Molecular Typing of Klebsiella pneumoniae Isolated from Medical Centers in Kermanshah Using Pulse Field Gel Electrophoresis

AUTHORS

Azam Elahi 1 , Alisha Akya 1 , Roya Chegene Lorestani 1 , Keyghobad Ghadiri 1 , Shokofe Baakhshii 2 , *

1 Infectious Diseases Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran

2 Department of Biology, Faculty of Basic Sciences, Islamic Azad University of Boroujerd, Khorramabad, Iran

How to Cite: Elahi A, Akya A, Chegene Lorestani R, Ghadiri K, Baakhshii S. Molecular Typing of Klebsiella pneumoniae Isolated from Medical Centers in Kermanshah Using Pulse Field Gel Electrophoresis, Arch Pediatr Infect Dis. 2019 ; 7(2):e84331. doi: 10.5812/pedinfect.84331.

ARTICLE INFORMATION

Archives of Pediatric Infectious Diseases: 7 (2); e84331
Published Online: April 14, 2019
Article Type: Research Article
Received: September 16, 2018
Revised: January 22, 2019
Accepted: March 2, 2019
Crossmark

Crossmark

CHEKING

READ FULL TEXT
Abstract

Background: Klebsiella pneumoniae is one of the important opportunistic pathogens causing serious infections, both community and hospital-acquired, with high resistance to antibiotics.

Objectives: We aimed to determine the molecular typing of K. pneumoniae isolates using pulse field gel electrophoresis (PFGE).

Methods: Sixty-two consecutive non-duplicate K. pneumoniae isolates were isolated from clinical specimens in three hospitals of Kermanshah, west of Iran. A total of K. pneumoniae was confirmed by API-20E kit. Antibiotic susceptibility testing and ESBL screening were performed following the genotyping of isolates using PFGE. The pattern of DNA bands was examined by the 6.6 version of the Gelcompar II (Applied Maths, Belgium). The calculation of similarities was done by the Dice coefficient, and the unweighted paired group method was used for cluster analysis (UPGMA).

Results: Fifty-eight percent of isolates were phenotypically ESBL positive. Twenty-nine pulsotypes (X1-29) were determined with various genotype patterns. Four clones (including 18 isolates) showed a close genetic relationship and were from ICU, burn and infectious wards in one hospital. Pulsotypes X15 to X29, each presented a unique genotype and the majority of these strains (> 50%) were from the emergency ward. Four isolates were non-typable.

Conclusions: Our results indicate the genotypic variation of K. pneumoniae isolates, which may suggest the different origins for isolates, as well as ongoing changes of bacterial genome. However, the presence of the isolates with similar genotype may show a common origin and consequently, the dissemination of strains in hospital wards, especially in ICU and burn wards. Therefore, Kermanshah hospitals need to establish an effective infectious control system to manage and monitor the spread of resistant strains.

Keywords

Klebsiella pneumoniae Molecular Typing Pulsed-Field Gel Electrophoresis

Copyright © 2019, Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited.

1. Background

Although Klebsiella pneumoniae is a part of gastrointestinal flora, it causes serious community and hospital-acquired infections (1). This opportunistic pathogen can cause pneumonia, urinary tract, skin, and soft tissue infections, in particular in intensive care unit (ICU), surgery, and pediatric wards of hospitals (2, 3). Some identified risk factors for K. pneumoniae infections are the long-term admission, nutrition through intravenous injection, and the mechanical ventilation (3). K. pneumoniae strains with multiple drug resistance (MDR) are frequently isolated from nosocomial infections (4). Due to exorbitance use of beta-lactam antibiotics in recent decades, K. pneumoniae isolates containing broad-spectrum beta-lactamases have been reported worldwide (5, 6). The resistance to Cephalosporins was initially reported in 1983 and then spread throughout the world (7).

