<i>Klebsiella pneumoniae</i>Carbapenemase–2, Buenos Aires, Argentina

Pasterán, Fernando; Otaegui, L.; Guerriero, Leonor; Radice, G.; Maggiora, R.; Rapoport, Melina; Faccone, Diego; Martino, Ana Di; Galas, Marcelo

doi:10.3201/eid1407.070826

Cited by 67 publications

(45 citation statements)

References 7 publications

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“…A recent study has shown that by use of benzo-thiophene-2-boronic acid as an inhibitor of AmpC enzymes, isolates with KPCs were wrongly inferred to have AmpC enzymes (17). Also, in two KPC-2-possessing clinical isolates from Argentina, synergism was detected between 3-aminophenylboronic acid disks and cefotaxime, ceftazidime, and carbapenem disks (20). It was assumed that the inhibitory activity of boronic acid was associated with the sole presence of the KPC enzyme, since no AmpC enzyme was detectable.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of Boronic Acid Disk Tests for Differentiating KPC-Possessing Klebsiella pneumoniae Isolates in the Clinical Laboratory

et al. 2009

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The worldwide increase in the occurrence and dissemination of KPC ␤-lactamases among gram-negative pathogens makes critical the early detection of these enzymes. Boronic acid disk tests using different antibiotic substrates were evaluated for detection of KPC-possessing Klebsiella pneumoniae isolates. A total of 57 genotypically confirmed KPC-possessing K. pneumoniae isolates with varying carbapenem MICs were examined. To measure the specificity of the tests, 106 non-KPC-possessing isolates (89 K. pneumoniae and 17 Escherichia coli isolates) were randomly selected among those exhibiting reduced susceptibility to cefoxitin, expanded-spectrum cephalosporins, or carbapenems. As many as 56, 53, and 40 of the non-KPC-possessing isolates harbored extended-spectrum ␤-lactamases, metallo-␤-lactamases, and plasmidmediated AmpC ␤-lactamases, respectively. By use of CLSI methodology and disks containing imipenem, meropenem, or cefepime, either alone or in combination with 400 g of boronic acid, all 57 KPC producers gave positive results (sensitivity, 100%) whereas all 106 non-KPC producers were negative (specificity, 100%). The meropenem duplicate disk with or without boronic acid demonstrated the largest differences in inhibition zone diameters between KPC producers and non-KPC producers. By use of disks containing ertapenem, all isolates were correctly differentiated except for five AmpC producers that gave falsepositive results (sensitivity, 100%; specificity, 95.3%). These practical and simple boronic acid disk tests promise to be very helpful for the accurate differentiation of KPC-possessing K. pneumoniae isolates, even in regions where different broad-spectrum ␤-lactamases are widespread.

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Section: Discussionmentioning

confidence: 99%

Evaluation of Boronic Acid Disk Tests for Differentiating KPC-Possessing Klebsiella pneumoniae Isolates in the Clinical Laboratory

et al. 2009

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“…For the testing of metallo-␤-lactamases (MBLs), 0.01 mM ZnSO4 (ICN) was added to the reaction mixture (17). Phenotypic APB inhibition of the imipenemase activities of extracts in the spectrophotometric assay was confirmed by adding 3 mM APB 10 min before the assay was performed (25).…”

Section: Methodsmentioning

confidence: 99%

“…Each one was performed in duplicate assays. (i) In the double-DD synergy tests (DDST), a set of disks with IPM (10 g), MEM (10 g), or ETP (10 g) were placed at several distances (10,15,20,25, or 30 mm, center to center) from a blank disk containing 300 g of APB (Sigma Chemicals, St. Louis, MO) (35) on a Muller-Hinton agar plate inoculated with a sample of the tested strain, adjusted to a 0.5 McFarland turbidity standard. APB disks were prepared before the DDST (by the addition of 10 l of 30-mg/ml APB solution to a filter disk) and stored at Ϫ20°C until use.…”

Section: Methodsmentioning

confidence: 99%

“…The isolation of total DNA was performed as described previously (18). Strains were analyzed for bla VIM, bla IMP , bla SPM , bla KPC , bla Sme , and bla OXA genes (subgroups I, II, and III) by using the primers described previously (18,21,25,26). For bla IMI and bla NMC-A , specific primers were designed (forward, 5Ј-CAGAGCAAATGAACGATTTC-3Ј; reverse, 5Ј-TGGTACGCTAGCACGAATAC-3Ј).…”

