scholarly journals First Report of blaIMP–4 and blaSRT–2 Coproducing Serratia marcescens Clinical Isolate in China

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiangning Huang ◽  
Siquan Shen ◽  
Qingyu Shi ◽  
Li Ding ◽  
Shi Wu ◽  
...  
Keyword(s):  
Serratia Marcescens ◽  
Genomic Sequence ◽  
Gc Content ◽  
Tertiary Hospital ◽  
Complete Sequence ◽  
Clinical Settings ◽  
Microdilution Method ◽  
Carbapenem Resistant ◽  
Query Coverage ◽  
Broth Microdilution Method

Carbapenem-resistant Enterobacterales (CRE) has become a major therapeutic concern in clinical settings, and carbapenemase genes have been widely reported in various bacteria. In Serratia marcescens, class A group carbapenemases including SME and KPC were mostly identified. However, there are few reports of metallo-β-lactamase-producing S. marcescens. Here, we isolated a carbapenem-resistant S. marcescens (S378) from a patient with asymptomatic urinary tract infection which was then identified as an IMP-4-producing S. marcescens at a tertiary hospital in Sichuan Province in southwest of China. The species were identified using MALDI-TOF MS, and carbapenemase-encoding genes were detected using PCR and DNA sequencing. The results of antimicrobial susceptibility testing by broth microdilution method indicated that the isolate S. marcescens S378 was resistant to meropenem (MIC = 32 μg/ml) and imipenem (MIC = 64 μg/ml) and intermediate to aztreonam (MIC = 8 μg/ml). The complete genomic sequence of S. marcescens was identified using Illumina (Illumina, San Diego, CA, United States) short-read sequencing (150 bp paired-end reads); five resistance genes had been identified, including blaIMP–4, blaSRT–2, aac(6′)-Ic, qnrS1, and tet(41). Conjugation experiments indicated that the blaIMP–4-carrying plasmid pS378P was conjugative. Complete sequence analysis of the plasmid pS378P bearing blaIMP–4 revealed that it was a 48,780-bp IncN-type plasmid with an average GC content of 50% and was nearly identical to pP378-IMP (99% nucleotide identity and query coverage).

scholarly journals Occurrence of NDM-1, VIM-1, and OXA-10 Co-Producing Providencia rettgeri Clinical Isolate in China

2022 ◽  
Vol 11 ◽  
Author(s):  
Siquan Shen ◽  
Xiangning Huang ◽  
Qingyu Shi ◽  
Yan Guo ◽  
Yang Yang ◽  
...  
Keyword(s):  
Genomic Sequence ◽  
New Delhi ◽  
Providencia Rettgeri ◽  
Hospital Acquired Infections ◽  
Microdilution Method ◽  
Query Coverage ◽  
Broth Microdilution Method ◽  
Tract Infections ◽  
Hospital Acquired ◽  
Complete Genomic

Providencia rettgeri is a nosocomial pathogen associated with urinary tract infections related to hospital-acquired Infections. In recent years, P. rettgeri clinical strains producing New Delhi Metallo-β-lactamase (NDM) and other β-lactamase which reduce the efficiency of antimicrobial therapy have been reported. However, there are few reports of P. rettgeri co-producing two metallo-β-lactamases in one isolate. Here, we first reported a P. rettgeri strain (P138) co-harboring blaNDM-1, blaVIM-1, and blaOXA-10. The specie were identified using MALDI-TOF MS. The results of antimicrobial susceptibility testing by broth microdilution method indicated that P. rettgeri P138 was resistant to meropenem (MIC = 64μg/ml), imipenem (MIC = 64μg/ml), and aztreonam (MIC = 32μg/ml). Conjugation experiments revealed that the blaNDM-1-carrying plasmid was transferrable. The carbapenemase genes were detected using PCR and confirmed by PCR-based sequencing. The complete genomic sequence of the P. rettgeri was identified using Illumina (Illumina, San Diego, CA, USA) short-read sequencing (150bp paired-end reads), and many common resistance genes had been identified, including blaNDM-1, blaVIM-1, blaOXA-10, aac(6’)-Il, aadA5, ant(2’’)-Ia, aadA1, aac(6’)-Ib3, aadA1, aph(3’)-Ia, aac(6’)-Ib-cr, qnrD1, qnrA1, and catA2. The blaNDM-1 gene was characterized by the following structure: IS110–TnpA–IntI1–aadB–IS91–GroEL–GroES–DsbD–PAI–ble–blaNDM-1–IS91–QnrS1–IS110. Blast comparison revealed that the blaNDM-1 gene structure shared >99% similarity with plasmid p5_SCLZS62 (99% nucleotide identity and query coverage). In summary, we isolated a P. rettgeri strain coproducing blaNDM-1, blaVIM-1, and blaOXA-10. To the best of our acknowledge, this was first reported in the world. The occurrence of the strain needs to be closely monitored.