An important epidemiological tool to control the infection is monitoring the local spread of resistant strains of the bacteria, especially in hospital environments (8). Researches on the bacterial genotypic homology can outline a better vision for the origin and dissemination patterns of K. pneumoniae infections (9). Among different molecular techniques for typing the bacterial genotype, pulse-field gel electrophoresis (PFGE) is often used as the standard method for typing of K. pneumoniae isolates (10). This method can differentiate only relatively major genetic events led to the changes in genomic fingerprinting patterns (11). Given the spread of multidrug-resistant strains of K. pneumoniae in our region, this study aimed to determine the molecular typing of K. pneumoniae isolates.

2. Objectives

We aimed to determine the molecular typing of K. pneumoniae isolates using PFGE.

3. Methods

3.1. Bacterial Isolates

This descriptive cross-sectional study was performed on 62 available and non-duplicate K. pneumoniae isolates. They were identified from 2013 to 2014, from clinical samples in Imam Khomeini, Imam Reza, and Taleghani hospitals in Kermanshah, west of Iran. All isolates were detected by biochemical and bacteriological tests and subsequently, confirmed by API20E kit (bio-Merieux, France).

3.2. Antibiotic Susceptibility Testing

Antimicrobial susceptibility testing for 6 beta-lactam antibiotics was carried out using disk diffusion method (12). The examined antibiotics were Penicillins (ampicillin (10 μg), piperacillin-tazobactam (100/10 μg)), Cephalosporins (cefazolin (30 μg), cefotaxime (30 μg)), Monobactams (aztreonam (30 μg)), Carbapenems (Meropenem (10 μg)) (Mast, England).

3.3. ESBL Phenotypic Confirmatory Test

This test was performed by the hybrid disk method according to the CLSI recommendations. In this method, both Ceftazidime (30 μg) and cefotaxime (30 μg) were used separately and in combination with Clavulanic acid (10 μg). For each isolate, if the diameter of the inhibited zone increased more than 5 mm for the antimicrobial agent in combination with Clavulanic acid, it was proposed as ESBL producer (12). K. pneumoniae ATCC700603 was used as a positive control and E. coli ATCC25922 was used as a negative control.

3.4. Pulsed-Field Gel Electrophoresis (PFGE)

The PFGE was done according to a previously described protocol with some modifications (13). K. pneumoniae isolates and Salmonella enterica serovar Braenderup H9812 (As DNA marker) genome were digested with 20U XbaI restriction enzyme (Fermentas, Lithuania). Electrophoresis was performed by CHEF MAPPER apparatus (Bio-Rad, USA) for 22 h at 14°C under the below conditions: 5 seconds initial switch time, 35 seconds final switch time, consist of angle, the voltage gradient of 120 degrees, 6 V/cm; ramping factor, linear. Gels were stained by ethidium bromide and visualized under the UV light by the Gel Doc apparatus (Bio-Rad, USA).

3.5. Software Analysis

The DNA pattern was analyzed by the 6.6 version of the Gelcompar II (Applied Maths, Belgium). The calculation of similarities was done by the Dice coefficient, and the unweighted paired group method was used for cluster analysis (UPGMA). According to the Tenover’s criteria, the isolates with more than 80% similarity in their DNA patterns were defined as a clone (11).

3.6. Statistical Analysis

All data were recorded and saved in an Excel file. Statistical analyses were performed using SPSS software (version 16). Variables were analyzed using chi-square test. In this study, A P value of ≤ 0.05 was considered statistically significant.

