Akturk, Hacer; Sutcu, Murat; Somer, Ayper; Aydın, Derya; Cihan, Rukiye; Ozdemir, Aslı; Coban, Asuman; Ince, Zeynep; Citak, Agop; Salman, Nuran
Little is known about factors associated with carbapenem-resistant Klebsiella pneumoniae infections in pediatric patients, who are initally colonized with carbapenem-resistant Klebsiella pneumoniae. A retrospective case-control study was conducted involving pediatric and neonatal intensive care units throughout a five-year period (January 2010-December 2014). Clinical and microbiological data were extracted from Hospital Infection Control Committee reports and patients' medical records. Risk factors were assessed in carbapenem-resistant Klebsiella pneumoniae colonized patients who developed subsequent systemic infection (cases) and compared to carbapenem-resistant Klebsiella pneumoniae colonized patients who did not develop infection (controls). Throughout the study period, 2.6% of patients admitted to neonatal intensive care units and 3.6% of patients admitted to pediatric intensive care units had become colonized with carbapenem-resistant Klebsiella pneumoniae. After a mean of 10.6±1.9 days (median: 7 days, range: 2-38 days) following detection of colonization, 39.0% of the carbapenem-resistant Klebsiella pneumoniae colonized patients in pediatric intensive care units and 18.1% of carbapenem-resistant Klebsiella pneumoniae colonized patients in neonatal intensive care units developed systemic carbapenem-resistant Klebsiella pneumoniae infection. Types of systemic carbapenem-resistant Klebsiella pneumoniae infections included bacteremia (n=15, 62.5%), ventilator-associated pneumonia (n=4, 16.6%), ventriculitis (n=2, 8.3%), intraabdominal infections (n=2, 8.3%), and urinary tract infection (n=1, 4.1%). A logistic regression model including parameters found significant in univariate analysis of carbapenem resistant Klebsiella pneumoniae colonization and carbapenem resistant Klebsiella pneumoniae infection groups revealed underlying metabolic disease (OR: 10.1; 95% CI: 2.7-37.2), previous carbapenem use (OR: 10.1; 95% CI: 2.2-40.1), neutropenia (OR: 13.8; 95% CI: 3
Li, Pengling; Wang, Min; Li, Xianping; Hu, Feihu; Yang, Min; Xie, Yixin; Cao, Wei; Xia, Xiaomeng; Zheng, Rong; Tian, Jingjing; Zhang, Kan; Chen, Fang; Tang, Aiguo
To investigate the mechanism leading to in vivo carbapenem resistance development in Klebsiella pneumoniae. Carbapenemase was detected using the modified carbapenem inactivation method. β-lactamases resistant genes were identified by PCR and sequencing. Clonal relatedness was evaluated by random amplified polymorphic DNA and multiple locus sequence typing. The relationship between sequence typing and resistant genes was analyzed by using the chi-squared test. All ST37 carbapenem-resistant isolates were bla OXA-1 positive and all ST37 carbapenem-sensitive isolates were bla OXA-1 negative at Stage I. A significant relationship between carbapenem resistance and bla OXA-1 was observed. The bla OXA-1 -positive rate was significantly higher in ST37 K. pneumoniae than others. This is the first study about the development of carbapenem resistance in vivo potentially mediated by bla OXA-1 in ST37 K. pneumoniae among neonates.
Humphries, Romney M; Yang, Shuan; Kim, Stephen; Muthusamy, Venkatara Raman; Russell, Dana; Trout, Alisa M; Zaroda, Teresa; Cheng, Quen J; Aldrovandi, Grace; Uslan, Daniel Zachary; Hemarajata, Peera; Rubin, Zachary Aaron
Carbapenem-resistant Klebsiella pneumoniae infections are increasingly prevalent in North American hospitals. We describe an outbreak of carbapenem-resistant K. pneumoniae containing the blaOXA-232 gene transmitted by contaminated duodenoscopes during endoscopic retrograde cholangiopancreatography (ERCP) procedures. An outbreak investigation was performed when 9 patients with blaOXA-232 carbapenem-resistant K. pneumoniae infections were identified at a tertiary care hospital. The investigation included 2 case-control studies, review of duodenoscope reprocessing procedures, and culture of devices. Carbapenem-resistant Enterobacteriacieae (CRE) isolates were evaluated with polymerase chain reaction analysis for carbapenemase genes, and isolates with the blaOXA-232 gene were subjected to whole-genome sequencing and chromosome single-nucleotide polymorphism analysis. On recognition of ERCP as a key risk factor for infection, targeted patient notification and CRE screening cultures were performed. Molecular testing ultimately identified 17 patients with blaOxa-232 carbapenem-resistant K. pneumoniae isolates, including 9 with infections, 7 asymptomatic carriers who had undergone ERCP, and 1 additional patient who had been hospitalized in India and was probably the initial carrier. Two case-control studies established a point-source outbreak associated with 2 specific duodenoscopes. A field investigation of the use, reprocessing, and storage of deuodenoscopes did not identify deviations from US Food and Drug Administration or manufacturer recommendations for reprocessing. This outbreak demonstrated the previously underappreciated potential for duodenoscopes to transmit disease, even after undergoing high-level disinfection according to manufacturers' guidelines.
Full Text Available In the nosocomial setting, antimicrobial-resistant Enterobacteriaceae are a growing challenge, and alarming trends in resistance are currently reported all over the world. Isolates of Enterobacteriaceae producing ampC β-lactamases and extended spectrum β-lactamases are endemic in many hospitals, and are frequently resistant also to other classes of antibiotics, such as fluoroquinolones and aminoglycosides. The risk of infections due to multi-drug resistant strains should be considered also for outpatients who have had recent contact with the health system. Both nosocomial and health-care associated infections should be treated with a combination of antibiotics active against multi-drug resistant Gram negative and methicillin-resistant Staphylococcus aureus. In the absence of effective antimicrobial stewardship programs, this aggressive therapeutic approach might lead to abuse of broad-spectrum antibiotics, with consequent increase in resistances. To contain the possible antibiotic overuse, several decisional strategies, often based on risk-score systems supporting the clinical decisions, have been proposed. In this context of high antibiotic selection pressure, carbapenem-resistant pathogens recently began to spread in many hospitals. Carbapenem-resistant Klebsiella pneumoniae, as well as carbapenem-resistant Acinetobacter baumannii and P. aeruginosa, represent the new major challenges to patient safety. Against these organisms the initial empiric treatment is generally ineffective. The poor clinical outcome associated with carbapenem- resistant K. pneumoniae infections is probably due to the delete in the beginning of an appropriate antibiotic treatment, rather than to the increased virulence of pathogens. Only few therapeutic options are available, including colistin, tigecycline, aminoglycosides and carbapenems in selected cases. Several combinations of these antibiotics have been used, but no ideal regimen has been currently established.
Hu, Yangmin; Ping, Yanting; Li, Leiqing; Xu, Huimin; Yan, Xiaofeng; Dai, Haibin
Carbapenem-resistant Klebsiella pneumoniae (CRKP) is rapidly emerging as a life-threatening nosocomial infection. In this study, we aim to identify risk factors, especially antibiotic use, for CRKP infection among intensive care unit (ICU) patients. This was a matched case-control study of a 67-bed ICU in a tertiary care teaching hospital from 1 January 2011 through 30 June 2013. The control cases were selected among the patients with carbapenem-susceptible Klebsiella pneumoniae (CSKP) and were matched with CRKP cases for year of ICU admission and site of infection. The clinical outcomes and antibiotic treatments were analyzed. One hundred and thirty patients were included in the study (65 cases and 65 controls). Bivariable analysis showed that age of patients (p = 0.044), number of antibiotic groups (p = 0.001), and exposure to carbapenems (p carbapenems, previous carbapenem exposure (p carbapenems is an independent risk factor for CRKP infection. Patients with this clinical factor should be targeted for interventions to reduce the subsequent risk of infection.
Hussein, K; Raz-Pasteur, A; Finkelstein, R; Neuberger, A; Shachor-Meyouhas, Y; Oren, I; Kassis, I
Carbapenem-resistant Enterobacteriaceae, especially Klebsiella spp., have become a major health problem recently worldwide. Since 2006 the incidence of carbapenem-resistant Klebsiella pneumoniae (CRKP) infections has increased substantially in Israel. Bloodstream infections (BSIs) caused by these strains have been associated with high rates of treatment failure and mortality. This study was designed to identify risk factors for carbapenem resistance among patients with healthcare-related (HCR) K. pneumoniae bacteraemia and predictors of mortality associated with HCR-CRKP bacteraemia compared with carbapenem-susceptible K. pneumoniae (CSKP). In this retrospective case-control study, all cases of K. pneumoniae bacteraemia during 2006-2008 were identified. Resistance patterns, underlying morbidities, risk factors for drug resistance and mortality rates were compared for patients with CRKP and CSKP bacteraemia. Two hundred and fourteen patients with CSKP bacteraemia were compared with 103 patients with CRKP bacteraemia. Severe, chronic comorbidities and prior antibiotic use were more frequent among patients with CRKP bacteraemia. On multivariate analysis prior use of macrolides and antibiotic exposure for ≥14 days remained the only independent factors associated with CRKP bacteraemia. Mortality rates of CRKP patients were significantly higher than those of CSKP patients. On multivariate analyses: bedridden status, chronic liver disease, Charlson comorbidity index ≥5, mechanical ventilation, and haemodialysis remained independently associated with mortality among patients with K. pneumoniae bacteraemia. Carbapenem resistance was not a risk factor for mortality. Previous antibiotic exposure is a risk factor for CRKP-BSI. Mortality among patients with K. pneumoniae bacteraemia is associated with serious comorbidities, but not with carbapenem resistance. Copyright © 2012 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.
Salsano, Antonio; Giacobbe, Daniele Roberto; Sportelli, Elena; Olivieri, Guido Maria; Brega, Carlotta; Di Biase, Carlo; Coppo, Erika; Marchese, Anna; Del Bono, Valerio; Viscoli, Claudio; Santini, Francesco
Patients undergoing major surgery are at increased risk of developing infections due to resistant organisms, including carbapenem-resistant Klebsiella pneumoniae (CR-Kp). In this study, we assessed risk factors for CR-Kp infections after open heart surgery in a teaching hospital in northern Italy. A retrospective study was conducted from January to December 2014. The primary outcome measure was postoperative CR-Kp infection, defined as a time-to-event end-point. The effect of potentially related variables was assessed by univariable and multivariable analyses. Secondary end-points were in-hospital mortality and 180-day postoperative mortality. Among 553 patients undergoing open heart surgery, 32 developed CR-Kp infections (6%). In the final multivariable model, CR-Kp colonization [hazard ratio (HR) 227.45, 95% confidence intervals (CI) 67.13-1225.20, P open heart surgery. CR-Kp infection after surgery significantly affected survival. Preventing colonization is conceivably the most effective current strategy to reduce the impact of CR-Kp. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
Girmenia, C; Rossolini, G M; Piciocchi, A; Bertaina, A; Pisapia, G; Pastore, D; Sica, S; Severino, A; Cudillo, L; Ciceri, F; Scimè, R; Lombardini, L; Viscoli, C; Rambaldi, A
Infections by carbapenem-resistant Klebsiella pneumoniae (CRKp) represent a challenging problem after SCT. A retrospective survey (January 2010 to July 2013) involving 52 Italian centers was performed to assess the epidemiology and the prognostic factors of CRKp infections in auto- and allo-SCT. Cases of CRKp infection were reported in 53.4% of centers. CRKp infections were documented in 25 auto-SCTs and 87 allo-SCTs, with an incidence of 0.4% (from 0.1% in 2010 to 0.7% in 2013) and 2% (from 0.4% in 2010 to 2.9% in 2013), respectively. A CRKp colonization documented before or after transplant was followed by an infection in 25.8% of auto-SCT and 39.2% of allo-SCT patients. The infection-related mortality rates were 16% and 64.4%, respectively. A pre-transplant CRKp infection (hazard ratio (HR) 0.33, 95% confidence intervals (CIs) 0.15-0.74; P=0.007) and a not CRKp-targeted first-line treatment (HR 2.67, 95% CI 1.43-4.99; P=0.002) were independent factors associated with an increased mortality in allo-SCT patients who developed a CRKp infection. Our study shows challenging findings of CRKp infections in SCT patients in Italy particularly after allo-SCT. The detection of carriers and the definition of early therapeutic strategies represent critical aspects of the management of CRKp infections after SCT.
Zhang, Rong; Wang, Xuan; Lü, Jianxin
To study the virulence and mechanism of carbapenem resistance of a clinical isolate of carbapenem-resistant K1 serotype Klebsiella pneumonia strain. Identification of isolate was carried out with VITEK-2 compact system. Antimicrobial susceptibility was determined by E-test; Metallo β-lactamases and carbapenemases screening were conducted by imipenem-EDTA double disc synergy test and modified Hodge test, respectively.Specific polymerehse chain reaction (PCR) and DNA sequencing were preformed to detect the virulence genes including K1, K2, K5, K20, K54, K57, magA, rmpA, wcaG and a series of β-lactamase resistence genes. Conjunction experiment was also performed. The plasmids of transconjugants were submitted to PCR-based replicon typing (PBRT) method. Molecular typing was performed by multilocus sequence typing (MLST). Antimicrobial susceptibility testing revealed that the Klebsiella pneumonia strain was resistant to most of the antibiotics used in clinic. Phynotype confirmary rest revealed the production of carbapanemases, while Metallo β-lactamases were negative; PCR and DNA sequencing confirmed the isolate was positive for blaKPC-2, blaCTX-M-15, blaTEM-1, blaSHV-1 and virulence genes K1, magA, rmpA, wcaG simultaneously; blaKPC-2 was transferred from donor to Escherichia EC600 by conjunction experiment, while no virulence genes were found in the transconjugants. PBRT revealed that Frep plasmid was found in transconjugants. MLST analysis revealed that this strain belonged to ST23. K1 serotype Klebsiella pneumonia strain carries virulence genes and carbapenem resistance gene blaKPC-2, noteworthily the carbapenem resistance genes can be transferred through horizontal transmission on plasmids.
Vergadi, Eleni; Bitsori, Maria; Maraki, Sofia; Galanakis, Emmanouil
Urinary tract infection (UTI) is a common bacterial infection in childhood with favourable outcome. However, the recent emergence of UTI caused by multidrug-resistant pathogens, such as carbapenem-resistant Enterobacteriaceae (CRE), has become a great concern worldwide. CRE are mainly responsible for nosocomial infections and community-onset CRE infections in healthy individuals are rare. In this study, we report a series of infants without substantial genitourinary abnormalities that were admitted with community-onset urinary tract infections (UTIs) caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) and we discuss their aetiology. We retrospectively reviewed the medical records of nine infants who presented from community to the paediatric ward with CRKP urinary tract infections, as well as all affected neonates of a concomitant CRKP outbreak that occurred in the neonatal intensive care unit (NICU) in a tertiary hospital (period from April 2009 to July 2012). We further retrieved all culture-proven CRKP infections of any site from 2007 to 2015 in our paediatric department. Over a 33-month period, nine infants, all males, aged 0.9-19.3 (median 4.0) months, were admitted to the Department of Paediatrics with UTI caused by CRKP. Three of them were diagnosed with urinary tract abnormalities but only one had vesicoureteral reflux (VUR), which was a UTI-associated one. History revealed that they had all been hospitalised in the same NICU during a concurrent long-lasting CRKP outbreak for a median of 17 (2-275) days and thereafter presented with CRKP UTI 15 to 207 (median 41) days after NICU discharge. The antibiotic susceptibility and phenotypic characteristics were identical among all isolates in NICU and the paediatric ward. The summary Figure shows a timeline of NICU hospitalisation indicative of its duration and subsequent CRKP UTI of study participants is presented. These cases illustrate that UTI caused by multidrug-resistant pathogens does not
Netikul, Thidarat; Kiratisin, Pattarachai
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. blaKPC-13 gene was found in a single isolate of Escherichia coli, Enterobacter cloacae and Citrobacter freundii, and blaIMP-14a was found in four isolates of Klebsiella pneumoniae. Carbapenem-resistant K. pneumoniae (CRKP) isolates were resistant to multiple carbapenems at a higher ratio than other CRE species, and thus were further characterized for resistance phenotypes, bla genotypes and molecular epidemiology. Most CRKP isolates harboured multiple bla genes, especially those related to extended-spectrum beta-lactamases. Seven CRKP isolates were resistant to all tested carbapenems, and showed decreased ompK35 and/or ompK36 porin gene expression. Molecular typing of CRKP based on pulsed-field gel electrophoresis (PFGE) demonstrated several unrelated clones. Multilocus sequence typing (MLST) was partially concordant with PFGE results and revealed that ST340, a member of drug-resistant K. pneumoniae clonal complex 258, was the most predominant clone, followed by ST48, ST11 and ST273. The novel ST1645 was identified from this study. ST340 has neither been shown to be predominated among CRKP from other studies, nor been reported in Thailand. Therefore, it emphases a critical concern to monitor and control the spread of CRKP. PMID:26407326
Abdul Momin, Muhd Haziq Fikry; Liakopoulos, Apostolos; Phee, Lynette M.; Wareham, David W.
Objectives Carbapenem-resistant Enterobacteriaceae (CRE) are identified as a major global health concern. The success of CRE is facilitated by the emergence, acquisition and spread of successful clones carrying plasmid-encoded resistance genes. In this study, an outbreak of carbapenem-resistant
Graziella Hanna Pereira
Full Text Available This study describes a carbapenem-resistant Klebsiella pneumoniae (CRKP outbreak that occurred from October 2008-December 2010. Polymerase chain reaction assays were performed to detect the blaKPC gene and molecular typing was performed using pulsed-field gel electrophoresis (PFGE. There were 33 CRKP infections; PFGE revealed five genotypes: genotype A in five (15%, B in 18 (55%, C in eight (24% and two unique profiles. Genotype B was disseminated in all hospital units and belonged to the same clone identified in 11 different hospitals in the state of São Paulo. Sixteen (48% patients died. Seven isolates (21% were resistant to polymyxin B and 45% were resistant to tigecycline and amikacin.
Full Text Available Hypervirulent and multidrug resistant Klebsiella pneumoniae strains pose a significant threat to the public health. In the present study, 21 carbapenem-resistant K. pneumoniae isolates (CRKP were determined by the string test as hypermucoviscous K. pneumoniae (HMKP, with the prevalence of 15.0% (21/140 among CRKP, and 1.1% (21/1838 among all K. pneumoniae isolates. Among them, 7 (33.3%, and 1 (4.76% isolate belonged to capsular serotype K20 and K2 respectively, while 13 (61.9%, 13/21 weren't successfully typed by capsular serotyping. All the 21 isolates were carbapenemase-producers and were positive for blaKPC-2. In addition to blaKPC-2, all the 21 isolates except one harbor blaSHV-11, and 15 carry extended-spectrum β-lactamase gene blaCTX-M-65. The virulence-associated genes with more than 90% of positive rates among 21 isolates included ureA (100%, 21/21, wabG (100%, 21/21, fimH (95.2%, 20/21, entB (95.2%, 20/21, ycf (95.2%, 20/21, ybtS (95.2%, 20/21, and iutA (90.5%, 19/21. rmpA and aerobactin were found in 57.1% (12/21 isolates. Five sequence types (STs were identified by multilocus sequence typing (MLST, including ST11 (11 K-non capsule typable and 5 K20 isolates, ST268 (1 K20 isolate and 1 K-non capsule typable isolate, ST65 (1 K2 isolate, ST692 (1 K-non capsule typable isolate, and ST595, a novel sequence type (1 K-non capsule typable isolate. Pulsed-field gel electrophoresis (PFGE results showed two major PFGE clusters, of which cluster A accounts for 6 ST11 isolates (28.6% and cluster B includes 8 ST11 isolates (38.1%, 8/21. Ten and six ST11 isolates were isolated from 2014 and 2015, respectively, while 8 were isolated from the same month of December in 2014. Ten isolates were collected from the intensive care unit (ICU, and all except one belonged to ST11. Additional 4 ST11 isolates were collected from patients in non-ICU wards, who had more than 10 days of ICU stay history in 2014 prior to transfer to their current wards where the
Seeberger, Peter H; Pereira, Claney L; Khan, Naeem; Xiao, Guozhi; Diago-Navarro, Elizabeth; Reppe, Katrin; Opitz, Bastian; Fries, Bettina C; Witzenrath, Martin
Hospital-acquired infections are an increasingly serious health concern. Infections caused by carpabenem-resistant Klebsiella pneumoniae (CR-Kp) are especially problematic, with a 50 % average survival rate. CR-Kp are isolated from patients with ever greater frequency, 7 % within the EU but 62 % in Greece. At a time when antibiotics are becoming less effective, no vaccines to protect from this severe bacterial infection exist. Herein, we describe the convergent [3+3] synthesis of the hexasaccharide repeating unit from its capsular polysaccharide and related sequences. Immunization with the synthetic hexasaccharide 1 glycoconjugate resulted in high titers of cross-reactive antibodies against CR-Kp CPS in mice and rabbits. Whole-cell ELISA was used to establish the surface staining of CR-Kp strains. The antibodies raised were found to promote phagocytosis. Thus, this semi-synthetic glycoconjugate is a lead for the development of a vaccine against a rapidly progressing, deadly bacterium. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Zhang, Xingyu; Chen, Di; Xu, Guifeng; Huang, Weichun; Wang, Xing
Infection by carbapenem-resistant Klebsiella pneumoniae (CR-KP) is a public health challenge worldwide, in particular among children, which was associated with high morbidity and mortality rates. There was limited data in pediatric populations, thus this study aimed to investigate molecular epidemiology and drug resistant mechanism of CR-KP strains from pediatric patients in Shanghai, China. A total of 41 clinical CR-KP isolates from sputum, urine, blood or drainage fluid were collected between July 2014 and May 2015 in Shanghai Children's Medical Center. Multilocus sequence typing (MLST), antibiotic susceptibility testing, PCR amplification and sequencing of the drug resistance associated genes were applied to all these isolates. MLST analysis revealed 16 distinct STs identified within the 41 isolates, among which the most frequently represented were ST11(19.5%),ST25(14.6%),ST76(14.6%),ST37(9.8%).One new ST was first identified. All CR-KP isolates showed MDR phenotypes and were resistance to ceftazidime, imipenem, piperacillin / tazobactam, ceftriaxone, ampicillin /sulbactam, aztreonam. They were confirmed as carbapenemase producer, NDM-1 (56.1%, 23/41), IMP (26.8%, 11/41), KPC-2 (22.0%, 9/41) were detected. Of note, two isolates carried simultaneously both NDM-1 and IMP-4. All CR-KP strains contained at least one of extended spectrum β-lactamase genes tested(TEM, SHV, OXA-1, CTX-M group) and six isolates carried both ESBL and AmpC genes(DHA-1). Among the penicllinase and β-lactamase genes, the most frequently one is SHV(92.7%,38/41), followed by TEM-1(68.3%,28/41), CTX-M-14(43.9%,18/41), CTX-M-15(43.9%,14/41), OXA-1(14.6%,6/41). In the present study, NDM-1-producing isolates was the predominant CR-KP strains in children, follow by IMP and KPC-producing strains. NDM-1and IMP-4 were more frequent than KPC-2 and showed a multiclonal background. Those suggested carbapenem-resistant in children is diverse, and certain resistance mechanisms differ from prevalent
Al-Zahrani, Ibrahim A; Alsiri, Bander A
To identify the prevalence of carbapenem-resistant Klebsiella pneumoniae (CRKP) and the most common types of cabapenemases among CRKP in the Southern (Asir) province hospitals, Saudi Arabia. Methods: The cross-sectional study was conducted between late April and September in 2015. A total of 54 Klebsiella pneumoniae (K. pneumoniae) isolates with reduced sensitivity to carbapenems were obtained from various clinical specimens of the 2 largest hospitals in the Southern province. Minimum inhibitory concentrations (MICs) of carbapenems were confirmed using E-test. Molecular detection of the most common carbapenemase genes (blaIMP, bla-carbapenem-hydrolyzing oxacillinase [OXA-48], blaVIM, bla-New Delhi metallo-ß-lactamas [NDM], and blaKPC) was performed using multiplex-polymerase chain reaction. Results: The current study found that increasing age and intensive care unit admission were associated with CRKP isolation. The major type of carbapenemases was OXA-48 with 81.5% (n=44) and it seems to reach an endemic level. New Delhi metallo-ß-lactamas (NDM) was the second most frequent carbapenemase by 7.4% (n=4) of isolates while Verona integron-encoded metallo-ß-lactamase (VIM) was reported only in one isolate. Conclusion: Saudi Arabia receives large numbers of visitors and migrant workers from OXA-48 and NDM endemic countries such as Turkey, India, and Pakistan every year.
Ibrahim A. Al-Zahrani
Full Text Available Objectives: To identify the prevalence of carbapenem-resistant Klebsiella pneumoniae (CRKP and the most common types of cabapenemases among CRKP in the Southern (Asir province hospitals, Saudi Arabia. Methods: The cross-sectional study was conducted between late April and September in 2015. A total of 54 Klebsiella pneumoniae (K. pneumoniae isolates with reduced sensitivity to carbapenems were obtained from various clinical specimens of the 2 largest hospitals in the Southern province. Minimum inhibitory concentrations (MICs of carbapenems were confirmed using E-test. Molecular detection of the most common carbapenemase genes (blaIMP, bla-carbapenem-hydrolyzing oxacillinase [OXA-48], blaVIM, bla-New Delhi metallo-ß-lactamas [NDM], and blaKPC was performed using multiplex-polymerase chain reaction. Results: The current study found that increasing age and intensive care unit admission were associated with CRKP isolation. The major type of carbapenemases was OXA-48 with 81.5% (n=44 and it seems to reach an endemic level. New Delhi metallo-ß-lactamas (NDM was the second most frequent carbapenemase by 7.4% (n=4 of isolates while Verona integron-encoded metallo-ß-lactamase (VIM was reported only in one isolate. Conclusion: Saudi Arabia receives large numbers of visitors and migrant workers from OXA-48 and NDM endemic countries such as Turkey, India, and Pakistan every year.
Full Text Available Purpose: To investigate the synergistic and bactericidal effects of antimicrobial combinations of any two of colistin, fosfomycin and tigecycline against the nine extended-spectrum Î²-lactamase (ESBL-producing Klebsiella pneumoniae (KP clinical isolates, including 4 carbapenem-susceptible strains and five imipenem and/or meropenem-resistant strains. Methods: InÂ vitro synergism and bactericidal activity of combination of colistin, fosfomycin and tigecycline were evaluated by time-kill studies in standard inoculum of bacterial densities of a suspension containing 5Â ÃÂ 105Â CFU/mL by using 1/2Ã MIC for each alone, and both 1/2Ã and 1/4Ã MIC for any two drugs. The settings of low MIC dosing were allowed to rapidly survey the most active drug combination. Results: The most active combination group was colistin plus tigecycline, showing synergy in 8 isolates and bactericidal activities in 6 isolates by using concentrations of 1/2Ã MIC and 1/4Ã MIC, respectively. The least active combination was tigecycline plus fosfomycin, which showed synergy in only 4 isolates and no bactericidal activities by using concentrations of 1/2Ã MIC and 1/4Ã MIC, respectively. Conclusions: The combination of tigecycline and colistin may be considered as a last-resort approach to the ESBL-producing KP infections, especially those isolates with carbapenem resistance. Keywords: Carbapenem resistance, Colistin, ESBL, Fosfomycin, Tigecycline
Katsiari, Maria; Panagiota, Giakkoupi; Likousi, Sophia; Roussou, Zoi; Polemis, Michalis; Alkiviadis Vatopoulos, C; Evangelia Platsouka, D; Maguina, Asimina
Acquisition of carbapenemase-producing Klebsiella pneumoniae (CP-Kp) strains poses a major threat to critically ill patients. The objectives of this study were to describe the epidemiology of CP-Kp isolates as well as the clinical outcome associated with the corresponding infections and to identify risk factors for mortality of intensive care unit (ICU) patients in a Greek hospital. A prospective, observational study was conducted in a nine-bed general ICU over a 2-year period (April 2010-March 2012). Imipenem-resistant K. pneumoniae isolates recovered from clinical samples of ICU patients were prospectively collected and studied for the presence of carbapenemases. Isolates were submitted to molecular typing using pulsed-field gel electrophoresis (PFGE). In total, 61 CP-Kp isolates (48 KPC-producers and 13 VIM-producers) were recovered from 58 ICU patients. The majority of KPC-producers were classified into a single PFGE type, indicating potent clonal dissemination. Among the 32 infected patients, bacteraemia was diagnosed in 16. Tigecycline+colistin was the most common combination antimicrobial regimen. Infection-attributable mortality was 43.8%. Regarding mortality risk factors, non-survivors were older (P=0.080), all of them presented with septic shock (P=0.010) and they had higher Sepsis-related Organ Failure Assessment (SOFA) scores at infection onset (P=0.004) compared with survivors. Appropriate definitive treatment and combination regimens were not associated with patient survival. In conclusion, CP-Kp infections are associated with limited treatment options and high in-hospital mortality. Effective measures for preventing dissemination of respective isolates in the hospital setting are required. Copyright Â© 2015 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.
Rimoldi, Sara Giordana; Gentile, Bernardina; Pagani, Cristina; Di Gregorio, Annamaria; Anselmo, Anna; Palozzi, Anna Maria; Fortunato, Antonella; Pittiglio, Valentina; Ridolfo, Anna Lisa; Gismondo, Maria Rita; Rizzardini, Giuliano; Lista, Florigio
The emergence of carbapenem-resistant Klebsiella pneumoniae strains is threatening antimicrobial treatment. Sixty-eight carbapenemase-producing K. pneumoniae strains isolated at Luigi Sacco University Hospital-ASST Fatebenefratelli Sacco (Milan, Italy) between 2012 and 2014 were characterised microbiologically and molecularly. They were tested for drug susceptibility and carbapenemase phenotypes, investigated by means of repetitive extra-genic palindromic polymerase chain reaction (REP-PCR), and fully sequenced by means of next-generation sequencing for the in silico analysis of multi-locus sequence typing (MLST), their resistome, virulome and plasmid content, and their core single nucleotide polymorphism (SNP) genotypes. All of the samples were resistant to carbapenems, other β-lactams and ciprofloxacin; many were resistant to aminoglycosides and tigecycline; and seven were resistant to colistin. Resistome analysis revealed the presence of blaKPC genes and, less frequently blaSHV, blaTEM, blaCTX-M and blaOXA, which are related to resistance to carbapenem and other β-lactams. Other genes conferring resistance to aminoglycoside, fluoroquinolone, phenicol, sulphonamide, tetracycline, trimethoprim and macrolide-lincosamide-streptogramin were also detected. Genes related to AcrAB-TolC efflux pump-dependent and pump-independent tigecycline resistance mechanisms were investigated, but it was not possible to clearly correlate the genomic features with tigecycline resistance because of the presence of a common mutation in susceptible, intermediate and resistant strains. Concerning colistin resistance, the mgrB gene was disrupted by an IS5-like element, and the mobile mcr-1 and mcr-2 genes were not detected in two cases. The virulome profile revealed type-3 fimbriae and iron uptake system genes, which are important during the colonisation stage in the mammalian host environment. The in silico detected plasmid replicons were classified as IncFIB(pQil), IncFIB(K), Col
Full Text Available We investigated the synergism of colistin and imipenem against a multidrug-resistant K. pneumoniae isolate which was recovered from a severe hip infection. PCR and DNA sequencing were used to characterize the outer membrane porin genes and the resistance genes mediating the common β-lactamases and carbapenemases. Synergism was evaluated by time-kill studies. The blaSHV-31, blaCMY-2, and blaDHA-1 were detected. Outer membrane porin genes analysis revealed loss of ompK36 and frame-shift mutation of ompK35. The common carbapenemase genes were not found. Time-kill studies demonstrated that a combination of 1x MIC of colistin (2 mg/L and 1x MIC of imipenem (8 mg/L was synergistic and bactericidal but with inoculum effect. Bactericidal activity without inoculum effect was observed by concentration of 2x MIC of colistin alone or plus 2x MIC of imipenem. In conclusion, colistin plus imipenem could be an alternative option to treat carbapenem-resistant K. pneumoniae infections.
Mapping the resistance-associated mobilome of a carbapenem-resistant Klebsiella pneumoniae strain reveals insights into factors shaping these regions and facilitates generation of a 'resistance-disarmed' model organism.
Bi, Dexi; Jiang, Xiaofei; Sheng, Zi-Ke; Ngmenterebo, David; Tai, Cui; Wang, Minggui; Deng, Zixin; Rajakumar, Kumar; Ou, Hong-Yu
This study aims to investigate the landscape of the mobile genome, with a focus on antibiotic resistance-associated factors in carbapenem-resistant Klebsiella pneumoniae. The mobile genome of the completely sequenced K. pneumoniae HS11286 strain (an ST11, carbapenem-resistant, near-pan-resistant, clinical isolate) was annotated in fine detail. The identified mobile genetic elements were mapped to the genetic contexts of resistance genes. The blaKPC-2 gene and a 26 kb region containing 12 clustered antibiotic resistance genes and one biocide resistance gene were deleted, and the MICs were determined again to ensure that antibiotic resistance had been lost. HS11286 contains six plasmids, 49 ISs, nine transposons, two separate In2-related integron remnants, two integrative and conjugative elements (ICEs) and seven prophages. Sixteen plasmid-borne resistance genes were identified, 14 of which were found to be directly associated with Tn1721-, Tn3-, Tn5393-, In2-, ISCR2- and ISCR3-derived elements. IS26 appears to have actively moulded several of these genetic regions. The deletion of blaKPC-2, followed by the deletion of a 26 kb region containing 12 clustered antibiotic resistance genes, progressively decreased the spectrum and level of resistance exhibited by the resultant mutant strains. This study has reiterated the role of plasmids as bearers of the vast majority of resistance genes in this species and has provided valuable insights into the vital role played by ISs, transposons and integrons in shaping the resistance-coding regions in this important strain. The 'resistance-disarmed' K. pneumoniae ST11 strain generated in this study will offer a more benign and readily genetically modifiable model organism for future extensive functional studies. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: firstname.lastname@example.org.
Morici, P; Florio, W; Rizzato, C; Ghelardi, E; Tavanti, A; Rossolini, G M; Lupetti, A
The spread of multi-drug resistant (MDR) Klebsiella pneumoniae strains producing carbapenemases points to a pressing need for new antibacterial agents. To this end, the in-vitro antibacterial activity of a synthetic N-terminal peptide of human lactoferrin, further referred to as hLF1-11, was evaluated against K. pneumoniae strains harboring different carbapenemase genes (i.e. OXA-48, KPC-2, KPC-3, VIM-1), with different susceptibility to colistin and other antibiotics, alone or in combination with conventional antibiotics (gentamicin, tigecycline, rifampicin, clindamycin, and clarithromycin). An antimicrobial peptide susceptibility assay was used to assess the bactericidal activity of hLF1-11 against the different K. pneumoniae strains tested. The synergistic activity was evaluated by a checkerboard titration method, and the fractional inhibitory concentration (FIC) index was calculated for the various combinations. hLF1-11 was more efficient in killing a K. pneumoniae strain susceptible to most antimicrobials (including colistin) than a colistin-susceptible strain and a colistin-resistant MDR K. pneumoniae strain. In addition, hLF1-11 exhibited a synergistic effect with the tested antibiotics against MDR K. pneumoniae strains. The results of this study indicate that resistance to hLF1-11 and colistin are not strictly associated, and suggest an hLF1-11-induced sensitizing effect of K. pneumoniae to antibiotics, especially to hydrophobic antibiotics, which are normally not effective on Gram-negative bacteria. Altogether, these data indicate that hLF1-11 in combination with antibiotics is a promising candidate to treat infections caused by MDR-K. pneumoniae strains.
A. Ahmad, V.K. Dwivedi * , and M. Chaudhary
To determine ef ect of Tobracef and imipenem drug on antioxidant enzyme actvity and lipid peroxidation leveland some biochemical parametrs in carbapenem resistant pneumonia infection rat model. Total 40 rats wereselected and diveded into 4 groups of 10 rats each. Group I was control group; group II was infected via A.baumanni bacterial strain. Group III and IV were infected plus treated group with tobracef and imipenemdrugs.Our results showed that a significant (p
M.C. El Bouamri
Conclusions: Antimicrobial susceptibility testing of urinary K. pneumoniae isolates showed a significantly high resistance to commonly used antimicrobial agents. These data highlight the need for regular surveillance of microbial resistance to improve infection control and guide the use of antimicrobial agents.
Effect of poly-hexamethylene biguanide hydrochloride (PHMB) treated non-sterile medical gloves upon the transmission of Streptococcus pyogenes, carbapenem-resistant E. coli, MRSA and Klebsiella pneumoniae from contact surfaces.
Ali, S; Wilson, A P R
Reduction of accidental contamination of the near-patient environment has potential to reduce acquisition of healthcare-associated infection(s). Although medical gloves should be removed when soiled or touching the environment, compliance is variable. The use of antimicrobial-impregnated medical gloves could reduce the horizontal-transfer of bacterial contamination between surfaces. Determine the activity of antimicrobial-impregnated gloves against common hospital pathogens: Streptococcus pyogenes, carbapenem-resistant E.coli (CREC), MRSA and ESBL-producing Klebsiella pneumoniae. Fingerpads (~1cm 2 ) of PHMB-treated and untreated gloves were inoculated with 10 μL (~10 4 colony-forming-units [cfu]) of test-bacteria prepared in heavy-soiling (0.5%BSA), blood or distilled-water (no-soiling) and sampled after 0.25, 1, 10 or 15 min contact-time. Donor surfaces (~1cm 2 computer-keys) contaminated with wet/dry inoculum were touched with the fingerpad of treated/untreated gloves and subsequently pressed onto recipient (uncontaminated) computer-keys. Approximately 4.50log 10 cfu of all bacteria persisted after 15 min on untreated gloves regardless of soil-type. In the absence of soiling, PHMB-treated gloves reduced surface-contamination by ~4.5log 10 cfu (>99.99%) within 10 min of contact-time but only ~2.5log 10 (>99.9%) and ~1.0log 10 reduction respectively when heavy-soiling or blood was present. Gloves became highly-contaminated (~4.52log 10 -4.91log 10 cfu) when handling recently-contaminated computer-keys. Untreated gloves contaminated "recipient" surfaces (~4.5log 10 cfu) while PHMB-treated gloves transferred fewer bacteria (2.4-3.6log 10 cfu). When surface contamination was dry, PHMB gloves transferred fewer bacteria (0.3-0.6log 10 cfu) to "recipient" surfaces than untreated gloves (1.0-1.9log 10 ; P gloves may be useful in preventing dissemination of organisms in the near-patient environment during routine care. However they are not a substitute for
: Sarita Nayak, Suman Singh, Soeb Jankhwala, Riddhi Pradhan
Full Text Available Klebsiella peumoniae, a capsulated gram negative bacillus is responsible for causing life threatening infections in humans. Carbapenems are the drug of choice for serious infection caused by multidrug resistant Klebsiella pneumoniae. The emergence of carbapenem resistance has made it extremely difficult to treat such infections resulting in significant morbidity and mortality. Aims: To study the prevalence of carbapenem resistance using ertapenem as a marker and to detect Klebsiella pneumoniae Carbapenemase (KPC producing Klebsiella pneumoniae as a mechanism of resistance. Material and Methods: The study included 102 patients from which Klebsiella pneumoniae isolated. Identification and antibiotic susceptibility testing of Klebsiella pneumoniae was performed on miniAPI (Analytical Profile Index, Semiautomated bacterial identification system according to Clinical and Laboratory Standards Institute (CLSI guidelines of 2011. The modified Hodge test was performed for detection of Carbapenemase production. Patient’s clinical and demographic details along with risk factors and co-morbid conditions, type of response to antimicrobial therapy and mortality were collected. Results: The prevalence of carbapenem resistance was found to be 30.41% with 16.6% KPC producing Klebsiella pneumoniae. The co-morbid conditions like immunocompromised state (p =0.042, prior antibiotics therapy (p=0.047, previous hospitalization (p =0.021, intensive care unit stay (p=0.047 and use of indwelling devices (p =0.013 were found to be significantly associated with carbapenem resistance. Adverse clinical outcomes (death or worsening among patients infected with ertapenem resistant patients was found to be statistically significant than ertapenem sensitive strains (p =0.008. Conclusions: A high degree of carbapenem resistance in present study is alarming and poses therapeutic dilemmas for clinicians. Initiating timely and appropriate infection control measures along with a
Gan, Han Ming; Rajasekaram, Ganeswrie; Eng, Wilhelm Wei Han; Kaniappan, Priyatharisni; Dhanoa, Amreeta
We report the whole-genome sequences of two carbapenem-resistant clinical isolates of Klebsiella quasipneumoniae subsp. similipneumoniae obtained from two different patients. Both strains contained three different extended-spectrum β-lactamase genes and showed strikingly high pairwise average nucleotide identity of 99.99% despite being isolated 3 years apart from the same hospital. Copyright © 2017 Gan et al.
A Novel IncA/C1 Group Conjugative Plasmid, Encoding VIM-1 Metallo-Beta-Lactamase, Mediates the Acquisition of Carbapenem Resistance in ST104 Klebsiella pneumoniae Isolates from Neonates in the Intensive Care Unit of V. Monaldi Hospital in Naples.
Esposito, Eliana P; Gaiarsa, Stefano; Del Franco, Mariateresa; Crivaro, Valeria; Bernardo, Mariano; Cuccurullo, Susanna; Pennino, Francesca; Triassi, Maria; Marone, Piero; Sassera, Davide; Zarrilli, Raffaele
The emergence of carbapenemase producing Enterobacteriaceae has raised major public health concern. The aim of this study was to investigate the molecular epidemiology and the mechanism of carbapenem resistance acquisition of multidrug-resistant Klebsiella pneumoniae isolates from 20 neonates in the neonatal intensive care unit (NICU) of the V. Monaldi Hospital in Naples, Italy, from April 2015 to March 2016. Genotype analysis by pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) identified PFGE type A and subtypes A1 and A2 in 17, 2, and 1 isolates, respectively, and assigned all isolates to sequence type (ST) 104. K. pneumoniae isolates were resistant to all classes of β-lactams including carbapenems, fosfomycin, gentamicin, and trimethoprim-sulfamethoxazole, but susceptible to quinolones, amikacin, and colistin. Conjugation experiments demonstrated that resistance to third-generation cephems and imipenem could be transferred along with an IncA/C plasmid containing the extended spectrum β-lactamase bla SHV -12 and carbapenem-hydrolyzing metallo-β-lactamase bla V IM-1 genes. The plasmid that we called pIncAC_KP4898 was 156,252 bp in size and included a typical IncA/C backbone, which was assigned to ST12 and core genome (cg) ST12.1 using the IncA/C plasmid MLST (PMLST) scheme. pIncAC_KP4898 showed a mosaic structure with bla V IM-1 into a class I integron, bla SHV -12 flanked by IS6 elements, a mercury resistance and a macrolide 2'-phosphotransferase clusters, ant(3″), aph(3″), aacA4, qnrA1, sul1 , and dfrA14 conferring resistance to aminoglycosides, quinolones, sulfonamides, and trimethoprim, respectively, several genes predicted to encode transfer functions and proteins involved in DNA transposition. The acquisition of pIncAC_KP4898 carrying bla V IM-1 and bla SHV -12 contributed to the spread of ST104 K. pneumoniae in the NICU of V. Monaldi Hospital in Naples.
A Novel IncA/C1 Group Conjugative Plasmid, Encoding VIM-1 Metallo-Beta-Lactamase, Mediates the Acquisition of Carbapenem Resistance in ST104 Klebsiella pneumoniae Isolates from Neonates in the Intensive Care Unit of V. Monaldi Hospital in Naples
Eliana P. Esposito
Full Text Available The emergence of carbapenemase producing Enterobacteriaceae has raised major public health concern. The aim of this study was to investigate the molecular epidemiology and the mechanism of carbapenem resistance acquisition of multidrug-resistant Klebsiella pneumoniae isolates from 20 neonates in the neonatal intensive care unit (NICU of the V. Monaldi Hospital in Naples, Italy, from April 2015 to March 2016. Genotype analysis by pulsed-field gel electrophoresis (PFGE and multi-locus sequence typing (MLST identified PFGE type A and subtypes A1 and A2 in 17, 2, and 1 isolates, respectively, and assigned all isolates to sequence type (ST 104. K. pneumoniae isolates were resistant to all classes of β-lactams including carbapenems, fosfomycin, gentamicin, and trimethoprim–sulfamethoxazole, but susceptible to quinolones, amikacin, and colistin. Conjugation experiments demonstrated that resistance to third-generation cephems and imipenem could be transferred along with an IncA/C plasmid containing the extended spectrum β-lactamase blaSHV -12 and carbapenem-hydrolyzing metallo-β-lactamase blaV IM-1 genes. The plasmid that we called pIncAC_KP4898 was 156,252 bp in size and included a typical IncA/C backbone, which was assigned to ST12 and core genome (cg ST12.1 using the IncA/C plasmid MLST (PMLST scheme. pIncAC_KP4898 showed a mosaic structure with blaV IM-1 into a class I integron, blaSHV -12 flanked by IS6 elements, a mercury resistance and a macrolide 2′-phosphotransferase clusters, ant(3″, aph(3″, aacA4, qnrA1, sul1, and dfrA14 conferring resistance to aminoglycosides, quinolones, sulfonamides, and trimethoprim, respectively, several genes predicted to encode transfer functions and proteins involved in DNA transposition. The acquisition of pIncAC_KP4898 carrying blaV IM-1 and blaSHV -12 contributed to the spread of ST104 K. pneumoniae in the NICU of V. Monaldi Hospital in Naples.
The Klebsiella pneumoniae carbapenemase (KPC) was detected in a carbapenem-resistant respiratory isolate of Klebsiella pneumoniae in an Irish hospital. This is the first report of a KPC-producing isolate in the Republic of Ireland. The isolate was resistant to all beta-lactams. Furthermore, it had reduced susceptibility to three other classes of non-beta-lactam antibiotics. The isolate was not associated with travel abroad. Detection of KPC-producing bacteria has important infection control and public health implications.
In Beom Jeong
Full Text Available Background Several antibiotics can be used to treat ventilator-associated pneumonia caused by carbapenem-resistant A. baumannii (CRAB-VAP including high-dose sulbactam. However, the effectiveness of high-dose sulbactam therapy is not well known. We report our experience with high-dose sulbactam for treatment of CRAB-VAP. Methods Medical records of patients with CRAB-VAP who were given high-dose sulbactam between May 2013 and June 2015 were reviewed. Results Fifty-eight patients with CRAB-VAP were treated with high-dose sulbactam. The mean age was 72.0 ± 15.2 years, and the acute physiology and chronic health evaluation II (APACHE II score was 15.1 ± 5.10 at the time of CRAB-VAP diagnosis. Early clinical improvement was observed in 65.5% of patients, and 30-day mortality was 29.3%. Early clinical failure (odds ratio [OR]: 8.720, confidence interval [CI]: 1.346-56.484; p = 0.023 and APACHE II score ≥ 14 at CRAB-VAP diagnosis (OR: 10.934, CI: 1.047-114.148; p = 0.046 were associated with 30-day mortality. Conclusions High-dose sulbactam therapy may be effective for the treatment of CRAB-VAP. However, early clinical failure was observed in 35% of patients and was associated with poor outcome.
Full Text Available Klebsiella pneumoniae invasive syndrome (KPIS is a rare clinical condition characterized by primary liver abscess associated with metastatic infection. Most case reports are from Southeast Asia, with only one case described in Portugal. The Authors present the case of a 44-year-old man with a history of fever, dry cough and cervicalgia. A thoracic computed tomography (CT scan showed multiple pulmonary and hepatic nodules, suggestive of metastatic malignancy. Both blood cultures and bronchoalveolar lavage were positive for Klebsiella pneumoniae. Imaging studies were repeated during his hospital stay, showing a reduction in both number and volume of identified lesions, thus revealing their infectious nature. This case illustrates how much this entity can mimic other illnesses.
Kalpoe, Jayant S; Al Naiemi, Nashwan; Poirel, Laurent; Nordmann, Patrice
Traditionally, bacteria in The Netherlands have low levels of resistance to antibiotics. This report describes what is believed to be the first carbapenem-resistant Klebsiella pneumoniae producing an OXA-48 type β-lactamase in The Netherlands. The isolate co-produced a CTX-M-15 type β-lactamase and was recovered from a patient who was transferred from a hospital in India to an intensive care unit in The Netherlands. His recovery in The Netherlands was complicated by pneumonia due to the carbapenem-resistant K. pneumoniae to which he eventually succumbed. Pre-emptive screening for carbapenem-resistant Enterobacteriaceae in selected patients could be imperative to maintain the low prevalence of these highly resistant bacteria in Dutch hospitals.
Zilberberg, Marya D; Nathanson, Brian H; Sulham, Kate; Fan, Weihong; Shorr, Andrew F
Drug resistance among gram-negative pathogens is a risk factor for inappropriate empiric treatment (IET), which in turn increases the risk for mortality. We explored the impact of carbapenem-resistant Enterobacteriaceae (CRE) on the risk of IET and of IET on outcomes in patients with Enterobacteriaceae infections. We conducted a retrospective cohort study in Premier Perspective database (2009-2013) of 175 US hospitals. We included all adult patients with community-onset culture-positive urinary tract infection (UTI), pneumonia, or sepsis as a principal diagnosis, or as a secondary diagnosis in the setting of respiratory failure, treated with antibiotics within 2 days of admission. We employed regression modeling to compute adjusted association of presence of CRE with risk of receiving IET, and of IET on hospital mortality, length of stay (LOS) and costs. Among 40,137 patients presenting to the hospital with an Enterobacteriaceae UTI, pneumonia or sepsis, 1227 (3.1%) were CRE. In both groups, the majority of the cases were UTI (51.4% CRE and 54.3% non-CRE). Those with CRE were younger (66.6+/-15.3 vs. 69.1+/-15.9 years, p pneumonia or sepsis was comparable to other national estimates. Infection with CRE was associated with a four-fold increased risk of receiving IET, which in turn increased mortality, LOS and costs.
Li, Yi; Sun, Qiao-Ling; Shen, Yingbo; Zhang, Yangjunna; Yang, Jun-Wen; Shu, Ling-Bin; Zhou, Hong-Wei; Wang, Yang; Wang, Bing; Zhang, Rong; Wang, Shaolin; Shen, Zhangqi
The global spread of carbapenem-resistant Enterobacteriaceae (CRE) is one of the most severe threats to human health in a clinical setting. The recent emergence of plasmid-mediated colistin resistance gene mcr-1 among 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 7,249 Enterobacteriaceae isolates were collected from clinical samples, among which 18.1% (1,311/7,249) were carbapenem resistant. Carbapenem-resistant Klebsiella pneumoniae and carbapenem-resistant Escherichia coli were the two most common CRE species, with Klebsiella pneumoniae carbapenemases (KPC) and New Delhi metallo-β-lactamases (NDM), respectively, responsible for the carbapenem resistance of the two species. Notably, >57.0% ( n = 589) of the K. pneumoniae isolates from the intensive care unit were carbapenem resistant. Furthermore, bla NDM-5 and mcr-1 were found to coexist in one E. coli isolate, 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 by K. pneumoniae in the studied hospital. Copyright © 2018 American Society for Microbiology.
Le Minh, Vien; Thi Khanh Nhu, Nguyen; Vinh Phat, Voong; Thompson, Corinne; Huong Lan, Nguyen Phu; Thieu Nga, Tran Vu; Thanh Tam, Pham Thi; Tuyen, Ha Thanh; Hoang Nhu, Tran Do; Van Hao, Nguyen; Thi Loan, Huynh; Minh Yen, Lam; Parry, Christopher M; Trung Nghia, Ho Dang; Campbell, James I; Hien, Tran Tinh; Thwaites, Louise; Thwaites, Guy; Van Vinh Chau, Nguyen; Baker, Stephen
Acinetobacter baumannii has become one of the major infection threats in intensive care units (ICUs) globally. Since 2008, A. baumannii has been the leading cause of ventilator-associated pneumonia (VAP) in our ICU at an infectious disease hospital in southern Vietnam. The emergence of this pathogen in our setting is consistent with the persistence of a specific clone exhibiting resistance to carbapenems. Antimicrobial combinations may be a strategy to treat infections caused by these carbapenem-resistant A. baumannii. Therefore, we assessed potential antimicrobial combinations against local carbapenem-resistant A. baumannii by measuring in vitro interactions of colistin with four antimicrobials that are locally certified for treating VAP. We first performed antimicrobial susceptibility testing and multilocus variable number tandem repeat analysis (MLVA) genotyping on 74 A. baumannii isolated from quantitative tracheal aspirates from patients with VAP over an 18-month period. These 74 isolates could be subdivided into 21 main clusters by MLVA and >80 % were resistant to carbapenems. We selected 56 representative isolates for in vitro combination synergy testing. Synergy was observed in four (7 %), seven (13 %), 20 (36 %) and 38 (68 %) isolates with combinations of colistin with ceftazidime, ceftriaxone, imipenem and meropenem, respectively. Notably, more carbapenem-resistant A. baumannii isolates (36/43; 84 %) exhibited synergistic activity with a combination of colistin and meropenem than carbapenem-susceptible A. baumannii isolates (2/13; 15 %) (P = 0.023; Fisher's exact test). Our findings suggest that combinations of colistin and meropenem should be considered when treating carbapenem-resistant A. baumannii infections in Vietnam, and we advocate clinical trials investigating combination therapy for VAP.
Lilian Silva Lavagnoli
Full Text Available ABSTRACT Objective: to identify possible risk factors for acquisition of Enterobacterial strains with a marker for resistance to carbapenems. Methods: exploratory case-control study performed in hospital settings. The study sample consisted of patients with biological specimens that tested positive for carbapenem-resistant Enterobacteriaceae (cases, with the disk diffusion test and Etest, and controls with biological samples testing negative for carbapenem-resistant Enterobacteriaceae. In all, 65 patients were included: 13 (20% cases and 52 (80% controls. Results: the microorganisms isolated were Serratia marcescens (6, Klebsiella pneumoniae (4, and Enterobacter cloacae (3. Univariate analysis revealed that length of hospitalization prior to sample collection (p=0.002 and having a surgical procedure (p=0.006 were statistically significant. In the multivariable logistic regression model, both were still significant, with odds ratios of 0.93 (p = 0.009; 95% CI: 0.89 to 0.98 for length of hospitalization prior to sample collection, and 9.28 (p = 0.05; 95% CI: 1.01 to 85.14 for having a surgical procedure. Conclusion: shorter hospitalization times and increased surveillance of patients undergoing surgery could play a decisive role in reducing the spread of carbapenem-resistant microorganisms in hospital settings.
Bossa Maria C
Full Text Available Abstract Background The emergence of KPC-producing K. pneumoniae has now become a global concern. KPC beta-lactamases are plasmid-borne and, like extended spectrum beta lactamases (ESBLs, can accumulate and transfer resistance determinants to other classes of antibiotics. Therefore, infection control guidelines on early identification and control of the spread of organisms carrying these resistant determinants are needed. Findings Klebsiella pneumoniae carbapenemase (KPC was detected in two isolates of carbapenem-resistant K. pneumoniae obtained from patients at an Italian teaching hospital. The first strain was isolated from a culture drawn from a central venous device (CVC in a patient with Crohn's disease who was admitted to a gastroenterology ward. The second was isolated from a urine sample collected from an indwelling urinary catheter in an intensive care unit (ICU patient with a subdural haematoma. The patients had not travelled abroad. Both isolates were resistant to all β-lactams and were susceptible to imipenem and meropenem but resistant to ertapenem. Isolates also showed resistance to other classes of non-β-lactam antibiotics, such as quinolones, aminoglycosides (with the exception for amikacin, trimethoprim-sulfamethoxazole (TMP-SMX and nitrofurantoin. They were determined to contain the plasmid encoding the carbapenemase gene bla-KPC and were also positive in the Hodge test. Conclusions This is the second report of KPC-producing isolates in Italy, but the first concerning KPC type 2 gene, and it may have important implications for controlling the transmission of microorganisms resistant to antibiotics.
Triplett, Eric W [Middleton, WI; Kaeppler, Shawn M [Oregon, WI; Chelius, Marisa K [Greeley, CO
A biological inoculant for enhancing the growth of plants is disclosed. The inoculant includes the bacterial strains Herbaspirillum seropedicae 2A, Pantoea agglomerans P101, Pantoea agglomerans P102, Klebsiella pneumoniae 342, Klebsiella pneumoniae zmvsy, Herbaspirillum seropedicae Z152, Gluconacetobacter diazotrophicus PA15, with or without a carrier. The inoculant also includes strains of the bacterium Pantoea agglomerans and K. pneumoniae which are able to enhance the growth of cereal grasses. Also disclosed are the novel bacterial strains Herbaspirillum seropedicae 2A, Pantoea agglomerans P101 and P102, and Klebsiella pneumoniae 342 and zmvsy.
Full Text Available Klebsiella pneumoniae carbapenemase (KPC was detected in two isolates of carbapenem-resistant K. pneumoniae in an italian teaching hospital. This is the first report of a KPC-producing isolates in our country. The first strain was isolated from a urine sample collected from a indwelling urinary catheter in a ICU-patient with subdural haematoma, while the second was from the culture of the central venous catheter (CVC in a patient affected by Crohn’s disease admitted in gastroenterology ward. Both were resistant to all ß-lactams, susceptible to imipenem and meropenem and resistant to ertapenem.They were resistant to other classes of non-ß-lactams antibiotics such as quinolones, aminoglycosides (with the exception of amikacin, trimethoprim-sulfamethoxazole (TMP-SMX as well as to nitrofurantoin.The isolates were not associated with travel abroad.They were found to contain the plasmid encoded carbapenemase gene blaKPC and were also positive to the Hodge’s test.The detection of KPC-producing bacteria has important implications in infection control and public health. The K. pneumoniae carbapenemase (KPC belong to class A ß-lactamases of the functional group 2f. Reported for the first time in U.S. in 2001, these agents were subsequently identified in Europe. KPC strains are typically resistant to penicillins, extended-spectrum cephalosporin and aztreonam and present a peculiar behavior against carbapenems in that MIC is close to the susceptibility value or is borderline (except for ertapenem.This pattern is often associated with resistance to quinolones.The information is conveyed by the resistance plasmids, thus explaining their diffusion and implication in outbreaks of KPC. Despite this, to date there are few reports concerning the isolation of this phenotype in Italy.The purpose of this paper is to present two clinical cases related to the isolation of KPC in our hospital. The KPC-producing strains have been respectively isolated: the first
Weinstein, Robert A.
Abstract Carbapenem-resistant Enterobacteriaceae (CRE) are a serious public health threat. Infections due to these organisms are associated with significant morbidity and mortality. Mechanisms of drug resistance in gram-negative bacteria (GNB) are numerous; β-lactamase genes carried on mobile genetic elements are a key mechanism for the rapid spread of antibiotic-resistant GNB worldwide. Transmissible carbapenem-resistance in Enterobacteriaceae has been recognized for the last 2 decades, but global dissemination of carbapenemase-producing Enterobacteriaceae (CPE) is a more recent problem that, once initiated, has been occurring at an alarming pace. In this article, we discuss the evolution of CRE, with a focus on the epidemiology of the CPE pandemic; review risk factors for colonization and infection with the most common transmissible CPE worldwide, Klebsiella pneumoniae carbapenemase–producing K. pneumoniae; and present strategies used to halt the striking spread of these deadly pathogens. PMID:28375512
Lari, AR; Azimi, L; Rahbar, M; Alaghehbandan, R; Sattarzadeh-Tabrizi, M
Wound infection associated with carbapenem-resistant Pseudomonas aeruginosa in burn patients is a growing problem. One of the main mechanisms of resistance to carbapenem antibiotics is the ability of P. aeruginosa to produce carbapenemase enzymes. Klebsiella pneumonia carbapemenase (KPC) is an important type of carbapenemase which can hydrolyze carbapenem antibiotics. The Modified Hodge Test (MHT) and boronic acid as a KPC inhibitor are two phenotypic methods used for detection of carbapen...
Nachimuthu, Ramesh; Subramani, Ramkumar; Maray, Suresh; Gothandam, K M; Sivamangala, Karthikeyan; Manohar, Prasanth; Bozdogan, Bülent
Carbapenem resistance is disseminating worldwide among Gram-negative bacteria. The aim of this study was to identify carbapenem-resistance level and to determine the mechanism of carbapenem resistance among clinical isolates from two centres in Tamil Nadu. In the present study, a total of 93 Gram-negative isolates, which is found to be resistant to carbapenem by disk diffusion test in two centres, were included. All isolates are identified at species level by 16S rRNA sequencing. Minimal inhibitory concentrations (MICs) of isolates for Meropenem were tested by agar dilution method. Presence of blaOXA, blaNDM, blaVIM, blaIMP and blaKPC genes was tested by PCR in all isolates. Amplicons were sequenced for confirmation of the genes. Among 93 isolates, 48 (%52) were Escherichia coli, 10 (%11) Klebsiella pneumoniae, nine (%10) Pseudomonas aeruginosa. Minimal inhibitory concentration results showed that of 93 suspected carbapenem-resistant isolates, 27 had meropenem MICs ≥ 2 μg/ml. The MIC range, MIC50 and MIC90 were 128 μg/ml, 0.12 and 16 μg/ml, respectively. Fig. 1 . Among meropenem-resistant isolates, E. coli were the most common (9/48, 22%), followed by K. pneumoniae (7/9, 77%), P. aeruginosa (6/10, 60%), Acinetobacter baumannii (2/2, 100%), Enterobacter hormaechei (2/3, 67%) and one Providencia rettgeri (1/1, 100%). PCR results showed that 16 of 93 carried blaNDM, three oxa181, and one imp4. Among blaNDM carriers, nine were E. coli, four Klebsiella pneumoniae, two E. hormaechei and one P. rettgeri. Three K. pneumoniae were OXA-181 carriers. The only imp4 carrier was P. aeruginosa. A total of seven carbapenem-resistant isolates were negatives by PCR for the genes studied. All carbapenem-resistance gene-positive isolates had meropenem MICs >2 μg/ml. Our results confirm the dissemination of NDM and emergence of OXA-181 beta-lactamase among Gram-negative bacteria in South India. This study showed the emergence of NDM producer in clinical isolates of E
Nov 21, 2011 ... the most common serious bacterial infections in infants ... UTI is a common cause of morbidity .... of ESBL and non-ESBL producing Escherichia coli and Klebsiella pneumonia. ... in hospital and community acquired infections.
da Silva, Kesia Esther; Maciel, Wirlaine Glauce; Sacchi, Flávia Patussi Correia; Carvalhaes, Cecilia Godoy; Rodrigues-Costa, Fernanda; da Silva, Ana Carolina Ramos; Croda, Mariana Garcia; Negrão, Fábio Juliano; Croda, Julio; Gales, Ana Cristina; Simionatto, Simone
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. The presence of β-lactamase-encoding genes was evaluated by PCR and DNA sequencing. Alterations in genes encoding K. pneumoniae outer membrane proteins were analysed by PCR and DNA sequencing as well as SDS-PAGE. Genetic relatedness among strains was determined by pulsed-field gel electrophoresis. This study included 94 patients. Longer hospitalisation, mechanical ventilation, catheters, and previous surgery were associated with KPC-producing K. pneumoniae. Sixty-eight strains showed resistance to carbapenems. Carbapenemase production was detected by MHT in 67 K. pneumoniae strains and by MALDI-TOF MS in 57. The presence of the blaKPC-2 gene was identified in 57 strains. The blaKPC-2 gene was not found in 11 carbapenem-resistant K. pneumoniae; instead, the blaCTX-M-1-like, blaCTX-M-2-like, blaCTX-M-8 like, blaCTX-M-14-like and blaSHV- like genes associated with OmpK35 and OmpK36 alterations were observed. Thirty-three KPC-producing K. pneumoniae strains were clonally related, and patients infected with these strains had a higher mortality rate (78.78 %). Our results show that KPC-producing K. pneumoniae was associated with several healthcare-related risk factors, including recent surgery.
Alvarez-Uria, Gerardo; Gandra, Sumanth; Mandal, Siddhartha; Laxminarayan, Ramanan
To project future antimicrobial resistance (AMR) in Escherichia coli and Klebsiella pneumoniae. Mixed linear models were constructed from a sample of countries with AMR data in the ResistanceMap database. Inverse probability weighting methods were used to account for countries without AMR data. The estimated prevalence of AMR in 2015 was 64.5% (95% confidence interval (CI) 42-87%) for third-generation cephalosporin-resistant (3GCR) Escherichia coli, 5.8% (95% CI 1.8-9.7%) for carbapenem-resistant (CR) E. coli, 66.9% (95% CI 47.1-86.8%) for 3GCR Klebsiella pneumoniae, and 23.4% (95% CI 7.4-39.4%) for CR K. pneumoniae. The projected AMR prevalence in 2030 was 77% (95% CI 55-99.1%) for 3GCR E. coli, 11.8% (95% CI 3.7-19.9%) for CR E. coli, 58.2% (95% CI 50.2-66.1%) for 3GCR K. pneumoniae, and 52.8% (95% CI 16.3-89.3%) for CR K. pneumoniae. The models suggest that third-generation cephalosporins and carbapenems could be ineffective against a sizeable proportion of infections by E. coli and K. pneumoniae in most parts of the world by 2030, supporting both the need to enhance stewardship efforts and to prioritize research and development of new antibiotics for resistant Enterobacteriaceae. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.
Full Text Available Klebsiella pneumoniae is one of the most clinically relevant species in immunocompromised individuals responsible for community-acquired and nosocomial infections, including pneumonias, urinary tract infections, bacteremias, and liver abscesses. Since the mid-1980s, hypervirulent K. pneumoniae, generally associated with the hypermucoviscosity phenotype, has emerged as a clinically significant pathogen responsible for serious disseminated infections, such as pyogenic liver abscesses, osteomyelitis, and endophthalmitis, in a generally younger and healthier population. Hypervirulent K. pneumoniae infections were primarily found in East Asia and now are increasingly being reported worldwide. Although most hypervirulent K. pneumoniae isolates are antibiotic-susceptible, some isolates with combined virulence and resistance, such as the carbapenem-resistant hypervirulent K. pneumoniae isolates, are increasingly being detected. The combination of multidrug resistance and enhanced virulence has the potential to cause the next clinical crisis. To better understand the basic biology of hypervirulent K. pneumoniae, this review will provide a summarization and discussion focused on epidemiology, hypervirulence-associated factors, and antibiotic resistance mechanisms of such hypervirulent strains. Epidemiological analysis of recent clinical isolates in China warns the global dissemination of hypervirulent K. pneumoniae strains with extensive antibiotic resistance in the near future. Therefore, an immediate response to recognize the global dissemination of this hypervirulent strain with resistance determinants is an urgent priority.
Full Text Available Klebsiella pneumoniae is an important cause of healthcare-associated infections worldwide. Selective pressure, the extensive use of antibiotics, and the conjugational transmission of antibiotic resistance genes across bacterial species and genera facilitate the emergence of multidrug-resistant (MDR K. pneumoniae. Here, we examined the occurrence, phenotypes and genetic features of MDR K. pneumoniae isolated from patients in intensive care units (ICUs at the First Affiliated Hospital of Xiamen University in Xiamen, China, from January to December 2011. Thirty-eight MDR K. pneumoniae strains were collected. These MDR K. pneumoniae isolates possessed at least seven antibiotic resistance determinants, which contribute to the high-level resistance of these bacteria to aminoglycosides, macrolides, quinolones and β-lactams. Among these isolates, 24 strains were extended-spectrum β-lactamase (ESBL producers, 2 strains were AmpC producers, and 12 strains were both ESBL and AmpC producers. The 38 MDR isolates also contained class I (28/38 and class II integrons (10/38. All 28 class I-positive isolates contained aacC1, aacC4, orfX, orfX’ and aadA1 genes. β-lactam resistance was conferred through blaSHV (22/38, blaTEM (10/38, and blaCTX-M (7/38. The highly conserved blaKPC-2 (37/38 and blaOXA-23(1/38 alleles were responsible for carbapenem resistance, and a gyrAsite mutation (27/38 and the plasmid-mediated qnrB gene (13/38 were responsible for quinolone resistance. Repetitive-sequence-based PCR (REP-PCR fingerprinting of these MDR strains revealed the presence of five groups and sixteen patterns. The MDR strains from unrelated groups showed different drug resistance patterns; however, some homologous strains also showed different drug resistance profiles. Therefore, REP-PCR-based analyses can provide information to evaluate the epidemic status of nosocomial infection caused by MDR K. pneumoniae; however, this test lacks the power to discriminate some
Siu, Leung-Kei Kristopher; Huang, David B; Chiang, Tom
KPC-producing carbapenem-resistant Klebsiella pneumoniae (CRKP) infections are associated with high mortality; however, their virulence determinants are not well defined. We investigated the virulence and plasmid transferability among KPC-containing K. pneumoniae isolates. KPC-2 and -3 were successfully conjugated and retained by a virulent K2 K. pneumoniae recipient isolate. Antimicrobial susceptibility testing showed KPC-2 and -3 donor strains were resistant to more than four classes of antibiotics while the K2 isolate was only initially resistant to ampicillin. After conjugation of KPC-2 and -3, the K2 K. pneumoniae transconjugants became resistant to all beta-lactams. Additionally, the KPC K2 K. pneumoniae transconjugants continued to retain its high serum resistance and murine lethality. Conjugation and retainment of KPC by virulent K2 K. pneumoniae and the ability of the tranconjugants to maintain its high serum resistance and murine lethality after conjugation was demonstrated in this study. These findings are concerning for the potential of KPC-like genes to disseminate among virulent K. pneumoniae isolates.
Full Text Available Background: Multi-drug resistant Klebsiella pneumoniae has been considered as a serious global threat. This study was done to investigate carbapenemase producing genomes among K. pneumoniae isolates in Isfahan, Central Iran. Materials and Methods: In a cross-sectional study from 2011 to 2012, 29 carbapenem resistant (according to disc diffusion method carbapenemase producing (according to modified Hodge test K. pneumoniae strains were collected from Intensive Care Unit (ICUs of Al-Zahra referral Hospital. In the strains with the lack of sensitivity to one or several carbapenems, beta-lactams, or beta-lactamases, there has been performed modified Hodge test to investigate carbapenmase and then only strains producing carbapenmases were selected for molecular methods. Results: In this study, there have been 29 cases of K. pneumoniae isolated from hospitalized patients in the (ICU. Three cases (10.3% contained blaVIM, 1 case (3.4% contained blaIMP, and 1 case (3.4% contained blaOXA. The genes blaNDM and blaKPC were not detected. Then, 16 cases (55.2% from positive cases of K. pneumoniae were related to the chip, 4 cases (13.8% to catheter, 6 cases (20.7% to urine, and 3 cases (10.3% to wound. Conclusion: It is necessary to monitor the epidemiologic changes of these carbapenemase genes in K. pneumoniae in our Hospital. More attention should be paid to nosocomial infection control measures. Other carbapenemase producing genes should be investigated.
Emerging antibiotic resistance due to extended spectrum β-lactamase (ESBL) production limited the use of β-lactam antibiotics against Escherichia coli and Klebsiella pneumoniae. This observational study was conducted at the Microbiology department of the Children's Hospital, Lahore Pakistan, from June, 2009 to ...
2-20mm) on Streptococcus pneumoniae and Proteus vulgaris when compared to the ... The result from this preliminary study suggests that the plant contains active compounds that .... Veterinary and Medical Laboratory Technology, Vom,. Jos.
