scholarly journals Extensive Genetic Diversity Identified among Sporadic Methicillin-Resistant Staphylococcus aureus Isolates Recovered in Irish Hospitals between 2000 and 2012

2014 ◽  
Vol 58 (4) ◽  
pp. 1907-1917 ◽  
Author(s):  
Peter M. Kinnevey ◽  
Anna C. Shore ◽  
Grainne I. Brennan ◽  
Derek J. Sullivan ◽  
Ralf Ehricht ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Sequence Type ◽  
Methicillin Resistant ◽  
Content Type ◽  
Type Assignment ◽  
Antimicrobial Resistance Genes ◽  
Microarray Profiling ◽  
Mrsa Strains ◽  
Ongoing Surveillance

ABSTRACTClonal replacement of predominant nosocomial methicillin-resistantStaphylococcus 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 representativepvl-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 byspatyping and DNA microarray profiling for multilocus sequence type (MLST) clonal complex (CC) and/or sequence type (ST) and SCCmectype assignment, as well as for detection of virulence and antimicrobial resistance genes. Conventional PCR-based SCCmecsubtyping was undertaken when necessary. Extensive diversity was detected, including 38spatypes, 13 MLST-CCs (including 18 STs among 62 isolates assigned to STs), and 25 SCCmectypes (including 2 possible novel SCCmecelements and 7 possible novel SCCmecsubtypes). Fifty-four MLST-spa-SCCmectype combinations were identified. Overall, 68.5% of isolates were assigned to nosocomial lineages, with ST8-t190-MRSA-IID/IIE ± SCCM1predominating (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 warranted for early detection of emerging clones and reservoirs of virulence, resistance, and SCCmecgenes.

scholarly journals Complete Genome Sequences of Canadian Epidemic Methicillin-Resistant Staphylococcus aureus Strains CMRSA3 and CMRSA6

2018 ◽  
Vol 7 (5) ◽  
Author(s):  
Jo-Ann McClure ◽  
Steven M. Shideler ◽  
Kunyan Zhang
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Clonal Complex ◽  
Virulent Strain ◽  
Sequence Type ◽  
Genome Sequences ◽  
Methicillin Resistant ◽  
Content Type ◽  
Mrsa Strains ◽  
Highly Virulent

Methicillin-resistant Staphylococcus aureus (MRSA) clonal complex 8 (CC8) sequence type 239 (ST239) represents a predominant hospital-associated MRSA sublineage present worldwide. The Canadian epidemic MRSA strains CMRSA3 and CMRSA6 are moderately virulent members of this group but are closely related to the highly virulent strain TW20.

scholarly journals DNA Microarray Profiling of a Diverse Collection of Nosocomial Methicillin-Resistant Staphylococcus aureus Isolates Assigns the Majority to the Correct Sequence Type and Staphylococcal Cassette Chromosomemec(SCCmec) Type and Results in the Subsequent Identification and Characterization of Novel SCCmec-SCCM1Composite Islands

2012 ◽  
Vol 56 (10) ◽  
pp. 5340-5355 ◽  
Author(s):  
Anna C. Shore ◽  
Orla M. Brennan ◽  
Emily C. Deasy ◽  
Angela S. Rossney ◽  
Peter M. Kinnevey ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Dna Sequence ◽  
Dna Microarray ◽  
Fusidic Acid ◽  
Sccmec Type ◽  
Sequence Type ◽  
Methicillin Resistant ◽  
Content Type ◽  
Resistance Phenotype ◽  
Microarray Profiling

