Results of the Italian infection-Carbapenem Resistance Evaluation Surveillance Trial (iCREST-IT): activity of ceftazidime/avibactam against Enterobacterales isolated from urine

2020 ◽  
Vol 75 (4) ◽  
pp. 979-983 ◽  
Author(s):  
Tommaso Giani ◽  
Alberto Antonelli ◽  
Samanta Sennati ◽  
Vincenzo Di Pilato ◽  
Adriana Chiarelli ◽  
...  

Abstract Objectives To assess the in vitro antibacterial activity of ceftazidime/avibactam against a recent Italian collection of carbapenem-resistant Enterobacterales (CRE) isolated from urine specimens. Methods Consecutive Gram-negative isolates from urine specimens, collected from inpatients in five Italian hospitals during the period October 2016 to February 2017, were screened for CRE phenotype using chromogenic selective medium and identified using MALDI-TOF MS. Antimicrobial susceptibility testing was performed by reference broth microdilution (BMD) and, for ceftazidime/avibactam, also by Etest® CZA. Results were interpreted according to the EUCAST breakpoints. All confirmed CRE were subjected to real-time PCR targeting blaKPC-type, blaVIM-type, blaNDM-type and blaOXA-48-type carbapenemase genes. Non-MBL-producing isolates resistant to ceftazidime/avibactam were subjected to WGS and their resistome and clonality were analysed. Results Overall, 318 non-replicate presumptive CRE were collected following screening of 9405 isolates of Enterobacterales (3.4%) on chromogenic selective medium. Molecular analysis revealed that 216 isolates were positive for a carbapenemase gene (of which 92.1%, 2.8%, 1.4% and 1.4% were positive for blaKPC-type, blaOXA-48-type, blaNDM-type and blaVIM-type, respectively). Against the confirmed carbapenemase-producing Enterobacterales (CPE), ceftazidime/avibactam was the most active compound, followed by colistin (susceptibility rates 91.6% and 69.4%, respectively). Compared with BMD, Etest® for ceftazidime/avibactam yielded consistent results (100% category agreement). All class B β-lactamase producers were resistant to ceftazidime/avibactam, while OXA-48 and KPC producers were susceptible, with the exception of seven KPC-producing isolates (4.2%). The latter exhibited an MIC of 16 to >32 mg/L, belonged to ST512, produced KPC-3 and showed alterations in the OmpK35 and Ompk36 porins. Conclusions Ceftazidime/avibactam showed potent in vitro activity against a recent Italian collection of CPE from urine.

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S412-S413
Author(s):  
Michael R Jacobs ◽  
Caryn E Good ◽  
Ayman M Abdelhamed ◽  
Daniel D Rhoads ◽  
Kristine M Hujer ◽  
...  

Abstract Background Plazomicin is a next-generation aminoglycoside with in vitro activity against multidrug-resistant Gram-negative species, including carbapenem-resistant isolates. The Consortium on Resistance Against Carbapenems in Klebsiella and other Enterobacteriaceae (CRACKLE) is a federally funded, prospective multicenter consortium of 20 hospitals from nine US healthcare systems to track carbapenem-resistant Enterobacteriaceae. Methods Minimum inhibitory concentrations (MICs) of plazomicin were determined by broth microdilution according to current CLSI guidelines against a collection of 697 carbapenem-resistant Klebsiella pneumoniae with defined carbapenem resistance mechanisms, including KPC and OXA carbapenemases. Isolates were submitted by participating CRACKLE centers. Results Carbapenemases present in study isolates included KPC-2 (n = 323), KPC-3 (n = 364), KPC-4 (n = 2), OXA-48 like (n = 7), and NDM (n = 1). Plazomicin MICs ranged from ≤0.12 to >32 mg/L, with MIC50 and MIC90 values of 0.25 and 1 mg/L, respectively (figure). MICs of 689 (98.8%) isolates were ≤4 mg/L, while MICs of the remaining eight isolates were >32 mg/L. Plazomicin MICs were related to specific carbapenemases present in isolates: of eight isolates with MICs >32 mg/L, seven contained OXA-48 like and one contained KPC-3, suggesting that these isolates possess an aminoglycoside-resistance mechanism on the same plasmid as their carbapenemase gene, such as a 16S ribosomal RNA methyltransferase, against which plazomicin is not active. Conclusion Plazomicin has good in vitro potency against a collection of carbapenemase-producing K. pneumoniae, with MIC90 value of 1 mg/L and MICs of ≤4 mg/L for 98.9% of isolates. Disclosures M. R. Jacobs, Achaogen: Investigator, Research grant. Shionogi: Investigator, Research grant. L. Connolly, Achaogen, Inc.: Consultant, Consulting fee. K. M. Krause, Achaogen: Employee, Salary. S. S. Richter, bioMerieux: Grant Investigator, Research grant. BD Diagnostics: Grant Investigator, Research grant. Roche: Grant Investigator, Research grant. Hologic: Grant Investigator, Research grant. Diasorin: Grant Investigator, Research grant. Accelerate: Grant Investigator, Research grant. Biofire: Grant Investigator, Research grant. D. Van Duin, achaogen: Scientific Advisor, Consulting fee. shionogi: Scientific Advisor, Consulting fee. Allergan: Scientific Advisor, Consulting fee. Astellas: Scientific Advisor, Consulting fee. Neumedicine: Scientific Advisor, Consulting fee. Roche: Scientific Advisor, Consulting fee. T2 Biosystems: Scientific Advisor, Consulting fee.