Full Text Available Carbapenemase-producing Klebsiella pneumoniae (KPC has emerged and spread throughout the world. A retrospective analysis was performed on carbapenem-resistant K. pneumoniae isolated at our teaching hospital during the period 2009–2010, when the initial outbreak occurred. To determine the mechanism(s that underlies the increased infectivity exhibited by KPC, Multilocus Sequence Typing (MLST was conducted. A series of plasmids was also extracted, sequenced and analyzed. Concurrently, the complete sequences of blaKPC−2-harboring plasmids deposited in GenBank were summarized and aligned. The blaKPC−2 and KlcAHS genes in the carbapenem-resistant K. pneumoniae isolates were examined. E. coli strains, carrying different Type I Restriction and Modification (RM systems, were selected to study the interaction between RM systems, anti-RM systems and horizontal gene transfer (HGT. The ST11 clone predominated among 102 carbapenem-resistant K. pneumoniae isolates, all harbored the blaKPC−2 gene; 98% contained the KlcAHS gene. KlcAHS was one of the core genes in the backbone region of most blaKPC−2 carrying plasmids. Type I RM systems in the host bacteria reduced the rate of pHS10842 plasmid transformation by 30- to 40-fold. Presence of the anti-restriction protein, KlcAHS, on the other hand, increased transformation efficiency by 3- to 6-fold. These results indicate that RM systems can significantly restrict HGT. In contrast, KlcAHS can disrupt the RM systems and promote HGT by transformation. These findings suggest that the anti-restriction protein, KlcAHS, represents a novel mechanism that facilitates the increased transfer of blaKPC-2 and KlcAHS-carrying plasmids among K. pneumoniae strains.
Full Text Available Context: Ventilator-associated pneumonia (VAP is a leading nosocomial infection in the intensive care unit (ICU. Members of Enterobacteriaceae are the most common causative agents and carbapenems are the most commonly used antibiotics. Metallo-beta-lactamase (MBL production leading to treatment failure may go unnoticed by routine disc diffusion susceptibility testing. Moreover, there is not much information on association of MBL-producing Enterobacteriaceae with ICU-acquired VAP. Therefore, a study was undertaken to find out the association of MBL-producing Enterobacteriaceae with VAP. Settings: This study was conducted in a large tertiary care hospital of North India with an eight-bed critical care unit. Materials and Methods: The respiratory samples (bronchoalveolar lavage, protected brush catheter specimens and endotracheal or transtracheal aspirates obtained from VAP patients (during January 2005-December 2006 were processed, isolated bacteria identified and their antibiotic susceptibilities tested as per standard protocols. The isolates of Enterobacteriaceae resistant to carbapenem were subjected to phenotypic and genotypic tests for the detection of MBLs. Results: Twelve of 64 isolates of Enterobacteriaceae were detected as MBL producers, bla IMP being the most prevalent gene. Additionally, in three strains, simultaneous coexistence of multiple MBL genes was detected. Conclusion: The coexistence of multiple MBL genes in Enterobacteriaceae is an alarming situation. As MBL genes are associated with integrons that can be embedded in transposons, which in turn can be accommodated on plasmids thereby resulting in a highly mobile genetic apparatus, the further spread of these genes in different pathogens is likely to occur.
Somily, Ali M; Garaween, Ghada A; Abukhalid, Norah; Absar, Muhammad M; Senok, Abiola C
In recent years, there has been a rapid dissemination of carbapenem resistant Enterobacteriaceae (CRE). This study aimed to compare phenotypic and molecular methods for detection and characterization of CRE isolates at a large tertiary care hospital in Saudi Arabia. This study was carried out between January 2011 and November 2013 at the King Khalid University Hospital (KKUH) in Saudi Arabia. Determination of presence of extended-spectrum beta-lactamases (ESBL) and carbapenem resistance was in accordance with Clinical and Laboratory Standards Institute (CLSI) guidelines. Phenotypic classification was done by the MASTDISCS(TM) ID inhibitor combination disk method. Genotypic characterization of ESBL and carbapenemase genes was performed by the Check-MDR CT102. Diversilab rep-PCR was used for the determination of clonal relationship. Of the 883 ESBL-positive Enterobacteriaceae detected during the study period, 14 (1.6%) isolates were carbapenem resistant. Both the molecular genotypic characterization and phenotypic testing were in agreement in the detection of all 8 metalo-beta-lactamases (MBL) producing isolates. Of these 8 MBL-producers, 5 were positive for blaNDM gene and 3 were positive for blaVIM gene. Molecular method identified additional blaOXA gene isolates while MASTDISCS(TM) ID detected one AmpC producer isolate. Both methods agreed in identifying 2 carbapenem resistant isolates which were negative for carbapenemase genes. Diversilab rep-PCR analysis of the 9 Klebsiella pneumoniae isolates revealed polyclonal distribution into eight clusters. MASTDISCS(TM) ID is a reliable simple cheap phenotypic method for detection of majority of carbapenemase genes with the exception of the blaOXA gene. We recommend to use such method in the clinical laboratory.
Zhang Chunsheng; Li Xuejun; Tai Hanzhen; Wang Guohua; Qi Shi
Objective: To evaluate the diagnostic value of radiology and CT scanning in Klebsiella pneumoniae. Methods: The clinical, radiologic data and CT films of 89 patients with Klebsiella pneumoniae were retrospectively analyzed. Results: Three types of chest X-ray and computed tomography (CT) findings for Klebsiella pneumonia were found. (1)Increased pulmonary markings occured in 31 cases. (2)35 cases with single lesions showed frequently involvement in the upper or lower lobe of right lung. When lesion was involved in the upper lobe, it developed oblique fissure shift down in radiology films and represent stalactitic symptom in CT imagining. (3)In 23 cases with Klebsiella pneumonia showed typical cavitary lung abscesses. Conclusion: The radiologic findings of Klebsiella pneumoniae were complicated and hard to make a good diagnosis. Combined the imaging features with the clinic data, sometimes, we can get the right diagnosis in some cases with typical Klebsiella pneumoniae. (authors)
Henson, Sonal P; Boinett, Christine J; Ellington, Matthew J; Kagia, Ngure; Mwarumba, Salim; Nyongesa, Sammy; Mturi, Neema; Kariuki, Samuel; Scott, J Anthony G; Thomson, Nicholas R; Morpeth, Susan C
Multidrug resistant (MDR) Klebsiella pneumoniae is a common cause of nosocomial infections worldwide. Recent years have seen an explosion of resistance to extended-spectrum β-lactamases (ESBLs) and emergence of carbapenem resistance. Here, we examine 198 invasive K. pneumoniae isolates collected from over a decade in Kilifi County Hospital (KCH) in Kenya. We observe a significant increase in MDR K. pneumoniae isolates, particularly to third generation cephalosporins conferred by ESBLs. Using whole-genome sequences, we describe the population structure and the distribution of antimicrobial resistance genes within it. More than half of the isolates examined in this study were ESBL-positive, encoding CTX-M-15, SHV-2, SHV-12 and SHV-27, and 79% were MDR conferring resistance to at least three antimicrobial classes. Although no isolates in our dataset were found to be resistant to carbapenems we did find a plasmid with the genetic architecture of a known New Delhi metallo-β-lactamase-1 (NDM)-carrying plasmid in 25 isolates. In the absence of carbapenem use in KCH and because of the instability of the NDM-1 gene in the plasmid, the NDM-1 gene has been lost in these isolates. Our data suggests that isolates that encode NDM-1 could be present in the population; should carbapenems be introduced as treatment in public hospitals in Kenya, resistance is likely to ensue rapidly. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.
is an important preventable cause of increased ... between July 2003 and December 2010, who developed a hospital-acquired Klebsiella pneumoniae infection, was undertaken to describe the trend in ..... Bacterial nosocomial pneumonia in.
Full Text Available Relata-se a ocorrência de graves sintomas de mastite hiperaguda em vaca, causada por Klebsiella pneumoniae, na terceira semana de lactação. Descrevem-se aspectos epidemiológicos, sintomas clínicos, procedimentos de diagnóstico microbiológico, conduta terapêutica e medidas de controle.
Full Text Available 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. However, it remains unclear if these observations can be transferred to K. pneumoniae harboring other mechanisms of carbapenem resistance. A three-dimensional synergy analysis was performed to evaluate the benefits of a triple combination with meropenem, tigecycline and colistin against 20 K. pneumoniae isolates harboring different β-lactamases. To examine the mechanism behind the clinically observed synergistic effect, efflux properties and outer membrane porin (Omp genes (ompK35 and ompK36 were also analyzed. Synergism was found for colistin-based double combinations for strains exhibiting high minimal inhibition concentrations against all of the three antibiotics. Adding a third antibiotic did not result in further increased synergistic effect in these strains. Antagonism did not occur. These results support the idea that colistin-based double combinations might be sufficient and the most effective combination partner for colistin should be chosen according to its MIC.
Lazarovitch, Tsilia; Amity, Keren; Coyle, Joseph R; Ackerman, Benjamin; Tal-Jasper, Ruthy; Ofer-Friedman, Hadas; Hayakawa, Kayoko; Bogan, Christopher; Lephart, Paul R; Kaplansky, Tamir; Maskit, Moran; Azouri, Tal; Zaidenstein, Ronit; Perez, Federico; Bonomo, Robert A; Kaye, Keith S; Marchaim, Dror
The pandemic of carbapenem-resistant Enterobacteriaceae (CRE) was primarily due to clonal spread of bla KPC producing Klebsiella pneumoniae. Thus, thoroughly studied CRE cohorts have consisted mostly of K. pneumoniae. To conduct an extensive epidemiologic analysis of carbapenem-resistant Enterobacter spp. (CREn) from 2 endemic and geographically distinct centers. CREn were investigated at an Israeli center (Assaf Harofeh Medical Center, January 2007 to July 2012) and at a US center (Detroit Medical Center, September 2008 to September 2009). bla KPC genes were queried by polymerase chain reaction. Repetitive extragenic palindromic polymerase chain reaction and pulsed-field gel electrophoresis were used to determine genetic relatedness. In this analysis, 68 unique patients with CREn were enrolled. Sixteen isolates (24%) were from wounds, and 33 (48%) represented colonization only. All isolates exhibited a positive Modified Hodge Test, but only 93% (27 of 29) contained bla KPC. Forty-three isolates (63%) were from elderly adults, and 5 (7.4%) were from neonates. Twenty-seven patients died in hospital (40.3% of infected patients). Enterobacter strains consisted of 4 separate clones from Assaf Harofeh Medical Center and of 4 distinct clones from Detroit Medical Center. In this study conducted at 2 distinct CRE endemic regions, there were unique epidemiologic features to CREn: (i) polyclonality, (ii) neonates accounting for more than 7% of cohort, and (iii) high rate of colonization (almost one-half of all cases represented colonization). Since false-positive Modified Hodge Tests in Enterobacter spp. are common, close monitoring of carbapenem resistance mechanisms (particularly carbapenemase production) among Enterobacter spp. is important.
Jin Young Lee
Full Text Available Background Carbapenem-resistant Enterobacteriaceae (CRE with acquired metallo β-lactamase (MBL resistance have been increasingly reported worldwide and associated with significant mortality and morbidity. Here, an outbreak of genetically related strains of Klebsiella pneumoniae producing the imipenemase (IMP-1 MBL in a medical intensive care unit (MICU in Korea is reported. Methods Since isolating carbapenem-resistant K. pneumoniae (CRKP at the MICU of the hospital on August 10, 2011, surveillance cultures for CRE in 31 hospitalized patients were performed from August to September 2011. Carbapenem resistance was determined based on the disk diffusion method outlined in the Clinical and Laboratory Standards Institute guidelines. Polymerase chain reaction (PCR was performed for genes coding for β-lactamase. Associations among isolates were assessed via pulsed-field gel electrophoresis (PFGE. In addition, a surveillance study of environmental cultures and health-care workers (HCWs was conducted in the MICU during the same time frame. Results During the study period, non-duplicated CRKP specimens were discovered in four patients in the MICU, suggestive of an outbreak. On August 10, 2011, CRKP was isolated from the sputum of a 79-year-old male patient who was admitted to the MICU. A surveillance study to detect additional CRE carriers by rectal swab revealed an additional three CRKP isolates. PCR and sequencing of the four isolates identified the presence of the IMP-1 gene. In addition, PFGE showed that the four isolated strains were genetically related. CRE was not identified in specimens taken from the hands of HCWs or other environmental sources during surveillance following the outbreak. Transmission of the carbapenemase-producing Enterobacteriaceae strain was controlled by isolation of the patients and strict contact precautions. Conclusions This study shows that rapid and systemic detection of CRE and strict infection controls are important
Follador, Rainer; Heinz, Eva; Wyres, Kelly L; Ellington, Matthew J; Kowarik, Michael; Holt, Kathryn E; Thomson, Nicholas R
Klebsiella pneumoniae is considered an urgent health concern due to the emergence of multi-drug-resistant strains for which vaccination offers a potential remedy. Vaccines based on surface polysaccharides are highly promising but need to address the high diversity of surface-exposed polysaccharides, synthesized as O-antigens (lipopolysaccharide, LPS) and K-antigens (capsule polysaccharide, CPS), present in K. pneumoniae . We present a comprehensive and clinically relevant study of the diversity of O- and K-antigen biosynthesis gene clusters across a global collection of over 500 K. pneumoniae whole-genome sequences and the seroepidemiology of human isolates from different infection types. Our study defines the genetic diversity of O- and K-antigen biosynthesis cluster sequences across this collection, identifying sequences for known serotypes as well as identifying novel LPS and CPS gene clusters found in circulating contemporary isolates. Serotypes O1, O2 and O3 were most prevalent in our sample set, accounting for approximately 80 % of all infections. In contrast, K serotypes showed an order of magnitude higher diversity and differ among infection types. In addition we investigated a potential association of O or K serotypes with phylogenetic lineage, infection type and the presence of known virulence genes. K1 and K2 serotypes, which are associated with hypervirulent K. pneumoniae , were associated with a higher abundance of virulence genes and more diverse O serotypes compared to other common K serotypes.
Logan, Latania K; Weinstein, Robert A
Carbapenem-resistant Enterobacteriaceae (CRE) are a serious public health threat. Infections due to these organisms are associated with significant morbidity and mortality. Mechanisms of drug resistance in gram-negative bacteria (GNB) are numerous; β-lactamase genes carried on mobile genetic elements are a key mechanism for the rapid spread of antibiotic-resistant GNB worldwide. Transmissible carbapenem-resistance in Enterobacteriaceae has been recognized for the last 2 decades, but global dissemination of carbapenemase-producing Enterobacteriaceae (CPE) is a more recent problem that, once initiated, has been occurring at an alarming pace. In this article, we discuss the evolution of CRE, with a focus on the epidemiology of the CPE pandemic; review risk factors for colonization and infection with the most common transmissible CPE worldwide, Klebsiella pneumoniae carbapenemase-producing K. pneumoniae; and present strategies used to halt the striking spread of these deadly pathogens. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail email@example.com.
Saseedharan, Sanjith; Sahu, Manisa; Pathrose, Edwin Joseph; Shivdas, Sarita
Carbapenem-resistant Enterobacteriaceae (CRE) are drug-resistant Gram-negative bacteria that are present in the community as well as in hospitals. Their infection and colonisation puts critically ill patients at high risk due to the drug-resistant nature of the strains and possible spreading of these organisms, even in a hospital environment. To examine the presence and types of Enterobacteriaceae species in patients admitted directly from the community. The present study was a one-month pilot conducted in the ICU of a tertiary care hospital in Mumbai, India in 2015. Faecal samples of patients admitted from the community directly to the ICU were analysed using tests like MHT (Modified Hodge) and EDTA for the presence of IMP (action on Imipenem) and KPC ( Klebsiella Test Pneumoniae Carbapenemase) producing strains of Enterobacteriaceae . Polymerase Chain Reaction (PCR) was performed to look for VIM , IMP , NDM 1, OXA , and KPC genes. Antibiotic Sensitivity Test was carried out as per CLSI guidelines. The results showed an alarming level of faecal carriage rates in adult ICU patients. Klebsiella pneumonia was the most common carbapenem-resistant isolate, closely followed by Escherichia coli . PCR results revealed nine strains were positive for bla (KPC) gene, from which 7 were Klebsiella pneumoniae and one each of Escherichia coli and Klebsiella oxytoca was observed. Antibiotic Sensitivity Test results showed that the isolates had maximum sensitivity to Colistin (100%) and Tigecycline (95%). These levels indicate that in the absence of CRE screenings, proper isolation of carrier patients is not possible, leading to possible spreading of these resistant bacteria strains in ICUs. A longer period of study is required to obtain more substantial data to validate the results of this pilot.
Linson, Sarah E.; Ojeda Saavedra, Matthew; Cantu, Concepcion; Davis, James J.; Brettin, Thomas; Olsen, Randall J.
ABSTRACT Klebsiella pneumoniae is a major threat to public health, causing significant morbidity and mortality worldwide. The emergence of highly drug-resistant strains is particularly concerning. There has been a recognition and division of Klebsiella pneumoniae into three distinct phylogenetic groups: Klebsiella pneumoniae, Klebsiella variicola, and Klebsiella quasipneumoniae. K. variicola and K. quasipneumoniae have often been described as opportunistic pathogens that have less virulence in humans than K. pneumoniae does. We recently sequenced the genomes of 1,777 extended-spectrum-beta-lactamase (ESBL)-producing K. pneumoniae isolates recovered from human infections and discovered that 28 strains were phylogenetically related to K. variicola and K. quasipneumoniae. Whole-genome sequencing of 95 additional non-ESBL-producing K. pneumoniae isolates recovered from patients found 12 K. quasipneumoniae strains. Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) analysis initially identified all patient isolates as K. pneumoniae, suggesting a potential pitfall in conventional clinical microbiology laboratory identification methods. Whole-genome sequence analysis revealed extensive sharing of core gene content and plasmid replicons among the Klebsiella species. For the first time, strains of both K. variicola and K. quasipneumoniae were found to carry the Klebsiella pneumoniae carbapenemase (KPC) gene, while another K. variicola strain was found to carry the New Delhi metallo-beta-lactamase 1 (NDM-1) gene. K. variicola and K. quasipneumoniae infections were not less virulent than K. pneumoniae infections, as assessed by in-hospital mortality and infection type. We also discovered evidence of homologous recombination in one K. variicola strain, as well as one strain from a novel Klebsiella species, which challenge the current understanding of interrelationships between clades of Klebsiella. IMPORTANCE Klebsiella
Cunha, Cheston B; Kassakian, Steven Z; Chan, Ryan; Tenover, Fred C; Ziakas, Panos; Chapin, Kimberle C; Mermel, Leonard A
There are increasing reports of multidrug-resistant gram-negative bacilli in nursing homes and acute care hospitals. We performed a point prevalence survey to detect fecal carriage of gram-negative bacteria carrying carbapenem resistance genes or which were otherwise resistant to carbapenem antibiotics among 500 consecutive admissions from local nursing homes to 2 hospitals in Providence, Rhode Island. We performed a case-control study to identify risk factors associated with carriage of carbapenem-resistant Enterobacteriaceae (CRE). There were 404 patients with 500 hospital admissions during which they had rectal swab samples cultured. Fecal carriage of any carbapenem-resistant or carbapenemase- producing gram-negative bacteria was found in 23 (4.6%) of the 500 hospital admissions, including 7 CRE (1.4%), 2 (0.4%) of which were Klebsiella pneumoniae carbapenemase (ie, blaKPC) producing (CPE) Citrobacter freundii, 1 of which was carbapenem susceptible by standard testing methods. Use of a gastrostomy tube was associated with CRE carriage (P = .04). We demonstrated fecal carriage of carbapenem-resistant or carbapenemase-producing gram-negative bacteria in 4.6% of nursing home patients admitted to 2 acute care hospitals, but only 0.4% of such admissions were patients with fecal carriage of CPE. Use of gastrostomy tubes was associated with fecal carriage of gram-negative bacteria with detectable carbapenem resistance. CRE fecal carriage is uncommon in our hospital admissions from nursing homes. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.
Fortini, Daniela; Villa, Laura; Feudi, Claudia; Pires, João; Bonura, Celestino; Mammina, Caterina; Endimiani, Andrea; Carattoli, Alessandra
A carbapenem-resistant sequence type 512 (ST512) Klebsiella pneumoniae carbapenemase 3 (KPC-3)-producing K. pneumoniae strain showing a novel variant plasmid content was isolated in Palermo, Italy, in 2014. ST512 is a worldwide successful clone associated with the spread of bla(KPC) genes located on the IncFIIk pKpQIL plasmid. In our ST512 strain, the bla(KPC-3) gene was unusually located on an IncX3 plasmid, whose complete sequence was determined. Two copies of bla(KPC-3)::Tn4401a caused by intramolecular transposition events were detected in the plasmid. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
Full Text Available Clinical isolates of carbapenem-resistant Klebsiella pneumoniae (K. pneumoniae strains are being increased worldwide. Five pan-resistant K. pneumoniae strains have been isolated from respiratory and ICU wards in a Chinese hospital, and reveal strong resistance to all β-lactams, fluoroquinolones and aminoglycosides. Totally 27 β-lactamase genes and 2 membrane pore protein (porin genes in 5 K. pneumoniae strains were screened by polymerase chain reaction (PCR. The results indicated that all of 5 K. pneumoniae strains carried blaTEM-1 and blaDHA-1 genes, as well as base deletion and mutation of OmpK35 or OmpK36 genes. Compared with carbapenem-sensitive isolates by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE, the resistant isolates markedly lacked the protein band of 34-40 kDa, which might be the outer membrane proteins of OmpK36 according to the electrophoresis mobility. In addition, the conjugation test was confirmed that blaDHA-1 mediated by plasmids could be transferred between resistant and sensitive strains. When reserpine (30 µg/mL and carbonyl cyanide m-chlorophenylhydrazone (CCCP (50 µg/mL were added in imipenem and meropenem, the MICs had no change against K. pneumoniae strains. These results suggest that both DHA-1 β-lactamase and loss or deficiency of porin OmpK36 may be the main reason for the cefoxitin and carbapenem resistance in K. pneumoniae strains in our hospital.
Schwaber, Mitchell J; Carmeli, Yehuda
In 2006 the Israeli healthcare system faced an unprecedented outbreak of carbapenem-resistant Enterobacteriaceae, primarily involving KPC-producing Klebsiella pneumoniae clonal complex CC258. This public health crisis exposed major gaps in infection control. In response, Israel established a national infection control infrastructure. The steps taken to build this infrastructure and benefits realized from its creation are described here. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: firstname.lastname@example.org.
Lin, Tzu-Lung; Pan, Yi-Jiun; Hsieh, Pei-Fang; Hsu, Chun-Ru; Wu, Meng-Chuan; Wang, Jin-Town
Analysis of the genome of Klebsiella pneumoniae NTUH-K2044 strain revealed the presence of two clustered regularly interspaced short palindromic repeats (CRISPR) arrays separated with CRISPR-associated (cas) genes. Carbapenem-resistant K. pneumoniae isolates were observed to be less likely to have CRISPR-Cas than sensitive strains (5/85 vs. 22/132). Removal of the transcriptional repressor, H-NS, was shown to prevent the transformation of plasmids carrying a spacer and putative proto-spacer adjacent motif (PAM). The CRISPR-Cas system also decreased pUC-4K plasmid stability, resulting in plasmid loss from the bacteria with acquisition of new spacers. Analysis of the acquired proto-spacers in pUC-4K indicated that 5'-TTN-3' was the preferred PAM in K. pneumoniae. Treatment of cells by imipenem induced hns expression, thereby decreasing cas3 expression and consequently repressed CRISPR-Cas activity resulted in increase of plasmid stability. In conclusion, NTUH-K2044 CRISPR-Cas contributes to decrease of plasmid transformation and stability. Through repression of CRISPR-Cas activity by induced H-NS, bacteria might be more able to acquire DNA to confront the challenge of imipenem.
Lin, Tzu-Lung; Pan, Yi-Jiun; Hsieh, Pei-Fang; Hsu, Chun-Ru; Wu, Meng-Chuan; Wang, Jin-Town
Analysis of the genome of Klebsiella pneumoniae NTUH-K2044 strain revealed the presence of two clustered regularly interspaced short palindromic repeats (CRISPR) arrays separated with CRISPR-associated (cas) genes. Carbapenem-resistant K. pneumoniae isolates were observed to be less likely to have CRISPR-Cas than sensitive strains (5/85 vs. 22/132). Removal of the transcriptional repressor, H-NS, was shown to prevent the transformation of plasmids carrying a spacer and putative proto-spacer adjacent motif (PAM). The CRISPR-Cas system also decreased pUC-4K plasmid stability, resulting in plasmid loss from the bacteria with acquisition of new spacers. Analysis of the acquired proto-spacers in pUC-4K indicated that 5′-TTN-3′ was the preferred PAM in K. pneumoniae. Treatment of cells by imipenem induced hns expression, thereby decreasing cas3 expression and consequently repressed CRISPR-Cas activity resulted in increase of plasmid stability. In conclusion, NTUH-K2044 CRISPR-Cas contributes to decrease of plasmid transformation and stability. Through repression of CRISPR-Cas activity by induced H-NS, bacteria might be more able to acquire DNA to confront the challenge of imipenem. PMID:27531594
Creyghton, W. M.; Lobatto, S.; Weening, J. J.
We report a 34-year-old male patient without prior medical history who presented with acute renal failure due to acute bacterial pyelonephritis. Both blood and urine cultures grew Klebsiella pneumoniae. Although a kidney biopsy revealed extensive necrosis and no viable glomeruli, renal function
During the course of her treatment she acquired various infections that led to her exposure to antimicrobials from almost all classes at various times; including bacteremia due to a pan-drug resistant Klebsiella pneumoniae and multi-drug resistant Acinetobacter baumannii. She was successfully treated with a combination of ...
Chen, Liang; Patel, Gopi; Gomez-Simmonds, Angela; Weston, Gregory; Kim, Angela C.; Seo, Susan K.; Rosenthal, Marnie E.; Sperber, Steven J.; Jenkins, Stephen G.; Hamula, Camille L.; Uhlemann, Anne-Catrin; Levi, Michael H.; Fries, Bettina C.; Juretschko, Stefan; Rojtman, Albert D.; Hong, Tao; Mathema, Barun; Jacobs, Michael R.; Walsh, Thomas J.; Bonomo, Robert A.; Kreiswirth, Barry N.
ABSTRACT Although the New York/New Jersey (NY/NJ) area is an epicenter for carbapenem-resistant Enterobacteriaceae (CRE), there are few multicenter studies of CRE from this region. We characterized patients with CRE bacteremia in 2013 at eight NY/NJ medical centers and determined the prevalence of carbapenem resistance among Enterobacteriaceae bloodstream isolates and CRE resistance mechanisms, genetic backgrounds, capsular types (cps), and antimicrobial susceptibilities. Of 121 patients with CRE bacteremia, 50% had cancer or had undergone transplantation. The prevalences of carbapenem resistance among Klebsiella pneumoniae, Enterobacter spp., and Escherichia coli bacteremias were 9.7%, 2.2%, and 0.1%, respectively. Ninety percent of CRE were K. pneumoniae and 92% produced K. pneumoniae carbapenemase (KPC-3, 48%; KPC-2, 44%). Two CRE produced NDM-1 and OXA-48 carbapenemases. Sequence type 258 (ST258) predominated among KPC-producing K. pneumoniae (KPC-Kp). The wzi154 allele, corresponding to cps-2, was present in 93% of KPC-3-Kp, whereas KPC-2-Kp had greater cps diversity. Ninety-nine percent of CRE were ceftazidime-avibactam (CAZ-AVI)-susceptible, although 42% of KPC-3-Kp had an CAZ-AVI MIC of ≥4/4 μg/ml. There was a median of 47 h from bacteremia onset until active antimicrobial therapy, 38% of patients had septic shock, and 49% died within 30 days. KPC-3-Kp bacteremia (adjusted odds ratio [aOR], 2.58; P = 0.045), cancer (aOR, 3.61, P = 0.01), and bacteremia onset in the intensive care unit (aOR, 3.79; P = 0.03) were independently associated with mortality. Active empirical therapy and combination therapy were not associated with survival. Despite a decade of experience with CRE, patients with CRE bacteremia have protracted delays in appropriate therapies and high mortality rates, highlighting the need for rapid diagnostics and evaluation of new therapeutics. PMID:28167547
Okada, Fumito [Oita University Faculty of Medicine, Department of Diagnostic and Interventional Radiology, Oita (Japan); Oita University Faculty of Medicine, Department of Radiology, Oita (Japan); Ando, Yumiko; Honda, Koichi; Nakayama, Tomoko; Kiyonaga, Maki; Ono, Asami; Tanoue, Shuichi; Maeda, Toru; Mori, Hiromu [Oita University Faculty of Medicine, Department of Diagnostic and Interventional Radiology, Oita (Japan)
The aim of this study was to assess the clinical and pulmonary thin-section CT findings in patients with acute Klebsiella pneumoniae pneumonia. We retrospectively evaluated thin-section CT examinations performed between January 1991 and December 2007 from 962 patients with acute Klebsiella pneumoniae pneumonia. Seven hundred and sixty-four cases with concurrent infectious diseases were excluded. Thus, our study group comprised 198 patients (118 male, 80 female; age range 18-97 years, mean age 61.5). Underlying diseases and clinical findings were assessed. Parenchymal abnormalities were evaluated along with the presence of enlarged lymph nodes and pleural effusion. CT findings in patients with acute Klebsiella pneumoniae pneumonia consisted mainly of ground-glass attenuation (100%), consolidation (91.4%), and intralobular reticular opacity (85.9%), which were found in the periphery (96%) of both sides of the lungs (72.2%) and were often associated with pleural effusion (53%). The underlying conditions in patients with Klebsiella pneumoniae pneumonia were alcoholism or smoking habit. (orig.)
Okada, Fumito; Ando, Yumiko; Honda, Koichi; Nakayama, Tomoko; Kiyonaga, Maki; Ono, Asami; Tanoue, Shuichi; Maeda, Toru; Mori, Hiromu
The aim of this study was to assess the clinical and pulmonary thin-section CT findings in patients with acute Klebsiella pneumoniae pneumonia. We retrospectively evaluated thin-section CT examinations performed between January 1991 and December 2007 from 962 patients with acute Klebsiella pneumoniae pneumonia. Seven hundred and sixty-four cases with concurrent infectious diseases were excluded. Thus, our study group comprised 198 patients (118 male, 80 female; age range 18-97 years, mean age 61.5). Underlying diseases and clinical findings were assessed. Parenchymal abnormalities were evaluated along with the presence of enlarged lymph nodes and pleural effusion. CT findings in patients with acute Klebsiella pneumoniae pneumonia consisted mainly of ground-glass attenuation (100%), consolidation (91.4%), and intralobular reticular opacity (85.9%), which were found in the periphery (96%) of both sides of the lungs (72.2%) and were often associated with pleural effusion (53%). The underlying conditions in patients with Klebsiella pneumoniae pneumonia were alcoholism or smoking habit. (orig.)
Full Text Available Abstract Background Klebsiella pneumoniae is a capsulated Gram negative bacterial pathogen and a frequent cause of nosocomial infections. Despite its clinical relevance, little is known about the features of the interaction between K. pneumoniae and lung epithelial cells on a cellular level, neither about the role of capsule polysaccharide, one of its best characterised virulence factors, in this interaction. Results The interaction between Klebsiella pneumoniae and cultured airway epithelial cells was analysed. K. pneumoniae infection triggered cytotoxicity, evident by cell rounding and detachment from the substrate. This effect required the presence of live bacteria and of capsule polysaccharide, since it was observed with isolates expressing different amounts of capsule and/or different serotypes but not with non-capsulated bacteria. Cytotoxicity was analysed by lactate dehydrogenase and formazan measurements, ethidium bromide uptake and analysis of DNA integrity, obtaining consistent and complementary results. Moreover, cytotoxicity of non-capsulated strains was restored by addition of purified capsule during infection. While a non-capsulated strain was avirulent in a mouse infection model, capsulated K. pneumoniae isolates displayed different degrees of virulence. Conclusion Our observations allocate a novel role to K. pneumoniae capsule in promotion of cytotoxicity. Although this effect is likely to be associated with virulence, strains expressing different capsule levels were not equally virulent. This fact suggests the existence of other bacterial requirements for virulence, together with capsule polysaccharide.
Tsai, Yu-Kuo; Liou, Ci-Hong; Fung, Chang-Phone; Lin, Jung-Chung; Siu, L. Kristopher
Resistance to carbapenems has been documented by the production of carbapenemase or the loss of porins combined with extended-spectrum β-lactamases or AmpC β-lactamases. However, no complete comparisons have been made regarding the contributions of each resistance mechanism towards carbapenem resistance. In this study, we genetically engineered mutants of Klebsiella pneumoniae with individual and combined resistance mechanisms, and then compared each resistance mechanism in response to ertapenem, imipenem, meropenem, doripenem and other antibiotics. Among the four studied carbapenems, ertapenem was the least active against the loss of porins, cephalosporinases and carbapenemases. In addition to the production of KPC-2 or NDM-1 alone, resistance to all four carbapenems could also be conferred by the loss of two major porins, OmpK35 and OmpK36, combined with CTX-M-15 or DHA-1 with its regulator AmpR. Because the loss of OmpK35/36 alone or the loss of a single porin combined with bla CTX-M-15 or bla DHA-1-ampR expression was only sufficient for ertapenem resistance, our results suggest that carbapenems other than ertapenem should still be effective against these strains and laboratory testing for non-susceptibility to other carbapenems should improve the accurate identification of these isolates. PMID:24265784
Sabirova, Julia S; Xavier, Basil Britto; Coppens, Jasmine; Zarkotou, Olympia; Lammens, Christine; Janssens, Lore; Burggrave, Ronald; Wagner, Trevor; Goossens, Herman; Malhotra-Kumar, Surbhi
We utilized whole-genome mapping (WGM) and WGS to characterize 12 clinical carbapenem-resistant Klebsiella pneumoniae strains (TGH1-TGH12). All strains were screened for carbapenemase genes by PCR, and typed by MLST, PFGE (XbaI) and WGM (AflII) (OpGen, USA). WGS (Illumina) was performed on TGH8 and TGH10. Reads were de novo assembled and annotated [SPAdes, Rapid Annotation Subsystem Technology (RAST)]. Contigs were aligned directly, and after in silico AflII restriction, with corresponding WGMs (MapSolver, OpGen; BioNumerics, Applied Maths). All 12 strains were ST383. Of the 12 strains, 11 were carbapenem resistant, 7 harboured blaKPC-2 and 11 harboured blaVIM-19. Varying the parameters for assigning WGM clusters showed that these were comparable to STs and to the eight PFGE types or subtypes (difference of three or more bands). A 95% similarity coefficient assigned all 12 WGMs to a single cluster, whereas a 99% similarity coefficient (or ≥10 unmatched-fragment difference) assigned the 12 WGMs to eight (sub)clusters. Based on a difference of three or more bands between PFGE profiles, the Simpson's diversity indices (SDIs) of WGM (0.94, Jackknife pseudo-values CI: 0.883-0.996) and PFGE (0.93, Jackknife pseudo-values CI: 0.828-1.000) were similar (P = 0.649). However, the discriminatory power of WGM was significantly higher (SDI: 0.94, Jackknife pseudo-values CI: 0.883-0.996) than that of PFGE profiles typed on a difference of seven or more bands (SDI: 0.53, Jackknife pseudo-values CI: 0.212-0.849) (P = 0.007). This study demonstrates the application of WGM to understanding the epidemiology of hospital-associated K. pneumoniae. Utilizing a combination of WGM and WGS, we also present here the first longitudinal genomic characterization of the highly dynamic carbapenem-resistant ST383 K. pneumoniae clone that is rapidly gaining importance in Europe. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial
Full Text Available The present study aimed to analyze the genetic similarity between genomic profiles of thirteen Klebsiella oxytoca and seven Klebsiella pneumoniae samples isolated from two different collections carried out in different places of dental offices. Random amplified polymorphic DNA (RAPD technique and similarity coefficients (calculated by Sorensen-Dice and simple matching were applied to determine their genetic profile of randomic DNA sequences. The majority of the isolates of K. pneumoniae and K. oxytoca presented similar coefficient values (e" 0.80. Thus, it was possible to identify that strain dissemination occurred mainly via the hands of the surgeon-dentists and, finally, to determine the genetic similarity of the strains from dental office environments.
Di Renzo, Dacia; Pappalepore, Nicola; Colangelo, Maurizia; Chiesa, Pierluigi Lelli
The management of acute scrotal swelling can be challenging in neonatal age, with scrotal infections being great mimickers of testicular torsion. Only a few unilateral cases of scrotal abscess have been previously reported, mostly caused by Staphylococcus and Salmonella. We describe the case of a newborn who developed bilateral scrotal abscesses caused by Klebsiella pneumoniae and discuss the rarity of the case, regarding both the bilaterality and the pathogen, never reported before.
Domenico, P; Salo, R J; Cross, A S; Cunha, B A
The polysaccharide capsule of Klebsiella pneumoniae is an important virulence factor that confers resistance to phagocytosis. The treatment of encapsulated bacteria with salicylate to inhibit capsule expression was found to enhance the phagocytosis of encapsulated bacteria by human neutrophils only in the presence of cell surface-specific antibodies. Both type-specific rabbit antisera and anticapsular human hyperimmune globulin were employed as opsonins. Salicylate significantly enhanced phag...
Igoche David Peter
Full Text Available In the Western world, cases of purulent pericarditis have become almost nonexistent with progress and advent of new immunizations against many causative organisms. We report Klebsiella pneumoniae pericarditis, a rare cause of this uncommon disease, hitherto unreported in Nigeria. K. pneumoniae, which is a rod-shaped, Gram-negative, facultative anaerobe, produces extended-spectrum beta-lactamases; hence, it is usually resistant to a lot of antibiotics and is associated with a significant case fatality rate. Our 13-year-old male patient had septic arthritis of the right hip joint came with a 3 weeks complaint of difficulty with breathing. He had respiratory distress, tachypnea, and tachycardia. Although blood pressure was normal, he had pulsus paradoxus, elevated jugular venous pressure, diffuse apex beat, and heart sounds were distant. Chest radiograph revealed an increased cardiothoracic ratio (0.86 with “water bottle” appearance. Transthoracic echocardiography confirmed pericardial effusion with cardiac tamponade. Echo-guided pericardiocentesis was done, and 340 ml of foul-smelling and creamy pus with greenish tinge was aspirated and this grew K. pneumoniae sensitive to ciprofloxacin and gentamycin but resistant to other conventional antibiotics. Recovery was complete after a week of pericardial tube drainage and 3 weeks of treatment. To the best of our knowledge, this is the first case of Klebsiella - induced pyopericardium and with successful management in a Nigerian child. Pyopericardium may follow rare causes such as K. pneumoniae infection with its unique antibiogram.
Righi, Elda; Peri, Anna Maria; Harris, Patrick N A; Wailan, Alexander M; Liborio, Mariana; Lane, Steven W; Paterson, David L
Carbapenem-resistant Gram-negative bacteria are recognized as a cause of difficult-to-treat infections associated with high mortality. To perform a systematic review of currently available data on distribution, characteristics and outcome associated with carbapenem-resistant bloodstream infections in adult neutropenic patients. Included studies were identified through Medline, Embase and Cochrane databases between January 1995 and April 2016. Random effect meta-analysis was used to quantify the association between carbapenem resistance and mortality and between carbapenem exposure and resistance. A total of 30 studies from 21 countries were included. Overall carbapenem resistance varied from 2% to 53% (median 9%) among studies. Infections due to carbapenem-resistant Pseudomonas spp . were reported in 18 (60%) studies showing high median resistance rates (44% of all carbapenem-resistant Gram-negatives and 19% of Pseudomonas isolates). Resistance of Enterobacteriaceae was less commonly reported and bloodstream infections due to carbapenem-resistant Klebsiella spp. were mainly documented from endemic areas (Greece, Italy, Israel). Carbapenem resistance in Acinetobacter spp. was reported in 9 (30%) studies (median resistance 58% of Acinetobacter isolates). Mortality rates ranged from 33% to 71% (median 50%) in patients with carbapenem-resistant infections. Carbapenem resistance appeared to correlate with mortality (OR 4.89, 95% CI 3.30-7.26) and previous exposure to carbapenems (OR 4.63, 95% CI 3.08-6.96). Carbapenem resistance represents a threat to neutropenic patients. In this group, resistance is likely promoted by previous carbapenem use and leads to high mortality rates. The knowledge of resistance patterns is crucial and can direct clinicians in the use of alternatives to carbapenem-based regimens. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please
Paczosa, Michelle K.
SUMMARY Klebsiella pneumoniae causes a wide range of infections, including pneumonias, urinary tract infections, bacteremias, and liver abscesses. Historically, K. pneumoniae has caused serious infection primarily in immunocompromised individuals, but the recent emergence and spread of hypervirulent strains have broadened the number of people susceptible to infections to include those who are healthy and immunosufficient. Furthermore, K. pneumoniae strains have become increasingly resistant to antibiotics, rendering infection by these strains very challenging to treat. The emergence of hypervirulent and antibiotic-resistant strains has driven a number of recent studies. Work has described the worldwide spread of one drug-resistant strain and a host defense axis, interleukin-17 (IL-17), that is important for controlling infection. Four factors, capsule, lipopolysaccharide, fimbriae, and siderophores, have been well studied and are important for virulence in at least one infection model. Several other factors have been less well characterized but are also important in at least one infection model. However, there is a significant amount of heterogeneity in K. pneumoniae strains, and not every factor plays the same critical role in all virulent Klebsiella strains. Recent studies have identified additional K. pneumoniae virulence factors and led to more insights about factors important for the growth of this pathogen at a variety of tissue sites. Many of these genes encode proteins that function in metabolism and the regulation of transcription. However, much work is left to be done in characterizing these newly discovered factors, understanding how infections differ between healthy and immunocompromised patients, and identifying attractive bacterial or host targets for treating these infections. PMID:27307579
Wu, Ping-Feng; Chuang, Chien; Su, Chin-Fang; Lin, Yi-Tsung; Chan, Yu-Jiun; Wang, Fu-Der; Chuang, Yin-Ching; Siu, L Kristopher; Fung, Chang-Phone
Carbapenem resistance in Klebsiella pneumoniae is important because of its increasing prevalence and limited therapeutic options. To investigate the clinical and microbiological characteristics of patients infected or colonized with carbapenem non-susceptible K. pneumoniae (CnsKP) in Taiwan, we conducted a retrospective study at Taipei Veterans General Hospital from January 2012 to November 2013. Carbapenem non-susceptibility was defined as a minimum inhibitory concentration (MIC) of ≥2 mg/L for imipenem or meropenem. A total of 105 cases with CnsKP were identified: 49 patients with infection and 56 patients with colonization. Thirty-one isolates had genes that encoded carbapenemases (29.5%), including K. pneumoniae carbapenemase (KPC)-2 (n = 27), KPC-3 (n = 1), VIM-1 (n = 1) and IMP-8 (n = 2). The in-hospital mortality among patients with CnsKP was 43.8%. A MIC for imipenem ≥16 μg/mL, nasogastric intubation and Acute Physiology and Chronic Health Evaluation II score were independent risk factors for in-hospital mortality for all patients with CnsKP. A MIC for imipenem ≥16 μg/mL was also an independent risk factor for 14-day mortality in patients with CnsKP. In conclusion, a positive culture for CnsKP was associated with high in-hospital mortality. A high imipenem MIC of CnsKP can predispose a patient to a poor prognosis.
Full Text Available Introduction. The dissemination of carbapenemase-producing Klebsiella pneumoniae strains is an increasing problem worldwide. KPC ß-lactamases are Ambler class A enzymes mostly plasmid-encoded; their global spread represents a threat to clinical patients care and public health. Multi locus sequence type (ST258 is currently the most spread K. pneumoniae clone associated with KPC enzymes. Here we report the first identification and multifocal spread of KPC-3 producing K. pneumoniae clinical strains belonging to ST512 in Italy. Materials and Methods. Fifty six carbapenem-resistant K. pneumoniae isolates were collected from 7 Italian hospitals during the period June 2009-May 2011. Isolates were obtained from different wards (spinal unit, medicine, hematology, etc. and biological samples (mostly rectal swabs, urine and blood. Species identification and antimicrobial susceptibilities were obtained by NBC46/NM40 Microscan panels (Siemens. MICs values were interpreted according to EUCAST 2011 breakpoints. Modified Hodge test and combined disk test with phenyl-boronic acid (BOR and EDTA were performed.The presence of blaKPC genes were confirmed by PCR and sequencing. A complete characterization of the produced ß-lactamases (BLs was obtained by IEF followed by PCR experiments using primers specific for the detection of blaCTX-M-, blaTEM- and blaSHV type genes. PFGE and multilocus sequence typing (MLST were both used to investigate clonal isolates relatedness. Results. All 56 isolates resulted positive for the presence of KPC-type carbapenemases by both phenotypical and molecular analysis. Fifteen isolates, chosen as representative, were further investigated. Ten out of 15 isolates harboring the blaKPC-2 gene clustered with the known ST258, while the remaining 5/10 belonged to the newly described ST512 and harbored the blaKPC-3 gene. ST512 isolates, from 3/7 hospitals, were collected from rectal swabs (40%, blood (20%, endotracheal aspirate (20% and
Davis, Gregg S.; Waits, Kara; Nordstrom, Lora; Weaver, Brett; Aziz, Maliha; Gauld, Lori; Grande, Heidi; Bigler, Rick; Horwinski, Joseph; Porter, Stephen; Stegger, Marc; Johnson, James R.; Liu, Cindy M.; Price, Lance B.
Background. ?Klebsiella pneumoniae is a common colonizer of the gastrointestinal tract of humans, companion animals, and livestock. To better understand potential contributions of foodborne K. pneumoniae to human clinical infections, we compared K. pneumoniae isolates from retail meat products and human clinical specimens to assess their similarity based on antibiotic resistance, genetic relatedness, and virulence. Methods. ?Klebsiella pneumoniae was isolated from retail meats from Flagstaff ...
Full Text Available Klebsiella pneumoniae is one of a coliform bacteria that causing mastitis. This disease were founded in dairy cows and can be prevented by vaccination. The research has been conducted to determine the inactive times, the protein concentration and profile of K. pneumoniae which inactivated by heating of 65oC as material of mastitis vaccine. The cells culture inactivated by the different times, i.e. 0, 10, 20, 30, 40, 50 and 60 minutes. The inactive times was determined by the drop test method, whereas the protein concentration of cells were determined by Lowry method. The results showed that the inactive times occured after 30 minute, and has a significant different on the protein concentration of bacteria cells that inactivated by the different times.
Woll, Christopher; Spotts, P. Hunter
The authors describe a case of "Klebsiella pneumoniae" liver abscess (KPLA) in a student presenting to a university student health center. The authors also provide a review of KPLA and invasive "Klebsiella pneumoniae" liver abscess syndrome (IKPLAS), including epidemiology, common clinical manifestations, standard diagnostic…
Malpani, A.R.; Sundaram, M.; Ramani, S.K.
This patient represents a unique combination of multicentric osteomyelitis due to Klebsiella pneumoniae, lesions in the skull, pathological fracture of a long bone and no evidence of pulmonary disease. That Klebsiella pneumoniae osteomyelitis can occur in sickle cell anemia should be considered when such bone changes are seen. The remarkable resolution on conservative management also needs to be noted. (orig./GDG)
Full Text Available Abstract: Antibiotic-resistant bacteria are spreading worldwide in medical settings but also in the environment. These resistant bacteria illustrate a major health problem in our times, and last-line antibiotics such as tigecycline represent an ultimate therapy option. Reports on tigecycline non-susceptible Enterobacteriaceae are presented with regard to medical settings but are rare with that for the environment. The aim of this study was to characterize two tigecycline non-susceptible Klebsiella pneumoniae isolates from the river Mur, and to question the resistance mechanism. The screening for chromosomal mutations revealed a deletion and a silent point mutation in one isolate and a point mutation in the other isolate all within the ramR allele. RamR acts as repressor and prevents overexpression of ramA. These mutations are likely to cause a resistant phenotype due to the overexpression of AcrAB-TolC. MLST revealed that the isolates belonged to two unrelated MLST types (ST2392 and ST2394. Both isolates only revealed resistance to tigecycline and tetracycline. This is one of the rare reports of tigecycline-resistant Klebsiella pneumoniae from surface water. The presence of two genetically different isolates suggests that the river water may bear substances that favor mutations that can lead to this efflux pump-driven resistance.
Vanegas, Johanna M; Parra, O Lorena; Jiménez, J Natalia
Gram-negative bacilli are a cause of serious infections in the pediatric population. Carbapenem are the treatment of choice for infections caused by multidrug-resistant Gram-negative bacilli, but the emergence of carbapenem resistance has substantially reduced access to effective antimicrobial regimens. Children are a population vulnerable to bacterial infections and the emergence of resistance can worsen prognosis. The aim of this study is to describe the clinical and molecular characteristics of infections caused by carbapenem-resistant Gram-negative bacilli in pediatric patients from five tertiary-care hospitals in Medellín, Colombia. A cross-sectional study was conducted in five tertiary-care hospitals from June 2012 to June 2014. All pediatric patients infected by carbapenem-resistant Gram-negative bacilli were included. Clinical information for each patient was obtained from medical records. Molecular analyses included PCR for detection of bla VIM, bla IMP bla NDM, bla OXA-48 and bla KPC genes and PFGE and MLST for molecular typing. A total of 59 patients were enrolled, most of them less than 1 year old (40.7 % n = 24), with a previous history of antibiotic use (94.9 %; n = 56) and healthcare-associated infections - predominately urinary tract infections (31.0 %; n = 18). Klebsiella pneumoniae was the most frequent bacteria (47.4 %), followed by Enterobacter cloacae (40.7 %) and Pseudomonas aeruginosa (11.9 %). For K. pneumoniae, KPC was the predominant resistance mechanism (85.7 %; n = 24) and ST14 was the most common clone (39.3 % n = 11), which included strains closely related by PFGE. In contrast, E. cloacae and P. aeruginosa were prevailing non-carbapenemase-producing isolates (only KPC and VIM were detected in 1 and 3 isolates, respectively) and high genetic diversity according to PFGE and MLST was found in the majority of the cases. In recent years, increasing carbapenem-resistant bacilli in children has become in a matter
Baig, M.; Brown, A.; Eswaramoorthy, S.; Swaminathan, S.
Klebsiella pneumoniae, a gram-negative enteric bacterium, is found in nosocomial infections which are acquired during hospital stays for about 10% of hospital patients in the United States. The crystal structure of a putative oxidoreductase from K. pneumoniae has been determined. The structural information of this K. pneumoniae protein was used to understand its function. Crystals of the putative oxidoreductase enzyme were obtained by the sitting drop vapor diffusion method using Polyethylene glycol (PEG) 3350, Bis-Tris buffer, pH 5.5 as precipitant. These crystals were used to collect X-ray data at beam line X12C of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL). The crystal structure was determined using the SHELX program and refi ned with CNS 1.1. This protein, which is involved in the catalysis of an oxidation-reduction (redox) reaction, has an alpha/beta structure. It utilizes nicotinamide adenine dinucleotide phosphate (NADP) or nicotine adenine dinucleotide (NAD) to perform its function. This structure could be used to determine the active and co-factor binding sites of the protein, information that could help pharmaceutical companies in drug design and in determining the protein’s relationship to disease treatment such as that for pneumonia and other related pathologies.
Renteria, M I; Biedenbach, D J; Bouchillon, S K; Hoban, D J; Raghubir, N; Sajben, P
Multidrug-resistant (MDR) Enterobacteriaceae are an emerging concern for healthcare providers. Infections caused by MDR pathogens are associated with increased costs, length of hospital stay, and morbidity and mortality rates. Carbapenem-resistant Enterobacteriaceae (CRE) continue to increase, and infections with these organisms are observed worldwide not only as hospital-acquired infections but also as community-acquired infections. Increasing antimicrobial resistance dictates the need for continued surveillance studies of common and MDR pathogens. The Tigecycline Evaluation Surveillance Trial (TEST) examined the susceptibility of pathogens isolated in Africa and the Middle East from 2007 to 2012. A total of 4155 Enterobacteriaceae isolates were evaluated to determine the in vitro activity and changes in resistance patterns for tigecycline and comparators. Carbapenem resistance was found in 191 (4.6%) of the isolates tested. Klebsiella pneumoniae was the most common CRE (64.9%), followed by Enterobacter cloacae (14.1%) and Escherichia coli (9.9%). Tigecycline MIC 90 values (minimum inhibitory concentration required to inhibit 90% of the isolates) were 2μg/mL against all of these enteric species, with susceptibility rates of 96.8%, 92.6% and 100%, respectively. Tigecycline had in vitro activity against CRE, with a 95.3% susceptibility rate. Copyright Â© 2014 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.
Isil Seyis Bilkay
Full Text Available In this study, optimization conditions for cyanide biodegradation by Klebsiella pneumoniae strain were determined to be 25 °C, pH=7 and 150 rpm at the concentration of 0.5 mM potassium cyanide in the medium. Additionally, it was found that K. pneumoniae strain is not only able to degrade potassium cyanide, but also to degrade potassium hexacyanoferrate(II trihydrate and sodium ferrocyanide decahydrate with the efficiencies of 85 and 87.5 %, respectively. Furthermore, this strain degraded potassium cyanide in the presence of different ions such as magnesium, nickel, cobalt, iron, chromium, arsenic and zinc, in variable concentrations (0.1, 0.25 and 0.5 mM and as a result the amount of the bacteria in the biodegradation media decreased with the increase of ion concentration. Lastly, it was also observed that sterile crude extract of K. pneumoniae strain degraded potassium cyanide on the fifth day of incubation. Based on these results, it is concluded that both culture and sterile crude extract of K. pnemoniae will be used in cyanide removal from different wastes.
Shaaban, Mona I; Shaker, Mohamed A; Mady, Fatma M
Carbapenem-resistance is an extremely growing medical threat in antibacterial therapy as the incurable resistant strains easily develop a multi-resistance action to other potent antimicrobial agents. Nonetheless, the protective delivery of current antibiotics using nano-carriers opens a tremendous approach in the antimicrobial therapy, allowing the nano-formulated antibiotics to beat these health threat pathogens. Herein, we encapsulated imipenem into biodegradable polymeric nanoparticles to destroy the imipenem-resistant bacteria and overcome the microbial adhesion and dissemination. Imipenem loaded poly Ɛ-caprolactone (PCL) and polylactide-co-glycolide (PLGA) nanocapsules were formulated using double emulsion evaporation method. The obtained nanocapsules were characterized for mean particle diameter, morphology, loading efficiency, and in vitro release. The in vitro antimicrobial and anti adhesion activities were evaluated against selected imipenem-resistant Klebsiella pneumoniae and Pseudomonas aeruginosa clinical isolates. The obtained results reveal that imipenem loaded PCL nano-formulation enhances the microbial susceptibility and antimicrobial activity of imipenem. The imipenem loaded PCL nanoparticles caused faster microbial killing within 2-3 h compared to the imipenem loaded PLGA and free drug. Successfully, PCL nanocapsules were able to protect imipenem from enzymatic degradation by resistant isolates and prevent the emergence of the resistant colonies, as it lowered the mutation prevention concentration of free imipenem by twofolds. Moreover, the imipenem loaded PCL eliminated bacterial attachment and the biofilm assembly of P. aeruginosa and K. pneumoniae planktonic bacteria by 74 and 78.4%, respectively. These promising results indicate that polymeric nanoparticles recover the efficacy of imipenem and can be considered as a new paradigm shift against multidrug-resistant isolates in treating severe bacterial infections.
Increasing Resistance to Extended-Spectrum Cephalosporins, Fluoroquinolone, and Carbapenem in Gram-Negative Bacilli and the Emergence of Carbapenem Non-Susceptibility in Klebsiella pneumoniae: Analysis of Korean Antimicrobial Resistance Monitoring System (KARMS) Data From 2013 to 2015.
Kim, Dokyun; Ahn, Ji Young; Lee, Chae Hoon; Jang, Sook Jin; Lee, Hyukmin; Yong, Dongeun; Jeong, Seok Hoon; Lee, Kyungwon
National surveillance of antimicrobial resistance becomes more important for the control of antimicrobial resistance and determination of treatment guidelines. We analyzed Korean Antimicrobial Resistance Monitoring System (KARMS) data collected from 2013 to 2015. Of the KARMS participants, 16 secondary or tertiary hospitals consecutively reported antimicrobial resistance rates from 2013 to 2015. Data from duplicate isolates and institutions with fewer than 20 isolates were excluded. To determine the long-term trends, previous KARMS data from 2004 to 2012 were also considered. The prevalence of methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium from 2013 to 2015 was 66-72% and 29-31%, respectively. The resistance rates of Escherichia coli to cefotaxime and cefepime gradually increased to 35% and 31%, respectively, and fluoroquinolone resistance reached 48% in 2015. The resistance rates of Klebsiella pneumoniae to cefotaxime, cefepime, and carbapenem were 38-41%, 33-41%, and carbapenem susceptibility rates of E. coli and K. pneumoniae decreased from 100% and 99.3% in 2011 to 99.0% and 97.0% in 2015, respectively. The resistance rate of Pseudomonas aeruginosa to carbapenem increased to 35% and the prevalence of carbapenem-resistant Acinetobacter baumannii increased from 77% in 2013 to 85% in 2015. Between 2013 and 2015, the resistance rates of E. coli to third- and fourth-generation cephalosporins increased continuously, while carbapenem-susceptibility gradually decreased, particularly in K. pneumoniae. The prevalence of carbapenem-resistant P. aeruginosa and A. baumannii increased significantly; therefore, few treatment options remain for these resistant strains. © The Korean Society for Laboratory Medicine
Satlin, Michael J; Chen, Liang; Patel, Gopi; Gomez-Simmonds, Angela; Weston, Gregory; Kim, Angela C; Seo, Susan K; Rosenthal, Marnie E; Sperber, Steven J; Jenkins, Stephen G; Hamula, Camille L; Uhlemann, Anne-Catrin; Levi, Michael H; Fries, Bettina C; Tang, Yi-Wei; Juretschko, Stefan; Rojtman, Albert D; Hong, Tao; Mathema, Barun; Jacobs, Michael R; Walsh, Thomas J; Bonomo, Robert A; Kreiswirth, Barry N
Although the New York/New Jersey (NY/NJ) area is an epicenter for carbapenem-resistant Enterobacteriaceae (CRE), there are few multicenter studies of CRE from this region. We characterized patients with CRE bacteremia in 2013 at eight NY/NJ medical centers and determined the prevalence of carbapenem resistance among Enterobacteriaceae bloodstream isolates and CRE resistance mechanisms, genetic backgrounds, capsular types ( cps ), and antimicrobial susceptibilities. Of 121 patients with CRE bacteremia, 50% had cancer or had undergone transplantation. The prevalences of carbapenem resistance among Klebsiella pneumoniae , Enterobacter spp., and Escherichia coli bacteremias were 9.7%, 2.2%, and 0.1%, respectively. Ninety percent of CRE were K. pneumoniae and 92% produced K. pneumoniae carbapenemase (KPC-3, 48%; KPC-2, 44%). Two CRE produced NDM-1 and OXA-48 carbapenemases. Sequence type 258 (ST258) predominated among KPC-producing K. pneumoniae (KPC- Kp ). The wzi154 allele, corresponding to cps-2 , was present in 93% of KPC-3- Kp , whereas KPC-2- Kp had greater cps diversity. Ninety-nine percent of CRE were ceftazidime-avibactam (CAZ-AVI)-susceptible, although 42% of KPC-3- Kp had an CAZ-AVI MIC of ≥4/4 μg/ml. There was a median of 47 h from bacteremia onset until active antimicrobial therapy, 38% of patients had septic shock, and 49% died within 30 days. KPC-3- Kp bacteremia (adjusted odds ratio [aOR], 2.58; P = 0.045), cancer (aOR, 3.61, P = 0.01), and bacteremia onset in the intensive care unit (aOR, 3.79; P = 0.03) were independently associated with mortality. Active empirical therapy and combination therapy were not associated with survival. Despite a decade of experience with CRE, patients with CRE bacteremia have protracted delays in appropriate therapies and high mortality rates, highlighting the need for rapid diagnostics and evaluation of new therapeutics. Copyright © 2017 American Society for Microbiology.
Pecora, Nicole D; Li, Ning; Allard, Marc; Li, Cong; Albano, Esperanza; Delaney, Mary; Dubois, Andrea; Onderdonk, Andrew B; Bry, Lynn
Carbapenem-resistant Enterobacteriaceae (CRE) are an urgent public health concern. Rapid identification of the resistance genes, their mobilization capacity, and strains carrying them is essential to direct hospital resources to prevent spread and improve patient outcomes. Whole-genome sequencing allows refined tracking of both chromosomal traits and associated mobile genetic elements that harbor resistance genes. To enhance surveillance of CREs, clinical isolates with phenotypic resistance to carbapenem antibiotics underwent whole-genome sequencing. Analysis of 41 isolates of Klebsiella pneumoniae and Enterobacter cloacae, collected over a 3-year period, identified K. pneumoniae carbapenemase (KPC) genes encoding KPC-2, -3, and -4 and OXA-48 carbapenemases. All occurred within transposons, including multiple Tn4401 transposon isoforms, embedded within more than 10 distinct plasmids representing incompatibility (Inc) groups IncR, -N, -A/C, -H, and -X. Using short-read sequencing, draft maps were generated of new KPC-carrying vectors, several of which were derivatives of the IncN plasmid pBK31551. Two strains also had Tn4401 chromosomal insertions. Integrated analyses of plasmid profiles and chromosomal single-nucleotide polymorphism (SNP) profiles refined the strain patterns and provided a baseline hospital mobilome to facilitate analysis of new isolates. When incorporated with patient epidemiological data, the findings identified limited outbreaks against a broader 3-year period of sporadic external entry of many different strains and resistance vectors into the hospital. These findings highlight the utility of genomic analyses in internal and external surveillance efforts to stem the transmission of drug-resistant strains within and across health care institutions. We demonstrate how detection of resistance genes within mobile elements and resistance-carrying strains furthers active surveillance efforts for drug resistance. Whole-genome sequencing is increasingly
Sabet, Mojgan; Tarazi, Ziad; Rubio-Aparicio, Debora; Nolan, Thomas G; Parkinson, Jonathan; Lomovskaya, Olga; Dudley, Michael N; Griffith, David C
The objective of these studies was to evaluate the exposures of meropenem and vaborbactam that would produce antibacterial activity and prevent resistance development in carbapenem-resistant Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae strains when tested at an inoculum of 10 8 CFU/ml. Thirteen K. pneumoniae isolates, three Enterobacter cloacae isolates, and one Escherichia coli isolate were examined in an in vitro hollow-fiber model over 32 h. Simulated dosage regimens of 1 to 2 g of meropenem with 1 to 2 g of vaborbactam, with meropenem administered every 8 h by a 3-h infusion based on phase 1 or phase 3 patient pharmacokinetic data, were studied in the model. A dosage of 2 g of meropenem in combination with 2 g of vaborbactam was bactericidal against K. pneumoniae , E. cloacae , and E. coli strains, with meropenem-vaborbactam MICs of up to 8 mg/liter. When the vaborbactam exposure was adjusted to the levels observed in patients enrolled in phase 3 trials (24-h free AUC, ∼550 mg · h/liter, versus 320 mg · h/liter in the phase 1 studies), 2 g of meropenem with 2 g of vaborbactam was also bactericidal against strains with meropenem-vaborbactam MICs of 16 mg/liter. In addition, this level of vaborbactam also suppressed the development of resistance observed using phase 1 exposures. In this pharmacodynamic model, exposures similar to 2 g of meropenem in combination with 2 g of vaborbactam administered every 8 h by a 3-h infusion in phase 3 trials produced antibacterial activity and suppressed the development of resistance against carbapenem-resistant KPC-producing strains of Enterobacteriaceae . Copyright © 2018 American Society for Microbiology.
Jana, Bimal; Cain, Amy K; Doerrler, William T; Boinett, Christine J; Fookes, Maria C; Parkhill, Julian; Guardabassi, Luca
Klebsiella pneumoniae causes severe lung and bloodstream infections that are difficult to treat due to multidrug resistance. We hypothesized that antimicrobial resistance can be reversed by targeting chromosomal non-essential genes that are not responsible for acquired resistance but essential for resistant bacteria under therapeutic concentrations of antimicrobials. Conditional essentiality of individual genes to antimicrobial resistance was evaluated in an epidemic multidrug-resistant clone of K. pneumoniae (ST258). We constructed a high-density transposon mutant library of >430,000 unique Tn5 insertions and measured mutant depletion upon exposure to three clinically relevant antimicrobials (colistin, imipenem or ciprofloxacin) by Transposon Directed Insertion-site Sequencing (TraDIS). Using this high-throughput approach, we defined three sets of chromosomal non-essential genes essential for growth during exposure to colistin (n = 35), imipenem (n = 1) or ciprofloxacin (n = 1) in addition to known resistance determinants, collectively termed the "secondary resistome". As proof of principle, we demonstrated that inactivation of a non-essential gene not previously found linked to colistin resistance (dedA) restored colistin susceptibility by reducing the minimum inhibitory concentration from 8 to 0.5 μg/ml, 4-fold below the susceptibility breakpoint (S ≤ 2 μg/ml). This finding suggests that the secondary resistome is a potential target for developing antimicrobial "helper" drugs that restore the efficacy of existing antimicrobials.
Braat, Henri; de Jong, Esther C.; van den Brande, Jan M. H.; Kapsenberg, Martien L.; Peppelenbosch, Maikel P.; van Tol, Eric A. F.; van Deventer, Sander J. H.
The reaction of the intestinal immune system to intestinal bacteria shows striking differences between various bacterial strains. Whereas Klebsiella pneumoniae induces a fierce proinflammatory reaction, the probiotic strain Lactobacillus rhamnosus has clear anti-inflammatory effect in
Vani Gopal; T Mangaiyarkarasi; R Gopal
Klebsiella is a Gram-negative bacterium that causes different types of health care-associated infections including pneumonia, bloodstream infections, surgical site infections and meningitis. We report here a case of Klebsiella pneumoniae meningitis in a patient with diabetes mellitus and Hansen′s disease. A middle-aged man with a known case of diabetes mellitus and Hansen′s disease presented with the complaints of blurred vision in the left eye and the patient was found to have cataract. Pati...
Janice M. Lage
Full Text Available A 40-year-old woman, gravida 9, with seven healthy children and a history of one abortion (p 7 + 1 , presented at 18 weeks of gestation with fever and malodorous vaginal discharge. Ultrasound revealed a macerated fetus. The placenta showed acute chorioamnionitis and acute villitis with microabscess formation. Blood and vaginal cultures both grew Klebsiella pneumoniae. This is the first reported case in English literature of Klebsiella pneumoniae causing suppurative placentitis leading to fetal demise.
Gunnarsson, Gudjon L; Brandt, Pernille B; Gad, Dorte
We report a case of monomicrobial necrotizing fasciitis caused by hypermucoviscous Klebsiella pneumoniae in an immunocompromised white male after travel to China. The K. pneumoniae isolate belonged to the K2 serotype, and carried the virulence factors RmpA and aerobactin. To the best of our...... knowledge this is the first report of necrotizing fasciitis caused by hypermucoviscous K. pneumoniae resembling the highly virulent K. pneumoniae isolates associated with liver abscess syndrome in Asia....
Rafailidis, Petros I; Falagas, Matthew E
To address the therapeutic management of carbapenem-resistant Enterobacteriaceae on the basis of literature of the last 12 months. Retrospective and prospective (nonrandomized noncontrolled) studies provide data regarding the management of infections due to carbapenem-resistant Enterobacteriaceae. The combination of a carbapenem with colistin or high-dose tigecycline or aminoglycoside or even triple carbapenem-containing combinations if the minimum inhibitory concentration (MIC) range of carbapenem (meropenem and imipenem) resistance is 8 mg/l or less seems to have an advantage over monotherapy with either colistin or tigecycline or fosfomycin. For Enterobacteriaceae with MIC for carbapenems over 8 mg/l, combination regimens involve colistin, tigecycline usually administered in a double dose than that suggested by its manufacturer, fosfomycin and aminoglycosides in various combinations. Suggestions based on the limited literature cannot be made safely. Combination regimens involving carbapenems for Enterobacteriaceae with MICs 8 mg/l or less for carbapenems (in dual combination with colistin or high-dose tigecycline or aminoglycoside or even triple combinations) seem to confer some therapeutic advantage over monotherapy. For Enterobacteriaceae with higher than the above-mentioned MICs, a combination of two or even three antibiotics among colistin, high-dose tigecycline, aminoglycoside and fosfomycin seems to confer decreased mortality.
Carbapenem resistance in Enterobacteriaceae is often plasmid mediated, necessitating stringent infection control practices. We describe an outbreak of carbapenem-resistant Providencia rettgeri involving 4 patients admitted to intensive care and high-care units at a tertiary hospital. Clinical and demographic characteristics ...
Bassetti, M; Giacobbe, D R; Giamarellou, H; Viscoli, C; Daikos, G L; Dimopoulos, G; De Rosa, F G; Giamarellos-Bourboulis, E J; Rossolini, G M; Righi, E; Karaiskos, I; Tumbarello, M; Nicolau, D P; Viale, P L; Poulakou, G
Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (KPC-KP) has become one of the most important contemporary pathogens, especially in endemic areas. To provide practical suggestion for physicians dealing with the management of KPC-KP infections in critically ill patients, based on expert opinions. PubMed search for relevant publications related to the management of KPC-KP infections. A panel of experts developed a list of 12 questions to be addressed. In view of the current lack of high-level evidence, they were asked to provide answers on the bases of their knowledge and experience in the field. The panel identified several key aspects to be addressed when dealing with KPC-KP in critically ill patients (preventing colonization in the patient, preventing infection in the colonized patient and colonization of his or her contacts, reducing mortality in the infected patient by rapidly diagnosing the causative agent and promptly adopting the best therapeutic strategy) and provided related suggestions that were based on the available observational literature and the experience of panel members. Diagnostic technologies could speed up the diagnosis of KPC-KP infections. Combination treatment should be preferred to monotherapy in cases of severe infections. For non-critically ill patients without severe infections, results from randomized clinical trials are needed for ultimately weighing benefits and costs of using combinations rather than monotherapy. Multifaceted infection control interventions are needed to decrease the rates of colonization and cross-transmission of KPC-KP. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
Lanini, Simone; Costa, Alessandro Nanni; Puro, Vincenzo; Procaccio, Francesco; Grossi, Paolo Antonio; Vespasiano, Francesca; Ricci, Andrea; Vesconi, Sergio; Ison, Michael G; Carmeli, Yehuda; Ippolito, Giuseppe
Bacterial infections remain a challenge to solid organ transplantation. Due to the alarming spread of carbapenem-resistant gram negative bacteria, these organisms have been frequently recognized as cause of severe infections in solid organ transplant recipients. Between 15 May and 30 September 2012 we enrolled 887 solid organ transplant recipients in Italy with the aim to describe the epidemiology of gram negative bacteria spreading, to explore potential risk factors and to assess the effect of early isolation of gram negative bacteria on recipients' mortality during the first 90 days after transplantation. During the study period 185 clinical isolates of gram negative bacteria were reported, for an incidence of 2.39 per 1000 recipient-days. Positive cultures for gram negative bacteria occurred early after transplantation (median time 26 days; incidence rate 4.33, 1.67 and 1.14 per 1,000 recipient-days in the first, second and third month after SOT, respectively). Forty-nine of these clinical isolates were due to carbapenem-resistant gram negative bacteria (26.5%; incidence 0.63 per 1000 recipient-days). Carbapenems resistance was particularly frequent among Klebsiella spp. isolates (49.1%). Recipients with longer hospital stay and those who received either heart or lung graft were at the highest risk of testing positive for any gram negative bacteria. Moreover recipients with longer hospital stay, lung recipients and those admitted to hospital for more than 48h before transplantation had the highest probability to have culture(s) positive for carbapenem-resistant gram negative bacteria. Forty-four organ recipients died (0.57 per 1000 recipient-days) during the study period. Recipients with at least one positive culture for carbapenem-resistant gram negative bacteria had a 10.23-fold higher mortality rate than those who did not. The isolation of gram-negative bacteria is most frequent among recipient with hospital stays >48 hours prior to transplant and in those
Full Text Available Bacterial infections remain a challenge to solid organ transplantation. Due to the alarming spread of carbapenem-resistant gram negative bacteria, these organisms have been frequently recognized as cause of severe infections in solid organ transplant recipients.Between 15 May and 30 September 2012 we enrolled 887 solid organ transplant recipients in Italy with the aim to describe the epidemiology of gram negative bacteria spreading, to explore potential risk factors and to assess the effect of early isolation of gram negative bacteria on recipients' mortality during the first 90 days after transplantation. During the study period 185 clinical isolates of gram negative bacteria were reported, for an incidence of 2.39 per 1000 recipient-days. Positive cultures for gram negative bacteria occurred early after transplantation (median time 26 days; incidence rate 4.33, 1.67 and 1.14 per 1,000 recipient-days in the first, second and third month after SOT, respectively. Forty-nine of these clinical isolates were due to carbapenem-resistant gram negative bacteria (26.5%; incidence 0.63 per 1000 recipient-days. Carbapenems resistance was particularly frequent among Klebsiella spp. isolates (49.1%. Recipients with longer hospital stay and those who received either heart or lung graft were at the highest risk of testing positive for any gram negative bacteria. Moreover recipients with longer hospital stay, lung recipients and those admitted to hospital for more than 48h before transplantation had the highest probability to have culture(s positive for carbapenem-resistant gram negative bacteria. Forty-four organ recipients died (0.57 per 1000 recipient-days during the study period. Recipients with at least one positive culture for carbapenem-resistant gram negative bacteria had a 10.23-fold higher mortality rate than those who did not.The isolation of gram-negative bacteria is most frequent among recipient with hospital stays >48 hours prior to transplant
Nypaver, Christina M.; Thornton, Margaret M.; Yin, Suellen M.; Bracho, David O.; Nelson, Patrick W.; Jones, Alan E.; Bortz, David M.; Younger, John G.
