scholarly journals Eugenol Provokes ROS-Mediated Membrane Damage-Associated Antibacterial Activity against Clinically Isolated Multidrug-Resistant Staphylococcus aureus Strains

2016 ◽  
Vol 9 ◽  
pp. IDRT.S31741 ◽  
Author(s):  
Balaram Das ◽  
Debasis Mandal ◽  
Sandeep Kumar Dash ◽  
Sourav Chattopadhyay ◽  
Satyajit Tripathy ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Membrane Damage ◽  
Reactive Oxygen Species Generation ◽  
Multidrug Resistant ◽  
Vancomycin Resistance ◽  
Resistance Pattern ◽  
Antibiotics Resistance ◽  
Aureus Infection ◽  
Vancomycin Resistant

Due to the indiscriminate use of antibiotics, resistance to antibiotics has increased remarkably in Staphylococcus aureus. Vancomycin is the final drug to treat the S. aureus infection, but nowadays, resistance to this antibiotic is also increasing. So, the investigation of antibiotic resistance pattern is important. As there is already resistance to vancomycin, there is an urgent need to develop a new kind of antimicrobial to treat S. aureus infection. Eugenol may be the new drug of choice. This study was conducted to evaluate the antibacterial activity of eugenol against vancomycin-resistant S. aureus isolated from clinical pus samples. Thirty six pus samples were included in the study. Samples were isolated, identified and antimicrobial susceptibility tests were performed as per routine laboratory protocol. The antimicrobial activity and mechanisms of killing of eugenol were studied. Out of 36 pus samples, only 20 isolates were confirmed as S. aureus strains and 6 isolates exhibited vancomycin resistance. Eugenol successfully destroyed the vancomycin-resistant strains via reactive oxygen species generation and membrane damage. The prevalence of vancomycin resistance is increased day by day in different countries, and necessary steps to prevent the spread and emergence of resistance should be taken. The findings of the study suggested that eugenol might be used to treat vancomycin-resistant S. aureus.

Emergence of CC8/ST239- SCCmec III/t421 tigecycline resistant and CC/ST22-SCCmec IV/t790 vancomycin resistant Staphylococcus aureus strains isolated from wound: A two-year multi-center study in Tehran, Iran

2021 ◽  
Keyword(s):  
Staphylococcus Aureus ◽  
Acquired Resistance ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Disk Diffusion Method ◽  
Cross Sectional ◽  
Phenotypic Resistance ◽  
Multiplex Pcr Assay ◽  
Vancomycin Resistant

Abstract Staphylococcus aureus as an opportunistic bacterial pathogen with intrinsic and acquired resistance to many antibiotics is a worldwide problem. The current study was undertaken to evaluate the resistance pattern, and determine the genetic types of multidrug-resistant S. aureus isolated from wound. This cross-sectional study was conducted over the period of two years (from December 2018 to November 2020) at the hospitals affiliated to Shahid Beheshti University of Medical Sciences, Tehran, Iran. In present study, 75 multidrug-resistant S. aureus isolates collected from wound infections were investigated. Phenotypic resistance was assessed by Kirby–Bauer disk diffusion method. Conventional PCR was performed for the detection of virulence encoding genes. Genotyping of strains was performed based on coa gene polymorphism using multiplex-PCR assay. SCCmec typing, spa typing and MLST were also used to characterize the genotype of the mupirocin, tigecycline and vancomycin resistant multidrug-resistant S. aureus isolates. All 75 multidrug-resistant S. aureus isolates in the study were confirmed as MRSA. Coagulase typing distinguished isolates into five genotypic patterns including III (40%), I (24%), IVb (16%), V (10.7%) and type X (9.3%). Resistance to tigecycline was detected in 4% of MDR-MRSA isolates and all belonged to CC8/ST239- SCCmec III/t421 lineage. According to our analysis, one VRSA strain was identified that belonged to coa type V and CC/ST22-SCCmec IV/t790 lineage. Resistance to mupirocin was detected in 9.3% of strains. All 7 mupirocin resistant MDR-MRSA isolates exhibited resistance to mupirocin in high level. Of these, 4 isolates belonged to CC/ST8-SCCmec IV/t008 (57.1%), 2 isolates belonged to CC/ST8-SCCmec IV/t064 (28.6%) and one isolate to CC/ST22-SCCmec IV/t790 (14.3%). Altogether, current survey provides a snapshot of the characteristics of S. aureus strains isolated from patients. Our observations highlighted type III as predominant coa type among multidrug-resistant MDR strains indicating low heterogeneity of these isolates. Our study also indicates the importance of continuous monitoring of the genotypes of MDR-MRSA isolates to prevent nosocomial outbreaks and the spread of MDR isolates.

scholarly journals Synergistic Effect between Cryptotanshinone and Antibiotics against Clinic Methicillin and Vancomycin-ResistantStaphylococcus aureus

