Global regulation of virulence determinants in Staphylococcus Aureus by the SarA protein family

2002 ◽  
Vol 7 (1-3) ◽  
pp. d1825 ◽  
Author(s):  
Ambrose, L Cheung
Keyword(s):  
Staphylococcus Aureus ◽  
Protein Family ◽  
Virulence Determinants ◽  
Global Regulation

scholarly journals The Prevalence of Virulence Determinants and Antibiotic Resistance Patterns in Methicillin—Resistant Staphylococcus aureus in a Nursing Home in Poland

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 427
Author(s):  
Martyna Kasela ◽  
Agnieszka Grzegorczyk ◽  
Bożena Nowakowicz-Dębek ◽  
Anna Malm
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Variable Number Tandem Repeat ◽  
Multidrug Resistant ◽  
Variable Number ◽  
Pulse Field ◽  
Virulence Determinants ◽  
Gene Encoding ◽  
Methicillin Resistant ◽  
Pulse Field Gel Electrophoresis

Nursing homes (NH) contribute to the regional spread of methicillin-resistant Staphylococcus aureus (MRSA). Moreover, residents are vulnerable to the colonization and subsequent infection of MRSA etiology. We aimed at investigating the molecular and phenotypic characteristics of 21 MRSA collected from the residents and personnel in an NH (Lublin, Poland) during 2018. All MRSA were screened for 20 genes encoding virulence determinants (sea-see, eta, etb, tst, lukS-F-PV, eno, cna, ebpS, fib, bbp, fnbA, fnbB, icaADBC) and for resistance to 18 antimicrobials. To establish the relatedness and clonal complexes of MRSA in NH we applied multiple-locus variable-number tandem-repeat fingerprinting (MLVF), pulse field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing. We identified four sequence types (ST) among two clonal complexes (CC): ST (CC22) known as EMRSA-15 as well as three novel STs—ST6295 (CC8), ST6293 (CC8) and ST6294. All tested MRSA were negative for sec, eta, etb, lukS-F-PV, bbp and ebpS genes. The most prevalent gene encoding toxin was sed (52.4%; n = 11/21), and adhesins were eno and fnbA (100%). Only 9.5% (n = 2/21) of MRSA were classified as multidrug-resistant. The emergence of novel MRSA with a unique virulence and the presence of epidemic clone EMRSA-15 creates challenges for controlling the spread of MRSA in NH.

scholarly journals Staphylococcus aureus CcpA Affects Virulence Determinant Production and Antibiotic Resistance

2006 ◽  
Vol 50 (4) ◽  
pp. 1183-1194 ◽  
Author(s):  
Kati Seidl ◽  
Martin Stucki ◽  
Martin Ruegg ◽  
Christiane Goerke ◽  
Christiane Wolz ◽  
...  
Keyword(s):  
Gene Expression ◽  
Staphylococcus Aureus ◽  
Capsular Polysaccharide ◽  
Protein A ◽  
Virulence Gene ◽  
Exponential Growth Phase ◽  
Virulence Determinants ◽  
Resistance Level ◽  
Virulence Gene Expression ◽  
Oxacillin Resistance

ABSTRACT Carbon catabolite protein A (CcpA) is known to function as a major regulator of gene expression in different gram-positive organisms. Deletion of the ccpA homologue (saCOL1786) in Staphylococcus aureus was found to affect growth, glucose metabolization, and transcription of selected virulence determinants. In liquid culture, deletion of CcpA decreased the growth rate and yield; however, the effect was only transient during the exponential-growth phase as long as glucose was present in the medium. Depletion of glucose and production of lactate was delayed, while the level of excretion of acetate was less affected and was even higher in the mutant culture. On solid medium, in contrast, growth of the ΔccpA mutant resulted in smaller colonies containing a lower number of CFU per colony. Deletion of CcpA had an effect on the expression of important virulence factors of S. aureus by down-regulating RNAIII, the effector molecule of the agr locus, and altering the transcription patterns of hla, encoding α-hemolysin, and spa, encoding protein A. CcpA inactivation markedly reduced the oxacillin resistance levels in the highly methicillin-resistant S. aureus strain COLn and the teicoplanin resistance level in a glycopeptide-intermediate-resistant S. aureus strain. The presence of CcpA in the capsular polysaccharide serotype 5 (CP5)-producing strain Newman abolished capsule formation and decreased cap operon transcription in the presence of glucose. The staphylococcal CcpA thus not only is involved in the regulation of carbon metabolism but seems to function as a modulator of virulence gene expression as well.

scholarly journals Prevalence of Methicillin Resistant and Virulence Determinants in Clinical Isolates of Staphylococcus aureus

