Genetic Characterization of a Vancomycin-Resistant Staphylococcus aureus Isolate from the Respiratory Tract of a Patient in a University Hospital in Northeastern Iran

Background. Global concerns have been raised due to upward trend of Vancomycin Intermediate Staphylococcus aureus (VISA) and Vancomycin Resistant Staphylococcus aureus (VRSA) reports which mean casting doubt on the absolute effectiveness of the last line of antibiotic treatment for S. aureus, vancomycin. Hence, epidemiological evaluation can improve global health care policies. Methodology. 171 Isolates of Staphylococcus aureus were collected from different types of clinical samples in selected hospitals in Isfahan, Mashhad, and Tehran, Iran. Then, they were evaluated by agar screening, disk diffusion, and MIC method to determine their resistance to vancomycin and methicillin. The isolated VISA strains were then confirmed with genetic analysis by the evaluation of mecA and vanA genes, SCCmec, agr, and spa type, and also toxin profiles. MLST was also performed. Results and Conclusion. Our data indicated that 67% of isolated S. aureus strains were resistant to methicillin. Furthermore, five isolates (2.9%) had intermediate resistance to vancomycin (VISA). In contrast to usual association of VISA with MRSA strains, we found two isolates of MSSA-VISA. Therefore, our data suggests a probable parallel growing trend of VISA towards MSSA, along with MRSA strains. However, more samples are required to confirm these primarily data. Moreover, genetic analysis of the isolated VISA strains revealed that these strains are endemic Asian clones.

Download Full-text

Recovery and Characterization of a 30.7-kDa Protein from Bacillus licheniformis Associated with Inhibitory Activity Against Methicillin-Resistant Staphylococcus aureus, Vancomycin-Resistant Enterococci, and Listeria monocytogenes

Marine Biotechnology ◽

10.1007/s10126-005-6160-4 ◽

2006 ◽

Vol 8 (6) ◽

pp. 587-592 ◽

Cited By ~ 9

Author(s):

Mamdoh T. Jamal ◽

Peter C. Morris ◽

Rasmus Hansen ◽

Derek J. Jamieson ◽

J. Grant Burgess ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Listeria Monocytogenes ◽

Bacillus Licheniformis ◽

Inhibitory Activity ◽

Methicillin Resistant Staphylococcus Aureus ◽

Methicillin Resistant ◽

Vancomycin Resistant Enterococci ◽

Vancomycin Resistant

Download Full-text

Characterization of Passage-Selected Vancomycin-Resistant Staphylococcus aureus Strains of Diverse Parental Backgrounds

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.44.2.294-303.2000 ◽

2000 ◽

Vol 44 (2) ◽

pp. 294-303 ◽

Cited By ~ 82

Author(s):

Richard F. Pfeltz ◽

Vineet K. Singh ◽

Jennifer L. Schmidt ◽

Michael A. Batten ◽

Christopher S. Baranyk ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Cell Walls ◽

