scholarly journals 548. Carbapenem-Resistant Acinetobacter baumannii Antibiotic Susceptibility Testing and Antibiogram Formation, Connecticut 2017–2019

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S261-S261
Author(s):  
Anu Paranandi ◽  
Meghan Maloney ◽  
Erin Grogan ◽  
Bobbie Macierowski ◽  
Diane Noel ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Treatment Options ◽  
Carbapenem Resistance ◽  
Acinetobacter Baumanii ◽  
Antibiotic Development ◽  
Carbapenem Resistant ◽  
Testing Susceptibility ◽  
Polymerase Chain ◽  
Infectious Disease Threat

Abstract Background Carbapenem-resistant Acinetobacter baumanii (CRAB) is an infectious disease threat with limited treatment options. Statewide CRAB reporting and isolate submission has been mandated in Connecticut (CT) since 2017, which allowed the creation of a statewide CRAB antibiogram to assist with empiric treatment options for CRAB. Methods Clinical CRAB isolates from 2017 through the first quarter of 2019 underwent carbapenemase and expanded susceptibility testing at the CT State Public Health Laboratory or the Antibiotic Resistance Laboratory Network regional lab for carbapenemase and expanded susceptibility testing. Susceptibility testing was done by broth microdilution and disk diffusion, and interpreted using Clinical and Laboratory Standards Institute breakpoints. Carbapenemase producers were detected by the modified carbapenem inactivation method. Polymerase chain reaction testing identified carbapenemase genes. Results Of the 64 CRAB isolates submitted, 40 remained after confirmation of carbapenem resistance, i.e., resistance to at least one carbapenem, and deduplication of patients. Of these, 19 were carbapenemase producers (CP), and 21 were non-carpabenemase producers (Non-CP). All isolates were non-susceptible to cefepime, ceftazidime, levofloxacin and all carbapenems. Colistin susceptibilities were available for 33 isolates, 32 (97%) of which were susceptible. Tobramycin susceptibilities were available for 31 isolates, only 10 (32%) of which were susceptible. Of the CP, all 15 were susceptible to colistin, but only 2 (14%) were susceptible to tobramycin. Of the Non-CP, 16 (89%) were susceptible to colistin, and 8 (47%) were susceptible to tobramycin. Most CRABs had a tigecycline minimum inhibitory concentration (MIC) of ≤2 μg/mL, with a higher proportion of Non-CP with lower MIC values than CP. Conclusion CRAB shows resistance to all carbapenems, and most non-carbapenem antibiotics except colistin and in rare circumstances tobramycin. Most CRAB isolates had tigecycline MICs of ≤2 μg/mL. The statewide antibiogram illustrates the lack of approved antibiotics for the treatment of CRAB, underscoring the importance of further antibiotic development for CRAB treatment. Disclosures All authors: No reported disclosures.

scholarly journals Investigation of Carbapenemase Genes in Carbapenem Resistant Enterobacterales Isolates: First KPC Report From Dokuz Eylul University Hospital

2021 ◽  
Author(s):  
Şeyda Şilan Okalin ◽  
Ayşe Nur Sarı Kaygısız ◽  
Mahmut Cem Ergon ◽  
İbrahim Mehmet Ali Öktem
Keyword(s):  
Treatment Options ◽  
Carbapenem Resistance ◽  
Tracheal Aspirate ◽  
University Hospital ◽  
Chain Reaction ◽  
Specific Primers ◽  
E Coli ◽  
Carbapenem Resistant ◽  
Carbapenemase Gene ◽  
Polymerase Chain