scholarly journals 681. In vitro Activity of the β-Lactamase Inhibitor QPX7728 in Combination with Several β-Lactams Against Acinetobacter baumannii (AB) and Pseudomonas aeruginosa (PSA)

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S310-S311 ◽  
Author(s):  
Olga Lomovskaya ◽  
Jill Lindley ◽  
Debora Rubio-Aparicio ◽  
Kirk J Nelson ◽  
Mariana Castanheira
Keyword(s):  
Resistance Mechanisms ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
In Vitro Activity ◽  
Microdilution Method ◽  
Carbapenem Resistant ◽  
Broth Microdilution Method ◽  
Data Representative ◽  
Lactamase Inhibitor

Abstract Background QPX7728 (QPX) is a novel broad-spectrum boron-containing inhibitor of serine- and metallo-β-lactamases (MBLs). We evaluated the in vitro activity of QPX combined with several β-lactams against carbapenem-resistant AB (CRAB) and PSA clinical isolates with varying β-lactam resistance mechanisms. Methods A total of 503 CRAB (meropenem [MEM] MIC ≥8 µg/mL) and 762 PSA clinical isolates were tested by the reference broth microdilution method against β-lactams alone and combined with QPX (4 µg/mL and 8 µg/mL). PSA isolates were selected to represent the normal distribution of MEM, ceftazidime–avibactam (CAZ-AVI), and ceftolozane-tazobactam (TOL-TAZ) resistance according to 2017 surveillance data (representative panel). Additionally, 262 PSA isolates that were either nonsusceptible (NS) to MEM (MIC, ≥4 µg/mL) or to TOL-TAZ (MIC, ≥8 µg/mL), or resistant (R) to CAZ-AVI (MIC, ≥16 µg/mL) (challenge panel) were also tested. Within this 262 strain challenge set, 56 strains carried MBLs and the majority also had nonfunctional OprD. Results Against CRAB, QPX at 4 and 8 µg/mL increased the potency of all β-lactams tested. MEM-QPX was the most potent combination (table) displaying MIC50/MIC90 at 1/8 and 0.5/4 µg/mL with QPX at fixed 4 and 8 µg/mL, respectively. Susceptibility (S) to MEM was restored in >95% of strains. Against the 500 PSA from the representative panel, S for all QPX combinations was >90%. For the challenge panel, TOL-QPX and piperacillin (PIP)-QPX were the most potent combinations, restoring S in 76–77% of strains. TOL-QPX and MEM-QPX or cefepime (FEP)-QPX restored the MIC values to S rates when applying the CLSI breakpoint for the compound alone (comparison purposes only) in ~90% and ~75% of non-MBL-producing strains, respectively, vs. 60–70% for TOL-TAZ and CAZ-AVI. PIP-QPX reduce the MIC values to S values for PIP-TAZ in ~60% of MBL-producing strains vs. 20–30% and 3–7% for other QPX combinations and non-QPX tested combinations, respectively. Conclusion Combinations of QPX with various β-lactam antibiotics displayed potent activity against CRAB and resistant PSA isolates and warrant further investigation. Disclosures All authors: No reported disclosures.