2014 ◽  
Vol 63 (10) ◽  
pp. 1316-1323 ◽  
Author(s):  
Alima Gharout-Sait ◽  
Samer-Ahmed Alsharapy ◽  
Lucien Brasme ◽  
Abdelaziz Touati ◽  
Rachida Kermas ◽  
...  

Ten carbapenem-resistant Enterobacteriaceae (eight Klebsiella pneumoniae isolates and two Enterobacter cloacae) isolates from Yemen were investigated using in vitro antimicrobial susceptibility testing, phenotypic carbapenemase detection, multilocus sequence typing (MLST) and replicon typing. Carbapenemase, extended-spectrum β-lactamase (ESBL) and plasmid-mediated quinolone resistance determinant genes were identified using PCR and sequencing. All of the 10 carbapenem-resistant Enterobacteriaceae were resistant to β-lactams, tobramycin, ciprofloxacin and cotrimoxazole. Imipenem, doripenem and meropenem MICs ranged from 2 to >32 mg l−1 and ertapenem MICs ranged from 6 to >32 mg l−1. All of the K. pneumoniae isolates showed ESBL activity in phenotypic tests. Genes encoding bla NDM were detected in all strains. All K. pneumoniae strains produced CTX-M-15 ESBL and SHV β-lactamases. TEM-1 β-lactamase was detected in seven isolates. Nine isolates were qnr positive including QnrB1, QnrA1 and QnrS1, and six isolates produced AAC-6′-Ib-cr. MLST identified five different sequence types (STs): ST1399, ST147, ST29, ST405 and ST340. Replicon typing showed the presence of IncFII1K plasmids in four transformants. To the best of our knowledge, this is the first report of NDM-1-producing Enterobacteriaceae isolates in Yemen.


Author(s):  
Şeyda Şilan Okalin ◽  
Ayşe Nur Sarı Kaygısız ◽  
Mahmut Cem Ergon ◽  
İbrahim Mehmet Ali Öktem

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.


Author(s):  
Fred C. Tenover

Infections caused by multidrug-resistant Gram-negative organisms have become a global threat. Such infections can be very difficult to treat, especially when they are caused by carbapenemase-producing organisms (CPO). Since infections caused by CPO tend to have worse outcomes than non-CPO infections, it is important to identify the type of carbapenemase present in the isolate or at least the Ambler Class (i.e., A, B, or D), to optimize therapy. Many of the newer beta-lactam/beta-lactamase inhibitor combinations are not active against organisms carrying Class B metallo-enzymes, so differentiating organisms with Class A or D carbapenemases from those with Class B enzymes rapidly is critical. Using molecular tests to detect and differentiate carbapenem-resistance genes (CRG) in bacterial isolates provides fast and actionable results, but utilization of these tests globally appears to be low. Detecting CRG directly in positive blood culture bottles or in syndromic panels coupled with bacterial identification are helpful when results are positive, however, even negative results can provide guidance for anti-infective therapy for key organism-drug combinations when linked to local epidemiology. This perspective will focus on the reluctance of laboratories to use molecular tests as aids to developing therapeutic strategies for infections caused by carbapenem-resistant organisms and how to overcome that reluctance.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S314-S314
Author(s):  
Alita Miller ◽  
Sarah McLeod ◽  
Tarun Mathur ◽  
Ian Morrissey