With an in vitro system that used a luminescent strain of Klebsiella pneumoniae to assess bacterial metabolic activity in near-real-time, we investigated the dynamics of complement-mediated attack in healthy individuals and in patients presenting to the emergency department with community-acquired severe sepsis. A novel mathematical/statistical model was developed to simplify light output trajectories over time into two fitted parameters, the rate of complement activation and the delay from activation to the onset of killing. Using Factor B–depleted serum, the alternative pathway was found to be the primary bactericidal effector: In the absence of B, C3 opsonization as measured by flow cytometry did not progress and bacteria proliferated near exponentially. Defects in bacterial killing were easily demonstrable in patients with severe sepsis compared with healthy volunteers. In most patients with sepsis, the rate of activation was higher than in normal subjects but was associated with a prolonged delay between activation and bacterial killing (P < 0.05 for both). Theoretical modeling suggested that this combination of accentuated but delayed function should allow successful bacterial killing but with significantly greater complement activation. The use of luminescent bacteria allowed for the development of a novel and powerful tool for assessing complement immunology for the purposes of mechanistic study and patient evaluation. PMID:20008281
Nypaver, Christina M; Thornton, Margaret M; Yin, Suellen M; Bracho, David O; Nelson, Patrick W; Jones, Alan E; Bortz, David M; Younger, John G
With an in vitro system that used a luminescent strain of Klebsiella pneumoniae to assess bacterial metabolic activity in near-real-time, we investigated the dynamics of complement-mediated attack in healthy individuals and in patients presenting to the emergency department with community-acquired severe sepsis. A novel mathematical/statistical model was developed to simplify light output trajectories over time into two fitted parameters, the rate of complement activation and the delay from activation to the onset of killing. Using Factor B-depleted serum, the alternative pathway was found to be the primary bactericidal effector: In the absence of B, C3 opsonization as measured by flow cytometry did not progress and bacteria proliferated near exponentially. Defects in bacterial killing were easily demonstrable in patients with severe sepsis compared with healthy volunteers. In most patients with sepsis, the rate of activation was higher than in normal subjects but was associated with a prolonged delay between activation and bacterial killing (P < 0.05 for both). Theoretical modeling suggested that this combination of accentuated but delayed function should allow successful bacterial killing but with significantly greater complement activation. The use of luminescent bacteria allowed for the development of a novel and powerful tool for assessing complement immunology for the purposes of mechanistic study and patient evaluation.
Klebsiella pneumoniae is a zoonotic, Gram-negative member of the family Enterobacteriaceae and is the causative agent of nosocomial septicemic, pneumonic, and urinary tract infections. Recently, pathogenic strains of K. pneumoniae sharing a hypermucoviscosity (HMV) phenotype have been attributed to ...
Thatte, V; Gill, S; Iyer, V N
Plasmid pCU1 was Kik+ (promotes killing of Klebsiella pneumoniae). All Tn5 insertions within the tra region of pCU1 were Kik-. Two other regions, kikA and kikB, were needed. They may be separated on different plasmids, but both must be mobilized into Klebsiella pneumoniae. Establishment of one kik region in K. pneumoniae followed by receipt of the second did not lead to killing. Kik was therefore intracellular and required concerted and transient action of both regions.
Full Text Available Bacterial meningitis remains a major cause of death and long-term neurologic sequelae worldwide. We present a case of fatal Klebsiella pneumoniae meningitis and concomitant disseminated intravascular coagulation (DIC in a 72-year-old woman with diabetes mellitus (DM. Both blood and cerebrospinal fluid cultures grew Klebsiella pneumoniae . Due to advanced age, newly recognized DM, K. pneumoniae bacteremia, and DIC, the prognosis of our patient was poor. Eight hours after arrival to the emergency department, cardiopulmonary resuscitation was necessary in this patient, but she died despite an early diagnosis and appropriate antibiotic therapy.
G. R. Sadrtdinova
Full Text Available The article acknowledges the formation of bacterial biofilms in strains of bacteria species Klebsiella oxytoca and Klebsiella pneumoniae when grown in liquid media under the influence of negative factors (chemical factor — containing agents. Biofilms, as a community of microorganisms cause many chronic infections (meningitis, inflammatory diseases of the oral cavity, urogenital infections and create problems in the industry (fouling of processing equipment, ship hulls, oil platforms, biocorrosion metal products. Ordinary disinfectants, such as chlorine and sodium chlorite, can not remove the biofilm, so finding an effective means of dealing with them is enough actual problem. Various antibacterial agents are ineffective in combating biofilms, since bacteria produce large amounts of polysaccharides — substances that help the colony stay without disintegration. Polysaccharide serves as a barrier layer for substances in water, including for biocides. This is the main reason for the survival of microorganisms even in the heavily chlorinated water. In the study the latest data took into account on the subject, especially concerning adverse effects of oxygen on the growth of bacterial cells and directs action as a factor in the formation of biofilms. In our study we analyzed the latest generation disinfectant as an influencing factor. Working concentrations were shown in three embodiments. The number of strains studied was 6 (3 strains of each species. All strains were obtained from the Department of Museum MVE and VSE Ulyanovsk State Agricultural Academy n.a. P.A. Stolypin. In our research the biofilm community formation phenomenon has been confirmed, marked differences in biofilm formation, depending on the intensity (in this case, concentration of the promoter and bacteria species. In vivo biofilm is easily destroyed by mechanical action (shaking test tubes with the medium. Biofilm recovery after this manipulation was not observed. The results
Full Text Available Necrotizing fasciitis caused by Klebsiella pneumoniae has been described in Southeast Asia, but has only recently begun to emerge in North America. The hypermucoviscous strain of K. pneumoniae is a particularly virulent strain known to cause devastatingly invasive infections, including necrotizing fasciitis. Here we present the first known case of necrotizing fasciitis caused by hypermucoviscous K. pneumoniae in North America. [West J Emerg Med. 2015;16(1:165–168.
Full Text Available Tigecycline is one of the last resort treatments for carbapenem-resistant Klebsiella pneumoniae (CRKP infections. Tigecycline resistance often occurs during the clinical treatment of CRKP, yet its mechanism has still not been clearly elucidated. This study presents an analysis of a tigecycline resistance mechanism that developed in clinical isolates from a 56-year-old female patient infected with CRKP during tigecycline treatment. Consecutive clonal consistent K. pneumoniae isolates were obtained during tigecycline treatment. Whole genome sequencing of the isolates was performed, and putative single nucleotide polymorphisms and insertion and deletion mutations were analyzed in susceptible and resistant isolates. The identified gene of interest was examined through experiments involving transformations and conjugations. Four isolates, two of which were susceptible and two resistant, were collected from the patient. All of the isolates belonged to Sequence Type 11 (ST11 and were classified as extensively drug resistant (XDR. One amino acid substitution S251A in TetA was identified in the tigecycline-resistant isolates. Subsequent transformation experiments confirmed the contribution of the TetA variant (S251A to tigecycline resistance. The transfer capacity of tigecycline resistance via this mutation was confirmed by conjugation experiments. Using southern blot hybridization and PCR assays, we further proved that the tetA gene was located on a transferable plasmid of ca. 65 kb in an Escherichia coli EC600 transconjugant. Our results provide direct in vivo evidence that evolution in the tetA gene can lead to tigecycline treatment failure in CRKP clinical strains that carry tetA. Moreover, the transfer capacity of tigecycline resistance mediated by mutated tetA is a threat.
He, Qingwen; Chen, Weiyuan; Huang, Liya; Lin, Qili; Zhang, Jingling; Liu, Rui; Li, Bin
Carbapenem-resistant Enterobacteriaceae (CRE) is prevalent around the world. Rapid and accurate detection of CRE is urgently needed to provide effective treatment. Automated identification systems have been widely used in clinical microbiology laboratories for rapid and high-efficient identification of pathogenic bacteria. However, critical evaluation and comparison are needed to determine the specificity and accuracy of different systems. The aim of this study was to evaluate the performance of three commonly used automated identification systems on the detection of CRE. A total of 81 non-repetitive clinical CRE isolates were collected from August 2011 to August 2012 in a Chinese university hospital, and all the isolates were confirmed to be resistant to carbapenems by the agar dilution method. The potential presence of carbapenemase genotypes of the 81 isolates was detected by PCR and sequencing. Using 81 clinical CRE isolates, we evaluated and compared the performance of three automated identification systems, MicroScan WalkAway 96 Plus, Phoenix 100, and Vitek 2 Compact, which are commonly used in China. To identify CRE, the comparator methodology was agar dilution method, while the PCR and sequencing was the comparator one to identify CPE. PCR and sequencing analysis showed that 48 of the 81 CRE isolates carried carbapenemase genes, including 23 (28.4 %) IMP-4, 14 (17.3 %) IMP-8, 5 (6.2 %) NDM-1, and 8 (9.9 %) KPC-2. Notably, one Klebsiella pneumoniae isolate produced both IMP-4 and NDM-1. One Klebsiella oxytoca isolate produced both KPC-2 and IMP-8. Of the 81 clinical CRE isolates, 56 (69.1 %), 33 (40.7 %) and 77 (95.1 %) were identified as CRE by MicroScan WalkAway 96 Plus, Phoenix 100, and Vitek 2 Compact, respectively. The sensitivities/specificities of MicroScan WalkAway, Phoenix 100 and Vitek 2 were 93.8/42.4 %, 54.2/66.7 %, and 75.0/36.4 %, respectively. The MicroScan WalkAway and Viteck2 systems are more reliable in clinical identification of
Jan 31, 2017 ... discharged, transmission from inanimate objects and healthcare workers is a ... Isolation of carbapenem-resistant NDM-1-positive Providencia rettgeri in Mexico. ... Australian Commission on Safety and Quality in Health Care.
U.S. Department of Health & Human Services — NNDSS - Table II. Carbapenemase-producing carbapenem-resistant Enterobacteriaceae - 2018. In this Table, provisional cases of selected notifiable diseases (≥1,000...
Full Text Available MeCab user dictionary for science technology term Klebsiella pneumoniae 名詞 一般 * * *... * 肺炎桿菌 ハイエンカンキン ハイエンカンキン Thesaurus2015 200906081834698320 C LS07 UNKNOWN_2 Klebsiella pneumoniae
INTRODUCTION: Klebsiella pneumoniae has emerged as a predominant cause of community-acquired mono-microbial pyogenic liver abscess. This was first described in Taiwan and has been widely reported in Asia. This infectious entity has been described in Europe, with single case reports predominating. METHODS: We present three cases in one year from our institution in Ireland and review the European literature to date. RESULTS\\/CONCLUSION: Klebsiella pneumoniae invasive liver abscess syndrome is now emerging in Europe and notably is not restricted to individuals of Asian descent.
Karampatakis, Theodoros; Geladari, Anastasia; Politi, Lida; Antachopoulos, Charalampos; Iosifidis, Elias; Tsiatsiou, Olga; Karyoti, Aggeliki; Papanikolaou, Vasileios; Tsakris, Athanassios; Roilides, Emmanuel
Solid-organ transplant recipients may display high rates of colonization and/or infection by multidrug-resistant bacteria. We analysed and compared the phenotypic and genotypic diversity of carbapenem-resistant (CR) strains of Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii isolated from patients in the Solid Organ Transplantation department of our hospital. Between March 2012 and August 2013, 56 CR strains from various biological fluids underwent antimicrobial susceptibility testing with VITEK 2, molecular analysis by PCR amplification and genotypic analysis with pulsed-field gel electrophoresis (PFGE). They were clustered according to antimicrobial drug susceptibility and genotypic profiles. Diversity analyses were performed by calculating Simpson's diversity index and applying computed rarefaction curves.Results/Key findings. Among K. pneumoniae, KP-producers predominated (57.1 %). VIM and OXA-23 carbapenemases prevailed among P. aeruginosa and A. baumannii (89.4 and 88.9 %, respectively). KPC-producing K. pneumoniae and OXA-23 A. baumannii were assigned in single PFGE pulsotypes. VIM-producing P. aeruginosa generated multiple pulsotypes. CR K. pneumoniae strains displayed phenotypic diversity in tigecycline, colistin (CS), amikacin (AMK), gentamicin (GEN) and co-trimoxazole (SXT) (16 clusters); P. aeruginosa displayed phenotypic diversity in cefepime (FEP), ceftazidime, aztreonam, piperacillin, piperacillin-tazobactam, AMK, GEN and CS (9 clusters); and A. baumannii displayed phenotypic diversity in AMK, GEN, SXT, FEP, tobramycin and rifampicin (8 clusters). The Simpson diversity indices for the interpretative phenotype and PFGE analysis were 0.89 and 0.6, respectively, for K. pneumoniae strains (P<0.001); 0.77 and 0.6 for P. aeruginosa (P=0.22); and 0.86 and 0.19 for A. baumannii (P=0.004). The presence of different antimicrobial susceptibility profiles does not preclude the possibility that two CR K. pneumoniae or A. baumannii
João Anes; Daniel Hurley; Marta Martins; Séamus Fanning; Séamus Fanning
Klebsiella pneumoniae is an important nosocomial pathogen with an extraordinary resistant phenotype due to a combination of acquired resistant-elements and efflux mechanisms. In this study a detailed molecular characterization of 11 K. pneumoniae isolates of clinical origin was carried out. Eleven clinical isolates were tested for their susceptibilities, by disk diffusion and broth microdilution and interpreted according to CLSI guidelines. Efflux activity was determined by measuring the extr...
Snitkin, Evan S; Won, Sarah; Pirani, Ali; Lapp, Zena; Weinstein, Robert A; Lolans, Karen; Hayden, Mary K
Development of effective strategies to limit the proliferation of multidrug-resistant organisms requires a thorough understanding of how such organisms spread among health care facilities. We sought to uncover the chains of transmission underlying a 2008 U.S. regional outbreak of carbapenem-resistant Klebsiella pneumoniae by performing an integrated analysis of genomic and interfacility patient-transfer data. Genomic analysis yielded a high-resolution transmission network that assigned directionality to regional transmission events and discriminated between intra- and interfacility transmission when epidemiologic data were ambiguous or misleading. Examining the genomic transmission network in the context of interfacility patient transfers (patient-sharing networks) supported the role of patient transfers in driving the outbreak, with genomic analysis revealing that a small subset of patient-transfer events was sufficient to explain regional spread. Further integration of the genomic and patient-sharing networks identified one nursing home as an important bridge facility early in the outbreak-a role that was not apparent from analysis of genomic or patient-transfer data alone. Last, we found that when simulating a real-time regional outbreak, our methodology was able to accurately infer the facility at which patients acquired their infections. This approach has the potential to identify facilities with high rates of intra- or interfacility transmission, data that will be useful for triggering targeted interventions to prevent further spread of multidrug-resistant organisms. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.
Brooks, Steven E; Walczak, Mary A; Malcolm, Sharon; Hameed, Rizwanullah
We describe intrinsic contamination with Klebsiella pneumoniae occurring during the manufacture of germicidal hand soap, labeled as containing 2% chlorhexidine, used throughout a 350-bed community medical center. A 3-year retrospective study failed to find evidence of increased incidence of clinical isolates of this strain.
Full Text Available Objectives. Study of multi-resistant Klebsiella pneumoniae strains isolated from blood cultures collected from in-patients of hospitals located in eastern Liguria, and evaluation of the susceptibility to carbapenems and other antibiotics by E-test and automated methods. Methods. At the Laboratory of Clinical Microbiology, of Lavagna Hospital in eastern Liguria, 397 Klebsiella pneumoniae strains were collected from in-patients from different wards of hospitals sites, during the year 2011. They included 115 isolates from blood cultures (aerobic and anaerobic and various biological materials. All strains were tested in the laboratory for their susceptibility to antibiotics. Results. Of the 115 strains of Klebsiella pneumoniae collected from blood cultures 59.1% showed resistance to imipenem, ertapenem, meropenem. Conclusions. The data show a high incidence of resistance to carbapenems in Klebsiella pneumoniae isolated from blood cultures.This is important to implement surveillance programs for control and prevention, but also reduce the intake of antibiotics when they are not strictly necessary.
Full Text Available Klebsiella pneumoniae T2-1-1 was isolated from the human tongue debris and subjected to whole genome sequencing on HiSeq platform and annotated on RAST. The nucleotide sequence of this genome was deposited into DDBJ/EMBL/GenBank under the accession JAQL00000000. Keywords: Human tongue surface, Oral cavity, Oral bacteria, Virulence
Andersen, Stig Ejdrup; Knudsen, Inge Jenny Dahl
BACKGROUND: Bacteria-producing extended spectrum β-lactamase (ESBL) enzymes are resistant to commonly used antimicrobials. In 2008, routine monitoring revealed a clonal hospital outbreak of ESBL-producing Klebsiella pneumoniae (ESBL-KP). METHODS: At a 510-bed Danish university hospital...... the application of a managed, multi-faceted intervention that does not require ongoing antibiotic stewardship....
Gautam, Raj Kamal; Nagar, Vandan; Shashidhar, Ravindranath
Klebsiella pneumoniae has been considered as an important foodborne pathogen which causes severe infections that include meningitis, bronchitis, bacteremia, pneumonia, and urinary tract infections in humans and animals. It is well known to most clinicians as a cause of community-acquired bacterial pneumonia. Klebsiella is an opportunistic pathogen, that primarily attacks neonates, infants, elderly and immuno-compromised patients and therefore impose a serious, emerging public health hazard globally. Contaminated sprouts, vegetables, seafood and other animal meat products are considered as main sources of Klebsiella infection. In the current study, radiation sensitivity of K. pneumoniae MTCC 109 was determined in different food samples. The decimal reduction dose (D 10 ) values of K. pneumoniae MTCC 109 in saline and nutrient broth at 0–4 °C were 0.116±0.009, 0.136±0.005 kGy, respectively. The mixed sprouts, fish and poultry samples were inoculated with K. pneumoniae MTCC 109 and exposed to gamma radiation to evaluate the effectiveness of radiation treatment in the elimination of K. pneumoniae. D 10 values of K. pneumoniae in mixed sprouts, poultry and fish samples were found to be 0.142±0.009, 0.125±0.0004 and 0.277±0.012 kGy, respectively. Radiation treatment with a 1.5 kGy dose resulted in the complete elimination of 3.1±1.8×10 5 CFU/g of K. pneumoniae from these food samples. No recovery of K. pneumoniae was observed in the 1.5 kGy treated samples stored at 4 °C up to 12 days, even after enrichment and selective plating. This study shows that a 1.5 kGy dose of irradiation treatment could lead to the complete elimination of 3.1±1.8×10 5 CFU/g of K. pneumoniae from mixed sprouts, poultry and fish samples. - Highlights: • K. pneumoniae MTCC 109 is sensitive to gamma radiation. • D 10 values is in the range of 0.116–0.277 kGy. • Dose of 1.5 kGy reduced K. pneumonia from 3.1±1.8×10 5 CFU/g to undetectable. • No recovery of K. pneumoniae
Pseudomonas aeruginosa, Streptococcus Pneumoniae and Serratia spp. Two of the children died in spite of early use of appropriate antibiotics as determined by antibiotic susceptibility testing. Phenotypic and molecualr investigation showed extended-spectrum β-lactamase (ESBL) producing K. pneumoniae to be ...
Suh, Ji-Yoeun; Son, Jun Seong; Chung, Doo Ryeon; Peck, Kyong Ran; Ko, Kwan Soo; Song, Jae-Hoon
In vitro activities of colistin and other drugs were tested against 221 Klebsiella pneumoniae isolates that were collected between 2006 and 2007 in nine tertiary care South Korean hospitals from patients with bacteremia. The clonality of colistin-resistant K. pneumoniae (CRKP) isolates was assessed by multilocus sequence typing (MLST). We found that 15 isolates (6.8%) were resistant to colistin. MLST showed that CRKP isolates were nonclonal, with colistin resistance in K. pneumoniae occurring independently and not by clonal spreading. PMID:19752282
Marimuthu, Kalisvar; Venkatachalam, Indumathi; Khong, Wei Xin; Koh, Tse Hsien; Cherng, Benjamin Pei Zhi; Van La, My; De, Partha Pratim; Krishnan, Prabha Unny; Tan, Thean Yen; Choon, Raymond Fong Kok; Pada, Surinder Kaur; Lam, Choong Weng; Ooi, Say Tat; Deepak, Rama Narayana; Smitasin, Nares; Tan, Eng Lee; Lee, Jia Jun; Kurup, Asok; Young, Barnaby; Sim, Nancy Tee Wen; Thoon, Koh Cheng; Fisher, Dale; Ling, Moi Lin; Peng, Brenda Ang Sze; Teo, Yik-Ying; Hsu, Li Yang; Lin, Raymond Tzer Pin; Ong, Rick Twee-Hee; Teo, Jeanette; Ng, Oon Tek
Since 2010, the incidence of carbapenem-resistant Enterobacteriaceae (CRE) has been increasing in Singapore. We analyzed the clinical and molecular epidemiology of CRE among adult inpatients in Singapore. Quarterly incidence of unique subjects (per 100000 patient-days) with positive clinical and surveillance cultures for CRE were estimated based on mandatory data submitted to the National Public Health Laboratory by public hospitals between 2010 and 2015. CRE-positive adult inpatients were prospectively recruited from 6 public sector hospitals between December 2013 and April 2015. Subjects answered a standardized epidemiologic questionnaire and provided samples for this study. Further clinical information was extracted from subjects' electronic medical records. Whole-genome sequencing was performed on study isolates to determine transmission clusters. Incidence of CRE clinical cultures among adult inpatients plateaued from 2013 (range: 7.73 to 10.32 per 100000 patient-days) following an initial increase between 2010 and end-2012. We prospectively recruited 249 subjects. Their median age was 65 years, 108 (43%) were female, and 161 (64.7%) had carbapenemase-producing Enterobacteriaceae (CPE). On multivariate analysis, prior carbapenem exposure (OR: 3.23; 95% CI: 1.67-6.25) and hematological malignancies (OR: 2.85; 95% CI: 1.10-7.41) were associated with non-carbapenemase-producing CRE (NCPE) (n = 88) compared with CPE (n = 161) subjects. Among 430 CRE isolates from the 249 subjects, 307(71.3%) were CPE, of which 154(50.2%) were blaKPC-positive, 97(31.6%) blaNDM-positive, and 42 (13.7%) blaOXA-positive. Klebsiella pneumoniae (n = 180, 41.9%), Escherichia coli (n = 129, 30.0%) and Enterobacter cloacae (n = 62, 14.4%) were the main Enterobacteriaceae species. WGS (n = 206) revealed diverse bacterial strain type (STs). The predominant blaKPC-positive plasmid was pHS102707 (n = 62, 55.4%) and the predominant blaNDM-positive plasmid was pNDM-ECS01 (n = 46, 48.9%). Five
Tarek A. Ahmad
Full Text Available Klebsiella pneumoniae is a major cause of nosocomial pneumonia, septicemia and urinary tract infections, especially in newborns, blood cancer patients, and other immunocompromised candidates. The control of K. pneumoniae is a complicated issue due to its tight pathogenesis. Immuno-prophylactic preparations, especially those directed toward the bacterium O-antigen, showed to be the most successful way to prevent the infection incidence. However, all previously proposed preparations were either of limited spectrum or non-maternal, and hence not targeting the main Klebsiella patients. Moreover, all preparations were directed only to prevent the respiratory diseases due to that pathogen. This article addresses the development of a method originally used to purify the non-capsular bacterial- endotoxins, as a new and easy method for vaccine production against K. pneumoniae. The application of this method was preceded by a biotechnological control of capsular polysaccharide production in K. pneumoniae. The new produced natural conjugate between the bacterial O-antigen and its outer membrane proteins was evaluated by physicochemical and immunological methods to investigate its purity, integrity, safety and immunogenicity. It showed to be pure, stable, safe for use, and able to elicit a protective immunoglobulin titer against different Klebsiella infections. This immune-response proved to be transferable to the offspring of the vaccinated experimental rabbits via placenta.
Gopal, Vani; Mangaiyarkarasi, T; Gopal, R
Klebsiella is a Gram-negative bacterium that causes different types of health care-associated infections including pneumonia, bloodstream infections, surgical site infections and meningitis. We report here a case of Klebsiella pneumoniae meningitis in a patient with diabetes mellitus and Hansen's disease. A middle-aged man with a known case of diabetes mellitus and Hansen's disease presented with the complaints of blurred vision in the left eye and the patient was found to have cataract. Patient was operated for cataract and Intraocular lens implanted. Patient developed headache and vomiting on the 4th post-operative day. Lumbar puncture was carried out and gram stain of cerebrospinal fluid showed Gram-negative bacilli in the direct smear and culture yielded a heavy growth of K. pneumoniae. The patient was treated with antimicrobials according to the susceptibility pattern. He initially showed improvement but later on developed altered sensorium and hypotension. Patient succumbed to infection in spite of all medical attention.
Full Text Available Salima Qamar, Najma Shaheen, Sadia Shakoor, Joveria Farooqi, Kauser Jabeen, Rumina Hasan Clinical Microbiology, Department of Pathology And Laboratory Medicine, Aga Khan University Hospital, Karachi, Pakistan Introduction: Management of infections with carbapenem-resistant Enterobacteriaceae (CRE is challenging. In recent times, agents such as colistin and fosfomycin have been used in combination with other antibiotics to treat such infections. In this study, we aim to seek frequency of colistin and fosfomycin resistance in CRE from Pakistan.Methods: This study was conducted at clinical laboratories, Aga Khan University Hospital. In total, 251 CRE were included in the study. Colistin minimum inhibitory concentrations (MICs were performed using broth microdilution (BMD method and VITEK® 2 system, whereas fosfomycin susceptibility was performed using Kirby–Bauer method. MIC50 and MIC90 were calculated for colistin and agreement between VITEK and BMD was also calculated.Results: Out of 251 strains colistin MIC of ≥4 µg/mL was seen in 40 (15.9%. Of these strains 20 (50% were Klebsiella pneumoniae. Colistin MIC50 and MIC90 were found to be 0.5 and 16 µg/mL, respectively. BMD and VITEK 2 showed 100% categorical agreement. Essential agreement was 88.5% with kappa score 0.733 indicating strong agreement between VITEK and BMD. 31 out of 251 (12.3% CREs were resistant to fosfomycin.Conclusion: Study shows frequency of colistin and fosfomycin resistance to be 15.9% and 12.3%, respectively. In countries where rate of CREs is high, emerging resistance against these last resort antibiotics is alarming as it leaves clinicians with almost no options to manage such multidrug resistant and extensively drug resistant infections. Keywords: emerging drug resistance, colistin resistance, fosfomycin resistance, carbapenam resistant enterobacteriaceae, salvage antibiotics
Fry, Ilona J; DeFrank, Joseph J
.... Fluoride-resistant (FR) ureases developed previously in our laboratory were >95% inhibited by 1% hydrogen peroxide. To overcome this problem, the FR mutant urease structural genes of Klebsiella pneumoniae were mutagenized in vitro in an E...
Loh, Li-Cher; Nor Izran Hanim bt Abdul Samad,; Rosdara Masayuni bt Mohd Sani,; Raman, Sree; Thayaparan, Tarmizi; Kumar, Shalini
Klebsiella pneumoniae ranks high as a cause of adult pneumonia requiring hospitalization in Malaysia. To study whether extended-spectrum b-lactamase (ESBL) producing K. pneumoniae was linked to hospital outcomes, we retrospectively studied 441 cases of adult respiratory tract infections with microbial proven K. pneumoniae from an urban-based university teaching hospital between 2003 and 2004. 47 (10.6%) cases had ESBL. Requirement for ventilation and median length of hospital stay, were great...
Kizny Gordon, Alice E; Mathers, Amy J; Cheong, Elaine Y L; Gottlieb, Thomas; Kotay, Shireen; Walker, A Sarah; Peto, Timothy E A; Crook, Derrick W; Stoesser, Nicole
Over the last 20 years there have been 32 reports of carbapenem-resistant organisms in the hospital water environment, with half of these occurring since 2010. The majority of these reports have described associated clinical outbreaks in the intensive care setting, affecting the critically ill and the immunocompromised. Drains, sinks, and faucets were most frequently colonized, and Pseudomonas aeruginosa the predominant organism. Imipenemase (IMP), Klebsiella pneumoniae carbapenemase (KPC), and Verona integron-encoded metallo-β-lactamase (VIM) were the most common carbapenemases found. Molecular typing was performed in almost all studies, with pulse field gel electrophoresis being most commonly used. Seventy-two percent of studies reported controlling outbreaks, of which just more than one-third eliminated the organism from the water environment. A combination of interventions seems to be most successful, including reinforcement of general infection control measures, alongside chemical disinfection. The most appropriate disinfection method remains unclear, however, and it is likely that replacement of colonized water reservoirs may be required for long-term clearance. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: email@example.com.
fereshte sadat Hashemizadeh
Results: In this study of 202 isolates of Klebsiella, 180 isolates (89.1% of K. pneumoniae and 22 isolates (10.9% of Klebsiella oxytoca were isolated from patients. More than 55% of isolates showed multiple-drug resistance and also above 40% resistance to imipeneme and meropeneme was recorded. The MIC of isolates which were resistant to carbapenemes was above 32µg/ml.The PCR results showed that 22 cases (11.9% of isolates had blakpc gene which most of them had been isolated from urine and blood samples of patients who were hospitalized in the ICU and pediatrics. Conclusion: Regarding the existence of blakpc gene in K. pneumoniae and possibility of transformation of these genes to the other bacteria, reconsideration in antibiotics consumption patterns and more attention to nosocomial infections control criteria are inevitable.
Labia, Roger; Fabre, Christian; Masson, Jean-Michel; Barthelemy, Michel; Heitz, Madeleine; Pitton, Jean-S
Klebsiella pneumoniae strain 11-03, moderately resistant to ampicillin and carbenicillin, produces one constitutive β-lactamase with an isoelectric point of 7.10 and a molecular weight of 20,000±500. The enzymatic activity is directed primarily against the penicillins, ampicillin being the best substrate. Some cephalosporins are also hydrolyzed to some extent but the affinity of the enzyme for these antibiotics is low (high Km values). It has not been possible to determine whether the biogene...
Guerra, Maria F L; Teixeira, Rodrigo H F; Ribeiro, Vanessa L; Cunha, Marcos P V; Oliveira, Maria G X; Davies, Yamê M; Silva, Ketrin C; Silva, Ana P S; Lincopan, Nilton; Moreno, Andrea M; Knöbl, Terezinha
This report describes an outbreak of suppurative peritonitis caused by Klebsiella pneumoniae in an adult female of captive golden-handed tamarin (Saguinus midas midas). Two virulent and multidrug-resistant strains were isolated and classified through MLST as ST60 and ST1263. The microbiological diagnosis works as a support tool for preventive measures. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Kong, Q T; Wu, Q L; Ma, Z F; Shen, S C
Oxygen sensitivity of the nifLA promoter of Klebsiella pneumoniae has been demonstrated. Studies on the oxygen regulation of nifB-lacZ and nifH-lacZ fusions in the presence of the nifLA operon, which contains either an intact or a deleted nifL gene, indicate that possibly both the nifL promoter and the nifL product are responsible for nif repression by oxygen.
Clinical studies have reported that the occurrence of carbapenem resistant E. coli is on the rise. This is of concern because carbapenem antibiotics are typically reserved for treating infections caused by bacteria resistant to other classes of antibiotics. Current literature st...
Dr. Mike Miller reads an abridged version of the article, Deaths Attributable to Carbapenem-Resistant Enterobacteriaceae Infections. Created: 8/6/2014 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID). Date Released: 8/13/2014.
Background. There are no paediatric reports of invasive infection caused by carbapenem-resistant Enterobacteriaceae (CRE) from Africa. Objectives. To document a series of cases of CRE infections at a tertiary children's hospital in Cape Town, South Africa, describing the clinical and microbiological findings in these ...
Weterings, V; Zhou, K; Rossen, J W; van Stenis, D; Thewessen, E; Kluytmans, J; Veenemans, J
We describe an outbreak of Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae (KPC-KP) ST258 that occurred in two institutions (a hospital and a nursing home) in the Netherlands between July and December 2013. In total, six patients were found to be positive for KPC-KP. All isolates were resistant to colistin and exhibited reduced susceptibility to gentamicin and tigecycline. In all settings, extensive environmental contamination was found. Whole genome sequencing revealed the presence of bla KPC-2 and bla SHV-12 genes, as well as the close relatedness of patient and environmental isolates. In the hospital setting, one transmission was detected, despite contact precautions. After upgrading to strict isolation, no further spread was found. After the transfer of the index patient to a nursing home in the same region, four further transmissions occurred. The outbreak in the nursing home was controlled by transferring all KPC-KP-positive residents to a separate location outside the nursing home, where a dedicated nursing team cared for patients. This outbreak illustrates that the spread of pan-resistant Enterobacteriaceae can be controlled, but may be difficult, particularly in long-term care facilities. It, therefore, poses a major threat to patient safety. Clear guidelines to control reservoirs in and outside the hospitals are urgently needed.
Oikonomou, Katerina G; Aye, Myint
BACKGROUND Liver abscesses represent a serious infection of hepatic parenchyma and are associated with significant morbidity and mortality. The emergence of a new hypervirulent variant of Klebsiella pneumoniae, which can cause serious infections in the Asian population, is under investigation. We report a case series of six Asian patients hospitalized at our institution from January 2013 to November 2015 for liver abscess due to Klebsiella pneumoniae. CASE REPORT Charts of six Asian patients were retrospectively reviewed. Four patients were male and two were female. The mean age was 53 years (range: 35-64 years). All patients had no known past medical history of immunodeficiency. Three patients had multiple liver abscesses at the time of initial presentation. In five patients, the source of entry of the pathogenic microorganism was unknown and in one patient the suspected source of entry was the gastrointestinal tract. In three patients there was also concomitant Klebsiella pneumoniae bacteremia. The mean duration of antibiotic treatment was seven weeks and the mean duration of hospital stay was 13.5 days. CONCLUSIONS Liver abscess should always be included in the differential diagnosis in cases of sepsis without obvious source and/or in the clinical scenarios of fever, abdominal pain, and liver lesions.
Andrés E. Marcoleta
Full Text Available Multiresistant and invasive hypervirulent Klebsiella pneumoniae strains have become one of the most urgent bacterial pathogen threats. Recent analyses revealed a high genomic plasticity of this species, harboring a variety of mobile genetic elements associated with virulent strains, encoding proteins of unknown function whose possible role in pathogenesis have not been addressed. K. pneumoniae virulence has been studied mainly in animal models such as mice and pigs, however, practical, financial, ethical and methodological issues limit the use of mammal hosts. Consequently, the development of simple and cost-effective experimental approaches with alternative host models is needed. In this work we described the use of both, the social amoeba and professional phagocyte Dictyostelium discoideum and the fish Danio rerio (zebrafish as surrogate host models to study K. pneumoniae virulence. We compared three K. pneumoniae clinical isolates evaluating their resistance to phagocytosis, intracellular survival, lethality, intestinal colonization, and innate immune cells recruitment. Optical transparency of both host models permitted studying the infective process in vivo, following the Klebsiella-host interactions through live-cell imaging. We demonstrated that K. pneumoniae RYC492, but not the multiresistant strains 700603 and BAA-1705, is virulent to both host models and elicits a strong immune response. Moreover, this strain showed a high resistance to phagocytosis by D. discoideum, an increased ability to form biofilms and a more prominent and irregular capsule. Besides, the strain 700603 showed the unique ability to replicate inside amoeba cells. Genomic comparison of the K. pneumoniae strains showed that the RYC492 strain has a higher overall content of virulence factors although no specific genes could be linked to its phagocytosis resistance, nor to the intracellular survival observed for the 700603 strain. Our results indicate that both zebrafish
Full Text Available Klebsiella pneumoniae carbapenemase (KPC is a carbapenemase increasingly reported worldwide in Enterobacteriaceae. The aim of this study was to analyze the virulence of several KPC-2-producing K. pneumoniae isolates. The studied strains were (i five KPC-2 clinical strains from different geographical origins, belonging to different ST-types and possessing plasmids of different incompatibility groups; (ii seven transformants obtained after electroporation of either these natural KPC plasmids or a recombinant plasmid harboring only the bla KPC-2 gene into reference strains K. pneumoniae ATCC10031/CIP53153; and (iii five clinical strains cured of plasmids. The virulence of K. pneumoniae isolates was evaluated in the Caenorhabditis elegans model. The clinical KPC producers and transformants were significantly less virulent (LT50: 5.5 days than K. pneumoniae reference strain (LT50: 4.3 days (p<0.01. However, the worldwide spread KPC-2 positive K. pneumoniae ST258 strains and reference strains containing plasmids extracted from K. pneumoniae ST258 strains had a higher virulence than KPC-2 strains belonging to other ST types (LT50: 5 days vs. 6 days, p<0.01. The increased virulence observed in cured strains confirmed this trend. The bla KPC-2 gene itself was not associated to increased virulence.
Mei, Xue; Wang, Hao-Xun; Li, Jian-Sheng; Liu, Xiao-Hui; Lu, Xiao-Fan; Li, Ya; Zhang, Wei-Yu; Tian, Yan-Ge
Dusuqing granules (DSQ) have been used in the treatment of bacterial pneumonia clinically, with remarkable benefits. This study was initiated to explore the effects of DSQ on pulmonary inflammation by regulating nuclear factor (NF)-κB/mitogen-activated protein kinase (MAPK) signaling in bacterial pneumonia rats. Rat model was duplicated with Klebsiella pneumonia by a one-time intratracheal injection. Rats were randomized into control, model, DSQ and levofloxacin (LVX) groups. After administrated with appropriate medicines for 7 days, lung tissues were harvested and prepared for pathological analysis, and interleukin (IL)-1, IL-6, monocyte chemotactic protein (MCP)-1and macrophage inflammatory protein (MIP)-2 detections. NF-κB mRNA was measured by real-time qPCR, and the phosphorylation and total proteins of P38MAPK, JNK46/54, ERK42/44 were determined by Western blotting. Marked pathological impairments were observed in model rats, whereas were improved in DSQ group. The cytokines levels, NF-κB mRNA expression and the phosphorylation of P38MAPK, JNK46/54 and ERK42/44 proteins were significantly higher in model group, and were significantly depressed in DSQ group. The protective effects of DSQ on Klebsiella pneumonia might be attributed to its inactivative effects of NF-κB/ MAPK pathway.
Perez-Vazquez, Maria; Oteo, Jesus; Garcia-Cobos, Silvia; Aracil, Belen; Harris, Simon R.; Ortega, Adriana; Fontanals, Dionisia; Manuel Hernandez, Juan; Solis, Sonia; Campos, Jose; Dougan, Gordon; Kingsley, Robert A.
The global emergence of OXA-48-producing Klebsiella pneumoniae clones is a significant threat to public health. We used WGS and phylogenetic analysis of Spanish isolates to investigate the population structure of bla(OXA-48-like)-expressing K. pneumoniae ST11 and ST405 and to determine the
Ewers, Christa; Stamm, Ivonne; Pfeifer, Yvonne
OBJECTIVES: To investigate the clinical relevance and molecular epidemiology of extended-spectrum β-lactamase (ESBL)-producing Klebsiella species in animals. METHODS: Antimicrobial susceptibilities and presence of ESBLs were examined among Klebsiella spp. (n = 1519) from clinical samples (>1200...... senders from Germany and other European countries) mainly from companion animals and horses from October 2008 to March 2010. Multilocus sequence typing (MLST) and PFGE were performed including human isolates for comparative purposes. RESULTS: The overall ESBL rate was 8% for Klebsiella pneumoniae subsp....... pneumoniae. Most K. pneumoniae subsp. pneumoniae ESBL producers were isolated from soft tissue infections (29.3%) and urinary tract infections (14.9%). The major ESBL type was CTX-M-15 (85.4%), located on different plasmid scaffolds (HI2, I1, FIA, FIB, FII, A/C, R and N). Other ESBL genes, such as bla...
Zaidah, Abdul Rahman; Mohammad, Nurul Izzah; Suraiya, Siti; Harun, Azian
Infections by multidrug-resistant gram-negative bacteria (MDR-GNB) have been continuously growing and pose challenge to health institution globally. Carbapenem-resistant Enterobacteriacea (CRE) was identified as one of the MDR-GNB which has limited treatment options and higher mortality compared to those of sensitive strains. We report an increased burden of CRE fecal carriage at a hospital in the North-eastern region of Malaysia. A retrospective descriptive study from August 2013 to December 2015 was conducted in the Medical Microbiology & Parasitology laboratory of Hospital Universiti Sains Malaysia, which is a tertiary teaching hospital with more than 700 beds. This hospital treats patients with various medical and surgical conditions. Suspected CRE from any clinical specimens received by the laboratory was identified and confirmed using standard protocols. Polymerase chain reaction (PCR) assay was performed to determine the genotype. Altogether, 8306 Enterobacteriaceae was isolated from various clinical specimens during the study period and 477/8306 (5.74%) were CRE. Majority of the isolated CRE were Klebsiella [408/477, (85.5%)], of which Klebsiella pneumoniae was the predominant species, 388/408 (95%). CRE were mainly isolated from rectal swab (screening), 235/477 (49.3%); urine, 76/477 (15.9%); blood, 46/477 (9.6%) and about 7.1% from tracheal aspirate. One hundred and thirty-six isolates were subjected to genotype determination and., 112/136 (82.4%) showed positive detection of New Delhi metallo-β-lactamase 1 (NDM-1) gene ( bla NDM1 ). The study noted a high numbers of CRE isolated especially from rectal swabs. Active screening results in significant cost pressures and therefore should be revisited and revised, especially in low resource settings.
Abdul Rahman Zaidah
Full Text Available Abstract Background Infections by multidrug-resistant gram-negative bacteria (MDR-GNB have been continuously growing and pose challenge to health institution globally. Carbapenem-resistant Enterobacteriacea (CRE was identified as one of the MDR-GNB which has limited treatment options and higher mortality compared to those of sensitive strains. We report an increased burden of CRE fecal carriage at a hospital in the North-eastern region of Malaysia. Methods A retrospective descriptive study from August 2013 to December 2015 was conducted in the Medical Microbiology & Parasitology laboratory of Hospital Universiti Sains Malaysia, which is a tertiary teaching hospital with more than 700 beds. This hospital treats patients with various medical and surgical conditions. Suspected CRE from any clinical specimens received by the laboratory was identified and confirmed using standard protocols. Polymerase chain reaction (PCR assay was performed to determine the genotype. Results Altogether, 8306 Enterobacteriaceae was isolated from various clinical specimens during the study period and 477/8306 (5.74% were CRE. Majority of the isolated CRE were Klebsiella [408/477, (85.5%], of which Klebsiella pneumoniae was the predominant species, 388/408 (95%. CRE were mainly isolated from rectal swab (screening, 235/477 (49.3%; urine, 76/477 (15.9%; blood, 46/477 (9.6% and about 7.1% from tracheal aspirate. One hundred and thirty-six isolates were subjected to genotype determination and., 112/136 (82.4% showed positive detection of New Delhi metallo-β-lactamase 1 (NDM-1 gene (bla NDM1. Conclusion The study noted a high numbers of CRE isolated especially from rectal swabs. Active screening results in significant cost pressures and therefore should be revisited and revised, especially in low resource settings.
Davis, Gregg S.; Waits, Kara; Nordstrom, Lora; Weaver, Brett; Aziz, Maliha; Gauld, Lori; Grande, Heidi; Bigler, Rick; Horwinski, Joseph; Porter, Stephen; Stegger, Marc; Johnson, James R.; Liu, Cindy M.; Price, Lance B.
Background. Klebsiella pneumoniae is a common colonizer of the gastrointestinal tract of humans, companion animals, and livestock. To better understand potential contributions of foodborne K. pneumoniae to human clinical infections, we compared K. pneumoniae isolates from retail meat products and human clinical specimens to assess their similarity based on antibiotic resistance, genetic relatedness, and virulence. Methods. Klebsiella pneumoniae was isolated from retail meats from Flagstaff grocery stores in 2012 and from urine and blood specimens from Flagstaff Medical Center in 2011–2012. Isolates underwent antibiotic susceptibility testing and whole-genome sequencing. Genetic relatedness of the isolates was assessed using multilocus sequence typing and phylogenetic analyses. Extraintestinal virulence of several closely related meat-source and urine isolates was assessed using a murine sepsis model. Results. Meat-source isolates were significantly more likely to be multidrug resistant and resistant to tetracycline and gentamicin than clinical isolates. Four sequence types occurred among both meat-source and clinical isolates. Phylogenetic analyses confirmed close relationships among meat-source and clinical isolates. Isolates from both sources showed similar virulence in the mouse sepsis model. Conclusions. Meat-source K. pneumoniae isolates were more likely than clinical isolates to be antibiotic resistant, which could reflect selective pressures from antibiotic use in food-animal production. The close genetic relatedness of meat-source and clinical isolates, coupled with similarities in virulence, suggest that the barriers to transmission between these 2 sources are low. Taken together, our results suggest that retail meat is a potential vehicle for transmitting virulent, antibiotic-resistant K. pneumoniae from food animals to humans. PMID:26206847
Derrick R Samuelson
Full Text Available Chronic alcohol consumption perturbs the normal intestinal microbial communities (dysbiosis. To investigate the relationship between alcohol-mediated dysbiosis and pulmonary host defense we developed a fecal adoptive transfer model, which allows us to investigate the impact of alcohol-induced gut dysbiosis on host immune response to an infectious challenge at a distal organ, independent of prevailing alcohol use. Male C57BL/6 mice were treated with a cocktail of antibiotics (ampicillin, gentamicin, neomycin, vancomycin, and metronidazole via daily gavage for two weeks. A separate group of animals was fed a chronic alcohol (or isocaloric dextrose pair-fed controls liquid diet for 10 days. Microbiota-depleted mice were recolonized with intestinal microbiota from alcohol-fed or pair-fed (control animals. Following recolonization groups of mice were sacrificed prior to and 48 hrs. post respiratory infection with Klebsiella pneumoniae. Klebsiella lung burden, lung immunology and inflammation, as well as intestinal immunology, inflammation, and barrier damage were examined. Results showed that alcohol-associated susceptibility to K. pneumoniae is, in part, mediated by gut dysbiosis, as alcohol-naïve animals recolonized with a microbiota isolated from alcohol-fed mice had an increased respiratory burden of K. pneumoniae compared to mice recolonized with a control microbiota. The increased susceptibility in alcohol-dysbiosis recolonized animals was associated with an increase in pulmonary inflammatory cytokines, and a decrease in the number of CD4+ and CD8+ T-cells in the lung following Klebsiella infection but an increase in T-cell counts in the intestinal tract following Klebsiella infection, suggesting intestinal T-cell sequestration as a factor in impaired lung host defense. Mice recolonized with an alcohol-dysbiotic microbiota also had increased intestinal damage as measured by increased levels of serum intestinal fatty acid binding protein
Thiago Pavoni Gomes Chagas
Full Text Available OBJECTIVE: The present study was undertaken to characterize CTX-M ESBL-producing Klebsiella pneumoniae collected from hospitals in different cities of Brazil. MATERIAL AND METHODS: Eighty-five K. pneumoniae strains isolated from hospitalized patients in six different hospitals of three cities of Brazil were analyzed. ESBL production was confirmed by the standard double-disk synergy test and the Etest®. The MIC50 and MIC90 for ESBL-producing isolates were determined by the Etest® method. The antimicrobial susceptibilities of bacterial isolates were determined using the agar diffusion method according to the CLSI. Screening for blaTEM, blaSHV, blaCTX-M genes and class 1 integron was performed by PCR amplification. To determine the genomic diversity of CTX-M-producers, isolates were analyzed by macrorestriction profile analysis following PFGE. RESULTS AND DISCUSSION: Seventy-one K. pneumoniae isolates were ESBL-producing. PCR and sequencing experiments detected 38 CTX-M-producing K. pneumoniae belonged to groups CTX-M 1, CTX-M 2, CTX-M 8 and CTX-M 9. The association of different types ESBL (CTX-M, SHV and TEM was frequent. All K. pneumoniae isolates carried class 1 integron. PFGE analysis revealed thirty-one clonal types among CTX-M-producing isolates. The data presented herein illustrate the diversity of genotypes of CTX-M producing K. pneumoniae among Brazilians hospitals.
Datta, Saswati; Roy, Subhasree; Chatterjee, Somdatta; Saha, Anindya; Sen, Barsha; Pal, Titir; Som, Tapas; Basu, Sulagna
Treatment of neonatal sepsis has become a challenge with the emergence of carbapenemase-producing bacteria. This study documents the trend of carbapenem susceptibility in Enterobacteriaceae that caused septicaemia in neonates over a five year period (2007–2011) and the molecular characterisation of Enterobacteriaceae resistant to carbapenems and cephalosporins. Hundred and five Enterobacteriaceae including Escherichia coli (n = 27), Klebsiella pneumoniae (n = 68) and Enterobacter spp. (n = 10) were isolated from blood of septicaemic neonates followed by antibiotic susceptibility tests, determination of MIC values, phenotypic and genotypic detection of β-lactamases. Carbapenem was the most active antimicrobial tested after tigecycline. CTX-M type was the most prevalent ESBL throughout the period (82%). New Delhi Metallo-β-lactamase-1 (NDM-1), which is a recent addition to the carbapenemase list, was the only carbapenemase identified in our setting. Fourteen percent of the isolates possessed bla NDM-1. Carbapenem non-susceptibility was first observed in 2007 and it was due to loss of Omp F/Ompk36 in combination with the presence of ESBLs/AmpCs. NDM-1 first emerged in E. coli during 2008; later in 2010, the resistance was detected in K. pneumoniae and E. cloacae isolates. NDM-1-producing isolates were resistant to other broad-spectrum antibiotics and possessed ESBLs, AmpCs, 16S-rRNA methylases, AAC(6′)-Ib-cr, bleomycin resistant gene and class 1 integron. Pulsed field gel electrophoresis of the NDM-1-producing isolates indicated that the isolates were clonally diverse. The study also showed that there was a significantly higher incidence of sepsis caused by NDM-1-harbouring isolates in the male sex, in neonates with low birth weight and neonates born at an extramural centre. However, sepsis with NDM-1-harbouring isolates did not result in a higher mortality rate. The study is the first to review the carbapenem resistance patterns in neonatal sepsis
Potter, Robert F; D'Souza, Alaric W; Dantas, Gautam
Carbapenems, our one-time silver bullet for multidrug resistant bacterial infections, are now threatened by widespread dissemination of carbapenem-resistant Enterobacteriaceae (CRE). Successful expansion of Enterobacteriaceae clonal groups and frequent horizontal gene transfer of carbapenemase expressing plasmids are causing increasing carbapenem resistance. Recent advances in genetic and phenotypic detection facilitate global surveillance of CRE diversity and prevalence. In particular, whole genome sequencing enabled efficient tracking, annotation, and study of genetic elements colocalized with carbapenemase genes on chromosomes and on plasmids. Improved characterization helps detail the co-occurrence of other antibiotic resistance genes in CRE isolates and helps identify pan-drug resistance mechanisms. The novel β-lactamase inhibitor, avibactam, combined with ceftazidime or aztreonam, is a promising CRE treatment compared to current colistin or tigecycline regimens. To halt increasing CRE-associated morbidity and mortality, we must continue quality, cooperative monitoring and urgently investigate novel treatments. Copyright Â© 2016 Elsevier Ltd. All rights reserved.
Potter, Robert F.; D’Souza, Alaric W.; Dantas, Gautam
Carbapenems, our one-time silver bullet for multidrug resistant bacterial infections, are now threatened by widespread dissemination of carbapenem-resistant Enterobacteriaceae (CRE). Successful expansion of Enterobacteriaceae clonal groups and frequent horizontal gene transfer of carbapenemase expressing plasmids are causing increasing carbapenem resistance. Recent advances in genetic and phenotypic detection facilitate global surveillance of CRE diversity and prevalence. In particular, whole genome sequencing enabled efficient tracking, annotation, and study of genetic elements colocalized with carbapenemase genes on chromosomes and on plasmids. Improved characterization helps detail the co-occurrence of other antibiotic resistance genes in CRE isolates and helps identify pan-drug resistance mechanisms. The novel β-lactamase inhibitor, avibactam, combined with ceftazidime or aztreonam, is a promising CRE treatment compared to current colistin or tigecycline regimens. To halt increasing CRE-associated morbidity and mortality, we must continue quality, cooperative monitoring and urgently investigate novel treatments. PMID:27912842
Full Text Available Klebsiella is a Gram-negative bacterium that causes different types of health care-associated infections including pneumonia, bloodstream infections, surgical site infections and meningitis. We report here a case of Klebsiella pneumoniae meningitis in a patient with diabetes mellitus and Hansen′s disease. A middle-aged man with a known case of diabetes mellitus and Hansen′s disease presented with the complaints of blurred vision in the left eye and the patient was found to have cataract. Patient was operated for cataract and Intraocular lens implanted. Patient developed headache and vomiting on the 4 th post-operative day. Lumbar puncture was carried out and gram stain of cerebrospinal fluid showed Gram-negative bacilli in the direct smear and culture yielded a heavy growth of K. pneumoniae. The patient was treated with antimicrobials according to the susceptibility pattern. He initially showed improvement but later on developed altered sensorium and hypotension. Patient succumbed to infection in spite of all medical attention.
Full Text Available Biofilms are communities of microorganisms covered with extracellular polymeric substances. Such biofilm phenotype makes the microorganism resistant to antibiotics and plays a role in wound chronicity. This results in prolonged hospital stays in ICU, greater cost, and increased mortality. Methods: Pus swabs (59 were collected from a tertiary care hospital near Chennai were processed and identified using standard procedure followed by antibiotic susceptibility testing and identification of carbapenem resistance by Modified Hodge test as per CLSI guidelines. The biofilm formation was tested using plastic microtiter plate method. Results: Out of 59 pus swabs, 51 yielded growth with 69 isolates and 8 yielded no growth. Among the 69 isolates, 51 were GNB and 18 were GPC. Biofilm detection was noted in 84.31% (43/51 GNB isolates with 0.1% crystal violet whereas 100% (51/51 showed biofilm positive with 0.1% safranin. About 74.50% (38/51 isolates of GNB were carbapenem resistant by screening with disk diffusion method. Only 24% (6/25 of GNB isolates among Enterobacteriaceae were positive by Modified Hodge test method. Conclusion: The result shows the association of biofilm production among carbapenem resistant isolates obtained from chronic wound infections.
Full Text Available Reduced susceptibility to carbapenems in Gram-negative pathogens is an emerging feature of the antibiotic-resistance phenomenom Reports about strains resistant to this class of antibiotics among Enterobacteriaceae, particularly in Klebsiella pneumoniae, are increasing.The aims of this study were to assess the incidence of Klebsiella pneumoniae with reduced susceptibility to carbapenems in Bologna area and to carry out the characterization of these strains.The study included isolates of K. pneumoniae that showed reduced susceptibility to carbapenems, as detected by an automated system (Vitek2, bioMérieux. Between January and May 2009, 26 strains were collected (mainly isolated from urinary samples.These isolates were tested for susceptibility to carbapenems by E-test, to define MIC values for meropenem and ertapenem. Moreover, to detect the production of metallo-beta lactamases (MBL and carbapenemases (KPC were respectively performed the Etest with imipenem and imipenem/EDTA (IPM-IPM/EDTA and the modified Hodge test. Susceptibility assays performed by E-test showed that 25/26 strains were susceptible to meropenem, while for ertapenem 20/26 strains resulted resistant.The modified Hodge test was positive for 1 strain, while all the isolates were negative to the IPM-IPM/EDTA E-test.These results show that, as recently reported, the majority of strains of K. pneumoniae exhibiting reduced susceptibility to carbapenems, especially to ertapenem, are characterized by the production of ESBLs, which likely is associated with the loss of porins. On the other side, one strain was found to produce KPC and this finding confirms that the diffusion of carbapenemases producing K. pneumoniae has also to be considered in this geographic area.
Wise, Mark G; Horvath, Elizabeth; Young, Katherine; Sahm, Daniel F; Kazmierczak, Krystyna M
To understand the diversity of porin disruption in Klebsiella pneumoniae, the major outer membrane protein (OMP) porins, OmpK35 and OmpK36, were examined in a set of isolates that did not harbour traditional carbapenem-hydrolysing enzymes, but nevertheless tested non-susceptible to ertapenem. A world-wide collection of Klebsiella pneumoniae isolates that were part of the Study for Monitoring Antimicrobial Resistance Trends (SMART) surveillance project over the years 2008-2014 were characterised with regard to their β-lactamase gene carriage and potential permeability defects. Four hundred and eighty-seven isolates that did not carry carbapenemase genes, but were non-susceptible to ertapenem, were investigated by sequence analysis of the genes encoding OmpK35 and OmpK36. Isolates without obvious genetic lesions in either major porin gene were further examined by outer membrane protein SDS-PAGE. The majority of isolates, 83.0 % (404/487), exhibited clear genetic disruption in either or both of the ompK35 and ompK36 genes. Among the proportion of the collection with the highest ertapenem MIC value (>4 mg l -1 ), 60.5 % (115/190) showed mutation in both porin genes. Isolates without obvious genetic mutations were examined by SDS-PAGE, and 90.4 % (75/83) were found to lack or show altered expression of at least one of the major OMPs when compared to an ertapenem sensitive control strain. This study illustrates that porin deficiency in Klebsiella pneumoniae is a widespread phenomenon, and in combination with ESBLs and/or AmpC enzymes, likely accounts for the elevated ertapenem MICs observed in this study.
Lima, Wanessa C; Balestrino, Damien; Forestier, Christiane; Cosson, Pierre
Recognition of bacteria by metazoans is mediated by receptors that recognize different types of microorganisms and elicit specific cellular responses. The soil amoebae Dictyostelium discoideum feeds upon a variable mixture of environmental bacteria, and it is expected to recognize and adapt to various food sources. To date, however, no bacteria-sensing mechanisms have been described. In this study, we isolated a Dictyostelium mutant (fspA KO) unable to grow in the presence of non-capsulated Klebsiella pneumoniae bacteria, but growing as efficiently as wild-type cells in the presence of other bacteria, such as Bacillus subtilis. fspA KO cells were also unable to respond to K. pneumoniae and more specifically to bacterially secreted folate in a chemokinetic assay, while they responded readily to B. subtilis. Remarkably, both WT and fspA KO cells were able to grow in the presence of capsulated LM21 K. pneumoniae, and responded to purified capsule, indicating that capsule recognition may represent an alternative, FspA-independent mechanism for K. pneumoniae sensing. When LM21 capsule synthesis genes were deleted, growth and chemokinetic response were lost for fspA KO cells, but not for WT cells. Altogether, these results indicate that Dictyostelium amoebae use specific recognition mechanisms to respond to different K. pneumoniae elements. © 2013 John Wiley & Sons Ltd.
Full Text Available Bacteremia, the presence of viable bacteria in the blood stream, is often associated with several clinical conditions. Bacteremia can lead to multiple organ failure if managed incorrectly, which makes providing suitable nutritional support vital for reducing bacteremia-associated mortality. In order to provide such information, we investigated the metabolic consequences of a Klebsiella pneumoniae (K. pneumoniae infection in vivo by employing a combination of (1H nuclear magnetic resonance spectroscopy and multivariate data analysis. K. pneumoniae was intravenously infused in rats; urine and plasma samples were collected at different time intervals. We found that K. pneumoniae-induced bacteremia stimulated glycolysis and the tricarboxylic acid cycle and also promoted oxidation of fatty acids and creatine phosphate to facilitate the energy-demanding host response. In addition, K. pneumoniae bacteremia also induced anti-endotoxin, anti-inflammatory and anti-oxidization responses in the host. Furthermore, bacteremia could cause a disturbance in the gut microbiotal functions as suggested by alterations in a range of amines and bacteria-host co-metabolites. Our results suggest that supplementation with glucose and a high-fat and choline-rich diet could ameliorate the burdens associated with bacteremia. Our research provides underlying pathological processes of bacteremia and a better understanding of the clinical and biochemical manifestations of bacteremia.
de Melo, Maíra Espíndola Silva; Cabral, Adriane Borges; Maciel, Maria Amélia Vieira; da Silveira, Vera Magalhães; de Souza Lopes, Ana Catarina
The objectives of this study were to determine the distribution of phylogenetic groups among Klebsiella pneumoniae isolates from Recife, Brazil and to assess the relationship between the groups and the isolation sites and resistance profile. Ninety four isolates of K. pneumoniae from hospital or community infections and from normal microbiota were analyzed by gyrA PCR-RFLP, antibiotic susceptibility, and adonitol fermentation. The results revealed the distinction of three phylogenetic groups, as it has also been reported in Europe, showing that these clusters are highly conserved within K. pneumoniae. Group KpI was dominantly represented by hospital and community isolates while groups KpII and KpIII displayed mainly normal microbiota isolates. The resistance to third generation cephalosporins, aztreonam, imipenem, amoxicillin/clavulanic acid, and streptomycin was only observed in KpI. The percentage of resistance was higher in KpI, followed by KpII and KpIII. The differences in the distribution of K. pneumoniae phylogenetic groups observed in this study suggest distinctive clinical and epidemiological characteristics among the three groups, which is important to understand the epidemiology of infections caused by this organism. This is the first study in Brazil on K. pneumoniae isolates from normal microbiota and community infections regarding the distribution of phylogenetic groups based on the gyrA gene.
Pantel, Alix; Richaud-Morel, Brigitte; Cazaban, Michel; Bouziges, Nicole; Sotto, Albert; Lavigne, Jean-Philippe
The spread of carbapenemase-producing Gram-negative rods is an emerging global problem. This study describes the epidemiologic features of an outbreak caused by an environmental reservoir of OXA-48-producing Klebsiella pneumoniae caused by persistence of the bacteria during 20 months in an intensive care unit in France. This report emphasizes the importance of early environmental screening to interrupt the transmission of carbapenemase-producingEnterobacteriaceae. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.
Bernardo Filho, M.; Pereira, J.A.A.; Boasquevisque, E.M.
The labeling of Klebsiella pneumoniae with technetium-99m (Tc-99m) seems to depend on the stannous ion (Sn ++ ) concentration. Starting at 3μg/ml of this ion is the suspension fluid an uptake of Tc-99m close to 90% was observed. The labeling is apparently strong, since the eluation of Tc-99m, after incubation of the tagged culture, in a water-bath at 37 0 C for several hours, was very weak. The viability of the culture was unaltered after treatment with tin and Tc-99m. (Author) [pt
Stacey, G; Zhu, J; Shah, V K; Shen, S C; Brill, W J
A single mutation, nifC1005 (Jin et al. Sci. Sin. 23:108-118, 1980), located between nifH and nifJ in the nif cluster of Klebsiella pneumoniae, genetically complemented mutations in each of the 17 known nif genes. This suggested that the mutation is located in a new nif gene. We showed by complementation analyses that only 3 of 12 nifJ mutations tested were complemented by nifC1005. Nitrogenase activity in cell extracts of the mutant with nifC1005 as well as NifJ- mutants was stimulated by th...
Full Text Available El lavado de manos es la medida de control más efectiva para interrumpir la transmisión de microorganismos patógenos nosocomiales. Sin embargo, la adherencia por parte del personal de salud es baja. Una nueva modalidad para la higiene de las manos, el frotado con alcohol-gel (AG, permite reducir el tiempo requerido y ofrece mayor comodidad. Con la finalidad de evaluar el efecto de la introducción del AG sobre las tasas de infecciones debidas a los tres agentes nosocomiales multirresistentes (Staphylococcus aureus, Klebsiella pneumoniae y Pseudomonas aeruginosa más frecuentes en nuestro hospital, se realizó un estudio observacional, comparando la incidencia de infecciones en los 12 meses previos y posteriores a la intervención. Luego de la introducción del AG se redujo de manera significativa la incidencia de infecciones debidas a Klebsiella pneumoniae BLEE (RR: 0.38, especialmente las bacteriemias (RR:0.10. El uso de AG ofrece condiciones que probablemente mejoren la adherencia del personal a la higiene de manos. Sin embargo, sobre la base de este estudio, no podemos concluir que el resultado observado se deba al AG en sí mismo o a una mayor adherencia a la práctica higiénica.Handwashing is considered the most important and effective infection control measure to prevent transmission of nosocomial pathogens. However, compliance with handwashing by health care workers is low. A new modality for hand hygiene is alcohol gel rub, which reduces time required, does not damage the skin and increases health care workers compliance. An observational study was conducted to assess the effect of alcohol-gel hand antiseptic on infection rates due to the 3 more frequent multi-resistant bacteria (Staphylococcus aureus, Klebsiella pneumoniae y Pseudomonas aeruginosa in our hospital. Two periods were compared, 12 months before and 12 months after starting alcohol gel use. The second period (AG use showed a significant reduction on incidence rates of
V. M. Brykhanov
Full Text Available Aim. Investigated the activity of methylethylpiridinol (6-methyl-2-ethyl-pyridin-3-ol hydrochloride in the comprehensive treatment of the experimental bacterial infection caused by Klebsiella pneumoniae.Materials and methods. The study was conducted on clinical isolates of Klebsiella pneumoniae. At the first stage of the study (in vitro studied the effect of methylethylpiridinol in concentrations 0,25–4 mM on the growth of the strain and the activity of the sublethal concentrations of antibiotics – gentamicin, ciprofloxacin, tetracycline, ceftazidime. In the second stage of the study (in vivo in rats Wistar simulated bacterial peritonitis by intraperitoneal injection of a suspension of Klebsiella pneumoniae and investigated the effect of methylethylpiridinol (80 mg/kg on the effectiveness of antibiotic therapy with gentamicin (30 mg/kg, ciprofloxacin (50 mg/kg, ceftazidime (120 mg/kg or tetracycline (80 mg/kg. The animal blood plasma was determined ceruloplasmin concentration (marker of the intensity of infectious-inflammatory process and thiobarbiturate-jet products, erythrocytes – the concentration of reduced glutathione, catalase and glutathione peroxidase.Results. It is found that a methylethylpiridinol inhibits the development of periodic bacterial cultures, but exhibits a pronounced antagonism with respect to gentamicin. Antioxidant slightly increases the activity of ciprofloxacin and tetracycline. The bacteriostatic effect of antioxidant reduces the action of ceftazidime in vitro. In conditions of chemotherapy by using of gentamicin and ciprofloxacin additional injection of methylethylpiridinol leads to the preservation of ceruloplasmin level to the level of non-treated animals without showing the antioxidant effect. Ceftazidime exhibits antioxidant effect, reduces the introduction of methylethylpiridinol. The antioxidant properties of methylethylpiridinol did not appear in the application of
Jhosef Franck Quispe Pari
Full Text Available Resumen Las carbapenemasas son uno de los mecanismos enzimáticos de resistencia antimicrobiana, que compromete la mayor parte de los antibióticos betalactámicos. Por lo general, su producción se debe al uso indiscriminado de antimicrobianos. A nivel mundial, la expansión de este mecanismo de resistencia es inminente y las medidas de control son limitadas. Con el objeto de discutir los problemas relacionados a este mecanismo emergente de resistencia, reportamos un caso de Klebsiella pneumoniae productora de carbapenemasas en Huancayo, la Región de la Sierra Central de Perú.
Ahmed, Ayaz; Khan, Anum Khalid; Anwar, Ayaz; Ali, Syed Abid; Shah, Muhammad Raza
Klebsiella pneumoniae (K. pneumoniae) is one of the major pathogen associated with nosocomial infections, especially catheter associated urinary tract infections which involved biofilm formation. This study was designed to evaluate the antibiofilm efficacy of gold nanoparticle conjugated with chlorhexidine (Au-CHX) against K. pneumoniae isolates. Au-CHX was synthesized and analyzed for stability by using UV-Visible spectrophotometry, atomic force microscopy (AFM), fourier transform infrared spectroscopy (FT-IR) and electrospray ionization mass spectroscopy (ESI-MS). Biofilm inhibition and eradication was performed by crystal violet, 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays and further confirmed by florescence and AFM microscopy. Au-CHX showed the maxima surface plasmon resonance (SPR) band at 535 nm, spherical morphology and polydispersity with size in the range of 20-100 nm. The micro molar concentrations (i.e. 25 and 100 μM) of Au-CHX completely inhibited the biofilm formation and metabolic activity within biofilms of K. pneumoniae reference and three tested clinical isolates, respectively. Time dependant biofilm inhibition assay showed that Au-CHX inhibited the early stage of biofilm formation. While at 75 and 100 μM concentrations, it also eradicated the established biofilms of K. pneumoniae isolates as compared to 2 mM chlorhexidine. Reduced florescence signals and surface roughness during microscopic analysis further confirms the antibiofilm activity of Au-CHX against K. pneumoniae ATCC13882 and clinical isolates. Thus it is concluded that chlorhexidine coated gold nanoparticle not only inhibits the biofilm formation of K. pneumoniae ATCC and clinical isolates but also eradicated the preformed biofilm. Copyright © 2016 Elsevier Ltd. All rights reserved.
Favre-Bonte, S.; Licht, Tine Rask; Forestier, C.
The role of the Klebsiella pneumoniae capsular polysaccharide (K antigen) during colonization of the mouse large intestine was assessed with mild-type K. pneumoniae LM21 and its isogenic capsule-defective mutant. When bacterial strains were fed alone to mice, the capsulated bacteria persisted...... in the intestinal tract at levels of 10(8) CFU/g of feces while the capsule-defective strain colonized at low levels, 10(4) CFU/g of feces. In mixed-infection experiments, the mutant was rapidly outcompeted by the wild type. In situ hybridization on colonic sections revealed that bacterial cells of both strains...... were evenly distributed in the mucus layer at day 1 after infection, while at day 20 the wild type remained dispersed and the capsule-defective strain was seen in clusters in the mucus layer. These results suggest that capsular polysaccharide plays an important role in the gut colonization ability of K...
Full Text Available Treating pathogens is becoming challenging because of multidrug resistance and availability of limited alternative therapies which has further confounded this problem. The situation becomes more alarming when multidrug resistant pathogens form a 3D structure known as biofilm. Biofilms are formed in most of the infections especially in chronic infections where it is difficult to eradicate them by conventional antibiotic therapy. Chemically synthesized nanoparticles are known to have antibiofilm activity but in the present study, an attempt was made to use amino acid functionalized silver nanoparticles alone and in combination with gentamicin to eradicate Klebsiella pneumoniae biofilm. Amino acid functionalized silver nanoparticles were not only able to disrupt biofilm in vitro but also led to the lowering of gentamicin dose when used in combination. To the best of our knowledge, this is the first study demonstrating the application of amino acid functionalized silver nanoparticles in the eradication of young and old K. pneumoniae biofilm.
Yucumá-Gutiérrez, Samuel; Duran-Gutiérrez, Luis F; Osorio-Pinzón, Johanna V; Álzate-Carvajal, Verónica; Mondragón-Cardona, Álvaro
El absceso hepático, continúa siendo un importante problema de salud pública. El causado por Klebsiella pneumoniae, se ha descrito en un 29% de los casos en algunas series. Con una mortalidad hasta del 11,3%, se presenta con mayor frecuencia en pacientes con diabetes mellitus, relacionándose con complicaciones a distancia, como meningitis, absceso cerebral y afección pulmonar. Se presenta el caso de un hombre sin factores de riesgo, con síndrome de absceso hepático por Klebsiella pneumoniae c...
