scholarly journals Staphylococcus aureus Susceptibility to Innate Antimicrobial Peptides, β-Defensins and CAP18, Expressed by Human Keratinocytes

2003 ◽  
Vol 71 (7) ◽  
pp. 3730-3739 ◽  
Author(s):  
Kazushige Midorikawa ◽  
Kazuhisa Ouhara ◽  
Hitoshi Komatsuzawa ◽  
Toshihisa Kawai ◽  
Sakuo Yamada ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Peptides ◽  
Bacterial Infection ◽  
Methicillin Resistance ◽  
Antimicrobial Effect ◽  
Human Keratinocytes ◽  
Innate Defense ◽  
Mrsa Strains ◽  
Insight Into ◽  
Increased Susceptibility

ABSTRACT The antimicrobial peptides human β-defensin-1 (hBD1), hBD2, hBD3, and CAP18 expressed by keratinocytes have been implicated in mediation of the innate defense against bacterial infection. To gain insight into Staphylococcus aureus infection, the susceptibility of S. aureus, including methicillin-resistant S. aureus (MRSA), to these antimicrobial peptides was examined. Based on quantitative PCR, expression of hBD2 mRNA by human keratinocytes was significantly induced by contact with S. aureus, and expression of hBD3 and CAP18 mRNA was slightly induced, while hBD1 mRNA was constitutively expressed irrespective of the presence of S. aureus. Ten clinical S. aureus isolates, including five MRSA isolates, induced various levels of expression of hBD2, hBD3, and CAP18 mRNA by human kertinocytes. The activities of hBD3 and CAP18 against S. aureus were found to be greater than those of hBD1 and hBD2. A total of 44 S. aureus clinical isolates, including 22 MRSA strains, were tested for susceptibility to hBD3 and CAP18. Twelve (55%) and 13 (59%) of the MRSA strains exhibited more than 20% survival in the presence of hBD3 (1 μg/ml) and CAP18 (0.5 μg/ml), respectively. However, only three (13%) and two (9%) of the methicillin-sensitive S. aureus isolates exhibited more than 20% survival with hBD3 and CAP18, respectively, suggesting that MRSA is more resistant to these peptides. A synergistic antimicrobial effect between suboptimal doses of methicillin and either hBD3 or CAP18 was observed with 10 MRSA strains. Furthermore, of several genes associated with methicillin resistance, inactivation of the fmtC gene in MRSA strain COL increased susceptibility to the antimicrobial effect mediated by hBD3 or CAP18.

scholarly journals Multiple Antimicrobial Effects of Hybrid Peptides Synthesized Based on the Sequence of Ribosomal S1 Protein from Staphylococcus aureus

2022 ◽  
Vol 23 (1) ◽  
pp. 524
Author(s):  
Sergey V. Kravchenko ◽  
Pavel A. Domnin ◽  
Sergei Y. Grishin ◽  
Alexander V. Panfilov ◽  
Viacheslav N. Azev ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Peptides ◽  
Pathogenic Bacteria ◽  
Antimicrobial Effect ◽  
Cell Penetrating Peptide ◽  
Gram Negative Bacteria ◽  
Antimicrobial Effects ◽  
Bacterial Proteins ◽  
Hybrid Peptides ◽  
Successful Approach

The need to develop new antimicrobial peptides is due to the high resistance of pathogenic bacteria to traditional antibiotics now and in the future. The creation of synthetic peptide constructs is a common and successful approach to the development of new antimicrobial peptides. In this work, we use a simple, flexible, and scalable technique to create hybrid antimicrobial peptides containing amyloidogenic regions of the ribosomal S1 protein from Staphylococcus aureus. While the cell-penetrating peptide allows the peptide to enter the bacterial cell, the amyloidogenic site provides an antimicrobial effect by coaggregating with functional bacterial proteins. We have demonstrated the antimicrobial effects of the R23F, R23DI, and R23EI hybrid peptides against Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Pseudomonas aeruginosa, Escherichia coli, and Bacillus cereus. R23F, R23DI, and R23EI can be used as antimicrobial peptides against Gram-positive and Gram-negative bacteria resistant to traditional antibiotics.

