scholarly journals Rapid Increase in Prevalence of Carbapenem-ResistantEnterobacteriaceae(CRE) and Emergence of Colistin Resistance Genemcr-1in CRE in a Hospital in Henan, China

2018 ◽  
Vol 56 (4) ◽  
Author(s):  
Yi Li ◽  
Qiao-ling Sun ◽  
Yingbo Shen ◽  
Yangjunna Zhang ◽  
Jun-wen Yang ◽  
...  

ABSTRACTThe global spread of carbapenem-resistantEnterobacteriaceae(CRE) is one of the most severe threats to human health in a clinical setting. The recent emergence of plasmid-mediated colistin resistance genemcr-1among CRE strains greatly compromises the use of colistin as a last resort for the treatment of infections caused by CRE. This study aimed to understand the current epidemiological trends and characteristics of CRE from a large hospital in Henan, the most populous province in China. From 2014 to 2016, a total of 7,249Enterobacteriaceaeisolates were collected from clinical samples, among which 18.1% (1,311/7,249) were carbapenem resistant. Carbapenem-resistantKlebsiella pneumoniaeand carbapenem-resistantEscherichia coliwere the two most common CRE species, withKlebsiella pneumoniaecarbapenemases (KPC) and New Delhi metallo-β-lactamases (NDM), respectively, responsible for the carbapenem resistance of the two species. Notably, >57.0% (n= 589) of theK. pneumoniaeisolates from the intensive care unit were carbapenem resistant. Furthermore,blaNDM-5andmcr-1were found to coexist in oneE. coliisolate, which exhibited resistance to almost all tested antibiotics. Overall, we observed a significant increase in the prevalence of CRE isolates during the study period and suggest that carbapenems may no longer be considered to be an effective treatment for infections caused byK. pneumoniaein the studied hospital.

2017 ◽  
Vol 61 (8) ◽  
Author(s):  
Astrid V. Cienfuegos-Gallet ◽  
Liang Chen ◽  
Barry N. Kreiswirth ◽  
J. Natalia Jiménez

ABSTRACT Here we describe the spread of colistin resistance in clinical isolates of carbapenem-resistant Klebsiella pneumoniae in Medellín, Colombia. Among 32 isolates collected between 2012 and 2014, 24 showed genetic alterations in mgrB. Nineteen isolates belonged to sequence type 512 (ST512) (or its single locus variant [SLV]) and harbored an 8.1-kb hsdMSR insertion corresponding to ISKpn25, indicating a clonal expansion of the resistant strain. The insertion region showed 100% identity to several plasmids, suggesting that the colistin resistance is mediated by chromosomal integration of plasmid DNA.


2020 ◽  
Vol 64 (12) ◽  
Author(s):  
Ana M. Rada ◽  
Elsa De La Cadena ◽  
Carlos Agudelo ◽  
Cesar Capataz ◽  
Nataly Orozco ◽  
...  

ABSTRACT Carbapenem-resistant Enterobacterales (CRE) pose a significant threat to global public health. The most important mechanism for carbapenem resistance is the production of carbapenemases. Klebsiella pneumoniae carbapenemase (KPC) represents one of the main carbapenemases worldwide. Complex mechanisms of blaKPC dissemination have been reported in Colombia, a country with a high endemicity of carbapenem resistance. Here, we characterized the dynamics of dissemination of blaKPC gene among CRE infecting and colonizing patients in three hospitals localized in a highly endemic area of Colombia (2013 and 2015). We identified the genomic characteristics of KPC-producing Enterobacterales recovered from patients infected/colonized and reconstructed the dynamics of dissemination of blaKPC-2 using both short and long read sequencing. We found that spread of blaKPC-2 among Enterobacterales in the participating hospitals was due to intra- and interspecies horizontal gene transfer (HGT) mediated by promiscuous plasmids associated with transposable elements that was originated from a multispecies outbreak of KPC-producing Enterobacterales in a neonatal intensive care unit. The plasmids were detected in isolates recovered in other units within the same hospital and nearby hospitals. The gene “epidemic” was driven by IncN-pST15-type plasmids carrying a novel Tn4401b structure and non-Tn4401 elements (NTEKPC) in Klebsiella spp., Escherichia coli, Enterobacter spp., and Citrobacter spp. Of note, mcr-9 was found to coexist with blaKPC-2 in species of the Enterobacter cloacae complex. Our findings suggest that the main mechanism for dissemination of blaKPC-2 is HGT mediated by highly transferable plasmids among species of Enterobacterales in infected/colonized patients, presenting a major challenge for public health interventions in developing countries such as Colombia.


