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Ghady Haidar, Cornelius J Clancy, Liang Chen, Palash Samanta, Ryan K Shields, Barry N Kreiswirth, M Hong Nguyen
We determined imipenem, imipenem-relebactam, ceftazidime and ceftazidime-avibactam minimum inhibitory concentrations (MICs) against 100 CRE isolates that underwent whole genome sequencing. KPCs were the most common carbapenemases. Forty-six isolates carried ESBLs. With the addition of relebactam, imipenem susceptibility increased from 8% to 88%. With the addition of avibactam, ceftazidime susceptibility increased from 0% to 85%. Neither imipenem-relebactam nor ceftazidime-avibactam was active against MBL-producers...
June 19, 2017: Antimicrobial Agents and Chemotherapy
Nyla Manning, Gregory Balabanian, Michael Rose, David Landman, John Quale
In this report, we examined the (1) activity of ceftazidime-avibactam against clinical isolates Klebsiella pneumoniae, including those harboring blaKPC, (2) potential mechanisms leading to reduced susceptibility, and (3) activity of ceftazidime-avibactam when combined with other agents. Of 802 carbapenem-resistant isolates of K. pneumoniae gathered from New York City from 1999 to 2014, all were susceptible to ceftazidime-avibactam. Minimum inhibitory concentrations (MICs) were higher in isolates with K. pneumoniae, with the carbapenemase (KPC)-3 (compared to KPC-2), and those with a frameshift mutation in ompK35...
June 7, 2017: Microbial Drug Resistance: MDR: Mechanisms, Epidemiology, and Disease
Anastasia I Lev, Evgeny I Astashkin, Rima Z Shaikhutdinova, Mikhail E Platonov, Nikolay N Kartsev, Nikolay V Volozhantsev, Olga N Ershova, Edward A Svetoch, Nadezhda K Fursova
Hospital Klebsiella pneumoniae strains (n = 196) were collected in 2012-16 from the patients of a Moscow neurosurgical intensive care unit. Klebsiella pneumoniae strains were multidrug-resistant and carried beta-lactamase genes blaSHV (97.4% of strains), blaCTX-M (84.7%), blaTEM (56.1%), blaOXA-48-like (49.0%) and blaNDM-1 (one strain), class 1 integrons (43.4% of strains) and porin protein ompK36 gene (100% of strains). The ompK36 porin protein gene disruption by insertion sequence (IS) elements and OmpK36 production loss in two strains were detected in this study...
May 1, 2017: FEMS Microbiology Letters
Zhen Shen, Baixing Ding, Meiping Ye, Peng Wang, Yingmin Bi, Shi Wu, Xiaogang Xu, Qinglan Guo, Minggui Wang
Objectives: To investigate mechanisms for the decreased susceptibility to ceftazidime/avibactam in KPC-producing Klebsiella pneumoniae (KPC-KP). Methods: A total of 24 isolates, 8 each with ceftazidime/avibactam MICs of 4-8, 1-2 and ≤0.5 mg/L, were randomly selected from 214 clinical isolates of KPC-KP, and the β-lactamase hydrolysis activity and porin expression profiles were determined. Plasmid profile and relative expression and copy number of the bla KPC gene were also analysed...
March 15, 2017: Journal of Antimicrobial Chemotherapy
Ryan K Shields, M Hong Nguyen, Ellen G Press, Liang Chen, Barry N Kreiswirth, Cornelius J Clancy
Ceftazidime-avibactam resistance is mediated by blaKPC-3 mutations, which restore carbapenem susceptibility. We subjected Klebsiella pneumoniae isolates with different blaKPC-3 mutations (n = 5) or wild-type blaKPC-3 (n = 2) to serial passages with meropenem. The meropenem MIC against each isolate increased. Mutations in the ompK36 porin gene evolved in 5 isolates. Among isolates with D179Y substitutions in KPC-3, blaKPC-3 mutations reverted to wild type, were replaced by new mutations, or were retained. Carbapenem treatment of ceftazidime-avibactam-resistant K...
May 2017: Antimicrobial Agents and Chemotherapy
Mariana Castanheira, Rodrigo E Mendes, Helio S Sader
Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae isolates have been increasingly reported worldwide, and therapeutic options to treat infections caused by these organisms are limited. We evaluated the activity of ceftazidime-avibactam and comparators against 456 Enterobacteriaceae isolates carrying blaKPC collected from 79 U.S. hospitals during 2012 to 2015. Overall, ceftazidime-avibactam (MIC50/90, 0.5/2 μg/ml; 99.3% susceptible) and tigecycline (MIC50/90, 0.5/1 μg/ml; 98.9% susceptible at ≤2 μg/ml) were the most active agents...
