PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of cidLink to Publisher's site
 
Clin Infect Dis. 2011 February 15; 52(4): 481–484.
PMCID: PMC3106237

Carbapenem Resistance in Klebsiella pneumoniae Due to the New Delhi Metallo-β-lactamase

Abstract

(See editorial commentary by Bronomo, on pages 485–487.)

Carbapenem resistance in Klebsiella pneumoniae is most notably due to the K. pneumoniae carbapenemase (KPC) β-lactamase. In this report, we describe the occurrence of a newly described mechanism of carbapenem resistance, the NDM-1 β-lactamase, in a patient who received medical attention (but was not hospitalized) in India.

The emergence of carbapenem resistance in K. pneumoniae has become a substantial clinical problem, most typically attributed to production of KPC [1]. KPC-producing organisms are most frequently found in the United States, but sizeable outbreaks have also occurred in Israel and Greece [2, 3]. Numerous other countries have now also been affected by KPC-producing organisms. KPC-producing K. pneumoniae cause considerable clinical problems because they are multidrug resistant, lacking susceptibility to β-lactam antibiotics, fluoroquinolones, and aminoglycosides [4]. Thus, therapy for clinically significant isolates rests on the use of tigecycline or polymyxins, both of which have been associated with development of resistance during treatment [5]. In addition, a dominant strain of KPC-producing K. pneumoniae (sequence type 258, as determined by multilocus sequence typing [MLST]) accounted for 70% of isolates in one study [6], suggesting some particular adaptiveness of this very resistant strain for the health care setting.

Table 1.
Comparison of the 2 Most Common Causes of Carbapenem Resistance in Enterobacteriaceae: Klebsiella pneumoniae Carbapenemase (KPC) and New Delhi Metallo-β-Lactamase (NDM) Type β-Lactamases

Carbapenem resistance in K. pneumoniae may be due to other causes; these include combinations of outer-membrane permeability loss and β-lactamase production [7] and the production of metallo-β-lactamases, such as those of the IMP or VIM groups [8]. With the exception of Greece [9], most countries have been spared the widespread occurrence of IMP- or VIM-producing K. pneumoniae. In this Brief Report, we review the latest cause of carbapenem resistance in K. pneumoniae to be described—the New Delhi metallo-β-lactamase enzyme, NDM-1. There is emerging evidence that NDM-1–producing K. pneumoniae is destined to create clinical issues at least as substantial as those caused by KPC-producing strains. By virtue of its epicenter in the huge population of India, the number of individuals affected by NDM-1–producing K. pneumoniae may already exceed that of KPC-producing K. pneumoniae.

CASE REPORT

An 87–year-old woman was brought to a hospital in Australia directly from the airport, immediately after arriving from India. The patient was an Australian resident of Indian origin who had visited Khanna, in the state of Punjab, from November 2009 to January 2010. While in India, she developed a chronic draining foot ulcer. She was treated in India with an unknown intravenous antibiotic, which she administered at home. She was never hospitalized in India.

At the time of arrival, she developed fever (temperature, 38.9 degrees), dysuria, and suprapubic pain. Urine culture grew K. pneumoniae and Escherichia coli resistant to multiple antibiotics. The K. pneumoniae isolate was resistant to ertapenem, imipenem, meropenem, ceftazidime, cefotaxime, cefoxitin, piperacillin-tazobactam, ticarcillin-clavulanate, nalidixic acid, ciprofloxacin, amikacin, gentamicin, and trimethoprim-sulphamethoxazole, as determined on the basis of CLSI standards [10]. The organism was susceptible to aztreonam, chloramphenicol, colistin (minimum inhibitory concentration [MIC], 0.25 μg/mL), and tigecycline (MIC, 1 μg/mL). The MICs of meropenem and doripenem were >32 μg/mL. Empirical treatment was given with intravenous ticarcillin-clavulanate. Despite the lack of susceptibility to this combination treatment, the patient's symptoms resolved, and she was discharged from hospital. Both the K. pneumoniae and E. coli isolates were also grown from a rectal swab specimen, which was plated on MacConkey agar that contained 8 μg/mL gentamicin.

