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Sample records for klebsiella pneumoniae b5055-induced

  1. Klebsiella pneumoniae splenic abscess.

    PubMed

    Gill, V; Marzocca, F J; Cunha, B A

    1994-01-01

    Splenic abscesses may be solitary or multiple and are unusual infections. Signs and symptoms are variable and do not always include left upper quadrant pain or tenderness, as the Case Report illustrate. Abscesses of the spleen may occur as a result of endocarditis or from hematogenous seeding from a distant focus of infection. Computed tomographic scan of the spleen is the diagnostic method of choice. We report a case of multiple splenic abscesses caused by Klebsiella pneumoniae that resulted from a Klebsiella urinary tract infection and was successfully managed with antibiotic therapy and splenectomy. PMID:8039997

  2. Klebsiella pneumoniae Bloodstream Infection

    PubMed Central

    Girometti, Nicolò; Lewis, Russell E.; Giannella, Maddalena; Ambretti, Simone; Bartoletti, Michele; Tedeschi, Sara; Tumietto, Fabio; Cristini, Francesco; Trapani, Filippo; Gaibani, Paolo; Viale, Pierluigi

    2014-01-01

    Abstract Multidrug resistance associated with extended-spectrum beta-lactamase (ESBL) and Klebsiella pneumoniae carbapenemase (KPC) among K. pneumoniae is endemic in southern Europe. We retrospectively analyzed the impact of resistance on the appropriateness of empirical therapy and treatment outcomes of K. pneumoniae bloodstream infections (BSIs) during a 2-year period at a 1420-bed tertiary-care teaching hospital in northern Italy. We identified 217 unique patient BSIs, including 92 (42%) KPC-positive, 49 (23%) ESBL-positive, and 1 (0.5%) metallo-beta-lactamase-positive isolates. Adequate empirical therapy was administered in 74% of infections caused by non-ESBL non-KPC strains, versus 33% of ESBL and 23% of KPC cases (p < 0.0001). To clarify the impact of resistance on BSI treatment outcomes, we compared several different models comprised of non-antibiotic treatment-related factors predictive of patients’ 30-day survival status. Acute Physiology and Chronic Health Evaluation (APACHE) II score determined at the time of positive blood culture was superior to other investigated models, correctly predicting survival status in 83% of the study cohort. In multivariate analysis accounting for APACHE II, receipt of inadequate empirical therapy was associated with nearly a twofold higher rate of death (adjusted hazard ratio 1.9, 95% confidence interval 1.1–3.4; p = 0.02). Multidrug-resistant K. pneumoniae accounted for two-thirds of all K. pneumoniae BSIs, high rates of inappropriate empirical therapy, and twofold higher rates of patient death irrespective of underlying illness. PMID:25398065

  3. Hypervirulent (hypermucoviscous) Klebsiella pneumoniae

    PubMed Central

    Shon, Alyssa S.; Bajwa, Rajinder P.S.; Russo, Thomas A.

    2013-01-01

    A new hypervirulent (hypermucoviscous) variant of Klebsiella pneumoniae has emerged. First described in the Asian Pacific Rim, it now increasingly recognized in Western countries. Defining clinical features are the ability to cause serious, life-threatening community-acquired infection in younger healthy hosts, including liver abscess, pneumonia, meningitis and endophthalmitis and the ability to metastatically spread, an unusual feature for enteric Gram-negative bacilli in the non-immunocompromised. Despite infecting a healthier population, significant morbidity and mortality occurs. Although epidemiologic features are still being defined, colonization, particularly intestinal colonization, appears to be a critical step leading to infection. However the route of entry remains unclear. The majority of cases described to date are in Asians, raising the issue of a genetic predisposition vs. geospecific strain acquisition. The traits that enhance its virulence when compared with “classical” K. pneumoniae are the ability to more efficiently acquire iron and perhaps an increase in capsule production, which confers the hypermucoviscous phenotype. An objective diagnostic test suitable for routine use in the clinical microbiology laboratory is needed. If/when these strains become increasingly resistant to antimicrobials, we will be faced with a frightening clinical scenario. PMID:23302790

  4. Carbapenemase-producing Klebsiella pneumoniae

    PubMed Central

    Deresinski, Stan

    2014-01-01

    The continuing emergence of infections due to multidrug resistant bacteria is a serious public health problem. Klebsiella pneumoniae, which commonly acquires resistance encoded on mobile genetic elements, including ones that encode carbapenemases, is a prime example. K. pneumoniae carrying such genetic material, including both blaKPC and genes encoding metallo-β-lactamases, have spread globally. Many carbapenemase-producing K. pneumoniae are resistant to multiple antibiotic classes beyond β-lactams, including tetracyclines, aminoglycosides, and fluoroquinolones. The optimal treatment, if any, for infections due to these organisms is unclear but, paradoxically, appears to often require the inclusion of an optimally administered carbapenem. PMID:25343037

  5. Klebsiella pneumoniae inoculants for enhancing plant growth

    SciTech Connect

    Triplett, Eric W.; Kaeppler, Shawn M.; Chelius, Marisa K.

    2008-07-01

    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.

  6. Klebsiella pneumoniae in orange juice concentrate.

    PubMed Central

    Fuentes, F A; Hazen, T C; López-Torres, A J; Rechani, P

    1985-01-01

    Fecal coliform-positive, capsule-forming Klebsiella pneumoniae cells were observed in high densities (10(4) to 10(8) CFU/100 ml) in two commercial batches of frozen orange juice concentrate at a cannery in Puerto Rico. Contamination of both lots was gross and included off colors and odors. Isolates of K. pneumoniae from these concentrates revealed growth at 4, 25, and 34 degrees C with generation times from 0.39 to 1.84 h. PMID:3893321

  7. Epidemiology and Virulence of Klebsiella pneumoniae.

    PubMed

    Clegg, Steven; Murphy, Caitlin N

    2016-02-01

    Strains of Klebsiella pneumoniae are frequently opportunistic pathogens implicated in urinary tract and catheter-associated urinary-tract infections of hospitalized patients and compromised individuals. Infections are particularly difficult to treat since most clinical isolates exhibit resistance to several antibiotics leading to treatment failure and the possibility of systemic dissemination. Infections of medical devices such as urinary catheters is a major site of K. pneumoniae infections and has been suggested to involve the formation of biofilms on these surfaces. Over the last decade there has been an increase in research activity designed to investigate the pathogenesis of K. pneumoniae in the urinary tract. These investigations have begun to define the bacterial factors that contribute to growth and biofilm formation. Several virulence factors have been demonstrated to mediate K. pneumoniae infectivity and include, but are most likely not limited to, adherence factors, capsule production, lipopolysaccharide presence, and siderophore activity. The development of both in vitro and in vivo models of infection will lead to further elucidation of the molecular pathogenesis of K. pneumoniae. As for most opportunistic infections, the role of host factors as well as bacterial traits are crucial in determining the outcome of infections. In addition, multidrug-resistant strains of these bacteria have become a serious problem in the treatment of Klebsiella infections and novel strategies to prevent and inhibit bacterial growth need to be developed. Overall, the frequency, significance, and morbidity associated with K. pneumoniae urinary tract infections have increased over many years. The emergence of these bacteria as sources of antibiotic resistance and pathogens of the urinary tract present a challenging problem for the clinician in terms of management and treatment of individuals.

  8. Klebsiella pneumoniae FimK Promotes Virulence in Murine Pneumonia.

    PubMed

    Rosen, David A; Hilliard, Julia K; Tiemann, Kristin M; Todd, Elizabeth M; Morley, S Celeste; Hunstad, David A

    2016-02-15

    Klebsiella pneumoniae, a chief cause of nosocomial pneumonia, is a versatile and commonly multidrug-resistant human pathogen for which further insight into pathogenesis is needed. We show that the pilus regulatory gene fimK promotes the virulence of K. pneumoniae strain TOP52 in murine pneumonia. This contrasts with the attenuating effect of fimK on urinary tract virulence, illustrating that a single factor may exert opposing effects on pathogenesis in distinct host niches. Loss of fimK in TOP52 pneumonia was associated with diminished lung bacterial burden, limited innate responses within the lung, and improved host survival. FimK expression was shown to promote serum resistance, capsule production, and protection from phagocytosis by host immune cells. Finally, while the widely used K. pneumoniae model strain 43816 produces rapid dissemination and death in mice, TOP52 caused largely localized pneumonia with limited lethality, thereby providing an alternative tool for studying K. pneumoniae pathogenesis and control within the lung.

  9. Understanding, preventing and eradicating Klebsiella pneumoniae biofilms.

    PubMed

    Ribeiro, Suzana Meira; Cardoso, Marlon Henrique; Cândido, Elizabete de Souza; Franco, Octávio Luiz

    2016-01-01

    The ability of pathogenic bacteria to aggregate and form biofilm represents a great problem for public health, since they present extracellular components that encase these micro-organisms, making them more resistant to antibiotics and host immune attack. This may become worse when antibiotic-resistant bacterial strains form biofilms. However, antibiofilm screens with different compounds may reveal potential therapies to prevent/treat biofilm infections. Here, we focused on Klebsiella pneumoniae, an opportunistic bacterium that causes different types of infections, including in the bloodstream, meninges, lungs, urinary system and at surgical sites. We also highlight aspects involved in the formation and maintenance of K. pneumoniae biofilms, as well as resistance and the emergence of new trends to combat this health challenge. PMID:27064296

  10. Klebsiella pneumoniae survives within macrophages by avoiding delivery to lysosomes.

    PubMed

    Cano, Victoria; March, Catalina; Insua, Jose Luis; Aguiló, Nacho; Llobet, Enrique; Moranta, David; Regueiro, Verónica; Brennan, Gerard P; Millán-Lou, Maria Isabel; Martín, Carlos; Garmendia, Junkal; Bengoechea, José A

    2015-11-01

    Klebsiella pneumoniae is an important cause of community-acquired and nosocomial pneumonia. Evidence indicates that Klebsiella might be able to persist intracellularly within a vacuolar compartment. This study was designed to investigate the interaction between Klebsiella and macrophages. Engulfment of K. pneumoniae was dependent on host cytoskeleton, cell plasma membrane lipid rafts and the activation of phosphoinositide 3-kinase (PI3K). Microscopy studies revealed that K. pneumoniae resides within a vacuolar compartment, the Klebsiella-containing vacuole (KCV), which traffics within vacuoles associated with the endocytic pathway. In contrast to UV-killed bacteria, the majority of live bacteria did not co-localize with markers of the lysosomal compartment. Our data suggest that K. pneumoniae triggers a programmed cell death in macrophages displaying features of apoptosis. Our efforts to identify the mechanism(s) whereby K. pneumoniae prevents the fusion of the lysosomes to the KCV uncovered the central role of the PI3K-Akt-Rab14 axis to control the phagosome maturation. Our data revealed that the capsule is dispensable for Klebsiella intracellular survival if bacteria were not opsonized. Furthermore, the environment found by Klebsiella within the KCV triggered the down-regulation of the expression of cps. Altogether, this study proves evidence that K. pneumoniae survives killing by macrophages by manipulating phagosome maturation that may contribute to Klebsiella pathogenesis.

  11. Receptor for Advanced Glycation End Products (RAGE) Serves a Protective Role during Klebsiella pneumoniae - Induced Pneumonia.

    PubMed

    Achouiti, Ahmed; de Vos, Alex F; van 't Veer, Cornelis; Florquin, Sandrine; Tanck, Michael W; Nawroth, Peter P; Bierhaus, Angelika; van der Poll, Tom; van Zoelen, Marieke A D

    2016-01-01

    Klebsiella species is the second most commonly isolated gram-negative organism in sepsis and a frequent causative pathogen in pneumonia. The receptor for advanced glycation end products (RAGE) is expressed on different cell types and plays a key role in diverse inflammatory responses. We here aimed to investigate the role of RAGE in the host response to Klebsiella (K.) pneumoniae pneumonia and intransally inoculated rage gene deficient (RAGE-/-) and normal wild-type (Wt) mice with K. pneumoniae. Klebsiella pneumonia resulted in an increased pulmonary expression of RAGE. Furthermore, the high-affinity RAGE ligand high mobility group box-1 was upregulated during K. pneumoniae pneumonia. RAGE deficiency impaired host defense as reflected by a worsened survival, increased bacterial outgrowth and dissemination in RAGE-/- mice. RAGE-/- neutrophils showed a diminished phagocytosing capacity of live K. pneumoniae in vitro. Relative to Wt mice, RAGE-/- mice demonstrated similar lung inflammation, and slightly elevated-if any-cytokine and chemokine levels and unchanged hepatocellular injury. In addition, RAGE-/- mice displayed an unaltered response to intranasally instilled Klebsiella lipopolysaccharide (LPS) with respect to pulmonary cell recruitment and local release of cytokines and chemokines. These data suggest that (endogenous) RAGE protects against K. pneumoniae pneumonia. Also, they demonstrate that RAGE contributes to an effective antibacterial defense during K. pneumoniae pneumonia, at least partly via its participation in the phagocytic properties of professional granulocytes. Additionally, our results indicate that RAGE is not essential for the induction of a local and systemic inflammatory response to either intact Klebsiella or Klebsiella LPS.

  12. Nosocomial Outbreak of Klebsiella pneumoniae Carbapenemase-Producing Klebsiella oxytoca in Austria

    PubMed Central

    Hoenigl, Martin; Valentin, Thomas; Zarfel, Gernot; Wuerstl, Benjamin; Leitner, Eva; Salzer, Helmut J. F.; Posch, Josefa; Krause, Robert

    2012-01-01

    To date, no outbreak of carbapenemase-producing bacteria has been reported for Austria. While outbreaks of Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae have been increasingly reported, no outbreak caused by KPC-producing Klebsiella oxytoca has been described yet, to the best of our knowledge. We report an outbreak of KPC-producing K. oxytoca. In 5 months, 31 KPC-producing Klebsiella oxytoca strains were isolated from five patients. All patients were admitted to the same medical intensive care unit in Austria. PMID:22290949

  13. Complete Genome Sequence of Klebsiella pneumoniae Carbapenemase-Producing K. pneumoniae Siphophage Sushi.

    PubMed

    Nguyen, Dat T; Lessor, Lauren E; Cahill, Jesse L; Rasche, Eric S; Kuty Everett, Gabriel F

    2015-09-03

    Klebsiella pneumoniae is a Gram-negative bacterium in the family Enterobacteriaceae. It is associated with numerous nosocomial infections, including respiratory and urinary tract infections in humans. The following reports the complete genome sequence of K. pneumoniae carbapenemase-producing K. pneumoniae T1-like siphophage Sushi and describes its major features.

  14. Complete Genome Sequence of Klebsiella pneumoniae Carbapenemase-Producing K. pneumoniae Siphophage Sushi.

    PubMed

    Nguyen, Dat T; Lessor, Lauren E; Cahill, Jesse L; Rasche, Eric S; Kuty Everett, Gabriel F

    2015-01-01

    Klebsiella pneumoniae is a Gram-negative bacterium in the family Enterobacteriaceae. It is associated with numerous nosocomial infections, including respiratory and urinary tract infections in humans. The following reports the complete genome sequence of K. pneumoniae carbapenemase-producing K. pneumoniae T1-like siphophage Sushi and describes its major features. PMID:26337889

  15. Antibiotic Resistance Related to Biofilm Formation in Klebsiella pneumoniae.

    PubMed

    Vuotto, Claudia; Longo, Francesca; Balice, Maria Pia; Donelli, Gianfranco; Varaldo, Pietro E

    2014-01-01

    The Gram-negative opportunistic pathogen, Klebsiella pneumoniae, is responsible for causing a spectrum of community-acquired and nosocomial infections and typically infects patients with indwelling medical devices, especially urinary catheters, on which this microorganism is able to grow as a biofilm. The increasingly frequent acquisition of antibiotic resistance by K. pneumoniae strains has given rise to a global spread of this multidrug-resistant pathogen, mostly at the hospital level. This scenario is exacerbated when it is noted that intrinsic resistance to antimicrobial agents dramatically increases when K. pneumoniae strains grow as a biofilm. This review will summarize the findings about the antibiotic resistance related to biofilm formation in K. pneumoniae.

  16. KPC-producing Klebsiella pneumoniae, finally targeting Turkey

    PubMed Central

    Labarca, J; Poirel, L; Özdamar, M; Turkoglü, S; Hakko, E; Nordmann, P

    2014-01-01

    We report here the first identification of the worldwide spread of Klebsiella pneumoniae carbapenemase-2-producing and carbapenem-resistant K. pneumoniae clone ST258 in Turkey, a country where the distantly-related carbapenemase OXA-48 is known to be endemic. Worryingly, this isolate was also resistant to colistin, now considered to be the last-resort antibiotic for carbapenem-resistant isolates. PMID:25356342

  17. Klebsiella pneumoniae triggers a cytotoxic effect on airway epithelial cells

    PubMed Central

    2009-01-01

    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. PMID:19650888

  18. Source and extent of Klebsiella pneumoniae in the paper industry.

    PubMed Central

    Caplenas, N R; Kanarek, M S; Dufour, A P

    1981-01-01

    Three pulp and paper mill processing plants were evaluated for fecal coliform and Klebsiella pneumoniae bacterial concentrations. Freshwater consumed by paper industries contained minimum detectable levels of K. pneumoniae, less than 10 organisms per 100 ml. Elevated concentrations of K. pneumoniae could be traced from early pulping stages to water processing reuse systems. Concentrations of K. pneumoniae (thermotolerant and thermointolerant) ranged from 40,000 organisms per 100 ml to an estimated 3 x 10(6) organisms per 100 ml. K. pneumoniae biotyping provided evidence for the selective growth and persistence of K. pneumoniae from the initial wood washing stages through to the final effluent discharge. Wastewater treatment had limited effects in reducing K. pneumoniae concentrations. K. pneumoniae levels ranged from 40 organisms per 100 ml to an estimated 10(6) organisms per 100 ml. The presence of K. pneumoniae in water indicates degraded water quality, and its significance with regard to human health effects has yet to be examined. PMID:7032419

  19. Antibiotic Resistance Related to Biofilm Formation in Klebsiella pneumoniae

    PubMed Central

    Vuotto, Claudia; Longo, Francesca; Balice, Maria Pia; Donelli, Gianfranco; Varaldo, Pietro E.

    2014-01-01

    The Gram-negative opportunistic pathogen, Klebsiella pneumoniae, is responsible for causing a spectrum of community-acquired and nosocomial infections and typically infects patients with indwelling medical devices, especially urinary catheters, on which this microorganism is able to grow as a biofilm. The increasingly frequent acquisition of antibiotic resistance by K. pneumoniae strains has given rise to a global spread of this multidrug-resistant pathogen, mostly at the hospital level. This scenario is exacerbated when it is noted that intrinsic resistance to antimicrobial agents dramatically increases when K. pneumoniae strains grow as a biofilm. This review will summarize the findings about the antibiotic resistance related to biofilm formation in K. pneumoniae. PMID:25438022

  20. Carbapenemase-producing Klebsiella pneumoniae: molecular and genetic decoding

    PubMed Central

    Chen, Liang; Mathema, Barun; Chavda, Kalyan D.; DeLeo, Frank R.; Bonomo, Robert A.; Kreiswirth, Barry N.

    2015-01-01

    Klebsiella pneumoniae carbapenemases (KPCs) were first identified in 1996 in the USA. Since then, regional outbreaks of KPC-producing K. pneumoniae have occurred in the USA, and have spread internationally. Dissemination of blaKPC involves both horizontal transfer of blaKPC genes and plasmids, and clonal spread. Of epidemiological significance, the international spread of KPC-producing K. pneumoniae is primarily associated with a single multilocus sequence type (ST), ST258, and its related variants. However, the molecular factors contributing to the success of ST258 largely remain unclear. Here, we review the recent progresses in understanding KPC-producing K. pneumoniae that is contributing to our knowledge of plasmid and genome composition and structure among the KPC epidemic clone, and identify possible factors that influence its epidemiological success. PMID:25304194

  1. Draft Genome Sequence of Klebsiella pneumoniae Strain AS Isolated from Zhejiang Provincial Hospital of TCM, China.

    PubMed

    Yang, Xue-Jing; Wang, Sai; Cao, Jun-Min; Hou, Jia-Hui

    2016-01-01

    Klebsiella pneumoniae is a Gram-negative, nonmotile, encapsulated, lactose-fermenting, facultative anaerobic, rod-shaped bacterium. Here we present draft genome assemblies of Klebsiella pneumoniae AS, which was isolated in China. The genomic information will provide a better understanding of the physiology, adaptation, and evolution of K. pneumoniae. PMID:27660770

  2. Draft Genome Sequence of Klebsiella pneumoniae Strain AS Isolated from Zhejiang Provincial Hospital of TCM, China.

    PubMed

    Yang, Xue-Jing; Wang, Sai; Cao, Jun-Min; Hou, Jia-Hui

    2016-09-22

    Klebsiella pneumoniae is a Gram-negative, nonmotile, encapsulated, lactose-fermenting, facultative anaerobic, rod-shaped bacterium. Here we present draft genome assemblies of Klebsiella pneumoniae AS, which was isolated in China. The genomic information will provide a better understanding of the physiology, adaptation, and evolution of K. pneumoniae.

  3. Draft Genome Sequence of Klebsiella pneumoniae Strain AS Isolated from Zhejiang Provincial Hospital of TCM, China

    PubMed Central

    Yang, Xue-Jing; Wang, Sai; Hou, Jia-Hui

    2016-01-01

    Klebsiella pneumoniae is a Gram-negative, nonmotile, encapsulated, lactose-fermenting, facultative anaerobic, rod-shaped bacterium. Here we present draft genome assemblies of Klebsiella pneumoniae AS, which was isolated in China. The genomic information will provide a better understanding of the physiology, adaptation, and evolution of K. pneumoniae. PMID:27660770

  4. A Second Outer-Core Region in Klebsiella pneumoniae Lipopolysaccharide†

    PubMed Central

    Regué, Miguel; Izquierdo, Luis; Fresno, Sandra; Piqué, Núria; Corsaro, Maria Michela; Naldi, Teresa; De Castro, Cristina; Waidelich, Dietmar; Merino, Susana; Tomás, Juan M.

    2005-01-01

    Up to now only one major type of core oligosaccharide has been found in the lipopolysaccharide of all Klebsiella pneumoniae strains analyzed. Applying a different screening approach, we identified a novel Klebsiella pneumoniae core (type 2). Both Klebsiella core types share the same inner core and the outer-core-proximal disaccharide, GlcN-(1,4)-GalA, but they differ in the GlcN substituents. In core type 2, the GlcpN residue is substituted at the O-4 position by the disaccharide β-Glcp(1-6)-α-Glcp(1, while in core type 1 the GlcpN residue is substituted at the O-6 position by either the disaccharide α-Hep(1-4)-α-Kdo(2 or a Kdo residue (Kdo is 3-deoxy-d-manno-octulosonic acid). This difference correlates with the presence of a three-gene region in the corresponding core biosynthetic clusters. Engineering of both core types by interchanging this specific region allowed studying the effect on virulence. The replacement of Klebsiella core type 1 in a highly type 2 virulent strain (52145) induces lower virulence than core type 2 in a murine infection model. PMID:15937181

  5. Complete Genome Sequence of Klebsiella pneumoniae YH43

    PubMed Central

    Ogura, Yoshitoshi; Hayashi, Tetsuya; Mizunoe, Yoshimitsu

    2016-01-01

    We report here the complete genome sequence of Klebsiella pneumoniae strain YH43, isolated from sweet potato. The genome consists of a single circular chromosome of 5,520,319 bp in length. It carries 8 copies of rRNA operons, 86 tRNA genes, 5,154 protein-coding genes, and the nif gene cluster for nitrogen fixation. PMID:27081127

  6. Isolation and characterization of Klebsiella pneumoniae unencapsulated mutants

    SciTech Connect

    Benedi, V.J.; Ciurana, B.; Tomas, J.M.

    1989-01-01

    Klebsiella pneumoniae mutants were obtained after UV irradiation and negative selection with anticapsular serum. Unencapsulation, rather than expression of a structurally altered capsule, was found in the mutants. The mutant strains showed no alterations in their outer membrane proteins and lipopolysaccharide, and a great similarity with the wild type in the properties tested (serum resistance, antimicrobial sensitivity, and lipopolysaccharide-specific bacteriophage sensitivity), with the exception of a higher cell surface hydrophobicity and resistance to bacteriophage FC3-9.

  7. Metabolism of benzonitrile and butyronitrile by Klebsiella pneumoniae

    SciTech Connect

    Nawaz, M.S.; Heinze, T.M.; Cerniglia, C.E. )

    1992-01-01

    A strain of Klebsiella pneumoniae that used aliphatic nitriles as the sole source of nitrogen was adapted to benzonitrile as the sole source of carbon and nitrogen. Gas chromatographic and mass spectral analyses of culture filtrates indicated that K. pneumoniae metabolized 8.4 mM benzonitrile to 4.0 mM benzoic acid and 2.7 mM ammonia. In addition, butyronitrile was metabolized to butyramide and ammonia. The isolate also degraded mixtures of benzonitrile and aliphatic nitriles. Cell extracts contained nitrile hydratase and amidase activities. The enzyme activities were higher with butyronitrile and butyramide than with benzonitrile and benzamide, and amidase activities were twofold higher than nitrile hydratase activities. K. pneumoniae appears promising for the bioremediation of sites contaminated with aliphatic and aromatic nitriles.

  8. Deciphering tissue-induced Klebsiella pneumoniae lipid A structure

    PubMed Central

    Llobet, Enrique; Martínez-Moliner, Verónica; Moranta, David; Dahlström, Käthe M.; Regueiro, Verónica; Tomás, Anna; Cano, Victoria; Pérez-Gutiérrez, Camino; Frank, Christian G.; Fernández-Carrasco, Helena; Insua, José Luis; Salminen, Tiina A.; Garmendia, Junkal; Bengoechea, José A.

    2015-01-01

    The outcome of an infection depends on host recognition of the pathogen, hence leading to the activation of signaling pathways controlling defense responses. A long-held belief is that the modification of the lipid A moiety of the lipopolysaccharide could help Gram-negative pathogens to evade innate immunity. However, direct evidence that this happens in vivo is lacking. Here we report the lipid A expressed in the tissues of infected mice by the human pathogen Klebsiella pneumoniae. Our findings demonstrate that Klebsiella remodels its lipid A in a tissue-dependent manner. Lipid A species found in the lungs are consistent with a 2-hydroxyacyl-modified lipid A dependent on the PhoPQ-regulated oxygenase LpxO. The in vivo lipid A pattern is lost in minimally passaged bacteria isolated from the tissues. LpxO-dependent modification reduces the activation of inflammatory responses and mediates resistance to antimicrobial peptides. An lpxO mutant is attenuated in vivo thereby highlighting the importance of this lipid A modification in Klebsiella infection biology. Colistin, one of the last options to treat multidrug-resistant Klebsiella infections, triggers the in vivo lipid A pattern. Moreover, colistin-resistant isolates already express the in vivo lipid A pattern. In these isolates, LpxO-dependent lipid A modification mediates resistance to colistin. Deciphering the lipid A expressed in vivo opens the possibility of designing novel therapeutics targeting the enzymes responsible for the in vivo lipid A pattern. PMID:26578797

  9. Deciphering tissue-induced Klebsiella pneumoniae lipid A structure.

    PubMed

    Llobet, Enrique; Martínez-Moliner, Verónica; Moranta, David; Dahlström, Käthe M; Regueiro, Verónica; Tomás, Anna; Cano, Victoria; Pérez-Gutiérrez, Camino; Frank, Christian G; Fernández-Carrasco, Helena; Insua, José Luis; Salminen, Tiina A; Garmendia, Junkal; Bengoechea, José A

    2015-11-17

    The outcome of an infection depends on host recognition of the pathogen, hence leading to the activation of signaling pathways controlling defense responses. A long-held belief is that the modification of the lipid A moiety of the lipopolysaccharide could help Gram-negative pathogens to evade innate immunity. However, direct evidence that this happens in vivo is lacking. Here we report the lipid A expressed in the tissues of infected mice by the human pathogen Klebsiella pneumoniae. Our findings demonstrate that Klebsiella remodels its lipid A in a tissue-dependent manner. Lipid A species found in the lungs are consistent with a 2-hydroxyacyl-modified lipid A dependent on the PhoPQ-regulated oxygenase LpxO. The in vivo lipid A pattern is lost in minimally passaged bacteria isolated from the tissues. LpxO-dependent modification reduces the activation of inflammatory responses and mediates resistance to antimicrobial peptides. An lpxO mutant is attenuated in vivo thereby highlighting the importance of this lipid A modification in Klebsiella infection biology. Colistin, one of the last options to treat multidrug-resistant Klebsiella infections, triggers the in vivo lipid A pattern. Moreover, colistin-resistant isolates already express the in vivo lipid A pattern. In these isolates, LpxO-dependent lipid A modification mediates resistance to colistin. Deciphering the lipid A expressed in vivo opens the possibility of designing novel therapeutics targeting the enzymes responsible for the in vivo lipid A pattern.

  10. Deciphering tissue-induced Klebsiella pneumoniae lipid A structure.

    PubMed

    Llobet, Enrique; Martínez-Moliner, Verónica; Moranta, David; Dahlström, Käthe M; Regueiro, Verónica; Tomás, Anna; Cano, Victoria; Pérez-Gutiérrez, Camino; Frank, Christian G; Fernández-Carrasco, Helena; Insua, José Luis; Salminen, Tiina A; Garmendia, Junkal; Bengoechea, José A

    2015-11-17

    The outcome of an infection depends on host recognition of the pathogen, hence leading to the activation of signaling pathways controlling defense responses. A long-held belief is that the modification of the lipid A moiety of the lipopolysaccharide could help Gram-negative pathogens to evade innate immunity. However, direct evidence that this happens in vivo is lacking. Here we report the lipid A expressed in the tissues of infected mice by the human pathogen Klebsiella pneumoniae. Our findings demonstrate that Klebsiella remodels its lipid A in a tissue-dependent manner. Lipid A species found in the lungs are consistent with a 2-hydroxyacyl-modified lipid A dependent on the PhoPQ-regulated oxygenase LpxO. The in vivo lipid A pattern is lost in minimally passaged bacteria isolated from the tissues. LpxO-dependent modification reduces the activation of inflammatory responses and mediates resistance to antimicrobial peptides. An lpxO mutant is attenuated in vivo thereby highlighting the importance of this lipid A modification in Klebsiella infection biology. Colistin, one of the last options to treat multidrug-resistant Klebsiella infections, triggers the in vivo lipid A pattern. Moreover, colistin-resistant isolates already express the in vivo lipid A pattern. In these isolates, LpxO-dependent lipid A modification mediates resistance to colistin. Deciphering the lipid A expressed in vivo opens the possibility of designing novel therapeutics targeting the enzymes responsible for the in vivo lipid A pattern. PMID:26578797

  11. Lipopolysaccharide-specific bacteriophage for Klebsiella pneumoniae C3.

    PubMed Central

    Tomás, J M; Jofre, J T

    1985-01-01

    Bacteriophage FC3-1 is one of several specific bacteriophages of Klebsiella pneumoniae C3 isolated in our laboratory. Unlike receptors for other Klebsiella phages, the bacteriophage FC3-1 receptor was shown to be lipopolysaccharide, specifically the polysaccharide fraction (O-antigen and core region). We concluded that capsular polysaccharide, outer membrane proteins, and lipid A were not involved in phage binding. Mutants resistant to this phage were isolated and were found to be devoid of lipopolysaccharide O-antigen by several criteria but to contain capsular material serologically identical to that of the wild type. The polysaccharide fraction was concluded to be the primary phage receptor, indicating that it is available to the phage. Images PMID:3888963

  12. Molecular characterization of clinical multidrug-resistant Klebsiella pneumoniae isolates

    PubMed Central

    2014-01-01

    Background Klebsiella pneumoniae is a frequent nosocomial pathogen, with the multidrug-resistant (MDR) K. pneumoniae being a major public health concern, frequently causing difficult-to-treat infections worldwide. The aim of this study was to investigate the molecular characterization of clinical MDR Klebsiella pneumoniae isolates. Methods A total of 27 non-duplicate MDR K. pneumoniae isolates with a CTX-CIP-AK resistance pattern were investigated for the prevalence of antimicrobial resistance genes including extended spectrum β-lactamase genes (ESBLs), plasmid-mediated quinolone resistance (PMQR) genes, 16S rRNA methylase (16S-RMTase) genes, and integrons by polymerase chain reaction (PCR) amplification and DNA sequencing. Plasmid replicons were typed by PCR-based replicon typing (PBRT). Multi-locus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) were carried out to characterize the strain relatedness. Results All the isolates co-harbored 3 or more resistance determinants. OqxAB, CTX-M-type ESBLs and RmtB were the most frequent determinants, distributed among19 (70.4%),18 (66.7%) and 8 (29.6%) strains. Fourteen isolates harbored class 1 integrons, with orfD-aacA4 being the most frequent gene cassette array. Class 3 integrons were less frequently identified and contained the gene cassette array of blaGES-1-blaOXA-10-aac(6′)-Ib. IncFII replicon was most commonly found in this collection. One cluster was observed with ≥80% similarity among profiles obtained by PFGE, and one sequence type (ST) by MLST, namely ST11, was observed in the cluster. Conclusion K. pneumoniae carbapenemase (KPC)–producing ST11 was the main clone detected. Of particular concern was the high prevalence of multiple resistance determinants, classs I integrons and IncFII plasmid replicon among these MDR strains, which provide advantages for the rapid development of MDR strains. PMID:24884610

  13. Isolation and characterisation of lytic bacteriophages of Klebsiella pneumoniae and Klebsiella oxytoca.

    PubMed

    Karumidze, Natia; Kusradze, Ia; Rigvava, Sophio; Goderdzishvili, Marine; Rajakumar, Kumar; Alavidze, Zemphira

    2013-03-01

    Klebsiella bacteria have emerged as an increasingly important cause of community-acquired nosocomial infections. Extensive use of broad-spectrum antibiotics in hospitalised patients has led to both increased carriage of Klebsiella and the development of multidrug-resistant strains that frequently produce extended-spectrum β-lactamases and/or other defences against antibiotics. Many of these strains are highly virulent and exhibit a strong propensity to spread. In this study, six lytic Klebsiella bacteriophages were isolated from sewage-contaminated river water in Georgia and characterised as phage therapy candidates. Two of the phages were investigated in greater detail. Biological properties, including phage morphology, nucleic acid composition, host range, growth phenotype, and thermal and pH stability were studied for all six phages. Limited sample sequencing was performed to define the phylogeny of the K. pneumoniae- and K. oxytoca-specific bacteriophages vB_Klp_5 and vB_Klox_2, respectively. Both of the latter phages had large burst sizes, efficient rates of adsorption and were stable under different adverse conditions. Phages reported in this study are double-stranded DNA bacterial viruses belonging to the families Podoviridae and Siphoviridae. One or more of the six phages was capable of efficiently lysing ~63 % of Klebsiella strains comprising a collection of 123 clinical isolates from Georgia and the United Kingdom. These phages exhibit a number of properties indicative of potential utility in phage therapy cocktails.

  14. Gluconic acid production by gad mutant of Klebsiella pneumoniae.

    PubMed

    Wang, Dexin; Wang, Chenhong; Wei, Dong; Shi, Jiping; Kim, Chul Ho; Jiang, Biao; Han, Zengsheng; Hao, Jian

    2016-08-01

    Klebsiella pneumoniae produces many economically important chemicals. Using glucose as a carbon source, the main metabolic product in K. pneumoniae is 2,3-butanediol. Gluconic acid is an intermediate of the glucose oxidation pathway. In the current study, a metabolic engineering strategy was used to develop a gluconic acid-producing K. pneumoniae strain. Deletion of gad, resulting in loss of gluconate dehydrogenase activity, led to the accumulation of gluconic acid in the culture broth. Gluconic acid accumulation by K. pneumoniae Δgad was an acid-dependent aerobic process, with accumulation observed at pH 5.5 or lower, and at higher levels of oxygen supplementation. Under all other conditions tested, 2,3-butanediol was the main metabolic product of the process. In fed batch fermentation, a final concentration of 422 g/L gluconic acid was produced by K. pneumoniae Δgad, and the conversion ratio of glucose to gluconic acid reached 1 g/g. The K. pneumoniae Δgad described in this study is the first genetically modified strain used for gluconic acid production, and this optimized method for gluconic acid production may have important industrial applications. Gluconic acid is an intermediate of this glucose oxidation pathway. Deletion of gad, resulting in loss of gluconate dehydrogenase activity, led to the accumulation of gluconic acid in the culture broth. In fed batch fermentation, a final concentration of 422 g/L gluconic acid was produced by the K. pneumoniae Δgad strain, and the conversion ratio of glucose to gluconic acid reached 1 g/g.

  15. Gluconic acid production by gad mutant of Klebsiella pneumoniae.

    PubMed

    Wang, Dexin; Wang, Chenhong; Wei, Dong; Shi, Jiping; Kim, Chul Ho; Jiang, Biao; Han, Zengsheng; Hao, Jian

    2016-08-01

    Klebsiella pneumoniae produces many economically important chemicals. Using glucose as a carbon source, the main metabolic product in K. pneumoniae is 2,3-butanediol. Gluconic acid is an intermediate of the glucose oxidation pathway. In the current study, a metabolic engineering strategy was used to develop a gluconic acid-producing K. pneumoniae strain. Deletion of gad, resulting in loss of gluconate dehydrogenase activity, led to the accumulation of gluconic acid in the culture broth. Gluconic acid accumulation by K. pneumoniae Δgad was an acid-dependent aerobic process, with accumulation observed at pH 5.5 or lower, and at higher levels of oxygen supplementation. Under all other conditions tested, 2,3-butanediol was the main metabolic product of the process. In fed batch fermentation, a final concentration of 422 g/L gluconic acid was produced by K. pneumoniae Δgad, and the conversion ratio of glucose to gluconic acid reached 1 g/g. The K. pneumoniae Δgad described in this study is the first genetically modified strain used for gluconic acid production, and this optimized method for gluconic acid production may have important industrial applications. Gluconic acid is an intermediate of this glucose oxidation pathway. Deletion of gad, resulting in loss of gluconate dehydrogenase activity, led to the accumulation of gluconic acid in the culture broth. In fed batch fermentation, a final concentration of 422 g/L gluconic acid was produced by the K. pneumoniae Δgad strain, and the conversion ratio of glucose to gluconic acid reached 1 g/g. PMID:27339313

  16. Klebsiella pneumoniae liver abscess in an immunocompetent child.

    PubMed

    Kwon, Jang-Mi; Jung, Hye Lim; Shim, Jae Won; Kim, Deok Soo; Shim, Jung Yeon; Park, Moon Soo

    2013-09-01

    Klebsiella pneumoniae has emerged as a leading pathogen that causes pyogenic liver abscesses (PLAs) in Korea. K. pneumoniae liver abscess (KLA) is potentially life threatening, and the diagnosis is difficult. In developed countries, PLA is rarely observed in children and is frequently associated with disorders of granulocyte function and previous abdominal infection. We observed a case of KLA in a healthy 12-year-old boy. To our knowledge, this is the first reported case of KLA in an immunocompetent child without an underlying disease in Korea. The patient was treated with percutaneous catheter drainage and antibiotics. The catheter was placed in the intrahepatic abscess for 3 weeks and parenteral antibiotics (ceftriaxone and amikacin) were administered for 4 weeks, followed by oral antibiotics (cefixime) for 2 weeks. We reported this case to raise awareness of KLA in immunocompetent children among physicians, and to review the diagnosis, risk factors, potential complications, and appropriate treatment of KLA.

  17. Granzymes A and B Regulate the Local Inflammatory Response during Klebsiella pneumoniae Pneumonia.

    PubMed

    García-Laorden, M Isabel; Stroo, Ingrid; Blok, Dana C; Florquin, Sandrine; Medema, Jan Paul; de Vos, Alex F; van der Poll, Tom

    2016-01-01

    Klebsiella pneumoniae is a common cause of hospital-acquired pneumonia. Granzymes (gzms), mainly found in cytotoxic lymphocytes, have been implicated as mediators of infection and inflammation. We here sought to investigate the role of gzmA and gzmB in the host response to K. pneumoniae-induced airway infection and sepsis. For this purpose, pneumonia was induced in wild-type (WT) and gzmA-deficient (gzmA-/-), gzmB-/- and gzmAxB-/- mice by intranasal infection with K. pneumoniae. In WT mice, gzmA and gzmB were mainly expressed by natural killer cells. Pneumonia was associated with reduced intracellular gzmA and increased intracellular gzmB levels. Gzm deficiency had little impact on antibacterial defence: gzmA-/- and gzmAxB-/- mice transiently showed modestly higher bacterial loads in the lungs but not in distant organs. GzmB-/- and, to a larger extent, gzmAxB-/- mice displayed transiently increased lung inflammation, reflected in the semi-quantitative histology scores and levels of pro-inflammatory cytokines and chemokines. Most differences between gzm-deficient and WT mice had disappeared during late-stage pneumonia. Gzm deficiency did not impact on distant organ injury or survival. These results suggest that gzmA and gzmB partly regulate local inflammation during early pneumonia but eventually play an insignificant role during pneumosepsis by the common human pathogen K. pneumoniae.

  18. CRYSTAL STRUCTURE ANALYSIS OF A PUTATIVE OXIDOREDUCTASE FROM KLEBSIELLA PNEUMONIAE

    SciTech Connect

    Baig, M.; Brown, A.; Eswaramoorthy, S.; Swaminathan, S.

    2009-01-01

    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.

  19. Multiple biotypes of Klebsiella pneumoniae in single clinical specimens.

    PubMed

    de Silva, M I; Rubin, S J

    1977-01-01

    The occurence of multiple biotypes of Klebsiella pneumoniae within single specimens was determined in 59 clinical specimens. Biotyping was performed on five colonies of K. pneumoniae from each specimen, using the API 20E system (Analytab, Inc., New York) for identification of Enterobacteriaceae with strict adherence to the manufacturer's instructions. Multiple biotypes of K. pneumoniae were present in 31% (18) of the clinical specimens. Twenty-eight colonies representative of specimens with single and multiple biotypes were tested further for biotype reproducibility. Whereas genus and species identification was 100% reproducible, variation of one or more biochemical tests on serial transfers resulted in biotype reproducibility of only 64%. The greatest variation in biochemical tests occurred with urease (14%), indole production (10%) and citrate utilization (9%). Multiple biotypes in single specimens appear to be due to both inherent differences among the colonies in the specimen and variability in the system used to determine biochemical reactions. The presence of multiple biotypes limits the usefulness of biochemical typing for epidemiological surveilance of K. pneumoniae.

  20. Klebsiella pneumoniae: characteristics of carbapenem resistance and virulence factors.

    PubMed

    Candan, Esra Deniz; Aksöz, Nilüfer

    2015-01-01

    Klebsiella pneumoniae, known as a major threat to public health, is the most common factor of nosocomial and community acquired infections. In this study, 50 K. pneumoniae clinical specimens isolated from bronchial, urea, blood, catheter, rectal, bile, tracheal and wound cultures were collected. These isolates were identified and carbapenem resistance was determined via an automated system, CHROMagar Orientation and CHROMagar KPC. The carbapenemase gene regions (blaIMP, blaVIM, blaOXA, blaNDM and blaKPC) and presence of virulence factors (magA, k2A, rmpA, wabG, uge, allS, entB, ycfM, kpn, wcaG, fimH, mrkD, iutA, iroN, hly ve cnf-1) of these isolates were determined by using Multiplex-PCR. The OXA-48 carbapenemase gene regions were determined in 33 of 50 K. pneumoniae strains. In addition, NDM-1 resistance in one, OXA-48 and NDM-1 resistance in four unusual K. pneumoniae isolates were detected. Virulence gene regions that were encountered among K. pneumoniae isolates were 88% wabG, 86% uge, 80% ycfM and 72% entB, related with capsule, capsule lipoprotein and external membrane protein, responsible for enterobactin production, respectively. Even though there was no significant difference between resistant and sensitive strains due to the virulence gene regions (P≥0.05), virulence factors in carbapenem resistant isolates were found to be more diverse. This study is important for both, to prevent the spread of carbapenem resistant infections and to plan for developing effective treatments. Moreover, this study is the first detailed study of the carbapenem resistance and virulence factors in K. pneumoniae strains.

  1. Preliminary investigation of a mice model of Klebsiella pneumoniae subsp. ozaenae induced pneumonia.

    PubMed

    Renois, Fanny; Jacques, Jérôme; Guillard, Thomas; Moret, Hélène; Pluot, Michel; Andreoletti, Laurent; de Champs, Christophe

    2011-11-01

    In the present study, we comparatively assessed the pathophysiological mechanisms developed during lung infection of BALB/C female mice infected by an original wild type Klebsiella pneumoniae subsp. ozaenae strain (CH137) or by a referent subspecies K. pneumoniae. subsp. pneumoniae strain (ATCC10031). The mice infected with 2.10⁶ CFU K. p. subsp. pneumoniae (n = 10) showed transient signs of infection and all of them recovered. All of those infected with 1.10⁶ CFU K. p. subsp. ozaenae (n = 10) developed pneumonia within 24 h and died between 48 and 72 h. Few macrophages, numerous polymorphonuclear cells and lymphocytes were observed in their lungs in opposite to K. p. subsp. pneumoniae. In bronchoalveolar lavage, a significant increase in MIP-2, IL-6, KC and MCP-1 levels was only observed in K. p. subsp. ozaenae infected mice whereas high levels of TNF-α were evidenced with the two subspecies. Our findings indicated a lethal effect of a wild type K. p. subsp. ozaenae strain by acute pneumonia reflecting an insufficient alveolar macrophage response. This model might be of a major interest to comparatively explore the pathogenicity of K. p. subsp ozaenae strains and to further explore the physiopathological mechanisms of gram-negative bacteria induced human pneumonia.

  2. Molecular Epidemiology of Colonizing and Infecting Isolates of Klebsiella pneumoniae

    PubMed Central

    Martin, Rebekah M.; Cao, Jie; Brisse, Sylvain; Passet, Virginie; Wu, Weisheng; Zhao, Lili; Malani, Preeti N.; Rao, Krishna

    2016-01-01

    ABSTRACT Klebsiella pneumoniae is among the most common causes of hospital-acquired infections and has emerged as an urgent threat to public health due to carbapenem antimicrobial resistance. K. pneumoniae commonly colonizes hospitalized patients and causes extraintestinal infections such as urinary tract infection, bloodstream infection (septicemia), and pneumonia. If colonization is an intermediate step before infection, then detection and characterization of colonizing isolates could enable strategies to prevent or empirically treat K. pneumoniae infections in hospitalized patients. However, the strength of the association between colonization and infection is unclear. To test the hypothesis that hospitalized patients become infected with their colonizing strain, 1,765 patients were screened for rectal colonization with K. pneumoniae, and extraintestinal isolates from these same patients were collected over a 3-month period in a cohort study design. The overall colonization prevalence was 23.0%. After adjustment for other patient factors, colonization was significantly associated with subsequent infection: 21 of 406 (5.2%) colonized patients later had extraintestinal infection, compared to 18 of 1,359 (1.3%) noncolonized patients (adjusted odds ratio [OR], 4.01; 95% confidence interval, 2.08 to 7.73; P < 0.001). Despite a high diversity of colonizing isolates, 7/7 respiratory, 4/4 urinary, and 2/5 bloodstream isolates from colonized patients matched the patient corresponding rectal swab isolates, based on wzi capsular typing, multilocus sequence typing (MLST), and whole-genome sequence analysis. These results suggest that K. pneumoniae colonization is directly associated with progression to extraintestinal infection. IMPORTANCE K. pneumoniae commonly infects hospitalized patients, and these infections are increasingly resistant to carbapenems, the antibiotics of last resort for life-threatening bacterial infections. To prevent and treat these infections, we

  3. Epidemiology of Carbapenem Resistant Klebsiella pneumoniae Infections in Mediterranean Countries

    PubMed Central

    Girmenia, Corrado; Serrao, Alessandra; Canichella, Martina

    2016-01-01

    Infections by Carbapenem-Resistant Enterobacteriaceae (CRE), in particular, carbapenem-resistant Klebsiella pneumoniae (CRKp), are a significant public health challenge worldwide. Resistance to carbapenems in enterobacteriaceae is linked to different mechanisms, including the production of the various types of enzymes like KPC, VIM, IMP, NDM, and OXA-48. Despite several attempts to control the spread of these infections at the local and national level, the epidemiological situation for CRKp had worsened in the last years in the Mediterranean area. The rate and types of CRKp isolates greatly differ in the various Mediterranean countries. KPC-producing K. pneumoniae is diffused particularly in the European countries bordering the Mediterranean Sea and is endemic in Greece and Italy. On the contrary, OXA-48-producing K. pneumoniae is endemic in Turkey and Malta and diffused at inter-regional level particularly in some North African and Middle East countries. The spread of these multiresistant pathogens in the world and the Mediterranean countries has been related to various epidemiological factors including the international transfer of patients coming from endemic areas. PMID:27441063

  4. Complete genome sequence of a Klebsiella pneumoniae strain isolated from a known cotton insect boll vector

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Klebsiella pneumoniae (associated with bacterial pneumonia) was previously isolated from Nezara viridula, a significant vector of cotton boll-rot pathogens. We provide the first annotated genome sequence of the cotton opportunistic strain K. pneumoniae 5-1. This data provides guidance to study the...

  5. Klebsiella pneumoniae Siderophores Induce Inflammation, Bacterial Dissemination, and HIF-1α Stabilization during Pneumonia

    PubMed Central

    Holden, Victoria I.; Breen, Paul; Houle, Sébastien; Dozois, Charles M.

    2016-01-01

    ABSTRACT Klebsiella pneumoniae is a Gram-negative pathogen responsible for a wide range of infections, including pneumonia and bacteremia, and is rapidly acquiring antibiotic resistance. K. pneumoniae requires secretion of siderophores, low-molecular-weight, high-affinity iron chelators, for bacterial replication and full virulence. The specific combination of siderophores secreted by K. pneumoniae during infection can impact tissue localization, systemic dissemination, and host survival. However, the effect of these potent iron chelators on the host during infection is unknown. In vitro, siderophores deplete epithelial cell iron, induce cytokine secretion, and activate the master transcription factor hypoxia inducible factor-1α (HIF-1α) protein that controls vascular permeability and inflammatory gene expression. Therefore, we hypothesized that siderophore secretion by K. pneumoniae directly contributes to inflammation and bacterial dissemination during pneumonia. To examine the effects of siderophore secretion independently of bacterial growth, we performed infections with tonB mutants that persist in vivo but are deficient in siderophore import. Using a murine model of pneumonia, we found that siderophore secretion by K. pneumoniae induces the secretion of interleukin-6 (IL-6), CXCL1, and CXCL2, as well as bacterial dissemination to the spleen, compared to siderophore-negative mutants at an equivalent bacterial number. Furthermore, we determined that siderophore-secreting K. pneumoniae stabilized HIF-1α in vivo and that bacterial dissemination to the spleen required alveolar epithelial HIF-1α. Our results indicate that siderophores act directly on the host to induce inflammatory cytokines and bacterial dissemination and that HIF-1α is a susceptibility factor for bacterial invasion during pneumonia. PMID:27624128

  6. Stepwise evolution of pandrug-resistance in Klebsiella pneumoniae.

    PubMed

    Zowawi, Hosam M; Forde, Brian M; Alfaresi, Mubarak; Alzarouni, Abdulqadir; Farahat, Yasser; Chong, Teik-Min; Yin, Wai-Fong; Chan, Kok-Gan; Li, Jian; Schembri, Mark A; Beatson, Scott A; Paterson, David L

    2015-01-01

    Carbapenem resistant Enterobacteriaceae (CRE) pose an urgent risk to global human health. CRE that are non-susceptible to all commercially available antibiotics threaten to return us to the pre-antibiotic era. Using Single Molecule Real Time (SMRT) sequencing we determined the complete genome of a pandrug-resistant Klebsiella pneumoniae isolate, representing the first complete genome sequence of CRE resistant to all commercially available antibiotics. The precise location of acquired antibiotic resistance elements, including mobile elements carrying genes for the OXA-181 carbapenemase, were defined. Intriguingly, we identified three chromosomal copies of an ISEcp1-bla(OXA-181) mobile element, one of which has disrupted the mgrB regulatory gene, accounting for resistance to colistin. Our findings provide the first description of pandrug-resistant CRE at the genomic level, and reveal the critical role of mobile resistance elements in accelerating the emergence of resistance to other last resort antibiotics. PMID:26478520

  7. Mechanisms of Klebsiella pneumoniae resistance to complement-mediated killing.

    PubMed Central

    Merino, S; Camprubí, S; Albertí, S; Benedí, V J; Tomás, J M

    1992-01-01

    The different mechanisms of Klebsiella pneumoniae resistance to complement-mediated killing were investigated by using different strains and isogenic mutants previously characterized for their surface components. We found that strains from serotypes whose K antigen masks the lipopolysaccharide (LPS) molecules (such as serotypes K1, K10, and K16) fail to activate complement, while strains with smooth LPS exposed at the cell surface (with or without K antigen) activate complement but are resistant to complement-mediated killing. The reasons for this resistance are that C3b binds far from the cell membrane and that the lytic final complex C5b-9 (membrane attack complex) is not formed. Isogenic rough mutants (K+ or K-) are serum sensitive because they bind C3b close to the cell membrane and the lytic complex (C5b-9) is formed. Images PMID:1587619

  8. Stepwise evolution of pandrug-resistance in Klebsiella pneumoniae

    PubMed Central

    Zowawi, Hosam M.; Forde, Brian M.; Alfaresi, Mubarak; Alzarouni, Abdulqadir; Farahat, Yasser; Chong, Teik-Min; Yin, Wai-Fong; Chan, Kok-Gan; Li, Jian; Schembri, Mark A.; Beatson, Scott A.; Paterson, David L.