Fahmi Yousef Khan; Mohammed Abukhattab; Mohammed AbuKamar; Deshmukh Anand
Objective: To describe the clinical presentation, underlying diseases, antimicrobial susceptibility, treatment and outcome of Klebsiella pneumoniae meningitis patients. Methods:This retrospective study involved all patients with 15 years of age or older who admitted to Hamad General Hospital with culture proven Klebsiella pneumoniae meningitis from January 1, 2007 to December 31, 2012. Results: A total of ten cases were identified (nine males and one female). Their mean age was (43.3±12.8) years. Eight patients (80%) had nosocomial meningitis with neurosurgery being the most frequent associated condition. Fever and altered consciousness were the most frequent symptom. Cerebrospinal fluid showed elevated protein and glucose levels. Gram stain showed Gram-negative rods in 50%of cases, while positive cerebrospinal fluid culture results were found in all patients. Multidrug resistance was observed in two cases, and all patients had received appropriate empirical and definitive antibiotic treatments. The mean duration of intravenous antimicrobial treatment was (19.3±7.0) d and all patients with external ventricular drains underwent removal of the device, while in-hospital mortality was 50%. Conclusions: The number of cases was too small to come up with therapeutic and prognostic conclusions. Further large-scale prospective study is needed.
Fahmi; Yousef; Khan; Mohammed; Abukhattab; Mohanuned; Abukamar; Deshmukh; Anand
Objective:To describe the clinical presentation,underlying diseases,antimicrobial susceptibility,treatment and outcome of Klebsiella pneumoniae meningitis patients.Methods:This retrospective study involved all patients with 15 years of age or older who admit ted to Hamad General Hospital with culture proven Klebsiella pneumoniae meningitis from January 1,2007 to December 31,2012.Results:A total of ten cases were identified mine males and one female).Their mean age was i43.3±12.8) years.Eight patients(80%) had nosocomial meningitis with neurosurgery being the most frequent associated condition.Fever and altered consciousness were the most frequent symptom.Cerebrospinal fluid showed elevated protein and glucose levels.Oram slain showed Gram—negative rods in 50%of cases,while positive cerebrospinal fluid culture results were found in all patients.Multidrug resistance was observed in two cases,and all patients had received appropriate empirical and definitive antibiotic treatments.The mean duration of intravenous antimicrobial treatment was(19.3±7.0) d and all patients with external ventricular drains underwent removal of the device,while in—hospital mortality was 50%.Conclusions:The number of cases was too small to come up with therapeutic and prognostic conclusions.Further large-scale prospective study is needed.
Van Laar, Tricia A.; Chen, Tsute; You, Tao
Klebsiella pneumoniae, a Gram-negative bacterium, is normally associated with pneumonia in patients with weakened immune systems. However, it is also a prevalent nosocomial infectious agent that can be found in infected surgical sites and combat wounds. Many of these clinical strains display multidrug resistance. We have worked with a clinical strain of K. pneumoniae that was initially isolated from a wound of an injured soldier. This strain demonstrated resistance to many commonly used antibiotics but sensitivity to carbapenems. This isolate was capable of forming biofilms in vitro, contributing to its increased antibiotic resistance and impaired clearance. We were interested in determining how sublethal concentrations of carbapenem treatment specifically affect K. pneumoniae biofilms both in morphology and in genomic expression. Scanning electron microscopy showed striking morphological differences between untreated and treated biofilms, including rounding, blebbing, and dimpling of treated cells. Comparative transcriptome analysis using RNA sequencing (RNA-Seq) technology identified a large number of open reading frames (ORFs) differentially regulated in response to carbapenem treatment at 2 and 24 h. ORFs upregulated with carbapenem treatment included genes involved in resistance, as well as those coding for antiporters and autoinducers. ORFs downregulated included those coding for metal transporters, membrane biosynthesis proteins, and motility proteins. Quantitative real-time PCR validated the general trend of some of these differentially regulated ORFs. Treatment of K. pneumoniae biofilms with sublethal concentrations of carbapenems induced a wide range of phenotypic and gene expression changes. This study reveals some of the mechanisms underlying how sublethal amounts of carbapenems could affect the overall fitness and pathogenic potential of K. pneumoniae biofilm cells. PMID:25583711
Juan Carlos Cataño Correa
Full Text Available
Worldwide, bacterial resistance is an increasingly serious problem, especially in hospital environments. Staphylococcus aureus and Escherichia coli are the most frequently isolated microorganisms in patients with nosocomial infections. In Medellín, Colombia, however, Klebsiella pneumoniae has become increasingly important in this kind of infection, for which reason this review was carried out.
It includes the following aspects: microbiology, epidemiology, dissemination, resistance to betalactamic antibiotics and its mechanisms, clinical impact and importance of the problem in this city.
La resistencia bacteriana es un problema serio, de magnitud creciente y presentación universal, que reviste gran importancia, especialmente en los ambientes hospitalarios; los microorganismos más frecuentemente aislados de pacientes con infecciones intrahospitalarias son Staphylococcus aureus y Escherichia coli. En Medellín, sin embargo, Klebsiella pneumoniae ha cobrado gran importancia en años recientes debido a su gran incremento como agente causal de ese tipo de infecciones, lo que motiva esta revisión. Se incluyen los siguientes aspectos: microbiología, epidemiología, diseminación, resistencia a los beta-lactámicos y sus mecanismos, impacto clínico e importancia del problema
O'Brien, D J
Five OXA-48-producing Klebsiella pneumoniae were detected in a tertiary referral hospital in Ireland between March and June 2011. They were found in the clinical isolates of five cases that were inpatients on general surgical wards. None of the cases had received healthcare at a facility outside of Ireland in the previous 12 months. This is the first report of OXA-48-producing K. pneumoniae in Ireland.
Full Text Available We report class A carbapenemase (KPC-3-producing Klebsiella pneumoniae meningitis in a 6-month-old child in Algeria. Multilocus sequence typing showed that the sequence type obtained corresponded to ST512, an allelic single-locus variant of the pandemic ST258 widely distributed in KPC producers from Europe. To our knowledge, this is the first report of KPC-3-producing K. pneumoniae ST512 in a North African country.
Hansen, Dennis Schrøder; Schumacher, Helga; Hansen, Frank
Most Gram-negative community-acquired and nosocomial infections are caused by Escherichia coli and Klebsiella pneumoniae, among which increasing resistance due to extended-spectrum β-lactamase (ESBL) is a major problem. We present data from the first Danish nationwide prevalence study on ESBL-pro......-producing E. coli, K. pneumoniae, and Proteus mirabilis in blood and urine cultures from hospitals and the community....
Marina Dos Santos Goncalves
Full Text Available Competition and cooperation phenomena occur within highly interactive biofilm communities and several non-biocides molecules produced by microorganisms have been described as impairing biofilm formation. In this study, we investigated the anti-biofilm capacities of an ubiquitous and biofilm producing bacterium, Klebsiella pneumoniae. Cell-free supernatant from K. pneumoniae planktonic cultures showed anti-biofilm effects on most Gram positive bacteria tested but also encompassed some Gram negative bacilli. The anti-biofilm non-bactericidal activity was further investigated on Staphylococcus epidermidis, by determining the biofilm biomass, microscopic observations and agglutination measurement through a magnetic bead-mediated agglutination test. Cell-free extracts from K. pneumoniae biofilm (supernatant and acellular matrix also showed an influence, although to a lesser extend. Chemical analyses indicated that the active molecule was a high molecular weight polysaccharide composed of five monosaccharides: galactose, glucose, rhamnose, glucuronic acid and glucosamine and the main following sugar linkage residues [→ 2-α-L-Rhap-(1 →]; [→ 4-α-L-Rhap-(1 →]; [α-D-Galp-(1 →]; [→ 2,3-α-D-Galp-(1 →]; [→ 3-β-D-Galp-(1 →] and, [→ 4-β-D-GlcAp-(1 →]. Characterization of this molecule indicated that this component was more likely capsular polysaccharide (CPS and precoating of abiotic surfaces with CPS extracts from different serotypes impaired the bacteria-surface interactions. Thus the CPS of Klebsiella would exhibit a pleiotropic activity during biofilm formation, both stimulating the initial adhesion and maturation steps as previously described, but also repelling potential competitors.
Full Text Available Abstract Background Knowledge of the etiology of pyogenic liver and pancreatic abscesses is an important factor in determining the success of combined surgical and antibiotic treatment. Literature shows geographical variations in the prevalence and distribution of causative organisms, and the spread of Klebsiella pneumoniae carbapenemase-producing bacteria is an emerging cause of abdominal infections. Case presentation We herein describe two cases of intra-abdominal abscesses due to monomicrobial infection by Klebsiella pneumoniae Sequence Type 258 producing K. pneumoniae carbapenemase 3 (KPC-Kp. In case 1, a 50-year-old HIV-negative Italian woman with chronic pancreatitis showed infection of a pancreatic pseudocystic lesion caused by KPC-Kp. In case 2, a 64-year-old HIV- negative Italian woman with pancreatic neoplasm and liver metastases developed a liver abscess due to KPC after surgery. Both women were admitted to our hospital but to different surgical units. The clonal relationship between the two isolates was investigated by pulsed-field gel electrophoresis (PFGE. In case 2, the patient was already colonized at admission and inter-hospital transmission of the pathogen was presumed. A long-term combination regimen of colistin with tigecycline and percutaneous drainage resulted in full recovery and clearance of the multidrug-resistant (MDR pathogen. Conclusions Timely microbiological diagnosis, the combined use of new and old antibiotics and radiological intervention appeared to be valuable in managing these serious conditions. The emergence and dissemination of MDR organisms is posing an increasing challenge for physicians to develop new therapeutic strategies and control and prevention frameworks.
S M Amudhan
Full Text Available Objectives: Acinetobacter baumannii is a significant pathogen in health care settings. In recent years, an increase in carbapenem resistance among A. baumannii due to Ambler class B metallo-beta-lactamases or class D OXA carbapenamases has been reported. In this study we detected the presence of OXA carbapenamases and coproduction of metallo-beta-lactamases (blaVIM and blaIMP by phenotypic and genotypic methods in carbapenem resistant clinical isolates of Acinetobacter baumannii. Materials and Methods: A total of 116 consecutive, non-duplicate carbapenem resistant A. baumannii isolated from various clinical specimens were included in the study. The modified Hodge test and inhibitor potentiated disk diffusion tests were done for the screening of carbapenamase and metallo-beta-lactamase production, respectively. Polymerase chain reaction (PCR was performed for the detection of OXA (blaOXA 23 like, blaOXA 24 like, blaOXA-51 like and blaOXA-58 like genes and metallo-beta-lactamases (blaVIM and blaIMP genes. Gene sequencing was performed for representative isolates. Results: Among 116 A. baumannii, OXA genes were detected in 106 isolates. BlaOXA 51 like (n = 99 and blaOXA -23 like (n = 95 were the most common and they coexisted in 89 isolates. blaOXA-24 like gene was detected in two isolates of which one also carried blaOXA-51 like and blaOXA-58 like genes. The modified Hodge test was positive in 113 isolates. The metallo-beta-lactamase screening test was positive in 92 isolates. blavim was detected in 54 isolates of which 1 also carried the blaIMP gene. Conclusions: blaOXA-23 like and bla OXA 51 like genes are the most common types of OXA carbapenamases while the blaVIM type is the most common type of metallo-beta-lactamase contributing to carbapenem resistance in clinical isolates of A. baumannii. The coproduction of OXA and metallo-beta-lactamases is not an uncommon phenomenon in A. baumannii.
Full Text Available Purpose : Amp C beta-lactamase are Ambler class C enzymes that confer resistance to extended spectrum cephalosporins and are not inhibited by beta-lactamase inhibitors. Their detection is crucial, since the phenotypic tests are not standardised leading to ambiguity in interpretation of results. This study was done to detect the types of Amp C prevalent in Escherichia coli and Klebsiella pneumoniae by multiplex polymerase chain reaction (PCR. Materials and Methods : Seventy-seven consecutive cefoxitin resistant clinical isolates of E. coli (n = 25 and K. pneumoniae (n = 52 were included in the study. Antibiotic susceptibility testing to various classes of antibiotics was performed by disc diffusion using Clinical Laboratory Standards Institute (CLSI guidelines. Minimum inhibitory concentration (MIC to cefoxitin, imipenem and meropenem were determined by broth microdilution method. Isolates were screened for production of Extended Spectrum Beta-Lactamase (ESBL. Multiplex PCR was performed for the detection of Amp C genes after phenotypic testing (Hodge test and inhibitor based test. Results : Cefoxitin Hodge test was positive in 40 isolates which included 20 E. coli and 20 K. pneumoniae. There was zone enhancement with boronic acid in 55 isolates, of which 36 were K. pneumoniae and 19 were E. coli. Multiplex PCR detected Amp C in 11/25 E. coli and 12/52 K. pneumoniae isolates. The Amp C genes detected were CIT (Amp C origin - Citrobacter freundii, DHA (Dhahran Hospital, Saudi Arabia, ACC (Ambler class C, EBC (Amp C origin - Enterobacter cloacae groups. ESBL was co-produced in 54 isolates. Conclusions : Amp C was detected in 29.87% of the study isolates. Majority of them co-produced ESBL. The most common Amp C was the CIT family. Screen tests for cefoxitin resistance may be falsely positive due to production of carbapenamases.
He, Miao; Ichinose, Takamichi; Yoshida, Seiichi; Yamamoto, Shoji; Inoue, Ken-ichiro; Takano, Hirohisa; Yanagisawa, Rie; Nishikawa, Masataka; Mori, Ikuko; Sun, Guifan; Shibamoto, Takayuki
Inhaling concomitants from Asian sand dust (ASD) may result in exacerbation of pneumonia by the pathogen. The exacerbating effect of ASD on pneumonia induced by Klebsiella pneumoniae (KP) was investigated in ICR mice. The organic substances adsorbed onto ASD collected from the atmosphere of Iki-island in Japan were excluded by heat treatment at 360 °C for 30 min. ICR mice were instilled intratracheally with ASD at doses of 0.05 mg or 0.2 mg/mouse four times at 2-week intervals (total dose of 0.2 mg or 0.8 mg/mouse) and were administrated with ASD in the presence or absence of KP at the last intratracheal instillation. Pathologically, ASD caused exacerbation of pneumonia by KP as shown by increased inflammatory cells within the bronchiolar and the alveolar compartments. ASD enhanced the neutrophil number dose dependently as well as the expression of cytokines (IL-1β, IL-6, IL-12, IFN-γ, TNF-α) and chemokines (KC, MCP-1, MIP-1α) related to KP in BALF. In an in vitro study using RAW264.7 cells, combined treatment of ASD and KP increased gene expression of IL-1β, IL-6, IFN-β, KC, MCP-1, and MIP-1α. The same treatment tended to increase the protein level of IL-1β, TNF-α and MCP-1 in a culture medium compared to each treatment alone. The combined treatment tended to increase the gene expression of Toll-like receptor 2 (TLR2), and NALP3, ASC and caspase-1 compared with KP alone. These results suggest that the exacerbation of pneumonia by ASD + KP was due to the enhanced production of pro-inflammatory mediators via activation of TLR2 and NALP3 inflammasome pathways in alveolar macrophages.
Al-Rabea, A A; Burwen, D R; Eldeen, M A; Fontaine, R E; Tenover, F; Jarvis, W R
To identify risk factors for Klebsiella pneumoniae bloodstream infections (BSI) in neonates in a hospital in the Kingdom of Saudi Arabia (KSA). Two case-control studies among hospitalized neonates during February 15-May 14, 1991, and a procedural and microbiological investigation. Hospital A, a maternity and children's hospital in KSA. Case patients had a blood culture positive for K pneumoniae after >2 days of hospitalization and had no evidence of a nonblood primary site of infection. When the 20 case patients were compared with controls, hospitalization in a critical-care unit (odds ratio [OR], 5.5; 95% confidence interval [CI95], 1.20-51.1; P=.03) was identified as a risk factor. When the case patients were compared with a second set of controls matched by critical-care status, receipt of a particular intravenous fluid (D10%/0.2NS; OR, 11.0; CI95, 1.42-85.2; P=.009) or a blood product (OR undefined; P=.04) were identified as risk factors. Infusates were administered via umbilical catheters for most case and control patients (19/20 vs 15/20, P>.05); catheters were manipulated more frequently in patients in critical-care units. Umbilical catheter tip, skin, or mucus membrane K pneumoniae colonization occurred in 47% and 53% of evaluated case and control patients, respectively. Available K pneumoniae isolates from blood cultures and colonization sites had identical antimicrobial susceptibility patterns. Emphasis on handwashing, careful preparation and administration of infusates, and aseptic technique for catheter insertion, maintenance, and manipulation was temporally associated with resolution of the epidemic. This outbreak was probably due to infusion therapy practices that led to BSI in nursery patients colonized with K pneumoniae. Both catheter-related infections and extrinsic contamination of infusates may have occurred. Hospital personnel should be aware of their potential to spread nosocomial pathogens from person to person and should implement Centers for
Full Text Available BACKGROUND: Beta-lactamase production and porin decrease are the well-recognized mechanisms of acquired beta-lactam resistance in Klebsiella pneumoniae isolates. However, such mechanisms proved to be absent in K. pneumoniae isolates that are non susceptible to cefoxitin (FOX and susceptible to amoxicillin+clavulanic acid in our hospital. Assessing the role of efflux pumps in this beta-lactam phenotype was the aim of this study. METHODOLOGY/FINDINGS: MICs of 9 beta-lactams, including cloxacillin (CLX, and other antibiotic families were tested alone and with an efflux pump inhibitor (EPI, then with both CLX (subinhibitory concentrations and EPI against 11 unique bacteremia K. pneumoniae isolates displaying the unusual phenotype, and 2 ATCC strains. CLX and EPI-dose dependent effects were studied on 4 representatives strains. CLX MICs significantly decreased when tested with EPI. A similar phenomenon was observed with piperacillin+tazobactam whereas MICs of the other beta-lactams significantly decreased only in the presence of both EPI and CLX. Thus, FOX MICs decreased 128 fold in the K. pneumoniae isolates but also 16 fold in ATCC strain. Restoration of FOX activity was CLX dose-dependent suggesting a competitive relationship between CLX and the other beta-lactams with regard to their efflux. For chloramphenicol, erythromycin and nalidixic acid whose resistance was also due to efflux, adding CLX to EPI did not increase their activity suggesting differences between the efflux process of these molecules and that of beta-lactams. CONCLUSION: This is the first study demonstrating that efflux mechanism plays a key role in the beta-lactam susceptibility of clinical isolates of K. pneumoniae. Such data clearly evidence that the involvement of efflux pumps in beta-lactam resistance is specially underestimated in clinical isolates.
He, Miao [Department of Environmental and Occupational Health, College of Public Health, China Medical University, 11001, Shenyang (China); Ichinose, Takamichi; Yoshida, Seiichi [Department of Health Sciences, Oita University of Nursing and Health Sciences, 870-1201, Oita (Japan); Yamamoto, Shoji; Inoue, Ken-ichiro; Takano, Hirohisa; Yanagisawa, Rie [Pathophysiology Research Team, National Institute for Environmental Studies, 305-8506, Tsukuba, Ibaraki (Japan); Nishikawa, Masataka; Mori, Ikuko [Environmental Chemistry Division, National Institute for Environmental Studies, 305-8506, Tsukuba, Ibaraki (Japan); Sun, Guifan [Department of Environmental and Occupational Health, College of Public Health, China Medical University, 11001, Shenyang (China); Shibamoto, Takayuki, E-mail: firstname.lastname@example.org [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States)
Inhaling concomitants from Asian sand dust (ASD) may result in exacerbation of pneumonia by the pathogen. The exacerbating effect of ASD on pneumonia induced by Klebsiella pneumoniae (KP) was investigated in ICR mice. The organic substances adsorbed onto ASD collected from the atmosphere of Iki-island in Japan were excluded by heat treatment at 360 °C for 30 min. ICR mice were instilled intratracheally with ASD at doses of 0.05 mg or 0.2 mg/mouse four times at 2-week intervals (total dose of 0.2 mg or 0.8 mg/mouse) and were administrated with ASD in the presence or absence of KP at the last intratracheal instillation. Pathologically, ASD caused exacerbation of pneumonia by KP as shown by increased inflammatory cells within the bronchiolar and the alveolar compartments. ASD enhanced the neutrophil number dose dependently as well as the expression of cytokines (IL-1β, IL-6, IL-12, IFN-γ, TNF-α) and chemokines (KC, MCP-1, MIP-1α) related to KP in BALF. In an in vitro study using RAW264.7 cells, combined treatment of ASD and KP increased gene expression of IL-1β, IL-6, IFN-β, KC, MCP-1, and MIP-1α. The same treatment tended to increase the protein level of IL-1β, TNF-α and MCP-1 in a culture medium compared to each treatment alone. The combined treatment tended to increase the gene expression of Toll-like receptor 2 (TLR2), and NALP3, ASC and caspase-1 compared with KP alone. These results suggest that the exacerbation of pneumonia by ASD + KP was due to the enhanced production of pro-inflammatory mediators via activation of TLR2 and NALP3 inflammasome pathways in alveolar macrophages.
Full Text Available Marguerite Monié,1 Laurence Drieux,2–4 Bernadette Nzili,1 Michèle Dicko,5 Catherine Goursot,1 Sandrine Greffard,6 Dominique Decré,3,4,7 Anthony Mézière1 1Assistance Publique-Hôpitaux de Paris (AP-HP, GHU Pitié Salpêtrière-Charles Foix, site Charles Foix, Service de Soins de Suite et Réadaptation orthogériatrique et polyvalent, Fondation d’Heur et Chemin Delatour, Ivry s/Seine, 2Assistance Publique-Hôpitaux de Paris, Hôpital Charles-Foix, Bactériologie-Hygiène, Paris, 3Sorbonne Universités, UPMC Univ Paris 06, CR7, Centre d’Immunologie et des Maladies Infectieuses, CIMI, team E13 (Bacteriology, Paris, 4INSERM, U1135, Centre d’Immunologie et des Maladies Infectieuses, CIMI, team E13 (Bacteriology, Paris, 5AP-HP, GHU Henri Mondor, Département de Médecine Interne et Gériatrie, Créteil, 6AP-HP, GHU Pitié Salpêtrière-Charles Foix, site Pitié Salpêtrière, Service de Médecine Gériatrique, Paris, 7AP-HP, Hôpital Saint-Antoine, Bactériologie-Hygiène, Paris, France Abstract: Klebsiella pneumoniae necrotizing fasciitis is a rare infection in regions outside of Asia. Here, we present a case of necrotizing fasciitis of the leg caused by K. pneumoniae in a 92-year-old French woman hospitalized in a geriatric rehabilitation unit. The patient initially presented with dermohypodermitis of the leg that developed from a dirty wound following a fall. A few hours later, this painful injury extended to the entire lower limb, with purplish discoloration of the skin, bullae, and necrosis. Septic shock rapidly appeared and the patient died 9 hours after the onset of symptoms. The patient was Caucasian, with no history of travel to Asia or any underlying disease. Computed tomography revealed no infectious metastatic loci. Blood cultures showed growth of capsular serotype K2 K. pneumoniae strains with virulence factors RmpA, yersiniabactin and aerobactin. This rare and fatal case of necrotizing fasciitis caused by a virulent strain
Tobes, Raquel; Codoñer, Francisco M.; López-Camacho, Elena; Salanueva, Iñigo J.; Manrique, Marina; Brozynska, Marta; Gómez-Gil, Rosa; Martínez-Blanch, Juan F.; Álvarez-Tejado, Miguel; Pareja, Eduardo
Klebsiella pneumoniae KpQ3 is a multidrug-resistant isolate obtained from a blood culture of a patient in a burn unit in the Hospital Universitario La Paz (Madrid, Spain) in 2008. The genome contains multiple antibiotic resistance genes, including a plasmid-mediated DHA-1 cephalosporinase gene. PMID:23469341
Kádár, Béla; Kocsis, Béla; Tóth, Ákos; Kristóf, Katalin; Felső, Péter; Kocsis, Béla; Böddi, Katalin; Szabó, Dóra
In this study, outer membrane proteins (OMPs) of colistin-resistant Klebsiella pneumoniae and Enterobacter asburiae were analyzed. One colistin-susceptible and three colistin-resistant K. pneumoniae sequence type 258 strains as well as one colistin-susceptible E. asburiae and its colistin-heteroresistant counterpart strain were involved in the study. OMP analysis of each strain was performed by microchip method. Matrix-assisted laser desorption ionization time of flight/mass spectrometry (MALDI-TOF/MS) investigation was carried out after separation of OMPs by two-dimensional gel electrophoresis and in-gel digestion. The MALDI-TOF/MS analysis of OMPs in the colistin-susceptible K. pneumoniae found 16 kDa proteins belonging to the LysM domain/BON superfamily, as well as DNA starvation proteins, whereas OmpX and OmpW were detected in the colistin-resistant counterpart strains. OmpC and OmpW were detected in the colistin-susceptible E. asburiae, whereas OmpA and OmpX were identified in the colistin-resistant counterpart. This study demonstrated that OMP differences were between colistin-susceptible and -resistant counterpart strains. The altered Gram-negative cell wall may contribute to acquired colistin resistance in Enterobacteriaceae.
Ashayeri-Panah, M; Eftekhar, F; Feizabadi, M M
To develop an optimized random amplified polymorphic DNA (RAPD) protocol for fingerprinting clinical isolates of Klebsiella pneumoniae. Employing factorial design of experiments, repeatable amplification patterns were obtained for 54 nosocomial isolates using 1 μmol 1(-1) primer, 4 mmol 1(-1) MgCl(2), 0·4 mmol 1(-1) dNTPs, 2·5 U Taq DNA polymerase and 90 ng DNA template in a total volume of 25 μl. The optimum thermocycling program was: initial denaturation at 94°C for 4 min followed by 50 cycles of 1 min at 94°C, 2 min at 34°C, 2 min at 72°C and a final extension at 72°C for 10 min. The optimized RAPD protocol was highly discriminatory (Simpson's diversity index, 0·982), and all isolates were typable with repeatable patterns (Pearson's similarity coefficient ≈ 100%). Seven main clusters were obtained on a similarity level of 70% and 32 distinct clusters on a similarity level of 85%, reflecting the heterogeneity of the isolates. Systematic optimization of RAPD generated reliable DNA fingerprints for nosocomial isolates of K. pneumoniae. This is the first report on RAPD optimization based on factorial design of experiments for discrimination of K. pneumoniae. © 2012 The Authors. Letters in Applied Microbiology © 2012 The Society for Applied Microbiology.
Henry, Christopher S.; Rotman, Ella; Lathem, Wyndham W.; Tyo, Keith E. J.; Hauser, Alan R.; Mandel, Mark J.
Klebsiella pneumoniae has a reputation for causing a wide range of infectious conditions, with numerous highly virulent and antibiotic-resistant strains. Metabolic models have the potential to provide insights into the growth behavior, nutrient requirements, essential genes, and candidate drug targets in these strains. Here we develop a metabolic model for KPPR1, a highly virulent strain of K. pneumoniae. We apply a combination of Biolog phenotype data and fitness data to validate and refine our KPPR1 model. The final model displays a predictive accuracy of 75% in identifying potential carbon and nitrogen sources for K. pneumoniae and of 99% in predicting nonessential genes in rich media. We demonstrate how this model is useful in studying the differences in the metabolic capabilities of the low-virulence MGH 78578 strain and the highly virulent KPPR1 strain. For example, we demonstrate that these strains differ in carbohydrate metabolism, including the ability to metabolize dulcitol as a primary carbon source. Our model makes numerous other predictions for follow-up verification and analysis.
Harada, Sohei; Ishii, Yoshikazu; Saga, Tomoo; Aoki, Kotaro; Tateda, Kazuhiro
Although severe infections caused by hypervirulent Klebsiella pneumoniae isolates, such as K1 isolates belonging to sequence type (ST) 23, have been a significant problem in Asian countries, epidemiology of these isolates in Japan remains unclear. We performed a nationwide molecular epidemiological study of K. pneumoniae K1 and K2 isolates in Japan. Of the 259K. pneumoniae isolates collected, 14 and 16 isolates were identified as capsular genotypes K1 and K2, respectively. All K1 isolates were ST23 or its closely related clones and showed high genetic similarity by pulsed-field gel electrophoresis (PFGE) and the DiversiLab system (DL). K2 isolates, belonging to ST14, ST25, ST65, ST86, and ST110, were more genetically diverse than K1 isolates. Isolates belonging to a specific ST showed identical virulence gene profiles with a few exceptions. PFGE and DL results using K1 and K2 isolates were generally in agreement. Copyright © 2018. Published by Elsevier Inc.
Delory, T; Seringe, E; Antoniotti, G; Novakova, I; Goulenok, C; Paysant, I; Boyer, S; Carbonne, A; Naas, T; Astagneau, P
Carbapenemase-producing Enterobacteriaceae (CPE) are becoming of immediate concern for infection control policies. Prompt detection of CPE on health care setting admission is crucial to halt the spread of an outbreak. We report a cluster of 13 Klebsiella pneumoniae carbapenemase (KPC)-2-producing K pneumoniae cases in a tertiary care hospital.The objective of this study was to identify contributing factors originating the outbreak. An outbreak investigation was conducted using descriptive epidemiology, observation of health care practices, and interviews of management staff. A root cause analysis was performed to identify patent and latent failures of infection control measures using the association of litigation and risk management method. The main patent failure was the delay in identifying KPC-2-producing K pneumoniae carriers. Contributing factors were work and environmental factors: understaffing, lack of predefined protocols, staff members' characteristics, and underlying patients' characteristics. Latent failures were as follows: no promotion of the national guidelines for prevention of CPE transmission, no clear procedure for the management of patients hospitalized abroad, no clear initiative for promoting a culture of quality in the hospital, biologic activity recently outsourced to a private laboratory, and poor communication among hospital members. Clinical management should be better promoted to control hospital outbreaks and should include team work and safety culture. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.
Conclusion: Emerging antimicrobial resistance in burn wound bacterial pathogens is a serious therapeutic challenge for clinicians. In the present study, most of the isolates were MDR. This finding indicated an alarming spread of resistant isolates and suggested that infection control strategies should be considered. Resistance to carbapenems is influenced by several factors, not all of which were evaluated in our study; however, the results showed that production of MBLs and overexpression of the mexB gene were the most frequent mechanisms in carbapenem-resistant isolates.
Fuursted, Kurt; Schøler, Lone; Hansen, Frank
, and in vitro virulence by assessing various virulence factors. The NDM-1 carrying K. pneumoniae isolate was the most virulent in the murine sepsis model but there was no clear cut correlation to in vitro virulence factors or killing in C. elegans. It is concluded that K. pneumoniae carrying NDM-1 have......The aim of the study was to compare and evaluate virulence in five strains of Klebsiella pneumoniae, including an isolate carrying New Delhi metallo-beta-lactamase-1 (NDM-1). In vivo virulence was assessed using a murine sepsis model and using the nematode Caenorhabditis elegans killing model...
Cruz, Diana P; Huertas, Mónica G; Lozano, Marcela; Zárate, Lina; Zambrano, María Mercedes
Klebsiella pneumoniae can be found in environmental habitats as well as in hospital settings where it is commonly associated with nosocomial infections. One of the factors that contribute to virulence is its capacity to form biofilms on diverse biotic and abiotic surfaces. The second messenger Bis-(3'-5')-cyclic dimeric GMP (c-di-GMP) is a ubiquitous signal in bacteria that controls biofilm formation as well as several other cellular processes. The cellular levels of this messenger are controlled by c-di-GMP synthesis and degradation catalyzed by diguanylate cyclase (DGC) and phophodiesterase (PDE) enzymes, respectively. Many bacteria contain multiple copies of these proteins with diverse organizational structure that highlight the complex regulatory mechanisms of this signaling network. This work was undertaken to identify DGCs and PDEs and analyze the domain structure of these proteins in K. pneumoniae. A search for conserved GGDEF and EAL domains in three sequenced K. pneumoniae genomes showed that there were multiple copies of GGDEF and EAL containing proteins. Both single domain and hybrid GGDEF proteins were identified: 21 in K. pneumoniae Kp342, 18 in K. pneumoniae MGH 78578 and 17 in K. pneumoniae NTUH-K2044. The majority had only the GGDEF domain, most with the GGEEF motif, and hybrid proteins containing both GGDEF and EAL domains were also found. The I site for allosteric control was identified only in single GGDEF domain proteins and not in hybrid proteins. EAL-only proteins, containing either intact or degenerate domains, were also identified: 15 in Kp342, 15 in MGH 78578 and 10 in NTUH-K2044. Several input sensory domains and transmembrane segments were identified, which together indicate complex regulatory circuits that in many cases can be membrane associated. The comparative analysis of proteins containing GGDEF/EAL domains in K. pneumoniae showed that most copies were shared among the three strains and that some were unique to a particular strain
Cruz Diana P
Full Text Available Abstract Background Klebsiella pneumoniae can be found in environmental habitats as well as in hospital settings where it is commonly associated with nosocomial infections. One of the factors that contribute to virulence is its capacity to form biofilms on diverse biotic and abiotic surfaces. The second messenger Bis-(3’-5’-cyclic dimeric GMP (c-di-GMP is a ubiquitous signal in bacteria that controls biofilm formation as well as several other cellular processes. The cellular levels of this messenger are controlled by c-di-GMP synthesis and degradation catalyzed by diguanylate cyclase (DGC and phophodiesterase (PDE enzymes, respectively. Many bacteria contain multiple copies of these proteins with diverse organizational structure that highlight the complex regulatory mechanisms of this signaling network. This work was undertaken to identify DGCs and PDEs and analyze the domain structure of these proteins in K. pneumoniae. Results A search for conserved GGDEF and EAL domains in three sequenced K. pneumoniae genomes showed that there were multiple copies of GGDEF and EAL containing proteins. Both single domain and hybrid GGDEF proteins were identified: 21 in K. pneumoniae Kp342, 18 in K. pneumoniae MGH 78578 and 17 in K. pneumoniae NTUH-K2044. The majority had only the GGDEF domain, most with the GGEEF motif, and hybrid proteins containing both GGDEF and EAL domains were also found. The I site for allosteric control was identified only in single GGDEF domain proteins and not in hybrid proteins. EAL-only proteins, containing either intact or degenerate domains, were also identified: 15 in Kp342, 15 in MGH 78578 and 10 in NTUH-K2044. Several input sensory domains and transmembrane segments were identified, which together indicate complex regulatory circuits that in many cases can be membrane associated. Conclusions The comparative analysis of proteins containing GGDEF/EAL domains in K. pneumoniae showed that most copies were shared among the
Full Text Available Abstract Background A few Japanese cases of hypermucoviscous Klebsiella pneumoniae (K. pneumoniae invasive syndrome have recently been reported. Although extrahepatic complications from bacteremic dissemination have been observed, infected aneurysms are rare. Furthermore, the primary source of infection is generally a liver abscess, and is rarely the prostate. Therefore, we report two atypical cases of hypermucoviscous K. pneumoniae invasive syndrome. Case presentation The first case was an 81-year-old Japanese man with no significant medical history, who was referred to our hospital for vision loss in his right eye. Contrast-enhanced whole-body computed tomography revealed abscesses in the liver and the prostate, and an infected left internal iliac artery aneurysm. Contrast-enhanced head magnetic resonance imaging revealed brain abscesses. Cultures of the liver abscess specimen and aqueous humor revealed K. pneumoniae with the hypermucoviscosity phenotype, which carried the magA gene (mucoviscosity-associated gene A and the rmpA gene (regulator of mucoid phenotype A. We performed enucleation of the right eyeball, percutaneous transhepatic drainage, coil embolization of the aneurysm, and administered a 6-week course of antibiotic treatment. The second case was a 69-year-old Japanese man with diabetes mellitus, who was referred to our hospital with fever, pollakiuria, and pain on urination. Contrast-enhanced whole-body computed tomography revealed lung and prostate abscesses, but no liver abscesses. Contrast-enhanced head magnetic resonance imaging revealed brain abscesses. The sputum, urine, prostate abscess specimen, and aqueous humor cultures revealed K. pneumoniae with the hypermucoviscosity phenotype, which carried magA and rmpA. We performed enucleation of the left eyeball, percutaneous drainage of the prostate abscess, and administered a 5-week course of antibiotic treatment. Conclusions Hypermucoviscous K. pneumoniae can cause infected
Huang, Dennis; Yu, Brenda; Diep, John K; Sharma, Rajnikant; Dudley, Michael; Monteiro, Jussimara; Kaye, Keith S; Pogue, Jason M; Abboud, Cely Saad; Rao, Gauri G
The multidrug resistance profiles of Klebsiella pneumoniae carbapenemase (KPC) producers have led to increased clinical polymyxin use. Combination therapy with polymyxins may improve treatment outcomes, but it is uncertain which combinations are most effective. Clinical successes with intravenous minocycline-based combination treatments have been reported for infections caused by carbapenemase-producing bacteria. The objective of this study was to evaluate the in vitro activity of polymyxin B and minocycline combination therapy against six KPC-2-producing K. pneumoniae isolates (minocycline MIC range, 2 to 32 mg/liter). Polymyxin B monotherapy (0.5, 1, 2, 4, and 16 mg/liter) resulted in a rapid reduction of up to 6 log in bactericidal activity followed by regrowth by 24 h. Minocycline monotherapy (1, 2, 4, 8, and 16 mg/liter) showed no reduction of activity of >1.34 log against all isolates, although concentrations of 8 and 16 mg/liter prolonged the time to regrowth. When the therapies were used in combination, rapid bactericidal activity was followed by slower regrowth, with synergy (60 of 120 combinations at 24 h, 19 of 120 combinations at 48 h) and additivity (43 of 120 combinations at 24 h, 44 of 120 combinations at 48 h) against all isolates. The extent of killing was greatest against the more susceptible polymyxin B isolates (MICs of ≤0.5 mg/liter) regardless of the minocycline MIC. The pharmacodynamic activity of combined polymyxin B-minocycline therapy against KPC-producing K. pneumoniae is dependent on polymyxin B susceptibility. Further in vitro and animal studies must be performed to fully evaluate the efficacy of this drug combination. Copyright © 2017 American Society for Microbiology.
Full Text Available New Delhi metallo-β-lactamase 1 (NDM-1 is a novel type of metallo-β-lactamase (MBL. Enterobacteriaceae carrying this NDM-1 encoding gene, blaNDM-1, have been identified worldwide. Bacteria carrying blaNDM-1 are not only resistant to carbapenem, but also highly resistant to many classes of antibiotics, which indicate the importance of prompt identification of these bacteria and implementation of strict infection control measures to prevent their transmission. Here, we report the first identification and management of a patient colonized with Klebsiella pneumoniae carrying blaNDM-1 in Taiwan, who returned from New Delhi where he had been hospitalized for a gun-shot injury.
Ramirez, Maria S; Traglia, German M; Lin, David L; Tran, Tung; Tolmasky, Marcelo E
Plasmids harbor genes coding for specific functions including virulence factors and antibiotic resistance that permit bacteria to survive the hostile environment found in the host and resist treatment. Together with other genetic elements such as integrons and transposons, and using a variety of mechanisms, plasmids participate in the dissemination of these traits resulting in the virtual elimination of barriers among different kinds of bacteria. In this article we review the current information about physiology and role in virulence and antibiotic resistance of plasmids from the gram-negative opportunistic pathogen Klebsiella pneumoniae . This bacterium has acquired multidrug resistance and is the causative agent of serious communityand hospital-acquired infections. It is also included in the recently defined ESKAPE group of bacteria that cause most of US hospital infections.
Higgins, James [USDA-ARS, Bldg 173, 10300 Baltimore Ave., Beltsville, MD 20705 (United States)], E-mail: email@example.com; Hohn, Christina [NCSU College of Veterinary Medicine, Raleigh, NC 27606 (United States)
Many surface and ground waters in the continental US are contaminated with a variety of chemical pollutants, which are usually present in concentrations in the ppm and ppb range. The effects of these pollutants on coliform bacteria, which are prominent members of the aquatic flora, are poorly understood. Using a microtiter plate assay, isolates of Escherichia coli (from chicken intestine and fresh water), and an isolate of Klebsiella pneumoniae (from bovine milk) were exposed to varying concentrations of common pollutants over a 24 h period. The herbicides/pesticides simazine, atrazine, and diazinon; the VOCs trichloroethene and MTBE; the estrogens estradiol and estrone; and caffeine, all failed to inhibit bacterial growth at ppm levels. Only ethylene glycol, and the herbicide 2,4-D, significantly inhibited bacterial growth compared to controls. These results suggest that the replication of coliform bacteria in fresh waters is not adversely impacted by many common pollutants. - Using a microtiter plate assay, E. coli and Klebsiella bacteria were exposed to a panel of common chemical pollutants of fresh water; only ethylene glycol and 2,4-D inhibited bacterial replication.
Full Text Available An outbreak of coliform mastitis is described in a dairy herd from the State of Rio de Janeiro, Brazil. During a four-month period 14 fatal cases of Klebsiella pneumoniae-related mastitis were observed in a herd of 104 lactating cows. The symptoms included peracute enterotoxemia in which the cows died 6 to 12 h after the detection of mastitis by CMT. Staphylococcus aureus and Streptococcus agalactiae Streptococcus agalactiae were also isolated although could not be associated with cases of acute fatal mastitis. Milking practices were also evaluated. The milking machine was being used correctly and adequate precautions for hygiene and pre-milking and post-milking teat dipping were used. The organism was sensitive to gentamicin. Therapy for acute toxic mastitis required early action for the treatment of infections, involving corticosteroids and fluid therapy. The use of a Klebsiella vaccine produced from the microorganisms isolated from the herd, associated with hygiene measures, resulted in the control of the outbreak.
Brhelova, Eva; Antonova, Mariya; Pardy, Filip; Kocmanova, Iva; Mayer, Jiri; Racil, Zdenek; Lengerova, Martina
Rapid identification and characterization of multidrug-resistant Klebsiella pneumoniae strains is necessary due to the increasing frequency of severe infections in patients. The decreasing cost of next-generation sequencing enables us to obtain a comprehensive overview of genetic information in one step. The aim of this study is to demonstrate and evaluate the utility and scope of the application of web-based databases to next-generation sequenced (NGS) data. The whole genomes of 11 clinical Klebsiella pneumoniae isolates were sequenced using Illumina MiSeq. Selected web-based tools were used to identify a variety of genetic characteristics, such as acquired antimicrobial resistance genes, multilocus sequence types, plasmid replicons, and identify virulence factors, such as virulence genes, cps clusters, urease-nickel clusters and efflux systems. Using web-based tools hosted by the Center for Genomic Epidemiology, we detected resistance to 8 main antimicrobial groups with at least 11 acquired resistance genes. The isolates were divided into eight sequence types (ST11, 23, 37, 323, 433, 495 and 562, and a new one, ST1646). All of the isolates carried replicons of large plasmids. Capsular types, virulence factors and genes coding AcrAB and OqxAB efflux pumps were detected using BIGSdb-Kp, whereas the selected virulence genes, identified in almost all of the isolates, were detected using CLC Genomic Workbench software. Applying appropriate web-based online tools to NGS data enables the rapid extraction of comprehensive information that can be used for more efficient diagnosis and treatment of patients, while data processing is free of charge, easy and time-efficient.
Full Text Available The growing number of Klebsiella pneumoniae infections, commonly acquired in hospitals, has drawn great concern. It has been shown that the K1 and K2 capsular serotypes are the most detrimental strains, particularly to those with diabetes. The K1 cps (capsular polysaccharide locus in the NTUH-2044 strain of the pyogenic liver abscess (PLA K. pneumoniae has been identified recently, but little is known about the functions of the genes therein. Here we report characterization of a group of cps genes and their roles in the pathogenesis of K1 K. pneumoniae. By sequential gene deletion, the cps gene cluster was first re-delimited between genes galF and ugd, which serve as up- and down-stream ends, respectively. Eight gene products were characterized in vitro and in vivo to be involved in the syntheses of UDP-glucose, UDP-glucuronic acid and GDP-fucose building units. Twelve genes were identified as virulence factors based on the observation that their deletion mutants became avirulent or lost K1 antigenicity. Furthermore, deletion of kp3706, kp3709 or kp3712 (ΔwcaI, ΔwcaG or Δatf, respectively, which are all involved in fucose biosynthesis, led to a broad range of transcriptional suppression for 52 upstream genes. The genes suppressed include those coding for unknown regulatory membrane proteins and six multidrug efflux system proteins, as well as proteins required for the K1 CPS biosynthesis. In support of the suppression of multidrug efflux genes, we showed that these three mutants became more sensitive to antibiotics. Taken together, the results suggest that kp3706, kp3709 or kp3712 genes are strongly related to the pathogenesis of K. pneumoniae K1.
Zhu, Hu; Liu, Hui-Jun; Ning, Shou-Jiao; Gao, Yu-Li
Bacterial cells communicate with one another using chemical signaling molecules. This phenomenon is termed quorum sensing (QS). QS in Klebsiella pneumoniae is mediated by the synthesis of interspecies autoinducer 2 (AI-2), a furanosyl borate diester molecule. The response of Type 2 QS to environmental cues such as carbon sources, the initial pH of the medium, and boracic acid was investigated in the present study using a Vibrio harveyi BB170 reporter assay and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis. The results show that glucose can affect AI-2 synthesis to the greatest extent, and 3.0% glucose can stimulate K. pneumoniae to produce more AI-2, with a four times increase in activity compared with that of the control culture. According to our previous research, Type 2 QS in K. pneumoniae is luxS dependent. Therefore, the close relationship between glucose concentration and luxS transcription level was confirmed with qRT-PCR technology. The results show that the response of QS to a fluctuating glucose concentration was observed as a change in the amount of luxS RNA transcripts. A maximum of luxS transcription appeared during the exponential growth phase when the glucose concentration was 30.0 g/L. At the same time, AI-2 production was also slightly impacted by the low initial pH. It is noteworthy that the addition of boracic acid at microdosage (0.1 g/L) can also induce AI-2 synthesis. Presumably, in K. pneumoniae, the 4,5-dihydroxy-2,3-pentanedione cyclizes by the addition of borate and loss of water, is hydrated, and is converted to the final AI-2 signaling molecule.
Bednarz-Misa, I; Serek, P; Dudek, B; Pawlak, A; Bugla-Płoskońska, G; Gamian, A
Klebsiella pneumoniae is a frequent cause of nosocomial respiratory, urinary and gastrointestinal tract infections and septicemia with the multidrug-resistant K. pneumoniae being a major public health concern. Outer membrane proteins (OMPs) are important virulence factors responsible for the appropriate adaptation to the host environment. They constitute of the antigens being the first in contact with infected organism. However, K. pneumoniae strains are heavily capsulated and it is important to establish the OMPs isolation procedure prior to proteomics extensive studies. In this study we used Zwittergent Z 3-14® as a detergent to isolate the OMPs from K. pneumoniae cells and resolve them using two-dimensional electrophoresis (2-DE). As a result we identified 134 protein spots. The OMPs identified in this study are possible candidates for the development of a protein-based vaccine against K. pneumoniae infections. Copyright © 2014 Elsevier B.V. All rights reserved.
Lee, Soojin; Kim, Borim; Yang, Jeongmo; Jeong, Daun; Park, Soohyun; Shin, Sang Heum; Kook, Jun Ho; Yang, Kap-Seok; Lee, Jinwon
The integration of transcriptomics and metabolomics can provide precise information on gene-to-metabolite networks for identifying the function of novel genes. The goal of this study was to identify novel gene functions involved in 2,3-butanediol (2,3-BDO) biosynthesis by a comprehensive analysis of the transcriptome and metabolome of five mutated Klebsiella pneumonia strains (∆wabG = SGSB100, ∆wabG∆budA = SGSB106, ∆wabG∆budB = SGSB107, ∆wabG∆budC = SGSB108, ∆wabG∆budABC = SGSB109). First, the transcriptomes of all five mutants were analyzed and the genes exhibiting reproducible changes in expression were determined. The transcriptome was well conserved among the five strains, and differences in gene expression occurred mainly in genes coding for 2,3-BDO biosynthesis (budA, budB, and budC) and the genes involved in the degradation of reactive oxygen, biosynthesis and transport of arginine, cysteine biosynthesis, sulfur metabolism, oxidoreductase reaction, and formate dehydrogenase reaction. Second, differences in the metabolome (estimated by carbon distribution, CO2 emission, and redox balance) among the five mutant strains due to gene alteration of the 2,3-BDO operon were detected. The functional genomics approach integrating metabolomics and transcriptomics in K. Pneumonia presented here provides an innovative means of identifying novel gene functions involved in 2,3-BDO biosynthesis metabolism and whole cell metabolism.
Lucas De Paula Ramos
Full Text Available This study evaluated the action of Pfaffia paniculata K., Juglans regia L., and Rosmarius officinalis L. extracts against planktonic form and biofilm of Klebsiella pneumoniae (ATCC 4352. Minimum inhibitory concentration (MIC and minimum microbicidal concentration (MMC values were determined for each extract by microdilution broth method, according to Clinical and Laboratory Standards Institute. Next, antimicrobial activity of the extracts on biofilm was analyzed. For this, standardized suspension at 107 UFC/mL of K. pneumoniae was distributed into 96-well microplates (n=10 and after 48 h at 37°C and biofilm was subjected to treatment for 5 min with the extracts at a concentration of 200 mg/mL. ANOVA and Tukey tests (5% were used to verify statistical significant reduction (p<0.05 of planktonic form and biofilm. P paniculata K., R. officinalis L., and J. regia L. showed reductions in biomass of 55.6, 58.1, and 18.65% and cell viability reduction of 72.4, 65.1, and 31.5%, respectively. The reduction obtained with P. paniculata and R. officinalis extracts was similar to the reduction obtained with chlorhexidine digluconate 2%. In conclusion, all extracts have microbicidal action on the planktonic form but only P. paniculata K. and R. officinalis L. were effective against biofilm.
Huertas, Mónica G; Zárate, Lina; Acosta, Iván C; Posada, Leonardo; Cruz, Diana P; Lozano, Marcela; Zambrano, María M
Klebsiella pneumoniae is an opportunistic pathogen important in hospital-acquired infections, which are complicated by the rise of drug-resistant strains and the capacity of cells to adhere to surfaces and form biofilms. In this work, we carried out an analysis of the genes in the K. pneumoniae yfiRNB operon, previously implicated in biofilm formation. The results indicated that in addition to the previously reported effect on type 3 fimbriae expression, this operon also affected biofilm formation due to changes in cellulose as part of the extracellular matrix. Deletion of yfiR resulted in enhanced biofilm formation and an altered colony phenotype indicative of cellulose overproduction when grown on solid indicator media. Extraction of polysaccharides and treatment with cellulase were consistent with the presence of cellulose in biofilms. The enhanced cellulose production did not, however, correlate with virulence as assessed using a Caenorhabditis elegans assay. In addition, cells bearing mutations in genes of the yfiRNB operon varied with respect to the WT control in terms of susceptibility to the antibiotics amikacin, ciprofloxacin, imipenem and meropenem. These results indicated that the yfiRNB operon is implicated in the production of exopolysaccharides that alter cell surface characteristics and the capacity to form biofilms--a phenotype that does not necessarily correlate with properties related with survival, such as resistance to antibiotics. © 2014 The Authors.
Yu, E.K.C.; Deschatelets, L.; Louis-Seize, G.; Saddler, J.N.
The bioconverison of cellulose and hemicellulose substrates to 2,3-butanediol by a sequential coculture approach was investigated with the cellulolytic fungus Trichoderma harzianum E58 and the fermentative bacterium Klebsiella pneumoniae. Vogel medium optimal for the production of the cellulolytic and xylanolytic enzymes of the fungus was found to be inhibitory to butanediol fermentation. This inhibition appeared to be due to a synergistic effect of various ingredients, particularly the salts, present in the fungal medium. The removal or replacement of such ingredients from Vogel medium led to the relief of fermentation inhibition, but the treatments also resulted in a significant decrease in fungal enzyme production. Resting cells of K. pneumoniae could be used for butanediol production in the fungal medium, indicating that the inhibitory effect on solvent production under such conditions was due to the indirect result of growing inhibition of the bacterial cells. The resting-cell approach could be combined with a fed-batch system for the direct conversion of 8 to 10% (wt/vol) of Solka-Floc or aspenwood xylan to butanediol at over 30% of the theoretical conversion efficiencies.
Awasthi, Shraddha; Srivastava, Pratap; Singh, Pardeep; Tiwary, D; Mishra, Pradeep Kumar
Biodegradation of plastics, which are the potential source of environmental pollution, has received a great deal of attention in the recent years. We aim to screen, identify, and characterize a bacterial strain capable of degrading high-density polyethylene (HDPE). In the present study, we studied HDPE biodegradation using a laboratory isolate, which was identified as Klebsiella pneumoniae CH001 (Accession No MF399051). The HDPE film was characterized by Universal Tensile Machine (UTM), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), and Atomic Force Microscope (AFM) before and after microbial incubation. We observed that this strain was capable of adhering strongly on HDPE surface and form a thick biofilm, when incubated in nutrient broth at 30 °C on 120 rpm for 60 days. UTM analysis showed a significant decrease in weight (18.4%) and reduction in tensile strength (60%) of HDPE film. Furthermore, SEM analysis showed the cracks on the HDPE surface, whereas AFM results showed an increase in surface roughness after bacterial incubation. Overall, these results indicate that K. pneumoniae CH001 can be used as potential candidate for HDPE degradation in eco-friendly and sustainable manner in the environment.
de Man, Tom J B; Lutgring, Joseph D; Lonsway, David R; Anderson, Karen F; Kiehlbauch, Julia A; Chen, Lei; Walters, Maroya Spalding; Sjölund-Karlsson, Maria; Rasheed, J Kamile; Kallen, Alexander; Halpin, Alison Laufer
Antimicrobial resistance is a threat to public health globally and leads to an estimated 23,000 deaths annually in the United States alone. Here, we report the genomic characterization of an unusual Klebsiella pneumoniae , nonsusceptible to all 26 antibiotics tested, that was isolated from a U.S. The isolate harbored four known beta-lactamase genes, including plasmid-mediated bla NDM-1 and bla CMY-6 , as well as chromosomal bla CTX-M-15 and bla SHV-28 , which accounted for resistance to all beta-lactams tested. In addition, sequence analysis identified mechanisms that could explain all other reported nonsusceptibility results, including nonsusceptibility to colistin, tigecycline, and chloramphenicol. Two plasmids, IncA/C2 and IncFIB, were closely related to mobile elements described previously and isolated from Gram-negative bacteria from China, Nepal, India, the United States, and Kenya, suggesting possible origins of the isolate and plasmids. This is one of the first K. pneumoniae isolates in the United States to have been reported to the Centers for Disease Control and Prevention (CDC) as nonsusceptible to all drugs tested, including all beta-lactams, colistin, and tigecycline. IMPORTANCE Antimicrobial resistance is a major public health threat worldwide. Bacteria that are nonsusceptible or resistant to all antimicrobials available are of major concern to patients and the public because of lack of treatment options and potential for spread. A Klebsiella pneumoniae strain that was nonsusceptible to all tested antibiotics was isolated from a U.S. Mechanisms that could explain all observed phenotypic antimicrobial resistance phenotypes, including resistance to colistin and beta-lactams, were identified through whole-genome sequencing. The large variety of resistance determinants identified demonstrates the usefulness of whole-genome sequencing for detecting these genes in an outbreak response. Sequencing of isolates with rare and unusual phenotypes can provide
Ramy A Fodah
Full Text Available Klebsiella pneumoniae is a bacterial pathogen of worldwide importance and a significant contributor to multiple disease presentations associated with both nosocomial and community acquired disease. ATCC 43816 is a well-studied K. pneumoniae strain which is capable of causing an acute respiratory disease in surrogate animal models. In this study, we performed sequencing of the ATCC 43816 genome to support future efforts characterizing genetic elements required for disease. Furthermore, we performed comparative genetic analyses to the previously sequenced genomes from NTUH-K2044 and MGH 78578 to gain an understanding of the conservation of known virulence determinants amongst the three strains. We found that ATCC 43816 and NTUH-K2044 both possess the known virulence determinant for yersiniabactin, as well as a Type 4 secretion system (T4SS, CRISPR system, and an acetonin catabolism locus, all absent from MGH 78578. While both NTUH-K2044 and MGH 78578 are clinical isolates, little is known about the disease potential of these strains in cell culture and animal models. Thus, we also performed functional analyses in the murine macrophage cell lines RAW264.7 and J774A.1 and found that MGH 78578 (K52 serotype was internalized at higher levels than ATCC 43816 (K2 and NTUH-K2044 (K1, consistent with previous characterization of the antiphagocytic properties of K1 and K2 serotype capsules. We also examined the three K. pneumoniae strains in a novel BALB/c respiratory disease model and found that ATCC 43816 and NTUH-K2044 are highly virulent (LD50<100 CFU while MGH 78578 is relatively avirulent.
Wang, Jingxuan; Zhao, Peng; Li, Ying; Xu, Lida; Tian, Pingfang
Klebsiella pneumoniae is a promising industrial species for bioproduction of bulk chemicals such as 1,3-propanediol, 2,3-butanediol and 3-hydroxypropionic acid (3-HP). However, lactic acid is a troublesome by-product when optimizing for 3-HP production. Therefore, it is highly desirable to minimize lactic acid. Here, we show that lactic acid synthesis can be largely blocked by an engineered CRISPR interference (CRISPRi) system in K. pneumoniae. EGFP was recruited as a reporter of this CRISPRi system. Fluorescence assay of this CRISPRi system showed that enhanced green fluorescent protein (EGFP) expression level was repressed by 85-90%. To further test this CRISPRi system, guide RNAs were designed to individually or simultaneously target four lactate-producing enzyme genes. Results showed that all lactate-producing enzyme genes were significantly repressed. Notably, D-lactate dehydrogenase (ldhA) was shown to be the most influential enzyme for lactic acid formation in micro-aerobic conditions, as inhibiting ldhA alone led to lactic acid level similar to simultaneously repressing four genes. In shake flask cultivation, the strain coexpressing puuC (an aldehyde dehydrogenase catalyzing 3-hydroxypropionaldehyde to 3-HP) and dCas9-sgRNA inhibiting ldhA produced 1.37-fold 3-HP relative to the reference strain. Furthermore, in bioreactor cultivation, this CRISPRi strain inhibiting ldhA produced 36.7 g/L 3-HP, but only generated 1 g/L lactic acid. Clearly, this engineered CRISPRi system largely simplified downstream separation of 3-HP from its isomer lactic acid, an extreme challenge for 3-HP bioprocess. This study offers a deep understanding of lactic acid metabolism in diverse species, and we believe that this CRISPRi system will facilitate biomanufacturing and functional genome studies of K. pneumoniae or beyond.
Full Text Available This study aimed to assess the frequency of Klebsiella pneumoniae in food samples and to detect antibiotic resistance phenotypes, antimicrobial resistance genes and the molecular subtypes of the recovered isolates. A total of 998 food samples were collected, and 99 (9.9% K. pneumoniae strains were isolated; the frequencies were 8.2% (4/49 in fresh raw seafood, 13.8% (26/188 in fresh raw chicken, 11.4% (34/297 in frozen raw food and 7.5% (35/464 in cooked food samples. Antimicrobial resistance was observed against 16 antimicrobials. The highest resistance rate was observed for ampicillin (92.3%, followed by tetracycline (31.3%, trimethoprim-sulfamethoxazole (18.2%, and chloramphenicol (10.1%. Two K. pneumoniae strains were identified as extended-spectrum β-lactamase (ESBL-one strain had three beta-lactamases genes (blaSHV, blaCTX-M-1, and blaCTX-M-10 and one had only the blaSHV gene. Nineteen multidrug-resistant (MDR strains were detected; the percentage of MDR strains in fresh raw chicken samples was significantly higher than in other sample types (P<0.05. Six of the 18 trimethoprim-sulfamethoxazole-resistant strains carried the folate pathway inhibitor gene (dhfr. Four isolates were screened by PCR for quinolone resistance genes; aac(6'-Ib-cr, qnrB, qnrA and qnrS were detected. In addition, gyrA gene mutations such as T247A (Ser83Ile, C248T (Ser83Phe, and A260C (Asp87Ala and a parC C240T (Ser80Ile mutation were identified. Five isolates were screened for aminoglycosides resistance genes; aacA4, aacC2, and aadA1 were detected. Pulsed-field gel electrophoresis-based subtyping identified 91 different patterns. Our results indicate that food, especially fresh raw chicken, is a reservoir of antimicrobial-resistant K. pneumoniae, and the potential health risks posed by such strains should not be underestimated. Our results demonstrated high prevalence, antibiotic resistance rate and genetic diversity of K. pneumoniae in food in China. Improved
Hagen, ten T.L.; Vianen, van W.; Savelkoul, H.F.J.; Heremans, H.; Buurman, W.A.; Bakker-Woudenberg, I.A.
We have previously shown that prophylactic administration of the liposome-encapsulated immunomodulating agents muramyl tripeptide phosphatidylethanolamine (MTPPE) and gamma interferon (IFN-) results in strongly increased survival of mice from a normally lethal septicemia with Klebsiella pneumoniae.
Chen, Shih-Chou; Lee, Ying-Yen; Chen, Ya-Hsin; Lin, Huey-Shyan; Wu, Tsung-Tien; Sheu, Shwu-Jiuan
To compare the characteristics, visual outcome, and prognostic factors of patients with endogenous endophthalmitis and to determine the association of endophthalmitis with Klebsiella pneumoniae infection. We retrospectively analyzed records of patients diagnosed with endogenous endophthalmitis from January 2002 to August 2013. A total of 86 patients were diagnosed with endogenous endophthalmitis; 48 patients were infected with K. pneumoniae, 28 patients were infected with other pathogens, and 10 were culture-negative. Diabetes mellitus was more prevalent among patients infected with K. pneumoniae. Liver abscess and urinary tract infection were the leading sources of infection in patients with and without a K. pneumoniae infection, respectively. In patients with endogenous endophthalmitis, poor initial vision (pendogenous endophthalmitis.
Arduino, Sonia M; Quiroga, María Paula; Ramírez, María Soledad; Merkier, Andrea Karina; Errecalde, Laura; Di Martino, Ana; Smayevsky, Jorgelina; Kaufman, Sara; Centrón, Daniela
Multiple transposons, integrons and carbapenemases were found in Klebsiella pneumoniae colistin-resistant isolates as well as a genomic resistance island of the AbaR type in Acinetobacter baumannii colistin-resistant isolates from different hospitals from Buenos Aires City. PFGE analysis showed a polyclonal dissemination of antimicrobial resistance mechanisms among K. pneumoniae isolates, while in A. baumannii isolates the epidemic clone 1 from South America was found. Resistance determinants associated with horizontal gene transfer are contributing to the evolution to pandrug resistance in both epidemic and sporadic clones.
Loucif, Lotfi; Kassah-Laouar, Ahmed; Saidi, Mahdia; Messala, Amina; Chelaghma, Widad; Rolain, Jean-Marc
Seven nonredundant ertapenem-resistant Klebsiella pneumoniae isolates were collected between May 2014 and 19 January 2015 in the nephrology and hematology units of Batna University Hospital in Algeria. All strains coproduced the bla OXA-48 , bla CTX-M-15 , bla SHV-1 , and bla TEM-1D genes. Six of these isolates belonged to the pandemic clone sequence type 101 (ST101). The bla OXA-48 gene was located on a conjugative IncL/M-type plasmid. This is the first known outbreak of OXA-48-producing K. pneumoniae isolates involving an ST101 clone in Batna University Hospital. Copyright © 2016, American Society for Microbiology. All Rights Reserved.
Pang, Changlong; Li, Ang; Cui, Di; Yang, Jixian; Ma, Fang; Guo, Haijuan
Klebsiella pneumoniae J1 is a Gram-negative strain, which belongs to a protein-based microbial flocculant-producing bacterium. However, little genetic information is known about this species. Here we carried out a whole-genome sequence analysis of this strain and report the complete genome sequence of this organism and its genetic basis for carbohydrate metabolism, capsule biosynthesis and transport system. Copyright © 2016 Elsevier B.V. All rights reserved.
Fabbri, Giuliana; Panico, Manuela; Dallolio, Laura; Suzzi, Roberta; Ciccia, Matilde; Sandri, Fabrizio; Farruggia, Patrizia
Klebsiella pneumoniae is a frequent cause of infectious outbreaks in Neonatal Intensive Care Units (NICUs). The aim of this paper is to describe an outbreak occurred in a 13-bed NICU and the control measures adopted in order to interrupt the chain of transmission. We described the microbiological investigations, the NICU staff compliance to the infection control measures by means of a specifically designed check-list and the control measures adopted. Six cases of primary bloodstream infection...
Daniel Romero-Alvarez; Jorge Reyes; Viviana Quezada; Carolina SatÃ¡n; Nelson Cevallos; SofÃa Barrera; Gabriel Trueba; Luis E. Escobar; JosÃ© E. VillacÃs
Objectives: To describe a clinical case of Klebsiella pneumoniae harboring a New Delhi metallo-Î²-lactamase (NDM) plasmid in Ecuador and to present a map of reports of NDM isolates in South America. Methods: The modified Hodge test, carbapenem inactivation method, imipenemâEDTA disk method (synergy), and Rapidec Carba NP test were used to identify antibiotic resistance mechanisms. The presence of resistance genes was explored with a conjugation assay, and molecular confirmation of NDM was per...
Full Text Available Klebsiella pneumoniae is a frequent cause of infectious outbreaks in Neonatal Intensive Care Units (NICUs. The aim of this paper is to describe an outbreak occurred in a 13-bed NICU and the control measures adopted in order to interrupt the chain of transmission. We described the microbiological investigations, the NICU staff compliance to the infection control measures by means of a specifically designed check-list and the control measures adopted. Six cases of primary bloodstream infections sustained by ampicillin/piperacillin-resistant Klebsiella pneumoniae were observed over a two-month period. One culture obtained from a 12% saccarose multiple-dose solution allowed the growth of Klebsiella pneumoniae. During the inspections performed by the Hospital Infection Control Team, using the check-list for the evaluation of the NICU staff compliance to the infection control measures, several breaches in the infection control policy were identified and control measures were adopted. In our case the definition of a specific check-list led to the adoption of the correct control measures. Further studies would be helpful in order to develop a standard check-list able to identify critical flows in the adhesion to the guidelines. It could be used in different NICUs and allow to obtain reproducible levels of infection control.
Fabbri, Giuliana; Panico, Manuela; Dallolio, Laura; Suzzi, Roberta; Ciccia, Matilde; Sandri, Fabrizio; Farruggia, Patrizia
Klebsiella pneumoniae is a frequent cause of infectious outbreaks in Neonatal Intensive Care Units (NICUs). The aim of this paper is to describe an outbreak occurred in a 13-bed NICU and the control measures adopted in order to interrupt the chain of transmission. We described the microbiological investigations, the NICU staff compliance to the infection control measures by means of a specifically designed check-list and the control measures adopted. Six cases of primary bloodstream infections sustained by ampicillin/piperacillin-resistant Klebsiella pneumoniae were observed over a two-month period. One culture obtained from a 12% saccarose multiple-dose solution allowed the growth of Klebsiella pneumoniae. During the inspections performed by the Hospital Infection Control Team, using the check-list for the evaluation of the NICU staff compliance to the infection control measures, several breaches in the infection control policy were identified and control measures were adopted. In our case the definition of a specific check-list led to the adoption of the correct control measures. Further studies would be helpful in order to develop a standard check-list able to identify critical flows in the adhesion to the guidelines. It could be used in different NICUs and allow to obtain reproducible levels of infection control.
Moubareck, Carole Ayoub; Mouftah, Shaimaa F; Pál, Tibor; Ghazawi, Akela; Halat, Dalal H; Nabi, Anju; AlSharhan, Mouza A; AlDeesi, Zulfa O; Peters, Christabel C; Celiloglu, Handan; Sannegowda, Manjunath; Sarkis, Dolla K; Sonnevend, Ágnes
Few studies have addressed the molecular epidemiology of carbapenem resistant Enterobacteriaceae (CRE) isolates in the Arabian Peninsula, and such investigations have been missing from Dubai, a major economical, tourism and medical centre of the region. The antibiotic susceptibility, the carbapenemase type produced, and the clonality of 89 CRE strains isolated in five major Dubai hospitals in June 2015 - June 2016 were determined. Thirty three percent of the collection of 70 K. pneumoniae, 13 E. coli and 6 other Enterobacteriaceae were extremely drug resistant, 27% were resistant to colistin, and 4.5% (four K. pneumoniae isolates) were resistant to all antibiotics tested. The colistin resistance rate in K. pneumoniae was 31.4%. None of the isolates carried mobile colistin resistance genes. Seventy-seven isolates produced carbapenemase: 53.3% OXA-48-like, 24.7% NDM, and 22.1% both OXA-48-like and NDM, respectively. PFGE clustered 50% of K. pneumoniae into a 35-membered group, which showed significant association with double carbapenemase production, with extreme drug resistance, and with being isolated from Emirati patients. Members of the cluster belonged to sequence type ST14. The rate of colistin resistance in K. pneumoniae ST14 was 37.1% vs. 27.1% of K. pneumoniae isolates outside of the cluster. Two of the panresistant K. pneumoniae isolates also belonged to ST14, whereas the other two were ST15 and ST231, respectively. In conclusion, beyond the overall high colistin resistance rate in CRE, the emergence of a highly resistant clone of K. pneumoniae ST14 in all Dubai hospitals investigated is a serious problem requiring immediate attention. Copyright © 2018. Published by Elsevier B.V.
Andersson, Patiyan; Tong, Steven Y C; Bell, Jan M; Turnidge, John D; Giffard, Philip M
Here we report a single nucleotide polymorphism (SNP) based genotyping method for Klebsiella pneumoniae utilising high-resolution melting (HRM) analysis of fragments within the multilocus sequence typing (MLST) loci. The approach is termed mini-MLST or Minim typing and it has previously been applied to Streptococcus pyogenes, Staphylococcus aureus and Enterococcus faecium. Six SNPs were derived from concatenated MLST sequences on the basis of maximisation of the Simpsons Index of Diversity (D). DNA fragments incorporating these SNPs and predicted to be suitable for HRM analysis were designed. Using the assumption that HRM alleles are defined by G+C content, Minim typing using six fragments was predicted to provide a D = 0.979 against known STs. The method was tested against 202 K. pneumoniae using a blinded approach in which the MLST analyses were performed after the HRM analyses. The HRM-based alleles were indeed in accordance with G+C content, and the Minim typing identified known STs and flagged new STs. The tonB MLST locus was determined to be very diverse, and the two Minim fragments located herein contribute greatly to the resolving power. However these fragments are refractory to amplification in a minority of isolates. Therefore, we assessed the performance of two additional formats: one using only the four fragments located outside the tonB gene (D = 0.929), and the other using HRM data from these four fragments in conjunction with sequencing of the tonB MLST fragment (D = 0.995). The HRM assays were developed on the Rotorgene 6000, and the method was shown to also be robust on the LightCycler 480, allowing a 384-well high through-put format. The assay provides rapid, robust and low-cost typing with fully portable results that can directly be related to current MLST data. Minim typing in combination with molecular screening for antibiotic resistance markers can be a powerful surveillance tool kit.