2020 ◽  
Vol 58 (6) ◽  
Author(s):  
Christian M. Gill ◽  
Maxwell J. Lasko ◽  
Tomefa E. Asempa ◽  
David P. Nicolau

ABSTRACT The prevalence of carbapenem-resistant Pseudomonas aeruginosa is increasing. Identification of carbapenemase-producing P. aeruginosa will have therapeutic, epidemiological, and infection control implications. This study evaluated the performance of the EDTA-modified carbapenem inactivation method (eCIM) in tandem with the modified carbapenem inactivation method (mCIM) against a large collection of clinical P. aeruginosa isolates (n = 103) to provide clinicians a phenotypic test that not only identifies carbapenemase production but also distinguishes between metallo-β-lactamase and serine-carbapenemase production in P. aeruginosa. The mCIM test was performed according to Clinical and Laboratory Standards Institute guidelines, while the eCIM was conducted as previously described for Enterobacteriaceae. Test performance was compared to the genotypic profile as the reference. mCIM testing successfully categorized 91% (112/123) of P. aeruginosa isolates as carbapenemases or non-carbapenemase producers, with discordant isolates being primarily Guiana extended-spectrum (GES)-type producers. To increase the sensitivity of the mCIM for GES-harboring isolates, a double inoculum, prolonged incubation, or both was evaluated, with each modification improving sensitivity to 100% (12/12). Upon eCIM testing, all Verona integrin-encoded metallo-β-lactamases (VIM; n = 27) and New Delhi metallo-β-lactamases (NDM; n = 13) tested had 100% concordance to their genotypic profiles, whereas all Klebsiella pneumoniae carbapenemase (KPC; n = 8) and GES (n = 12) isolates tested negative, as expected, in the presence of EDTA. The eCIM failed to identify all imipenemase (IMP)-producing (n = 22) and Sao Paulo metallo-β-lactamase (SPM)-producing (n = 14) isolates. KPC-, VIM-, and NDM-producing P. aeruginosa were well defined by the conventional mCIM and eCIM testing methods; additional modifications appear required to differentiate GES-, IMP-, and SPM-producing isolates.


2020 ◽  
Vol 64 (6) ◽  
Author(s):  
Ching-Hsun Wang ◽  
L. Kristopher Siu ◽  
Feng-Yee Chang ◽  
Yu-Kuo Tsai ◽  
Yi-Tsung Lin ◽  
...  

ABSTRACT We report the first clinical Escherichia coli strain EC3000 with concomitant chromosomal colistin and carbapenem resistance. A novel in-frame deletion, Δ6-11 (RPISLR), in pmrB that contributes to colistin resistance was verified using recombinant DNA techniques. Although being less fit than the wild-type (WT) strain or EC3000 revertant (chromosomal replacement of WT pmrB in EC3000), a portion of serially passaged EC3000 strains preserving colistin resistance without selective pressure raises the concern for further spread.


2011 ◽  
Vol 55 (10) ◽  
pp. 4742-4747 ◽  
Author(s):  
Laura García-Sureda ◽  
Antonio Doménech-Sánchez ◽  
Mariette Barbier ◽  
Carlos Juan ◽  
Joan Gascó ◽  
...  

ABSTRACTClinical isolates ofKlebsiella pneumoniaeresistant to carbapenems are being isolated with increasing frequency. Loss of the expression of the major nonspecific porins OmpK35/36 is a frequent feature in these isolates. In this study, we looked for porins that could compensate for the loss of the major porins in carbapenem-resistant organisms. Comparison of the outer membrane proteins from twoK. pneumoniaeclinical isogenic isolates that are susceptible (KpCS-1) and resistant (KpCR-1) to carbapenems revealed the absence of OmpK35/36 and the presence of a new 26-kDa protein in the resistant isolate. An identical result was obtained when another pair of isogenic isolates that are homoresistant (Kpn-3) and heteroresistant (Kpn-17) to carbapenems were compared. Mass spectrometry and DNA sequencing analysis demonstrated that this new protein, designated OmpK26, is a small monomeric oligogalacturonate-specific porin that belongs to the KdgM family of porins. Insertion-duplication mutagenesis of the OmpK26 coding gene,yjhA, in the carbapenem-resistant, porin-deficient isolate KpCR-1 caused the expression of OmpK36 and the reversion to the carbapenem-susceptible phenotype, suggesting that OmpK26 is indispensable for KpCR-1 to lose OmpK36 and become resistant to these antibiotics. Moreover, loss of the major porin and expression of OmpK26 reducedin vitrofitness and attenuated virulence in a murine model of acute systemic infection. Altogether, these results indicate that expression of the oligogalacturonate-specific porin OmpK26 compensates for the absence of OmpK35/36 and allows carbapenem resistance inK. pneumoniaebut cannot restore the fitness of the microorganism.