Objective: In recent years, increasing carbapenem resistance of Enterobacterales bacteria limits treatment options, considerably. The main mechanism of this resistance is the production of carbapenemase enzymes. The aim of this study is to determine carbapenemase gene types in Enterobacterales isolates from our hospitalized patients and assess the clonal associations of the isolates with KPC gene. Method: A total of 48 clinical Enterobacterales isolates resistant to at least one carbapeneme and received between January 2019 and March 2019 were included in the study. Sample types were consisted of urine, blood, tracheal aspirate, wound and sputum. Of these isolates, three were Escherichia coli while 45 were Klebsiella pneumoniae. Types of carbapenemases were investigated by polymerase chain reaction, using specific primers for VIM, IMP, NDM, KPC and OXA-48 genes. PFGE was performed to determine the clonal associations between blaKPC positive K. pnemoniae isolates. Results: According to the results, blaOXA-48 (n=2) and blaKPC (n=1) were found to be present among E. coli isolates. Regarding 45 K. pneumoniae isolates; only blaOXA-48 and only blaNDM were present in 30 and two isolates, respectively. Seven K. pneumoniae isolates were found positive for both blaOXA-48 and blaNDM. Remaining K. pneumoniae isolates (n=6) harboured only blaKPC. None of the isolates were positive for blaIMP and blaVIM. PFGE analysis showed four isolates had the same pulsotype (A), while two had different pulsotypes (B-C). Conclusion: To our knowledge, this is the first report of KPC gene isolated in Dokuz Eylul University Hospital.

scholarly journals blaIMP and blaVIM mediated carbapenem resistance in Pseudomonas and Acinetobacter species in India

2012 ◽  
Vol 6 (11) ◽  
pp. 757-762 ◽  
Author(s):  
M Shanthi Amudhan ◽  
Uma Sekar ◽  
Arunagiri Kamalanathan ◽  
Sekar Balaraman
Keyword(s):  
Clinical Laboratory ◽  
Ethylenediaminetetraacetic Acid ◽  
Treatment Options ◽  
Carbapenem Resistance ◽  
Pseudomonas Stutzeri ◽  
Acinetobacter Species ◽  
Carbapenem Resistant ◽  
Rapid Spread ◽  
The Common ◽  
Polymerase Chain

Introduction: The emergence and rapid spread of blaIMP and blaVIM metallo-beta-lactamase (MBL) producing Gram-negative bacteria causing nosocomial infections are of concern worldwide due to limited treatment options. Methodology: A total of 179 nonreplicate, consecutive, carbapenem resistant Pseudomonas aeruginosa (61), Acinetobacter baumannii (116), Acinetobacter lwoffii (1) and Pseudomonas stutzeri (1) isolated from patients hospitalized for 48 hours or more were included in the study. The minimum inhibitory concentrations (MIC) to imipenem and meropenem were determined and interpreted according to Clinical Laboratory Standards Institute guidelines. The Modified Hodge Test (MHT) and inhibitor potentiated disk diffusion tests with ethylenediaminetetraacetic acid (EDTA) were used for screening of carbapenamases and MBL production respectively. Polymerase chain reaction (PCR) was performed for the detection of MBL (blaVIM and blaIMP) genes. Gene sequencing was performed for representative isolates. Results: MHT was positive in 94.4% (n = 169). MBL screening with EDTA was positive in 80.4% (n = 144). MBL genes bla VIM and bla IMP were detected in 92 (51.4%) isolates. Bla VIM alone was detected in 89 isolates while two isolates had bla IMP alone. One isolate had both bla VIM and bla IMP. Among the P. aeruginosa, 36 carried the MBL gene. In A. baumannii, 54 carried the MBL gene. Bla VIM was found in P. stutzeri and A. lwoffii isolates. Conclusion: Carbapenem resistance in P. aeruginosa and A. baumannii is chiefly mediated by MBL production. The common MBL gene is the blaVIM.

scholarly journals A comparative evaluation of two chromogenic media for surveillance of carbapenem-resistant Enterobacterales with non-carbapenemase-producing or carbapenemase-producing strains other than blaKPC: blaGES-5, blaNDM-1 or blaVIM-2

2019 ◽  
Vol 43 (3) ◽  
pp. 173-176
Author(s):  
Chang-Hun Park
Keyword(s):  
Rapid Detection ◽  
Comparative Evaluation ◽  
Susceptibility Testing ◽  
Rapid Identification ◽  
Surveillance Program ◽  
Contact Precaution ◽  
Chain Reaction ◽  
Carbapenem Resistant ◽  
Control And Prevention ◽  
Polymerase Chain

