29 research outputs found

    Table_2_Epidemiological characteristics of SHV, cmlv, and FosA6-producing carbapenem-resistant Klebsiella pneumoniae based on whole genome sequences in Jiangsu, China.xlsx

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    Carbapenem-resistant Klebsiella pneumoniae (CRKP), particularly those with high virulence, cause invasive disease in clinical settings. An epidemiological investigation was conducted on the evolution, virulence, and antimicrobial resistance of CRKP isolates in two tertiary teaching hospitals in Jiangsu, China from November 2020 to December 2021. There were 31 different CRKP strains discovered. We performed whole genome sequencing (WGS) on 13 SHV, cmlv, and FosA6-producing CRKP to reveal molecular characteristics. Five ST15/ST11 isolates had CRISPR-Cas systems. By conjugation tests, KPC-2 can be transmitted horizontally to E. coil. A conjugative pHN7A8-related multi-resistance plasmid (KPC-2, blaCTX-M-65, blaTEM-1, fosA3, catII, and rmtB) was first discovered in CRKP clinical isolates. Using bacteriological testing, a serum killing assay, and an infection model with Galleria mellonella, three ST11-K64 KPC-2 generating carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) were identified. These strains harbored a virulent plasmid and an IncFII-family pKPC/pHN7A8 conjugative plasmid, which led to hypervirulence and resistance. One of these CR-hvKPs, which co-harbored KPC-2, NDM-6, SHV-182, SHV-64, and blaCTX-M-122 genes, was first discovered. Importantly, this CR-hvKP strain also produced biofilm and had non-inferior fitness. The widespread use of ceftazidime/avibactam might provide this CR-hvKP with a selective advantage; hence, immediate action is required to stop its dissemination. Another important finding is the novel ST6136 in K. pneumoniae. Finally, the sterilization efficiency rates of Fe2C nanoparticles in CRKP were more than 98%. Furthermore, our novel antibacterial Fe2C nanoparticles may also provide a therapeutic strategy for infections.</p

    Table_3_Epidemiological characteristics of SHV, cmlv, and FosA6-producing carbapenem-resistant Klebsiella pneumoniae based on whole genome sequences in Jiangsu, China.xlsx

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    Carbapenem-resistant Klebsiella pneumoniae (CRKP), particularly those with high virulence, cause invasive disease in clinical settings. An epidemiological investigation was conducted on the evolution, virulence, and antimicrobial resistance of CRKP isolates in two tertiary teaching hospitals in Jiangsu, China from November 2020 to December 2021. There were 31 different CRKP strains discovered. We performed whole genome sequencing (WGS) on 13 SHV, cmlv, and FosA6-producing CRKP to reveal molecular characteristics. Five ST15/ST11 isolates had CRISPR-Cas systems. By conjugation tests, KPC-2 can be transmitted horizontally to E. coil. A conjugative pHN7A8-related multi-resistance plasmid (KPC-2, blaCTX-M-65, blaTEM-1, fosA3, catII, and rmtB) was first discovered in CRKP clinical isolates. Using bacteriological testing, a serum killing assay, and an infection model with Galleria mellonella, three ST11-K64 KPC-2 generating carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) were identified. These strains harbored a virulent plasmid and an IncFII-family pKPC/pHN7A8 conjugative plasmid, which led to hypervirulence and resistance. One of these CR-hvKPs, which co-harbored KPC-2, NDM-6, SHV-182, SHV-64, and blaCTX-M-122 genes, was first discovered. Importantly, this CR-hvKP strain also produced biofilm and had non-inferior fitness. The widespread use of ceftazidime/avibactam might provide this CR-hvKP with a selective advantage; hence, immediate action is required to stop its dissemination. Another important finding is the novel ST6136 in K. pneumoniae. Finally, the sterilization efficiency rates of Fe2C nanoparticles in CRKP were more than 98%. Furthermore, our novel antibacterial Fe2C nanoparticles may also provide a therapeutic strategy for infections.</p

    Table_1_Epidemiological characteristics of SHV, cmlv, and FosA6-producing carbapenem-resistant Klebsiella pneumoniae based on whole genome sequences in Jiangsu, China.xlsx

    No full text
    Carbapenem-resistant Klebsiella pneumoniae (CRKP), particularly those with high virulence, cause invasive disease in clinical settings. An epidemiological investigation was conducted on the evolution, virulence, and antimicrobial resistance of CRKP isolates in two tertiary teaching hospitals in Jiangsu, China from November 2020 to December 2021. There were 31 different CRKP strains discovered. We performed whole genome sequencing (WGS) on 13 SHV, cmlv, and FosA6-producing CRKP to reveal molecular characteristics. Five ST15/ST11 isolates had CRISPR-Cas systems. By conjugation tests, KPC-2 can be transmitted horizontally to E. coil. A conjugative pHN7A8-related multi-resistance plasmid (KPC-2, blaCTX-M-65, blaTEM-1, fosA3, catII, and rmtB) was first discovered in CRKP clinical isolates. Using bacteriological testing, a serum killing assay, and an infection model with Galleria mellonella, three ST11-K64 KPC-2 generating carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) were identified. These strains harbored a virulent plasmid and an IncFII-family pKPC/pHN7A8 conjugative plasmid, which led to hypervirulence and resistance. One of these CR-hvKPs, which co-harbored KPC-2, NDM-6, SHV-182, SHV-64, and blaCTX-M-122 genes, was first discovered. Importantly, this CR-hvKP strain also produced biofilm and had non-inferior fitness. The widespread use of ceftazidime/avibactam might provide this CR-hvKP with a selective advantage; hence, immediate action is required to stop its dissemination. Another important finding is the novel ST6136 in K. pneumoniae. Finally, the sterilization efficiency rates of Fe2C nanoparticles in CRKP were more than 98%. Furthermore, our novel antibacterial Fe2C nanoparticles may also provide a therapeutic strategy for infections.</p

    Sensitivity analysis of the allele-specific PCR assay.