    2015-01-01

    Carbapenem resistant Enterobacteriaceae (CRE) pose an urgent risk to global human health. CRE that are non-susceptible to all commercially available antibiotics threaten to return us to the pre-antibiotic era. Using Single Molecule Real Time (SMRT) sequencing we determined the complete genome of a pandrug-resistant Klebsiella pneumoniae isolate, representing the first complete genome sequence of CRE resistant to all commercially available antibiotics. The precise location of acquired antibiotic resistance elements, including mobile elements carrying genes for the OXA-181 carbapenemase, were defined. Intriguingly, we identified three chromosomal copies of an ISEcp1-blaOXA-181 mobile element, one of which has disrupted the mgrB regulatory gene, accounting for resistance to colistin. Our findings provide the first description of pandrug-resistant CRE at the genomic level, and reveal the critical role of mobile resistance elements in accelerating the emergence of resistance to other last resort antibiotics. PMID:26478520

  9. Emergence of OXA-48-Producing Klebsiella pneumoniae in Taiwan

    PubMed Central

    Ma, Ling; Wang, Jann-Tay; Wu, Tsu-Lan; Siu, L. Kristopher; Chuang, Yin-Ching; Lin, Jung-Chung; Lu, Min-Chi; Lu, Po-Liang

    2015-01-01

    The isolation of OXA-48-producing Enterobacteriaceae has increased dramatically in Mediterranean countries in the past 10 years, and has recently emerged in Asia. Between January 2012 and May 2014, a total of 760 carbapenem non-susceptible Klebsiella pneumoniae (CnSKP) isolates were collected during a Taiwan national surveillance. Carbapenemases were detected in 210 CnSKP isolates (27.6%), including 162 KPC-2 (n = 1), KPC-3, KPC-17, and NDM-1 (n = 1 each), OXA-48 (n = 4), IMP-8 (n = 18), and VIM-1 (n = 24). The four blaOXA-48 CnSKP isolates were detected in late 2013. Herein we report the emergence OXA-48-producing K. pneumoniae isolates in Taiwan. PFGE analysis revealed that the four isolates belonged to three different pulsotypes. Three isolates harboured blaCTX-M genes and belonged to MLST type ST11. In addition, the plasmids belonged to the incompatibility group, IncA/C. One isolate belonged to ST116 and the plasmid incompatibility group was non-typeable. The sequence upstream of the blaOXA-48 gene in all four isolates was identical to pKPOXA-48N1, a blaOXA-48-carrying plasmid. This is the first report of OXA-48-producing Enterobacteriaceae in Taiwan and the second report to identify blaOXA-48 on an IncA/C plasmid in K. pneumoniae. Given that three isolates belong to the same pandemic clone (ST11) and possess the IncA/C plasmid and similar plasmid digestion profile that indicated the role of clonal spread or plasmid for dissemination of blaOXA-48 gene, the emergence of OXA-48-producing K. pneumoniae in Taiwan is of great concern. PMID:26414183

  10. Identification of Antigenic Proteins of the Nosocomial Pathogen Klebsiella pneumoniae

    PubMed Central

    Hoppe, Sebastian; Bier, Frank F.; von Nickisch-Rosenegk, Markus

    2014-01-01

    The continuous expansion of nosocomial infections around the globe has become a precarious situation. Key challenges include mounting dissemination of multiple resistances to antibiotics, the easy transmission and the growing mortality rates of hospital-acquired bacterial diseases. Thus, new ways to rapidly detect these infections are vital. Consequently, researchers around the globe pursue innovative approaches for point-of-care devices. In many cases the specific interaction of an antigen and a corresponding antibody is pivotal. However, the knowledge about suitable antigens is lacking. The aim of this study was to identify novel antigens as specific diagnostic markers. Additionally, these proteins might be aptly used for the generation of vaccines to improve current treatment options. Hence, a cDNA-based expression library was constructed and screened via microarrays to detect novel antigens of Klebsiella pneumoniae, a prominent agent of nosocomial infections well-known for its extensive antibiotics resistance, especially by extended-spectrum beta-lactamases (ESBL). After screening 1536 clones, 14 previously unknown immunogenic proteins were identified. Subsequently, each protein was expressed in full-length and its immunodominant character examined by ELISA and microarray analyses. Consequently, six proteins were selected for epitope mapping and three thereof possessed linear epitopes. After specificity analysis, homology survey and 3d structural modelling, one epitope sequence GAVVALSTTFA of KPN_00363, an ion channel protein, was identified harboring specificity for K. pneumoniae. The remaining epitopes showed ambiguous results regarding the specificity for K. pneumoniae. The approach adopted herein has been successfully utilized to discover novel antigens of Campylobacter jejuni and Salmonella enterica antigens before. Now, we have transferred this knowledge to the key nosocomial agent, K. pneumoniae. By identifying several novel antigens and their linear

  11. Emergence of OXA-48-Producing Klebsiella pneumoniae in Taiwan.

    PubMed

    Ma, Ling; Wang, Jann-Tay; Wu, Tsu-Lan; Siu, L Kristopher; Chuang, Yin-Ching; Lin, Jung-Chung; Lu, Min-Chi; Lu, Po-Liang

    2015-01-01

    The isolation of OXA-48-producing Enterobacteriaceae has increased dramatically in Mediterranean countries in the past 10 years, and has recently emerged in Asia. Between January 2012 and May 2014, a total of 760 carbapenem non-susceptible Klebsiella pneumoniae (CnSKP) isolates were collected during a Taiwan national surveillance. Carbapenemases were detected in 210 CnSKP isolates (27.6%), including 162 KPC-2 (n = 1), KPC-3, KPC-17, and NDM-1 (n = 1 each), OXA-48 (n = 4), IMP-8 (n = 18), and VIM-1 (n = 24). The four blaOXA-48 CnSKP isolates were detected in late 2013. Herein we report the emergence OXA-48-producing K. pneumoniae isolates in Taiwan. PFGE analysis revealed that the four isolates belonged to three different pulsotypes. Three isolates harboured blaCTX-M genes and belonged to MLST type ST11. In addition, the plasmids belonged to the incompatibility group, IncA/C. One isolate belonged to ST116 and the plasmid incompatibility group was non-typeable. The sequence upstream of the blaOXA-48 gene in all four isolates was identical to pKPOXA-48N1, a blaOXA-48-carrying plasmid. This is the first report of OXA-48-producing Enterobacteriaceae in Taiwan and the second report to identify blaOXA-48 on an IncA/C plasmid in K. pneumoniae. Given that three isolates belong to the same pandemic clone (ST11) and possess the IncA/C plasmid and similar plasmid digestion profile that indicated the role of clonal spread or plasmid for dissemination of blaOXA-48 gene, the emergence of OXA-48-producing K. pneumoniae in Taiwan is of great concern. PMID:26414183

  12. Nitrogen fixation by immobilized NIF derepressed Klebsiella pneumoniae cells

    SciTech Connect

    Venkatasubramanian, K.; Toda, Y.

    1980-01-01

    In vitro production of ammonia through biological means poses a number of challenges. The organisms should be able to accumulate considerable concentrations of ammonia in the medium. Secondly, nonphotosynthetic organisms must be supplied with high-energy substrates to carry out the fixation reaction. Thirdly, the organisms must be kept in a viable state to produce ammonia over long periods of time. In this article, preliminary results on the production of ammonia by a mutant strain of Klebsiella pneumoniae in continuous reactor systems are discussed. Continuous production of ammonia becomes feasible through the immobilization of the whole microbial cells and then through the use of the resulting catalyst system in a flow-through reactor. The rationale for immobilizing microbial cells and the advantages of such an approach over traditional fermentation processes are briefly described as they relate to the microbial production of ammonia. The microbial cells can be immobilized in such a way that their viability is still maintained in the immobilized state. This, in turn, obviates addition of cofactors, which is often an expensive step associated with immobilized multi-enzyme systems. Reconstituted bovine-hide collagen as the carrier matrix for fixing the cells was the carrier of choice for our work on immobilized Klebsiella cells. Polyacrylamide gels were examined as an alternate carrier matrix but results from this were found to be inferior to those collagen immobilized cell system.

  13. Molecular characterization of multidrug-resistant Klebsiella pneumoniae isolates.

    PubMed

    Hou, Xiang-hua; Song, Xiu-yu; Ma, Xiao-bo; Zhang, Shi-yang; Zhang, Jia-qin

    2015-01-01

    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 bla SHV (22/38), bla TEM (10/38), and bla CTX-M (7/38). The highly conserved bla KPC-2 (37/38) and bla OXA-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

  14. Molecular characterization of multidrug-resistant Klebsiella pneumoniae isolates

    PubMed Central

    Hou, Xiang-hua; Song, Xiu-yu; Ma, Xiao-bo; Zhang, Shi-yang; Zhang, Jia-qin

    2015-01-01

    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 bla SHV (22/38), bla TEM (10/38), and bla CTX-M (7/38). The highly conserved bla KPC-2 (37/38) and bla OXA-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

  15. Molecular characterization of multidrug-resistant Klebsiella pneumoniae isolates.

    PubMed

    Hou, Xiang-hua; Song, Xiu-yu; Ma, Xiao-bo; Zhang, Shi-yang; Zhang, Jia-qin

    2015-01-01

    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 bla SHV (22/38), bla TEM (10/38), and bla CTX-M (7/38). The highly conserved bla KPC-2 (37/38) and bla OXA-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

  16. Presence of Nitrogen Fixing Klebsiella pneumoniae in the gut of the Formosan Subterranean Termite (Coptotermes formosanus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A gram-negative facultative anaerobic enteric bacterium, Klebsiella pneumoniae was isolated from the hindgut of the Formosan subterranean termite (FST). It was characterized using, Fatty acid methyl ester (FAME) analysis, BIOLOG assay, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-...

  17. Molecular epidemiological characteristics of Klebsiella pneumoniae associated with bacteremia among patients with pneumonia.

    PubMed

    Ito, Ryota; Shindo, Yuichiro; Kobayashi, Daisuke; Ando, Masahiko; Jin, Wanchun; Wachino, Jun-ichi; Yamada, Keiko; Kimura, Kouji; Yagi, Tetsuya; Hasegawa, Yoshinori; Arakawa, Yoshichika

    2015-03-01

    Some important virulence factors have been elucidated in Klebsiella pneumoniae infections. We investigated the relationship between virulence factors and multilocus sequence types (STs) and assessed the risk factors for bacteremia in patients with pneumonia due to K. pneumoniae. From April 2004 through April 2012, a total of 120 K. pneumoniae isolates from patients with pneumonia (23 with bacteremia and 97 without bacteremia) were collected from 10 medical institutions in Japan. Additionally, 10 strains of K. pneumoniae serotype K2 that were isolated >30 years ago were included in this study. These isolates were characterized using multilocus sequence typing (MLST), and the characteristics of their virulence factors, such as hypermucoviscosity phenotype and RmpA and aerobactin production between patients with and without bacteremia, were examined. MLST analysis was performed on the 120 isolates from patients with pneumonia, and some sequence type groups were defined as genetic lineages (GLs). GL65 was more prevalent among patients with bacteremia (21.7%) than in those without bacteremia (7.2%). The majority of the strains with serotype K2 were classified into GL14 or GL65, and rmpA and the gene for aerobactin were present in all GL65-K2 strains but absent in all GL14-K2 strains. In a multivariate analysis, the independent risk factors for bacteremia included GL65 (adjusted odds ratio [AOR], 9.46; 95% confidence interval [CI], 1.81 to 49.31), as well as neoplastic disease (AOR, 9.94; 95% CI, 2.61 to 37.92), immunosuppression (AOR, 17.85; 95% CI, 1.49 to 214.17), and hypoalbuminemia (AOR, 4.76; 95% CI, 1.29 to 17.61). GL65 was more prevalent among patients with bacteremia and was associated with the virulence factors of K. pneumoniae.

  18. Acute placental infection due to Klebsiella pneumoniae: report of a unique case.

    PubMed Central

    Sheikh, Salwa S; Amr, Samir S; Lage, Janice M

    2005-01-01

    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. PMID:16040328

  19. Klebsiella pneumoniae produces no histamine: Raoultella planticola and Raoultella ornithinolytica strains are histamine producers.

    PubMed

    Kanki, Masashi; Yoda, Tomoko; Tsukamoto, Teizo; Shibata, Tadayoshi

    2002-07-01

    Histamine fish poisoning is caused by histamine-producing bacteria (HPB). Klebsiella pneumoniae and Klebsiella oxytoca are the best-known HPB in fish. However, 22 strains of HPB from fish first identified as K. pneumoniae or K. oxytoca by commercialized systems were later correctly identified as Raoultella planticola (formerly Klebsiella planticola) by additional tests. Similarly, five strains of Raoultella ornithinolytica (formerly Klebsiella ornithinolytica) were isolated from fish as new HPB. R. planticola and R. ornithinolytica strains were equal in their histamine-producing capabilities and were determined to possess the hdc genes, encoding histidine decarboxylase. On the other hand, a collection of 61 strains of K. pneumoniae and 18 strains of K. oxytoca produced no histamine.

  20. Expression of Klebsiella pneumoniae nif genes in Proteus mirabilis.

    PubMed

    Postgate, J R; Kent, H M

    1985-08-01

    Self-transmissible plasmids carrying his and nif genes from Klebsiella pneumoniae have been introduced into three his mutants of Proteus mirabilis: strains 5006-1, WR19 and WR20. Expression of his by the transconjugants was unequivocal, if slightly temperature-sensitive, but none was Nif+ when tested for acetylene reduction in anaerobic glucose medium using inocula from rich or glucose-minimal aerobic agar cultures. Succinate or pyruvate in place of glucose, low glucose, lower temperature or elevated Na2MoO4 did not allow nif expression and no nitrogenase MoFe-protein peptide was detected immunologically after exposure to conditions in which diazotrophic enterobacteria, normal or genetically constructed, derepress nif. One strain, P. mirabilis WR19, carrying the his nif Kmr plasmid pMF250 was examined in detail. The nif activator gene nifA was introduced on the plasmid pCK1. Such derivatives remained Nif- when tested, after aerobic growth on rich agar media, with normal or low glucose, with succinate or with elevated Mo. However, pre-conditioning by aerobic growth on glucose-minimal agar led to subsequent anaerobic expression of nif in glucose medium from pMF250 in WR19 carrying pCK1. NH+4 or proline could serve as N-source in the glucose-minimal agar. Maximum activity was about 5% of that of K. pneumoniae in our assay conditions. Material cross-reacting with anti-serum to the nitrogenase MoFe protein was formed. Nitrogenase activity was not 'switched off' by NH+4. P. mirabilis WR19 (pCK1) showed NH+4-constitutive temperature-sensitive kanamycin resistance (a nif-related phenotype of this plasmid) in aerobic glucose minimal medium.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Draft Genome Sequence of a Klebsiella pneumoniae Strain (New Sequence Type 2357) Carrying Tn3926.

    PubMed

    Weng, Xing-Bei; Mi, Zu-Huang; Wang, Chun-Xin; Zhu, Jian-Ming

    2016-01-01

    We present the draft genome sequence of a Klebsiella pneumoniae carbapenemase-producing sequence type 2357 (ST2357) strain, NB60, which contains drug-resistant genes encoding resistance to beta-lactams, fluoroquinolones, aminoglycosides, trimethoprim-sulfamethoxazole, colistin, macrolides, and tetracycline. Strain NB60 was isolated from human blood, making it an important tool for studying K. pneumoniae pathogenesis. PMID:27660779

  2. Carbapenem Resistance in Klebsiella pneumoniae Due to the New Delhi Metallo-β-lactamase

    PubMed Central

    Sidjabat, Hanna; Nimmo, Graeme R.; Walsh, Timothy R.; Binotto, Enzo; Htin, Anthony; Hayashi, Yoshiro; Li, Jian; Nation, Roger L.; George, Narelle

    2011-01-01

    (See editorial commentary by Bronomo, on pages 485–487.) Carbapenem resistance in Klebsiella pneumoniae is most notably due to the K. pneumoniae carbapenemase (KPC) β-lactamase. In this report, we describe the occurrence of a newly described mechanism of carbapenem resistance, the NDM-1 β-lactamase, in a patient who received medical attention (but was not hospitalized) in India. PMID:21258100

  3. Draft Genome Sequence of a Klebsiella pneumoniae Strain (New Sequence Type 2357) Carrying Tn3926

    PubMed Central

    Mi, Zu-huang; Wang, Chun-xin; Zhu, Jian-ming

    2016-01-01

    We present the draft genome sequence of a Klebsiella pneumoniae carbapenemase–producing sequence type 2357 (ST2357) strain, NB60, which contains drug-resistant genes encoding resistance to beta-lactams, fluoroquinolones, aminoglycosides, trimethoprim-sulfamethoxazole, colistin, macrolides, and tetracycline. Strain NB60 was isolated from human blood, making it an important tool for studying K. pneumoniae pathogenesis. PMID:27660779

  4. Phenotypic and genotypic characterization of Klebsiella pneumonia recovered from nonhuman primates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  5. Conventional NK cells can produce IL-22 and promote host defense in Klebsiella pneumoniae pneumonia.

    PubMed

    Xu, Xin; Weiss, Ido D; Zhang, Hongwei H; Singh, Satya P; Wynn, Thomas A; Wilson, Mark S; Farber, Joshua M

    2014-02-15

    It was reported that host defense against pulmonary Klebsiella pneumoniae infection requires IL-22, which was proposed to be of T cell origin. Supporting a role for IL-22, we found that Il22(-/-) mice had decreased survival compared with wild-type mice after intratracheal infection with K. pneumoniae. Surprisingly, however, Rag2(-/-) mice did not differ from wild-type mice in survival or levels of IL-22 in the lungs postinfection with K. pneumoniae. In contrast, K. pneumoniae-infected Rag2(-/-)Il2rg(-/-) mice failed to produce IL-22. These data suggested a possible role for NK cells or other innate lymphoid cells in host defense and production of IL-22. Unlike NK cell-like innate lymphoid cells that produce IL-22 and display a surface phenotype of NK1.1(-)NKp46(+)CCR6(+), lung NK cells showed the conventional phenotype, NK1.1(+)NKp46(+)CCR6(-). Mice depleted of NK cells using anti-asialo GM1 showed decreased survival and higher lung bacterial counts, as well as increased dissemination of K. pneumoniae to blood and liver, compared with control-treated mice. NK cell depletion also led to decreased production of IL-22 in the lung. Within 1 d postinfection, although there was no increase in the number of lung NK cells, a subset of lung NK cells became competent to produce IL-22, and such cells were found in both wild-type and Rag2(-/-) mice. Our data suggest that, during pulmonary infection of mice with K. pneumoniae, conventional NK cells are required for optimal host defense, which includes the production of IL-22.

  6. Cephalosporin resistance in Klebsiella pneumoniae from Nova Scotia, Canada.

    PubMed

    Melano, Roberto G; Davidson, Ross J; Musgrave, Heather L; Forward, Kevin R

    2006-10-01

    From 2116 Klebsiella pneumoniae strains isolated between January 2001 and December 2002 in Nova Scotia, Canada, 25 (1.18%) showed a reduced susceptibility to cefoxitin or extended-spectrum cephalosporins. Narrow-spectrum beta-lactamase genes (bla(SHV-11), bla(SHV-1), bla(SHV-26), bla(SHV-32), bla(SHV-36), and bla(SHV-40)) were the most prevalent. Four new variants were identified (bla(LEN-17), bla(OKP-B-13), bla(OKP-B-14), and bla(OKP-A-11)), representing the 1st description of bla(OKP) in the Americas. Among the extended-spectrum beta-lactamase (ESBL) genes, bla(SHV-2), bla(SHV2a), bla(SHV-12), and bla(CTX-M-15) were detected (ESBL prevalence of 0.14%). Nineteen strains were resistant to cefoxitin (MIC, 32 to >256 microg/mL). Nevertheless, an AmpC-like activity was detected in only 1 strain, which expressed CMY-2. The combined effects of narrow-spectrum beta-lactamase production and decreased or nonexpression of OmpK35/36 porins did not account for the cefoxitin resistance observed in some of these strains. PMID:16769193

  7. Structure of 2-oxo-3-deoxygalactonate kinase from Klebsiella pneumoniae

    PubMed Central

    Michalska, Karolina; Cuff, Marianne E.; Tesar, Christine; Feldmann, Brian; Joachimiak, Andrzej

    2011-01-01

    In most organisms, efficient d-galactose utilization requires the highly conserved Leloir pathway that converts d-galactose to d-glucose 1-phosphate. However, in some bacterial and fungal species alternative routes of d-galactose assimilation have been identified. In the so-called De Ley–Doudoroff pathway, d-galactose is metabolized into pyruvate and d-­glyceraldehyde 3-phosphate in five consecutive reactions carried out by specific enzymes. The penultimate step in this pathway involves the phosphorylation of 2-oxo-3-deoxygalactonate to 2-oxo-3-deoxygalactonate 6-phosphate catalyzed by 2-­oxo-3-deoxygalactonate kinase, with ATP serving as a phosphoryl-group donor. Here, a crystal structure of 2-oxo-3-deoxygalactonate kinase from Klebsiella pneumoniae determined at 2.1 Å resolution is reported, the first structure of an enzyme from the De Ley–Doudoroff pathway. Structural comparison indicates that the enzyme belongs to the ASKHA (acetate and sugar kinases/hsc70/actin) family of phosphotransferases. The protein is composed of two α/β domains, each of which contains a core common to all family members. Additional elements introduced between conserved structural motifs define the unique features of 2-oxo-3-deoxygalactonate kinase and possibly determine the biological function of the protein. PMID:21795809

  8. Structure of 2-oxo-3-deoxygalactonate kinase from Klebsiella pneumoniae

    SciTech Connect

    Michalska, Karolina; Cuff, Marianne E.; Tesar, Christine; Feldmann, Brian; Joachimiak, Andrzej

    2011-08-01

    The crystal structure of 2-oxo-3-deoxygalactonate kinase from the De Ley–Doudoroff pathway of galactose metabolism has been determined at 2.1 Å resolution. In most organisms, efficient d-galactose utilization requires the highly conserved Leloir pathway that converts d-galactose to d-glucose 1-phosphate. However, in some bacterial and fungal species alternative routes of d-galactose assimilation have been identified. In the so-called De Ley–Doudoroff pathway, d-galactose is metabolized into pyruvate and d-glyceraldehyde 3-phosphate in five consecutive reactions carried out by specific enzymes. The penultimate step in this pathway involves the phosphorylation of 2-oxo-3-deoxygalactonate to 2-oxo-3-deoxygalactonate 6-phosphate catalyzed by 2-oxo-3-deoxygalactonate kinase, with ATP serving as a phosphoryl-group donor. Here, a crystal structure of 2-oxo-3-deoxygalactonate kinase from Klebsiella pneumoniae determined at 2.1 Å resolution is reported, the first structure of an enzyme from the De Ley–Doudoroff pathway. Structural comparison indicates that the enzyme belongs to the ASKHA (acetate and sugar kinases/hsc70/actin) family of phosphotransferases. The protein is composed of two α/β domains, each of which contains a core common to all family members. Additional elements introduced between conserved structural motifs define the unique features of 2-oxo-3-deoxygalactonate kinase and possibly determine the biological function of the protein.

  9. Activity of imipenem against Klebsiella pneumoniae biofilms in vitro and in vivo.

    PubMed

    Chen, Ping; Seth, Akhil K; Abercrombie, Johnathan J; Mustoe, Thomas A; Leung, Kai P

    2014-01-01

    Encapsulated Klebsiella pneumoniae has emerged as one of the most clinically relevant and more frequently encountered opportunistic pathogens in combat wounds as the result of nosocomial infection. In this report, we show that imipenem displayed potent activity against established K. pneumoniae biofilms under both static and flow conditions in vitro. Using a rabbit ear model, we also demonstrated that imipenem was highly effective against preformed K. pneumoniae biofilms in wounds.

  10. Ventilator-associated pneumonia caused by colistin-resistant KPC-producing Klebsiella pneumoniae: a case report and literature review.

    PubMed

    Viaggi, Bruno; Sbrana, Francesco; Malacarne, Paolo; Tascini, Carlo

    2015-05-01

    Klebsiella pneumoniae producing KPC-type carbapenemase causes severe nosocomial infection at a high mortality rate. Nosocomial pneumonia in particular is associated with high mortality, likely due to the unfavorable pulmonary pharmacokinetics of the antibiotics used against this agent. Therefore, early and accurate microbiological identification and susceptibility evaluation are crucial in order to optimize antibiotic therapy. We report a case of ventilator-associated pneumonia caused by colistin-resistant K. pneumoniae producing KPC-type carbapenemase treated using a carbapenem-sparing therapy and tailored according to the serum procalcitonin concentration in order to limit the duration of antibiotic therapy.

  11. Community-onset Klebsiella pneumoniae pneumonia in Taiwan: clinical features of the disease and associated microbiological characteristics of isolates from pneumonia and nasopharynx

    PubMed Central

    Lin, Yi-Tsung; Wang, Yu-Ping; Wang, Fu-Der; Fung, Chang-Phone

    2015-01-01

    Klebsiella pneumoniae is an important cause of community-onset pneumonia in Asian countries and South Africa. We investigated the clinical characteristics of K. pneumoniae causing community-onset pneumonia, and the associated microbiological features between K. pneumoniae isolates from pneumonia and those from the nasopharynx in Taiwan. This study was conducted at the Taipei Veterans General Hospital during July, 2012 to February, 2014. The clinical characteristics in patients with community-onset K. pneumoniae pneumonia were analyzed. K. pneumoniae isolates from the nasopharynx of adults attending otorhinolaryngology outpatient clinics were collected to compare their microbiological features with those from pneumonia. Capsular genotypes, antimicrobial susceptibility, and multilocus sequence type (MLST) were determined among these strains. Ninety-one patients with community-onset K. pneumoniae pneumonia were enrolled. We found a high mortality (29.7%) among these patients. Capsular types K1, K2, K5, K20, K54, and K57 accounted for ∼70% of the K. pneumoniae isolates causing pneumonia, and ∼70% of all the K. pneumoniae strains isolated from the nasopharynx of patients in outpatient clinics. The MLST profiles further demonstrated the genetic relatedness between most pneumonia isolates and those from the nasopharynx. In conclusion, our results show that community-onset pneumonia caused by K. pneumoniae was associated with high mortality and could have a reservoir in the nasopharynx. To tackle this high-mortality disease, the distribution of capsular types in the nasopharynx might have implications for future vaccine development. PMID:25741336

  12. Community-onset Klebsiella pneumoniae pneumonia in Taiwan: clinical features of the disease and associated microbiological characteristics of isolates from pneumonia and nasopharynx.

    PubMed

    Lin, Yi-Tsung; Wang, Yu-Ping; Wang, Fu-Der; Fung, Chang-Phone

    2015-01-01

    Klebsiella pneumoniae is an important cause of community-onset pneumonia in Asian countries and South Africa. We investigated the clinical characteristics of K. pneumoniae causing community-onset pneumonia, and the associated microbiological features between K. pneumoniae isolates from pneumonia and those from the nasopharynx in Taiwan. This study was conducted at the Taipei Veterans General Hospital during July, 2012 to February, 2014. The clinical characteristics in patients with community-onset K. pneumoniae pneumonia were analyzed. K. pneumoniae isolates from the nasopharynx of adults attending otorhinolaryngology outpatient clinics were collected to compare their microbiological features with those from pneumonia. Capsular genotypes, antimicrobial susceptibility, and multilocus sequence type (MLST) were determined among these strains. Ninety-one patients with community-onset K. pneumoniae pneumonia were enrolled. We found a high mortality (29.7%) among these patients. Capsular types K1, K2, K5, K20, K54, and K57 accounted for ∼70% of the K. pneumoniae isolates causing pneumonia, and ∼70% of all the K. pneumoniae strains isolated from the nasopharynx of patients in outpatient clinics. The MLST profiles further demonstrated the genetic relatedness between most pneumonia isolates and those from the nasopharynx. In conclusion, our results show that community-onset pneumonia caused by K. pneumoniae was associated with high mortality and could have a reservoir in the nasopharynx. To tackle this high-mortality disease, the distribution of capsular types in the nasopharynx might have implications for future vaccine development.

  13. Effect of Porins and Plasmid-Mediated AmpC β-Lactamases on the Efficacy of β-Lactams in Rat Pneumonia Caused by Klebsiella pneumoniae

    PubMed Central

    Padilla, Emma; Alonso, Diana; Doménech-Sánchez, Antonio; Gomez, Cristina; Pérez, José Luis; Albertí, Sebastián; Borrell, Nuria

    2006-01-01

    The in vivo activities of imipenem, meropenem, and cefepime were studied in a model of rat pneumonia caused by a plasmid-mediated AmpC β-lactamase ACT-1-producing Klebsiella pneumoniae strain (K. pneumoniae strain 12) and a derivative porin-deficient mutant (K. pneumoniae strain 12dp). No differences between these activities were seen with K. pneumoniae 12. Only meropenem showed an activity slightly better than that of imipenem with K. pneumoniae 12dp. PMID:16723600

  14. Destruction of single-species biofilms of Escherichia coli or Klebsiella pneumoniae subsp. pneumoniae by dextranase, lactoferrin, and lysozyme

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The activity of dextranase, lactoferrin, lysozyme, and nisin against biofilms composed of either Klebsiella pneumonia or Escherichia coli was examined using the MBEC Assay™. Mature biofilms were treated and then sonicated to remove the adherent biofilm. This material was quantified using a lumines...

  15. Klebsiella pneumonia: An unusual cause of ophthalmia neonatorum in a healthy newborn.

    PubMed

    Kumar, Jaya B; Silverstein, Evan; Wallace, David K

    2015-12-01

    Ophthalmia neonatorum is one of the most common infections during the neonatal period. Chlamydia trachomatis and Neisseria gonorrhoea must be ruled out, given their high virulence and systemic complications. We describe a case of ophthalmia neonatroum from Klebsiella pneumonia. Gram-negative organisms have been reported in hospital-acquired conjunctivitis (HAC), but we are unaware of any published reports of K. pneumonia conjunctivitis in an otherwise healthy full-term infant born in the United States who has received prophylaxis. It is important to promptly identify and treat Klebsiella conjunctivitis because it can lead to severe complications. PMID:26691043

  16. Application of factorial designs for optimization of cyclodextrin glycosyltransferase production from Klebsiella pneumoniae pneumoniae AS-22.

    PubMed

    Gawande, B N; Patkar, A Y

    1999-07-20

    Production of cyclodextrin glycosyltransferase (CGTase) from Klebsiella pneumoniae pneumoniae AS-22 was optimized in shake flasks using a statistical experimental design approach. Effect of various components in the basal medium, like carbon, nitrogen, phosphorus, and mineral sources as well as initial pH and temperature, were tested on enzyme production. The optimum concentrations of the selected media components were determined using statistical experimental designs. Two level fractional factorial designs in five variables, namely, dextrin, peptone, yeast extract, ammonium dihydrogen orthophosphate, and magnesium sulphate concentrations were constructed. The optimum medium composition thus found consisted of 49.3 g/L dextrin, 20.6 g/L peptone, 18.3 g/L yeast extract, 6.7 g/L ammonium dihydrogen orthophosphate, and 0.5 g/L magnesium sulphate. The maximum CGTase activity obtained was 21.4 U/mL in 28 h of incubation. The cell growth and CGTase production profiles were studied with the optimized medium in shake flasks and in 1-L fermenters. It was observed that the enzyme production was growth associated both in shake flask and in fermenter, although it was slower in shake flask. The maximum CGTase activity obtained in the fermenter was 32.5 U/mL in 16 h. The optimized medium resulted in about 9-fold increase in the enzyme activity as compared to that obtained in the basal medium in shake flask as well as in fermenter. PMID:10397852

  17. Distinct Contributions of Neutrophils and CCR2+ Monocytes to Pulmonary Clearance of Different Klebsiella pneumoniae Strains.

    PubMed

    Xiong, Huizhong; Carter, Rebecca A; Leiner, Ingrid M; Tang, Yi-Wei; Chen, Liang; Kreiswirth, Barry N; Pamer, Eric G

    2015-09-01

    Klebsiella pneumoniae is a common respiratory pathogen, with some strains having developed broad resistance to clinically available antibiotics. Humans can become infected with many different K. pneumoniae strains that vary in genetic background, antibiotic susceptibility, capsule composition, and mucoid phenotype. Genome comparisons have revealed differences between K. pneumoniae strains, but the impact of genomic variability on immune-mediated clearance of pneumonia remains unclear. Experimental studies of pneumonia in mice have used the rodent-adapted 43816 strain of K. pneumoniae and demonstrated that neutrophils are essential for optimal host defense. It remains unclear, however, whether CCR2(+) monocytes contribute to K. pneumoniae clearance from the lung. We selectively depleted neutrophils, CCR2(+) monocytes, or both from immunocompetent mice and determined susceptibility to infection by the 43816 strain and 4 newly isolated clinical K. pneumoniae strains. The clinical K. pneumoniae strains, including one carbapenem-resistant ST258 strain, are less virulent than 43816. Optimal clearance of each of the 5 strains required either neutrophils or CCR2(+) monocytes. Selective neutrophil depletion markedly worsened infection with K. pneumoniae strain 43816 and three clinical isolates but did not increase susceptibility of mice to infection with the carbapenem-resistant K. pneumoniae ST258 strain. Depletion of CCR2(+) monocytes delayed recovery from infection with each of the 5 K. pneumoniae strains, revealing a contribution of these cells to bacterial clearance from the lung. Our findings demonstrate strain-dependent variation in the contributions of neutrophils and CCR2(+) monocytes to clearance of K. pneumoniae pulmonary infection.

  18. Frequency of Klebsiella pneumoniae carbapenemase (KPC)-producing and non-KPC-producing Klebsiella species contamination of healthcare workers and the environment.

    PubMed

    Rock, Clare; Thom, Kerri A; Masnick, Max; Johnson, J Kristie; Harris, Anthony D; Morgan, Daniel J

    2014-04-01

    We examined contamination of healthcare worker (HCW) gown and gloves after caring for patients with Klebsiella pneumoniae carbapenemase (KPC)-producing and non-KPC-producing Klebsiella as a proxy for horizontal transmission. The rate of contamination with Klebsiella species is similar to that of contamination with methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococcus, with 31 (14%) of 220 of HCW-patient interactions resulting in contamination of gloves and gowns. PMID:24602950

  19. Characterization of nifH mutations of Klebsiella pneumoniae.

    PubMed Central

    Chang, C L; Davis, L C; Rider, M; Takemoto, D J

    1988-01-01

    Nucleotide changes in the nifH gene of Klebsiella pneumoniae were identified by DNA cloning and sequencing of six selected mutant strains. The strains were UN60, C-640-GC----TGC; UN116, C-67-TC----TTC; UN117, G-688-AG----AAG; UN1041, CG-302-C----CAC; UN1678, GC-713-C----GTC; and UN1795, G-439-AG----AAG. Their corresponding amino acid substitutions were UN60, Arg-214----Cys; UN116, Leu-23----Phe; UN117, Glu-230----Lys; UN1041, Arg-101----His; UN1678, Ala-238----Val; and UN1795, Glu-147----Lys. Results from Western and Northern blots of the mutant strains showed significant reductions in both steady-state levels of the accumulated Fe protein and nifH mRNA during derepression in the presence of serine. The relative specific activities of the nitrogenases in strains UN60, UN1041, and UN1795 were less than 2% of the wild type, whereas those in UN116, UN117, and UN1678 were between 28 and 40% of the wild type during enhanced derepression with serine. The residues of Arg-101 (UN1041), Glu-147 (UN1795), and Arg-214 (UN60) were invariant in sequences of a dozen diazotrophs that have been examined thus far. In UN1041, in which Arg-101 of the Fe protein was replaced by His, the Fe protein had a larger apparent molecular weight than that of the other strains on sodium dodecyl sulfate-gel electrophoresis, as detected with rabbit antiserum raised against the C-terminal peptide of the wild-type Fe protein. The reduced levels of nifH mRNA in point mutant strains suggests that nifH (the gene or gene product) may be involved in self-regulation. mRNA transcripts of different sizes were detected when a nifH-specific probe, CCKp2003, was used in the Northern blot hybridization. Images PMID:2457577

  20. First Report of Ceftazidime-Avibactam Resistance in a KPC-3-Expressing Klebsiella pneumoniae Isolate

    PubMed Central

    Yang, Shangxin; Hemarajata, Peera; Ward, Kevin W.; Miller, Shelley A.; Gregson, Aric

    2015-01-01

    Ceftazidime-avibactam is the first antimicrobial approved by the U.S. FDA for the treatment of carbapenem-resistant Enterobacteriaceae. Avibactam, a non-β-lactam β-lactamase inhibitor, inactivates class A serine carbapenemases, including Klebsiella pneumoniae carbapenemase (KPC). We report a KPC-producing K. pneumoniae isolate resistant to ceftazidime-avibactam (MIC, 32/4 μg/ml) from a patient with no prior treatment with ceftazidime-avibactam. PMID:26195508

  1. A case of lobar pneumonia and sepsis with death caused by invasive Klebsiella rhinoscleromatis infection.

    PubMed

    Kumade, Eri; Furusyo, Norihiro; Takeshima, Norito; Kishihara, Yasuhiro; Mitsumoto-Kaseida, Fujiko; Etoh, Yoshitaka; Murata, Masayuki; Hayashi, Jun

    2016-10-01

    Klebsiella pneumoniae often causes pneumonia and other infections in heavy drinkers and patients with diabetes. Pneumonia caused by Klebsiella rhinoscleromatis, a subspecies of K. pneumoniae, has not been previously reported. We report a case of pneumonia caused by K. rhinoscleromatis. A 68-year-old man with type 2 diabetes visited our department complaining fever and fatigue for 10 days and cough and bloody sputum for two days. His Japan Coma Scale score was I-1, body temperature 38.3 °C, blood pressure 85/51 mmHg, pulse 135 bpm, and peripheral capillary oxygen saturation level 92% (room air). He had no abnormal breathing sounds. His white blood cell count had decreased to 2600/μL, and his C-reactive protein level was high, at 35.9 mg/dL. Chest computed tomography revealed lobar pneumonia in the right upper lobe and pneumonia in the left upper division. Klebsiella was suspected based on the result of a sputum smear examination. He was diagnosed with septic shock due to pneumonia and was immediately admitted. Intravenous antibacterial (levofloxacin) treatment was initiated, however, he died 13 h after presenting at the hospital. Subsequently, K. rhinoscleromatis was detected in sputum and blood culture. Additional testing determined the bacteria to be a highly pathogenic hypermucoviscosity phenotype and the cause of the fatal lobar pneumonia. Although cases of rhinoscleroma and bacteremia caused by K. rhinoscleromatis infection have been reported, this is the first report of a case with sepsis caused by fulminant pneumonia.

  2. [The changing epidemiology of extended spectrum β-lactamase-producing Klebsiella pneumoniae].

    PubMed

    Elhani, Dalèle; Bakir, Leila; Aouni, Mahjoub

    2011-01-01

    In the last two decades, Klebsiella pneumoniae demonstrated some characteristics of acquisition of plasmids coding extended spectrum β-lactamases (ESBL). The review data showed an increase in worldwide prevalence of ESBL and a temporal shift in the prevalence of ESBL types in K. pneumoniae during this last decade. CTX-M-15 seems to be the predominant ESBL type in K. pneumoniae in some parts of the world. The dissemination of several nosocomial CTX-M-15-producing K. pneumoniae clones was reported unlike the worldwide dissemination of a single virulent ST131 CTX-M-15 producing Escherichia coli clone. The diversity of plasmids carrying the bla(CTX-M-15) gene in K. pneumoniae suggested the frequent transfer of this gene between different replicons. The acquisition of the bla(CTX-M-15) gene by K. pneumoniae was probably occurred via horizontal transfer from E. coli.

  3. Immunoproteomic to Analysis the Pathogenicity Factors in Leukopenia Caused by Klebsiella Pneumonia Bacteremia

    PubMed Central

    Liu, Haiyan; Cheng, Zhongle; Song, Wen; Wu, Wenyong; Zhou, Zheng

    2014-01-01

    Incidences of leukopenia caused by bacteremia have increased significantly and it is associated with prolonged hospital stay and increased cost. Immunoproteomic is a promising method to identify pathogenicity factors of different diseases. In the present study, we used immunoproteomic to analysis the pathogenicity factors in leukopenia caused by Klebsiella Pneumonia bacteremia. Approximately 40 protein spots localized in the 4 to 7 pI range were detected on two-dimensional electrophoresis gels, and 6 differentially expressed protein spots between 10 and 170 kDa were identified. Pathogenicity factors including S-adenosylmethionine synthetase, pyruvate dehydrogenase, glutathione synthetase, UDP-galactose-4-epimerase, acetate kinase A and elongation factor tu (EF-Tu). In validation of the pathogenicity factor, we used western blotting to show that Klebsiella pneumonia had higher (EF-Tu) expression when they accompanied by leukopenia rather than leukocytosis. Thus, we report 6 pathogenicity factors of leukopenia caused by Klebsiella pneumonia bacteremia, including 5 housekeeping enzymes and EF-Tu. We suggest EF-Tu could be a potential pathogenicity factor for leukopenia caused by Klebsiella pneumonia. PMID:25330314

  4. Suppurative peritonitis by Klebsiella pneumoniae in captive gold-handed tamarin (Saguinus midas midas).

    PubMed

    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

    2016-02-01

    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. PMID:26620445

  5. Whole genome analysis of Klebsiella pneumoniae T2-1-1 from human oral cavity

    PubMed Central

    Chan, Kok-Gan; Yin, Wai-Fong; Chan, Xin-Yue

    2015-01-01

    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. PMID:26981378

  6. Whole genome analysis of Klebsiella pneumoniae T2-1-1 from human oral cavity.

    PubMed

    Chan, Kok-Gan; Yin, Wai-Fong; Chan, Xin-Yue

    2016-03-01

    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.

  7. Klebsiella pneumoniae Strains Producing Extended-Spectrum β-Lactamases in Spain: Microbiological and Clinical Features▿

    PubMed Central

    de Alegría, C. Ruiz; Rodríguez-Baño, J.; Cano, M. E.; Hernández-Bello, J. R.; Calvo, J.; Román, E.; Díaz, M. A.; Pascual, A.; Martínez-Martínez, L.

    2011-01-01

    Extended-spectrum β-lactamases (ESBL) of the CTX-M, SHV, and TEM families were recognized in 76 (67%), 31 (27%), and 6 (5%) isolates, respectively, among 162 ESBL-producing Klebsiella pneumoniae (ESBL-Kp) strains obtained in a multicenter study in Spain. Predisposing factors for ESBL-Kp acquisition included invasive procedures, mechanical ventilation, and previous antimicrobial use. PMID:21191059

  8. Klebsiella pneumoniae strains producing extended-spectrum beta-lactamases in Spain: microbiological and clinical features.

    PubMed

    Ruiz de Alegría, C; Rodríguez-Baño, J; Cano, M E; Hernández-Bello, J R; Calvo, J; Román, E; Díaz, M A; Pascual, A; Martínez-Martínez, L

    2011-03-01

    Extended-spectrum β-lactamases (ESBL) of the CTX-M, SHV, and TEM families were recognized in 76 (67%), 31 (27%), and 6 (5%) isolates, respectively, among 162 ESBL-producing Klebsiella pneumoniae (ESBL-Kp) strains obtained in a multicenter study in Spain. Predisposing factors for ESBL-Kp acquisition included invasive procedures, mechanical ventilation, and previous antimicrobial use.

  9. Two Genome Sequences of Klebsiella pneumoniae Strains with Sequence Type 23 and Capsular Serotype K1

    PubMed Central

    Lin, Hsi-Hsu; Chen, Yao-Shen; Hsiao, Hao-Wen; Hsueh, Pei-Tan; Ni, Wei-Fen

    2016-01-01

    Here, we report the whole-genome sequences of Klebsiella pneumoniae ED2 and ED23, isolated, respectively, from bacteremic patients with liver abscesses (ED2) and patients with primary liver abscess and metastatic meningitis (ED23). Both strains were of multilocus sequence type 23 with capsule serotype K1. PMID:27795261

  10. Klebsiella pneumoniae strains producing extended-spectrum beta-lactamases in Spain: microbiological and clinical features.

    PubMed

    Ruiz de Alegría, C; Rodríguez-Baño, J; Cano, M E; Hernández-Bello, J R; Calvo, J; Román, E; Díaz, M A; Pascual, A; Martínez-Martínez, L

    2011-03-01

    Extended-spectrum β-lactamases (ESBL) of the CTX-M, SHV, and TEM families were recognized in 76 (67%), 31 (27%), and 6 (5%) isolates, respectively, among 162 ESBL-producing Klebsiella pneumoniae (ESBL-Kp) strains obtained in a multicenter study in Spain. Predisposing factors for ESBL-Kp acquisition included invasive procedures, mechanical ventilation, and previous antimicrobial use. PMID:21191059

  11. Successful Treatment of Carbapenemase-Producing Pandrug-Resistant Klebsiella pneumoniae Bacteremia.

    PubMed

    Camargo, Jose F; Simkins, Jacques; Beduschi, Thiago; Tekin, Akin; Aragon, Laura; Pérez-Cardona, Armando; Prado, Clara E; Morris, Michele I; Abbo, Lilian M; Cantón, Rafael

    2015-10-01

    New antibiotic options are urgently needed for the treatment of carbapenem-resistant Enterobacteriaceae infections. We report a 64-year-old female with prolonged hospitalization following an intestinal transplant who developed refractory bacteremia due to a serine carbapenemase-producing pandrug-resistant isolate of Klebsiella pneumoniae. After failing multiple antimicrobial regimens, the patient was successfully treated.

  12. Successful Treatment of Carbapenemase-Producing Pandrug-Resistant Klebsiella pneumoniae Bacteremia

    PubMed Central

    Simkins, Jacques; Beduschi, Thiago; Tekin, Akin; Aragon, Laura; Pérez-Cardona, Armando; Prado, Clara E.; Morris, Michele I.; Abbo, Lilian M.

    2015-01-01

    New antibiotic options are urgently needed for the treatment of carbapenem-resistant Enterobacteriaceae infections. We report a 64-year-old female with prolonged hospitalization following an intestinal transplant who developed refractory bacteremia due to a serine carbapenemase-producing pandrug-resistant isolate of Klebsiella pneumoniae. After failing multiple antimicrobial regimens, the patient was successfully treated. PMID:26386029

  13. Suppurative peritonitis by Klebsiella pneumoniae in captive gold-handed tamarin (Saguinus midas midas).

    PubMed

    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

    2016-02-01

    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.

  14. Genomic Sequence of Klebsiella pneumoniae IIEMP-3, a Vitamin B12-Producing Strain from Indonesian Tempeh.

    PubMed

    Yulandi, Adi; Sugiokto, Febri Gunawan; Febrilina; Suwanto, Antonius

    2016-02-25

    Klebsiella pneumoniae strain IIEMP-3, isolated from Indonesian tempeh, is a vitamin B12-producing strain that exhibited a different genetic profile from pathogenic isolates. Here we report the draft genome sequence of strain IIEMP-3, which may provide insights on the nature of fermentation, nutrition, and immunological function of Indonesian tempeh.

  15. Mycotic aneurysm caused by gas-forming serotype K5 Klebsiella pneumoniae.

    PubMed

    Chen, Yi-Jung; Chen, Shey-Ying; Wang, Jin-Town; Hsueh, Po-Ren

    2009-03-01

    We describe the first documented case of mycotic aneurysm caused by gas-forming serotype K5, and rmpA and iuc positive Klebsiella pneumonia with a hypermucoviscosity phenotype in a diabetic patient. The patient received ceftriaxone for one month and underwent aorto-bi-iliac grafting and inferior mesenteric artery reimplantation and recovered well.

  16. Resistance of Klebsiella Pneumoniae clinical isolates: linkage of outer membrane proteins (omps) with production esbls

    PubMed Central

    Marques, Lívia Érika Carlos; de Oliveira, Danielle Ferreira; Marques, Márcia Maria Mendes; da Silva, Ana Raquel Araújo; Alves, Carlucio Roberto; Guedes, Maria Izabel Florindo

    2011-01-01

    Three isolates of Klebsiella pneumoniae, collected from the University Hospital in Fortaleza, Brazil, were analyzed to determine their resistance to multiple antibiotics. The results of this study showed that the resistance of the clinically isolated bacteria is associated with the production of extended-spectrum beta-lactamases (ESLBs) and loss of outer membrane proteins. PMID:24031656

  17. Structural determination of the polysaccharide isolated from biofilms produced by a clinical strain of Klebsiella pneumoniae.

    PubMed

    Cescutti, Paola; De Benedetto, Gianluigi; Rizzo, Roberto

    2016-07-22

    Klebsiella pneumoniae are Gram negative opportunistic pathogens producing capsular (K) polysaccharides. Seventy-seven different K antigens have been described and they are the basis for K serotyping. Capsular polysaccharides are important virulence factors and have a relevant role for the structure of biofilm communities. Nevertheless, little information is available on the polysaccharides produced in biofilm matrices by Klebsiella spp. In the present study, a clinical isolate of Klebsiella pneumoniae was grown both on cellulose membranes deposited on agar plates, where it formed an adherent biofilm, and in liquid medium, where it formed floating biofilms (flocs). Extraction and purification of the polysaccharide fraction showed that only one main carbohydrate polymer was present in both adherent biofilms and flocs. Composition and linkage analysis, Smith degradation followed by ESI-MS, 1D and 2D NMR spectroscopy revealed that the polysaccharide belong to the type K24 and has the following structure. PMID:27182661

  18. Identification of putative plant pathogenic determinants from a draft genome sequence of an opportunistic klebsiella pneumoniae strain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Klebsiella pneumoniae has been known historically as a causal agent of bacterial pneumonia. More recently, K. pneumoniaerepresentatives have been shown to have a broad ecological distribution and are recognized nitrogen-fixers. Previously, we demonstrated the capacity of K. pneumoniae strain Kp 5-1R...

  19. Carbapenemase-Producing Klebsiella pneumoniae in Romania: A Six-Month Survey.

    PubMed

    Lixandru, Brandusa Elena; Cotar, Ani Ioana; Straut, Monica; Usein, Codruta Romanita; Cristea, Dana; Ciontea, Simona; Tatu-Chitoiu, Dorina; Codita, Irina; Rafila, Alexandru; Nica, Maria; Buzea, Mariana; Baicus, Anda; Ghita, Mihaela Camelia; Nistor, Irina; Tuchiluş, Cristina; Indreas, Marina; Antohe, Felicia; Glasner, Corinna; Grundmann, Hajo; Jasir, Aftab; Damian, Maria

    2015-01-01

    This study presents the first characterization of carbapenem-non-susceptible Klebsiella pneumoniae isolates by means of a structured six-month survey performed in Romania as part of an Europe-wide investigation. Klebsiella pneumoniae clinical isolates from different anatomical sites were tested for antibiotic susceptibility by phenotypic methods and confirmed by PCR for the presence of four carbapenemase genes. Genome macrorestriction fingerprinting with XbaI was used to analyze the relatedness of carbapenemase-producing Klebsiella pneumoniae isolates collected from eight hospitals. Among 75 non-susceptible isolates, 65 were carbapenemase producers. The most frequently identified genotype was OXA-48 (n = 51 isolates), eight isolates were positive for blaNDM-1 gene, four had the blaKPC-2 gene, whereas two were positive for blaVIM-1. The analysis of PFGE profiles of OXA-48 and NDM-1 producing K. pneumoniae suggests inter-hospitals and regional transmission of epidemic clones. This study presents the first description of K. pneumoniae strains harbouring blaKPC-2 and blaVIM-1 genes in Romania. The results of this study highlight the urgent need for the strengthening of hospital infection control measures in Romania in order to curb the further spread of the antibiotic resistance.

  20. Molecular Epidemiology of Two Klebsiella pneumoniae Mastitis Outbreaks on a Dairy Farm in New York State▿

    PubMed Central

    Munoz, Marcos A.; Welcome, Francis L.; Schukken, Ynte H.; Zadoks, Ruth N.

    2007-01-01

    Klebsiella spp. have become an important cause of clinical mastitis in dairy cows in New York State. We describe the occurrence of two Klebsiella mastitis outbreaks on a single dairy farm. Klebsiella isolates from milk, feces, and environmental sources were compared using random amplified polymorphic DNA (RAPD)-PCR typing. The first mastitis outbreak was caused by a single strain of Klebsiella pneumoniae, RAPD type A, which was detected in milk from eight cows. RAPD type A was also isolated from the rubber liners of milking machine units after milking of infected cows and from bedding in the outbreak pen. Predominance of a single strain could indicate contagious transmission of the organism or exposure of multiple cows to an environmental point source. No new cases with RAPD type A were observed after implementation of intervention measures that targeted the prevention of transmission via the milking machine as well as improvement of environmental hygiene. A second outbreak of Klebsiella mastitis that occurred several weeks later was caused by multiple RAPD types, which rules out contagious transmission and indicates opportunistic infections originating from the environment. The diversity of Klebsiella strains as quantified with Simpson's index of discrimination was significantly higher for isolates from fecal, feed, and water samples than for isolates from milk samples. Several isolates from bedding material that had the phenotypic appearance of Klebsiella spp. were identified as being Raoultella planticola and Raoultella terrigena based on rpoB sequencing. PMID:17928424

  1. Bacteriophage-loaded nanostructured lipid carrier: improved pharmacokinetics mediates effective resolution of Klebsiella pneumoniae-induced lobar pneumonia.

