In vitro emergence of fluoroquinolone resistance in Cutibacterium (formerly Propionibacterium ) acnes and molecular characterization of mutations in the gyrA gene

ABSTRACT Moraxella catarrhalis causes respiratory infections. In this study, fluoroquinolone-resistant strains were selected in vitro to evaluate the mechanism of fluoroquinolone resistance. Strains with reduced fluoroquinolone susceptibility were obtained by stepwise selection in levofloxacin, and fluoroquinolone targets gyr and par were sequenced. Six novel mutations in GyrA (D84Y, T594dup, and A722dup), GyrB (E479K and D439N), and ParE (Q395R) involved in M. catarrhalis resistance to fluoroquinolones were revealed.

Download Full-text

In Vitro Characterization of the Antibacterial Spectrum of Novel Bacterial Type II Topoisomerase Inhibitors of the Aminobenzimidazole Class

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.50.4.1228-1237.2006 ◽

2006 ◽

Vol 50 (4) ◽

pp. 1228-1237 ◽

Cited By ~ 56

Author(s):

Nagraj Mani ◽

Christian H. Gross ◽

Jonathan D. Parsons ◽

Brian Hanzelka ◽

Ute Müh ◽

...

Keyword(s):

Bacterial Resistance ◽

Wide Spectrum ◽

Dna Gyrase ◽

Antibacterial Activities ◽

Mechanisms Of Action ◽

Fluoroquinolone Resistance ◽

Topoisomerase Iv ◽

Low Frequencies

ABSTRACT Antibiotics with novel mechanisms of action are becoming increasingly important in the battle against bacterial resistance to all currently used classes of antibiotics. Bacterial DNA gyrase and topoisomerase IV (topoIV) are the familiar targets of fluoroquinolone and coumarin antibiotics. Here we present the characterization of two members of a new class of synthetic bacterial topoII ATPase inhibitors: VRT-125853 and VRT-752586. These aminobenzimidazole compounds were potent inhibitors of both DNA gyrase and topoIV and had excellent antibacterial activities against a wide spectrum of problematic pathogens responsible for both nosocomial and community-acquired infections, including staphylococci, streptococci, enterococci, and mycobacteria. Consistent with the novelty of their structures and mechanisms of action, antibacterial potency was unaffected by commonly encountered resistance phenotypes, including fluoroquinolone resistance. In time-kill assays, VRT-125853 and VRT-752586 were bactericidal against Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecalis, and Haemophilus influenzae, causing 3-log reductions in viable cells within 24 h. Finally, similar to the fluoroquinolones, relatively low frequencies of spontaneous resistance to VRT-125853 and VRT-752586 were found, a property consistent with their in vitro dual-targeting activities.

Download Full-text

SureSelect targeted enrichment, a new cost effective method for the whole genome sequencing of Candidatus Liberibacter asiaticus

Scientific Reports ◽

10.1038/s41598-019-55144-4 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

Weili Cai ◽

Schyler Nunziata ◽

John Rascoe ◽

Michael J. Stulberg

Keyword(s):

Whole Genome Sequencing ◽

Molecular Characterization ◽

Genome Sequencing ◽

Whole Genome Sequence ◽

Whole Genome ◽

Genome Coverage ◽

Metagenomic Sample ◽

Liberibacter Asiaticus

AbstractHuanglongbing (HLB) is a worldwide deadly citrus disease caused by the phloem-limited bacteria ‘Candidatus Liberibacter asiaticus’ (CLas) vectored by Asian citrus psyllids. In order to effectively manage this disease, it is crucial to understand the relationship among the bacterial isolates from different geographical locations. Whole genome sequencing approaches will provide more precise molecular characterization of the diversity among populations. Due to the lack of in vitro culture, obtaining the whole genome sequence of CLas is still a challenge, especially for medium to low titer samples. Hundreds of millions of sequencing reads are needed to get good coverage of CLas from an HLB positive citrus sample. In order to overcome this limitation, we present here a new method, Agilent SureSelect XT HS target enrichment, which can specifically enrich CLas from a metagenomic sample while greatly reducing cost and increasing whole genome coverage of the pathogen. In this study, the CLas genome was successfully sequenced with 99.3% genome coverage and over 72X sequencing coverage from low titer tissue samples (equivalent to 28.52 Cq using Li 16 S qPCR). More importantly, this method also effectively captures regions of diversity in the CLas genome, which provides precise molecular characterization of different strains.

Download Full-text

The Proteome of Brain Capillary Endothelial Cells: Toward a Molecular Characterization of an In Vitro Blood–Brain Barrier Model

Expression Profiling in Neuroscience - Neuromethods ◽

10.1007/978-1-61779-448-3_10 ◽

2011 ◽

pp. 161-179 ◽

Cited By ~ 2

Author(s):

Sophie Duban-Deweer ◽

Christophe Flahaut ◽

Yannis Karamanos

Keyword(s):

Endothelial Cells ◽

Molecular Characterization ◽

Blood Brain Barrier ◽

Brain Barrier ◽

Brain Capillary ◽

Blood Brain Barrier Model ◽

Capillary Endothelial Cells ◽

Barrier Model

Download Full-text

Molecular Characterization of HOXA2 and HOXA3 Binding Properties

Journal of Developmental Biology ◽

10.3390/jdb9040055 ◽

2021 ◽

Vol 9 (4) ◽

pp. 55

Author(s):

Joshua Mallen ◽

Manisha Kalsan ◽

Peyman Zarrineh ◽

Laure Bridoux ◽

Shandar Ahmad ◽

...

Keyword(s):

Transcription Factors ◽

Molecular Characterization ◽

Sequence Motif ◽

Body Parts ◽

Binding Affinities ◽

Binding Properties ◽

Functional Consequences

The highly conserved HOX homeodomain (HD) transcription factors (TFs) establish the identity of different body parts along the antero–posterior axis of bilaterian animals. Segment diversification and the morphogenesis of different structures is achieved by generating precise patterns of HOX expression along the antero–posterior axis and by the ability of different HOX TFs to instruct unique and specific transcriptional programs. However, HOX binding properties in vitro, characterised by the recognition of similar AT-rich binding sequences, do not account for the ability of different HOX to instruct segment-specific transcriptional programs. To address this problem, we previously compared HOXA2 and HOXA3 binding in vivo. Here, we explore if sequence motif enrichments observed in vivo are explained by binding affinities in vitro. Unexpectedly, we found that the highest enriched motif in HOXA2 peaks was not recognised by HOXA2 in vitro, highlighting the importance of investigating HOX binding in its physiological context. We also report the ability of HOXA2 and HOXA3 to heterodimerise, which may have functional consequences for the HOX patterning function in vivo.

Download Full-text