Phenotypic detection of a metallo-β-lactamase was made in the K. pneumoniae isolate by using inhibition of the enzyme by EDTA [10]. Polymerase chain reaction (PCR) and sequencing for antibiotic-resistance genes was positive for blaNDM-1, blaCMY-6, blaSHV, and blaDHA. The isolate was also positive for aac-6′-1b and rmtC [1113]. PCR for the detection of blaNDM-1 was performed using forward primer (5′-GGGCCGTATGAGTGA-3′) and reverse primer (5′-GAAGCTGAGCACCGCATTAG-3′), which amplifiy a 758-bp fragment.

Transferability of blaNDM-carrying plasmids to laboratory strains of E. coli was conducted by transformation of extracted plasmids [12, 13] into Top10 E. coli (Invitrogen) and by conjugation with rifampin-resistant E. coli K - 12. Transformants and transconjugants were selected on Luria-Bertani agar supplemented with ceftazidime, 2 μg/mL. blaNDM-1 together with blaCMY-6, aac-6’-1b, and rmtC were successfully transferred by transformation and conjugation, which were confirmed by PCR and sequencing. To differentiate the successful transconjugants from the donor (NDM-1 producing K. pneumoniae), E. coli species-specific PCR was performed for the transconjugants [14]. The size of the plasmid was ~70kb. The transformants and transconjugants were resistant to ertapenem, meropenem, imipenem, ceftazidime, cefotaxime, cefoxitin, amikacin, and gentamicin. The MICs in the transformants to meropenem and doripenem were 32 and 24 μg/mL, respectively.

MLST was performed as described on the MLST website (http://www.pasteur.fr/recherche/genopole/PF8/mlst/Kpneumoniae.html). Allelic numbers were obtained on the basis of sequences of 7 housekeeping genes [6]. According to this typing scheme, the K. pneumoniae isolate was ST147.

DISCUSSION

Antibiotic-resistant K. pneumoniae has been a notable hospital pathogen for ≥4 decades. Sequentially, aminoglycoside resistance in K. pneumoniae in the 1970s, third-generation cephalosporin resistance by way of extended-spectrum β-lactamases in the 1980s and 1990s, and then carbapenem resistance in this century have been major problems. KPC-producing K. pneumoniae has become a substantial international issue [1]. The presence of KPC producers increases reliance on polymyxins or tigecycline as “workhorse” therapy. Increased use of any antibiotic hastens development of resistance to that class. Numerous reports of polymyxin- or tigecycline-resistant K. pneumoniae now exist [1524]. Given the lack of new antibiotics active against multidrug-resistant gram-negative bacilli, a potential now exists for K. pneumoniae resistant to all commercially available antibiotics. The emergence of NDM-producing K. pneumoniae heightens this risk.

The first isolate from India known to produce NDM was retrospectively found in a survey of isolates from 2006 [25]. A number of reports now document the widespread occurrence of NDM-producing K. pneumoniae in India and Pakistan. NDM producers have been detected in ≥10 major population centers in India, traversing both the north and south of the country [25, 26]. Of consecutive carbapenem-resistant Enterobacteriaceae collected in 3 months in late 2009 in a single hospital in Mumbai, 91.7% were NDM producers [25]. Although surveillance studies are lacking, it is known that at least 10% of K. pneumoniae in some hospitals in India are carbapenem resistant (T.R.W.; unpublished data). Similar problems exist in Pakistan, where NDM producers have been documented in at least 8 cities [26]. Given the populations of India (1184 million) and Pakistan (170 million), it can be appreciated that NDM producers may already be creating a massive problem in this region. Enterobacteriaceae other than K. pneumoniae, such as E. coli and Enterobacter cloacae, are also affected [26].

Since the first report of NDM-producing K. pneumoniae from Sweden in December 2009 (the patient had received medical care in New Delhi) [27], NDM producers have been detected in the United Kingdom [26, 28], the United States [29], Kenya [30], Japan [31], Canada [32], Belgium [31], the Netherlands [31], and Australia [33, 34]. In the United Kingdom, 25 different laboratories have reported NDM-producing organisms [26]. In the United States, the Centers for Disease Control and Prevention have reported three NDM-producing isolates, from patients in 3 different states [29]. The vast majority of the patients in these countries had received prior medical care in India [2629, 33, 34].

