scholarly journals Transmission and Persistence of Livestock-Associated Methicillin-Resistant Staphylococcus aureus among Veterinarians and Their Household Members

2014 ◽  
Vol 81 (1) ◽  
pp. 124-129 ◽  
Author(s):  
T. Bosch ◽  
E. Verkade ◽  
M. van Luit ◽  
F. Landman ◽  
J. Kluytmans ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Genotypic Variation ◽  
Methicillin Resistant ◽  
Content Type ◽  
Genome Maps ◽  
Household Members ◽  
Mrsa Strains ◽  
Prospective Longitudinal

ABSTRACTAfter the first isolation of livestock-associated methicillin-resistantStaphylococcus aureus(LA-MRSA) in 2003, this MRSA variant quickly became the predominant MRSA obtained from humans as part of the Dutch national MRSA surveillance. Previous studies have suggested that human-to-human transmission of LA-MRSA, compared to that of other MRSA lineages, rarely occurs. However, these reports describe the transmission of LA-MRSA based on epidemiology and limited molecular characterization of isolates, making it difficult to assess whether transmission actually occurred. In this study, we used whole-genome maps (WGMs) to identify possible transmission of LA-MRSA between humans. For this, we used LA-MRSA isolates originating from a 2-year prospective longitudinal cohort study in which livestock veterinarians and their household members were repeatedly sampled for the presence ofS. aureus. A considerable degree of genotypic variation among LA-MRSA strains was observed. However, there was very limited variability between the maps of the isolates originating from the same veterinarian, indicating that each of the veterinarians persistently carried or had reacquired the same LA-MRSA strain. Comparison of WGMs revealed that LA-MRSA transmission had likely occurred within virtually every veterinarian household. Yet only a single LA-MRSA strain per household appeared to be involved in transmission. The results corroborate our previous finding that LA-MRSA is genetically diverse. Furthermore, this study shows that transmission of LA-MRSA between humans occurs and that carriage of LA-MRSA can be persistent, thus posing a potential risk for spread of this highly resistant pathogen in the community.

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 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 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 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 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 Characterization of Gentamicin-Susceptible Strains of Methicillin-Resistant Staphylococcus aureus Involved in Nosocomial Spread

1998 ◽  
Vol 36 (1) ◽  
pp. 81-85 ◽  
Author(s):  
Nadine Lemaître ◽  
Wladimir Sougakoff ◽  
Afef Masmoudi ◽  
Marie-Hélène Fievet ◽  
Roland Bismuth ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Dna Hybridization ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Pulsed Field Gel Electrophoresis ◽  
Cross Infection ◽  
Methicillin Resistant ◽  
Resistance Patterns ◽  
Mrsa Strains ◽  
Selection Of

We report an outbreak of epidemic Staphylococcus aureusstrains characterized by an unusual heterogeneous resistance to methicillin and resistance to tobramycin but susceptibility to gentamicin (gentamicin-susceptible methicillin-resistant S. aureus [GS-MRSA]), contrasting with gentamicin-resistant homogeneous MRSA (GR-MRSA) that have been endemic in our hospital since the 1970s. A total of 97 GS-MRSA strains, which were shown by DNA hybridization to carry the mecA and ant(4′)-Iagenes, were studied. The 40 GS-MRSA strains isolated at the beginning of the outbreak (January 1992 to June 1993) were typed by using resistance patterns, phage typing, serotyping, and pulsed-field gel electrophoresis and were compared with GR-MRSA and methicillin-susceptible S. aureus (MSSA) strains isolated during the same period. Two dominant clones, A::1 and B::3, and one minor clone, C::5, were identified among the 40 GS-MRSA strains, according to pulsotypes (A to C) and their resistance patterns (1, 3, and 5), which were distinguishable from those of GR-MRSA and MSSA strains. A selection of 57 GS-MRSA strains, isolated from 1994 to 1996, were clustered in the same three clones. However, their distribution had changed in comparison with that in the 1992 to 1993 period: clone A::1 remained dominant (47 versus 42.5%), whereas clone B::3 progressively declined (5 versus 35%) and clone C::5, the most susceptible to antibiotics, spread (44 versus 2.5%). Epidemiological investigations revealed that some clones had been introduced via patients transferred from other hospitals and that cross-infection occurred within and between wards. Major changes in the use of antibiotics, especially aminoglycosides, cyclines, and macrolides, likely played a role in the emergence and spread of GS-MRSA strains.

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.

scholarly journals Molecular Characterization of Community-Associated Methicillin-Resistant Staphylococcus aureus in Iranian Burn Patients

2019 ◽  
Vol 14 (4) ◽  
pp. 284-289 ◽  
Author(s):  
Samira Tajik ◽  
Shahin Najar Peerayeh ◽  
Bita Bakhshi ◽  
Reza Golmohammadi
Keyword(s):  
Staphylococcus Aureus ◽  
Molecular Characterization ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Significant Proportion ◽  
Burn Patients ◽  
Burn Wound ◽  
Methicillin Resistant ◽  
Pfge Typing ◽  
Mrsa Strains

Background & Objective: Methicillin-resistant Staphylococcus aureus (MRSA) is reported as one of the important bacterial causes of burn wound infections. This study was carried out to investigate molecular characterization of community-associated MRSA (CA-MRSA) isolated from Iranian burn patients. Methods: A total of 31 isolates of S. aureus were collected fromthe Motahari Burns Hospital (Tehran, Iran) in 2016. All isolates were collected from outpatients and inpatients within 48 hours of admission. The mecA, pvl, tsst-1, hla-α, and psmα genes detecting, SCCmec, agr and PFGE typing were done. Results: A total of 13 (41.9%) isolates were cefoxitin-resistant and mecA-positive, which were considered as MRSA. The SCCmec typing MRSA strains revealed type II in 1 (7.7%), type III in 9 (69.2%), and other types in 3 isolates (23.7%) cases. The agrtyping of all 31 isolates showed that 14 (45.2%), 1 (3.2%), 6 (19.4%), and 10 (32.3%) strains belonged to agr groups 1, 3, 4, and unknown type, respectively. The pvl, tsst-1, hla-α, and psmα genes were positive in 3 (9.7%), 4 (12.9%), 21 (67.7%), and 31 (100%) isolates, respectively. Considering the cut-off values of ≥50%, 3 groups of related isolates (cluster A1, B1, and C1) in PFGE study were observed. Conclusion: The MRSA strains of this study were initially isolated as Community-associated S. aureus (CA-MRSA); however molecular characterization showed that a significant proportion of them had hospital-associated MRSA (HA-MRSA) features. Therefore, it is likely that the HA-MRSA strains are spread among the community.

scholarly journals Complete Genome Sequence of the Methicillin-Resistant Staphylococcus aureus Colonizing Strain M92

2017 ◽  
Vol 5 (23) ◽  
Author(s):  
Jo-Ann McClure ◽  
Kunyan Zhang
Keyword(s):  
Staphylococcus Aureus ◽  
Complete Genome ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Hospital Staff ◽  
Nasal Colonization ◽  
Methicillin Resistant ◽  
Content Type ◽  
Mrsa Strains ◽  
Highly Virulent ◽  
Insight Into

ABSTRACT M92 is a methicillin-resistant Staphylococcus aureus (MRSA) colonizing strain belonging to ST239-MRSA-III. It frequently shows local nasal colonization in our hospital staff, but has never been associated with infection. We sequenced the complete genome of M92, in order to compare it to highly virulent MRSA strains to gain insight into MRSA virulence factors.

Sign in / Sign up

Export Citation Format

Share Document