4. Results

From 62 isolates of K. pneumoniae, 37 (59.6%), 16 (25.8%), 9 (14.5%) isolates were from Imam Khomeini Hospital, Imam Reza hospital and Taleghani hospitals, respectively. Seventeen (27.4%), 16 (25.8%), 12 (19.3%), 6 (9.6%) isolates were from the emergency unit, burning ward, ICU, and infectious ward, respectively. Eleven (17.7%) isolates were from other departments. The samples consisted of 33 (53.2%) urine samples, 16 (25.8% ) burns, 7 (11.3% ) samples of respiratory secretion, and 6 (9.6%) samples from other specimens (blood and ascites). They belonged to 30 (48.3%) males and 32 (51.6%) females with an average age of 41.5 ± 9.3 years. Antibiotic susceptibility testing results showed resistance to ampicillin was 62 (100%), Cephazolin 50 (80.6%), cefotaxime 42 (67.7%), aztreonam 38 (61.2%), piperacillin-tazobactam 21 (33.8%), and Meropenem 2 (3.3%) isolates. The antibiotical resistance according to the pulsotypes of isolates is presented in Table 1. The antibiotic resistance isolates showed no significant homogenous genetic pattern clones (P > 0.05).

Table 1. Antibiotics Resistance of Selected K. pneumoniae Clusters
Cluster TagNumber of Isolates in Each ClusterHospitalESBL Positive, %Resistant Number, %
Piperacillin-TazobactamMeropenemAztreonamCefotaximeCefazolinAmpicillin
X16A2 (33.3)3 (50)1 (16.6)4 (66.6)4 (66.6)6 (100)6 (100)
X25A4 (80)2 (40)04 (80)5 (100)5 (100)5 (100)
X35B2 (40)002 (40)2 (40)2 (40)5 (100)
X44A2 (50)3 (75)02 (50)3 (75)4 (100)4 (100)
X53A3 (100)2 (66.6)03 (100)3 (100)3 (100)3 (100)
X63C3 (100)2 (66.6)03 (100)3 (100)3 (100)3 (100)
X73A2 (66.6)01 (33.3)2 (66.6)2 (66.6)2 (66.6)3 (100)
X82A & B1 (50)001 (50)1 (50)1 (50)2 (100)
X92B2 (100)1 (50)02 (100)2 (100)2 (100)2 (100)
X102B000001 (50)2 (100)
X112A2 (100)002 (100)2 (100)2 (100)2 (100)
X122A2 (100)1 (50)02 (100)2 (100)2 (100)2 (100)
X132A & B2 (100)001 (50)2 (100)2 (100)2 (100)
X142B1 (50)1 (50)01 (50)1 (50)1 (50)2 (100)
(X15-29)15A & B & C5 (33)5 (33)07 (46)8 (53)12 (80)15 (100)
Non-typable4A & B3 (75)1 (25)02 (50)2 (50)2 (50)4 (100)
Total62A & B & C3621238425062

Abbreviations: A, Imam Khomeini Hospital; B, Imam Reza Hospital; and C, Taleghani Hospital.

ESBL production was phenotypically determined in 36 (58%) isolates. The PFGE results showed the majority of isolates had 14-19 DNA bands (16 bands on average) (Figures 1 and 2). According to the DNA fingerprinting of isolates, 29 clusters (X1-29) were differentiated, which included 14 clones and 15 unique clusters. Twenty-seven strains from one hospital constituted 9 clustered (Figure 2). Each one of the X15 to X29 Clusters had a unique genotype and the majority of their strains (> 50%) were from the emergency ward. Four isolates with diverse origins were non-typable by PFGE.

CHEF profiles of K. pneumoniae strains. (M): H9812 strain of Salmonella serotype Braenderup as a molecular marker. Lane 1 and 8: non-typable strains
Figure 1. CHEF profiles of K. pneumoniae strains. (M): H9812 strain of Salmonella serotype Braenderup as a molecular marker. Lane 1 and 8: non-typable strains
Phylogenetic relationship among isolates of K. pneumoniae using PFGE data. The strains were clustered using UPGMA.
Figure 2. Phylogenetic relationship among isolates of K. pneumoniae using PFGE data. The strains were clustered using UPGMA.