Medical care in India and Pakistan is often sought by individuals visiting relatives in their country of origin. The Indian diaspora (a term used to describe people of Indian origin living permanently outside of India) are estimated to number > 24 million: 11 nations (including the United States, Saudi Arabia, United Kingdom, and Canada) have nonresident Indian populations exceeding 1 million (http://indiandiaspora.nic.in). The Pakistani diaspora is also considerable, estimated to number ≥7 million individuals (http://www.opf.org.pk). In addition, “medical tourism” to India is increasingly popular. A recent case of NDM-producing Providencia rettgeri in an Australian who received elective plastic surgery in India is illustrative of this phenomenon [33]. Current data would suggest that recent hospitalization in India or Pakistan greatly increases the risk that an individual is colonized with an NDM-producing strain. Strong consideration should be given to screening patients who have undergone recent hospitalizations in India or Pakistan for carbapenem-resistant organisms and for preemptively using contact isolation precautions.

The isolate recovered from the patient who we describe was K. pneumoniae ST147. The only previous report using MLST showed an NDM-producer that was ST14 [27]. The vast majority of KPC-producing K. pneumoniae isolates are ST258, although occasional KPC-producers are ST14 [6]. In a recently published evaluation, 26 NDM-producers from a single institution in Haryana, India, belonged to a single pulsed-field gel electrophoresis profile implying clonal spread [26]. However, isolates from another Indian institution showed no similarity with each other [26]. British isolates have also been quite diverse [26]. There is clear evidence from the Haryana molecular epidemiology that institutional outbreaks can occur. However, global spread appears to be due to a wide diversity of strains, indicating that a wide variety of NDM producers are circulating in India. Thus far, 2 NDM-producing E. coli isolates (1 from Canada and 1 from Australia) were ST101 [34, 35].

Although the isolate we characterized was susceptible to colistin, the full threat of NDM producers was illustrated by a recent report in which 1 NDM-producing K. pneumoniae isolate had a colistin MIC > 32 mg/L [26]. Without doubt, NDM producers are destined to provide problems at least as great as KPC producers (Table 1). That the full extent of this impending catastrophe may be played out in developing nations should not reduce the need for urgent intervention.

Acknowledgments

Potential conflicts of interest. RL.N. has received grants from the National Institutes of Health and Australian National Health and Medical Research Council, and also received. Travel/ accommodations/meeting expense reimbursement from ICAAC. DL.P. is a consultant for Leo Pharmaceuticals, Novartis, Johnson&Johnson, Merck, and AstraZeneca. T.R.W. has received institutional grant support from Wyeth, and payment for lectures/speaker's bureau from Pfizer.