ABSTRACTOne hundred seventy-five isolates representative of methicillin-resistantStaphylococcus aureus(MRSA) clones that predominated in Irish hospitals between 1971 and 2004 and that previously underwent multilocus sequence typing (MLST) and staphylococcal cassette chromosomemec(SCCmec) typing were characterized byspatyping (175 isolates) and DNA microarray profiling (107 isolates). The isolates belonged to 26 sequence type (ST)-SCCmectypes and subtypes and 35spatypes. The array assigned all isolates to the correct MLST clonal complex (CC), and 94% (100/107) were assigned an ST, with 98% (98/100) correlating with MLST. The array assigned all isolates to the correct SCCmectype, but subtyping of only some SCCmecelements was possible. Additional SCCmec/SCC genes or DNA sequence variation not detected by SCCmectyping was detected by array profiling, including the SCC-fusidic acid resistance determinant Q6GD50/fusC. Novel SCCmec/SCC composite islands (CIs) were detected among CC8 isolates and comprised SCCmecIIA-IIE, IVE, IVF, or IVg and accrAB4-SCC element with 99% DNA sequence identity to SCCM1from ST8/t024-MRSA, SCCmecVIII, and SCC-CI inStaphylococcus epidermidis. The array showed that the majority of isolates harbored one or more superantigen (94%; 100/107) and immune evasion cluster (91%; 97/107) genes. Apart from fusidic acid and trimethoprim resistance, the correlation between isolate antimicrobial resistance phenotype and the presence of specific resistance genes was ≥97%. Array profiling allowed high-throughput, accurate assignment of MRSA to CCs/STs and SCCmectypes and provided further evidence of the diversity of SCCmec/SCC. In most cases, array profiling can accurately predict the resistance phenotype of an isolate.

scholarly journals In VitroActivities of Antibiotics and Antimicrobial Cationic Peptides Alone and in Combination against Methicillin-Resistant Staphylococcus aureus Biofilms

2012 ◽  
Vol 56 (12) ◽  
pp. 6366-6371 ◽  
Author(s):  
Emel Mataraci ◽  
Sibel Dosler
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Antibiofilm Activity ◽  
Cationic Peptides ◽  
Planktonic Cells ◽  
Methicillin Resistant ◽  
Content Type ◽  
Mrsa Strains ◽  
Almost All

ABSTRACTMethicillin-resistantStaphylococcus aureus(MRSA) strains are most often found as hospital- and community-acquired infections. The danger of MRSA infections results from not only the emergence of multidrug resistance but also the occurrence of bacteria that form strong biofilms. We investigated thein vitroactivities of antibiotics (daptomycin, linezolid, teichoplanine, azithromycin, and ciprofloxacin) and antimicrobial cationic peptides {AMPs; indolicidin, CAMA [cecropin (1-7)–melittin A (2-9) amide], and nisin} alone or in combination against MRSA ATCC 43300 biofilms. The MICs and minimum biofilm eradication concentrations (MBECs) were determined by the broth microdilution technique. Antibiotic and AMP combinations were assessed using the checkerboard technique. For MRSA planktonic cells, MICs of antibiotics and AMPs ranged between 0.125 and 512 and 8 and 16 mg/liter, respectively, and the MBEC values were between 512 and 5,120 and 640 mg/liter, respectively. With a fractional inhibitory concentration of ≤0.5 as the borderline, synergistic interactions against MRSA biofilms were frequent with almost all antibiotic-antibiotic and antibiotic-AMP combinations. Against planktonic cells, they generally had an additive effect. No antagonism was observed. All of the antibiotics, AMPs, and their combinations were able to inhibit the attachment of bacteria at 1/10 MIC and biofilm formation at 1× MIC. Biofilm-associated MRSA was not affected by therapeutically achievable concentrations of antimicrobial agents. Use of a combination of antimicrobial agents can provide a synergistic effect, which rapidly enhances antibiofilm activity and may help prevent or delay the emergence of resistance. AMPs seem to be good candidates for further investigations in the treatment of MRSA biofilms, alone or in combination with antibiotics.

scholarly journals Draft Genome Sequences of 50 Methicillin-Resistant Staphylococcus aureus Sequence Type 5 Isolates Obtained from a U.S. Hospital

2017 ◽  
Vol 5 (44) ◽  
Author(s):  
Samantha J. Hau ◽  
Darrell O. Bayles ◽  
David P. Alt ◽  
Tracy L. Nicholson
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Draft Genome ◽  
Sequence Type ◽  
Genome Sequences ◽  
Methicillin Resistant ◽  
Content Type ◽  
Related Disease ◽  
Antimicrobial Resistance Genes