Abstract Background The incidence of infections caused by multidrug-resistant Acinetobacter baumannii is increasing at an alarming rate in Southeast Asia and other parts of the world. Sulbactam (SUL) has intrinsic antibacterial activity against A. baumannii; however, the prevalence of β-lactamases in this species has limited its therapeutic use. Durlobactam (ETX2514, DUR) is a novel β-lactamase inhibitor with broad-spectrum activity against Ambler class A, C and D β-lactamases. DUR restores SUL in vitro activity against multidrug-resistant A. baumannii. Against >3,600 globally diverse, clinical isolates from 2012–2017, addition of 4 mg/L DUR reduced the SUL MIC90 from >32 to 2 mg/L. SUL-DUR is currently in Phase 3 clinical development for the treatment of infections caused by carbapenem-resistant Acinetobacter spp.The goal of this study was to determine the activity of SUL-DUR and comparator antibiotics (amikacin (AMK), ampicillin-sulbactam (AMP-SUL), cefoperazone-sulbactam (CFP-SUL) and meropenem (MEM)) against A. baumannii isolated from hospitalized patients in India. Methods A total of 121 clinical A. baumannii isolates from multiple hospital settings and infection sources were collected between 2016–2019 from six geographically diverse hospitals in India. Species identification was performed by MALDI-TOF. Susceptibility of these isolates to SUL-DUR (10µg/10µg) and comparator antibiotics was determined by disk diffusion using CLSI methodology and interpretive criteria, except for CFP-SUL, for which resistance was defined using breakpoints from the CFP-SUL package insert. Results As shown in Table 1, resistance of this collection of isolates to marketed agents was extremely high. In contrast, based on preliminary breakpoint criteria, only 11.5% of isolates were resistant to SUL-DUR. Conclusion The in vitro antibacterial activity of SUL-DUR was significantly more potent than comparator agents against multidrug-resistant A. baumannii isolates collected from diverse sites in India. These data support the continued development of SUL-DUR for the treatment of antibiotic-resistant infections caused by A. baumannii. Disclosures All authors: No reported disclosures.


2020 ◽  
Vol 75 (6) ◽  
pp. 1439-1442
Author(s):  
Ling-Han Kong ◽  
Rong Xiang ◽  
Yu-Long Wang ◽  
Shun-Kang Wu ◽  
Chang-Wei Lei ◽  
...  

Abstract Objectives To characterize the genetic environment of the carbapenem resistance determinant in Proteus vulgaris of swine origin. Methods The carbapenem-resistant P. vulgaris strain BC22 was isolated from a faecal swab from a diseased pig with diarrhoea in Sichuan Province of China in 2018. The presence of carbapenemase genes was screened by PCR. WGS and bioinformatics analysis were performed to analyse the genetic environment of the carbapenem resistance determinant. Results P. vulgaris strain BC22 was found to harbour the carbapenemase gene blaNDM-1. WGS data revealed that blaNDM-1 was located in a truncated ISAba125 composite transposon. The carbapenem resistance gene blaNDM-1 and 20 other resistance genes, including the multiresistance gene cfr and the bifunctional aminoglycoside/quinolone resistance gene aac(6′)-lb-cr, were located in a novel SXT/R391 integrative and conjugative element (ICE). This new SXT/R391 ICE of 148.7 kb was chromosomally located, and could be transferred to Escherichia coli. Conclusions Here, we report a carbapenemase gene, blaNDM-1, integrated into an SXT/R391 ICE. Our study highlights that this SXT/R391 ICE may facilitate the dissemination of clinically important resistance genes such as blaNDM-1, cfr and aac(6′)-lb-cr.


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.


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