Scholarly article on topic 'The emergence of OXA-48- and NDM-1-positive Klebsiella pneumoniae in Riyadh, Saudi Arabia'

The emergence of OXA-48- and NDM-1-positive Klebsiella pneumoniae in Riyadh, Saudi Arabia Academic research paper on "Clinical medicine"

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Abstract of research paper on Clinical medicine, author of scientific article — Atef Shibl, Mohamed Al-Agamy, Ziad Memish, Abiola Senok, Shamshad Abdul Khader, et al.

Summary Objectives To investigate the emergence of NDM-, OXA-48-, and VIM-producing Klebsiella pneumoniae in Saudi Arabia. Methods From June to December 2011, we obtained K. pneumoniae isolates with reduced sensitivity to carbapenem identified in Riyadh, Saudi Arabia. Only non-duplicate clinical and surveillance isolates obtained from inpatients were included. PCR amplification was carried out for the detection of extended-spectrum beta-lactamase genes (bla CTX-M, bla TEM, bla SHV) and carbapenemase genes (bla KPC, bla VIM, bla IMP, bla NDM, and bla OXA-48). Susceptibility to imipenem, meropenem, amikacin, gentamicin, trimethoprim–sulfamethoxazole, and colistin was determined. Results Of the 60 K. pneumoniae isolates studied, 45 were from patients in the intensive care unit. Forty-seven isolates harbored bla OXA-48, 12 were positive for bla NDM, and one for bla VIM. No isolate harbored a combination of these resistance genes. No isolate harbored bla KPC or bla IMP. All 37 bla CTX-M-positive isolates belonged to CTX-M group 1, and 29 were positive for a combination of bla CTX-M and bla OXA-48. bla TEM and bla SHV genes were found in 17 and 39 isolates, respectively. All isolates were imipenem- and meropenem-resistant, with a high rate of co-resistance to the other antibiotics. Three bla OXA-48-positive isolates with colistin resistance were detected. Conclusion Multidrug-resistant K. pneumoniae isolates harboring bla OXA-48, bla NDM, and colistin resistance are emerging in Saudi Arabia.

Academic research paper on topic "The emergence of OXA-48- and NDM-1-positive Klebsiella pneumoniae in Riyadh, Saudi Arabia"

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ARTICLE IN PRESS

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ELSEVIER

Contents lists available at ScienceDirect

International Journal of Infectious Diseases

journal homepage: www.elsevier.com/locate/ijid

The emergence of OXA-48- and NDM-1-positive Klebsiella pneumoniae in Riyadh, Saudi Arabia

Atef Shibla,b'*, Mohamed Al-Agamya, Ziad Memishb,c, Abiola Senokb, Shamshad Abdul Khaderd, Abdullah Assiric

a College of Pharmacy, King Saud University, Riyadh, Saudi Arabia

b Department of Pathology and Pharmacology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia c Preventive Medicine Directorate, Ministry of Health, Riyadh, Saudi Arabia d King Saud Medical City, Riyadh, Saudi Arabia

ARTICLE INFO

SUMMARY

Article history:

Received 29 May 2013

Received in revised form 16 June 2013

Accepted 16 June 2013

Corresponding Editor: Eskild Petersen,

Aarhus, Denmark

Keywords:

Klebsiella pneumoniae

OXA-48

Carbapenemases Metallo-beta-lactamases Carbapenem-hydrolyzing class D Saudi Arabia

Objectives: To investigate the emergence of NDM-, OXA-48-, and VIM-producing Klebsiella pneumoniae in Saudi Arabia.

Methods: From June to December 2011, we obtained K. pneumoniae isolates with reduced sensitivity to carbapenem identified in Riyadh, Saudi Arabia. Only non-duplicate clinical and surveillance isolates obtained from inpatients were included. PCR amplification was carried out for the detection of extended-spectrum beta-lactamase genes (blaCTX-M, blaTEM, blaSHV) and carbapenemase genes (blaKPC, blaVIM, blaIMP, blaNDM, and blaOXA-48). Susceptibility to imipenem, meropenem, amikacin, gentamicin, trimethoprim-sulfamethoxazole, and colistin was determined.