scholarly journals Results from the China Antimicrobial Surveillance Network (CHINET) in 2017 of the In Vitro Activities of Ceftazidime-Avibactam and Ceftolozane-Tazobactam against Clinical Isolates of Enterobacteriaceae and Pseudomonas aeruginosa

2019 ◽  
Vol 63 (4) ◽  
Author(s):  
Dandan Yin ◽  
Shi Wu ◽  
Yang Yang ◽  
Qingyu Shi ◽  
Dong Dong ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Clinical Isolates ◽  
Surveillance Network ◽  
Content Type ◽  
Highly Active ◽  
Microdilution Method ◽  
Carbapenem Resistant ◽  
Antimicrobial Surveillance ◽  
Broth Microdilution Method

ABSTRACT The in vitro activities of ceftazidime-avibactam (CZA), ceftolozane-tazobactam (C-T), and comparators were determined for 1,774 isolates of Enterobacteriaceae and 524 isolates of Pseudomonas aeruginosa collected by 30 medical centers from the China Antimicrobial Surveillance Network (CHINET) in 2017. Antimicrobial susceptibility testing was performed by the CLSI broth microdilution method, and blaKPC and blaNDM were detected by PCR for all carbapenem-resistant Enterobacteriaceae (CRE). Ceftazidime-avibactam demonstrated potent activity against almost all Enterobacteriaceae (94.6% susceptibility; MIC50, ≤0.25 mg/liter; MIC90, ≤0.25 to >32 mg/liter) and good activity against P. aeruginosa (86.5% susceptibility; MIC50/90, 2/16 mg/liter). Among the CRE, 50.8% (189/372 isolates) were positive for blaKPC-2, which mainly existed in ceftazidime-avibactam-susceptible Klebsiella pneumoniae isolates (92.1%, 174/189). Among the CRE, 17.7% (66/372 isolates) were positive for blaNDM, which mainly existed in strains resistant to ceftazidime-avibactam (71.7%, 66/92). Ceftolozane-tazobactam showed good in vitro activity against Escherichia coli and Proteus mirabilis (MIC50/90, ≤0.5/2 mg/liter; 90.5 and 93.8% susceptibility, respectively), and the rates of susceptibility of K. pneumoniae (MIC50/90, 2/>64 mg/liter) and P. aeruginosa (MIC50/90, 1/8 mg/liter) were 52.7% and 88.5%, respectively. Among the CRE strains, 28.6% of E. coli isolates and 85% of K. pneumoniae isolates were still susceptible to ceftazidime-avibactam, but only 7.1% and 1.9% of them, respectively, were susceptible to ceftolozane-tazobactam. The rates of susceptibility of the carbapenem-resistant P. aeruginosa isolates to ceftazidime-avibactam (65.7%) and ceftolozane-tazobactam (68%) were similar. Overall, both ceftazidime-avibactam and ceftolozane-tazobactam were highly active against clinical isolates of Enterobacteriaceae and P. aeruginosa recently collected across China, and ceftazidime-avibactam showed activity superior to that of ceftolozane-tazobactam against Enterobacteriaceae, whereas ceftolozane-tazobactam showed a better effect against P. aeruginosa.

scholarly journals Molecular Characterization of blaIMP–4-Carrying Enterobacterales in Henan Province of China

2021 ◽  
Vol 12 ◽  
Author(s):  
Wentian Liu ◽  
Huiyue Dong ◽  
Tingting Yan ◽  
Xuchun Liu ◽  
Jing Cheng ◽  
...  
Keyword(s):  
Plasmid Stability ◽  
Multidrug Resistant ◽  
Complete Sequence ◽  
Molecular Characteristics ◽  
Carbapenem Resistant ◽  
Predominant Type ◽  
Tertiary Teaching ◽  
Query Coverage ◽  
Tertiary Teaching Hospital ◽  
Positive Isolate