Abstract Background Infections caused by carbapenem-resistant Enterobacterales (CREs) are an emerging problem associated with high rates of morbidity and mortality. CREs are divided into two categories (carbapenemase-producing [CP] CRE and non-CP CRE). The most prevalent carbapenemase produced by Enterobacterales is Klebsiella pneumoniae carbapenemase (KPC) in Korea. Rapid identification of CREs is clinically important in infection control precaution. We compared the performance of two chromogenic media (chromID CARBA agar and CHROMagar KPC agar) for non-CP CREs or CP CREs with blaGES-5, blaNDM-1 or blaVIM-2 in a Korean hospital. Methods The study was carried out during a 3-month period from April to June 2017 during the surveillance program for CRE colonization. Antimicrobial susceptibility testing (AST) and polymerase chain reaction (PCR) were performed at the Korean Centers for Disease Control and Prevention. Results A total of 45 rectal swabs from 42 hospitalized patients were examined. Sensitivity of both chromID CARBA and CHROMagar KPC were 100% for CP CREs; and 50% and 100% for non-CP CREs, respectively. Specificity of chromID CARBA and CHROMagar KPC were 89.2% and 70.3% for CP CRE, respectively; and 76.9% and 66.7% for non-CP CRE, respectively. Conclusions The CHROMagar KPC is useful to monitor non-CP and CP CREs. The chromID CARBA is efficient for rapid detection of CP CREs requiring high contact precaution.

scholarly journals Prevalence and Carbapenem Resistance of Acinetobacter baumannii and Other Than A. baumannii Isolates From Intensive Care Units (ICUs) and non-ICUs

2020 ◽  
Vol 41 (S1) ◽  
pp. s356-s357
Author(s):  
Tomasz Kasperski ◽  
Biophage Pharma S.A. Kraków ◽  
Agnieszka Chmielarczyk ◽  
Monika Pomorska-Wesolowska ◽  
Dorota Romaniszyn ◽  
...  
Keyword(s):  
Intensive Care ◽  
Inhibitory Concentration ◽  
Carbapenem Resistance ◽  
Diagnostic Methods ◽  
Clinical Settings ◽  
Gram Negative Bacteria ◽  
Carbapenem Resistant ◽  
Therapeutic Problem ◽  
Hospital Associated Infections ◽  
Very High