2018 ◽  
Vol 10 (1) ◽  
pp. 108-115
Author(s):  
Manjunath Chavadi ◽  
Rahul Narasanna ◽  
Ashajyothi Chavan ◽  
Ajay Kumar Oli ◽  
Chandrakanth Kelmani. R
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Morphology ◽  
Methicillin Resistance ◽  
Protein A ◽  
Clinical Isolates ◽  
Clinical Samples ◽  
Virulence Determinants ◽  
Methicillin Resistant ◽  
Alternative Medicines ◽  
Mrsa Strains

Introduction:Methicillin-resistantStaphylococcus aureus(MRSA) is the major threat that is a result of the uncontrolled use of antibiotics causing a huge loss in health, so understanding their prevalence is necessary as a public health measure.Objective:The aim of this study was to determine the prevalence of methicillin-resistant MRSA and virulence determinant among associatedS. aureusfrom the clinical samples obtained from various hospital and health care centers of the Gulbarga region in India.Materials and Methods:All the collected samples were subjected for the screening ofS. aureusand were further characterized by conventional and molecular methods including their antibiotic profiling. Further, the response of methicillin antibiotic on cell morphology was studied using scanning electron microscopy.Results:A total 126S. aureuswas isolated from the clinical samples which showed, 100% resistant to penicillin, 55.5% to oxacillin, 75.3% to ampicillin, 70.6% to streptomycin, 66.6% to gentamicin, 8.7% to vancomycin and 6.3% to teicoplanin. The selected MRSA strains were found to possessmecA(gene coding for penicillin-binding protein 2A) andfemA(factor essential for methicillin resistance)genetic determinants in their genome with virulence determinants such as Coagulase (coa) and the X region of the protein A (spa)gene. Further, the methicillin response in resistantS. aureusshowed to be enlarged and malformed on cell morphology.Conclusion:The molecular typing of clinical isolates ofS. aureusin this study was highly virulent and also resistant to methicillin; this will assist health professionals to control, exploration of alternative medicines and new approaches to combat Staphylococcal infections more efficiently by using targeted therapy.

Molecular Characterization, Virulence Determinants, and Antimicrobial Resistance Profile of Methicillin-Resistant Staphylococcus aureus in the North of Iran; a High Prevalence of ST239-SCCmec III/t037 Clone

Chemotherapy ◽  
2021 ◽  
pp. 1-10
Author(s):  
Hao Ying ◽  
Trias Mahmudiono ◽  
Tawfeeq Alghazali ◽  
Walid Kamal Abdelbasset ◽  
Parand Khadivar ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Health Concern ◽  
Diffusion Method ◽  
Virulence Determinants ◽  
Disk Diffusion Method ◽  
Methicillin Resistant ◽  
The North ◽  
Effective Manner ◽  
High Prevalence ◽  
North Of Iran

<b><i>Objectives:</i></b> Emergence and prevalence of methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) have become a major universal health concern, limiting therapeutic options. <b><i>Methods:</i></b> A total number of 37 MRSA isolates, including 19 clinical isolates from hospitalized patients and 18 colonizing isolates from health care workers were identified from 3 hospitals, in Gorgan, North of Iran. Antimicrobial susceptibility test was performed using the disk diffusion method and E-test. The presence of virulence and antibiotic resistance determinants were evaluated by PCR. The genotypical characterization was further analyzed using multi-locus sequence, <i>spa</i>, staphylococcal cassette chromosome, <i>mec</i> (SCC<i>mec)</i>, and <i>agr</i> typing. <b><i>Results:</i></b> The frequency of MRSA among <i>S. aureus</i> isolates was 38.14% (37/97). The most frequent <i>S. aureus</i> resistant isolates were found to be obstinate against penicillin (98%) and gentamicin (82.5%). Additionally, the lowest resistance rates were found against daptomycin (0%), vancomycin (2.7%), and quinupristin-dalfopristin (5.4%). All MRSA isolates were susceptible to daptomycin with minimum inhibitory concentration (MIC)50/MIC90 of 0.25/0.5 μg/mL. One isolate belonging to sequence type 239 (ST239)-SCC<i>mec</i>III/t037 clone (MIC ≥16 μg/mL) was resistant to vancomycin. All but 1 isolate that shares ST22-SCC<i>mec</i> IV/t790 strain were positive for both <i>tsst</i> and <i>pvl</i> genes. The most predominant MRSA isolates (27%) were associated with ST239-SCC<i>mec</i> III/t037, and ST239-SCC<i>mec</i> III/t924 (16.2%) clones, subsequently. In our study, circulating MRSA strains were genetically diverse with a high prevalence of ST239-SCC<i>mec</i> III/t037 clone. <b><i>Conclusion:</i></b> These findings emphasize the need for future and continuous surveillance studies on MRSA to prevent the dissemination of existing multidrug resistance MRSA clones in an effective manner.

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