010: retrospective cohort study and time-series intervention analysis.

    PubMed

    Lawes, Timothy; Edwards, Becky; López-Lozano, José-Maria; Gould, Ian

    2012-01-01

    To describe secular trends in Staphylococcus aureus bacteraemia (SAB) and to assess the impacts of infection control practices, including universal methicillin-resistant Staphylococcus aureus (MRSA) admission screening on associated clinical burdens. Retrospective cohort study and multivariate time-series analysis linking microbiology, patient management and health intelligence databases. Teaching hospital in North East Scotland. All patients admitted to Aberdeen Royal Infirmary between 1 January 2006 and 31 December 2010: n=420 452 admissions and 1 430 052 acute occupied bed days (AOBDs). Universal admission screening programme for MRSA (August 2008) incorporating isolation and decolonisation. PRIMARY AND SECONDARY MEASURES: Hospital-wide prevalence density, hospital-associated incidence density and death within 30 days of MRSA or methicillin-sensitive Staphylococcus aureus (MSSA) bacteraemia. Between 2006 and 2010, prevalence density of all SAB declined by 41%, from 0.73 to 0.50 cases/1000 AOBDs (p=0.002 for trend), and 30-day mortality from 26% to 14% (p=0.013). Significant reductions were observed in MRSA bacteraemia only. Overnight admissions screened for MRSA rose from 43% during selective screening to >90% within 4 months of universal screening. In multivariate time-series analysis (R(2) 0.45 to 0.68), universal screening was associated with a 19% reduction in prevalence density of MRSA bacteraemia (-0.035, 95% CI -0.049 to -0.021/1000 AOBDs; p<0.001), a 29% fall in hospital-associated incidence density (-0.029, 95% CI -0.035 to -0.023/1000 AOBDs; p<0.001) and a 46% reduction in 30-day mortality (-15.6, 95% CI -24.1% to -7.1%; p<0.001). Positive associations with fluoroquinolone and cephalosporin use suggested that antibiotic stewardship reduced prevalence density of MRSA bacteraemia by 0.027 (95% CI 0.015 to 0.039)/1000 AOBDs. Rates of MSSA bacteraemia were not significantly affected by screening or antibiotic use. Declining clinical burdens from SAB

  16. Characterization of Toxin Genes and Antimicrobial Susceptibility of Staphylococcus aureus Isolates in Fishery Products in Iran

    PubMed Central

    Arfatahery, Noushin; Davoodabadi, Abolfazl; Abedimohtasab, Taranehpeimaneh

    2016-01-01

    Staphylococcus aureus is one of the most common causes of seafood-borne diseases worldwide, which are attributable to the contamination of food by preformed enterotoxins. In this study, a total of 206 (34.3%) Staphylococcus aureus strains were obtained from 600 fish and shrimp samples and were tested for their antimicrobial susceptibility. We assessed the prevalence of the genes responsible for the staphylococcal enterotoxins (SEA, SEB) and toxic shock syndrome toxin 1 (TSST-1) genes. The results indicated that 34% of aqua food samples were contaminated with S. aureus, and 23.8% of these isolates were mec-A-positive. Sixty-four percent of the strains isolated from contaminated seafood was enterotoxigenic S. aureus, and 28.2% of SEs were MRSA-positive. The most prevalent genotype was characterized by the presence of the sea gene (45.2%), followed by the seb gene (18.5%), and the tst gene encoding TSST-1 was found in eight strains (3.9%). Of the 206 S. aureus isolates, 189 strains (84.9%) were resistant to at least one antibiotic. Given the frequent outbreaks of enterotoxigenic MRSA, it is necessary to make revisions to mandatory programmes to facilitate improved hygiene practices during fishing, aquaculture, processing, and sales to prevent the contamination of fishery products in Iran. PMID:27694813

  17. Characteristics of the community-genotype sequence type 72 methicillin-resistant Staphylococcus aureus isolates that underlie their persistence in hospitals.

    PubMed

    Joo, Eun-Jeong; Choi, Ji-Young; Chung, Doo Ryeon; Song, Jae-Hoon; Ko, Kwan Soo

    2016-06-01

    Panton-Valentine leukocidin-negative methicillin-resistant Staphylococcus aureus (MRSA) clone ST72, known as a major community-associated MRSA in Korea, has emerged as an important pathogen in hospitals. To understand bacterial properties that underlie transformation of this clone into a nosocomial pathogen, we compared characteristics of the community-genotype ST72 MRSA isolates with those of ST5 and ST239 MRSA, which have been predominant nosocomial MRSA clones in Korea. Several genes associated with adhesion and virulence were absent or rarely found in ST72 isolates. Many ST72 isolates (70.1%) belonged to agr group I, but the agr group of other ST72 isolates could not be determined. As indicated by d-hemolysin production, ST72 isolates expressed fully functional agr, whereas agr dysfunction was observed in ST5 and ST239 isolates. In the biofilm formation assay, no upregulation of biofilm-forming activity of ST72 MRSA was detected. However, ST72 isolates demonstrated persistence under hypotonic and desiccating conditions (survival rates 72.3% and 33.9%, respectively), which was similar to characteristics of ST5 or ST239 isolates. ST72- MRSA isolates showed low virulence, but properties of their functional agr system could facilitate their spread in hospitals. In conclusion, tolerance to stressful environments, e.g., hypotonic and dry conditions, may also contribute to survival of the community-associated MRSA clones in healthcare facilities.

