Several beta-lactamase-producing, penicillin-resistant strains of Neisseria gonorrhoeae were examined for R plasmids. Penicillin-resistant strains isolated from men returning from the Far East and their contacts contained a 4.4 x 10(6)-dalton plasmid in common. Transformation studies and the isolation of a spontaneous penicillin-susceptible segregant showed that the structural gene for beta-lac...

The goal of this research was to examine the role of cytotoxic T lymphocytes (CTL) in the control of Rhodococcus equi and specifically to determine if R. equi-specific CD8+ CTL occurred in the blood of immune horses. Equine peripheral blood mononuclear cells stimulated with antigen-presenting cells either infected with R. equi or exposed to soluble R. equi antigen lysed R. equi-infected target ...

Mupirocin resistance in Staphylococcus aureus is increasingly being reported in many parts of the world. This study describes the epidemiology and laboratory characterization of mupirocin-resistant methicillin-resistant S. aureus (MRSA) strains in Canadian hospitals. Broth microdilution susceptibility testing of 4,980 MRSA isolates obtained between 1995 and 2004 from 32 Canadian hospitals was d...

no. ISTN3X; 96% identical), comprising one of Tn3-like inverted repeats and putative coding regions for transposase, resolvase (also called repressor), and ampicillin resistance. The resistance gene encodes a TEM-1 type β-lactamase. (The sequence has been registered to DDBJ/GenBank/ EMBL with accession no. AB103092.) Conjugative transferability of p981123 between S. Enteritidis strains was exam...

Resveratrol (R), a plant polyphenol, is known to reduce Cu (II) to Cu (I) generating reactive oxygen species that can cleave plasmid DNA. Here we report a surprising observation of a paradoxical relationship between R and Cu whereby plasmid DNA cleaving / degrading activity of R-Cu increased progressively as the ratio of R to Cu was increased i.e., the concentration of Cu was successively reduc...

Forty-nine fast-growing Rhizobium strains from the nodules of 26 different tropical legume genera were screened to find isolates that would (i) nodulate, e.g., winged beans, so producing large nodules for RNA and protein isolation; (ii) also nodulate various small-seeded legumes, thus allowing screening of large numbers of mutants; and (iii) harbor plasmids containing nif structural genes as we...

Environmental conditions under which fitness tradeoffs of plasmid carriage are balanced to facilitate plasmid persistence remain elusive. Periodic selection for plasmid-encoded traits due to the spatial and temporal variation typical in most natural environments (such as soil particles, plant leaf and root surfaces, gut linings, and the skin) may play a role. However, quantification of selectio...

The endogenous plasmid pRA2 from Pseudomonas alcaligenes NCIB 9867 was determined to have 32,743 bp with a G+C content of 59.8%. Sequence analysis predicted a total of 29 open reading frames, with approximately half of them contributing towards the functions of plasmid replication, mobilization, and stability. The Pac25I restriction-modification system and two mobile elements, Tn5563 and IS1633...

The 24.5-megadalton plasmid of Neisseria gonorrhoeae is required for transfer of R-factors and possibly chromosomal markers during conjugal matings between gonococcal strains. We constructed a physical map of one such plasmid, pLE2451, using EcoRI, BglII, and HincII site-specific restriction endonucleases. The patterns of deoxyribonucleic acid digestion obtained with this plasmid were identical...