The clusters with the genetic pattern of X1, X2, X4, and X7 (18 strains) were from Imam Khomeini Hospital, which showed the most genetic similarity. The majority of these strains were from ICU, as well as burning and infectious wards. They were presented as the prevalent clones. The highest genomic homology was for X1 and X7 clones associated with ICU and burning ward.

The ESBL producing isolates showed no significant homogenous genetic pattern clones (P > 0.05).

Clone X3 was comprised of isolates from the Emergency Department of Imam Reza Hospital and remarkably similar to the X1, X2, X4, and X7 clones from Imam Khomeini Hospital. The members of X6 clone were from the internal and surgery wards and ICU. There was no significant correlation between the resistance to beta-lactam antibiotics and clusters.

5. Discussion

The results of this study show that most of the K. pneumoniae isolates produce ESBL, which may lead to clonal dissemination of resistant strains. This is consistent with other studies, which have shown that the ESBL producing isolates in hospitalized patients are more likely to be exposed to antimicrobial agents, especially to the third generation Cephalosporins (14). Carbapenems still show good efficacy against ESBL producing K. pneumoniae isolates (2). However, emerging resistance to this group of antibiotics may limit their potency in the future. The tremendous increase in the prevalence of ESBLs among bacteria is a serious alarm since the majority of them are multi-drug resistant. In addition to observing the high diversity of isolates, we also observed similar strains. The genotypic polymorphism probably indicates the genetic diversity of isolates or the different origins of them. Given the various types of clinical samples and several medical centers for sampling, it is not unexpected that the isolates might be acquired from different sources. Similarly, several researches on K. pneumoniae isolates in Iran from 2008 to 2014 showed the genotype diversity between isolates of this bacterium. For example, studies on 35 and 54 K. pneumoniae isolates using PFGE (with 85% similarity of isolates), reported 21 and 42 different clusters, respectively (15, 16). Other studies on 71 and 31 of ESBL producing K. pneumoniae isolates using PFGE, have reported 62 and 26 genotypes, respectively (17, 18). These studies also used isolates from various clinical samples, including urine, lung secretions, blood, wounds, and sputum. The results of the above studies are consistent with our results for high genotype diversity among isolates. Furthermore, the research in Asian countries on K. pneumoniae, including studies on 256 and 93 isolates using PFGE, resulted in 136 and 41 different genotypes, respectively (19, 20). The results of these studies are also similar to our results in terms of the various genomic patterns of isolates. However, some studies have reported fewer varieties of K. pneumoniae isolates. For example, in a study conducted on 92 of ESBL-producing K. pneumoniae isolates mostly from neonatal units, only 13 genotype patterns were identified (21). One explanation could be the fact that the most isolates in this study were from limited sources in one hospital. Studies on 26, 66, and 57 isolates of K. pneumoniae in Canada, Bosnia and Herzegovina, and Jamaica using PFGE resulted in 3, 4, and 10 deferent genotypes, respectively (22-24). These studies also evaluated the isolates from limited sources, which may explain their genotypic similarity.

The strains with a similar genotypic pattern among our isolates may suggest the dissemination of these strains through the hospital environment, in particular, in ICU and burn ward. The hospitalized patients such as burned patients are at high risk of infection with various nosocomial pathogens due to the destruction of the skin barrier, suppression of the immune system, and invasive procedures (25). The transmission of resistant strains in the hospital environment may happen in various ways, including hospital staff or contaminated devices, equipment, and cleaners. These bacterial strains can cause nosocomial infections with a limited choice of effective antibiotics for their treatment.

There was no significant correlation between genotypes with the ESBL production and antibiotic resistance phenotypes. Since the most ESBL and antibiotic resistance genes on plasmid are small sequences (40 - 50 Kb), they may not be detected in PFGE bands (26). The average number of PFGE bands of our isolates was consistent with the results of other studies, indicating good genome digestion by the restriction enzyme in our study (17, 21, 22, 27-30).