  18. Update on the prevention and control of community-acquired meticillin-resistant Staphylococcus aureus (CA-MRSA).

    PubMed

    Skov, Robert; Christiansen, Keryn; Dancer, Stephanie J; Daum, Robert S; Dryden, Matthew; Huang, Yhu-Chering; Lowy, Franklin D

    2012-03-01

    The rapid dissemination of community-acquired meticillin-resistant Staphylococcus aureus (CA-MRSA) since the early 2000s and the appearance of new successful lineages is a matter of concern. The burden of these infections varies widely between different groups of individuals and in different regions of the world. Estimating the total burden of disease is therefore problematic. Skin and soft-tissue infections, often in otherwise healthy young individuals, are the most common clinical manifestation of these infections. The antibiotic susceptibilities of these strains also vary, although they are often more susceptible to 'traditional' antibiotics than related hospital-acquired strains. Preventing the dissemination of these organisms throughout the general population requires a multifaceted approach, including screening and decolonisation, general hygiene and cleaning measures, antibiotic stewardship programmes and, in the future, vaccination. The current evidence on the prevention and control of CA-MRSA is appraised and summarised in this review.

  19. Staphylococcal enterotoxin B toxic shock syndrome induced by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA).

    PubMed

    Kashiwada, Takeru; Kikuchi, Ken; Abe, Shinji; Kato, Hidehito; Hayashi, Hiroki; Morimoto, Taisuke; Kamio, Koichiro; Usuki, Jiro; Takeda, Shinhiro; Tanaka, Keiji; Imanishi, Ken'ichi; Yagi, Junji; Azuma, Arata; Gemma, Akihiko

    2012-01-01

    We herein report a case of toxic shock syndrome (TSS) associated with the 2009 pandemic H1N1 (pH1N1) influenza virus and a community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infection in a 16-year-old Vietnamese girl. Staphylococcal enterotoxin B (SEB) was detected in the patient's serum, and the level of anti-SEB antibodies was found to be elevated. A flow cytometric analysis showed evidence of activated SEB-reactive Vβ3+ and Vβ12+ T cells. These data suggest that the CA-MRSA-induced activation of SEB-reactive T cells may cause TSS in patients with pH1N1 virus infection. Moreover, this is the first report describing immunological confirmation of SEB contributing directly to TSS in a patient fulfilling the diagnostic criteria of TSS.

  20. Frequency of resistance to methicillin and other antimicrobial agents among Staphylococcus aureus strains isolated from pigs and their human handlers in Trinidad

    PubMed Central

    Gordon, Annika; Marshall, Jennelle; Ramdass, Kris; Stewart-Johnson, Alva; Adesiyun, Abiodun

    2014-01-01

    Background Methicillin-resistant Staphylococcus aureus (MRSA) has emerged recently worldwide in production animals, particularly pigs and veal calves, which act as reservoirs for MRSA strains for human infection. The study determined the prevalence of MRSA and other resistant strains of S. aureus isolated from the anterior nares of pigs and human handlers on pig farms in Trinidad. Methods Isolation of S. aureus was done by concurrently inoculating Baird-Parker agar (BPA) and Chromagar MRSA (CHROM) with swab samples and isolates were identified using standard methods. Suspect MRSA isolates from Chromagar and BPA were subjected to confirmatory test using Oxoid PBP2 latex agglutination test. The disc diffusion method was used to determine resistance to antimicrobial agents. Results The frequency of isolation of MRSA was 2.1% (15 of 723) for pigs but 0.0% (0 of 72) for humans. Generally, for isolates of S. aureus from humans there was a high frequency of resistance compared with those from pigs, which had moderate resistance to the following antimicrobials: penicillin G (54.5%, 51.5%), ampicillin (59.1%, 49.5%), and streptomycin (59.1%, 37.1%), respectively. There was moderate resistance to tetracycline (36.4%, 41.2%) and gentamycin (27.2%, 23.7%) for human and pig S. aureus isolates, respectively, and low resistance to sulfamethoxazole-trimethoprim (4.5%, 6.2%) and norfloxacin (9.1%, 12.4%), respectively. The frequency of resistance to oxacillin by the disc method was 36.4 and 34.0% from S. aureus isolates from humans and pigs, respectively. Out of a total of 78 isolates of S. aureus from both human and pig sources that were resistant to oxacillin by the disc diffusion method, only 15 (19.2%) were confirmed as MRSA by the PBP'2 latex test kit. Conclusions The detection of MRSA strains in pigs, albeit at a low frequency, coupled with a high frequency of resistance to commonly used antimicrobial agents in pig and humans could have zoonotic and therapeutic implications

  1. Performance of the cobas MRSA/SA Test for Simultaneous Detection of Methicillin-Susceptible and Methicillin-Resistant Staphylococcus aureus From Nasal Swabs.

    PubMed

    Peterson, Lance R; Woods, Christopher W; Davis, Thomas E; Wang, Zi-Xuam; Young, Stephen A; Osiecki, John C; Lewinski, Michael A; Liesenfeld, Oliver

    2017-08-01

    Health care-associated methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus (SA) infections are continuing problems. Rapidly determining the MRSA colonization status of a patient facilitates practice to reduce spread of MRSA clinical disease. Sensitive detection of all SA prior to surgery, followed by decolonization, can significantly reduce postoperative infection from this pathogen. Our goal was to validate a new automated assay for this testing. We compared performance of the cobas MRSA/SA Test on the cobas 4800 System to direct and enriched chromogenic culture using nasal swabs collected from patients at six United States sites. Compared to direct and enriched culture, the sensitivity for MRSA and SA was 93.1% and 93.9%, and the specificity was 97.5% and 94.2%, respectively. After discrepancy analysis, the sensitivity for MRSA and SA was 97.1% and 98.6%, and the specificity was 98.3% and 95.5%, respectively. Compared to direct culture, sensitivity for detecting any SA was 99.6%. The cobas MRSA/SA Test is an effective tool to simultaneously perform surveillance testing for nasal colonization of both MRSA and MSSA.

  2. The herbal-derived honokiol and magnolol enhances immune response to infection with methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA).

