Characterization of blaCMY-11, an AmpC-type plasmid-mediated beta-lactamase gene in a Korean clinical isolate of Escherichia coli

Lee, Sangeun; Kim, Jae Young; Lee, Gyu Sang; Cheon, Seok Ho; An, Young Jun; Jeong, Seok Hoon; Lee, Kye Joon

doi:10.1093/jac/49.2.269

Cited by 31 publications

(33 citation statements)

References 9 publications

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“…Transconjugants were selected on Muller-Hinton agar supplemented with rifampin (100 mg/liter) to inhibit the growth of the donor strain and with imipenem (1 mg/liter) to inhibit the growth of the recipient strain. Crude bacterial extracts were obtained from clinical isolates after centrifugation of sonicated culture as previously described (12). Sonic extracts were used for the determination of isoelectric points (pIs) and ␤-lactamase activity.…”

Section: Methodsmentioning

confidence: 99%

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Investigation of a Nosocomial Outbreak of Imipenem-Resistant Acinetobacter baumannii Producing the OXA-23 β-Lactamase in Korea

Jeon¹,

et al. 2005

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We investigated an outbreak of Acinetobacter baumannii in an intensive care unit and in the surgery, medicine, neurology, and urology wards of the Kosin University Gospel Hospital in Busan, Korea. The outbreak involved 36 cases of infection by A. baumannii producing the OXA-23 ␤-lactamase over an 8-month period and was caused by a single pulsed-field gel electrophoresis clone. The epidemic isolates were characterized by a modified cloverleaf synergy test. Isoelectric focusing of crude bacterial extracts detected one nitrocefin-positive band with a pI value of 6.65. PCR amplification and characterization of the amplicons by direct sequencing indicated that the epidemic isolates carried a bla OXA-23 determinant. The epidemic isolates were characterized by a multidrug resistance phenotype that remained unchanged over the outbreak, including penicillins, cephamycins, extended-spectrum cephalosporins, carbapenems, monobactams, and aminoglycosides. This study shows that the bla OXA-23 resistance determinant may become an emerging therapeutic problem.Acinetobacter baumannii has emerged as an important nosocomial pathogen in outbreaks of hospital infections and is ranked second after Pseudomonas aeruginosa among nosocomial pathogens of aerobic nonfermentative gram-negative bacilli (17,19). A. baumannii causes respiratory and urinary tract infections, meningitis, endocarditis, burn infections, and wound sepsis, especially in intensive care units (ICUs) (4). A. baumannii infections are often difficult to eradicate due to high-level resistance to many antibiotics as a result of both intrinsic and acquired mechanisms. ␤-Lactamase production is the most important mechanism of acquired ␤-lactam resistance in gram-negative pathogens (21). Carbapenems (e.g., imipenem and meropenem) have become the drugs of choice against Acinetobacter infections in many centers but are being compromised by the emergence of carbapenem-hydrolyzing ␤-lactamase (carbapenemase) of molecular classes B and D (14). Class B carbapenemases found thus far in Acinetobacter spp. include various IMP-and VIM-type metallo-␤-lactamases (http: //www.lahey.org/studies/webt.asp), but most Acinetobacter spp. produce zinc-independent members of ␤-lactamase molecular class D (1). Sequenced carbapenemases of this latter class from that species include the following two distinct clusters: (i) the OXA-23-like cluster (OXA-23 and -27) and (ii) the OXA-24-like cluster . OXA-23 and OXA-27 have 99% amino acid identity, whereas they have only 60% identity with those of OXA-24-like cluster (1,3,6,7).Over an 8-month period from January to August 2003, 193 A. baumannii isolates were isolated from 193 patients hospitalized at the Kosin University Gospel Hospital. The purpose of the present study was to investigate an outbreak of A. baumannii in Korea and to characterize the imipenem resistance mechanism of the outbreak isolates. MATERIALS AND METHODS Bacterial strains and susceptibility tests. A total of 193 nonrepetitive clinical isolates of A. baumannii were isolated from Ja...

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Section: Methodsmentioning

confidence: 99%

“…Sonic extracts were used for the determination of isoelectric points (pIs) and ␤-lactamase activity. Isoelectric focusing (IEF) was performed in Ready Gel precast IEF polyacrylamide gels (Bio-Rad, Hercules, Calif.) as previously described (12). Gels were developed with 0.5 mM nitrocefin (Merck, Whitehouse Station, N.J.).…”

Section: Methodsmentioning

confidence: 99%

Investigation of a Nosocomial Outbreak of Imipenem-Resistant Acinetobacter baumannii Producing the OXA-23 β-Lactamase in Korea

Jeon¹,

et al. 2005

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“…After overnight incubation at 37°C, the production of an ESBL by the test organism was inferred by the presence of characteristic distortions of the inhibition zones indicative of clavulanate potentiation of the activity of the test drug. MICs were determined on Muller-Hinton agar plates (Difco Laboratories, Detroit, Mich.) containing serially twofold-diluted betalactams as previously described (12).…”