ABSTRACT Methicillin-resistant Staphylococcus aureus (MRSA) can be a commensal or pathogen in humans. Pathogenicity and disease are related to the acquisition of mobile genetic elements encoding virulence and antimicrobial resistance genes. Here, we report draft genome sequences for 50 clinical MRSA isolates from humans with MRSA-related disease.

scholarly journals Pilot Evaluation of a Fully Automated Bioinformatics System for Analysis of Methicillin-Resistant Staphylococcus aureus Genomes and Detection of Outbreaks

2019 ◽  
Vol 57 (11) ◽  
Author(s):  
Nicholas M. Brown ◽  
Beth Blane ◽  
Kathy E. Raven ◽  
Narender Kumar ◽  
Danielle Leek ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pilot Study ◽  
Genetic Relatedness ◽  
Sequence Type ◽  
Outbreak Detection ◽  
Clinical Microbiology Laboratory ◽  
Methicillin Resistant ◽  
Content Type ◽  
Analysis Methods ◽  
Type Assignment

ABSTRACT Genomic surveillance that combines bacterial sequencing and epidemiological information will become the gold standard for outbreak detection, but its clinical translation is hampered by the lack of automated interpretation tools. We performed a prospective pilot study to evaluate the analysis of methicillin-resistant Staphylococcus aureus (MRSA) genomes using the Next Gen Diagnostics (NGD) automated bioinformatics system. Seventeen unselected MRSA-positive patients were identified in a clinical microbiology laboratory in England over a period of 2 weeks in 2018, and 1 MRSA isolate per case was sequenced on the Illumina MiniSeq instrument. The NGD system automatically activated after sequencing and processed fastq folders to determine species, multilocus sequence type, the presence of a mec gene, antibiotic susceptibility predictions, and genetic relatedness based on mapping to a reference MRSA genome and detection of pairwise core genome single-nucleotide polymorphisms. The NGD system required 90 s per sample to automatically analyze data from each run, the results of which were automatically displayed. The same data were independently analyzed using a research-based approach. There was full concordance between the two analysis methods regarding species (S. aureus), detection of mecA, sequence type assignment, and detection of genetic determinants of resistance. Both analysis methods identified two MRSA clusters based on relatedness, one of which contained 3 cases that were involved in an outbreak linked to a clinic and ward associated with diabetic patient care. We conclude that, in this pilot study, the NGD system provided rapid and accurate data that could support infection control practices.

scholarly journals Draft Genome Sequence of a Sequence Type 398 Methicillin-Resistant Staphylococcus aureus Isolate from a Danish Dairy Cow with Mastitis

2017 ◽  
Vol 5 (23) ◽  
Author(s):  
Troels Ronco ◽  
Marc Stegger ◽  
Karl Pedersen
Keyword(s):  
Staphylococcus Aureus ◽  
Genome Sequence ◽  
Dairy Cow ◽  
Draft Genome ◽  
Sequence Type ◽  
Draft Genome Sequence ◽  
Methicillin Resistant ◽  
Content Type ◽  
Mrsa Strains ◽  
Danish Dairy

ABSTRACT Livestock-associated (LA) methicillin-resistant Staphylococcus aureus (MRSA) strains of sequence type 398 (ST398) colonize both humans and various livestock species. In 2016, an ST398 LA-MRSA isolate (Sa52) was collected from a Danish dairy cow with mastitis, and here, we report the draft genome sequence of strain Sa52.

scholarly journals Molecular Characteristics and In Vitro Susceptibility to Antimicrobial Agents, Including the Des-Fluoro(6) Quinolone DX-619, of Panton-Valentine Leucocidin-Positive Methicillin-Resistant Staphylococcus aureus Isolates from the Community and Hospitals

2006 ◽  
Vol 50 (12) ◽  
pp. 4077-4086 ◽  
Author(s):  
Tatsuo Yamamoto ◽  
Soshi Dohmae ◽  
Kohei Saito ◽  
Taketo Otsuka ◽  
Tomomi Takano ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Sequence Type ◽  
Molecular Characteristics ◽  
Staphylococcal Protein A ◽  
In Vitro Susceptibility ◽  
Genetic Traits ◽  
Methicillin Resistant ◽  
Single Locus Variant ◽  
Mrsa Strains