Background:Acinetobacter spp are gram-negative bacteria that have emerged as a leading cause of hospital-associated infections, most often in the intensive care unit (ICU) setting. This is particularly important in Poland, where the prevalence of A. baumannii in various types of infections, including bloodstream infection (BSI), pneumonia, skin and soft-tissue infection (SSTI), and urinary tract infection (UTI) is higher than in neighboring countries. Recently, other Acinetobacter spp, including A. lwoffii or A. ursingii, have been found to be clinically relevant. In Poland, we have also observed a very rapid increase in antimicrobial resistance, significantly faster for A. baumannii than for other nosocomial pathogens. Methods: A study was conducted in 12 southern Polish hospitals, including 3 ICUs, from January 1 to December 31, 2018. Only adult hospitalized patients were included. Strains were identified using the MALDI-TOF method. Carbapenem resistance was determined using the minimum inhibitory concentration (MIC). Results: During the study, 194 strains belonging to the Acinetobacter genus were isolated. A. baumannii was the dominant species, 88.1% (n = 171), and 23 isolates (11.9%) were other Acinetobacter spp: A. ursingii (n = 5), A. lwofii (n = 4), A. haemolyticus (n = 4), A. junii (n = 3), A. radioresistens (n = 2), A. bereziniae (n = 2), and A. johnsonii (n = 2). Moreover, 15 Acinetobacter strains were collected from ICUs. The most Acinetobacter strains were isolated from SSTIs (n = 115) from non-ICU settings. Non–A. baumannii strains were also most frequently isolated from SSTIs; they constituted 11.3% of all Acinetobacter strains from this type of infection (n = 13). The total Acinetobacter prevalence was 2.6%, whereas the prevalence in the ICU setting was 7%. Acinetobacter prevalence in SSTIs was 10.4%. In pneumonia, Acinetobacter prevalence was 18.6% for ICUs (n = 13) and 2.7% for non-ICUs (n = 46). Strains from UTIs were isolated only with the non-ICU setting, and their prevalence was 0.7% (n = 14). More than half of the tested strains (52.1%) were resistant to carbapenems, but all non–A. baumannii strains were susceptible. The highest resistance to carbapenems was among strains from pneumonia cases in ICUs (58.3%) and resistance among all strains isolated from ICU was 50%. However, even higher resistance was noted among SSTI strains from non-ICUs (61.7%). Conclusions: Increasingly, more than A. baumannii, other species among Acinetobacter strains are isolated from patients hospitalized in Polish hospitals. To assess the significance of non–A. baumannii spp in clinical settings, precise species identification is needed. Therefore, the diagnostic methods used must be improved. Carbapenem-resistant A. baumannii infections are the biggest problem in pneumonia patients in ICUs and in SSTI patients in other hospital departments. Carbapenem resistance occurs in a very high percentage of A. baumannii strains; among non–A. baumannii strains it is not yet a therapeutic problem.Funding: NoneDisclosures: None

Molecular detection of blaOXA-23gene and blaOXA-51 gene in carbapenem resistant strains of Acinetobacterbaumannii in patients with ventilator associated pneumonia at tertiary care hospital

2021 ◽  
Vol 71 (11) ◽  
pp. 2576-2581
Author(s):  
Saima Ishtiaq ◽  
Sidrah Saleem ◽  
Abdul Waheed ◽  
Arslan Ahmed Alvi
Keyword(s):  
Acinetobacter Baumannii ◽  
Tertiary Care ◽  
Carbapenem Resistance ◽  
Conventional Polymerase Chain Reaction ◽  
Diffusion Method ◽  
Military Hospital ◽  
Care Hospital ◽  
Acinetobacter Baumanii ◽  
Cross Sectional ◽  
Carbapenem Resistant

Objective: To evaluate carbapenem resistance and to detect blaOXA-23 and blaOXA-51 genes in carbapenem-resistant acinetobacter baumanii isolates recovered from patients having pneumonia secondry to ventilation. Methods: The cross-sectional study was conducted from July 2017 to June 2018 at the Department of Microbiology, University of Health Sciences, Lahore, Pakistan, and comprised endotracheal aspirates / tracheobroncheal lavage samples from patients irrespective of age and gender who developed pneumonia after being on the ventilator for 48 hrs at the Combined Military Hospital, and Jinnah Hospital, Lahore.  The samples were inoculated on MacConkey and blood agar and aerobically incubated at a temperature of 370C for 18-24 hours. The isolated organisms were further assessed by standard morphological, cultural and biochemical profile. Antibiotic susceptibility was done by Kirby-Bauer disc diffusion method. Carbapenem-resistant acinetobacter baumannii were checked for carbapenemase production using Modified Hodge Test. Conventional polymerase chain reaction and agarose gel electrophoreses were performed to detect blaOXA-23 and blaOXA-51 genes. Data was analysed using SPSS 17. Results: Out of 157 samples, 92(58.6%) yielded growth of bacteria, and, among them, 39(42.4%) were identified as acinetobacter baumannii. All (100%) acinetobacter baumannii cases showed resistance to carbapenem, were producing carbapenemase enzyme, and were positive for blaOXA-51 gene. The blaOXA-23 gene was amplified in 38(97.4%) isolates. Conclusion: BlaOXA-23 gene appeared to be the major cause of carbapenem resistance. Continuous...

