Plasmid-mediated qnr genes provide only a modest decrease in quinolone susceptibility but facilitate the selection of higher-level resistance. In Escherichia coli strain J53 without qnr, ciprofloxacin resistance often involves mutations in the GyrA subunit of DNA gyrase. Mutations in gyrA were absent, however, when 43 mutants with decreased ciprofloxacin susceptibility were selected from J53(pM...

From January 1981 to December 2003, susceptibility to nalidixic acid was tested in 10,504 nontyphoid Salmonella enterica isolates from patients with acute enteric disease in Gipuzkoa, Spain. The prevalence of nalidixic acid resistance steadily increased from less than 0.5% before 1991 to 38.5% in 2003, mainly due to the increase in resistance among isolates of the most prevalent serovar, S. ent...

BACKGROUND/PURPOSE The purpose of this study is to describe clinical characteristics of Salmonella bacteremia in adult patients and analyze ciprofloxacin-nonsusceptible isolates. METHODS A total of 101 Salmonella blood isolates from adult patients were collected from January 2011 to December 2013 in MacKay Memorial Hospital. Eight ciprofloxacin-nonsusceptible Salmonella blood isolates were sc...

26 China is one of the countries with the highest multidrug-resistant (MDR) 27 and fluroquinolone (FQ)-resistant TB burden country globally. 28 Nevertheless, knowledge on the prevalence and molecular 29 characterization of FQ-resistant Mycobacterium tuberculosis (M. 30 tuberculosis) isolates from this region remains not numerous. In this study, 31 by utilizing agar proportion susceptibility met...

Ciprofloxacin is one of the most widely used antibiotics for the treatment of several infections caused by Gram-negative bacteria, like E. coli. Changes in gyrA, encoding GyrA subunit of DNA gyrase, cause the resistance to ciprofloxacin. Some ciprofloxacin resistant gyrA mutants acquired constitutive expression of marRAB operon due to the gaining mutations in marR, a repressor of this operon. T...

Fluoroquinolone resistance in Mycobacterium tuberculosis can be conferred by mutations in gyrA or gyrB. The prevalence of resistance mutations outside the quinolone resistance-determining region (QRDR) of gyrA or gyrB is unclear, since such regions are rarely sequenced. M. tuberculosis isolates from 1,111 patients with newly diagnosed culture-confirmed tuberculosis diagnosed in Tennessee from 2...

We investigated the contribution of quinolone resistance-determining region (QRDR) mutations to fluoroquinolone (enrofloxacin, orbifloxacin and danofloxacin) susceptibility in 58 Mycoplasma bovis isolates from dairy cattle in Japan. Fluoroquinolone non-resistant isolates (fluoroquinolone-MICs≤2 μg/ml) possessed no QRDR mutations (19 isolates) or Ser83Leu in GyrA (32 isolates). Fluoroquinolone-r...

Abstract. Martani NS, Notobroto HB, Wasito EB, Jabal AR. 2022. The role of merA Gene Mercury-resistant Escherichia coli from Kahayan River, Central Kalimantan, Indonesia in emerging antibiotic resistance. Biodiversitas 23: 6629-6634. This study collected nine water samples the upstream, middle, and downstream parts river, which was heavily contaminated with mercury (Hg). sampled following colle...