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Jeong-Dan Cha ◽  
Jeong-Ho Lee ◽  
Kyung Min Choi ◽  
Sung-Mi Choi ◽  
Jeong Hye Park
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Medicinal Plant ◽  
Synergistic Effect ◽  
Antibacterial Agent ◽  
Salvia Miltiorrhiza ◽  
Multidrug Resistant ◽  
Vancomycin Resistant ◽  
Multidrug Resistant Pathogens ◽  
Time Kill

Cryptotanshinone (CT), a major tanshinone of medicinal plantSalvia miltiorrhizaBunge, demonstrated strong antibacterial activity against clinic isolated methicillin and vancomycin-resistantStaphylococcus aureus(MRSA and VRSA) in this experiment. The CT was determined against clinic isolated MRSA 1–16 with MIC and MBC values ranging from 4 to 32 and 8 to 128 μg/mL; for MSSA 1-2 from 16 to 32 μg/mL and 64 to 128 μg/mL; for VRSA 1-2 from 2 to 4 μg/mL and 4 to 16 μg/mL, respectively. The range of MIC50and MIC90of CT was 0.5–8 μg/mL and 4–64 μg/mL, respectively. The combination effects of CT with antibiotics were synergistic (FIC index<0.5) against most of tested clinic isolated MRSA, MSSA, and VRSA except additive, MRSA 4 and 16 in oxacillin, MRSA 6, 12, and 15 in ampicillin, and MRSA 6, 11, and 15 in vancomycin (FIC index < 0.75–1.0). Furthermore, a time-kill study showed that the growth of the tested bacteria was completely attenuated after 2–6 h of treatment with the 1/2 MIC of CT, regardless of whether it was administered alone or with ampicillin, oxacillin, or vancomycin. The results suggest that CT could be employed as a natural antibacterial agent against multidrug-resistant pathogens infection.

scholarly journals New Antimicrobials Based on the Adarotene Scaffold with Activity against Multi-Drug Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococcus

Antibiotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 126
Author(s):  
Salvatore Princiotto ◽  
Stefania Mazzini ◽  
Loana Musso ◽  
Fabio Arena ◽  
Sabrina Dallavalle ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Anticancer Activity ◽  
Bactericidal Effect ◽  
Biological Assessment ◽  
Drug Resistant ◽  
Vancomycin Resistant Enterococcus ◽  
Vancomycin Resistant ◽  
Global Increase ◽  
Common Infections

The global increase in infections by multi-drug resistant (MDR) pathogens is severely impacting our ability to successfully treat common infections. Herein, we report the antibacterial activity against S. aureus and E. faecalis (including some MDR strains) of a panel of adarotene-related synthetic retinoids. In many cases, these compounds showed, together with favorable MICs, a detectable bactericidal effect. We found that the pattern of substitution on adarotene could be modulated to obtain selectivity for antibacterial over the known anticancer activity of these compounds. NMR experiments allowed us to define the interaction between adarotene and a model of microorganism membrane. Biological assessment confirmed that the scaffold of adarotene is promising for further developments of non-toxic antimicrobials active on MDR strains.

scholarly journals Staphylococcus aureus Infections in Malaysia: A Review of Antimicrobial Resistance and Characteristics of the Clinical Isolates, 1990–2017

Antibiotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 128 ◽  
Author(s):  
Ainal Mardziah Che Hamzah ◽  
Chew Chieng Yeo ◽  
Suat Moi Puah ◽  
Kek Heng Chua ◽  
Ching Hoong Chew
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Sccmec Type ◽  
Epidemiological Data ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Type Iv ◽  
Resistant Strains ◽  
Vancomycin Resistant ◽  
Comprehensive Surveillance

Staphylococcus aureus is an important nosocomial pathogen and its multidrug resistant strains, particularly methicillin-resistant S. aureus (MRSA), poses a serious threat to public health due to its limited therapeutic options. The increasing MRSA resistance towards vancomycin, which is the current drug of last resort, gives a great challenge to the treatment and management of MRSA infections. While vancomycin resistance among Malaysian MRSA isolates has yet to be documented, a case of vancomycin resistant S. aureus has been reported in our neighboring country, Indonesia. In this review, we present the antimicrobial resistance profiles of S. aureus clinical isolates in Malaysia with data obtained from the Malaysian National Surveillance on Antimicrobial Resistance (NSAR) reports as well as various peer-reviewed published records spanning a period of nearly three decades (1990–2017). We also review the clonal types and characteristics of Malaysian S. aureus isolates, where hospital-associated (HA) MRSA isolates tend to carry staphylococcal cassette chromosome mec (SCCmec) type III and were of sequence type (ST)239, whereas community-associated (CA) isolates are mostly SCCmec type IV/V and ST30. More comprehensive surveillance data that include molecular epidemiological data would enable further in-depth understanding of Malaysian S. aureus isolates.

scholarly journals Production of a New Thiopeptide Antibiotic, TP-1161, by a Marine Nocardiopsis Species

2010 ◽  
Vol 76 (15) ◽  
pp. 4969-4976 ◽  
Author(s):  
Kerstin Engelhardt ◽  
Kristin F. Degnes ◽  
Michael Kemmler ◽  
Harald Bredholt ◽  
Espen Fj�rvik ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Molecular Taxonomy ◽  
Multidrug Resistant ◽  
Peptide Antibiotic ◽  
Indicator Organisms ◽  
Bacterial Strains ◽  
Pcr Screening ◽  
Vancomycin Resistant ◽  
Antibacterial And Antifungal