Carbapenem-resistant Enterobacterales (CRE) pose a serious threat to clinical management and public health. We investigated the molecular characteristics of 12 IMP-4 metallo-β-lactamase-producing strains, namely, 5 Enterobacter cloacae, 3 Escherichia coli, 2 Klebsiella pneumoniae, and 2 Citrobacter freundii. These strains were collected from a tertiary teaching hospital in Zhengzhou from 2013 to 2015. The minimum inhibitory concentration (MIC) results showed that each blaIMP–4-positive isolate was multidrug-resistant (MDR) but susceptible to colistin. All of the E. coli belonged to ST167, two C. freundii isolates belonged to ST396, and diverse ST types were identified in E. cloacae and K. pneumoniae. S1-PFGE, Southern blotting, and PCR-based replicon typing assays showed that the blaIMP–4-carrying plasmids ranged from ∼52 to ∼360 kb and belonged to FII, FIB, HI2/HI2A, and N types. N plasmids were the predominant type (8/12, 66.7%). Plasmid stability testing indicated that the blaIMP–4-carrying N-type plasmid is more stable than the other types of plasmids. Conjugative assays revealed that three of the blaIMP–4-carrying N plasmids were transferrable. Complete sequence analysis of a representative N type (pIMP-ECL14–57) revealed that it was nearly identical to pIMP-FJ1503 (KU051710) (99% nucleotide identity and query coverage), an N-type blaIMP–4-carrying epidemic plasmid in a C. freundii strain. PCR mapping indicated that a transposon-like structure [IS6100-mobC-intron (K1.pn.I3)-blaIMP–4-IntI1-IS26] was highly conserved in all of the N plasmids. IS26 involved recombination events that resulted in variable structures of this transposon-like module in FII and FIB plasmids. The blaIMP–4 gene was captured by a sul1-type integron In1589 on HI2/HI2A plasmid pIMP-ECL-13–46.

scholarly journals Ceftazidime–avibactam and ceftolozane–tazobactam susceptibility of multidrug resistant Pseudomonas aeruginosa strains in Hungary

2020 ◽  
pp. 1-5 ◽  
Author(s):  
Dustin O'Neall ◽  
Emese Juhász ◽  
Ákos Tóth ◽  
Edit Urbán ◽  
Judit Szabó ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Inhibitory Concentration ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Test Results ◽  
Diffusion Test ◽  
Microdilution Method ◽  
Carbapenem Resistant ◽  
Gradient Diffusion ◽  
Broth Microdilution Method

Abstract Our objective was to compare the activity ceftazidime-avibactam (C/A) and ceftolozane–tazobactam (C/T) against multidrug (including carbapenem) resistant Pseudomonas aeruginosa clinical isolates collected from six diagnostic centers in Hungary and to reveal the genetic background of their carbapenem resistance. Two hundred and fifty consecutive, non-duplicate, carbapenem-resistant multidrug resistant (MDR) P. aeruginosa isolates were collected in 2017. Minimal inhibitory concentration values of ceftazidime, cefepime, piperacillin/tazobactam, C/A and C/T were determined by broth microdilution method and gradient diffusion test. Carbapenem inactivation method (CIM) test was performed on all isolates. Carbapenemase-encoding blaVIM, blaIMP, blaKPC, blaOXA-48-like and blaNDM genes were identified by multiplex PCR. Of the isolates tested, 33.6& and 32.4& showed resistance to C/A and C/T, respectively. According to the CIM test results, 26& of the isolates were classified as carbapenemase producers. The susceptibility of P. aeruginosa isolates to C/A and C/T without carbapenemase production was 89& and 91&, respectively. Of the CIM-positive isolates, 80& were positive for blaVIM and 11& for blaNDM. The prevalence of Verona integron-encoded metallo-beta-lactamase (VIM)-type carbapenemase was 20.8&. NDM was present in 2.8& of the isolates. Although the rate of carbapenemase-producing P. aeruginosa strains is high, a negative CIM result indicates that either C/A or C/T could be effective even if carbapenem resistance has been observed.