Results: Of the 60 K. pneumoniae isolates studied, 45 were from patients in the intensive care unit. Forty-seven isolates harbored blaOXA-48, 12 were positive for blaNDM, and one for blaVIM. No isolate harbored a combination of these resistance genes. No isolate harbored blaKPC or blaIMP. All 37 blaCTX -M-positive isolates belonged to CTX-M group 1, and 29 were positive for a combination of blaCTX-M and blaOXA-48. blaTEM and blaSHV genes were found in 17 and 39 isolates, respectively. All isolates were imipenem- and meropenem-resistant, with a high rate of co-resistance to the other antibiotics. Three blaOXA-48-positive isolates with colistin resistance were detected.

Conclusion: Multidrug-resistant K. pneumoniae isolates harboring blaOXA-48, blaNDM, and colistin resistance are emerging in Saudi Arabia.

© 2013 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

1. Introduction

Over the last couple of decades, the emergence and rapid dissemination of extended-spectrum beta-lactamase (ESBL)-pro-ducing bacteria has led to the increased utilization of carbapenems in clinical practice. This is largely because ESBL-producers, which are capable of hydrolyzing penicillins, broad-spectrum cephalos-porins, and monobactams, also harbor resistance genes for other antibiotics, thus making carbapenems the last option for the treatment of serious infections associated with these organisms.1 A consequence of this increased utilization of carbapenems has been the emergence of isolates with resistance genes that code for carbapenemases.2 Among the Enterobacteriaceae, clinically significant carbapenemases are the Ambler molecular class A (KPC), class B (VIM, IMP, NDM), and class D (OXA-48) types.3 These are mostly

* Corresponding author. Tel.: +966 5 0530 2775; fax: +966 1 468 3813. E-mail addresses: amshibl@ksu.edu.sa, amshibl1@yahoo.com (A. Shibl).

found in K. pneumoniae isolates and are also frequently associated with serious nosocomial infections and outbreaks. Prior to the first report of NDM-1 (New Delhi metallo-beta-lactamase) in 2009, the VIM (Verona integron-encoded MBLs) and IMP (active on imipenem) types were the common metallo-beta-lactamases identified in Enterobacteriaceae.4,5 NDM-1, which originated in India, has now been isolated in Europe, Asia, North America, and Australasia, mostly from patients with a history of prior hospitalization in the Indian subcontinent.6-11 NDM-producers are of particular concern as they also harbor multiple chromosom-ally and plasmid-encoded resistance genes resulting in a multi-drug-resistant phenotype.12,13 The carbapenem-hydrolyzing class D beta-lactamase (CHDL) OXA-48 was first described in a K. pneumoniae isolate from Turkey in 2004 and is now endemic in that country.14 CHDL OXA-48 is now endemic in countries around the Mediterranean and is rapidly spreading into other countries in Europe.15-19 To date, six OXA-48-like variants have been identified, including OXA-181, which has recently been identified in India in association with b/aNDM-1 and b/aViM-5 genes.20,21

1201-9712/$36.00 - see front matter © 2013 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved. http://dx.doi.Org/10.1016/j.ijid.2013.06.016

Please cite this article in press as: Shibl A, et al. The emergence of OXA-48- and NDM-1-positive Klebsiella pneumoniae in Riyadh, Saudi Arabia. Int J Infect Dis (2013), http://dx.doi.org/10.1016/j.ijid.2013.06.016

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In 2011, Poirel et al. reported the first identification of NDM-1-producing isolates in the Arabian Peninsula and the Middle East.22 Similar reports of Enterobacteriaceae harboring WaNDM-1 have also emerged from Kuwait and Lebanon.23,24 The recent identification of 11 NDM-1, five OXA-48, and one NDM-1 plus OXA-181 producers among carbapenem-resistant enterobacterial isolates from Oman, suggests that carbapenemase producers are now emerging in the region.25 In Saudi Arabia, unpublished data suggest that carbapenem-resistant K. pneumoniae are being isolated in patients with serious nosocomial infections. We present the first report documenting the emergence of NDM-, OXA-48-, and VIM-producing K. pneumoniae in Saudi Arabia.

2. Methods

The study was carried out in Riyadh, Saudi Arabia, from June to December 2011. During the study period, all non-duplicate clinical

and surveillance isolates of K. pneumoniae obtained from inpatients that showed reduced sensitivity to carbapenem were characterized.

