“A total of 1,870 nonduplicate clinical Enterobacteriaceae from 13 teaching hospitals located in 11 provinces of mainland China from 2011 to 2012 were screened for the presence of the bla(NDM) gene. The high-throughput mTOR inhibitor MiSeq sequencing method and comparative genomics were used to analyze the genetic environment of bla(NDM) among these isolates. Three bla(NDM-1)-carrying Klebsiella pneumoniae (0.16%, 3/1,870), isolated from a teaching hospital in Xi’an, exhibited high levels of resistance to all -lactams, but remained susceptible to amikacin, tigecycline, and polymyxin B. These three isolates, belonging to ST147,
presented an identical pulsed-field gel electrophoresis pattern. The IncX3 plasmid, pNDM-SX04 (KC876051) showed 99% identity with plasmid pNDM-HN380 (JX104760). Comparative analysis of the genetic environment of bla(NDM-1) with previously published plasmids revealed the same 7,830-bp basic mobile element, which may have been derived from Acinetobacter spp. Partial ISAba125, ISAba125 promoter, bla(NDM-1), and ble(MBL) could serve as the minimal mobile vehicle facilitating horizontal
transfer of the bla(NDM-1) gene. To our knowledge, this is the first report of an outbreak of bla(NDM-1)-carrying ST147 K. pneumoniae. Although the prevalence spread by the bla(NDM-1) gene prevalence is at a low frequency in mainland China, a dynamic national surveillance of this gene is needed due to its potential transferability.”
“This review briefly addresses what has selleck screening library been
learned FRAX597 about resistance durability in recent years, as well as the questions that still remain. Molecular analyses of major gene interactions have potential to contribute to both breeding for resistance and improved understanding of virulence impacts on pathogen fitness. Though the molecular basis of quantitative resistance is less clear, substantial evidence has accumulated for the relative simplicity of inheritance. There is increasing evidence for specific interactions with quantitative resistance, though implications of this for durability are still unknown. Mechanisms by which resistance gene pyramids contribute to durability remain elusive, though ideas have been generated for identifying gene combinations that may be more durable. Though cultivar mixtures and related approaches have been used successfully, identifying the diseases and conditions that are most conducive to the use of diversity has been surprisingly difficult, and the selective influence of diversity on pathogen populations is complex. The importance of considering resistance durability in a landscape context has received increasing emphasis and is an important future area of research. Experimental systems are being developed to test resistance gene deployment strategies that previously could be addressed only with logic and observation.