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    <p>(<b>A</b>) <b>Sensitivity analysis using the bacterial genomic DNA.</b> The detection limit was determined as 10 pg of bacterial DNA for <i>E. coli</i> serotypes O2 and O18 strains, and 500 pg of bacterial DNA for <i>E. coli</i> serotypes O1 and O78 strains, respectively. (<b>B</b>) <b>Sensitivity analysis using the bacterial culture.</b> The detection limit was determined as 10 CFUs of <i>E. coli</i> serotypes O2 and O18 strains, and 1,000 CFUs of <i>E. coli</i> serotypes O1 and O78 strains, respectively. Lane M: DL2000 Marker.</p

    Sensitivity analysis of the allele-specific PCR assay.

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    <p>(<b>A</b>) <b>Sensitivity analysis using the bacterial genomic DNA.</b> The detection limit was determined as 10 pg of bacterial DNA for <i>E. coli</i> serotypes O2 and O18 strains, and 500 pg of bacterial DNA for <i>E. coli</i> serotypes O1 and O78 strains, respectively. (<b>B</b>) <b>Sensitivity analysis using the bacterial culture.</b> The detection limit was determined as 10 CFUs of <i>E. coli</i> serotypes O2 and O18 strains, and 1,000 CFUs of <i>E. coli</i> serotypes O1 and O78 strains, respectively. Lane M: DL2000 Marker.</p

    The <i>rfb</i> gene clusters of <i>E. coli</i> serotypes O1, O2, O18 and O78 strains.

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    <p>The black arrows correspond to <i>gnd</i> and <i>galF</i> genes. Grey arrows correspond to <i>rfb</i> gene cluster and the gene names are <i>italic</i> indicated. The length of <i>rfb</i> gene cluster was also shown. In the PCR reaction system, the universal forward primer was used for all the sero-typing amplification with specific reverse primers. The bold lines below the <i>gnd</i> gene indicate the size of the PCR products for different <i>E. coli</i> serotype strains, which allow the differentiation of the O types. Primers and their locations were also indicated.</p

    The product profiles of <i>E. coli</i> serotypes O1, O2, O18 and O78 strains amplified using the allele-specific PCR.

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    <p>Lane M: DL2000 DNA Marker; O1, O2, O18 and O78 represent PCR products for O1, O2, O18 and O78 strains respectively. Lane 1: APEC O1 strain; Lane 2: APEC strain DE47; Lane 3: APEC strain DE14; Lane 4: APEC strain DE17; Lane 5: APEC strain RS218; Lane 6: APEC strain CE66; Lane 7: APEC strain DE48; Lane 8: APEC strain DE65; Lane 9: Negative control.</p

    Primers used in this study.

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    a<p>The primers were designed based on the gene sequences of <i>wekO</i>, <i>wekS</i>, <i>wekW</i> and <i>wzx</i> in the <i>rfb</i> gene cluster of respective serotypes of <i>E. coli</i> strains.</p

    Bacterial strains used in this study.

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    a<p>CVCC, Chinese Veterinary Culture Collection Center, China.</p>b<p>ATCC, American Type Culture Collection, USA.</p

    Image_4_A Novel PhoP/PhoQ Regulation Pathway Modulates the Survival of Extraintestinal Pathogenic Escherichia coli in Macrophages.TIF

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    <p>The extraintestinal pathogenic Escherichia coli (ExPEC) is a typical facultative intracellular bacterial pathogen. Sensing the environmental stimuli and undertaking adaptive change are crucial for ExPEC to successfully colonize in specific extraintestinal niches. The previous studies show that pathogens exploit two-component systems (TCSs) in response to the host environments during its infection. The PhoP/PhoQ is a typical TCS which is ubiquitous in Gram-negative bacteria. However, there is an incompletely understanding about critical regulatory roles of PhoP/PhoQ in ExPEC pathogenesis. Conjugative ColV-related plasmids are responsible for ExPEC virulence, which is associated with ExPEC zoonotic risk. In this study, the molecular characteristics of HlyF, Mig-14 ortholog (Mig-14p), and OmpT variant (OmpTp) encoded by ColV plasmids were identified. Mig-14p and OmpTp played important roles in conferring ExPEC resistance to cationic antimicrobial peptides (CAMPs) during the infection. Moreover, HlyF and Mig-14p acted as intracellular survival factors to promote ExPEC resistance to macrophages killing. The hlyF and Mig-14p formed an operon in ExPEC ColV plasmid, and PhoP acted as a transcriptional activator of hlyF operon by directly binding to the P<sub>hlyF</sub> promoter. The acidic pH and CAMPs could additively stimulate ExPEC PhoQ/PhoP activities to upregulate the expression of HlyF and Mig-14p. Our studies revealed that the novel PhoP/PhoQ-HlyF signaling pathway directly upregulates the production of ExPEC outer membrane vesicles. Furthermore, our study first clarified that this PhoP/PhoQ-HlyF pathway was essential for ExPEC intracellular survival in macrophages. It was required to prevent the fusion of ExPEC-containing phagosomes with lysosomes. Moreover, PhoP/PhoQ-HlyF pathway facilitated the inhibition of the phagolysosomal acidification and disruption of the phagolysosomal membranes. In addition, this pathway might promote the formation of ExPEC-containing autophagosome during ExPEC replication in macrophages. Collectively, our studies suggested that PhoP/PhoQ system and CloV plasmids could facilitate ExPEC survival and replication within macrophages.</p
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