2.1. Phenotypic detection ofESBLs and MBLs

ESBL screening was carried out by disk diffusion using ceftazidime (30 mg) and cefpodoxime (10 mg), in accordance with the recommendations of the Clinical and Laboratory Standards Institute (CLSI) guidelines.26 Confirmation of ESBL phenotype was carried out using the ESBL Etest following the manufacturer's guidelines. Determination of the production of carbapenemase was carried out by modified Hodge test in accordance with the CLSI guidelines and Pasteran et al.26,27 Metallo-beta-lactamase (MBL) production was determined using Etest MBL strips (imipenem/ imipenem + ethylenediaminetetraacetic acid (EDTA)), in accordance with the manufacturer's directions. A >8-fold reduction in

Table 1

Characterization and antibiotic susceptibility profile of OXA-48-positive isolates Isolate No. Location of patient Specimen Beta lactamase genes Antibiotic susceptibility pattern

GEN AMK TMP-SMX CIP COL

1 ICU Blood blacTx-M; blasHv R R s R s

2 ICU Blood - R R R R s

3 ICU Sputum blasHv R I R R ND

4 ICU Blood blacTx-M; blasHv s R R R s

5 ICU Urine blacTX-M R R s R s

6 ICU Sputum blacTx-M; blasHv; bla-TEM R R R R s

7 Surgical ward Urine blacTX-M; blaSHv s R s s s

8 Medical ward Urine blasHv s R s R s

9 ICU Blood blacTx-M; blasHv; blaTEM R R R R s

10 Medical ward Sputum blaTEM R R s R R

11 ICU Suction port - R R R R s

12 ICU Rectal blasHv R R R R s

13 ICU Rectal blacTx-M; blasHv R R R s R

14 ICU Rectal blacTx-M; blasHv R R s R s

15 ICU Rectal blacTx-M; blasHv R R R R s

16 ICU Blood blacTx-M; blaTEM s R R s s

17 ICU Suction port blaTEM R R s R s

18 ICU Sputum blacTx-M; blasHv; blaTEM R R R R s

19 ICU Sputum blasHv; blaTEM R R R R s

20 Medical ward Rectal blacTx-M; blaTEM R R R R s

21 Surgical ward Urine blasHv; blaTEM R R R R s

22 Medical ward Sputum blacTx-M R R R R s

23 ICU Rectal blacTx-M R R R R s

24 ICU Rectal blacTx-M R R R R s

25 Medical ward Rectal blacTx-M; blasHv R R R R s

26 ICU Rectal blacTx-M; blasHv s R s s s

27 ICU Sputum blacTx-M R I s R s

28 Surgical ward Wound blacTx-M; blasHv; blaTEM s R R R s

29 ICU Sputum blaTEM R R R R s

30 Surgical ward Urine blacTx-M; blasHv; blaTEM s s R R s

31 Surgical ward Rectal blasHv s R R I s

32 Surgical ward Urine blacTx-M R R R R s

33 ICU Blood blasHv s R R R s

34 ICU Wound blacTx-M; blasHv R R s R R

35 ICU Urine blacTx-M R R R R s

36 Surgical ward Wound blacTx-M; blasHv; blaTEM s R R R s

37 ICU Sputum blasHv s R R R s

38 Surgical ward Wound blasHv R R s R s

39 ICU Urine blacTx-M; blasHv R s s R s

40 ICU Sputum blasHv R R R R s

41 ICU Blood blaTEM R R R R s

42 ICU Wound blacTx-M; blasHv R R R R s

43 ICU Wound blasHv; blaTEM s R s R s

44 ICU Wound blacTx-M; blasHv s R R R s

45 ICU Rectal blasHv; blaTEM s R R s s

46 ICU Rectal blacTx-M s R R R s

47 ICU Urine blacTx-M R R R s s

Total blacTx-M = 30 blasHv = 32 blaTEM = 16 R=32 R = 45 R=33 R = 41 R=3

GEN, gentamicin; AMK, amikacin; TMP-SMX, trimethoprim-sulfamethoxazole; CIP, ciprofloxacin; COL, colistin; ICU, intensive care unit; R, resistant; S, sensitive; I, intermediate resistant; ND, not done.