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.

scholarly journals Staphylococcus aureus Infection of Epidermal Keratinocytes Promotes Expression of Innate Antimicrobial Peptides

2005 ◽  
Vol 73 (8) ◽  
pp. 5241-5244 ◽  
Author(s):  
Barbara E. Menzies ◽  
Aimee Kenoyer
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Human Keratinocytes ◽  
Lipoteichoic Acid ◽  
Epidermal Keratinocytes ◽  
Aureus Infection ◽  
Inflammatory Stimuli ◽  
Peptide Expression ◽  
Antimicrobial Peptide Expression

ABSTRACT Keratinocytes upregulate expression of endogenous antimicrobial peptides in response to inflammatory stimuli. We show that both viable and heat-inactivated Staphylococcus aureus and lipoteichoic acid differentially alter expression of these peptides upon contact with human keratinocytes. The findings indicate a diversity of staphylococcal factors involved in upregulation of antimicrobial peptide expression in cutaneous epithelia.

scholarly journals Effects of stigmata maydis on the methicillin resistantStaphylococus aureusbiofilm formation

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6461
Author(s):  
Fei Shang ◽  
Long Li ◽  
Lumin Yu ◽  
Jingtian Ni ◽  
Xiaolin Chen ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Cows ◽  
Biofilm Formation ◽  
Methicillin Resistance ◽  
Biological Activities ◽  
Aqueous Extracts ◽  
Corn Silk ◽  
Reverse Transcription Pcr ◽  
Mammary Gland Tissue ◽  
Mrsa Strains

BackgroundMastitis is an inflammatory reaction of the mammary gland tissue, which causes huge losses to dairy farms throughout the world.Staphylococcus aureusis the most frequent agent associated with this disease.Staphylococcus aureusisolates, which have the ability to form biofilms, usually lead to chronic mastitis in dairy cows. Moreover, methicillin resistance of the bacteria further complicates the treatment of this disease. Stigmata maydis (corn silk), a traditional Chinese medicine, possess many biological activities.MethodsIn this study, we performed antibacterial activity assays, biofilm formation assays and real-time reverse transcription PCR experiments to investigate the effect of stigmata maydis (corn silk) on biofilm formation and vancomycin susceptibility of methicillin-resistantStaphylococcus aureus(MRSA) strains isolated from dairy cows with mastitis.ResultsIn this study, the aqueous extracts of stigmata maydis inhibited the biofilm formation ability of MRSA strains and increased the vancomycin susceptibility of the strains under biofilm-cultured conditions.ConclusionThis study proves that the aqueous extracts of stigmata maydis inhibit the biofilm formation ability of MRSA strains and increase the vancomycin susceptibility of the MRSA strains under biofilm-cultured conditions.

scholarly journals Jumping the Barrier to β-Lactam Resistance in Staphylococcus aureus

2003 ◽  
Vol 185 (18) ◽  
pp. 5465-5472 ◽  
Author(s):  
Yuki Katayama ◽  
Hong-Zhong Zhang ◽  
Dong Hong ◽  
Henry F. Chambers
Keyword(s):  
Staphylococcus Aureus ◽  
Potential Role ◽  
Methicillin Resistance ◽  
Population Analysis ◽  
Regulatory Genes ◽  
Resistance Determinant ◽  
Host Chromosome ◽  
Resistance Phenotype ◽  
Mrsa Strains