5.1. Conclusions

Our results offer suitable data on molecular epidemiology of K. pneumoniae isolates in Kermanshah, especially hospital environment. The diversity patterns of K. pneumoniae genotypes indicate the various origins of strains isolated from hospitalized patients. However, the presence of some strains with similar genotypes in clusters can show a common source for these strains and may reflect the clonal spread through hospital environments, especially in ICU and burn ward of hospitals. Therefore, as a requirement, Kermanshah hospitals should implement a more effective system of infection control to reduce the dissemination of highly resistant strains of bacteria within the hospital environment.

Acknowledgements

Footnotes

References

  • 1.

    Martin RM, Bachman MA. Colonization, infection, and the accessory genome of Klebsiella pneumoniae. Front Cell Infect Microbiol. 2018;8:4. doi: 10.3389/fcimb.2018.00004. [PubMed: 29404282]. [PubMed Central: PMC5786545].

  • 2.

    Paterson DL, Ko WC, Von Gottberg A, Mohapatra S, Casellas JM, Goossens H, et al. Antibiotic therapy for Klebsiella pneumoniae bacteremia: Implications of production of extended-spectrum beta-lactamases. Clin Infect Dis. 2004;39(1):31-7. doi: 10.1086/420816. [PubMed: 15206050].

  • 3.

    Paczosa MK, Mecsas J. Klebsiella pneumoniae: Going on the offense with a strong defense. Microbiol Mol Biol Rev. 2016;80(3):629-61. doi: 10.1128/MMBR.00078-15. [PubMed: 27307579]. [PubMed Central: PMC4981674].

  • 4.

    Apondi OE, Oduor OC, Gye BK, Kipkoech MK. High prevalence of multi-drug resistant Klebsiella pneumoniae in a tertiary teaching hospital in Western Kenya. Afr J Infect Dis. 2016;10(2):89-95. doi: 10.21010/ajid.v10i2.3. [PubMed: 28480442]. [PubMed Central: PMC5411993].

  • 5.

    Benner KW, Prabhakaran P, Lowros AS. Epidemiology of infections due to extended-spectrum Beta-lactamase-producing bacteria in a pediatric intensive care unit. J Pediatr Pharmacol Ther. 2014;19(2):83-90. doi: 10.5863/1551-6776-19.2.83. [PubMed: 25024667]. [PubMed Central: PMC4093669].

  • 6.

    Azimi L, Erajiyan G, Talebi M, Owlia P, Bina M, Shojaie A, et al. Phenotypic and molecular characterization of plasmid mediated ampc among clinical isolates of Klebsiella pneumoniae isolated from different Hospitals in Tehran. J Clin Diagn Res. 2015;9(4):DC01-3. doi: 10.7860/JCDR/2015/11037.5797. [PubMed: 26046018]. [PubMed Central: PMC4437065].

  • 7.

    Ali Abdel Rahim KA, Ali Mohamed AM. Prevalence of extended spectrum Beta-lactamase-producing Klebsiella pneumoniae in clinical isolates. Jundishapur J Microbiol. 2014;7(11). e17114. doi: 10.5812/jjm.17114. [PubMed: 25774279]. [PubMed Central: PMC4332241].

  • 8.

    Johnson AP. Surveillance of antibiotic resistance. Philos Trans R Soc Lond B Biol Sci. 2015;370(1670):20140080. doi: 10.1098/rstb.2014.0080. [PubMed: 25918439]. [PubMed Central: PMC4424431].

  • 9.

    Akya A, Elahi A, Chegenelorestani R, Rezaee M. Dissemination of multidrug-resistant, class I and II integrons and molecular typing of CTX-M-producing Klebsiella pneumoniae. Int J Appl Basic Med Res. 2018;8(2):100-5. doi: 10.4103/ijabmr.IJABMR_333_16. [PubMed: 29744322]. [PubMed Central: PMC5932916].

  • 10.

