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Introduction: Carbapenem-resistant Klebsiella pneumoniae (CRKP) has been widespread in coastal cities of eastern China since 2009. However, how CRKP spreads and evolves in southwest China is unclear. Aim: We investigated the genetic characteristics and dissemination mechanisms of carbapenemase genes in forty-one non-repetitive CRKP isolates collected from a southwest hospital, Kunming, Yunnan, during 2010– 2013. Methodology: Drug susceptibilities were analyzed by using VITEK 2 compact system. Genetic relationships were ascertained based on multilocus sequence typing (MLST) and Pulsed-field gel electrophoresis (PFGE) analysis. Genetic backgrounds of blaKPC-2 and blaNDM-1 were revealed by DNA walking and high-throughput sequencing. Results: All isolates were highly resistant to common antibiotics except for tigecycline. In total, 34 blaKPC-2, 3 blaNDM-1, 1 blaIMP-4 and 3 blaIMP-26 genes were identified and KP67 plasmid 1 co-harbored blaNDM-1 and blaIMP-26. Five sequence types, namely ST11, ST290, ST340, ST395 and ST437, were recognized by MLST. Surprisingly, blaKPC-2 was only detected in ST11 strains. We described a clonal dissemination of fosA3-positive IncR-IncF33:A-:B- multireplicon plasmid carrying the gene cassettes IS 26-ΔTn 3-ISKpn27-blaKPC-2-ΔISKpn6-korC-klcA-ΔrepB-Tn 1721 in all ST11 isolates. Three blaNDM-1 positive isolates belonged to three different ST types and their blaNDM-1 genetic backgrounds were also distinct. Interestingly, the flanking regions of blaNDM-1 in KP67 and KP72 were duplicated into one to five copies in a form of tandem repeat by the transposition of IS 91 like element. The blaNDM-1 of KP82 was carried on a common IncX3 plasmid. Conclusion: This study described the early epidemiological characteristics of blaKPC-2/blaNDM-1-carrying CRKP, and reported a new tandem repeat pattern of blaNDM-1 cluster in Yunnan. These findings extend our knowledge on the carbapenemase gene evolutions. [ABSTRACT FROM AUTHOR]

Two new species of Christisonia (Orobanchaceae), Christisonia hekouensis Gui L.Zhang, J.D.Ya & W.B.Yu and Christisonia dentosa J.D.Ya, Gui L.Zhang & W.B.Yu, found during botanical surveys in Southeast Yunnan, China, are described and illustrated. The two new species are similar to C. kwangtungensis bearing rose-red flowers and conspicuously inflated corolla tubes, and phylogenetic analyses strongly support the three species as monophyletic. However, C. hekouensis can be distinguished from C. kwangtungensis and C. dentosa by having externally puberulent calyces and corollas, corolla lobes with serrulate margins, styles that are pink and glabrous or sparsely capitate-glandular pubescent above, and with anthers less than 2 mm below the stigma. Christisonia dentosa differs from C. kwangtungensis and C. hekouensis by having dentate corolla lobe margins, internally capitate-glandular pubescent corollas, styles distinctly capitate-glandular pubescent above, and more than six anthers which are up to 10 mm below the stigma. [ABSTRACT FROM AUTHOR]

Potentially toxic metals in farmland soil have recently become a significant environmental concern in China. In this study, the occurrence and distribution of eight (8) heavy metals (HMs) were investigated from 54 topsoil samples obtained across 18 provinces. Human health and ecological hazards associated with HMs were assessed through different risk characterization indices and their sources predicted. The statistically mean concentrations of HMs ranged from 0.08 to 70.05 mg kg−1, which were below the determined threshold values for agricultural lands according to the Chinese National Standard (GB 15618–2018). The respective ecological risk index ( E r i) of HMs revealed that they posed a lower risk ( E r i < 40) but their potential cumulative ecological risk (RI) was determined as a considerable risk (300 ≤ RI < 600). Spatial distribution and heterogeneities of HMs were found to be highly concentrated in the southern parts (e.g., Yunnan, Guangdong) of China, particularly for Arsenic (As), Zinc (Zn), and Chromium (Cr). PMF model was found capable of efficiently elucidating respective sources of HMs across the studied provinces as most were impacted by geological/pedogenic and anthropogenic activities (e.g., agricultural, industrial discharge fallouts). Probabilistic health risk assessment indicated that the non-carcinogenic risk (NCR) and total carcinogenic risk (TCR) of HMs in both adults and children were low and acceptable. [Display omitted] [ABSTRACT FROM AUTHOR]