    PubMed

    Singla, Saloni; Harjai, Kusum; Katare, Om Prakash; Chhibber, Sanjay

    2015-07-15

    This study examined the therapeutic and prophylactic potential of bacteriophages in a mouse model of Klebsiella pneumoniae lobar pneumonia. Phages were administered intraperitoneally. Liposome-entrapped phages (LP) were effective in treating infection, even when therapy was delayed by 3 days after the induction of pneumonia. In contrast, nonliposomal phages provided protection when administered 24 hours after infection. Administration of nonliposomal phages 6 hours prior to intranasal bacterial challenge resulted in complete protection, compared with LP, which was effective even when administered 48 hours prior to infection. Increased reduction and a greater increment in the levels of proinflammatory and antiinflammatory cytokines, respectively, in homogenates of lung from LP-treated mice were suggestive of increased efficacy of LP in the treatment of pneumonia. This is the first study to assess liposomes as a delivery vehicle for phage, and the results confirm the superiority of LP for both therapeutic and prophylactic applications.

  2. Pathogenicity of Aeromonas hydrophila, Klebsiella pneumoniae, and Proteus mirabilis to brown tree frogs (Litoria ewingii).

    PubMed

    Schadich, Ermin; Cole, Anthony L J

    2010-04-01

    Bacterial dermatosepticemia, a systemic infectious bacterial disease of frogs, can be caused by several opportunistic gram-negative bacterial species including Aeromonas hydrophila, Chryseobacterium indologenes, Chryseobacterium meningosepticum, Citrobacter freundii, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, and Serratia liquifaciens. Here we determined the pathogenicity of 3 bacterial species (Aeromonas hydrophila, Klebsiella pneumoniae, and Proteus mirabilis) associated with an outbreak of fatal dermatosepticemia in New Zealand Litoria ewingii frogs. A bath challenge method was used to expose test frogs to individual bacterial species (2 x 10(7) cfu/mL in pond water); control frogs were exposed to uninfected pond water. None of the control frogs or those exposed to A. hydrophila or P. mirabilis showed any morbidity or mortality. Morbidity and mortality was 40% among frogs exposed to K. pneumonia, and the organism was reisolated from the hearts, spleens, and livers of affected animals.

  3. Susceptibility of Klebsiella pneumoniae on coriander leaves to liquid- and vapor-phase ethanol.

    PubMed

    Krusong, Warawut; Pornpukdeewatana, Soisuda; Teerarak, Montinee

    2016-05-01

    The bio-control of ethanol on Klebsiella pneumoniae on fresh coriander leaves for significantly reducing consumer health risk was investigated. Washed and sterilized leaves of coriander were inoculated with K. pneumoniae cultured in Trypticase Soy broth. Susceptibility of the K. pneumoniae to liquid- and evaporated vapor-phase ethanol (EVE) was then examined in vitro Complete inhibition of K. pneumoniae was found with 18% (v/v) liquid ethanol. Exposure for 15 min to EVE (9.00 ± 0.8 mmol L(-1)) completely destroyed K. pneumoniae (4.04 ± 0.02 log CFU/ml) spread on Mueller Hilton agar at 30 ± 2°C. The effect of EVE with and without evaporated water vapor (EWV) on the susceptibility of K. pneumoniae on fresh coriander leaves was examined. While exposure to EVE affected the survival of K. pneumoniae, the degree of reduction depended on both the inoculation level and the EWV. Complete reduction of K. pneumoniae was achieved for the low inoculation level by EVE alone (37 ± 2% relative humidity; RH) but susceptibility was reduced with EWV (high RH; 80 ± 2%). Scanning electron microscope (SEM) images of inoculated coriander leaves confirm the effects of EVE in reducing levels of K. pneumoniae Exposure to EVE alone proved an effective bio-control for K. pneumoniae on fresh coriander leaves.

  4. Susceptibility of Klebsiella pneumoniae on coriander leaves to liquid- and vapor-phase ethanol.

    PubMed

    Krusong, Warawut; Pornpukdeewatana, Soisuda; Teerarak, Montinee

    2016-05-01

    The bio-control of ethanol on Klebsiella pneumoniae on fresh coriander leaves for significantly reducing consumer health risk was investigated. Washed and sterilized leaves of coriander were inoculated with K. pneumoniae cultured in Trypticase Soy broth. Susceptibility of the K. pneumoniae to liquid- and evaporated vapor-phase ethanol (EVE) was then examined in vitro Complete inhibition of K. pneumoniae was found with 18% (v/v) liquid ethanol. Exposure for 15 min to EVE (9.00 ± 0.8 mmol L(-1)) completely destroyed K. pneumoniae (4.04 ± 0.02 log CFU/ml) spread on Mueller Hilton agar at 30 ± 2°C. The effect of EVE with and without evaporated water vapor (EWV) on the susceptibility of K. pneumoniae on fresh coriander leaves was examined. While exposure to EVE affected the survival of K. pneumoniae, the degree of reduction depended on both the inoculation level and the EWV. Complete reduction of K. pneumoniae was achieved for the low inoculation level by EVE alone (37 ± 2% relative humidity; RH) but susceptibility was reduced with EWV (high RH; 80 ± 2%). Scanning electron microscope (SEM) images of inoculated coriander leaves confirm the effects of EVE in reducing levels of K. pneumoniae Exposure to EVE alone proved an effective bio-control for K. pneumoniae on fresh coriander leaves. PMID:27020413

  5. Recent Research Examining Links Among Klebsiella pneumoniae from Food, Food Animals, and Human Extraintestinal Infections.

    PubMed

    Davis, Gregg S; Price, Lance B

    2016-06-01

    Klebsiella pneumoniae is a colonizer of livestock, a contaminant of retail meats and vegetables, and a cause of extraintestinal infections in humans. Antibiotic-resistant strains of K. pneumoniae are becoming increasingly prevalent among hospital and community-acquired infections. Antibiotics are used extensively in conventional food-animal production, where they select for antibiotic-resistant bacteria. Antibiotic-resistant K. pneumoniae has been isolated from livestock as well as from a variety of retail meats, seafood, and vegetables. Furthermore, recent phylogenetic analyses suggest close relationships between K. pneumoniae from humans and livestock. Therefore, it is essential that we quantify the contribution of foodborne K. pneumoniae to antibiotic-resistant human infections. PMID:27022987

  6. X-linked agammaglobulinemia combined with juvenile idiopathic arthritis and invasive Klebsiella pneumoniae polyarticular septic arthritis.

    PubMed

    Zhu, Zaihua; Kang, Yuli; Lin, Zhenlang; Huang, Yanjing; Lv, Huoyang; Li, Yasong

    2015-02-01

    X-linked agammaglobulinemia (XLA) is a primary immunodeficiency disease caused by mutations in the Bruton's tyrosine kinase (BTK) gene. XLA can also present in combination with juvenile idiopathic arthritis (JIA), the major chronic rheumatologic disease in children. We report herein the first known case of a juvenile patient diagnosed with XLA combined with JIA that later developed into invasive Klebsiella pneumoniae polyarticular septic polyarthritis. An additional comprehensive review of XLA combined with JIA and invasive K. pneumoniae septic arthritis is also presented. XLA was identified by the detection of BTK mutations while the diagnosis of JIA was established by clinical and laboratory assessments. Septic arthritis caused by invasive K. pneumoniae was confirmed by culturing of the synovia and gene detection of the isolates. Invasive K. pneumoniae infections can not only result in liver abscesses but also septic arthritis, although this is rare. XLA combined with JIA may contribute to invasive K. pneumoniae infection.

  7. Neonatal Brain Abscess due to Extended-Spectrum Beta-Lactamase Producing Klebsiella pneumoniae

    PubMed Central

    Mondal, Monojit; Thapa, Rajoo; Mallick, Debkrishna; Datta, Asok Kumar

    2014-01-01

    Klebsiella pneumoniae (K. pneumoniae) causing brain abscess in newborn infants is rare. Presented herein, is a 27-day-old male neonate who developed two frontal lobe abscesses in association with K. pneumoniae sepsis and meningitis. Antibiotic susceptibility testing utilizing the double-disk synergy method (Cefotaxime and Amoxycillin-Clavulanate) confirmed the extended spectrum beta-lactamase (ESBL) production by the isolate. He was treated simultaneously with antibiotics (Meropenem and Amikacin) and abscess aspiration through the anterior fontanelle, with less than satisfactory outcome. ESBL producing K. pneumoniae brain abscess in neonates is extremely rare in the English literature. Emperical carbapenems and aminoglycoside coverage in neonates with K. pneumoniae sepsis and brain abscess, especially in areas with high rate of ESBL producing bacteria may be warranted. PMID:25584278

  8. An Outbreak of Infections Caused by a Klebsiella pneumoniae ST11 Clone Coproducing Klebsiella pneumoniae Carbapenemase-2 and RmtB in a Chinese Teaching Hospital

    PubMed Central

    Li, Jun; Zou, Ming-Xiang; Wang, Hai-Chen; Dou, Qing-Ya; Hu, Yong-Mei; Yan, Qun; Liu, Wen-En

    2016-01-01

    Background: Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae bacteria, which cause serious disease outbreaks worldwide, was rarely detected in Xiangya Hospital, prior to an outbreak that occurred from August 4, 2014, to March 17, 2015. The aim of this study was to analyze the epidemiology and molecular characteristics of the K. pneumoniae strains isolated during the outbreak. Methods: Nonduplicate carbapenem-resistant K. pneumoniae isolates were screened for blaKPC-2 and multiple other resistance determinants using polymerase chain reaction. Subsequent studies included pulsed-field gel electrophoresis (PFGE), multilocus sequence typing, analysis of plasmids, and genetic organization of blaKPC-2 locus. Results: Seventeen blaKPC-2-positive K. pneumoniae were identified. A wide range of resistant determinants was detected. Most isolates (88.2%) coharbored blaKPC-2 and rmtB in addition to other resistance genes, including blaSHV-1, blaTEM-1, and aac(3)-IIa. The blaKPC-2 and rmtB genes were located on the conjugative IncFIB-type plasmid. Genetic organization of blaKPC-2 locusin most strains was consistent with that of the plasmid pKP048. Four types (A1, A2, A3, and B) were detected by PFGE, and Type A1, an ST11, was the predominant PFGE type. A novel K. pneumoniae sequence type (ST1883) related to ST11 was discovered. Conclusions: These isolates in our study appeared to be clonal and ST11 K. pneumoniae was the predominant clone attributed to the outbreak. Coharbing of blaKPC-2 and rmtB, which were located on a transferable plasmid, in clinical K. pneumoniae isolates may lead to the emergence of a new pattern of drug resistance. PMID:27569227

  9. Quantifying the clinical virulence of Klebsiella pneumoniae producing carbapenemase Klebsiella pneumoniae with a Galleria mellonella model and a pilot study to translate to patient outcomes

    PubMed Central

    2014-01-01

    Background Previous studies may have overestimated morbidity and mortality due to Klebsiella pneumoniae producing carbapenemase (KPC) Klebsiella pneumoniae infections because of difficulties in modeling patient comorbidities. This pilot study sought to evaluate KPC virulence by combining clinical and Galleria mellonella models in patients with K. pneumoniae blood stream infections (BSIs). Methods G. mellonella were inoculated using KPC(+) and KPC(−) isolates from these patients. Extent and rapidity of insect mortality was analyzed. Patients were stratified by KPC BSI status. Clinical outcomes of mortality and length of stay post-infection for survivors (LOS) were analyzed. Median virulence scores calculated from the insect studies were imputed in the clinical model. Results The in-vivo model revealed greater mortality in KPC(−) isolates (p < 0.001). Fifteen patients with KPC(+) BSI were matched with 60 patients with KPC(−) BSI. Hospital mortality was greater in the KPC(+) group versus the KPC(−) group (OR 3.79, 95% CI 1.00 - 14.34). LOS was longer in the KPC(+) group (p < 0.01). Conversely the virulence score attenuated the association between KPC(+) status and mortality and LOS in the final translational models. Conclusions KPC(+) status was associated with decreased virulence in GM. Opposite findings were observed in patients. This pilot study demonstrates that measured virulence from GM may differ from human estimates of virulence. PMID:24428847

  10. Clinical and microbiological characteristics of tigecycline non-susceptible Klebsiella pneumoniae bacteremia in Taiwan

    PubMed Central

    2014-01-01

    Background Resistance among Klebsiella pneumoniae to most antibiotics is on the rise. Tigecycline has been considered as one of the few therapeutic options available to treat multidrug-resistant bacteria. We investigated the clinical and microbiological characteristics of tigecycline non-susceptible K. pneumoniae bacteremia. Methods Adult patients with tigecycline non-susceptible K. pneumoniae bacteremia at a medical center in Taiwan over a 3-year period were enrolled. K. pneumoniae isolates were identified by the E-test using criteria set by the US Food and Drug Administration (FDA). Data on the clinical features of patients were collected from medical records. Genes for β-lactamases, antimicrobial susceptibilities and pulsed-field gel electrophoresis (PFGE) results were determined for all isolates. Results Of 36 patients, 27 had nosocomial bacteremia. Overall 28-day mortality was 38.9%. The MIC50 and MIC90 of tigecycline were 6 and 8 mg/L, respectively. No carbapenemase was detected among the 36 isolates. Twenty isolates carried extended spectrum β-lactamases and/or DHA-1 genes. No major cluster of isolates was found among the 36 isolates by PFGE. Intensive care unit onset of tigecycline non-susceptible Klebsiella pneumoniae bacteremia was the only independent risk factor for 28-day mortality. Conclusions The high mortality of patients with tigecycline non-susceptible K. pneumoniae bacteremia may suggest a critical problem. Further study to identify the possible risk factors for its development and further investigation of this type of bacteremia is necessary. PMID:24380631

  11. KlebSeq, a Diagnostic Tool for Surveillance, Detection, and Monitoring of Klebsiella pneumoniae.

    PubMed

    Bowers, Jolene R; Lemmer, Darrin; Sahl, Jason W; Pearson, Talima; Driebe, Elizabeth M; Wojack, Bette; Saubolle, Michael A; Engelthaler, David M; Keim, Paul

    2016-10-01

    Health care-acquired infections (HAIs) kill tens of thousands of people each year and add significantly to health care costs. Multidrug-resistant and epidemic strains are a large proportion of HAI agents, and multidrug-resistant strains of Klebsiella pneumoniae, a leading HAI agent, have caused an urgent public health crisis. In the health care environment, patient colonization by K. pneumoniae precedes infection, and transmission via colonization leads to outbreaks. Periodic patient screening for K. pneumoniae colonization has the potential to curb the number of HAIs. In this report, we describe the design and validation of KlebSeq, a highly informative screening tool that detects Klebsiella species and identifies clinically important strains and characteristics by using highly multiplexed amplicon sequencing without a live-culturing step. We demonstrate the utility of this tool on several complex specimen types, including urine, wound swabs and tissue, and several types of respiratory and fecal specimens, showing K. pneumoniae species and clonal group identification and antimicrobial resistance and virulence profiling, including capsule typing. Use of this amplicon sequencing tool to screen patients for Klebsiella carriage could inform health care staff of the risk of infection and outbreak potential. KlebSeq also serves as a model for next-generation molecular tools for public health and health care, as expansion of this tool can be used for several other HAI agents or applications. PMID:27510832

  12. KlebSeq, a Diagnostic Tool for Surveillance, Detection, and Monitoring of Klebsiella pneumoniae

    PubMed Central

    Lemmer, Darrin; Sahl, Jason W.; Pearson, Talima; Driebe, Elizabeth M.; Wojack, Bette; Saubolle, Michael A.; Engelthaler, David M.; Keim, Paul

    2016-01-01

    Health care-acquired infections (HAIs) kill tens of thousands of people each year and add significantly to health care costs. Multidrug-resistant and epidemic strains are a large proportion of HAI agents, and multidrug-resistant strains of Klebsiella pneumoniae, a leading HAI agent, have caused an urgent public health crisis. In the health care environment, patient colonization by K. pneumoniae precedes infection, and transmission via colonization leads to outbreaks. Periodic patient screening for K. pneumoniae colonization has the potential to curb the number of HAIs. In this report, we describe the design and validation of KlebSeq, a highly informative screening tool that detects Klebsiella species and identifies clinically important strains and characteristics by using highly multiplexed amplicon sequencing without a live-culturing step. We demonstrate the utility of this tool on several complex specimen types, including urine, wound swabs and tissue, and several types of respiratory and fecal specimens, showing K. pneumoniae species and clonal group identification and antimicrobial resistance and virulence profiling, including capsule typing. Use of this amplicon sequencing tool to screen patients for Klebsiella carriage could inform health care staff of the risk of infection and outbreak potential. KlebSeq also serves as a model for next-generation molecular tools for public health and health care, as expansion of this tool can be used for several other HAI agents or applications. PMID:27510832

  13. Effect of radiation processing in elimination of Klebsiella pneumoniae from food

    NASA Astrophysics Data System (ADS)

    Gautam, Raj Kamal; Nagar, Vandan; Shashidhar, Ravindranath

    2015-10-01

    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 (D10) 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. D10 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±1.8×105 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±1.8×105 CFU/g of K. pneumoniae from mixed sprouts, poultry and fish samples.

  14. Klebsiella pneumoniae and type 3 fimbriae: nosocomial infection, regulation and biofilm formation.

    PubMed

    Murphy, Caitlin N; Clegg, Steven

    2012-08-01

    The Gram-negative opportunistic pathogen Klebsiella pneumoniae is responsible for causing a spectrum of nosocomial and community-acquired infections. Globally, K. pneumoniae is a frequently encountered hospital-acquired opportunistic pathogen that typically infects patients with indwelling medical devices. Biofilm formation on these devices is important in the pathogenesis of these bacteria, and in K. pneumoniae, type 3 fimbriae have been identified as appendages mediating the formation of biofilms on biotic and abiotic surfaces. The factors influencing the regulation of type 3 fimbrial gene expression are largely unknown but recent investigations have indicated that gene expression is regulated, at least in part, by the intracellular levels of cyclic di-GMP. In this review, we have highlighted the recent studies that have worked to elucidate the mechanism by which type 3 fimbrial expression is controlled and the studies that have established the importance of type 3 fimbriae for biofilm formation and nosocomial infection by K. pneumoniae.

  15. Isolation and Characterization of Aquatic-Borne Klebsiella pneumoniae from Tropical Estuaries in Malaysia

    PubMed Central

    Barati, Anis; Ghaderpour, Aziz; Chew, Li Lee; Bong, Chui Wei; Thong, Kwai Lin; Chong, Ving Ching; Chai, Lay Ching

    2016-01-01

    Klebsiella pneumoniae is an opportunistic pathogen that is responsible for causing nosocomial and community-acquired infections. Despite its common presence in soil and aquatic environments, the virulence potential of K. pneumoniae isolates of environmental origin is largely unknown. Hence, in this study, K. pneumoniae isolated from the estuarine waters and sediments of the Matang mangrove estuary were screened for potential virulence characteristics: antibiotic susceptibility, morphotype on Congo red agar, biofilm formation, presence of exopolysaccharide and capsule, possession of virulence genes (fimH, magA, ugE, wabG and rmpA) and their genomic fingerprints. A total of 55 strains of K. pneumoniae were isolated from both human-distributed sites (located along Sangga Besar River) and control sites (located along Selinsing River) where less human activity was observed, indicated that K. pneumoniae is ubiquitous in the environment. However, the detection of potentially virulent strains at the downstream of Kuala Sepetang village has suggested an anthropogenic contamination source. In conclusion, the findings from this study indicate that the Matang mangrove estuary could harbor potentially pathogenic K. pneumoniae with risk to public health. More studies are required to compare the environmental K. pneumoniae strains with the community-acquired K. pneumoniae strains. PMID:27092516

  16. Evaluation of the efficacy of a bacteriophage in the treatment of pneumonia induced by multidrug resistance Klebsiella pneumoniae in mice.

    PubMed

    Cao, Fang; Wang, Xitao; Wang, Linhui; Li, Zhen; Che, Jian; Wang, Lili; Li, Xiaoyu; Cao, Zhenhui; Zhang, Jiancheng; Jin, Liji; Xu, Yongping

    2015-01-01

    Multidrug-resistant Klebsiella pneumoniae (MRKP) has steadily grown beyond antibiotic control. However, a bacteriophage is considered to be a potential antibiotic alternative for treating bacterial infections. In this study, a lytic bacteriophage, phage 1513, was isolated using a clinical MRKP isolate KP 1513 as the host and was characterized. It produced a clear plaque with a halo and was classified as Siphoviridae. It had a short latent period of 30 min, a burst size of 264 and could inhibit KP 1513 growth in vitro with a dose-dependent pattern. Intranasal administration of a single dose of 2×10(9) PFU/mouse 2 h after KP 1513 inoculation was able to protect mice against lethal pneumonia. In a sublethal pneumonia model, phage-treated mice exhibited a lower level of K. pneumoniae burden in the lungs as compared to the untreated control. These mice lost less body weight and exhibited lower levels of inflammatory cytokines in their lungs. Lung lesion conditions were obviously improved by phage therapy. Therefore, phage 1513 has a great effect in vitro and in vivo, which has potential to be used as an alternative to an antibiotic treatment of pneumonia that is caused by the multidrug-resistant K. pneumoniae.

  17. [Controlling infection and spread of carbapenems-resistant Klebsiella pneumoniae among burn patients].

    PubMed

    Huan, Jingning

    2015-02-01

    The emergence and spread of carbapenems-resistant Klebsiella pneumoniae (CRKP) in burn ward is an important threat to burn management. CRKP isolates are resistant to almost all available antibiotics and are susceptible only to polymyxins and tigecycline. The mechanism of the drug resistance of CRKP is associated with the plasmid-encoded carbapenemase Klebsiella pneumoniae carbapenemase (KPC), a carbapenem-hydrolyzing β-lactamase. Antibiotics which can currently be used to treat CRKP infection include polymyxins, tigecycline, and some aminoglycosides. The efficacy of using antibiotics in combination is better than that of single-agent therapy for the treatment of CRKP infection in bloodstream. In order to control CRKP infection in burn patients, strategies for preventing CRKP dissemination in burn ward are strongly advocated.

  18. Isolation and characterization of lambda specialized transducing bacteriophages carrying Klebsiella pneumoniae nif genes.

    PubMed Central

    MacNeil, D; Howe, M M; Brill, W J

    1980-01-01

    Seve lambda dnif specialized transducing bacteriophages were isolated from Escherichia coli strains containing plasmids carrying the his-nif region of Klebsiella pneumoniae. These phages collectively carry deoxyribonucleic acid for all of the genes in the nif regulon and adjacent deoxyribonucleic acid of K. pneumoniae. The phages were isolated by using Mu insertions in the nif region to direct the integration of lambda pMu phages in nif via formation of lambda pMu-Mu dilysogens which, upon induction, yielded lambda dnif phages. This procedure should be generally applicable for isolating lambda specialized transducing phages carrying genes from E. coli or other bacteria. PMID:6245064

  19. Aminoglycosides for Treatment of Bacteremia Due to Carbapenem-Resistant Klebsiella pneumoniae

    PubMed Central

    Shields, Ryan K.; Press, Ellen G.; Nguyen, M. Hong

    2016-01-01

    Aminoglycoside treatment of carbapenem-resistant (CR) Klebsiella pneumoniae bacteremia was associated with a 70% rate (23/33) of 30-day survival. Successful treatment was associated with sources of bacteremia amenable to reliable aminoglycoside pharmacokinetics (P = 0.037), acute physiology and chronic health evaluation II (APACHE II) scores of <20 (P = 0.16), and nonfatal underlying diseases (P = 0.015). Success rates were 78% and 100% if ≥2 and all 3 factors were present, respectively. Clinicians may consider the use of aminoglycosides against CR K. pneumoniae bacteremia if strains are susceptible and the sources of infection are amenable to reliable pharmacokinetics. PMID:26926642

  20. Production of 1,3-propanediol by Klebsiella pneumoniae from glycerol broth.

    PubMed

    Cheng, Ke-Ke; Zhang, Jian-An; Liu, De-Hua; Sun, Yan; Yang, Ming-De; Xu, Jing-Ming

    2006-11-01

    Broth containing 152 g glycerol l(-1) from Candida krusei culture was converted to 1,3-propanediol by Klebsiella pneumoniae. Residual glucose in the broth promoted growth of K. pneumoniae while acetate was inhibitory. After desalination treatment of glycerol broth by electrodialysis, the acetate in the broth was removed. A fed-batch culture with electrodialytically pretreated broth as substrate was developed giving 53 g 1,3-propanediol l(-1) with a yield of 0.41 g g(-1) glycerol and a productivity of 0.94 g l(-1) h(-1).

  1. KPC-2-producing Klebsiella pneumoniae in a hospital in the Midwest region of Brazil.

    PubMed

    Biberg, Camila Arguelo; Rodrigues, Ana Claudia Souza; do Carmo, Sidiane Ferreira; Chaves, Claudia Elizabeth Volpe; Gales, Ana Cristina; Chang, Marilene Rodrigues

    2015-06-01

    The emergence of β-lactamase-producing Enterobacteriaceae in the last few decades has become major challenge faced by hospitals. In this study, isolates of Klebsiella pneumoniae carbapenemase-2 (KPC-2)-producing K. pneumoniae from a tertiary hospital in Mato Grosso do Sul, Brazil, were characterized. Bacterial identification was performed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF; Bruker Daltonics, Germany) mass spectrometry. The minimum inhibitory concentrations of carbapenems were determined using the agar dilution method as recommended by the Clinical Laboratory Standards Institute guidelines. Carbapenemase production was detected using the modified Hodge test (MHT) and polymerase chain reaction (PCR), followed by DNA sequencing. Of 360 (12.2%) K. pneumoniae isolates obtained between May 2009 and May 2010, 44 (12.2%) were carbapenem nonsusceptible. Of these 44 isolates, thirty-six K. pneumoniae isolates that were positive by MHT and PCR carried the bla KPC-2 gene. Thus, KPC-2producing Klebsiella pneumoniae has been present in a Brazilian hospital located in the Midwest region since at least 2009. PMID:26273265

  2. KPC-2-producing Klebsiella pneumoniae in a hospital in the Midwest region of Brazil.

    PubMed

    Biberg, Camila Arguelo; Rodrigues, Ana Claudia Souza; do Carmo, Sidiane Ferreira; Chaves, Claudia Elizabeth Volpe; Gales, Ana Cristina; Chang, Marilene Rodrigues

    2015-06-01

    The emergence of β-lactamase-producing Enterobacteriaceae in the last few decades has become major challenge faced by hospitals. In this study, isolates of Klebsiella pneumoniae carbapenemase-2 (KPC-2)-producing K. pneumoniae from a tertiary hospital in Mato Grosso do Sul, Brazil, were characterized. Bacterial identification was performed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF; Bruker Daltonics, Germany) mass spectrometry. The minimum inhibitory concentrations of carbapenems were determined using the agar dilution method as recommended by the Clinical Laboratory Standards Institute guidelines. Carbapenemase production was detected using the modified Hodge test (MHT) and polymerase chain reaction (PCR), followed by DNA sequencing. Of 360 (12.2%) K. pneumoniae isolates obtained between May 2009 and May 2010, 44 (12.2%) were carbapenem nonsusceptible. Of these 44 isolates, thirty-six K. pneumoniae isolates that were positive by MHT and PCR carried the bla KPC-2 gene. Thus, KPC-2producing Klebsiella pneumoniae has been present in a Brazilian hospital located in the Midwest region since at least 2009.

  3. Spread of OXA-48-Positive Carbapenem-Resistant Klebsiella pneumoniae Isolates in Istanbul, Turkey▿

    PubMed Central

    Carrër, Amélie; Poirel, Laurent; Eraksoy, Haluk; Cagatay, A. Atahan; Badur, Selim; Nordmann, Patrice

    2008-01-01

    The first outbreak of carbapenem-resistant Klebsiella pneumoniae isolates producing the plasmid-encoded carbapenem-hydrolyzing oxacillinase OXA-48 is reported. The 39 isolates belonged to two different clones and were collected at the University Hospital of Istanbul, Turkey, from May 2006 to February 2007, and they coproduced various β-lactamases (SHV-12, OXA-9, and TEM-1 for clone A and CTX-M-15, TEM-1, and OXA-1 for clone B). PMID:18519712

  4. Oxygen sensitivity of the nifLA promoter of Klebsiella pneumoniae

    SciTech Connect

    Kong, Q.T.; Wu, Q.L.; Ma, Z.F.; Shen, S.C.

    1986-05-01

    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 possible both the nifL promoter and the nifL product are responsible for nif repression by oxygen.

  5. Ischaemic distal limb necrosis and Klebsiella pneumoniae infection associated with arterial catheterisation in a cat.

    PubMed

    Bowlt, Kelly L; Bortolami, Elisa; Harley, Ross; Murison, Pamela; Wallace, Adrian

    2013-12-01

    This case report describes dorsal pedal arterial thrombosis and infection with Klebsiella pneumoniae subsequent to arterial catheter placement in a cat. The complication led to avascular necrosis of the metatarsal and pedal soft tissue. The catheter was placed for blood pressure monitoring during surgery for correction of a peritoneopericardial diaphragmatic hernia. The exact mechanism of thrombosis was unclear. Amputation of the limb was required and the histopathological findings are presented. This is the first report of such a complication.

  6. A simple method for extracting C-phycocyanin from Spirulina platensis using Klebsiella pneumoniae.

    PubMed

    Zhu, Y; Chen, X B; Wang, K B; Li, Y X; Bai, K Z; Kuang, T Y; Ji, H B

    2007-02-01

    C-phycocyanin (C-PC) was extracted from fresh Spirulina platensis by deploying a species of non-pathogenic nitrogen-fixing bacteria, namely, Klebsiella pneumoniae. The algal slurry was neither washed nor centrifuged; the bacterial culture was poured into the slurry, the vessel sealed, and crude C-PC extracted after about 24 h. The extraction was clean and efficient, and the purity and concentration of C-PC proved to be of adequate quality.

  7. Novel VIM Metallo-β-Lactamase Variant, VIM-24, from a Klebsiella pneumoniae Isolate from Colombia▿

    PubMed Central

    Montealegre, Maria Camila; Correa, Adriana; Briceño, David F.; Rosas, Natalia C.; De La Cadena, Elsa; Ruiz, Sory J.; Mojica, Maria F.; Camargo, Ruben Dario; Zuluaga, Ivan; Marin, Adriana; Quinn, John P.; Villegas, Maria Virginia

    2011-01-01

    We report the emergence of a novel VIM variant (VIM-24) in a Klebsiella pneumoniae isolate in Colombia. The isolate displays MICs for carbapenems below the resistance breakpoints, posing a real challenge for its detection. The blaVIM-24 gene was located within a class 1 integron carried on a large plasmid. Further studies are needed to clarify its epidemiological and clinical impact. PMID:21282438

  8. Carbapenem-Resistant Klebsiella pneumoniae: Results of a Laboratory Surveillance Program in an Italian General Hospital (August 2014-January 2015) : Surveillance of Carbapenem-resistant Klebsiella pneumoniae.

    PubMed

    Monari, Claudia; Merlini, Luca; Nardelli, Emanuela; Cacioni, Maria; Repetto, Antonella; Mencacci, Antonella; Vecchiarelli, Anna

    2016-01-01

    In this study we report the analysis of 131 Klebsiella pneumoniae (K. pneumoniae) clinical isolates from patients hospitalized in various wards, of Perugia General Hospital, from August 2014 to January 2015. Forty two isolates (32.1 %), were resistant to at least one carbapenem antibiotic and, among these isolates, 14 (33.3 %) exhibited resistance to colistin. All isolates were carbapenemases producers and 41 (97.6 %) harboured the bla KPC gene. Carbapenem-resistant K. pneumoniae isolates (CRKPs) were, also, typed for the genotypic diversity and the results revealed the circulation of two major clusters.This surveillance study evidences the spread of CRKP isolates in Perugia General Hospital and confirms that carbapenem-resistant K. pneumoniae isolates have reached epidemic dissemination in Italy. In addition the percentage of resistance to colistin resulted to be less than that observed in other hospital laboratories across Italy. In conclusion the circulation of these isolates should be monitored and appropriate policy of surveillance must be used, in a target manner, in order to reduce the spread of carbapenem-resistant isolates. PMID:26810235

  9. An outbreak of colistin-resistant Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae in the Netherlands (July to December 2013), with inter-institutional spread.

    PubMed

    Weterings, V; Zhou, K; Rossen, J W; van Stenis, D; Thewessen, E; Kluytmans, J; Veenemans, J

    2015-08-01

    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. PMID:26067658

  10. First evidence of polar flagella in Klebsiella pneumoniae isolated from a patient with neonatal sepsis.

    PubMed

    Carabarin-Lima, Alejandro; León-Izurieta, Libia; Rocha-Gracia, Rosa Del Carmen; Castañeda-Lucio, Miguel; Torres, Carmen; Gutiérrez-Cazarez, Zita; González-Posos, Sirenia; Martínez de la Peña, Claudia F; Martinez-Laguna, Ygnacio; Lozano-Zarain, Patricia

    2016-08-01

    The genus Klebsiella belongs to the family Enterobacteriaceae, and is currently considered to be non-motile and non-flagellated. In the present work, 25 Klebsiella strains isolated from nosocomial infections were assessed for motility under different growth conditions. One Klebsiella isolate, KpBUAP021, demonstrated a swim-like motility phenotype. The K. pneumoniae genotype was confirmed by 16S rRNA and rpoB gene sequence analysis. Multilocus sequence typing analysis also revealed that the KpBUAP021 strain places it in the ST345 sequence type, and belongs to the phylogenetic Kpl group. Transmission electron microscopy and the Ryu staining technique revealed that KpBUAP021 expresses polar flagella. Finally, the presence of fliC, fliA and flgH genes in this K. pneumoniae strain was confirmed. This report presents the first evidence for flagella-mediated motility in a K. pneumoniae clinical isolate, and represents an important finding related to its evolution and pathogenic potential. PMID:27283194

  11. First evidence of polar flagella in Klebsiella pneumoniae isolated from a patient with neonatal sepsis.

    PubMed

    Carabarin-Lima, Alejandro; León-Izurieta, Libia; Rocha-Gracia, Rosa Del Carmen; Castañeda-Lucio, Miguel; Torres, Carmen; Gutiérrez-Cazarez, Zita; González-Posos, Sirenia; Martínez de la Peña, Claudia F; Martinez-Laguna, Ygnacio; Lozano-Zarain, Patricia

    2016-08-01

    The genus Klebsiella belongs to the family Enterobacteriaceae, and is currently considered to be non-motile and non-flagellated. In the present work, 25 Klebsiella strains isolated from nosocomial infections were assessed for motility under different growth conditions. One Klebsiella isolate, KpBUAP021, demonstrated a swim-like motility phenotype. The K. pneumoniae genotype was confirmed by 16S rRNA and rpoB gene sequence analysis. Multilocus sequence typing analysis also revealed that the KpBUAP021 strain places it in the ST345 sequence type, and belongs to the phylogenetic Kpl group. Transmission electron microscopy and the Ryu staining technique revealed that KpBUAP021 expresses polar flagella. Finally, the presence of fliC, fliA and flgH genes in this K. pneumoniae strain was confirmed. This report presents the first evidence for flagella-mediated motility in a K. pneumoniae clinical isolate, and represents an important finding related to its evolution and pathogenic potential.

  12. Distinct promoters affect pyrroloquinoline quinone production in recombinant Escherichia coli and Klebsiella pneumoniae.

    PubMed

    Sun, Jiguo; Han, Zengye; Ge, Xizhen; Tian, Pingfang

    2014-10-01

    Pyrroloquinoline quinone (PQQ) is a versatile quinone cofactor participating in numerous biological processes. Klebsiella pneumoniae can naturally synthesize PQQ for harboring intact PQQ synthesis genes. Previous metabolic engineering of K. pneumoniae failed to overproduce PQQ due to the employment of strong promoter in expression vector. Here we report that a moderate rather than strong promoter is efficient for PQQ production. To screen an appropriate promoter, a total of four distinct promoters-lac promoter, pk promoter of glycerol dehydratase gene (dhaB1), promoter of kanamycin resistance gene, and T7 promoter (as the control)-were individually used for overexpressing the endogenous PQQ genes in K. pneumoniae along with heterologous expression in Escherichia coli. We found that all recombinant K. pneumoniae strains produced more PQQ than recombinant E. coli strains that carried corresponding vectors, indicating that K. pneumoniae is superior to E. coli for the production of PQQ. Particularly, the recombinant K. pneumoniae recruiting the promoter of kanamycin resistance gene produced the highest PQQ (1,700 nmol), revealing that a moderate rather than strong promoter is efficient for PQQ production. Furthermore, PQQ production was roughly proportional to glucose concentration increasing from 0.5 to 1.5 g/L, implying the synergism between PQQ biosynthesis and glucose utilization. This study not only provides a feasible strategy for production of PQQ in K. pneumoniae, but also reveals the exquisite synchronization among PQQ biosynthesis, glucose metabolism, and cell proliferation.

  13. Fulminant mediastinitis due to extended-spectrum beta-lactamase-producing Klebsiella pneumoniae: atypical presentation and spreading following cardiac surgery†

    PubMed Central

    Valenzuela, Horacio; Carrascal, Yolanda; Maroto, Laura; Arce, Nuria

    2013-01-01

    Mediastinitis due to Klebsiella pneumoniae, related to thoracic wall contamination after cardiac surgery, has rarely been described. We aim to report a case of fulminant mediastinitis due to extended-spectrum beta-lactamase-producing K. pneumoniae, secondary to a disseminated concomitant pulmonary infection. The patient remained pauci-symptomatic until clinical manifestations of sepsis acutely appeared. PMID:23416348

  14. Clonal dissemination of multilocus sequence type 11 Klebsiella pneumoniae carbapenemase - producing K. pneumoniae in a Chinese teaching hospital.

    PubMed

    Sun, Kangde; Chen, Xu; Li, Chunsheng; Yu, Zhongmin; Zhou, Qi; Yan, Yuzhong

    2015-02-01

    Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae has disseminated rapidly in China. We aimed to analyze the molecular epidemiology of four KPC-producing K. pneumoniae strains isolated from a suspected clonal outbreak during a 3-month period and to track the dissemination of KPC-producing K. pneumonia retrospectively. We created antimicrobial susceptibility profiles using an automated broth microdilution system and broth microdilution methods. We screened carbapenemase and KPC phenotypes using the modified Hodge test and meropenem-boronic acid (BA) disk test, respectively. We identified β-lactamase genes with PCR and sequencing. We investigated clonal relatedness for epidemiological comparison using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). All isolates expressed multidrug resistance and yielded positive results for the modified Hodge and meropenem-BA disk tests. The isolates all carried blaKPC -2 , and coproduced CTX-M-type extended-spectrum β-lactamase. PFGE and MLST showed that the isolates were clonally related. The PFGE patterns of these isolates had ≥90% similarity. We found a single clone, sequence type (ST) 11, and its typical dissemination mode resembled clonal spread. The dissemination of KPC-producing K. pneumoniae is clonally related and there is probable local transmission of a successful ST11 clone.

  15. Phagocytosis and Killing of Carbapenem-Resistant ST258 Klebsiella pneumoniae by Human Neutrophils.

    PubMed

    Kobayashi, Scott D; Porter, Adeline R; Dorward, David W; Brinkworth, Amanda J; Chen, Liang; Kreiswirth, Barry N; DeLeo, Frank R

    2016-05-15

    Carbapenem-resistant Klebsiella pneumoniae strains classified as multilocus sequence type 258 (ST258) are among the most widespread multidrug-resistant hospital-acquired pathogens. Treatment of infections caused by these organisms is difficult, and mortality is high. The basis for the success of ST258, outside of antibiotic resistance, remains incompletely determined. Here we tested the hypothesis that ST258K. pneumoniae has enhanced capacity to circumvent killing by human neutrophils, the primary cellular defense against bacterial infections. There was limited binding and uptake of ST258 by human neutrophils, and correspondingly, there was limited killing of bacteria. On the other hand, transmission electron microscopy revealed that any ingested organisms were degraded readily within neutrophil phagosomes, thus indicating that survival in the neutrophil assays is due to limited phagocytosis, rather than to microbicide resistance after uptake. Our findings suggest that enhancing neutrophil phagocytosis is a potential therapeutic approach for treatment of infection caused by carbapenem-resistant ST258K. pneumoniae.

  16. Intermingled Klebsiella pneumoniae Populations Between Retail Meats and Human Urinary Tract Infections

    PubMed Central

    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.

    2015-01-01

    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

  17. Retrospective investigation of the clinical effects of tazobactam/piperacillin and sulbactam/ampicillin on aspiration pneumonia caused by Klebsiella pneumoniae.

    PubMed

    Tsukada, Hiroki; Sakai, Kunihiko; Cho, Hiromi; Kimura, Yuka; Tetsuka, Takafumi; Nakajima, Haruhiko; Ito, Kazuhiko

    2012-10-01

    Klebsiella pneumoniae is an important causative bacterium of aspiration pneumonia in many elderly patients. We retrospectively investigated the clinical effects of the early treatment of aspiration pneumonia and background factors in 24 patients from whom Klebsiella pneumoniae was isolated. Sulbactam/ampicillin (SBT/ABPC) was selected for early treatment in 12 of the 24 patients diagnosed with aspiration pneumonia, and tazobactam/piperacillin (TAZ/PIPC) was selected for the other patients. The effective rates and success rates of early treatment were significantly higher in the TAZ/PIPC group than in the SBT/ABPC group (p = 0.003 and 0.027, respectively). Although no significant difference was noted because of the limited number of cases, the survival rates after 30 days were 91.7 and 58.3 % in the TAZ/PIPC and SBT/ABPC groups, respectively. Several bacteria isolated with Klebsiella pneumoniae were resistant bacteria, such as methicillin-resistant Staphylococcus aureus or Pseudomonas aeruginosa, and no anaerobe or extended-spectrum β-lactamase-producing Klebsiella pneumoniae was isolated. Thirteen and 11 of the 24 cases were classified as healthcare-associated pneumonia (HCAP) and hospital-acquired pneumonia (HAP), respectively, with no case classified as community-acquired pneumonia (CAP). As population aging progresses, the frequency of aspiration pneumonia classified as HCAP will increase. To cover anaerobes, it is necessary to select antibacterial drugs, such as TAZ/PIPC, for early treatment in consideration of resistant gram-negative bacteria to improve the outcome, and not drugs with weak activity against these bacteria.

  18. A high-resolution genomic analysis of multidrug-resistant hospital outbreaks of Klebsiella pneumoniae

    PubMed Central

    Chung The, Hao; Karkey, Abhilasha; Pham Thanh, Duy; Boinett, Christine J; Cain, Amy K; Ellington, Matthew; Baker, Kate S; Dongol, Sabina; Thompson, Corinne; Harris, Simon R; Jombart, Thibaut; Le Thi Phuong, Tu; Tran Do Hoang, Nhu; Ha Thanh, Tuyen; Shretha, Shrijana; Joshi, Suchita; Basnyat, Buddha; Thwaites, Guy; Thomson, Nicholas R; Rabaa, Maia A; Baker, Stephen

    2015-01-01

    Multidrug-resistant (MDR) Klebsiella pneumoniae has become a leading cause of nosocomial infections worldwide. Despite its prominence, little is known about the genetic diversity of K. pneumoniae in resource-poor hospital settings. Through whole-genome sequencing (WGS), we reconstructed an outbreak of MDR K. pneumoniae occurring on high-dependency wards in a hospital in Kathmandu during 2012 with a case-fatality rate of 75%. The WGS analysis permitted the identification of two MDR K. pneumoniae lineages causing distinct outbreaks within the complex endemic K. pneumoniae. Using phylogenetic reconstruction and lineage-specific PCR, our data predicted a scenario in which K. pneumoniae, circulating for 6 months before the outbreak, underwent a series of ward-specific clonal expansions after the acquisition of genes facilitating virulence and MDR. We suggest that the early detection of a specific NDM-1 containing lineage in 2011 would have alerted the high-dependency ward staff to intervene. We argue that some form of real-time genetic characterisation, alongside clade-specific PCR during an outbreak, should be factored into future healthcare infection control practices in both high- and low-income settings. PMID:25712531

  19. Role of Novel Multidrug Efflux Pump Involved in Drug Resistance in Klebsiella pneumoniae

    PubMed Central

    Srinivasan, Vijaya Bharathi; Singh, Bharat Bhushan; Priyadarshi, Nitesh; Chauhan, Neeraj Kumar; Rajamohan, Govindan

    2014-01-01

    Background Multidrug resistant Klebsiella pneumoniae have caused major therapeutic problems worldwide due to the emergence of the extended-spectrum β-lactamase producing strains. Although there are >10 major facilitator super family (MFS) efflux pumps annotated in the genome sequence of the K. pneumoniae bacillus, apparently less is known about their physiological relevance. Principal Findings Insertional inactivation of kpnGH resulting in increased susceptibility to antibiotics such as azithromycin, ceftazidime, ciprofloxacin, ertapenem, erythromycin, gentamicin, imipenem, ticarcillin, norfloxacin, polymyxin-B, piperacillin, spectinomycin, tobramycin and streptomycin, including dyes and detergents such as ethidium bromide, acriflavine, deoxycholate, sodium dodecyl sulphate, and disinfectants benzalkonium chloride, chlorhexidine and triclosan signifies the wide substrate specificity of the transporter in K. pneumoniae. Growth inactivation and direct fluorimetric efflux assays provide evidence that kpnGH mediates antimicrobial resistance by active extrusion in K. pneumoniae. The kpnGH isogenic mutant displayed decreased tolerance to cell envelope stressors emphasizing its added role in K. pneumoniae physiology. Conclusions and Significance The MFS efflux pump KpnGH involves in crucial physiological functions besides being an intrinsic resistance determinant in K. pneumoniae. PMID:24823362

  20. Epidemiology of invasive Klebsiella pneumoniae with hypermucoviscosity phenotype in a research colony of nonhuman primates.

    PubMed

    Burke, Robin L; Whitehouse, Chris A; Taylor, Justin K; Selby, Edward B

    2009-12-01

    Invasive Klebsiella pneumoniae with hypermucoviscosity phenotype (HMV K. pneumoniae) is an emerging human pathogen that, over the past 20 y, has resulted in a distinct clinical syndrome characterized by pyogenic liver abscesses sometimes complicated by bacteremia, meningitis, and endophthalmitis. Infections occur predominantly in Taiwan and other Asian countries, but HMV K. pneumoniae is considered an emerging infectious disease in the United States and other Western countries. In 2005, fatal multisystemic disease was attributed to HMV K. pneumoniae in African green monkeys (AGM) at our institution. After identification of a cluster of subclinically infected macaques in March and April 2008, screening of all colony nonhuman primates by oropharyngeal and rectal culture revealed 19 subclinically infected rhesus and cynomolgus macaques. PCR testing for 2 genes associated with HMV K. pneumoniae, rmpA and magA, suggested genetic variability in the samples. Random amplified polymorphic DNA analysis on a subset of clinical isolates confirmed a high degree of genetic diversity between the samples. Environmental testing did not reveal evidence of aerosol or droplet transmission of the organism in housing areas. Further research is needed to characterize HMV K. pneumoniae, particularly with regard to genetic differences among bacterial strains and their relationship to human disease and to the apparent susceptibility of AGM to this organism. PMID:20034435

  1. The Klebsiella pneumoniae wabG Gene: Role in Biosynthesis of the Core Lipopolysaccharide and Virulence

    PubMed Central

    Izquierdo, Luis; Coderch, Núria; Piqué, Nuria; Bedini, Emiliano; Michela Corsaro, Maria; Merino, Susana; Fresno, Sandra; Tomás, Juan M.; Regué, Miguel

    2003-01-01

    To determine the function of the wabG gene in the biosynthesis of the core lipopolysaccharide (LPS) of Klebsiella pneumoniae, we constructed wabG nonpolar mutants. Data obtained from the comparative chemical and structural analysis of LPS samples obtained from the wild type, the mutant strain, and the complemented mutant demonstrated that the wabG gene is involved in attachment to α-l-glycero-d-manno-heptopyranose II (l,d-HeppII) at the O-3 position of an α-d-galactopyranosyluronic acid (α-d-GalAp) residue. K. pneumoniae nonpolar wabG mutants were devoid of the cell-attached capsular polysaccharide but were still able to produce capsular polysaccharide. Similar results were obtained with K. pneumoniae nonpolar waaC and waaF mutants, which produce shorter LPS core molecules than do wabG mutants. Other outer core K. pneumoniae nonpolar mutants in the waa gene cluster were encapsulated. K. pneumoniae waaC, waaF, and wabG mutants were avirulent when tested in different animal models. Furthermore, these mutants were more sensitive to some hydrophobic compounds than the wild-type strains. All these characteristics were rescued by reintroduction of the waaC, waaF, and wabG genes from K. pneumoniae. PMID:14645282

  2. Genetic Characterization of the Klebsiella pneumoniae waa Gene Cluster, Involved in Core Lipopolysaccharide Biosynthesis

    PubMed Central

    Regué, Miguel; Climent, Núria; Abitiu, Nihal; Coderch, Núria; Merino, Susana; Izquierdo, Luis; Altarriba, Maria; Tomás, Juan M.

    2001-01-01

    A recombinant cosmid containing genes involved in Klebsiella pneumoniae C3 core lipopolysaccharide biosynthesis was identified by its ability to confer bacteriocin 28b resistance to Escherichia coli K-12. The recombinant cosmid contains 12 genes, the whole waa gene cluster, flanked by kbl and coaD genes, as was found in E. coli K-12. PCR amplification analysis showed that this cluster is conserved in representative K. pneumoniae strains. Partial nucleotide sequence determination showed that the same genes and gene order are found in K. pneumoniae subsp. ozaenae, for which the core chemical structure is known. Complementation analysis of known waa mutants from E. coli K-12 and/or Salmonella enterica led to the identification of genes involved in biosynthesis of the inner core backbone that are shared by these three members of the Enterobacteriaceae. K. pneumoniae orf10 mutants showed a two-log-fold reduction in a mice virulence assay and a strong decrease in capsule amount. Analysis of a constructed K. pneumoniae waaE deletion mutant suggests that the WaaE protein is involved in the transfer of the branch β-d-Glc to the O-4 position of l-glycero-d-manno-heptose I, a feature shared by K. pneumoniae, Proteus mirabilis, and Yersinia enterocolitica. PMID:11371519

  3. SitA contributes to the virulence of Klebsiella pneumoniae in a mouse infection model.

    PubMed

    Sun, Wei-Sheng W; Syu, Wan-Jr; Ho, Wen-Li; Lin, Ching-Nan; Tsai, Shih-Feng; Wang, Shao-Hung

    2014-02-01

    Klebsiella pneumoniae is an opportunistic pathogen, which causes a wide range of nosocomial infections. Recently, antibiotic resistance makes K. pneumoniae infection difficult to deal with. Investigation on virulence determinants of K. pneumoniae can provide more information about pathogenesis and unveil new targets for treatment or vaccine development. In this study, SitA, a Fur-regulated divalent cation transporter, was found significantly increased when K. pneumoniae was cultured in a nutrient-limited condition. A sitA-deletion strain (ΔsitA) was created to characterize the importance of SitA in virulence. ΔsitA showed higher sensitivity toward hydroperoxide than its parental strain. In a mouse intraperitoneal infection model, the survival rate of mice infected with ΔsitA strain increased greatly when compared with that of mice infected with the parental strain, suggesting that sitA deletion attenuates the bacterial virulence in vivo. To test whether ΔsitA strain is a potential vaccine candidate, mice were immunized with inactivated bacteria and then challenged with the wild-type strain. The results showed that using ΔsitA mutant protected mice better than using the wild-type strain or the capsule-negative congenic bacteria. In summary, SitA was found being important for the growth of K. pneumoniae in vivo and deleting sitA might be a potential approach to generate vaccines against K. pneumoniae.

  4. A high-resolution genomic analysis of multidrug-resistant hospital outbreaks of Klebsiella pneumoniae.

    PubMed

    Chung The, Hao; Karkey, Abhilasha; Pham Thanh, Duy; Boinett, Christine J; Cain, Amy K; Ellington, Matthew; Baker, Kate S; Dongol, Sabina; Thompson, Corinne; Harris, Simon R; Jombart, Thibaut; Le Thi Phuong, Tu; Tran Do Hoang, Nhu; Ha Thanh, Tuyen; Shretha, Shrijana; Joshi, Suchita; Basnyat, Buddha; Thwaites, Guy; Thomson, Nicholas R; Rabaa, Maia A; Baker, Stephen

    2015-03-01

    Multidrug-resistant (MDR) Klebsiella pneumoniae has become a leading cause of nosocomial infections worldwide. Despite its prominence, little is known about the genetic diversity of K. pneumoniae in resource-poor hospital settings. Through whole-genome sequencing (WGS), we reconstructed an outbreak of MDR K. pneumoniae occurring on high-dependency wards in a hospital in Kathmandu during 2012 with a case-fatality rate of 75%. The WGS analysis permitted the identification of two MDR K. pneumoniae lineages causing distinct outbreaks within the complex endemic K. pneumoniae. Using phylogenetic reconstruction and lineage-specific PCR, our data predicted a scenario in which K. pneumoniae, circulating for 6 months before the outbreak, underwent a series of ward-specific clonal expansions after the acquisition of genes facilitating virulence and MDR. We suggest that the early detection of a specific NDM-1 containing lineage in 2011 would have alerted the high-dependency ward staff to intervene. We argue that some form of real-time genetic characterisation, alongside clade-specific PCR during an outbreak, should be factored into future healthcare infection control practices in both high- and low-income settings. PMID:25712531

  5. Survival in lake water of Klebsiella pneumoniae discharged by a paper mill.

    PubMed Central

    Niemelä, S I; Väätänen, P

    1982-01-01

    We investigated survival of Klebsiella pneumoniae in freshwater, by determining bacterial densities at eight temperatures between 0 and 20 degrees C at various distances from the discharge area in a lake receiving bacteria mainly from a paper mill. An mFC-inositol-carbenicillin-agar medium was used for Klebsiella enumeration by the membrane filter method. About 90% of the bacteria forming typical colonies on this medium were identified as Klebsiella species. About 10% of the bacteria were false positive, and, an equal percentage were false negative. Semilogarithmic plots of bacterial densities as a function of distance were found to be linear, with slopes depending on water temperature. The average velocity of the flow was estimated from the travel-of-bacterial-density minima caused by production stops. Regression equations were calculated for the dependence of death rate on temperature alone and on both temperature and discharge. The temperature coefficient (Q10) of the death rate was estimated to be 2.1 +/- 0.4. The decimal reduction time (T90) of K. pneumoniae at 0 degrees C was calculated to be about 24 days, and that at 20 degrees C was slightly over 5 days. The regression model was verified by independent observations. Factors affecting the reliability of the estimates were evaluated. PMID:6751227

  6. Genotyping of Klebsiella Pneumonia Strains Isolated from Eldly Inpatients by Multiple-locus Variable-number Tandem-repeat Analysis.

