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Background: This study aims to characterize genetically related class 1 integrons In1069, In893 and In1287 to In1290, and to further propose a scheme of stepwise integration or excision of individual gene cassettes (GCs) to generation of these integron variations., Methods: Six of 139 non-redundant Enterobacteriaceae strains were studied by bacterial antimicrobial susceptibility testing, detection of carbapenemase activity, and integron sequencing and sequence comparison., Results: Six novel class 1 integrons, In0, In1069, and In1287 to In1290, together with the previously characterized In893, were determined from the above strains. An unusual bla KPC-2 -carrying In0 and the bla IMP-30 -carrying In1069 coexists in a single isolate of Escherichia coli . In0 contains a PcH1 promoter and a truncated aacA4'-3 gene cassette (GC aacA4'-3 ), as well as a bla KPC-2 -containing region of Tn 6296 integrated between PcH1 and GC aacA4'-3 . In1069 carries GC bla IMP-30 and GC aacA4'-3 in this order. The other five integrons, In893 and In1287 to In1290, are genetically related to In1069, and all possess a core GC aacA4'-3 . The integration or excision of one or more individual gene cassettes, such as GC bla IMP-30 , GC aadA16 , GC catB3 , GC arr3 and GC dfrA27 , upstream or downstream of GC aacA4'-3 generates various gene cassettes arrays among these five integrons., Conclusions: These findings provide the insight into stepwise and parallel evolution of In1069-associated integron variations likely under antibiotic selection pressure in clinical settings.

Background: Intrauterine balloon aortic valvuloplasty (IUBAV) has been used for critical aortic stenosis. However, it is necessary to determine the fetal impairments such as preterm birth after this approach and to find a way to prevent or reduce them., Methods: In the present study, we evaluated the therapeutic value of indomethacin (IDM) and dexamethasone (DXS) on reducing the preterm birth rate in experimental goats after IUBAV., Results: Our results indicated that the administration of IDM/DXS significantly reduced the rate of premature birth. IDM/DXS treatment led to preservation of myocardial ultrastructure with less damage, and amelioration of the fetal and placental circulation. Furthermore, we found that norepinephrine (NE) level was positively associated with the degree of myocardial damage. IDM/DXS administration led to a significant decrease of operation-induced increase of NE levels, which may be associated with the protective effects of IDM/DXS. Lastly, we found that the administration of IDM/DXS did not induce the risk of ductus arteriosus closure or slow down fetal growth., Conclusions: Our results indicate that IDM/DXS promotes a better gestational outcome at least partially by reducing stress response during and after the operation of IUBAV in the goat model. IDM/DXS may be a useful application in human patients during IUBAV intervention.