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Complete sequences of KPC-2-encoding plasmid p628-KPC and CTX-M-55-encoding p628-CTXM coexisted in Klebsiella pneumoniae.

Wang L, Fang H, Feng J, Yin Z, Xie X, Zhu X, Wang J, Chen W, Yang R, Du H, Zhou D - Front Microbiol (2015)

Bottom Line: A carbapenem-resistant Klebsiella pneumoniae strain 628 was isolated from a human case of intracranial infection in a Chinese teaching hospital.ΔTn3-ISKpn27-bla KPC-2-ΔISKpn6-ΔTn1722 and this transposon together with a mercury resistance (mer) gene locus constitutes a 34 kb acquired drug-resistance region. bla KPC-2 has two transcription starts (nucleotides G and C located at 39 and 250 bp upstream of its coding region respectively) which correspond to two promoters, i.e., the intrinsic P1 and the upstream ISKpn27/Tn3-provided P2 with the core -35/-10 elements TAATCC/TTACAT and TTGACA/AATAAT respectively. bla CTX-M-55 is mobilized in an ISEcp1-bla CTX-M-55-Δorf477 transposition unit and appears to be the sole drug-resistant determinant in p628-CTXM. bla CTX-M-55 possesses a single transcription start (nucleotides G located at 116 bp upstream of its coding region) corresponding to the ISEcp1-provided P1 promoter with the core -35/-10 element TTGAAA/TACAAT.All the above detected promoters display a characteristic of constitutive expression.

View Article: PubMed Central - PubMed

Affiliation: Department of Clinical Laboratory, The First Hospital Affiliated to Henan University Kaifeng, China.

ABSTRACT
A carbapenem-resistant Klebsiella pneumoniae strain 628 was isolated from a human case of intracranial infection in a Chinese teaching hospital. Strain 628 produces KPC-2 and CTX-M-55 encoded by two different conjugative plasmids, i.e., the IncFIIK plasmid p628-KPC and the IncI1 plasmid p628-CTXM respectively. bla KPC-2 is captured by a Tn1722-based unit transposon with a linear structure. ΔTn3-ISKpn27-bla KPC-2-ΔISKpn6-ΔTn1722 and this transposon together with a mercury resistance (mer) gene locus constitutes a 34 kb acquired drug-resistance region. bla KPC-2 has two transcription starts (nucleotides G and C located at 39 and 250 bp upstream of its coding region respectively) which correspond to two promoters, i.e., the intrinsic P1 and the upstream ISKpn27/Tn3-provided P2 with the core -35/-10 elements TAATCC/TTACAT and TTGACA/AATAAT respectively. bla CTX-M-55 is mobilized in an ISEcp1-bla CTX-M-55-Δorf477 transposition unit and appears to be the sole drug-resistant determinant in p628-CTXM. bla CTX-M-55 possesses a single transcription start (nucleotides G located at 116 bp upstream of its coding region) corresponding to the ISEcp1-provided P1 promoter with the core -35/-10 element TTGAAA/TACAAT. All the above detected promoters display a characteristic of constitutive expression. Coexistence of bla KPC and bla CTX-M in K. pneumoniae has been reported many times but this is the first report to gain deep insights into genetic platforms, promoters, and expression of the two coexisting bla genes with determination of entire nucleotide sequences of the two corresponding plasmids.

No MeSH data available.


Related in: MedlinePlus

Linear comparison of sequenced plasmids. Genes are denoted by arrows and colored based on gene function classification. Shading regions denote regions of homology (>98% nucleotide similarity). Included are p628-KPC (A) and p628-CTXM (B) and their closely related plasmids.
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Figure 2: Linear comparison of sequenced plasmids. Genes are denoted by arrows and colored based on gene function classification. Shading regions denote regions of homology (>98% nucleotide similarity). Included are p628-KPC (A) and p628-CTXM (B) and their closely related plasmids.

Mentions: The entire nucleotide sequence of p628-KPC is 105,008 bp in length, forming a circular plasmid with an average G+C content of 53.22 and a total of 127 open reading frames (ORFs) annotated (Figure 1A). p628-KPC belongs to the IncFIIK incompatibility group and harbors IncFIIKrepA and the second IncFIB-like repA2, both of which encode replication initiation proteins. The p628-KPC backbone, 67,515 bp in length, is composed of DNA regions for plasmid replication (repA and repA2) and stability (parAB, stbAB, ssb, etc), and conjugal transfer (tra, trb, etc), which show >98% sequence identity to the corresponding regions of the IncFIIK plasmids pKPN4 (GenBank accession number CP000649), pKP048 (Jiang et al., 2010), and pKPHS2 (CP003224) (Figure 2A). The overall structure of p628-KPC is most similar to that of pKPHS2 (91% query coverage and 98% maximum nucleotide identity) (Figure 2A). pKPN4 is recovered from clinical K. pneumoniae MGH 78578 and represents the reference IncFIIK plasmid, carrying blaSHV−12 (cephalosporin resistance), and aac(6′) and aadA (aminoglycoside resistance). pKP048 and pKPHS2 are from two KPC-2-producing clinical K. pneumoniae isolates from China.