Microbiological efficiency of the combinations of two carbapenems against antibiotic resistant Klebsiella pneumoniae strains

2021 ◽  
Vol 66 (5) ◽  
pp. 304-309
Author(s):  
D. V. Tapalski ◽  
E. V. Timoshkova ◽  
T. A. Petrovskaya ◽  
O. V. Osipkina ◽  
I. A. Karpov
Keyword(s):  
Antibiotic Therapy ◽  
Synergistic Activity ◽  
Antibiotic Resistant ◽  
Microdilution Method ◽  
Carbapenem Resistant ◽  
Extensively Drug Resistant ◽  
Dosage Regimens ◽  
Broth Microdilution Method ◽  
Phosphoethanolamine Transferases

Combined antibiotic therapy is widely used for infections caused by carbapenem-resistant K. pneumoniae. The objective of this work was to identify the synergistic activity of combinations of two carbapenems against multidrug- and extensively drug-resistant K. pneumoniae strains producing various types of carbapenemases. For 60 antibiotic-resistant K. pneumoniae strains isolated in 8 cities of Belarus, the minimum inhibitory concentrations (MIC) of colistin and carbapenems were determined by subsequent broth microdilution method, and the genes of carbapenemases and phosphoethanolamine transferases were detected. The checkerboard method was used to determine the sensitivity to the combination of ertapenem and doripenem. High MIC values of carbapenems were revealed for NDM carbapenemase-producing strains (MIC50 of meropenem 64 mg/L, MIC50 of doripenem 64 mg/L). Doripenem was more active; MIC of doripenem ≤ 16 mg/L (low level of resistance) was determined in 28 (46.7%) strains, MIC of meropenem ≤ 16 mg/L - in 8 (13.3% of strains). The effect of potentiating the activity of doripenem with ertapenem at a fixed pharmacokinetic / pharmacodynamic concentration was observed for 20.0% of the strains producing KPC carbapenemase and 29.0% of the strains producing OXA-48 carbapenemase. The potentiating effect was independent of the presence of colistin resistance. Thus, the ability of ertapenem to potentiate the antimicrobial activity of doripenem and meropenem against some of the strains producing serine carbapenemases (KPC and OXA-48) was confirmed. The necessity of routine determination of the true MIC values of carbapenems was shown to optimize their dosage regimens and select the combination antibiotic therapy regimens.

scholarly journals Activity of Meropenem-Vaborbactam Against Enterobacteriaceae Isolates Carrying blaKPC Collected Worldwide

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S377-S377 ◽  
Author(s):  
Mariana Castanheira ◽  
Rodrigo E Mendes ◽  
Leonard R Duncan ◽  
Leah N Woosley ◽  
Robert K Flamm
Keyword(s):  
Antimicrobial Agents ◽  
Active Agent ◽  
E Coli ◽  
Microdilution Method ◽  
Carbapenem Resistant ◽  
Broth Microdilution Method ◽  
Wholly Owned Subsidiary ◽  
Us Fda ◽  
Carbapenem Resistant Enterobacteriaceae ◽  
Research Grant