References

1. Nordmann P, Cuzon G, Naas T. The real threat of Klebsiella pneumoniae carbapenemase-producing bacteria. Lancet Infect Dis. 2009;9:228–36. [PubMed]
2. Leavitt A, Carmeli Y, Chmelnitsky I, Goren MG, Ofek I, Navon-Venezia S. Molecular epidemiology, sequence types, and plasmid analyses of KPC-producing Klebsiella pneumoniae strains in Israel. Antimicrob Agents Chemother. 2010;54:3002–6. [PMC free article] [PubMed]
3. Souli M, Galani I, Antoniadou A, et al. An outbreak of infection due to β-Lactamase Klebsiella pneumoniae Carbapenemase 2-producing K. pneumoniae in a Greek University Hospital: molecular characterization, epidemiology, and outcomes. Clin Infect Dis. 2010;50:364–73. [PubMed]
4. Bratu S, Landman D, Haag R, et al. Rapid spread of carbapenem-resistant Klebsiella pneumoniae in New York City: a new threat to our antibiotic armamentarium. Arch Intern Med. 2005;165:1430–5. [PubMed]
5. Peleg AY, Hooper DC. Hospital-acquired infections due to gram-negative bacteria. N Engl J Med. 2010;362:1804–13. [PMC free article] [PubMed]
6. Kitchel B, Rasheed JK, Patel JB, et al. Molecular epidemiology of KPC-producing Klebsiella pneumoniae isolates in the United States: clonal expansion of multilocus sequence type 258. Antimicrob Agents Chemother. 2009;53:3365–70. [PMC free article] [PubMed]
7. Bradford PA, Urban C, Mariano N, Projan SJ, Rahal JJ, Bush K. Imipenem resistance in Klebsiella pneumoniae is associated with the combination of ACT-1, a plasmid-mediated AmpC β-lactamase, and the loss of an outer membrane protein. Antimicrob Agents Chemother. 1997;41:563–9. [PMC free article] [PubMed]
8. Walsh TR, Toleman MA, Poirel L, Nordmann P. Metallo-β-lactamases: the quiet before the storm? Clin Microbiol Rev. 2005;18:306–25. [PMC free article] [PubMed]
9. Souli M, Kontopidou FV, Papadomichelakis E, Galani I, Armaganidis A, Giamarellou H. Clinical experience of serious infections caused by Enterobacteriaceae producing VIM-1 metallo-β-lactamase in a Greek University Hospital. Clin Infect Dis. 2008;46:847–54. [PubMed]
10. Franklin C, Liolios L, Peleg AY. Phenotypic detection of carbapenem-susceptible metallo-β-lactamase-producing gram-negative bacilli in the clinical laboratory. J Clin Microbiol. 2006;44:3139–44. [PMC free article] [PubMed]
11. Poirel L, Naas T, Nicolas D, et al. Characterization of VIM-2, a carbapenem-hydrolyzing metallo-β-lactamase and its plasmid- and integron-borne gene from a Pseudomonas aeruginosa clinical isolate in France. Antimicrob Agents Chemother. 2000;44:891–7. [PMC free article] [PubMed]
12. Sidjabat HE, Paterson DL, Adams-Haduch JM, et al. Molecular epidemiology of CTX-M-producing Escherichia coli isolates at a tertiary medical center in western Pennsylvania. Antimicrob Agents Chemother. 2009;53:4733–9. [PMC free article] [PubMed]
13. Sidjabat HE, Silveira FP, Potoski BA, et al. Interspecies spread of Klebsiella pneumoniae carbapenemase gene in a single patient. Clin Infect Dis. 2009;49:1736–8. [PubMed]
14. Chen J, Griffiths MW. PCR differentiation of Escherichia coli from other gram-negative bacteria using primers derived from the nucleotide sequences flanking the gene encoding the universal stress protein. Lett Appl Microbiol. 1998;27:369–71. [PubMed]
15. Antoniadou A, Kontopidou F, Poulakou G, et al. Colistin-resistant isolates of Klebsiella pneumoniae emerging in intensive care unit patients: first report of a multiclonal cluster. J Antimicrob Chemother. 2007;59:786–90. [PubMed]
16. Endimiani A, Patel G, Hujer KM, et al. In vitro activity of fosfomycin against blaKPC-containing Klebsiella pneumoniae isolates, including those nonsusceptible to tigecycline and/or colistin. Antimicrob Agents Chemother. 2010;54:526–9. [PMC free article] [PubMed]
17. Garrison MW, Mutters R, Dowzicky MJ. In vitro activity of tigecycline and comparator agents against a global collection of Gram-negative and Gram-positive organisms: tigecycline Evaluation and Surveillance Trial 2004 to 2007. Diagn Microbiol Infect Dis. 2009;65:288–99. [PubMed]
