• Title/Summary/Keyword: Methicillin-resistant Staphylococcus aureus (MRSA)

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A Study on the Antibacterial Activity of Chitosan on the MRSA by the Shake Flask Method and Modified Shake Flask Method (Shake Flask Method와 개량 Shake Flask Method에 의한 키토산의 MRSA 향균성 평가)

  • Choi, Jeong-Im;Jeon, Dong-Won
    • Fashion & Textile Research Journal
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    • v.5 no.1
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    • pp.64-70
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    • 2003
  • Water-insoluble chitosan with molecular weight of 2,000,000, 580,000, 80,000, and 40,000 and more than 90% of degree of deacetylation were prepared to test antibacterial activity of chitosan against a pathogenic bacteria, methicillin resistant Staphylococcus aureus (MRSA). As experimental method, the Shake Flask Method (SFM) and Modified Shake Flask Method (MSFM) were applicated. The anti-microbial activity of chitosan/acetic acid aqueous solution is consistent irrespective of Mw of chitosan. MIC value of SFM measurement was 0.2 ppm, and MIC value of modified SFM measurement was 25 ppm. But MIC value of chitosan/acetic add solution and chitosan treated cotton filter paper was equally 5 ppm. The antibacterial activities of chitosan were different in different test measurements employed. The antibacterial activities of chitosan/acetic acid solution and chitosan treated cotton filter paper were also different. Therefore, it needs to be pointed out that the test measurements of anti-microbial activity have some problems.

Molecular Typing of Staphylococcus aureus Strains from Domestic Animals and Humans by REP-PCR Analysis (REP-PCR을 이용한 국내 사람과 동물유래 Staphylococcus aureus 분리주의 Molecular Typing)

  • Woo Yong-Ku;Kim Shin
    • Korean Journal of Microbiology
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    • v.41 no.1
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    • pp.60-66
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    • 2005
  • To select the rapid and efficient molecular subtyping method for epidemiologic monitoring of Staphylococcus aureus (S. aureus) strains at clinical laboratory levels, a total 116 of S. aureus and MRSA (methicillin-resistant S. aureus) strains from diverse animal species [Korean cattle, goat, pig, dog, chicken, mouse] and also humans were analyzed. To evaluate the discriminatory ability (DA) of individual PCR methods, random amplified polymorphic of DNA [RAPD; 4M & RA primer], repetitive extragenic palindromic sequences PCR (REP-PCR), and enterobacterial repetitive intergenic consensus sequences PCR (ERIC-PCR) methods were conducted and then compared on their Simpson's index of diversity (SID) values based on the dendrogram patterns, which was produced by software program (BiolD2+ & GelCompar II). In first, RAPD using the 4M primer (SID 0.915) was expressed more higher SID value than that of RA primer (SID 0.874). 4M primer was expressed more powerful DA than RA. Both REP-PCR (SID 0.930) and ERIC-PCR (SID 0.929) methods showed much more higher DA than that of RAPD. According to the present results, both REP-PCR and ERIC-PCR among the tested analysis methods were found as the most reliable and discriminative molecular subtyping method, because they expressed the highest DA for the present S. aureus and MRSA strains.

Antibacterial and Radical Scavenging Epoxycyclohexenones and Aromatic Polyols from a Marine Isolate of the Fungus Aspergillus

  • Li, Yong;Li, Xifeng;Son, Byeng-Wha
    • Natural Product Sciences
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    • v.11 no.3
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    • pp.136-138
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    • 2005
  • Bioassay-guided fractionation of an organic extract of the broth from the marine-derived fungus of the genus Aspergillus led to the isolation of the polyketides, (+)-epoxydon (1), (+)-epoxydon monoacetate (2), gentisyl alcohol (3), 3-chlorogentisyl alcohol (4), and methylhydroquinone (5). Compounds 1-5 showed a potent antibacterial activity against the methicillin-resistant and multidrug-resistant Staphylococcus aureus (MRSA and MDRSA) with MIC (minimum inhibitory concentration) values of 12.5, 12.5, 12.5, 50.0, and $6.2\;{\mu}g/mL$, respectively. Compounds 1-4 also exhibited a significant radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) with $IC_{50}$ values of 6.0, 15.0, 7.0, and $1.0\;{\mu}M$, respectively.

New Production of Antibacterial Polycyclic Quinazoline Alkaloid, Thielaviazoline, from Anthranilic Acid by the Marine-Mudflat-Derived Fungus Thielavia sp.

  • Leutou, Alain Simplice;Yun, Keumja;Son, Byeng Wha
    • Natural Product Sciences
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    • v.22 no.3
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    • pp.216-219
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    • 2016
  • The microbial transformation of anthranilic acid (1) by the marine-mudflat-derived fungus Thielavia sp. produced an antibacterial polycyclic quinazoline alkaloid, thielaviazoline (2). The stereostructure of the metabolite was assigned based on detailed spectroscopic data analyses including comparison of the NMR ($^1H$ and $^{13}C$) data with those of reported compound (2). Compound 2 displayed in vitro antimicrobial activity against methicillin-resistant and multidrug-resistant Staphylococcus aureus (MRSA and MDRSA), with minimum inhibitory concentrations (MICs) of 6.25 and $12.5{\mu}g/mL$, respectively. Compound 2 also showed potent radical-scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) with an $IC_{50}$ of $11{\mu}M$, which was more active than the positive control, L-ascorbic acid ($IC_{50}$, $20.0{\mu}M$).

Synthesis and 3D-QSAR of p-Hydroxybenzohydrazide Derivatives With Antimicrobial Activity Against Multidrug-Resistant Staphylococcus aureus (다중의약품에 저항하는 Staphylococcus aureus 균에 항균성을 가지는 파라-히드록시벤조히드라자이드 유도체의 합성과 구조-활성관계 3차원 정량분석)

  • Bhole, Ritesh P.;Bhusari, Kishore P.
    • Journal of the Korean Chemical Society
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    • v.54 no.1
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    • pp.77-87
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    • 2010
  • Hospital-acquired methicillin-resistant Staphylococcus aureus (MRSA) has been an increasing problem worldwide since the initial reports over 40 years ago. To examine new drug leads with potential antibacterial activities, Various N'-[(-3-substituted-4-oxo-1,3-thiazolidin-2-ylidene]-4-hydroxy benzohydrazide (4a-4.i) and N'-[-(3,4-disubstituted)-1,3-thiazolidin-2ylidene)]-4-hydroxybenzohydrazide from (5.a-5.i) to (10.a-10.i) were synthesized using appropriate synthetic route. The entire test compounds (4.a-4.i) and from (5.a-5.i) to (10.a-10.i) were assayed in vitro against s. aureus strain. The minimum inhibitory concentration (MIC) was determined for test compounds and for reference standards. The test compounds showed significant antibacterial activity against the strains used, when tested in vitro. In general, p-hydroxybenzohydrazide ring and substituted thiazoline ring are essential for antimicrobial activity. Among the compounds tested, compounds 6.f, 7.g, 9.f and 10.f, 10 i were found to be most potent. The test compounds were found nontoxic upto the dose level of 2000 ${\mu}g$/mL. The intact compounds were then subjected for 3D-QSAR studies. 3D-QSAR study based on the principal of alignment of pharmacophoric features by Schrodinger PHASE module. The 3D-QSAR study allowed us to confirm the preferential binding mode of p-hydroxybenzohydrazide inside the active site.

Associated-Genes and Virulence Factors of Staphylococcus aureus Isolated from Nasal Cavity of Neonates (신생아 비강에서 분리된 황색포도구균의 병원성 인자와 관련 유전자)

  • Kim, Yung Bu;Moon, Ji Young;Park, Jae Hong
    • Clinical and Experimental Pediatrics
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    • v.46 no.1
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    • pp.24-32
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    • 2003
  • Purpose : Nosocomial infection with Staphylococcus aureus, especially methicillin resistant S. aureus, has become a serious concern in the neonatal intensive care unit. The aim of this study is to investigate the virulence factors, and the relationship between the antibiotic resistance and the associated genes of Staphylococcus aureus isolated from nasal cavity of neonates. Methods : Fifty one isolates of S. aureus were obtained from nasal swab taken in 28 neonates in the NICU and nursery of Pusan National University Hospital between February and May, 2001. They were tested in regard to antibiotic susceptibility, coagulase test and typing, plasmid DNA profile, as well as reactivity to enterotoxin A-E(sea, seb, sec, sed, see) genes and toxic shock syndrome toxin-1(tst) gene by polymerase chain reaction(PCR). Associated genes such as mecA, mecR1, mecI, and femA were also determined by PCR. The origin of MRSA strains was assessed using DNA fingerprinting by arbitrarily-primed polymerase chain reaction(AP-PCR). Results : Twenty three(45.1%) and six(11.8%) isolates were resistant to oxacillin and vancomycin respectively. Multidrug resistance to three or more of the antibiotics tested was observed in 51.0% of the isolates. Forty two isolates were coagulase positive and twenty two isolates had mecA gene. Sixteen isolates had both mecA and femA genes and had type I-III plasmids. 64.7% of isolates carried sec gene, and 80.4% carried tst gene. DNA fingerprinting by AP-PCR for 12 MRSA strains showed 10 distinct patterns, suggesting different origins. Conclusion : We confirmed that the prevalence of nasal carriage of S. aureus and the incidence of antimicrobial-resistant S. aureus, especially vancomycin resistance, is very high in neonates who were admitted in NICU and nursery. It is possible that these pathogens are responsible for serious nosocomial infections in neonates. The need for improved surveillance and continuous control of pathogens is emphasized.

Comparative in vitro Antibacterial Activity of DA-1131, A New Carbapenem Antibiotic(I)

  • Kim, Gye-Won;Chang, Min-Sun;Lee, Kyung-Won;Chong, Yun-Sop;Junnick Yang
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1996.04a
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    • pp.232-232
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    • 1996
  • DA-1131은 gram positive bacteria와 Pseudomonas aeruginosa를 포함한 gram negative bacteria에 대하여 광범위한 항균 spectrum과 우수한 항균력을 나타내었다. 각종 임상분리균주에 대한 항균력 시험 결과, gram positive bacteria 중 methicillin-resistant Staphylococcus aureus(MRSA)에 대하여는 DA-1131이 가장 우수한 항균력을 나타내었으며, methicillin-susceptible S. aureus(MSSA)에 대하여는 MEPM, CPR 및 CAZ보다 약 2-50배의 우수한 항균력을 나타내었으나 IPM/CS보다는 동등이하의 항균력을 나타내었다. Gram negative bacteria에 대하여는 IPM/CS, CAZ 및 CPR보다 우수한 항균력을 나타내어 0.2 $\mu\textrm{g}$/$m\ell$ 이하의 농도에서 91%의 Serratia marcescens, 89%의 Proteus mirabilis, 76%의 Morganella morganii 및 시험에 사용된 Enterobacteriaceae에 속하는 전균주의 생육이 억제되었다. P. aeruginosa 에 대하여 DA-1131은 1.56 $\mu\textrm{g}$/$m\ell$ 이하의 농도로 시험균주 전체의 생육을 저해하였으며, MEPM의 약 2배, IPM/CS의 약 4배의 강한 항균력을 나타내었다. CAZ에 내성인 Enterobacteriaceae 임상분리균주에 대한 DA-1131의 항균력은 CAZ 감수성균주에 대한 항균력과 동일한 것으로 나타났다.

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Inhibitory Effect of Metal Surface on the Antimicrobial Resistance Microorganism (금속표면이 항생제 내성균주의 생육억제에 미치는 영향)

  • Kim, Jung-Beom;Kim, Jae-Kwang;Kim, Hyunjung;Cho, Eun Jung;Park, Yeon-Joon;Lee, Hae Kyung
    • Annals of Clinical Microbiology
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    • v.21 no.4
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    • pp.80-85
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    • 2018
  • Background: The aim of this study was to comparatively evaluate the bactericidal effects of copper, brass (copper 78%, tin 22%), and stainless steel against methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium (VREFM), and multidrug-resistant Pseudomonas aeruginosa (MRPA). Methods: The isolates (MRSA, VREFM, MRPA) used in this study were mixed wild type 3 strains isolated from patients treated at Uijeongbu St. Mary's Hospital in 2017. These strains showed patterns of multidrug resistance. The lyophilized strains were inoculated into and incubated for 24 hr in tryptic soy broth at $35^{\circ}C$. The initial bacterial inoculum concentration was adjusted to $10^5CFU/mL$. A 100-mL bacterial suspension was incubated in containers made of brass (copper 78%, tin 22%), copper (above 99% purity), and stainless steel at $35^{\circ}C$. Viable counts of bacteria strains were measured for 9 days. Results: In this study, the bactericidal effects of copper and brass on MRSA, VREFM, and MRPA were verified. The bactericidal effect of stainless steel was much weaker than those of copper and brass. The bactericidal effect was stronger on MRPA than on MRSA or VREFM. Conclusion: To prevent cross infection of multidrug resistant bacteria in hospitals, further studies of longer duration are needed for testing of copper materials on objects such as door knobs, faucets, and bed rails.