    PubMed

    Zhang, Yuan-Yuan; Xu, Ya-Ping; DU, Peng-Cheng; Qiang, Yu-Jun; Zhang, Wen; Chen, Chen; Yu, Ji-Hong; Guo, Jun

    2016-08-01

    Objective To investigate the genotype of klebsiella pneumonia strains isolated from eldly inpatients by multiple-locus variable-number tandem-repeat analysis. Methods Totally 184 klebsiella pneumonia strains,isolated from eldly inpatients,were collected,and their genome DNA were extracted. The polymorphism of 7 variable-number tandem-repeat locus in the DNA samples was analyzed by multiple primers polymerase chain reaction and capillary electrophoresis. The clustering analysis of genotyping was carried out with the BioNumerics 5.1 software. Results A total of 139 genotypes were identified in 184 klebsiella pneumonia clinical strains,showing obvious genetic polymorphisms. With clustering analysis of genotypes,all the strains were categorized into three gene clusters (genogroups 1,2,and 3). The genogroup 1 was the biggest cluster,containing 93.06% of the isolated strains. Conclusion There was a predominant cluster in the klebsiella pneumonia strains isolated from eldly inpatients in our center,and the major source of klebsiella pneumonia infection remained the nosocomial infection. PMID:27594157

  7. Detection and genotype analysis of AmpC β-lactamase in Klebsiella pneumoniae from tertiary hospitals

    PubMed Central

    LIU, XIANG-QUN; LIU, YONG-RUI

    2016-01-01

    The aim of the present study was to investigate the phenotype and genotype of plasmid-mediated AmpC (pAmpC) β-lactamase in Klebsiella pneumoniae and its antibiotic resistance. A total of 130 non-repetitive clinical isolates of Klebsiella pneumoniae, obtained from tertiary hospitals, were phenotypically screened for pAmpC β-lactamase production with the cefoxitin disk diffusion test. β-lactamase genes in the screened isolates were detected using multiplex polymerase chain reaction (PCR); carbapenemase genes in pAmpC β-lactamase-producing isolates that were resistant to imipenem were detected using PCR. Out of the 130 isolates of Klebsiella pneumoniae, 62 strains (47.7%) were resistant to cefoxitin, including 14 strains (10.8%) positive for pAmpC β-lactamase (DHA type), among which 12 strains (85.7%) were susceptible to imipenem, and 2 strains, which were carrying Klebsiella pneumoniae carbapenemase (KPC)-2 gene, were resistant to imipenem. The pAmpC β-lactamase-producing Klebsiella pneumoniae isolates from the tertiary hospitals were mainly of DHA-1 genotype, and the majority were susceptible to carbapenems; drug-resistant strains were associated with KPC-2 expression. PMID:27347082

  8. Risk factors for KPC-producing Klebsiella pneumoniae: watch out for surgery.

    PubMed

    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

    2016-06-01

    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. PMID:27002853

  9. Global Dissemination of Carbapenemase-Producing Klebsiella pneumoniae: Epidemiology, Genetic Context, Treatment Options, and Detection Methods

    PubMed Central

    Lee, Chang-Ro; Lee, Jung Hun; Park, Kwang Seung; Kim, Young Bae; Jeong, Byeong Chul; Lee, Sang Hee

    2016-01-01

    The emergence of carbapenem-resistant Gram-negative pathogens poses a serious threat to public health worldwide. In particular, the increasing prevalence of carbapenem-resistant Klebsiella pneumoniae is a major source of concern. K. pneumoniae carbapenemases (KPCs) and carbapenemases of the oxacillinase-48 (OXA-48) type have been reported worldwide. New Delhi metallo-β-lactamase (NDM) carbapenemases were originally identified in Sweden in 2008 and have spread worldwide rapidly. In this review, we summarize the epidemiology of K. pneumoniae producing three carbapenemases (KPCs, NDMs, and OXA-48-like). Although the prevalence of each resistant strain varies geographically, K. pneumoniae producing KPCs, NDMs, and OXA-48-like carbapenemases have become rapidly disseminated. In addition, we used recently published molecular and genetic studies to analyze the mechanisms by which these three carbapenemases, and major K. pneumoniae clones, such as ST258 and ST11, have become globally prevalent. Because carbapenemase-producing K. pneumoniae are often resistant to most β-lactam antibiotics and many other non-β-lactam molecules, the therapeutic options available to treat infection with these strains are limited to colistin, polymyxin B, fosfomycin, tigecycline, and selected aminoglycosides. Although, combination therapy has been recommended for the treatment of severe carbapenemase-producing K. pneumoniae infections, the clinical evidence for this strategy is currently limited, and more accurate randomized controlled trials will be required to establish the most effective treatment regimen. Moreover, because rapid and accurate identification of the carbapenemase type found in K. pneumoniae may be difficult to achieve through phenotypic antibiotic susceptibility tests, novel molecular detection techniques are currently being developed. PMID:27379038

  10. Global Dissemination of Carbapenemase-Producing Klebsiella pneumoniae: Epidemiology, Genetic Context, Treatment Options, and Detection Methods.

    PubMed

    Lee, Chang-Ro; Lee, Jung Hun; Park, Kwang Seung; Kim, Young Bae; Jeong, Byeong Chul; Lee, Sang Hee

    2016-01-01

    The emergence of carbapenem-resistant Gram-negative pathogens poses a serious threat to public health worldwide. In particular, the increasing prevalence of carbapenem-resistant Klebsiella pneumoniae is a major source of concern. K. pneumoniae carbapenemases (KPCs) and carbapenemases of the oxacillinase-48 (OXA-48) type have been reported worldwide. New Delhi metallo-β-lactamase (NDM) carbapenemases were originally identified in Sweden in 2008 and have spread worldwide rapidly. In this review, we summarize the epidemiology of K. pneumoniae producing three carbapenemases (KPCs, NDMs, and OXA-48-like). Although the prevalence of each resistant strain varies geographically, K. pneumoniae producing KPCs, NDMs, and OXA-48-like carbapenemases have become rapidly disseminated. In addition, we used recently published molecular and genetic studies to analyze the mechanisms by which these three carbapenemases, and major K. pneumoniae clones, such as ST258 and ST11, have become globally prevalent. Because carbapenemase-producing K. pneumoniae are often resistant to most β-lactam antibiotics and many other non-β-lactam molecules, the therapeutic options available to treat infection with these strains are limited to colistin, polymyxin B, fosfomycin, tigecycline, and selected aminoglycosides. Although, combination therapy has been recommended for the treatment of severe carbapenemase-producing K. pneumoniae infections, the clinical evidence for this strategy is currently limited, and more accurate randomized controlled trials will be required to establish the most effective treatment regimen. Moreover, because rapid and accurate identification of the carbapenemase type found in K. pneumoniae may be difficult to achieve through phenotypic antibiotic susceptibility tests, novel molecular detection techniques are currently being developed. PMID:27379038

  11. Risk factors for KPC-producing Klebsiella pneumoniae: watch out for surgery.

    PubMed

    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

    2016-06-01

    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.

  12. Genomic definition of hypervirulent and multidrug-resistant Klebsiella pneumoniae clonal groups.

    PubMed

    Bialek-Davenet, Suzanne; Criscuolo, Alexis; Ailloud, Florent; Passet, Virginie; Jones, Louis; Delannoy-Vieillard, Anne-Sophie; Garin, Benoit; Le Hello, Simon; Arlet, Guillaume; Nicolas-Chanoine, Marie-Hélène; Decré, Dominique; Brisse, Sylvain

    2014-11-01

    Multidrug-resistant and highly virulent Klebsiella pneumoniae isolates are emerging, but the clonal groups (CGs) corresponding to these high-risk strains have remained imprecisely defined. We aimed to identify K. pneumoniae CGs on the basis of genome-wide sequence variation and to provide a simple bioinformatics tool to extract virulence and resistance gene data from genomic data. We sequenced 48 K. pneumoniae isolates, mostly of serotypes K1 and K2, and compared the genomes with 119 publicly available genomes. A total of 694 highly conserved genes were included in a core-genome multilocus sequence typing scheme, and cluster analysis of the data enabled precise definition of globally distributed hypervirulent and multidrug-resistant CGs. In addition, we created a freely accessible database, BIGSdb-Kp, to enable rapid extraction of medically and epidemiologically relevant information from genomic sequences of K. pneumoniae. Although drug-resistant and virulent K. pneumoniae populations were largely nonoverlapping, isolates with combined virulence and resistance features were detected.

  13. Genomic definition of hypervirulent and multidrug-resistant Klebsiella pneumoniae clonal groups.

    PubMed

    Bialek-Davenet, Suzanne; Criscuolo, Alexis; Ailloud, Florent; Passet, Virginie; Jones, Louis; Delannoy-Vieillard, Anne-Sophie; Garin, Benoit; Le Hello, Simon; Arlet, Guillaume; Nicolas-Chanoine, Marie-Hélène; Decré, Dominique; Brisse, Sylvain

    2014-11-01

    Multidrug-resistant and highly virulent Klebsiella pneumoniae isolates are emerging, but the clonal groups (CGs) corresponding to these high-risk strains have remained imprecisely defined. We aimed to identify K. pneumoniae CGs on the basis of genome-wide sequence variation and to provide a simple bioinformatics tool to extract virulence and resistance gene data from genomic data. We sequenced 48 K. pneumoniae isolates, mostly of serotypes K1 and K2, and compared the genomes with 119 publicly available genomes. A total of 694 highly conserved genes were included in a core-genome multilocus sequence typing scheme, and cluster analysis of the data enabled precise definition of globally distributed hypervirulent and multidrug-resistant CGs. In addition, we created a freely accessible database, BIGSdb-Kp, to enable rapid extraction of medically and epidemiologically relevant information from genomic sequences of K. pneumoniae. Although drug-resistant and virulent K. pneumoniae populations were largely nonoverlapping, isolates with combined virulence and resistance features were detected. PMID:25341126

  14. Role of hydrogen generation by Klebsiella pneumoniae in the oral cavity.

    PubMed

    Kanazuru, Tomoko; Sato, Eisuke F; Nagata, Kumiko; Matsui, Hiroshi; Watanabe, Kunihiko; Kasahara, Emiko; Jikumaru, Mika; Inoue, June; Inoue, Masayasu

    2010-12-01

    Some gastrointestinal bacteria synthesize hydrogen (H(2)) by fermentation. Despite the presence of bactericidal factors in human saliva, a large number of bacteria also live in the oral cavity. It has never been shown that oral bacteria also produce H(2) or what role H(2) might play in the oral cavity. It was found that a significant amount of H(2) is synthesized in the oral cavity of healthy human subjects, and that its generation is enhanced by the presence of glucose but inhibited by either teeth brushing or sterilization with povidone iodine. These observations suggest the presence of H(2)-generating bacteria in the oral cavity. The screening of commensal bacteria in the oral cavity revealed that a variety of anaerobic bacteria generate H(2). Among them, Klebsiella pneumoniae (K. pneumoniae) generated significantly large amounts of H(2) in the presence of glucose. Biochemical analysis revealed that various proteins in K. pneumoniae are carbonylated under standard culture conditions, and that oxidative stress induced by the presence of Fe(++) and H(2)O(2) increases the number of carbonylated proteins, particularly when their hydrogenase activity is inhibited by KCN. Inhibition of H(2) generation markedly suppresses the growth of K. pneumoniae. These observations suggest that H(2) generation and/or the reduction of oxidative stress is important for the survival and growth of K. pneumoniae in the oral cavity.

  15. Multidrug-resistant Klebsiella pneumoniae isolated from farm environments and retail products in Oklahoma.

    PubMed

    Kim, Shin-Hee; Wei, Cheng-I; Tzou, Ywh-Min; An, Haejung

    2005-10-01

    Multidrug-resistant enteric bacteria were isolated from turkey, cattle, and chicken farms and retail meat products in Oklahoma. Among the isolated species, multidrug-resistant Klebsiella pneumoniae was prevalently isolated from most of the collected samples. Therefore, a total of 132 isolates of K. pneumoniae were characterized to understand their potential roles in the dissemination of antibiotic-resistance genes in the food chains. Multidrug-resistant K. pneumoniae was most frequently recovered from a turkey farm and ground turkey products among the tested samples. All isolates were resistant to ampicillin, tetracycline, streptomycin, gentamycin, and kanamycin. Class 1 integrons located in plasmids were identified as a common carrier of the aadA1 gene, encoding resistance to streptomycin and spectinomycin. Production of beta-lactamase in the K. pneumoniae isolates played a major role in the resistance to beta-lactam agents. Most isolates (96%) possessed bla(SHV1). Five strains were able to express both SHV-11 (pI 6.2) and TEM-1 (pI 5.2) beta-lactamase. Transfer of these antibiotic-resistance genes to Escherichia coli was demonstrated by transconjugation. The bacterial genomic DNA restriction patterns by pulsed-field gel electrophoresis showed that the same clones of multidrug-resistant K. pneumoniae remained in feathers, feed, feces, and drinking water in turkey environments, indicating the possible dissemination of antibiotic-resistance genes in the ecosystem and cross-contamination of antibiotic-resistant bacteria during processing and distribution of products.

  16. Klebsiella pneumoniae alleviates influenza-induced acute lung injury via limiting NK cell expansion.

    PubMed

    Wang, Jian; Li, Fengqi; Sun, Rui; Gao, Xiang; Wei, Haiming; Tian, Zhigang

    2014-08-01

    A protective effect induced by bacterial preinfection upon a subsequent lethal influenza virus infection has been observed, but the underlying immune mechanisms have not yet been fully elucidated. In this study, we used a mouse model of Klebsiella pneumoniae preinfection to gain insight into how bacterial preinfection influences the subsequent lethal influenza virus infection. We found that K. pneumoniae preinfection significantly attenuated lung immune injury and decreased mortality during influenza virus infection, but K. pneumoniae-specific immunity was not involved in this cross-protection against influenza virus. K. pneumoniae preinfection limited NK cell expansion, which was involved in influenza-induced immune injury and death. Furthermore, K. pneumoniae preinfection could not control NK cell expansion and death during influenza virus infection in Rag1(-/-) mice, but adoptive transfer of T cells from wild-type mice was able to restore this protective effect. Our data suggest that the adaptive immune response activated by bacterial infection limits the excessive innate immune response induced by a subsequent influenza infection, ultimately protecting mice from death.

  17. Genomic Definition of Hypervirulent and Multidrug-Resistant Klebsiella pneumoniae Clonal Groups

    PubMed Central

    Bialek-Davenet, Suzanne; Criscuolo, Alexis; Ailloud, Florent; Passet, Virginie; Jones, Louis; Delannoy-Vieillard, Anne-Sophie; Garin, Benoit; Le Hello, Simon; Arlet, Guillaume; Nicolas-Chanoine, Marie-Hélène; Decré, Dominique

    2014-01-01

    Multidrug-resistant and highly virulent Klebsiella pneumoniae isolates are emerging, but the clonal groups (CGs) corresponding to these high-risk strains have remained imprecisely defined. We aimed to identify K. pneumoniae CGs on the basis of genome-wide sequence variation and to provide a simple bioinformatics tool to extract virulence and resistance gene data from genomic data. We sequenced 48 K. pneumoniae isolates, mostly of serotypes K1 and K2, and compared the genomes with 119 publicly available genomes. A total of 694 highly conserved genes were included in a core-genome multilocus sequence typing scheme, and cluster analysis of the data enabled precise definition of globally distributed hypervirulent and multidrug-resistant CGs. In addition, we created a freely accessible database, BIGSdb-Kp, to enable rapid extraction of medically and epidemiologically relevant information from genomic sequences of K. pneumoniae. Although drug-resistant and virulent K. pneumoniae populations were largely nonoverlapping, isolates with combined virulence and resistance features were detected. PMID:25341126

  18. First report of chronic pulmonary infection by KPC-3-producing and colistin-resistant Klebsiella pneumoniae sequence type 258 (ST258) in an adult patient with cystic fibrosis.

    PubMed

    Delfino, Emanuele; Giacobbe, Daniele Roberto; Del Bono, Valerio; Coppo, Erika; Marchese, Anna; Manno, Graziana; Morelli, Patrizia; Minicucci, Laura; Viscoli, Claudio

    2015-04-01

    The spread of Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae continues to increase, and the possible development of KPC-producing K. pneumoniae infections in cystic fibrosis (CF) patients is a matter of concern. Here, we describe the establishment of a chronic lung infection due to a colistin-resistant KPC-producing K. pneumoniae isolate in an Italian CF patient. PMID:25653395

  19. First Report of Chronic Pulmonary Infection by KPC-3-Producing and Colistin-Resistant Klebsiella pneumoniae Sequence Type 258 (ST258) in an Adult Patient with Cystic Fibrosis

    PubMed Central

    Delfino, Emanuele; Del Bono, Valerio; Coppo, Erika; Marchese, Anna; Manno, Graziana; Morelli, Patrizia; Minicucci, Laura; Viscoli, Claudio

    2015-01-01

    The spread of Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae continues to increase, and the possible development of KPC-producing K. pneumoniae infections in cystic fibrosis (CF) patients is a matter of concern. Here, we describe the establishment of a chronic lung infection due to a colistin-resistant KPC-producing K. pneumoniae isolate in an Italian CF patient. PMID:25653395

  20. The modified Hodge test is a useful tool for ruling out klebsiella pneumoniae carbapenemase

    PubMed Central

    Cury, Ana Paula; Andreazzi, Denise; Maffucci, Márcia; Caiaffa-Junior, Hélio Hehl; Rossi, Flávia

    2012-01-01

    OBJECTIVE: Enterobacteriaceae bacteria harboring Klebsiella pneumoniae carbapenemase are a serious worldwide threat. The molecular identification of these pathogens is not routine in Brazilian hospitals, and a rapid phenotypic screening test is desirable. This study aims to evaluate the modified Hodge test as a phenotypic screening test for Klebsiella pneumoniae carbapenemase. METHOD: From April 2009 to July 2011, all Enterobacteriaceae bacteria that were not susceptible to ertapenem according to Vitek2 analysis were analyzed with the modified Hodge test. All positive isolates and a random subset of negative isolates were also assayed for the presence of blaKPC. Isolates that were positive in modified Hodge tests were sub-classified as true-positives (E. coli touched the ertapenem disk) or inconclusive (distortion of the inhibition zone of E. coli, but growth did not reach the ertapenem disk). Negative results were defined as samples with no distortion of the inhibition zone around the ertapenem disk. RESULTS: Among the 1521 isolates of Enterobacteriaceae bacteria that were not susceptible to ertapenem, 30% were positive for blaKPC, and 35% were positive according to the modified Hodge test (81% specificity). Under the proposed sub-classification, true positives showed a 98% agreement with the blaKPC results. The negative predictive value of the modified Hodge test for detection was 100%. KPC producers showed high antimicrobial resistance rates, but 90% and 77% of these isolates were susceptible to aminoglycoside and tigecycline, respectively. CONCLUSION: Standardizing the modified Hodge test interpretation may improve the specificity of KPC detection. In this study, negative test results ruled out 100% of the isolates harboring Klebsiella pneumoniae carbapenemase-2. The test may therefore be regarded as a good epidemiological tool. PMID:23295597

  1. Emergence of Carbapenem-Resistant Serotype K1 Hypervirulent Klebsiella pneumoniae Strains in China.

    PubMed

    Zhang, Rong; Lin, Dachuan; Chan, Edward Wai-Chi; Gu, Danxia; Chen, Gong-Xiang; Chen, Sheng

    2016-01-01

    We report the emergence of five carbapenem-resistant K1 hypervirulent Klebsiella pneumoniae (hvKP) strains which caused fatal infections in hospital patients in Zhejiang Province, China, upon entry through surgical wounds. Genotyping results revealed the existence of three genetically related strains which exhibited a new sequence type, ST1797, and revealed that all strains harbored the magA and wcaG virulence genes and a plasmid-borne bla(KPC-2) gene. These findings indicate that K1 hvKP is simultaneously hypervirulent, multidrug resistant, and transmissible. PMID:26574010

  2. A Neonatal Septic Arthritis Case Caused by Klebsiella pneumoniae: A Case Report

    PubMed Central

    Ozsari, Tamer; Ozdemir, Özmert M.A; Kiliç, Ilknur

    2016-01-01

    Septic arthritis is encountered very rarely during the neonatal period and its diagnosis can delay because of atypical symptoms, thus it may lead to serious sequelae. The sequale can be prevented by early diagnosis and concomitant treatment. In neonates, pain can be experienced as a result of pseudoparalysis and of movement of the effected joints. A 17-day-old neonatal patient was brought to our hospital with complaint of unrest and then diagnosed with septic arthritis due to propagation of Klebsiella pneumoniae in joint fluid culture was represented because of the rarity of such a case. PMID:27042550

  3. Infection of mice by aerosols of Klebsiella pneumoniae under hyperbaric conditions.

    PubMed Central

    Heckly, R J; Chatigny, M A; Dimmick, R L

    1980-01-01

    Both the physical behavior of aerosols and survival of airborne Serratia marcescens in hyperbaric chambers with a helium-air mixture at 20 atm of pressure was approximately the same as in the system at ambient pressures. Exposure of mice to aerosols of Klebsiella pneumoniae at 1-, 2-, and 17-atm (ca. 101-, 203-, and 1,722-kPa) pressures of helium-oxygen mixture showed that the number of viable organisms constituting a 50% lethal dose was not significantly affected by the hyperbaric conditions. Images PMID:6996616

  4. Detection and characterization of OXA-48-producing Klebsiella pneumoniae originated in Bulgaria.

    PubMed

    Sabtcheva, Stefana; Ivanov, Ivan N; Todorova, Bozhana; Simeonov, Yordan; Dobreva, Elina; Ivanova, Krasimira; Velinov, Tzvetan; Kantardjiev, Todor

    2016-10-01

    We report the identification of OXA-48-producing Klebsiella pneumoniae, causing peritonitis in a cancer patient admitted to the Oncology Hospital in Sofia. The isolate had reduced susceptibility to carbapenems but remained susceptible to extended-spectrum cephalosporins. PCR and sequencing confirmed the presence of blaOXA-48 gene flanked by two intact copies of IS1999 on truncated ΔTn1999.1. This transposon was located on unusual non-typeable 29-kb plasmid that could be transferred only by transformation. Multilocus sequence typing (MLST) indicated the presence of the sequence type ST530.This is the first documented infection due to OXA-48-producing Enterobacteriaceae strain in Bulgaria.

  5. Biochemical and Structural Characterization of a Ureidoglycine Aminotransferase in the Klebsiella pneumoniae Uric Acid Catabolic Pathway

    SciTech Connect

    French, Jarrod B.; Ealick, Steven E.

    2010-09-03

    Many plants, fungi, and bacteria catabolize allantoin as a mechanism for nitrogen assimilation. Recent reports have shown that in plants and some bacteria the product of hydrolysis of allantoin by allantoinase is the unstable intermediate ureidoglycine. While this molecule can spontaneously decay, genetic analysis of some bacterial genomes indicates that an aminotransferase may be present in the pathway. Here we present evidence that Klebsiella pneumoniae HpxJ is an aminotransferase that preferentially converts ureidoglycine and an {alpha}-keto acid into oxalurate and the corresponding amino acid. We determined the crystal structure of HpxJ, allowing us to present an explanation for substrate specificity.

  6. Citrate substitutes for homocitrate in nitrogenase of a nifV mutant of Klebsiella pneumoniae

    SciTech Connect

    Liang, Jihong; Madden, M.; Shah, V.K.; Burris, R.H. )

    1990-09-18

    An organic acid extracted from purified dinitrogenase isolated from a nifV mutant of Klebsiella pneumoniae has been identified as citric acid. H{sub 2} evolution by the citrate-containing dinitrogenase is partially inhibited by CO, and by some substrates for nitrogenase. The response of maximum velocities to changes in pH for both the wild-type and the NifV{sup {minus}} dinitrogenase was compared. No substantial differences between the enzymes were observed, but there are minor differences. Both enzymes are stable in the pH range 4.8-10, but the enzyme activities dropped dramatically below pH 6.2.

  7. Outbreak of NDM-1-Producing Klebsiella pneumoniae in a Neonatal Unit in Colombia

    PubMed Central

    Olarte Escobar, Narda María; Castro-Cardozo, Betsy; Valderrama Márquez, Ismael Alberto; Garzón Aguilar, Martha Isabel; Martinez de la Barrera, Leslie; Barrero Barreto, Esther Rocio; Marquez-Ortiz, Ricaurte Alejandro; Moncada Guayazán, Maria Victoria; Vanegas Gómez, Natasha

    2013-01-01

    Six multiresistant, NDM-1-producing Klebsiella pneumoniae strains were recovered from an outbreak that affected six neonatal patients in a Colombian hospital. Molecular analysis showed that all of the isolates harbored the blaNDM-1, qnrA, and intI1 genes and were clonally related. Multilocus sequence typing showed that the isolates belonged to a new sequence type (ST1043) that was different from the sequence types that had previously been reported. This is the first report of NDM-1-producing isolates in South America. PMID:23357776

  8. Acquisition of Broad-Spectrum Cephalosporin Resistance Leading to Colistin Resistance in Klebsiella pneumoniae

    PubMed Central

    Jayol, Aurélie; Nordmann, Patrice; Desroches, Marine; Decousser, Jean-Winoc

    2016-01-01

    An extended-spectrum β-lactamase (ESBL)-producing and colistin-resistant Klebsiella pneumoniae clinical isolate was recovered from a patient who was treated with cefotaxime. This isolate harbored a blaCTX-M-15 ESBL gene that was associated with an ISEcp1 insertion sequence. Transposition of that tandem occurred within the chromosomal mgrB gene, leading to inactivation of the mgrB gene and consequently to acquired resistance to colistin. We showed here a coselection of colistin resistance as a result of a broad-spectrum cephalosporin selective pressure. PMID:26953194

  9. Emergence of Carbapenem-Resistant Serotype K1 Hypervirulent Klebsiella pneumoniae Strains in China.

    PubMed

    Zhang, Rong; Lin, Dachuan; Chan, Edward Wai-Chi; Gu, Danxia; Chen, Gong-Xiang; Chen, Sheng

    2015-11-16

    We report the emergence of five carbapenem-resistant K1 hypervirulent Klebsiella pneumoniae (hvKP) strains which caused fatal infections in hospital patients in Zhejiang Province, China, upon entry through surgical wounds. Genotyping results revealed the existence of three genetically related strains which exhibited a new sequence type, ST1797, and revealed that all strains harbored the magA and wcaG virulence genes and a plasmid-borne bla(KPC-2) gene. These findings indicate that K1 hvKP is simultaneously hypervirulent, multidrug resistant, and transmissible.

  10. Population variability of the FimH type 1 fimbrial adhesin in Klebsiella pneumoniae.

    PubMed

    Stahlhut, Steen G; Chattopadhyay, Sujay; Struve, Carsten; Weissman, Scott J; Aprikian, Pavel; Libby, Stephen J; Fang, Ferric C; Krogfelt, Karen Angeliki; Sokurenko, Evgeni V

    2009-03-01

    FimH is an adhesive subunit of type 1 fimbriae expressed by different enterobacterial species. The enteric bacterium Klebsiella pneumoniae is an environmental organism that is also a frequent cause of sepsis, urinary tract infection (UTI), and liver abscess. Type 1 fimbriae have been shown to be critical for the ability of K. pneumoniae to cause UTI in a murine model. We show here that the K. pneumoniae fimH gene is found in 90% of strains from various environmental and clinical sources. The fimH alleles exhibit relatively low nucleotide and structural diversity but are prone to frequent horizontal-transfer events between different bacterial clones. Addition of the fimH locus to multiple-locus sequence typing significantly improved the resolution of the clonal structure of pathogenic strains, including the K1 encapsulated liver isolates. In addition, the K. pneumoniae FimH protein is targeted by adaptive point mutations, though not to the same extent as FimH from uropathogenic Escherichia coli or TonB from the same K. pneumoniae strains. Such adaptive mutations include a single amino acid deletion from the signal peptide that might affect the length of the fimbrial rod by affecting FimH translocation into the periplasm. Another FimH mutation (S62A) occurred in the course of endemic circulation of a nosocomial uropathogenic clone of K. pneumoniae. This mutation is identical to one found in a highly virulent uropathogenic strain of E. coli, suggesting that the FimH mutations are pathoadaptive in nature. Considering the abundance of type 1 fimbriae in Enterobacteriaceae, our present finding that fimH genes are subject to adaptive microevolution substantiates the importance of type 1 fimbria-mediated adhesion in K. pneumoniae.

  11. Biofilm inhibitory effect of chlorhexidine conjugated gold nanoparticles against Klebsiella pneumoniae.

    PubMed

    Ahmed, Ayaz; Khan, Anum Khalid; Anwar, Ayaz; Ali, Syed Abid; Shah, Muhammad Raza

    2016-09-01

    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.

  12. Biofilm inhibitory effect of chlorhexidine conjugated gold nanoparticles against Klebsiella pneumoniae.

    PubMed

    Ahmed, Ayaz; Khan, Anum Khalid; Anwar, Ayaz; Ali, Syed Abid; Shah, Muhammad Raza

    2016-09-01

    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. PMID:27321770

  13. Protection against Klebsiella pneumoniae Using Lithium Chloride in an Intragastric Infection Model

    PubMed Central

    Kuo, Chih-Feng; Chiu, Ching-Chen; Lin, Wei-Chen; Huang, Wan-Hui; Chen, Li-Yang

    2014-01-01

    Intragastric Klebsiella pneumoniae infections of mice can cause liver abscesses, necrosis of liver tissues, and bacteremia. Lithium chloride, a widely prescribed drug for bipolar mood disorder, has been reported to possess anti-inflammatory properties. Using an intragastric infection model, the effects of LiCl on K. pneumoniae infections were examined. Providing mice with drinking water containing LiCl immediately after infection protected them from K. pneumoniae-induced death and liver injuries, such as necrosis of liver tissues, as well as increasing blood levels of aspartate aminotransferase and alanine aminotransferase, in a dose-dependent manner. LiCl administered as late as 24 h postinfection still provided protection. Monitoring of the LiCl concentrations in the sera of K. pneumoniae-infected mice showed that approximately 0.33 mM LiCl was the most effective dose for protecting mice against infections, which is lower than the clinically toxic dose of LiCl. Surveys of bacterial counts and cytokine expression levels in LiCl-treated mice revealed that both were effectively inhibited in blood and liver tissues. Using in vitro assays, we found that LiCl (5 μM to 1 mM) did not directly interfere with the growth of K. pneumoniae but made K. pneumoniae cells lose the mucoid phenotype and become more susceptible to macrophage killing. Furthermore, low doses of LiCl also partially enhanced the bactericidal activity of macrophages. Taken together, these data suggest that LiCl is an alternative therapeutic agent for K. pneumoniae-induced liver infections. PMID:25534739

  14. Spectrum of excess mortality due to carbapenem-resistant Klebsiella pneumoniae infections.

    PubMed

    Hauck, C; Cober, E; Richter, S S; Perez, F; Salata, R A; Kalayjian, R C; Watkins, R R; Scalera, N M; Doi, Y; Kaye, K S; Evans, S; Fowler, V G; Bonomo, R A; van Duin, D

    2016-06-01

    Patients infected or colonized with carbapenem-resistant Klebsiella pneumoniae (CRKp) are often chronically and acutely ill, which results in substantial mortality unrelated to infection. Therefore, estimating excess mortality due to CRKp infections is challenging. The Consortium on Resistance against Carbapenems in K. pneumoniae (CRACKLE) is a prospective multicenter study. Here, patients in CRACKLE were evaluated at the time of their first CRKp bloodstream infection (BSI), pneumonia or urinary tract infection (UTI). A control cohort of patients with CRKp urinary colonization without CRKp infection was constructed. Excess hospital mortality was defined as mortality in cases after subtracting mortality in controls. In addition, the adjusted hazard ratios (aHR) for time-to-hospital-mortality at 30 days associated with infection compared with colonization were calculated in Cox proportional hazard models. In the study period, 260 patients with CRKp infections were included in the BSI (90 patients), pneumonia (49 patients) and UTI (121 patients) groups, who were compared with 223 controls. All-cause hospital mortality in controls was 12%. Excess hospital mortality was 27% in both patients with BSI and those with pneumonia. Excess hospital mortality was not observed in patients with UTI. In multivariable analyses, BSI and pneumonia compared with controls were associated with aHR of 2.59 (95% CI 1.52-4.50, p <0.001) and 3.44 (95% CI 1.80-6.48, p <0.001), respectively. In conclusion, in patients with CRKp infection, pneumonia is associated with the highest excess hospital mortality. Patients with BSI have slightly lower excess hospital mortality rates, whereas excess hospital mortality was not observed in hospitalized patients with UTI.

  15. Clonal dissemination of Klebsiella pneumoniae ST258 harbouring KPC-2 in Argentina.

    PubMed

    Gomez, S A; Pasteran, F G; Faccone, D; Tijet, N; Rapoport, M; Lucero, C; Lastovetska, O; Albornoz, E; Galas, M; Melano, R G; Corso, A; Petroni, A

    2011-10-01

    The present work describes the abrupt emergence of Klebsiella pneumoniae carbapenemase (KPC) and characterizes the first 79 KPC-producing enterobacteria from Argentina (isolated from 2006 to 2010). The emergence of bla(KPC-2) was characterized by two patterns of dispersion: the first was the sporadic occurrence in diverse enterobacteria from distant geographical regions, harbouring plasmids of different incompatibility groups and bla(KPC-2) in an unusual genetic environment flanked by ISKpn8-Δbla(TEM-1) and ISKpn6-like. bla(KPC-2) was associated with IncL/M transferable plasmids; the second was the abrupt clonal spread of K. pneumoniae ST258 harbouring bla(KPC-2) in Tn4401a.

  16. Klebsiella pneumoniae harbouring OXA-48 carbapenemase in a Libyan refugee in Italy.

    PubMed

    Kocsis, E; Savio, C; Piccoli, M; Cornaglia, G; Mazzariol, A

    2013-09-01

    A carbapenem-resistant Klebsiella pneumoniae was isolated from a blood-culture of an inpatient from Libya, hospitalized in the intensive-care unit of Negrar Hospital, Italy. The clinical isolate carried the following β-lactamase genes, bla(TEM -1), bla(SHV -11), bla(OXA -1), bla(CTX -M-15) and bla(OXA -48), respectively. The bla(OXA -48) gene was inserted in the Tn1999.2 transposon type, carried on a conjugative, 60-kilobase plasmid, that presented an L/M backbone, hosted by a multidrug-resistant ST 101 K. pneumoniae strain. Our report highlights the international transfer of bla(OXA -48) gene and the importance of screening measures of multidrug-resistant Enterobacteriaceae.

  17. Nitrogen fixation by Klebsiella pneumoniae is inhibited by certain multicopy hybrid nif plasmids.

    PubMed

    Riedel, G E; Brown, S E; Ausubel, F M

    1983-01-01

    In our studies of nif gene regulation, we have observed that certain hybrid nif plasmids drastically inhibit the expression of the chromosomal nif genes of Klebsiella pneumonia. Wild-type (Nif+) K. pneumoniae strains that acquire certain hybrid nif plasmids also acquire the Nif- phenotype; these strains lose 90 to 99% of all detectable nitrogen fixation activity and grow poorly (or not at all) on solid media with N2 as the sole nitrogen source. We describe experiments which defined this inhibition of the Nif+ phenotype by hybrid nif plasmids and identify and characterize four nif DNA regions associated with this inhibition. We show that plasmids carrying these nif regions could recombine with, but not complement, nif chromosomal mutations. Our results suggest that inhibition of the Nif+ phenotype will provide a useful bioassay for some of the factors that mediate nif gene expression.

  18. Open Conversion after Aortic Endograft Infection Caused by Colistin-Resistant, Carbapenemase-Producing Klebsiella pneumoniae

    PubMed Central

    Menna, Danilo; Sirignano, Pasqualino; Capoccia, Laura; Mansour, Wassim; Speziale, Francesco

    2016-01-01

    A 62-year-old man presented with fever, abdominal pain, and malaise 13 months after emergency endovascular aortic repair. Computed tomographic angiograms showed a periprosthetic fluid and gas collection, so infection was diagnosed. Open conversion was performed, involving endograft explantation and in situ aortic reconstruction. Cultures and the explanted prosthesis were positive for carbapenemase-producing Klebsiella pneumoniae, resistant to colistin. Because of the sparse data on endograft infections caused by this pathogen, we placed the patient on an empiric double-carbapenem regimen for 4 weeks. Symptomatic recovery occurred after 21 days. On the 30th day, we deployed a stent to treat a new pseudoaneurysm. Three years later, the patient had no signs of persistent or recurrent infection. We think that this is the first report of aortic endograft infection caused by colistin-resistant, carbapenemase-producing K. pneumoniae. PMID:27777535

  19. Neutral red-mediated microbial electrosynthesis by Escherichia coli, Klebsiella pneumoniae, and Zymomonas mobilis.

    PubMed

    Harrington, Timothy D; Mohamed, Abdelrhman; Tran, Vi N; Biria, Saeid; Gargouri, Mahmoud; Park, Jeong-Jin; Gang, David R; Beyenal, Haluk

    2015-11-01

    The aim of this work was to compare the effects of electrosynthesis on different bacterial species. The effects of neutral red-mediated electrosynthesis on the metabolite profiles of three microorganisms: Escherichia coli, Klebsiella pneumoniae, and Zymomonas mobilis, were measured and compared and contrasted. A statistically comprehensive analysis of neutral red-mediated electrosynthesis is presented using the analysis of end-product profiles, current delivered, and changes in cellular protein expression. K. pneumoniae displayed the most dramatic response to electrosynthesis of the three bacteria, producing 93% more ethanol and 76% more lactate vs. control fermentation with no neutral red and no electron delivery. Z. mobilis showed no response to electrosynthesis except elevated acetate titers. Stoichiometric comparison showed that NAD(+) reduction by neutral red could not account for changes in metabolites during electrosynthesis. Neutral red-mediated electrosynthesis was shown to have multifarious effects on the three species.

  20. Heteroresistance to colistin in Klebsiella pneumoniae associated with alterations in the PhoPQ regulatory system.

    PubMed

    Jayol, Aurélie; Nordmann, Patrice; Brink, Adrian; Poirel, Laurent

    2015-05-01

    A multidrug-resistant Klebsiella pneumoniae isolate exhibiting heteroresistance to colistin was investigated. The colistin-resistant subpopulation harbored a single amino acid change (Asp191Tyr) in protein PhoP, which is part of the PhoPQ two-component system that activates pmrHFIJKLM expression responsible for l-aminoarabinose synthesis and polymyxin resistance. Complementation assays with a wild-type phoP gene restored full susceptibility to colistin. Then, analysis of the colistin-susceptible subpopulation showed a partial deletion (25 bp) in the phoP gene compared to that in the colistin-resistant subpopulation. That deletion disrupted the reading frame of phoP, leading to a longer and inactive protein (255 versus 223 amino acids long). This is the first report showing the involvement of mutation(s) in PhoP in colistin resistance. Furthermore, this is the first study to decipher the mechanisms leading to colistin heteroresistance in K. pneumoniae.

  1. Role of capsule and O antigen in resistance of Klebsiella pneumoniae to serum bactericidal activity.

    PubMed Central

    Tomás, J M; Benedí, V J; Ciurana, B; Jofre, J

    1986-01-01

    The ability of Klebsiella pneumoniae strains to resist the bactericidal activity of serum was quantitated. The K. pneumoniae strains tested included mutants lacking the capsular polysaccharide and mutants having a modified lipopolysaccharide structure. The last mutants were obtained as phage-resistant mutants, and their lipopolysaccharide was characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and chemical analysis. Serum-resistant mutants derived from phage-resistant mutants (lipopolysaccharide mutants) were also characterized. Resistance to the bactericidal activity of complement was mediated by the lipopolysaccharide, especially by the O-antigen polysaccharide chains. The capsular polysaccharide seemed not to play any important role in resistance to serum bactericidal activity in this bacterium. Images PMID:3531020

  2. Lemierre's Syndrome Caused by Klebsiella pneumoniae in a Diabetic Patient: A Case Report and Review of the Literature

    PubMed Central

    Chuncharunee, Alan

    2015-01-01

    Lemierre's syndrome is characterized by an oropharyngeal infection with internal jugular vein thrombosis followed by metastatic infections in other organs. This infection is usually caused by Fusobacterium spp. In this report, we present a rare case of Klebsiella pneumoniae-associated Lemierre's syndrome in a patient with poorly-controlled diabetes mellitus. The infection was complicated by septic emboli in many organs, which led to the patient's death, despite combined antibiotics, anticoagulant therapy, and surgical intervention. Therein, a literature review was performed for reported cases of Lemierre's syndrome caused by Klebsiella pneumoniae and the results are summarized here. PMID:26279962

  3. Structure of a quinolone-stabilized cleavage complex of topoisomerase IV from Klebsiella pneumoniae and comparison with a related Streptococcus pneumoniae complex

    PubMed Central

    Veselkov, Dennis A.; Laponogov, Ivan; Pan, Xiao-Su; Selvarajah, Jogitha; Skamrova, Galyna B.; Branstrom, Arthur; Narasimhan, Jana; Prasad, Josyula V. N. Vara; Fisher, L. Mark; Sanderson, Mark R.

    2016-01-01

    Klebsiella pneumoniae is a Gram-negative bacterium that is responsible for a range of common infections, including pulmonary pneumonia, bloodstream infections and meningitis. Certain strains of Klebsiella have become highly resistant to antibiotics. Despite the vast amount of research carried out on this class of bacteria, the molecular structure of its topoisomerase IV, a type II topoisomerase essential for catalysing chromosomal segregation, had remained unknown. In this paper, the structure of its DNA-cleavage complex is reported at 3.35 Å resolution. The complex is comprised of ParC breakage-reunion and ParE TOPRIM domains of K. pneumoniae topoisomerase IV with DNA stabilized by levofloxacin, a broad-spectrum fluoroquinolone antimicrobial agent. This complex is compared with a similar complex from Streptococcus pneumoniae, which has recently been solved. PMID:27050128

  4. Molecular Characterization of Klebsiella pneumoniae Carbapenemase (KPC)-Producing Enterobacteriaceae in Ontario, Canada, 2008-2011

    PubMed Central

    Tijet, Nathalie; Sheth, Prameet M.; Lastovetska, Olga; Chung, Catherine; Patel, Samir N.; Melano, Roberto G.

    2014-01-01

    Due to the lack of detailed reports of Klebsiella pneumoniae carbapenemase (KPC)-producing enterobacteria in Ontario, Canada, we perform a molecular characterization of KPC-producing Enterobacteriaceae submitted to the provincial reference laboratory from 2008 to 2011. Susceptibility profiles were accessed by E-test. Molecular types of isolates were determined by pulse-field gel electrophoresis (PFGE) and multilocus sequence typing. Screening of ß-lactamase genes was performed by multiplex PCR and alleles were identified by DNA sequencing. The genetic platform of blaKPC gene was analyzed by PCR. Plasmid replicons were typed using PCR-based typing approach. KPC-plasmids were also evaluated by S1 nuclease-PFGE and Southern blot. Thirty unique clinical isolates (26 Klebsiella pneumoniae, 2 Enterobacter cloacae, 1 Citrobacter freundii and 1 Raoultella ornithinolytica) were identified as blaKPC positive: 4 in 2008, 3 in 2009, 10 in 2010 and 13 in 2011. The majority exhibited resistance to carbapenems, cephalosporins and fluoroquinolones and two isolates were also resistant to colistin. The isolates harbored blaKPC-2 (n = 23) or blaKPC-3 (n = 7). blaTEM-1 (n = 27) was commonly detected and occasionally blaOXA-1 (n = 3) and blaCTX-M-15 (n = 1). As expected, all K. pneumoniae isolates carried blaSHV-11. blaKPC genes were identified on Tn4401a (n = 20) or b (n = 10) isoforms, on plasmids of different sizes belonging to the incompatibility groups IncFIIA (n = 19), IncN (n = 3), IncI2 (n = 3), IncFrep (n = 2) and IncA/C (n = 1). The occurrence of KPC ß-lactamase in Ontario was mainly associated with the spread of the K. pneumoniae clone ST258. PMID:25549365

  5. Molecular characterization of Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae in Ontario, Canada, 2008-2011.

    PubMed

    Tijet, Nathalie; Sheth, Prameet M; Lastovetska, Olga; Chung, Catherine; Patel, Samir N; Melano, Roberto G

    2014-01-01

    Due to the lack of detailed reports of Klebsiella pneumoniae carbapenemase (KPC)-producing enterobacteria in Ontario, Canada, we perform a molecular characterization of KPC-producing Enterobacteriaceae submitted to the provincial reference laboratory from 2008 to 2011. Susceptibility profiles were accessed by E-test. Molecular types of isolates were determined by pulse-field gel electrophoresis (PFGE) and multilocus sequence typing. Screening of ß-lactamase genes was performed by multiplex PCR and alleles were identified by DNA sequencing. The genetic platform of blaKPC gene was analyzed by PCR. Plasmid replicons were typed using PCR-based typing approach. KPC-plasmids were also evaluated by S1 nuclease-PFGE and Southern blot. Thirty unique clinical isolates (26 Klebsiella pneumoniae, 2 Enterobacter cloacae, 1 Citrobacter freundii and 1 Raoultella ornithinolytica) were identified as blaKPC positive: 4 in 2008, 3 in 2009, 10 in 2010 and 13 in 2011. The majority exhibited resistance to carbapenems, cephalosporins and fluoroquinolones and two isolates were also resistant to colistin. The isolates harbored blaKPC-2 (n = 23) or blaKPC-3 (n = 7). blaTEM-1 (n = 27) was commonly detected and occasionally blaOXA-1 (n = 3) and blaCTX-M-15 (n = 1). As expected, all K. pneumoniae isolates carried blaSHV-11. blaKPC genes were identified on Tn4401a (n = 20) or b (n = 10) isoforms, on plasmids of different sizes belonging to the incompatibility groups IncFIIA (n = 19), IncN (n = 3), IncI2 (n = 3), IncFrep (n = 2) and IncA/C (n = 1). The occurrence of KPC ß-lactamase in Ontario was mainly associated with the spread of the K. pneumoniae clone ST258. PMID:25549365

  6. Biosynthesis of poly(3-hydroxypropionate) from glycerol using engineered Klebsiella pneumoniae strain without vitamin B12

    PubMed Central

    Feng, Xinjun; Xian, Mo; Liu, Wei; Xu, Chao; Zhang, Haibo; Zhao, Guang

    2015-01-01

    Poly(3-hydroxypropionate) (P3HP) is a biodegradable and biocompatible thermoplastic. Previous studies demonstrated that engineered Escherichia coli strains can produce P3HP with supplementation of expensive vitamin B12. The present study examined the production of P3HP from glycerol in the recombinant Klebsiella pneumoniae strain, which naturally synthesizes vitamin B12. The genes glycerol dehydratase and its reactivation factor (dhaB123, gdrA, and gdrB from K. pneumoniae), aldehyde dehydrogenase (aldH from E. coli) were cloned and expressed in K. pneumoniae to produce 3-hydroxypropionate (3HP), with 2 genes (dhaT and yqhD) for biosynthesis of 1,3-propanediol were deleted. To obtain P3HP production, propionyl-CoA synthetase (prpE from E. coli) and polyhydroxyalkanoate synthase (phaC from Ralstonia eutropha) were introduced. Under the appropriate aeration condition, the cell yield and P3HP content were 0.24 g/L and 12.7% (wt/wt [cell dry weight]) respectively along with 2.03 g/L 3HP after 48 h cultivation. Although the yield is relatively low, this study shows the feasibility of producing P3HP in K. pneumoniae from glycerol without vitamin B12 for the first time. The results also suggest that the aeration conditions should be optimized carefully for the efficient production of P3HP. PMID:25621933

  7. Secondary acylation of Klebsiella pneumoniae lipopolysaccharide contributes to sensitivity to antibacterial peptides.

    PubMed

    Clements, Abigail; Tull, Dedreia; Jenney, Adam W; Farn, Jacinta L; Kim, Sang-Hyun; Bishop, Russell E; McPhee, Joseph B; Hancock, Robert E W; Hartland, Elizabeth L; Pearse, Martin J; Wijburg, Odilia L C; Jackson, David C; McConville, Malcolm J; Strugnell, Richard A

    2007-05-25

    Klebsiella pneumoniae is an important cause of nosocomial Gram-negative sepsis. Lipopolysaccharide (LPS) is considered to be a major virulence determinant of this encapsulated bacterium and most mutations to the lipid A anchor of LPS are conditionally lethal to the bacterium. We studied the role of LPS acylation in K. pneumoniae disease pathogenesis by using a mutation of lpxM (msbB/waaN), which encodes the enzyme responsible for late secondary acylation of immature lipid A molecules. A K. pneumoniae B5055 (K2:O1) lpxM mutant was found to be attenuated for growth in the lungs in a mouse pneumonia model leading to reduced lethality of the bacterium. B5055DeltalpxM exhibited similar sensitivity to phagocytosis or complement-mediated lysis than B5055, unlike the non-encapsulated mutant B5055nm. In vitro, B5055DeltalpxM showed increased permeability of the outer membrane and an increased susceptibility to certain antibacterial peptides suggesting that in vivo attenuation may be due in part to sensitivity to antibacterial peptides present in the lungs of BALB/c mice. These data support the view that lipopolysaccharide acylation plays a important role in providing Gram-negative bacteria some resistance to structural and innate defenses and especially the antibacterial properties of detergents (e.g. bile) and cationic defensins.

  8. Quinolone therapy of Klebsiella pneumoniae sepsis following irradiation: Comparison of pefloxacin, ciprofloxacin, and ofloxacin

    SciTech Connect

    Brook, I.; Elliott, T.B.; Ledney, G.D. )

    1990-05-01

    Exposure to whole-body irradiation is associated with fatal gram-negative sepsis. The effect of oral therapy with three quinolones, pefloxacin, ciprofloxacin, and ofloxacin, for orally acquired Klebsiella pneumoniae infection was tested in B6D2F1 mice exposed to 8.0 Gy whole-body irradiation from bilaterally positioned 60Co sources. A dose of 10(8) organisms was given orally 2 days after irradiation, and therapy was started 1 day later. Quinolones reduced colonization of the ileum with K. pneumoniae: 16 of 28 (57%) untreated mice harbored the organisms, compared to only 12 of 90 (13%) mice treated with quinolones (P less than 0.005). K. pneumoniae was isolated from the livers of 6 of 28 untreated mice, compared to only 1 of 90 treated mice (P less than 0.001). Only 5 of 20 (25%) untreated mice survived for at least 30 days compared with 17 of 20 (85%) mice treated with ofloxacin, 15 of 20 (75%) mice treated with pefloxacin, and 14 of 20 (70%) treated with ciprofloxacin (P less than 0.05). These data illustrate the efficacy of quinolones for oral therapy of orally acquired K. pneumoniae infection in irradiated hosts.

  9. Clonal dissemination of multilocus sequence type ST15 KPC-2-producing Klebsiella pneumoniae in Bulgaria.

    PubMed

    Markovska, Rumyana; Stoeva, Temenuga; Schneider, Ines; Boyanova, Lyudmila; Popova, Valentina; Dacheva, Daniela; Kaneva, Radka; Bauernfeind, Adolf; Mitev, Vanyo; Mitov, Ivan

    2015-10-01

    A total of 36 consecutive clinical and two fecal-screening carbapenem-resistant Klebsiella pneumoniae isolates from two Bulgarian university hospitals (Varna and Pleven) were investigated. Susceptibility testing, conjugation experiments, and plasmid replicon typing were carried out. Beta-lactamases were characterized by isoelectric focusing, PCR, and sequencing. Clonal relatedness was investigated by RAPD and multilocus sequence typing (MLST). Most of the isolates demonstrated multidrug resistance profile. Amikacin and tigecycline retained good activity with susceptibility rates of 95 and 87%, respectively. The resistance rate to colistin was 63%. Six RAPD- and MLST-types were identified: the dominating MLST-type was ST15 (27 isolates), followed by ST76 (six isolates), and ST1350 (two isolates). ST101, ST258, and ST151 were detected once. All except one of the K. pneumoniae produced KPC-2, mostly in combination with CTX-M-15, while for one isolate (ST101) the enzymes OXA-48 and CTX-M-14 were found. All KPC-2-producing transconjugants revealed the presence of IncFII plasmid. The OXA-48- and CTX-M-14-producing isolate showed the presence of L/M replicon type. The dissemination of KPC-2-producing K.pneumoniae in Bulgaria is mainly due to the sustained spread of successful ST15 clone and to a lesser extent of ST76 clone. This is the first report of OXA-48 producing ST101 K. pneumoniae in Bulgaria.