ABSTRACT Although the staphylococcal methicillin resistance determinant, mecA, resides on a mobile genetic element, staphylococcus cassette chromosome mec (SCCmec), its distribution in nature is limited to as few as five clusters of related methicillin-resistant Staphylococcus aureus (MRSA) clones. To investigate the potential role of the host chromosome in clonal restriction of the methicillin resistance determinant, we constructed plasmid pYK20, carrying intact mecA, and introduced it into several methicillin-susceptible Staphylococcus aureus strains, five of which were naive hosts (i.e., mecA not previously resident on the host chromosome) and five of which were experienced hosts (i.e., methicillin-susceptible variants of MRSA strains from which SCCmec was excised). We next assessed the effect of the recipient background on the methicillin resistance phenotype by population analysis, by assaying the mecA expression of PBP2a by Western blot analysis, and by screening for mutations affecting mecA. Each experienced host transformed with pYK20 had a resistance phenotype and expressed PBP2a similar to that of the parent with chromosomal SCCmec, but naive hosts transformed with pYK20 selected against its expression, indicative of a host barrier. Either inducible β-lactamase regulatory genes blaR1-blaI or homologous regulatory genes mecR1-mecI, which control mecA expression, acted as compensatory elements, permitting the maintenance and expression of plasmid-carried mecA.

Susceptibility of clinical Staphylococcus aureus isolates to innate defense antimicrobial peptides

2011 ◽  
Vol 13 (8-9) ◽  
pp. 761-765 ◽  
Author(s):  
Siegbert Rieg ◽  
Achim J. Kaasch ◽  
Julian Wehrle ◽  
Silke C. Hofmann ◽  
Magdalena Szymaniak-Vits ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Peptides ◽  
Innate Defense

scholarly journals Methicillin-resistant Staphylococcus aureus (MRSA) in a tertiary surgical and trauma hospital in Benghazi, Libya

2011 ◽  
Vol 5 (10) ◽  
pp. 723-726 ◽  
Author(s):  
Najat Buzaid ◽  
Abdel-Naser Elzouki ◽  
Ibrahim Taher ◽  
Khalifa Sifaw Ghenghesh
Keyword(s):  
Staphylococcus Aureus ◽  
Fusidic Acid ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Methicillin Resistance ◽  
Age Groups ◽  
Resistant Organism ◽  
Surveillance Program ◽  
Term Care ◽  
Methicillin Resistant ◽  
Mrsa Strains

Introduction: Methicillin resistant Staphylococcus aureus (MRSA) is a multidrug resistant organism that threatens the continued effectiveness of antibiotics worldwide and causes a threat almost exclusively in hospitals and long-term care settings. This study investigated the prevalence of MRSA strains and their sensitivity patterns against various antibiotics used for treating hospitalized patients in a major tertiary surgical hospital in Benghazi, Libya. Methodology: We investigated 200 non-duplicate S. aureus strains isolated from different clinical specimens submitted to the Microbiology Laboratory at Aljala Surgical and Trauma Hospital, Benghazi, Libya from April to July 2007. Isolates were tested for methicillin resistance by the oxacillin disc-diffusion assay according to Clinical and Laboratory Standards Institute guidelines. MRSA strains were tested for antimicrobial resistance (i.e., vancomycin, ciprofloxacin, erythromycin, chloramphenicol and fusidic acid) using commercial discs. Information on patient demographics and clinical disease was also collected. Results: Of the isolates examined 31% (62/200) were MRSA. No significant differences were observed in the prevalence of MRSA among S. aureus from females or males or from different age groups. Most MRSA were isolated from burns and surgical wound infections. Antibiotic resistance patterns of 62 patients with MRSA to vancomycin, ciprofloxacin, fusidic acid, chloramphenicol and erythromycin were 17.7%, 33.9%, 41.9%, 38.7% and 46.8% of cases, respectively. Conclusion: MRSA prevalence in our hospital was high and this may be the case for other hospitals in Libya. A sound surveillance program of nosocomial infections is urgently needed to reduce the incidence of infections due to MRSA and other antimicrobial-resistant pathogens in Libyan hospitals.