    PubMed

    Choi, Eun-Jin; Kim, Hyung-Ip; Kim, Ji-Ae; Jun, Soo Youn; Kang, Sang Hyeon; Park, Dong June; Son, Seok-Jun; Kim, Younghoon; Shin, Ok Sarah

    2015-05-01

    The emergence of antibiotic resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA) reminds us an urgent need to develop a new immune-modulating agent for preventing S. aureus infection. In this study, we found that herbal medicines, honokiol and magnolol, caused a significant cellular immune modulatory effect during S. aureus infection. In mouse macrophages, these compounds drove upregulation of an antioxidant effect in response to S. aureus, resulting in a dampened total cellular reactive oxygen species (ROS) production and decreased production of inflammatory cytokines/chemokines, whereas honokiol induced increased types I and III interferon messenger RNA (mRNA) expression levels in response to MSSA infection. Moreover, the internalization of S. aureus by human alveolar epithelial cells was inhibited by these compounds. Furthermore, honokiol and magnolol treatment promoted a delay in killing during MSSA infection in Caenorhabditis elegans, suggesting antimicrobial function in vivo. In conclusion, honokiol and magnolol may be considered as attractive immune-modulating treatment for S. aureus infection.

  3. [Investigation of the efficacy of some disinfectants against nosocomial Staphylococcus aureus and Enterococcus spp. isolates].

    PubMed

    Eryılmaz, Müjde; Akın, Ahmet; Arıkan Akan, Ozay

    2011-07-01

    Nosocomial infections which exhibit an increasing trend worldwide, are important contributors to morbidity and mortality. Most bacteria that cause nosocomial infections can retain their viability even after exposure to disinfectants in routine practice. This study was conducted to determine the susceptibilities of nosocomial Staphylococcus aureus and Enterococcus spp. isolates to various disinfectants. A total of 30 S.aureus [16 were methicillin-resistant (MRSA), 14 were methicillin-susceptible (MSSA)] and 21 Enterococcus spp. (13 E.faecalis, 7 E.faecium, 1 non-typable Enterococcus spp.) strains isolated from clinical samples of hospitalized patients as nosocomial infection agents in the Central Microbiology Laboratory of Ibn-i Sina Hospital, Ankara University, Faculty of Medicine, were included in the study. Glutaraldehyde (2% wt/vol), chlorhexidine gluconate (4% wt/vol), 2-propanol (70% vol/vol), povidone iodine (7.5% wt/vol), povidone iodine (10% wt/vol) and hydrogen peroxide (3% wt/vol) susceptibilities of the isolates were investigated by quantitative suspension test at contact times of 3, 5, and 10 minutes. All of the isolates were found susceptible to glutaraldehyde (2%), chlorhexidine gluconate (4%), povidone iodine (7.5%), povidone iodine (10%) and 2-propanol (70%) at all tested contact times. However, 12 S.aureus (5 MSSA, 7 MRSA) and 3 enterococci (2 E.faecium, 1 E.faecalis) isolates were found susceptible to hydrogen peroxide (3%) at 3 minutes contact time; 11 S.aureus (4 MSSA, 7 MRSA) and 7 E.faecalis isolates were found susceptible at 5 minutes contact time, and 6 S.aureus (4 MSSA, 2 MRSA) and 3 enterococci (1 E.faecium, 2 E.faecalis) isolates were found susceptible at 10 minutes contact time. One MSSA and 8 enterococci (4 E.faecium, 3 E.faecalis, 1 Enterococcus spp.) isolates were found resistant to hydrogen peroxide (3%) at 10 minutes contact time. In conclusion, glutaraldehyde (2%), chlorhexidine gluconate (4%), povidone iodine (7.5%), povidone

  4. Antimicrobial susceptibility of Staphylococcus aureus isolated from children with impetigo in China from 2003 to 2007 shows community-associated methicillin-resistant Staphylococcus aureus to be uncommon and heterogeneous.

    PubMed

    Liu, Y; Kong, F; Zhang, X; Brown, M; Ma, L; Yang, Y

    2009-12-01

    The number of patients with impetigo caused by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has been increasing. To investigate the antimicrobial susceptibility of S. aureus causing impetigo in children in China from 2003 to 2007 and further characterize isolates of CA-MRSA. We examined 984 S. aureus isolates for antimicrobial susceptibility to 11 antimicrobials using the agar dilution method. CA-MRSA isolates were analysed for Panton-Valentine leucocidin (PVL) genes, and staphylococcal cassette chromosome mec (SCCmec) typing was performed. The largest proportion (94.5%) of strains were resistant to penicillin, followed by erythromycin (86.2%) and clindamycin (69.6%). In total 772 of 984 (78.5%) S. aureus strains were multiresistant. The incidence of CA-MRSA was 1.1%, with a high rate of resistance to clindamycin (90.9%) and tetracycline (72.7%), but all were susceptible to ciprofloxacin. The susceptibility profiles of MRSA to other antimicrobial agents were similar to those of methicillin-sensitive S. aureus (MSSA). None of the S. aureus strains were resistant to vancomycin and fusidic acid; moreover, only one strain was resistant to mupirocin. Typing of the SCCmec showed that 54.5% were type IV, 18.2% were type V and 9.1% were type VI. All the PVL-positive CA-MRSA carried SCCmec type IV. CA-MRSA is still relatively uncommon and heterogeneous in children in China. Penicillin and erythromycin are no longer appropriate agents. Effective antibiotic agents for patients with impetigo are mupirocin and fusidic acid.

  5. High frequency of multidrug-resistant Staphylococcus aureus with SCCmec type III and Spa types t037 and t631 isolated from burn patients in southwest of Iran.