March 2017: Antimicrobial Agents and Chemotherapy
D Vubil, R Figueiredo, T Reis, C Canha, L Boaventura, G J DA Silva
To date, only a few sporadic cases of infections due to Klebsiella pneumoniae carbapenemase (KPC) producers have been reported in Portugal. Here, we report for the first time an outbreak of K. pneumoniae KPC-3 producers in a tertiary-care hospital during 2013. Twenty-seven ertapenem-resistant K. pneumoniae were identified in patients at a tertiary-care hospital during 2013 isolated predominantly from urine (48·1%) and blood (25·9%) cultures. All isolates were highly resistant to β-lactam antibiotics and most showed intermediate resistance to imipenem...
February 2017: Epidemiology and Infection
Etsuko Sugawara, Seiji Kojima, Hiroshi Nikaido
Klebsiella pneumoniae, one of the most important nosocomial pathogens, is becoming a major problem in health care because of its resistance to multiple antibiotics, including cephalosporins of the latest generation and, more recently, even carbapenems. This is largely due to the spread of plasmid-encoded extended-spectrum β-lactamases. However, antimicrobial agents must first penetrate the outer membrane barrier in order to reach their targets, and hydrophilic and charged β-lactams presumably diffuse through the porin channels...
December 1, 2016: Journal of Bacteriology
Jia Du, Jianming Cao, Lizhen Shen, Wenzi Bi, Xiaoxiao Zhang, Haiyang Liu, Hong Lu, Tieli Zhou
The emergence of extensively drug-resistant (XDR) Klebsiella pneumoniae has become a major challenge worldwide. In this study, we characterized the phenotypes and genetic features of nine XDR K. pneumoniae isolates from an integrated hospital in Zhejiang province, China, from September to October 2014. These XDR K. pneumoniae possessed at least five resistance determinants which contribute to highly resistant to β-lactam, β-lactam/inhibitor combinations, aminoglycosides, quinolones, carbapenems, chloroamphenicol and fosfomycin...
October 2016: Journal of Medical Microbiology
Willames M B S Martins, Adriana G Nicoletti, Silvia R Santos, Jorge L M Sampaio, Ana C Gales
BKC-1 is a new class A serine carbapenemase that was recently identified in Klebsiella pneumoniae clinical isolates. The principal objective of this study was to evaluate the frequency of blaBKC-1 by testing a collection of Klebsiella isolates. Only 2 of 635 Klebsiella isolates (0.3%) carried blaBKC-1 The two BKC-1-producing isolates belonged to clonal complex 442 and possessed identical pulsed-field gel electrophoresis patterns. The blaBKC-1 gene was inserted into a 10-kb plasmid that was identical to the previously reported plasmid, p60136...
August 2016: Antimicrobial Agents and Chemotherapy
Theodoros Karampatakis, Charalampos Antachopoulos, Elias Iosifidis, Athanassios Tsakris, Emmanuel Roilides
Hospital infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) constitute a worldwide problem associated with high rates of treatment failure and mortality. In Greece, CRKP have emerged in 2002 due to VIM carbapenemase production and later due to KPC, NDM and OXA-48-like carbapenemases that have become endemic. The molecular epidemiology of CRKP strains is dynamic, as antibiotic consumption and worldwide traveling are strongly associated with global spread of CRKP isolates. Lately, porin defects, such as disruption of OmpK35 and production of OmpK36 variant, have also contributed to carbapenem resistance...
June 2016: Future Microbiology
Kamonwan Lunha, Aroonwadee Chanawong, Aroonlug Lulitanond, Chotechana Wilailuckana, Nicha Charoensri, Lumyai Wonglakorn, Pimjai Saenjamla, Prajuab Chaimanee, Sunpetch Angkititrakul, Ploenchan Chetchotisakd
Five blaOXA-48-like-carrying Enterobacteriaceae isolates collected from two Thai patients in December 2012 were characterized. Three Klebsiella pneumoniae isolates giving two different pulsed-field gel electrophoresis patterns and sequence types (ST11 and ST37) from patient 1 harbored blaOXA-48 locating on Tn1999.2, whereas two Escherichia coli isolates with the same pulsotype and ST5 from Patient 2 carried ISEcp1-associated blaOXA-181. One K. pneumoniae strain had blaSHV-12, blaDHA-1, qnrB, and qnrS, while another strain harbored blaCTX-M-15, qnrS and aac(6')-Ib-cr...
June 2016: Diagnostic Microbiology and Infectious Disease
Kesia Esther da Silva, Wirlaine Glauce Maciel, Flávia Patussi Correia Sacchi, Cecilia Godoy Carvalhaes, Fernanda Rodrigues-Costa, Ana Carolina Ramos da Silva, Mariana Garcia Croda, Fábio Juliano Negrão, Julio Croda, Ana Cristina Gales, Simone Simionatto
This study describes the molecular characteristics and risk factors associated with carbapenem-resistant Klebsiella pneumoniae strains. Risk factors associated with KPC-producing K. pneumoniae strains were investigated in this case-control study from May 2011 to May 2013. Bacterial identification was performed by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). Antimicrobial susceptibility was determined by broth microdilution. Carbapenemase production was assessed by both modified Hodge test (MHT) and ertapenem hydrolysis using MALDI-TOF MS...