    Li W, Raoult D, Fournier PE. Bacterial strain typing in the genomic era. FEMS Microbiol Rev. 2009;33(5):892-916. doi: 10.1111/j.1574-6976.2009.00182.x. [PubMed: 19453749].

  • 11.

    Tenover FC, Arbeit RD, Goering RV, Mickelsen PA, Murray BE, Persing DH, et al. Interpreting chromosomal DNA restriction patterns produced by pulsed-field gel electrophoresis: Criteria for bacterial strain typing. J Clin Microbiol. 1995;33(9):2233-9. [PubMed: 7494007]. [PubMed Central: PMC228385].

  • 12.

    Clinical and Laboratory Standards Institute (CLSI). Performance standards for antimicrobial susceptibility testing. Clinical and Laboratory Standards Institute; 2011.

  • 13.

    Durmaz R, Otlu B, Koksal F, Hosoglu S, Ozturk R, Ersoy Y, et al. The optimization of a rapid pulsed-field gel electrophoresis protocol for the typing of Acinetobacter baumannii, Escherichia coli and Klebsiella spp. Jpn J Infect Dis. 2009;62(5):372-7. [PubMed: 19762987].

  • 14.

    Kothari S, Mishra V, Ranjan N, Singh A. Third generation cephalosporin-resistance in Klebsiella pneumoniae isolates: An emerging threat. Int J Basic Clin Pharmacol. 2013;2(1):56. doi: 10.5455/2319-2003.ijbcp20130111.

  • 15.

    Ashayeri-Panah M, Feizabadi MM, Eftekhar F. Correlation of multi-drug resistance, integron and blaESBL gene carriage with genetic fingerprints of extended-spectrum beta-lactamase producing Klebsiella pneumoniae. Jundishapur J Microbiol. 2014;7(2). e8747. doi: 10.5812/jjm.8747. [PubMed: 25147670]. [PubMed Central: PMC4138679].

  • 16.

    Ashayeri-Panah M, Eftekhar F, Ghamsari MM, Parvin M, Feizabadi MM. Genetic profiling of Klebsiella pneumoniae: Comparison of pulsed field gel electrophoresis and random amplified polymorphic DNA. Braz J Microbiol. 2013;44(3):823-8. doi: 10.1590/S1517-83822013005000055. [PubMed: 24516423]. [PubMed Central: PMC3910195].

  • 17.

    Feizabadi MM, Mahamadi-Yeganeh S, Mirsalehian A, Mirafshar SM, Mahboobi M, Nili F, et al. Genetic characterization of ESBL producing strains of Klebsiella pneumoniae from Tehran hospitals. J Infection Develop Countries. 2010;4(10). doi: 10.3855/jidc.1059.

  • 18.

    Nematzadeh S, Shahcheraghi F, Feizabadi MM, Nikbin VS, Nasehi L. Molecular characterization of CTX-Mbeta-lactamases among Klebsiella pneumoniae isolated from patients at Tehran hospitals. Indian J Med Microbiol. 2011;29(3):254-7. doi: 10.4103/0255-0857.83908. [PubMed: 21860105].

  • 19.

    Lau YJ, Hu BS, Wu WL, Lin YH, Chang HY, Shi ZY. Identification of a major cluster of Klebsiella pneumoniae isolates from patients with liver abscess in Taiwan. J Clin Microbiol. 2000;38(1):412-4. [PubMed: 10618128]. [PubMed Central: PMC88736].

  • 20.

    Al-Marzooq F, Mohd Yusof MY, Tay ST. Molecular analysis of ciprofloxacin resistance mechanisms in Malaysian ESBL-producing Klebsiella pneumoniae isolates and development of mismatch amplification mutation assays (MAMA) for rapid detection of gyrA and parC mutations. Biomed Res Int. 2014;2014:601630. doi: 10.1155/2014/601630. [PubMed: 24860827]. [PubMed Central: PMC4000930].

  • 21.

