scholarly journals Molecular Features of Virulence and Resistance Mechanisms in Nosocomial and Community-Acquired Staphylococcus aureus

2019 ◽  
Author(s):  
Irina Gheorghe ◽  
Marcela Popa ◽  
Luminiţa Gabriela Măruţescu
Keyword(s):  
Staphylococcus Aureus ◽  
Resistance Mechanisms ◽  
Molecular Features

Emerging Antimicrobial Resistance Among Methicillin Resistant Staphylococcus Aureus (MRSA) in a Tertiary Care Centre in North India

JMS SKIMS ◽  
2020 ◽  
Vol 23 (1) ◽  
pp. 48-49
Author(s):  
Javaid Ahmad Bhat ◽  
Shariq Rashid Masoodi
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Tertiary Care ◽  
Resistance Mechanisms ◽  
North India ◽  
Global Public Health ◽  
Care Centre ◽  
Tertiary Care Centre ◽  
Effective Prevention ◽  
Mupirocin Resistance

Apropos to the article by Dr Bali, titled “Mupirocin resistance in clinical isolates of methicillin-sensitive and resistant Staphylococcus aureus in a tertiary care centre of North India” (1), the authors have raised important issue of emerging antimicrobial resistance (AMR). Antimicrobial resistance is an increasingly serious threat to global public health that requires action across all government sectors and society. As per WHO, AMR lurks the effective prevention and management of an ever-increasing spectrum of infections caused by bacteria, parasites, fungi and viruses. Novel resistance mechanisms are emerging and spreading globally, threatening the man’s ability to treat common infectious diseases.

5-Benzylidene-4-Oxazolidinones are Synergistic with Antibiotics for the Treatment of Staphylococcus Aureus Biofilms

2019 ◽  
Author(s):  
Bram Frohock ◽  
Jessica M. Gilbertie ◽  
Jennifer C. Daiker ◽  
Lauren V. Schnabel ◽  
Joshua Pierce
Keyword(s):  
Staphylococcus Aureus ◽  
Human Health ◽  
Matrix Model ◽  
Bacterial Load ◽  
Collagen Matrix ◽  
Resistance Mechanisms ◽  
Novel Therapeutics ◽  
Innovative Treatment ◽  
Antibiotic Action ◽  
Biofilm Infection

<div>The failure of frontline antibiotics in the clinic is one of the most serious threats to human health and requires a multitude of novel therapeutics and innovative treatment approaches to curtail the growing crisis. In addition to traditional resistance mechanisms resulting in the lack of efficacy of many antibiotics, most chronic and recurring infections are further made tolerant to antibiotic action by the presence of biofilms. Herein, we report an expanded set of 5-benzylidene-4-oxazolidinones that are able to inhibit the formation of Staphylococcus aureus biofilms, disperse preformed biofilms and in combination with common antibiotics are able to significantly reduce the bacterial load in a robust collagen-matrix model of biofilm infection.</div>

scholarly journals Staphylococcus aureus: A Review of Antimicrobial Resistance Mechanisms

2018 ◽  
Vol 4 (2) ◽  
Author(s):  
Asinamai Athliamai Bitrus ◽  
Olabode Mayowa Peter ◽  
Muhammad Adamu Abbas ◽  
Mohammed Dauda Goni
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Resistance Mechanisms

scholarly journals Genomic investigation of Staphylococcus aureus recovered from Gambian women and newborns following an oral dose of intra-partum azithromycin

2019 ◽  
Vol 74 (11) ◽  
pp. 3170-3178
Author(s):  
Abdoulie Bojang ◽  
Sarah L Baines ◽  
Liam Donovan ◽  
Romain Guerillot ◽  
Kerrie Stevens ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Drug Resistance ◽  
Epidemiological Data ◽  
Resistance Mechanisms ◽  
Post Intervention ◽  
Main Trial ◽  
Long Read ◽  
Macrolide Resistance Gene ◽  
Genome Analyses ◽  
Study Participants

Abstract Background Oral azithromycin given during labour reduces carriage of bacteria responsible for neonatal sepsis, including Staphylococcus aureus. However, there is concern that this may promote drug resistance. Objectives Here, we combine genomic and epidemiological data on S. aureus isolated from mothers and babies in a randomized intra-partum azithromycin trial (PregnAnZI) to describe bacterial population dynamics and resistance mechanisms. Methods Participants from both arms of the trial, who carried S. aureus in day 3 and day 28 samples post-intervention, were included. Sixty-six S. aureus isolates (from 7 mothers and 10 babies) underwent comparative genome analyses and the data were then combined with epidemiological data. Trial registration (main trial): ClinicalTrials.gov Identifier NCT01800942. Results Seven S. aureus STs were identified, with ST5 dominant (n = 40, 61.0%), followed by ST15 (n = 11, 17.0%). ST5 predominated in the placebo arm (73.0% versus 49.0%, P = 0.039) and ST15 in the azithromycin arm (27.0% versus 6.0%, P = 0.022). In azithromycin-resistant isolates, msr(A) was the main macrolide resistance gene (n = 36, 80%). Ten study participants, from both trial arms, acquired azithromycin-resistant S. aureus after initially harbouring a susceptible isolate. In nine (90%) of these cases, the acquired clone was an msr(A)-containing ST5 S. aureus. Long-read sequencing demonstrated that in ST5, msr(A) was found on an MDR plasmid. Conclusions Our data reveal in this Gambian population the presence of a dominant clone of S. aureus harbouring plasmid-encoded azithromycin resistance, which was acquired by participants in both arms of the study. Understanding these resistance dynamics is crucial to defining the public health drug resistance impacts of azithromycin prophylaxis given during labour in Africa.