Methicillin Resistance ◽

Surface Hydrophobicity ◽

Whole Cell ◽

Transmission Electron ◽

Vancomycin Mics ◽

Vancomycin Resistant ◽

Doubling Times

ABSTRACT A series of 12 Staphylococcus aureus strains of various genetic backgrounds, methicillin resistance levels, and autolytic activities were subjected to selection for the glycopeptide-intermediate S. aureus (GISA) susceptibility phenotype on increasing concentrations of vancomycin. Six strains acquired the phenotype rapidly, two did so slowly, and four failed to do so. The vancomycin MICs for the GISA strains ranged from 4 to 16 μg/ml, were stable to 20 nonselective passages, and expressed resistance homogeneously. Neither ease of acquisition of the GISA phenotype nor the MIC attained correlated with methicillin resistance hetero- versus homogeneity or autolytic deficiency or sufficiency. Oxacillin MICs were generally unchanged between parent and GISA strains, although the mec members of both isogenic methicillin-susceptible and methicillin-resistant pairs acquired the GISA phenotype more rapidly and to higher MICs than did their susceptible counterparts. Transmission electron microscopy revealed that the GISA strains appeared normal in the absence of vancomycin but had thickened and diffuse cell walls when grown with vancomycin at one-half the MIC. Common features among GISAs were reduced doubling times, decreased lysostaphin susceptibilities, and reduced whole-cell and zymographic autolytic activities in the absence of vancomycin. This, with surface hydrophobicity differences, indicated that even in the absence of vancomycin the GISA cell walls differed from those of the parents. Autolytic activities were further reduced by the inclusion of vancomycin in whole-cell and zymographic studies. The six least vancomycin-susceptible GISA strains exhibited an increased capacity to remove vancomycin from the medium versus their parent lines. This study suggests that while some elements of the GISA phenotype are strain specific, many are common to the phenotype although their expression is influenced by genetic background. GISA strains with similar glycopeptide MICs may express individual components of the phenotype to different extents.

Download Full-text

Correlation between antimicrobial consumption and incidence of health-care-associated infections due to methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci at a university hospital in Taiwan from 2000 to 2010

Journal of Microbiology Immunology and Infection ◽

10.1016/j.jmii.2013.10.008 ◽

2015 ◽

Vol 48 (4) ◽

pp. 431-436 ◽

Cited By ~ 13

Author(s):

Chih-Cheng Lai ◽

Chen-Chen Chu ◽

Aristine Cheng ◽

Yu-Tsung Huang ◽

Po-Ren Hsueh

Keyword(s):

Health Care ◽

Staphylococcus Aureus ◽

Methicillin Resistant Staphylococcus Aureus ◽

University Hospital ◽

Antimicrobial Consumption ◽

Methicillin Resistant ◽

Vancomycin Resistant Enterococci ◽

Health Care Associated Infections ◽

Vancomycin Resistant

Download Full-text

Genetic characterization of two methicillin-resistant Staphylococcus aureus spa type t127 strains isolated from workers in the dairy production chain in Greece

Acta Microbiologica et Immunologica Hungarica ◽

10.1556/030.2021.01460 ◽

2021 ◽

Author(s):

Theodoros Karampatakis ◽

Panagiotis Papadopoulos ◽

Katerina Tsergouli ◽

Apostolos S. Angelidis ◽

Daniel Sergelidis ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Genetic Characterization ◽

Food Handler ◽

Dairy Production ◽

Whole Genome ◽

Genome Sequences ◽

Production Chain ◽

Methicillin Resistant ◽

Mrsa Strains

AbstractMethicillin-resistant Staphylococcus aureus (MRSA) constitutes a constant threat for the public health. Aim of the present study was to analyse the whole genome sequences of two MRSA strains belonging to Staphylococcus protein A (spa) type t127 isolated from humans working in two distantly located dairy production farms in Greece.MRSA strains were isolated from the nasal cavity of a food handler in a milk industry in Epirus, northwestern Greece (E-MRSA), and a person working in a cattle farm in Thrace, northeastern Greece (T-MRSA). Whole genome sequences taken using next generation sequencing were analysed for resistance and virulence genes applying various bioinformatic tools.Both isolates were assigned to ST1-IVa-t127 type, and they were transferring genes conferring resistance to tetracycline, β-lactams, and aminoglycosides; T-MRSA was carrying additional genes leading to macrolide, lincosamide and streptogramin B (MLSB) resistance. Both isolates were carrying three plasmid replicon types, rep5, rep7 and rep16, while T-MRSA harboured also rep10 and rep15. E-MRSA carried scn and sak genes which were absent from T-MRSA.In conclusion, the genetic characterization of two unrelated ST1-IVa-t127 MRSA strains isolated from humans in close contact with livestock in Greece can be used as basis for further epidemiological and evolutionary studies.

Download Full-text