ABSTRACTHighly virulent, community-acquired methicillin-resistantStaphylococcus aureus(MRSA) strains with Panton-Valentine leucocidin (PVL) genes have been found increasingly worldwide. Among a total of 2,101 MRSA strains isolated from patients in hospitals in Japan, two were positive for PVL genes. One strain was identified as a community-acquired MRSA strain with genotype sequence type 30 (ST30) andspa(staphylococcal protein A gene) type 19 from Japan and was resistant only to β-lactam antimicrobial agents. The other strain was closely related to PVL+multidrug-resistant, hospital-acquired MRSA strains (ST30,spatype 43) derived from nosocomial outbreaks in the 1980s to 1990s in Japan but with a divergent sequence type, ST765 (a single-locus variant of ST30). Twenty-two PVL+MRSA strains, including those from Japan and those from other countries with various sequence types (ST1, ST8, ST30, ST59, and ST80) and genotypes, were examined for susceptibility to 31 antimicrobial agents. Among the agents, DX-619, a des-fluoro(6) quinolone, showed the greatest activity, followed by rifampin and sitafloxacin, a fluoroquinolone. The data suggest that DX-619 exhibits a superior activity against PVL+MRSA strains with various virulence genetic traits from the community as well as from hospitals.

scholarly journals Evaluation of Ceftaroline Alone and in Combination against Biofilm-Producing Methicillin-Resistant Staphylococcus aureus with Reduced Susceptibility to Daptomycin and Vancomycin in anIn VitroPharmacokinetic/Pharmacodynamic Model

2015 ◽  
Vol 59 (8) ◽  
pp. 4497-4503 ◽  
Author(s):  
Katie E. Barber ◽  
Jordan R. Smith ◽  
Cortney E. Ireland ◽  
Blaise R. Boles ◽  
Warren E. Rose ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Medical Device ◽  
Bloodstream Infections ◽  
Methicillin Resistant ◽  
Content Type ◽  
Elimination Half ◽  
Antimicrobial Protection ◽  
Mrsa Strains ◽  
Post Hoc

ABSTRACTAnnually, medical device infections are associated with >250,000 catheter-associated bloodstream infections (CLABSI), with up to 25% mortality.Staphylococcus aureus, a primary pathogen in these infections, is capable of biofilm production, allowing organism persistence in harsh environments, offering antimicrobial protection. With increases inS. aureusisolates with reduced susceptibility to current agents, ceftaroline (CPT) offers a therapeutic alternative. Therefore, we evaluated whether CPT would have a role against biofilm-producing methicillin-resistantS. aureus(MRSA), including those with decreased susceptibilities to alternative agents. In this study, we investigated CPT activity alone or combined with daptomycin (DAP) or rifampin (RIF) against 3 clinical biofilm-producing MRSA strains in anin vitrobiofilm pharmacokinetic/pharmacodynamic (PK/PD) model. Simulated antimicrobial regimens were as follows: 600 mg of CPT every 8 h (q8h) (free maximum concentration of drug [fCmax], 17.04 mg/liter; elimination half-life [t1/2], 2.66 h), 12 mg/kg of body weight/day of DAP (fCmax, 14.7 mg/liter;t1/2, 8 h), and 450 mg of RIF q12h (fCmax, 3.5 mg/liter;t1/2, 3.4 h), CPT plus DAP, and CPT plus RIF. Samples were obtained and plated to determine colony counts. Differences in log10CFU/cm2were evaluated by analysis of variance with Tukey'spost hoctest. The strains were CPT and vancomycin susceptible and DAP nonsusceptible (DNS). CPT displayed activity throughout the experiment. DAP demonstrated initial activity with regrowth at 24 h in all strains. RIF was comparable to the drug-free control, and little benefit was observed when combined with CPT. CPT plus DAP displayed potent activity, with an average log10CFU/cm2reduction of 3.33 ± 1.01 from baseline. CPT demonstrated activity against biofilm-producing DNS MRSA. CPT plus DAP displayed therapeutic enhancement over monotherapy, providing a potential option for difficult-to-treat medical device infections.