    Mshana SE, Hain T, Domann E, Lyamuya EF, Chakraborty T, Imirzalioglu C. Predominance of Klebsiella pneumoniae ST14 carrying CTX-M-15 causing neonatal sepsis in Tanzania. BMC Infect Dis. 2013;13:466. doi: 10.1186/1471-2334-13-466. [PubMed: 24099282]. [PubMed Central: PMC3851032].

  • 22.

    Tijet N, Sheth PM, Lastovetska O, Chung C, Patel SN, Melano RG. Molecular characterization of Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae in Ontario, Canada, 2008-2011. PLoS One. 2014;9(12). e116421. doi: 10.1371/journal.pone.0116421. [PubMed: 25549365]. [PubMed Central: PMC4280202].

  • 23.

    Dedeic-Ljubovic A, Hukic M, Pfeifer Y, Witte W, Padilla E, Lopez-Ramis I, et al. Emergence of CTX-M-15 extended-spectrum beta-lactamase-producing Klebsiella pneumoniae isolates in Bosnia and Herzegovina. Clin Microbiol Infect. 2010;16(2):152-6. doi: 10.1111/j.1469-0691.2009.03018.x. [PubMed: 19686282].

  • 24.

    Christian NA, Roye-Green K, Smikle M. Molecular epidemiology of multidrug resistant extended spectrum beta-lactamase producing Klebsiella pneumoniae at a Jamaican hospital, 2000-2004. BMC Microbiol. 2010;10:27. doi: 10.1186/1471-2180-10-27. [PubMed: 20109209]. [PubMed Central: PMC2824695].

  • 25.

    Azimi L, Motevallian A, Ebrahimzadeh Namvar A, Asghari B, Lari AR. Nosocomial infections in burned patients in Motahari Hospital, Tehran, Iran. Dermatol Res Pract. 2011;2011:436952. doi: 10.1155/2011/436952. [PubMed: 22203838]. [PubMed Central: PMC3235664].

  • 26.

    Birren BW, Lai E, Hood L, Simon MI. Pulsed field gel electrophoresis techniques for separating 1- to 50-kilobase DNA fragments. Anal Biochem. 1989;177(2):282-6. doi: 10.1016/0003-2697(89)90052-3. [PubMed: 2729546].

  • 27.

    Donati V, Feltrin F, Hendriksen RS, Svendsen CA, Cordaro G, Garcia-Fernandez A, et al. Extended-spectrum-beta-lactamases, AmpC beta-lactamases and plasmid mediated quinolone resistance in klebsiella spp. from companion animals in Italy. PLoS One. 2014;9(3). e90564. doi: 10.1371/journal.pone.0090564. [PubMed: 24595207]. [PubMed Central: PMC3942433].

  • 28.

    Lin CF, Hsu SK, Chen CH, Huang JR, Lo HH. Genotypic detection and molecular epidemiology of extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae in a regional hospital in central Taiwan. J Med Microbiol. 2010;59(Pt 6):665-71. doi: 10.1099/jmm.0.015818-0. [PubMed: 20150317].

  • 29.

    Salimizand H, Shahcheraghi F, Kalantar E, Badmasti F, Mousavi SF. Molecular characterization of class 1 integrons and gene cassettes in multidrug resistant (MDR) Klebsiella spp. isolated from hospitalized and outpatients in Iran, 2009. Iran J Microbiol. 2013;5(1):48-55. [PubMed: 23466743]. [PubMed Central: PMC3577558].

  • 30.

    Rodriguez EC, Saavedra SY, Leal AL, Alvarez C, Olarte N, Valderrama A, et al. [The spread of KPC-3 Klebsiella pneumoniae in hospitals in Bogota over a three-year period (2008-2010)]. Biomedica. 2014;34 Suppl 1:224-31. Spanish. doi: 10.1590/S0120-41572014000500025. [PubMed: 24968054].

  • COMMENTS

    LEAVE A COMMENT HERE: