scholarly journals Novel Types of Staphylococcal Cassette ChromosomemecElements Identified in Clonal Complex 398 Methicillin-Resistant Staphylococcus aureus Strains

2011 ◽  
Vol 55 (6) ◽  
pp. 3046-3050 ◽  
Author(s):  
Shanshuang Li ◽  
Robert Leo Skov ◽  
Xiao Han ◽  
Anders Rhod Larsen ◽  
Jesper Larsen ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Clonal Complex ◽  
Subtype C ◽  
Methicillin Resistant ◽  
Content Type ◽  
Original Host ◽  
Mrsa Strains ◽  
Type V ◽  
Staphylococcal Cassette Chromosome

ABSTRACTThe structures of staphylococcal cassette chromosomemec(SCCmec) elements carried by 31 clonal complex 398 (CC398) methicillin-resistantStaphylococcus aureus(MRSA) strains isolated from the participants at a conference were analyzed. The SCCmecs were classified into novel types, namely, IX, X, V(5C2&5) subtype c, and IVa. Type V(5C2&5) subtype c, IX, and X SCCmecs carried genes conferring resistance to metals. The structures of SCCmecs from CC398 strains were distinct from those normally found in humans, adding to the evidence that humans are not the original host for CC398.

scholarly journals Scope and Predictive Genetic/Phenotypic Signatures of Bicarbonate (NaHCO3) Responsiveness and β-Lactam Sensitization in Methicillin-Resistant Staphylococcus aureus

2020 ◽  
Vol 64 (5) ◽  
Author(s):  
Selvi C. Ersoy ◽  
Mariam Otmishi ◽  
Vanessa T. Milan ◽  
Liang Li ◽  
Youngju Pak ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Clonal Complex ◽  
Population Analysis ◽  
Methicillin Resistant ◽  
Content Type ◽  
Mueller Hinton ◽  
Testing Medium ◽  
Mrsa Strains ◽  
Mueller Hinton Broth

ABSTRACT Addition of sodium bicarbonate (NaHCO3) to standard antimicrobial susceptibility testing medium reveals certain methicillin-resistant Staphylococcus aureus (MRSA) strains to be highly susceptible to β-lactams. We investigated the prevalence of this phenotype (NaHCO3 responsiveness) to two β-lactams among 58 clinical MRSA bloodstream isolates. Of note, ∼75% and ∼36% of isolates displayed the NaHCO3 responsiveness phenotype to cefazolin (CFZ) and oxacillin (OXA), respectively. Neither intrinsic β-lactam MICs in standard Mueller-Hinton broth (MHB) nor population analysis profiles were predictive of this phenotype. Several genotypic markers (clonal complex 8 [CC8]; agr I and spa t008) were associated with NaHCO3 responsiveness for OXA.

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 Copresence oftet(K) andtet(M) in Livestock-Associated Methicillin-Resistant Staphylococcus aureus Clonal Complex 398 Is Associated with Increased Fitness during Exposure to Sublethal Concentrations of Tetracycline

2016 ◽  
Vol 60 (7) ◽  
pp. 4401-4403 ◽  
Author(s):  
Jesper Larsen ◽  
Julie Clasen ◽  
Julie E. Hansen ◽  
Wilhelm Paulander ◽  
Andreas Petersen ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Resistance Gene ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Clonal Complex ◽  
Tetracycline Resistance ◽  
Tetracycline Resistance Gene ◽  
Methicillin Resistant ◽  
Content Type ◽  
Sublethal Concentrations ◽  
Staphylococcal Cassette Chromosome

ABSTRACTThe tetracycline resistance genetet(K) was shown to be integrated within the predominant staphylococcal cassette chromosomemec(SCCmec) element of Danish livestock-associated methicillin-resistantStaphylococcus aureusCC398 (LA-MRSA CC398). These LA-MRSA CC398 isolates already possessedtet(M), but the acquisition oftet(K) significantly improved their fitness at sublethal concentrations of tetracycline. Becausetet(K) is genetically linked to SCCmec, the use of tetracycline in food animals may have contributed to the successful spread of LA-MRSA CC398.

scholarly journals Detection ofmecA- andmecC-Positive Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates by the New Xpert MRSA Gen 3 PCR Assay: TABLE 1

2015 ◽  
Vol 54 (1) ◽  
pp. 180-184 ◽  
Author(s):  
Karsten Becker ◽  
Olivier Denis ◽  
Sandrine Roisin ◽  
Alexander Mellmann ◽  
Evgeny A. Idelevich ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Pcr Assay ◽  
Coagulase Negative Staphylococci ◽  
Methicillin Resistant ◽  
Content Type ◽  
Mrsa Strains ◽  
Staphylococcal Cassette Chromosome

An advanced methicillin-resistantStaphylococcus aureus(MRSA) detection PCR approach targeting SCCmec-orfXalong withmecAandmecCwas evaluated forS. aureusand coagulase-negative staphylococci. The possession ofmecAand/ormecCwas correctly confirmed in all cases. All methicillin-susceptibleS. aureusstrains (n= 98; including staphylococcal cassette chromosomemecelement [SCCmec] remnants) and 98.1% of the MRSA strains (n= 160, including 10mecC-positive MRSA) were accurately categorized.