18. Hussein K, Sprecher H, Mashiach T, Oren I, Kassis I, Finkelstein R. Carbapenem resistance among Klebsiella pneumoniae isolates: risk factors, molecular characteristics, and susceptibility patterns. Infect Control Hosp Epidemiol. 2009;30:666–71. [PubMed]
19. Lee J, Patel G, Huprikar S, Calfee DP, Jenkins SG. Decreased susceptibility to polymyxin B during treatment for carbapenem-resistant Klebsiella pneumoniae infection. J Clin Microbiol. 2009;47:1611–2. [PMC free article] [PubMed]
20. Matthaiou DK, Michalopoulos A, Rafailidis PI, et al. Risk factors associated with the isolation of colistin-resistant gram-negative bacteria: a matched case-control study. Crit Care Med. 2008;36:807–11. [PubMed]
21. Samonis G, Matthaiou DK, Kofteridis D, Maraki S, Falagas ME. In vitro susceptibility to various antibiotics of colistin-resistant gram-negative bacterial isolates in a general tertiary hospital in Crete, Greece. Clin Infect Dis. 2010;50:1689–91. [PubMed]
22. Suh JY, Son JS, Chung DR, Peck KR, Ko KS, Song JH. Nonclonal emergence of colistin-resistant Klebsiella pneumoniae isolates from blood samples in South Korea. Antimicrob Agents Chemother. 2010;54:560–2. [PMC free article] [PubMed]
23. Toth A, Damjanova I, Puskas E, et al. Emergence of a colistin-resistant KPC-2-producing Klebsiella pneumoniae ST258 clone in Hungary. Eur J Clin Microbiol Infect Dis. 2010;29:765–9. [PubMed]
24. Zarkotou O, Pournaras S, Voulgari E, et al. Risk factors and outcomes associated with acquisition of colistin-resistant KPC-producing Klebsiella pneumoniae: a matched case-control study. J Clin Microbiol. 2010;48:2271–4. [PMC free article] [PubMed]
25. Deshpande LM, Mendes RE, Castanheira M, Mathai D, Bell J, Jones RN. 50th Interscience Conference on Antimicrobial Agents and Chemotherapy. Boston: American Society for Microbiology; 2010. Dissemination of NDM-1-producing Enterobacteriaceae in India [abstract C2-701]
26. Kumarasamy K, Toleman MA, Walsh TR, et al. Emergence of a new antibiotic resistance mechanism in India, Pakistan and the UK: is this the end of conventional antibiotics for Enterobacteriaceae? Lancet Infect Dis. 2010;10:597–602. [PMC free article] [PubMed]
27. Yong D, Toleman MA, Giske CG, et al. Characterization of a new metallo-β-lactamase gene, bla(NDM-1), and a novel erythromycin esterase gene carried on a unique genetic structure in Klebsiella pneumoniae sequence type 14 from India. Antimicrob Agents Chemother. 2009;53:5046–54. [PMC free article] [PubMed]
28. Muir A, Weinbren MJ. New Delhi metallo-β-lactamase: a cautionary tale. J Hosp Infect. 2010;75:239–40. [PubMed]
29. Centers for Disease Control and Prevention. Detection of Enterobacteriaceae isolates carrying metallo-β-lactamase—United States, 2010. MMWR Morb Mortal Wkly Rep. 2010;59:750. [PubMed]
30. Poirel L, Revathi G, Bernabeu S, Nordmann P. 50th Interscience Conference on Antimicrobial Agents and Chemotherapy. Boston: American Society for Microbiology; 2010. Emergence of metallo-β-lactamase NDM-1 producing Klebsiella pneumoniaein Kenya [abstract C1-1334]
31. Nordmann P. Interscience Conference on Antimicrobial Agents and Chemotherapy. Boston: American Society for Microbiology; 2010. Current situation on spread of metallo-β-lactamases in Enterobacteriaceae [abstract C1-1331]
32. Pitout JD. The latest threat in the war on antimicrobial resistance. Lancet Infect Dis. 2010;10:578–9. [PubMed]
33. Fernando GA, Collignon PJ, Bell JM. A risk for returned travellers: the “post-antibiotic era” Med J Aust. 2010;193:59. [PubMed]
34. Poirel L, Lagrutta E, Taylor P, Pham J, Nordmann P. Emergence of metallo-ss-lactamase NDM-1-producing multidrug resistant Escherichia coli in Australia. Antimicrob Agents Chemother. 2010;54:4914–6. [PMC free article] [PubMed]
35. Peirano G, Ahmed-Bentley J, Woodford N, Pitout J. 50th Interscience Conference on Antimicrobial Agents and Chemotherapy. Boston: American Society for Microbiology; 2010. The characteristics of a metallo-β-lactamase producing Escherichia coli isolated in Canada from a patient with recent travel to India [abstract C1-675a]

Articles from Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America are provided here courtesy of Oxford University Press