ABSTRACT Twenty-seven marine sediment- and sponge-derived actinomycetes with a preference for or dependence on seawater for growth were classified at the genus level using molecular taxonomy. Their potential to produce bioactive secondary metabolites was analyzed by PCR screening for genes involved in polyketide and nonribosomal peptide antibiotic synthesis. Using microwell cultures, conditions for the production of antibacterial and antifungal compounds were identified for 15 of the 27 isolates subjected to this screening. Nine of the 15 active extracts were also active against multiresistant Gram-positive bacterial and/or fungal indicator organisms, including vancomycin-resistant Enterococcus faecium and multidrug-resistant Candida albicans. Activity-guided fractionation of fermentation extracts of isolate TFS65-07, showing strong antibacterial activity and classified as a Nocardiopsis species, allowed the identification and purification of the active compound. Structure elucidation revealed this compound to be a new thiopeptide antibiotic with a rare aminoacetone moiety. The in vitro antibacterial activity of this thiopeptide, designated TP-1161, against a panel of bacterial strains was determined.

scholarly journals High Colonization Rate and Heterogeneity of ESBL- and Carbapenemase-Producing Enterobacteriaceae Isolated from Gull Feces in Lisbon, Portugal

2020 ◽  
Vol 8 (10) ◽  
pp. 1487
Author(s):  
Marta Aires-de-Sousa ◽  
Claudine Fournier ◽  
Elizeth Lopes ◽  
Hermínia de Lencastre ◽  
Patrice Nordmann ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Bacterial Species ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria ◽  
Vancomycin Resistant Enterococci ◽  
Vancomycin Resistant ◽  
Encoding Genes

In order to evaluate whether seagulls living on the Lisbon coastline, Portugal, might be colonized and consequently represent potential spreaders of multidrug-resistant bacteria, a total of 88 gull fecal samples were screened for detection of extended-spectrum β-lactamase (ESBL)- or carbapenemase-producing Enterobacteriaceae for methicillin-resistant Staphylococcus aureus (MRSA) and for vancomycin-resistant Enterococci (VRE). A large proportion of samples yielded carbapenemase- or ESBL-producing Enterobacteriaceae (16% and 55%, respectively), while only two MRSA and two VRE were detected. Mating-out assays followed by PCR and whole-plasmid sequencing allowed to identify carbapenemase and ESBL encoding genes. Among 24 carbapenemase-producing isolates, there were mainly Klebsiella pneumoniae (50%) and Escherichia coli (33%). OXA-181 was the most common carbapenemase identified (54%), followed by OXA-48 (25%) and KPC-2 (17%). Ten different ESBLs were found among 62 ESBL-producing isolates, mainly being CTX-M-type enzymes (87%). Co-occurrence in single samples of multiple ESBL- and carbapenemase producers belonging to different bacterial species was observed in some cases. Seagulls constitute an important source for spreading multidrug-resistant bacteria in the environment and their gut microbiota a formidable microenvironment for transfer of resistance genes within bacterial species.

scholarly journals Antimicrobial Resistance in Bacterial Pathogens and Detection of Carbapenemases in Klebsiella pneumoniae Isolates from Hospital Wastewater

Antibiotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 85 ◽  
Author(s):  
Hercules Sakkas ◽  
Petros Bozidis ◽  
Afrodite Ilia ◽  
George Mpekoulis ◽  
Chrissanthy Papadopoulou
Keyword(s):  
Staphylococcus Aureus ◽  
Klebsiella Pneumoniae ◽  
Pathogenic Bacteria ◽  
Multidrug Resistant ◽  
Rapid Identification ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Screening Methods ◽  
Extended Spectrum Beta Lactamase ◽  
Vancomycin Resistant

During a six-month period (October 2017–March 2018), the prevalence and susceptibility of important pathogenic bacteria isolated from 12 hospital raw sewage samples in North Western Greece was investigated. The samples were analyzed for methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), extended-spectrum beta-lactamase (ESBL) producing Escherichia coli, carbapenemase-producing Klebsiella pneumoniae (CKP), and multidrug-resistant Pseudomonas aeruginosa. Antimicrobial susceptibility testing was performed using the agar diffusion method according to the recommendations of the Clinical and Laboratory Standards Institute. The diversity of carbapenemases harboring K. pneumoniae was examined by two phenotyping screening methods (modified Hodge test and combined disk test), a new immunochromatographic rapid assay (RESIST-4 O.K.N.V.) and a polymerase chain reaction (PCR). The results demonstrated the prevalence of MRSA, vancomycin-resistant Staphylococcus aureus (VRSA), VRE, and CKP in the examined hospital raw sewage samples. In addition, the aforementioned methods which are currently used in clinical laboratories for the rapid identification and detection of resistant bacteria and genes, performed sufficiently to provide reliable results in terms of accuracy and efficiency.

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