scholarly journals Characterization of an IncFIB/IncHI1B plasmid encoding efflux pump TMexCD1-TOprJ1 in a clinical tigecycline and carbapenem-resistant Klebsiella pneumoniae strain

2021 ◽  
Author(s):  
Xuemei Yang ◽  
Lianwei Ye ◽  
Edward Wai-Chi Chan ◽  
Rong Zhang ◽  
Sheng Chen
Keyword(s):  
Klebsiella Pneumoniae ◽  
Efflux Pump ◽  
Carbapenem Resistant ◽  
Resistance Nodulation Division ◽  
Multiple Drugs

A novel plasmid-encoded resistance-nodulation-division efflux pump, TMexCD1-TOprJ1, conferring resistance to multiple drugs including tigecycline has been identified in Klebsiella pneumoniae strains recently (1, 2).…

scholarly journals Emergence of a Plasmid-Encoded Resistance-Nodulation-Division Efflux Pump Conferring Resistance to Multiple Drugs, Including Tigecycline, in Klebsiella pneumoniae

mBio ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Luchao Lv ◽  
Miao Wan ◽  
Chengzhen Wang ◽  
Xun Gao ◽  
Qiwen Yang ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Gene Cluster ◽  
Efflux Pump ◽  
Gene Clusters ◽  
Site Specific ◽  
Content Type ◽  
E Coli ◽  
Carbapenem Resistant ◽  
Resistance Nodulation Division ◽  
Rnd Efflux Pump

ABSTRACT Transporters belonging to the chromosomally encoded resistance-nodulation-division (RND) superfamily mediate multidrug resistance in Gram-negative bacteria. However, the cotransfer of large gene clusters encoding RND-type pumps from the chromosome to a plasmid appears infrequent, and no plasmid-mediated RND efflux pump gene cluster has yet been found to confer resistance to tigecycline. Here, we identified a novel RND efflux pump gene cluster, designated tmexCD1-toprJ1, on plasmids from five pandrug-resistant Klebsiella pneumoniae isolates of animal origin. TMexCD1-TOprJ1 increased (by 4- to 32-fold) the MICs of tetracyclines (including tigecycline and eravacycline), quinolones, cephalosporins, and aminoglycosides for K. pneumoniae, Escherichia coli, and Salmonella. TMexCD1-TOprJ1 is closely related (64.5% to 77.8% amino acid identity) to the MexCD-OprJ efflux pump encoded on the chromosome of Pseudomonas aeruginosa. In an IncFIA plasmid, pHNAH8I, the tmexCD1-toprJ1 gene cluster lies adjacent to two genes encoding site-specific integrases, which may have been responsible for its acquisition. Expression of TMexCD1-TOprJ1 in E. coli resulted in increased tigecycline efflux and in K. pneumoniae negated the efficacy of tigecycline in an in vivo infection model. Expression of TMexCD1-TOprJ1 reduced the growth of E. coli and Salmonella but not K. pneumoniae. tmexCD1-toprJ1-positive Enterobacteriaceae isolates were rare in humans (0.08%) but more common in chicken fecal (14.3%) and retail meat (3.4%) samples. Plasmid-borne tmexCD1-toprJ1-like gene clusters were identified in sequences in GenBank from Enterobacteriaceae and Pseudomonas strains from multiple continents. The possibility of further global dissemination of the tmexCD1-toprJ1 gene cluster and its analogues in Enterobacteriaceae via plasmids may be an important consideration for public health planning. IMPORTANCE In an era of increasing concerns about antimicrobial resistance, tigecycline is likely to have a critically important role in the treatment of carbapenem-resistant Enterobacteriaceae, the most problematic pathogens in human clinical settings—especially carbapenem-resistant K. pneumoniae. Here, we identified a new plasmid-borne RND-type tigecycline resistance determinant, TMexCD1-TOprJ1, which is widespread among K. pneumoniae isolates from food animals. tmexCD1-toprJ1 appears to have originated from the chromosome of a Pseudomonas species and may have been transferred onto plasmids by adjacent site-specific integrases. Although tmexCD1-toprJ1 still appears to be rare in human clinical isolates, considering the transferability of the tmexCD1-toprJ1 gene cluster and the broad substrate spectrum of TMexCD1-TOprJ1, further dissemination of this mobile tigecycline resistance determinant is possible. Therefore, from a “One Health” perspective, measures are urgently needed to monitor and control its further spread. The current low prevalence in human clinical isolates provides a precious time window to design and implement measures to tackle this.

scholarly journals Characterization of Plasmid-Encoded Resistance-Nodulation-Division Efflux Pump in Klebsiella pneumoniae and Klebsiella quasipneumoniae from Patients in China