Complete sequences of KPC-2-encoding plasmid p628-KPC and CTX-M-55-encoding p628-CTXM coexisted in Klebsiella pneumoniae.

Wang L, Fang H, Feng J, Yin Z, Xie X, Zhu X, Wang J, Chen W, Yang R, Du H, Zhou D - Front Microbiol (2015)

Linear comparison of sequenced plasmids. Genes are denoted by arrows and colored based on gene function classification. Shading regions denote regions of homology (>98% nucleotide similarity). Included are p628-KPC (A) and p628-CTXM (B) and their closely related plasmids.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541600&req=5

Figure 2: Linear comparison of sequenced plasmids. Genes are denoted by arrows and colored based on gene function classification. Shading regions denote regions of homology (>98% nucleotide similarity). Included are p628-KPC (A) and p628-CTXM (B) and their closely related plasmids.
Mentions: The entire nucleotide sequence of p628-KPC is 105,008 bp in length, forming a circular plasmid with an average G+C content of 53.22 and a total of 127 open reading frames (ORFs) annotated (Figure 1A). p628-KPC belongs to the IncFIIK incompatibility group and harbors IncFIIKrepA and the second IncFIB-like repA2, both of which encode replication initiation proteins. The p628-KPC backbone, 67,515 bp in length, is composed of DNA regions for plasmid replication (repA and repA2) and stability (parAB, stbAB, ssb, etc), and conjugal transfer (tra, trb, etc), which show >98% sequence identity to the corresponding regions of the IncFIIK plasmids pKPN4 (GenBank accession number CP000649), pKP048 (Jiang et al., 2010), and pKPHS2 (CP003224) (Figure 2A). The overall structure of p628-KPC is most similar to that of pKPHS2 (91% query coverage and 98% maximum nucleotide identity) (Figure 2A). pKPN4 is recovered from clinical K. pneumoniae MGH 78578 and represents the reference IncFIIK plasmid, carrying blaSHV−12 (cephalosporin resistance), and aac(6′) and aadA (aminoglycoside resistance). pKP048 and pKPHS2 are from two KPC-2-producing clinical K. pneumoniae isolates from China.

Bottom Line: A carbapenem-resistant Klebsiella pneumoniae strain 628 was isolated from a human case of intracranial infection in a Chinese teaching hospital.ΔTn3-ISKpn27-bla KPC-2-ΔISKpn6-ΔTn1722 and this transposon together with a mercury resistance (mer) gene locus constitutes a 34 kb acquired drug-resistance region. bla KPC-2 has two transcription starts (nucleotides G and C located at 39 and 250 bp upstream of its coding region respectively) which correspond to two promoters, i.e., the intrinsic P1 and the upstream ISKpn27/Tn3-provided P2 with the core -35/-10 elements TAATCC/TTACAT and TTGACA/AATAAT respectively. bla CTX-M-55 is mobilized in an ISEcp1-bla CTX-M-55-Δorf477 transposition unit and appears to be the sole drug-resistant determinant in p628-CTXM. bla CTX-M-55 possesses a single transcription start (nucleotides G located at 116 bp upstream of its coding region) corresponding to the ISEcp1-provided P1 promoter with the core -35/-10 element TTGAAA/TACAAT.All the above detected promoters display a characteristic of constitutive expression.

View Article: PubMed Central - PubMed

Affiliation: Department of Clinical Laboratory, The First Hospital Affiliated to Henan University Kaifeng, China.

ABSTRACT
A carbapenem-resistant Klebsiella pneumoniae strain 628 was isolated from a human case of intracranial infection in a Chinese teaching hospital. Strain 628 produces KPC-2 and CTX-M-55 encoded by two different conjugative plasmids, i.e., the IncFIIK plasmid p628-KPC and the IncI1 plasmid p628-CTXM respectively. bla KPC-2 is captured by a Tn1722-based unit transposon with a linear structure. ΔTn3-ISKpn27-bla KPC-2-ΔISKpn6-ΔTn1722 and this transposon together with a mercury resistance (mer) gene locus constitutes a 34 kb acquired drug-resistance region. bla KPC-2 has two transcription starts (nucleotides G and C located at 39 and 250 bp upstream of its coding region respectively) which correspond to two promoters, i.e., the intrinsic P1 and the upstream ISKpn27/Tn3-provided P2 with the core -35/-10 elements TAATCC/TTACAT and TTGACA/AATAAT respectively. bla CTX-M-55 is mobilized in an ISEcp1-bla CTX-M-55-Δorf477 transposition unit and appears to be the sole drug-resistant determinant in p628-CTXM. bla CTX-M-55 possesses a single transcription start (nucleotides G located at 116 bp upstream of its coding region) corresponding to the ISEcp1-provided P1 promoter with the core -35/-10 element TTGAAA/TACAAT. All the above detected promoters display a characteristic of constitutive expression. Coexistence of bla KPC and bla CTX-M in K. pneumoniae has been reported many times but this is the first report to gain deep insights into genetic platforms, promoters, and expression of the two coexisting bla genes with determination of entire nucleotide sequences of the two corresponding plasmids.

No MeSH data available.


Related in: MedlinePlus