    PubMed

    Parhizgari, Najmeh; Khoramrooz, Seyed Sajjad; Malek Hosseini, Seyed Ali Asghar; Marashifard, Masoud; Yazdanpanah, Mahboobeh; Emaneini, Mohammad; Gharibpour, Farzaneh; Mirzaii, Mehdi; Darban-Sarokhalil, Davood; Moein, Masoud; Naraki, Mahmood

    2016-03-01

    Methicilin resistance Staphylococcus aureus (MRSA) infections are the major challenges in hospitals, especially in the burn units. The use of molecular typing methods is essential for tracking the spread of S. aureus infection and epidemiological investigations. The aim of this study was to find the profile of the spa types and also the prevalence of each SCCmec type of S. aureus strains in a central burn hospital in southwest of Iran. A total of 81 non-duplicate S. aureus were isolated from burn patients between April 2011 and February 2012. The susceptibility of the isolates against 13 different antibiotics was tested by disk agar diffusion (DAD) method. MRSA strains were identified by amplification of mecA gene. Multiplex-polymerase chain reaction (PCR) technique was used to determine the SCCmec types of MRSA strains and all the S. aureus isolates were typed by spa typing method. Detection of mecA gene showed that 70 (86.4%) of the isolates were MRSA. The highest rate of resistance was observed for penicillin (97.5%) and erythromycin (77.8%). None of the isolates were resistant to vancomycin. Sixty-seven of the 70 MRSA isolates harbored only SCCmec type III and three untypeable isolates. Five different spa types were detected. The most common spa types were t037 (42.5%) and t631 (34.5%) and were only found in MRSA isolates. Only SCCmec type III was found in burn patients which emphasizes the HA-MRSA origin of these strains. Only five different spa types identified in this study are in accordance with one SCCmec type which indicates that a limited number of bacterial colons are circulated in the burn unit in this hospital.

  6. High frequency of S. aureus (MSSA-MRSA) in children under 1 year old with skin and soft tissue infections.

    PubMed

    Salazar, Lorena; Quiceno, Judy Natalia Jimenez

    2017-09-20

    Staphylococcus aureus is responsible for a large number of infections in pediatric population; however, information about the behavior of such infections in this population is limited. The aim of the study was to describe the clinical, epidemiological, and molecular characteristics of infections caused by methicillin-susceptible and resistant S. aureus (MSSA-MRSA) in a pediatric population. A cross-sectional descriptive study in patients from birth to 14 years of age from three high-complexity institutions was conducted (2008-2010). All patients infected with MRSA and a representative sample of patients infected with MSSA were included. Clinical and epidemiological information was obtained from medical records and molecular characterization included spa typing, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST). In addition, staphylococcal cassette chromosome mec (SCCmec) and virulence factor genes were detected. A total of 182 patients, 65 with MSSA infections and 117 with MRSA infections, were included in the study; 41.4% of the patients being under 1 year. The most frequent infections were of the skin and soft tissues. Backgrounds such as having stayed in day care centers and previous use of antibiotics were more common in patients with MRSA infections (p≤0.05). Sixteen clonal complexes were identified and MSSA strains were more diverse. The most common cassette was SCCmec IVc (70.8%), which was linked to pvl. In contrast with other locations, a prevalence of infections in children under 1 year of age in the city could be observed; this emphasizes the importance of epidemiological knowledge at the local level. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  7. Imidazolidine-4-one derivatives in the search for novel chemosensitizers of Staphylococcus aureus MRSA: synthesis, biological evaluation and molecular modeling studies.

    PubMed

    Matys, Anna; Podlewska, Sabina; Witek, Karolina; Witek, Jagna; Bojarski, Andrzej J; Schabikowski, Jakub; Otrębska-Machaj, Ewa; Latacz, Gniewomir; Szymańska, Ewa; Kieć-Kononowicz, Katarzyna; Molnar, Joseph; Amaral, Leonard; Handzlik, Jadwiga

    2015-08-28

    A series of amine derivatives of 5-aromatic imidazolidine-4-ones (7-19), representing three subgroups: piperazine derivatives of 5-arylideneimidazolones (7-13), piperazine derivatives of 5-arylideneimidazolidine-2,4-dione (14-16) and primary amines of 5-naphthyl-5-methylimidazolidine-2,4-diones (17-19), was evaluated for their ability to improve antibiotics effectiveness in two strains of Gram-positive Staphylococcus aureus: ATCC 25923 (a reference strain) and MRSA (methicillin resistant S. aureus) HEMSA 5 (a resistant clinical isolate). The latter compounds (17-19) were obtained by 4-step synthesis using Bucherer-Bergs condensation, two-phase bromoalkylation and Gabriel reactions. The naphthalen derivative: (Z)-5-(naphthalen-2-ylmethylene)-2-(piperazin-1-yl)-3H-imidazol-4(5H)-one (10) was the most potent in combination with β-lactam antibiotics and ciprofloxacin against the resistant strain. The high potency to increase efficacy of oxacillin was noted for (Z)-5-(anthracen-10-ylmethylene)-2-(piperazin-1-yl)-3H-imidazol-4(5H)one (12) too. In order to explain the mechanism of action of the compounds 10 and 12, docking studies with the use of crystal structures of a penicillin binding protein (PBP2a) and MecR1 were carried out. Their outcomes suggested that the most probable mechanism of action of the active compounds is the interaction with MecR1. Molecular dynamic experiments performed for the active compounds and compound 13 (structurally similar to 12) supported this hypothesis and provided possible explanation of activity dependencies of the tested compounds in terms of the restoration of antibiotic efficacy in S. aureus MRSA HEMSA 5.

  8. Methicillin-resistant Staphylococcus aureus in nasal surveillance swabs at an intensive care unit: an evaluation of the LightCycler MRSA advanced test.