scholarly journals Inducible Clindamycin Resistance Among the Staphylococcus aureus Colonizing the Anterior Nares of School Children of Udupi Taluk

2014 ◽  
Vol 4 (1) ◽  
pp. 337-340 ◽  
Author(s):  
S Govindan ◽  
C A Mohammed ◽  
I Bairy
Keyword(s):  
Staphylococcus Aureus ◽  
Infection Control ◽  
Methicillin Resistance ◽  
Control Strategies ◽  
Nasal Carriage ◽  
Paediatric Population ◽  
Inducible Clindamycin Resistance ◽  
Health Authorities ◽  
Public Health Authorities ◽  
Mrsa Strains

Clindamycin is one of the preferred antibiotics in the treatment of Staphylococcus aureus (SA) skin and soft tissue infections. However the emergence of inducible clindamycin resistant SA is a major concern for clinicians in the management of such infections. Information about such resistant strains of SA colonizing the anterior nares is very important in planning infection control strategies. The objective of the current study was to assess the proportion of SA showing inducible clindamycin resistance and also to know their association with methicillin resistance. Among the isolates, 11.6% (44/378) strains were showing positive D test which indicates inducible clindamycin resistance and a highly significant 71% (12/17) inducible clindamycin resistance was also noticed in the case of MRSA. The nasal carriage of inducible clindamycin resistant SA showing a significant association with MRSA strains by the paediatric population from this area warrants the inclusion of D test in the routine antibiotic susceptibility testing of SA isolates. Information about the MLSBi status among the colonizing strains would also help the public health authorities to plan and implement infection control strategies at the community level.DOI: http://dx.doi.org/10.3126/nje.v4i1.10136 Nepal Journal of Epidemiology 2014;4 (1): 337-340

scholarly journals ThemecAHomologmecCConfers Resistance against β-Lactams in Staphylococcus aureus Irrespective of the Genetic Strain Background

2014 ◽  
Vol 58 (7) ◽  
pp. 3791-3798 ◽  
Author(s):  
Britta Ballhausen ◽  
André Kriegeskorte ◽  
Nina Schleimer ◽  
Georg Peters ◽  
Karsten Becker
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistance ◽  
Regulatory System ◽  
Wild Type ◽  
Beta Lactam ◽  
Beta Lactams ◽  
Content Type ◽  
Genetic Strain ◽  
Mrsa Strains ◽  
Strain Background

ABSTRACTIn staphylococci, methicillin resistance is mediated bymecA-encoded penicillin-binding protein 2a (PBP2a), which has a low affinity for beta-lactams. Recently, a novel PBP2a homolog was described as being encoded bymecC, which shares only 70% similarity tomecA. To prove thatmecCis the genetic determinant that confers methicillin resistance inStaphylococcus aureus, amecCknockout strain was generated. TheS. aureusΔmecCstrain showed considerably reduced oxacillin and cefoxitin MICs (0.25 and 4 μg/ml, respectively) compared to those of the corresponding wild-type methicillin-resistantS. aureus(MRSA) strain (8 and 16 μg/ml, respectively). Complementing the mutant intranswith wild-typemecCrestored the resistance to oxacillin and cefoxitin. By expressingmecCandmecAin differentS. aureusclonal lineages, we found thatmecCmediates resistance irrespective of the genetic strain background, yielding oxacillin and cefoxitin MIC values comparable to those withmecA. In addition, we showed thatmecCexpression is inducible by oxacillin, which supports the assumption that a functional beta-lactam-dependent regulatory system is active in MRSA strains possessing staphylococcal cassette chromosomemec(SCCmec) type XI. In summary, we showed thatmecCis inducible by oxacillin and mediates beta-lactam resistance in SCCmectype XI-carrying strains as well as in differentS. aureusgenetic backgrounds. Furthermore, our results could explain the comparatively low MICs for clinicalmecC-harboringS. aureusisolates.

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