scholarly journals Complete Genome Sequence of Systemically Disseminated Sequence Type 8 Staphylococcal Cassette Chromosome mec Type IVl Community-Acquired Methicillin-Resistant Staphylococcus aureus

2017 ◽  
Vol 5 (35) ◽  
Author(s):  
Junzo Hisatsune ◽  
Hideharu Hagiya ◽  
Sumiko Shiota ◽  
Motoyuki Sugai
Keyword(s):  
Staphylococcus Aureus ◽  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Sequence Type ◽  
Methicillin Resistant ◽  
Content Type ◽  
Staphylococcal Cassette Chromosome ◽  
Epidermal Cell Differentiation

ABSTRACT Staphylococcus aureus JH4899, a community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) isolate collected from a patient with systematically disseminated infection, is classified as sequence type 8 and carries the staphylococcal cassette chromosome mec type IVl (SCCmecIVl). It produces TSST-1, SEC, a newly discovered enterotoxin (SE1), and epidermal cell differentiation inhibitor A (EDIN-A). Here, we present the complete genome sequence of the chromosome and a plasmid harboring the se1 and ednA genes.

scholarly journals AUC/MIC Pharmacodynamic Target Is Not a Good Predictor of Vancomycin Efficacy in Methicillin-Resistant Staphylococcus aureus Experimental Endocarditis

2017 ◽  
Vol 61 (6) ◽  
Author(s):  
Ximena Castañeda ◽  
Cristina García-de-la-Mària ◽  
Oriol Gasch ◽  
Juan M. Pericas ◽  
Yolanda Armero ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Good Predictor ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Area Under The Curve ◽  
Methicillin Resistant ◽  
Bacterial Counts ◽  
Content Type ◽  
Treatment Groups ◽  
Mrsa Strains

ABSTRACT The aim of this in vivo study was to compare the efficacy of vancomycin at standard doses (VAN-SD) to that of VAN at adjusted doses (VAN-AD) in achieving a VAN area under the curve/MIC ratio (AUC/MIC) of ≥400 against three methicillin-resistant Staphylococcus aureus (MRSA) strains with different microdilution VAN MICs in an experimental endocarditis model. The valve vegetation bacterial counts after 48 h of VAN therapy were compared, and no differences were observed between the two treatment groups for any of the three strains tested. Overall, for VAN-SD and VAN-AD, the rates of sterile vegetations were 15/45 (33.3%) and 21/49 (42.8%) (P = 0.343), while the medians (interquartile ranges [IQRs]) for log10 CFU/g of vegetation were 2 (0 to 6.9) and 2 (0 to 4.5) (P = 0.384), respectively. In conclusion, this VAN AUC/MIC pharmacodynamic target was not a good predictor of vancomycin efficacy in MRSA experimental endocarditis.

scholarly journals Complete Genome Sequences of Eight Methicillin-Resistant Staphylococcus aureus Strains Isolated from Patients in Japan

2019 ◽  
Vol 8 (47) ◽  
Author(s):  
Miyako Hikichi ◽  
Miki Nagao ◽  
Kazunori Murase ◽  
Chihiro Aikawa ◽  
Takashi Nozawa ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Soft Tissue ◽  
Complete Genome ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Clinical Manifestations ◽  
Invasive Disease ◽  
Genome Sequences ◽  
Methicillin Resistant ◽  
Content Type ◽  
Mrsa Strains

Methicillin-resistant Staphylococcus aureus (MRSA) is a major pathogen causing nosocomial infections, and the clinical manifestations of MRSA range from asymptomatic colonization of the nasal mucosa to soft tissue infection to fulminant invasive disease. Here, we report the complete genome sequences of eight MRSA strains isolated from patients in Japan.

scholarly journals Modulation ofccrABExpression and SCCmecExcision by an Inverted Repeat Element and SarS in Methicillin-Resistant Staphylococcus aureus

2015 ◽  
Vol 59 (10) ◽  
pp. 6223-6232 ◽  
Author(s):  
Shijie Zhang ◽  
Ronghua Ma ◽  
Xiaoyu Liu ◽  
Xu Zhang ◽  
Baolin Sun
Keyword(s):  
Staphylococcus Aureus ◽  
Inverted Repeat ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Regulatory Mechanism ◽  
Human Pathogen ◽  
Entire Family ◽  
Methicillin Resistant ◽  
Content Type ◽  
Mrsa Strains ◽  
Dna Affinity Chromatography