scholarly journals Molecular Characterization of Carbapenem-Resistant Acinetobacter baumannii Clinical Isolates from Egyptian Patients

2020 ◽  
Author(s):  
Reem M Hassan ◽  
Sherifa T Salem ◽  
Saly Ismail Mostafa Hassan ◽  
Asmaa Sayed Hegab ◽  
Yasmine S Elkholy
Keyword(s):  
Acinetobacter Baumannii ◽  
Molecular Characterization ◽  
Antimicrobial Agents ◽  
Treatment Options ◽  
Carbapenem Resistance ◽  
Clinical Isolates ◽  
Common Mechanism ◽  
Carbapenem Resistant ◽  
Egyptian Patients ◽  
Global Threat

AbstractAcinetobacter baumannii (A. baumannii) represents a global threat owing to its ability to resist most of the currently available antimicrobial agents. Moreover, emergence of carbapenem resistant A. baumannii (CR-AB) isolates limits the available treatment options. Enzymatic degradation by variety of ß-lactamases, have been identified as the most common mechanism of carbapenem resistance in A. baumannii. The alarming increase in the prevalence of CR-AB necessitates continuous screening and molecular characterization to appreciate the problem. The present study was performed to assess the prevalence and characterize carbapenemases among 206 CR-AB isolated from various clinical specimens collected from different intensive care units at Kasr Al-Aini Hospital.All isolates were confirmed to be A. baumannii by detection of the blaOXA-51-like gene. Molecular screening of 13 common Ambler class bla carbapenemases genes in addition to insertion sequence (IS-1) upstream OXA-23 was performed by using four sets of multiplex PCR, followed by identification using gene sequencing technology. Among the investigated genes, the prevalence of blaOXA-23, and blaOXA-58 were 77.7%, and 1.9%, respectively. The ISAba1 was detected in 10% of the blaOXA-23 positive isolates. The prevalence of metallo-β-lactamases (MBLs) studied; blaNDM-1, blaSPM, blaVIM, blaSIM-1 were 11.7%, 6.3%, 0.5%, and 0.5% respectively. One of class A; bla KPC was detected in 10.7% of the investigated isolates. blaOXA-24/40, blaIMP, blaGES, blaVEB and blaGIM were not detected in any of the studied isolates. Moreover, 18.4% of the isolates have shown to harbor two or more of the screened bla genes. We concluded that the most prevalent type of ß-lactamases genes among CR-AB isolates collected from Egyptian patients were blaOXA-23 followed by blaNDM-1 and blaKPC.Author summaryCarbapenem-resistant A. baumannii has become a real global health threat. The aim of the present study was to characterize and to assess the prevalence of carbapenemases among 206 CR-AB clinical isolates from Egyptian patients. We concluded that the most prevalent type of ß-lactamases genes among CR-AB isolates collected from Egyptian patients were blaOXA-23 followed by blaNDM-1 and blaKPC. In this study, ISAba1 was detected upstream 10% of blaOXA-23 positive isolates only which indicates that the spread of resistance among Acinetobacter isolates could be either chromosomal or plamid-mediated.

scholarly journals Prevalence of Carbapenem Resistant Enterobacteriaceae in a Tertiary Care Hospital of Gujarat, India

2021 ◽  
Author(s):  
Chirag Manojkumar Modi ◽  
Suman Praveen Singh ◽  
Yagnesh Gajanand Pandya ◽  
Chirag Premjibhai Patel ◽  
Rupal Minesh Patel
Keyword(s):  
Tertiary Care Hospital ◽  
Demographic Data ◽  
Treatment Options ◽  
Tertiary Care ◽  
Carbapenem Resistance ◽  
Defined Daily Dose ◽  
Sample Type ◽  
Care Hospital ◽  
Carbapenem Resistant ◽  
Carbapenem Resistant Enterobacteriaceae