2020 ◽  
Author(s):  
Ruowen He ◽  
Yongqiang Yang ◽  
Yiping Wu ◽  
Lan-Lan Zhong ◽  
Yanxian Yang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Klebsiella Pneumoniae ◽  
Urinary Tract Infections ◽  
Efflux Pump ◽  
Multidrug Resistant ◽  
Efflux Pump Inhibitor ◽  
Resistance Nodulation Division ◽  
Tract Infections

Two multidrug-resistant (MDR) mcr-1 harboring Klebsiella pneumoniae isolates from patients with urinary tract infections, and one MDR Klebsiella quasipneumoniae isolate from a patient with bloodstream infection were identified to carry tmexCD1-toprJ1. The addition of the efflux pump inhibitor reduced the tigecycline MIC against all three isolates by 8- to 16-fold. The pKQBSI104-1 transferred from K. quasipneumoniae to Escherichia coli J53 via conjugation. The tmexCD1-toprJ1-carrying plasmids pKP15ZE495-1 (102,569 bp) and pKQBSI104-1 (121,996 bp) were completely sequenced and analyzed.

scholarly journals Molecular Epidemiology and Characterization of Carbapenem-Resistant Klebsiella pneumoniae Isolated from Urine at a Teaching Hospital in Taiwan

2021 ◽  
Vol 9 (2) ◽  
pp. 271
Author(s):  
Yuarn-Jang Lee ◽  
Chih-Hung Huang ◽  
Noor Andryan Ilsan ◽  
I-Hui Lee ◽  
Tzu-Wen Huang
Keyword(s):  
Klebsiella Pneumoniae ◽  
Teaching Hospital ◽  
Efflux Pump ◽  
Resistance Mechanisms ◽  
Pcr Analysis ◽  
Carbapenem Resistant ◽  
High Prevalence ◽  
Antimicrobial Susceptibility Tests ◽  
Susceptibility Tests ◽  
Tract Infections

Urinary tract infections (UTIs) are common in clinics and hospitals and are associated with a high economic burden. Enterobacterium Klebsiella pneumoniae is a prevalent agent causing UTIs. A high prevalence of carbapenem-resistant K. pneumoniae (CRKP) has emerged recently and is continuing to increase. Seventeen urinary CRKP isolates collected at a teaching hospital in Taiwan from December 2016 to September 2017 were analyzed to elucidate their drug resistance mechanisms. Two-thirds of the isolates were obtained from outpatients. Antimicrobial susceptibility tests demonstrated multidrug resistance in all the isolates. Multilocus sequence typing analysis showed high diversity among the isolates. PCR analysis demonstrated the presence of carbapenemases in three isolates. All isolates carried at least one other extended-spectrum β-lactamase, including TEM, DHA, and CTX-M. Fifteen isolates contained mutations in one of the outer membrane porins that were assessed. The expression levels of the acrB and/or oqxB efflux pump genes, as determined by qRT-PCR, were upregulated in 11 isolates. Six isolates might have utilized other efflux pumps or antimicrobial resistance mechanisms. These analyses demonstrated a highly diverse population and the presence of complex resistance mechanisms in urinary isolates of K. pneumoniae.

scholarly journals Characterization of resistance mechanisms of Enterobacter cloacae Complex co-resistant to carbapenem and colistin

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shixing Liu ◽  
Renchi Fang ◽  
Ying Zhang ◽  
Lijiang Chen ◽  
Na Huang ◽  
...  
Keyword(s):  
Lipid A ◽  
Efflux Pump ◽  
Resistance Mechanism ◽  
Carbapenem Resistance ◽  
Enterobacter Cloacae ◽  
Resistance Mechanisms ◽  
Colistin Resistance ◽  
Carbapenem Resistant ◽  
Horizontal Spread

Abstract Background The emergence of carbapenem-resistant and colistin-resistant ECC pose a huge challenge to infection control. The purpose of this study was to clarify the mechanism of the carbapenems and colistin co-resistance in Enterobacter cloacae Complex (ECC) strains. Results This study showed that the mechanisms of carbapenem resistance in this study are: 1. Generating carbapenemase (7 of 19); 2. The production of AmpC or ESBLs combined with decreased expression of out membrane protein (12 of 19). hsp60 sequence analysis suggested 10 of 19 the strains belong to colistin hetero-resistant clusters and the mechanism of colistin resistance is increasing expression of acrA in the efflux pump AcrAB-TolC alone (18 of 19) or accompanied by a decrease of affinity between colistin and outer membrane caused by the modification of lipid A (14 of 19). Moreover, an ECC strain co-harboring plasmid-mediated mcr-4.3 and blaNDM-1 has been found. Conclusions This study suggested that there is no overlap between the resistance mechanism of co-resistant ECC strains to carbapenem and colistin. However, the emergence of strain co-harboring plasmid-mediated resistance genes indicated that ECC is a potential carrier for the horizontal spread of carbapenems and colistin resistance.