  10. Klebsiella pneumoniae subsp. pneumoniae–bacteriophage combination from the caecal effluent of a healthy woman

    PubMed Central

    Neve, Horst; Heller, Knut J.; Turton, Jane F.; Mahony, Jennifer; Sanderson, Jeremy D.; Hudspith, Barry; Gibson, Glenn R.; McCartney, Anne L.

    2015-01-01

    A sample of caecal effluent was obtained from a female patient who had undergone a routine colonoscopic examination. Bacteria were isolated anaerobically from the sample, and screened against the remaining filtered caecal effluent in an attempt to isolate bacteriophages (phages). A lytic phage, named KLPN1, was isolated on a strain identified as Klebsiella pneumoniae subsp. pneumoniae (capsular type K2, rmpA+). This Siphoviridae phage presents a rosette-like tail tip and exhibits depolymerase activity, as demonstrated by the formation of plaque-surrounding haloes that increased in size over the course of incubation. When screened against a panel of clinical isolates of K. pneumoniae subsp. pneumoniae, phage KLPN1 was shown to infect and lyse capsular type K2 strains, though it did not exhibit depolymerase activity on such hosts. The genome of KLPN1 was determined to be 49,037 bp (50.53 %GC) in length, encompassing 73 predicted ORFs, of which 23 represented genes associated with structure, host recognition, packaging, DNA replication and cell lysis. On the basis of sequence analyses, phages KLPN1 (GenBank: KR262148) and 1513 (a member of the family Siphoviridae, GenBank: KP658157) were found to be two new members of the genus “Kp36likevirus.” PMID:26246963

  11. High Production of 3-Hydroxypropionic Acid in Klebsiella pneumoniae by Systematic Optimization of Glycerol Metabolism

    PubMed Central

    Li, Ying; Wang, Xi; Ge, Xizhen; Tian, Pingfang

    2016-01-01

    3-Hydroxypropionic acid (3-HP) is an important platform chemical proposed by the United States Department of Energy. 3-HP can be converted to a series of bulk chemicals. Biological production of 3-HP has made great progress in recent years. However, low yield of 3-HP restricts its commercialization. In this study, systematic optimization was conducted towards high-yield production of 3-HP in Klebsiella pneumoniae. We first investigated appropriate promoters for the key enzyme (aldehyde dehydrogenase, ALDH) in 3-HP biosynthesis, and found that IPTG-inducible tac promoter enabled overexpression of an endogenous ALDH (PuuC) in K. pneumoniae. We optimized the metabolic flux and found that blocking the synthesis of lactic acid and acetic acid significantly increased the production of 3-HP. Additionally, fermentation conditions were optimized and scaled-up cultivation were investigated. The highest 3-HP titer was observed at 83.8 g/L with a high conversion ratio of 54% on substrate glycerol. Furthermore, a flux distribution model of glycerol metabolism in K. pneumoniae was proposed based on in silico analysis. To our knowledge, this is the highest 3-HP production in K. pneumoniae. This work has significantly advanced biological production of 3-HP from renewable carbon sources. PMID:27230116

  12. Increased Susceptibility to Klebsiella Pneumonia and Mortality in GSNOR-Deficient Mice

    PubMed Central

    Tang, Chi-Hui; Seeley, Eric J.; Huang, Xiaozhu; Wolters, Paul J.; Liu, Limin

    2013-01-01

    S-nitrosoglutathione reductase (GSNOR) is a key denitrosylase and critically important for protecting immune and other cells from nitrosative stress. Pharmacological inhibition of GSNOR is being actively pursued as a therapeutic approach to increase S-nitrosoglutathione levels for the treatment of asthma and cystic fibrosis. In the present study, we employed GSNOR-deficient (GSNOR−/−) mice to investigate whether inactivation of GSNOR may increase susceptibility to pulmonary infection by Klebsiella pneumoniae, a common cause of nosocomial pneumonia. We found that compared to wild-type mice, bacterial colony forming units 48 hours after intranasal infection with K. pneumoniae were increased over four folds in lung and spleen and strikingly, over a thousand folds in blood of GSNOR−/− mice. Lung injury was comparable between infected wild-type and GSNOR−/− mice, but inflammation and injury was significantly elevated in spleen of GSNOR−/− mice. Whereas all wild-type mice survived 48 hours after infection, 10 of 23 GSNOR−/− mice died. Thus, GSNOR appears to play a crucial role in controlling pulmonary and systemic infection by K. pneumoniae. Our results suggest that patients treated in clinical trials with inhibitors of GSNOR should be carefully monitored for signs of infection. PMID:24239886

  13. Carbapenemase-Producing Klebsiella pneumoniae, a Key Pathogen Set for Global Nosocomial Dominance.

    PubMed

    Pitout, Johann D D; Nordmann, Patrice; Poirel, Laurent

    2015-10-01

    The management of infections due to Klebsiella pneumoniae has been complicated by the emergence of antimicrobial resistance, especially to carbapenems. Resistance to carbapenems in K. pneumoniae involves multiple mechanisms, including the production of carbapenemases (e.g., KPC, NDM, VIM, OXA-48-like), as well as alterations in outer membrane permeability mediated by the loss of porins and the upregulation of efflux systems. The latter two mechanisms are often combined with high levels of other types of β-lactamases (e.g., AmpC). K. pneumoniae sequence type 258 (ST258) emerged during the early to mid-2000s as an important human pathogen and has spread extensively throughout the world. ST258 comprises two distinct lineages, namely, clades I and II, and it seems that ST258 is a hybrid clone that was created by a large recombination event between ST11 and ST442. Incompatibility group F plasmids with blaKPC have contributed significantly to the success of ST258. The optimal treatment of infections due to carbapenemase-producing K. pneumoniae remains unknown. Some newer agents show promise for treating infections due to KPC producers; however, effective options for the treatment of NDM producers remain elusive.

  14. Carbapenemase-Producing Klebsiella pneumoniae, a Key Pathogen Set for Global Nosocomial Dominance

    PubMed Central

    Nordmann, Patrice; Poirel, Laurent

    2015-01-01

    The management of infections due to Klebsiella pneumoniae has been complicated by the emergence of antimicrobial resistance, especially to carbapenems. Resistance to carbapenems in K. pneumoniae involves multiple mechanisms, including the production of carbapenemases (e.g., KPC, NDM, VIM, OXA-48-like), as well as alterations in outer membrane permeability mediated by the loss of porins and the upregulation of efflux systems. The latter two mechanisms are often combined with high levels of other types of β-lactamases (e.g., AmpC). K. pneumoniae sequence type 258 (ST258) emerged during the early to mid-2000s as an important human pathogen and has spread extensively throughout the world. ST258 comprises two distinct lineages, namely, clades I and II, and it seems that ST258 is a hybrid clone that was created by a large recombination event between ST11 and ST442. Incompatibility group F plasmids with blaKPC have contributed significantly to the success of ST258. The optimal treatment of infections due to carbapenemase-producing K. pneumoniae remains unknown. Some newer agents show promise for treating infections due to KPC producers; however, effective options for the treatment of NDM producers remain elusive. PMID:26169401

  15. Biosynthesis of poly(3-hydroxypropionate) from glycerol using engineered Klebsiella pneumoniae strain without vitamin B12.

    PubMed

    Feng, Xinjun; Xian, Mo; Liu, Wei; Xu, Chao; Zhang, Haibo; Zhao, Guang

    2015-01-01

    Poly(3-hydroxypropionate) (P3HP) is a biodegradable and biocompatible thermoplastic. Previous studies demonstrated that engineered Escherichia coli strains can produce P3HP with supplementation of expensive vitamin B12. The present study examined the production of P3HP from glycerol in the recombinant Klebsiella pneumoniae strain, which naturally synthesizes vitamin B12. The genes glycerol dehydratase and its reactivation factor (dhaB123, gdrA, and gdrB from K. pneumoniae), aldehyde dehydrogenase (aldH from E. coli) were cloned and expressed in K. pneumoniae to produce 3-hydroxypropionate (3HP), with 2 genes (dhaT and yqhD) for biosynthesis of 1,3-propanediol were deleted. To obtain P3HP production, propionyl-CoA synthetase (prpE from E. coli) and polyhydroxyalkanoate synthase (phaC from Ralstonia eutropha) were introduced. Under the appropriate aeration condition, the cell yield and P3HP content were 0.24 g/L and 12.7% (wt/wt [cell dry weight]) respectively along with 2.03 g/L 3HP after 48 h cultivation. Although the yield is relatively low, this study shows the feasibility of producing P3HP in K. pneumoniae from glycerol without vitamin B12 for the first time. The results also suggest that the aeration conditions should be optimized carefully for the efficient production of P3HP. PMID:25621933

  16. Genetically similar isolates of Klebsiella pneumoniae serotype K1 causing liver abscesses in three continents.

    PubMed

    Turton, Jane F; Englender, Hilary; Gabriel, Samantha N; Turton, Sarah E; Kaufmann, Mary E; Pitt, Tyrone L

    2007-05-01

    The magA gene was sought in hypermucoviscous isolates of Klebsiella spp., the Klebsiella K serotype reference strains and in isolates of the K1 serotype of Klebsiella pneumoniae from the UK, Hong Kong, Israel, Taiwan and Australia. Only K1 isolates were PCR positive for magA; this gene was found in all such isolates tested. Hypermucoviscosity was not confined to magA positive isolates, nor was it found in all magA positive isolates. Comparison of XbaI PFGE profiles revealed that most (19/23) of the magA positive isolates clustered within 72 % similarity, with a further subcluster of isolates, from three different continents, clustering within >80 %. All of the 16 isolates tested within the main cluster had the same sequence type (ST 23) by multilocus sequence typing, with the exception of one isolate, which had a single nucleotide difference at one of the seven loci. This study indicates that a genotype strongly associated with highly invasive disease in Taiwan, where large numbers of cases have been reported, is geographically very widespread.

  17. Aeromonas punctata derived depolymerase that disrupts the integrity of Klebsiella pneumoniae capsule: optimization of depolymerase production.

    PubMed

    Bansal, Shruti; Soni, Sanjeev Kumar; Harjai, Kusum; Chhibber, Sanjay

    2014-07-01

    Formation of dense, highly hydrated biofilm structures pose a risk for public and environmental health. Extracellular polymeric substances encompassing biofilms offer 1000-fold greater resistance as compared to the planktonic cells. Using enzymes as anti-biofouling agents, will improve penetration of antimicrobials and increase susceptibility of biofilms to components of immune system. The challenge of using enzymes derived from unrelated bacteria for the degradation of capsular matrix of Klebsiella pneumoniae has not been dealt in the past. Thus, statistical optimization was done to enhance depolymerase production by Aeromonas punctata, directed against the exopolysaccharide matrix of Klebsiella pneumoniae B5055, capable of substituting the available phage borne depolymerase enzyme. Optimization via central composite design (CCD) resulted in 16-fold enhancement in depolymerase yield (166.65 µmoles ml(-1)  min(-1) ) over unoptimized medium. Out of the 19 variables, media composition giving maximum expression levels of the enzyme consisted of 1 mg ml(-1) galactose and ammonium chloride, 1.5 mg ml(-1) each of capsular polysaccharide (CPS) and magnesium sulfate. Tryptic peptide analysis of the purified 29 kDa band by Matrix assisted laser desorption ionization-time of flight (MALDI-TOF) showed a high homology with a protein of unknown function from Aeromonas cavaie Ae398. Further improvements in the enzyme can lead to its successful development as prophylactic and/or a therapeutic agent.

  18. Porin Loss Impacts the Host Inflammatory Response to Outer Membrane Vesicles of Klebsiella pneumoniae.

    PubMed

    Turner, Kelli L; Cahill, Bethaney K; Dilello, Sarah K; Gutel, Dedra; Brunson, Debra N; Albertí, Sebastián; Ellis, Terri N

    2016-03-01

    Antibiotic-resistant strains of Klebsiella pneumoniae often exhibit porin loss. In this study, we investigated how porin loss impacted the composition of secreted outer membrane vesicles as well as their ability to trigger proinflammatory cytokine secretion by macrophages. We hypothesize that porin loss associated with antibiotic resistance will directly impact both the composition of outer membrane vesicles and their interactions with phagocytic cells. Using clonally related clinical isolates of extended-spectrum beta-lactamase (ESBL)-positive Klebsiella pneumoniae with different patterns of porin expression, we demonstrated that altered expression of OmpK35 and OmpK36 results in broad alterations to the protein profile of secreted vesicles. Additionally, the level of OmpA incorporation was elevated in strains lacking a single porin. Porin loss significantly impacted macrophage inflammatory responses to purified vesicles. Outer membrane vesicles lacking both OmpK35 and OmpK36 elicited significantly lower levels of proinflammatory cytokine secretion than vesicles from strains expressing one or both porins. These data demonstrate that antibiotic resistance-associated porin loss has a broad and significant effect on both the composition of outer membrane vesicles and their interactions with phagocytic cells, which may impact bacterial survival and inflammatory reactions in the host.

  19. Genomic identification of nitrogen-fixing Klebsiella variicola, K. pneumoniae and K. quasipneumoniae.

    PubMed

    Chen, Mingyue; Li, Yuanyuan; Li, Shuying; Tang, Lie; Zheng, Jingwu; An, Qianli

    2016-01-01

    It was difficult to differentiate Klebsiella pneumoniae, K. quasipneumoniae and K. variicola by biochemical and phenotypic tests. Genomics increase the resolution and credibility of taxonomy for closely-related species. Here, we obtained the complete genome sequence of the K. variicola type strain DSM 15968(T) (=F2R9(T)). The genome of the type strain is a circular chromosome of 5,521,203 bp with 57.56% GC content. From 540 Klebsiella strains whose genomes had been publicly available as at 3 March 2015, we identified 21 strains belonging to K. variicola and 8 strains belonging to K. quasipneumoniae based on the genome average nucleotide identities (ANI). All the K. variicola strains, one K. pneumoniae strain and five K. quasipneumoniae strains contained nitrogen-fixing genes. A phylogenomic analysis showed clear species demarcations for these nitrogen-fixing bacteria. In accordance with the key biochemical characteristics of K. variicola, the idnO gene encoding 5-keto-D-gluconate 5-reductase for utilization of 5-keto-D-gluconate and the sorCDFBAME operon for catabolism of L-sorbose were present whereas the rbtRDKT operon for catabolism of adonitol was absent in the genomes of K. variicola strains. Therefore, the genomic analyses supported the ANI-based species delineation; the genome sequence of the K. variicola type strain provides the reference genome for genomic identification of K. variicola, which is a nitrogen-fixing species.

  20. Porin Loss Impacts the Host Inflammatory Response to Outer Membrane Vesicles of Klebsiella pneumoniae

    PubMed Central

    Turner, Kelli L.; Cahill, Bethaney K.; Dilello, Sarah K.; Gutel, Dedra; Brunson, Debra N.; Albertí, Sebastián

    2015-01-01

    Antibiotic-resistant strains of Klebsiella pneumoniae often exhibit porin loss. In this study, we investigated how porin loss impacted the composition of secreted outer membrane vesicles as well as their ability to trigger proinflammatory cytokine secretion by macrophages. We hypothesize that porin loss associated with antibiotic resistance will directly impact both the composition of outer membrane vesicles and their interactions with phagocytic cells. Using clonally related clinical isolates of extended-spectrum beta-lactamase (ESBL)-positive Klebsiella pneumoniae with different patterns of porin expression, we demonstrated that altered expression of OmpK35 and OmpK36 results in broad alterations to the protein profile of secreted vesicles. Additionally, the level of OmpA incorporation was elevated in strains lacking a single porin. Porin loss significantly impacted macrophage inflammatory responses to purified vesicles. Outer membrane vesicles lacking both OmpK35 and OmpK36 elicited significantly lower levels of proinflammatory cytokine secretion than vesicles from strains expressing one or both porins. These data demonstrate that antibiotic resistance-associated porin loss has a broad and significant effect on both the composition of outer membrane vesicles and their interactions with phagocytic cells, which may impact bacterial survival and inflammatory reactions in the host. PMID:26666932

  1. Pulmonary surfactant as vehicle for intratracheally instilled tobramycin in mice infected with Klebsiella pneumoniae.

    PubMed Central

    van't Veen, A.; Mouton, J. W.; Gommers, D.; Lachmann, B.

    1996-01-01

    1. The use of pulmonary surfactant has been proposed as a vehicle for antibiotic delivery to the alveolar compartment of the lung. This study investigated survival rates of mice with a respiratory Klebsiella pneumoniae infection treated intratracheally with tobramycin using a natural exogenous surfactant preparation as vehicle. 2. At day 1 after infection, animals were injected intratracheally with 20 microliters of the following solutions: (1) a mixture of surfactant (500 micrograms) and tobramycin (250 micrograms); (2) tobramycin (250 micrograms) alone; (3) surfactant (500 micrograms) alone; and (4) NaHCO3 buffer (control, sham-treatment). A fifth group received no treatment (control). Deaths were registered every 12 h for 8 consecutive days. 3. The results show an increased survival in the group receiving the surfactant-tobramycin mixture compared to the group receiving tobramycin alone (P < 0.05), the group receiving surfactant alone (P < 0.01) and the control groups (P < 0.01). It is concluded that intratracheal instillation of surfactant-tobramycin is superior to tobramycin alone in protecting animals from death due to a respiratory Klebsiella pneumoniae infection. PMID:8937717

  2. Multi-functional analysis of Klebsiella pneumoniae fimbrial types in adherence and biofilm formation

    PubMed Central

    Alcántar-Curiel, María D.; Blackburn, Dana; Saldaña, Zeus; Gayosso-Vázquez, Catalina; Iovine, Nicole; De la Cruz, Miguel A.; Girón, Jorge A.

    2013-01-01

    Klebsiella pneumoniae is an opportunistic pathogen frequently associated with nosocomially acquired infections. Host cell adherence and biofilm formation of K. pneumoniae isolates is mediated by type 1 (T1P) and type 3 (MR/K) pili whose major fimbrial subunits are encoded by the fimA and mrkA genes, respectively. The E. coli common pilus (ECP) is an adhesive structure produced by all E. coli pathogroups and a homolog of the ecpABCDE operon is present in the K. pneumoniae genome. In this study, we aimed to determine the prevalence of these three fimbrial genes among a collection of 69 clinical and environmental K. pneumoniae strains and to establish a correlation with fimbrial production during cell adherence and biofilm formation. The PCR-based survey demonstrated that 96% of the K. pneumoniae strains contained ecpA and 94% of these strains produced ECP during adhesion to cultured epithelial cells. Eighty percent of the strains forming biofilms on glass produced ECP, suggesting that ECP is required, at least in vitro, for expression of these phenotypes. The fim operon was found in 100% of the strains and T1P was detected in 96% of these strains. While all the strains examined contained mrkA, only 57% of them produced MR/K fimbriae, alone or together with ECP. In summary, this study highlights the ability of K. pneumoniae strains to produce ECP, which may represent a new important adhesive structure of this organism. Further, it defines the multi-fimbrial nature of the interaction of this nosocomial pathogen with host epithelial cells and inert surfaces. PMID:23302788

  3. Multi-functional analysis of Klebsiella pneumoniae fimbrial types in adherence and biofilm formation.

    PubMed

    Alcántar-Curiel, María D; Blackburn, Dana; Saldaña, Zeus; Gayosso-Vázquez, Catalina; Iovine, Nicole M; De la Cruz, Miguel A; Girón, Jorge A

    2013-02-15

    Klebsiella pneumoniae is an opportunistic pathogen frequently associated with nosocomially acquired infections. Host cell adherence and biofilm formation of K. pneumoniae isolates is mediated by type 1 (T1P) and type 3 (MR/K) pili whose major fimbrial subunits are encoded by the fimA and mrkA genes, respectively. The E. coli common pilus (ECP) is an adhesive structure produced by all E. coli pathogroups and a homolog of the ecpABCDE operon is present in the K. pneumoniae genome. In this study, we aimed to determine the prevalence of these three fimbrial genes among a collection of 69 clinical and environmental K. pneumoniae strains and to establish a correlation with fimbrial production during cell adherence and biofilm formation. The PCR-based survey demonstrated that 96% of the K. pneumoniae strains contained ecpA and 94% of these strains produced ECP during adhesion to cultured epithelial cells. Eighty percent of the strains forming biofilms on glass produced ECP, suggesting that ECP is required, at least in vitro, for expression of these phenotypes. The fim operon was found in 100% of the strains and T1P was detected in 96% of these strains. While all the strains examined contained mrkA, only 57% of them produced MR/K fimbriae, alone or together with ECP. In summary, this study highlights the ability of K. pneumoniae strains to produce ECP, which may represent a new important adhesive structure of this organism. Further, it defines the multi-fimbrial nature of the interaction of this nosocomial pathogen with host epithelial cells and inert surfaces. PMID:23302788

  4. Sublethal concentrations of carbapenems alter cell morphology and genomic expression of Klebsiella pneumoniae biofilms.

    PubMed

    Van Laar, Tricia A; Chen, Tsute; You, Tao; Leung, Kai P

    2015-03-01

    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

  5. Evaluation of Biofilm Formation Among Klebsiella pneumoniae Isolates and Molecular Characterization by ERIC-PCR

    PubMed Central

    Seifi, Kimia; Kazemian, Hossein; Heidari, Hamid; Rezagholizadeh, Fereshteh; Saee, Yasaman; Shirvani, Fariba; Houri, Hamidreza

    2016-01-01

    Background: Klebsiella pneumoniae is among the most frequently recovered etiologic agents from nosocomial infections. This opportunistic pathogen can generate a thick layer of biofilm as one of its important virulence factors, enabling the bacteria to attach to living or abiotic surfaces, which contributes to drug resistance. Objectives: The resistance of biofilm-mediated infections to effective chemotherapy has adverse effects on patient outcomes and survival. Therefore, the aim of the present study was to evaluate the biofilm-formation capacity of clinical K. pneumoniae isolates and to perform a molecular characterization using enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) to determine the dominant biofilm-producing genotype. Patients and Methods: In the present study, 94 K. pneumoniae isolates were obtained from two hospitals in Tehran, Iran. Biofilm formation was assayed by a modified procedure, then ERIC-PCR was carried out. Results: The distributions of the clinical specimens used in this study were 61.7% from urine, 18.1% from wounds, 11.7% from sputum, and 8.5% from blood. Among these isolates, 33% formed fully established biofilms, 52.1% were categorized as moderately biofilm-producing, 8.5% formed weak biofilms, and 6.4% were non-biofilm-producers. Genotyping of K. pneumoniae revealed 31 different ERIC types. Biofilm-formation ability in a special ERIC type was not observed. Conclusions: Our results indicated that an enormous proportion of K. pneumoniae isolated from sputum and surgical-wound swabs produced fully established biofilms. It is reasonable to assume the existence of a relationship between the site of infection and the formation of biofilm. A high level of genetic diversity among the K. pneumoniae strains was observed. PMID:27099694

  6. Sublethal Concentrations of Carbapenems Alter Cell Morphology and Genomic Expression of Klebsiella pneumoniae Biofilms

    PubMed Central

    Van Laar, Tricia A.; Chen, Tsute; You, Tao

    2015-01-01

    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

  7. Sublethal concentrations of carbapenems alter cell morphology and genomic expression of Klebsiella pneumoniae biofilms.

    PubMed

    Van Laar, Tricia A; Chen, Tsute; You, Tao; Leung, Kai P

    2015-03-01

    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.

  8. Genome-Wide Identification of Klebsiella pneumoniae Fitness Genes during Lung Infection

    PubMed Central

    Breen, Paul; Deornellas, Valerie; Mu, Qiao; Zhao, Lili; Wu, Weisheng; Cavalcoli, James D.; Mobley, Harry L. T.

    2015-01-01

    ABSTRACT Klebsiella pneumoniae is an urgent public health threat because of resistance to carbapenems, antibiotics of last resort against Gram-negative bacterial infections. Despite the fact that K. pneumoniae is a leading cause of pneumonia in hospitalized patients, the bacterial factors required to cause disease are poorly understood. Insertion site sequencing combines transposon mutagenesis with high-throughput sequencing to simultaneously screen thousands of insertion mutants for fitness defects during infection. Using the recently sequenced K. pneumoniae strain KPPR1 in a well-established mouse model of pneumonia, insertion site sequencing was performed on a pool of >25,000 transposon mutants. The relative fitness requirement of each gene was ranked based on the ratio of lung to inoculum read counts and concordance between insertions in the same gene. This analysis revealed over 300 mutants with at least a 2-fold fitness defect and 69 with defects ranging from 10- to >2,000-fold. Construction of 6 isogenic mutants for use in competitive infections with the wild type confirmed their requirement for lung fitness. Critical fitness genes included those for the synthesis of branched-chain and aromatic amino acids that are essential in mice and humans, the transcriptional elongation factor RfaH, and the copper efflux pump CopA. The majority of fitness genes were conserved among reference strains representative of diverse pathotypes. These results indicate that regulation of outer membrane components and synthesis of amino acids that are essential to its host are critical for K. pneumoniae fitness in the lung. PMID:26060277

  9. Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae at a single institution: insights into endemicity from whole-genome sequencing.

    PubMed

    Mathers, Amy J; Stoesser, Nicole; Sheppard, Anna E; Pankhurst, Louise; Giess, Adam; Yeh, Anthony J; Didelot, Xavier; Turner, Stephen D; Sebra, Robert; Kasarskis, Andrew; Peto, Tim; Crook, Derrick; Sifri, Costi D

    2015-03-01

    The global emergence of Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-Kp) multilocus sequence type ST258 is widely recognized. Less is known about the molecular and epidemiological details of non-ST258 K. pneumoniae in the setting of an outbreak mediated by an endemic plasmid. We describe the interplay of blaKPC plasmids and K. pneumoniae strains and their relationship to the location of acquisition in a U.S. health care institution. Whole-genome sequencing (WGS) analysis was applied to KPC-Kp clinical isolates collected from a single institution over 5 years following the introduction of blaKPC in August 2007, as well as two plasmid transformants. KPC-Kp from 37 patients yielded 16 distinct sequence types (STs). Two novel conjugative blaKPC plasmids (pKPC_UVA01 and pKPC_UVA02), carried by the hospital index case, accounted for the presence of blaKPC in 21/37 (57%) subsequent cases. Thirteen (35%) isolates represented an emergent lineage, ST941, which contained pKPC_UVA01 in 5/13 (38%) and pKPC_UVA02 in 6/13 (46%) cases. Seven (19%) isolates were the epidemic KPC-Kp strain, ST258, mostly imported from elsewhere and not carrying pKPC_UVA01 or pKPC_UVA02. Using WGS-based analysis of clinical isolates and plasmid transformants, we demonstrate the unexpected dispersal of blaKPC to many non-ST258 lineages in a hospital through spread of at least two novel blaKPC plasmids. In contrast, ST258 KPC-Kp was imported into the institution on numerous occasions, with other blaKPC plasmid vectors and without sustained transmission. Instead, a newly recognized KPC-Kp strain, ST941, became associated with both novel blaKPC plasmids and spread locally, making it a future candidate for clinical persistence and dissemination. PMID:25561339

  10. Polymyxin Resistance Caused by mgrB Inactivation Is Not Associated with Significant Biological Cost in Klebsiella pneumoniae

    PubMed Central

    Cannatelli, Antonio; Santos-Lopez, Alfonso; Giani, Tommaso; Gonzalez-Zorn, Bruno

    2015-01-01

    The inactivation of the mgrB gene, which encodes a negative-feedback regulator of the PhoPQ signaling system, was recently shown to be a common mutational mechanism responsible for acquired polymyxin resistance among carbapenemase-producing Klebsiella pneumoniae strains from clinical sources. In this work, we show that mgrB mutants can easily be selected in vitro from different K. pneumoniae lineages, and mgrB inactivation is not associated with a significant biological cost. PMID:25691629

  11. Emergence of New Delhi Metallo-Beta-Lactamase (NDM-1) and Klebsiella pneumoniae Carbapenemase (KPC-2) in South Africa

    PubMed Central

    Coetzee, Jennifer; Clay, Cornelis G.; Sithole, Sindi; Richards, Guy A.; Poirel, Laurent; Nordmann, Patrice

    2012-01-01

    This report documents emergence of New Delhi metallo-beta-lactamase (NDM-1) and Klebsiella pneumoniae carbapenemase (KPC-2) in K. pneumoniae and Enterobacter cloacae in South Africa. NDM-1 producers have not been described in South Africa, and this is the first instance that KPC producers have been identified in Africa. The two patients infected with these carbapenemase-producing bacteria demised. PMID:22116157

  12. Genomic Epidemiology of an Endoscope-Associated Outbreak of Klebsiella pneumoniae Carbapenemase (KPC)-Producing K. pneumoniae

    PubMed Central

    Marsh, Jane W.; Krauland, Mary G.; Nelson, Jemma S.; Schlackman, Jessica L.; Brooks, Anthony M.; Pasculle, A. William; Shutt, Kathleen A.; Doi, Yohei; Querry, Ashley M.; Muto, Carlene A.; Harrison, Lee H.

    2015-01-01

    Increased incidence of infections due to Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae (KPC-Kp) was noted among patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) at a single hospital. An epidemiologic investigation identified KPC-Kp and non-KPC-producing, extended-spectrum β-lactamase (ESBL)-producing Kp in cultures from 2 endoscopes. Genotyping was performed on patient and endoscope isolates to characterize the microbial genomics of the outbreak. Genetic similarity of 51 Kp isolates from 37 patients and 3 endoscopes was assessed by pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). Five patient and 2 endoscope isolates underwent whole genome sequencing (WGS). Two KPC-encoding plasmids were characterized by single molecule, real-time sequencing. Plasmid diversity was assessed by endonuclease digestion. Genomic and epidemiologic data were used in conjunction to investigate the outbreak source. Two clusters of Kp patient isolates were genetically related to endoscope isolates by PFGE. A subset of patient isolates were collected post-ERCP, suggesting ERCP endoscopes as a possible source. A phylogeny of 7 Kp genomes from patient and endoscope isolates supported ERCP as a potential source of transmission. Differences in gene content defined 5 ST258 subclades and identified 2 of the subclades as outbreak-associated. A novel KPC-encoding plasmid, pKp28 helped define and track one endoscope-associated ST258 subclade. WGS demonstrated high genetic relatedness of patient and ERCP endoscope isolates suggesting ERCP-associated transmission of ST258 KPC-Kp. Gene and plasmid content discriminated the outbreak from endemic ST258 populations and assisted with the molecular epidemiologic investigation of an extended KPC-Kp outbreak. PMID:26637170

  13. Genomic Epidemiology of an Endoscope-Associated Outbreak of Klebsiella pneumoniae Carbapenemase (KPC)-Producing K. pneumoniae.

    PubMed

    Marsh, Jane W; Krauland, Mary G; Nelson, Jemma S; Schlackman, Jessica L; Brooks, Anthony M; Pasculle, A William; Shutt, Kathleen A; Doi, Yohei; Querry, Ashley M; Muto, Carlene A; Harrison, Lee H

    2015-01-01

    Increased incidence of infections due to Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae (KPC-Kp) was noted among patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) at a single hospital. An epidemiologic investigation identified KPC-Kp and non-KPC-producing, extended-spectrum β-lactamase (ESBL)-producing Kp in cultures from 2 endoscopes. Genotyping was performed on patient and endoscope isolates to characterize the microbial genomics of the outbreak. Genetic similarity of 51 Kp isolates from 37 patients and 3 endoscopes was assessed by pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). Five patient and 2 endoscope isolates underwent whole genome sequencing (WGS). Two KPC-encoding plasmids were characterized by single molecule, real-time sequencing. Plasmid diversity was assessed by endonuclease digestion. Genomic and epidemiologic data were used in conjunction to investigate the outbreak source. Two clusters of Kp patient isolates were genetically related to endoscope isolates by PFGE. A subset of patient isolates were collected post-ERCP, suggesting ERCP endoscopes as a possible source. A phylogeny of 7 Kp genomes from patient and endoscope isolates supported ERCP as a potential source of transmission. Differences in gene content defined 5 ST258 subclades and identified 2 of the subclades as outbreak-associated. A novel KPC-encoding plasmid, pKp28 helped define and track one endoscope-associated ST258 subclade. WGS demonstrated high genetic relatedness of patient and ERCP endoscope isolates suggesting ERCP-associated transmission of ST258 KPC-Kp. Gene and plasmid content discriminated the outbreak from endemic ST258 populations and assisted with the molecular epidemiologic investigation of an extended KPC-Kp outbreak. PMID:26637170

  14. In-vivo study of the nuclear quadrupole interaction of99Mo (β- 99)Tc in nitrogenase of Klebsiella pneumoniaein nitrogenase of Klebsiella pneumoniae

    NASA Astrophysics Data System (ADS)

    Mottner, P.; Lerf, A.; Ni, X.; Butz, T.; Erfkamp, J.; Müller, A.

    1990-08-01

    We report on the first TDPAC-measurements of the nuclear quadrupole interaction (NQI) of (NQI) of99Mo(β-)99Tc in the nitrogenase of the bacteria Klebsiella pneumoniae. Because nitrogenase is the only Mo-containing enzyme in Klebsiella pneumoniae under the chosen conditions, no further isolation of this enzyme was necessary. The majority of the incorporated99Mo is subjected to a well defined NQI with ω=365(7) Mrad/s, η=1 and a reorientational correlation time of τcoττ≈10nsec and is attributed to the active site of the FeMo cofactor. During sample preparation we noted a pronounced affinity of the bacteria to99mTc.

  15. Risk Factors and Outcomes of Carbapenem-Resistant Klebsiella pneumoniae Infections in Liver Transplant Recipients

    PubMed Central

    Pereira, Marcus R.; Scully, Brendan F.; Pouch, Stephanie M.; Uhlemann, Anne-Catrin; Goudie, Stella; Emond, Jean E.; Verna, Elizabeth C.

    2016-01-01

    Carbapenem-resistant Klebsiella pneumoniae (CRKP) infection is increasing in incidence and is associated with increased mortality in liver transplantation (LT) recipients. We performed a retrospective cohort study of all patients transplanted between January 2010 and January 2013 to identify the incidence and risk factors for post-LT CRKP infection and evaluate the impact of this infection on outcomes in a CRKP-endemic area. We studied 304 recipients, of whom 20 (6.6%) developed CRKP and 36 (11.8%) carbapenem-susceptible Klebsiella pneumoniae (CSKP) infections in the year following LT. Among the 20 recipients with post-LT CRKP infection, 8 (40%) were infected in ≥ 2 sites; 13 (65%) had surgical site–intra-abdominal infections; 12 (60%) had pneumonia; and 3 (15%) had a urinary tract infection. There were 6 patients with a CRKP infection before LT, 5 of whom developed a CRKP infection after LT. Significant risk factors for post-LT CRKP infection in multivariate analysis included laboratory Model for End-Stage Liver Disease at LT (odds ratio [OR], 1.07; P = 0.001), hepatocellular carcinoma (OR, 3.19; P = 0.02), Roux-en-Y biliary choledochojejunostomy (OR, 3.15; P = 0.04), and bile leak (OR, 5.89; P = 0.001). One-year estimated patient survival was 55% (95% confidence interval, 31%–73%), 72% (55%–84%), and 93% (89%–96%), for patients with CRKP, CSKP, and no Klebsiella pneumoniae infection, respectively. In multivariate analysis, CRKP (hazard ratio [HR], 6.92; P < 0.001) and CSKP infections (CSKP, HR, 3.84; P < 0.001), as well as bile leak (HR, 2.10; P = 0.03) were the strongest predictors of post-LT mortality. In an endemic area, post-LT CRKP infection is common, occurring in 6.6% of recipients, and is strongly associated with post-LT mortality. Improved strategies for screening and prevention of CRKP infection are urgently needed. PMID:26136397

  16. Risk factors and outcomes of carbapenem-resistant Klebsiella pneumoniae infections in liver transplant recipients.

    PubMed

    Pereira, Marcus R; Scully, Brendan F; Pouch, Stephanie M; Uhlemann, Anne-Catrin; Goudie, Stella; Emond, Jean E; Verna, Elizabeth C

    2015-12-01

    Carbapenem-resistant Klebsiella pneumoniae (CRKP) infection is increasing in incidence and is associated with increased mortality in liver transplantation (LT) recipients. We performed a retrospective cohort study of all patients transplanted between January 2010 and January 2013 to identify the incidence and risk factors for post-LT CRKP infection and evaluate the impact of this infection on outcomes in a CRKP-endemic area. We studied 304 recipients, of whom 20 (6.6%) developed CRKP and 36 (11.8%) carbapenem-susceptible Klebsiella pneumoniae (CSKP) infections in the year following LT. Among the 20 recipients with post-LT CRKP infection, 8 (40%) were infected in ≥ 2 sites; 13 (65%) had surgical site-intra-abdominal infections; 12 (60%) had pneumonia; and 3 (15%) had a urinary tract infection. There were 6 patients with a CRKP infection before LT, 5 of whom developed a CRKP infection after LT. Significant risk factors for post-LT CRKP infection in multivariate analysis included laboratory Model for End-Stage Liver Disease at LT (odds ratio [OR], 1.07; P = 0.001), hepatocellular carcinoma (OR, 3.19; P = 0.02), Roux-en-Y biliary choledochojejunostomy (OR, 3.15; P = 0.04), and bile leak (OR, 5.89; P = 0.001). One-year estimated patient survival was 55% (95% confidence interval, 31%-73%), 72% (55%-84%), and 93% (89%-96%), for patients with CRKP, CSKP, and no Klebsiella pneumoniae infection, respectively. In multivariate analysis, CRKP (hazard ratio [HR], 6.92; P < 0.001) and CSKP infections (CSKP, HR, 3.84; P < 0.001), as well as bile leak (HR, 2.10; P = 0.03) were the strongest predictors of post-LT mortality. In an endemic area, post-LT CRKP infection is common, occurring in 6.6% of recipients, and is strongly associated with post-LT mortality. Improved strategies for screening and prevention of CRKP infection are urgently needed.

  17. Characterization of BKC-1 class A carbapenemase from Klebsiella pneumoniae clinical isolates in Brazil.

    PubMed

    Nicoletti, Adriana Giannini; Marcondes, Marcelo F M; Martins, Willames M B S; Almeida, Luiz G P; Nicolás, Marisa F; Vasconcelos, Ana T R; Oliveira, Vitor; Gales, Ana Cristina

    2015-09-01

    Three Klebsiella pneumoniae clinical isolates demonstrating carbapenem resistance were recovered from different patients hospitalized at two medical centers in São Paulo, Brazil. Resistance to all β-lactams, quinolones, and some aminoglycosides was observed for these isolates that were susceptible to polymyxin B. Carbapenem hydrolysis, which was inhibited by clavulanic acid, was observed for all K. pneumoniae isolates that belonged to the same pulsed-field gel electrophoresis (PFGE) type and a novel sequence type (ST), ST1781 (clonal complex 442 [CC442]). A 10-kb nonconjugative incompatibility group Q (IncQ) plasmid, denominated p60136, was transferred to Escherichia coli strain TOP10 cells by electroporation. The full sequencing of p60136 showed that it was composed of a mobilization system, ISKpn23, the phosphotransferase aph3A-VI, and a 941-bp open reading frame (ORF) that codified a 313-amino acid protein. This ORF was named bla BKC-1. Brazilian Klebsiella carbapenemase-1 (BKC-1) showed a pI of 6.0 and possessed the highest identity (63%) with a β-lactamase of Sinorhizobium meliloti, an environmental bacterium. Hydrolysis studies demonstrated that purified BKC-1 not only hydrolyzed carbapenems but also penicillins, cephalosporins, and monobactams. However, the carbapenems were less efficiently hydrolyzed due to their very low kcat values (0.0016 to 0.031 s(-1)). In fact, oxacillin was the best substrate for BKC-1 (kcat /Km , 53,522.6 mM(-1) s(-1)). Here, we report a new class A carbapenemase, confirming the diversity and rapid evolution of β-lactamases in K. pneumoniae clinical isolates. PMID:26055384

  18. Interaction of non-human primate complement and antibodies with hypermucoviscous Klebsiella pneumoniae.

    PubMed

    Soto, Esteban; Marchi, Sylvia; Beierschmitt, Amy; Kearney, Michael; Francis, Stewart; VanNess, Kimberly; Vandenplas, Michel; Thrall, MaryAnna; Palmour, Roberta

    2016-01-01

    Emergent hypermucoviscosity (HMV) phenotypes of Klebsiella pneumoniae have been associated with increased invasiveness and pathogenicity in primates. In this study, we investigated the interaction of African green monkeys (AGM) (Chlorocebus aethiops sabaeus) complement and antibody with HMV and non-HMV isolates as in vitro models of primate infection. Significantly greater survival of HMV isolates was evident after incubation in normal serum or whole blood (p < 0.05) of AGM donors when compared to non-HMV strains. Greater survival of HMV strains (p < 0.05) was found after incubation in whole blood and serum from seropositive donors when compared to seronegative donor samples. Additionally, significantly greater amounts of K. pneumoniae were phagocytozed by AGM leukocytes when complement was active (p < 0.05), but no difference in uptake was observed when serum from seropositive or seronegative animals was used in challenged cells utilizing flow cytometry. Results demonstrate that interaction of cellular and humoral immune elements play a role in the in vitro killing of K. pneumoniae, particularly HMV isolates. Neither AGM serum, nor washed whole blood effectively killed HMV isolates; however, assays using heparinized whole blood of seronegative donors significantly reduced viability of HMV and non-HMV strains. The lack of bacterial killing observed in seropositive donors treatments could be at least partially associated with low IgG2 present in these animals. A better understanding of the pathogenesis of klebsiellosis in primates and host immune response is necessary to identify surface molecules that can induce both opsonizing and bactericidal antibody facilitating killing of Klebsiella, and the development of vaccines in human and animals. PMID:26951091

  19. Characterization of BKC-1 Class A Carbapenemase from Klebsiella pneumoniae Clinical Isolates in Brazil

    PubMed Central

    Marcondes, Marcelo F. M.; Martins, Willames M. B. S.; Almeida, Luiz G. P.; Nicolás, Marisa F.; Vasconcelos, Ana T. R.; Oliveira, Vitor; Gales, Ana Cristina

    2015-01-01

    Three Klebsiella pneumoniae clinical isolates demonstrating carbapenem resistance were recovered from different patients hospitalized at two medical centers in São Paulo, Brazil. Resistance to all β-lactams, quinolones, and some aminoglycosides was observed for these isolates that were susceptible to polymyxin B. Carbapenem hydrolysis, which was inhibited by clavulanic acid, was observed for all K. pneumoniae isolates that belonged to the same pulsed-field gel electrophoresis (PFGE) type and a novel sequence type (ST), ST1781 (clonal complex 442 [CC442]). A 10-kb nonconjugative incompatibility group Q (IncQ) plasmid, denominated p60136, was transferred to Escherichia coli strain TOP10 cells by electroporation. The full sequencing of p60136 showed that it was composed of a mobilization system, ISKpn23, the phosphotransferase aph3A-VI, and a 941-bp open reading frame (ORF) that codified a 313-amino acid protein. This ORF was named blaBKC-1. Brazilian Klebsiella carbapenemase-1 (BKC-1) showed a pI of 6.0 and possessed the highest identity (63%) with a β-lactamase of Sinorhizobium meliloti, an environmental bacterium. Hydrolysis studies demonstrated that purified BKC-1 not only hydrolyzed carbapenems but also penicillins, cephalosporins, and monobactams. However, the carbapenems were less efficiently hydrolyzed due to their very low kcat values (0.0016 to 0.031 s−1). In fact, oxacillin was the best substrate for BKC-1 (kcat/Km, 53,522.6 mM−1 s−1). Here, we report a new class A carbapenemase, confirming the diversity and rapid evolution of β-lactamases in K. pneumoniae clinical isolates. PMID:26055384

  20. Anti-biofilm activity: a function of Klebsiella pneumoniae capsular polysaccharide.

    PubMed

    Goncalves, Marina Dos Santos; Delattre, Cédric; Balestrino, Damien; Charbonnel, Nicolas; Elboutachfaiti, Redouan; Wadouachi, Anne; Badel, Stéphanie; Bernardi, Thierry; Michaud, Philippe; Forestier, Christiane

    2014-01-01

    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. PMID:24932475

  1. Interaction of non-human primate complement and antibodies with hypermucoviscous Klebsiella pneumoniae.

    PubMed

    Soto, Esteban; Marchi, Sylvia; Beierschmitt, Amy; Kearney, Michael; Francis, Stewart; VanNess, Kimberly; Vandenplas, Michel; Thrall, MaryAnna; Palmour, Roberta

    2016-03-08

    Emergent hypermucoviscosity (HMV) phenotypes of Klebsiella pneumoniae have been associated with increased invasiveness and pathogenicity in primates. In this study, we investigated the interaction of African green monkeys (AGM) (Chlorocebus aethiops sabaeus) complement and antibody with HMV and non-HMV isolates as in vitro models of primate infection. Significantly greater survival of HMV isolates was evident after incubation in normal serum or whole blood (p < 0.05) of AGM donors when compared to non-HMV strains. Greater survival of HMV strains (p < 0.05) was found after incubation in whole blood and serum from seropositive donors when compared to seronegative donor samples. Additionally, significantly greater amounts of K. pneumoniae were phagocytozed by AGM leukocytes when complement was active (p < 0.05), but no difference in uptake was observed when serum from seropositive or seronegative animals was used in challenged cells utilizing flow cytometry. Results demonstrate that interaction of cellular and humoral immune elements play a role in the in vitro killing of K. pneumoniae, particularly HMV isolates. Neither AGM serum, nor washed whole blood effectively killed HMV isolates; however, assays using heparinized whole blood of seronegative donors significantly reduced viability of HMV and non-HMV strains. The lack of bacterial killing observed in seropositive donors treatments could be at least partially associated with low IgG2 present in these animals. A better understanding of the pathogenesis of klebsiellosis in primates and host immune response is necessary to identify surface molecules that can induce both opsonizing and bactericidal antibody facilitating killing of Klebsiella, and the development of vaccines in human and animals.

  2. Anti-Biofilm Activity: A Function of Klebsiella pneumoniae Capsular Polysaccharide

    PubMed Central

    Dos Santos Goncalves, Marina; Delattre, Cédric; Balestrino, Damien; Charbonnel, Nicolas; Elboutachfaiti, Redouan; Wadouachi, Anne; Badel, Stéphanie; Bernardi, Thierry; Michaud, Philippe; Forestier, Christiane

    2014-01-01

    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. PMID:24932475

  3. Hypervirulent Klebsiella pneumoniae induced ventilator-associated pneumonia in mechanically ventilated patients in China.

    PubMed

    Yan, Q; Zhou, M; Zou, M; Liu, W-e

    2016-03-01

    The purpose of this study was to investigate the clinical characteristics of hypervirulent K. pneumoniae (hvKP) induced ventilator-associated pneumonia (VAP) and the microbiological characteristics and epidemiology of the hvKP strains. A retrospective study of 49 mechanically ventilated patients with K. pneumoniae induced VAP was conducted at a university hospital in China from January 2014 to December 2014. Clinical characteristics and K. pneumoniae antimicrobial susceptibility and biofilm formation were analyzed. Genes of capsular serotypes K1, K2, K5, K20, K54 and K57 and virulence factors plasmid rmpA(p-rmpA), iroB, iucA, mrkD, entB, iutA, ybtS, kfu and allS were also evaluated. Multilocus sequence typing (MLST) and random amplified polymorphic DNA (RAPD) analyses were used to study the clonal relationship of the K. pneumoniae strains. Strains possessed p-rmpA and iroB and iucA were defined as hvKP. Of 49 patients, 14 patients (28.6 %) were infected by hvKP. Antimicrobial resistant rate was significantly higher in cKP than that in hvKP. One ST29 K54 extended-spectrum-beta-lactamase (ESBL) producing hvKP strain was detected. The prevalence of K1 and K2 in hvKP was 42.9 % and 21.4 %, respectively. The incidences of K1, K2, K20, p-rmpA, iroB, iucA, iutA, Kfu and alls were significantly higher in hvKP than those in cKP. ST23 was dominant among hvKP strains, and all the ST23 strains had identical RAPD pattern. hvKP has become a common pathogen of VAP in mechanically ventilated patients in China. Clinicians should increase awareness of hvKP induced VAP and enhance epidemiologic surveillance.

  4. Coproduction of KPC-2 and QnrB19 in Klebsiella pneumoniae ST340 isolate in Brazil.

    PubMed

    Martins, Willames M B S; Almeida, Anna C S; Nicoletti, Adriana G; Cayô, Rodrigo; Gales, Ana C; Alves, Luiz C; Brayner, Fábio B; Vilela, Marinalda A; Morais, Márcia M C

    2015-12-01

    Few reports described the presence of bla(KPC) and qnr genes in the same isolate. This study reports the combination of bla(KPC-2) and qnrB19 genes in Klebsiella pneumoniae ST340 isolate in Brazil. These findings draw attention to this combination in ST340 isolate, which is part of the CC258, disseminated in Latin America. PMID:26458280

  5. Genetic diversity of genes encoding OKP and LEN beta-lactamases produced by clinical Klebsiella pneumoniae strains in Portugal.

    PubMed

    Mendonça, Nuno; Ferreira, Eugénia; Caniça, Manuela

    2009-03-01

    Of the 308 clinical Klebsiella pneumoniae strains collected in 21 Portuguese health institutions, 11 encoded for LEN and 9 for OKP enzymes; of these, 15 were new enzymes. Ninety-one percent of LEN and all OKP producer strains were resistant to amoxicillin. We demonstrate that these beta-lactamase were highly diverse.

  6. Complete Genome Sequence of a Klebsiella pneumoniae Strain Carrying blaNDM-1 on a Multidrug Resistance Plasmid

    PubMed Central

    Lau, Anna F.; Palmore, Tara N.; Frank, Karen M.; Segre, Julia A.

    2016-01-01

    Here, we report the genome sequence of a blaNDM-1-positive Klebsiella pneumoniae AATZP isolate cultured from a perirectal surveillance swab collected upon admission of a patient to the NIH Clinical Center in 2014. Genome sequencing of this isolate revealed three plasmids, including one carrying the blaNDM-1 gene encoding resistance to carbapenems. PMID:27417839

  7. Clostridium difficile ribotype 033 colitis in a patient following broad-spectrum antibiotic treatment for KPCproducing Klebsiella pneumoniae infection, Italy.

    PubMed

    Grandesso, Stefano; Arena, Fabio; Eseme, Franklin Esoka; Panese, Sandro; Henrici De Angelis, Lucia; Spigaglia, Patrizia; Barbanti, Fabrizio; Rossolini, Gian Maria

    2016-09-01

    This report describes a case of Clostridium difficile ribotype 033 colitis in a patient treated with multiple antibiotics for KPC-producing Klebsiella pneumoniae pancreatitis. Diagnostic, clinical and therapeutic features are discussed. To the best of our knowledge, this is the first case of C. difficile ribotype 033 clinical infection reported from Italy. PMID:27602425

  8. 1H and 13C NMR characterization and secondary structure of the K2 polysaccharide of Klebsiella pneumoniae strain 52145.

    PubMed

    Corsaro, Maria Michela; De Castro, Cristina; Naldi, Teresa; Parrilli, Michelangelo; Tomás, Juan M; Regué, Miguel

    2005-09-26

    The complete (1)H and (13)C NMR characterization of the tetrasaccharide repeating unit from the K2 polysaccharide of Klebsiella pneumoniae strain 52145 is reported. [chemical structure] In addition a model for its secondary structure was suggested on the basis of dynamic and molecular calculations.

  9. Complete Genome Sequence of Klebsiella pneumoniae Strain HKUOPLC, a Cellulose-Degrading Bacterium Isolated from Giant Panda Feces.

    PubMed

    Lu, Matthew Guan-Xi; Jiang, Jingwei; Liu, Lirui; Ma, Angel Po-Yee; Leung, Frederick Chi-Ching

    2015-01-01

    We report here the complete genome sequence of Klebsiella pneumoniae strain HKUOPLC, isolated from a giant panda fecal sample collected from Ocean Park, Hong Kong. The complete genome of this bacterium may contribute to the discovery of efficient cellulose-degrading pathways.

  10. KPC-2 producing Klebsiella pneumoniae and Escherichia coli co-infection in a catheter-related infection.

    PubMed

    Leão, R S; Carvalho-Assef, A P D' A; Correal, J C D; Silva, R V; Goldemberg, D C; Asensi, M D; Marques, E A

    2011-03-01

    We describe the first report of simultaneous blood infection with KPC-2 producing Klebsiella pneumoniae and Escherichia coli in a Brazilian patient. We highlight the importance of implementing efficient infection control measures to limit the spread of these phenotypes in a hospital setting.

  11. Complete Genome Sequence of Klebsiella pneumoniae Strain HKUOPLC, a Cellulose-Degrading Bacterium Isolated from Giant Panda Feces.

    PubMed

    Lu, Matthew Guan-Xi; Jiang, Jingwei; Liu, Lirui; Ma, Angel Po-Yee; Leung, Frederick Chi-Ching

    2015-01-01

    We report here the complete genome sequence of Klebsiella pneumoniae strain HKUOPLC, isolated from a giant panda fecal sample collected from Ocean Park, Hong Kong. The complete genome of this bacterium may contribute to the discovery of efficient cellulose-degrading pathways. PMID:26564041

  12. Coproduction of KPC-2 and QnrB19 in Klebsiella pneumoniae ST340 isolate in Brazil.

    PubMed

    Martins, Willames M B S; Almeida, Anna C S; Nicoletti, Adriana G; Cayô, Rodrigo; Gales, Ana C; Alves, Luiz C; Brayner, Fábio B; Vilela, Marinalda A; Morais, Márcia M C

    2015-12-01

    Few reports described the presence of bla(KPC) and qnr genes in the same isolate. This study reports the combination of bla(KPC-2) and qnrB19 genes in Klebsiella pneumoniae ST340 isolate in Brazil. These findings draw attention to this combination in ST340 isolate, which is part of the CC258, disseminated in Latin America.