    PubMed

    Huh, Hee Jin; Kim, Eu Suk; Chae, Seok Lae

    2012-11-01

    We compared the LightCycler MRSA advanced test (Roche Diagnostics, Germany) with enrichment culture methods to evaluate the relative diagnostic performance of the LightCycler MRSA advanced test for active surveillance in a high-prevalence setting. A total of 342 nasal swab specimens were obtained from patients in the intensive care unit at admission and on the seventh day for follow-up. The results of LightCycler MRSA advanced test were compared to those of the enrichment culture. For discrepant results, mecA gene PCR was performed. For the detection of methicillin-resistant Staphylococcus aureus (MRSA), the LightCycler MRSA advanced test showed 98.5% sensitivity and 78.6% specificity and had positive and negative predictive values of 75.0% and 98.8%, respectively. A total of 46 samples had discrepant results between the LightCycler MRSA advanced test and enrichment culture. Of the 44 specimens that were positive in the LightCycler MRSA advanced test but negative by enrichment culture, mecA genes were detected in 37 specimens. In addition, of the original 44 cases, 21 patients had a history of MRSA colonization or infection within the last month; of those 21 specimens, 20 were positive for mecA gene as shown by PCR. Seven mecA-negative discrepant specimens comprised 3 methicillin-sensitive S. aureus-culture positive and only 2 patients had MRSA infections. Despite its low specificity and positive predictive value, the LightCycler MRSA advanced test could serve as a rapid test for patients colonized with MRSA.

  9. Characterization of nasal methicillin-resistant Staphylococcus aureus isolated from international human and veterinary surgeons.

    PubMed

    Post, Virginia; Harris, Llinos G; Morgenstern, Mario; Geoff Richards, R; Sheppard, Samuel K; Fintan Moriarty, T

    2017-03-01

    Nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA) is poorly described for surgeons, despite the increased exposure to nosocomial pathogens and at-risk patients. This study investigated the molecular epidemiology and antimicrobial resistance of 26 MRSA isolates cultured from the nares of an international cross-sectional study of 1166 human and 60 veterinary surgeons. All isolates were subjected to agr, spa and multilocus sequence typing, and the presence of 22 virulence factors was screened for by PCR. Additionally, biofilm-forming ability, haemolytic activity, staphyloxanthin production and antibiotic resistance were determined. The genome of a rifampicin-resistant MRSA was sequenced. Approximately half of the isolates belonged to well-described clonal lineages, ST1, ST5, ST8, ST45 and ST59, that have previously been associated with severe infections and increased patient mortality. Two of the three veterinarian MRSA belonged to epidemic livestock-associated MRSA clonal lineages (ST398 and ST8) previously associated with high transmission potential between animals and humans. The isolates did not display any consistent virulence gene pattern, and 35 % of the isolates carried at least one of the Panton-Valentine leukocidin (lukFS-PV), exfoliative toxin (eta) or toxic shock syndrome (tst) genes. Resistance to rifampicin was detected in one veterinarian isolate and was found to be due to three mutations in the rpoB gene. Surgeons occupy a critical position in the healthcare profession due to their close contact with patients. In this study, surgeons were found to be colonized with MRSA at low rates, similar to those of the general population, and the colonizing strains were often common clonal lineages.

  10. The Impact of Methicillin-Resistant Staphylococcus aureus (MRSA) and Vancomycin-Resistant Enterococcus (VRE) Flags on Hospital Operations.

    PubMed

    Shenoy, Erica S; Lee, Hang; Hou, Taige; Ware, Winston; Ryan, Erin E; Hooper, David C; Walensky, Rochelle P

    2016-07-01

    OBJECTIVE To determine the impact of methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus (MRSA/VRE) designations, or flags, on selected hospital operational outcomes. DESIGN Retrospective cohort study of inpatients admitted to the Massachusetts General Hospital during 2010-2011. METHODS Operational outcomes were time to bed arrival, acuity-unrelated within-hospital transfers, and length of stay. Covariates considered included demographic and clinical characteristics: age, gender, severity of illness on admission, admit day of week, residence prior to admission, hospitalization within the prior 30 days, clinical service, and discharge destination. RESULTS Overall, 81,288 admissions were included. After adjusting for covariates, patients with a MRSA/VRE flag at the time of admission experienced a mean delay in time to bed arrival of 1.03 hours (9.63 hours [95% CI, 9.39-9.88] vs 8.60 hours [95% CI, 8.47-8.73]). These patients had 1.19 times the odds of experiencing an acuity-unrelated within-hospital transfer [95% CI, 1.13-1.26] and a mean length of stay 1.76 days longer (7.03 days [95% CI, 6.82-7.24] vs 5.27 days [95% CI, 5.15-5.38]) than patients with no MRSA/VRE flag. CONCLUSIONS MRSA/VRE designation was associated with delays in time to bed arrival, increased likelihood of acuity-unrelated within-hospital transfers and extended length of stay. Efforts to identify patients who have cleared MRSA/VRE colonization are critically important to mitigate inefficient use of resources and to improve inpatient flow. Infect Control Hosp Epidemiol 2016;37:782-790.

  11. The Importance of Nursing Homes in the Spread of Methicillin-Resistant Staphylococcus aureus (MRSA) Among Hospitals

    PubMed Central

    Lee, Bruce Y.; Bartsch, Sarah M.; Wong, Kim F.; Singh, Ashima; Avery, Taliser R.; Kim, Diane S.; Brown, Shawn T.; Murphy, Courtney R.; Yilmaz, S. Levent; Potter, Margaret A.; Huang, Susan S.