scholarly journals Summary of Linezolid Activity and Resistance Mechanisms Detected during the 2012 LEADER Surveillance Program for the United States

2013 ◽  
Vol 58 (2) ◽  
pp. 1243-1247 ◽  
Author(s):  
Rodrigo E. Mendes ◽  
Robert K. Flamm ◽  
Patricia A. Hogan ◽  
James E. Ross ◽  
Ronald N. Jones
Keyword(s):  
United States ◽  
Staphylococcus Aureus ◽  
Susceptibility Testing ◽  
The United States ◽  
Resistance Mechanisms ◽  
Regulatory Approval ◽  
Surveillance Program ◽  
Gram Positive ◽  
Content Type

ABSTRACTThis study summarizes the linezolid susceptibility testing results for 7,429 Gram-positive pathogens from 60 U.S. sites collected during the 2012 sampling year for the LEADER Program. Linezolid showed potent activity when tested against 2,980Staphylococcus aureusisolates, inhibiting all but 3 at ≤2 μg/ml. Similarly, linezolid showed coverage against 99.5% of enterococci, as well as for all streptococci tested. These results confirm a long record of linezolid activity against U.S. Gram-positive isolates since regulatory approval in 2000.

scholarly journals Advanced Resistance Studies Identify Two Discrete Mechanisms in Staphylococcus aureus to Overcome Antibacterial Compounds that Target Biotin Protein Ligase

Antibiotics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 165 ◽  
Author(s):  
Andrew J. Hayes ◽  
Jiulia Satiaputra ◽  
Louise M. Sternicki ◽  
Ashleigh S. Paparella ◽  
Zikai Feng ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Transcriptional Repression ◽  
Molecular Mechanisms ◽  
Resistance Mechanism ◽  
Resistance Mechanisms ◽  
Resistance Rate ◽  
Biotin Protein Ligase ◽  
Essential Enzyme

Biotin protein ligase (BPL) inhibitors are a novel class of antibacterial that target clinically important methicillin-resistant Staphylococcus aureus (S. aureus). In S. aureus, BPL is a bifunctional protein responsible for enzymatic biotinylation of two biotin-dependent enzymes, as well as serving as a transcriptional repressor that controls biotin synthesis and import. In this report, we investigate the mechanisms of action and resistance for a potent anti-BPL, an antibacterial compound, biotinyl-acylsulfamide adenosine (BASA). We show that BASA acts by both inhibiting the enzymatic activity of BPL in vitro, as well as functioning as a transcription co-repressor. A low spontaneous resistance rate was measured for the compound (<10−9) and whole-genome sequencing of strains evolved during serial passaging in the presence of BASA identified two discrete resistance mechanisms. In the first, deletion of the biotin-dependent enzyme pyruvate carboxylase is proposed to prioritize the utilization of bioavailable biotin for the essential enzyme acetyl-CoA carboxylase. In the second, a D200E missense mutation in BPL reduced DNA binding in vitro and transcriptional repression in vivo. We propose that this second resistance mechanism promotes bioavailability of biotin by derepressing its synthesis and import, such that free biotin may outcompete the inhibitor for binding BPL. This study provides new insights into the molecular mechanisms governing antibacterial activity and resistance of BPL inhibitors in S. aureus.

scholarly journals Inhibitory Spectra and Modes of Antimicrobial Action of Gallotannins from Mango Kernels (Mangifera indicaL.)

2011 ◽  
Vol 77 (7) ◽  
pp. 2215-2223 ◽  
Author(s):  
Christina Engels ◽  
Andreas Schieber ◽  
Michael G. Gänzle
Keyword(s):  
Staphylococcus Aureus ◽  
Wild Type Strain ◽  
Antimicrobial Activities ◽  
Resistance Mechanisms ◽  
Gram Negative Bacteria ◽  
Wild Type ◽  
Gram Positive Bacteria ◽  
Food Borne ◽  
Membrane Bound ◽  
Bacteria And Fungi

