Evolution of community- and healthcare-associated methicillin-resistant Staphylococcus aureus

Uhlemann, Anne‐Catrin; Otto, Michael; Lowy, Franklin D.; DeLeo, Frank R.

doi:10.1016/j.meegid.2013.04.030

Cited by 164 publications

(176 citation statements)

References 128 publications

(214 reference statements)

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“…MRSA is a serious current health care concern with both community-associated MRSA and health care-associated MRSA are growing threats to the immune compromised patients (Broekema et al, 2009). Furthermore, it is a major pathogen that causes a wide variety of diseases from common and mostly uncomplicated to severe invasive infections such as intravenous catheter associated infections, ventilator associated pneumonias and surgical wound infections (Uhlemann et al, 2013). On the other hand, P .aeruginosais one of the major causes of nosocomial infections that is highly related to opportunistic infections among hospitalized patients.…”

Section: Science Publicationsmentioning

confidence: 99%

IDENTIFICATION AND MODE OF ACTION OF ANTIBACTERIAL COMPONENTS FROM <I>MELASTOMA MALABATHRICUM</I> LINN LEAVES

Alwash¹

2013

American Journal of Infectious Diseases

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The present study aimed to assess the antibacterial activity of the methanol extract of Melastoma Malabathricum Leaves (MMML), active fraction of M. malabathricum leaves (ML5) and isolated kaempferol-3-O-(2",6"-di-O-p-trans-coumaroyl)-β-glucopyranoside (Kf) and to describe the preliminary mode of action against Gram-positive and Gram-negative bacteria. The MMML extract was fractionated by Vacuum Liquid Chromatography (VLC) to afford M. malabathricum leaves fractions (ML1-ML6) of increasing polarities. Bioassay-guided fractionation (direct-TLC bioautography) revealed that fraction of M. malabathricum Leaves (ML5) had the highest antibacterial activity. Therefore, the ML5 was further subjected to Column Chromatography (CC) to afford Kaempferol-3-O-(2",6"-di-O-p-trans-coumaroyl)-β-glucopyranoside (Kf). The compound structure was elucidated using data obtained from 1 H NMR and 13 C NMR spectra. Antibacterial activity of MMML, ML5 and bioactive constituents Kf against Staphylococcus aureus reference strain, Methicillin-Resistant S. Aureus reference strain (MRSA), 11 clinical MRSA isolates, 3 clinical Pseudomonas aeruginosa isolates and P. aeruginosa reference strain was evaluated through disk diffusion method and Minimum Inhibitory Concentration (MIC). The time kill assay and field emission scanning electron microscopy was used to determine the preliminary mode of action. The data obtained from disk diffusion method and MIC showed that the MMML, ML5 and Kf showed antibacterial activity against all test bacteria with various values. Generally, the ML5 and Kf exhibited the highest antibacterial activity with the largest zones of inhibition and lowest MIC values against S. aureus and all tested MRSA. The MMML exerted the strongest killing effect against all tested bacteria while the overall performance of ML5 and Kf were significantly more effective against S. aureus and MRSA than P. aeruginosa. Field emission scanning electron microscopy revealed irregular bacterial surface indicating that the MMML, ML5 and Kf disrupted the integrity of membrane. The results obtained showed that MMML, ML5 and Kf have potential alternative to antibiotics.

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Section: Science Publicationsmentioning

confidence: 99%

IDENTIFICATION AND MODE OF ACTION OF ANTIBACTERIAL COMPONENTS FROM <I>MELASTOMA MALABATHRICUM</I> LINN LEAVES

Alwash¹

2013

American Journal of Infectious Diseases

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“…34 However, the majority of USA300-associated infections involve superficial wounds or abscesses, 45 and USA300 isolates are not common outside of North America. [46][47][48] Among predominant MRSA clones worldwide are the CP8C lineages ST1, ST30, ST59, ST80, and ST239 and the CP5C lineages ST5 and ST22.…”

Section: Discussionmentioning

confidence: 99%

Antibodies toStaphylococcus aureuscapsular polysaccharides 5 and 8 perform similarlyin vitrobut are functionally distinctin vivo