Full Text Available Here we report a single nucleotide polymorphism (SNP based genotyping method for Klebsiella pneumoniae utilising high-resolution melting (HRM analysis of fragments within the multilocus sequence typing (MLST loci. The approach is termed mini-MLST or Minim typing and it has previously been applied to Streptococcus pyogenes, Staphylococcus aureus and Enterococcus faecium. Six SNPs were derived from concatenated MLST sequences on the basis of maximisation of the Simpsons Index of Diversity (D. DNA fragments incorporating these SNPs and predicted to be suitable for HRM analysis were designed. Using the assumption that HRM alleles are defined by G+C content, Minim typing using six fragments was predicted to provide a D = 0.979 against known STs. The method was tested against 202 K. pneumoniae using a blinded approach in which the MLST analyses were performed after the HRM analyses. The HRM-based alleles were indeed in accordance with G+C content, and the Minim typing identified known STs and flagged new STs. The tonB MLST locus was determined to be very diverse, and the two Minim fragments located herein contribute greatly to the resolving power. However these fragments are refractory to amplification in a minority of isolates. Therefore, we assessed the performance of two additional formats: one using only the four fragments located outside the tonB gene (D = 0.929, and the other using HRM data from these four fragments in conjunction with sequencing of the tonB MLST fragment (D = 0.995. The HRM assays were developed on the Rotorgene 6000, and the method was shown to also be robust on the LightCycler 480, allowing a 384-well high through-put format. The assay provides rapid, robust and low-cost typing with fully portable results that can directly be related to current MLST data. Minim typing in combination with molecular screening for antibiotic resistance markers can be a powerful surveillance tool kit.
Miller, Shelley; Humphries, Romney M
Carbapenemases, enzymes that hydrolyze carbapenem-class antimicrobials, pose serious clinical and diagnostic challenges, including their recent rapid spread among members of the Enterobacteriaceae, a family with no inherent carbapenem resistance. Currently there is no one-size-fits-all method for detecting carbapenem-resistant Enterobacteriaceae (CRE) in the laboratory, nor how to differentiate carbapenemase-producers (CP) from isolates that are carbapenem-resistant via other or combined mechanisms. This article reviews definitions for CRE and CP-CRE, and discusses current phenotypic and molecular methods available to the clinical laboratory for the detection of both CP and non-CP CRE. Expert commentary: Routine evaluation of carbapenem resistance mechanism by the routine clinical laboratory are not necessary for patient care, as clinical breakpoints best predict response. However, evaluation for carbapenemase is integral to infection control efforts, and laboratories should have the capacity to do such testing, either in house or by submitting isolates to a reference laboratory.
V S Tshisevhe
Full Text Available The emergence of resistance to multiple antimicrobial agents in pathogenic bacteria is a significant public health threat, as there are limited effective antimicrobial agents for infections caused by multidrug-resistant (MDR bacteria. Several MDR bacteria are now frequently detected. Carbapenem resistance in Enterobacteriaceae is often plasmid mediated, necessitating stringent infection control practices. We describe an outbreak of carbapenem-resistant Providencia rettgeri involving 4 patients admitted to intensive care and high-care units at a tertiary hospital. Clinical and demographic characteristics of 4 patients with carbapenem-resistant P. rettgeri were documented. All P. rettgeri isolated in these cases had a carbapenem-resistant antibiogram, with resistance to imipenem, ertapenem and meropenem. These cases could be epidemiologically linked. A multiprong approach, simultaneously targeting antibiotic stewardship, universal precautions and appropriate transmission-based precaution practices, is integral to prevention and control of nosocomial infections.
Petrovici, Cristina G; Dorobăţ, Carmen; Matei, Mioara; Teodor, Andra; Luca, V; Miftode, Egidia
Infections in diabetic patient remains an important cause of morbidity and mortality, triggering and maintaining a prolonged metabolic imbalance. Emergence of extented spectrum beta-lactmase (ESBL) in Escherichia coli and Klebsiella pneumoniae is a major concern, because of the atypical manner infection acts in this group of imunodepressed patients and also for the limited therapeutic solutions. For this reason we have evaluated the profile of antimicrobial resistance of these pathogens in both diabetic and non diabetic patients. The aim of this study was to evaluate, in a retrospective case control study, the antibiotic susceptibility pattern in isolates of E. coli and Klebsiella spp. from different biological products in 49 diabetics and 150 non-diabetics admitted in The Clinical Hospital of Infectious Diseases Iaşi over a period of two years. Most of strains of E. coli and Klebsiella spp. ESBL positive were found in uroculture. Significant differences in E. coli resistance rate between diabetics and nondiabetics were noted for amoxicillin-clavulanic acid and ciprofloxacin (31,4% vs.13,98%, p=0,04, respectively 52,9% vs. 24,46%, p=0,004). More isolates of ESBL positive K. pneumoniae were found in diabetic patients (50% vs. 24%). Ciprofloxacin resistance of K. pneumoniae was significantly higher in diabetics (75% vs 39%; p=0,05). There was no resistance in E. coli and K. pneumoniae isolates to imipenem in the diabetic group. The high resistance rate to quinolones and 3rd generation cefalosporins limits their use for the treatment of Escherichia coli and K. pneumoniae infections. Other alternatives for empiric therapy in community and nosocomial-acquired infections in diabetic patient remains carbapenems, aminoglycosides and colimycin.
Harakeh, M S; Berg, J D; Hoff, J C; Matin, A
The resistance of bacteria to antimicrobial agents could be influenced by growth environment. The susceptibility of two enteric bacteria, Yersinia enterocolitica and Klebsiella pneumoniae, to chlorine dioxide was investigated. These organisms were grown in a defined medium in a chemostat and the influence of growth rate, temperature, and cell density on the susceptibility was studied. All inactivation experiments were conducted with a dose of 0.25 mg of chlorine dioxide per liter in phosphate-buffered saline at pH 7.0 and 23 degrees C. The results indicated that populations grown under conditions that more closely approximate natural aquatic environments, e.g., low temperatures and growth at submaximal rates caused by nutrient limitation, were most resistant. The conclusion from this study is that antecedent growth conditions have a profound effect on the susceptibility of bacteria to disinfectants, and it is more appropriate to use the chemostat-grown bacteria as test organisms to evaluate the efficacy of a certain disinfectant.
Sammeta V. Raju
Full Text Available Alcohol abuse has been associated with increased susceptibility to pulmonary infection. It is not fully defined how alcohol contributes to the host defense compromise. Here primary human airway epithelial cells were cultured at an air-liquid interface to form a differentiated and polarized epithelium. This unique culture model allowed us to closely mimic lung infection in the context of alcohol abuse by basolateral alcohol exposure and apical live bacterial challenge. Application of clinically relevant concentrations of alcohol for 24 h did not significantly alter epithelial integrity or barrier function. When apically challenged with viable Klebsiella pneumoniae, the cultured epithelia had an enhanced tightness which was unaffected by alcohol. Further, alcohol enhanced apical bacterial growth, but not bacterial binding to the cells. The cultured epithelium in the absence of any treatment or stimulation had a base-level IL-6 and IL-8 secretion. Apical bacterial challenge significantly elevated the basolateral secretion of inflammatory cytokines including IL-2, IL-4, IL-6, IL-8, IFN-γ, GM-CSF, and TNF-α. However, alcohol suppressed the observed cytokine burst in response to infection. Addition of adenosine receptor agonists negated the suppression of IL-6 and TNF-α. Thus, acute alcohol alters the epithelial cytokine response to infection, which can be partially mitigated by adenosine receptor agonists.
Neeraj Kumar Tulara
Full Text Available Urinary tract infection (UTI is a common and painful human illness that, unfortunately not responsive to commonly used antibiotics in current practice. The role of fosfomycin and nitrofurantoin in the era of growing bacteria resistance has been widely discussed. In this study, we aimed to know the local antimicrobial susceptibilities, fosfomycin and nitrofurantoin susceptibility in particular, for urinary extended-spectrum-beta-lactamase-producing Escherichia coli and Escherichia pneumoniae (ESBL-EC and ESBL-KP isolates in our hospital. We collected 464 urine isolates, including 384 ESBL-EC and 80 ESBL-KP isolates. Of 464 urine isolates culture positive ESBL-UTIs, EC caused 384 (82.75%, followed by Klebsiella in 80 (17.24%. Carbapenems and Colistin seems to remain as the first line therapy for the majority of ESBL-UTIs in the local setting. Colistin and fosfomycin remains the most sensitive antibiotic while nitrofurantoin still preserves the good sensitivity against ESBL and found to be an only oral sensitive antibiotic.
Full Text Available A novel tannase producing bacterial strain was isolated from rhizospheric soil of Acacia species and identified as Klebsiella pneumoniae KP715242. A 3.25-fold increase in tannase production was achieved upon optimization with central composite design using response surface methodology. Four variables namely pH, temperature, incubation period, and agitation speed were used to optimize significant correlation between the effects of these variables on tannase production. A second-order polynomial was fitted to data and validated by ANOVA. The results showed a complex relationship between variables and response given that all factors were significant and could explain 99.6% of the total variation. The maximum production was obtained at 5.2 pH, 34.97 °C temperature, 103.34 rpm agitation speed and 91.34 h of incubation time. The experimental values were in good agreement with the predicted ones and the models were highly significant with a correlation coefficient (R2 of 0.99 and a highly significant F-value of 319.37.
Forcina, A; Baldan, R; Marasco, V; Cichero, P; Bondanza, A; Noviello, M; Piemontese, S; Soliman, C; Greco, R; Lorentino, F; Giglio, F; Messina, C; Carrabba, M; Bernardi, M; Peccatori, J; Moro, M; Biancardi, A; Nizzero, P; Scarpellini, P; Cirillo, D M; Mancini, N; Corti, C; Clementi, M; Ciceri, F
Carbapenemase-producing Klebsiella pneumoniae (KPC-Kp) infections are an emerging cause of death after hematopoietic stem cell transplantation (HSCT). In allogeneic transplants, mortality rate may rise up to 60%. We retrospectively evaluated 540 patients receiving a transplant from an auto- or an allogeneic source between January 2011 and October 2015. After an Institutional increase in the prevalence of KPC-Kp bloodstream infections (BSI) in June 2012, from July 2012, 366 consecutive patients received the following preventive measures: (i) weekly rectal swabs for surveillance; (ii) contact precautions in carriers (iii) early-targeted therapy in neutropenic febrile carriers. Molecular typing identified KPC-Kp clone ST512 as the main clone responsible for colonization, BSI and outbreaks. After the introduction of these preventive measures, the cumulative incidence of KPC-Kp BSI (P=0.01) and septic shocks (P=0.01) at 1 year after HSCT was significantly reduced. KPC-Kp infection-mortality dropped from 62.5% (pre-intervention) to 16.6% (post-intervention). Day 100 transplant-related mortality and KPC-Kp infection-related mortality after allogeneic HSCT were reduced from 22% to 10% (P=0.001) and from 4% to 1% (P=0.04), respectively. None of the pre-HSCT carriers was excluded from transplant. These results suggest that active surveillance, contact precautions and early-targeted therapies, may efficiently control KPC-Kp spread and related mortality even after allogeneic HSCT.
Benincasa, Monica; Lagatolla, Cristina; Dolzani, Lucilla; Milan, Annalisa; Pacor, Sabrina; Liut, Gianfranco; Tossi, Alessandro; Cescutti, Paola; Rizzo, Roberto
Biofilm matrices of two Klebsiella pneumoniae clinical isolates, KpTs101 and KpTs113, were investigated for their polysaccharide composition and protective effects against antimicrobial peptides. Both strains were good biofilm producers, with KpTs113 forming flocs with very low adhesive properties to supports. Matrix exopolysaccharides were isolated and their monosaccharide composition and glycosidic linkage types were defined. KpTs101 polysaccharide is neutral and composed only of galactose, in both pyranose and furanose ring configurations. Conversely, KpTs113 polysaccharide is anionic due to glucuronic acid units, and also contains glucose and mannose residues. The susceptibility of the two strains to two bovine cathelicidin antimicrobial peptides, BMAP-27 and Bac7(1-35), was assessed using both planktonic cultures and biofilms. Biofilm matrices exerted a relevant protection against both antimicrobials, which act with quite different mechanisms. Similar protection was also detected when antimicrobial peptides were tested against planktonic bacteria in the presence of the polysaccharides extracted from KpTs101 and KpTs113 biofilms, suggesting sequestering adduct formation with antimicrobials. Circular dichroism experiments on BMAP-27 in the presence of increasing amounts of either polysaccharide confirmed their ability to interact with the peptide and induce an α-helical conformation.
Caracterización de Klebsiella pneumoniae productora de la beta-lactamasa SHV-5, en una unidad de cuidados intensivos Characterization of SHV-5 beta-lactamase-producing Klebsiella pneumoniae in an intensive care unit
Full Text Available OBJETIVO: Caracterizar molecularmente los aislamientos de Klebsiella pneumoniae obtenidos de pacientes pediátricos y del personal de salud en la unidad de cuidados intensivos de un hospital de tercer nivel de atención en la Ciudad de México, Distrito Federal. MATERIAL Y MÉTODOS: Se analizaron 15 aislamientos de Klebsiella pneumoniae colectadas de un brote durante el mes de junio de 1996, ocho de pacientes y siete de personal del Hospital Infantil de México. Los aislamientos fueron caracterizados por electroforesis en gel de campos pulsados (EGCP, amplificación azarosa del polimorfismo de ADN por reacción en cadena de la polimerasa (AAPD-PCR, y serotipificación, isoelectroenfoque de beta-lactamasas y secuenciación nucleotídica de productos de la reacción en cadena de la polimerasa. RESULTADOS: El serotipo predominante fue el 61 y correlacionó con los perfiles de AAPD-PCR y EGCP en 11 de los 15 aislamientos. Se identificó una clona predominante productora de SHV-5 con una alta letalidad. CONCLUSIONES: Las técnicas de biología molecular fueron herramientas muy útiles en la caracterización de la clona de K. pneumoniae identificada en pacientes y el personal hospitalario, que sugirieron una posible transmisión cruzada. Estos resultados ilustran que se debe apoyar el fortalecimiento de los programas de control para evitar la diseminación de infecciones nosocomiales en esa unidad en estudio.OBJECTIVE: To perform the molecular characterization of Klebsiella pneumoniae isolates from pediatric patients and health care workers at the intensive care unit of a tertiary care hospital in Mexico City. MATERIAL AND METHODS: Fifteen Klebsiella pneumoniae isolates collected during an outbreak in June 1996 were analyzed; eight were from patients and seven from health care workers of Mexico's Children's Hospital. Characterization of isolates was carried out by pulsed field gel electrophoresis (PFGE, random amplified polymorphic DNA polymerase
Ko, Kwan Soo; Yeom, Joon-Sup; Lee, Mi Young; Peck, Kyong Ran
In this study, we investigated the molecular characteristics of extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae isolates that were recovered from an outbreak in a Korean hospital. A new multilocus sequence typing (MLST) scheme for K. pneumoniae based on five housekeeping genes was developed and was evaluated for 43 ESBL-producing isolates from an outbreak as well as 38 surveillance isolates from Korea and also a reference strain. Overall, a total of 37 sequence types (STs) and six clonal complexes (CCs) were identified among the 82 K. pneumoniae isolates. The result of MLST analysis was concordant with that of pulsedfield gel electrophoresis. Most of the outbreak isolates belonged to a certain clone (ST2), and they produced SHV-1 and CTX-M14 enzymes, which was a different feature from that of the K. pneumoniae isolates from other Korean hospitals (ST20 and SHV-12). We also found a different distribution of CCs between ESBL-producing and -nonproducing K. pneumoniae isolates. The MLST method we developed in this study could provide unambiguous and well-resolved data for the epidemiologic study of K. pneumoniae. The outbreak isolates showed different molecular characteristics from the other K. pneumoniae isolates from other Korean hospitals. PMID:18303199
Rodrigo de Carvalho Santana
Full Text Available Abstract: INTRODUCTION Klebsiella pneumoniae has become an increasingly important etiologic agent of nosocomial infections in recent years. This is mainly due to the expression of virulence factors and development of resistance to several antimicrobial drugs. METHODS This retrospective study examines data obtained from the microbiology laboratory of a Brazilian tertiary-care hospital. To assess temporal trends in prevalence and antimicrobial susceptibility, K. pneumoniae isolates were analyzed from 2000 to 2013. The relative frequencies of K. pneumoniae isolation were calculated among all Gram-negative bacilli isolated in each period analyzed. Susceptibility tests were performed using automated systems. RESULTS: From 2000-2006, K. pneumonia isolates comprised 10.7% of isolated Gram-negative bacilli (455/4260. From 2007-2013, this percentage was 18.1% (965/5331. Strictly considering isolates from bloodstream infections, the relative annual prevalence of K. pneumoniae increased from 14-17% to 27-32% during the same periods. A progressive decrease in K. pneumoniae susceptibility to all antimicrobial agents assessed was detected. Partial resistance was also observed to antimicrobial drugs that have been used more recently, such as colistin and tigecycline. CONCLUSIONS Our study indicates that K. pneumoniae has become a major pathogen among hospitalized patients and confirms its recent trend of increasing antimicrobial resistance.
Full Text Available The spread of enterobacteria producing extended-spectrum ß-lactamases (ESBLs is sharply increasing in Italy, while the detection of isolates resistant to carbapenems is still sporadic. Isolates of Klebsiella pneumoniae resistant to all cephalosporins, aminoglycosides and fluoroquinolones have been isolated in Trieste since 2008. Because of the altered profile of resistance to carbapenems, these strains were reported as ESBL-negative and possible carbapenemases producer by the expert system, leaving tigecycline as the only therapeutic choice.The purpose of this study is the characterization of the mechanisms involved in resistance to carbapenems in these strains and the evaluation of a reliable and simple test for phenotypic confirmation of ESBL and/or carbapenemase production. 25 isolates of MDR K. pneumoniae were collected between October 2008 and May 2009, mainly from urinary samples of elderly patients hospitalized in medicine wards. Identification and susceptibility testing were performed using the Vitek 2 system.The double-disc (DD test was used to check the production of ESBLs, while imipenem and imipenem-EDTA synergy test was used to detect the production of metallo-ßlactamase (MBL. Carbapenemase activity was tested by an hydrolysis assay and the production of MBLs was also investigated by PCR. The DD synergy test highlighted the possible production of ESBLs in 18 out of 22 strains, considered as negative by Vitek. All ESBLs producers tested positive for the blaCTX-M-15 allele. Only one isolate was resistant to carbapenems and resulted positive for production of MBL by the phenotypic test.The crude extract showed carbapenemase activity inhibited by EDTA; PCR test gave positive result for a blaVIM-type allele. PCR analysis performed on representative isolates, followed by sequencing, showed that coding sequence of ompk35 was not functional. Results of this study confirmed the emergence of ESBL-positive strains of K. pneumoniae that
Glöer, Jens; Thummer, Robert; Ullrich, Heike; Schmitz, Ruth A
In the diazotroph Klebsiella pneumoniae, the nitrogen sensory protein GlnK mediates the cellular nitrogen status towards the NifL/NifA system that regulates transcription of the nitrogen fixation genes in response to ammonium and molecular oxygen. To identify amino acids of GlnK essential for this signal transduction by protein-protein interaction, we performed random point mutagenesis by PCR amplification under conditions of reduced Taq polymerase fidelity. Three thousand two hundred mutated glnK genes were screened to identify those that would no longer complement a K. pneumoniaeDeltaglnK strain for growth under nitrogen fixing conditions. Twenty-four candidates resulting in a Nif(-) phenotype were identified, carrying 1-11 amino acid changes in GlnK. Based on these findings, as well as structural data, several single mutations were introduced into glnK by site-directed mutagenesis, and the Nif phenotype and the respective effects on NifA-mediated nif gene induction was monitored in K. pneumoniae using a chromosomal nifK'-'lacZ fusion. Single amino acid changes resulting in significant nif gene inhibition under nitrogen limiting conditions were located within the highly conserved T-loop (A43G, A49T and N54D), the body of the protein (G87V and K79E) and in the C-terminal region (I100M, R103S, E106Q and D108G). Complex formation analyses between GlnK (wild-type or derivatives) and NifL or NifA in response to 2-oxoglutarate indicated that: (a) besides the T-loop, the C-terminal region of GlnK is essential for the interaction with NifL and NifA and (b) GlnK binds both proteins in the absence of 2-oxoglutarate, whereas, in the presence of 2-oxoglutarate, NifA is released but NifL remains bound to GlnK.
Zhao, Miao; Bulman, Zackery P; Lenhard, Justin R; Satlin, Michael J; Kreiswirth, Barry N; Walsh, Thomas J; Marrocco, Amanda; Bergen, Phillip J; Nation, Roger L; Li, Jian; Zhang, Jing; Tsuji, Brian T
KPC-producing Klebsiella pneumoniae are an emerging public health problem around the globe. We defined the combinatorial pharmacodynamics and ability to suppress resistance of two 'old' antibiotics, fosfomycin and colistin, in time-kill experiments and hollow-fibre infection models (HFIM). Two KPC-2-producing K. pneumoniae isolates were used: one susceptible to both colistin and fosfomycin (KPC 9A: MIC colistin 0.25 mg/L and MIC fosfomycin ≤8 mg/L) and the other resistant to colistin and susceptible to fosfomycin (KPC 5A: MIC colistin 64 mg/L and MIC fosfomycin 32 mg/L). Time-kill experiments assessed an array of colistin and fosfomycin concentrations against both isolates. Colistin and fosfomycin pharmacokinetics from critically ill patients were simulated in the HFIM to define the pharmacodynamic activity of humanized regimens over 5 days against KPC 9A. In time-kill experiments, synergy was demonstrated for all colistin/fosfomycin combinations containing >8 mg/L fosfomycin against the double-susceptible KPC strain, 9A. Synergy versus KPC strain 5A was only achieved at the highest concentrations of colistin (4 mg/L) and fosfomycin (512 mg/L) at 48 h. In the HFIM, colistin or fosfomycin monotherapies resulted in rapid proliferation of resistant subpopulations; KPC 9A regrew by 24 h. In contrast to the monotherapies, the colistin/fosfomycin combination resulted in a rapid 6.15 log 10 cfu/mL reduction of KPC 9A by 6 h and complete suppression of resistant subpopulations until 120 h. Colistin and fosfomycin may represent an important treatment option for KPC-producing K. pneumoniae otherwise resistant to traditional antibiotics. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: firstname.lastname@example.org.
Full Text Available Objectives: To describe a clinical case of Klebsiella pneumoniae harboring a New Delhi metallo-Î²-lactamase (NDM plasmid in Ecuador and to present a map of reports of NDM isolates in South America. Methods: The modified Hodge test, carbapenem inactivation method, imipenemâEDTA disk method (synergy, and Rapidec Carba NP test were used to identify antibiotic resistance mechanisms. The presence of resistance genes was explored with a conjugation assay, and molecular confirmation of NDM was performed by PCR and DNA sequencing. Plasmid characterization was conducted by PCR-based replicon typing. A literature review was performed in Google Scholar and PubMed to identify reports from South America. Results: An HIV-infected patient, who had never traveled abroad, developed a bloodstream infection caused by K. pneumoniae ST147 harboring the NDM-1 resistance gene in a plasmid from the IncA/C group. Local circulation of NDM has also been described in other South American countries, in particular in Colombia and Brazil, although published scientific records were not found for other countries. Conclusions: This report presents the first evidence of autochthonous circulation of the NDM-1 resistance gene harbored by an IncA/C plasmid isolated from a K. pneumoniae ST147 in Ecuador. Efforts should be implemented to monitor and characterize the spatial and temporal distribution of NDM in Ecuador and other countries of South America. Keywords: NDM, South America, Klebsiella pneumoniae, Antibiotic resistance, Plasmid
van der Steen, Matthijs; Leenstra, Tjalling; Kluytmans, Jan A J W; van der Bij, Akke K
We investigated time trends in extended-spectrum cephalosporin-resistant Escherichia coli and Klebsiella pneumoniae isolates from different patient settings in The Netherlands from 2008-2012. E. coli and K. pneumoniae isolates from blood and urine samples of patients > = 18 years were selected from
Khalit S. Khaertynov
Full Text Available Klebsiella pneumoniae is one of the most important infectious agents among neonates. This pathogen has a potential to develop an increased antimicrobial resistance and virulence. The classic non-virulent strain of K. pneumoniae, producing an extended-spectrum beta-lactamases (ESBL, is associated with nosocomial infection mainly in preterm neonates. Hypervirulent K. pneumoniae strains are associated with invasive infection among previously healthy ambulatory patients, and most of them exhibit antimicrobial susceptibility. During the last few years, several cases of diseases caused by hypervirulent K. pneumoniae producing ESBL have been registered in different geographical regions of the world. However, reports of such cases in neonates are rare. Here, we reported that this pathogen can cause pyogenic meningitis in full-term neonate with poor prognosis. A previously healthy, full-term, 12-day-old neonate was admitted to the infectious diseases hospital with suspected meningitis. The clinical symptoms included loss of appetite, irritability, fever, seizures, and a bulging anterior fontanelle. The analysis of the cerebrospinal fluid confirmed the diagnosis of meningitis. Blood and cerebrospinal fluid cultures were positive for K. pneumoniae, producing ESBL. K. pneumoniae isolates were resistant to aminopenicillins, 3rd generation cephalosporins but were sensitive to imipenem and meropenem. The “string test” was positive. The study of the virulence factors of K. pneumoniae by PCR revealed the presence of the rmpA gene. A combination of K. pneumoniae virulence and drug resistance complicated by cerebral oedema led to the death of the neonate. We concluded that both the risk of developing severe forms of infection and the outcome of the disease due to K. pneumonia are associated with the phenotypic features of the pathogen such as its antibiotic susceptibility and virulence factors. Emergence of the ESBL-producing strain of hypervirulent K
Das, Debanu; Kozbial, Piotr; Han, Gye Won; Carlton, Dennis; Jaroszewski, Lukasz; Abdubek, Polat; Astakhova, Tamara; Axelrod, Herbert L.; Bakolitsa, Constantina; Chen, Connie; Chiu, Hsiu-Ju; Chiu, Michelle; Clayton, Thomas; Deller, Marc C.; Duan, Lian; Ellrott, Kyle; Elsliger, Marc-André; Ernst, Dustin; Farr, Carol L.; Feuerhelm, Julie; Grzechnik, Anna; Grant, Joanna C.; Jin, Kevin K.; Johnson, Hope A.; Klock, Heath E.; Knuth, Mark W.; Krishna, S. Sri; Kumar, Abhinav; Marciano, David; McMullan, Daniel; Miller, Mitchell D.; Morse, Andrew T.; Nigoghossian, Edward; Nopakun, Amanda; Okach, Linda; Oommachen, Silvya; Paulsen, Jessica; Puckett, Christina; Reyes, Ron; Rife, Christopher L.; Sefcovic, Natasha; Tien, Henry J.; Trame, Christine B.; Bedem, Henry van den; Weekes, Dana; Wooten, Tiffany; Xu, Qingping; Hodgson, Keith O.; Wooley, John; Deacon, Ashley M.; Godzik, Adam; Lesley, Scott A.; Wilson, Ian A.
KPN03535 is a protein unique to K. pneumoniae. The crystal structure reveals that KPN03535 represents a novel variant of the OB-fold and is likely to be a DNA-binding lipoprotein. KPN03535 (gi|152972051) is a putative lipoprotein of unknown function that is secreted by Klebsiella pneumoniae MGH 78578. The crystal structure reveals that despite a lack of any detectable sequence similarity to known structures, it is a novel variant of the OB-fold and structurally similar to the bacterial Cpx-pathway protein NlpE, single-stranded DNA-binding (SSB) proteins and toxins. K. pneumoniae MGH 78578 forms part of the normal human skin, mouth and gut flora and is an opportunistic pathogen that is linked to about 8% of all hospital-acquired infections in the USA. This structure provides the foundation for further investigations into this divergent member of the OB-fold family
Padmini, Nagarajan; Ajilda, Antony Alex Kennedy; Sivakumar, Natesan; Selvakumar, Gopal
Drug resistance is a phenomenon where by an organism becomes fully or partially resistant to drugs or antibiotics being used against it. Antibiotic resistance poses an exacting intimidation for people with underlying medical immune conditions or weakened immune systems. Infections caused by the enzyme extended spectrum β-lactamase (ESBL) producing multi drug resistance (MDR) Enterobacteriaceae especially Escherichia coli and Klebsiella pneumoniae are resistant to a broad range of beta lactams, including third generation cephalosporins. Among all the pathogens, these two MDR E. coli and K. pneumoniae have emerged as one of the world's greatest health threats in past two decades. The nosocomial infections caused by these ESBL producing MDR E. coli and K. pneumoniae complicated the therapy and limit treatment options. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Akya, Alisha; Elahi, Azam; Chegenelorestani, Roya; Rezaee, Mahya
Klebsiella pneumoniae ( K. pneumoniae ) is an important opportunistic pathogen causes serious community and hospital-acquired infections, which is highly resistant to antibiotics. We aimed to determine the frequency of multidrug resistant (MDR) and molecular typing of clinical isolates of K. pneumoniae . One hundred isolates of K. pneumoniae were collected from clinical samples in three general hospitals in Kermanshah. The antimicrobial susceptibility and extended-spectrum beta-lactamases (ESBL) production of isolates were determined using disk diffusion and combined disk methods, respectively. The bla CTX-M gene, class I and II integrons were detected using polymerase chain reaction. The bla CTX-M positive isolates were selected for genotyping using pulsed-field gel electrophoresis (PFGE). MDR phenotype was observed in 56% of isolates. The 40% of isolates were ESBL positive and 35 isolates contained bla CTX-M . Class I and II of integrons were detected in 50 (89.2%) and 39 (69.6%) of MDR isolates, respectively. PFGE patterns of K. pneumoniae bla CTX-M positive isolates indicated 19 clusters (X 1-19 ) with different genotype patterns. The study findings highlight the concern of circulating MDR strains of K. pneumoniae with bla CTX-M and class I and II integrons in Kermanshah hospitals. The presence of integrons among isolates may facilitate the spread of new resistance genes in this bacterium. Therefore, surveillance for the spread of MDR strains of this bacterium is recommended in hospitals.
Full Text Available Abstract Background Capsular serotypes K1 and K2 of Klebsiella pneumoniae are thought to the major virulence determinants responsible for liver abscess. The intestine is one of the major reservoirs of K. pneumoniae, and epidemiological studies have suggested that the majority of K. pneumoniae infections are preceded by colonization of the gastrointestinal tract. The possibility of fecal-oral transmission in liver abscess has been raised on the basis of molecular typing of isolates. Data on the serotype distribution of K. pneumoniae in stool samples from healthy individuals has not been previously reported. This study investigated the seroepidemiology of K. pneumoniae isolates from the intestinal tract of healthy Chinese in Asian countries. Stool specimens from healthy adult Chinese residents of Taiwan, Japan, Hong Kong, China, Thailand, Malaysia, Singapore, and Vietnam were collected from August 2004 to August 2010 for analysis. Results Serotypes K1/K2 accounted for 9.8% of all K. pneumoniae isolates from stools in all countries. There was no significant difference in the prevalence of K1/K2 isolates among the countries excluding Thailand and Vietnam. The antimicrobial susceptibility pattern was nearly the same in K. pneumoniae isolates. The result of pulsed-field gel electrophoresis revealed no major clonal cluster of serotype K1 isolates. Conclusions The result showed that Chinese ethnicity itself might be a major factor predisposing to intestinal colonization by serotype K1/K2 K. pneumoniae isolates. The prevalent serotype K1/K2 isolates may partially correspond to the prevalence of K. pneumoniae liver abscess in Asian countries.
Holt, Kathryn E.; Wertheim, Heiman; Zadoks, Ruth N.; Baker, Stephen; Whitehouse, Chris A.; Dance, David; Jenney, Adam; Connor, Thomas R.; Hsu, Li Yang; Severin, Juliëtte; Brisse, Sylvain; Cao, Hanwei; Wilksch, Jonathan; Gorrie, Claire; Schultz, Mark B.; Edwards, David J.; Nguyen, Kinh Van; Nguyen, Trung Vu; Dao, Trinh Tuyet; Mensink, Martijn; Minh, Vien Le; Nhu, Nguyen Thi Khanh; Schultsz, Constance; Kuntaman, Kuntaman; Newton, Paul N.; Moore, Catrin E.; Strugnell, Richard A.; Thomson, Nicholas R.
Klebsiella pneumoniae is now recognized as an urgent threat to human health because of the emergence of multidrug-resistant strains associated with hospital outbreaks and hypervirulent strains associated with severe community-acquired infections. K. pneumoniae is ubiquitous in the environment and can colonize and infect both plants and animals. However, little is known about the population structure of K. pneumoniae, so it is difficult to recognize or understand the emergence of clinically important clones within this highly genetically diverse species. Here we present a detailed genomic framework for K. pneumoniae based on whole-genome sequencing of more than 300 human and animal isolates spanning four continents. Our data provide genome-wide support for the splitting of K. pneumoniae into three distinct species, KpI (K. pneumoniae), KpII (K. quasipneumoniae), and KpIII (K. variicola). Further, for K. pneumoniae (KpI), the entity most frequently associated with human infection, we show the existence of >150 deeply branching lineages including numerous multidrug-resistant or hypervirulent clones. We show K. pneumoniae has a large accessory genome approaching 30,000 protein-coding genes, including a number of virulence functions that are significantly associated with invasive community-acquired disease in humans. In our dataset, antimicrobial resistance genes were common among human carriage isolates and hospital-acquired infections, which generally lacked the genes associated with invasive disease. The convergence of virulence and resistance genes potentially could lead to the emergence of untreatable invasive K. pneumoniae infections; our data provide the whole-genome framework against which to track the emergence of such threats. PMID:26100894
Andersson, Patiyan; Tong, Steven Y. C.; Bell, Jan M.; Turnidge, John D.; Giffard, Philip M.
Here we report a single nucleotide polymorphism (SNP) based genotyping method for Klebsiella pneumoniae utilising high-resolution melting (HRM) analysis of fragments within the multilocus sequence typing (MLST) loci. The approach is termed mini-MLST or Minim typing and it has previously been applied to Streptococcus pyogenes, Staphylococcus aureus and Enterococcus faecium. Six SNPs were derived from concatenated MLST sequences on the basis of maximisation of the Simpsons Index of Diversity (D). DNA fragments incorporating these SNPs and predicted to be suitable for HRM analysis were designed. Using the assumption that HRM alleles are defined by G+C content, Minim typing using six fragments was predicted to provide a D = 0.979 against known STs. The method was tested against 202 K. pneumoniae using a blinded approach in which the MLST analyses were performed after the HRM analyses. The HRM-based alleles were indeed in accordance with G+C content, and the Minim typing identified known STs and flagged new STs. The tonB MLST locus was determined to be very diverse, and the two Minim fragments located herein contribute greatly to the resolving power. However these fragments are refractory to amplification in a minority of isolates. Therefore, we assessed the performance of two additional formats: one using only the four fragments located outside the tonB gene (D = 0.929), and the other using HRM data from these four fragments in conjunction with sequencing of the tonB MLST fragment (D = 0.995). The HRM assays were developed on the Rotorgene 6000, and the method was shown to also be robust on the LightCycler 480, allowing a 384-well high through-put format. The assay provides rapid, robust and low-cost typing with fully portable results that can directly be related to current MLST data. Minim typing in combination with molecular screening for antibiotic resistance markers can be a powerful surveillance tool kit. PMID:22428067
Full Text Available PURPOSE: Porins are outer membrane protein (OMP that form water filled channels that permit the diffusion of small hydrophilic solutes like -lactam antibiotics across the outer membrane. Two major porins that facilitate diffusion of antimicrobials have been described in Klebsiella spp. and Escherichia coli. The present study was carried out to examine the role of porins among Extended Spectrum -Lactamase (ESBL and AmpC -Lactamase positive strains of Klebsiella spp. and E.coli. METHODS: Preparation of OMP from phenotypically characterized clinical isolates K.pneumoniae and E.coli and the separation of the proteins by sodium dodecyl sulfate - polyacrylamide gel electrophoresis were performed as per a previously described procedure. RESULTS: OMP analysis revealed that cefoxitin and ceftazidime resistance was mediated by loss of a porin Omp K35 in the isolates of K.pneumoniae and E.coli. CONCLUSIONS: Loss of porin mediated resistance mechanism against cefoxitin was observed among the multidrug resistant K.pneumoniae and E.coli.
Park, Eun-Ah; Kim, You-Tae; Cho, Jae-Hyun; Ryu, Sangryeol; Lee, Ju-Hoon
Klebsiella is a genus of well-known opportunistic human pathogens that are associated with diabetes mellitus and chronic pulmonary obstruction; however, this pathogen is often resistant to multiple drugs. To control this pathogen, two Klebsiella-infecting phages, K. oxytoca phage PKO111 and K. pneumoniae phage PKP126, were isolated from a sewage sample. Analysis of their host range revealed that they infect K. pneumoniae and K. oxytoca, suggesting host specificity for members of the genus Klebsiella. Stability tests confirmed that the phages are stable under various temperature (4 to 60 °C) and pH (3 to 11) conditions. A challenge assay showed that PKO111 and PKP126 inhibit growth of their host strains by 2 log and 4 log, respectively. Complete genome sequencing of the phages revealed that their genome sizes are quite different (168,758 bp for PKO111 and 50,934 bp for PKP126). Their genome annotation results showed that they have no human virulence-related genes, an important safety consideration. In addition, no lysogen-formation gene cluster was detected in either phage genome, suggesting that they are both virulent phages in their bacterial hosts. Based on these results, PKO111 and PKP126 may be good candidates for development of biocontrol agents against members of the genus Klebsiella for therapeutic purposes. A comparative analysis of tail-associated gene clusters of PKO111 and PKP126 revealed relatively low homology, suggesting that they might differ in the way they recognize and infect their specific hosts.
Loh, Li-Cher; Nor Izran Hanim bt Abdul Samad; Rosdara Masayuni bt Mohd Sani; Raman, Sree; Thayaparan, Tarmizi; Kumar, Shalini
Klebsiella pneumoniae ranks high as a cause of adult pneumonia requiring hospitalization in Malaysia. To study whether extended-spectrum b-lactamase (ESBL) producing K. pneumoniae was linked to hospital outcomes, we retrospectively studied 441 cases of adult respiratory tract infections with microbial proven K. pneumoniae from an urban-based university teaching hospital between 2003 and 2004. 47 (10.6%) cases had ESBL. Requirement for ventilation and median length of hospital stay, were greater in ‘ESBL’ than in ‘non-ESBL’ group [34% vs. 7.4%, p<0.001; 14 days vs. 5 days, p<0.001 respectively] but not crude hospital mortality rate [21.3% vs. 12.4%, p=0.092]. There was a four-fold increased risk of requiring ventilation [4.61 (2.72–7.85)] when ESBL was present. Our findings support the association of ESBL producing K. pneumoniae with adversed hospital outcomes and reiterate the need for vigilance on the part of treating clinicians. PMID:22993489
Kallay, Z.; Trnovec, T.; Durisova, M.; Mazurova, E.; Navarova, J.; Plskova, M.; Kettner, M.
Sublethal irradiation was used to suppress the immunity response of the organism. Following the development of infection with Klebsiella pneumoniae the therapeutical effect was compared of intramuscular administration and of inhalation of gentamicin. Intramuscular administration was statistically significant for reducing the mortality of infected guinea pigs as against non-treated animals at days 7 to 10 after irradiation. Administration by inhalation had the same effect between days 12 and 25 after irradiation. The weight and blood counts of the animals were observed during the experiment. (M.D.)
Hirsch, Elizabeth B.; Ledesma, Kimberly R.; Chang, Kai-Tai; Schwartz, Michael S.; Motyl, Mary R.
Carbapenem-resistant bacteria represent a significant treatment challenge due to the lack of active antimicrobials available. MK-7655 is a novel β-lactamase inhibitor under clinical development. We investigated the combined killing activity of imipenem and MK-7655 against four imipenem-resistant bacterial strains, using a mathematical model previously evaluated in our laboratory. Time-kill studies (TKS) were conducted with imipenem and MK-7655 against a KPC-2-producing Klebsiella pneumoniae isolate (KP6339) as well as 3 Pseudomonas aeruginosa isolates (PA24226, PA24227, and PA24228) with OprD porin deletions and overexpression of AmpC. TKS were performed using 25 clinically achievable concentration combinations in a 5-by-5 array. Bacterial burden at 24 h was determined in triplicate by quantitative culture and mathematically modeled using a three-dimensional response surface. Mathematical model assessments were evaluated experimentally using clinically relevant dosing regimens of imipenem, with or without MK-7655, in a hollow-fiber infection model (HFIM). The combination of imipenem and MK-7655 was synergistic for all strains. Interaction indices were as follows: for KP6339, 0.50 (95% confidence interval [CI], 0.42 to 0.58); for PA24226, 0.60 (95% CI, 0.58 to 0.62); for PA24227, 0.70 (95% CI, 0.66 to 0.74); and for PA24228, 0.55 (95% CI, 0.49 to 0.61). In the HFIM, imipenem plus MK-7655 considerably reduced the bacterial burden at 24 h, while failure with imipenem alone was seen against all isolates. Sustained suppression of bacterial growth at 72 h was achieved with simulated doses of 500 mg imipenem plus 500 mg MK-7655 in 2 (KP6339 and PA24227) strains, and it was achieved in an additional strain (PA24228) when the imipenem dose was increased to 1,000 mg. Additional studies are being conducted to determine the optimal dose and combinations to be used in clinical investigations. PMID:22526311
Björn A Espedido
Full Text Available Whole genome sequencing was used to characterize the resistome of intensive care unit (ICU outbreak-associated carbapenem-resistant K. pneumoniae isolates. Importantly, and of particular concern, the carbapenem-hydrolyzing β-lactamase gene bla(OXA-48 and the extended-spectrum β-lactamase gene bla(CTX-M-14, were identified on a single broad host-range conjugative plasmid. This represents the first report of bla(OXA-48 in Australia and highlights the importance of resistance gene surveillance, as such plasmids can silently spread amongst enterobacterial populations and have the potential to drastically limit treatment options. Furthermore, the in vivo evolution of these isolates was also examined after 18 months of intra-abdominal carriage in a patient that transited through the ICU during the outbreak period. Reflecting the clonality of K. pneumoniae, only 11 single nucleotide polymorphisms (SNPs were accumulated during this time-period and many of these were associated with genes involved in tolerance/resistance to antibiotics, metals or organic solvents, and transcriptional regulation. Collectively, these SNPs are likely to be associated with changes in virulence (at least to some extent that have refined the in vivo colonization capacity of the original outbreak isolate.
Espedido, Björn A.; Steen, Jason A.; Ziochos, Helen; Grimmond, Sean M.; Cooper, Matthew A.; Gosbell, Iain B.; van Hal, Sebastiaan J.; Jensen, Slade O.
Whole genome sequencing was used to characterize the resistome of intensive care unit (ICU) outbreak-associated carbapenem-resistant K. pneumoniae isolates. Importantly, and of particular concern, the carbapenem-hydrolyzing β-lactamase gene bla OXA-48 and the extended-spectrum β-lactamase gene bla CTX-M-14, were identified on a single broad host-range conjugative plasmid. This represents the first report of bla OXA-48 in Australia and highlights the importance of resistance gene surveillance, as such plasmids can silently spread amongst enterobacterial populations and have the potential to drastically limit treatment options. Furthermore, the in vivo evolution of these isolates was also examined after 18 months of intra-abdominal carriage in a patient that transited through the ICU during the outbreak period. Reflecting the clonality of K. pneumoniae, only 11 single nucleotide polymorphisms (SNPs) were accumulated during this time-period and many of these were associated with genes involved in tolerance/resistance to antibiotics, metals or organic solvents, and transcriptional regulation. Collectively, these SNPs are likely to be associated with changes in virulence (at least to some extent) that have refined the in vivo colonization capacity of the original outbreak isolate. PMID:23555831
Procop, Gary W; Tuohy, Marion J; Wilson, Deborah A; Williams, Delisa; Hadziyannis, Emilia; Hall, Gerri S
Extended spectrum beta-lactamases are modified beta-lactamase enzymes that impart resistance to third-generation cephalosporins and make all beta-lactam antibiotics and cephalosporins useless for therapy. We compared the antimicrobial susceptibility profiles of extended-spectrum beta-lactamase (ESBL)-producing and non-ESBL-producing isolates of Klebsiella pneumoniae. The ESBL producers had significantly diminished susceptibility compared with the non-ESBL producers for gentamicin (P < .001), tobramycin (P < .001), amikacin (P < .005), trimethoprim-sulfamethoxazole (P < .01), ciprofloxacin (P < .001), and nitrofurantoin (P < .001). All isolates were susceptible to imipenem. ESBL-producing K pneumoniae may also be resistant to non-beta-lactam antibiotics. Therefore, susceptibility testing of these isolates is critical for guiding therapy.
Christensen, Sarah Christine; Nissen, Erling; Arvin, Erik
. aquaticus on microbial water quality in non-chlorinated drinking water in controlled laboratory experiments. Pure cultures of the indicator organisms Escherichia coli and Klebsiella pneumoniae and the pathogen Campylobacter jejuni as well as naturally occurring heterotrophic drinking water bacteria...... decreased over time, following a first order decay with half lives of 5.3, 18.4 and 1.3 days, respectively. A. aquaticus did not affect survival of indicators and pathogens substantially whereas HPC were influenced by presence of dead A. aquaticus. Growth rates increased with an average of 48% for bacteria...... grown on R-2A agar and an average of 83% for bacteria grown on yeast extract agar when dead A. aquaticus were present compared to no and living A. aquaticus present. A. aquaticus associated E. coli, K. pneumoniae and C. jejuni were measured (up to 25 per living and 500 per dead A. aquaticus) and so were...
Full Text Available BACKGROUND: Klebsiella pneumoniae is one of the major pathogens causing hospital-acquired multidrug-resistant infections. The capsular polysaccharide (CPS is an important virulence factor of K. pneumoniae. With 78 capsular types discovered thus far, an association between capsular type and the pathogenicity of K. pneumoniae has been observed. METHODOLOGY/PRINCIPAL FINDINGS: To investigate an initially non-typeable K. pneumoniae UTI isolate NTUH-K1790N, the cps gene region was sequenced. By NTUH-K1790N cps-PCR genotyping, serotyping and determination using a newly isolated capsular type-specific bacteriophage, we found that NTUH-K1790N and three other isolates Ca0507, Ca0421 and C1975 possessed a new capsular type, which we named KN2. Analysis of a KN2 CPS(- mutant confirmed the role of capsule as the target recognized by the antiserum and the phage. A newly described lytic phage specific for KN2 K. pneumoniae, named 0507-KN2-1, was isolated and characterized using transmission electron microscopy. Whole-genome sequencing of 0507-KN2-1 revealed a 159 991 bp double-stranded DNA genome with a G+C content of 46.7% and at least 154 open reading frames. Based on its morphological and genomic characteristics, 0507-KN2-1 was classified as a member of the Myoviridae phage family. Further analysis of this phage revealed a 3738-bp gene encoding a putative polysaccharide depolymerase. A recombinant form of this protein was produced and assayed to confirm its enzymatic activity and specificity to KN2 capsular polysaccharides. KN2 K. pneumoniae strains exhibited greater sensitivity to this depolymerase than these did to the cognate phage, as determined by spot analysis. CONCLUSIONS/SIGNIFICANCE: Here we report that a group of clinical strains possess a novel Klebsiella capsular type. We identified a KN2-specific phage and its polysaccharide depolymerase, which could be used for efficient capsular typing. The lytic phage and depolymerase also have potential as
Tal-Jasper, Ruthy; Katz, David E; Amrami, Nadav; Ravid, Dor; Avivi, Dori; Zaidenstein, Ronit; Lazarovitch, Tsilia; Dadon, Mor; Kaye, Keith S; Marchaim, Dror
Carbapenems are considered the treatment of choice for Acinetobacter baumannii infections. Many facilities implement preventive measures toward only carbapenem-resistant A. baumannii (CRAB). However, the independent role of the carbapenem resistance determinant on patient outcomes remains controversial. In a 6-year analysis of adults with A. baumannii bloodstream infection (BSI), the outcomes of 149 CRAB isolates were compared to those of 91 patients with carbapenem-susceptible A. baumannii In bivariable analyses, CRAB BSIs were significantly associated with worse outcomes and with a delay in the initiation of appropriate antimicrobial therapy (DAAT). However, in multivariable analyses, carbapenem resistance status was no longer associated with poor outcomes, while DAAT remained an independent predictor. The epidemiological significance of A. baumannii should not be determined by its resistance to carbapenems. Copyright © 2016, American Society for Microbiology. All Rights Reserved.
Full Text Available La emergencia de enterobacterias productoras de carbapenemasas de tipo Nueva Delhi Metalo beta-lactamasas (NDM, representan, hoy en día, un verdadero problema de salud pública mundial. La presencia de este mecanismo de resistencia limita o anula las opciones terapéuticas para combatir a estas bacterias. En Latinoamérica, las cifras son cada vez más elevadas, pues se reportan en Guatemala, Colombia, Chile, Argentina, entre otros. Perú no ha descrito, hasta la fecha, la presencia de este patrón de resistencia; sin embargo, desde hace varios años se presume de su existencia. Se describen nueve casos de Klebsiella pneumoniae NDM, como agentes infecciosos o colonizantes, en pacientes críticamente enfermos, en su mayoría con patología neuroquirúrgica, del Hospital Nacional Dos de Mayo, en Lima - Perú. Los pacientes de la serie descrita a continuación, representan los primeros reportes de Klebsiella pneumoniae NDM en el Perú.
Mavroidi, Angeliki; Katsiari, Maria; Likousi, Sofia; Palla, Eleftheria; Roussou, Zoi; Nikolaou, Charikleia; Maguina, Asimina; Platsouka, Evangelia D
The emergence of colistin resistance may further contribute to treatment failure of infection caused by multidrug-resistant (MDR) Klebsiella pneumoniae. The colistin resistance rates were determined and colistin-resistant carbapenemase-producing K. pneumoniae (COL-R CP-Kp) were characterized over an 18-month period in a Greek hospital. Out of 135 carbapenemase producers, 19 isolates (14%) were categorized as resistant to colistin. Phenotypic and molecular characterization of the COL-R CP-Kp isolates revealed that all were MDR blaKPC producers and, excluding one isolate of MLST ST383, belonged to the international clonal lineage ST258. Furthermore, PCR amplification and sequencing of the mgrB locus revealed nucleotide sequences of different sizes and insertions of IS1- and IS5-like mobile elements. The majority (63%) of the COL-R blaKPC producers was recovered from patients in the intensive care unit (ICU) and clinical data indicated that all patients should have acquired these isolates in the ICU. The findings of the present study underscore a concerning evolution of colistin resistance in a setting of high K. pneumoniae carbapenemase (KPC)-Kp endemicity, such as Greece. Thus, continuous surveillance, molecular characterization, prudent use of antibiotics, and implementation of infection control measures for K. pneumoniae are urgent.
Seo, Ryota; Kudo, Daisuke; Gu, Yoshiaki; Yano, Hisakazu; Aoyagi, Tetsuji; Omura, Taku; Irino, Shigemi; Kaku, Mitsuo; Kushimoto, Shigeki
Klebsiella pneumonia is a well-known human pathogen, and recently, a distinct invasive syndrome caused by K. pneumoniae serotypes K1 and K2 has been recognized in Southeast Asia. This syndrome is characterized by primary liver abscess and extrahepatic complications resulting from bacteremic dissemination. We report the first adult case of primary liver abscess caused by the definite K2 serotyped pathogen, with endogenous endophthalmitis in Japan. A 64-year-old woman was admitted to a nearby hospital for a high fever and diarrhea. She had visual loss of her right eye, renal dysfunction, and thrombocytopenia within 24 h from admission. She was transferred to our institution. On admission, she had no alteration of mental status and normal vital signs; however, she had almost complete ablepsia of the right eye. Laboratory data showed severe inflammation, liver dysfunction, thrombocytopenia, an increased serum creatinine level, and coagulopathy. Computed tomography showed a low density area in the right lobe of the liver. Invasive liver abscess syndrome probably caused by K. pneumonia was highly suspected and immediately administered broad-spectrum antibiotics for severe sepsis. Concurrently, endogenous endophthalmitis was diagnosed, and we performed vitrectomy on the day of admission. The blood culture showed K. pneumoniae infection. Percutaneous drainage of the liver abscess was also performed. Although she was discharged in a good general condition on day 22, she had complete ablepsia of the right eye. The K2A gene was detected by polymerase chain reaction (PCR), which is consistent with the K2 serotype. PCR was also positive for the virulence-associated gene rmpA. Final diagnosis was invasive liver abscess syndrome caused by K2 serotype K. pneumonia. Although the primary liver abscess caused by K. pneumoniae with a hypermucoviscous phenotype is infrequently reported outside Southeast Asia, physicians should recognize this syndrome, and appropriate diagnosis and
Lee, Yangsoon; Kim, Bong-Soo; Chun, Jongsik; Yong, Ji Hyun; Lee, Yeong Seon; Yoo, Jung Sik; Yong, Dongeun; Hong, Seong Geun; D'Souza, Roshan; Thomson, Kenneth S; Lee, Kyungwon; Chong, Yunsop
We analyzed the whole genome sequence and resistome of the outbreak Klebsiella pneumoniae strain MP14 and compared it with those of K. pneumoniae carbapenemase- (KPC-) producing isolates that showed high similarity in the NCBI genome database. A KPC-2-producing multidrug-resistant (MDR) K. pneumoniae clinical isolate was obtained from a patient admitted to a Korean hospital in 2011. The strain MP14 was resistant to all tested β-lactams including monobactam, amikacin, levofloxacin, and cotrimoxazole, but susceptible to tigecycline and colistin. Resistome analysis showed the presence of β-lactamase genes including bla KPC-2, bla SHV-11, bla TEM-169, and bla OXA-9. MP14 also possessed aac(6'-)Ib, aadA2, and aph(3'-)Ia as aminoglycoside resistance-encoding genes, mph(A) for macrolides, oqxA and oqxB for quinolone, catA1 for phenicol, sul1 for sulfonamide, and dfrA12 for trimethoprim. Both SNP tree and cgMLST analysis showed the close relatedness with the KPC producers (KPNIH strains) isolated from an outbreak in the USA and colistin-resistant strains isolated in Italy. The plasmid-scaffold genes in plasmids pKpQil, pKpQil-IT, pKPN3, or pKPN-IT were identified in MP14, KPNIH, and Italian strains. The KPC-2-producing MDR K. pneumoniae ST258 stain isolated in Korea was highly clonally related with MDR K. pneumoniae strains from the USA and Italy. Global spread of KPC-producing K. pneumoniae is a worrying phenomenon.
Full Text Available We analyzed the whole genome sequence and resistome of the outbreak Klebsiella pneumoniae strain MP14 and compared it with those of K. pneumoniae carbapenemase- (KPC- producing isolates that showed high similarity in the NCBI genome database. A KPC-2-producing multidrug-resistant (MDR K. pneumoniae clinical isolate was obtained from a patient admitted to a Korean hospital in 2011. The strain MP14 was resistant to all tested β-lactams including monobactam, amikacin, levofloxacin, and cotrimoxazole, but susceptible to tigecycline and colistin. Resistome analysis showed the presence of β-lactamase genes including blaKPC-2, blaSHV-11, blaTEM-169, and blaOXA-9. MP14 also possessed aac(6′-Ib, aadA2, and aph(3′-Ia as aminoglycoside resistance-encoding genes, mph(A for macrolides, oqxA and oqxB for quinolone, catA1 for phenicol, sul1 for sulfonamide, and dfrA12 for trimethoprim. Both SNP tree and cgMLST analysis showed the close relatedness with the KPC producers (KPNIH strains isolated from an outbreak in the USA and colistin-resistant strains isolated in Italy. The plasmid-scaffold genes in plasmids pKpQil, pKpQil-IT, pKPN3, or pKPN-IT were identified in MP14, KPNIH, and Italian strains. The KPC-2-producing MDR K. pneumoniae ST258 stain isolated in Korea was highly clonally related with MDR K. pneumoniae strains from the USA and Italy. Global spread of KPC-producing K. pneumoniae is a worrying phenomenon.
Antimicrobial activity of essential oils of cultivated oregano (Origanum vulgare, sage (Salvia officinalis, and thyme (Thymus vulgaris against clinical isolates of Escherichia coli, Klebsiella oxytoca, and Klebsiella pneumoniae
Full Text Available Background: Oregano (Origanum vulgare, sage (Salvia officinalis, and thyme (Thymus vulgaris are aromatic plants with ornamental, culinary, and phytotherapeutic use all over the world. In Europe, they are traditionally used in the southern countries, particularly in the Mediterranean region. The antimicrobial activities of the essential oils (EOs derived from those plants have captured the attention of scientists as they could be used as alternatives to the increasing resistance of traditional antibiotics against pathogen infections. Therefore, significant interest in the cultivation of various aromatic and medicinal plants is recorded during the last years. However, to gain a proper and marketable chemotype various factors during the cultivation should be considered as the geographical morphology, climatic, and farming conditions. In this frame, we have studied the antimicrobial efficiency of the EOs from oregano, sage, and thyme cultivated under different conditions in a region of NE Greece in comparison to the data available in literature. Methods: Plants were purchased from a certified supplier, planted, and cultivated in an experimental field under different conditions and harvested after 9 months. EOs were extracted by using a Clevenger apparatus and tested for their antibacterial properties (Minimum inhibitory concentration – MIC against clinical isolates of multidrug resistant Escherichia coli (n=27, Klebsiella oxytoca (n=7, and Klebsiella pneumoniae (n=16 strains by using the broth microdilution assay. Results: Our results showed that the most sensitive organism was K. oxytoca with a mean value of MIC of 0.9 µg/mL for oregano EOs and 8.1 µg/mL for thyme. The second most sensitive strain was K. pneumoniae with mean MIC values of 9.5 µg/mL for thyme and 73.5 µg/mL for oregano EOs. E. coli strains were among the most resistant to EOs antimicrobial action as the observed MICs were 24.8–28.6 µg/mL for thyme and above 125 µg/mL for
Antimicrobial activity of essential oils of cultivated oregano (Origanum vulgare), sage (Salvia officinalis), and thyme (Thymus vulgaris) against clinical isolates of Escherichia coli, Klebsiella oxytoca, and Klebsiella pneumoniae.
Fournomiti, Maria; Kimbaris, Athanasios; Mantzourani, Ioanna; Plessas, Stavros; Theodoridou, Irene; Papaemmanouil, Virginia; Kapsiotis, Ioannis; Panopoulou, Maria; Stavropoulou, Elisavet; Bezirtzoglou, Eugenia E; Alexopoulos, Athanasios
Oregano (Origanum vulgare), sage (Salvia officinalis), and thyme (Thymus vulgaris) are aromatic plants with ornamental, culinary, and phytotherapeutic use all over the world. In Europe, they are traditionally used in the southern countries, particularly in the Mediterranean region. The antimicrobial activities of the essential oils (EOs) derived from those plants have captured the attention of scientists as they could be used as alternatives to the increasing resistance of traditional antibiotics against pathogen infections. Therefore, significant interest in the cultivation of various aromatic and medicinal plants is recorded during the last years. However, to gain a proper and marketable chemotype various factors during the cultivation should be considered as the geographical morphology, climatic, and farming conditions. In this frame, we have studied the antimicrobial efficiency of the EOs from oregano, sage, and thyme cultivated under different conditions in a region of NE Greece in comparison to the data available in literature. Plants were purchased from a certified supplier, planted, and cultivated in an experimental field under different conditions and harvested after 9 months. EOs were extracted by using a Clevenger apparatus and tested for their antibacterial properties (Minimum inhibitory concentration - MIC) against clinical isolates of multidrug resistant Escherichia coli (n=27), Klebsiella oxytoca (n=7), and Klebsiella pneumoniae (n=16) strains by using the broth microdilution assay. Our results showed that the most sensitive organism was K. oxytoca with a mean value of MIC of 0.9 µg/mL for oregano EOs and 8.1 µg/mL for thyme. The second most sensitive strain was K. pneumoniae with mean MIC values of 9.5 µg/mL for thyme and 73.5 µg/mL for oregano EOs. E. coli strains were among the most resistant to EOs antimicrobial action as the observed MICs were 24.8-28.6 µg/mL for thyme and above 125 µg/mL for thyme and sage. Most efficient were the EOs
Antimicrobial activity of essential oils of cultivated oregano (Origanum vulgare), sage (Salvia officinalis), and thyme (Thymus vulgaris) against clinical isolates of Escherichia coli, Klebsiella oxytoca, and Klebsiella pneumoniae
Fournomiti, Maria; Kimbaris, Athanasios; Mantzourani, Ioanna; Plessas, Stavros; Theodoridou, Irene; Papaemmanouil, Virginia; Kapsiotis, Ioannis; Panopoulou, Maria; Stavropoulou, Elisavet; Bezirtzoglou, Eugenia E.; Alexopoulos, Athanasios
Background Oregano (Origanum vulgare), sage (Salvia officinalis), and thyme (Thymus vulgaris) are aromatic plants with ornamental, culinary, and phytotherapeutic use all over the world. In Europe, they are traditionally used in the southern countries, particularly in the Mediterranean region. The antimicrobial activities of the essential oils (EOs) derived from those plants have captured the attention of scientists as they could be used as alternatives to the increasing resistance of traditional antibiotics against pathogen infections. Therefore, significant interest in the cultivation of various aromatic and medicinal plants is recorded during the last years. However, to gain a proper and marketable chemotype various factors during the cultivation should be considered as the geographical morphology, climatic, and farming conditions. In this frame, we have studied the antimicrobial efficiency of the EOs from oregano, sage, and thyme cultivated under different conditions in a region of NE Greece in comparison to the data available in literature. Methods Plants were purchased from a certified supplier, planted, and cultivated in an experimental field under different conditions and harvested after 9 months. EOs were extracted by using a Clevenger apparatus and tested for their antibacterial properties (Minimum inhibitory concentration – MIC) against clinical isolates of multidrug resistant Escherichia coli (n=27), Klebsiella oxytoca (n=7), and Klebsiella pneumoniae (n=16) strains by using the broth microdilution assay. Results Our results showed that the most sensitive organism was K. oxytoca with a mean value of MIC of 0.9 µg/mL for oregano EOs and 8.1 µg/mL for thyme. The second most sensitive strain was K. pneumoniae with mean MIC values of 9.5 µg/mL for thyme and 73.5 µg/mL for oregano EOs. E. coli strains were among the most resistant to EOs antimicrobial action as the observed MICs were 24.8–28.6 µg/mL for thyme and above 125 µg/mL for thyme and sage
Mahmoudi, Shima; Pourakbari, Babak; Rahbarimanesh, Aliakbar; Abdolsalehi, Mohammad Reza; Ghadiri, Keyghobad; Mamishi, Setareh
Klebsiella pneumoniae is a common cause of nosocomial infections; however, there is limited information in Iran regarding nosocomial outbreaks due to extended-spectrum β-lactamase (ESBL) producing K pneumoniae strains, particularly using molecular methods. The present study focused on the molecular mechanism of ESBL resistance and genetic relatedness in K. pneumoniae isolates causing nosocomial infections in an Iranian referral hospital. This study was evaluated the antimicrobial resistance and molecular epidemiology of K. pneumoniae causing nosocomial infections between October 2013 and March 2014. The ESBL detection was carried out for all the isolates by the CLSI method and PCR was carried out for the detection of the blaSHV, blaTEM, and blaCTX-M genes among ESBL-producing K. pneumonia. Molecular typing of the K. pneumoniae was performed using random amplification of polymorphic DNA-polymerase chain reaction (RAPD-PCR). A total of 30 isolates of K. pneumoniae were used for epidemiological analysis. High rates of resistance to cefotaxime (n=29, 97%), cefazolin (n=29, 97%), cefepime (n=25, 83%) and gentamicin (n=23, 77%) were observed. A total of 29 strains (97%) produced ESBLs. The frequency of blaSHV, blaCTX-M and blaTEM genes among these isolates were 83% (n=25), 70% (n=21) and 57% (n=17), respectively. Surprisingly 11 isolated (37%) carried blaSHV, blaCTX-M and blaTEM genes simultaneously. Moreover, the concurrent presence of "blaSHV and blaCTX-M" and "blaSHV and blaTEM" was seen in 8 (27%) and 4 (13%) isolates, respectively. RAPD-PCR analyses revealed that K. pneumoniae isolates belonged to 2 RAPD-PCR types among which one cluster counted for 28 isolates. To our knowledge this is the first published report of nosocomial outbreak of ESBL-producing K. pneumoniae in children in Iran. Although the epidemiology of nosocomial infections with ESBL-producing organisms has not yet been explored in depth in Iran, our findings suggest that ESBL-producing organisms are
Jonsson, Anna-Karin; Larsson, Anders; Tängdén, Thomas; Melhus, Åsa; Lannergård, Anders
Background: Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae is an emerging therapeutic challenge, especially in the treatment of urinary tract infections. Following an outbreak of CTX-M-15 Klebsiella pneumoniae in Uppsala, Sweden, an orphan drug trial on IgY chicken antibodies was undertaken in an attempt to eradicate faecal carriage of ESBL-producing K. pneumoniae and Escherichia coli.Methods: Hens were immunised with epitopes from freeze-dried, whole-cell bacteria (ESBL...
Skalweit, Marion J; Li, Mei
Genetic screening of Pseudomonas aeruginosa (PSDA) and Acinetobacter baumannii (ACB) reveals genes that confer increased susceptibility to β-lactams when disrupted, suggesting novel drug targets. One such target is lytic transglycosylase. Bulgecin A (BlgA) is a natural product of Pseudomonas mesoacidophila and a lytic transglycosolase inhibitor that works synergistically with β-lactams targeting PBP3 for Enterobacteriaceae. BlgA also weakly inhibits di-Zn 2+ metallo-β-lactamases like L1 of Stenotrophomonas maltophilia . We hypothesized that because of its unique mechanism of action, BlgA could restore susceptibility to carbapenems in carbapenem-resistant PSDA (CR-PSDA) and carbapenem-resistant ACB, as well as ACB resistant to sulbactam. A BlgA-containing extract was prepared using a previously published protocol. CR-PSDA clinical isolates demonstrating a variety of carbapenem resistance mechanisms (VIM-2 carbapenemases, efflux mechanisms, and AmpC producer expression) were characterized with agar dilution minimum inhibitory concentration (MIC) testing and polymerase chain reaction. Growth curves using these strains were prepared using meropenem, BlgA extract, and meropenem plus BlgA extract. A concentrated Blg A extract combined with low concentrations of meropenem, was able to inhibit the growth of clinical strains of CR-PSDA for strains that had meropenem MICs ≥8 mg/L by agar dilution, and a clinical strain of an OXA-24 producing ACB that had a meropenem MIC >32 mg/L and intermediate ampicillin/sulbactam susceptibility. Similar experiments were conducted on a TEM-1 producing ACB strain resistant to sulbactam. BlgA with ampicillin/sulbactam inhibited the growth of this organism. As in Enterobacteriaceae, BlgA appears to restore the efficacy of meropenem in suppressing the growth of CR-PSDA and carbapenem-resistant ACB strains with a variety of common carbapenem resistance mechanisms. BlgA extract also inhibits VIM-2 β-lactamase in vitro. BlgA may prove to be
Full Text Available Genome-wide transcription start site (TSS profiles of the enterobacteria Escherichia coli and Klebsiella pneumoniae were experimentally determined through modified 5' RACE followed by deep sequencing of intact primary mRNA. This identified 3,746 and 3,143 TSSs for E. coli and K. pneumoniae, respectively. Experimentally determined TSSs were then used to define promoter regions and 5' UTRs upstream of coding genes. Comparative analysis of these regulatory elements revealed the use of multiple TSSs, identical sequence motifs of promoter and Shine-Dalgarno sequence, reflecting conserved gene expression apparatuses between the two species. In both species, over 70% of primary transcripts were expressed from operons having orthologous genes during exponential growth. However, expressed orthologous genes in E. coli and K. pneumoniae showed a strikingly different organization of upstream regulatory regions with only 20% identical promoters with TSSs in both species. Over 40% of promoters had TSSs identified in only one species, despite conserved promoter sequences existing in the other species. 662 conserved promoters having TSSs in both species resulted in the same number of comparable 5' UTR pairs, and that regulatory element was found to be the most variant region in sequence among promoter, 5' UTR, and ORF. In K. pneumoniae, 48 sRNAs were predicted and 36 of them were expressed during exponential growth. Among them, 34 orthologous sRNAs between two species were analyzed in depth, and the analysis showed that many sRNAs of K. pneumoniae, including pleiotropic sRNAs such as rprA, arcZ, and sgrS, may work in the same way as in E. coli. These results reveal a new dimension of comparative genomics such that a comparison of two genomes needs to be comprehensive over all levels of genome organization.
Schroll, C.; Barken, Kim Bundvig; Krogfelt, K.A.
nosocomial infections. Most clinical K. pneumoniae isolates express two types of fimbrial adhesins, type 1 fimbriae and type 3 fimbriae. In this study, we characterized the role of type 1 and type 3 fimbriae in K. pneumoniae biofilm formation. Results: Isogenic fimbriae mutants of the clinical K. pneumoniae...... of planktonic cells. Type 1 fimbriae did not influence biofilm formation and the expression of type 1 fimbriae was found to be down-regulated in biofilm forming cells. In contrast, expression of type 3 fimbriae was found to strongly promote biofilm formation. Conclusion: By use of well defined isogenic mutants...... we found that type 3 fimbriae, but not type 1 fimbriae, strongly promote biofilm formation in K. pneumoniae C3091. As the vast majority of clinical K. pneumoniae isolates express type 3 fimbriae, this fimbrial adhesin may play a significant role in development of catheter associated K. pneumoniae...
Dautzenberg, M J D; Haverkate, M R; Bonten, M J M; Bootsma, M C J
Objectives Observational studies have suggested that Escherichia coli sequence type (ST) 131 and Klebsiella pneumoniae ST258 have hyperendemic properties. This would be obvious from continuously high incidence and/or prevalence of carriage or infection with these bacteria in specific patient populations. Hyperendemicity could result from increased transmissibility, longer duration of infectiousness, and/or higher pathogenic potential as compared with other lineages of the same species. The aim of our research is to quantitatively estimate these critical parameters for E. coli ST131 and K. pneumoniae ST258, in order to investigate whether E. coli ST131 and K. pneumoniae ST258 are truly hyperendemic clones. Primary outcome measures A systematic literature search was performed to assess the evidence of transmissibility, duration of infectiousness, and pathogenicity for E. coli ST131 and K. pneumoniae ST258. Meta-regression was performed to quantify these characteristics. Results The systematic literature search yielded 639 articles, of which 19 data sources provided information on transmissibility (E. coli ST131 n=9; K. pneumoniae ST258 n=10)), 2 on duration of infectiousness (E. coli ST131 n=2), and 324 on pathogenicity (E. coli ST131 n=285; K. pneumoniae ST258 n=39). Available data on duration of carriage and on transmissibility were insufficient for quantitative assessment. In multivariable meta-regression E. coli isolates causing infection were associated with ST131, compared to isolates only causing colonisation, suggesting that E. coli ST131 can be considered more pathogenic than non-ST131 isolates. Date of isolation, location and resistance mechanism also influenced the prevalence of ST131. E. coli ST131 was 3.2 (95% CI 2.0 to 5.0) times more pathogenic than non-ST131. For K. pneumoniae ST258 there were not enough data for meta-regression assessing the influence of colonisation versus infection on ST258 prevalence. Conclusions With the currently available data
Strahilevitz, Jacob; Engelstein, Dalia; Adler, Amos; Temper, Violeta; Moses, Allon E.; Block, Colin; Robicsek, Ari
Clinical isolates of Klebsiella pneumoniae and Enterobacter spp. collected from 1990 through 2005 at a tertiary care center were studied for qnr genes. Isolates bearing these genes emerged in the mid-1990s, coinciding with the time of a rapid increase in fluoroquinolone resistance. Sixty percent of these isolates were ciprofloxacin susceptible by CLSI breakpoints. PMID:17526754
I.A.J.M. Bakker-Woudenberg (Irma); M.T. ten Kate (Marian); W.H.F. Goessens (Wil); J.W. Mouton (Johan)
textabstractThe pharmacokinetic/pharmacodynamic (PK/PD) indices that define the therapeutic effect of the betalactam ceftazidime in a rat model of Klebsiella pneumoniae lung infection were investigated in relation to treatment duration and treatment endpoint. Treatment was started 24 h after
Arcondeguy, T.; van Heeswijk, W.C.; Merrick, M.
In Klebsiella pneumoniae, nitrogen fixation (nif) genes are regulated in response to fixed nitrogen and oxygen. The activity of the nif-specific transcriptional activator NifA is modulated by NifL, which mediates both oxygen and nitrogen control. The signal transduction protein GlnK is required to
Bosch, Thijs; Lutgens, Suzanne P M; Hermans, Mirjam H A; Wever, Peter C; Schneeberger, Peter M.; Renders, Nicole H M; Leenders, Alexander C. A. P.; Kluytmans, Jan A. J. W.; Schoffelen, Annelot F; Notermans, Daan; Witteveen, Sandra; Bathoorn, Erik; Schouls, Leo M.