  13. Genome Sequence of Klebsiella pneumoniae YZUSK-4, a Bacterium Proposed as a Starter Culture for Fermented Meat Products.

    PubMed

    Yu, Hai; Yin, Yongqi; Xu, Lin; Yan, Ming; Fang, Weiming; Ge, Qingfeng

    2015-07-23

    Klebsiella pneumoniae strain YZUSK-4, isolated from Chinese RuGao ham, is an efficient branched-chain aminotransferase-producing bacterium that can be used widely in fermented meat products to enhance flavor. The draft genome sequence of strain YZUSK-4 may provide useful genetic information on branched-chain amino acid aminotransferase production and branched-chain amino acid metabolism.

  14. In vitro activities of 15 oral beta-lactams against Klebsiella pneumoniae harboring new extended-spectrum beta-lactamases.

    PubMed Central

    Kitzis, M D; Liassine, N; Ferré, B; Gutmann, L; Acar, J F; Goldstein, F

    1990-01-01

    The activities of 15 oral beta-lactams against Klebsiella pneumoniae harboring new extended-spectrum beta-lactamases were studied. All compounds were affected by these enzymes, especially by the SHV derivatives. Except for ceftibuten, the compounds with the greatest intrinsic activity were more affected by the presence of these enzymes than were older compounds with moderate intrinsic activity. PMID:2285291

  15. Asian sand dust enhances murine lung inflammation caused by Klebsiella pneumoniae

    SciTech Connect

    He, Miao; Ichinose, Takamichi; Yoshida, Seiichi; Yamamoto, Shoji; Inoue, Ken-ichiro; Takano, Hirohisa; Yanagisawa, Rie; Nishikawa, Masataka; Mori, Ikuko; Sun, Guifan; Shibamoto, Takayuki

    2012-01-15

    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.

  16. Tracking a hospital outbreak of KPC-producing ST11 Klebsiella pneumoniae with whole genome sequencing.

    PubMed

    Jiang, Y; Wei, Z; Wang, Y; Hua, X; Feng, Y; Yu, Y

    2015-11-01

    An outbreak of carbapenem-resistant Klebsiella pneumoniae strains emerged at a hospital, and was tracked in order to understand the spread of these infectious pathogens. A total of 66 K. pneumoniae strains were collected from sterile samples in 2012. The MICs of 20 antimicrobial agents were determined for all strains. Molecular typing was performed with pulsed-field gel electrophoresis (PFGE). Twelve blaKPC-producing K. pneumoniae strains isolated from ten patients were selected for whole genome sequencing. Phylogenetic reconstruction of these 12 strains was performed by the use of single-nucleotide polymorphism (SNP) row sequences of each draft genome sequence. Plasmids from the 12 strains were separated by S1 digestion and PFGE. The 12 K. pneumoniae strains isolated from the ten patients were deemed to be representative of the hospital outbreak, owing to their similar PFGE patterns. These 12 blaKPC-producing strains conferred multidrug resistance, which contrasted with the remaining 54, more susceptible, strains in the hospital. Differences in SNPs between each draft genome of the blaKPC-producing strains partitioned the 12 outbreak strains into three separate clades. The patients with each clade shared close hospital units. All 12 strains harboured at least one multidrug resistance plasmid. Strains showing high-level resistance may facilitate nosocomial dissemination and result in an infectious pathogen outbreak. Although the 12 blaKPC-producing K. pneumoniae strains possessed similar PFGE patterns, SNP variations throughout the genome allowed the strains to be divided into three clades. These results suggest that three independent transmission events led to hospital-wide dissemination of the outbreak strains.

  17. Functional Genomic Screen Identifies Klebsiella pneumoniae Factors Implicated in Blocking Nuclear Factor κB (NF-κB) Signaling.

    PubMed

    Tomás, Anna; Lery, Leticia; Regueiro, Verónica; Pérez-Gutiérrez, Camino; Martínez, Verónica; Moranta, David; Llobet, Enrique; González-Nicolau, Mar; Insua, Jose L; Tomas, Juan M; Sansonetti, Philippe J; Tournebize, Régis; Bengoechea, José A

    2015-07-01

    Klebsiella pneumoniae is an etiologic agent of community-acquired and nosocomial pneumonia. It has been shown that K. pneumoniae infections are characterized by reduced early inflammatory response. Recently our group has shown that K. pneumoniae dampens the activation of inflammatory responses by antagonizing the activation of the NF-κB canonical pathway. Our results revealed that K. pneumoniae capsule polysaccharide (CPS) was necessary but not sufficient to attenuate inflammation. To identify additional Klebsiella factors required to dampen inflammation, we standardized and applied a high-throughput gain-of-function screen to examine a Klebsiella transposon mutant library. We identified 114 mutants that triggered the activation of NF-κB. Two gene ontology categories accounted for half of the loci identified in the screening: metabolism and transport genes (32% of the mutants) and envelope-related genes (17%). Characterization of the mutants revealed that the lack of the enterobactin siderophore was linked to a reduced CPS expression, which in turn underlined the NF-κB activation induced by the mutant. The lipopolysaccharide (LPS) O-polysaccharide and the pullulanase (PulA) type 2 secretion system (T2SS) are required for full effectiveness of the immune evasion. Importantly, these factors do not play a redundant role. The fact that LPS O-polysaccharide and T2SS mutant-induced responses were dependent on TLR2-TLR4-MyD88 activation suggested that LPS O-polysaccharide and PulA perturbed Toll-like receptor (TLR)-dependent recognition of K. pneumoniae. Finally, we demonstrate that LPS O-polysaccharide and pulA mutants are attenuated in the pneumonia mouse model. We propose that LPS O-polysaccharide and PulA T2SS could be new targets for the design of new antimicrobials. Increasing TLR-governed defense responses might provide also selective alternatives for the management of K. pneumoniae pneumonia.

  18. Functional Genomic Screen Identifies Klebsiella pneumoniae Factors Implicated in Blocking Nuclear Factor κB (NF-κB) Signaling*

    PubMed Central

    Tomás, Anna; Lery, Leticia; Regueiro, Verónica; Pérez-Gutiérrez, Camino; Martínez, Verónica; Moranta, David; Llobet, Enrique; González-Nicolau, Mar; Insua, Jose L.; Tomas, Juan M.; Sansonetti, Philippe J.; Tournebize, Régis; Bengoechea, José A.

    2015-01-01

    Klebsiella pneumoniae is an etiologic agent of community-acquired and nosocomial pneumonia. It has been shown that K. pneumoniae infections are characterized by reduced early inflammatory response. Recently our group has shown that K. pneumoniae dampens the activation of inflammatory responses by antagonizing the activation of the NF-κB canonical pathway. Our results revealed that K. pneumoniae capsule polysaccharide (CPS) was necessary but not sufficient to attenuate inflammation. To identify additional Klebsiella factors required to dampen inflammation, we standardized and applied a high-throughput gain-of-function screen to examine a Klebsiella transposon mutant library. We identified 114 mutants that triggered the activation of NF-κB. Two gene ontology categories accounted for half of the loci identified in the screening: metabolism and transport genes (32% of the mutants) and envelope-related genes (17%). Characterization of the mutants revealed that the lack of the enterobactin siderophore was linked to a reduced CPS expression, which in turn underlined the NF-κB activation induced by the mutant. The lipopolysaccharide (LPS) O-polysaccharide and the pullulanase (PulA) type 2 secretion system (T2SS) are required for full effectiveness of the immune evasion. Importantly, these factors do not play a redundant role. The fact that LPS O-polysaccharide and T2SS mutant-induced responses were dependent on TLR2-TLR4-MyD88 activation suggested that LPS O-polysaccharide and PulA perturbed Toll-like receptor (TLR)-dependent recognition of K. pneumoniae. Finally, we demonstrate that LPS O-polysaccharide and pulA mutants are attenuated in the pneumonia mouse model. We propose that LPS O-polysaccharide and PulA T2SS could be new targets for the design of new antimicrobials. Increasing TLR-governed defense responses might provide also selective alternatives for the management of K. pneumoniae pneumonia. PMID:25971969

  19. Acquired resistance to innate immune clearance promotes Klebsiella pneumoniae ST258 pulmonary infection

    PubMed Central

    Ahn, Danielle; Peñaloza, Hernán; Wang, Zheng; Wickersham, Matthew; Parker, Dane; Patel, Purvi; Koller, Antonius; Chen, Emily I.; Bueno, Susan M.; Uhlemann, Anne-Catrin; Prince, Alice

    2016-01-01

    Adaptive changes in the genome of a locally predominant clinical isolate of the multidrug-resistant Klebsiella pneumoniae ST258 (KP35) were identified and help to explain the selection of this strain as a successful pulmonary pathogen. The acquisition of 4 new ortholog groups, including an arginine transporter, enabled KP35 to outcompete related ST258 strains lacking these genes. KP35 infection elicited a monocytic response, dominated by Ly6Chi monocytic myeloid-derived suppressor cells that lacked phagocytic capabilities, expressed IL-10, arginase, and antiinflammatory surface markers. In comparison with other K. pneumoniae strains, KP35 induced global changes in the phagocytic response identified with proteomics, including evasion of Ca2+ and calpain activation necessary for phagocytic killing, confirmed in functional studies with neutrophils. This comprehensive analysis of an ST258 K. pneumoniae isolate reveals ongoing genetic adaptation to host microenvironments and innate immune clearance mechanisms that complements its repertoire of antimicrobial resistance genes and facilitates persistence in the lung. PMID:27777978

  20. Physical, biochemical, and immunological characterization of a thermostable amidase from Klebsiella pneumoniae NCTR 1.

    PubMed Central

    Nawaz, M S; Khan, A A; Bhattacharayya, D; Siitonen, P H; Cerniglia, C E

    1996-01-01

    An amidase capable of degrading acrylamide and aliphatic amides was purified to apparent homogeneity from Klebsiella pneumoniae NCTR 1. The enzyme is a monomer with an apparent molecular weight of 62,000. The pH and temperature optima of the enzyme were 7.0 and 65 degrees C, respectively. The purified amidase contained 11 5,5-dithiobis(2-nitrobenzoate) (DTNB)-titratable sulfhydryl (SH) groups. In the native enzyme 1.0 SH group readily reacted with DTNB with no detectable loss of activity. Titration of the next 3.0 SH groups with DTNB resulted in a loss of activity of more than 70%. The remaining seven inaccessible SH groups could be titrated only in the presence of 8 M guanidine hydrochloride. Titration of SH groups was strongly inhibited by carboxymethylation and KMnO4, suggesting the presence of SH groups at the active site(s). Inductively coupled plasma-atomic emission spectrometry analysis indicated that the native amidase contains 0.33 mol of cobalt and 0.33 mol of iron per mol of the native enzyme. Polyclonal antiserum against K. pneumoniae amidase was raised in rabbits, and immunochemical comparisons were made with amidases from Rhodococcus sp., Mycobacterium smegmatis, Pseudomonas chlororaphis B23, and Methylophilus methylotrophus. The antiserum immunoprecipitated and immunoreacted with the amidases of K. pneumoniae and P. chlororaphis B23. The antiserum failed to immunoreact or immunoprecipitate with other amidases. PMID:8636044

  1. Genomic and transcriptomic analysis of NDM-1 Klebsiella pneumoniae in spaceflight reveal mechanisms underlying environmental adaptability.

    PubMed

    Li, Jia; Liu, Fei; Wang, Qi; Ge, Pupu; Woo, Patrick C Y; Yan, Jinghua; Zhao, Yanlin; Gao, George F; Liu, Cui Hua; Liu, Changting

    2014-01-01

    The emergence and rapid spread of New Delhi Metallo-beta-lactamase-1 (NDM-1)-producing Klebsiella pneumoniae strains has caused a great concern worldwide. To better understand the mechanisms underlying environmental adaptation of those highly drug-resistant K. pneumoniae strains, we took advantage of the China's Shenzhou 10 spacecraft mission to conduct comparative genomic and transcriptomic analysis of a NDM-1 K. pneumoniae strain (ATCC BAA-2146) being cultivated under different conditions. The samples were recovered from semisolid medium placed on the ground (D strain), in simulated space condition (M strain), or in Shenzhou 10 spacecraft (T strain) for analysis. Our data revealed multiple variations underlying pathogen adaptation into different environments in terms of changes in morphology, H2O2 tolerance and biofilm formation ability, genomic stability and regulation of metabolic pathways. Additionally, we found a few non-coding RNAs to be differentially regulated. The results are helpful for better understanding the adaptive mechanisms of drug-resistant bacterial pathogens. PMID:25163721

  2. Genomic and transcriptomic analysis of NDM-1 Klebsiella pneumoniae in spaceflight reveal mechanisms underlying environmental adaptability

    PubMed Central

    Li, Jia; Liu, Fei; Wang, Qi; Ge, Pupu; Woo, Patrick C. Y.; Yan, Jinghua; Zhao, Yanlin; Gao, George F.; Liu, Cui Hua; Liu, Changting

    2014-01-01

    The emergence and rapid spread of New Delhi Metallo-beta-lactamase-1 (NDM-1)-producing Klebsiella pneumoniae strains has caused a great concern worldwide. To better understand the mechanisms underlying environmental adaptation of those highly drug-resistant K. pneumoniae strains, we took advantage of the China's Shenzhou 10 spacecraft mission to conduct comparative genomic and transcriptomic analysis of a NDM-1 K. pneumoniae strain (ATCC BAA-2146) being cultivated under different conditions. The samples were recovered from semisolid medium placed on the ground (D strain), in simulated space condition (M strain), or in Shenzhou 10 spacecraft (T strain) for analysis. Our data revealed multiple variations underlying pathogen adaptation into different environments in terms of changes in morphology, H2O2 tolerance and biofilm formation ability, genomic stability and regulation of metabolic pathways. Additionally, we found a few non-coding RNAs to be differentially regulated. The results are helpful for better understanding the adaptive mechanisms of drug-resistant bacterial pathogens. PMID:25163721

  3. Deep transcriptome profiling of clinical Klebsiella pneumoniae isolates reveals strain and sequence type-specific adaptation.

    PubMed

    Bruchmann, Sebastian; Muthukumarasamy, Uthayakumar; Pohl, Sarah; Preusse, Matthias; Bielecka, Agata; Nicolai, Tanja; Hamann, Isabell; Hillert, Roger; Kola, Axel; Gastmeier, Petra; Eckweiler, Denitsa; Häussler, Susanne

    2015-11-01

    Health-care-associated infections by multi-drug-resistant bacteria constitute one of the greatest challenges to modern medicine. Bacterial pathogens devise various mechanisms to withstand the activity of a wide range of antimicrobial compounds, among which the acquisition of carbapenemases is one of the most concerning. In Klebsiella pneumoniae, the dissemination of the K. pneumoniae carbapenemase is tightly connected to the global spread of certain clonal lineages. Although antibiotic resistance is a key driver for the global distribution of epidemic high-risk clones, there seem to be other adaptive traits that may explain their success. Here, we exploited the power of deep transcriptome profiling (RNA-seq) to shed light on the transcriptomic landscape of 37 clinical K. pneumoniae isolates of diverse phylogenetic origins. We identified a large set of 3346 genes which was expressed in all isolates. While the core-transcriptome profiles varied substantially between groups of different sequence types, they were more homogenous among isolates of the same sequence type. We furthermore linked the detailed information on differentially expressed genes with the clinically relevant phenotypes of biofilm formation and bacterial virulence. This allowed for the identification of a diminished expression of biofilm-specific genes within the low biofilm producing ST258 isolates as a sequence type-specific trait. PMID:26261087

  4. Nosocomial infections by Klebsiella pneumoniae carbapenemase producing enterobacteria in a teaching hospital

    PubMed Central

    Seibert, Gabriela; Hörner, Rosmari; Meneghetti, Bettina Holzschuh; Righi, Roselene Alves; Forno, Nara Lucia Frasson Dal; Salla, Adenilde

    2014-01-01

    Objective To analyze the profile of patients with microorganisms resistant to carbapenems, and the prevalence of the enzyme Klebsiella pneumoniae carbapenemase in interobacteriaceae. Methods Retrospective descriptive study. From the isolation in bacteriological tests ordered by clinicians, we described the clinical and epidemiological characteristics of patients with enterobacteria resistants to carbapenems at a university hospital, between March and October 2013. Results We included 47 isolated patients in this study, all exhibiting resistance to carbapenems, including 9 patients who were confirmed as infected/colonized with K. pneumoniae carbapenemase. Isolation in tracheal aspirates (12; 25.5%) predominated. The resistance to ertapenem, meropenem, and imipenem was 91.5%, 83.0% and 80.0%, respectively. Aminoglycosides was the class of antimicrobials that showed the highest sensitivity, 91.5% being sensitive to amikacin and 57.4% to gentamicin. Conclusion The K. pneumoniae carbapenemase was an important agent in graun isotaling in hospital intection. The limited therapeutic options emphasize the need for rapid laboratory detection, as well as the implementation of measures to prevent and control the spread of these pathogens. PMID:25295446

  5. Reduced susceptibility of carbapenem-resistant Klebsiella pneumoniae to biocides: An emerging threat.

    PubMed

    Bhatia, M; Loomba, P S; Mishra, B; Dogra, V; Thakur, A

    2016-01-01

    Dealing with carbapenem-resistant Klebsiella pneumoniae (CR-Kp) strains, which are generally pan-drug resistant, is an uphill task for health care professionals. Owing to limited therapeutic options and the possibility of development of resistance to commonly used biocides in hospital settings, CR-Kp infections pose a serious threat of emergence of a dreaded pandemic. The aim of the study was to highlight the possibility of emergence of biocide resistance among CR-Kp strains. A case study was conducted in a Super-specialty Hospital in September 2015. A 65-year-old female patient post-laparotomy was admitted to the General Intensive Care Unit of a Super-specialty Hospital. CR-Kp was isolated from the blood and mucus trap samples of this patient. Susceptibility testing of three commonly used biocides in our hospital, namely sodium hypochlorite (4% available chlorine), 5% w/v povidone iodine (0.5% w/v of available iodine) and absolute ethanol (99.9%), respectively, was carried out using K. pneumoniae ATCC 700603 as control. The test isolate showed reduced susceptibility to sodium hypochlorite in comparison to K. pneumoniae ATCC 700603. The possibility of emergence of biocide resistance among CR-Kp strains poses a threat of disrupting our ongoing efforts for implementation of effective infection control measures. PMID:27514961

  6. Virulence and antimicrobial resistance of Klebsiella pneumoniae isolated from passerine and psittacine birds.

    PubMed

    Davies, Y M; Cunha, M P V; Oliveira, M G X; Oliveira, M C V; Philadelpho, N; Romero, D C; Milanelo, L; Guimarães, M B; Ferreira, A J P; Moreno, A M; Sá, L R M; Knöbl, T

    2016-01-01

    Klebsiella pneumoniae is considered one of the most important Gram-negative opportunistic pathogens. The contact between humans and birds poses health risks to both. The aim of this study was to investigate the resistance and virulence of K. pneumoniae isolates from psittacines and passerines, seized from illegal trade in Brazil. We analysed 32 strains isolated from birds of the orders Psittaciformes and Passeriformes by polymerase chain reaction (PCR) for virulence factor genes. Antibiotic resistance was assessed by disk diffusion assay and PCR. The results indicated that fimH (100%), uge (96.8%), kfu (81.2%) and irp-2 (68.7%) were the most common virulence genes, followed by kpn (46.8%), K2 (43.7%), mrkD (34.3%) and iroN (15.6%). The combination of virulence genes resulted in a great diversity of genotypes and the heterogeneity of the strains is also confirmed in the analysis by amplified fragment length polymorphism. The susceptibility profiles of the K. pneumoniae showed 25% of multiple antibiotic resistance strains. We identified seven strains that presented non-extended spectrum beta lactamase blaSHV variants SHV-1 and SHV-11 and one strain positive to the blaTEM-1 gene. Plasmid-mediated quinolone resistance was present in 10 strains (10/32). The data obtained in this study reveal the pathogenic potential of this pathogen and highlight the need for surveillance and monitoring.

  7. Immunoprotective potential of polysaccharide-tetanus toxoid conjugate in Klebsiella pneumoniae induced lobar pneumonia in rats.

    PubMed

    Chhibber, S; Rani, Mamta; Vanashree, Yadav

    2005-01-01

    The polysaccharide (PS) derived from K. pneumoniae NCTC 5055 lipopolysaccharide (LPS) was covalently linked to tetanus toxoid by using carbodimide with adipic acid dihydrazide as a spacer molecule. The conjugate was found to be non-toxic and non-pyrogenic at 100 microg dose level. At a similar dose, the conjugate did not elicit any local skin reaction on intradermal preparatory injection in rabbits. The conjugate was immunoprotective as was evident from the decrease in relative colonization of bacteria in lungs of immunized rats as compared to the control animals. Immunization with the conjugate resulted in alveolar macrophage activation in terms of their ability to phagocytose bacteria in vitro. PMID:15691064

  8. Polymer production by Klebsiella pneumoniae 4-hydroxyphenylacetic acid hydroxylase genes cloned in Escherichia coli.

    PubMed Central

    Gibello, A; Ferrer, E; Sanz, J; Martin, M

    1995-01-01

    The expression of Klebsiella pneumoniae hpaA and hpaH genes, which code for 4-hydroxyphenylacetic acid hydroxylase in Escherichia coli K-12 derivative strains, is associated with the production of a dark brown pigment in the cultures. This pigment has been identified as a polymer which shows several of the characteristics reported for microbial melanins and results from the oxidative activity of 4-hydroxyphenylacetic acid hydroxylase on some dihydroxylated compounds to form o-quinones. A dibenzoquinone is formed from the oxidation of different mono- or dihydroxylated aromatic compounds by the enzyme prior to polymerization. We report a hydroxylase activity, other than tyrosinase, that is associated with the synthesis of a bacterial melanin. PMID:8534083

  9. Structure and Function of CutC Choline Lyase from Human Microbiota Bacterium Klebsiella pneumoniae*

    PubMed Central

    Kalnins, Gints; Kuka, Janis; Grinberga, Solveiga; Makrecka-Kuka, Marina; Liepinsh, Edgars; Dambrova, Maija; Tars, Kaspars

    2015-01-01

    CutC choline trimethylamine-lyase is an anaerobic bacterial glycyl radical enzyme (GRE) that cleaves choline to produce trimethylamine (TMA) and acetaldehyde. In humans, TMA is produced exclusively by the intestinal microbiota, and its metabolite, trimethylamine oxide, has been associated with a higher risk of cardiovascular diseases. Therefore, information about the three-dimensional structures of TMA-producing enzymes is important for microbiota-targeted drug discovery. We have cloned, expressed, and purified the CutC GRE and the activating enzyme CutD from Klebsiella pneumoniae, a representative of the human microbiota. We have determined the first crystal structures of both the choline-bound and choline-free forms of CutC and have discovered that binding of choline at the ligand-binding site triggers conformational changes in the enzyme structure, a feature that has not been observed for any other characterized GRE. PMID:26187464

  10. Tigecycline Therapy for Carbapenem-Resistant Klebsiella pneumoniae (CRKP) Bacteriuria Leads to Tigecycline Resistance

    PubMed Central

    van Duin, David; Cober, Eric; Richter, Sandra S.; Perez, Federico; Cline, Marianne; Kaye, Keith S.; Kalayjian, Robert C.; Salata, Robert A.; Evans, Scott; Fowler, Vance G.; Bonomo, Robert A.

    2014-01-01

    Carbapenem-resistant Klebsiella pneumoniae (CRKP) is an increasing global threat. Here, we describe the prevalence and impact of tigecycline use in a cohort of patients with CRKP bacteriuria nested within a multicenter, prospective study. In the 21 month study period, 260 unique patients were included. Tigecycline was given to 80 (31%) patients. The use of tigecycline during the index hospitalization was significantly associated with the subsequent development of tigecycline resistance in the same patient (OR 6.13, 95%CI 1.15–48.65, p=0.03). In conclusion, the use of tigecycline with CRKP bacteriuria is common, and is associated with the subsequent development of tigecycline resistance. PMID:24931918

  11. Structural and kinetic insights into the mechanism of 5-hydroxyisourate hydrolase from Klebsiella pneumoniae

    SciTech Connect

    French, Jarrod B.; Ealick, Steven E.

    2011-07-19

    The stereospecific oxidative degradation of uric acid to (S)-allantoin has recently been demonstrated to proceed via two unstable intermediates and requires three separate enzymatic reactions. The second step of this reaction, the conversion of 5-hydroxyisourate (HIU) to 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline, is catalyzed by HIU hydrolase (HIUH). The high-resolution crystal structure of HIUH from the opportunistic pathogen Klebsiella pneumoniae (KpHIUH) has been determined. KpHIUH is a homotetrameric protein that, based on sequence and structural similarity, belongs to the transthyretin-related protein family. In addition, the steady-state kinetic parameters for this enzyme and four active-site mutants have been measured. These data provide valuable insight into the functional roles of the active-site residues. Based upon the structural and kinetic data, a mechanism is proposed for the KpHIUH-catalyzed reaction.

  12. First characterization of inhibitor-resistant TEM (IRT) beta-lactamases in Klebsiella pneumoniae strains.

    PubMed Central

    Lemozy, J; Sirot, D; Chanal, C; Huc, C; Labia, R; Dabernat, H; Sirot, J

    1995-01-01

    Two clinical strains of Klebsiella pneumoniae, TP 01 and TP 02, presented resistance to amoxicillin-clavulanate and were fully susceptible to cephalothin. These strains produced two beta-lactamases, SHV-1 and a TEM enzyme with a pI of 5.2. The previously described changes Arg-244-->Cys and Arg-244-->Ser in IRT-1 and IRT-2 (A. Belaaouaj, C. Lapoumeroulie, M. M. Caniça, G. Vedel, P. Nevot, R. Krishnamoorthy, and G. Paul, FEMS Microbiol. Lett. 120:75-80, 1994) were found in TEM enzymes from the TP 01 and TP 02 strains, respectively. This is the first report of inhibitor-resistant TEM (IRT) in species other than Escherichia coli from the family Enterobacteriaceae. PMID:8585751

  13. Starvation and nutrient resuscitation of Klebsiella pneumoniae isolated from oil well waters.

    PubMed

    Lappin-Scott, H M; Cusack, F; MacLeod, A; Costerton, J W

    1988-06-01

    Klebsiella pneumoniae isolated from oil well waters reduced in size in response to nutrient starvation. The cells remained viable during starvation and later were able to grow rapidly when stimulated by nutrients. The heterotrophic potential, culture absorbance and extracellular polysaccharide production decreased during cell starvation whereas an initial increase in colony-forming units was observed on agar plates. Transmission electron microscopy (TEM) after 24 d revealed that the cells had changed to small rods or cocci between 0.5 by 0.25 micron and 0.87 by 0.55 micron. When transferred to half-strength brain heart infusion medium, TEM showed cell division and rod-shaped cells after 45 min and full resuscitation within 4 h. Cell response was much slower in sodium citrate medium and resuscitation took 8 h.

  14. Molecular Analysis of Antibiotic Resistance Determinants and Plasmids in Malaysian Isolates of Multidrug Resistant Klebsiella pneumoniae

    PubMed Central

    Al-Marzooq, Farah; Mohd Yusof, Mohd Yasim; Tay, Sun Tee

    2015-01-01

    Infections caused by multidrug resistant Klebsiella pneumoniae have been increasingly reported in many parts of the world. A total of 93 Malaysian multidrug resistant K. pneumoniae isolated from patients attending to University of Malaya Medical Center, Kuala Lumpur, Malaysia from 2010-2012 were investigated for antibiotic resistance determinants including extended-spectrum beta-lactamases (ESBLs), aminoglycoside and trimethoprim/sulfamethoxazole resistance genes and plasmid replicons. CTX-M-15 (91.3%) was the predominant ESBL gene detected in this study. aacC2 gene (67.7%) was the most common gene detected in aminoglycoside-resistant isolates. Trimethoprim/sulfamethoxazole resistance (90.3%) was attributed to the presence of sul1 (53.8%) and dfrA (59.1%) genes in the isolates. Multiple plasmid replicons (1-4) were detected in 95.7% of the isolates. FIIK was the dominant replicon detected together with 13 other types of plasmid replicons. Conjugative plasmids (1-3 plasmids of ~3-100 kb) were obtained from 27 of 43 K. pneumoniae isolates. An ESBL gene (either CTX-M-15, CTX-M-3 or SHV-12) was detected from each transconjugant. Co-detection with at least one of other antibiotic resistance determinants [sul1, dfrA, aacC2, aac(6ˊ)-Ib, aac(6ˊ)-Ib-cr and qnrB] was noted in most conjugative plasmids. The transconjugants were resistant to multiple antibiotics including β-lactams, gentamicin and cotrimoxazole, but not ciprofloxacin. This is the first study describing the characterization of plasmids circulating in Malaysian multidrug resistant K. pneumoniae isolates. The results of this study suggest the diffusion of highly diverse plasmids with multiple antibiotic resistance determinants among the Malaysian isolates. Effective infection control measures and antibiotic stewardship programs should be adopted to limit the spread of the multidrug resistant bacteria in healthcare settings. PMID:26203651

  15. Molecular Analysis of Antibiotic Resistance Determinants and Plasmids in Malaysian Isolates of Multidrug Resistant Klebsiella pneumoniae.

    PubMed

    Al-Marzooq, Farah; Mohd Yusof, Mohd Yasim; Tay, Sun Tee

    2015-01-01

    Infections caused by multidrug resistant Klebsiella pneumoniae have been increasingly reported in many parts of the world. A total of 93 Malaysian multidrug resistant K. pneumoniae isolated from patients attending to University of Malaya Medical Center, Kuala Lumpur, Malaysia from 2010-2012 were investigated for antibiotic resistance determinants including extended-spectrum beta-lactamases (ESBLs), aminoglycoside and trimethoprim/sulfamethoxazole resistance genes and plasmid replicons. CTX-M-15 (91.3%) was the predominant ESBL gene detected in this study. aacC2 gene (67.7%) was the most common gene detected in aminoglycoside-resistant isolates. Trimethoprim/sulfamethoxazole resistance (90.3%) was attributed to the presence of sul1 (53.8%) and dfrA (59.1%) genes in the isolates. Multiple plasmid replicons (1-4) were detected in 95.7% of the isolates. FIIK was the dominant replicon detected together with 13 other types of plasmid replicons. Conjugative plasmids (1-3 plasmids of ~3-100 kb) were obtained from 27 of 43 K. pneumoniae isolates. An ESBL gene (either CTX-M-15, CTX-M-3 or SHV-12) was detected from each transconjugant. Co-detection with at least one of other antibiotic resistance determinants [sul1, dfrA, aacC2, aac(6')-Ib, aac(6')-Ib-cr and qnrB] was noted in most conjugative plasmids. The transconjugants were resistant to multiple antibiotics including β-lactams, gentamicin and cotrimoxazole, but not ciprofloxacin. This is the first study describing the characterization of plasmids circulating in Malaysian multidrug resistant K. pneumoniae isolates. The results of this study suggest the diffusion of highly diverse plasmids with multiple antibiotic resistance determinants among the Malaysian isolates. Effective infection control measures and antibiotic stewardship programs should be adopted to limit the spread of the multidrug resistant bacteria in healthcare settings.

  16. Rapid Detection of K1 Hypervirulent Klebsiella pneumoniae by MALDI-TOF MS

    PubMed Central

    Huang, Yonglu; Li, Jiaping; Gu, Danxia; Fang, Ying; Chan, Edward W.; Chen, Sheng; Zhang, Rong

    2015-01-01

    Hypervirulent strains of Klebsiella pneumoniae (hvKP) are genetic variants of K. pneumoniae which can cause life-threatening community-acquired infection in healthy individuals. Currently, methods for efficient differentiation between classic K. pneumoniae (cKP) and hvKP strains are not available, often causing delay in diagnosis and treatment of hvKP infections. To address this issue, we devised a Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) approach for rapid identification of K1 hvKP strains. Four standard algorithms, genetic algorithm (GA), support vector machine (SVM), supervised neural network (SNN), and quick classifier (QC), were tested for their power to differentiate between K1 and non-K1 strains, among which SVM was the most reliable algorithm. Analysis of the receiver operating characteristic curves of the interest peaks generated by the SVM model was found to confer highly accurate detection sensitivity and specificity, consistently producing distinguishable profiles for K1 hvKP and non-K1 strains. Of the 43 K. pneumoniae modeling strains tested by this approach, all were correctly identified as K1 hvKP and non-K1 capsule type. Of the 20 non-K1 and 17 K1 hvKP validation isolates, the accuracy of K1 hvKP and non-K1 identification was 94.1 and 90.0%, respectively, according to the SVM model. In summary, the MALDI-TOF MS approach can be applied alongside the conventional genotyping techniques to provide rapid and accurate diagnosis, and hence prompt treatment of infections caused by hvKP. PMID:26733976

  17. Identification of Outer Membrane and Exoproteins of Carbapenem-Resistant Multilocus Sequence Type 258 Klebsiella pneumoniae

    PubMed Central

    Brinkworth, Amanda J.; Hammer, Carl H.; Olano, L. Renee; Kobayashi, Scott D.; Chen, Liang; Kreiswirth, Barry N.; DeLeo, Frank R.

    2015-01-01

    Carbapenem-resistant Klebsiella pneumoniae strains have emerged as a cause of life-threatening infections in susceptible individuals (e.g., transplant recipients and critically ill patients). Strains classified as multilocus sequence type (ST) 258 are among the most prominent causes of carbapenem-resistant K. pneumoniae infections worldwide, but the basis for the success of this lineage remains incompletely determined. To gain a more comprehensive view of the molecules potentially involved in the success of ST258, we used a proteomics approach to identify surface-associated and culture supernatant proteins produced by ST258. Protein samples were prepared from varied culture conditions in vitro, and were analyzed by a combination of two-dimensional electrophoresis and liquid chromatography followed by tandem mass spectrometry (LC-MS/MS). We identified a total of 193 proteins in outer membrane preparations from bacteria cultured in Luria-Bertani broth (LB) or RPMI 1640 tissue culture media (RPMI). Compared with LB, several iron-acquisition proteins, including IutA, HmuR, HmuS, CirA, FepA, FitA, FoxA, FhuD, and YfeX, were more highly expressed in RPMI. Of the 177 proteins identified in spent media, only the fimbrial subunit, MrkA, was predicted to be extracellular, a finding that suggests few proteins (or a limited quantity) are freely secreted by ST258. Notably, we discovered 203 proteins not reported in previous K. pneumoniae proteome studies. In silico modeling of proteins with unknown function revealed several proteins with beta-barrel transmembrane structures typical of porins, as well as possible host-interacting proteins. Taken together, these findings contribute several new targets for the mechanistic study of drug-resistance and pathogenesis by ST258 K. pneumoniae isolates. PMID:25893665

  18. Cloning and expression of Klebsiella pneumoniae genes coding for citrate transport and fermentation.

    PubMed

    Schwarz, E; Oesterhelt, D

    1985-06-01

    Three Escherichia coli clones (DH1/Cit1, DH1/Cit2 and DH1/Cit3) capable of utilizing citrate as a sole carbon source were isolated from a cosmid bank of Klebsiella pneumoniae wild-type DNA. Two of these clones (DH1/Cit1 and DH1/Cit2) only grew aerobically on citrate minimal medium, the third clone (DH1/Cit3) could also be cultured under fermentative conditions. The aerobic as well as the anaerobic generation times of the three clones were from 4.5 to 7 h. Whereas clone DH1/Cit3 showed a pronounced lag phase on citrate when the cells were pre-grown in medium without citrate, clone DH1/Cit1 immediately started growth, while with clone DH1/Cit2 a short lag phase could be observed upon transfer to citrate minimal medium. Restriction analyses of the three plasmids showed that no common fragments had been cloned. The length of the inserts were 13 and 6 kb for the aerobic Cit+ clones and 27 kb (10 kb) for the anaerobic one. Cultures of the anaerobic Cit+ clone were analyzed by immunoblotting techniques and shown to contain oxaloacetate decarboxylase, which confers citrate utilization under anaerobic conditions to K. pneumoniae. Enzyme assays demonstrated the active state of this biotin-containing membrane protein. The specific activity in vesicle preparations from the E. coli clone was 30% of the wild-type K. pneumoniae vesicles. Citrate acts as an inducer of enzyme protein synthesis in the E. coli clone as it does in K. pneumoniae.

  19. R-plasmid-encoded adhesive factor in Klebsiella pneumoniae strains responsible for human nosocomial infections.

    PubMed Central

    Darfeuille-Michaud, A; Jallat, C; Aubel, D; Sirot, D; Rich, C; Sirot, J; Joly, B

    1992-01-01

    Klebsiella pneumoniae strains involved in hospital outbreaks of nosocomial infections, such as suppurative lesions, bacteremia, and septicemia, were resistant to multiple antibiotics including broad-spectrum cephalosporins. Epidemiologic investigations revealed that the reservoir for these K. pneumoniae strains was the gastrointestinal tracts of the patients. The study of the adherence ability of the strains reported here showed that these bacteria adhered to the microvilli of the Caco-2 cell line. This adhesion was mediated by a nonfimbrial protein with a molecular mass of 29,000 Da designated CF29K. Pretreatment of bacteria with antibodies raised against CF29K or Caco-2 cells with purified CF29K prevented the adhesion of K. pneumoniae strains to Caco-2 cells. CF29K immunologically cross-reacted with the CS31A surface protein of Escherichia coli strains involved in septicemia in calves. Genes encoding CF29K were located on a high-molecular-weight conjugative R plasmid, which transferred to E. coli K-12. Transconjugants expressed a large amount of CF29K protein and adhered to the brush border of Caco-2 cells. These findings show that K. pneumoniae strains were able to colonize the human intestinal tract through a plasmid-encoded 29,000-Da surface protein. Hybridization experiments indicated that the gene encoding resistance to broad-spectrum cephalosporins by the production of CAZ-1 enzyme and the gene encoding the adhesive property to intestinal cells were both located on a 20- to 22-kb EcoRI restriction DNA fragment. Genes encoding aerobactin and the ferric aerobactin receptor were also found on this R plasmid. Images PMID:1345909

  20. Derepression of Mineral Phosphate Solubilization Phenotype by Insertional Inactivation of iclR in Klebsiella pneumoniae

    PubMed Central

    Pandya, Maharshi; Jog, Rahul; G, Naresh Kumar; Rajkumar, Shalini

    2015-01-01

    The mode of succinate mediated repression of mineral phosphate solubilization and the role of repressor in suppressing phosphate solubilization phenotype of two free-living nitrogen fixing Klebsiella pneumoniae strains was studied. Organic acid mediated mineral phosphate solubilization phenotype of oxalic acid producing Klebsiella pneumoniae SM6 and SM11 were transcriptionally repressed by IclR in presence of succinate as carbon source. Oxalic acid production and expression of genes of the glyoxylate shunt (aceBAK) was found only in glucose but not in succinate- and glucose+succinate-grown cells. IclR, repressor of aceBAK operon, was inactivated using an allelic exchange system resulting in derepressed mineral phosphate solubilization phenotype through constitutive expression of the glyoxylate shunt. Insertional inactivation of iclR resulted in increased activity of the glyoxylate shunt enzymes even in succinate-grown cells. An augmented phosphate solubilization up to 54 and 59% soluble phosphate release was attained in glucose+succinate-grown SM6Δ and SM11Δ strains respectively, compared to glucose-grown cells, whereas phosphate solubilization was absent or negligible in wildtype cells grown in glucose+succinate. Both wildtype and iclR deletion strains showed similar indole-3-acetic acid production. Wheat seeds inoculated with wildtype SM6 and SM11 improved both root and shoot length by 1.2 fold. However, iclR deletion SM6Δ and SM11Δ strains increased root and shoot length by 1.5 and 1.4 folds, respectively, compared to uninoculated controls. The repressor inactivated phosphate solubilizers better served the purpose of constitutive phosphate solubilization in pot experiments, where presence of other carbon sources (e.g., succinate) might repress mineral phosphate solubilization phenotype of wildtype strains. PMID:26381651

  1. Critical issues for Klebsiella pneumoniae KPC-carbapenemase producing K. pneumoniae infections: a critical agenda.

    PubMed

    De Rosa, Francesco G; Corcione, Silvia; Cavallo, Rossana; Di Perri, Giovanni; Bassetti, Matteo

    2015-01-01

    The wide dissemination of carbapenemase producing K. pneumoniae (KPC-Kp) has caused a public health crisis of global dimensions, due to the serious infections in hospitalized patients associated with high mortality. In 2014, we aim to review clinical data on KPC-Kp at a time when a pro-active strategy (combating the problem before it is established) is no longer useful, focusing on epidemiology, patient risk profile, infection control, digestive tract colonization and treatment issues such as the role of carbapenems or carbapenem sparing strategies, colistin and resistance, dual carbapenem administration and the role of tigecycline. All these issues are illustrated prospectively to provide a forum for a Consensus strategy when not only intensive care units but also medical and surgical wards are affected by the epidemics. PMID:25689539

  2. Molecular epidemiology of KPC-2-producing Enterobacteriaceae (non-Klebsiella pneumoniae) isolated from Brazil.

    PubMed

    Tavares, Carolina Padilha; Pereira, Polyana Silva; Marques, Elizabeth de Andrade; Faria, Celio; de Souza, Maria da Penha Araújo Herkenhoff; de Almeida, Robmary; Alves, Carlene de Fátima Morais; Asensi, Marise Dutra; Carvalho-Assef, Ana Paula D'Alincourt

    2015-08-01

    In Brazil, since 2009, there has been an ever increasing widespread of the bla(KPC-2) gene, mainly in Klebsiella pneumoniae. This study aims to assess the molecular epidemiology and genetic background of this gene in Enterobacteriaceae (non-K. pneumoniae) species from 9 Brazilian states between 2009 and 2011. Three hundred eighty-seven isolates were analyzed exhibiting nonsusceptibility to carbapenems, in which the bla(KPC-2) gene was detected in 21.4%. By disk diffusion and E-test, these isolates exhibited high rates of resistance to most of the antimicrobials tested, including tigecycline (45.6% nonsusceptible) and polymyxin B (16.5%), the most resistant species being Enterobacter aerogenes and Enterobacter cloacae. We found great clonal diversity and a variety of bla(KPC-2)-carrying plasmids, all of them exhibiting a partial Tn4401 structure. Therefore, this study demonstrates the dissemination of KPC-2 in 9 Enterobacteriaceae species, including species that were not previously described such as Pantoea agglomerans and Providencia stuartii. PMID:25935630

  3. Dissemination of clonally related multidrug-resistant Klebsiella pneumoniae in Ireland.

    PubMed

    Morris, D; O'Connor, M; Izdebski, R; Corcoran, M; Ludden, C E; McGrath, E; Buckley, V; Cryan, B; Gniadkowski, M; Cormican, M

    2016-01-01

    In October 2012, an outbreak of gentamicin-resistant, ciprofloxacin non-susceptible extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae occurred in a neonatal intensive care unit in Ireland. In order to determine whether the outbreak strain was more widely dispersed in the country, 137 isolates of K. pneumoniae with this resistance phenotype collected from 17 hospitals throughout Ireland between January 2011 and July 2013 were examined. ESBL production was confirmed phenotypically and all isolates were screened for susceptibility to 19 antimicrobial agents and for the presence of genes encoding bla TEM, bla SHV, bla OXA, and bla CTX-M; 22 isolates were also screened for bla KPC, bla NDM, bla VIM, bla IMP and bla OXA-48 genes. All isolates harboured bla SHV and bla CTX-M and were resistant to ciprofloxacin, gentamicin, nalidixic acid, amoxicillin-clavulanate, and cefpodoxime; 15 were resistant to ertapenem, seven to meropenem and five isolates were confirmed as carbapenemase producers. Pulsed-field gel electrophoresis of all isolates identified 16 major clusters, with two clusters comprising 61% of the entire collection. Multilocus sequence typing of a subset of these isolates identified a novel type, ST1236, a single locus variant of ST48. Data suggest that two major clonal groups, ST1236/ST48 (CG43) and ST15/ST14 (CG15) have been circulating in Ireland since at least January 2011. PMID:26113052

  4. Control of carbapenemase-producing Klebsiella pneumoniae: a region-wide intervention.

    PubMed

    Gagliotti, C; Cappelli, V; Carretto, E; Marchi, M; Pan, A; Ragni, P; Sarti, M; Suzzi, R; Tura, G A; Moro, M L

    2014-10-30

    Starting in 2010, there was a sharp increase in infections caused by Klebsiella pneumoniae resistant to carbapenems in the Emilia-Romagna region in Italy. A region-wide intervention to control the spread of carbapenemase-producing K. pneumoniae (CPKP) in Emilia-Romagna was carried out, based on a regional guideline issued in July 2011. The infection control measures recommended to the Health Trusts (HTs) were: phenotypic confirmation of carbapenemase production, active surveillance of asymptomatic carriers and contact isolation precautions for carriers. A specific surveillance system was activated and the implementation of control measures in HTs was followed up. A significant linear increase of incident CPKP cases over time (p<0.001) was observed at regional level in Emilia-Romagna in the pre-intervention period, while the number of cases remained stable after the launch of the intervention (p=0.48). Considering the patients hospitalised in five HTs that provided detailed data on incident cases, a downward trend was observed in incidence after the release of the regional guidelines (from 32 to 15 cases per 100,000 hospital patient days). The spread of CPKP in Emilia-Romagna was contained by a centrally-coordinated intervention. A further reduction in CPKP rates might be achieved by increased compliance with guidelines and specific activities of antibiotic stewardship.

  5. Effect of subinihibitory and inhibitory concentrations of Plectranthus amboinicus (Lour.) Spreng essential oil on Klebsiella pneumoniae.

    PubMed

    Gonçalves, Thially Braga; Braga, Milena Aguiar; de Oliveira, Francisco F M; Santiago, Gilvandete M P; Carvalho, Cibele B M; Brito e Cabral, Paula; de Melo Santiago, Thiago; Sousa, Jeanlex S; Barros, Eduardo Bedê; do Nascimento, Ronaldo Ferreira; Nagao-Dias, Aparecida T

    2012-08-15

    We evaluated the antimicrobial activity and some mechanisms used by subinhibitory and inhibitory concentrations of the essential oil, obtained from leaves of Plectranthus amboinicus, against a standard strain of Klebsiella pneumoniae and 5 multiresistant clinical isolates of the bacteria. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC), the rate of kill and the pH sensitivity of the essential oil were determined by microdilution tests performed in 96-well plates. Subinhibitory and inhibitory concentrations of the essential oil were tested in order to check its action on K. pneumoniae membrane permeability, capsule expression, urease activity and cell morphology. The MIC and MBC of the essential oil were 0.09±0.01%. A complete inhibition of the bacterial growth was observed after 2 h of incubation with twice the MIC of the essential oil. A better MIC was found when neutral or alkaline pH broth was used. Alteration in membrane permeability was found by the increase of crystal violet uptake when the bacteria were incubated with twice the MIC levels of the essential oil. The urease activity could be prevented when all the subinhibitory concentrations were tested in comparison to the untreated group (p<0.001). Alteration of the bacterial morphology besides inhibition of the capsule expression was verified by atomic force microscopy, and Anthony's stain method, respectively. Our data allow us to conclude that the essential oil of P. amboinicus can be a good candidate for future research. PMID:22776104

  6. Fine-structure mapping and complementation analysis of nif (nitrogen fixation) genes in Klebsiella pneumoniae.

    PubMed Central

    MacNeil, T; MacNeil, D; Roberts, G P; Supiano, M A; Brill, W J

    1978-01-01

    Four hundred and eighty-nine independent Nif- strains containing 260 point, 130 millimicron-induced, and 99 deletion mutations in nif in the Klebsiella pneumoniae chromosome were isolated. Three hundred and ninety insertion and point mutations were mapped with millimicron-induced deletions carried on 44 plasmids derived from pTM4010, a recombinant R factor containing the his-nif region of K. pneumoniae. The 99 chromosomal deletions in the nif region were mapped with 69 derivatives of pTM4010 carrying insertion and point mutations in nif. Complementation analysis between 84 derivatives of pTM4010 carrying nif mutations and Rec- derivatives of the 390 Nif- mutants identified 14 genes. The nif mutations were ordered into 49 deletion groups with a gene order of his...nifQBALFMVSNEKDHJ. Complementation analysis of millimicron-induced, amber, frameshift, and deletion mutations indicates there are five polycistronic and two monocistronic operons: nifQ nifB, nifA nifL, nifF, nifM nifV nifS, nifN nifE, nifK nifD nifH, and nifJ. Transcription is from right to left in all polycistronic operons. PMID:361693

  7. Emergence of KPC-producing Klebsiella pneumoniae in Uruguay: infection control and molecular characterization

    PubMed Central

    Marquez, C; Ingold, A; Echeverría, N; Acevedo, A; Vignoli, R; García-Fulgueiras, V; Viroga, J; Gonzalez, O; Odizzio, V; Etulain, K; Nuñez, E; Albornoz, H; Borthagaray, G; Galiana, A

    2014-01-01

    We describe the first outbreak of Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-KP), the infection control measures adopted and the shift in resistance patterns of isolates during antibiotic treatment. The ST258 KPC-KP strain exhibited a multiresistant antibiotic phenotype including co-resistance to gentamycin, colistin and tigecycline intermediate susceptibility. Isolates before and after treatment had different behaviour concerning their antibiotic susceptibility and the population analysis profile study. A progressive increase in the aminoglycosides (acquiring amicacin resistance) and β-lactam MICs, and a decreased susceptibility to fosfomycin was observed throughout the administration of combined antimicrobial regimens including meropenem. A high meropenem resistance KPC-KP homogeneous population (MIC 256 Jg/mL), could arise from the meropenem heterogeneous low-level resistance KPC-KP population (MIC 8 Jg/mL), by the selective pressure of the prolonged meropenem therapy. The kpc gene was inserted in a Tn4401 isoform a, and no transconjugants were detected. The core measures adopted were successful to prevent evolution towards resistance dissemination. PMID:25356345

  8. Butanediol production from cellulose and hemicellulose by Klebsiella pneumoniae grown in sequential coculture with Trichoderma harzianum

    SciTech Connect

    Yu, E.K.C.; Deschatelets, L.; Louis-Seize, G.; Saddler, J.N.

    1985-10-01

    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.

  9. Structural and kinetic insights into the mechanism of 5-hydroxyisourate hydrolase from Klebsiella pneumoniae

    SciTech Connect

    French, Jarrod B.; Ealick, Steven E.

    2011-08-01

    The crystal structure of 5-hydroxyisourate hydrolase from K. pneumoniae and the steady-state kinetic parameters of the native enzyme as well as several mutants provide insights into the catalytic mechanism of this enzyme and the possible roles of the active-site residues. The stereospecific oxidative degradation of uric acid to (S)-allantoin has recently been demonstrated to proceed via two unstable intermediates and requires three separate enzymatic reactions. The second step of this reaction, the conversion of 5-hydroxyisourate (HIU) to 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline, is catalyzed by HIU hydrolase (HIUH). The high-resolution crystal structure of HIUH from the opportunistic pathogen Klebsiella pneumoniae (KpHIUH) has been determined. KpHIUH is a homotetrameric protein that, based on sequence and structural similarity, belongs to the transthyretin-related protein family. In addition, the steady-state kinetic parameters for this enzyme and four active-site mutants have been measured. These data provide valuable insight into the functional roles of the active-site residues. Based upon the structural and kinetic data, a mechanism is proposed for the KpHIUH-catalyzed reaction.

  10. Structural and Mechanistic Studies on Klebsiella pneumoniae 2-Oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline Decarboxylase

    SciTech Connect

    French, Jarrod B.; Ealick, Steven E.

    2010-11-12

    The stereospecific oxidative degradation of uric acid to (S)-allantoin was recently shown to proceed via three enzymatic steps. The final conversion is a decarboxylation of the unstable intermediate 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline (OHCU) and is catalyzed by OHCU decarboxylase. Here we present the structures of Klebsiella pneumoniae OHCU decarboxylase in unliganded form and with bound allantoin. These structures provide evidence that ligand binding organizes the active site residues for catalysis. Modeling of the substrate and intermediates provides additional support for this hypothesis. In addition we characterize the steady state kinetics of this enzyme and report the first OHCU decarboxylase inhibitor, allopurinol, a structural isomer of hypoxanthine. This molecule is a competitive inhibitor of K. pneumoniae OHCU decarboxylase with a K{sub i} of 30 {+-} 2 {micro}m. Circular dichroism measurements confirm structural observations that this inhibitor disrupts the necessary organization of the active site. Our structural and biochemical studies also provide further insights into the mechanism of catalysis of OHCU decarboxylation.