    2013-01-01

    Background Hospital infection control strategies and programs may not consider control of methicillin-resistant Staphylococcus aureus (MRSA) in nursing homes in a county. Methods Using our Regional Healthcare Ecosystem Analyst (RHEA), we augmented our existing agent-based model of all hospitals in Orange County (OC), California, by adding all nursing homes and then simulated MRSA outbreaks in various healthcare facilities. Results The addition of nursing homes substantially changed MRSA transmission dynamics throughout the County. The presence of nursing homes substantially potentiated the effects of hospital outbreaks on other hospitals, leading to an average 46.2% (range: 3.3–156.1%) relative increase above and beyond the impact when only hospitals are included for an outbreak in OC’s largest hospital. An outbreak in the largest hospital affected all other hospitals (average 2.1% relative prevalence increase) and the majority (~90%) of nursing homes (average 3.2% relative increase) after six months. An outbreak in the largest nursing home had effects on multiple OC hospitals, increasing MRSA prevalence in directly connected hospitals by an average 0.3% and in hospitals not directly connected via patient transfers by an average 0.1% after six months. A nursing home outbreak also had some effect on MRSA prevalence in other nursing homes. Conclusions Nursing homes, even those not connected by direct patient transfers, may be a vital component of a hospital’s infection control strategy. To achieve effective control, a hospital may want to better understand how regional nursing homes and hospitals are connected via both direct and indirect (with intervening stays at home) patient sharing. PMID:23358388

  12. The importance of nursing homes in the spread of methicillin-resistant Staphylococcus aureus (MRSA) among hospitals.

    PubMed

    Lee, Bruce Y; Bartsch, Sarah M; Wong, Kim F; Singh, Ashima; Avery, Taliser R; Kim, Diane S; Brown, Shawn T; Murphy, Courtney R; Yilmaz, Server Levent; Potter, Margaret A; Huang, Susan S

    2013-03-01

    Hospital infection control strategies and programs may not consider control of methicillin-resistant Staphylococcus aureus (MRSA) in nursing homes in a county. Using our Regional Healthcare Ecosystem Analyst, we augmented our existing agent-based model of all hospitals in Orange County (OC), California, by adding all nursing homes and then simulated MRSA outbreaks in various health care facilities. The addition of nursing homes substantially changed MRSA transmission dynamics throughout the county. The presence of nursing homes substantially potentiated the effects of hospital outbreaks on other hospitals, leading to an average 46.2% (range, 3.3%-156.1%) relative increase above and beyond the impact when only hospitals are included for an outbreak in OC's largest hospital. An outbreak in the largest hospital affected all other hospitals (average 2.1% relative prevalence increase) and the majority (~90%) of nursing homes (average 3.2% relative increase) after 6 months. An outbreak in the largest nursing home had effects on multiple OC hospitals, increasing MRSA prevalence in directly connected hospitals by an average 0.3% and in hospitals not directly connected through patient transfers by an average 0.1% after 6 months. A nursing home outbreak also had some effect on MRSA prevalence in other nursing homes. Nursing homes, even those not connected by direct patient transfers, may be a vital component of a hospital's infection control strategy. To achieve effective control, a hospital may want to better understand how regional nursing homes and hospitals are connected through both direct and indirect (with intervening stays at home) patient sharing.

  13. Antimicrobial susceptibility and resistance mechanisms of methicillin resistant Staphylococcus aureus isolated from 12 Hospitals in Turkey.

    PubMed

    Yıldız, Ömer; Çoban, Ahmet Yılmaz; Şener, Aslı Gamze; Coşkuner, Seher Ayten; Bayramoğlu, Gülçin; Güdücüoğlu, Hüseyin; Özyurt, Mustafa; Tatman-Otkun, Müşerref; Karabiber, Nihal; Özkütük, Nuri; Aktepe, Orhan; Öncü, Serkan; Arslan, Uğur; Bozdoğan, Bülent

    2014-09-16

    Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most important nosocomial pathogens and is also emerging in Turkish hospitals. The aim of this study was to determine the antimicrobial susceptibility profiles of MRSA isolated from Turkish hospitals. A total of 397 MRSA strains isolated from 12 hospitals in Turkey were included to present study. Antimicrobial susceptibilities were tested using agar dilution method. Presence of ermA, ermB, ermC, msrA, tetM, tetK, linA and aac-aph genes were studied by PCR. All strains were susceptible to vancomycin and linezolid. The susceptibility rates for fusidic acid, lincomycin, erythromycin, tetracyclin, gentamycin, kanamycin, and, ciprofloxacin were 91.9%, 41.1%, 27.2%, 11.8%, 8.5%, 8.3% and 6.8%, respectively. Lincomycin inactivation was positive for 3 isolates. Of 225 erythromycin resistant isolates 48 had ermA, 20 had ermC, and 128 had ermA-C. PCR was negative for 15 strains. Of 3 isolates with lincomycin inactivation one had linA and msrA. Of 358 gentamycin resistant isolates 334 had aac-aph and 24 were negatives. Among 350 tetracyclin resistant isolates 314 had tetM. Of 36 tetM negative isolates 10 had tetK. MRSA isolates from Turkish hospitals were multiresistant to antimicrobials. Quinolone and gentamycin resistance levels were high and macrolide and lincosamide resistance were relatively low. Susceptibility rates for fusidic asid were high. Linezolide and vancomycin resistance are not emerged. The most common resistance genes were ermA, tetM and aac-aph. Evolution of antimicrobial susceptibilities and resistance genes profiles of MRSA isolates should be surveyed at regional and national level for accurate treatment of patients and to control dissemination of resistance genes.

