scholarly journals KPC-mediated resistance to ceftazidime-avibactam and collateral effects in Klebsiella pneumoniae

Author(s):  
Jacqueline Findlay ◽  
Laurent Poirel ◽  
Mario Juhas ◽  
Patrice Nordmann

Carbapenem-resistant Enterobacterales, such as KPC-producing Klebsiella pneumoniae , represent a major threat to public health due to their rapid spread. Novel drug combinations such as ceftazidime-avibactam (CZA), combining a broad-spectrum cephalosporin along with a broad-spectrum ß-lactamase inhibitor, have recently been introduced and have been shown to exhibit excellent activity towards multidrug-resistant KPC-producing Enterobacterale strains. However, CZA-resistant K. pneumoniae isolates are now being increasingly reported, mostly corresponding to producers of KPC variants. In this study, we evaluated in vitro the nature of the mutations in the KPC-2 and KPC-3 ß-lactamase sequences (the most frequent KPC-type enzymes) that lead to CZA resistance, and the subsequent effects of these mutations on susceptibility to other ß-lactam antibiotics. Single-step in vitro selection assays were conducted resulting in the identification of a series of mutations in the KPC sequence which conferred the ability to those mutated enzymes to confer resistance to CZA. Hence, 16 KPC-2 variants and 10 KPC-3 variants were obtained. Production of the KPC variants in an Escherichia coli recombinant strain resulted in a concomitant increased susceptibility to broad-spectrum cephalosporins and carbapenems, with the exceptions of ceftazidime and piperacillin-tazobactam, compared to wild-type KPC enzymes. Enzymatic assays showed that all of the KPC variants identified exhibited an increased affinity toward ceftazidime and a slightly decreased sensitivity to avibactam, sustaining their impact on CZA resistance. However their respective carbapenemase activities were concurrently negatively impacted.

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S721-S721
Author(s):  
Mark Estabrook ◽  
Krystyna Kazmierczak ◽  
Francis Arhin ◽  
Daniel F Sahm

Abstract Background Hypervirulent Klebsiella pneumoniae (hvKp), unlike classical K. pneumoniae (cKp), are often responsible for community-acquired infections in otherwise healthy individuals. The acquisition of hypervirulence genes by sequence type 11 (ST11) carbapenem-resistant (CR) Kp endemic in Asia is a grave threat. Aztreonam-avibactam (ATM-AVI) is a monobactam combined with a β-lactamase inhibitor for the treatment of infections caused by Enterobacterales isolates that carry Class A, B, C and some Class D β-lactamases. Methods 487 K. pneumoniae isolates were collected from 17 sites in China in 2019 as a part of the ATLAS global surveillance study. 220 isolates with MICs >1 µg/ml to meropenem (MEM), ceftazidime or ATM were selected for whole genome sequencing (Illumina Hiseq 2x150 bp reads). Analyses were carried out using the CLC Genomics Workbench (Qiagen). Presence of the aerobactin synthesis locus differentiated hvKp and cKp. Antimicrobial susceptibility was determined by CLSI broth microdilution. Results Of the 487 isolates, MIC90 values for ATM-AVI (0.5 µg/ml; Table) were lower than those for any comparator tested, with only two isolates testing with MIC >4 µg/ml. Of the isolates sequenced, 82/220 (37.3%) were ST11. 53/82 (64.6%) of these ST11 isolates were hvKp (ATM-AVI, MIC90 1 µg/ml; range, 0.25-4 µg/ml) and showed percentages of susceptibility < 90% to three last-line agents (0% MEM-susceptible (S); 18.9% amikacin (AMK)-S; 88.7% tigecycline (TGC)-S). Isolates of other STs (Non-ST11) were less frequently identified as hvKp (24/138, 17.4%) and more Non-ST-11 hvKp and cKp alike were S to MEM and AMK relative to isolates of ST11 (75.0-86.8% MEM-S; 83.3-96.5% AMK-S). Likewise, the ATM-AVI MIC90 value (0.25 µg/ml) was 4-fold lower for Non-ST11 isolates. Results Table Conclusion CR ST11 hvKp represented at least 10.9% of the collected Kp isolates. ATM-AVI retained potent in vitro activity against these isolates which displayed resistance to a range of last-line agents. CST and TGC also displayed some activity but are limited in utility due to nephrotoxicity and poor accumulation in blood, respectively. The spread of virulence factors leading to the complicated clinical presentation of hvKp infection into multidrug-resistant lineages warrants continued surveillance. Disclosures Mark Estabrook, PhD, IHMA (Employee)Pfizer, Inc. (Independent Contractor) Krystyna Kazmierczak, PhD, IHMA (Employee)Pfizer, Inc. (Independent Contractor) Francis Arhin, PhD, Pfizer, Inc. (Employee) Daniel F. Sahm, PhD, IHMA (Employee)Pfizer, Inc. (Independent Contractor)