  11. Dissemination of clonally related multidrug-resistant Klebsiella pneumoniae in Ireland.

    PubMed

    Morris, D; O'Connor, M; Izdebski, R; Corcoran, M; Ludden, C E; McGrath, E; Buckley, V; Cryan, B; Gniadkowski, M; Cormican, M

    2016-01-01

    In October 2012, an outbreak of gentamicin-resistant, ciprofloxacin non-susceptible extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae occurred in a neonatal intensive care unit in Ireland. In order to determine whether the outbreak strain was more widely dispersed in the country, 137 isolates of K. pneumoniae with this resistance phenotype collected from 17 hospitals throughout Ireland between January 2011 and July 2013 were examined. ESBL production was confirmed phenotypically and all isolates were screened for susceptibility to 19 antimicrobial agents and for the presence of genes encoding bla TEM, bla SHV, bla OXA, and bla CTX-M; 22 isolates were also screened for bla KPC, bla NDM, bla VIM, bla IMP and bla OXA-48 genes. All isolates harboured bla SHV and bla CTX-M and were resistant to ciprofloxacin, gentamicin, nalidixic acid, amoxicillin-clavulanate, and cefpodoxime; 15 were resistant to ertapenem, seven to meropenem and five isolates were confirmed as carbapenemase producers. Pulsed-field gel electrophoresis of all isolates identified 16 major clusters, with two clusters comprising 61% of the entire collection. Multilocus sequence typing of a subset of these isolates identified a novel type, ST1236, a single locus variant of ST48. Data suggest that two major clonal groups, ST1236/ST48 (CG43) and ST15/ST14 (CG15) have been circulating in Ireland since at least January 2011.

  12. Contribution of the Klebsiella pneumoniae Capsule to Bacterial Aggregate and Biofilm Microstructures▿ †

    PubMed Central

    Dzul, Stephen P.; Thornton, Margaret M.; Hohne, Danial N.; Stewart, Elizabeth J.; Shah, Aayush A.; Bortz, David M.; Solomon, Michael J.; Younger, John G.

    2011-01-01

    We studied the interaction between capsule production and hydrodynamic growth conditions on the internal and macroscopic structure of biofilms and spontaneously formed aggregates of Klebsiella pneumoniae. Wild-type and capsule-deficient strains were studied as biofilms and under strong and mild hydrodynamic conditions. Internal organization of multicellular structures was determined with a novel image-processing algorithm for feature extraction from high-resolution confocal microscopy. Measures included interbacterial spacing and local angular alignment of individual bacteria. Macroscopic organization was measured via the size distribution of aggregate populations forming under various conditions. Compared with wild-type organisms, unencapsulated mutant organisms formed more organized aggregates with less variability in interbacterial spacing and greater interbacterial angular alignment. Internal aggregate structure was not detectably affected by the severity of hydrodynamic growth conditions. However, hydrodynamic conditions affected both wild-type and mutant aggregate size distributions. Bacteria grown under high-speed shaking conditions (i.e., at Reynolds' numbers beyond the laminar-turbulent transition) formed few multicellular aggregates while clumpy growth was common in bacteria grown under milder conditions. Our results indicate that both capsule and environment contribute to the structure of communities of K. pneumoniae, with capsule exerting influence at an interbacterial length scale and fluid dynamic forces affecting overall particle size. PMID:21239544

  13. Biofilm formation of Klebsiella pneumoniae on urethral catheters requires either type 1 or type 3 fimbriae.

    PubMed

    Stahlhut, Steen G; Struve, Carsten; Krogfelt, Karen A; Reisner, Andreas

    2012-07-01

    Urinary catheters are standard medical devices utilized in both hospital and nursing home settings, but are associated with a high frequency of catheter-associated urinary tract infections (CAUTI). In particular, biofilm formation on the catheter surface by uropathogens such as Klebsiella pneumoniae causes severe problems. Here we demonstrate that type 1 and type 3 fimbriae expressed by K. pneumoniae enhance biofilm formation on urinary catheters in a catheterized bladder model that mirrors the physico-chemical conditions present in catheterized patients. Furthermore, we show that both fimbrial types are able to functionally compensate for each other during biofilm formation on urinary catheters. In situ monitoring of fimbrial expression revealed that neither of the two fimbrial types is expressed when cells are grown planktonically. Interestingly, during biofilm formation on catheters, both fimbrial types are expressed, suggesting that they are both important in promoting biofilm formation on catheters. Additionally, transformed into and expressed by a nonfimbriated Escherichia coli strain, both fimbrial types significantly increased biofilm formation on catheters compared with the wild-type E. coli strain. The widespread occurrence of the two fimbrial types in different species of pathogenic bacteria stresses the need for further assessment of their role during urinary tract infections.

  14. Antibacterial effect of scandium and indium complexes of enterochelin on Klebsiella pneumoniae.

    PubMed Central

    Rogers, H J; Synge, C; Woods, V E

    1980-01-01

    A number of studies point to the conclusion that enterochelin, the iron chelator produced by a number of pathogenic enterobacteria, may be an essential metabolite for bacterial multiplication within the host. The compound removes iron from complexes with the host iron-binding proteins transferrin and lactoferrin, and the resulting ferric enterochelin is assimilated by the bacterial cell. It was reasoned that complexes of enterochelin with ions other than Fe3+ might act as antimetabolites and inhibit bacterial multiplication by interfering with the assimilation of ferric enterochelin. Enterochelin forms complexes with a number of group III and transition metal ions. The complex containing scandium exerts a bacteriostatic effect on Klebsiella pneumoniae in serum, whereas the indium complex induces a large increase in the generation time. The Fe3+ complexes of other microbial iron-transporting compounds are capable of reversing the bacteriostatic effect of the Sc3+ complex of enterochelin, suggesting that the compound acts solely by interfering with the enterochelin system of iron transport. Preliminary experiments show that the Sc3+ complex probably acts as a competitive inhibitor of ferric enterochelin. The Sc3+ complex of enterochelin exerts a therapeutic effect on intraperitoneal K. pneumoniae infections in mice similar to that obtained with kanamycin sulfate. PMID:6448022

  15. Enhanced Promoter Activity by Replenishment of Sigma Factor rpoE in Klebsiella pneumoniae.

    PubMed

    Chen, Liuni; Li, Ying; Tian, Pingfang

    2016-06-01

    Plasmid-dependent overexpression of enzyme(s) aims to divert carbon flux toward a desired compound. One drawback of this strategy is compromise of growth due to massive consumption of host resources. Here we show that replenishment of sigma factor rpoE improves the growth of Klebsiella pneumoniae. The gene rpoE was expressed alone or coexpressed with Ald4 (an aldehyde dehydrogenase from Saccharomyces cerevisiae) in K. pneumoniae. We found that the Ald4 activity was higher in the strain coexpressing Ald4 and rpoE (32.3 U/mg) than that expressing Ald4 alone (29.9 U/mg). Additionally, under shake-flask conditions, the strain coexpressing Ald4 and rpoE produced 0.5 g 3-hydroxypropionic acid (3-HP) and 9.8 g 1,3-propanediol (1,3-PD) per liter in 24 h, which were 1.6- and 0.85-fold enhancement, respectively, compared to those expressing Ald4 alone. Notably, under non-optimized bioreactor conditions, the strain coexpressing Ald4 and rpoE produced 13.5 g 3-HP and 37.8 g 1,3-PD per liter with glycerol conversion ratio of 0.45 mol/mol. These results indicate that replenishment of rpoE enhanced promoter activity and stimulated glycerol consumption. PMID:27570311

  16. Molybdenum carbide as anodic catalyst for microbial fuel cell based on Klebsiella pneumoniae.

    PubMed

    Zeng, Lizhen; Zhang, Lixia; Li, Weishan; Zhao, Shaofei; Lei, Jianfei; Zhou, Zhihui

    2010-08-15

    A pure beta-molybdenum carbide (M(O2)C) with a Brunauer-Emmett-Teller (BET) special surface area of 77.5 m2/g, prepared by solution derived precursor, was used as anodic catalyst of microbial fuel cell (MFC) based on Klebsiella pneumoniae (K. pneumoniae). The electrochemical activity of the prepared M(O2)C and the performance of the MFC were investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and polarization curve measurement. The results show that the prepared M(O2)C has high electrocatalytic activity and is a potential alternative to platinum as the anodic catalyst of MFCs. The maximum power density of single-cube MFC with 6.0 mg/cm2 M(O2)C as anodic catalyst is 2.39 W/m3. This power density is far higher than that of the MFC with carbon felt as anode without any catalyst (0.61 W/m3), and comparable to that of the MFC using 0.5 mg/cm2 Pt as anodic catalyst (3.64 W/m3).

  17. Inhibitory potential of Buffalo (Bubalus bubalis) colostrum immunoglobulin G on Klebsiella pneumoniae.

    PubMed

    L S, Mamatha Bhanu; Nishimura, S-I; H S, Aparna

    2016-07-01

    The unique components of colostrum like free oligosaccharides and glycoconjugates are known to offer resistance to enzymatic digestion in the gastrointestinal tract and have the ability to inhibit the localized adherence of enteropathogens to the digestive tract of the neonates. In this context, we have evaluated the in vitro effect of buffalo colostrum immunoglobulin G on human pathogen Klebsiella pneumoniae, a predominant multidrug resistant pathogen associated with nasocomial infections. The investigation revealed growth inhibitory potential of immunoglobulin G in a dose dependent manner supported by scanning electron microscopic studies. The N-glycan enriched fraction of immunoglobulin G after PNGase treatment was found more effective, comparable to ampicillin than native immunoglobulin G supporting the fact that colostrum derived oligosaccharides is crucial and act as ideal substrates for undesirable and pathogenic bacteria. The MALDI TOF/TOF analysis confirmed the glycostructures of abundant N-glycans of immunoglobulin G exerting antibacterial activity. The proteomic analysis revealed variations between control and treated cells and expression of chemotaxis-CheY protein (14kDa) was evidenced in response to immunoglobulin G treatment. Hence, it would be interesting to investigate the mode of inhibition of multidrug-resistant K. pneumoniae by buffalo colostrum immunoglobulin G with the identification of a newly expressed signalling protein.

  18. Heteroresistance to Colistin in Klebsiella pneumoniae Associated with Alterations in the PhoPQ Regulatory System

    PubMed Central

    Jayol, Aurélie; Nordmann, Patrice; Brink, Adrian

    2015-01-01

    A multidrug-resistant Klebsiella pneumoniae isolate exhibiting heteroresistance to colistin was investigated. The colistin-resistant subpopulation harbored a single amino acid change (Asp191Tyr) in protein PhoP, which is part of the PhoPQ two-component system that activates pmrHFIJKLM expression responsible for l-aminoarabinose synthesis and polymyxin resistance. Complementation assays with a wild-type phoP gene restored full susceptibility to colistin. Then, analysis of the colistin-susceptible subpopulation showed a partial deletion (25 bp) in the phoP gene compared to that in the colistin-resistant subpopulation. That deletion disrupted the reading frame of phoP, leading to a longer and inactive protein (255 versus 223 amino acids long). This is the first report showing the involvement of mutation(s) in PhoP in colistin resistance. Furthermore, this is the first study to decipher the mechanisms leading to colistin heteroresistance in K. pneumoniae. PMID:25733503

  19. Modeling and Robustness Analysis of Biochemical Networks of Glycerol Metabolism by Klebsiella Pneumoniae

    NASA Astrophysics Data System (ADS)

    Ye, Jianxiong; Feng, Enmin; Wang, Lei; Xiu, Zhilong; Sun, Yaqin

    Glycerol bioconversion to 1,3-propanediol (1,3-PD) by Klebsiella pneumoniae (K. pneumoniae) can be characterized by an intricate network of interactions among biochemical fluxes, metabolic compounds, key enzymes and genetic regulatory. To date, there still exist some uncertain factors in this complex network because of the limitation in bio-techniques, especially in measuring techniques for intracellular substances. In this paper, among these uncertain factors, we aim to infer the transport mechanisms of glycerol and 1,3-PD across the cell membrane, which have received intensive interest in recent years. On the basis of different inferences of the transport mechanisms, we reconstruct various metabolic networks correspondingly and subsequently develop their dynamical systems (S-systems). To determine the most reasonable metabolic network from all possible ones, we establish a quantitative definition of biological robustness and undertake parameter identification and robustness analysis for each system. Numerical results show that it is most possible that both glycerol and 1,3-PD pass the cell membrane by active transport and passive diffusion.

  20. Emergence of ST147 Klebsiella pneumoniae Producing OXA-204 Carbapenemase in a University Hospital, Tunisia.

    PubMed

    Grami, Raoudha; Mansour, Wejdene; Ben Haj Khalifa, Anis; Dahmen, Safia; Chatre, Pierre; Haenni, Marisa; Aouni, Mahjoub; Madec, Jean-Yves

    2016-03-01

    Molecular features of the first carbapenem-resistant Klebsiella pneumoniae isolates (KP1 and KP2) from the University Hospital Tahar Sfar, Tunisia, were investigated. Antimicrobial susceptibility testing, multilocus sequence typing, S1 nuclease pulsed-field gel electrophoresis, Southern blot, and polymerase chain reaction (PCR)-based replicon typing were performed. Extended-spectrum β-lactamases and carbapenemase genes were detected by PCR and sequencing. Both isolates were multidrug resistant. KP1 was of sequence type (ST) ST101 and exhibited blaCTX-M-15 and blaTEM-1 on an untypeable plasmid and blaOXA-48 on an IncL/M plasmid. KP2 was genetically unrelated to KP1 (ST147) and harbored an IncA/C plasmid carrying blaCMY-4 and the blaOXA-48 derivative gene: blaOXA-204. This study reports the second case worldwide of an OXA-204-producing K. pneumoniae isolate from the same country, however, in a different genetic background.

  1. Pneumonia and bacteremia in a golden-headed lion tamarin (Leontopithecus chrysomelas) caused by Klebsiella pneumoniae subsp. pneumoniae during a translocation program of free-ranging animals in Brazil.

    PubMed

    Bueno, Marina G; Iovine, Renata O; Torres, Luciana N; Catão-Dias, José L; Pissinatti, Alcides; Kierulff, Maria C M; Carvalho, Vania M

    2015-05-01

    Klebsiella pneumoniae is an important emerging pathogen in humans, particularly the invasive hypermucoviscosity (HMV) phenotype. In addition, the organism is an important public health concern because of nosocomial infections and antimicrobial resistance. Nonhuman primates in captivity are susceptible to Klebsiella, particularly when a stress factor is involved. Infections vary depending on the species but can cause significant morbidity and mortality in these animals. The objective of this study was to describe a case of bronchopneumonia and bacteremia caused by Klebsiella pneumoniae in a free-ranging golden-headed lion tamarin (Leontopithecus chrysomelas) caught and maintained in quarantine during a translocation program for conservation purposes. An adult male, that had showed emaciation and apathy, was clinically examined and, despite being provided supportive therapy, died 2 days after onset of clinical signs. At postmortem examination, generalized bilateral pneumonia and pericarditis were observed. Tissue samples were fixed in 10% formalin for histology, and pulmonary tissues and cardiac blood were collected for microbiologic diagnostic procedures. Bacteria that were shown to be HMV K. pneumoniae subsp. pneumoniae strains were isolated from the pulmonary fluids and cardiac blood in pure cultures. Severe bronchopneumonia was the main pathological finding. The consequences of the confirmed presence of the HMV phenotype of K. pneumoniae subsp. pneumoniae in this wildlife species for human, animal, and ecosystem health should be determined. These results demonstrate the importance of quarantine and potential pathogen screening during wildlife translocation procedures.

  2. Evaluation of antibacterial effects of Zataria multiflora Boiss extracts against ESBL-producing Klebsiella pneumoniae strains

    PubMed Central

    Dadashi, Masoud; Hashemi, Ali; Eslami, Gita; Fallah, Fatemeh; Goudarzi, Hossein; Erfanimanesh, Soroor; Taherpour, Arezou

    2016-01-01

    Objective: There are few therapeutic options for treatment of multidrug resistant Klebsiella pneumoniae isolates as a hospital infectious agent (nosocomial infection). The aim of this study was to evaluate the antibacterial activity of Zataria multiflora Boiss extracts against ESBL-producing Klebsiella pneumoniae strains. Materials and Methods: This study was conducted on 100 K. pneumoniae isolates from two hospitals in Tehran, Iran. Antibiotic susceptibility tests were performed by Kirby-Bauer disc diffusion and microdilution broth methods and detection of ESBL was carried out according to CLSI guidelines. The blaCTX-M-15 plasmid gene was detected by PCR and sequencing methods. Extracts susceptibility test was performed by broth microdilution method. Results: Among 100 K. pneumoniae strains, 48 (48%) were ESBL positive. In this study, fosfomycin, colistin and tigecycline were more active than other antibiotics. The existence of blaCTX-M-15 was detected in 30 (62.5%) of 48 ESBL-producing isolates. The chloroformic extract showed potent activity against ESBL-producing K. pneumoniae strains (MIC50 = 1.56 mg/ml and MIC90=3.12mg/ml). The MIC50 and MIC90 (The MIC50 represents the MIC value at which ≥50% of the isolates in a test population are inhibited and the MIC90 represents the MIC value at which ≥90% of the strains within a test population are inhibited) were 3.12 and 6.25 mg/ml and 6.25 and 12.5 mg/ml for methanolic and acetonic extracts, respectively. Conclusion: The incidence of ESBL-producing K. pneumoniae is very high. Therefore, detection of ESBL-producing K. pneumoniae isolates is of great importance in identifying drug resistance patterns in K. pneumoniae isolates and in control of infections. Zataria multiflora may have the potential to be used against multidrug resistant organisms such as clinical isolates of ESBL-producing K. pneumoniae. PMID:27462557

  3. Therapeutic Role of Interleukin 22 in Experimental Intra-abdominal Klebsiella pneumoniae Infection in Mice

    PubMed Central

    Zheng, Mingquan; Horne, William; McAleer, Jeremy P.; Pociask, Derek; Eddens, Taylor; Good, Misty; Gao, Bin

    2016-01-01

    Interleukin 22 (IL-22) is an IL-10-related cytokine produced by T helper 17 (Th17) cells and other immune cells that signals via IL-22 receptor alpha 1 (IL-22Ra1), which is expressed on epithelial tissues, as well as hepatocytes. IL-22 has been shown to have hepatoprotective effects that are mediated by signal transducer and activator of transcription 3 (STAT3) signaling. However, it is unclear whether IL-22 can directly regulate antimicrobial programs in the liver. To test this hypothesis, hepatocyte-specific IL-22Ra1 knockout (Il22Ra1Hep−/−) and Stat3 knockout (Stat3Hep−/−) mice were generated and subjected to intra-abdominal infection with Klebsiella pneumoniae, which results in liver injury and necrosis. We found that overexpression of IL-22 or therapeutic administration of recombinant IL-22 (rIL-22), given 2 h postinfection, significantly reduced the bacterial burden in both the liver and spleen. The antimicrobial activity of rIL-22 required hepatic Il22Ra1 and Stat3. Serum from rIL-22-treated mice showed potent bacteriostatic activity against K. pneumoniae, which was dependent on lipocalin 2 (LCN2). However, in vivo, rIL-22-induced antimicrobial activity was only partially reduced in LCN2-deficient mice. We found that rIL-22 also induced serum amyloid A2 (SAA2) and that SAA2 had anti-K. pneumoniae bactericidal activity in vitro. These results demonstrate that IL-22, through IL-22Ra1 and STAT3 singling, can induce intrinsic antimicrobial activity in the liver, which is due in part to LCN2 and SAA2. Therefore, IL-22 may be a useful adjunct in treating hepatic and intra-abdominal infections. PMID:26729763

  4. Plasmid Dynamics in KPC-Positive Klebsiella pneumoniae during Long-Term Patient Colonization

    PubMed Central

    Park, Morgan; Deming, Clayton; Thomas, Pamela J.; Young, Alice C.; Coleman, Holly; Sison, Christina; Weingarten, Rebecca A.; Lau, Anna F.; Dekker, John P.; Palmore, Tara N.; Frank, Karen M.

    2016-01-01

    ABSTRACT Carbapenem-resistant Klebsiella pneumoniae strains are formidable hospital pathogens that pose a serious threat to patients around the globe due to a rising incidence in health care facilities, high mortality rates associated with infection, and potential to spread antibiotic resistance to other bacterial species, such as Escherichia coli. Over 6 months in 2011, 17 patients at the National Institutes of Health (NIH) Clinical Center became colonized with a highly virulent, transmissible carbapenem-resistant strain of K. pneumoniae. Our real-time genomic sequencing tracked patient-to-patient routes of transmission and informed epidemiologists’ actions to monitor and control this outbreak. Two of these patients remained colonized with carbapenemase-producing organisms for at least 2 to 4 years, providing the opportunity to undertake a focused genomic study of long-term colonization with antibiotic-resistant bacteria. Whole-genome sequencing studies shed light on the underlying complex microbial colonization, including mixed or evolving bacterial populations and gain or loss of plasmids. Isolates from NIH patient 15 showed complex plasmid rearrangements, leaving the chromosome and the blaKPC-carrying plasmid intact but rearranging the two other plasmids of this outbreak strain. NIH patient 16 has shown continuous colonization with blaKPC-positive organisms across multiple time points spanning 2011 to 2015. Genomic studies defined a complex pattern of succession and plasmid transmission across two different K. pneumoniae sequence types and an E. coli isolate. These findings demonstrate the utility of genomic methods for understanding strain succession, genome plasticity, and long-term carriage of antibiotic-resistant organisms. PMID:27353756

  5. Quorum quenching activity of Syzygium cumini (L.) Skeels and its anthocyanin malvidin against Klebsiella pneumoniae.

    PubMed

    Gopu, Venkadesaperumal; Kothandapani, Sundar; Shetty, Prathapkumar Halady

    2015-02-01

    Many bacterial species use their intercellular signaling mechanism called quorum sensing (QS), which is found to be implicated in various factors including bacterial pathogenicity and food spoilage. Interrupting the bacterial communication is an attractive strategy to develop novel QS-based antibacterial drugs. Present study is aimed to investigate the quorum sensing inhibitory activity of Syzygium cumini and its anti-biofilm property against opportunistic pathogen using a biosensor strain Chromobacterium violaceum CV026. Ethanol extract of S. cumini was investigated for its anti-QS activity, and the possible active component was identified by docking with LasR receptor protein. Based on docking analysis, methanol extract was enriched for its total anthocyanin (STA) and its effect on QS regulated phenotypes was assessed. STA specifically inhibited the violacein production in C. violaceum; biofilm formation and EPS production in Klebsiella pneumoniae up to 82, 79.94 and 64.29% respectively. Synergistic activity of conventional antibiotics with STA enhanced the susceptibility of K. pneumoniae up to 58.45%. Molecular docking analysis of active components attributes the QSI activity of S. cumini to malvidin. Malvidin exhibited highest ligand binding with LasR receptor protein with docking score more than -7. Effect of malvidin to interrupt the QS regulated phenotypes was also assessed, and it was found to reduce the violacein production, biofilm formation and EPS production of K. pneumoniae in a concentration-dependent manner. These findings suggest that S. cumini can be used as novel QS-based antibacterial/anti-biofilm agent to manage food-borne pathogens and to increase food safety.

  6. Artificial Klebsiella pneumoniae biofilm model mimicking in vivo system: altered morphological characteristics and antibiotic resistance.

    PubMed

    Singla, Saloni; Harjai, Kusum; Chhibber, Sanjay

    2014-04-01

    The purpose of this study was to develop a biofilm model of Klebsiella pneumoniae B5055, mimicking in vivo biofilm system so as to determine susceptibility of different phases of biofilm to antibiotics by three-dimensional analysis. Artificial mature biofilm of K. pneumoniae was made on black, polycarbonate membranes. Biofilm structure was visualized by scanning electron microscope (SEM) and confocal laser scanning microscopy (CLSM). Viable count method, CLSM and SEM analysis confirmed that mature, uniform and viable biofilms can be formed on the polycarbonate membranes by this method. The three-dimensional heterogeneity of biofilm was confirmed on the basis of results of CLSM, which is an important characteristics of in vivo biofilm system. Staining with the LIVE/DEAD BacLight viability kit and acridine orange suggested that the center of biofilm had more inactive cells compared with actively dividing cells on the periphery. Amikacin at a concentration of 40 μg ml⁻¹ was effective against younger biofilm whereas ineffective against older biofilm that showed sparsely populated dead cells using the BacLight viability staining kit. Role of altered morphological characteristics toward increased antibiotic susceptibility was also studied for different phases of K. pneumoniae biofilm by CLSM and light microscopy. Thickness of biofilm increased from 0.093 to 0.231 mm with time. So, both heterogeneity and thickness of the biofilm are likely to influence the ineffectiveness of amikacin in older biofilm. The present model holds considerable clinical relevance and may be useful for evaluating the efficacy of antimicrobial agent on bacterial biofilms in vitro.

  7. Quorum quenching activity of Syzygium cumini (L.) Skeels and its anthocyanin malvidin against Klebsiella pneumoniae.

    PubMed

    Gopu, Venkadesaperumal; Kothandapani, Sundar; Shetty, Prathapkumar Halady

    2015-02-01

    Many bacterial species use their intercellular signaling mechanism called quorum sensing (QS), which is found to be implicated in various factors including bacterial pathogenicity and food spoilage. Interrupting the bacterial communication is an attractive strategy to develop novel QS-based antibacterial drugs. Present study is aimed to investigate the quorum sensing inhibitory activity of Syzygium cumini and its anti-biofilm property against opportunistic pathogen using a biosensor strain Chromobacterium violaceum CV026. Ethanol extract of S. cumini was investigated for its anti-QS activity, and the possible active component was identified by docking with LasR receptor protein. Based on docking analysis, methanol extract was enriched for its total anthocyanin (STA) and its effect on QS regulated phenotypes was assessed. STA specifically inhibited the violacein production in C. violaceum; biofilm formation and EPS production in Klebsiella pneumoniae up to 82, 79.94 and 64.29% respectively. Synergistic activity of conventional antibiotics with STA enhanced the susceptibility of K. pneumoniae up to 58.45%. Molecular docking analysis of active components attributes the QSI activity of S. cumini to malvidin. Malvidin exhibited highest ligand binding with LasR receptor protein with docking score more than -7. Effect of malvidin to interrupt the QS regulated phenotypes was also assessed, and it was found to reduce the violacein production, biofilm formation and EPS production of K. pneumoniae in a concentration-dependent manner. These findings suggest that S. cumini can be used as novel QS-based antibacterial/anti-biofilm agent to manage food-borne pathogens and to increase food safety. PMID:25637095

  8. The fur gene from Klebsiella pneumoniae: characterization, genomic organization and phylogenetic analysis.

    PubMed

    Achenbach, L A; Yang, W

    1997-02-01

    The Fur (ferric uptake regulator) protein controls the expression of a number of bacterial virulence determinants including those involved in iron uptake. The fur gene was cloned and characterized from Klebsiella pneumoniae. The gene is preceded by a single autoregulated promoter whose -10 region overlaps the putative Fur binding site. The autoregulated nature of the K. pneumoniae fur gene and functionality of the encoded Fur repressor were tested in Fur titration and complementation assays. A partial open reading frame upstream from the fur gene was identified as a flavodoxin (fldA) gene. An open reading frame located 50 bases downstream from the fur stop codon appears to be a truncated citA gene that, if functional, would encode only the carboxy terminus of a citrate utilization protein. The fldA-fur arrangement is also present in Escherichia coli. However, the fur-citA arrangement found in K. pneumoniae is novel. It appears that the chromosomal region downstream from the fur gene is unstable and, thus, variable even in closely related bacterial lineages. To assess of the ability of the Fur protein sequence to reflect organismal phylogeny, the Fur protein tree was compared to the tree of 16S rRNA (ribosomal RNA). The Fur dataset comprises almost an order of magnitude fewer characters than the 16S rRNA but is nonetheless able to track the phylogenetic signal reasonably well, suggesting that the fur gene, like the 16S rDNA, may not be subject to horizontal gene transfer in these bacteria.

  9. Frequency, Antimicrobial Resistance and Genetic Diversity of Klebsiella pneumoniae in Food Samples

    PubMed Central

    Pang, Zhizhao; Qin, Tian; Ren, Hongyu; Pan, Zhuo; Zhou, Jikun

    2016-01-01

    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

  10. High Prevalence of Hypervirulent Klebsiella pneumoniae Infection in China: Geographic Distribution, Clinical Characteristics, and Antimicrobial Resistance.

    PubMed

    Zhang, Yawei; Zhao, Chunjiang; Wang, Qi; Wang, Xiaojuan; Chen, Hongbin; Li, Henan; Zhang, Feifei; Li, Shuguang; Wang, Ruobing; Wang, Hui

    2016-10-01

    Hypervirulent Klebsiella pneumoniae (hvKP) is traditionally defined by hypermucoviscosity, but data based on genetic background are limited. Antimicrobial-resistant hvKP has been increasingly reported but has not yet been systematically studied. K. pneumoniae isolates from bloodstream infections, hospital-acquired pneumonia, and intra-abdominal infections were collected from 10 cities in China during February to July 2013. Clinical data were collected from medical records. All K. pneumoniae isolates were investigated by antimicrobial susceptibility testing, string test, extended-spectrum β-lactamase (ESBL) gene detection, capsular serotypes, virulence gene profiles, and multilocus sequence typing. hvKP was defined by aerobactin detection. Of 230 K. pneumoniae isolates, 37.8% were hvKP. The prevalence of hvKP varied among different cities, with the highest rate in Wuhan (73.9%) and the lowest in Zhejiang (8.3%). Hypermucoviscosity and the presence of K1, K2, K20, and rmpA genes were strongly associated with hvKP (P < 0.001). A significantly higher incidence of liver abscess (P = 0.026), sepsis (P = 0.038), and invasive infections (P = 0.043) was caused by hvKP. Cancer (odds ratio [OR], 2.285) and diabetes mellitus (OR, 2.256) appeared to be independent variables associated with hvKP infections by multivariate analysis. Importantly, 12.6% of hvKP isolates produced ESBLs, and most of them carried blaCTX-M genes. Patients with neutropenia (37.5% versus 5.6%; P = 0.020), history of systemic steroid therapy (37.5% versus 5.6%; P = 0.020), and combination therapy (62.5% versus 16.7%; P = 0.009) were more likely to be infected with ESBL-producing hvKP. The prevalence of hvKP is high in China and has a varied geographic distribution. ESBL-producing hvKP is emerging, suggesting an urgent need to enhance clinical awareness, especially for immunocompromised patients receiving combination therapy. PMID:27480857

  11. Frequency, Antimicrobial Resistance and Genetic Diversity of Klebsiella pneumoniae in Food Samples.

    PubMed

    Guo, Yumei; Zhou, Haijian; Qin, Liyun; Pang, Zhizhao; Qin, Tian; Ren, Hongyu; Pan, Zhuo; Zhou, Jikun

    2016-01-01

    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

  12. Klebsiella pneumoniae invasive liver abscess syndrome with purulent meningitis and septic shock: A case from mainland China

    PubMed Central

    Qian, Yun; Wong, Chi-Chun; Lai, San-Chuan; Lin, Zheng-Hua; Zheng, Wei-Liang; Zhao, Hui; Pan, Kong-Han; Chen, Shu-Jie; Si, Jian-Min

    2016-01-01

    We present a rare case of invasive liver abscess syndrome due to Klebsiella pneumoniae (K. pneumoniae) with metastatic meningitis and septic shock. A previously healthy, 55-year-old female patient developed fever, liver abscess, septic shock, purulent meningitis and metastatic hydrocephalus. Upon admission, the clinical manifestations, laboratory and imaging examinations were compatible with a diagnosis of K. pneumoniae primary liver abscess. Her distal metastasis infection involved meningitis and hydrocephalus, which could flare abruptly and be life threatening. Even with early adequate drainage and antibiotic therapy, the patient’s condition deteriorated and she ultimately died. To the best of our knowledge, this is the first case of K. pneumoniae invasive liver abscess syndrome with septic meningitis reported in mainland China. Our findings reflect the need for a better understanding of the epidemiology, risk factors, complications, comorbid medical conditions and treatment of this disease. PMID:26973425

  13. [Microbial contamination of water by pipe and tube materials. 3. Behavior of E. coli, Citrobacter freundii and Klebsiella pneumoniae].

    PubMed

    Schoenen, D; Schlömer, G

    1989-08-01

    Materials water comes into contact with can promote the microbial growth as it could be shown before. The reaction of an unspecific microorganism flora and of Legionella pneumophila in pipes and hoses has been described in the two previous communications. The investigation with L. pneumophila has shown that even a pathogen organism can grow upon the materials. Therefore it was of special interest to prove whether indicator organisms for the testing of drinking water can grow in pipes and hoses as well. Escherichia coli, Citrobacter freundii and Klebsiella pneumoniae grew after the experimental contamination for many weeks on the rubber hose until the test was finally stopped, in the other pipes and hoses (glass, high-grade steel, PVC, PE, PA, PTFE and silicone) E. coli could be found for maximal 7 weeks, Citrobacter freundii for 1 week and Klebsiella pneumoniae for maximal 3 weeks. In the copper pipe the organisms could be found only for a few days. PMID:2673263

  14. Transposons and integrons in colistin-resistant clones of Klebsiella pneumoniae and Acinetobacter baumannii with epidemic or sporadic behaviour.

    PubMed

    Arduino, Sonia M; Quiroga, María Paula; Ramírez, María Soledad; Merkier, Andrea Karina; Errecalde, Laura; Di Martino, Ana; Smayevsky, Jorgelina; Kaufman, Sara; Centrón, Daniela

    2012-10-01

    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.

  15. Ertapenem-Containing Double-Carbapenem Therapy for Treatment of Infections Caused by Carbapenem-Resistant Klebsiella pneumoniae.

    PubMed

    Cprek, Jessica B; Gallagher, Jason C

    2015-11-09

    We describe outcomes of patients with infections with carbapenem-resistant Klebsiella pneumoniae (CRKP) who received ertapenem-containing double-carbapenem therapy (ECDCT). Clinical success was observed in 7/18 (39%) patients overall: bloodstream infections, 3/7 (43%); pneumonia, 1/5 (20%); intraabdominal infections, 0/2 (0%); urinary tract infections, 2/3 (67%); and a skin and skin structure infection, 1/1 (100%). Microbiologic success was observed in 11/14 (79%) evaluable patients; 5/18 (28%) patients died. ECDCT may be effective for CRKP infections with limited treatment options.

  16. Vaccination with Klebsiella pneumoniae-derived extracellular vesicles protects against bacteria-induced lethality via both humoral and cellular immunity.

    PubMed

    Lee, Won-Hee; Choi, Hyun-Il; Hong, Sung-Wook; Kim, Kwang-Sun; Gho, Yong Song; Jeon, Seong Gyu

    2015-01-01

    The emergence of multidrug-resistant Klebsiella pneumoniae highlights the need to develop preventive measures to ameliorate Klebsiella infections. Bacteria-derived extracellular vesicles (EVs) are spherical nanometer-sized proteolipids enriched with outer membrane proteins. Gram-negative bacteria-derived EVs have gained interest for use as nonliving complex vaccines. In the present study, we evaluated whether K. pneumoniae-derived EVs confer protection against bacteria-induced lethality. K. pneumoniae-derived EVs isolated from in vitro bacterial culture supernatants induced innate immunity, including the upregulation of co-stimulatory molecule expression and proinflammatory mediator production. EV vaccination via the intraperitoneal route elicited EV-reactive antibodies and interferon-gamma-producing T-cell responses. Three vaccinations with the EVs prevented bacteria-induced lethality. As verified by sera and splenocytes adoptive transfer, the protective effect of EV vaccination was dependent on both humoral and cellular immunity. Taken together, these findings suggest that K. pneumoniae-derived EVs are a novel vaccine candidate against K. pneumoniae infections. PMID:26358222

  17. Vaccination with Klebsiella pneumoniae-derived extracellular vesicles protects against bacteria-induced lethality via both humoral and cellular immunity

    PubMed Central

    Lee, Won-Hee; Choi, Hyun-Il; Hong, Sung-Wook; Kim, Kwang-sun; Gho, Yong Song; Jeon, Seong Gyu

    2015-01-01

    The emergence of multidrug-resistant Klebsiella pneumoniae highlights the need to develop preventive measures to ameliorate Klebsiella infections. Bacteria-derived extracellular vesicles (EVs) are spherical nanometer-sized proteolipids enriched with outer membrane proteins. Gram-negative bacteria-derived EVs have gained interest for use as nonliving complex vaccines. In the present study, we evaluated whether K. pneumoniae-derived EVs confer protection against bacteria-induced lethality. K. pneumoniae-derived EVs isolated from in vitro bacterial culture supernatants induced innate immunity, including the upregulation of co-stimulatory molecule expression and proinflammatory mediator production. EV vaccination via the intraperitoneal route elicited EV-reactive antibodies and interferon-gamma-producing T-cell responses. Three vaccinations with the EVs prevented bacteria-induced lethality. As verified by sera and splenocytes adoptive transfer, the protective effect of EV vaccination was dependent on both humoral and cellular immunity. Taken together, these findings suggest that K. pneumoniae-derived EVs are a novel vaccine candidate against K. pneumoniae infections. PMID:26358222

  18. Intrapatient emergence of OXA-247: a novel carbapenemase found in a patient previously infected with OXA-163-producing Klebsiella pneumoniae.

    PubMed

    Gomez, S; Pasteran, F; Faccone, D; Bettiol, M; Veliz, O; De Belder, D; Rapoport, M; Gatti, B; Petroni, A; Corso, A

    2013-05-01

    Two genetically related Klebsiella pneumoniae strains carrying OXA-type carbapenemases were isolated from a single patient 1 month apart. Kpn163 harboured OXA-163 and Kpn247 a new variant named OXA-247 that showed susceptibility to carbapenems and expanded-spectrum cephalosporins similar to OXA-48. Our epidemiological, biochemical and molecular results suggest the intrapatient emergence of blaOXA -247 from blaOXA -163.

  19. Complete genome sequence of Klebsiella pneumoniae J1, a protein-based microbial flocculant-producing bacterium.

    PubMed

    Pang, Changlong; Li, Ang; Cui, Di; Yang, Jixian; Ma, Fang; Guo, Haijuan

    2016-02-20

    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. PMID:26806487

  20. First Case of Liver Abscess in Scandinavia Due to the International Hypervirulent Klebsiella Pneumoniae Clone ST23

    PubMed Central

    Gundestrup, Svend; Struve, Carsten; Stahlhut, Steen G.; Hansen, Dennis Schrøder

    2014-01-01

    This is the first case report from Scandinavia of a pyogenic liver abscess caused by a Klebsiella pneumoniae isolate belonging to the international hyper virulent clone ST23. The patient, an 85-year old Caucasian, had no history of foreign travel or any classical predisposing factors for infection. The isolate was hypermucoviscous of capsular serotype K1 and carried the virulence factors aerobactin, allS, kfu and rmpA. PMID:24688609

  1. Outbreak of Ampicillin/Piperacillin-Resistant Klebsiella Pneumoniae in a Neonatal Intensive Care Unit (NICU): Investigation and Control Measures

    PubMed Central

    Fabbri, Giuliana; Panico, Manuela; Dallolio, Laura; Suzzi, Roberta; Ciccia, Matilde; Sandri, Fabrizio; Farruggia, Patrizia

    2013-01-01

    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. PMID:23442560

  2. Role of Antibiotic Penetration Limitation in Klebsiella pneumoniae Biofilm Resistance to Ampicillin and Ciprofloxacin

    PubMed Central

    Anderl, Jeff N.; Franklin, Michael J.; Stewart, Philip S.

    2000-01-01

    The penetration of two antibiotics, ampicillin and ciprofloxacin, through biofilms developed in an in vitro model system was investigated. The susceptibilities of biofilms and corresponding freely suspended bacteria to killing by the antibiotics were also measured. Biofilms of Klebsiella pneumoniae were developed on microporous membranes resting on agar nutrient medium. The susceptibilities of planktonic cultures and biofilms to 10 times the MIC were determined. Antibiotic penetration through biofilms was measured by assaying the concentration of antibiotic that diffused through the biofilm to an overlying filter disk. Parallel experiments were performed with a mutant K. pneumoniae strain in which β-lactamase activity was eliminated. For wild-type K. pneumoniae grown in suspension culture, ampicillin and ciprofloxacin MICs were 500 and 0.18 μg/ml, respectively. The log reductions in the number of CFU of planktonic wild-type bacteria after 4 h of treatment at 10 times the MIC were 4.43 ± 0.33 and 4.14 ± 0.33 for ampicillin and ciprofloxacin, respectively. Biofilms of the same strain were much less susceptible, yielding log reductions in the number of CFU of −0.06 ± 0.06 and 1.02 ± 0.04 for ampicillin and ciprofloxacin, respectively, for the same treatment. The number of CFU in the biofilms after 24 h of antibiotic exposure was not statistically different from the number after 4 h of treatment. Ampicillin did not penetrate wild-type K. pneumoniae biofilms, whereas ciprofloxacin and a nonreactive tracer (chloride ion) penetrated the biofilms quickly. The concentration of ciprofloxacin reached the MIC throughout the biofilm within 20 min. Ampicillin penetrated biofilms formed by a β-lactamase-deficient mutant. However, the biofilms formed by this mutant were resistant to ampicillin treatment, exhibiting a 0.18 ± 0.07 log reduction in the number of CFU after 4 h of exposure and a 1.64 ± 0.33 log reduction in the number of CFU after 24 h of exposure. Poor

  3. [Structure and function of class 1 integron in clinical isolates of Klebsiella pneumoniae].

    PubMed

    Yuejin, Zhang; Qingli, Chang; Qian, Wang; Junwan, Lu; Huan, Wang; Peizhen, Li; Jun, Ying; Qiyu, Bao; Yunliang, Hu

    2014-06-01

    To investigate molecular mechanism of multi-resistance of Klebsiella pneumoniae and its spreading, 179 strains isolated from different clinical samples in the period of 2002-2007 with serious resistance to 14 anti-bacterial agents were examined. Among them, 118 (65.9%) were resistant to at least two anti-bacterial agents; 36.3% (65/179) were found to contain class 1 integrons. There was a significant difference for resistance rate between the integron positive and the negative groups, especially for antimicrobial agents of aminoglycosides, quinolones and sulfonamides (P<0.01). Gene cassette structures of the class 1 integrons in these bacteria were analyzed and their resistance genes were further cloned and tested for antibiotic resistance activities. Fifteen gene cassettes were identified with dfrA17-aadA5 being the most popular form. Three recombinant plasmids pET28a-dhfr17, pET28a-dhfr17-orfF and pET28a-dhfr17-orfF-aadA2 were cloned from a gene cassette of dhfr17-orfF-aadA2. When introduced into a recipient E. coli strain BL21, all of them rendered resistance to co-trimoxazole, with minimum inhibitory concentration (MIC) value up to 256 µg/µL. The E. coli BL21 carrying pET28a- dhfr17 or pET28a-dhfr17-orfF had the same MIC value of 8 µg/µL to streptomycin as the recipient strain without plasmid. However, the E. coli carrying pET28a-dhfr17-orfF-aadA2 was resistant to streptomycin with MIC level up to 256 µg/µL. In conclusion, class 1 integrons were regularly identified in Klebsiella pneumoniae. They mainly carry resistance genes against antimicrobial agents of aminoglycosides and sulfonamide. Transferable plasmid carrying integrons with resistance genes may play an important role in resistance spreading among bacterial species.

  4. Survey and rapid detection of Klebsiella pneumoniae in clinical samples targeting the rcsA gene in Beijing, China.

    PubMed

    Dong, Derong; Liu, Wei; Li, Huan; Wang, Yufei; Li, Xinran; Zou, Dayang; Yang, Zhan; Huang, Simo; Zhou, Dongsheng; Huang, Liuyu; Yuan, Jing

    2015-01-01

    Klebsiella pneumoniae is a wide-spread nosocomial pathogen. A rapid and sensitive molecular method for the detection of K. pneumoniae in clinical samples is needed to guide therapeutic treatment. In this study, we first described a loop-mediated isothermal amplification (LAMP) method for the rapid detection of capsular polysaccharide synthesis regulating gene rcsA from K. pneumoniaein clinical samples by using two methods including real-time turbidity monitoring and fluorescence detection to assess the reaction. Then dissemination of K. pneumoniae strains was investigated from ICU patients in three top hospitals in Beijing, China. The results showed that the detection limit of the LAMP method was 0.115 pg/μl DNA within 60 min under isothermal conditions (61°C), a 100-fold increase in sensitivity compared with conventional PCR. All 30 non- K. pneumoniae strains tested were negative for LAMP detection, indicating the high specificity of the LAMP reaction. To evaluate the application of the LAMP assay to clinical diagnosis, of 110 clinical sputum samples collected from ICU patients with clinically suspected multi-resistant infections in China, a total of 32 K. pneumoniae isolates were identified for LAMP-based surveillance of rcsA. All isolates belonged to nine different K. pneumoniae multilocus sequence typing (MLST) groups. Strikingly, of the 32 K. pneumoniae strains, 18 contained the Klebsiella pneumoniae Carbapenemase (KPC)-encoding gene bla KPC-2 and had high resistance to β-lactam antibiotics. Moreover, K. pneumoniae WJ-64 was discovered to contain bla KPC-2 and bla NDM-1genes simultaneously in the isolate. Our data showed the high prevalence of bla KPC-2 among K. pneumoniae and co-occurrence of many resistant genes in the clinical strains signal a rapid and continuing evolution of K. pneumoniae. In conclusion, we have developed a rapid and sensitive visual K. pneumoniae detection LAMP assay, which could be a useful tool for clinical screening, on

  5. Survey and rapid detection of Klebsiella pneumoniae in clinical samples targeting the rcsA gene in Beijing, China

    PubMed Central

    Dong, Derong; Liu, Wei; Li, Huan; Wang, Yufei; Li, Xinran; Zou, Dayang; Yang, Zhan; Huang, Simo; Zhou, Dongsheng; Huang, Liuyu; Yuan, Jing

    2015-01-01

    Klebsiella pneumoniae is a wide-spread nosocomial pathogen. A rapid and sensitive molecular method for the detection of K. pneumoniae in clinical samples is needed to guide therapeutic treatment. In this study, we first described a loop-mediated isothermal amplification (LAMP) method for the rapid detection of capsular polysaccharide synthesis regulating gene rcsA from K. pneumoniaein clinical samples by using two methods including real-time turbidity monitoring and fluorescence detection to assess the reaction. Then dissemination of K. pneumoniae strains was investigated from ICU patients in three top hospitals in Beijing, China. The results showed that the detection limit of the LAMP method was 0.115 pg/μl DNA within 60 min under isothermal conditions (61°C), a 100-fold increase in sensitivity compared with conventional PCR. All 30 non- K. pneumoniae strains tested were negative for LAMP detection, indicating the high specificity of the LAMP reaction. To evaluate the application of the LAMP assay to clinical diagnosis, of 110 clinical sputum samples collected from ICU patients with clinically suspected multi-resistant infections in China, a total of 32 K. pneumoniae isolates were identified for LAMP-based surveillance of rcsA. All isolates belonged to nine different K. pneumoniae multilocus sequence typing (MLST) groups. Strikingly, of the 32 K. pneumoniae strains, 18 contained the Klebsiella pneumoniae Carbapenemase (KPC)-encoding gene blaKPC-2 and had high resistance to β-lactam antibiotics. Moreover, K. pneumoniae WJ-64 was discovered to contain blaKPC-2 and blaNDM-1genes simultaneously in the isolate. Our data showed the high prevalence of blaKPC-2 among K. pneumoniae and co-occurrence of many resistant genes in the clinical strains signal a rapid and continuing evolution of K. pneumoniae. In conclusion, we have developed a rapid and sensitive visual K. pneumoniae detection LAMP assay, which could be a useful tool for clinical screening, on-site diagnosis

  6. Predictors of outcome in ICU patients with septic shock caused by Klebsiella pneumoniae carbapenemase-producing K. pneumoniae.

    PubMed

    Falcone, M; Russo, A; Iacovelli, A; Restuccia, G; Ceccarelli, G; Giordano, A; Farcomeni, A; Morelli, A; Venditti, M

    2016-05-01

    The aim of this study was to identify factors associated with mortality in intensive care unit patients with Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-Kp) septic shock. A retrospective analysis of intensive care unit patients with KPC-Kp infection and septic shock observed in a large teaching hospital from November 2010 to December 2014 was performed. A total of 111 patients were included in the study. The most frequent source of infection was unknown-focus bacteraemia in 53 patients (47.7%). The rate of resistance to colistin was 51.3%; 30-day mortality was reported for 44 patients (39.6%). Surviving patients were more frequently treated with an initial therapy (within 24 hours) including two or more antibiotics displaying in vitro activity against the isolated KPC-Kp strain (41.8 vs. 18.1%, p 0.01) and were also more likely to receive a definitive therapy including two or more in vitro active antibiotics (85.1 vs. 15.9%, p <0.001). Cox regression analysis revealed that a colistin-containing antibiotic regimen (hazard ratio (HR) 0.21, confidence interval (CI) 95% 0.05-0.72, p <0.001), use of two or more in vitro active antibiotics as definite therapy (HR 0.08, CI 95% 0.02-0.21, p <0.001) and control of removable source of infection (HR 0.14, CI 95% 0.04-0.25, p <0.001) were associated with favourable outcome; colistin resistance (HR 8.09, CI 95% 3.14-11.23, p 0.001) and intra-abdominal source of infection (HR 2.92, CI 95% 2.11-4.12, p 0.002) were associated with death. In conclusion, use of a definitive therapy with at least two antibiotics displaying in vitro activity against the KPC-Kp isolates was the most important determinant of favourable outcome, whilst isolation of colistin-resistant strains was associated with death in septic patients with KPC-Kp infection.

  7. Outbreak of NDM-1-producing Klebsiella pneumoniae ST76 and ST37 isolates in neonates.

    PubMed

    Zhu, J; Sun, L; Ding, B; Yang, Y; Xu, X; Liu, W; Zhu, D; Yang, F; Zhang, H; Hu, F

    2016-04-01

    The purpose of this study was to investigate the epidemiological characteristics of carbapenem-resistant Klebsiella pneumoniae (CRKP) in Shanghai Children's Hospital in China. Twenty-two non-duplicate CRKP strains were collected from pediatric patients between March and June in 2014. Antimicrobial susceptibility testing was conducted by the agar dilution method. Beta-lactamases were characterized by polymerase chain reaction (PCR) and DNA sequencing. The transferability of bla NDM-1 was investigated by conjugation experiment. The plasmids bearing antibiotic resistance genes were characterized by S1 nuclease pulsed-field gel electrophoresis (S1-PFGE) and Southern hybridization. Clonal relatedness was evaluated by PFGE and multilocus sequence typing (MLST). The clinical data of patients were retrospectively reviewed. The 22 CRKP strains were resistant to most of the antimicrobial agents tested, except tigecycline and colistin. Overall, 59, 77, and 100 % of these strains were resistant to imipenem, meropenem, and ertapenem, respectively. The bla NDM-1 was positive in 77.3 % (17/22) of the CRKP strains, of which the 16 isolates from inpatients were designated as ST37 (n = 9) and ST76 (n =7) and one isolate from an outpatient belonged to ST846. The 17 bla NDM-1-positive isolates belonged to PFGE type A (n = 9), type C (n = 7), or type B (n = 1). The plasmids bearing bla NDM-1 could be transferred into recipient Escherichia coli J53 through conjugation in 88.2 % (15/17) of the strains. The hybridization results showed that the plasmids carrying the bla NDM-1 gene were approximately 50-240 kb in size. This is the first report of an outbreak caused by NDM-1-producing K. pneumoniae ST76 and ST37 among neonates. PMID:26803822

  8. Roles of β-Lactamases and Porins in Activities of Carbapenems and Cephalosporins against Klebsiella pneumoniae

    PubMed Central

    Martínez-Martínez, Luis; Pascual, Alvaro; Hernández-Allés, Santiago; Alvarez-Díaz, Dolores; Suárez, Ana Isabel; Tran, John; Benedí, Vicente Javier; Jacoby, George A.

    1999-01-01

    Two clinical isolates of extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae were noted to be less susceptible than expected to imipenem. Both were missing outer membrane proteins that serve as channels for antibiotic entry. The role of β-lactamase in resistance was investigated by eliminating the original ESBL and introducing plasmids encoding various ESBLs and AmpC β-lactamase types, by studying the effect of an increased inoculum, and by evaluating interactions with β-lactamase inhibitors. The contribution of porin deficiency was investigated by restoring a functional ompK36 gene on a plasmid. Plasmids encoding AmpC-type β-lactamases provided resistance to imipenem (up to 64 μg/ml) and meropenem (up to 16 μg/ml) in strains deficient in porins. Carbapenem resistance showed little inoculum effect, was not affected by clavulanate but was blocked by BRL 42715, and was diminished if OmpK36 porin was restored. Plasmids encoding TEM- and SHV-type ESBLs conferred resistance to cefepime and cefpirome, as well as to earlier oxyimino-β-lactams. This resistance was magnified with an increased inoculum, was blocked by clavulanate, and was also lowered by OmpK36 porin restoration. In addition, SHV-2 β-lactamase had a small effect on carbapenem resistance (imipenem MIC, 4 μg/ml, increasing to 16 μg/ml with a higher inoculum) when porins were absent. In K. pneumoniae porin loss can thus augment resistance provided either by TEM- or SHV-type ESBLs or by plasmid-mediated AmpC enzymes to include the latest oxyimino-β-lactams and carbapenems. PMID:10390220

  9. Constitutive expression of nitrogen fixation (nif) genes of Klebsiella pneumoniae due to a DNA duplication.

    PubMed

    Sibold, L; Elmerich, C

    1982-01-01

    A spontaneous mutant of Klebsiella pneumoniae exhibiting nitrogen fixing activity in the presence of ammonia was isolated from a nifL ::Mu mutant. The main features of the nif constitutive mutation, designated nif-8388, were as follows: (i) neither ammonia nor bases repressed, but amino acids partially repressed, nitrogen fixation; (ii) the mutation caused an escape from the regulatory effect of glnA and glnG mutations of K. pneumoniae but not that of a glnF mutation; (iii) it enabled the activation of the nifH -lac fusion in the presence of oxygen with or without ammonia and a nifL -lac fusion in the presence of ammonia without oxygen; (iv) the mutation allowed nitrogen fixation at 37 degrees C when plasmid-borne. Restriction analysis and Southern hybridization using Mu DNA and the 8.1-kb nifQBALF EcoRI fragment as probes demonstrated that the nif-8388 mutation was a tandem duplication of 10 kb in the nifL region in which no Mu DNA was present. This duplication led to an operon fusion between nifLA and his since Nifc expression was shown to be increased with a specific inducer of the his operon. These results provide further evidence that the nifA product is a nif-specific activator, and that the nifL product is involved in oxygen repression and temperature control. In addition, they suggest that there is an autoactivation of nifLA transcription by the nifA product and that glnF could act in nif regulation by a mechanism other than the glnG-mediated control of nifLA transcription. PMID:6327278

  10. Pyrroloquinoline Quinone Biogenesis: Demonstration that PqqE from Klebsiella pneumoniae is a Radical SAM Enzyme†

    PubMed Central

    Wecksler, Stephen R.; Stoll, Stefan; Tran, Ha; Magnusson, Olafur T.; Wu, Shu-pao; King, David; Britt, R. David; Klinman, Judith P.

