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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

Alignment of blaCTX−M upstream sequences. The 153–235 bp upstream sequences together with the start codon of the blaCTX−M genes were aligned by CLUSTALW. Shown were core promoter regions, −35 and −10 elements, transcription starts, SD sequences for ribosome recognition, and translation starts. Asterisks indicate the identical nucleotides
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Figure 7: Alignment of blaCTX−M upstream sequences. The 153–235 bp upstream sequences together with the start codon of the blaCTX−M genes were aligned by CLUSTALW. Shown were core promoter regions, −35 and −10 elements, transcription starts, SD sequences for ribosome recognition, and translation starts. Asterisks indicate the identical nucleotides

Mentions: Spacer regions between ISEcp1 and blaCTX−M−55 from different ISEcp1-blaCTX−M−55 isoforms display three different lengths, namely 45 bp (e.g., blap1081−CTXMCTX−M−55) (Qu et al., 2014), 48 bp (e.g. blap628−CTXMCTX−M−55), and 127 bp (e.g., blaJQ343851CTX−M−55). Two promoters, TTGAAA-N18-TACAAT-N6-G (organized as -35 element/-10 element/transcription start; named P1) and TTGACT-N18-TTTCGT-N6-C (P2), are experimentally identified for blaAF550415CTX−M−3 with a 127 bp spacer and moreover, the ISEcp1-provided promoter P1 is stronger and more important than the intrinsic P2 promoter in the 127 bp spacer (Ma et al., 2011). The above result is applicable to the blaCTX−M−55 genes with the 127 bp spacer (Figure 7), because their ISEcp1+spacer region is identical to the counterpart of blaAF550415CTX−M−3.


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)

Alignment of blaCTX−M upstream sequences. The 153–235 bp upstream sequences together with the start codon of the blaCTX−M genes were aligned by CLUSTALW. Shown were core promoter regions, −35 and −10 elements, transcription starts, SD sequences for ribosome recognition, and translation starts. Asterisks indicate the identical nucleotides
© Copyright Policy
Related In: Results  -  Collection

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

Figure 7: Alignment of blaCTX−M upstream sequences. The 153–235 bp upstream sequences together with the start codon of the blaCTX−M genes were aligned by CLUSTALW. Shown were core promoter regions, −35 and −10 elements, transcription starts, SD sequences for ribosome recognition, and translation starts. Asterisks indicate the identical nucleotides
Mentions: Spacer regions between ISEcp1 and blaCTX−M−55 from different ISEcp1-blaCTX−M−55 isoforms display three different lengths, namely 45 bp (e.g., blap1081−CTXMCTX−M−55) (Qu et al., 2014), 48 bp (e.g. blap628−CTXMCTX−M−55), and 127 bp (e.g., blaJQ343851CTX−M−55). Two promoters, TTGAAA-N18-TACAAT-N6-G (organized as -35 element/-10 element/transcription start; named P1) and TTGACT-N18-TTTCGT-N6-C (P2), are experimentally identified for blaAF550415CTX−M−3 with a 127 bp spacer and moreover, the ISEcp1-provided promoter P1 is stronger and more important than the intrinsic P2 promoter in the 127 bp spacer (Ma et al., 2011). The above result is applicable to the blaCTX−M−55 genes with the 127 bp spacer (Figure 7), because their ISEcp1+spacer region is identical to the counterpart of blaAF550415CTX−M−3.

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