scholarly journals Molecular Basis of Resistance to Selected Antimicrobial Agents in the Emerging Zoonotic Pathogen Streptococcus suis

2015 ◽  
Vol 53 (7) ◽  
pp. 2332-2336 ◽  
Author(s):  
Mamata Gurung ◽  
Migma Dorji Tamang ◽  
Dong Chan Moon ◽  
Su-Ran Kim ◽  
Jin-Ha Jeong ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Antimicrobial Agents ◽  
Single Point ◽  
Point Mutations ◽  
Streptococcus Suis ◽  
Quinolone Resistance ◽  
Content Type ◽  
Zoonotic Pathogen ◽  
Single Point Mutations

Characterization of 227Streptococcus suisstrains isolated from pigs during 2010 to 2013 showed high levels of resistance to clindamycin (95.6%), tilmicosin (94.7%), tylosin (93.8%), oxytetracycline (89.4%), chlortetracycline (86.8%), tiamulin (72.7%), neomycin (70.0%), enrofloxacin (56.4%), penicillin (56.4%), ceftiofur (55.9%), and gentamicin (55.1%). Resistance to tetracyclines, macrolides, aminoglycosides, and fluoroquinolone was attributed to thetetgene,erm(B),erm(C),mph(C), andmef(A) and/ormef(E) genes,aph(3′)-IIIaandaac(6′)-Ie-aph(2″)-Iagenes, and single point mutations in the quinolone resistance-determining region of ParC and GyrA, respectively.

scholarly journals First Characterization of Fluoroquinolone Resistance in Streptococcus suis

2006 ◽  
Vol 51 (2) ◽  
pp. 777-782 ◽  
Author(s):  
Jose Antonio Escudero ◽  
Alvaro San Millan ◽  
Ana Catalan ◽  
Adela G. de la Campa ◽  
Estefania Rivero ◽  
...  
Keyword(s):  
Horizontal Gene Transfer ◽  
Single Point ◽  
Point Mutations ◽  
Streptococcus Suis ◽  
Fluoroquinolone Resistance ◽  
Genes Encoding ◽  
Resistant Strains ◽  
Single Point Mutations ◽  
Clonal Spread

ABSTRACT We have identified and sequenced the genes encoding the quinolone-resistance determining region (QRDR) of ParC and GyrA in fluoroquinolone-susceptible and -resistant Streptococcus suis clinical isolates. Resistance is the consequence of single point mutations in the QRDRs of ParC and GyrA and is not due to clonal spread of resistant strains or horizontal gene transfer with other bacteria.

scholarly journals Functional Characterization of AbaQ, a Novel Efflux Pump Mediating Quinolone Resistance inAcinetobacter baumannii

2018 ◽  
Vol 62 (9) ◽  
Author(s):  
María Pérez-Varela ◽  
Jordi Corral ◽  
Jesús Aranda ◽  
Jordi Barbé
Keyword(s):  
Acinetobacter Baumannii ◽  
Antimicrobial Agents ◽  
Efflux Pump ◽  
Functional Characterization ◽  
Multidrug Resistant ◽  
Quinolone Resistance ◽  
Nosocomial Pathogen ◽  
Content Type ◽  
Mfs Transporter

ABSTRACTAcinetobacter baumanniihas emerged as an important multidrug-resistant nosocomial pathogen. In previous work, we identified a putative MFS transporter, AU097_RS17040, involved in the pathogenicity ofA. baumannii(M. Pérez-Varela, J. Corral, J. A. Vallejo, S. Rumbo-Feal, G. Bou, J. Aranda, and J. Barbé, Infect Immun 85:e00327-17, 2017,https://doi.org/10.1128/IAI.00327-17). In this study, we analyzed the susceptibility to diverse antimicrobial agents ofA. baumanniicells defective in this transporter, referred to as AbaQ. Our results showed that AbaQ is mainly involved in the extrusion of quinolone-type drugs inA. baumannii.

scholarly journals Long-Term Dissemination of CTX-M-5-Producing Hypermutable Salmonella enterica Serovar Typhimurium Sequence Type 328 Strains in Russia, Belarus, and Kazakhstan