ABSTRACTThis study investigated the antimicrobial activities and modes of action of penta-, hexa-, hepta-, octa-, nona-, and deca-O-galloylglucose (gallotannins) isolated from mango kernels. The MICs and minimum bactericidal concentrations (MBCs) against food-borne bacteria and fungi were determined using a critical dilution assay. Gram-positive bacteria were generally more susceptible to gallotannins than were Gram-negative bacteria. The MICs of gallotannins againstBacillus subtilis,Bacillus cereus,Clostridium botulinum,Campylobacter jejuni,Listeria monocytogenes, andStaphylococcus aureuswere 0.2 g liter−1or less; enterotoxigenicEscherichia coliandSalmonella entericawere inhibited by 0.5 to 1 g liter−1, and lactic acid bacteria were resistant. The use of lipopolysaccharide mutants ofS. entericaindicated that the outer membrane confers resistance toward gallotannins. Supplementation of LB medium with iron eliminated the inhibitory activity of gallotannins againstStaphylococcus aureus, and siderophore-deficient mutants ofS. entericawere less resistant toward gallotannins than was the wild-type strain. Hepta-O-galloylglucose sensitizedLactobacillus plantarumTMW1.460 to hop extract, indicating inactivation of hop resistance mechanisms, e.g., the multidrug resistance (MDR) transporter HorA. Carbohydrate metabolism ofLactococcus lactisMG1363, a conditionally respiring organism, was influenced by hepta-O-galloylglucose when grown under aerobic conditions and in the presence of heme but not under anaerobic conditions, indicating that gallotannins influence the respiratory chain. In conclusion, the inhibitory activities of gallotannins are attributable to their strong affinity for iron and likely additionally relate to the inactivation of membrane-bound proteins.

scholarly journals Genetic Relatedness and Diversity of Staphylococcus aureus from Different Reservoirs: Humans and Animals of Livestock, Poultry, Zoo, and Aquaculture

2020 ◽  
Vol 8 (9) ◽  
pp. 1345
Author(s):  
Vanessa Salgueiro ◽  
Vera Manageiro ◽  
Narcisa M. Bandarra ◽  
Eugénia Ferreira ◽  
Lurdes Clemente ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Genetic Relatedness ◽  
Meca Gene ◽  
Resistance Mechanisms ◽  
Animal Origin ◽  
Antibiotic Resistant ◽  
Typing Methods ◽  
Phylogenetic Lineages ◽  
Spa Types

The main aim of this study was the characterization of antibiotic resistance mechanisms in 82 Staphylococcus aureus strains isolated from humans and animals. Antibiotic susceptibility testing was performed on all S. aureus isolates accordingly, and antibiotic-resistant genes were investigated by genotypic methods. The genetic diversity of S. aureus was studied through spa, multilocus sequence typing (MLST), and agr typing methods. The majority of S. aureus from human sources were resistant to cefoxitin (and harbor the mecA gene) and fluoroquinolones, whereas only four strains of S. aureus from animal sources revealed resistance to ciprofloxacin. In the set of S. aureus isolated from humans, the most frequent spa, MLST, and agr group were t032, ST22, and I, respectively. In strains from animal origin the most common spa, MLST, and agr group found were t2383, ST398, and III/not typable, respectively. S. aureus from humans and animals were identified either in clonal complexes CC5, CC30, and CC398, suggesting that they have the same putative founder in their evolution. Considering the three CCs encompassing strains from human and animal reservoirs with different spa-types, we can hypothesize that this might reflect an adaptation to different phylogenetic lineages in those reservoirs (host species) probably associated to genetic diversification of pre-existing strains.

scholarly journals In vivo development of heterogeneous glycopeptide-intermediate Staphylococcus aureus (hGISA), GISA and daptomycin resistance in a patient with meticillin-resistant S. aureus endocarditis

2009 ◽  
Vol 58 (3) ◽  
pp. 376-380 ◽  
Author(s):  
Andrew Kirby ◽  
Kavya Mohandas ◽  
Caroline Broughton ◽  
Timothy J. Neal ◽  
Godfrey W. Smith ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Infective Endocarditis ◽  
Central Venous Catheter ◽  
Venous Catheter ◽  
Resistance Mechanisms ◽  
Central Venous ◽  
Glycopeptide Resistance ◽  
Mrsa Infection ◽  
Central Venous Catheter Infection

We report a patient who developed a meticillin-resistant Staphylococcus aureus (MRSA) central venous catheter infection complicated by infective endocarditis. The patient was initially treated with glycopeptides, which led to the development of heterogeneous glycopeptide resistance, the detection of which required the use of a macro Etest screening test. Subsequently, the causative strain, confirmed by PFGE as a UK epidemic MRSA-15, was treated with daptomycin, and again resistance developed in vivo. The development in vivo of resistance to both these agents suggests that the resistance mechanisms may be associated. We suggest that the clinician managing MRSA infection should anticipate daptomycin resistance when reduced glycopeptide susceptibility is detected.

scholarly journals Persistent Staphylococcus aureus nasal colonization in ambulatory human immunodeficiency virus-infected patients in Nigeria: Risk factors and molecular features

2016 ◽  
Vol 49 (6) ◽  
pp. 992-995 ◽  
Author(s):  
Adesola Olufunmilayo Olalekan ◽  
Samuel Sunday Taiwo ◽  
Stella Ifeanyi Smith ◽  
Adebayo Osagie Shittu ◽  
Deboye Oriade Kolawole ◽  
...  
Keyword(s):  
Risk Factors ◽  
Staphylococcus Aureus ◽  
Human Immunodeficiency Virus ◽  
Nasal Colonization ◽  
Molecular Features ◽  
Immunodeficiency Virus
Sign in / Sign up

Export Citation Format

Share Document