Abstract Background Meropenem-vaborbactam (MER-VAB) is a carbapenem-β-lactamase inhibitor combination with enhanced activity against KPC-producing Enterobacteriaceae recently evaluated in a phase 3 clinical trials for cUTIs and infections due to CRE. We analyzed the activity of MER-VAB against 517 isolates carrying blaKPC collected worldwide during 2014–16. Methods Enterobacteriaceae isolates (n = 34,069) from 34 countries were susceptibility (S) tested by reference broth microdilution method for MER-VAB (at fixed 8 µg/mL) and comparators. Carbapenem-resistant Enterobacteriaceae (CRE; CLSI criteria) were submitted to PCR/Sanger sequencing or next-generation sequencing for blaKPC screening. Results A total of 517 (1.5%) carried blaKPC and 6 variants were observed: 293 blaKPC-3, 218 blaKPC-2, 2 blaKPC-4, 2 blaKPC-17, and 1 each of blaKPC-2-like and blaKPC-12. Isolates were mainly K. pneumoniae (437), but also 32 E. cloacae, 13 K. oxytoca, 12 E. coli, 12 S. marcescens, and 4 other species. Isolates carrying blaKPC were detected in 17 countries. The occurrence ranged from <0.1% to 11.3%, being higher in Brazil, Italy (9.3%), Poland (5.6%), and Argentina (5.2%). MER-VAB inhibited 514/517 (99.4%) isolates carrying blaKPC at ≤8 µg/mL and this compound was the most active agent tested against these isolates (MIC50/90, 0.12/1 µg/mL). Three isolates displaying elevated MER-VAB MIC values (>8 µg/mL) co-harbored blaNDM-1 or blaOXA-48-like in addition to blaKPC or had a missense mutation on OmpK35. MER alone (MIC50/90, 32/>32 µg/mL), imipenem (MIC50/90, >8/>8 µg/mL), and doripenem (MIC50/90, >4/>4 µg/mL) were not active against isolates harboring blaKPC. Amikacin (MIC50/90, 16/>32 µg/mL) and gentamicin (MIC50/90, 2/>8) µg/mL inhibited only 54.9% and 57.3% of the isolates (CLSI breakpoint). Colistin (MIC50/90, ≤0.5/>8 µg/mL; 70.4% S/EUCAST breakpoint) and tigecycline (MIC50/90, 0.5/1 µg/mL; 99.4% S/US FDA criteria) were the most active comparators. Conclusion The occurrence of blaKPC is still low overall, but can be as high as 5–10% in a few countries and occur in species other than Klebsiella. KPC-producers are highly resistant to available antimicrobial agents and MER-VAB will be a useful alternative to treat infections caused by these organisms. Disclosures M. Castanheira, Rempex, a wholly owned subsidiary of The Medicines Company: Research Contractor, Research grant; R. E. Mendes, Rempex, a wholly owned subsidiary of The Medicines Company: Research Contractor, Research grant; L. R. Duncan, Rempex, a wholly owned subsidiary of The Medicines Company: Research Contractor, Research grant; L. N. Woosley, Rempex, a wholly owned subsidiary of The Medicines Company: Research Contractor, Research grant; R. K. Flamm, Rempex, a wholly owned subsidiary of The Medicines Company: Research Contractor, Research grant

scholarly journals Susceptibility to antibiotic combinations of Klebsiella pneumoniae and Acinetobacter baumannii strains isolated from COVID-19 patients

2021 ◽  
Vol 18 (4) ◽  
pp. 33-40
Author(s):  
D. V. Tapalski ◽  
E. V. Karpova
Keyword(s):  
Klebsiella Pneumoniae ◽  
Bactericidal Activity ◽  
Antibacterial Effect ◽  
Bactericidal Effect ◽  
Bacteriostatic Activity ◽  
Broth Microdilution ◽  
Colistin Resistance ◽  
Microdilution Method ◽  
Carbapenem Resistant ◽  
Broth Microdilution Method