Author(s):  
Ghena M Sobh ◽  
Abdul Karim El Karaaoui ◽  
Mira El Chaar ◽  
George F Araj

Ceftazidime-avibactam (CZA) has been introduced as a novel drug to essentially combat the rising trends of carbapenem resistant Enterobacteriaceae. In the absence of in vitro data about the activity of this drug against carbapenem resistant (CR) Escherichia coli and Klebsiella pneumoniae in Lebanon, this study was warranted.


2014 ◽  
Vol 59 (2) ◽  
pp. 1038-1047 ◽  
Author(s):  
Yi-Jiun Pan ◽  
Tzu-Lung Lin ◽  
Yi-Tsung Lin ◽  
Po-An Su ◽  
Chun-Tang Chen ◽  
...  

ABSTRACTKlebsiella pneumoniaeis an important human pathogen associated with a variety of diseases, and the prevalence of multidrug-resistantK. pneumoniae(MDRKP) is rapidly increasing. Here we determined the capsular types of 85 carbapenem-resistantK. pneumoniae(CRKP) strains bywzcsequencing and investigated the presence of carbapenemases and integrons among CRKP strains. Ten CRKP strains (12%) were positive for carbapenemase (imipenemase, 6/85 strains;K. pneumoniaecarbapenemase, 3/85 strains; Verona integron-encoded metallo-β-lactamase, 1/85 strains). Capsular type K64 accounted for 32 CRKP strains (38%), followed by K62 (13%), K24 (8%), KN2 (7%), and K28 (6%). Sequence types (STs) were determined by multilocus sequence typing (MLST), and the results indicated that ST11, which accounted for 47% of these CRKP strains (40/85 strains), was the major ST. We further isolated a K64-specific capsule depolymerase (K64dep), which could enhance serum and neutrophil killingin vitroand increase survival rates for K64K. pneumoniae-inoculated mice. The toxicity study demonstrated that mice treated with K64dep showed normal biochemical parameters and no significant histopathological changes of liver, kidney, and spleen, indicating that enzyme treatment did not cause toxicity in mice. Therefore, the findings of capsular type clustering among CRKP strains and effective treatment with capsule depolymerase for MDRKP infections are important for capsule-based vaccine development and therapy.


Antibiotics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 560
Author(s):  
Teresa Fasciana ◽  
Andrea Ciammaruconi ◽  
Bernardina Gentile ◽  
Paola Di Carlo ◽  
Roberta Virruso ◽  
...  

Rapid identification and characterization of multidrug-resistant Klebsiella pneumoniae strains is essential to diagnose severe infections in patients. In clinical routine practice, K. pneumoniae is frequently identified and characterized for outbreak investigation. Pulsed-field gel electrophoresis or multilocus sequence typing could be used, but, unfortunately, these methods are time-consuming, laborious, expensive, and do not provide any information about the presence of resistance and virulence genes. In recent years, the decreasing cost of next-generation sequencing and its easy use have led to it being considered a useful method, not only for outbreak surveillance but also for rapid identification and evaluation, in a single step, of virulence factors and resistance genes. Carbapenem-resistant strains of K. pneumoniae have become endemic in Italy, and in these strains the ability to form biofilms, communities of bacteria fixed in an extracellular matrix, can defend the pathogen from the host immune response as well as from antibiotics, improving its persistence in epithelial tissues and on medical device surfaces.


PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246003
Author(s):  
Gleyce Hellen de Almeida de Souza ◽  
Joyce Alencar dos Santos Radai ◽  
Marcia Soares Mattos Vaz ◽  
Kesia Esther da Silva ◽  
Thiago Leite Fraga ◽  
...  

