Molecular characterization of rifampin-resistant Neisseria meningitidis

Abstract

Primers were designed to amplify the rpoB gene of Neisseria meningitidis. The region of the gene amplified covered clusters I and II of the rifampin resistance (Rifr) mutation sites identified in Escherichia coli. DNAs from six Rifr isolates and 21 rifampin-susceptible isolates from the United Kingdom representing a number of serogroups were amplified and sequenced. All six Rifr isolates had identical DNA sequences and the same amino acid change, a His to an Asn change at position 35 (H35N). This His residue is equivalent to the His residue at position 526 in E. coli, one of the known Rifr mutation sites. DNAs from an additional six Rifr mutations generated in vitro were amplified and sequenced. Three had H35Y changes, one had an H35R change, one had an H35N change and one had an S40F change. The predominance of mutations at the His residue at position 35 in Rifr N. meningitidis isolates suggests that it plays a critical role in the selection of antibiotic-resistant variants. All six Rifr isolates belonged to the same clonal group when analyzed by restriction enzyme analysis and pulsed-field gel electrophoresis. These data suggest that a single clone of Rifr N. meningitidis is present and widespread throughout the United Kingdom.

Effects of Rice Seed Surface Sterilization with Hypochlorite on Inoculated Burkholderia vietnamiensis

“…Apart from these missense mutations in the region studied, the DNA sequences were identical to the sequence of the wild-type strain. All the mutations observed in B. vietnamiensis strains were previously associated with rifampin resistance in other bacteria (7,20,25,34). In this study, the majority of mutations occurred in codon 526 (E. coli The results of this study thus demonstrate that the use of hypochlorite as a seed surface disinfectant to prepare gnotobiotic models is a source of artifacts; not only does hypochlorite kill surface contaminants, but it also causes the death of most subsequently inoculated bacteria.…”

“…We quantified two mutations, one conferring resistance to rifampin and one conferring resistance to nalidixic acid, and we studied the following classical targets of these mutations: for rifampin resistance, a short central conserved region of rpoB which codes for the RNA polymerase ␤ subunit (7,19,34,41); and for nalidixic acid resistance, a small region at the 5Ј end of gyrA, the socalled quinolone resistance-determining region (QRDR) (this region is highly conserved in all known bacterial gyrases, and Nal r mutations affect amino acid residues equivalent to Ala-67 through Gln-106 encoded by the Escherichia coli gene [44]). …”

Emergence of Resistance to Rifampin and Rifalazil in Chlamydophila pneumoniae and Chlamydia trachomatis

“…Resistance to this class of antibiotics frequently occurs in other species, correlating with point mutations in their target gene, encoding RNA polymerase beta (rpoB) (2,4,14). The emergence of resistance to rifampin in vitro has been demonstrated in C. trachomatis (9,15,22,25,26).…”

Detección de cepas de Neisseria meningitidis resistentes a rifampicina en el Uruguay

“…Gabriel Pérez Giffoni, 1 Gabriela García Gabarrot, 1 Adriana Alfonso, 2 Mónica Pujadas 3 y Teresa Camou 1 La recomendación de iniciar de forma inmediata la administración de quimioprofilaxis a los contactos cercanos de cada caso de enfermedad meningocócica para prevenir los casos secundarios es universalmente aceptada y se aplica en la mayor parte de los países. La definición de contactos cercanos se refiere a las personas que comparten el hogar con el caso y otras con un grado equivalente de contacto.…”