June 2016: Journal of Medical Microbiology
Alex Agyekum, Alicia Fajardo-Lubián, Xiaoman Ai, Andrew N Ginn, Zhiyong Zong, Xuejun Guo, John Turnidge, Sally R Partridge, Jonathan R Iredell
The minimal concentration of antibiotic required to inhibit the growth of different isolates of a given species with no acquired resistance mechanisms has a normal distribution. We have previously shown that the presence or absence of transmissible antibiotic resistance genes has excellent predictive power for phenotype. In this study, we analyzed the distribution of six β-lactam antibiotic susceptibility phenotypes associated with commonly acquired resistance genes in Enterobacteriaceae in Sydney, Australia...
May 2016: Journal of Clinical Microbiology
Zumaana Rafiq, Nithin Sam, Rama Vaidyanathan
Klebsiella pneumoniae U25 is a multidrug resistant strain isolated from a tertiary care hospital in Chennai, India. Here, we report the complete annotated genome sequence of strain U25 obtained using PacBio RSII. This is the first report of the whole genome of K. pneumoniaespecies from Chennai. It consists of a single circular chromosome of size 5,491,870-bp and two plasmids of size 211,813 and 172,619-bp. The genes associated with multidrug resistance were identified. The chromosome of U25 was found to have eight antibiotic resistant genes [blaOXA-1,blaSHV-28, aac(6')1b-cr,catB3, oqxAB, dfrA1]...
February 2016: Memórias do Instituto Oswaldo Cruz
Thidarat Netikul, Pattarachai Kiratisin
Carbapenem-resistant Enterobacteriaceae (CRE) has increasingly spread worldwide in the past decade. The prevalence and characteristics of CRE in Thailand are unknown. In this study, we conducted a 2-year surveillance of CRE among 12,741 clinical isolates of Enterobacteriaceae at the largest university hospital in Thailand with molecular characterization of beta-lactamase (bla) genes, including carbapenemase genes. The CRE prevalence was 1.4%. blaKPC-13 and blaIMP-14a were the only carbapenemase genes detected among these CRE isolates...
2015: PloS One
Yan-Yan Hu, Jia-Chang Cai, Hong-Wei Zhou, Rong Zhang, Gong-Xiang Chen
The rapid and cost-efficient determination of carbapenem resistance is an important prerequisite for the choice of an adequate antibiotic therapy. A MALDI-TOF MS-based assay was set up to detect porins in the current study. A loss of the components of porin alone such as OmpK35/OmpK36 or together with the production of carbapenemases will augment the carbapenem resistance. Ten strains of Escherichia coli and eight strains of Klebsiella pneumoniae were conducted for both sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and MALDI-TOF MS analysis...
2015: Frontiers in Microbiology
Jing-Jou Yan, Po-Xing Zheng, Ming-Cheng Wang, Shu-Huei Tsai, Li-Rong Wang, Jiunn-Jong Wu
The OmpK36 porin plays a role in carbapenem resistance and may contribute to bacterial virulence in Klebsiella pneumoniae. This study aimed to investigate the characteristics of different groups of K. pneumoniae separated by ompK36 typing. Among 226 nonduplicate K. pneumoniae bloodstream isolates collected at a Taiwanese hospital in 2011, four ompK36 types, designated types A, B, C, and D, were identified by PCR in 61, 28, 100, and 36 isolates, respectively; 1 isolate was untypeable. Statistical analysis showed significantly higher rates of antimicrobial resistance (all tested antibiotics except meropenem), extended-spectrum β-lactamases or DHA-1 (47...
October 2015: Journal of Clinical Microbiology
Ryan K Shields, Cornelius J Clancy, Binghua Hao, Liang Chen, Ellen G Press, Nicole M Iovine, Barry N Kreiswirth, M Hong Nguyen
Avibactam is a novel β-lactamase inhibitor with affinity for Klebsiella pneumoniae carbapenemases (KPCs). In combination with ceftazidime, the agent demonstrates activity against KPC-producing K. pneumoniae (KPC-Kp). KPC-Kp strains are genetically diverse and harbor multiple resistance determinants, including defects in outer membrane proteins and extended-spectrum β-lactamases (ESBLs). Mutations in porin gene ompK36 confer high-level carbapenem resistance to KPC-Kp strains. Whether specific mechanisms of antimicrobial resistance also influence the activity of ceftazidime-avibactam is unknown...
September 2015: Antimicrobial Agents and Chemotherapy
Claudia Stein, Oliwia Makarewicz, Jürgen A Bohnert, Yvonne Pfeifer, Miriam Kesselmeier, Stefan Hagel, Mathias W Pletz
The spread of carbapenem-non-susceptible Klebsiella pneumoniae strains bearing different resistance determinants is a rising problem worldwide. Especially infections with KPC (Klebsiella pneumoniae carbapenemase) - producers are associated with high mortality rates due to limited treatment options. Recent clinical studies of KPC-blood stream infections revealed that colistin-based combination therapy with a carbapenem and/or tigecycline was associated with significantly decreased mortality rates when compared to colistin monotherapy...
2015: PloS One
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