et al. 2016

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The capsular polysaccharide (CP) produced by Staphylococcus aureus is a virulence factor that allows the organism to evade uptake and killing by host neutrophils. Polyclonal antibodies to the serotype 5 (CP5) and type 8 (CP8) capsular polysaccharides are opsonic and protect mice against experimental bacteremia provoked by encapsulated staphylococci. Thus, passive immunotherapy using CP antibodies has been considered for the prevention or treatment of invasive antibioticresistant S. aureus infections. In this report, we generated monoclonal antibodies (mAbs) against S. aureus CP5 or CP8. Backbone specific mAbs reacted with native and O-deacetylated CPs, whereas Oacetyl specific mAbs reacted only with native CPs. Reference strains of S. aureus and a selection of clinical isolates reacted by colony immunoblot with the CP5 and CP8 mAbs in a serotype-specific manner. The mAbs mediated in vitro CP type-specific opsonophagocytic killing of S. aureus strains, and mice passively immunized with CP5 mAbs were protected against S. aureus bacteremia. Neither CP8-specific mAbs or polyclonal antibodies protected mice against bacteremia provoked by serotype 8 S. aureus clinical isolates, although these same antibodies did protect against a serotype 5 S. aureus strain genetically engineered to produce CP8. We detected soluble CP8 in culture supernatants of serotype 8 clinical isolates and in the plasma of infected animals. Serotype 5 S. aureus released significantly less soluble CP5 in vitro and in vivo. The release of soluble CP8 by S. aureus may contribute to the inability of CP8 vaccines or antibodies to protect against serotype 8 staphylococcal infections.

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“…Consequently, staphylococci have been subjected to many molecular epidemiology studies 80 , including WGS analyses [41][42][43][44][45][46]82 . Many areas of the biology and pathology of these organisms have been investigated, including their evolution (particularly the origins of MRSA) in hospitals and communities 83,84 , the spread of clones among animals and humans 85 , the dynamics of colonization and infection 86 , and outbreak detection and control 87 . Although WGS is increasingly used in these investigations, it is difficult to compare the data generated in different studies, as they are typically available only as short reads.…”

Section: Applying Gene-by-gene Analysismentioning

confidence: 99%

MLST revisited: the gene-by-gene approach to bacterial genomics

et al. 2013

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Multilocus sequence typing (MLST) was proposed in 1998 as a portable sequence-based method for identifying clonal relationships among bacteria. Today, in the whole-genome era of microbiology, the need for systematic, standardized descriptions of bacterial genotypic variation remains a priority. Here, to meet this need, we draw on the successes of MLST and 16S rRNA gene sequencing to propose a hierarchical gene-by-gene approach that reflects functional and evolutionary relationships and catalogues bacteria 'from domain to strain'. Our gene-based typing approach using online platforms such as the Bacterial Isolate Genome Sequence Database (BIGSdb) allows the scalable organization and analysis of whole-genome sequence data.Advances in nucleotide-sequencing technology have provided unparalleled access to the enormous genetic diversity that has accumulated in the bacterial domain during 3.5-4 billion years of evolution 1 . Numerous sets of whole-genome sequencing (WGS) data for bacterial isolates (BOX 1) are available 2 , and metagenomic studies using these technologies continue to reveal further, seemingly boundless, diversity in bacterial communities 3 . Faced with this plethora of information, microbiologists must develop structured means of describing this diversity and of linking phenotype and genotype, thereby facilitating an improved understanding of the microbiological world. Given that we have precise information on the function of only a very small proportion of bacterial genes, and no knowledge at all about most, this is a formidable, if extremely exciting, challenge.Here, we focus primarily on pathogenic bacteria, although the concepts discussed are applicable more widely to all bacteria and archaea. Bacterial pathogens played a crucial part in the development of experimental microbiology and remain the most intensively studied prokaryotes more than 100 years later 4 . Pathogens have emerged across the diversity of the bacterial -but, interestingly, not the archaeal -domain on many occasions and are both polyphyletic and highly diverse. Thus, although pathogens represent only a tiny subset of the bacterial world, the challenges faced by the clinical microbiology laboratory are representative of those faced by microbiology as a whole.Taxonomic and functional analyses are based on the observations that diversity among bacteria is not continuous and that distinct, stable types with particular properties exist 5 . These founding principles of microbiology 6 have been upheld by much subsequent research, but the study of such clusters remains largely descriptive, and the evolutionary mechanisms that led to cluster emergence and persistence remain incompletely understood 7,8 . Structuring is also evident within bacterial genomes, as diversity is unevenly distributed among genes Pre-WGS cataloguing of diversityA major advance in defining bacterial diversity was the proposal, by the late Carl Woese and colleagues, of a universal and 'natural' -that is, genealogical -classification system based on small-su...

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Evolution of community- and healthcare-associated methicillin-resistant Staphylococcus aureus

Cited by 164 publications

References 128 publications

IDENTIFICATION AND MODE OF ACTION OF ANTIBACTERIAL COMPONENTS FROM <I>MELASTOMA MALABATHRICUM</I> LINN LEAVES

IDENTIFICATION AND MODE OF ACTION OF ANTIBACTERIAL COMPONENTS FROM <I>MELASTOMA MALABATHRICUM</I> LINN LEAVES

Antibodies toStaphylococcus aureuscapsular polysaccharides 5 and 8 perform similarlyin vitrobut are functionally distinctin vivo

MLST revisited: the gene-by-gene approach to bacterial genomics

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