2014 ◽  
Vol 58 (9) ◽  
pp. 5202-5210 ◽  
Author(s):  
Varvara K. Kozyreva ◽  
Elena N. Ilina ◽  
Maja V. Malakhova ◽  
Alessandra Carattoli ◽  
Ilya S. Azizov ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Genetic Relatedness ◽  
Single Point ◽  
Point Mutations ◽  
Sequence Type ◽  
Quinolone Resistance ◽  
Resistance Mutations ◽  
Content Type ◽  
Serovar Typhimurium

ABSTRACTIn this paper, we present evidence of long-term circulation of cefotaxime-resistant clonally relatedSalmonella entericaserovar Typhimurium strains over a broad geographic area. The genetic relatedness of 88 isolates collected from multiple outbreaks and sporadic cases of nosocomial salmonellosis in various parts of Russia, Belarus, and Kazakhstan from 1996 to 2009 was established by multilocus tandem-repeat analysis (MLVA) and multilocus sequence typing (MLST). The isolates belong to sequence type 328 (ST328) and produce CTX-M-5 β-lactamase, whose gene is carried by highly related non-self-conjugative but mobilizable plasmids. Resistance to nalidixic acid and low-level resistance to ciprofloxacin is present in 37 (42%) of the isolates and in all cases is determined by various single point mutations in thegyrAgene quinolone resistance-determining region (QRDR). Isolates of the described clonal group exhibit a hypermutable phenotype that probably facilitates independent acquisition of quinolone resistance mutations.

scholarly journals Characterization of a Lineage C.36 SARS-CoV-2 Isolate with Reduced Susceptibility to Neutralization Circulating in Lombardy, Italy

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1514
Author(s):  
Matteo Castelli ◽  
Andreina Baj ◽  
Elena Criscuolo ◽  
Roberto Ferrarese ◽  
Roberta A. Diotti ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Single Point ◽  
Point Mutations ◽  
Humoral Response ◽  
Genomic Sequencing ◽  
Single Point Mutations

SARS-CoV-2 spike is evolving to maximize transmissibility and evade the humoral response. The massive genomic sequencing of SARS-CoV-2 isolates has led to the identification of single-point mutations and deletions, often having the recurrence of hotspots, associated with advantageous phenotypes. We report the isolation and molecular characterization of a SARS-CoV-2 strain, belonging to a lineage (C.36) not previously associated with concerning traits, which shows decreased susceptibility to vaccine sera neutralization.

scholarly journals In Vivo Selection of Campylobacter Isolates with High Levels of Fluoroquinolone Resistance Associated with gyrA Mutations and the Function of the CmeABC Efflux Pump

2003 ◽  
Vol 47 (1) ◽  
pp. 390-394 ◽  
Author(s):  
Naidan Luo ◽  
Orhan Sahin ◽  
Jun Lin ◽  
Linda O. Michel ◽  
Qijing Zhang
Keyword(s):  
Intestinal Tract ◽  
Antimicrobial Agents ◽  
Efflux Pump ◽  
Single Point ◽  
Point Mutations ◽  
Fluoroquinolone Resistance ◽  
Quinolone Antibiotics ◽  
Single Point Mutations ◽  
Selection Of

ABSTRACT Enrofloxacin treatment of chickens infected with fluoroquinolone(FQ)-sensitive Campylobacter promoted the emergence of FQ-resistant Campylobacter mutants which propagated in the intestinal tract and recolonized the chickens. The recovered isolates were highly resistant to quinolone antibiotics but remained susceptible to non-FQ antimicrobial agents. Specific single-point mutations in the gyrA gene and the function of the CmeABC efflux pump were linked to the acquired FQ resistance. These results reveal that Campylobacter is hypermutable in vivo under the selection pressure of FQ and highlight the need for the prudent use of FQ antibiotics.

scholarly journals Characterization of a novel large deletion and single point mutations in the BRCA1gene in a Greek cohort of families with suspected hereditary breast cancer