In the Netherlands, the number of cases of infection with New Delhi metallo-beta-lactamase (NDM)-positive Enterobacteriaceae is low. Here, we report an outbreak of NDM-1-producing Klebsiella pneumoniae infection in a Dutch hospital with interspecies transfer of the resistance plasmid and unexpected
Bosch, Thijs; Lutgens, Suzanne P M; Hermans, Mirjam H A; Wever, Peter C; Schneeberger, Peter M; Renders, Nicole H M; Leenders, Alexander C A P; Kluytmans, Jan A J W; Schoffelen, Annelot; Notermans, Daan; Witteveen, Sandra; Bathoorn, Erik; Schouls, Leo M
In the Netherlands, the number of cases of infection with New Delhi metallo-beta-lactamase (NDM)-positive Enterobacteriaceae is low. Here, we report an outbreak of NDM-1-producing Klebsiella pneumoniae infection in a Dutch hospital with interspecies transfer of the resistance plasmid and unexpected
Donk, C.F. van der; Beisser, P.S.; Hoogkamp-Korstanje, J.A.A.; Bruggeman, C.A.; Stobberingh, E.E.; Waar, K.; Vogels, W.H.; Bloembergen, P.; Beunders, A.J.; Rietra, P.; Hendrix, M.G.; Bijlmer, H.A.; Jongh, B.M. de; Hendriks, W.D.; Sturm, P.D.J.; Buiting, A.G.M.; Sabbe, L.J.; Trienekens, T.A.; Dessel, H. van
OBJECTIVES: We evaluated the changes in antibiotic resistance from 1998 to 2009 of Klebsiella pneumoniae isolated from the intensive care units (ICUs) and urology services of 14 Dutch hospitals and the consequences for empirical therapy. METHODS: Quantitative antibiotic susceptibility testing of K.
Fitzpatrick, Margaret; Zembower, Teresa; Malczynski, Michael; Qi, Chao; Bolon, Maureen K.
Optimal surveillance strategies for identifying patients colonized with and at risk for transmitting carbapenem-resistant Enterobacteriaceae (CRE) are urgently needed. We instituted an enhanced surveillance program for CRE that identified unrecognized CRE-colonized patients but failed to identify possible CRE transmissions. We also identified risk factors associated with transmitting CRE.
Clinical studies have reported that the occurrence of carbapenem-resistant E. coli is on the rise. This is of concern because carbapenem antibiotics are typically reserved for treating infections caused by bacteria resistant to other classes of antibiotics. Current literature st...
Mózes, Julianna; Ebrahimi, Fatemeh; Gorácz, Orsolya; Miszti, Cecília; Kardos, Gábor
This study investigated the molecular epidemiology of Acinetobacter baumannii in the University of Debrecen in relation to antibiotic consumption. Overall and ward-specific antibiotic consumption was measured by the number of defined daily doses (DDD) per 100 bed-days between 2002 and 2012. Consumption was analysed against the number of A. baumannii positive patients per 100 bed-days, number of isolates per positive sample, and proportion of carbapenem resistant A. baumannii, using time-series analysis. Altogether 160 A. baumannii isolates from different wards were collected and analysed. Carbapenemase genes bla(OXA-23-like), bla(OXA-24-like), bla(OXA-48-like), bla(OXA-51-like), bla(OXA-58-like) and integrons were sought by PCR. Relatedness of isolates was assessed by PFGE. Prevalence and carbapenem resistance of A. baumannii were statistically associated with carbapenem consumption. Prevalence data followed carbapenem usage with three quarterly lags (r = 0.51-0.53, Pcarbapenem consumption was associated with the carbapenem-susceptible cluster, as well as with the carbapenem-susceptible isolates in the cluster with variable susceptibility. Wards with high carbapenem usage almost exclusively harboured isolates from carbapenem-resistant clusters. All clusters were dominated by isolates of one or two wards, but most wards were represented in multiple clusters. Increases in prevalence and carbapenem resistance of A. baumannii were associated with usage of meropenem and ertapenem but not of imipenem, which led to the spread of multiple clones in the University. © 2014 The Authors.
Tommassen - van Boxtel, Ria; Wattel, Agnes A.; Arenas Busto, Jesus; Goessens, Wil H.F.; Tommassen, J
Although AmpC β-lactamases can barely degrade carbapenems, if at all, they can sequester them and prevent them from reaching their targets. Thus, carbapenem resistance in Escherichia coli and other Enterobacteriaceae can result from AmpC production and simultaneous reduction of antibiotic influx
Full Text Available The variability of carbapenem-resistant Pseudomonas aeruginosa strains (CRPA isolated from urine and respiratory samples in a large microbiological laboratory, serving several health care settings, and from effluents of two wastewater treatment plants (WWTP from the same region was assessed by PFGE typing and by resistance to 10 antibiotics. During the 12-month period altogether 213 carbapenem-resistant P. aeruginosa isolates were cultured and distributed into 65 pulsotypes and ten resistance profiles. For representatives of all 65 pulsotypes 49 different MLSTs were determined. Variability of clinical and environmental strains was comparable, 130 carbapenem-resistant P. aeruginosa obtained from 109 patients were distributed into 38 pulsotypes, while 83 isolates from WWTPs were classified into 31 pulsotypes. Only 9 pulsotypes were shared between two or more settings (hospital or WWTP. Ten MLST were determined for those prevalent pulsotypes, two of them (ST111 and ST235 are among most successful CRPA types worldwide. Clinical and environmental carbapenem-resistant P. aeruginosa strains differed in antibiotic resistance. The highest proportion of clinical isolates was resistant to piperacillin/tazobactam (52.3% and ceftazidime (42.3%. The highest proportion of environmental isolates was resistant to ceftazidime (37.1% and ciprofloxacin (35.5%. The majority of isolates was resistant only to imipenem and/or meropenem. Strains with additional resistances were distributed into nine different patterns. All of them included clinically relevant strains, while environmental strains showed only four additional different patterns.
Full Text Available The emergence and dissemination of carbapenem-resistant Escherichia coli (E. coli strains is a main risk for global public health, but little is known of carbapenemase producing E. coli in Henan, China. The study was undertaken to investigate the prevalence and mechanism of carbapenem-resistant E. coli strains in a hospital in Xinxiang, Henan, China, 2014. A total of 5 carbapenemase-producing E. coli strains were screened from 1014 isolates. We found that they were all resistant to meropenem and imipenem. Amikacin showed the best sensitivity, with gentamicin coming up next. The positive rate of blaNDM was 80% (4/5. The sequencing results showed that two isolates belonged to blaNDM-1 whereas other 2 isolates carried the blaNDM-5. Other carbapenemase genes including blaIMP, blaVIM, blaKPC and blaOXA-48 were not detected. The blaCTX-M-15, blaTEM-1, sul2, aad, and aac(6”–Ib–cr were also detected. MLST analysis showed that NDM-producing E. coli were sporadic. Conjugation test indicated blaNDM could be transferred. In conclusion, the blaNDM was the principal resistance mechanism of carbapenem-resistant E. coli in the hospital, Henan, China. Keywords: blaNDM, Carbapenem-resistant, Escherichia coli
Kizirgil, Ahmet; Demirdag, Kutbettin; Ozden, Mehmet; Bulut, Yasemin; Yakupogullari, Yusuf; Toraman, Zulal Asci
Extended spectrum beta-lactamases (ESBLs) usually associated with multiple drug resistance, including beta-lactam and non-beta-lactam antibiotics. This resistance can cause Limitation in the choice of drugs appropriate for using in clinical practice, especially in life-threatening infections. In this study we aimed to investigate in vitro activity of meropenem, ciprofloxacine and amikacin against ESBL-producing and non-producing blood isolates of Escherichia coli and Klebsiella pneumoniae strains. Fifty-eight E. coli (21 ESBL-producing, 37 non-ESBL producing) and 99 K. pneumoniae (54 ESBL-producing, 45 non-ESBL producing) strains were included in the study. The presence of ESBL was investigated by double disk synergy test and E-test methods. Antibiotic susceptibility test was done by microdilution method according to NCCLS guideline. In vitro susceptibilities of ESBL producing E. coli and K. pneumoniae strains were found as 100% for meropenem, 33.3% and 25.9% for ciprofloxacine, 94.5% and 83.3% for amikacin. It was observed that; meropenem was equally active agent in both ESBL-producing and non-producing strains, and its activity was not affected by ESBL production. Whereas amikacin activity was minimally affected and ciprofloxacine activity was markedly decreased by ESBL production. In conclusion, meropenem seems to be better choice of antibiotic should be used for ESBL positive life-threatening infections, because of remaining highest activity.
Antoinette A T P Brink
Full Text Available Genotyping of Klebsiella pneumoniae is indispensable for management of nosocomial infections, monitoring of emerging strains--including extended-spectrum beta-lactamase (ESBL producers-, and general epidemiology. Such objectives require a high-resolution genotyping method with a fixed scheme that allows (1 long-term retrospective and prospective assessment, (2 objective result readout and (3 library storage for database development and exchangeable results. We have developed a multiple-locus variable number tandem repeat analysis (MLVA using a single-tube fluorescently primed multiplex PCR for 8 Variable Number Tandem Repeats (VNTRs and automated fragment size analysis. The type allocation scheme was optimized using 224 K. pneumoniae clinical isolates, which yielded 101 MLVA types. The method was compared to the gold standard multilocus sequence typing (MLST using a subset of these clinical isolates (n = 95 and found to be highly concordant, with at least as high a resolution but with considerably less hands-on time. Our results position this MLVA scheme as an appropriate, high-throughput and relatively low-cost tool for K. pneumoniae epidemiology.
Diego B. Nóbrega
Full Text Available The objectives of this study were to isolate Klebsiella pneumoniae from different sources in three dairy cattle herds, to use the pulsed-field gel electrophoresis (PFGE to measure genotypic similarities between isolates within a dairy herd, to verify the production of extended-spectrum β-lactamases (ESBLs by the double-disk synergy test (DDST, and to use the PCR to detect the main ESBLs subgroups genes. Three dairy farms were selected based on previous mastitis outbreaks caused by K. pneumoniae. Milk samples were collected from lactating cows and from the bulk tank. Swabs were performed in different locations, including milking parlors, waiting room, soil, animal's hind limbs and rectum. K. pneumoniae was isolated from 27 cases of intramammary infections (IMI and from 41 swabs. For farm A isolates from IMI and bulk tank were considered of the same PGFE subtype. One isolate from a bulk tank, three from IMI cases and four from environmental samples were positive in the DDST test. All eight DDST positive isolates harbored the bla shv gene, one harbored the bla tem gene, and three harbored the bla ctx-m gene, including the bulk tank isolate. Our study confirms that ESBL producing bacteria is present in different locations in dairy farms, and may be responsible for IMI. The detection of ESBLs on dairy herds could be a major concern for both public and animal health.
Full Text Available OBJECTIVES: Septic pulmonary embolism caused by a Klebsiella (K. pneumoniae liver abscess is rare but can cause considerable morbidity and mortality. However, clinical information regarding this condition is limited. This study was conducted to elucidate the full disease spectrum to improve its diagnosis and treatment. METHOD: We reviewed the clinical characteristics, imaging findings, and clinical courses of 14 patients diagnosed with septic pulmonary embolism caused by a K. pneumoniae liver abscess over a period of 9 years. RESULTS: The two most prevalent symptoms were fever and shortness of breath. Computed tomography findings included a feeding vessel sign (79%, nodules with or without cavities (79%, pleural effusions (71%, peripheral wedge-shaped opacities (64%, patchy ground-glass opacities (50%, air bronchograms within a nodule (36%, consolidations (21%, halo signs (14%, and lung abscesses (14%. Nine (64% of the patients developed severe complications and required intensive care. According to follow-up chest radiography, the infiltrates and consolidations were resolved within two weeks, and the nodular opacities were resolved within one month. Two (14% patients died of septic shock; one patient had metastatic meningitis, and the other had metastatic pericarditis. CONCLUSION: The clinical presentations ranged from insidious illness with fever and respiratory symptoms to respiratory failure and septic shock. A broad spectrum of imaging findings, ranging from nodules to multiple consolidations, was detected. Septic pulmonary embolism caused by a K. pneumoniae liver abscess combined with the metastatic infection of other vital organs confers a poor prognosis.
Full Text Available Adequate detection of the production of carbapenemase in Enterobacteriaceae isolates is crucial for infection control measures and the appropriate choice of antimicrobial therapy. In this study, we investigated the frequency of false positive results for the detection of carbapenemases in carbapenemase-negative Escherichia coli and Klebsiella pneumoniae clinical isolates by the modified Hodge test (MHT. Three hundred and one E. coli and K. pneumoniae clinical isolates were investigated. All produced extended spectrum β-lactamases (ESBLs but were susceptible to carbapenems. Antimicrobial susceptibility testing was performed by the disk diffusion and agar dilution methods. The MHT was performed using the standard inoculum of test organisms recommended by the CLSI. Genes that encoded ESBLs and carbapenemases were identified by PCR and DNA sequencing. Among the 301 clinical isolates, none of the isolates conformed to the criteria for carbapenemase screening recommended by the CLSI. The susceptibility rates for imipenem, meropenem, and ertapenem all were 100.0%, 100.0%, and 100.0%, respectively. Of the 301 E. coli and K. pneumoniae isolates, none produced carbapenemase. The MHT gave a positive result for 3.3% (10/301 of the isolates. False positive results can occur when the MHT is used to detect carbapenemase in ESBL-producing isolates and clinical laboratories must be aware of this fact.
Romero-Alvarez, Daniel; Reyes, Jorge; Quezada, Viviana; Satán, Carolina; Cevallos, Nelson; Barrera, Sofía; Trueba, Gabriel; Escobar, Luis E; Villacís, José E
To describe a clinical case of Klebsiella pneumoniae harboring a New Delhi metallo-β-lactamase (NDM) plasmid in Ecuador and to present a map of reports of NDM isolates in South America. The modified Hodge test, carbapenem inactivation method, imipenem-EDTA disk method (synergy), and Rapidec Carba NP test were used to identify antibiotic resistance mechanisms. The presence of resistance genes was explored with a conjugation assay, and molecular confirmation of NDM was performed by PCR and DNA sequencing. Plasmid characterization was conducted by PCR-based replicon typing. A literature review was performed in Google Scholar and PubMed to identify reports from South America. An HIV-infected patient, who had never traveled abroad, developed a bloodstream infection caused by K. pneumoniae ST147 harboring the NDM-1 resistance gene in a plasmid from the IncA/C group. Local circulation of NDM has also been described in other South American countries, in particular in Colombia and Brazil, although published scientific records were not found for other countries. This report presents the first evidence of autochthonous circulation of the NDM-1 resistance gene harbored by an IncA/C plasmid isolated from a K. pneumoniae ST147 in Ecuador. Efforts should be implemented to monitor and characterize the spatial and temporal distribution of NDM in Ecuador and other countries of South America. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
de Gouvêa Erika
Full Text Available Abstract Background Infection with carbapenem-resistant Acinetobacter baumannii has been associated with high morbidity and mortality in solid organ transplant recipients. The main objective of this study was to assess the influence of carbapenem resistance and other potential risk factors on the outcome of A. baumannii infection after kidney and liver transplantation. Methods Retrospective study of a case series of A. baumannii infection among liver and renal transplant recipients. The primary outcome was death associated with A. baumannii infection. Multivariate logistic regression was used to assess the influence of carbapenem resistance and other covariates on the outcome. Results Forty-nine cases of A. baumannii infection affecting 24 kidney and 25 liver transplant recipients were studied. Eighteen cases (37% were caused by carbapenem-resistant isolates. There were 17 (35% deaths associated with A. baumannii infection. In unadjusted analysis, liver transplantation (p = 0.003, acquisition in intensive care unit (p = 0.001, extra-urinary site of infection (p A. baumannii infection. The number of deaths associated with A. baumannii infection was higher among patients infected with carbapenem-resistant isolates, but the difference was not significant (p = 0.28. In multivariate analysis, the risk of A. baumannii-associated mortality was higher in patients with infection acquired in the intensive care unit (odds ratio [OR] = 34.8, p = 0.01 and on mechanical ventilation (OR = 15.2, p = 0.04. Appropriate empiric antimicrobial therapy was associated with significantly lower mortality (OR = 0.04, p = 0.03, but carbapenem resistance had no impact on it (OR = 0.73, p = 0.70. Conclusion These findings suggest that A. baumannii-associated mortality among liver and kidney transplant recipients is influenced by baseline clinical severity and by the early start of appropriate therapy, but not by carbapenem
Avaliação fenotípica da enzima Klebsiella pneumoniae carbapenemase (KPC em Enterobacteriaceae de ambiente hospitalar Phenotypic research on Klebsiella pneumoniae carbapenemase (KPC enzyme in Enterobacteriaceae from hospitals
Full Text Available INTRODUÇÃO E OBJETIVO: A resistência bacteriana é problema frequente e importante no ambiente nosocomial. Nesse contexto, várias bactérias apresentam habilidade de desenvolver mecanismos de resistência enzimáticos, destacando-se as Enterobacteriaceae. Nesta família de microrganismos, a produção de Klebsiella pneumoniae carbapenemase (KPC é um mecanismo emergente, o que justifica sua vigilância constante. MATERIAL E MÉTODO: Este trabalho pesquisou o fenótipo de KPC em 30 isolados clínicos de enterobactérias resistentes a cefalosporinas de terceira geração e sensibilidade diminuída a carbapenem oriundas de dois hospitais (em Porto Alegre e na Grande Porto Alegre, RS. Realizou-se discodifusão com imipenem, meropenem e ertapenem, e 14 cepas com halo INTRODUCTION AND OBJECTIVE: Bacterial resistance is a frequent and important problem in the nosocomial environment. In this context, several bacteria have the ability to develop mechanisms of enzymatic resistance, mainly Enterobacteriaceae. In this family of microorganisms, the production of Klebsiella pneumoniae carbapenemase (KPC is an emerging mechanism, which should be under constant observation. MATERIAL AND METHOD: This study investigated the phenotype of KPC in 30 clinical isolates of Enterobacteriaceae resistant to third generation cephalosporin and carbapenem from two hospitals (Porto Alegre city and Porto Alegre, RS. It was performed disk diffusion method with imipenem, meropenem and ertapenem. Additionally, 14 strains with halo < 22 mm for the last antimicrobial agent underwent modified Hodge test. RESULTS: No sample showed carbapenemase (Hodge negative. DISCUSSION: Despite the fact there was no carbapenemase, resistance to carbapenems is possibly attributed to the presence of beta-lactamases AmpC and/or ESBL associated with changes in the permeability of porin channels. CONCLUSION: Given the emerging nature of KPC, it is important to trace it in Enterobacteriaceae
Pulzová, L.; Navrátilová, Lucie; Comor, L.
Roč. 23, č. 4 (2017), s. 413-420 ISSN 1076-6294 Institutional support: RVO:61389030 Keywords : drug resistance * efflux pumps * influx * Klebsiella * porin Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 2.306, year: 2016
Alcántar-Curiel, María Dolores; García-Torres, Luis Francisco; González-Chávez, María Inés; Morfín-Otero, Rayo; Gayosso-Vázquez, Catalina; Jarillo-Quijada, Ma Dolores; Fernández-Vázquez, José Luis; Giono-Cerezo, Silvia; Rodríguez-Noriega, Eduardo; Santos-Preciado, José Ignacio
Acinetobacter baumannii is an emerging pathogen worldwide that is most commonly associated with nosocomial infections and multi-drug resistance. In the present study we determined the mechanisms of carbapenem resistance and clonal diversity of A. baumannii nosocomial isolates in Hospital Civil de Guadalajara, Mexico. A total of 303 clinical isolates of A. baumannii identified during a period expanding from 2004-2011 were analyzed for carbapenem resistance using several microbiological and molecular methods. Clonal relatedness of these isolates was determined using pulsed-field gel electrophoresis. Of the 303 isolates, 84% were resistant to meropenem, 71.3% to imipenem and 78.3% the resistant isolates were positive for metallo-β-lactamases as determined by the phenotypic assay. In addition, 49.6% of carbapenem-intermediate or -resistant isolates carried the blaOXA-72 gene and 1.2% carried the blaVIM-1 gene. Efflux pump phenotype was responsible for reduced susceptibility to meropenem in 14.5% and to imipenem in 31.6% of the resistant isolates, respectively in the presence of the efflux pump inhibitor, carbonyl cyanide 3-chlorophenylhydrazone. Strains representing different carbapenem-resistant patterns exhibited reduced expression of 22, 29, 33, and 43 kDa OMPs. Among the bacterial collection studied, 48 different clones were identified, two of which were predominant and persistently transmitted. Carbapenemase production in combination with efflux pump expression, reduction in OMPs expression and the cross-transmission of clones appear to be major contributors to the high frequency of carbapenem-resistance observed in A. baumannii. To our knowledge, this is the first study to define the molecular mechanisms associated with carbapenem-resistance in A. baumannii in Mexico. Copyright © 2014 IMSS. Published by Elsevier Inc. All rights reserved.
Mohanty, Srujana; Maurya, Vijeta; Gaind, Rajni; Deb, Monorama
Pseudomonas aeruginosa and Acinetobcter spp. are important nosocomial pathogens and carbapenem resistance is an emerging threat. Therapeutic options for infections with these isolates include colistin. This study was conducted to determine the prevalence of carbapenem resistance in P. aeruginosa and Acinetobacter spp. bloodstream isolates, phenotypically characterize the resistance mechanisms and evaluate the in vitro activity of colistin. Consecutive 145 (95 P.aeruginosa and 50 Acinetobacter spp.) non-repeat isolates were included. Antibiotic susceptibility testing was performed per CLSI guidelines. MIC for carbapenems and colistin was performed using Etest. Isolates showing reduced susceptibility or resistance to the carbapenems were tested for metallo-β-lactamase (MBL) production using imipenem-EDTA combined disk and MBL Etest. Carbapenem resistance was observed in 40% P. aeruginosa and 66.0% Acinetobacter spp. Carbapenem-resistant (CA-R) isolates were significantly (p carbapenem-susceptible isolates. Approximately half of the CA-R strains were multidrug-resistant, and 3.1-5.5% were resistant to all antibiotics tested. MBL was found in 76.3% and 69.7% of the P. aeruginosa and Acinetobacter spp., respectively. Colistin resistance was observed in three (6.0%) Acinetobacter isolates and eight (8.4%) P. aeruginosa. MIC50 for carbapenems were two to four times higher for MBL-positive compared to MBL-negative isolates, but no difference was seen in MIC for colistin. Carbapenem resistance was observed to be mediated by MBL in a considerable number of isolates. Colistin is an alternative for infections caused by CA-R isolates; however, MIC testing should be performed whenever clinical use of colistin is considered.
Huang, Weihua; Wang, Guiqing; Sebra, Robert; Zhuge, Jian; Yin, Changhong; Aguero-Rosenfeld, Maria E.; Schuetz, Audrey N.; Dimitrova, Nevenka; Fallon, John T.
The extended-spectrum-β-lactamase (ESBL)- and Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae represent serious and urgent threats to public health. In a retrospective study of multidrug-resistant K. pneumoniae, we identified three clinical isolates, CN1, CR14, and NY9, carrying both blaCTX-M and blaKPC genes. The complete genomes of these three K. pneumoniae isolates were de novo assembled by using both short- and long-read whole-genome sequencing. In CR14 and NY9, bla...
Hicks, Katherine A.; Ealick, Steven E.
HpxW from the ubiquitous pathogen
Barfod, Toke Seierøe; Wibroe, Elisabeth Arnberg; Braüner, Julie Vestergaard
of the percentage of bacterial isolates that are covered by the most commonly used antibiotics in the area of Copenhagen and to provide clinicians with a practical tool to help chose the right antimicrobial treatment for their patients. METHODS: We conducted a study of all bacteria isolates tested for antimicrobial...... susceptibility at Hvidovre Hospital, Denmark, from 2004 to 2008. Due to a suspected rise in resistance in Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae after this period, updated data for these bacteria are shown for selected antibiotics until 2014. The department receives samples from...... in resistance patterns were noted up to 2014. CONCLUSIONS: A comprehensive and manageable inventory of the resistance patterns of the major bacteria covering the 2004-2008 period is presented. Clinicians are encouraged to use the pocket-size table as guidance when choosing antibiotic treatment. FUNDING: none...
Barfod, Toke Seierøe; Wibroe, Elisabeth Arnberg; Braüner, Julie Vestergaard
in resistance patterns were noted up to 2014. CONCLUSIONS: A comprehensive and manageable inventory of the resistance patterns of the major bacteria covering the 2004-2008 period is presented. Clinicians are encouraged to use the pocket-size table as guidance when choosing antibiotic treatment. FUNDING: none......INTRODUCTION: Development of antimicrobial resistance is an ongoing and increasing problem. To provide the best possible treatment for patients it is crucial that clinicians are aware of the local antimicrobial susceptibility patterns. The aim of this study was to present an overview...... susceptibility at Hvidovre Hospital, Denmark, from 2004 to 2008. Due to a suspected rise in resistance in Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae after this period, updated data for these bacteria are shown for selected antibiotics until 2014. The department receives samples from...
Fadeeva, Maria S; Yakovtseva, Evgenia A; Belevich, Galina A; Bertsova, Yulia V; Bogachev, Alexander V
The expression of genes encoding sodium-translocating NADH:quinone oxidoreductase (Na(+)-NQR) was studied in the marine bacterium Vibrio harveyi and in the enterobacterium Klebsiella pneumoniae. It has been shown that such parameters as NaCl concentration, pH value, and presence of an uncoupler in the growth media do not influence significantly the level of nqr expression. However, nqr expression depends on the growth substrates used by these bacteria. Na(+)-NQR is highly repressed in V. harveyi during anaerobic growth, and nqr expression is modulated by electron acceptors and values of their redox potentials. The latter effect was shown to be independent of the ArcAB regulatory system.
Zhang, Hui; Yang, Qiwen; Liao, Kang; Ni, Yuxing; Yu, Yunsong; Hu, Bijie; Sun, Ziyong; Huang, Wenxiang; Wang, Yong; Wu, Anhua; Feng, Xianju; Luo, Yanping; Chu, Yunzhuo; Chen, Shulan; Cao, Bin; Su, Jianrong; Duan, Qiong; Zhang, Shufang; Shao, Haifeng; Kong, Haishen; Gui, Bingdong; Hu, Zhidong; Badal, Robert; Xu, Yingchun
To evaluate in vitro susceptibilities of aerobic and facultative Gram-negative bacterial (GNB) isolates from intra-abdominal infections (IAIs) to 12 selected antimicrobials in Chinese hospitals from 2012 to 2014. Hospital acquired (HA) and community acquired (CA) IAIs were collected from 21 centers in 16 Chinese cities. Extended spectrum beta-lactamase (ESBL) status and antimicrobial susceptibilities were determined at a central laboratory using CLSI broth microdilution and interpretive standards. From all isolated strains the Enterobacteriaceae (81.1%) Escherichia coli accounted for 45.4% and Klebsiella pneumoniae for 20.1%, followed by Enterobacter cloacae (5.2%), Proteus mirabilis (2.1%), Citrobacter freundii (1.8%), Enterobacter aerogenes (1.8%), Klebsiella oxytoca (1.4%), Morganella morganii (1.2%), Serratia marcescens (0.7%), Citrobacter koseri (0.3%), Proteus vulgaris (0.3%) and others (1.0%). Non- Enterobacteriaceae (18.9%) included Pseudomonas aeruginosa (9.8%), Acinetobacter baumannii (6.7%), Stenotrophomonas maltophilia (0.9%), Aeromonas hydrophila (0.4%) and others (1.1%). ESBL-screen positive Escherichia coli isolates (ESBL+) showed a decreasing trend from 67.5% in 2012 to 58.9% in 2014 of all Escherichia coli isolates and the percentage of ESBL+ Klebsiella pneumoniae isolates also decreased from 2012 through 2014 (40.4% to 26.6%), which was due to reduced percentages of ESBL+ isolates in HA IAIs for both bacteria. The overall susceptibilities of all 5160 IAI isolates were 87.53% to amikacin (AMK), 78.12% to piperacillin-tazobactam (TZP) 81.41% to imipenem (IMP) and 73.12% to ertapenem (ETP). The susceptibility of ESBL-screen positive Escherichia coli strains was 96.77%-98.8% to IPM, 91.26%-93.16% to ETP, 89.48%-92.75% to AMK and 84.86%-89.34% to TZP, while ESBL-screen positive Klebsiella pneumoniae strains were 70.56%-80.15% susceptible to ETP, 80.0%-87.5% to IPM, 83.82%-87.06% to AMK and 63.53%-68.38% to TZP within the three year study
Purighalla, Swathi; Esakimuthu, Sarita; Reddy, Mallika; Varghese, George K; Richard, Vijay S; Sambandamurthy, Vasan K
The purpose of this study was to evaluate the discriminatory power of two DNA-based technique and a protein-based technique for the typing of nosocomial isolates of Klebsiella pneumoniae. A second objective was to determine the antimicrobial susceptibility pattern and characterise the presence of genes encoding extended-spectrum beta-lactamases (ESBLs) and carbapenemases. Forty-six K. pneumoniae isolates from patients with bloodstream infections at a tertiary care hospital in India between December 2014 and December 2015 were studied. All isolates were typed using enterobacterial repetitive intergenic consensus sequence-polymerase chain reaction (ERIC-PCR), randomly amplified polymorphic DNA (RAPD) analysis and matrix-assisted laser desorption ionisation time-of-flight (MALDI-TOF) mass spectrometry. Antimicrobial susceptibility profiles and ESBLs were detected using the BD Phoenix system. The types of ESBL and carbapenemase genes present were detected using PCR. Isolates were subtyped into 31, 30 and 33 distinct genotypes by ERIC-PCR, RAPD and MALDI-TOF, respectively. Several isolates displaying identical DNA fingerprints were binned into different branches based on their proteomic fingerprint. Antimicrobial susceptibility tests revealed that 33/46 strains were multidrug resistant (MDR); a majority of the strains (83%) were sensitive to colistin. PCR-based analysis demonstrated 19 strains to harbour two or more ESBL and carbapenemase genes. ERIC-PCR was the most reproducible method for typing K. pneumoniae isolates and could not be substituted by MALDI-TOF for clonality analysis. A high degree of genetic diversity and the presence of MDR genes highlight the challenges in treating K. pneumoniae-associated infections.
Full Text Available Purpose: The purpose of this study was to evaluate the discriminatory power of two DNA-based technique and a protein-based technique for the typing of nosocomial isolates of Klebsiella pneumoniae. A second objective was to determine the antimicrobial susceptibility pattern and characterise the presence of genes encoding extended-spectrum beta-lactamases (ESBLs and carbapenemases. Materials and Methods: Forty-six K. pneumoniae isolates from patients with bloodstream infections at a tertiary care hospital in India between December 2014 and December 2015 were studied. All isolates were typed using enterobacterial repetitive intergenic consensus sequence-polymerase chain reaction (ERIC-PCR, randomly amplified polymorphic DNA (RAPD analysis and matrix-assisted laser desorption ionisation time-of-flight (MALDI-TOF mass spectrometry. Antimicrobial susceptibility profiles and ESBLs were detected using the BD Phoenix system. The types of ESBL and carbapenemase genes present were detected using PCR. Results: Isolates were subtyped into 31, 30 and 33 distinct genotypes by ERIC-PCR, RAPD and MALDI-TOF, respectively. Several isolates displaying identical DNA fingerprints were binned into different branches based on their proteomic fingerprint. Antimicrobial susceptibility tests revealed that 33/46 strains were multidrug resistant (MDR; a majority of the strains (83% were sensitive to colistin. PCR-based analysis demonstrated 19 strains to harbour two or more ESBL and carbapenemase genes. Conclusion: ERIC-PCR was the most reproducible method for typing K. pneumoniae isolates and could not be substituted by MALDI-TOF for clonality analysis. A high degree of genetic diversity and the presence of MDR genes highlight the challenges in treating K. pneumoniae-associated infections.
Osman, Kamelia M; Hassan, Hany M; Orabi, Ahmed; Abdelhafez, Ahmed S T
Studies on the prevalence and virulence genes of Klebsiella mastitis pathogens in a buffalo population are undocumented. Also, the association of rmpA kfu, uge, magA, Aerobactin, K1 and K2 virulent factors with K. pneumoniae buffalo, and cow mastitis is unreported. The virulence of K. pneumoniae was evaluated through both phenotypic and molecular assays. In vivo virulence was assessed by the Vero cell cytotoxicity, suckling mouse assay and mice lethality test. Antimicrobial susceptibility was tested by disk diffusion method. The 45 K. pneumoniae isolates from buffalo (n = 10/232) and cow (n = 35/293) milk were isolated (45/525; 8.6%) and screened via PCR for seven virulence genes encoding uridine diphosphate galactose 4 epimerase encoding gene responsible for capsule and smooth lipopolysaccharide synthesis (uge), siderophores (kfu and aerobactin), protectines or invasins (rmpA and magA), and the capsule and hypermucoviscosity (K1 and K2). The most common virulence genes were rmpA, kfu, uge, and magA (77.8% each). Aerobactin and K1 genes were found at medium rates of 66.7% each and K2 (55.6%). The Vero cell cytotoxicity and LD (50) in mice were found in 100% of isolates. A multidrug resistance pattern was observed for 40% of the antimicrobials. The distribution of virulence profiles indicate a role of rmpA, kfu, uge, magA, Aerobactin, and K1 and K2 in pathogenicity of K. pneumoniae in udder infections and invasiveness, and constitutes a threat for vulnerable animals, even more if they are in combination with antibiotic resistance.
Li, Feng; Yin, Changji; Sun, Liming; Li, Yuanxiu; Guo, Xuewu; Song, Hao
Microbial fuel cell (MFC) is an eco-friendly bio-electrochemical sys-tem that uses microorganism as biocatalyst to convert biomass into electricity. Glycerol, as a waste in the biodiesel refinery processes, is an appealing substrate for MFC. Nevertheless, glycerol cannot be utilized as carbon source by well-known exoelectrogens such as Shewanella oneidensis. Herein, to generate electricity by rapidly harnessing glycerol, the authors rationally constructed a Klebsiella pneumoniae-Shewanella oneidensis microbial consortium to efficiently harvest electricity from glyc-erol, in which K. pneumoniae converted glycerol into lactate, fed to S. oneidensis as carbon source and electron donor. To improve electricity output, the authors systematically engineered the consortium in terms of carbon flux distribution and efficiency of extracellular electron transfer (EET). To direct more carbon flux to lactate biosynthesis in K. pneumoniae, the authors eliminated the ethanol pathway by knocking out the alcohol dehydrogenase gene (adhE), and enhanced lactate biosynthesis by heterologously expressing a lactate dehydrogen-ase gene (ldhD) from Lactobacillus bulgaricus and a lactate transporter gene (lldP) from Escherichia coli. To facilitate EET between S. oneidensis and anode surfaces, a biosynthetic flavins pathway from Bacillus subtilis is introduced into S. oneidensis. The author further optimized the glycerol concentration, thus S. oneidensis could be continuously fed with lactate synthesized from K. pneumoniae at a constant rate. Our glycerol-fed MFC generated a maximum power density of 19.9 mW/m 2 , significantly higher than that of the wild-type consor-tium. This work suggested that engineering microbial consortia is an effi-cient strategy to expand the spectrum of usable carbon sources and promote electricity power production in MFCs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Eibach, Daniel; Dekker, Denise; Gyau Boahen, Kennedy; Wiafe Akenten, Charity; Sarpong, Nimako; Belmar Campos, Cristina; Berneking, Laura; Aepfelbacher, Martin; Krumkamp, Ralf; Owusu-Dabo, Ellis; May, Jürgen
Antibiotic use in animal husbandry has raised concerns on the spread of resistant bacteria. Currently animal products are traded globally with unprecedented ease, which has been challenging the control of antimicrobial resistance. This study aims to detect and characterize extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae from imported and locally produced poultry products sold in Ghana. Local and imported chicken meat was collected from 94 stores and markets throughout Kumasi (Ghana) and cultured on selective ESBL screening agar. Phenotypic ESBL-producing E. coli and K. pneumoniae isolates were confirmed by combined disc test and further characterized by antibiotic susceptibility testing, amplification of the bla CTX-M , bla TEM and bla SHV genes as well as multilocus sequence typing (MLST) and linked to the country of origin. Out of 200 meat samples, 71 (36%) samples revealed 81 ESBL-producing isolates (46 E. coli and 35 K. pneumoniae), with 44% (30/68) of local poultry and 31% (41/132) of imported products being contaminated. Most ESBL-producing isolates harboured the bla CTX-M-15 gene (61/81, 75%) and the dominant Sequence Types (ST) were ST2570 (7/35, 20%) among K. pneumoniae and ST10 (5/46, 11%) among E. coli. High numbers of ESBL-producing bacteria, particularly on local but also imported poultry meat, represent a potential source for human colonization and infection as well as spread within the community. Surveillance along the poultry production-food-consumer chain would be a valuable tool to identify sources of emerging multidrug resistant pathogens in Ghana. Copyright © 2018 Elsevier B.V. All rights reserved.
Christensen, Sarah C B; Nissen, Erling; Arvin, Erik; Albrechtsen, Hans-Jørgen
Water lice, Asellus aquaticus (isopoda), frequently occur in drinking water distribution systems where they are a nuisance to consumers and water utilities. Whether they are solely an aesthetic problem or also affect the microbial water quality is a matter of interest. We studied the influence of A. aquaticus on microbial water quality in non-chlorinated drinking water in controlled laboratory experiments. Pure cultures of the indicator organisms Escherichia coli and Klebsiella pneumoniae and the pathogen Campylobacter jejuni as well as naturally occurring heterotrophic drinking water bacteria (measured as heterotrophic plate counts, HPC) were investigated in microcosms at 7 °C, containing non-sterilised drinking water, drinking water sediment and A. aquaticus collected from a non-chlorinated ground water based drinking water supply system. Concentrations of E. coli, K. pneumoniae and C. jejuni decreased over time, following a first order decay with half lives of 5.3, 18.4 and 1.3 days, respectively. A. aquaticus did not affect survival of indicators and pathogens substantially whereas HPC were influenced by presence of dead A. aquaticus. Growth rates increased with an average of 48% for bacteria grown on R-2A agar and an average of 83% for bacteria grown on yeast extract agar when dead A. aquaticus were present compared to no and living A. aquaticus present. A. aquaticus associated E. coli, K. pneumoniae and C. jejuni were measured (up to 25 per living and 500 per dead A. aquaticus) and so were A. aquaticus associated heterotrophic bacteria (>1.8*10(4) CFU per living and >6*10(4) CFU per dead A. aquaticus). A. aquaticus did not serve as an optimised habitat that increased survival of indicators and pathogens, since A. aquaticus associated E. coli, K. pneumoniae and C. jejuni were only measured as long as the bacteria were also present in the water and sediment. Copyright © 2012 Elsevier Ltd. All rights reserved.
Hasibuan, Mirzan; Suryanto, Dwi; Lia Kusumawati, R.
The application of antibiotics expanded-spectrum third-generation cephalosporin for the treatment of infectious diseases in hospitals is known contribute to increasing resistance due to the presence of the blaCTX-M gene in the bacteria producing ESBLs. This study was aimed to detect ESBLs, isolate phenotype and blaCTX-M genes on Escherichia coli and Klebsiella pneumoniae collected from H. Adam Malik Central Hospital. Phenotypes of the bacterial were detection using Vitek two compact, while the blaCTX-M genes were detection using polymerase chain reaction technique. The results showed that 85 (100%) isolates were ESBLs consisted of 41(48%) of Escherichia coli, and 44 (52%) of Klebsiella pneumoniae, respectively. blaCTX-M genes were detection in 62 (72.94%) of the isolates which 31 (36.47%) were Escherichia coli, and 31 (36.47%) of the isolates were Klebsiella pneumoniae, respectively. This study indicates the high prevalence of blaCTX-M genes in Escherichia coli and Klebsiella pneumoniea causing bacterial antibiotic resistance.
Conclusion: Our results support the view that DNA adenine methylation plays an important role in modulating the pathogenicity of K. pneumoniae genotype K1. The incomplete attenuation indicates the existence of other regulatory factors.
Roe, W D; Rogers, L; Pinpimai, K; Dittmer, K; Marshall, J; Chilvers, B L
This study describes a syndrome of neonatal septicemia and meningitis in New Zealand sea lions, caused by a strain of Klebsiella pneumoniae that is phenotypically similar to strains causing environmentally-acquired septicemia and neuro-invasive disease in humans. Between late 2006 and early 2010, 123 pups from the Enderby Island breeding colony died of K. pneumoniae infection, with lesions including fibrinous to fibrinosuppurative meningitis, subdural hemorrhage, septic arthritis, herniation and hemorrhage of the cerebellar vermis, lymphadenitis and cellulitis. This infection was responsible for 58% of observed pup mortality over this time period, with most deaths occurring in the latter part of the breeding season (mid February onwards). The results of this study suggest that the pattern of this disease has changed since it was first described in 2002, when most deaths occurred early in the season (early to mid-January), and that it is an important and consistent cause of pup mortality in this population. In addition, a similar disease syndrome and bacterial strain was diagnosed in a single pup in a fragile recolonizing New Zealand sea lion population on mainland New Zealand, and the potential effect on this population is unknown but could have a negative impact on recolonisation at this site. Copyright © 2015 Elsevier B.V. All rights reserved.
Full Text Available S-thanatin (Ts was a short antimicrobial peptide with selective antibacterial activity. In this study, we aimed to design a drug carrier with specific bacterial targeting potential. The positively charged Ts was modified onto the liposome surface by linking Ts to the constituent lipids via a PEG linker. The benefits of this design were evaluated by preparing a series of liposomes and comparing their biological effects in vitro and in vivo. The particle size and Zeta potential of the constructed liposomes were measured with a Zetasizer Nano ZS system and a confocal laser scanning microscope (CLSM. The in vitro drug delivery potential was evaluated by measuring the cellular uptake of encapsulated levofloxacin using HPLC. Ts-linked liposome or its conjugates with quantum dots favored bacterial cells, and increased the bacterial uptake of levofloxacin. In antimicrobial assays, the Ts and levofloxacin combination showed a synergistic effect, and Ts-LPs-LEV exhibited excellent activity against the quality control stain Klebsiella pneumoniae ATCC 700603 and restored the susceptibility of multidrug-resistant K. pneumoniae clinical isolates to levofloxacin in vitro. Furthermore, Ts-LPs-LEV markedly reduced the lethality rate of the septic shock and resulted in rapid bacterial clearance in mouse models receiving clinical MDR isolates. These results suggest that the Ts-functionalized liposome may be a promising antibiotic delivery system for clinical infectious disorders caused by MDR bacteria, in particular the sepsis related diseases.
Jolene R Bowers
Full Text Available Multidrug-resistant Klebsiella pneumoniae producing the KPC carbapenemase have rapidly spread throughout the world, causing severe healthcare-associated infections with limited antimicrobial treatment options. Dissemination of KPC-producing K. pneumoniae is largely attributed to expansion of a single dominant strain, ST258. In this study, we explore phylogenetic relationships and evolution within ST258 and its clonal group, CG258, using whole genome sequence analysis of 167 isolates from 20 countries collected over 17 years. Our results show a common ST258 ancestor emerged from its diverse parental clonal group around 1995 and likely acquired blaKPC prior to dissemination. Over the past two decades, ST258 has remained highly clonal despite diversity in accessory elements and divergence in the capsule polysaccharide synthesis locus. Apart from the large recombination event that gave rise to ST258, few mutations set it apart from its clonal group. However, one mutation occurs in a global transcription regulator. Characterization of outer membrane protein sequences revealed a profile in ST258 that includes a truncated OmpK35 and modified OmpK37. Our work illuminates potential genomic contributors to the pathogenic success of ST258, helps us better understand the global dissemination of this strain, and identifies genetic markers unique to ST258.
Johnson, Jeremiah G; Murphy, Caitlin N; Sippy, Jean; Johnson, Tylor J; Clegg, Steven
Klebsiella pneumoniae is an opportunistic pathogen which frequently causes hospital-acquired urinary and respiratory tract infections. K. pneumoniae may establish these infections in vivo following adherence, using the type 3 fimbriae, to indwelling devices coated with extracellular matrix components. Using a colony immunoblot screen, we identified transposon insertion mutants which were deficient for type 3 fimbrial surface production. One of these mutants possessed a transposon insertion within a gene, designated mrkI, encoding a putative transcriptional regulator. A site-directed mutant of this gene was constructed and shown to be deficient for fimbrial surface expression under aerobic conditions. MrkI mutants have a significantly decreased ability to form biofilms on both abiotic and extracellular matrix-coated surfaces. This gene was found to be cotranscribed with a gene predicted to encode a PilZ domain-containing protein, designated MrkH. This protein was found to bind cyclic-di-GMP (c-di-GMP) and regulate type 3 fimbrial expression.
de Maio Carrilho, Claudia M D; de Oliveira, Larissa Marques; Gaudereto, Juliana; Perozin, Jamile S; Urbano, Mariana Ragassi; Camargo, Carlos H; Grion, Cintia M C; Levin, Anna Sara S; Costa, Silvia F
To describe the clinical and microbiological data of carbapenem-resistant Enterobacteriaceae (CRE) infections, the treatment used, hospital- and infection-related mortality, and risk factors for death. A prospective cohort conducted from March 2011 to December 2012. Clinical, demographic, and microbiological data such as in vitro sensitivity, clonality, carbapenemase gene mortality related to infection, and overall mortality were evaluated. Data were analyzed using Epi Info version 7.0 (CDC, Atlanta, GA, USA) and SPSS (Chicago, IL, USA). One hundred and twenty-seven patients were evaluated. Pneumonia, 52 (42 %), and urinary tract infections (UTI), 51 (40.2 %), were the most frequent sites of infection. The isolates were polyclonal; the Bla KPC gene was found in 75.6 % of isolates, and 27 % of isolates were resistant to colistin. Mortality related to infection was 34.6 %, and was higher among patients with pneumonia (61.4 %). Combination therapy was used in 98 (77.2 %), and monotherapy in 22.8 %; 96.5 % of them were UTI patients. Shock, age, and dialysis were independent risk factors for death. There was no difference in infection-related death comparing colistin-susceptible and colistin-resistant infections (p = 0.46); neither in survival rate comparing the use of combination therapy with two drugs or more than two drugs (p = 0.32). CRE infection mortality was higher among patients with pneumonia. Infections caused by colistin-resistant isolates did not increase mortality. The use of more than two drugs on combination therapy did not show a protective effect on outcome. The isolates were polyclonal, and the bla KPC gene was the only carbapenemase found. Shock, dialysis, and age over 60 years were independent risk factors for death.
Full Text Available Purpose: To explore the metabolic characterization of host responses to drainage-resistant Klebsiella pneumoniae liver abscesses (DRKPLAs with serum 1H-nuclear magnetic resonance (NMR spectroscopy.Materials and Methods: The hospital records of all patients with a diagnosis of a liver abscess between June 2015 and December 2016 were retrieved from an electronic hospital database. Eighty-six patients with Klebsiella pneumoniae (K. pneumoniae liver abscesses who underwent percutaneous drainage were identified. Twenty patients with confirmed DRKPLAs were studied. Moreover, we identified 20 consecutive patients with drainage-sensitive Klebsiella pneumoniae liver abscesses (DSKPLAs as controls. Serum samples from the two groups were analyzed with 1H NMR spectroscopy. Partial least squares discriminant analysis (PLS-DA was used to perform 1H NMR metabolic profiling. Metabolites were identified using the Human Metabolome Database, and pathway analysis was performed with MetaboAnalyst 3.0.Results: The PLS-DA test was able to discriminate between the two groups. Five key metabolites that contributed to their discrimination were identified. Glucose, lactate, and 3-hydroxybutyrate were found to be upregulated in DRKPLAs, whereas glutamine and alanine were downregulated compared with the DSKPLAs. Pathway analysis indicated that amino acid metabolisms were significantly different between the DRKPLAs and the DSKPLAs. The D-glutamine and D-glutamate metabolisms exhibited the greatest influences.Conclusions: The five key metabolites identified in our study may be potential targets for guiding novel therapeutics of DRKPLAs and are worthy of additional investigation.
Full Text Available Chaperone/usher (CU assembly pathway is used by a wide range of Enterobacteriaceae to assemble adhesive surface structures called pili or fimbriae that play a role in bacteria-host cell interactions. In silico analysis revealed that the genome of Klebsiella pneumoniae LM21 harbors eight chromosomal CU loci belonging to γκп and ϭ clusters. Of these, only two correspond to previously described operons, namely type 1 and type 3-encoding operons. Isogenic usher deletion mutants of K. pneumoniae LM21 were constructed for each locus and their role in adhesion to animal (Intestine 407 and plant (Arabidopsis thaliana cells, biofilm formation and murine intestinal colonization was investigated. Type 3 pili usher deleted mutant was impaired in all assays, whereas type 1 pili usher deleted mutant only showed attenuation in adhesion to plant cells and in intestinal colonization. The LM21ΔkpjC mutant was impaired in its capacity to adhere to Arabidopsis cells and to colonize the murine intestine, either alone or in co-inoculation experiments. Deletion of LM21kpgC induced a significant decrease in biofilm formation, in adhesion to animal cells and in colonization of the mice intestine. The LM21∆kpaC and LM21∆kpeC mutants were only attenuated in biofilm formation and the adhesion abilities to Arabidopsis cells, respectively. No clear in vitro or in vivo effect was observed for LM21∆kpbC and LM21∆kpdC mutants. The multiplicity of CU loci in K. pneumoniae genome and their specific adhesion pattern probably reflect the ability of the bacteria to adhere to different substrates in its diverse ecological niches.
Khater, Fida; Balestrino, Damien; Charbonnel, Nicolas; Dufayard, Jean François; Brisse, Sylvain; Forestier, Christiane
Chaperone/usher (CU) assembly pathway is used by a wide range of Enterobacteriaceae to assemble adhesive surface structures called pili or fimbriae that play a role in bacteria-host cell interactions. In silico analysis revealed that the genome of Klebsiella pneumoniae LM21 harbors eight chromosomal CU loci belonging to γκп and ϭ clusters. Of these, only two correspond to previously described operons, namely type 1 and type 3-encoding operons. Isogenic usher deletion mutants of K. pneumoniae LM21 were constructed for each locus and their role in adhesion to animal (Intestine 407) and plant (Arabidopsis thaliana) cells, biofilm formation and murine intestinal colonization was investigated. Type 3 pili usher deleted mutant was impaired in all assays, whereas type 1 pili usher deleted mutant only showed attenuation in adhesion to plant cells and in intestinal colonization. The LM21ΔkpjC mutant was impaired in its capacity to adhere to Arabidopsis cells and to colonize the murine intestine, either alone or in co-inoculation experiments. Deletion of LM21kpgC induced a significant decrease in biofilm formation, in adhesion to animal cells and in colonization of the mice intestine. The LM21∆kpaC and LM21∆kpeC mutants were only attenuated in biofilm formation and the adhesion abilities to Arabidopsis cells, respectively. No clear in vitro or in vivo effect was observed for LM21∆kpbC and LM21∆kpdC mutants. The multiplicity of CU loci in K. pneumoniae genome and their specific adhesion pattern probably reflect the ability of the bacteria to adhere to different substrates in its diverse ecological niches. PMID:25751658
Full Text Available Abstract INTRODUCTION: Infections caused by β-lactamase-producing gram-negative bacteria, such as Klebsiella pneumoniae, are increasing globally with high morbidity and mortality. The aim of the current study was to determine antimicrobial susceptibility patterns and the prevalence of antibiotic resistance genes (β-lactamase and integron genes using multiplex PCR. METHODS One-hundred K. pneumoniae isolates were collected from different clinical samples. Antibiotic susceptibility testing was performed with thirteen different antibiotics. Multiplex-PCR was used to detect β-lactamase (bla TEM, bla CTX-M, bla SHV , bla VEB, bla PER, bla GES, bla VIM, bla IMP, bla OXA, and bla KPC and integron genes (int I, int II, and int III. RESULTS: The highest and lowest rate of resistance was exhibited against amikacin (93% and imipenem (8%, respectively. The frequency of β-lactamase-positive K. pneumoniae was 37%, and the prevalence of the bla TEM, bla CTX-M, bla SHV , bla VEB, bla PER, bla GES, bla VIM, bla IMP, bla OXA, and bla KPC genes was 38%, 24%, 19%, 12%, 6%, 11%, 33%, 0%, 28%, and 23%, respectively. Of the 100 isolates, eight (8% were positive for class I integrons; however, class II and III integrons were not detected in any of the strains. CONCLUSIONS: These results indicate co-carriage of a number of β-lactamase genes and antibiotic resistance integrons on the same plasmids harboring multi-drug resistance genes. It seems that these properties help to decrease treatment complications due to resistant bacterial infections by rapid detection, infection-control programs and prevention of transmission of drug resistance.
Srijan, Apichai; Margulieux, Katie R; Ruekit, Sirigade; Snesrud, Erik; Maybank, Rosslyn; Serichantalergs, Oralak; Kormanee, Rosarin; Sukhchat, Prawet; Sriyabhaya, Jossin; Hinkle, Mary; Crawford, John M; McGann, Patrick; Swierczewski, Brett E
Multidrug-resistant Klebsiella pneumoniae strains are one of the most prevalent causes of nosocomial infections and pose an increasingly dangerous public health threat. The lack of remaining treatment options has resulted in the utilization of older drug classes, including colistin. As a drug of last resort, the discovery of plasmid-mediated colistin resistance by mcr-1 denotes the potential development of pandrug-resistant bacterial pathogens. To address the emergence of the mcr-1 gene, 118 gram-negative Enterobacteriaceae isolated from clinical samples collected at Queen Sirikit Naval Hospital in Chonburi, Thailand were screened for colistin resistance using automated antimicrobial susceptibility testing and conventional PCR screening. Two K. pneumoniae strains, QS17-0029 and QS17-0161, were positive for mcr-1, and both isolates were sequenced to closure using short- and long-read whole-genome sequencing. QS17-0029 carried 16 antibiotic resistance genes in addition to mcr-1, including 2 carbapenemases, bla NDM-1 and bla OXA-232 . QS17-0161 carried 13 antibiotic resistance genes in addition to mcr-1, including the extended-spectrum β-lactamase bla CTX-M-55 . Both isolates carried multiple plasmids, but mcr-1 was located alone on highly similar 33.9 Kb IncX4 plasmids in both isolates. The IncX4 plasmid shared considerable homology to other mcr-1-containing IncX4 plasmids. This is the first report of a clinical K. pneumoniae strain from Thailand carrying mcr-1 as well as the first strain to simultaneously carry mcr-1 and multiple carbapenemase genes (QS17-0029). The identification and characterization of these isolates serves to highlight the urgent need for continued surveillance and intervention in Southeast Asia, where extensively drug-resistant pathogens are being increasingly identified in hospital-associated infections.
Messai, Y; Iabadene, H; Benhassine, T; Alouache, S; Tazir, M; Gautier, V; Arlet, G; Bakour, R
To determine the prevalence and the diversity of extended-spectrum beta-lactamases (ESBLs) in 196 Klebsiella pneumoniae clinical isolates collected from three hospitals in Algiers. Antibiograms were done on Mueller-Hinton agar plates with the disc-diffusion method and MICs were determined by agar-dilution method. Mating experiments were performed in agar medium. Plasmid DNA was extracted by the alcalin-lysis method. Total DNA was extracted with a Qiagen mini kit and screened for bla(TEM) and bla(CTX-M) genes by PCR. Linkage of bla(CTX-M) genes with insertion sequence ISEcp1B and class 1 integrons was investigated by PCR. PCR products were sequenced by the Sanger method. The epidemiological relationships between ESBL-producing K. pneumoniae isolates were analyzed by ERIC-PCR. Thirty-nine (19.9%) isolates were found to produce ESBLs belonging to CTX-M-1 group and TEM penicillinases (CTX-M-3, CTX-M-15 and TEM-1). ERIC-PCR analysis showed that the isolates are genetically unrelated. The bla(TEM) and bla(CTX-M) genes as well as aminoglycosides and sulfonamides resistance determinants were found located in self-transferable plasmids of approximately 85 kb. The class 1 integrons and the insertion sequence ISEcp1B were present in the isolates and in their transconjugants. ISEcp1B was found genetically linked to the bla(CTX-M) genes and located 127bp upstream, with the presence of the V and W sequences. The study revealed a high rate of ESBL-producing K. pneumoniae in Algerian hospitals, resulting from horizontal dissemination of mobile bla(CTX-M) genes.
Caltagirone, Mariasofia; Bitar, Ibrahim; Piazza, Aurora; Spalla, Melissa; Nucleo, Elisabetta; Navarra, Antonella; Migliavacca, Roberta
A 62-year-old patient was transferred to the cardiac rehabilitation unit of the I.R.C.C.S. Fondazione S. Maugeri after undergoing a heart transplantation at the Acute Care Hospital I.R.C.C.S. S. Matteo of Pavia. On 1 August 2013 and during hospitalization in the rehabilitation unit, Klebsiella oxytoca and Citrobacter koseri clinical isolates were simultaneously recovered from the patient's preputial swab. Both the K. oxytoca and C. koseri strains were carbapenem- resistant by MicroScan System (Beckman Coulter). Carbapenem-resistant K. pneumoniae had previously been reported in the same rehabilitation facility. The aim of the study was to identify the carbapenem resistance mechanisms among the enterobacterial species recovered. Phenotypic screening tests useful to detect the β-lactamases/carbapenemases were performed. Carbapenem MICs were obtained by Etest. AmpC and MBL encoding genes were identified by PCR and sequencing. Conjugation assays and plasmid characterization were performed. Both of the K. oxytoca and C. koseri isolates were multi drug resistant, showing resistance to amoxicillin-clavulanic acid, three generation cephalosporins, ertapenem (K. oxytoca MIC, >32 mg/L; C. koseri MIC, 4 mg/L), imipenem (K. oxytoca MIC, 4 mg/L; C. koseri MIC, 12 mg/L), thrimethoprim sulphamethoxazole and gentamicin. Susceptibility was retained to fluoroquinolones, colistin and tigecycline. Molecular characterization confirmed the co-presence of blaCMY-4 and blaVIM-4 determinants in a 150 Kb transferable plasmid of IncA/C group. This case is the first detection in Italy of the K. oxytoca and C. koseri clinical isolates co-producing the CMY-4 and VIM-4 enzymes.
Goodman, K E; Simner, P J; Tamma, P D; Milstone, A M
The Centers for Disease Control and Prevention (CDC) defines carbapenem-resistant Enterobacteriaceae (CRE) based upon a phenotypic demonstration of carbapenem resistance. However, considerable heterogeneity exists within this definitional umbrella. CRE may mechanistically differ by whether they do or do not produce carbapenemases. Moreover, patients can acquire CRE through multiple pathways: endogenously through antibiotic selective pressure on intestinal microbiota, exogenously through horizontal transmission or through a combination of these factors. Some evidence suggests that non-carbapenemase-producing CRE may be more frequently acquired by antibiotic exposure and carbapenemase-producing CRE via horizontal transmission, but definitive data are lacking. This review examines types of CRE resistance mechanisms, antibiotic exposure and horizontal transmission pathways of CRE acquisition, and the implications of these heterogeneities to the development of evidence-based CRE healthcare epidemiology policies. In our Expert Commentary & Five-Year View, we outline specific nosocomial CRE knowledge gaps and potential methodological approaches for their resolution.
M. Tsala (Marilena); S. Vourli (Sophia); Georgiou, P.-C. (Panagiota-Christina); S. Pournaras (Spyros); A. Tsakris (Athanassios); G.L. Daikos (George); J.W. Mouton (Johan); J. Meletiadis (Joseph)
textabstractObjectives: Because the pharmacokinetic/pharmacodynamic (PK/PD) characteristics of colistin against Enterobacteriaceae are not well explored, we studied the activity of colistin against K. pneumoniae in an in vitro PK/PD model simulating different dosing regimens. Methods: Three clinical
van Boxtel, Ria; Wattel, Agnes A; Arenas, Jesús; Goessens, Wil H F; Tommassen, Jan
Although AmpC β-lactamases can barely degrade carbapenems, if at all, they can sequester them and prevent them from reaching their targets. Thus, carbapenem resistance in Escherichia coli and other Enterobacteriaceae can result from AmpC production and simultaneous reduction of antibiotic influx into the periplasm by mutations in the porin genes. Here we investigated the route and genetic mechanisms of acquisition of carbapenem resistance in a clinical E. coli isolate carrying bla CMY-2 on a plasmid by selecting for mutants that are resistant to increasing concentrations of meropenem. In the first step, the expression of OmpC, the only porin produced in the strain under laboratory conditions, was lost, leading to reduced susceptibility to meropenem. In the second step, the expression of the CMY-2 β-lactamase was upregulated, leading to resistance to meropenem. The loss of OmpC was due to the insertion of an IS1 element into the ompC gene or to frameshift mutations and premature stop codons in this gene. The bla CMY-2 gene was found to be located on an IncIγ plasmid, and overproduction of the CMY-2 enzyme resulted from an increased plasmid copy number due to a nucleotide substitution in the inc gene. The clinical relevance of these genetic mechanisms became evident from the analysis of previously isolated carbapenem-resistant clinical isolates, which appeared to carry similar mutations. Copyright © 2016 American Society for Microbiology.
Viehman, J. Alexander; Nguyen, Minh-Hong; Doi, Yohei
Acinetobacter baumannii is a leading cause of healthcare-associated infections worldwide. Due to various intrinsic and acquired mechanisms of resistance, most β-lactam agents are not effective against many strains, and carbapenems have played an important role in therapy. Recent trends show many infections are caused by carbapenem-resistant, or even extensively drug-resistant (XDR) strains, for which effective therapy is not well established. Evidence to date suggests that colistin constitutes the backbone of therapy, but the unique pharmacokinetic properties of colistin have led many to suggest the use of combination antimicrobial therapy. However, the combination of agents and dosing regimens that delivers the best clinical efficacy while minimizing toxicity is yet to be defined. Carbapenems, sulbactam, rifampin and tigecycline have been the most studied in the context of combination therapy. Most data regarding therapy for invasive, resistant A. baumannii infections come from uncontrolled case series and retrospective analyses, though some clinical trials have been completed and others are underway. Early institution of appropriate antimicrobial therapy is shown to consistently improve survival of patients with carbapenem-resistant and XDR A. baumannii infection, but the choice of empiric therapy in these infections remains an open question. This review summarizes the most current knowledge regarding the epidemiology, mechanisms of resistance, and treatment considerations of carbapenem-resistant and XDR A. baumannii. PMID:25091170
Full Text Available The bacterial enzyme New Delhi metallo-β-lactamase hydrolyzes almost all β-lactam antibiotics, including carbapenems, which are drugs of last resort for severe bacterial infections. The spread of carbapenem-resistant Enterobacteriaceae that carry the New Delhi metallo-β-lactamase gene, blaNDM, poses a serious threat to public health. In this study, we genetically characterized eight carbapenem-resistant Escherichia coli isolates from a tertiary care hospital in Yangon, Myanmar. The eight isolates belonged to five multilocus-sequence types and harbored multiple antimicrobial-resistance genes, resulting in resistance against nearly all of the antimicrobial agents tested, except colistin and fosfomycin. Nine plasmids harboring blaNDM genes were identified from these isolates. Multiple blaNDM genes were found in the distinct Inc-replicon types of the following plasmids: an IncA/C2 plasmid harboring blaNDM-1 (n = 1, IncX3 plasmids harboring blaNDM-4 (n = 2 or blaNDM-7 (n = 1, IncFII plasmids harboring blaNDM-4 (n = 1 or blaNDM-5 (n = 3, and a multireplicon F plasmid harboring blaNDM-5 (n = 1. Comparative analysis highlighted the diversity of the blaNDM-harboring plasmids and their distinct characteristics, which depended on plasmid replicon types. The results indicate circulation of phylogenetically distinct strains of carbapenem-resistant E. coli with various plasmids harboring blaNDM genes in the hospital.
Apisarnthanarak, Anucha; Khan, Erum; Ghafur, Abdul
SUMMARY Carbapenem-resistant Gram-negative bacteria, in particular the Acinetobacter baumannii-calcoaceticus complex and Enterobacteriaceae, are escalating global public health threats. We review the epidemiology and prevalence of these carbapenem-resistant Gram-negative bacteria among countries in South and Southeast Asia, where the rates of resistance are some of the highest in the world. These countries house more than a third of the world's population, and several are also major medical tourism destinations. There are significant data gaps, and the almost universal lack of comprehensive surveillance programs that include molecular epidemiologic testing has made it difficult to understand the origins and extent of the problem in depth. A complex combination of factors such as inappropriate prescription of antibiotics, overstretched health systems, and international travel (including the phenomenon of medical tourism) probably led to the rapid rise and spread of these bacteria in hospitals in South and Southeast Asia. In India, Pakistan, and Vietnam, carbapenem-resistant Enterobacteriaceae have also been found in the environment and community, likely as a consequence of poor environmental hygiene and sanitation. Considerable political will and effort, including from countries outside these regions, are vital in order to reduce the prevalence of such bacteria in South and Southeast Asia and prevent their global spread. PMID:27795305
Hsu, Li-Yang; Apisarnthanarak, Anucha; Khan, Erum; Suwantarat, Nuntra; Ghafur, Abdul; Tambyah, Paul Anantharajah
Carbapenem-resistant Gram-negative bacteria, in particular the Acinetobacter baumannii-calcoaceticus complex and Enterobacteriaceae, are escalating global public health threats. We review the epidemiology and prevalence of these carbapenem-resistant Gram-negative bacteria among countries in South and Southeast Asia, where the rates of resistance are some of the highest in the world. These countries house more than a third of the world's population, and several are also major medical tourism destinations. There are significant data gaps, and the almost universal lack of comprehensive surveillance programs that include molecular epidemiologic testing has made it difficult to understand the origins and extent of the problem in depth. A complex combination of factors such as inappropriate prescription of antibiotics, overstretched health systems, and international travel (including the phenomenon of medical tourism) probably led to the rapid rise and spread of these bacteria in hospitals in South and Southeast Asia. In India, Pakistan, and Vietnam, carbapenem-resistant Enterobacteriaceae have also been found in the environment and community, likely as a consequence of poor environmental hygiene and sanitation. Considerable political will and effort, including from countries outside these regions, are vital in order to reduce the prevalence of such bacteria in South and Southeast Asia and prevent their global spread. Copyright © 2016 American Society for Microbiology.
Hermansen, L T; Loft, A G; Christiansen, A A
OBJECTIVES: To investigate whether antibody response patterns against Klebsiella pneumoniae capsular serotypes can discriminate patients with axial spondyloarthritis (axSpA) from patients with non-specific low back pain (LBP). METHOD: Immunoglobulin (Ig)G and IgA antibodies against K. pneumoniae...... capsular serotypes K2, K26, K36, and K50 were measured, and antibody seropositivity compared between groups and analysed for patient correlation in five different groups: (a) 96 patients fulfilling the Assessment of SpondyloArthritis International Society (ASAS) classification criteria for axSpA; (b) 38...... ankylosing spondylitis (AS) served as the negative and positive control groups. RESULTS: There was no difference in IgG and IgA seropositivity against all serotypes between the axSpA, non-axSpA, and LBP groups. No significant correlations were found between anti-Klebsiella antibodies and age, gender, HLA-B27...
Shoja, Saeed; Moosavian, Mojtaba; Rostami, Soodabeh; Farahani, Abbas; Peymani, Amir; Ahmadi, Khadijeh; Ebrahimifard, Nasim
Carbapenem-resistant Acinetobacter baumannii has emerged as an important cause of infection in burn patients. This study aimed to characterize the antimicrobial susceptibility pattern, determine the prevalence of oxacillinase and metallo-beta-lactamase (MBL) genes, and type the A. baumannii isolates obtained from burn patients. During a 1-year period, a total of 40 nonduplicated isolates of A. baumannii were obtained from burn patients who were hospitalized in the Taleghani Burn Hospital in Ahvaz, in the southwest of Iran. Testing for antimicrobial susceptibility was carried out by disk diffusion and E-test. To screen MBL production, a double disk synergy and MBL E-test were performed. The presence of bla OXA-23-like , bla OXA-24-like , bla OXA-51-like and bla OXA-58-like , bla VIM , bla IMP and bla SPM , and bla NDM was sought by polymerase chain reaction (PCR). Repetitive extragenic palindromic sequence-based PCR was carried out for determination of isolates clonality. Overall, 92.5% of isolates were carbapenem-resistant. Polymyxin B, colistin, and ampicillin-sulbactam were the most effective agents in vitro, with a susceptibility rate of 100%, 97.5%, and 72.5%, respectively. According to the double disk synergy and E-test, 55.6% and 97.3% of isolates were MBL producers, respectively. Furthermore, 70% of isolates harbored bla OXA-23-like and 20% were positive for bla OXA-24-like. However, no encoding genes were detected for bla VIM , bla IMP and bla SPM , bla NDM , and bla OXA-58-like . Repetitive extragenic palindromic sequence-based PCR revealed that carbapenem-resistant isolates belonged to four clones, including A, B, C, and D; the predominant clones were B and C. The rate of carbapenem resistance was high, and it appeared that bla OXA-23-like and bla OXA-24-like contributed to the carbapenem resistance of A. baumannii isolates. This result suggests that the two predominant clones of A. baumannii were spread among burn patients. In order to prevent future
Anderl, Jeff N; Zahller, Jeff; Roe, Frank; Stewart, Philip S
Biofilms formed by Klebsiella pneumoniae resisted killing during prolonged exposure to ampicillin or ciprofloxacin even though these agents have been shown to penetrate bacterial aggregates. Bacteria dispersed from biofilms into medium quickly regained most of their susceptibility. Experiments with free-floating bacteria showed that stationary-phase bacteria were protected from killing by either antibiotic, especially when the test was performed in medium lacking carbon and nitrogen sources. These results suggested that the antibiotic tolerance of biofilm bacteria could be explained by nutrient limitation in the biofilm leading to stationary-phase existence of at least some of the cells in the biofilm. This mechanism was supported by experimental characterization of nutrient availability and growth status in biofilms. The average specific growth rate of bacteria in biofilms was only 0.032 h(-1) compared to the specific growth rate of planktonic bacteria of 0.59 h(-1) measured in the same medium. Glucose did not penetrate all the way through the biofilm, and oxygen was shown to penetrate only into the upper 100 micro m. The specific catalase activity was elevated in biofilm bacteria to a level similar to that of stationary-phase planktonic cells. Transmission electron microscopy revealed that bacteria were affected by ampicillin near the periphery of the biofilm but were not affected in the interior. Taken together, these results indicate that K. pneumoniae in this system experience nutrient limitation locally within the biofilm, leading to zones in which the bacteria enter stationary phase and are growing slowly or not at all. In these inactive regions, bacteria are less susceptible to killing by antibiotics.
N O Yilmaz
Full Text Available Background: Detecting plasmid-mediated AmpC (pAmpC β-lactamase-producing organism is important for optimal infection control and providing accurate and effective treatment option for physicians. Objectives: The aim of this study was to investigate the prevalence of pAmpC β-lactamase and compare the results of boronic acid (BA disk test with other phenotypic tests detecting AmpC positive isolates. Materials and Methods: A total of 273 clinical isolates of Klebsiella pneumoniae (n: 82 and Escherichia coli (n: 191 were analysed. The presence of pAmpC β-lactamase was determined by BA disk test, cefoxitin (FOX screening test, modified three dimensional test (M3DT, and multiplex polymerase chain reaction (PCR. Pulsed-field gel electrophoresis was performed to evaluate the genetic similarities between isolates. To detect extended spectrum β-lactamases (ESBL in the presence of AmpC β-lactamase, ESBL confirmation test was carried out with and without BA solution. Results: Of the 273 strains tested, 127 strains were found FOX resistant, 114 were positive by M3DT, 108 were positive in BA disk test, and the multiplex PCR detected 24 pAmpC β-lactamase-positive isolate. The prevalence of AmpC-producing strains was 10.9% in E. coli and 3.6% in K. pneumoniae in the tested population by PCR. CIT and MOX group genes were predominant type in these strains. Conclusion: These results emphasize that clinical laboratories should consider testing the presence of pAmpC enzymes particularly in FOX-resistant isolates, and BA disk test will improve detection of this emerging resistance phenotype.