Please cite this article in press as: Shibl A, et al. The emergence of OXA-48- and NDM-l-positive Klebsiella pneumoniae in Riyadh, Saudi Arabia. Int J Infect Dis (2013), http://dx.doi.Org/10.1016/j.ijid.2013.06.016

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imipenem minimum inhibitory concentration (MIC) in the presence of EDTA, or a phantom zone, was taken as indicative of MBL production.

2.2. Detection of resistance genes

PCR amplification was carried out for the detection of blaESBL (blaCTX-M, blaTEM, blaSHV) with primers described previously.28 PCR amplification was carried out for the detection of ESBL genes (blaCTX-M, blaTEM, blaSHV) and carbapenemase genes (blaKPC, blaVIM, blaiMp, blasiM, blaaM, blasPM, blaNDM, and blaoxA-48) using previously described primers and methodology.29-32 The subgroups of CTX-M were determined by PCR using the procedures of Woodford et al.33

2.3. Antibiotic susceptibility

MICs of imipenem and meropenem were determined by Etest, as described previously, in accordance with CLSI guidelines.26 Sensitivity to a panel of antibiotics including amikacin, gentamicin, trimethoprim-sulfamethoxazole, and colistin, was assessed.

3. Results

A total of 60 K. pneumoniae isolates were identified and studied. The majority of these were from patients in the intensive care unit (ICU; n = 45), while others were from patients on the surgical and medical wards. Specimen sources were blood (n = 9), rectal swabs (n = 16), sputum (n = 13), urine (n = H), wound (n = 9), and suction swab (n = 2). All isolates were confirmed to be carbapenemase-producers by modified Hodge test. The carbapenemase gene blaOXA-48 was detected in 47 (78%) isolates, blaNDM-1 in 12 (20%), and blaVIM in one (1.6%). No isolate harbored a combination of blaNDM-1 and blaOXA-48. None of the isolates harbored either blaKPC or blaIMP. Thirty-seven isolates were positive for blaCTX-M and all belonged to CTX-M group 1. Twenty-nine were positive for both

blaCTX-M and blaOXA-48. The blaTEM and blaSHV genes were detected

in 17 and 39 isolates, respectively. All isolates were resistant to imipenem and meropenem. The distribution, characterization, and antibiotic susceptibility profile of blaOXA-48-positive and blaNDM-1-positive isolates are shown in Tables 1 and 2, respectively. There was a high degree of resistance to amikacin, gentamicin, ciprofloxacin, and trimethoprim-sulfamethoxazole. Three isolates with resistance to colistin were identified and they were positive for blaoXA-48 (Table 1).

4. Discussion

The dissemination of K. pneumoniae isolates harboring carba-penemase resistance genes, in particular blaOXA-48 and blaNDM-1, continues unabated, and reports describing these isolates are emerging from different parts of the world. In the Arabian Gulf region, NDM-1, OXA-48, and OXA-181 carbapenemase-producing Enterobacteriaceae have been reported in Oman.22 In addition, the detection of blaNDM ^-positive K. pneumoniae in two patients at a tertiary care teaching hospital in Kuwait has been reported.24 A PubMed search did not identify any published report describing the occurrence and distribution of blaOXA-48- and blaNDM-1-producing Enterobacteriaceae in Saudi Arabia. The data presented here, based on a 6-month survey, provide the first insight into the widespread occurrence of K. pneumoniae isolates harboring blaOXA-48 and blaNDM-1 among patients in healthcare facilities in Riyadh, Saudi Arabia. The majority of the isolates were from clinical specimens and were from patients in the ICU. This indicates that in this setting K. pneumoniae isolates producing carbapenemases are associated with nosocomial infections in seriously ill patients. Although India and Pakistan are considered to be the main reservoir for NDM-producing isolates, it has been suggested that the Middle East region might be a secondary reservoir for the spread of blaNDM-1 isolates as there is a high frequency of population movement between Saudi Arabia and the Indian subcontinent.34,35 We speculate that a similar population movement with Turkey, where K. pneumoniae with blaOXA-48 is endemic, might explain the high occurrence of isolates with this resistance gene in our setting, although the absence of data on travel history for the patients precludes any firm conclusions being drawn. The emergence of blaNDM-1 and blaOXA-48 isolates in our setting has significant implications as it is not uncommon for patients from Saudi Arabia to travel abroad for further healthcare services, raising the possibility of dissemination of these isolates into other countries. Indeed, such dissemination via health tourism was demonstrated in a recently published report of the first two clinical cases of OXA-48-type carbapenemase-producing Enterobacteriaceae in the USA, in which one of the patients had a history of recent hospitalization in Saudi Arabia.36