2014 ◽  
Vol 59 (1) ◽  
pp. 553-557 ◽  
Author(s):  
Kyle D. Brizendine ◽  
Sandra S. Richter ◽  
Eric D. Cober ◽  
David van Duin

ABSTRACTCarbapenem-resistantKlebsiella pneumoniae(CRKP) is an emerging pathogen with a devastating impact on organ transplant recipients (OTRs). Data describing urinary tract infections (UTIs) due to CRKP, compared to extended-spectrum β-lactamase (ESBL)-producing and susceptibleK. pneumoniae, are lacking. We conducted a retrospective cohort study comparing OTRs with a first episode of UTI due to CRKP, ESBL-producingK. pneumoniae, or susceptibleK. pneumoniae. We identified 108 individuals; 22 (20%) had UTIs due to CRKP, 22 (20%) due to ESBL-producingK. pneumoniae, and 64 (60%) due to susceptibleK. pneumoniae. Compared to susceptibleK. pneumoniae(27%), patients with UTIs due to CRKP or ESBL-producingK. pneumoniaewere more likely to have a ≥24-hour stay in the intensive care unit (ICU) before or after development of the UTI (64% and 77%, respectively;P< 0.001). Among 105/108 hospitalized patients (97%), the median lengths of stay prior to UTI with CRKP or ESBL-producingK. pneumoniae(7 and 8 days, respectively) were significantly longer than that for susceptibleK. pneumoniae(1 day;P< 0.001). Clinical failure was observed for 8 patients (36%) with CRKP, 4 (18%) with ESBL-producingK. pneumoniae, and 9 (14%) with susceptibleK. pneumoniae(P= 0.073). Microbiological failure was seen for 10 patients (45%) with CRKP, compared with 2 (9%) with ESBL-producingK. pneumoniaeand 2 (3%) with susceptibleK. pneumoniae(P< 0.001). In multivariable logistic regression analyses, CRKP was associated with greater odds of microbiological failure (versus ESBL-producingK. pneumoniae: odds ratio [OR], 9.36, 95% confidence interval [CI], 1.94 to 72.1; versus susceptibleK. pneumoniae: OR, 31.4, 95% CI, 5.91 to 264). In conclusion, CRKP is associated with ICU admission, long length of stay, and microbiological failure among OTRs with UTIs. Greater numbers are needed to determine risk factors for infection and differences in meaningful endpoints associated with carbapenem resistance.


2016 ◽  
Vol 60 (6) ◽  
pp. 3709-3716 ◽  
Author(s):  
Yi-Hsiang Cheng ◽  
Tzu-Lung Lin ◽  
Yi-Tsung Lin ◽  
Jin-Town Wang

Colistin is a last-resort antibiotic for treatment of carbapenem-resistantKlebsiella pneumoniae. A recent study indicated that missense mutations in the CrrB protein contribute to colistin resistance. In our previous study, mechanisms of colistin resistance were defined in 17 of 26 colistin-resistantK. pneumoniaeclinical isolates. Of the remaining nine strains, eight were highly resistant to colistin. In the present study,crrABsequences were determined for these eight strains. Six separate amino acid substitutions in CrrB (Q10L, Y31H, W140R, N141I, P151S, and S195N) were detected. Site-directed mutagenesis was used to generatecrrBloci harboring individual missense mutations; introduction of the mutated genes into a susceptible strain, A4528, resulted in 64- to 1,024-fold increases in colistin MICs. ThesecrrBmutants showed increased accumulation ofH239_3062,H239_3059,pmrA,pmrC, andpmrHtranscripts by quantitative reverse transcription (qRT)-PCR. Deletion ofH239_3062(but not that ofH239_3059) in the A4528crrB(N141I) strain attenuated resistance to colistin, andH239_3062was accordingly namedcrrC. Similarly, accumulation ofpmrA,pmrC, andpmrHtranscripts induced bycrrB(N141I) was significantly attenuated upon deletion ofcrrC. Complementation ofcrrCrestored resistance to colistin and accumulation ofpmrA,pmrC, andpmrHtranscripts in acrrB(N141I) ΔcrrCstrain. In conclusion, novel individual CrrB amino acid substitutions (Y31H, W140R, N141I, P151S, and S195N) were shown to be responsible for colistin resistance. We hypothesize that CrrB mutations induce CrrC expression, thereby inducing elevated expression of thepmrHFIJKLMoperon andpmrC(an effect mediated via the PmrAB two-component system) and yielding increased colistin resistance.