Dissemination of carbapenem-resistant Klebsiella pneumoniae poses a threat to the successful treatment of bacterial diseases and increases the need for new antibacterial agents development. The objective of this study was to determine the antimicrobial activity of carvacrol against multidrug-resistant K. pneumoniae. Carbapenemase production was detected by MALDI-TOF. The PCR and sequencing showed that the blaKPC-2, blaOXA-48, blaNDM-1, blaCTX-M-8 genes were present in carbapenem-resistant K. pneumoniae strains. The polymyxin-resistant K. pneumoniae strain exhibited alterations in mgrB gene. The antimicrobial activity of carvacrol was evaluated in vitro using broth microdilution and time-kill methods. For this, carbapenem-resistant K. pneumoniae and polymyxin-resistant strains, were evaluated. The in vitro results showed that carvacrol had antimicrobial activity against all isolates evaluated. The survival curves showed that carvacrol eradicated all of the bacterial cells within 4 h. The antimicrobial effect of carvacrol in vivo was determined using a mouse model of infection with Klebsiella pneumoniae carbapenemase (KPC). The treatment with carvacrol was associated with increased survival, and significantly reduced bacterial load in peritoneal lavage. In addition, groups treated with carvacrol, had a significant reduction in the total numbers of white cell and significantly increased of platelets when compared to the untreated group. In vivo and in vitro studies showed that carvacrol regimens exhibited significant antimicrobial activity against KPC-producing K. pneumoniae, making it an interesting candidate for development of alternative treatments.


2019 ◽  
Vol 75 (3) ◽  
pp. 559-565 ◽  
Author(s):  
Siqiang Niu ◽  
Jie Wei ◽  
Chunhong Zou ◽  
Kalyan D Chavda ◽  
Jingnan Lv ◽  
...  

Abstract Objectives To examine the in vitro selection of aztreonam/avibactam resistance among MBL-producing Klebsiella pneumoniae and to understand the mechanism of increased resistance. Methods The MICs of aztreonam were determined with and without avibactam (4 mg/L) using a broth microdilution method. Single-step and multi-step mutant selection was conducted on five MBL-producing K. pneumoniae strains, including two dual carbapenemase producers. Genomic sequencing and gene cloning were performed to investigate the mechanism of increased resistance. Results We examined the MICs for 68 MBL-producing K. pneumoniae isolates, including 13 dual carbapenemase producers. Compared with aztreonam alone, the addition of avibactam (4 mg/L) reduced the MICs for all isolates by >128-fold, with MIC50 and MIC90 values of 0.25 and 1 mg/L, respectively. One NDM-1-, OXA-48-, CTX-M-15- and CMY-16-positive ST101 K. pneumoniae strain was selected to be resistant to aztreonam/avibactam, with a >16-fold increase in MIC (>128 mg/L). WGS revealed that the resistant mutants lost the blaNDM-1 gene, but acquired amino acid substitutions in CMY-16 (Tyr150Ser and Asn346His). Construction of blaCMY-16 mutants confirmed that the substitutions (Tyr150Ser and Asn346His) were primarily responsible for the decreased susceptibility to aztreonam/avibactam. In addition, transfer of blaCMY-16 mutant (Tyr150Ser and Asn346His) plasmid constructs into certain clinical carbapenemase-producing isolates demonstrated >64-fold increased MICs of aztreonam/avibactam and aztreonam/avibactam/ceftazidime. Conclusions Aztreonam in combination with avibactam showed potent in vitro activity against MBL-producing K. pneumoniae. However, our study suggested the likelihood of aztreonam/avibactam resistance among MBL- and AmpC-co-producing strains and clinical practice should beware of the possibility of the emerging resistance.


2010 ◽  
Vol 54 (6) ◽  
pp. 2732-2734 ◽  
Author(s):  
Carl Urban ◽  
Noriel Mariano ◽  
James J. Rahal

ABSTRACT In vitro double and triple bactericidal activities of doripenem, polymyxin B, and rifampin were assessed against 20 carbapenem-resistant clinical isolates with different mechanisms of carbapenem resistance. Bactericidal activity was achieved in 90% of all bacteria assayed using combinations of polymyxin B, doripenem, and rifampin against five each of the carbapenem-resistant Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Escherichia coli isolates studied. Combinations with these antibacterials may provide a strategy for treatment of patients infected with such organisms.


2021 ◽  
Author(s):  
Simone Eckstein ◽  
Jana Stender ◽  
Sonia Mzoughi ◽  
Kilian Vogele ◽  
Jana Kühn ◽  
...  

