Roger Bonomo, M.D.

Multiplex real-time PCR assay for detection and classification of Klebsiella pneumoniae carbapenemase gene (bla KPC) variants
Chen, Liang; Mediavilla, Jose R; Endimiani, Andrea; Rosenthal, Marnie E; Zhao, Yanan; Bonomo, Robert A; Kreiswirth, Barry N
2011 Feb;49(2):579-585, Journal of clinical microbiology
Carbapenem resistance mediated by plasmid-borne Klebsiella pneumoniae carbapenemases (KPC) is an emerging problem of significant clinical importance in Gram-negative bacteria. Multiple KPC gene variants (bla(KPC)) have been reported, with KPC-2 (bla(KPC-2)) and KPC-3 (bla(KPC-3)) associated with epidemic outbreaks in New York City and various international settings. Here, we describe the development of a multiplex real-time PCR assay using molecular beacons (MB-PCR) for rapid and accurate identification of bla(KPC) variants. The assay consists of six molecular beacons and two oligonucleotide primer pairs, allowing for detection and classification of all currently described bla(KPC) variants (bla(KPC-2) to bla(KPC-11)). The MB-PCR detection limit was 5 to 40 DNA copies per reaction and 4 CFU per reaction using laboratory-prepared samples. The MB-PCR probes were highly specific for each bla(KPC) variant, and cross-reactivity was not observed using DNA isolated from several bacterial species. A total of 457 clinical Gram-negative isolates were successfully characterized by our MB-PCR assay, with bla(KPC-3) and bla(KPC-2) identified as the most common types in the New York/New Jersey metropolitan region. The MB-PCR assay described herein is rapid, sensitive, and specific and should be useful for understanding the ongoing evolution of carbapenem resistance in Gram-negative bacteria. As novel bla(KPC) variants continue to emerge, the MB-PCR assay can be modified in response to epidemiologic developments
— id: 138306, year: 2011, vol: 49, page: 579, stat: Journal Article,

Status report on carbapenemases: challenges and prospects
Patel, Gopi; Bonomo, Robert A
2011 May;9(5):555-570, Expert review of anti-infective therapy
Antimicrobial resistance in hospital and community-onset bacterial infections is a significant source of patient morbidity and mortality. In the past decade, we have witnessed the increasing recovery of carbapenem-resistant Gram-negative bacteria. For many isolates, carbapenem resistance is due to the production of carbapenemases, beta-lactamases that can inactivate carbapenems and frequently other beta-lactam antibiotics. Currently, these enzymes are mainly found in three different beta-lactamase classes (class A, B and D). Regardless of the molecular classification, there are few antimicrobials available to treat infections with these organisms and data regarding agents in development are limited to in vitro studies. This article focuses on the epidemiology of carbapenemase-producing Gram-negative bacteria. We also review available agents and those in development with potential activity against this evolving threat
— id: 137954, year: 2011, vol: 9, page: 555, stat: Journal Article,

In vitro activity of fosfomycin against blaKPC-containing Klebsiella pneumoniae isolates, including those nonsusceptible to tigecycline and/or colistin
Endimiani, Andrea; Patel, Gopi; Hujer, Kristine M; Swaminathan, Mahesh; Perez, Federico; Rice, Louis B; Jacobs, Michael R; Bonomo, Robert A
2010 Jan;54(1):526-529, Antimicrobial agents & chemotherapy
In vitro activity of fosfomycin was evaluated against 68 bla(KPC)-possessing Klebsiella pneumoniae (KpKPC) isolates, including 23 tigecycline- and/or colistin-nonsusceptible strains. By agar dilution, 93% of the overall KpKPC were susceptible (MIC(50/90) of 16/64 microg/ml, respectively). The subgroup of 23 tigecycline- and/or colistin-nonsusceptible strains showed susceptibility rates of 87% (MIC(50/90) of 32/128 microg/ml, respectively). Notably, 5 out of 6 extremely drug-resistant (tigecycline and colistin nonsusceptible) KpKPC were susceptible to fosfomycin. Compared to agar dilution, disk diffusion was more accurate than Etest
— id: 132241, year: 2010, vol: 54, page: 526, stat: Journal Article,