Falco Restrepo, Aura Dayana; Velásquez Nieves, Mariel Alexandra; Takiff, Howard
Klebsiella pneumoniae carbapenemase (KPC)-producing bacteria are amongst the most important causative agents of nosocomial infections worldwide. Isolates of this bacterium have been identified in Venezuela but little is known about their local spread. The aim of this study was to perform the molecular characterization of KPC-producing strains isolated from 2012 to 2013 in a public hospital in Caracas, Venezuela. Twenty-two K. pneumoniae clinical isolates phenotypically classified as KPC producing were subjected to PCR screening for the presence of bla KPC genes and their location within transposon Tn4401. The bla KPC PCR product was sequenced to identify the KPC alleles. Genotypic analysis was performed by means of repetitive extragenic palindromic PCR (rep-PCR) and Multi Locus Sequence Typing (MLST). Finally, conjugation and electroporation assays were used to determine whether the bla KPC genes were found in plasmids. All isolates contained the bla KPC-2 variant, and 21 of the 22 were associated with the Tn4401b isoform. The strains were distributed in 8 sequence types (ST), three of which were new. Conjugation and electroporation assays indicated that 95.5% (n=21/22) of the isolates contained the bla KPC gene in plasmids. This study on circulating bacterial strains and the identification of KPC alleles may help to understand the routes of dissemination and control their spread within this hospital. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.
Lee, N Y; Wu, J J; Lin, S H; Ko, W C; Tsai, L H; Yan, J J
This study was conducted in order to characterize carbapenem-nonsusceptible Klebsiella pneumoniae isolates and to evaluate the impacts of recently lowered interpretative breakpoints for carbapenems for Enterobacteriaceae. Among 152 K. pneumoniae bloodstream isolates suspected as AmpC or extended-spectrum β-lactamase (ESBL) producers, 58 (38.2%) isolates were currently interpreted as nonsusceptible to ertapenem, imipenem, or meropenem, and 42 (72.4%) of them were categorized as carbapenem-susceptible by the previous criteria. The high revision rate was associated with the predominance (79.3%) of DHA-1 among the carbapenem-nonsusceptible isolates due to both polyclonal and clonal spread. ESBLs were common (~57%) in both ertapenem-susceptible and -nonsusceptible isolates; however, 84.8% of the carbapenem-nonsusceptible isolates were also AmpC producers. The IMP-8 metallo-β-lactamase was detected in three isolates. Polyacrylamide gel electrophoresis suggested decreased OmpK35 expression in all but one ertapenem-nonsusceptible isolate, and genetic disruptions of ompK35 and ompK36 were detected in 30 and six ertapenem-nonsusceptible isolates, respectively. A comparison between patients infected by AmpC- or ESBL-producing ertapenem-susceptible (n=62) isolates and those with isolates revised as ertapenem-nonsusceptible (n=41) revealed more cases of malignancies (36.6% versus 14.5%; p=0.01) and higher Charlson score (p=0.033) among the patients with ertapenem-nonsusceptible isolates; however, the acquisition of an isolate revised as carbapenem-nonsusceptible was not identified as an independent mortality risk factor.
Full Text Available Na+/H+ exchange is essential for survival of all organisms, having a role in the regulation of the intracellular Na+ concentration, pH and cell volume. Furthermore, Na+/H+ exchangers were shown to be involved in the virulence of the bacterium Yersinia pestis, indicating they might be potential targets for novel antibiotic treatments. The model system for Na+/H+ exchangers is the NhaA transporter from Escherichia coli, EcNhaA. Therefore, the general transport mechanism of NhaA exchangers is currently well characterized. However, much less is known about NhaB exchangers, with only a limited number of studies available. The pathogen Klebsiella pneumoniae, which is a major source of nosocomial infection, possesses three electrogenic Na+/H+ exchangers, KpNhaA1, KpNhaA2 and KpNhaB, none of which have been previously investigated. Our aim in this study was to functionally characterize KpNhaB using solid supported membrane-based electrophysiology as the main investigation technique, and thus provide the first electrophysiological investigation of an NhaB Na+/H+ exchanger. We found that NhaB can be described by the same competition-based mechanism that was shown to be valid for electrogenic NhaA and NapA, and for electroneutral NhaP Na+/H+ exchangers. For comparison we also characterized the activity of KpNhaA1 and KpNhaA2 and found that the three exchangers have complementary activity profiles, which is likely a survival advantage for K. pneumoniae when faced with environments of different salinity and pH. This underlines their importance as potential antibiotic drug targets.
Prima Nanda Fauziah
Full Text Available Lactobacillus bulgaricus produces lactic acid and bacteriocin which have been reported to have various pharmacologic properties, including their role an antibacterial agent. Klebsiella pneumoniae, as an agent of pneumonia, remains a public health problem in tropical countries. This study was aimed to observe the antibacterial activities of lactic acid filtrate and bacteriocins of L. bulgaricus toward againsts K. pneumoniae strains by in vitro experiment. The experiment took place in Microbiology Laboratory, Teaching Hospital, Padjadjaran University, Bandung, August–October 2012. In vitro laboratory analytic study has been conducted on lactic acid filtrate and bacteriocins of L. bulgaricus against the K. pneumoniae strains. The study used agar pour plate and agar disk diffusion method and analyzed by ANAVA followed by Duncan’s multiple range test (DMRT. The 30% lactic acid filtrate and 20% bacteriocins filtrate concentrations of L. bulgaricus showed bactericidal characteristics againts the growth of K. pneumoniae strains. Greater concentration of lactic acid filtrate and bacteriocins of L. bulgaricus led toincreasing effect of growth inhibition zones of K. pneumoniae strains. Statistical analysis of variance (ANOVA showed that the greatest concentration effect of L. bulgaricus filtratefor inhibiting K. pneumoniae strains was achieved in 90% lactic acid filtrate concentration treatment, whereas the greatest inhibition zones for K. pneumoniae ATCC 700603 was obtaubed in 90% bacteriocins filtrate concentration, amounting 16.667 mm. In conclusion, lactic acid filtrate and bacteriocins L. bulgaricus have antibacterial effects on K. pneumoniae. The level of antibacterial effect of L. bulgaricus against the growth of K. pneumoniae strains depends on the type of filtrate, L. bulgaricus filtrate concentration, and K. pneumoniae strain.
Rechenchoski, Daniele Zendrini; Dambrozio, Angélica Marim Lopes; Vivan, Ana Carolina Polano; Schuroff, Paulo Alfonso; Burgos, Tatiane das Neves; Pelisson, Marsileni; Perugini, Marcia Regina Eches; Vespero, Eliana Carolina
The production of KPC (Klebsiella pneumoniae carbapenemase) is the major mechanism of resistance to carbapenem agents in enterobacterias. In this context, forty KPC-producing Enterobacter spp. clinical isolates were studied. It was evaluated the activity of antimicrobial agents: polymyxin B, tigecycline, ertapenem, imipenem and meropenem, and was performed a comparison of the methodologies used to determine the susceptibility: broth microdilution, Etest ® (bioMérieux), Vitek 2 ® automated system (bioMérieux) and disc diffusion. It was calculated the minimum inhibitory concentration (MIC) for each antimicrobial and polymyxin B showed the lowest concentrations for broth microdilution. Errors also were calculated among the techniques, tigecycline and ertapenem were the antibiotics with the largest and the lower number of discrepancies, respectively. Moreover, Vitek 2 ® automated system was the method most similar compared to the broth microdilution. Therefore, is important to evaluate the performance of new methods in comparison to the reference method, broth microdilution. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.
Robustillo Rodela, A; Díaz-Agero Pérez, C; Sanchez Sagrado, T; Ruiz-Garbajosa, P; Pita López, M J; Monge, V
This report describes the epidemiological features of the first outbreak caused by KPC3 carbapenemase-producing Klebsiella pneumoniae (KPC-3-KP) in Spain and how it was effectively controlled. From 16 September 2009 to the end of February 2010, seven patients infected or colonised with KPC-3-KP were detected. Stool surveillance cultures were recovered from patients, doctors, nurses, nursing assistants, cleaners and hospital porters working in the affected units. Hand swabs were taken from workers and patients’ relatives for culturing. Environmental samples were also taken. Patients infected or colonised with KPC-3-KP were placed in single rooms under contact precautions and 4% chlorhexidine soap was used for their daily hygiene. Staff attended educational seminars and workshops on hand hygiene and isolation of patients. An alcohol-based disinfectant was used for surface cleaning and disinfecting. The floor was cleaned with a disinfectant containing benzalkonium chloride and didecyldimethylammonium. All samples collected were negative for KPC-3-KP. After implementing the control measures, no further cases were reported in the affected units. All cases had comorbidities, long hospital stay and aggressive/intensive antimicrobial treatment. This study emphasises the importance of early intensification of infection control to interrupt the transmission of KPC-producing organisms.
Hayden, Mary K; Lin, Michael Y; Lolans, Karen; Weiner, Shayna; Blom, Donald; Moore, Nicholas M; Fogg, Louis; Henry, David; Lyles, Rosie; Thurlow, Caroline; Sikka, Monica; Hines, David; Weinstein, Robert A
Klebsiella pneumoniae carbapenemase-producing Enterobacteriaceae (hereafter "KPC") are an increasing threat to healthcare institutions. Long-term acute-care hospitals (LTACHs) have especially high prevalence of KPC. Using a stepped-wedge design, we tested whether a bundled intervention (screening patients for KPC rectal colonization upon admission and every other week; contact isolation and geographic separation of KPC-positive patients in ward cohorts or single rooms; bathing all patients daily with chlorhexidine gluconate; and healthcare-worker education and adherence monitoring) would reduce colonization and infection due to KPC in 4 LTACHs with high endemic KPC prevalence. The study was conducted between 1 February 2010 and 30 June 2013; 3894 patients were enrolled during the preintervention period (lasting from 16 to 29 months), and 2951 patients were enrolled during the intervention period (lasting from 12 to 19 months). KPC colonization prevalence was stable during preintervention (average, 45.8%; 95% confidence interval [CI], 42.1%-49.5%), declined early during intervention, then reached a plateau (34.3%; 95% CI, 32.4%-36.2%; Pinfection, all-cause bacteremia, and blood culture contamination in a high-risk LTACH population. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: email@example.com.
Li, Lili; Zhou, Sheng; Ji, Huasong; Gao, Ren; Qin, Qiwei
The industrially important organic compound 1,3-propanediol (1,3-PDO) is mainly used as a building block for the production of various polymers. In the present study, response surface methodology protocol was followed to determine and optimize fermentation conditions for the maximum production of 1,3-PDO using marine-derived Klebsiella pneumoniae HSL4. Four nutritional supplements together with three independent culture conditions were optimized as follows: 29.3 g/L glycerol, 8.0 g/L K2 HPO4, 7.6 g/L (NH4)2 SO4, 3.0 g/L KH2 PO4, pH 7.1, cultivation at 35°C for 12 h. Under the optimal conditions, a maximum 1,3-PDO concentration of 14.5 g/L, a productivity of 1.21 g/(L·h) and a conversion of glycerol of 0.49 g/g were obtained. In comparison with the control conditions, fermentation under the optimized conditions achieved an increase of 38.8% in 1,3-PDO concentration, 39.0% in productivity and 25.7% in glycerol conversion in flask. This enhancement trend was further confirmed when the fermentation was conducted in a 5-L fermentor. The optimized fermentation conditions could be an important basis for developing lowcost, large-scale methods for industrial production of 1,3-PDO in the future.
Chérif, Thouraya; Saidani, Mabrouka; Decré, Dominique; Boutiba-Ben Boubaker, Ilhem; Arlet, Guillaume
Over a period of 40 months, plasmid-mediated AmpC β-lactamases were detected in Tunis, Tunisia, in 78 isolates (0.59%) of Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis. In 67 isolates, only one ampC gene was detected, i.e., blaCMY-2-type (n = 33), blaACC (n = 23), blaDHA (n = 6) or blaEBC (n = 5). Multiple ampC genes were detected in 11 isolates, with the following distribution: blaMOX-2, blaFOX-3, and blaCMY-4/16 (n = 6), blaFOX-3 and blaMOX-2 (n = 3), and blaCMY-4 and blaMOX-2 (n = 2). A great variety of plasmids carrying these genes was found, independently of the species and the bla gene. If the genetic context of blaCMY-2-type is variable, that of blaMOX-2, reported in part previously, is unique and that of blaFOX-3 is unique and new. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
Castinel, Aurélie; Grinberg, Alex; Pattison, Rebecca; Duignan, Pádraig; Pomroy, Bill; Rogers, Lynn; Wilkinson, Ian
The 2001/2002 and 2002/2003 breeding seasons of New Zealand sea lions (NZSLs) on the Auckland Islands were marked by a high pup mortality caused by acute bacterial infections. As part of a health survey from 1998/1999 to 2004/2005, tissues and swabs of lesions had been collected at necropsy to identify the bacteria associated with pup mortality. Klebsiella pneumoniae was grown in pure culture from 83% of various organs and lesions in 2001/2002 and 76% in 2002/2003, and less frequently in the following seasons (56% in 2003/2004 and 49% in 2004/2005). Pup isolates of K. pneumoniae showed identical minimal inhibitory concentrations (MIC) of cefuroxime, neomycin, cephalotin, cephalexin and dihydrostreptomycin, suggesting clonal aetiology of the pathogen. Isolates also tested negative for production of extended-spectrum beta-lactamases (ESBLs), which was not in favour of an anthropogenetic origin of the epidemic strain. Pulsed-field gel electrophoresis (PFGE) of XbaI DNA macrorestriction fragments was performed on isolates of K. pneumoniae and Klebsiella oxytoca from 35 pups, thee NZSL adult females, and from three human patients for comparison. PFGE showed that pup isolates of K. pneumoniae were genetically indistinguishable but were neither related to K. pneumoniae from humans and from NZSL adults, nor to K. oxytoca from NZSLs. It is concluded that the 2001/2002 and 2002/2003 epidemics at Sandy Bay rookery were caused by a single K. pneumoniae clonal lineage, genetically different from the strain carried by adult NZSLs. An anthropogenic origin of the K. pneumoniae clone could not be confirmed, but further investigations are required to rule-out such occurrence.
Full Text Available Abstract Background and Objectives: Increasing emergence of fluoroquinolone resistance among clinical isolates of Klebsiella pneumoniae (K. pneumoniae, has limited the treatment options for treatment of infections caused by these bacteria. The aim of this study was to investigate the dissemination of genes encoding AcrAB and QepA efflux pumps among K. pneumoniae strains. Methods: This study was carried out on 117 K. pneumoniae strains isolated from patients hospitalized in selected hospitals in Tehran city, 2015-2016, Iran. Antimicrobial susceptibility tests were performed using disk diffusion method (based on CLSI guidelines and identification of acr A, acr B and qep A genes using PCR assay. Results: In this study, colistin and tigecycline had the best effect against clinical isolates of K. pneumoniae. According to PCR results, 110 (94% isolates had acrA gene and 102 (87% isolates had acrB gene, respectively. The qepA gene was not found in any of the K. pneumoniae strains. Conclusion: According to the results of the present study, dissemination of the genes encoding AcrAB efflux pumps among K. pneumoniae strains, which cause resistance to fluoroquinolones, is a matter of concern. Therefore, infection control and prevention of the spread of drug-resistant bacteria requires careful management in drug prescription and identification of resistant isolates.
Balestrino, D.; Haagensen, Janus Anders Juul; Rich, C.
Quorum sensing is a process by which bacteria communicate by using secreted chemical signaling molecules called autoinducers. Many bacterial species modulate the expression of a wide variety of physiological functions in response to changes in population density by this mechanism. In this study, ...... steps of biofilm formation. These data suggest that a LuxS-dependent signal plays a role in the early stages of biofilm formation by K. pneumoniae....... observed in minimal medium supplemented with glycerol. To determine the potential role of luxS in colonization processes, a K. pneumoniae luxS isogenic mutant was constructed and tested for its capacity to form biofilms in vitro on an abiotic surface and to colonize the intestinal tract in a murine model....... No difference was observed in the level of intestinal colonization between the wild-type strain and the luxS mutant. Microscopic analysis of biofilm structures revealed that the luxS mutant was able to form a mature biofilm but with reduced capacities in the development of microcolonies, mostly in the early...
Full Text Available Klebsiella pneumoniae is the predominant pathogen isolated from liver abscesses of diabetic patients in Asian countries. However, the effects of elevated blood glucose levels on the virulence of this pathogen remain largely unknown. Type 3 fimbriae, encoded by the mrkABCDF genes, are important virulence factors in K. pneumoniae pathogenesis. In this study, the effects of exogenous glucose and the intracellular cyclic AMP (cAMP signaling pathway on type 3 fimbriae expression regulation were investigated. The production of MrkA, the major subunit of type 3 fimbriae, was increased in glucose-rich medium, whereas cAMP supplementation reversed the effect. MrkA production was markedly increased by cyaA or crp deletion, but slightly decreased by cpdA deletion. In addition, the mRNA levels of mrkABCDF genes and the activity of PmrkA were increased in Δcrp strain, as well as the mRNA levels of mrkHIJ genes that encode cyclic di-GMP (c-di-GMP-related regulatory proteins that influence type 3 fimbriae expression. Moreover, the activities of PmrkHI and PmrkJ were decreased in ΔlacZΔcrp strain. These results indicate that CRP-cAMP down-regulates mrkABCDF and mrkHIJ at the transcriptional level. Further deletion of mrkH or mrkI in Δcrp strain diminished the production of MrkA, indicating that MrkH and MrkI are required for the CRP regulation of type 3 fimbriae expression. Furthermore, the high activity of PmrkHI in the ΔlacZΔcrp strain was diminished in ΔlacZΔcrpΔmrkHI, but increased in the ΔlacZΔcrpΔmrkJ strain. Deletion of crp increased the intracellular c-di-GMP concentration and reduced the phosphodiesterase activity. Moreover, we found that the mRNA levels of multiple genes related to c-di-GMP metabolism were altered in Δcrp strain. These indicate that CRP regulates type 3 fimbriae expression indirectly via the c-di-GMP signaling pathway. In conclusion, we found evidence of a coordinated regulation of type 3 fimbriae expression by the CRP
Primary acute conununity-acquired pneumonia was unconunon. ... organisms such as Klebsiella spp. are frequent causes of nosocomial infections."o The larrer ... Accepted 11 Sep 1992. recognised cause of community-acquired Gram-nega-.
Jacobs, David M; Safir, M Courtney; Huang, Dennis; Minhaj, Faisal; Parker, Adam; Rao, Gauri G
The spread of carbapenemase-producing K. pneumoniae (CPKP) has become a significant problem worldwide. Combination therapy for CPKP is encouraging, but polymyxin resistance to many antibiotics is hampering effective treatment. Combination therapy with three or more antibiotics is being increasingly reported, therefore we performed a systematic review of triple combination cases in an effort to evaluate their clinical effectiveness for CPKP infections. The PubMed database was searched to identify all published clinical outcomes of CPKP infections treated with triple combination therapy. Articles were stratified into two tiers depending on the level of clinical detail provided. A tier 1 study included: antibiotic regimen, regimen-specific outcome, patient status at onset of infection, and source of infection. Articles not reaching these criteria were considered tier 2. Thirty-three studies were eligible, 23 tier 1 and ten tier 2. Among tier 1 studies, 53 cases were included in this analysis. The most common infection was pneumonia (31%) followed by primary or catheter-related bacteremia (21%) and urinary tract infection (17%). Different combinations of antibiotic classes were utilized in triple combinations, the most common being a polymyxin (colistin or polymyxin B, 86.8%), tigecycline (73.6%), aminoglycoside (43.4%), or carbapenem (43.4%). Clinical and microbiological failure occurred in 14/39 patients (35.9%) and 22/42 patients (52.4%), respectively. Overall mortality for patients treated with triple combination therapy was 35.8% (19/53 patients). Triple combination therapy is being considered as a treatment option for CPKP. Polymyxin-based therapy is the backbone antibiotic in these regimens, but its effectiveness needs establishing in prospective clinical trials.
Mokhtari, Narges; Daneshpajouh, Shahram; Seyedbagheri, Seyedali; Atashdehghan, Reza; Abdi, Khosro; Sarkar, Saeed; Minaian, Sara; Shahverdi, Hamid Reza; Shahverdi, Ahmad Reza
This study has investigated different visible-light irradiation's effect on the formation of silver nanoparticles from silver nitrate using the culture supernatant of Klebsiella pneumonia. Our study shows that visible-light emission can significantly prompt the synthesis of silver nanoparticles. Also, the study experimentally investigated the liquid mixing process effect on silver nanoparticle synthesis by visible-light irradiation. This study successfully synthesized uniformly dispersed silver nanoparticles with a uniform size and shape in the range of 1-6 nm with an average size of 3 nm. Furthermore, the study investigated the mechanism of the reduction of silver ions by culture supernatant of K. pneumonia, and used X-ray diffraction to characterize silver chloride as an intermediate compound. Silver chloride was prepared synthetically and used as a substrate for the synthesis of silver nanoparticles by culture supernatant of K. pneumonia. The silver nanoparticles have been prepared from silver chloride during this investigation for the first time.
Pilo, Paola; Vogt, Debora; Origgi, Francesco C; Endimiani, Andrea; Peterson, Susanne; Perreten, Vincent
Klebsiella pneumoniae of sequence type (ST) 11 is a hyper-epidemic nosocomial clone spreading worldwide among humans and also emerging in pets. In this report, we describe a clinical case of fatal sepsis due to this multidrug-resistant (MDR) pathogen in a Eurasian beaver. The isolate showed resistance to six different classes of antimicrobials including third generation cephalosporins and fluoroquinolones. This is the first report describing the detection of a MDR K. pneumoniae ST11 in a free-ranging animal. Our finding highlights the potential for environmental dissemination of hyper-epidemic clones of K. pneumoniae and possible spread in wildlife and cause epizootics. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.
Mokhtari, Narges [Department of Pharmaceutical Biotechnology and Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Daneshpajouh, Shahram; Seyedbagheri, Seyedali; Atashdehghan, Reza [Hydrometallurgy Research Unit, Research and Development Center, National Iranian Copper Industries Company, Sarcheshmeh, Rafsanjan (Iran, Islamic Republic of); Abdi, Khosro [Department of Pharmaceutical Biotechnology and Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Sarkar, Saeed [Research Center for Science and Technology in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Minaian, Sara [Department of Pharmaceutical Biotechnology and Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Shahverdi, Hamid Reza [Department of Material Science, Faculty of Engineering, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Shahverdi, Ahmad Reza, E-mail: firstname.lastname@example.org [Department of Pharmaceutical Biotechnology and Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)
This study has investigated different visible-light irradiation's effect on the formation of silver nanoparticles from silver nitrate using the culture supernatant of Klebsiella pneumonia. Our study shows that visible-light emission can significantly prompt the synthesis of silver nanoparticles. Also, the study experimentally investigated the liquid mixing process effect on silver nanoparticle synthesis by visible-light irradiation. This study successfully synthesized uniformly dispersed silver nanoparticles with a uniform size and shape in the range of 1-6 nm with an average size of 3 nm. Furthermore, the study investigated the mechanism of the reduction of silver ions by culture supernatant of K. pneumonia, and used X-ray diffraction to characterize silver chloride as an intermediate compound. Silver chloride was prepared synthetically and used as a substrate for the synthesis of silver nanoparticles by culture supernatant of K. pneumonia. The silver nanoparticles have been prepared from silver chloride during this investigation for the first time.
McDougall, David A J; Morton, Anthony P; Playford, E Geoffrey
The objective of this study was to determine the association between ertapenem and antipseudomonal carbapenem use and carbapenem resistance in Pseudomonas aeruginosa in 12 hospitals in Queensland, Australia. Data on usage of ertapenem and other antipseudomonal carbapenems, measured in defined daily doses per 1000 occupied bed-days, were collated using statewide pharmacy dispensing and distribution software from January 2007 until June 2011. The prevalence of unique carbapenem-resistant P. aeruginosa isolates derived from statewide laboratory information systems was collected for the same time period. Mixed-effects models were used to determine any relationship between ertapenem and antipseudomonal carbapenem usage and carbapenem resistance among P. aeruginosa isolates in the 12 hospitals analysed. No relationship between ertapenem usage and P. aeruginosa carbapenem resistance was observed. The introduction of ertapenem did not replace antipseudomonal carbapenem prescribing to any significant extent. However, an association between greater usage of antipseudomonal carbapenems and greater P. aeruginosa carbapenem resistance was demonstrated. It is likely that the only mechanism by which ertapenem can improve P. aeruginosa resistance patterns is by being used as a substitute for, rather than in addition to, antipseudomonal carbapenems.
Munoz-Price, L Silvia; Rosa, Rossana; Castro, Jose G; Laowansiri, Panthipa; Latibeaudiere, Rachel; Namias, Nicholas; Tarima, Sergey
To determine the time-dependent effect of antibiotics on the initial acquisition of carbapenem-resistant Acinetobacter baumannii. Retrospective cohort study. Forty-bed trauma ICU in Miami, FL. All consecutive patients admitted to the unit from November 1, 2010, to November 30, 2011. None. Patients underwent surveillance cultures at admission to the unit and weekly thereafter. The primary outcome was the acquisition of carbapenem-resistant A. baumannii on surveillance cultures. Daily antibiotic exposures during the time of observation were used to construct time-dependent variables, including cumulative exposures (in grams and daily observed doses [defined daily doses]). Among 360 patients, 45 (12.5%) became colonized with carbapenem-resistant A. baumannii. Adjusted Cox models showed that each additional point in the Acute Physiologic and Chronic Health Evaluation score increased the hazard by 4.8% (hazard ratio, 1.048; 95% CI, 1.010-1.087; p = 0.0124) and time-dependent exposure to carbapenems quadrupled the hazard (hazard ratio, 4.087; 95% CI, 1.873-8.920; p = 0.0004) of acquiring carbapenem-resistant A. baumannii. Additionally, adjusted Cox models determined that every additional carbapenem defined daily dose increased the hazard of acquiring carbapenem-resistant A. baumannii by 5.1% (hazard ratio, 1.051; 95% CI, 1.007-1.093; p = 0.0243). Carbapenem exposure quadrupled the hazards of acquiring A. baumannii even after controlling for severity of illness.
Singkham-In, Uthaibhorn; Chatsuwan, Tanittha
Carbapenem-resistant Acinetobacter baumannii clinical isolates (n=23) were investigated for carbapenem resistance mechanisms and in vitro activities of carbapenems in combination with amikacin, colistin, or fosfomycin. Major carbapenem resistance mechanism was OXA-23 production. The vast majority of these isolates were OXA-23-producing A. baumannii ST195 and ST542, followed by novel STs, ST1417, and ST1423. The interuption of carO by a novel insertion sequence, ISAba40, was found in two isolates. The combinations of imipenem and fosfomycin, meropenem and amikacin, imipenem and amikacin, and imipenem and colistin were synergistic against carbapenem-resistant A. baumannii by 65.2%, 46.2%, 30.8%, and 17.4%, respectively. Surprisingly, the combination of imipenem and fosfomycin was the most effective in this study against A. baumannii, which is intrinsically resistant to fosfomycin. Imipenem and fosfomycin inhibit cell wall synthesis; therefore, fosfomycin may be an adjuvant and enhance the inhibition of cell wall synthesis of carbapenem-resistant A. baumannii when combined with imipenem. Copyright © 2018. Published by Elsevier Inc.
Tsai, Ming-Han; Wu, Tsu-Lan; Su, Lin-Hui; Lo, Wei-Lin; Chen, Chyi-Liang; Liang, Yi-Hua; Chiu, Cheng-Hsun
Pseudomonas aeruginosa isolates that were initially carbapenem-susceptible and later became selective carbapenem-resistant following antimicrobial therapy were identified from individual cases during the same hospitalisation. Cross-resistance to other β-lactams was not found and their susceptibilities remained identical in consecutive isolates. Real-time quantitative reverse transcription PCR was performed to investigate the role of OprD, an outer membrane protein regulating the entry of carbapenems, in the appearance of carbapenem-resistant-only P. aeruginosa (CROPA). Fifteen paired isolates of carbapenem-susceptible P. aeruginosa (CS-PA) and CROPA were identified. All of the cases had carbapenem exposure history within 1 month before the appearance of CROPA (mean 10 days). Reduced OprD expression was found in 93% (14/15) of the isolates, suggesting that oprD inactivation was the major contributor to selective carbapenem resistance. Of the 14 cases with CROPA due to oprD mutation, 71% (10/14) were persistent infection, as genotype analysis revealed that their paired strains were isogenic; 29% (4/14) represented re-infections as they were heterogenic, suggesting that oprD-deficient CROPA existed in the hospital and that carbapenem selective pressure promoted its spread to patients. We conclude that CROPA may occur soon after the use of carbapenems to treat CS-PA infections and that oprD mutation is the major mechanism of resistance in CROPA. Restriction of empirical use of carbapenems by antibiotic stewardship is important to halt the occurrence of CROPA. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.
Temkin, Elizabeth; Torre-Cisneros, Julian; Beovic, Bojana; Benito, Natividad; Giannella, Maddalena; Gilarranz, Raúl; Jeremiah, Cameron; Loeches, Belén; Machuca, Isabel; Jiménez-Martín, María José; Martínez, José Antonio; Mora-Rillo, Marta; Navas, Enrique; Osthoff, Michael; Pozo, Juan Carlos; Ramos Ramos, Juan Carlos; Rodriguez, Marina; Sánchez-García, Miguel; Viale, Pierluigi; Wolff, Michel
ABSTRACT Ceftazidime-avibactam (CAZ-AVI) is a recently approved β-lactam–β-lactamase inhibitor combination with the potential to treat serious infections caused by carbapenem-resistant organisms. Few patients with such infections were included in the CAZ-AVI clinical trials, and clinical experience is lacking. We present a case series of patients with infections caused by carbapenem-resistant Enterobacteriaceae (CRE) or Pseudomonas aeruginosa (CRPa) who were treated with CAZ-AVI salvage therapy on a compassionate-use basis. Physicians who had prescribed CAZ-AVI completed a case report form. We used descriptive statistics to summarize patient characteristics and treatment outcomes. We used the Wilcoxon rank sum test and Fisher's exact test to compare patients by treatment outcome. The sample included 36 patients infected with CRE and two with CRPa. The most common infections were intra-abdominal. Physicians categorized 60.5% of patients as having life-threatening infections. All but two patients received other antibiotics before CAZ-AVI, for a median of 13 days. The median duration of CAZ-AVI treatment was 16 days. Twenty-five patients (65.8%) concurrently received other antibiotics to which their pathogen was nonresistant in vitro. Twenty-eight patients (73.7%, 95% confidence interval [CI], 56.9 to 86.6%) experienced clinical and/or microbiological cure. Five patients (20.8%) with documented microbiological cure died, whereas 10 patients (71.4%) with no documented microbiological cure died (P = 0.01). In three-quarters of cases, CAZ-AVI (alone or combined with other antibiotics) cured infections caused by carbapenem-resistant organisms, 95% of which had failed previous therapy. Microbiological cure was associated with improved survival. CAZ-AVI shows promising clinical results for infections for which treatment options are limited. PMID:27895014
Evaluation of the Clinical and Laboratory Standards Institute phenotypic confirmatory test to detect the presence of extended-spectrum β-lactamases from 4005 Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae and Proteus mirabilis isolates.
Morrissey, Ian; Bouchillon, Samuel K; Hackel, Meredith; Biedenbach, Douglas J; Hawser, Stephen; Hoban, Daryl; Badal, Robert E
A subset of Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae and Proteus mirabilis isolates collected for the Study for Monitoring Antimicrobial Resistance Trends that were positive for the Clinical and Laboratory Standards Institute (CLSI) extended-spectrum β-lactamase (ESBL) phenotypic confirmatory test (n = 3245) or had an ertapenem MIC of ≥0.5 µg ml(-1) (n = 293), or both (n = 467), were analysed for ESBL genes. Most ESBL phenotype E. coli or K. pneumoniae possessed an ESBL gene (95.8 and 88.4 %, respectively), and this was 93.1 % if carbapenem-non-susceptible K. pneumoniae were removed. This rate was lower for P. mirabilis (73.4 %) and K. oxytoca (62.5 %). Virtually all ESBL-positive isolates (99.5 %) were cefotaxime non-susceptible [CLSI or European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints)]. Fewer isolates (82 %) were ceftazidime non-susceptible (CLSI breakpoints). In addition, 21.1 % of E. coli, 25 % of K. oxytoca and 78.7 % of P. mirabilis isolates were ceftazidime susceptible but ESBL positive. This suggests that CLSI breakpoints for ceftazidime are too high to detect ESBLs. The lower EUCAST breakpoints detected ESBLs in E. coli and K. oxytoca better, but 59.6 % of ESBL-positive isolates of P. mirabilis were ceftazidime susceptible. For isolates with ertapenem MICs ≥0.5 µg ml(-1), more accurate ESBL phenotype analysis was observed for E. coli and K. pneumoniae (sensitivity >95 % for both, specificity 94.4 and 54.1 %, respectively). If carbapenemase-positive K. pneumoniae were excluded, the specificity increased to 78 %. The positive predictive values for the ESBL phenotypic test with E. coli and K. pneumoniae were 97.6 and 81.8 %, respectively, and negative predictive values were 75.9 and 95.2 %, respectively. We therefore suggest that it would be prudent to confirm phenotypic ESBL-positive P. mirabilis, K. pneumoniae and K. oxytoca with molecular analysis.
Zhang, Jie; van Aartsen, Jon Jurriaan; Jiang, Xiaofei; Shao, Yucheng; Tai, Cui; He, Xinyi; Tan, Zhilei; Deng, Zixin; Jia, Shiru; Rajakumar, Kumar; Ou, Hong-Yu
Klebsiella pneumoniae is an important bacterial pathogen of man that is commonly associated with opportunistic and hospital-associated infections. Increasing levels of multiple-antibiotic resistance associated with this species pose a major emerging clinical problem. This organism also occurs naturally in other diverse environments, including the soil. Consistent with its varied lifestyle and membership of the Enterobacteriaceae family, K. pneumoniae genomes exhibit highly plastic architecture comprising a core genome backbone interspersed with numerous and varied alien genomic islands. In this study the size of the presently known K. pneumoniae pan-genome gene pool was estimated through analysis of complete sequences of three chromosomes and 31 plasmids belonging to K. pneumoniae strains. In addition, using a PCR-based strategy the genomic content of eight tRNA/tmRNA gene sites that serve as DNA insertion hotspots were investigated in 28 diverse environmental and clinical strains of K. pneumoniae. Sequencing and characterization of five newly identified horizontally-acquired tmRNA-associated islands further expanded the archived K. pneumoniae gene pool to a total of 7648 unique gene members. Large-scale investigation of the content of tRNA/tmRNA hotspots will be useful to identify and/or survey accessory sequences dispersed amongst hundreds to thousands of members of many key bacterial species. Copyright © 2010 Elsevier B.V. All rights reserved.
Ranjbar, Reza; Memariani, Hamed; Sorouri, Rahim; Memariani, Mojtaba
Klebsiella pneumoniae is one of the most important agents of community-acquired urinary tract infection (CA-UTI). In addition to extended-spectrum β-lactamases (ESBLs), a number of virulence factors have been shown to play an important role in the pathogenesis of K. pneumoniae, including capsule, siderophores, and adhesins. Little is known about the genetic diversity and virulence content of the CTX-M-15-producing K. pneumoniae isolated from CA-UTI in Iran. A total of 152 K. pneumoniae isolates were collected from CA-UTI patients in Tehran from September 2015 through April 2016. Out of 152 isolates, 40 (26.3%) carried bla CTX-M-15 . PCR was performed for detection of virulence genes in CTX-M-15-producing isolates. Furthermore, all of these isolates were subjected to multiple-locus variable-number of tandem repeat (VNTR) analysis (MLVA). Using MLVA method, 36 types were identified. CTX-M-15-producing K. pneumoniae isolates were grouped into 5 clonal complexes (CCs). Of these isolates, mrkD was the most prevalent virulence gene (95%), followed by kpn (60%), rmpA (37.5%), irp (35%), and magA (2.5%). No correlation between MLVA types or CCs and virulence genes or antibiotic resistance patterns was observed. Overall, it is thought that CTX-M-15-producing K. pneumoniae strains isolated from CA-UTI have arisen from different clones. Copyright © 2016 Elsevier Ltd. All rights reserved.
Matthijs van der Steen
Full Text Available We investigated time trends in extended-spectrum cephalosporin-resistant Escherichia coli and Klebsiella pneumoniae isolates from different patient settings in The Netherlands from 2008-2012. E. coli and K. pneumoniae isolates from blood and urine samples of patients > = 18 years were selected from the Dutch Infectious Disease Surveillance System-Antimicrobial Resistance (ISIS-AR database. We used multivariable Poisson regression to study the rate per year of blood stream infections by susceptible and resistant isolates, and generalized estimating equation (GEE log-binomial regression for trends in the proportion of extended-spectrum cephalosporin-resistant isolates. Susceptibility data of 197,513 E. coli and 38,244 K. pneumoniae isolates were included. The proportion of extended-spectrum cephalosporin-resistant E. coli and K. pneumoniae isolates from urine and blood samples increased in all patient settings, except for K. pneumoniae isolates from patients admitted to intensive care units. For K. pneumoniae, there was a different time trend between various patient groups (p<0.01, with a significantly higher increase in extended-spectrum cephalosporin-resistant isolates from patients attending a general practitioner than in isolates from hospitalized patients. For E. coli, the increasing time trends did not differ among different patient groups. This nationwide study shows a general increase in extended-spectrum cephalosporin-resistant E. coli and K. pneumoniae isolates. However, differences in trends between E. coli en K. pneumoniae underline the importance of E. coli as a community-pathogen and its subsequent influence on hospital resistance level, while for K. pneumoniae the level of resistance within the hospital seems less influenced by the resistance trends in the community.
Pruthvishree, B S; Vinodh Kumar, O R; Sinha, D K; Malik, Y P S; Dubal, Z B; Desingu, P A; Shivakumar, M; Krishnaswamy, N; Singh, B R
A cross-sectional study was conducted in 10 government-organized pig farms between 2014 and 2016 representing seven states of India to understand the epidemiology of carbapenem resistance in the Escherichia coli. In this study, fecal sample (n = 673) from non-diarrheic (n = 501) and diarrheic (n = 172) piglets were processed for isolation of carbapenem resistant E. coli. Of 673, E. coli isolate (n = 112) was genotyped for confirming the carbapenem resistance and associated virulence factors. Of the 112 isolates, 23 were phenotypically resistant to carbapenem and 8 were carrying the New Delhi metallo beta-lactamase (blaNDM) gene. The carbapenem-resistant isolates also produced extended spectrum beta-lactamases and were multidrug resistant. The PCR-based pathotyping revealed the presence of stx1, stx2, eae and hlyA genes. The enterobacterial repetitive intergenic consensus PCR dendrogram analysis of the isolates yielded three distinct clusters. The statistical analysis revealed no association between carriages of carbapenem-resistant E. coli in different breed of piglets however, location, sex, health status of piglets and age showed significant difference. The spatial analysis with SaTScan helped in identification of carbapenem-resistant clusters. The presence of carbapenem resistant E. coli isolates with virulence genes in the piglet poses a potential public health risk through possible access and spread via the food chain and environment. Efflux pump may also play an important role in carbapenem resistance in piglet E. coli isolates. Furthermore, identification of risk factors in relation to spatial clusters will help in designing preventive strategies for reducing the risk of spread of carbapenem resistant bacteria. 1. Piglets harbor carbapenem resistant E. coli and have great public health significance. 2. Apart from carbapenemase, efflux pump is also important for carbapenem resistance. 3. This is the first report of blaNDM in the piglets from India. © 2017
Wang, Zhe-Chong; Liu, Chia-Jui; Huang, Ying-Jung; Wang, Yu-Seng; Peng, Hwei-Ling
In the Klebsiella pneumoniae CG43 genome, the divergently transcribed genes coding for PecS, the MarR-type transcription factor, and PecM, the drug metabolite transporter, are located between the type 1 and type 3 fimbrial gene clusters. The intergenic sequence pecO between pecS and pecM contains three putative PecS binding sites and a CpxR box. Electrophoretic mobility shift assay revealed that the recombinant PecS and CpxR could specifically bind to the pecO sequence, and the specific interaction of PecS and pecO could be attenuated by urate. The expression of pecS and pecM was negatively regulated by CpxAR and PecS, and was inducible by exogenous urate in the absence of cpxAR. Compared with CG43S3ΔcpxAR, the derived mutants CG43S3ΔcpxARΔpecS and CG43S3ΔcpxARΔpecSΔpecM exerted similar levels of sensitivity to H2O2 or paraquat, but higher levels of mannose-sensitive yeast agglutination activity and FimA production. The promoter activity and transcript levels of fimA in CG43S3ΔcpxAR were also increased by deleting pecS. However, no binding activity between PecS and the fimA promoter could be observed. Nevertheless, PecS deletion could reduce the expression of the global regulator HNS and release the negative effect of HNS on FimA expression. In CG43S3ΔcpxAR, the expression of FimA as well as PecS was inducible by urate, whilst urate-induced FimA expression was inhibited by the deletion of pecS. Taken together, we propose that K. pneumoniae PecS indirectly and negatively regulates the expression of type 1 fimbriae, and the regulation is urate-inducible in the absence of CpxAR.
Yang, Chih-Chao; Wu, Chien-Hsing; Lee, Chien-Te; Liu, Han-Tsung; Chen, Jin-Bor; Chiu, Chien-Hua; Chen, Chih-Hung; Chuang, Feng-Rong
In the face of increasing treatment options for extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-Kp) hemodialysis (HD) access-related bacteremia, the difference in clinical effectiveness between ertapenem and flomoxef remains unclear. We conducted this retrospective study to determine their efficacies and treatment outcomes. Patients on maintenance HD with fistula-, graft-, or catheter-related ESBL-Kp bacteremia were enrolled. Data related to clinical features and antibiotic treatments were collected. Outcome was determined by mortality resulting from bacteremia during the 14-day period after the collection of the first positive blood culture for flomoxef-susceptible ESBL-Kp. The 64 patients studied had severe septicemia as determined by the Pitt bacteremia score; 50% (32/64) were in the intensive care unit (ICU) at the time of bacteremia. Old age (>65 years; 57.8%), malnutrition (albumin30 days; 75%) were also highly prevalent. The study population comprised nine fistula-, 10 graft-, and 45 HD catheter-related bacteremia cases, and the mortality rate was high (38/64, 59.4%). The mortality rate was significantly higher in the flomoxef treatment group than in the ertapenem treatment group (22/30, 73% vs. 16/34, 47%, pflomoxef use (odds ratio (OR) 2.52, 95% confidence interval (CI) 1.34-35.17) and Pitt bacteremia score (OR 4.37, 95% CI 1.28-5.26) were independently associated with mortality. In accordance with our previous study, our results have demonstrated the inferiority of flomoxef to carbapenems in the treatment of HD access-related ESBL-Kp bacteremia and provide an insight into the possibility of using ertapenem rather than flomoxef as an initial or de-escalating therapy for infections caused by ESBL-producing bacteria.
Li, Xiaomin; Liu, Liang; Liu, Tongxu; Yuan, Tian; Zhang, Wei; Li, Fangbai; Zhou, Shungui; Li, Yongtao
Quinone groups in exogenous electron shuttles can accelerate extracellular electron transfer (EET) from bacteria to insoluble terminal electron acceptors, such as Fe(III) oxides and electrodes, which are important in biogeochemical redox processes and microbial electricity generation. However, the relationship between quinone-mediated EET performance and electron-shuttling properties of the quinones remains incompletely characterized. This study investigates the effects of a series of synthetic quinones (SQs) on goethite reduction and current generation by a fermenting bacterium Klebsiella pneumoniae L17. In addition, the voltammetric behavior and electron transfer capacities (ETCs) of SQ, including electron accepting (EAC) and donating (EDC) capacities, is also examined using electrochemical methods. The results showed that SQ can significantly increase both the Fe(III) reduction rates and current outputs of L17. Each tested SQ reversibly accepted and donated electrons as indicated by the cyclic voltammograms. The EAC and EDC results showed that Carmine and Alizarin had low relative capacities of electron transfer, whereas 9,10-anthraquinone-2,6-disulfonic acid (AQDS), 2-hydroxy-1,4-naphthoquinone (2-HNQ), and 5-hydroxy-1,4-naphthoquinone (5-HNQ) showed stronger relative ETC, and 9,10-anthraquinone-2-carboxylic acid (AQC) and 9,10-anthraquinone-2-sulfonic acid (AQS) had high relative ETC. Enhancement of microbial goethite reduction kinetics and current outputs by SQ had a good linear relationship with their ETC, indicating that the effectiveness of quinone-mediated EET may be strongly dependent on the ETC of the quinones. Therefore, the presence of quinone compounds and fermenting microorganisms may increase the diversity of microbial populations that contribute to element transformation in natural environments. Moreover, ETC determination of different SQ would help to evaluate their performance for microbial EET under anoxic conditions. Copyright © 2013 Elsevier
Lyles, Rosie D; Moore, Nicholas M; Weiner, Shayna B; Sikka, Monica; Lin, Michael Y; Weinstein, Robert A; Hayden, Mary K; Sinkowitz-Cochran, Ronda L
To identify differences in organizational culture and better understand motivators to implementation of a bundle intervention to control Klebsiella pneumoniae carbapenemase-producing Enterobacteriaceae (KPC). Mixed-methods study. Four long-term acute care hospitals (LTACHs) in Chicago. LTACH staff across 3 strata of employees (administration, midlevel management, and frontline clinical workers). Qualitative interviews or focus groups and completion of a quantitative questionnaire. Eighty employees (frontline, 72.5%; midlevel, 17.5%; administration, 10%) completed surveys and participated in qualitative discussions in August 2012. Although 82.3% of respondents felt that quality improvement was a priority at their LTACH, there were statistically significant differences in organizational culture between staff strata, with administrative-level having higher organizational culture scores (ie, more favorable responses) than midlevel or frontline staff. When asked to rank the success of the KPC control program, mean response was 8.0 (95% confidence interval, 7.6-8.5), indicating a high level of agreement with the perception that the program was a success. Patient safety and personal safety were reported most often as personal motivators for intervention adherence. The most convergent theme related to prevention across groups was that proper hand hygiene is vital to prevention of KPC transmission. Despite differences in organizational culture across 3 strata of LTACH employees, the high degree of convergence in motivation, understanding, and beliefs related to implementation of a KPC control bundle suggests that all levels of staff may be able to align perspectives when faced with a key infection control problem and quality improvement initiative.
Kumar, Mukesh; Singh, Amrinder; Beniwal, Vikas; Salar, Raj Kumar
Tannase (tannin acyl hydrolase E.C 18.104.22.168) is an inducible, largely extracellular enzyme that causes the hydrolysis of ester and depside bonds present in various substrates. Large scale industrial application of this enzyme is very limited owing to its high production costs. In the present study, cost effective production of tannase by Klebsiella pneumoniae KP715242 was studied under submerged fermentation using different tannin rich agro-residues like Indian gooseberry leaves (Phyllanthus emblica), Black plum leaves (Syzygium cumini), Eucalyptus leaves (Eucalyptus glogus) and Babul leaves (Acacia nilotica). Among all agro-residues, Indian gooseberry leaves were found to be the best substrate for tannase production under submerged fermentation. Sequential optimization approach using Taguchi orthogonal array screening and response surface methodology was adopted to optimize the fermentation variables in order to enhance the enzyme production. Eleven medium components were screened primarily by Taguchi orthogonal array design to identify the most contributing factors towards the enzyme production. The four most significant contributing variables affecting tannase production were found to be pH (23.62 %), tannin extract (20.70 %), temperature (20.33 %) and incubation time (14.99 %). These factors were further optimized with central composite design using response surface methodology. Maximum tannase production was observed at 5.52 pH, 39.72 °C temperature, 91.82 h of incubation time and 2.17 % tannin content. The enzyme activity was enhanced by 1.26 fold under these optimized conditions. The present study emphasizes the use of agro-residues as a potential substrate with an aim to lower down the input costs for tannase production so that the enzyme could be used proficiently for commercial purposes.
Full Text Available BACKGROUND: Carbapenemase-producing Klebsiella pneumoniae (CPKP has been established as important nosocomial pathogen in many geographic regions. Transmission from patient to patient via the hands of healthcare workers is the main route of spread in the acute-care setting. METHODOLOGY/PRINCIPAL FINDINGS: Epidemiological and infection control data were recorded during a prospective observational study conducted in a surgical unit of a tertiary-care hospital in Greece. Surveillance culture for CPKP were obtained from all patients upon admission and weekly thereafter. The Ross-Macdonald model for vector-borne diseases was applied to obtain estimates for the basic reproduction number R(0 (average number of secondary cases per primary case in the absence of infection control and assess the impact of infection control measures on CPKP containment in endemic and hyperendemic settings. Eighteen of 850 patients were colonized with CPKP on admission and 51 acquired CPKP during hospilazation. R(0 reached 2 and exceeded unity for long periods of time under the observed hand hygiene compliance (21%. The minimum hand hygiene compliance level necessary to control transmission was 50%. Reduction of 60% to 90% in colonized patients on admission, through active surveillance culture, contact precautions and isolation/cohorting, in combination with 60% compliance in hand hygiene would result in rapid decline in CPKP prevalence within 8-12 weeks. Antibiotics restrictions did not have a substantial benefit when an aggressive control strategy was implemented. CONCLUSIONS/SIGNIFICANCE: Surveillance culture on admission and isolation/cohorting of colonized patients coupled with moderate hand hygiene compliance and contact precautions may lead to rapid control of CPKP in endemic and hyperendemic healthcare settings.
Sypsa, Vana; Psichogiou, Mina; Bouzala, Georgia-Aikaterina; Hadjihannas, Linos; Hatzakis, Angelos; Daikos, Georgios L.
Background Carbapenemase-producing Klebsiella pneumoniae (CPKP) has been established as important nosocomial pathogen in many geographic regions. Transmission from patient to patient via the hands of healthcare workers is the main route of spread in the acute-care setting. Methodology/Principal Findings Epidemiological and infection control data were recorded during a prospective observational study conducted in a surgical unit of a tertiary-care hospital in Greece. Surveillance culture for CPKP were obtained from all patients upon admission and weekly thereafter. The Ross-Macdonald model for vector-borne diseases was applied to obtain estimates for the basic reproduction number R0 (average number of secondary cases per primary case in the absence of infection control) and assess the impact of infection control measures on CPKP containment in endemic and hyperendemic settings. Eighteen of 850 patients were colonized with CPKP on admission and 51 acquired CPKP during hospilazation. R0 reached 2 and exceeded unity for long periods of time under the observed hand hygiene compliance (21%). The minimum hand hygiene compliance level necessary to control transmission was 50%. Reduction of 60% to 90% in colonized patients on admission, through active surveillance culture, contact precautions and isolation/cohorting, in combination with 60% compliance in hand hygiene would result in rapid decline in CPKP prevalence within 8–12 weeks. Antibiotics restrictions did not have a substantial benefit when an aggressive control strategy was implemented. Conclusions/Significance Surveillance culture on admission and isolation/cohorting of colonized patients coupled with moderate hand hygiene compliance and contact precautions may lead to rapid control of CPKP in endemic and hyperendemic healthcare settings. PMID:22859965
Shankar, Chaitra; Nabarro, Laura E B; Anandan, Shalini; Veeraraghavan, Balaji
Carbapenem-resistant organisms are increasingly common worldwide, particularly in India and are associated with high mortality rates especially in patients with severe infection such as bacteremia. Existing drugs such as carbapenems and polymyxins have a number of disadvantages, but remain the mainstay of treatment. The tetracycline class of antibiotics was first produced in the 1940s. Minocycline, tetracycline derivative, although licensed for treatment of wide range of infections, has not been considered for treatment of multidrug-resistant organisms until recently and needs further in vivo studies. Tigecycline, a derivative of minocycline, although with certain disadvantages, has been frequently used in the treatment of carbapenem-resistant organisms. In this article, we review the properties of minocycline and tigecycline, the common mechanisms of resistance, and assess their role in the management of carbapenem-resistant organisms.
Shah, Pooja G; Shah, Sweta R
Infections caused by carbapenem-resistant bacteria constitute a major challenge for current medical practice. To describe treatment and outcome of carbapenem-resistant Gram-negative bacilli (GNB) blood-stream infection (BSI) caused by these organisms at a tertiary care hospital in Mumbai. Carbapenem-resistant isolates from blood cultures were collected from January 2013 to April 2013. Identification and antimicrobial susceptibility testing were performed using Vitek 2 analyzer (Biomerieux Ltd.). Carbapenemase production was detected by modified Hodge's test (MHT). Patient's medical history, treatment and co-morbid conditions were noted. Outcomes of BSIs were evaluated. Forty-two isolates of carbapenem-resistant GNB isolated from BSIs were Enterobacteriaceae spp. (19), Acinetobacter baumannii (15), and Pseudomonas aeruginosa (8). Colistin had maximum in vitro activity with 97% against Enterobacteriaceae, 100% against Acinetobacter, and 100% activity against Pseudomonas aeruginosa isolates. Positivity of MHT was 92.9%. Outcome of colistin mono and combination therapy was comparable with 83% and 79%, respectively. Outcome of colistin and carbapenem combination therapy was found to be 100 percent. High incidences of bacteremia by carbapenem-resistant GNB including Enterobacteriaceae is a worrisome trend. Treatment options are compromised and only available option is colistin which has its own limitation. Colistin monotherapy may be non-inferior compared to combination therapy for treating BSIs caused by isolates with minimum inhibitory concentration (MIC) for colistin as ≤0.5 mg/l. Combined use of the colistin and carbapenem may provide good therapeutic options for BSI caused by carbapenem-resistant GNB and warrants further investigations.
Webb, Hattie E; Bugarel, Marie; den Bakker, Henk C; Nightingale, Kendra K; Granier, Sophie A; Scott, H Morgan; Loneragan, Guy H
A study was conducted to recover carbapenem-resistant bacteria from the faeces of dairy cattle and identify the underlying genetic mechanisms associated with reduced phenotypic susceptibility to carbapenems. One hundred and fifty-nine faecal samples from dairy cattle were screened for carbapenem-resistant bacteria. Phenotypic screening was conducted on two media containing ertapenem. The isolates from the screening step were characterised via disk diffusion, Modified Hodge, and Carba NP assays. Carbapenem-resistant bacteria and carbapenemase-producing isolates were subjected to Gram staining and biochemical testing to include Gram-negative bacilli. Whole genome sequencing was performed on bacteria that exhibited either a carbapenemase-producing phenotype or were not susceptible to ertapenem and were presumptively Enterobacteriaceae. Of 323 isolates collected from the screening media, 28 were selected for WGS; 21 of which were based on a carbapenemase-producing phenotype and 7 were presumptively Enterobacteriaceae and not susceptible to ertapenem. Based on analysis of WGS data, isolates included: 3 Escherichia coli harbouring blaCMY-2 and truncated ompF genes; 8 Aeromonas harbouring blacphA-like genes; 1 Acinetobacter baumannii harbouring a novel blaOXA gene (blaOXA-497); and 6 Pseudomonas with conserved domains of various carbapenemase-producing genes. Carbapenem resistant bacteria appear to be rare in cattle. Nonetheless, carbapenem-resistant bacteria were detected across various genera and were found to harbour a variety of mechanisms conferring reduced susceptibility. The development and dissemination of carbapenem-resistant bacteria in livestock would have grave implications for therapeutic treatment options in human medicine; thus, continued monitoring of carbapenem susceptibility among enteric bacteria of livestock is warranted.
Timofte, Dorina; Maciuca, Iuliana E; Evans, Nicholas J; Williams, Helen; Wattret, Andrew; Fick, Jenny C; Williams, Nicola J
Recent reports raised concerns about the role that farm stock may play in the dissemination of extended-spectrum β-lactamase (ESBL)-producing bacteria. This study characterized the ESBLs in two Escherichia coli and three Klebsiella pneumoniae subsp. pneumoniae isolates from cases of clinical bovine mastitis in the United Kingdom. Bacterial culture and sensitivity testing of bovine mastitic milk samples identified Gram-negative cefpodoxime-resistant isolates, which were assessed for their ESBL phenotypes. Conjugation experiments and PCR-based replicon typing (PBRT) were used for characterization of transferable plasmids. E. coli isolates belonged to sequence type 88 (ST88; determined by multilocus sequence typing) and carried blaCTX-M-15 and blaTEM-1, while K. pneumoniae subsp. pneumoniae isolates carried blaSHV-12 and blaTEM-1. Conjugation experiments demonstrated that blaCTX-M-15 and blaTEM-1 were carried on a conjugative plasmid in E. coli, and PBRT identified this to be an IncI1 plasmid. The resistance genes were nontransferable in K. pneumoniae subsp. pneumoniae isolates. Moreover, in the E. coli isolates, an association of ISEcp1 and IS26 with blaCTX-M-15 was found where the IS26 element was inserted upstream of both ISEcp1 and the blaCTX-M promoter, a genetic arrangement highly similar to that described in some United Kingdom human isolates. We report the first cases in Europe of bovine mastitis due to E. coli CTX-M-15 and also of bovine mastitis due to K. pneumoniae subsp. pneumoniae SHV-12 β-lactamases in the United Kingdom. We also describe the genetic environment of blaCTX-M-15 and highlight the role that IncI1 plasmids may play in the spread and dissemination of ESBL genes, which have been described in both human and cattle isolates.
Pravin K. Nair
Full Text Available Objective: The emergence of Carbapenem Resistant Enterobacteriaceae (CRE in recent times has become a serious threat to public health due to the high mortality, potential dissemination rates and limited treatment options associated with these organisms. Thus, the present study was conducted in our tertiary care hospital in Mumbai, to retrospectively analyze the prevalence of CRE in the hospital. Methods: The study was carried out in the microbiology department of the tertiary care hospital over a period of 12 months. The samples tested were clinical samples from hospitalized and Out-Patient Department (OPD patients sent to the department for microbiological testing. CRE isolates were identified using the Vitek 2- Compact system (BioMérieux, France. Results: A CRE prevalence rate of 12.26% was obtained from the study, from which the majority of the isolates were detected in urine samples (46%. Although most of the CRE isolates were detected in patient samples from the wards (42% and the ICU (26%, a significant number of isolates was also detected from the OPD patients (19%. Conclusion:Thus, the study shows a significant rate of carbapenem resistance among Enterobacteriaceae isolated from hospitalized and OPD patients. This emphasizes the urgent need for CRE control at the hospital and community level, and to rationalize the use of antibiotics. J Microbiol Infect Dis 2013;3(4: 207-210
Iara Rossi Gonçalves
Full Text Available Abstract Pseudomonas aeruginosa is an opportunistic pathogen that causes frequently nosocomial infections, currently becoming more difficult to treat due to the various resistance mechanisms and different virulence factors. The purpose of this study was to determine the risk factors independently associated with the development of bacteremia by carbapenem-resistant P. aeruginosa, the frequency of virulence genes in metallo-β-lactamases producers and to evaluate their ability to produce biofilm. We conducted a case–control study in the Uberlândia Federal University – Hospital Clinic, Brazil. Polymerase Chain Reaction was performed for metallo-β-lactamases and virulence genes. Adhesion and biofilm assays were done by quantitative tests. Among the 157 strains analyzed, 73.9% were multidrug-resistant, 43.9% were resistant to carbapenems, 16.1% were phenotypically positive for metallo-β-lactamases, and of these, 10.7% were positive for blaSPM gene and 5.3% positive for blaVIM. The multivariable analysis showed that mechanical ventilation, enteral/nasogastric tubes, primary bacteremia with unknown focus, and inappropriate therapy were independent risk factors associated with bacteremia. All tested strains were characterized as strongly biofilm producers. A higher mortality was found among patients with bacteremia by carbapenem-resistant P. aeruginosa strains, associated independently with extrinsic risk factors, however it was not evident the association with the presence of virulence and metallo-β-lactamases genes.
Full Text Available La resistencia a carbapenémicos en Klebsiella pneumoniae ha aumentado de manera considerable, incrementando las tasas de morbimortalidad. El objetivo de este trabajo fue describir las características epidemiológicas, microbiológicas y las medidas de intervención que permitieron el control exitoso de un brote de Klebsiella pneumoniae productora de KPC-2. Métodos: El estudio se realizó en 2 periodos: el primero durante el brote, con instauración de un protocolo de medidas de intervención; y el segundo, de seguimiento posbrote. Se realizaron pruebas de identificación y susceptibilidad por sistema automatizado, tamización de carbapenemasas por test de Hodge modificado, PCR para detección de los genes bla KPC , bla KPC-2 , NDM-1 y estudio de clonalidad por electroforesis de campos pulsados. Resultados: Durante el brote, se identificaron 18 aislamientos de Klebsiella pneumoniae productora de KPC en 11 pacientes. Tres casos fueron confirmados como infección intrahospitalaria. La técnica de PCR reveló la presencia del gen bla KPC en 21 de 22 aislamientos (pacientes y medio ambiente y se identificó la presencia de un clon con una similitud superior al 75%. En el periodo posbrote los cultivos ambientales y de búsqueda de colonizados fueron negativos. Discusión: Se evidenció un control exitoso del brote producido por un clon. La implementación de un protocolo de intervención y la monitorización de su cumplimiento, la comunicación efectiva y el trabajo en equipo fueron indispensables para evitar su propagación y evitar un comportamiento endémico posbrote.
Kamaladevi, Arumugam; Balamurugan, Krishnaswamy
In the present study, the effect of Lactic Acid Bacteria (LAB) was investigated at the molecular level using the model organism Caenorhabditis elegans against Klebsiella pneumoniae. Out of the 13 LAB screened, Lactobacillus casei displayed excellent protective efficacy by prolonging the survival of K. pneumoniae-infected nematodes. Pretreatment with L. casei significantly decreased bacterial colonization and rescued K. pneumoniae-infected C. elegans from various physiological impairments. The concomitant upregulation of key immune genes that regulate the TLR, RACK-1 as well as the p38 MAPK pathway rather than the IIS and ERK pathway suggested that the plausible immunomodulatory mechanism of L. casei could be by triggering the TLR, RACK-1 and p38 MAPK pathway. Furthermore, the hyper-susceptibility of L. casei treated loss-of-function mutants of the tol-1, RACK-1 and p38 MAPK pathway (sek-1 and pmk-1) to K. pneumoniae infection and gene expression analysis suggested that L. casei triggered a TLR mediated RACK-1 dependent p38 MAPK pathway to increase host resistance and protect nematodes against K. pneumoniae infection.
Kader, Abdulrahman A.; Kumar, A.; Krishna, A.; Zaman, M.N.
We prospectively studied an accelerated phenotypic method by incorporating the double disk synergy test in the standard Kirby-Bauer disk diffusion susceptibility testing, to evaluate a protocol for the rapid detection of extended of extended-spectrum B-lactamases (ESBL) in urinary isolates of Escherichia coli (E. coli) and Klebsiella, pneumoniae (K. pneumoniae). All ESBL-positive isolates were confirmed by the standard Clinical Laboratory Standards Institute (CLSI) confirmatory disk diffusion method. Between November 2004 and December 2005, a total of 6988 urine specimens were analyzed of which 776 (11%) showed significant growth. They included E. coli in 577 cases (74%) and K. pneumoniae in 199 (25.6%). Of these, 63 E. coli (8%) and 15 K. pneumoniae (7.5%) were positive for ESBL by the accelerated and CLSI methods. Compared to the standard CLSI method, the accelerated method reduced the ESBL detection time from two days to one day. We conclude that the accelerated ESBL detection technique used by us in this study is a reliable and rapid method for detecting ESBL in urinary isolates of E. coli and K. pneumoniae. (author)
Cheong, Youjin; Kim, Young Jin; Kang, Heeyoon; Choi, Samjin; Lee, Hee Joo
Although many methodologies have been developed to identify unknown bacteria, bacterial identification in clinical microbiology remains a complex and time-consuming procedure. To address this problem, we developed a label-free method for rapidly identifying clinically relevant multilocus sequencing typing-verified quinolone-resistant Klebsiella pneumoniae strains. We also applied the method to identify three strains from colony samples, ATCC70063 (control), ST11 and ST15; these are the prevalent quinolone-resistant K. pneumoniae strains in East Asia. The colonies were identified using a drop-coating deposition surface-enhanced Raman scattering (DCD-SERS) procedure coupled with a multivariate statistical method. Our workflow exhibited an enhancement factor of 11.3 × 106 to Raman intensities, high reproducibility (relative standard deviation of 7.4%), and a sensitive limit of detection (100 pM rhodamine 6G), with a correlation coefficient of 0.98. All quinolone-resistant K. pneumoniae strains showed similar spectral Raman shifts (high correlations) regardless of bacterial type, as well as different Raman vibrational modes compared to Escherichia coli strains. Our proposed DCD-SERS procedure coupled with the multivariate statistics-based identification method achieved excellent performance in discriminating similar microbes from one another and also in subtyping of K. pneumoniae strains. Therefore, our label-free DCD-SERS procedure coupled with the computational decision supporting method is a potentially useful method for the rapid identification of clinically relevant K. pneumoniae strains.
Full Text Available Extended spectrum β-lactamases production is one of the most common mechanism of resistance to extendedspectrum β-lactam antibiotics is increasing worldwide. Twenty five strains of Klebsiella pneumoniae isolated from clinicalspecimens were tested. Based on the phenotypic confirmatory test all these strains were defined as ESBL producers namedESBL(+. The plasmid DNA from each strains was used to investigate the presence of blaSHV genes responsible for extendedspectrum β-lactamases production. Moreover, susceptibility of these strains to antibiotic other than β-lactams in was tested.
Zhong, Xue-Shan; Ge, Jing; Chen, Shao-Wei; Xiong, Yi-Quan; Zheng, Xue-Yan; Qiu, Min; Huo, Shu-Ting; Chen, Qing
To investigate antimicrobial resistance of Klebsiella pneumoniae and Pseudomonas aeruginosa isolates in fecal samples from rat-like animals. Rat-like animals were captured using cages around a hospital and the neighboring residential area between March and October, 2015. K. pneumoniae and P. aeruginosa were isolated from the fecal samples of the captured animals. Antimicrobial susceptibility test was performed according to the guidelines of Clinical and Laboratory Standards Institute (2014). A total of 329 rat-like animals were captured, including 205 Suncus murinus, 111 Rattus norvegicus, 5 Rattus flavipectus and 8 Mus musculus. The positivity rates of K. pneumoniae and P. aeruginosa were 78.4% and 34.7% in the fecal samples from the captured animals, respectively. K. pneumoniae isolates from Suncus murinus showed a high resistance to ampicillin, cephazolin, nitrofurantoin, piperacillin and cefotaxime (with resistance rates of 100%, 51.2%, 44.2%, 37.2%, and 23.3%, respectively), and K. pneumoniae isolates from Rattus spp. showed a similar drug-resistance profile. The prevalence rates of multidrug resistance and ESBLs were 40.9% and 10.7%, respectively. P. aeruginosa from both Suncus murinus and Rattus spp. exhibited the highest resistance rates to aztreonam (12.4% and 16.0%, respectively), followed by penicillins and fluoroquinolones. P. aeruginosa isolates were susceptible to cephems, aminoglycosides and carbapenems (with resistance rates below 5%). K. pneumoniae and P. aeruginosa isolated from rat-like animals showed drug-resistance profiles similar to those of the strains isolated from clinical patients, suggesting that the possible transmission of K. pneumoniae and P. aeruginosa between rat-like animals and human beings.
Derrick E Fouts
Full Text Available We report here the sequencing and analysis of the genome of the nitrogen-fixing endophyte, Klebsiella pneumoniae 342. Although K. pneumoniae 342 is a member of the enteric bacteria, it serves as a model for studies of endophytic, plant-bacterial associations due to its efficient colonization of plant tissues (including maize and wheat, two of the most important crops in the world, while maintaining a mutualistic relationship that encompasses supplying organic nitrogen to the host plant. Genomic analysis examined K. pneumoniae 342 for the presence of previously identified genes from other bacteria involved in colonization of, or growth in, plants. From this set, approximately one-third were identified in K. pneumoniae 342, suggesting additional factors most likely contribute to its endophytic lifestyle. Comparative genome analyses were used to provide new insights into this question. Results included the identification of metabolic pathways and other features devoted to processing plant-derived cellulosic and aromatic compounds, and a robust complement of transport genes (15.4%, one of the highest percentages in bacterial genomes sequenced. Although virulence and antibiotic resistance genes were predicted, experiments conducted using mouse models showed pathogenicity to be attenuated in this strain. Comparative genomic analyses with the presumed human pathogen K. pneumoniae MGH78578 revealed that MGH78578 apparently cannot fix nitrogen, and the distribution of genes essential to surface attachment, secretion, transport, and regulation and signaling varied between each genome, which may indicate critical divergences between the strains that influence their preferred host ranges and lifestyles (endophytic plant associations for K. pneumoniae 342 and presumably human pathogenesis for MGH78578. Little genome information is available concerning endophytic bacteria. The K. pneumoniae 342 genome will drive new research into this less-understood, but
Full Text Available Aim To determine the prevalence of ESBL-producing Escherichia coli and Klebsiella pneumoniae strains isolated from urine of nonhospitalized patients during a three-year period, to determine their antibiotic susceptibility, investigate the transfer of ESBL genes with cotransfer of resistance and to characterize isolated beta-lactamases. Methods Antimicrobial susceptibility was determined by disk diffusion and broth microdilution methods. The double-disk test was used for ESBL detection. Transfer of resistance was performed by broth mating method and characterization of isolated beta-lactamases by polymerase chain reaction. Results The prevalence of ESBL-producing E. coli was 1.5% and of K. pneumoniae 4.1% with its different distribution according to patients`age and gender. ESBL-producing K. pneumoniae showed high resistance rates to aminoglycosides, cotrimoxazole, nitrofurantoin and quinolones while ESBL-producing E. coli isolates, with exception of high aminoglycoside resistance, showed low resistance rates to other antibiotics. Successful conjugation of ESBL genes was obtained with 25% E. coli and 76.2% K. pneumoniae strains. Comparing to E. coli, K. pneumoniae strains showed higher rates of aminoglycosideand cotrimoxazole resistance cotransfer. Beta-lactamases of investigated strains belonged to TEM, SHV and CTX-M families.Conclusion The existence of multiple-resistant ESBL-producing E. coli and K. pneumoniae strains was confirmed in observed outpatient population. ESBL-producing K. pneumoniae isolates, in contrast toESBL-producing E. coli, showed higher resistance rates to non-beta-lactam antibiotics, probably caused by cotransfer of resistance genes located on the same plasmid as ESBL genes. It is important to monitor the prevalence of such strains and their possible spreading in the outpatient population of the Zagreb region
Solovieva, Ekaterina V; Myakinina, Vera P; Kislichkina, Angelina A; Krasilnikova, Valentina M; Verevkin, Vladimir V; Mochalov, Vladimir V; Lev, Anastasia I; Fursova, Nadezhda K; Volozhantsev, Nikolay V
Hypermucoviscous (HV) strains of capsular types K1, K2 and K57 are the most virulent representatives of the Klebsiella pneumoniae species. Eight novel bacteriophages lytic for HV K. pneumoniae were isolated and characterized. Three bacteriophages, KpV41, KpV475, and KpV71 were found to have a lytic activity against mainly K. pneumoniae of capsular type K1. Two phages, KpV74, and KpV763 were lytic for K2 capsular type K. pneumoniae, and the phage KpV767 was specific to K57-type K. pneumoniae only. Two more phages, KpV766, and KpV48 had no capsular specificity. The phage genomes consist of a linear double-stranded DNA of 40,395-44,623bp including direct terminal repeats of 180-246 bp. The G + C contents are 52.3-54.2 % that is slightly lower than that of genomes of K. pneumoniae strains being used for phage propagation. According to the genome structures, sequence similarity and phylogenetic data, the phages are classified within the genus Kp32virus and Kp34virus of subfamily Autographivirinae, family Podoviridae. In the phage genomes, genes encoding proteins with putative motifs of polysaccharide depolymerase were identified. Depolymerase genes of phages KpV71 and KpV74 lytic for hypermucoviscous K. pneumoniae of K1 and K2 capsular type, respectively, were cloned and expressed in Escherichia coli, and the recombinant gene products were purified. The specificity and polysaccharide-degrading activity of the recombinant depolymerases were demonstrated. Copyright © 2017 Elsevier B.V. All rights reserved.