ABSTRACTMethicillin-resistantStaphylococcus aureus(MRSA) is a notorious human pathogen that can cause a broad spectrum of infections. MRSA strains are resistant to almost the entire family of β-lactam antibiotics due to the acquisition of staphylococcal cassette chromosomemec(SCCmec). The chromosome cassette recombinases A and B, encoded byccrABgenes located on SCCmec, play a key role in the excision of SCCmec. Studies have shown thatccrABgenes are expressed in only a minority of cells, suggesting the involvement of a subtle regulatory mechanism inccrABexpression which has not been uncovered. Here, we found that an inverted repeat (IR) element, existing extensively and conservatively within theccrABpromoter of different SCCmectypes, played a repressive role inccrABexpression and SCCmecexcision in MRSA strain N315. Replacement of the IR sequence led to a significant increase inccrABexpression and curing of SCCmecfrom strain N315 cells. In addition, we identified the transcriptional regulator SarS using DNA-affinity chromatography and further demonstrated that SarS can bind to the IR sequence and upregulateccrABexpression and SCCmecexcision. These findings reveal a molecular mechanism regulatingccrABexpression and SCCmecexcision and may provide mechanic insights into the lateral transfer of SCCmecand spread of antibiotic resistance inS. aureus.

scholarly journals Molecular analysis of methicillin-resistant Staphylococcus aureus isolates from four teaching hospitals in Iran: The emergence of Novel MRSA ST- SCCmec clones

2020 ◽  
Author(s):  
Farzaneh Firoozeh ◽  
Mitra Omidi ◽  
Mahmood Saffari ◽  
Hossein Sedaghat ◽  
Mohammad Zibaei
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Teaching Hospitals ◽  
Diffusion Method ◽  
Methicillin Resistant ◽  
Resistance Patterns ◽  
Mrsa Strains ◽  
Type V ◽  
Resistance Rates ◽  
Antibiotic Resistance Patterns

Abstract Background: The global spread of methicillin-resistant Staphylococcus aureus (MRSA) infections necessitates the use of validated methods for the identification and typing of this bacterium. This study aimed to determine the distribution of main molecular types of MRSA strain circulating among hospitalized patients in teaching hospitals in Isfahan and Kashan. Methods: A total of 146 Staphylococcus aureus strains were isolated from patients in four teaching hospitals in Isfahan and Kashan during June 2017 to September 2018. The antibiotic resistance patterns of Staphylococcus aureus strains were performed by disc diffusion method. The MRSA strains were identified phenotypically and confirmed by PCR assay. The prevalence of microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) genes among MRSA strains was evaluated by multiplex PCR. The genotypes of MRSA strains were determined by multi-locus sequence type and SCC mec typing. Results: Of 146 Staphylococcus aureus isolates 24 (16.4%) isolates identified as MRSA strains. According to antibiotic susceptibility testing the highest resistance rates were seen to erythromycin, cefoxitin and clindamycin. All of Staphylococcus aureus isolates were sensitive to vancomycin whereas 3 (2.1%) isolates were resistant to linezolid. Three different SCC mec types were obtained among MRSA strains including 16 (66.7%) SCC mec type V, 3 (12.5%) SCC mec type III and 5 (20.8%) SCC mec type II. Of 24 MRSA isolates 20 (83.3%) carried MSCRAMMs genes including eno (70.8%), fib (54.1%) , cna (25.0%), fnbB (16.6%) , ebps 5 (20.8%), and fnbA , bbp and clfA genes were not detected. MLST analysis revealed 11 sequence types among MRSA isolates as follows: ST239, ST239, ST291, ST22, ST861, ST 889, ST8, ST59, ST343, ST772, ST6 and ST1465. Also seven MLST-based clonal complexes (CCs) were identified among MRSA strains including: CC8, CC7, CC398, CC59, CC22, CC1 and CC5. Conclusions: A relatively high diversity was found in MRSA genotypes in Kashan and Isfahan hospitals, and seven clonal complexes were identified. Pandemic MRSA clones including CC8 and CC22 were the most prevalent clones and the novel ST types including ST1465, ST861, ST 889 and ST772 are reported for the first time in Iran in the present study. In addition the high prevalence of MSCRAMMs genes in MRSA isolates demonstrates the high potential of these strains for pathogenicity.

scholarly journals Telavancin Is Active against Experimental Aortic Valve Endocarditis Caused by Daptomycin- and Methicillin-Resistant Staphylococcus aureus Strains

2016 ◽  
Vol 61 (2) ◽  
Author(s):  
Wessam Abdelhady ◽  
Arnold S. Bayer ◽  
Rachelle Gonzales ◽  
Liang Li ◽  
Yan Q. Xiong
Keyword(s):  
Staphylococcus Aureus ◽  
Aortic Valve ◽  
Untreated Control ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Infection Model ◽  
Methicillin Resistant ◽  
Content Type ◽  
Mrsa Strains ◽  
Culture Negative

ABSTRACT We compared the efficacy of telavancin (TLV) and daptomycin (DAP) in an experimental rabbit endocarditis model caused by two clinically derived daptomycin-resistant (DAPr) methicillin-resistant Staphylococcus aureus (MRSA) strains. TLV treatment significantly reduced MRSA densities in all target tissues and increased the percentage of these organs rendered culture negative compared to those with the untreated control or DAP-treated animals. These results demonstrate that TLV has potent in vivo efficacy against DAPr MRSA isolates in this invasive endovascular infection model.

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