Objective. To assess the susceptibility of K.pneumoniae and A.baumanii strains isolated from hospitalized COVID-19 patients to antibiotics and their combinations.Materials and methods. The minimum inhibitory concentrations (MICs) of meropenem and colistin were determined for 47 A.baumannii and 51K.pneumoniaestrains isolated from the hospitalized COVID-19 patients by the broth microdilution method. The susceptibility to 11 antibiotic combinations was assessed using the method of multiple combination bactericidal testing.Results. Colistin resistance was detected in 31.9 % of A.baumannii strains (MIC50 — 0.5 mg/l, MIC90 — 16 mg/l) and in 80.4 % of K.pneumoniaestrains (MIC50 — 16 mg/l, MIC90 — 256 mg/l). It has been shown that double antibiotic combinations with the inclusion of colistin exhibit bactericidal or bacteriostatic activity against 76.6–87.2 % of A.baumannii strains. Combinations with the addition of meropenem, colistin and macrolides exhibited bactericidal activity against 78.4–80.4 % of K.pneumoniae strains. Combinations of two carbapenems were not active, the combination of meropenem-colistin had a bactericidal effect only in 13.7 % of K.pneumoniae strains.Conclusion. Widespread colistin resistance was found in carbapenem-resistant K.pneumoniae and A.baumannii strains isolated from the hospitalized COVID-19 patients. The combinations of antibiotics that have a synergistic antibacterial effect in their pharmacokinetic/pharmacodynamic concentrations have been determined.

scholarly journals Resistance phenotype and molecular epidemiology of Carbapenem-resistant Klebsiella pneumoniae isolates in Shanghai

2020 ◽  
Author(s):  
Jue Zhang ◽  
Wenxia Zhang ◽  
Hongyou Chen ◽  
Chen Chen ◽  
Junhao Chen ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Klebsiella Pneumoniae ◽  
Molecular Epidemiology ◽  
Genetic Relatedness ◽  
Control Strategies ◽  
Microdilution Method ◽  
Carbapenem Resistant ◽  
Broth Microdilution Method ◽  
Polymerase Chain ◽  
Relationship Of

Abstract Background: The emergence and wide global spread of carbapenem-resistant Klebsiella pneumoniae (CRKP) isolates are of great concern, and the aim of this study was to investigate drug resistance, molecular epidemiology, and genetic relationship of CRKP isolates from patients in Shanghai, China. Methods: A retrospective study was conducted from April 2018 to July 2019, and a total of 133 CRKP isolates were collected. Antimicrobial susceptibility was determined by VITEK-2 automated microbiology analyzer platform (bioMérieux, France) and the broth microdilution method. Polymerase chain reaction (PCR) assays were used to investigate the presence of drug resistance genes. A modified carbapenem inactivation method (mCIM) was performed to detect carbapenemases. Multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) were conducted for genetic relatedness of 50 CRKP isolates selected. Results: Among 670 isolates of K. pneumoniae, 133 (19.85%) strains were identified as carbapenem-resistant K. pneumoniae (CRKP), of which, 76.69% (102/133) strains were isolated from ICUs. All the 133 CRKP isolates were found to be carbapenemase-producers and harbor blaKPC-2 gene. No other carbapenemase genes of blaNDM, blaOXA−48, blaVIM, and blaIMP were detected. Furthermore, β-lactamase genes of blaSHV, blaCTX, and blaTEM were the most common resistance-associated genes among these KPC-2 producing isolates. All the 133 CRKP strains displayed more than 95% of resistance to cephalosporins and carbapenems, except for gentamicin, Trimethoprim-sulfamethoxazole, amikacin, tigecycline and colistin. The most common sequence type was ST11, accounting for 90.0% of the 50 CRKP selected, followed by ST15 (10%). PFGE analysis clustered the 50 KPC-2-producing isolates into seven (A-G) distinct clonal clusters at 85% cut off. Of which, cluster A and G were the two major clusters, accounting for the majority of the strains collected in emergency ICU and neurosurgical ICU. And all the strains of cluster D and E were collected in cardiothoracic surgery ICU, expect for one strain collected in one outpatient. Conclusion: The KPC-2-producing K.pneumoniae belonged to ST11 was widely disseminated in ICUs, and active and effective surveillance of infection control strategies was initiated to limit the spread of CRKP strains.

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