Full Text Available Abstract: INTRODUCTION: Due to the wide use of tigecycline in the treatment of severe infections caused by multidrug-resistant (MDR bacteria, clinical resistance to tigecycline has increased in recent years. Here, we investigated the relationship between tigecycline resistance and the expression of efflux pumps. METHODS: Clinical isolates of Acinetobacter baumannii and Klebsiella pneumoniae were consecutively collected from hospitalized patients in three hospitals. The minimum inhibitory concentration (MIC of tigecycline was determined using the broth microdilution method. Expression levels of efflux pump genes and regulators were examined by quantitative real-time reverse transcription polymerase chain reaction. The correlations between tigecycline MICs and gene expression levels were analyzed. RESULTS: Overall, 1,026 A. baumannii and 725 K. pneumoniae strains were collected. Most strains were isolated from sputum. The tigecycline resistance rate was 13.4% in A. baumannii isolates and 6.5% in K. pneumoniae isolates. Overexpression of AdeABC and AcrAB-TolC efflux systems was observed found in clinical tigecycline-resistant isolates. The tigecycline MIC had a linear relationship with the adeB expression level in A. baumannii isolates, but not with the acrB expression level in K. pneumoniae isolates. There were significant linear trends in the overexpression of ramA as the tigecycline MIC increased in K. pneumoniae isolates. CONCLUSIONS: Tigecycline resistance in A. baumannii and K. pneumoniae was strongly associated with the overexpression of efflux systems. More studies are needed to elucidate whether there are other regulators that affect the expression of adeB in A. baumannii and how ramA affects the expression of acrB in K. pneumoniae.
Alexsandra Maria Silva Lima
Full Text Available Introduction The high prevalence of Klebsiella pneumoniae infections is related to the ability of K. pneumoniae to acquire and disseminate exogenous genes associated with mobile elements, such as R plasmids, transposons and integrons. This study investigated the presence of class 1 integrons in clinical and microbiota isolates of K. pneumoniae belonging to different phylogenetic groups and correlated these results with the antimicrobial resistance profiles of the studied isolates. Methods Of the 51 isolates of K. pneumoniae selected for this study, 29 were from multidrug-resistant clinical isolates, and 22 were from children's microbiota. The susceptibility profile was determined using the disk diffusion method, and class 1 integrons were detected through polymerase chain reaction (PCR. Results The results showed that none of the 22 microbiota isolates carried class 1 integrons. Among the 29 clinical isolates, 19 (65.5% contained class 1 integrons, and resistance to sulfamethoxazole/trimethoprim was identified in 18 of these isolates (94.7%. Among the K. pneumoniae isolates with class 1 integrons, 47% belonged to the KpI phylogenetic group, and one isolate (14.3% carrying these genetic elements belonged to the KpIII group. Conclusions The wide variety of detected class 1 integrons supports the presence of high rates of antimicrobial resistance, genetic variability, and rapid dissemination of beta-lactamase genes among K. pneumoniae clinical isolates in recent years in hospitals in Recife-PE, Brazil. The findings of this study indicate that the surveillance of K. pneumoniae integrons in clinical isolates could be useful for monitoring the spread of antibiotic resistance genes in the hospital environment.
Ostria-Hernández, Martha Lorena; Sánchez-Vallejo, Carlos Javier; Ibarra, J Antonio; Castro-Escarpulli, Graciela
In recent years the emergence of multidrug resistant Klebsiella pneumoniae strains has been an increasingly common event. This opportunistic species is one of the five main bacterial pathogens that cause hospital infections worldwide and multidrug resistance has been associated with the presence of high molecular weight plasmids. Plasmids are generally acquired through horizontal transfer and therefore is possible that systems that prevent the entry of foreign genetic material are inactive or absent. One of these systems is CRISPR/Cas. However, little is known regarding the clustered regularly interspaced short palindromic repeats and their associated Cas proteins (CRISPR/Cas) system in K. pneumoniae. The adaptive immune system CRISPR/Cas has been shown to limit the entry of foreign genetic elements into bacterial organisms and in some bacteria it has been shown to be involved in regulation of virulence genes. Thus in this work we used bioinformatics tools to determine the presence or absence of CRISPR/Cas systems in available K. pneumoniae genomes. The complete CRISPR/Cas system was identified in two out of the eight complete K. pneumoniae genomes sequences and in four out of the 44 available draft genomes sequences. The cas genes in these strains comprises eight cas genes similar to those found in Escherichia coli, suggesting they belong to the type I-E group, although their arrangement is slightly different. As for the CRISPR sequences, the average lengths of the direct repeats and spacers were 29 and 33 bp, respectively. BLAST searches demonstrated that 38 of the 116 spacer sequences (33%) are significantly similar to either plasmid, phage or genome sequences, while the remaining 78 sequences (67%) showed no significant similarity to other sequences. The region where the CRISPR/Cas systems were located is the same in all the Klebsiella genomes containing it, it has a syntenic architecture, and is located among genes encoding for proteins likely involved in
Long, S Wesley; Olsen, Randall J; Eagar, Todd N; Beres, Stephen B; Zhao, Picheng; Davis, James J; Brettin, Thomas; Xia, Fangfang; Musser, James M
Klebsiella pneumoniae is a major human pathogen responsible for high morbidity and mortality rates. The emergence and spread of strains resistant to multiple antimicrobial agents and documented large nosocomial outbreaks are especially concerning. To develop new therapeutic strategies for K. pneumoniae , it is imperative to understand the population genomic structure of strains causing human infections. To address this knowledge gap, we sequenced the genomes of 1,777 extended-spectrum beta-lactamase-producing K. pneumoniae strains cultured from patients in the 2,000-bed Houston Methodist Hospital system between September 2011 and May 2015, representing a comprehensive, population-based strain sample. Strains of largely uncharacterized clonal group 307 (CG307) caused more infections than those of well-studied epidemic CG258. Strains varied markedly in gene content and had an extensive array of small and very large plasmids, often containing antimicrobial resistance genes. Some patients with multiple strains cultured over time were infected with genetically distinct clones. We identified 15 strains expressing the New Delhi metallo-beta-lactamase 1 (NDM-1) enzyme that confers broad resistance to nearly all beta-lactam antibiotics. Transcriptome sequencing analysis of 10 phylogenetically diverse strains showed that the global transcriptome of each strain was unique and highly variable. Experimental mouse infection provided new information about immunological parameters of host-pathogen interaction. We exploited the large data set to develop whole-genome sequence-based classifiers that accurately predict clinical antimicrobial resistance for 12 of the 16 antibiotics tested. We conclude that analysis of large, comprehensive, population-based strain samples can assist understanding of the molecular diversity of these organisms and contribute to enhanced translational research. IMPORTANCE Klebsiella pneumoniae causes human infections that are increasingly difficult to
Carlson-Banning, Kimberly M; Chou, Andrew; Liu, Zhen; Hamill, Richard J; Song, Yongcheng; Zechiedrich, Lynn
Antibiotic-resistant infections caused by gram-negative bacteria are a major healthcare concern. Repurposing drugs circumvents the time and money limitations associated with developing new antimicrobial agents needed to combat these antibiotic-resistant infections. Here we identified the off-patent antifungal agent, ciclopirox, as a candidate to repurpose for antibiotic use. To test the efficacy of ciclopirox against antibiotic-resistant pathogens, we used a curated collection of Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae clinical isolates that are representative of known antibiotic resistance phenotypes. We found that ciclopirox, at 5-15 µg/ml concentrations, inhibited bacterial growth regardless of the antibiotic resistance status. At these same concentrations, ciclopirox reduced growth of Pseudomonas aeruginosa clinical isolates, but some of these pathogens required higher ciclopirox concentrations to completely block growth. To determine how ciclopirox inhibits bacterial growth, we performed an overexpression screen in E. coli. This screen revealed that galE, which encodes UDP-glucose 4-epimerase, rescued bacterial growth at otherwise restrictive ciclopirox concentrations. We found that ciclopirox does not inhibit epimerization of UDP-galactose by purified E. coli GalE; however, ΔgalU, ΔgalE, ΔrfaI, or ΔrfaB mutant strains all have lower ciclopirox minimum inhibitory concentrations than the parent strain. The galU, galE, rfaI, and rfaB genes all encode enzymes that use UDP-galactose or UDP-glucose for galactose metabolism and lipopolysaccharide (LPS) biosynthesis. Indeed, we found that ciclopirox altered LPS composition of an E. coli clinical isolate. Taken together, our data demonstrate that ciclopirox affects galactose metabolism and LPS biosynthesis, two pathways important for bacterial growth and virulence. The lack of any reported fungal resistance to ciclopirox in over twenty years of use in the clinic, its excellent safety
Full Text Available Shirui Tan,1,2,* Changpei Gan,1,3,* Rongpeng Li,1 Yan Ye,1 Shuang Zhang,1,3 Xu Wu,1 Yi Yan Yang,4 Weimin Fan,5 Min Wu11Department of Basic Sciences, School of Medicine and Health Sciences University of North Dakota, Grand Forks, ND, USA; 2Laboratory of Biochemistry and Molecular Biology, School of Life Sciences, Yunnan University, Kunming, People’s Republic of China; 3State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, People’s Republic of China; 4Institute of Bioengineering and Nanotechnology, The Nanos, Singapore; 5Program of Innovative Cancer Therapeutics, First Affiliated Hospital of Zhejiang University College of Medicine, Hangzhou, People’s Republic of China *These authors contributed equally to this work Abstract: Klebsiella pneumoniae (Kp is one of the most common pathogens in nosocomial infections and is increasingly becoming multiple drug resistant. However, the molecular pathogenesis of Kp in causing tissue injury and dysregulated host defense remains elusive, further dampening the development of novel therapeutic measures. We have previously screened a series of synthetic antimicrobial beta-sheet forming peptides and identified a peptide (IRIKIRIK; ie, IK8L with a broad range of bactericidal activity and low cytotoxicity in vitro. Here, employing an animal model, we investigated the antibacterial effects of IK8L in acute infection and demonstrated that peritoneal injection of IK8L to mice down-regulated inflammatory cytokines, alleviated lung injury, and importantly, decreased mortality compared to sham-injected controls. In addition, a math model was used to evaluate in vivo imaging data and predict infection progression in infected live animals. Mechanistically, IK8L can kill Kp by inhibiting biofilm formation and modulating production of inflammatory cytokines through the STAT3/JAK signaling both in vitro and in vivo. Collectively, these findings reveal that IK8L may have potential for
Horikoshi, Yuho; Suwa, Junichi; Higuchi, Hiroshi; Kaneko, Tetsuji; Furuichi, Mihoko; Aizawa, Yuta; Fukuoka, Kahoru; Okazaki, Kaoru; Ito, Kenta; Shoji, Takayo
The impact of pediatric antimicrobial stewardship programs (ASP) on antimicrobial resistance (AMR) remains largely unknown. This study aimed to evaluate the AMR for carbapenem of Gram-negative bacilli (GNB) and carbapenem use with infectious diseases consultation after the implementation of an ASP. This quasi-experimental study was conducted at Tokyo Metropolitan Children's Medical Center in Japan. The pre- and post-intervention periods were April 2010 to September 2011 and October 2011 to March 2017, respectively. The pre-intervention phase consisted of consultations with the infectious diseases service alone. The ASP was implemented during the post-intervention phase. The carbapenem resistance rates of GNB were calculated. The correlation between carbapenem resistance rates and carbapenem day of therapy (DOT) was examined. The outcome metrics were compared by average length of hospitalization, all-cause mortality, and infection-related mortality. A positive correlation was observed between the carbapenem resistance rate in Pseudomonas aeruginosa and DOT (0.76, p=0.04). The carbapenem resistance rate in P. aeruginosa (pcarbapenem use and resistance in P. aeruginosa, leading to favorable outcomes in terms of length of hospitalization and infection-related mortality. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.
Souza Lopes, Ana Catarina; Rodrigues, Juliana Falcão; Cabral, Adriane Borges; da Silva, Maíra Espíndola; Leal, Nilma Cintra; da Silveira, Vera Magalhães; de Morais Júnior, Marcos Antônio
Eighty-five isolates of Klebsiella pneumoniae and Enterobacter spp., originating from hospital- and community-acquired infections and from oropharyngeal and faecal microbiota from patients in Recife-PE, Brazil, were analyzed regarding the presence of irp2 gene. This is a Yersinia typical gene involved in the synthesis of siderophore yersiniabactin. DNA sequencing confirmed the identity of irp2 gene in five K. pneumoniae, five Enterobacter aerogenes and one Enterobacter amnigenus isolates. To our knowledge in the current literature, this is the first report of the irp2 gene in E. amnigenus, a species considered an unusual human pathogen, and in K. pneumoniae and E. aerogenes isolates from the normal microbiota and from community infections, respectively. Additionally, the analyses of nucleotide and amino acid sequences suggest the irp2 genes derived from isolates used in this study are more closely related to that of Yersinia pestis P.CE882 than to that of Yersinia enterocolitica 8081. These data demonstrated that K. pneumoniae and Enterobacter spp. from normal microbiota and from community- and hospital-acquired infections possess virulence factors important for the establishment of extra-intestinal infections. Copyright © 2016 Elsevier Ltd. All rights reserved.
Raquel Teles de Menezes
Full Text Available Klebsiella pneumoniae é um dos patógenos que possui grande resistência a vários antimicrobianos. A Terapia Fotodinâmica Antimicrobiana (PDT vem sendo estudada como novo recurso no combate à resistência bacteriana. Objetivo: Avaliar a ação antimicrobiana da PDT em K. pneumoniae utilizando como modelo de infecção in vivo Galleria mellonella. Métodos: Foram inoculados 10µL da suspensão padronizada de K. pneumoniae ATCC 4352 na última proleg esquerda de cada larva selecionada de G. mellonella. Decorridos 30 minutos, as larvas foram submetidas a PDT, com o uso do fotossensibilizador Azul de metileno e Laser de Arseneto de Gálio Alumínio. Passadas 24h, por sete dias o número de lagartas mortas foi anotado para a realização da curva de sobrevivência. Resultados: A PDT contribuiu para melhora da sobrevida das larvas, porém sem apresentar diferença estatística significante. Conclusão: A PDT apresentou atividade antimicrobiana contra a cepa de K. pneumoniae ATCC 4352.
Full Text Available Background: Urinary tract infection (UTI is the second prevalent infection in human mostly caused by Escherichia coli and Klebsiella pneumonia. The aim of this study was to determine the antibiotic resistance profile and detect the prevalence of antibiotic resistance encoding genes in K .pneumoniae isolated from UTI. Materials and Methods: Fifty K. pneumonia strains isolated from 122 UTI samples of hospitalized patients in Payambaran Hospital (Tehran, Iran which were subjected to this study (2014 were confirmed by standard biochemical tests. Isolates were tested for susceptibility to 10 antimicrobial drugs by using disk diffusion method. Antibiotic resistance encoding genes frequently include the aadA1, aac(3-IV, sul1, blaSHV, Cat1, cmlA, tetA, tetB, dfrA1, CITM, qnr in isolates were determined by PCR. Results: The highest antibiotic resistance in K. pneumoniae isolates were for Tetracycline and the lowest resistance (2% for Gentamicin and Imipenem. To determine the frequency of antibiotic resistant genes, 64% and 4% of isolates had tetA and Gentamicin-(aac(3-IV resistant genes, respectively. Conclusion: Frequency of antibiotic resistance encoding genes may have important and basic role in the occurrence and transfer of antibiotic resistance which can be due to the indiscriminate use of antibiotics.
Siu, L Kristopher; Tsai, Yu-Kuo; Lin, Jung-Chung; Chen, Te-Li; Fung, Chang-Phone; Chang, Feng-Yee
In this study, a novel colloidal gold-based immunochromatographic strip (ICS) containing anti-Klebsiella pneumoniae capsular polysaccharide polyclonal antibodies was developed to specifically detect K. pneumoniae serotypes K1 and K2. Capsular polysaccharide K1 and K2 antigens were first used to produce polyclonal anti-K1 and anti-K2 antibodies. Reference strains with different serotypes, nontypeable K. pneumoniae strains, and other bacterial species were then used to assess the sensitivity and specificity of these test strips. The detection limit was found to be 10 5 CFU, and the ICSs were stable for 6 months when stored at room temperature. No false-positive or false-negative results were observed, and equivalent results were obtained compared to those of more conventional test methods, such as PCR or serum agglutination. In conclusion, the ICS developed here requires no technical expertise and allows for the specific, rapid, and simultaneous detection of K. pneumoniae serotypes K1 and K2. Copyright © 2016, American Society for Microbiology. All Rights Reserved.
Mogna, Luca; Deidda, Francesca; Nicola, Stefania; Amoruso, Angela; Del Piano, Mario; Mogna, Giovanni
To determine the in vitro antimicrobial activity of selected Lactobacillus strains isolated from the feces of healthy humans against Klebsiella pneumoniae. Klebsiella is ubiquitous in nature and may colonize the skin, the pharynx, or the gastrointestinal tract of humans. Despite the widespread use of antibiotic molecules with a broad spectrum in hospitalized patients, an increased overall load of klebsiellae as well as the subsequent development of multidrug-resistant strains able to synthesize extended-spectrum beta-lactamase have been registered. These strains are particularly virulent, express capsular-type K55, and have a considerable ability to propagate. The 4 strains Lactobacillus paracasei LPC01 (CNCM I-1390), Lactobacillus rhamnosus LR04 (DSM 16605), Bifidobacterium longum B2274 (DSM 24707), and Lactobacillus delbrueckii subsp. delbrueckii LDD01 (DSM 22106) were tested. The analysis was performed using both a disc-diffusion assay and the broth-dilution procedure, also including an evaluation of the supernatants obtained from a fresh broth culture of each bacterium. L. delbrueckii subsp. delbrueckii LDD01 demonstrated the best inhibitory results among all the tested strains. The antibacterial activity of the supernatant was retained even after treatment with α-amylase and neutralization with NaOH 1N, thus suggesting the protein structure of the inhibitory molecule. In contrast, it was completely lost after treatment with proteinase K. Overall results suggest that the inhibitory effect of L. delbrueckii subsp. delbrueckii LDD01 should be attributed to the production of a bacteriocin. This strain may be prospectively useful for strengthening probiotic formulations and possibly counteract infections by K. pneumoniae in humans.
The prevalence of Carbapenem resistance among Enterobacteriacae species is increasing and poses a potential major public health risk. In recent years, several new carbapenemases have been identified, including New Delhi metallo-β-lactamase (NDM). A 78-year-old non-smoking female with prior medical history of type 2 diabetes mellitus, gastroesophageal reflux disease (GERD) and prior coronary artery bypass grafting was referred to our respiratory outpatient service for evaluation of a chronic cough and dyspnoea in 2013. Clinical examination revealed bibasal pulmonary crepitations but was otherwise unremarkable. Computed tomography of the chest demonstrated atelectasis of the lingula and right middle lobe. She underwent bronchoscopy, which demonstrated laryngeal mucosa inflammation, consistent with her GERD. There was no growth on bacterial, fungal or mycobacterial bronchial washings cultures.
Huang, Weihua; Wang, Guiqing; Sebra, Robert; Zhuge, Jian; Yin, Changhong; Aguero-Rosenfeld, Maria E; Schuetz, Audrey N; Dimitrova, Nevenka; Fallon, John T
The extended-spectrum-β-lactamase (ESBL)- and Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae represent serious and urgent threats to public health. In a retrospective study of multidrug-resistant K. pneumoniae , we identified three clinical isolates, CN1, CR14, and NY9, carrying both bla CTX-M and bla KPC genes. The complete genomes of these three K. pneumoniae isolates were de novo assembled by using both short- and long-read whole-genome sequencing. In CR14 and NY9, bla CTX-M and bla KPC were carried on two different plasmids. In contrast, CN1 had one copy of bla KPC-2 and three copies of bla CTX-M-15 integrated in the chromosome, for which the bla CTX-M-15 genes were linked to an insertion sequence, IS Ecp1 , whereas the bla KPC-2 gene was in the context of a Tn 4401a transposition unit conjugated with a PsP3-like prophage. Intriguingly, downstream of the Tn 4401a-bla KPC-2 -prophage genomic island, CN1 also carried a clustered regularly interspaced short palindromic repeat (CRISPR)- cas array with four spacers targeting a variety of K. pneumoniae plasmids harboring antimicrobial resistance genes. Comparative genomic analysis revealed that there were two subtypes of type I-E CRISPR- cas in K. pneumoniae strains and suggested that the evolving CRISPR- cas , with its acquired novel spacer, induced the mobilization of antimicrobial resistance genes from plasmids into the chromosome. The integration and dissemination of multiple copies of bla CTX-M and bla KPC from plasmids to chromosome depicts the complex pandemic scenario of multidrug-resistant K. pneumoniae Additionally, the implications from this study also raise concerns for the application of a CRISPR- cas strategy against antimicrobial resistance. Copyright © 2017 American Society for Microbiology.
Full Text Available Aim: This study was carried out to determine the presence of blaTEM , blaSHV and blaCTX-M genes in extended-spectrum β-lactamase (ESBL producing Escherichia coli (E. coli and Klebsiella pneumoniae (K. pneumoniae at a tertiary care referral hospital in Northeast India. Materials and Methods: A total of 270 E. coli and 219 K. pneumoniae isolates were recovered during the period between August 2009 and July 2010. Kirby-Bauer disk diffusion method was performed to determine the antibiotic resistance pattern. Screening and phenotypic confirmatory test for ESBL production were performed using standard disc diffusion methods. Each of the initial ESBL screening test isolate was investigated for the presence of blaTEM , blaSHV and blaCTX-M genes via polymerase chain reaction (PCR using gene-specific primers. Results: Phenotypic confirmatory test able to detect ESBL production in 73.58% of E. coli and 67.24% of K. pneumoniae. However, PCR amplification showed the presence of one or more ESBL genes in each of the initial ESBL screening positive isolate. Among three ESBL genotypes, the most prevalent genotype was found to be blaCTX-M in E. coli (88.67% and blaTEM in K. pneumoniae (77.58% ESBL producing isolates. Majority of ESBL producing isolates possess more than one ESBL genes. Conclusion: This study constituted a primer report on high prevalence of blaTEM and blaCTX-M genes in ESBL producing isolates of E. coli and K. pneumoniae and denotes the need of more extensive studies on these antibiotic genes to determine the magnitude of the problem of antibiotic resistance exiting in this locality.
Tacão, Marta; Correia, António; Henriques, Isabel S
Carbapenems are last-resort antibiotics to handle serious infections caused by multiresistant bacteria. The incidence of resistance to these antibiotics has been increasing and new resistance mechanisms have emerged. The dissemination of carbapenem resistance in the environment has been overlooked. The main goal of this research was to assess the prevalence and diversity of carbapenem-resistant bacteria in riverine ecosystems. The presence of frequently reported carbapenemase-encoding genes was inspected. The proportion of imipenem-resistant bacteria was on average 2.24 CFU/ml. Imipenem-resistant strains (n=110) were identified as Pseudomonas spp., Stenotrophomonas maltophilia, Aeromonas spp., Chromobacterium haemolyticum, Shewanella xiamenensis, and members of Enterobacteriaceae. Carbapenem-resistant bacteria were highly resistant to other beta-lactams such as quinolones, aminoglycosides, chloramphenicol, tetracyclines, and sulfamethoxazole/trimethoprim. Carbapenem resistance was mostly associated with intrinsically resistant bacteria. As intrinsic resistance mechanisms, we have identified the blaCphA gene in 77.3% of Aeromonas spp., blaL1 in all S. maltophilia, and blaOXA-48-like in all S. xiamenensis. As acquired resistance mechanisms, we have detected the blaVIM-2 gene in six Pseudomonas spp. (5.45%). Integrons with gene cassettes encoding resistance to aminoglycosides (aacA and aacC genes), trimethoprim (dfrB1b), and carbapenems (blaVIM-2) were found in Pseudomonas spp. Results suggest that carbapenem resistance dissemination in riverine ecosystems is still at an early stage. Nevertheless, monitoring these aquatic compartments for the presence of resistance genes and its host organisms is essential to outline strategies to minimize resistance dissemination.
Full Text Available Carbapenem-resistant A. baumannii present a significant therapeutic challenge for the treatment of nosocomial infections in many European countries. Although it is known that the gradient of A. baumannii prevalence increases from northern to southern Europe, this study provides the first data from Serbia. Twenty-eight carbapenem-resistant A. baumannii clinical isolates were collected at a Serbian pediatric hospital during a 2-year period. The majority of isolates (67.68% belonged to the sequence type Group 1, European clonal complex II. All isolates harbored intrinsic OXA-51 and AmpC cephalosporinase. OXA-23 was detected in 16 isolates (57.14%, OXA-24 in 23 isolates (82.14% and OXA-58 in 11 isolates (39.29%. Six of the isolates (21.43% harbored all of the analyzed oxacillinases, except OXA-143 and OXA-235 that were not detected in this study. Production of oxacillinases was detected in different pulsotypes indicating the presence of horizontal gene transfer. NDM-1, VIM and IMP were not detected in analyzed clinical A. baumannii isolates. ISAba1 insertion sequence was present upstream of OXA-51 in one isolate, upstream of AmpC in 13 isolates and upstream of OXA-23 in 10 isolates. In silico analysis of carO sequences from analyzed A. baumannii isolates revealed the existence of two out of six highly polymorphic CarO variants. The phylogenetic analysis of CarO protein among Acinetobacter species revised the previous classification CarO variants into three groups based on strong bootstraps scores in the tree analysis. Group I comprises four variants (I-IV while Groups II and III contain only one variant each. One half of the Serbian clinical isolates belong to Group I variant I, while the other half belongs to Group I variant III.
Carmen Paz Oplustil
Full Text Available Surveillance programs are essential to detect the increase of antimicrobial resistance, and several different programs are being conducted in many countries. The RESISTNET is a surveillance program for bacterial resistance against several antimicrobial agents initiated in 1998 among Latin American countries. In Brazil, several centers were invited to join this surveillance and a total of 11 centers (6 from São Paulo and 5 from other states participated in the study. All results were analyzed using the WHONET program. A total of 894 Escherichia coli, 386 Klebsiella pneumoniae, 70 Shigella spp and 57 Salmonella spp strains were analyzed in this study from April, 1998, to April, 1999. Susceptibility testing was performed by the disk diffusion method using NCCLS 1998 guidelines for several different drugs. For all strains, imipenem was the most effective drug (100% of the strains were susceptible. Klebsiella pneumoniae presented a high resistance rate to ampicillin (96.4%. The rate of probable ESBL producers among K. pneumoniae strains was 36.3%, most of them being isolated from catheters (58.8%. Among all Escherichia coli strains analyzed, the highest resistance rate was found for trimethoprim/sulfamethoxazole (46.9% and the majority of the resistant strains were isolated from urine samples (47.8%. Among Salmonella spp, the resistance rates were low for all antibiotics tested. For Shigella spp strains there was a high resistance to trimethoprim/sulfamethoxazole (80.0%. No resistance to ceftriaxone was observed in these strains. Surveillance of antimicrobial resistance is critical for the successful management of infectious diseases. The results of this survey show significant resistance rates among these bacteria which are responsible for several types of human infections.
Full Text Available Abstract Background The aim of this study was to describe a novel trimethoprim resistance gene cassette, designated dfrA30, within a class 1 integron in a facultatively oligotrophic, multiple antibiotic and human serum resistant test strain, MB45, in a population of oligotrophic bacteria isolated from the river Mahananda; and to test the efficiency of surface bound acetate on zinc oxide quantum dots (ZnO QDs as bactericidal agent on MB45. Methods Diluted Luria broth/Agar (10-3 media was used to cultivate the oligotrophic bacteria from water sample. Multiple antibiotic resistant bacteria were selected by employing replica plate method. A rapid assay was performed to determine the sensitivity/resistance of the test strain to human serum. Variable region of class 1 integron was cloned, sequenced and the expression of gene coding for antibiotic resistance was done in Escherichia coli JM 109. Identity of culture was determined by biochemical phenotyping and 16S rRNA gene sequence analyses. A phylogenetic tree was constructed based on representative trimethoprim resistance-mediating DfrA proteins retrieved from GenBank. Growth kinetic studies for the strain MB45 were performed in presence of varied concentrations of ZnO QDs. Results and conclusions The facultatively oligotrophic strain, MB45, resistant to human serum and ten antibiotics trimethoprim, cotrimoxazole, ampicillin, gentamycin, netilmicin, tobramycin, chloramphenicol, cefotaxime, kanamycin and streptomycin, has been identified as a new strain of Klebsiella pneumoniae. A novel dfr gene, designated as dfrA30, found integrated in class 1 integron was responsible for resistance to trimethoprim in Klebsiella pneumoniae strain MB45. The growth of wild strain MB45 was 100% arrested at 500 mg/L concentration of ZnO QDs. To our knowledge this is the first report on application of ZnO quantum dots to kill multiple antibiotics and serum resistant K. pneumoniae strain.
Full Text Available Klebsiella pneumoniae bacteremia biofilm traits and distribution characteristics have not been clarified. This study aimed to determine the prevalence and characteristics of K. pneumoniae bacteremia biofilm formation (BF and to explore the virulence factors associated with K. pneumoniae BF. A total of 250 K. pneumoniae bacteremia isolates were collected from patients in Shenzhen and Shanghai, China. Virulence genes in their genomes were detected by PCR. The isolates were subjected to multilocus sequence typing (MLST and clonal complex (CC classification based on housekeeping genes. Biofilms were detected by crystal violet staining. Greater BF was observed in isolates from young adults (<40 years old than in those from seniors (≥65 years old; P = 0.002. MLST yielded 65 different sequence types (STs, with the most represented STs being ST11, ST23, and ST65, and the main CCs were CC23 and CC65; CC23 isolates exhibited greater BF than CC65 or ST11 isolates (both P < 0.001. BF was more pronounced among magA(K1, aero+, rmpA+, rmpA2+, allS+, wcaG+, and iutA+ isolates than in isolates that were negative for these virulence factors. Multivariate regression analysis revealed only wcaG as an independent risk factor for BF (odds ratio 11.426, P < 0.001, and BF was decreased when wcaG was silenced by antisense RNA. In conclusion, BF in K. pneumoniae bacteremia isolates was found to be associated with CC23 classification and the presence of the wcaG virulence factor gene.
Full Text Available Background: Extended-spectrum beta-lactamase (ESBL-producing Enterobacteriaceae is an emerging therapeutic challenge, especially in the treatment of urinary tract infections. Following an outbreak of CTX-M-15 Klebsiella pneumoniae in Uppsala, Sweden, an orphan drug trial on IgY chicken antibodies was undertaken in an attempt to eradicate faecal carriage of ESBL-producing K. pneumoniae and Escherichia coli. Methods: Hens were immunised with epitopes from freeze-dried, whole-cell bacteria (ESBL-producing K. pneumoniae and E. coli and recombinant proteins of two K. pneumoniae fimbriae subunits (fimH and mrkD. The egg yolks were processed according to good manufacturing practice and the product was stored at−20°C until used. Using an internal database from the outbreak and the regular laboratory database, faecal carriers were identified and recruited from May 2005 to December 2013. The participants were randomised in a placebo-controlled 1:1 manner. Results: From 749 eligible patients, 327 (44% had deceased, and only 91 (12% were recruited and signed the informed consent. In the initial screening performed using the polymerase chain reaction, 24 participants were ESBL positive and subsequently randomised and treated with either the study drug or a placebo. The study was powered for 124 participants. Because of a very high dropout rate, the study was prematurely terminated. From the outbreak cohort (n=247, only eight patients were screened, and only one was positive with the outbreak strain in faeces. Conclusions: The present study design, using IgY chicken antibodies for the eradication of ESBL-producing K. pneumonia and E. coli, was ineffective in reaching its goal due to high mortality and other factors resulting in a low inclusion rate. Spontaneous eradication of ESBL-producing bacteria was frequently observed in recruited participants, which is consistent with previous reports.
Full Text Available The enterobacterium, Klebsiella pneumoniae invades the intestinal epithelium of humans by interfering with multiple host cell response. To uncover a system-level overview of host response during infection, we analyzed the global dynamics of protein profiling in Caenorhabditis elegans using quantitative proteomics approach. Comparison of protein samples of nematodes exposed to K. pneumoniae for 12, 24, and 36 h by 2DE revealed several changes in host proteome. A total of 266 host-encoded proteins were identified by 2DE MALDI-MS/MS and LC-MS/MS and the interacting partners of the identified proteins were predicted by STRING 10.0 analysis. In order to understand the interacting partners of regulatory proteins with similar or close pI ranges, a liquid IEF was performed and the isolated fractions containing proteins were identified by LC-MS/MS. Functional bioinformatics analysis on identified proteins deciphered that they were mostly related to the metabolism, dauer formation, apoptosis, endocytosis, signal transduction, translation, developmental, and reproduction process. Gene enrichment analysis suggested that the metabolic process as the most overrepresented pathway regulated against K. pneumoniae infection. The dauer-like formation in infected C. elegans along with intestinal atrophy and ROS during the physiological analysis indicated that the regulation of metabolic pathway is probably through the involvement of mTOR. Immunoblot analysis supported the above notion that the K. pneumoniae infection induced protein mis-folding in host by involving PI3Kinase/AKT-1/mTOR mediated pathway. Furthermore, the susceptibility of pdi-2, akt-1, and mTOR C. elegans mutants confirmed the role and involvement of PI3K/AKT/mTOR pathway in mediating protein mis-folding which appear to be translating the vulnerability of host defense toward K. pneumoniae infection.
Full Text Available Background: Extended-spectrum β-lactamase (ESBL-producing is a significant resistant mechanism to β-lactams in Enterobacteriaceae, especially in Klebsiella pneumoniae. The main objectives of this study were to genetically characterize urinary clinical isolates of K. pneumoniae through the investigating of blaTEM, blaCTX-M and using molecular typing by Enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR method. We also determined the frequency of antibiotic resistance of K. pneumoniae strains to characterize the β-lactamases included. Materials and Methods: A cross-sectional study was carried out to evaluate 98 strains of K. pneumoniae isolated from urine culture of outpatients referred to Al-Zahra Hospital, Isfahan, Iran. Antibiotic susceptibility testing was performed using Kirby–Bauer's method. Screening of ESBLs was carried out using double-disk screening test. PCR technique was performed to detect TEM and CTX-M genes. The total DNA of each strain was tested by ERIC-PCR. Results: In 98 K. pneumoniae studied clinical isolates, 25.5% were ESBL producing and 44.9% multidrug-resistant (MDR. From 25 ESBL isolates, 23 (92% cases showed MDR phenotype. In ESBL producing isolates, 23 (92% were blaCTX-M and 19 (76% blaTEM positive. The antimicrobial drug susceptibilities of ESBL isolates indicated high resistant rates for cefotaxime and ceftazidime. All 25 ESBL producing isolates were resistant to cefotaxime. Complex patterns of fingerprints isolates showed that 36% of the isolates were belonged to the cluster no 5. Conclusion: This study revealed high antimicrobial resistance rates among ESBL isolates which can lead to various health difficulties. Epidemiological data collection from patients is recommended to develop the strategies to manage antibiotic resistance.
Chen, Nan; Wang, Lin-Lin; Xue, Juan; Ma, Xiang-Bo; Zhao, Sheng; Rong, Rui-Xue; Li, Hong-Quan; Ding, Liang; Zheng, Ming-Zhi; Chen, Ying-Ying; Duan, Fei; Shen, Yue-Liang
K1 or K2 serotype Klebsiella pneumoniae isolate caused clinical pyogenic liver abscess (KLA) infection is prevalent in many areas. It has been identified that K1 or K2 serotype K. pneumoniae isolates caused KLA infection in mice by oral inoculation. In our study, K1 serotype K. pneumoniae isolate Kp1002 with hypermucoviscosity (HV)-positive phenotype caused KLA infection in C57BL/6 mice by oral inoculation. Simultaneously, non-serotype K1 and K2 isolate Kp1014 with HV-negative phenotype failed to cause KLA infection in the same manner. It seems that gastrointestinal tract translocation is the pathway by which K1 or K2 serotype K. pneumoniae caused KLA infection. Liquid chromatography-tandem mass spectrometry was used to further analyze metabolic profile changes in mice with KLA infection. Data showed that after Kp1002 or Kp1014 oral inoculation, serum Phosphatidylcholine (PC) and Lysophosphatidylcholine (LPC) levels significantly changed in mice. Some PC and LPC molecules showed changes both in the Kp1002 KLA group and the Kp1014 no-KLA group compared with the control group. The level of 18:1/18:2-PC significantly changed in the Kp1002 KLA group compared with the control group, but showed no change between the Kp1014 no-KLA group and the control group. The level of 18:1/18:2-PC might have been particularly affected by KLA infection caused by K1 serotype K. pneumoniae Kp1002. It may be a potential biomarker for KLA infection. Copyright © 2014 Elsevier Ltd. All rights reserved.
Jonsson, Anna-Karin; Larsson, Anders; Tängdén, Thomas; Melhus, Åsa; Lannergård, Anders
Background Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae is an emerging therapeutic challenge, especially in the treatment of urinary tract infections. Following an outbreak of CTX-M-15 Klebsiella pneumoniae in Uppsala, Sweden, an orphan drug trial on IgY chicken antibodies was undertaken in an attempt to eradicate faecal carriage of ESBL-producing K. pneumoniae and Escherichia coli. Methods Hens were immunised with epitopes from freeze-dried, whole-cell bacteria (ESBL-producing K. pneumoniae and E. coli) and recombinant proteins of two K. pneumoniae fimbriae subunits (fimH and mrkD). The egg yolks were processed according to good manufacturing practice and the product was stored at−20°C until used. Using an internal database from the outbreak and the regular laboratory database, faecal carriers were identified and recruited from May 2005 to December 2013. The participants were randomised in a placebo-controlled 1:1 manner. Results From 749 eligible patients, 327 (44%) had deceased, and only 91 (12%) were recruited and signed the informed consent. In the initial screening performed using the polymerase chain reaction, 24 participants were ESBL positive and subsequently randomised and treated with either the study drug or a placebo. The study was powered for 124 participants. Because of a very high dropout rate, the study was prematurely terminated. From the outbreak cohort (n=247), only eight patients were screened, and only one was positive with the outbreak strain in faeces. Conclusions The present study design, using IgY chicken antibodies for the eradication of ESBL-producing K. pneumonia and E. coli, was ineffective in reaching its goal due to high mortality and other factors resulting in a low inclusion rate. Spontaneous eradication of ESBL-producing bacteria was frequently observed in recruited participants, which is consistent with previous reports. PMID:26560861
Sachse, Svea; Bresan, Stephanie; Erhard, Marcel; Edel, Birgit; Pfister, Wolfgang; Saupe, Angela; Rödel, Jürgen
Extended spectrum of β-lactam (ESBL) resistance of Klebsiella pneumoniae has become an increasing problem in hospital infections. Typing of isolates is important to establish the intrahospital surveillance of resistant clones. In this study, the discriminatory potential of randomly amplified polymorphic DNA and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) analyses were compared with multilocus sequence typing (MLST) by using 17 β-lactam-resistant K. pneumoniae isolates of different genotypes. MLST alleles were distributed in 8 sequence types (STs). Among ESBL strains of the same ST, the presence of different β-lactamase genes was common. RAPD band patterns also revealed 8 types that corresponded to MLST-defined genotypes in 15 out of 17 cases. MALDI-TOF analysis could differentiate 5 clusters of strains. The results of this work show that RAPD may be usable as a rapid screening method for the intrahospital surveillance of K. pneumoniae, allowing a discrimination of clonally related strains. MALDI-TOF-based typing was not strongly corresponding to genotyping and warrants further investigation. Copyright © 2014 Elsevier Inc. All rights reserved.
Kim, Hong-Seok; Chon, Jung-Whan; Kim, Young-Ji; Kim, Dong-Hyeon; Kim, Mu-sang; Seo, Kun-Ho
The objective of this investigation was to determine the prevalence and characteristics of extended-spectrum-β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae in ready-to-eat (RTE) vegetables. A total of 189 RTE vegetable samples (91 sprouts and 98 mixed salads) were collected in a retail market in South Korea from October 2012 to February 2013. The prevalence of ESBL-producing E. coli and K. pneumoniae was 10.1%. Of these, 94.7% were from the sprout samples. All isolates were resistant to cefotaxime, and many of the ESBL producers were also resistant to non-β-lactam antibiotics, including gentamicin, trimethoprim/sulfamethoxazole, and ciprofloxacin (73.7%, 63.2%, and 26.3% respectively). TEM-1, SHV-1, -2, -11, -12, -27, -28 and -61, and CTX-M-14, -15 and -55 β-lactamases were detected alone or in combination. The genetic platforms of all CTX-M producing isolates were ISEcp1-blaCTX-M-orf477 and ISEcp1-blaCTX-M-IS903 in CTX-M groups 1 and 9, respectively. To our knowledge, this is the first report of the prevalence and characterization of ESBL-producing E. coli and K. pneumoniae isolated from RTE vegetables. The results of this study indicate that RTE vegetables, sprouts, in particular, may play a role in spreading antimicrobial resistant bacteria and ESBL genes to humans. Copyright © 2015 Elsevier B.V. All rights reserved.
Jeong, Daun; Yang, Jeongmo; Lee, Soojin; Kim, Borim; Um, Youngsoon; Kim, Youngrok; Ha, Kyoung-Su; Lee, Jinwon
Klebsiella pneumoniae is known to produce 2,3-butanediol (2,3-BDO), a valuable chemical. In K. pneumoniae, the 2,3-BDO operon (budBAC) is involved in the production of 2,3-BDO. To observe the physiological role of the 2,3-BDO operon in a mixed acid fermentation, we constructed a budBAC-deleted strain (SGSB109). The production of extracellular metabolites, CO2 emission, carbon distribution, and NADH/NAD(+) balance of SGSB109 were compared with the parent strain (SGSB100). When comparing the carbon distribution at 15 hr, four significant differences were observed: in 2,3-BDO biosynthesis, lactate and acetate production (lactate and acetate production increased 2.3-fold and 4.1-fold in SGSB109 compared to SGSB100), CO2 emission (higher in SGSB100), and carbon substrate uptake (higher in SGSB100). Previous studies on the inactivation of the 2,3-BDO operon were focused on the increase of 1,3-propanediol production. Few studies have been done observing the role of 2,3-BDO biosynthesis. This study provides a prime insight into the role of 2,3-BDO biosynthesis of K. pneumoniae.
Lee, Jina; Oh, Chi Eun; Choi, Eun Hwa; Lee, Hoan Jong
Increasing antimicrobial resistance is related to the selective pressure exerted by antibiotic usage. This study evaluated the impact of the increased use of piperacillin/tazobactam (TZP) on the selection of antibiotic resistance. From 1999 to 2010, Escherichia coli and Klebsiella pneumoniae invasive isolates obtained from hospitalized Korean children were analyzed in antibiotic susceptibility tests and subjected to characterization of the β-lactamase types. Antibiotic consumption data were also analyzed. Between January 1999 and December 2010, 409 invasive isolates of E. coli (n=170) and K. pneumoniae (n=239) were obtained. A rebound of extended-spectrum β-lactamase (ESBL) prevalence with an increase in total antibiotics was noted. Non-susceptibility to TZP was determined in 7.6% of E. coli isolates and 20.9% of K. pneumoniae isolates. Despite the increase in TZP usage, the overall prevalence of TZP resistance did not significantly increase over time, especially in E. coli. The mechanisms for TZP resistance included the presence of AmpC producers, possible TEM-1 hyperproducers, and multiple β-lactamases in individual organisms of a given isolate. Replacement of only the antibiotic class appears to be insufficient to control antibiotic resistance, and continued efforts to decrease overall antibiotic pressure are needed, especially in highly endemic situations. Copyright © 2013 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
Elena De Carolis
Full Text Available Nowadays, the global spread of resistance to oxyimino-cephalosporins in Enterobacteriaceae implies the need for novel diagnostics that can rapidly target resistant organisms from these bacterial species.In this study, we developed and evaluated a Direct Mass Spectrometry assay for Beta-Lactamase (D-MSBL that allows direct identification of (oxyiminocephalosporin-resistant Escherichia coli or Klebsiella pneumoniae from positive blood cultures (BCs, by using the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS technology.The D-MSBL assay was performed on 93 E. coli or K. pneumoniae growing BC samples that were shortly co-incubated with cefotaxime (CTX as the indicator cephalosporin. Susceptibility and resistance defining peaks from the samples' mass spectra were analyzed by a novel algorithm for bacterial organism classification. The D-MSBL assay allowed discrimination between E. coli and K. pneumoniae that were resistant or susceptible to CTX with a sensitivity of 86.8% and a specificity of 98.2%.The proposed algorithm-based D-MSBL assay, if integrated in the routine laboratory diagnostic workflow, may be useful to enhance the establishment of appropriate antibiotic therapy and to control the threat of oxyimino-cephalosporin resistance in hospital.
De Carolis, Elena; Paoletti, Silvia; Nagel, Domenico; Vella, Antonietta; Mello, Enrica; Palucci, Ivana; De Angelis, Giulia; D'Inzeo, Tiziana; Sanguinetti, Maurizio; Posteraro, Brunella; Spanu, Teresa
Nowadays, the global spread of resistance to oxyimino-cephalosporins in Enterobacteriaceae implies the need for novel diagnostics that can rapidly target resistant organisms from these bacterial species. In this study, we developed and evaluated a Direct Mass Spectrometry assay for Beta-Lactamase (D-MSBL) that allows direct identification of (oxyimino)cephalosporin-resistant Escherichia coli or Klebsiella pneumoniae from positive blood cultures (BCs), by using the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) technology. The D-MSBL assay was performed on 93 E. coli or K. pneumoniae growing BC samples that were shortly co-incubated with cefotaxime (CTX) as the indicator cephalosporin. Susceptibility and resistance defining peaks from the samples' mass spectra were analyzed by a novel algorithm for bacterial organism classification. The D-MSBL assay allowed discrimination between E. coli and K. pneumoniae that were resistant or susceptible to CTX with a sensitivity of 86.8% and a specificity of 98.2%. The proposed algorithm-based D-MSBL assay, if integrated in the routine laboratory diagnostic workflow, may be useful to enhance the establishment of appropriate antibiotic therapy and to control the threat of oxyimino-cephalosporin resistance in hospital.
Ng, Deborah H L; Marimuthu, Kalisvar; Lee, Jia Jun; Khong, Wei Xin; Ng, Oon Tek; Zhang, Wei; Poh, Bee Fong; Rao, Pooja; Raj, Maya Devi Rajinder; Ang, Brenda; De, Partha Pratim
In May 2015, we noticed an increase in carbapenem-resistant Acinetobacter baumannii (CRAB) infections in the Medical Intensive Care Unit (MICU). To investigate this, we studied the extent of environmental contamination and subsequent onward clonal transmission of CRAB. We conducted a one-day point prevalence screening (PPS) of the patients and environment in the MICU. We screened patients using endotracheal tube aspirates and swabs from nares, axillae, groin, rectum, wounds, and exit sites of drains. We collected environmental samples from patients' rooms and environment outside the patients' rooms. CRAB isolates from the PPS and clinical samples over the subsequent one month were studied for genetic relatedness by whole genome sequencing (WGS). We collected 34 samples from seven patients and 244 samples from the environment. On the day of PPS, we identified 8 CRAB carriers: 3 who screened positive and 5 previously known clinical infections. We detected environmental contamination in nearly two-thirds of the rooms housing patients with CRAB. WGS demonstrated genetic clustering of isolates within rooms but not across rooms. We analysed 4 CRAB isolates from clinical samples following the PPS. One genetically-related CRAB was identified in the respiratory sample of a patient with nosocomial pneumonia, who was admitted to the MICU five days after the PPS. The extensive environmental colonization of CRAB by patients highlights the importance of environmental hygiene. The transmission dynamics of CRAB needs further investigation.
ANTIBACTERIAL ACTIVITIES OF DRIED LEAF EXTRACTS OF CARICA PAPAYA, PTEROCARPUS SOYAUXII, AND VERNONIA AMYGDALINA ON CLINICAL ISOLATES OF ESCHERICHIA COLI, KLEBSIELLA PNEUMONIAE, STAPHYLOCOCCUS AUREUS AND BACILLUS SUBTILIS
Full Text Available The antibacterial activities of cold and hot ethanol extracts of air-dried leaves of Carica papaya, Pterocarpus soyauxii, and Vernonia amygdalina on clinical isolates of Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and Bacillus subtilis were investigated. The cup-plate agar method was used to determine bacterial susceptibility. All the plant extracts screened were potent on the entire clinical isolates tested. However, there was no significant difference in the inhibition zone diameters of the plant extracts screened (on all the test isolates. There was also no significant difference in the inhibition zone diameters between the cold and hot ethanol extracts of each plant. Phytochemical analysis revealed the presence of alkaloids, anthroquinone, flavonoids, saponins, steroids, tannins, terpenoids and glycosides in all leaf samples. The results obtained here reveal the antibacterial potentials of the leaf extracts of Carica papaya, Pterocarpus soyauxii, and Vernonia amygdalina, and suggests their possible exploitation for the development of novel herbal-based antimicrobials.
Rodríguez Martínez, J M; Díaz-de Alba, P; Lopez-Cerero; Ruiz-Carrascoso, G; Gomez-Gil, R; Pascual, A
A study is presented on the presence of quinolone resistance qnrB1 genes in clinical isolates belonging to the largest series of infections caused by OXA-48-producing Klebsiella pneumoniae in a single-centre outbreak in Spain. Evidence is also provided, according to in vitro results, that there is a possibility of co-transfer of plasmid harbouring blaOXA-48 with an other plasmid harbouring qnrB1 in presence of low antibiotic concentrations of fluoroquinolones, showing the risk of multi-resistance screening. Copyright © 2013 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.
Full Text Available The objective of this study was to characterize blaOXA-23 harbouring Acinetobacter indicus-like strains from cattle including genomic and phylogenetic analyses, antimicrobial susceptibility testing and evaluation of pathogenicity in vitro and in vivo. Nasal and rectal swabs (n = 45 from cattle in Germany were screened for carbapenem-non-susceptible Acinetobacter spp. Thereby, two carbapenem resistant Acinetobacter spp. from the nasal cavities of two calves could be isolated. MALDI-TOF mass spectrometry and 16S rDNA sequencing identified these isolates as A. indicus-like. A phylogenetic tree based on partial rpoB sequences indicated closest relation of the two bovine isolates to the A. indicus type strain A648T and human clinical A. indicus isolates, while whole genome comparison revealed considerable intraspecies diversity. High mimimum inhibitory concentrations were observed for carbapenems and other antibiotics including fluoroquinolones and gentamicin. Whole genome sequencing and PCR mapping revealed that both isolates harboured blaOXA-23 localized on the chromosome and surrounded by interrupted Tn2008 transposon structures. Since the pathogenic potential of A. indicus is unknown, pathogenicity was assessed employing the Galleria (G. mellonella infection model and an in vitro cytotoxicity assay using A549 human lung epithelial cells. Pathogenicity in vivo (G. mellonella killing assay and in vitro (cytotoxicity assay of the two A. indicus-like isolates was lower compared to A. baumannii ATCC 17978 and similar to A. lwoffii ATCC 15309. The reduced pathogenicity of A. indicus compared to A. baumannii correlated with the absence of important virulence genes encoding like phospholipase C1+C2, acinetobactin outer membrane protein BauA, RND-type efflux system proteins AdeRS and AdeAB or the trimeric autotransporter adhesin Ata. The emergence of carbapenem-resistant A. indicus-like strains from cattle carrying blaOXA-23 on transposable elements and
Gniadek, Thomas J.; Carroll, Karen C.
The non-glucose-fermenting Gram-negative bacilli Pseudomonas aeruginosa and Acinetobacter baumannii are increasingly acquiring carbapenem resistance. Given their intrinsic antibiotic resistance, this can cause extremely difficult-to-treat infections. Additionally, resistance gene transfer can occur between Gram-negative species, regardless of their ability to ferment glucose. Thus, the acquisition of carbapenemase genes by these organisms increases the risk of carbapenemase spread in general. Ultimately, infection control practitioners and clinical microbiologists need to work together to determine the risk carried by carbapenem-resistant non-glucose-fermenting Gram-negative bacilli (CR-NF) in their institution and what methods should be considered for surveillance and detection of CR-NF. PMID:26912753
Full Text Available Clinical isolates of Klebsiella pneumoniae are divided into three phylogroups and differ in their virulence factor contents. The aim of this study was to determine an association between phylogroup, virulence factors and mortality following bloodstream infection (BSI caused by Klebsiella pneumoniae. Isolates from all adult patients with BSI caused by K. pneumoniae admitted to Karolinska University Hospital, Solna between 2007 and 2009 (n = 139 were included in the study. Phylogenetic analysis was performed based on multilocus sequence typing (MLST data. Testing for mucoid phenotype, multiplex PCR determining serotypes K1, K2, K5, K20, K54 and K57, and testing for virulence factors connected to more severe disease in previous studies, was also performed. Data was retrieved from medical records including age, sex, comorbidity, central and urinary catheters, time to adequate treatment, hospital-acquired infection, and mortality, to identify risk factors. The primary end-point was 30- day mortality. The three K. pneumoniae phylogroups were represented: KpI (n = 96, KpII (corresponding to K. quasipneumoniae, n = 9 and KpIII (corresponding to K. variicola, n = 34. Phylogroups were not significantly different in baseline characteristics. Overall, the 30-day mortality was 24/139 (17.3%. Isolates belonging to KpIII were associated with the highest 30-day mortality (10/34 cases, 29.4%, whereas KpI isolates were associated with mortality in 13/96 cases (13.5%. This difference was significant both in univariate statistical analysis (P = 0.037 and in multivariate analysis adjusting for age and comorbidity (OR 3.03 (95% CI: 1.10-8.36. Only three of the isolates causing mortality within 30 days belonged to any of the virulent serotypes (K54, n = 1, had a mucoid phenotype (n = 1 and/or contained virulence genes (wcaG n = 1 and wcaG/allS n = 1. In conclusion, the results indicate higher mortality among patients infected with
Kabir, Muhammad Humaun; Bakhrouf, Amina; Kalin, Mats; Nauclér, Pontus; Brisse, Sylvain; Giske, Christian G.
Clinical isolates of Klebsiella pneumoniae are divided into three phylogroups and differ in their virulence factor contents. The aim of this study was to determine an association between phylogroup, virulence factors and mortality following bloodstream infection (BSI) caused by Klebsiella pneumoniae. Isolates from all adult patients with BSI caused by K. pneumoniae admitted to Karolinska University Hospital, Solna between 2007 and 2009 (n = 139) were included in the study. Phylogenetic analysis was performed based on multilocus sequence typing (MLST) data. Testing for mucoid phenotype, multiplex PCR determining serotypes K1, K2, K5, K20, K54 and K57, and testing for virulence factors connected to more severe disease in previous studies, was also performed. Data was retrieved from medical records including age, sex, comorbidity, central and urinary catheters, time to adequate treatment, hospital-acquired infection, and mortality, to identify risk factors. The primary end-point was 30- day mortality. The three K. pneumoniae phylogroups were represented: KpI (n = 96), KpII (corresponding to K. quasipneumoniae, n = 9) and KpIII (corresponding to K. variicola, n = 34). Phylogroups were not significantly different in baseline characteristics. Overall, the 30-day mortality was 24/139 (17.3%). Isolates belonging to KpIII were associated with the highest 30-day mortality (10/34 cases, 29.4%), whereas KpI isolates were associated with mortality in 13/96 cases (13.5%). This difference was significant both in univariate statistical analysis (P = 0.037) and in multivariate analysis adjusting for age and comorbidity (OR 3.03 (95% CI: 1.10–8.36). Only three of the isolates causing mortality within 30 days belonged to any of the virulent serotypes (K54, n = 1), had a mucoid phenotype (n = 1) and/or contained virulence genes (wcaG n = 1 and wcaG/allS n = 1). In conclusion, the results indicate higher mortality among patients infected with
Wang, Aihua; Yang, Yonghong; Lu, Quan; Wang, Yi; Chen, Yuan; Deng, Li; Ding, Hui; Deng, Qiulian; Wang, Li; Shen, Xuzhuang
The plasmid-mediated quinolone resistance qnr genes in clinical isolates in adults have been described in different countries; however, the frequency of their occurrence has not been detected in pediatric patients. A total of 410 clinical isolates of Klebsiella pneumoniae, identified as producers of an extended-spectrum beta-lactamase (ESBL), or AmpC beta-lactamase, were collected from five children's hospitals in China during 2005-2006. The isolates were screened for the presence of the qnrA, qnrB, and qnrS genes, and then the harboring qnr gene isolates were detected for a bla gene coding for the TEM, SHV, CTX-M, and plasmid-mediated ampC gene by a PCR experiment. Ninety-two isolates (22.7%) were positive for the qnr gene, including 10 of qnrA (2.4%), 25 of qnrB (6.1%), and 62 of qnrS (15.1%). Eighty-one of the 92 (88.0%) qnr-positive isolates carried at least one bla gene for TEM, SHV, CTX-M, or DHA-1. The ciprofloxacin resistance increased 16-256-fold and oflaxacin resistance increased 2-32-fold in transconjugants, respectively. These results indicated that the plasmid-mediated qnr quinolone resistance gene was qnrS, followed by qnrB and qnrA. Most of the isolates also carried a bla gene coding ESBL or ampC gene coding DHA-1 among Klebsiella pneumoniae isolated from Chinese pediatric patients.
Horng, Yu-Tze; Chang, Kai-Chih; Chou, Ta-Chung; Yu, Chung-Jen; Chien, Chih-Ching; Wei, Yu-Hong; Soo, Po-Chi
1,3-Propanediol (1,3-PD) can be used for the industrial synthesis of a variety of compounds, including polyesters, polyethers, and polyurethanes. 1,3-PD is generated from petrochemical and microbial sources. 1,3-Propanediol is a typical product of glycerol fermentation, while acetate, lactate, 2,3-butanediol, and ethanol also accumulate during the process. Substrate and product inhibition limit the final concentration of 1,3-propanediol in the fermentation broth. It is impossible to increase the yield of 1,3-propanediol by using the traditional whole-cell fermentation process. In this study, dhaD and dhaK, the genes for glycerol dehydrogenase and dihydroxyacetone kinase, respectively, were inactivated by homologous recombination in Klebsiella pneumoniae. The dhaD/dhaK double mutant (designated TC100), selected from 5,000 single or double cross homologous recombination mutants, was confirmed as a double cross by using polymerase chain reaction. Analysis of the cell-free supernatant with high-performance liquid chromatography revealed elimination of lactate and 2,3-butanediol, as well as ethanol accumulation in TC100, compared with the wild-type strain. Furthermore, 1,3-propanediol productivity was increased in the TC100 strain expressing glycerol dehydratase and 1,3-PDO dehydrogenase regulated by the arabinose P(BAD) promoter. The genetic engineering and medium formulation approaches used here should aid in the separation of 1,3-propanediol from lactate, 2,3-butanediol, and ethanol and lead to increased production of 1,3-propanediol in Klebsiella pneumoniae.
Full Text Available Spinal epidural abscess is a severe, generally pyogenic, infection of the epidural space of spinal cord or cauda equina. The swelling caused by the abscess leads to compression or vascular disruption of neurological structures that requires urgent surgical decompression to avoid significant permanent disability. We share a rare case of Klebsiella pneumoniae spinal epidural abscess secondary to haematogenous spread of previous lung infection that presented late at our centre with cauda equina syndrome that showed good short-term outcome in delayed decompression. A 50-year old female presented with one-week history of persistent low back pain with progressively worsening bilateral lower limb weakness for seven days and urinary retention associated with saddle anesthesia of 2-day duration. Magnetic resonance imaging with contrast of the lumbo-sacral region showed an intramuscular collection of abscess at left gluteus maximus and left multifidus muscle with a L3-L5 posteriorly placed extradural lesion enhancing peripherally on contrast, suggestive of epidural abscess that compressed the cauda equina. The pus was drained using the posterior lumbar approach. Tissue and pus culture revealed Klebsiella pneumoniae, suggestive of bacterial infection. The patient made immediate improvement of muscle power over bilateral lower limbs postoperative followed by ability to control micturition and defecation in the 4th post-operative day. A good short-term outcome in delayed decompression of cauda equine syndrome is extremely rare. Aggressive surgical decompression combined with antibiotic therapy led to good short-term outcome in this patient despite delayed decompression of more than 48 hours.
Genc, Ozlem; Aksu, Evrim
Our goal was to compare a rapid test (OXA-48K-SeT) and four different chromogenic media (CHROMagar KPC, CHROMagar mSuperCARBA, ChromID Carba and ChromID OXA-48) for the detection of OXA-48 producing Klebsiella pneumoniae isolates and spiked urine/blood samples with these bacteria. In total 100 K.pneumoniae isolates, including 60 OXA-48 positive, 15 other carbapenemase producing, 15 Extended spectrum betalactamases (ESBL) positive and 10 carbapenem sensitive K.pneumoniae were included in the study. After all samples were inoculated into all chromogenic media, temocillin discs were placed onto the media. OXA-48K-SeT was studied according to the manufacturer's instructions and the lower detection limit was determined. Sensitivities and specificities of all chromogenic media and rapid test were detected as 100%. All of the OXA-48 producers were found resistant to temocillin on all chromogenic media. The lower detection limit of the rapid assay was determined as 10 6 in both direct bacterial samples and in spiked urine/blood samples. As a result, four chromogenic culture media and OXA-48 K-SeT can be used safely for detection of OXA-48 positive K.pneumoniae isolates. Although direct clinical specimens were not used, our study suggests that this media and OXA-48 K-SeT may be used in patient samples like blood and urine. Further studies are needed to assess this suggestion. Copyright © 2018 Elsevier B.V. All rights reserved.
Lodise, Thomas; Ye, Michael J; Zhao, Qi
This large-scale retrospective analysis ( n = 60,551) of the Premier inpatient database (1 January 2011 to 31 December 2014) found an overall prevalence of carbapenem-resistant Enterobacteriaceae strains of 2.3% (range, 0.9% to 5.8% by geographic region) among patients with infections due to Enterobacteriaceae Ongoing monitoring and development of decision support tools/algorithms are needed for identification of high-risk patients. Copyright © 2017 American Society for Microbiology.
Kalam, K.; Kumar, S.; Ali, S.; Baqi, S.; Qamar, F.
Objective: To identify the risk factors for carbapenem resistant bacteraemia and mortality due to gram negative bacteraemia in a developing country. Methods: A prospective cohort study was conducted at the Sindh Institute of Urology and Transplantation (SIUT) from June to October 2012. Hospitalized patients > 15 years of age with gram negative bacteraemia were included and followed for a period of 2 weeks for in hospital mortality. Data was collected and analyzed for 243 subjects. Multivariate analysis was used to determine the risk factors for carbapenem resistant bacteraemia and mortality due to gram negative bacteraemia. Crude and adjusted odds ratio and 95% CI are reported. Results: A total of 729 out of 1535 (47.5%) cultures were positive for gram negative isolates. Out of 243 subjects, 117 (48%) had an MDR isolate. Having an MDR isolate on culture (AOR, 2.33; 95% CI, 1.35 -4.0), having multiple positive cultures (AOR, 1.8; 95% CI, 0.94 -3.4) and stay in ICU >48 hours (AOR, 2.0 ; 95% CI, 1.12 -3.78) were identified as significant risk factors for mortality due to gram negative organisms. Risk factors for carbapenem resistant bacteraemia were age >50 years (AOR, 1.83; 95% CI, 1.0-3.5), septic shock on presentation (AOR 2.53; 95% CI, 1.03 -6.2) , ICU stay of >72 hours (AOR 2.40; 95% CI, 1.14-5.0) and receiving immunosuppressant medications (AOR 2.23; 95% CI, 0.74 - 6.7). Conclusion: There is a high burden of MDR and carbapenem resistant gram negative bacteraemia, with a high mortality rate. (author)
Bauer, Seth R.; Neuner, Elizabeth A.; Lam, Simon W.
There are limited treatment options for carbapenem-resistant Gram-negative infections. Currently, there are suggestions in the literature that combination therapy should be used, which frequently includes antibiotics to which the causative pathogen demonstrates in vitro resistance. This case-control study evaluated risk factors associated with all-cause mortality rates for critically ill patients with carbapenem-resistant Gram-negative bacteremia. Adult patients who were admitted to an intensive care unit with sepsis and a blood culture positive for Gram-negative bacteria resistant to a carbapenem were included. Patients with polymicrobial, recurrent, or breakthrough infections were excluded. Included patients were classified as survivors (controls) or nonsurvivors (cases) at 30 days after the positive blood culture. Of 302 patients screened, 168 patients were included, of whom 90 patients died (53.6% [cases]) and 78 survived (46.4% [controls]) at 30 days. More survivors received appropriate antibiotics (antibiotics with in vitro activity) than did nonsurvivors (93.6% versus 53.3%; P carbapenems) (87.2% versus 80%; P = 0.21). After adjustment for baseline factors with multivariable logistic regression, combination therapy was independently associated with decreased risk of death (odds ratio, 0.19 [95% confidence interval, 0.06 to 0.56]; P carbapenem-resistant Gram-negative bacteremia. However, that association is lost if in vitro activity is not considered. PMID:25845872
Kim, Dae Hun; Choi, Ji-Young; Kim, Hae Won; Kim, So Hyun; Chung, Doo Ryeon; Peck, Kyong Ran; Thamlikitkul, Visanu; So, Thomas Man-Kit; Yasin, Rohani M D; Hsueh, Po-Ren; Carlos, Celia C; Hsu, Li Yang; Buntaran, Latre; Lalitha, M K; Song, Jae-Hoon; Ko, Kwan Soo
In this surveillance study, we identified the genotypes, carbapenem resistance determinants, and structural variations of AbaR-type resistance islands among carbapenem-resistant Acinetobacter baumannii (CRAB) isolates from nine Asian locales. Clonal complex 92 (CC92), corresponding to global clone 2 (GC2), was the most prevalent in most Asian locales (83/108 isolates; 76.9%). CC108, or GC1, was a predominant clone in India. OXA-23 oxacillinase was detected in CRAB isolates from most Asian locales except Taiwan. blaOXA-24 was found in CRAB isolates from Taiwan. AbaR4-type resistance islands, which were divided into six subtypes, were identified in most CRAB isolates investigated. Five isolates from India, Malaysia, Singapore, and Hong Kong contained AbaR3-type resistance islands. Of these, three isolates harbored both AbaR3- and AbaR4-type resistance islands simultaneously. In this study, GC2 was revealed as a prevalent clone in most Asian locales, with the AbaR4-type resistance island predominant, with diverse variants. The significance of this study lies in identifying the spread of global clones of carbapenem-resistant A. baumannii in Asia.
Goic-Barisic, Ivana; Hrenovic, Jasna; Kovacic, Ana; Musić, Martina Šeruga
Six carbapenem-resistant isolates of Acinetobacter baumannii were recovered from untreated and treated municipal wastewater of the capital city of Zagreb, Croatia. Molecular identification of environmental isolates of A. baumannii was performed by amplification, sequencing, and phylogenetic analyses of rpoB gene. The presence of bla OXA genes encoding OXA-type carbapenemases (OXA-51-like, OXA-23, and OXA-40-like) was confirmed by multiplex PCR and sequencing. Phylogenetic analyses corroborated the affiliation of detected bla OXA genes to three different clusters and showed association of environmental OXAs with those described from clinical isolates. This result suggests that isolates recovered from municipal wastewater are most probably of clinical origin. Furthermore, the presence of OXA-40-like (OXA-72) in an environmental A. baumannii isolate is reported for the first time. Persistence of A. baumannii harboring the clinically important OXAs in the wastewater treatment process poses a potentially significant source for horizontal gene transfer and implications for wider spread of antibiotic resistance genes.
Livorsi, Daniel J; Chorazy, Margaret L; Schweizer, Marin L; Balkenende, Erin C; Blevins, Amy E; Nair, Rajeshwari; Samore, Matthew H; Nelson, Richard E; Khader, Karim; Perencevich, Eli N
Carbapenem-resistant Enterobacteriaceae (CRE) pose an urgent public health threat in the United States. An important step in planning and monitoring a national response to CRE is understanding its epidemiology and associated outcomes. We conducted a systematic literature review of studies that investigated incidence and outcomes of CRE infection in the US. We performed searches in MEDLINE via Ovid, CDSR, DARE, CENTRAL, NHS EED, Scopus, and Web of Science for articles published from 1/1/2000 to 2/1/2016 about the incidence and outcomes of CRE at US sites. Five studies evaluated incidence, but many used differing definitions for cases. Across the entire US population, the reported incidence of CRE was 0.3-2.93 infections per 100,000 person-years. Infection rates were highest in long-term acute-care (LTAC) hospitals. There was insufficient data to assess trends in infection rates over time. Four studies evaluated outcomes. Mortality was higher in CRE patients in some but not all studies. While the incidence of CRE infections in the United States remains low on a national level, the incidence is highest in LTACs. Studies assessing outcomes in CRE-infected patients are limited in number, small in size, and have reached conflicting results. Future research should measure a variety of clinical outcomes and adequately adjust for confounders to better assess the full burden of CRE.
Fursova, Nadezhda K; Astashkin, Eugeny I; Knyazeva, Anastasia I; Kartsev, Nikolay N; Leonova, Ekaterina S; Ershova, Olga N; Alexandrova, Irina A; Kurdyumova, Natalia V; Sazikina, Svetlana Yu; Volozhantsev, Nikolay V; Svetoch, Edward A; Dyatlov, Ivan A
The spread of carbapenemase-producing Enterobacteriaceae (CPE) is a great problem of healthcare worldwide. Study of the spread for bla OXA-48-like genes coding epidemically significant carbapenemases among hospital pathogens is important for the regional and global epidemiology of antimicrobial resistance. Antibacterial resistant isolates of Klebsiella pneumoniae (n = 95) from 54 patients, P. mirabilis (n = 32) from 20 patients, Enterobacter aerogenes (n = 6) from four patients, and Enterobacter cloacae (n = 4) from four patients were collected from January, 2013 to October, 2014 in neurosurgical intensive care unit (ICU) of the Burdenko Neurosurgery Institute, Moscow. Characteristics of the isolates were done using susceptibility tests, PCR detection of the resistance genes, genotyping, conjugation, DNA sequencing, and bioinformatic analysis. Major strains under study were multi drug resistant (MDR), resistant to three or more functional classes of drugs simultaneously-98.9 % K. pneumoniae, 100 % P. mirabilis, one E. aerogenes isolate, and one E. cloacae isolate. Molecular-genetic mechanism of MDR in K. pneumoniae and P. mirabilis isolates were based on carrying of epidemic extended-spectrum beta-lactamase bla CTX-M-15 gene (87.2 and 90.6 % accordingly), carbapenemase bla OXA-48-like gene (55.3 and 23.3 % accordingly), and class 1 (54.8 and 31.3 % accordingly) and class 2 (90.6 % P. mirabilis) integrons. The bla OXA-48-like-positive K. pneumoniae were collected during whole two-year surveillance period, while P. mirabilis and Enterobacter spp. carrying bla OXA-48-like genes were detected only after four and 18 months after the research start, respectively. The bla OXA-48-like gene acquisition was shown for P. mirabilis isolates collected from five patients and for E. cloacae isolate collected from one patient during their stay in the ICU, presumably from bla OXA-48-like-positive K. pneumoniae. The source of the bla OXA-244 gene acquired by E
Yeh, Kuo-Ming; Chiu, Sheng-Kung; Lin, Chii-Lan; Huang, Li-Yueh; Tsai, Yu-Kuo; Chang, Jen-Chang; Lin, Jung-Chung; Chang, Feng-Yee; Siu, Leung-Kei
The virulence role of surface antigens in a single serotype of Klebsiella pneumoniae strain have been studied, but little is known about whether their contribution will vary