scholarly journals Characterization of RarA, a Novel AraC Family Multidrug Resistance Regulator in Klebsiella pneumoniae

2012 ◽  
Vol 56 (8) ◽  
pp. 4450-4458 ◽  
Author(s):  
Mark Veleba ◽  
Paul G. Higgins ◽  
Gerardo Gonzalez ◽  
Harald Seifert ◽  
Thamarai Schneiders
Keyword(s):  
Multidrug Resistance ◽  
Klebsiella Pneumoniae ◽  
Efflux Pump ◽  
Content Type ◽  
Resistance Phenotype ◽  
Serratia Proteamaculans ◽  
Virulence Potential ◽  
Article Type ◽  
Acrab Efflux Pump

ABSTRACTTranscriptional regulators, such as SoxS, RamA, MarA, and Rob, which upregulate the AcrAB efflux pump, have been shown to be associated with multidrug resistance in clinically relevant Gram-negative bacteria. In addition to the multidrug resistance phenotype, these regulators have also been shown to play a role in the cellular metabolism and possibly the virulence potential of microbial cells. As such, the increased expression of these proteins is likely to cause pleiotropic phenotypes.Klebsiella pneumoniaeis a major nosocomial pathogen which can express the SoxS, MarA, Rob, and RamA proteins, and the accompanying paper shows that the increased transcription oframAis associated with tigecycline resistance (M. Veleba and T. Schneiders, Antimicrob. Agents Chemother. 56:4466–4467, 2012). Bioinformatic analyses of the availableKlebsiellagenome sequences show that an additional AraC-type regulator is encoded chromosomally. In this work, we characterize this novel AraC-type regulator, hereby called RarA (Regulator of antibiotic resistance A), which is encoded inK. pneumoniae,Enterobactersp. 638,Serratia proteamaculans568, andEnterobacter cloacae. We show that the overexpression ofrarAresults in a multidrug resistance phenotype which requires a functional AcrAB efflux pump but is independent of the other AraC regulators. Quantitative real-time PCR experiments show thatrarA(MGH 78578 KPN_02968) and its neighboring efflux pump operonoqxAB(KPN_02969_02970) are consistently upregulated in clinical isolates collected from various geographical locations (Chile, Turkey, and Germany). Our results suggest thatrarAoverexpression upregulates theoqxABefflux pump. Additionally, it appears thatoqxR, encoding a GntR-type regulator adjacent to theoqxABoperon, is able to downregulate the expression of theoqxABefflux pump, where OqxR complementation resulted in reductions to olaquindox MICs.

scholarly journals Tigecycline resistance among carbapenem-resistant Klebsiella Pneumoniae: Clinical characteristics and expression levels of efflux pump genes

PLoS ONE ◽  
2017 ◽  
Vol 12 (4) ◽  
pp. e0175140 ◽  
Author(s):  
Sheng-Kang Chiu ◽  
Ming-Chin Chan ◽  
Li-Yueh Huang ◽  
Yi-Tsung Lin ◽  
Jung-Chung Lin ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Clinical Characteristics ◽  
Efflux Pump ◽  
Expression Levels ◽  
Carbapenem Resistant

scholarly journals Phenotypic and Molecular Characteristics of the MDR Efflux Pump Gene-Carrying Stenotrophomonas maltophilia Strains Isolated in Warsaw, Poland

Biology ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 105
Author(s):  
Olga M. Zając ◽  
Stefan Tyski ◽  
Agnieszka E. Laudy
Keyword(s):  
Molecular Typing ◽  
Stenotrophomonas Maltophilia ◽  
Efflux Pump ◽  
Pulsed Field Gel Electrophoresis ◽  
Molecular Characteristics ◽  
The World ◽  
Genes Encoding ◽  
Resistance Nodulation Division ◽  
Sequence Types

An increase of nosocomial infections caused by Stenotrophomonas maltophilia strains has recently been observed all over the world. The isolation of these bacteria from the blood is of particular concern. In this study we performed the phenotypic and genotypic characterization of 94 S. maltophilia isolates, including isolates from patients hospitalized in a tertiary Warsaw hospital (n = 79) and from outpatients (n = 15). All isolates were found to be susceptible to trimethoprim-sulfamethoxazole and minocycline, while 44/94 isolates demonstrated a reduction in susceptibility to levofloxacin. A large genetic variation was observed among the isolates tested by pulsed-field gel electrophoresis. A clonal relationship with 100% similarity was observed between isolates within two sub-pulsotypes: the first included nine bloodstream isolates and the second involved six. Multilocus sequence typing showed two new sequence types (ST498 and ST499) deposited in public databases for molecular typing. Moreover, the presence of genes encoding ten different efflux pumps from the resistance-nodulation-division family and the ATP-binding cassette family was shown in the majority of the 94 isolates. The obtained knowledge about the prevalence of efflux pump genes in clinical S. maltophilia strains makes it possible to predict the scale of the risk of resistance emergence in strains as a result of gene overexpression.