Section: Methodsmentioning

confidence: 99%

“…Unexpectedly, we discovered unusual inhibition of organisms possessing KPC by 3-aminophenylboronic acid (APB), which may be attributed solely to the presence of this carbapenemase (25). Afterwards, Doi et al and, in a subsequent study with a larger series of strains, Tsakris et al demonstrated the overwhelming effectiveness of APB for the detection of Klebsiella pneumoniae possessing KPC (7,32).…”

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confidence: 97%

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Sensitive Screening Tests for Suspected Class A Carbapenemase Production in Species of Enterobacteriaceae

et al. 2009

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The detection of class A serine-carbapenemases among species of Enterobacteriaceae remains a challenging issue. Methods of identification for routine use in clinical microbiology laboratories have not been standardized to date. We developed a novel screening methodology suitable for countries with high basal levels of carbapenem resistance due to non-carbapenemase-mediated mechanisms and standardized several simple confirmatory methods that allow the recognition of bacteria producing class A carbapenemases, including KPC, Sme, IMI, NMC-A, and GES, by using boronic acid (BA) derivatives. A total of 28 genetically unrelated Enterobacteriaceae strains producing several class A carbapenemases were tested. Thirty-eight genetically unrelated negative controls were included. The isolates were tested against imipenem (IPM), meropenem (MEM), and ertapenem (ETP) by MIC and disk diffusion assays in order to select appropriate tools to screen for suspected carbapenemase production. It was possible to differentiate class A carbapenemase-producing bacteria from non-carbapenemase-producing bacteria by using solely the routine IPM susceptibility tests. The modified Hodge test was evaluated and found to be highly sensitive, although false-positive results were documented. Novel BA-based methods (a double-disk synergy test and combined-disk and MIC tests) using IPM, MEM, and ETP, in combination with 3-aminophenylboronic acid as an inhibitor, were designed as confirmatory tools. On the basis of the performance of these methods, a sensitive flow chart for suspicion and confirmation of class A carbapenemase production in species of Enterobacteriaceae was designed. By using this methodology, isolates producing KPC, GES, Sme, IMI, and NMC-A carbapenemases were successfully distinguished from those producing other classes of ␤-lactamases (extended-spectrum ␤-lactamases, AmpCs, and metallo-␤-lactamases, etc). These methods will rapidly provide useful information needed for targeting antimicrobial therapy and appropriate infection control.

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α‐Triazolylboronic Acids: A Promising Scaffold for Effective Inhibitors of KPCs

et al. 2020

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Boronic acids are known reversible covalent inhibitors of serine β‐lactamases. The selectivity and high potency of specific boronates bearing an amide side chain that mimics the β‐lactam's amide side chain have been advanced in several studies. Herein, we describe a new class of boronic acids in which the amide group is replaced by a bioisostere triazole. The boronic acids were obtained in a two‐step synthesis that relies on the solid and versatile copper‐catalyzed azide–alkyne cycloaddition (CuAAC) followed by boronate deprotection. All of the compounds show very good inhibition of the Klebsiella pneumoniae carbapenemase KPC‐2, with Ki values ranging from 1 nM to 1 μM, and most of them are able to restore cefepime activity against K. pneumoniae harboring blaKPC‐2. In particular, compound 1 e, bearing a sulfonamide substituted by a thiophene ring, proved to be an excellent KPC‐2 inhibitor (Ki=30 nM); it restored cefepime susceptibility in KPC‐Kpn cells (MIC=0.5 μg/mL) with values similar to that of vaborbactam (Ki=20 nM, MIC in KPC‐Kpn 0.5 μg/mL). Our findings suggest that α‐triazolylboronates might represent an effective scaffold for the treatment of KPC‐mediated infections.

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Klebsiella pneumoniaeCarbapenemase–2, Buenos Aires, Argentina

Cited by 67 publications

References 7 publications

Evaluation of Boronic Acid Disk Tests for Differentiating KPC-Possessing Klebsiella pneumoniae Isolates in the Clinical Laboratory

Evaluation of Boronic Acid Disk Tests for Differentiating KPC-Possessing Klebsiella pneumoniae Isolates in the Clinical Laboratory

Sensitive Screening Tests for Suspected Class A Carbapenemase Production in Species of Enterobacteriaceae

α‐Triazolylboronic Acids: A Promising Scaffold for Effective Inhibitors of KPCs

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