2012 ◽  
Vol 6 (05) ◽  
pp. 457-461 ◽  
Author(s):  
Rima I El-Herte ◽  
George F Araj ◽  
Ghassan M Matar ◽  
Maysa Baroud ◽  
Zeina A Kanafani ◽  
...  

Carbapenem resistance has been encountered globally with poor outcome of infected patients. NDM-1 (New Delhi metallo-beta-lactamase) gene containing organisms have emerged and are now spreading in all continents. This is the first report of Iraqi patients referred to Lebanon from whom carbapenem resistant Enterobacteriaceae were recovered. The genes involved in carbapenem resistance were bla-OXA-48   and the novel NDM-1. This report highlights the alarming introduction of such resistance among Enterobacteriaecae to this country.


2020 ◽  
Author(s):  
Jun-Ying Zhu ◽  
Guang-Yu Wang ◽  
Qing Wei ◽  
Zhen Shen ◽  
Qiong Li ◽  
...  

Abstract Background: Although carbapenem-resistant Klebsiella pneumoniae (CRKP) and hypermucoviscous K. pneumoniae (HMKP) were largely non-overlapping, the recent emergence of CR-HMKP has raised great alarm in the world. We compared the molecular characteristics of CRKP, HMKP and CR-HMKP isolates.Results: 220 cases of K. pneumoniae isolates was collected and identified between Jan 2015 and Dec 2016 from Renji Hospital. Carbapenem resistance test and string test were performed to screen CRKP, HMKP and CR-HMKP isolates. All the CRKP, HMKP and CR-HMKP isolates were investigated for capsular genotyping, virulence genes and resistance genes by PCR and DNA sequencing. Multilocus sequence typing (MLST) was used to characterize isolates sequence types (STs). Serum killing assay and mouse lethality assay were respectively performed to confirm the virulence of the isolates in vitro and in vivo. Of 220 K. pneumoniae,71 HMKP, 84 CRKP and 8 CR-HMKP were identified. Resistance rate to carbapenems was significantly higher in CRKP than HMKP and CR-HMKP. For MLST and serotyping, ST23 (26.8%),K1 (33.8%) and K2 (23.9%) serotypes were the most common in HMKP isolates while ST11 (84.5%, 100%) and K-nontypable (91.6%, 100%) were the predominant types in CRKP and CR-HMKP isolates. The existence of virulence genes rmpA, magA and iutA was significantly higher in HMKP while the prevalence of resistance gene blaKPC-2 was higher in CRKP and CR-HMKP. Virulence test in vivo and in vitro both showed the lower virulence of CRKP and CR-HMKP compared to HMKP.Conclusions: In spite of low virulence, the emergence of CR-HMKP indicates a confluence of hypermucoviscous phenotype and carbapenem resistance. Furthermore, the similar molecular characteristics between CRKP and CR-HMKP suggested that CR-HMKP might evolve from CRKP.


2019 ◽  
Vol 63 (9) ◽  
Author(s):  
Ning Dong ◽  
Qiaoling Sun ◽  
Yonglu Huang ◽  
Lingbin Shu ◽  
Lianwei Ye ◽  
...  

ABSTRACT We report the identification of a carbapenem-resistant, hypervirulent Klebsiella pneumoniae (hvKp) strain which produced the carbapenemase VIM-1. Genomic analysis showed that the strain belonged to sequence type ST23 and serotype K1, a major hvKp clone, and harbored three resistance-encoding plasmids. Among them, a blaVIM-1-bearing plasmid was found to possess a mosaic structure presumably generated by multiple gene mobilization events. This finding indicates that hvKp actively acquires mobile resistance-encoding elements, facilitating simultaneous expression of hypervirulence and carbapenem-resistance.


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