Only one isolate was found with blaVIM and no KPC isolates were identified, indicating that these are not major sources of carbapenemases in our setting. The plasmid-encoded KPC enzyme was first identified in a K. pneumoniae isolate from North Carolina, USA.37 Since 2001, these isolates have spread across the USA, with reports of KPC-producers across 38 states.37,38 Although

Table 2

Characterization and antibiotic susceptibility profile of NDM-1-positive isolates

Isolate No. Location of patient Specimen Other resistance genes present Antibiotic susceptibility pattern

GEN AMK tmp-smx CIP COL

1 ICU Sputum blasHv R R R R s

2 ICU Urine blaTEM R R R R s

3 Surgical ward Rectal blaCTX-M R R s R s

4 ICU Wound blaTEM s R s R s

5 ICU Rectal blaCTX-M', blasHv R R R R s

6 ICU Blood blaCTX-M; blasHv R R R R s

7 ICU Wound blaCTX-M, blasHv R R R R s

8 ICU Blood blaCTX-M R R R R s

9 ICU Rectal blaCTX-M; blaSHv R s R R s

10 ICU Sputum blaCTX-M; blaSHv R R R R s

11 ICU Sputum - R R R R s

12 Surgical ward Urine blaCTX-M; blaSHv R R R R s

Total blaCTX-M = 8 blasHv =7 blaTEM = 2 R = 11 R= 11 R= 10 R= 12 R=0

GEN, gentamicin; AMK, amikacin; TMP-SMX, trimethoprim-sulfamethoxazole; CIP, ciprofloxacin; COL, colistin; ICU, intensive care unit; R, resistant; S, sensitive.

Please cite this article in press as: Shibl A, et al. The emergence of OXA-48- and NDM-l-positive Klebsiella pneumoniae in Riyadh, Saudi Arabia. Int J Infect Dis (2013), http://dx.doi.Org/10.1016/j.ijid.2013.06.016

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KPC-producers are now being identified at an alarming rate across Europe, facilitated mostly by clonal dissemination, to the best of our knowledge there is no published report of b/aKPC-positive isolates from the Arabian Peninsula.39

The antibiotic susceptibility profile of our isolates is in keeping with the reported multidrug-resistant phenotype associated with isolates harboring b/aNDM-1 and b/aOXA-48. The weak hydrolytic effect on carbapenems exhibited by OXA-48-producers is not affected by EDTA or clavulanic acid, but is enhanced if there is associated ESBL activity and outer membrane permeability defects.14 Thus the co-existence of beta-lactamase genes such as demonstrated in our isolates, enhances the antimicrobial resistance, particularly in b/aOXA-48 isolates. As colistin remains one of the last drugs of choice for the treatment of infections caused by carbapenemase-producing Enterobacteriaceae, the finding of car-bapenemase-producers with resistance to this, as reported herein, is of major concern. Although this report has documented the widespread occurrence of these isolates in our setting, a major limitation is the absence of detailed epidemiological data and molecular characterization. Hence, we suggest that there is an urgent need for further studies to clearly map out the epidemiology and to conduct molecular characterization of carbapenemase-producing isolates in Saudi Arabia. Healthcare facilities in the country need to be aware of the emergence of these multidrug-resistant isolates, as these are of significant public health concern both in the hospital and community setting. A process of enhanced surveillance for the detection of these multidrug-resistant pathogens is urgently advocated so that patients can be identified quickly and appropriate infection control measures instituted to stem further dissemination.

Acknowledgement

The authors extend their appreciation to the Deanship of Scientific Research at King Saud University for funding the work through the research group project No. RGP-VPP-038.

Conflict of interest: The authors declare that they have no competing interests.

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Please cite this article in press as: shibl A, et al. The emergence of OxA-48- and NDM-1-positive Klebsiella pneumoniae in Riyadh, saudi Arabia. Int J Infect Dis (2013), http://dx.doi.org/10.1016/j.ijid.2013.06.016