Section: Methodsmentioning

confidence: 99%

“…Plasmid-mediated AmpC betalactamases are often expressed in large amounts and can pose therapeutic problems (16). Plasmid-mediated AmpC beta-lactamases have been recently reported for K. pneumoniae (CMY-1, CMY-2, CMY-8, MOX-1, MOX-2, FOX-1, FOX-5, LAT-1, LAT-2, LAT-2b, ACT-1, MIR-1, and ACC-1), Klebsiella oxytoca (CMY-5 and FOX-3), E. coli (CMY-4, CMY-6, CMY-7, CMY-9, FOX-2, FOX-4, BIL-1, LAT-3, and LAT-4), Salmonella enterica serovar Enteritidis (DHA-1), Pseudomonas mirabilis (CMY-3), and S. enterica serovar Senftenberg (CMY2b) (12). In view of the risk of spreading of ESBL and AmpC resistance determinants among enterobacterial isolates, it is important to elucidate the mechanism of resistance in isolates that are resistant to extended-spectrum beta-lactams.…”

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confidence: 99%

Molecular Characterization of Extended-Spectrum Beta-Lactamases Produced by Clinical Isolates of Klebsiella pneumoniae and Escherichia coli from a Korean Nationwide Survey

et al. 2004

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To determine the prevalence and genotypes of extended-spectrum beta-lactamases (ESBLs) among clinical isolates of Klebsiella pneumoniae and Escherichia coli, we performed antibiotic susceptibility testing, pI determination, induction testing, transconjugation, and DNA sequencing analysis. Among the 509 isolates collected from 13 university hospitals in Korea, 39.2% produced ESBLs. ESBL-producing isolates were detected in every region in Korea. A total of 44.6% of the isolates produced both TEM-and SHV-type ESBLs, and 52% of ESBL-producing isolates transferred resistance to ceftazidime by transconjugation. The ESBLs were TEM-19, TEM-20, TEM-52, SHV-2a, SHV-12, and one new variant identified for the first time in Korea, namely, TEM-116. TEM-1 and SHV-12 were by far the most common variants. TEM-1, TEM-116, and SHV-12 showed a high prevalence in K. pneumoniae. Two isolates (E. coli SH16 and K. pneumoniae SV3) produced CMY-1-like beta-lactamases, which play a decisive role in resistance to cefoxitin and cefotetan, as well as TEM-type enzymes (TEM-20 and TEM-52, respectively). Using MIC patterns and DNA sequencing analysis, we postulated a possible evolution scheme among TEM-type beta-lactamases in Korea: from TEM-1 to TEM-19, from TEM-19 to TEM-20, and from TEM-20 to TEM-52.

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“…ISCR1 elements have been found adjacent to a number of cephalosporinase genes, including bla DHA-1 (originating from the chromosome of M. morganii) (103), bla CMY-1 and bla to bla (3,23,55,110) (thought to originate from an Aeromonas sp. ), and a variant of bla CMY -type genes, bla MOX-1 (41) (Fig.…”

Section: Iscr1mentioning

confidence: 99%

IS CR Elements: Novel Gene-Capturing Systems of the 21st Century?

Toleman

Bennett

Walsh

2006

Microbiol Mol Biol Rev

529

481

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SUMMARY “Common regions” (CRs), such as Orf513, are being increasingly linked to mega-antibiotic-resistant regions. While their overall nucleotide sequences show little identity to other mobile elements, amino acid alignments indicate that they possess the key motifs of IS91-like elements, which have been linked to the mobility ent plasmids in pathogenic Escherichia coli. Further inspection reveals that they possess an IS91-like origin of replication and termination sites (terIS), and therefore CRs probably transpose via a rolling-circle replication mechanism. Accordingly, in this review we have renamed CRs as ISCRs to give a more accurate reflection of their functional properties. The genetic context surrounding ISCRs indicates that they can procure 5′ sequences via misreading of the cognate terIS, i.e., “unchecked transposition.” Clinically, the most worrying aspect of ISCRs is that they are increasingly being linked with more potent examples of resistance, i.e., metallo-β-lactamases in Pseudomonas aeruginosa and co-trimoxazole resistance in Stenotrophomonas maltophilia. Furthermore, if ISCR elements do move via “unchecked RC transposition,” as has been speculated for ISCR1, then this mechanism provides antibiotic resistance genes with a highly mobile genetic vehicle that could greatly exceed the effects of previously reported mobile genetic mechanisms. It has been hypothesized that bacteria will surprise us by extending their “genetic construction kit” to procure and evince additional DNA and, therefore, antibiotic resistance genes. It appears that ISCR elements have now firmly established themselves within that regimen.

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Characterization of blaCMY-11, an AmpC-type plasmid-mediated beta-lactamase gene in a Korean clinical isolate of Escherichia coli

Cited by 31 publications

References 9 publications

Investigation of a Nosocomial Outbreak of Imipenem-Resistant Acinetobacter baumannii Producing the OXA-23 β-Lactamase in Korea

Investigation of a Nosocomial Outbreak of Imipenem-Resistant Acinetobacter baumannii Producing the OXA-23 β-Lactamase in Korea

Molecular Characterization of Extended-Spectrum Beta-Lactamases Produced by Clinical Isolates of Klebsiella pneumoniae and Escherichia coli from a Korean Nationwide Survey

IS CR Elements: Novel Gene-Capturing Systems of the 21st Century?

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