BMC Cancer ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Ioulia Belogianni ◽  
Angela Apessos ◽  
Markos Mihalatos ◽  
Evangelia Razi ◽  
Stefanos Labropoulos ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Hereditary Breast Cancer ◽  
Single Point ◽  
Point Mutations ◽  
Large Deletion ◽  
Single Point Mutations

Cupin Variants as Macromolecular Ligand Library for Stereoselective Michael Addition of Nitroalkanes

2019 ◽  
Author(s):  
Nobutaka Fujieda ◽  
Miho Yuasa ◽  
Yosuke Nishikawa ◽  
Genji Kurisu ◽  
Shinobu Itoh ◽  
...  
Keyword(s):  
Michael Addition ◽  
In Silico ◽  
Addition Reaction ◽  
Single Point ◽  
Point Mutations ◽  
Unsaturated Ketone ◽  
Michael Addition Reaction ◽  
Beta Barrel ◽  
Cupin Superfamily ◽  
Single Point Mutations

Cupin superfamily proteins (TM1459) work as a macromolecular ligand framework with a double-stranded beta-barrel structure ligating to a Cu ion through histidine side chains. Variegating the first coordination sphere of TM1459 revealed that H52A and H54A/H58A mutants effectively catalyzed the diastereo- and enantio-selective Michael addition reaction of nitroalkanes to an α,β-unsaturated ketone. Moreover, in silico substrate docking signified C106N and F104W single-point mutations, which inverted the diastereoselectivity of H52A and further improved the stereoselectivity of H54A/H58A, respectively.

Single-Point Mutations in Qβ Virus-like Particles Change Binding to Cells

2021 ◽  
Author(s):  
Marisa L. Martino ◽  
Stephen N. Crooke ◽  
Marianne Manchester ◽  
M.G. Finn
Keyword(s):  
Single Point ◽  
Point Mutations ◽  
Virus Like Particles ◽  
Single Point Mutations

scholarly journals Physiological and Transcriptional Characterization of Persistent and Nonpersistent Listeria monocytogenes Isolates

2011 ◽  
Vol 77 (18) ◽  
pp. 6559-6569 ◽  
Author(s):  
Edward M. Fox ◽  
Nola Leonard ◽  
Kieran Jordan
Keyword(s):  
Listeria Monocytogenes ◽  
Antimicrobial Agents ◽  
Cetylpyridinium Chloride ◽  
Phenotype Microarray ◽  
Content Type ◽  
Benzethonium Chloride ◽  
Transcriptomic Sequencing ◽  
Ammonium Compounds ◽  
Compare Gene Expression

ABSTRACTThis study aimed to characterize physiological differences between persistent and presumed nonpersistentListeria monocytogenesstrains isolated at processing facilities and to investigate the molecular basis for this by transcriptomic sequencing. Full metabolic profiles of two strains, one persistent and one nonpersistent, were initially screened using Biolog's Phenotype MicroArray (PM) technology. Based on these results, in which major differences from selected antimicrobial agents were detected, another persistent strain and two nonpersistent strains were characterized using two antimicrobial PMs. Resistance to quaternary ammonium compounds (QACs) was shown to be higher among persistent strains. Growth of persistent and nonpersistent strains in various concentrations of the QACs benzethonium chloride (BZT) and cetylpyridinium chloride (CPC) was determined. Transcriptomic sequencing of a persistent and a presumed nonpersistent strain was performed to compare gene expression among these strains in the presence and absence of BZT. Two strains, designated “frequent persisters” because they were the most frequently isolated at the processing facility, showed overall higher resistance to QACs. Transcriptome analysis showed that BZT induced a complex peptidoglycan (PG) biosynthesis response, which may play a key role in BZT resistance. Comparison of persistent and nonpersistent strains indicated that transcription of many genes was upregulated among persistent strains. This included three gene operons:pdu,cob-cbi, andeut. These genes may play a role in the persistence ofL. monocytogenesoutside the human host.

Sign in / Sign up

Export Citation Format

Share Document