Carbapenem-resistant Enterobacteriaceae and Acinetobacter baumannii: assessing their impact on organ transplantation
Patel G; Perez F; Bonomo RA
2010 Oct 7;:?-? #, Current opinion in organ transplantation
PURPOSE OF REVIEW: This review highlights the impact of carbapenem-resistant Enterobacteriaceae and carbapenem-resistant Acinetobacter baumannii on patients who have undergone organ transplantation and explores both available and potential agents to treat infections caused by these multidrug-resistant (MDR) pathogens. RECENT FINDINGS: Few antimicrobials exist to treat carbapenem-resistant Gram-negative infections, and resistance to salvage therapies is escalating. Organ transplantation appears to be a risk factor for infections with Klebsiella pneumoniae carbapenemase-producing Enterobacteriaceae. Isolation of these MDR bacteria is increasing and may be associated with allograft failure and mortality. In the majority of cases, aminoglycosides, polymyxins, and tigecycline have been employed to treat these infections. Anecdotal successes exist but these antibiotics may be unreliable. Few novel agents are in development. SUMMARY: Bacterial infections remain a leading cause of posttransplantation morbidity and mortality. Carbapenem resistance is a significant threat to allograft and patient survival. With few antimicrobials being developed, transplant centers may be forced to make decisions regarding surveillance, empiric antimicrobial regimens, and transplant candidacy in the setting of carriage of MDR pathogens. There is an urgent need for collaborative studies to address the clinical impact of these infections on transplantation
— id: 138132, year: 2010, vol: , page: ?, stat: Journal Article,

Characterization of blaKPC-containing Klebsiella pneumoniae isolates detected in different institutions in the Eastern USA
Endimiani, Andrea; Hujer, Andrea M; Perez, Federico; Bethel, Christopher R; Hujer, Kristine M; Kroeger, Jennifer; Oethinger, Margret; Paterson, David L; Adams, Mark D; Jacobs, Michael R; Diekema, Daniel J; Hall, Gerri S; Jenkins, Stephen G; Rice, Louis B; Tenover, Fred C; Bonomo, Robert A
2009 Mar;63(3):427-437, Journal of antimicrobial chemotherapy
BACKGROUND: The emergence of bla(KPC)-containing Klebsiella pneumoniae (KPC-Kp) isolates is attracting significant attention. Outbreaks in the Eastern USA have created serious treatment and infection control problems. A comparative multi-institutional analysis of these strains has not yet been performed. METHODS: We analysed 42 KPC-Kp recovered during 2006-07 from five institutions located in the Eastern USA. Antimicrobial susceptibility tests, analytical isoelectric focusing (aIEF), PCR and sequencing of bla genes, PFGE and rep-PCR were performed. Results By in vitro testing, KPC-Kp isolates were highly resistant to all non-carbapenem beta-lactams (MIC(90)s >or= 128 mg/L). Among carbapenems, MIC(50/90)s were 4/64 mg/L for imipenem and meropenem, 4/32 mg/L for doripenem and 8/128 for ertapenem. Combinations of clavulanate or tazobactam with a carbapenem or cefepime did not significantly lower the MIC values. Genetic analysis revealed that the isolates possessed the following bla genes: bla(KPC-2) (59.5%), bla(KPC-3) (40.5%), bla(TEM-1) (90.5%), bla(SHV-11) (95.2%) and bla(SHV-12) (50.0%). aIEF of crude beta-lactamase extracts from these strains supported our findings, showing beta-lactamases at pIs of 5.4, 7.6 and 8.2. The mean number of beta-lactamases was 3.5 (range 3-5). PFGE demonstrated that 32 (76.2%) isolates were clonally related (type A). Type A KPC-Kp isolates (20 bla(KPC-2) and 12 bla(KPC-3)) were detected in each of the five institutions. rep-PCR showed patterns consistent with PFGE. CONCLUSIONS: We demonstrated the complex beta-lactamase background of KPC-Kp isolates that are emerging in multiple centres in the Eastern USA. The prevalence of a single dominant clone suggests that interstate transmission has occurred
— id: 133663, year: 2009, vol: 63, page: 427, stat: Journal Article,

Presence of plasmid-mediated quinolone resistance in Klebsiella pneumoniae isolates possessing blaKPC in the United States
Endimiani, Andrea; Carias, Lenore L; Hujer, Andrea M; Bethel, Christopher R; Hujer, Kristine M; Perez, Federico; Hutton, Rebecca A; Fox, William R; Hall, Geraldine S; Jacobs, Michael R; Paterson, David L; Rice, Louis B; Jenkins, Stephen G; Tenover, Fred C; Bonomo, Robert A
2008 Jul;52(7):2680-2682, Antimicrobial agents & chemotherapy
The presence of plasmid-mediated quinolone resistance genes [i.e., qnrA, qnrB, qnrS, aac(6')-Ib-cr, and qepA] was evaluated among 42 bla(KPC)-containing Klebsiella pneumoniae isolates collected in the eastern United States. One isolate carried the bla(KPC-3) and qnrB19 genes on the same conjugative plasmid, whereas another carried the bla(KPC-3) and qnrA1 genes on separate plasmids
— id: 133595, year: 2008, vol: 52, page: 2680, stat: Journal Article,