scholarly journals Isolation and characterization of a sequence type 25 carbapenem-resistant hypervirulent Klebsiella pneumoniae from the mid-south region of China

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Jun Li ◽  
Zi-Yan Huang ◽  
Ting Yu ◽  
Xiao-Yan Tao ◽  
Yong-Mei Hu ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Capsular Polysaccharide ◽  
Control Strategies ◽  
Virulence Gene ◽  
Sequence Type ◽  
Pfge Typing ◽  
Main Cluster ◽  
Carbapenem Resistant ◽  
Isolation And Characterization

Abstract Background The molecular characterization of carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) isolates is not well studied. Our goal was to investigate the molecular epidemiology of CR-hvKP strains that were isolated from a Chinese hospital. Results All clinical carbapenem-resistant K. pneumoniae (CR-KP) isolates were collected and identified from patient samples between 2014 and 2017 from a Chinese hospital. The samples were subjected to screening for CR-hvKP by string test and the detection of the aerobactin gene. CR-hvKP isolates were further confirmed through neutrophil phagocytosis and a mice lethality assay. The CR-hvKP isolates were investigated for their capsular genotyping, virulence gene profiles, and the expression of carbapenemase genes by PCR and DNA sequencing. Multilocus sequence type (MLST) and pulsed-field gel electrophoresis (PFGE) were performed to exclude the homology of these isolates. Twenty strains were identified as CR-hvKP. These strains were resistant to imipenem and several other antibiotics, however, most were susceptible to amikacin. Notably, two isolates were not susceptible to tigecycline. Capsular polysaccharide synthesis genotyping revealed that 17 of the 20 CR-hvKP strains belonged to the K2 serotype, while the others belonged to serotypes other than K1, K2, K5, K20, and K57. The strains were found to be positive for 10 types of virulence genes and a variety of these genes coexisted in the same strain. Two carbapenemase genes were identified: blaKPC-2 (13/20) and blaNDM-1 (1/20). PFGE typing revealed eight clusters comprising isolates that belonged to MLST types ST25, ST11 and ST375, respectively. PFGE cluster A was identified as the main cluster, which included 11 isolates that belong to ST25 and mainly from ICU department. Conclusions Our findings suggest that hospital-acquired infections may contribute in part to the CR-hvKP strains identified in this study. It also suggests that ST25 CR-hvKP strain has a clonal distribution in our hospital. Therefore, effective surveillance and strict infection control strategies should be implemented to prevent outbreak by CR-hvKP strains in hospitals setting.

scholarly journals Molecular Characterization of Carbapenemase-Producing Escherichia coli and Klebsiella pneumoniae in the Countries of the Gulf Cooperation Council: Dominance of OXA-48 and NDM Producers

2014 ◽  
Vol 58 (6) ◽  
pp. 3085-3090 ◽  
Author(s):  
Hosam M. Zowawi ◽  
Anna L. Sartor ◽  
Hanan H. Balkhy ◽  
Timothy R. Walsh ◽  
Sameera M. Al Johani ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
United Arab Emirates ◽  
Gulf Cooperation Council ◽  
Mechanisms Of Resistance ◽  
Antibiotic Resistant ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Resistant Genes ◽  
Gcc Countries

ABSTRACTThe molecular epidemiology and mechanisms of resistance of carbapenem-resistantEnterobacteriaceae(CRE) were determined in hospitals in the countries of the Gulf Cooperation Council (GCC), namely, Saudi Arabia, United Arab Emirates, Oman, Qatar, Bahrain, and Kuwait. Isolates were subjected to PCR-based detection of antibiotic-resistant genes and repetitive sequence-based PCR (rep-PCR) assessments of clonality. Sixty-two isolates which screened positive for potential carbapenemase production were assessed, and 45 were found to produce carbapenemase. The most common carbapenemases were of the OXA-48 (35 isolates) and NDM (16 isolates) types; 6 isolates were found to coproduce the OXA-48 and NDM types. No KPC-type, VIM-type, or IMP-type producers were detected. Multiple clones were detected with seven clusters of clonally relatedKlebsiella pneumoniae. Awareness of CRE in GCC countries has important implications for controlling the spread of CRE in the Middle East and in hospitals accommodating patients transferred from the region.

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