Abstract Background Multidrug-resistant Klebsiella pneumoniaespp (Kp) are emerging agents of severe infections of the respiratory and urinary tract or wounds, and progression to fatal septicemia. The use of bacteriophages is currently being considered as an effective alternative or adjuvant to antibiotic treatment. Results In this study, we report K-typing of 163 carbapenem-resistant Kp (CRKP) isolated 2014–2018 at the Military Hospital of Instruction of Tunis (MHT), Tunisia, using wzi gene sequencing. Thereby, we found that K64 Kp strains are associated with increased case/fatality rates, especially at the intensive care unit (ICU). Furthermore, we characterized a lytic Kp phage, vB_KpP_TUN1 (phage TUN1), isolated from waste water samples of the ICU at the MHT. Whole genome sequencing showed that this phage belongs to the Podoviridae family and encodes one putative depolymerase specifically digesting K64 Kp capsules. Furthermore, we could successfully assemble phage TUN1 in a non-replicative host (E. coli) raising the possibility of in vitro assembly in the absence of live bacterial hosts. Therefore, phage TUN1 is a promising candidate to be used as an adjuvant or an alternative to antibiotic therapy in CRKP infections, facilitating regulatory approval of phage therapy. Conclusions The lytic phage TUN1, efficiently lyses K64 Kp strains associated with increased case/fatality rates at body temperature. Together with its ability to be rescued in a non-replicative host these features enhance the utility of this phage as antibacterial agent.


Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1919
Author(s):  
Elsayim Rasha ◽  
AlOthman Monerah ◽  
Alkhulaifi Manal ◽  
Ali Rehab ◽  
Doud Mohammed ◽  
...  

Recently, concerns have been raised globally about antimicrobial resistance, the prevalence of which has increased significantly. Carbapenem-resistant Klebsiella pneumoniae (KPC) is considered one of the most common resistant bacteria, which has spread to ICUs in Saudi Arabia. This study was established to investigate the antibacterial activity of biosynthesized zinc oxide nanoparticles (ZnO-NPs) against KPC in vitro and in vivo. In this study, we used the aqueous extract of Acacia nilotica (L.) fruits to mediate the synthesis of ZnO-NPs. The nanoparticles produced were characterized by UV-vis spectroscopy, zetasizer and zeta potential analyses, X-ray diffraction (XRD) spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). The antimicrobial activity of ZnO-NPs against KPC was determined via the well diffusion method, and determining minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), the results showed low MIC and MBC when compared with the MIC and MBC of Imipenem and Meropenem antibiotics. The results of in vitro analysis were supported by the results upon applying ZnO-NP ointment to promote wound closure of rats, which showed better wound healing than the results with imipenem ointment. The biosynthesized ZnO-NPs showed good potential for use against bacteria due to their small size, applicability, and low toxicity to human cells.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S782-S782
Author(s):  
Sailaja Puttagunta ◽  
Maya Kahan-Haanum ◽  
Sharon Kredo-Russo ◽  
Eyal Weinstock ◽  
Efrat Khabra ◽  
...  

Abstract Background The prevalence of extended-spectrum beta-lactamase (ESBL) producing and carbapenem resistant (CR) Klebsiella pneumoniae (KP) has significantly risen in all geographic regions. Infections due to these bacteria are associated with high mortality across different infection types. Even with newer options, there remains an unmet need for safe and effective therapeutic options to treat infections caused by ESBL and CR KP. Phage therapy offers a novel approach with an unprecedented and orthogonal mechanism of action for treatment of diseases caused by pathogenic bacterial strains that are insufficiently addressed by available antibiotics. Phage-based therapies confer a high strain-level specificity and have a strong intrinsic safety profile. Here we describe the identification of novel phages that can effectively target antibiotic resistant KP strains. Host range of the 21 phages on 33 strain KP panel via solid culture infectivity assays. Red marks resistance to infection while sensitivity to phage is marked in green Methods KP clinical strains were isolated from human stool specimens preserved in glycerol. Selective culturing was carried, followed by testing of individual colonies for motility, indole and urease production, sequenced and analyzed by Kleborate tool to determine antibiotic resistant genes. Natural phages were isolated from plaques that developed on susceptible bacterial targets, sequenced and characterized. Results Antibiotic-resistant KP strains encoding beta lactamase genes or a carbapenemase (n=33) were isolated from healthy individuals (n=3), and patients with inflammatory bowel disease (n=26) or primary sclerosing cholangitis (n=3). Isolates sequencing revealed bla CTX-M15 and/or bla SHV encoding strains and carbapenamase KPC-2. A panel of 21 phages targeting the beta-lactamase- and carbapenemase-producing KP strains were identified. Phage sequencing revealed that all phages belong to the Caudovirales order and include 6 Siphoviridae, 14 Myoviridae, and 1 Podoviridae. In vitro lytic activity of the phages was tested on the isolated bacteria and revealed a coverage of 70% of the 33 isolated antibiotic resistant strains, >50% of which were targeted by multiple phages. Conclusion Collectively, these results demonstrate the feasibility of identifying phage with potent activity against antibiotic resistant KP strains, and may provide a novel therapeutic approach for treatment of ESBL and CR KP infections. Disclosures All Authors: No reported disclosures


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