  14. Rifampicin-fosfomycin coating for cementless endoprostheses: antimicrobial effects against methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Alt, Volker; Kirchhof, Kristin; Seim, Florian; Hrubesch, Isabelle; Lips, Katrin S; Mannel, Henrich; Domann, Eugen; Schnettler, Reinhard

    2014-10-01

    New strategies to decrease infection rates in cementless arthroplasty are needed, especially in the context of the growing incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections. The purpose of this study was to investigate the antimicrobial activity of a rifampicin-fosfomycin coating against methicillin-sensitive Staphylococcus aureus (MSSA) and MRSA in a rabbit infection prophylaxis model. Uncoated or rifampicin-fosfomycin-coated K-wires were inserted into the intramedullary canal of the tibia in rabbits and contaminated with an inoculation dose of 10(5) or 10(6) colony-forming units of MSSA EDCC 5055 in study 1 and MRSA T6625930 in study 2, respectively. After 28days the animals were killed and clinical, histological and microbiological assessment, including pulse-field gel electrophoresis, was conducted. Positive culture growth in agar plate testing and/or clinical signs and/or histological signs were defined positive for infection. Statistical evaluation was performed using Fisher's exact test. Both studies showed a statistically significant reduction of infection rates for rifampicin-fosfomycin-coated implants compared to uncoated K-wires (P=0.015). In both studies none of the 12 animals that were treated with a rifampicin-fosfomycin-coated implant showed clinical signs of infection or a positive agar plate testing result. In both studies, one animal of the coating group showed the presence of sporadic bacteria with concomitant inflammatory signs in histology. The control groups in both studies exhibited an infection rate of 100% with clear clinical signs of infection and positive culture growth in all animals. In summary, the rifampicin-fosfomycin-coating showed excellent antimicrobial activity against both MSSA and MRSA, and therefore warrants further clinical testing.

  15. Characterization of Methicillin-Resistant Staphylococcus aureus Isolates from Food and Food Products of Poultry Origin in Germany ▿

    PubMed Central

    Feßler, Andrea T.; Kadlec, Kristina; Hassel, Melanie; Hauschild, Tomasz; Eidam, Christopher; Ehricht, Ralf; Monecke, Stefan; Schwarz, Stefan

    2011-01-01

    During a survey of fresh chicken and turkey meat as well as chicken and turkey meat products for the presence of methicillin-resistant Staphylococcus aureus (MRSA) isolates in Germany, 32 (37.2%) of 86 samples were MRSA positive. Twenty-eight of these MRSA isolates belonged to clonal complex 398 (CC398), which is widespread among food-producing animals. These CC398 isolates carried SCCmec elements of type IV or V and exhibited spa type t011, t034, t899, t2346 or t6574 and either the known dru types dt2b, dt6j, dt10a, dt10q, dt11a, dt11v, and dt11ab or the novel dru types dt6m, dt10as, and dt10at. In addition, two MRSA sequence type 9 (ST9) isolates with a type IV SCCmec cassette, spa type t1430, and dru type dt10a as well as single MRSA ST5 and ST1791 isolates with a type III SCCmec cassette, spa type t002, and dru type dt9v were identified. All but two isolates were classified as multiresistant. A wide variety of resistance phenotypes and genotypes were detected. All isolates were negative for the major virulence factors, such as Panton-Valentine leukocidin, toxic shock syndrome toxin 1, or exfoliative toxins. In contrast to the MRSA CC398 isolates, the four ST9, ST5, or ST1791 isolates harbored the egc gene cluster for enterotoxin G, I, M, N, O, and U genes. Although the relevance of contamination of fresh poultry meat or poultry products with MRSA is currently unclear, the presence of multiresistant and, in part, enterotoxigenic MRSA emphasizes the need for further studies to elucidate possible health hazards for consumers. PMID:21724898

  16. Molecular epidemiology of Staphylococcus aureus strains isolated from inpatients with infected diabetic foot ulcers in an Algerian University Hospital.

    PubMed

    Djahmi, N; Messad, N; Nedjai, S; Moussaoui, A; Mazouz, D; Richard, J-L; Sotto, A; Lavigne, J-P

    2013-09-01

    Staphylococcus aureus is the most common pathogen cultured from diabetic foot infection (DFI). The consequence of its spread to soft tissue and bony structures is a major causal factor for lower-limb amputation. The objective of the study was to explore ecological data and epidemiological characteristics of S. aureus strains isolated from DFI in an Algerian hospital setting. Patients were included if they were admitted for DFI in the Department of Diabetology at the Annaba University Hospital from April 2011 to March 2012. Ulcers were classified according to the Infectious Diseases Society of America/International Working Group on the Diabetic Foot classification system. All S. aureus isolates were analysed. Using oligonucleotide arrays, S. aureus resistance and virulence genes were determined and each isolate was affiliated to a clonal complex. Among the 128 patients, 277 strains were isolated from 183 samples (1.51 isolate per sample). Aerobic Gram-negative bacilli were the most common isolated organisms (54.9% of all isolates). The study of ecological data highlighted the extremely high rate of multidrug-resistant organisms (MDROs) (58.5% of all isolates). The situation was especially striking for S. aureus [(85.9% were methicillin-resistant S. aureus (MRSA)], Klebsiella pneumonia (83.8%) and Escherichia coli (60%). Among the S. aureus isolates, 82.2% of MRSA belonged to ST239, one of the most worldwide disseminated clones. Ten strains (13.7%) belonged to the European clone PVL+ ST80. ermA, aacA-aphD, aphA, tetM, fosB, sek, seq, lukDE, fnbB, cap8 and agr group 1 genes were significantly associated with MRSA strains (p <0.01). The study shows for the first time the alarming prevalence of MDROs in DFI in Algeria. ©2013 The Authors Clinical Microbiology and Infection ©2013 European Society of Clinical Microbiology and Infectious Diseases.