Increased Antibiotic Resistance of Methicillin-Resistant Staphylococcus aureus USA300 Δpsm Mutants and a Complementation Study of Δpsm Mutants Using Synthetic Phenol-Soluble Modulins

  • Song, Hun-Suk;Bhatia, Shashi Kant;Choi, Tae-Rim;Gurav, Ranjit;Kim, Hyun Joong;Lee, Sun Mi;Park, Sol Lee;Lee, Hye Soo;Joo, Hwang-Soo;Kim, Wooseong;Seo, Seung-Oh;Yang, Yung-Hun
    • Journal of Microbiology and Biotechnology
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    • v.31 no.1
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    • pp.115-122
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    • 2021
  • Phenol-soluble modulins (PSMs) are responsible for regulating biofilm formation, persister cell formation, pmtR expression, host cell lysis, and anti-bacterial effects. To determine the effect of psm deletion on methicillin-resistant Staphylococcus aureus, we investigated psm deletion mutants including Δpsmα, Δpsmβ, and Δpsmαβ. These mutants exhibited increased β-lactam antibiotic resistance to ampicillin and oxacillin that was shown to be caused by increased N-acetylmannosamine kinase (nanK) mRNA expression, which regulates persister cell formation, leading to changes in the pattern of phospholipid fatty acids resulting in increased anteiso-C15:0, and increased membrane hydrophobicity with the deletion of PSMs. When synthetic PSMs were applied to Δpsmα and Δpsmβ mutants, treatment of Δpsmα with PSMα1-4 and Δpsmβ with PSMβ1-2 restored the sensitivity to oxacillin and slightly reduced the biofilm formation. Addition of a single fragment showed that α1, α2, α3, and β2 had an inhibiting effect on biofilms in Δpsmα; however, β1 showed an enhancing effect on biofilms in Δpsmβ. This study demonstrates a possible reason for the increased antibiotic resistance in psm mutants and the effect of PSMs on biofilm formation.

Antibacterial Activity of Bacillus sp. DH-9 Isolated from Sea Water (해수 분리 세균 Bacillus sp. DH-9의 항균활성)

  • Kim, Young-Man;Kim, Do-Kyun;Kim, Nam-Hee;Byun, Tae-Hwan;Kim, Ah-Ra;Lee, Eun-Woo;Kwon, Hyun-Ju;Kim, Byung-Woo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.43 no.1
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    • pp.33-38
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    • 2010
  • Emerging of antibiotic resistance of pathogenic bacteria is now a very serious problem in the clinics to treat the diseases, which have been easy to cure by antibiotic treatments before. Unfortunately, antibiotics developed till now are not effective any more against the resistant bacteria. Lots of efforts to discover new antibiotics having novel and unique structures and functions are really urgent and undergoing in the whole world. In this study, we tried to screen and isolate Same unique bacterial strains producing antibacterial substances from the sea water, which is the poor environment for bacteria 10 make their growing. Three bacterial strains among 916 strains isolated showed inhibition clear zone on the marine agar plate growing pathogenic bacteria including Acinetobacter baumannii, Edwardsiella tarda, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella enterica. One of them, which was identified as Bacillus sp. DH-9 from 16S rRNA gene analysis, showed especially considerable antibacterial activity against S. aureus which is notorious for methicillin resistant S. aureus (MRSA). The growth of S. aureus was totally inhibited when the supernatant of Bacillus sp. DH-9 culture was treated on.