Publications by authors named "N A Villagra"
The speciation of occurred by acquisition of genomic islands from other bacterial species and continued to diverge into subspecies and serovars with diferent range of host. serovar Typhimurium (STM) is a generalist pathogen infecting hosts that include birds, mice, and humans, whilst serovar Typhi (STY) is a restricted-host pathogen, infecting only humans. Despite their ranges of hosts, STM and STY possess 97-98% identity.
View Article and Find Full Text PDFFew sclerophyllous plants from the central coast of Chile have been systematically studied. This work describes the phytochemical composition and antimicrobial properties of Pers. (sin.
View Article and Find Full Text PDFBroad antibacterial spectrum, high oral bioavailability and excellent tissue penetration combined with safety and few, yet rare, unwanted effects, have made the quinolones class of antimicrobials one of the most used in inpatients and outpatients. Initially discovered during the search for improved chloroquine-derivative molecules with increased anti-malarial activity, today the quinolones, intended as antimicrobials, comprehend four generations that progressively have been extending antimicrobial spectrum and clinical use. The quinolone class of antimicrobials exerts its antimicrobial actions through inhibiting DNA gyrase and Topoisomerase IV that in turn inhibits synthesis of DNA and RNA.
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- Ciprofloxacin is the primary treatment for Typhi infections, but reduced susceptibility to this drug has been observed, prompting research to enhance its efficacy by targeting new genetic factors.
- In a study involving 3,216 transposon mutants of Typhi, five mutants with increased ciprofloxacin susceptibility were identified, with one notable mutant linked to the glutamine synthetase-coding gene, which also showed higher expression of the OmpF protein, facilitating ciprofloxacin uptake.
- The research found that manipulating the expression of specific genes significantly affected susceptibility to ciprofloxacin, highlighting the complex regulatory networks involved and the potential for genetic approaches to combat antibiotic resistance.
Microbiomes are vast communities of microorganisms and viruses that populate all natural ecosystems. Viruses have been considered to be the most variable component of microbiomes, as supported by virome surveys and examples of high genomic mosaicism. However, recent evidence suggests that the human gut virome is remarkably stable compared with that of other environments.
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