scholarly journals Activity of Debio1452, a FabI Inhibitor with Potent Activity against Staphylococcus aureus and Coagulase-Negative Staphylococcus spp., Including Multidrug-Resistant Strains

2015 ◽  
Vol 59 (5) ◽  
pp. 2583-2587 ◽  
Author(s):  
Robert K. Flamm ◽  
Paul R. Rhomberg ◽  
Nachum Kaplan ◽  
Ronald N. Jones ◽  
David J. Farrell
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Fatty Acid Biosynthesis ◽  
Multidrug Resistant ◽  
Coagulase Negative Staphylococcus ◽  
Significant Activity ◽  
Coagulase Negative Staphylococci ◽  
Content Type ◽  
Mrsa Strains ◽  
Human Infections

ABSTRACTStaphylococcus aureusand coagulase-negative staphylococci (CoNS) are responsible for a wide variety of human infections. The investigational antibacterial Debio1450 (previously AFN-1720), a prodrug of Debio1452 (previously AFN-1252), specifically targets staphylococci without significant activity against other Gram-positive or Gram-negative species. Debio1452 inhibits FabI, an enzyme critical to fatty acid biosynthesis in staphylococci. The activity of Debio1452 against CoNS, methicillin-susceptibleS. aureus(MSSA), and methicillin-resistantS. aureus(MRSA), including significant clones, was determined. A globally diverse collection of 574 patient isolates from 35 countries was tested that included CoNS (6 species, 103 strains), MSSA (154 strains), MRSA (163 strains), and molecularly characterized strains (includingspa-typed MRSA clones; 154 strains). The isolates were tested for susceptibility by CLSI broth microdilution methods against Debio1452 and 10 comparators. The susceptibility rates for the comparators were determined using CLSI and EUCAST breakpoint criteria. AllS. aureusand CoNS strains were inhibited by Debio1452 concentrations of ≤0.12 and ≤0.5 μg/ml, respectively. The MIC50s for MSSA, MRSA, and molecularly characterized MRSA strains were 0.004 μg/ml, and the MIC90s ranged from 0.008 to 0.03 μg/ml. The MICs were higher for the CoNS isolates (MIC50/90, 0.015/0.12 μg/ml). AmongS. aureusstrains, resistance was common for erythromycin (61.6%), levofloxacin (49.0%), clindamycin (27.6%), tetracycline (15.7%), and trimethoprim-sulfamethoxazole (7.0%). Debio1452 demonstrated potent activity against MSSA, MRSA, and CoNS. Debio1452 showed significantly greater activity overall (MIC50, 0.004 μg/ml) than the other agents tested against these staphylococcal species, which included dominant MRSA clones and strains resistant to currently utilized antimicrobial agents.

scholarly journals Complete Genome Sequences of Methicillin-Resistant Staphylococcus aureus Strains 110900 and 128254, Two Representatives of the CRISPR-Cas-Carrying Sequence Type 630/spa Type t4549 Lineage

2020 ◽  
Vol 9 (41) ◽  
Author(s):  
Raphael N. Sieber ◽  
Søren Overballe-Petersen ◽  
Hülya Kaya ◽  
Anders R. Larsen ◽  
Andreas Petersen
Keyword(s):  
Staphylococcus Aureus ◽  
Complete Genome ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Nordic Countries ◽  
Sequence Type ◽  
Genome Sequences ◽  
Methicillin Resistant ◽  
Content Type ◽  
Spa Type

ABSTRACT Methicillin-resistant Staphylococcus aureus (MRSA) sequence type 630 (ST630) and spa type t4549 is an emerging lineage in Nordic countries, and some representatives carry the CRISPR-Cas system. Here, the complete genome sequences of two isolates from this lineage are presented, comprising chromosomes of 2,918,239 and 2,877,083 nucleotides, respectively, and a 2,473-nucleotide plasmid carrying erm(C).

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