Introduction: Carbapenem Resistant Enterobacteriaceae (CRE) are major cause of community as well as healthcare associated infections and have limited treatment options. Measuring the magnitude of the problem of CRE, it is important for making strategies to lower its spread. Aim: To assess the incidence and prevalence rate of CRE in a tertiary care hospital of Gujarat, India. Materials and Methods: Retrospective data was collected for a period from 2014 to 2018 using Laboratory Information System (LIS). Prevalence of CRE was determined as number of CRE isolated per 100 Enterobacteriaceae isolated during the study period whereas incidence rate was determined as number of CRE cases per 1000 patient-days. Consumption of Carbapenems was calculated as Defined Daily Dose (DDD) per 1000 patient-days. Demographic data including age, gender, location in the hospital and sample type from which CRE was isolated was also analysed using Microsoft Excel. Results: The incidence of CRE cases per 1000 patient-days in 2014 to 2018 was 1.66, 2.11, 1.90, 2.26 and 1.91, respectively with an overall incidence of 1.99 per 1000 patient-days. The overall prevalence of CRE over a period of five years was found to be 29.07%. Klebsiellasp. was the most common CRE and had the highest percentage of Carbapenem resistance among all Enterobacteriaceae. Conclusion: The rate of CRE in present study was high and worrisome. Screening of the patient for CRE, source isolation and stringent implementation of infection control practices is required to confine the spread of CRE in this institute.

scholarly journals Emerging resistance to carbapenem among Gram-negative bacteria in a tertiary care hospital

2020 ◽  
Vol 11 (SPL2) ◽  
pp. 153-156
Author(s):  
Pooja Nair ◽  
Renu Mathews ◽  
Kalyani M
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Tertiary Care Hospital ◽  
Tertiary Care ◽  
Carbapenem Resistance ◽  
Clinical Samples ◽  
Care Hospital ◽  
Gram Negative ◽  
Carbapenem Resistant ◽  
Diffusion Technique

The emergence of bacterial antibiotic resistance is a cardinal concern in the health care system. The spread of resistance in Enterobacteriaceae and non-fermenters to the currently available drugs make the treatment of serious nosocomial infections troublesome.  The purpose of the study is to find out the carbapenem resistance among Gram-negative bacilli in a tertiary care hospital. Antibiotic susceptibility pattern of 1913 aerobic Gram-negative bacilli isolated from clinical samples was made for a period of 6 months. All the isolates were tested for susceptibility to antibiotics by the Kirby-Bauer disc diffusion technique according to CLSI guidelines. Carbapenemase production was confirmed by the Modified Hodge Test (MHT). Minimum Inhibitory Concentration (MIC) by Epsilometer (E) test was performed (for Imipenem and Meropenem) for carbapenem-resistant strains. A total of 1731 clinical samples, 1913 Gram-negative bacilli were isolated. 1476 (77.1%) were Enterobacteriaceae and 433 (22.6%) were non-fermenters. 54 were carbapenemase-producing Gram-negative bacilli. Meropenem E test was done for carbapenemase-producing Gram-negative bacilli. The minimum inhibitory concentration for Meropenem ranged from 0.002μg/ml to 32μg/ml. To overcome the problem of emerging resistance, combined interaction and cooperation of microbiologists, clinicians and the infection control team is needed.

scholarly journals Molecular characterization of resistance mechanisms in Pseudomonas aeruginosa isolates resistant to carbapenems

2018 ◽  
Vol 11 (12) ◽  
pp. 935-943 ◽  
Author(s):  
Mona Shaaban ◽  
Ahmed Al-Qahtani ◽  
Mohammed Al-Ahdal ◽  
Rasha Barwa
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Real Time ◽  
Real Time Pcr ◽  
Treatment Options ◽  
Carbapenem Resistance ◽  
Pulse Field ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Pcr Analysis ◽  
Carbapenem Resistant