  17. Molecular Typing and Virulence Characteristic of Methicillin-Resistant Staphylococcus Aureus Isolates from Pediatric Patients in Bucaramanga, Colombia

    PubMed Central

    Machuca, Mayra Alejandra; Sosa, Luis Miguel; González, Clara Isabel

    2013-01-01

    Background Staphylococcus aureus is among the most common global nosocomial pathogens. The emergence and spread of methicillin-resistant Staphylococcus aureus (MRSA) is a public health problem worldwide that causes nosocomial and community infections. The goals of this study were to establish the clonal complexes (CC) of the isolates of MRSA obtained from pediatric patients in a university hospital in Colombia and to investigate its molecular characteristics based on the virulence genes and the genes of staphylococcal toxins and adhesins. Methods A total of 53 MRSA isolates from pediatric patients with local or systemic infections were collected. The MRSA isolates were typed based on the SCCmec, MLST, spa and agr genes. The molecular characterization included the detection of Panton-Valentine Leukocidin, superantigenic and exfoliative toxins, and adhesin genes. The correlation between the molecular types identified and the profile of virulence factors was determined for all isolates. Results Four CC were identified, including CC8, CC5, CC80 and CC78. The ST8-MRSA-IVc-agrI was the predominant clone among the isolates, followed by the ST5-MRSA-I-agrII and ST5-MRSA-IVc-agrII clones. Twelve spa types were identified, of which t10796 and t10799 were new repeat sequences. The isolates were carriers of toxin genes, and hlg (100%), sek (92%) and pvl (88%) were the most frequent. Ten toxin gene profiles were observed, and the most frequent were seq-sek-hlg (22.6%), sek-hlg (22.6%), seb-seq-sek-hlg (18.9%) and seb-sek-hlg (15.1%). The adhesion genes were present in most of the MRSA isolates, including the following: clf-A (89%), clf-B (87%), fnb-A (83%) and ica (83%). The majority of the strains carried SCCmec-IVc and were identified as causing nosocomial infection. No significant association between a molecular type and the virulence factors was found. Conclusion Four major MRSA clone complexes were identified among the isolates. ST8-MRSA-IVc-agrI pvl+ (USA300-LV) was the

  18. POSAiDA: presence of Staphylococcus aureus/MRSA and Enterococcus/VRE in Danish ambulances. A cross-sectional study.

    PubMed

    Vikke, Heidi Storm; Giebner, Matthias

    2016-03-30

    Every year approximately one out of ten Danish patients contracts a healthcare associated infection (HAI). Staphylococcus aureus and Enterococcus are prominent in the group of pathogenic bacteria that underlie HAIs, causing unnecessary inconvenience and prolonging hospitalization. Bacterial colonization often occurs due to indirect patient-to-patient transmission, caused by poor hygiene compliance. This study aims to determine the level of contamination with S. aureus/MRSA and Enterococcus/VRE on presumed clean blood pressure cuffs in the Danish ambulances. Blood pressure cuffs were tested for contamination with S. aureus and Enterococcus when being cleaned according to everyday guidelines in this cross-sectional study. Imprints were performed with specific agar plates after cleaning with ethanol wipes. Positive imprints were typed and antibiotic susceptibility was determined. Both S. aureus and Enterococcus were found on blood pressure cuffs thought to be clean, however, to a limited extent. The average level of contamination by S. aureus was 0.54 CFU per 25 cm(2) (SD 1.98). Minimum and maximum values ranged from 0 to 12 CFU per 25 cm(2) and 10% of the 50 samples were positive. The average level of contamination by Enterococcus was 0.06 CFU per 25 cm(2) (SD 0.42). Minimum and maximum values ranged from 0 to 3 CFU per 25 cm(2) and 2% of the 50 samples were positive. All S. aureus isolates were found to be methicillin susceptible S. aureus (MSSA) and the one Enterococcus isolate was identified as Enterococcus faecalis, negative for vancomycin resistance genes. Staphylococcus aureus and Enterococcus were detectable on equipment thought to be clean. However, all detected bacteria showed susceptibility towards methicillin or vancomycin. Findings of pathogens after cleaning may be due to cross-contamination, improper cleaning and limited effect of the currently used cleaning procedure and are thought to affect the risk of infection. Therefore, we recommend a thorough

  19. Isolation and characterization of Staphylococcus aureus strains from a Paso del Norte dairy.

    PubMed

    Matyi, S A; Dupre, J M; Johnson, W L; Hoyt, P R; White, D G; Brody, T; Odenwald, W F; Gustafson, J E

    2013-06-01

    The primary purpose of this study was to determine if methicillin-resistant Staphylococcus aureus (MRSA) strains could be identified in the milk of dairy cattle in a Paso del Norte region dairy of the United States. Using physiological and PCR-based identification schemes, a total of 40 Staph. aureus strains were isolated from 29 raw milk samples of 133 total samples analyzed. Pulsed-field gel electrophoresis after digestion with the SmaI enzyme revealed that the 40 confirmed strains were represented by 5 pulsed-field types, which each contained 3 or more strains. Of 7 hospital strains isolated from cows undergoing antibiotic therapy, 3 demonstrated resistance to 3 or more antimicrobial classes and displayed similar pulsed-field gel electrophoresis patterns. A secondary purpose of this study was to elucidate the evolutionary relationships of strains isolated in this study to genomically characterized Staph. aureus strains. Therefore, Roche 454 GS (Roche Diagnostics Corp., Dallas, TX) pyrosequencing was used to produce draft genome sequences of an MRSA raw milk isolate (H29) and a methicillin-susceptible Staph. aureus (PB32). Analysis using the BLASTn database (http://blast.ncbi.nlm.nih.gov/) demonstrated that the H29 draft genome was highly homologous to the human MRSA strain JH1, yet the β-lactamase plasmid carried by H29 was different from that carried by JH1. Genomic analysis of H29 also clearly explained the multidrug resistance phenotype of this raw milk isolate. Analysis of the PB32 draft genome (using BLASTn) demonstrated that this raw milk isolate was most related to human MRSA strain 04-02981. Although PB32 is not a MRSA, the PB32 draft genome did reveal the presence of a unique staphylococcal cassette mec (SCCmec) remnant. In addition, the PB32 draft genome revealed the presence of a novel bovine staphylococcal pathogenicity island, SaPIbovPB32. This study demonstrates the presence of clones closely related to human and (or) bovine Staph. aureus strains