Introduction: Emergence of carbapenem resistance in Pseudomonas aeruginosa increases the therapeutic dilemma. In this study, we investigated various mechanisms involved in the resistance of P. aeruginosa clinical isolates to carbapenems. Methodology: P. aeruginosa isolates were isolated from different clinical samples. The antimicrobial susceptibility was evaluated by disc diffusion method. Carbapenemases were detected among carbapenem resistant isolates. Expression level of mexB and oprD was determined by real-time PCR. Molecular relatedness among isolates was detected based on pulse-field gel electrophoresis (PFGE). Results: Ninety P. aeruginosa isolates were purified from clinical specimens. High levels of resistance to imipenem and meropenem were detected in 16 isolates. PCR analysis of carbapenemases indicated the prevalence of Verona integron-encoded metallo-beta-lactamase (VIM); four isolates produced only VIM enzymes (VIM-1 or VIM-2), while the remaining twelve co-produced both VIM-1 or VIM-2 and NDM enzymes. Additionally, real-time PCR analysis elucidated high expression levels of mexB in seven of the carbapenem resistant isolates and low expression of oprD in seven isolates. The identified carbapenem-resistant isolates were clustered into eleven PFGE profiles where clusters E1 and E2 involved isolates exhibiting multiple carbapenemase genes (blaNDM-1, blaVIM-1 and blaVIM-2). Conclusion: Various mechanisms underlying carbapenem resistance have been detected in our P. aeruginosa cohort of isolates. Emergence of P. aeruginosa as a reservoir of multiple carbapenemases is increasing over time limiting the treatment options to this serious infection. This increases the urgency for infection control practices to reduce the incidence of this infection.

scholarly journals Characterization of IncHI1B Plasmids Encoding Efflux Pump TmexCD2-ToprJ2 in Carbapenem-Resistant Klebsiella variicola, Klebsiella quasipneumoniae, and Klebsiella michiganensis Strains

2021 ◽  
Vol 12 ◽  
Author(s):  
Yujiao Wang ◽  
Bo Zhu ◽  
Min Liu ◽  
Xiutao Dong ◽  
Jianping Ma ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Efflux Pump ◽  
Resistance Mechanism ◽  
Carbapenem Resistance ◽  
Health Concern ◽  
Close Monitoring ◽  
Carbapenem Resistant ◽  
Resistance Nodulation Division ◽  
Tertiary Hospitals ◽  
Severe Infections

Tigecycline serves as one of the last-resort antibiotics to treat severe infections caused by carbapenem-resistant Enterobacterales. Recently, a novel plasmid-mediated resistance-nodulation-division (RND)-type efflux pump gene cluster, TmexCD1-ToprJ1, and its variants, TmexCD2-ToprJ2 and TmexCD3-ToprJ3, encoding tetracyclines and tigecycline resistance, were revealed. In this study, we reported three TmexCD2-ToprJ2-harboring Klebsiella species strains, collected from two teaching tertiary hospitals in China, including one K. quasipneumoniae, one K. variicola, and one K. michiganensis. The three strains were characterized by antimicrobial susceptibility testing (AST), conjugation assay, WGS, and bioinformatics analysis. AST showed that K. variicola and K. quasipneumoniae strains were resistant to tigecycline with MIC values of 4μg/ml, whereas the K. michiganensis was susceptible to tigecycline with an MIC value of 1μg/ml. The TmexCD2-ToprJ2 clusters were located on three similar IncHI1B plasmids, of which two co-harbored the metallo-β-lactamase gene blaNDM-1. Conjugation experiments showed that all three plasmids were capable of self-transfer via conjugation. Our results showed, for the first time, that this novel plasmid-mediated tigecycline resistance mechanism TmexCD2-ToprJ2 has spread into different Klebsiella species, and clinical susceptibility testing may fail to detect. The co-occurrence of blaNDM-1 and TmexCD2-ToprJ2 in the same plasmid is of particular public health concern as the convergence of “mosaic” plasmids can confer both tigecycline and carbapenem resistance. Its further spread into other clinical high-risk Klebsiella clones will likely exacerbate the antimicrobial resistance crisis. A close monitoring of the dissemination of TmexCD-ToprJ encoding resistance should be considered.

Sign in / Sign up

Export Citation Format

Share Document