    2009-01-01

    Biogenesis of pyrroloquinoline quinone (PQQ) in Klebsiella pneumoniae requires the expression of six genes (pqqA-F). One of these genes (pqqE) encodes a 43 kDa protein (PqqE) that plays a role in the initial steps in PQQ formation (Veletrop et al. (1995) J. Bacteriol. 177, 5088-5098). PqqE contains two highly conserved cysteine motifs at the N and C-termini, with the N-terminal motif comprised of a consensus sequence of CX3CX2C that is unique to a family of proteins known as radical S-adenosyl-L-methionine (SAM) enzymes (Sofia et al. (2001) Nucleic Acids Res. 29, 1097-1106). PqqE from K. pneumoniae was cloned into E. coli and expressed as the native protein and with an N-terminal His6-tag. Anaerobic expression and purification of the His6-tag PqqE results in an enzyme with a brownish-red hue indicative of Fe-S cluster formation. Spectroscopic and physical analyses indicate that PqqE contains a mixture of Fe-S clusters, with the predominant form of the enzyme containing two [4Fe-4S] clusters. PqqE isolated anaerobically yields active enzyme capable of cleaving SAM to methionine and 5′-deoxyadenosine in an uncoupled reaction (kobs = 0.011 ± 0.001 min-1). In this reaction, the 5′-deoxyadenosyl radical either abstracts a hydrogen atom from a solvent accessible position in the enzyme or obtains a proton and electron from buffer. The putative PQQ substrate PqqA has not yet been shown to be modified by PqqE, implying either that PqqA must be modified before becoming the substrate for PqqE and/or that another protein in the biosynthetic pathway is critical for the initial steps in PQQ biogenesis. PMID:19746930

  11. Minim typing--a rapid and low cost MLST based typing tool for Klebsiella pneumoniae.

    PubMed

    Andersson, Patiyan; Tong, Steven Y C; Bell, Jan M; Turnidge, John D; Giffard, Philip M

    2012-01-01

    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

  12. A model for predicting nosocomial carbapenem-resistant Klebsiella pneumoniae infection

    PubMed Central

    Yang, Duo; Xie, Zeqiang; Xin, Xuli; Xue, Wenying; Zhang, Man

    2016-01-01

    Mortality associated with infections due to carbapenem-resistant Klebsiella pneumoniae (CR-KP) is high and the infections need to be predicted early. The risk factors for CR-KP infection are heterogeneous. The aim of the present study was to construct a model allowing for the early prediction of CR-KP infection. Nosocomial infections due to K. pneumoniae were evaluated retrospectively over a 2-year period. The case cohort consisted of 370 inpatients with CR-KP infection. For each case enrolled, two matched controls with no CR-KP infection during their hospitalization were randomly selected. Matching involved month of admission, ward, as well as interval days. The Vitek 2 system was used for identification of isolates and antimicrobial susceptibility testing. General linear model with logistic regression was used to identify possible risk factors. The predicted power of the model was expressed as the area under the receiver-operating characteristic curve. Age, male gender, with cardiovascular disease, hospital stay, recent admission to intensive care unit, indwelling urinary catheter, mechanical ventilation, recent β-lactam-β-lactamase inhibitors, fourth-generation cephalosporins and/or carbapenems therapy were independent risk factors for CR-KP infection. Models predicting CR-KP infection developed by cumulative risk factors exhibited good power, with areas under the receiver-operating characteristic curves of 0.902 [95% confidence interval (CI), 0.883–0.920; P<0.001] and 0.899 (95% CI, 0.877–0.921; P<0.001) after filtering by age (≥70 years). The Yonden index was at the maximum when the cumulative risk factors were ≥3 in the two prediction models. The results show that the prediction model developed in the present study might be useful for controlling infections caused by CR-KP strains.

  13. Interaction between complement subcomponent C1q and the Klebsiella pneumoniae porin OmpK36.

    PubMed Central

    Albertí, S; Marqués, G; Hernández-Allés, S; Rubires, X; Tomás, J M; Vivanco, F; Benedí, V J

    1996-01-01

    The interaction between C1q, a subcomponent of the complement classical pathway component C1, and OmpK36, a porin protein from Klebsiella pneumoniae, was studied in a solid-phase direct-binding assay, inhibition assays with the purified globular and collagen-like regions of C1q, and cross-linking experiments. We have shown that the binding of C1q to the OmpK36 porin of the serum-sensitive strain K. pneumoniae KT707 occurs in an in vivo situation and that this binding leads to activation of the complement classical pathway and the subsequent deposition of complement components C3b and C5b-9 on the OmpK36 porin. Scatchard analysis of the binding of [125I]C1q to the OmpK36 porin showed two binding sites with dissociation constants of 1.5 and 75 nM. The decrease of [125I]C1q binding to the OmpK36 porin in buffer with increasing salt concentrations and the pIs of the C1q subcomponent (10.3) and OmpK36 porin (4.5) suggest that charged amino acids are involved in the binding phenomenon. In inhibition assays, only the globular regions of C1q inhibited the interaction between C1q and OmpK36 porin, demonstrating that C1q binds to porin through its globular region and not through the collagen-like stalks. PMID:8890231

  14. Plugging of a model rock system by using starved bacteria. [Klebsiella pneumoniae

    SciTech Connect

    MacLeod, F.A.; Lappin-Scott, H.M.; Costerton, J.W.

    1988-06-01

    The effects of starvation on bacterial penetration through artificial rock cores were examined. Klebsiella pneumoniae was starved in a simple salts solution for a duration of up to 4 weeks. These cell suspensions were injected into sintered glass bead cores, and the resulting reductions in core permeabilities were recorded. Vegetative cell cultures of K. pneumoniae grown in a sodium citrate medium were injected into other, similar cores, and the reductions in core permeabilities were recorded. The starved cell suspensions did not completely block the core pores, whereas the vegetative cultures reduced core permeability to less than 1%. Scanning electron microscopy of core section infiltrated with either vegetative or starved cells showed that the former produced shallow skin plugs and copious amounts of glycocalyx at the inlet face, whereas the latter produced very little glycocalyx and the cells were distributed evenly throughout the length of the core. The use of a DNA assay to produce a cell distribution profile showed that, compared with the vegetative cells, starved bacteria were able to penetrate deeper into the cores. This was due to the smaller size of the cells and the reduction in biofilm production. This ability of starved bacteria to penetrate further into cores than the normal-size vegetative cells can be usefully applied to selective plugging for enhanced oil recovery. To further test the suitability of starved cells for use in selective plugging, the activities of starved cells present within cores were monitored before and after nutrient stimulation. Our data indicate that with nutrient stimulation, the starved cells lose their metabolic dormancy and produce reductions in core permeability due to cell growth and polymer production.

  15. Multiple product inhibition and growth modeling of Clostridium butyricum and Klebsiella pneumoniae in glycerol fermentation

    SciTech Connect

    Zeng, A.P.; Ross, A.; Biebl, H.; Tag, C.; Guenzel, B.; Deckwer, W.D. . Biochemical Engineering Division)

    1994-10-01

    The inhibition potentials of products and substrate on the growth of Clostridium butyricum and Klebsiella pneumoniae in the glycerol fermentation are examined from experimental data and with a mathematical model. Whereas the inhibition potential of externally added and self-produced 1,3-propanediol is essentially the same, butyric acid produced by the culture is more toxic than that externally added. The same seems to apply for acetic acid. The inhibitory effect of butyric acid is due to the total concentration instead of its undissociated form. For acetic acid, it cannot be distinguished between the total concentration and the undissociated form. The inhibition effects of products and substrate in the glycerol fermentation are irrespective of the strains, and, therefore, the same growth model can be used. The maximum product concentrations tolerated are 0.35 g/L for undissociated acetic acid, 10.1 g/L for total butyric acid, 16.6 g/L for ethanol, 71.4 g/L for 1,3-propanediol, and 187.6 g/L for glycerol, which are applicable to C. butyricum and K. pneumoniae growth under a variety of conditions. For 55 steady-states, which were obtained from different types of continuous cultures over a pH range of 5.3--8.5 and under both substrate limitation and substrate excess, the proposed growth model fits the experimental data with an average deviation of 17.0%. The deviation of model description from experimental values reduces of 11.4% if only the steady-states with excessive substrate are considered.

  16. 1,3-Propanediol production by Escherichia coli expressing genes from the Klebsiella pneumoniae dha regulon

    SciTech Connect

    I-Teh Tong; Hans H. Liao; Cameron, D.C. )

    1991-12-01

    The dha regulon in Klebsiella pneumoniae enables the organism to grown anaerobically on glycerol and produce 1,3-propanediol (1,3-PD). Escherichia coli, which does not have a dha system, is unable to grow anaerobically on glycerol without an exogenous electron acceptor and does not produce 1,3-PD. A genomic library of K. pneumoniae ATCC 25955 constructed in E. coli AG1 was enriched for the ability to grow anaerobically on glycerol and dihydoxyacetone and was screened for the production of 1, 3-PD. The cosmid pTC1 (42.5 kn total with an 18.2-kb major insert) was isolated from a 1,3-PD-producing strain of E. coli and found to possess enzymatic activities associated with four genes of the dha regulon: glycersol dehydratase (dhaB), 1,3-PD oxidoreductase (dhaT), glycerol dehydrogenase (dhaD), and dihydroxyacetone kinase (dhaK). All four activities were inducible by the presence of glycerol. When E. coli AG1/pTC1 was grown on complex medium plus glycerol, the yield of 1, 3-PD from glycerol was 0.46 mol/mol. The major fermentation by-products were formate, acetate, and D-lactate. 1,3-PD is an intermediate in organic synthesis and polymer production. The 1,3-PD fermentation provides a useful model system for studying the interaction of a biochemical pathway in a foreign host and for developing strategies for metabolic pathway engineering.

  17. Predictive models for identification of hospitalized patients harboring KPC-producing Klebsiella pneumoniae.

    PubMed

    Tumbarello, Mario; Trecarichi, Enrico Maria; Tumietto, Fabio; Del Bono, Valerio; De Rosa, Francesco Giuseppe; Bassetti, Matteo; Losito, Angela Raffaella; Tedeschi, Sara; Saffioti, Carolina; Corcione, Silvia; Giannella, Maddalena; Raffaelli, Francesca; Pagani, Nicole; Bartoletti, Michele; Spanu, Teresa; Marchese, Anna; Cauda, Roberto; Viscoli, Claudio; Viale, Pierluigi

    2014-06-01

    The production of Klebsiella pneumoniae carbapenemases (KPCs) by Enterobacteriaceae has become a significant problem in recent years. To identify factors that could predict isolation of KPC-producing K. pneumoniae (KPCKP) in clinical samples from hospitalized patients, we conducted a retrospective, matched (1:2) case-control study in five large Italian hospitals. The case cohort consisted of adult inpatients whose hospital stay included at least one documented isolation of a KPCKP strain from a clinical specimen. For each case enrolled, we randomly selected two matched controls with no KPCKP-positive cultures of any type during their hospitalization. Matching involved hospital, ward, and month/year of admission, as well as time at risk for KPCKP isolation. A subgroup analysis was also carried out to identify risk factors specifically associated with true KPCKP infection. During the study period, KPCKP was isolated from clinical samples of 657 patients; 426 of these cases appeared to be true infections. Independent predictors of KPCKP isolation were recent admission to an intensive care unit (ICU), indwelling urinary catheter, central venous catheter (CVC), and/or surgical drain, ≥ 2 recent hospitalizations, hematological cancer, and recent fluoroquinolone and/or carbapenem therapy. A Charlson index of ≥ 3, indwelling CVC, recent surgery, neutropenia, ≥ 2 recent hospitalizations, and recent fluoroquinolone and/or carbapenem therapy were independent risk factors for KPCKP infection. Models developed to predict KPCKP isolation and KPCKP infection displayed good predictive power, with the areas under the receiver-operating characteristic curves of 0.82 (95% confidence interval [CI], 0.80 to 0.84) and 0.82 (95% CI, 0.80 to 0.85), respectively. This study provides novel information which might be useful for the clinical management of patients harboring KPCKP and for controlling the spread of this organism.

  18. Rapid acquisition of decreased carbapenem susceptibility in a strain of Klebsiella pneumoniae arising during meropenem therapy.

    PubMed

    Findlay, J; Hamouda, A; Dancer, S J; Amyes, S G B

    2012-02-01

    A strain of Klebsiella pneumoniae (K1) was isolated from a catheterized patient with a urinary tract infection. The patient was subsequently treated with meropenem, after which K. pneumoniae (K2) was once again isolated from the patient's urine. Susceptibility testing showed that strain K1 was fully susceptible to carbapenem antibiotics with the exception of ertapenem, to which it exhibited intermediate resistance, whilst K2 was resistant to ertapenem and meropenem. From pulsed-field gel electrophoresis profiling both strains exhibited identical banding patterns. Both contained CTX-M-15, OXA-1, SHV-1 and TEM-1 β-lactamase genes following PCR analyses. Outer membrane protein analysis demonstrated that K1 and K2 lacked an OMP of c. 40 kDa, with an additional OMP of c. 36 kDa missing from K2. Mutation studies showed that the K2 OMP phenotype could be selected by single-step carbapenem-resistant mutants of K1. Expression of transcriptional activator ramA and efflux pump component gene acrA were up-regulated in both strains by RT-PCR. Neither strain expressed ompK35, but ompK36 was found in both. Sequence analysis revealed gene sequences of ompK35, ompK36 and ramR in both strains; notably, ramR contained a mutation resulting in a premature stop codon. Transconjugation studies demonstrated transfer of a plasmid into E. coli encoding the CTX-M-15, TEM-1 and OXA-1 β-lactamases. We concluded that the carbapenem-resistant phenotype observed from this patient was attributable to a combination of CTX-M-15 β-lactamase, up-regulated efflux and altered outer membrane permeability, and that K2 arose from K1 as a direct result of meropenem therapy.

  19. Contribution of fucose-containing capsules in Klebsiella pneumoniae to bacterial virulence in mice.

    PubMed

    Wu, June Hsieh; Wu, Albert M; Tsai, Cheng Gie; Chang, Xin-Yu; Tsai, Shih-Feng; Wu, Ting-Shu

    2008-01-01

    Bacterium Klebsiella pneumoniae (KP) contains a prominent capsule. Clinical infections usually are associated with pneumonia or urinary tract infection (UTI). Emerging evidence implicates KP in severe liver abscess especially in diabetic patients. The goal of this study was to investigate the capsular polysaccharides from KP of liver abscess (hepatic-KP) and of UTI-KP. The composition of capsular polysaccharides was analyzed by capillary high-performance liquid chromatography (HPLC, Dionex system). The terminal sugars were assayed by binding ability to lectins. The results showed that the capsule of a hepatic KP (KpL1) from a diabetic patient contained fucose, while the capsule from UTI-KP (KpU1) did not. The absence of fucose was verified by the absence of detectable polymerase chain reaction (PCR) fragment for fucose synthesis genes, gmd and wcaG in KpU1. Mice infected with the KpL1 showed high fatality, whereas those infected with the KpU1 showed high survival rate. The KpL1 capsule was reactive to lectins AAA and AAL, which detect fucose, while the KpU1 capsule was reactive to lectin GNA, which detects mannose. Phagocytosis experiment in mouse peritoneal cavity indicated that the peritoneal macrophages could interact with KpU1, while rare association of KpL1 with macrophages was observed. This study revealed that different polysaccharides were displayed on the bacterial capsules of virulent KpL1 as compared with the less virulent KpU1. Interaction of KpU1 with mice peritoneal macrophages was more prominent than that of KpL1. The possession of fucose might contribute to KpL1 virulence by avoiding phagocytosis since fucose on bacteria had been implicated in immune evasion.

  20. Minim typing--a rapid and low cost MLST based typing tool for Klebsiella pneumoniae.

    PubMed

    Andersson, Patiyan; Tong, Steven Y C; Bell, Jan M; Turnidge, John D; Giffard, Philip M

    2012-01-01

    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.

  1. Genome Sequence of a Multidrug-Resistant Strain of Klebsiella pneumoniae, BAMC 07-18, Isolated from a Combat Injury Wound.

    PubMed

    Van Laar, Tricia A; Chen, Tsute; Childers, Brandon M; Chen, Ping; Abercrombie, Johnathan J; Leung, Kai P

    2014-11-26

    Klebsiella pneumoniae is an important infectious agent of surgical sites and combat wounds. Antibiotic resistance and tolerance are common impediments to the healing of chronic infections. Here, we report the genome sequence of a highly multidrug-resistant strain of K. pneumoniae, BAMC 07-18, isolated from a combat wound of a soldier.

  2. Genome Sequence of a Multidrug-Resistant Strain of Klebsiella pneumoniae, BAMC 07-18, Isolated from a Combat Injury Wound

    PubMed Central

    Van Laar, Tricia A.; Chen, Tsute; Childers, Brandon M.; Chen, Ping; Abercrombie, Johnathan J.

    2014-01-01

    Klebsiella pneumoniae is an important infectious agent of surgical sites and combat wounds. Antibiotic resistance and tolerance are common impediments to the healing of chronic infections. Here, we report the genome sequence of a highly multidrug-resistant strain of K. pneumoniae, BAMC 07-18, isolated from a combat wound of a soldier. PMID:25428975

  3. Draft Genome of Multidrug-Resistant Klebsiella pneumoniae 223/14 Carrying KPC-6, Isolated from a General Hospital in Malaysia

    PubMed Central

    Ahmad, Norazah; Chong, Teik Min; Hashim, Rohaidah; Shukor, Surianti; Yin, Wai-Fong; Chan, Kok-Gan

    2015-01-01

    We performed whole genome sequencing on a clinical multidrug-resistant Klebsiella pneumoniae strain 223/14. Investigation into its draft genome revealed the presence of KPC-6 variant, suggesting carbapenemase is present in this isolate. We found a plasmid-borne KPC gene (882 bp) inserted between two transposase genes in the genome of K. pneumoniae 223/14. PMID:26816553

  4. Large Nosocomial Outbreak of Colistin-Resistant, Carbapenemase-Producing Klebsiella pneumoniae Traced to Clonal Expansion of an mgrB Deletion Mutant

    PubMed Central

    Giani, Tommaso; Arena, Fabio; Vaggelli, Guendalina; Conte, Viola; Chiarelli, Adriana; Henrici De Angelis, Lucia; Fornaini, Rossella; Grazzini, Maddalena; Niccolini, Fabrizio; Pecile, Patrizia

    2015-01-01

    We describe a large hospital outbreak (93 bloodstream infections) of colistin-resistant Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae isolates which was mirrored by increased colistin consumption. The outbreak was mostly traced to the clonal expansion of an mgrB deletion mutant of an ST512 strain that produced KPC-3. PMID:26202124

  5. Short communication: comparison of virulence factors in Klebsiella pneumoniae strains associated with multiple or single cases of mastitis.

    PubMed

    Kanevsky-Mullarky, I; Nedrow, A J; Garst, S; Wark, W; Dickenson, M; Petersson-Wolfe, C S; Zadoks, R N

    2014-01-01

    Klebsiella pneumoniae mastitis in dairy cattle is generally due to an opportunistic infection from the environment, resulting in large heterogeneity among mastitis-causing strains within a herd. However, in mastitis outbreaks in 4 herds, several strains of K. pneumoniae were identified as the cause of infection in multiple cows, suggesting increased ability to either cause disease or evade host defenses. In this study, differences in capsule formation and immune evasion were compared in 5 pairs of K. pneumoniae strains, where one strain in each pair was associated with multiple cases of mastitis and the other with a single case of mastitis. Production of capsular polysaccharide, ability to evade killing by polymorphonuclear neutrophilic leukocytes (PMNL), and the relationship between the 2 were evaluated for each strain grown in broth or milk. Growth of isolates in skim milk increased capsule size and ability to evade killing by PMNL, depending on strain type. Specifically, strains associated with multiple cases of mastitis had increased capsule size in skim milk. Strains associated with single cases of mastitis were better able to evade killing by PMNL when grown in skim milk. Our results, although preliminary, suggest that the 2 groups of strains may constitute different subpopulations of K. pneumoniae. However, our findings do not indicate that capsule or evasions of killing by PMNL explain increased mastitis outbreaks with Klebsiella. Further work will explain the enhanced ability of some strains to cause mastitis in dairy cows.

  6. Three Dimensional Checkerboard Synergy Analysis of Colistin, Meropenem, Tigecycline against Multidrug-Resistant Clinical Klebsiella pneumonia Isolates

    PubMed Central

    Bohnert, Jürgen A.; Pfeifer, Yvonne; Kesselmeier, Miriam; Hagel, Stefan; Pletz, Mathias W.

    2015-01-01

    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. PMID:26067824

  7. Short communication: comparison of virulence factors in Klebsiella pneumoniae strains associated with multiple or single cases of mastitis.

    PubMed

    Kanevsky-Mullarky, I; Nedrow, A J; Garst, S; Wark, W; Dickenson, M; Petersson-Wolfe, C S; Zadoks, R N

    2014-01-01

    Klebsiella pneumoniae mastitis in dairy cattle is generally due to an opportunistic infection from the environment, resulting in large heterogeneity among mastitis-causing strains within a herd. However, in mastitis outbreaks in 4 herds, several strains of K. pneumoniae were identified as the cause of infection in multiple cows, suggesting increased ability to either cause disease or evade host defenses. In this study, differences in capsule formation and immune evasion were compared in 5 pairs of K. pneumoniae strains, where one strain in each pair was associated with multiple cases of mastitis and the other with a single case of mastitis. Production of capsular polysaccharide, ability to evade killing by polymorphonuclear neutrophilic leukocytes (PMNL), and the relationship between the 2 were evaluated for each strain grown in broth or milk. Growth of isolates in skim milk increased capsule size and ability to evade killing by PMNL, depending on strain type. Specifically, strains associated with multiple cases of mastitis had increased capsule size in skim milk. Strains associated with single cases of mastitis were better able to evade killing by PMNL when grown in skim milk. Our results, although preliminary, suggest that the 2 groups of strains may constitute different subpopulations of K. pneumoniae. However, our findings do not indicate that capsule or evasions of killing by PMNL explain increased mastitis outbreaks with Klebsiella. Further work will explain the enhanced ability of some strains to cause mastitis in dairy cows. PMID:24534505

  8. Three Dimensional Checkerboard Synergy Analysis of Colistin, Meropenem, Tigecycline against Multidrug-Resistant Clinical Klebsiella pneumonia Isolates.

    PubMed

    Stein, Claudia; Makarewicz, Oliwia; Bohnert, Jürgen A; Pfeifer, Yvonne; Kesselmeier, Miriam; Hagel, Stefan; Pletz, Mathias W

    2015-01-01

    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.

  9. Biofilms from Klebsiella pneumoniae: Matrix Polysaccharide Structure and Interactions with Antimicrobial Peptides.

    PubMed

    Benincasa, Monica; Lagatolla, Cristina; Dolzani, Lucilla; Milan, Annalisa; Pacor, Sabrina; Liut, Gianfranco; Tossi, Alessandro; Cescutti, Paola; Rizzo, Roberto

    2016-01-01

    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. PMID:27681920

  10. First Report of Klebsiella pneumoniae-Carbapenemase-3-Producing Escherichia coli ST479 in Poland.

    PubMed

    Ojdana, Dominika; Sacha, Paweł; Olszańska, Dorota; Majewski, Piotr; Wieczorek, Piotr; Jaworowska, Jadwiga; Sieńko, Anna; Jurczak, Anna; Tryniszewska, Elżbieta

    2015-01-01

    An increase in the antibiotic resistance among members of the Enterobacteriaceae family has been observed worldwide. Multidrug-resistant Gram-negative rods are increasingly reported. The treatment of infections caused by Escherichia coli and other Enterobacteriaceae has become an important clinical problem associated with reduced therapeutic possibilities. Antimicrobial carbapenems are considered the last line of defense against multidrug-resistant Gram-negative bacteria. Unfortunately, an increase of carbapenem resistance due to the production of Klebsiella pneumoniae carbapenemase (KPC) enzymes has been observed. In this study we describe the ability of E. coli to produce carbapenemase enzymes based on the results of the combination disc assay with boronic acid performed according to guidelines established by the European Community on Antimicrobial Susceptibility Testing (EUCAST) and the biochemical Carba NP test. Moreover, we evaluated the presence of genes responsible for the production of carbapenemases (bla KPC, bla VIM, bla IMP, bla OXA-48) and genes encoding other β-lactamases (bla SHV, bla TEM, bla CTX-M) among E. coli isolate. The tested isolate of E. coli that possessed the bla KPC-3 and bla TEM-34 genes was identified. The tested strain exhibited susceptibility to colistin (0.38 μg/mL) and tigecycline (1 μg/mL). This is the first detection of bla KPC-3 in an E. coli ST479 in Poland. PMID:26339599

  11. Carbapenemases in Klebsiella pneumoniae and Other Enterobacteriaceae: an Evolving Crisis of Global Dimensions

    PubMed Central

    Tzouvelekis, L. S.; Markogiannakis, A.; Psichogiou, M.; Tassios, P. T.

    2012-01-01

    Summary: The spread of Enterobacteriaceae, primarily Klebsiella pneumoniae, producing KPC, VIM, IMP, and NDM carbapenemases, is causing an unprecedented public health crisis. Carbapenemase-producing enterobacteria (CPE) infect mainly hospitalized patients but also have been spreading in long-term care facilities. Given their multidrug resistance, therapeutic options are limited and, as discussed here, should be reevaluated and optimized. Based on susceptibility data, colistin and tigecycline are commonly used to treat CPE infections. Nevertheless, a review of the literature revealed high failure rates in cases of monotherapy with these drugs, whilst monotherapy with either a carbapenem or an aminoglycoside appeared to be more effective. Combination therapies not including carbapenems were comparable to aminoglycoside and carbapenem monotherapies. Higher success rates have been achieved with carbapenem-containing combinations. Pharmacodynamic simulations and experimental infections indicate that modification of the current patterns of carbapenem use against CPE warrants further attention. Epidemiological data, though fragmentary in many countries, indicate CPE foci and transmission routes, to some extent, whilst also underlining the lack of international collaborative systems that could react promptly and effectively. Fortunately, there are sound studies showing successful containment of CPE by bundles of measures, among which the most important are active surveillance cultures, separation of carriers, and assignment of dedicated nursing staff. PMID:23034326

  12. Evidences of gentamicin resistance amplification in Klebsiella pneumoniae isolated from faeces of hospitalized newborns.

    PubMed

    Barros, J C; Pinheiro, S R; Bozza, M; Gueiros-Filho, F J; Bello, A R; Lopes, U G; Pereira, J A

    1999-01-01

    The intestinal microbiota, a barrier to the establishment of pathogenic bacteria, is also an important reservoir of opportunistic pathogens. It plays a key role in the process of resistance-genes dissemination, commonly carried by specialized genetic elements, like plasmids, phages, and conjugative transposons. We obtained from strains of enterobacteria, isolated from faeces of newborns in a university hospital nursery, indication of phenotypical gentamicin resistance amplification (frequencies of 10(-3) to 10(-5), compatible with transposition frequencies). Southern blotting assays showed strong hybridization signals for both plasmidial and chromosomal regions in DNA extracted from variants selected at high gentamicin concentrations, using as a probe a labeled cloned insert containing aminoglycoside modifying enzyme (AME) gene sequence originated from a plasmid of a Klebsiella pneumoniae strain previously isolated in the same hospital. Further, we found indications of inactivation to other resistance genes in variants selected under similar conditions, as well as, indications of co-amplification of other AME markers (amikacin). Since the intestinal environment is a scenario of selective processes due to the therapeutic and prophylactic use of antimicrobial agents, the processes of amplification of low level antimicrobial resistance (not usually detected or sought by common methods used for antibiotic resistance surveillance) might compromise the effectiveness of antibiotic chemotherapy.

  13. Biofilms from Klebsiella pneumoniae: Matrix Polysaccharide Structure and Interactions with Antimicrobial Peptides.

    PubMed

    Benincasa, Monica; Lagatolla, Cristina; Dolzani, Lucilla; Milan, Annalisa; Pacor, Sabrina; Liut, Gianfranco; Tossi, Alessandro; Cescutti, Paola; Rizzo, Roberto

    2016-01-01

    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.

  14. Structural elucidation and biological studies of a novel exopolysaccaride from Klebsiella pneumoniae PB12.

    PubMed

    Mandal, Amit K; Sen, Ipsita K; Maity, Prasenjit; Chattopadhyay, Sourav; Chakraborty, Ranadhir; Roy, Somenath; Islam, Syed S

    2015-08-01

    An exopolysaccharide (KNPS) of an average molecular weight ∼1.8×10(5) Da was isolated from the culture medium of Klebsiella pneumoniae PB12. Structural characterization of KNPS was carried out using sugar and methylation analysis, Smith degradation and 1D/2D NMR experiments. Sugar analysis showed that the KNPS composed of arabinose, galactose, 3-O-methyl-galctose and glucose in a molar ratio of nearly 4:3:1:1. The proposed repeating unit of the KNPS has a backbone chain consisting of two (1→6)-galactopyranosyl residues, two (1→5)-arabinofuranosyl residues, one (1→6)-glucopyranosyl residue and one (1→3)-arabinopyranosyl residue, out of which one (1→6)-galactopyranosyl residue was branched at O-2 position with a (1→2)-linked-galactopyranosyl residue terminated with non reducing arabinofuranosyl residue and one (1→5)-arabinofuranosyl residue branched at O-3 position with non reducing end 3-O-Me-galactopyranosyl residue. KNPS was found non-toxic toward human lymphocyte up to the dosage of 100 μg/ml. KNPS enhanced malondialdehyde (MDA), reactive oxygen species (ROS), and have the potential to alter the ratio of oxidized glutathione (GSSG) and reduced glutathione (GSH) levels in the cellular system.

  15. Klebsiella pneumoniae nitrogenase. Mechanism of acetylene reduction and its inhibition by carbon monoxide.

    PubMed Central

    Lowe, D J; Fisher, K; Thorneley, R N

    1990-01-01

    The electron flux through the MoFe-protein of nitrogenase from Klebsiella pneumoniae determines the absolute and relative rates of 2H+ reduction to H2 and acetylene (C2H2) reduction to ethylene (C2H4) at saturating levels of reductant (Na2S2O4) and MgATP. High electron flux, induced by a high Fe-protein (Kp2)/MoFe protein (Kp1) ratio, favours C2H2 reduction. These data can be explained if ethylene, the two-electron reduction product of C2H2, is not released until three electrons have been transferred from Kp2 to Kp1. This explanation is also consistent with a pre-steady-state lag phase for C2H4 formation of 250 ms observed when functioning enzyme is quenched with acid. Electron flux through nitrogenase is inhibited by C2H2 at high protein concentrations. This is because the association rate between Kp1 and oxidized Kp2 is enhanced by C2H2, leading to an increased steady-state concentration of the inhibitory complex Kp2oxKp1C2H2. This effect is not relieved by CO. Thus CO and C2H2 (or C2H4) must be bound at the same time to distinct sites, presumably at Mo or Fe centres, on the enzyme. PMID:2268290

  16. The Major Surface-Associated Saccharides of Klebsiella pneumoniae Contribute to Host Cell Association

    PubMed Central

    Clements, Abigail; Gaboriaud, Fabien; Duval, Jérôme F. L.; Farn, Jacinta L.; Jenney, Adam W.; Lithgow, Trevor; Wijburg, Odilia L. C.; Hartland, Elizabeth L.; Strugnell, Richard A.

    2008-01-01

    Analysing the pathogenic mechanisms of a bacterium requires an understanding of the composition of the bacterial cell surface. The bacterial surface provides the first barrier against innate immune mechanisms as well as mediating attachment to cells/surfaces to resist clearance. We utilised a series of Klebsiella pneumoniae mutants in which the two major polysaccharide layers, capsule and lipopolysaccharide (LPS), were absent or truncated, to investigate the ability of these layers to protect against innate immune mechanisms and to associate with eukaryotic cells. The capsule alone was found to be essential for resistance to complement mediated killing while both capsule and LPS were involved in cell-association, albeit through different mechanisms. The capsule impeded cell-association while the LPS saccharides increased cell-association in a non-specific manner. The electrohydrodynamic characteristics of the strains suggested the differing interaction of each bacterial strain with eukaryotic cells could be partly explained by the charge density displayed by the outermost polysaccharide layer. This highlights the importance of considering not only specific adhesin:ligand interactions commonly studied in adherence assays but also the initial non-specific interactions governed largely by the electrostatic interaction forces. PMID:19043570

  17. Structural elucidation and biological studies of a novel exopolysaccaride from Klebsiella pneumoniae PB12.

    PubMed

    Mandal, Amit K; Sen, Ipsita K; Maity, Prasenjit; Chattopadhyay, Sourav; Chakraborty, Ranadhir; Roy, Somenath; Islam, Syed S

    2015-08-01

    An exopolysaccharide (KNPS) of an average molecular weight ∼1.8×10(5) Da was isolated from the culture medium of Klebsiella pneumoniae PB12. Structural characterization of KNPS was carried out using sugar and methylation analysis, Smith degradation and 1D/2D NMR experiments. Sugar analysis showed that the KNPS composed of arabinose, galactose, 3-O-methyl-galctose and glucose in a molar ratio of nearly 4:3:1:1. The proposed repeating unit of the KNPS has a backbone chain consisting of two (1→6)-galactopyranosyl residues, two (1→5)-arabinofuranosyl residues, one (1→6)-glucopyranosyl residue and one (1→3)-arabinopyranosyl residue, out of which one (1→6)-galactopyranosyl residue was branched at O-2 position with a (1→2)-linked-galactopyranosyl residue terminated with non reducing arabinofuranosyl residue and one (1→5)-arabinofuranosyl residue branched at O-3 position with non reducing end 3-O-Me-galactopyranosyl residue. KNPS was found non-toxic toward human lymphocyte up to the dosage of 100 μg/ml. KNPS enhanced malondialdehyde (MDA), reactive oxygen species (ROS), and have the potential to alter the ratio of oxidized glutathione (GSSG) and reduced glutathione (GSH) levels in the cellular system. PMID:25999015

  18. Klebsiella pneumoniae liver abscess in diabetic patients: association of glycemic control with the clinical characteristics

    PubMed Central

    2013-01-01

    Background Klebsiella pneumoniae liver abscess (KPLA) has been reported with increasing frequency in East Asian countries in the past 3 decades, especially in Taiwan and Korea. Diabetes is a well-known risk factor for KPLA and highly associated with septic metastatic complications from KPLA. We investigated the association of glycemic control in diabetic patients with the clinical characteristics of KPLA in Taiwan. Methods Adult diabetic patients with KPLA were identified retrospectively in a medical center from January 2007 to January 2012. Clinical characteristics were compared among patients with different levels of current hemoglobin A1c (HbA1c). Risk factors for metastatic infection from KPLA were analyzed. Results Patients with uncontrolled glycemia (HbA1c ≥ 7%) were significantly younger than those with controlled glycemia (HbA1c < 7%). Patients with uncontrolled glycemia had the trend to have a higher rate of gas-forming liver abscess, cryptogenic liver abscess, and metastatic infection than those with controlled glycemia. Cryptogenic liver abscess and metastatic infection were more common in the poor glycemic control group (HbA1c value >; 10%) after adjustment with age. HbA1c level and abscess < 5 cm were independent risk factors for metastatic complications from KPLA. Conclusions Glycemic control in diabetic patients played an essential role in the clinical characteristics of KPLA, especially in metastatic complications from KPLA. PMID:23363608

  19. Biofilms from Klebsiella pneumoniae: Matrix Polysaccharide Structure and Interactions with Antimicrobial Peptides

    PubMed Central

    Benincasa, Monica; Lagatolla, Cristina; Dolzani, Lucilla; Milan, Annalisa; Pacor, Sabrina; Liut, Gianfranco; Tossi, Alessandro; Cescutti, Paola; Rizzo, Roberto

    2016-01-01

    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. PMID:27681920

  20. The mechanism of Klebsiella pneumoniae nitrogenase action. Pre-steady-state kinetics of H2 formation.

    PubMed Central

    Lowe, D J; Thorneley, R N

    1984-01-01

    A comprehensive model for the mechanism of nitrogenase action is used to simulate pre-steady-state kinetic data for H2 evolution in the presence and in the absence of N2, obtained by using a rapid-quench technique with nitrogenase from Klebsiella pneumoniae. These simulations use independently determined rate constants that define the model in terms of the following partial reactions: component protein association and dissociation, electron transfer from Fe protein to MoFe protein coupled to the hydrolysis of MgATP, reduction of oxidized Fe protein by Na2S2O4, reversible N2 binding by H2 displacement and H2 evolution. Two rate-limiting dissociations of oxidized Fe protein from reduced MoFe protein precede H2 evolution, which occurs from the free MoFe protein. Thus Fe protein suppresses H2 evolution by binding to the MoFe protein. This is a necessary condition for efficient N2 binding to reduced MoFe protein. PMID:6395861

  1. Mutation in fucose synthesis gene of Klebsiella pneumoniae affects capsule composition and virulence in mice.

    PubMed

    Pan, Po-Chang; Chen, Hui-Wen; Wu, Po-Kuan; Wu, Yu-Yang; Lin, Chun-Hung; Wu, June H

    2011-02-01

    The emerging pathogenicity of Klebsiella pneumoniae (KP) is evident by the increasing number of clinical cases of liver abscess (LA) due to KP infection. A unique property of KP is its thick mucoid capsule. The bacterial capsule has been found to contain fucose in KP strains causing LA but not in those causing urinary tract infections. The products of the gmd and wcaG genes are responsible for converting mannose to fucose in KP. A KP strain, KpL1, which is known to have a high death rate in infected mice, was mutated by inserting an apramycin-resistance gene into the gmd. The mutant expressed genes upstream and downstream of gmd, but not gmd itself, as determined by reverse transcriptase polymerase chain reaction. The DNA mapping confirmed the disruption of the gmd gene. This mutant decreased its ability to kill infected mice and showed decreased virulence in infected HepG2 cells. Compared with wild-type KpL1, the gmd mutant lost fucose in capsular polysaccharides, increased biofilm formation and interacted more readily with macrophages. The mutant displayed morphological changes with long filament forms and less uniform sizes. The mutation also converted the serotype from K1 of wild-type to K2 and weak K3. The results indicate that disruption of the fucose synthesis gene affected the pathophysiology of this bacterium and may be related to the virulence of this KpL1 strain.

  2. Biofilms from Klebsiella pneumoniae: Matrix Polysaccharide Structure and Interactions with Antimicrobial Peptides

    PubMed Central

    Benincasa, Monica; Lagatolla, Cristina; Dolzani, Lucilla; Milan, Annalisa; Pacor, Sabrina; Liut, Gianfranco; Tossi, Alessandro; Cescutti, Paola; Rizzo, Roberto

    2016-01-01

    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.

  3. The mechanism of Klebsiella pneumoniae nitrogenase action. Pre-steady-state kinetics of H2 formation.

    PubMed

    Lowe, D J; Thorneley, R N

    1984-12-15

    A comprehensive model for the mechanism of nitrogenase action is used to simulate pre-steady-state kinetic data for H2 evolution in the presence and in the absence of N2, obtained by using a rapid-quench technique with nitrogenase from Klebsiella pneumoniae. These simulations use independently determined rate constants that define the model in terms of the following partial reactions: component protein association and dissociation, electron transfer from Fe protein to MoFe protein coupled to the hydrolysis of MgATP, reduction of oxidized Fe protein by Na2S2O4, reversible N2 binding by H2 displacement and H2 evolution. Two rate-limiting dissociations of oxidized Fe protein from reduced MoFe protein precede H2 evolution, which occurs from the free MoFe protein. Thus Fe protein suppresses H2 evolution by binding to the MoFe protein. This is a necessary condition for efficient N2 binding to reduced MoFe protein.

  4. Fe(III) oxides accelerate microbial nitrate reduction and electricity generation by Klebsiella pneumoniae L17.

    PubMed

    Liu, Tongxu; Li, Xiaomin; Zhang, Wei; Hu, Min; Li, Fangbai

    2014-06-01

    Klebsiella pneumoniae L17 is a fermentative bacterium that can reduce iron oxide and generate electricity under anoxic conditions, as previously reported. This study reveals that K. pneumoniae L17 is also capable of dissimilatory nitrate reduction, producing NO2(-), NH4(+), NO and N2O under anoxic conditions. The presence of Fe(III) oxides (i.e., α-FeOOH, γ-FeOOH, α-Fe2O3 and γ-Fe2O3) significantly accelerates the reduction of nitrate and generation of electricity by K. pneumoniae L17, which is similar to a previous report regarding another fermentative bacterium, Bacillus. No significant nitrate reduction was observed upon treatment with Fe(2+) or α-FeOOH+Fe(2+), but a slight facilitation of nitrate reduction and electricity generation was observed upon treatment with L17+Fe(2+). This result suggests that aqueous Fe(II) or mineral-adsorbed Fe(II) cannot reduce nitrate abiotically but that L17 can catalyze the reduction of nitrate and generation of electricity in the presence of Fe(II) (which might exist as cell surface-bound Fe(II)). To rule out the potential effect of Fe(II) produced by L17 during microbial iron reduction, treatments with the addition of TiO2 or Al2O3 instead of Fe(III) oxides also exhibited accelerated microbial nitrate reduction and electricity generation, indicating that cell-mineral sorption did account for the acceleration effect. However, the acceleration caused by Fe(III) oxides is only partially attributed to the cell surface-bound Fe(II) and cell-mineral sorption but may be driven by the iron oxide conduction band-mediated electron transfer from L17 to nitrate or an electrode, as proposed previously. The current study extends the diversity of bacteria of which nitrate reduction and electricity generation can be facilitated by the presence of iron oxides and confirms the positive role of Fe(III) oxides on microbial nitrate reduction and electricity generation by particular fermentative bacteria in anoxic environments.

  5. Towards understanding the nitrogen signal transduction for nif gene expression in Klebsiella pneumoniae.

    PubMed

    Glöer, Jens; Thummer, Robert; Ullrich, Heike; Schmitz, Ruth A

    2008-12-01

    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.

  6. Extended-Spectrum β-Lactamase (ESBL)-Producing Klebsiella pneumoniae in Bulk Tank Milk from Dairy Farms in Indonesia.

    PubMed

    Sudarwanto, Mirnawati; Akineden, Ömer; Odenthal, Sabrina; Gross, Madeleine; Usleber, Ewald

    2015-07-01

    Bulk tank milk from 80 dairy farms located in the West Java Region of Indonesia was analyzed for the presence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae. Isolates from seven dairy farms were ESBL positive, and all were identified as Klebsiella pneumoniae. The isolates showed ESBL-characteristic antibiotic resistance patterns. Further analysis revealed that all K. pneumoniae isolates harbored the blaSHV gene, and two isolates were additionally positive for the blaTEM-1 and blaCTX-M-15 genes. Isolates from different farms were clonally diverse according to macrorestriction analysis. The results indicate that the relatively high frequency of ESBL-producing K. pneumoniae in bulk tank milk implies the risk that milk is both a source of local exposure and a vector contributing to the supraregional spread of antibiotic-resistant bacteria by trade.

  7. Modeling Meropenem Treatment, Alone and in Combination with Daptomycin, for KPC-Producing Klebsiella pneumoniae Strains with Unusually Low Carbapenem MICs.

    PubMed

    Gagetti, P; Pasteran, F; Martinez, M P; Fatouraei, M; Gu, J; Fernandez, R; Paz, L; Rose, W E; Corso, A; Rosato, A E

    2016-08-01

    Klebsiella pneumoniae strains producing K. pneumoniae carbapenemase (KPC) cause serious infections in debilitated and immunocompromised patients and are associated with prolonged hospital stays and increased mortality rates. Daptomycin is a lipopeptide used against Staphylococcus aureus infection and considered inactive against Gram-negative bacteria. We investigated the effectiveness of a daptomycin-meropenem combination by synergy kill curve and a pharmacokinetic/pharmacodynamic model. The combination may represent a novel therapeutic strategy against infections caused by KPC-producing K. pneumoniae strains.

  8. Genomic analysis of diversity, population structure, virulence, and antimicrobial resistance in Klebsiella pneumoniae, an urgent threat to public health

    PubMed Central

    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.

    2015-01-01

    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

  9. Seroepidemiology of Klebsiella pneumoniae colonizing the intestinal tract of healthy chinese and overseas chinese adults in Asian countries

    PubMed Central

    2012-01-01

    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. PMID:22260182

  10. Genomic analysis of diversity, population structure, virulence, and antimicrobial resistance in Klebsiella pneumoniae, an urgent threat to public health.

    PubMed

    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

    2015-07-01

    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.

  11. CTX-M β-Lactamase–producing Klebsiella pneumoniae in Suburban New York City, New York, USA

    PubMed Central

    Huang, Tiangui; Surendraiah, Pavan Kumar Makam; Wang, Kemeng; Komal, Rashida; Zhuge, Jian; Chern, Chian-Ru; Kryszuk, Alexander A.; King, Cassidy; Wormser, Gary P.

    2013-01-01

    CTX-M extended-spectrum β-lactamase (ESBL)–producing Klebsiella pneumoniae isolates are infrequently reported in the United States. In this study, we analyzed nonduplicate ESBL-producing K. pneumoniae and Escherichia coli clinical isolates collected during 2005–2012 at a tertiary care medical center in suburban New York City, USA, for the presence of blaCTX-M, blaSHV, blaTEM, and blaKPC genes. Despite a high prevalence of blaCTX-M genes in ESBL-producing E. coli since 2005, blaCTX-M genes were not detected in K. pneumoniae until 2009. The prevalence of CTX-M–producing K. pneumoniae increased significantly over time from 1.7% during 2005–2009 to 26.4% during 2010–2012 (p<0.0001). CTX-M-15 was the dominant CTX-M genotype. Pulsed-field gel electrophoresis and multilocus sequence typing revealed high genetic heterogeneities in CTX-M–producing K. pneumoniae isolates. This study demonstrates the recent emergence and polyclonal spread of multidrug resistant CTX-M–producing K. pneumoniae isolates among patients in a hospital setting in the United States. PMID:24188126

  12. Klebsiella pneumoniae: Development of Carbapenem Resistance due to Acquisition of blaNDM-1 During Antimicrobial Therapy in Twin Infants with Pneumonia

    PubMed Central

    Zhu, Junying; Ding, Baixing; Xu, Xiaogang; Zhu, Demei; Yang, Fan; Zhang, Hong; Hu, Fupin

    2015-01-01

    Objectives: To identify the mechanism of in vivo development of carbapenem resistance in Klebsiella pneumoniae.Methods: Seven sequential isolates of K. pneumoniae were obtained from twin infants with pneumonia. Antimicrobial susceptibility testing was performed by agar dilution method. Carbapenemases including KPC and MβL were initially screened using phenotypic methods, and carbapenemase-encoding genes were identified by polymerase chain reaction and amplicon sequencing. Plasmids of all clinical isolates and the conjugants of resistant isolates were estimated by S1 pulsed-field gel electrophoresis (PFGE). Molecular typing were conducted by PFGE of XbaI-digested genomic DNA and multilocus sequence typing.Results: For old brother, the first and third isolates were susceptible to meropenem, whereas the second and fourth isolates were resistant (MICs 16 mg/L). The first and second isolates from the young brother were susceptible to meropenem whereas the third isolate was resistant. All the resistant isolates produced NDM-1 metallo-β-lactamase. PFGE of XbaI-digested DNA revealed almost identical patterns with similarity indices of above 92% for all the seven isolates. All the isolates had the same sequence type named sequence type 37 (ST37).Conclusion: To our knowledge, this is the first documented case of development of carbapenem resistance in vivo mediated by NDM-1 metallo-β-lactamase in K. pneumoniae during treatment of pneumonia with meropenem. PMID:26733952

  13. Direct ertapenem disk screening method for identification of KPC-producing Klebsiella pneumoniae and Escherichia coli in surveillance swab specimens.

    PubMed

    Lolans, Karen; Calvert, Karen; Won, Sarah; Clark, James; Hayden, Mary K

    2010-03-01

    Klebsiella pneumoniae carbapenemase (KPC) production in Gram-negative bacilli is an increasing problem worldwide. Rectal swab surveillance is recommended as a component of infection prevention programs, yet few screening methods are published. We compared detection of KPC-producing Klebsiella pneumoniae and Escherichia coli in surveillance specimens by 2 methods: (i) inoculation of swabs in tryptic soy broth containing 2 microg/ml imipenem followed by plating to MacConkey agar (MAC) (method 1) and (ii) streaking swabs on MAC onto which a 10-microg ertapenem disk was then placed (method 2). Simulated rectal swab specimens of challenge isolates from a collection of well-characterized K. pneumoniae and E. coli strains and salvage rectal swab specimens collected from patients at 4 different health care facilities over a 7-month period were tested. The gold-standard comparator was bla(KPC) PCR testing of isolates. Method 1 detected 4/9 (44%) KPC-positive challenge isolates. By method 2, 9/9 KPC-positive challenge isolates exhibited zones of inhibition of < or = 27 mm; all KPC-negative isolates exhibited zones of inhibition greater than 27 mm. The sensitivity and specificity of method 1 for detection of KPC-positive K. pneumoniae and E. coli in 149 rectal swab specimens were 65.6% (95% confidence interval [CI], 46.8% to 80.8%) and 49.6% (95% CI, 40.3% to 58.9%), respectively. With method 2, a zone diameter of < or = 27 mm had a sensitivity of 97.0% (95% CI, 82.5% to 99.8%) and specificity of 90.5% (95% CI, 83.3% to 94.9%) for detection of KPC in rectal swab specimens. Direct ertapenem disk testing is simpler, more sensitive, and more specific than selective broth enrichment with imipenem for detection of KPC-producing K. pneumoniae and E. coli in surveillance specimens.

  14. Bloodstream infections among carriers of carbapenem-resistant Klebsiella pneumoniae: etiology, incidence and predictors.

    PubMed

    Amit, S; Mishali, H; Kotlovsky, T; Schwaber, M J; Carmeli, Y

    2015-01-01

    Carriers of carbapenem-resistant Klebsiella pneumoniae (CRKP) are increasingly recognised through active surveillance in much of the world. We studied incidence, aetiology and predictors of bloodstream infections (BSI) among such carriers. Via a retrospective cohort study conducted in a tertiary care teaching hospital, we examined occurrence of BSI within 45 days of CRKP carrier detection. Three nested case-control studies were conducted to analyse parameters associated with all-cause (ALL), Gram-negative rod (GNR) and CRKP BSI. Cases and controls were compared with respect to demographics, clinical parameters and recent receipt of antibiotics. A total of 431 patients were identified as CRKP carriers (28% by clinical culture, 72% by rectal surveillance), mean age was 75.2 years. Twenty percent of the patients (n = 85) developed BSI, of them 80% (n = 68) with GNR. Of 83 GNR isolates, 58 (70%) were Enterobacteriaceae, of which 19 were CRKP and 20 were extended-spectrum β-lactamase (ESBL) producers (23% and 24% of total GNR, respectively); 29% of the GNR isolates were nonfermenters (14.5% Pseudomonas aeruginosa, 14.5% Acinetobacter baumannii). Mechanical ventilation predicted ALL BSI (p = 0.04), whereas Clostridium difficile-associated diarrhoea predicted GNR BSI (p = 0.04). Receipt of broad-spectrum antibiotics (piperacillin-tazobactam, amikacin, imipenem) was significantly associated with ALL BSI or GNR BSI. No exposure independently predicted CRKP BSI. We conclude that patients detected as CRKP carriers are at high risk for BSI within 45 days of detection, primarily with multidrug-resistant GNR. Lack of predictive factors differentiating between pathogens and associated high mortality raises once more the dilemma regarding the appropriate empiric therapy for CRKP carriers who develop severe sepsis. PMID:25636924

  15. Interhospital spread of NDM-7-producing Klebsiella pneumoniae belonging to ST437 in Spain.

    PubMed

    Seara, Nieves; Oteo, Jesús; Carrillo, Raquel; Pérez-Blanco, Verónica; Mingorance, Jesús; Gómez-Gil, Rosa; Herruzo, Rafael; Pérez-Vázquez, María; Astray, Jenaro; García-Rodríguez, Julio; Ruiz-Velasco, Luis Moisés; Campos, José; de Burgos, Carmen; Ruiz-Carrascoso, Guillermo

    2015-08-01

    This study describes an interhospital spread of carbapenem-resistant Klebsiella pneumoniae (CRKP) producing NDM-7 carbapenemase that started in December 2013 in Madrid, Spain. NDM-7-producing CRKP were isolated from urine, rectal swabs or blood samples from seven patients admitted to three different hospitals (Hospital Universitario La Paz, Hospital de Cantoblanco and Hospital Central de la Cruz Roja). The isolates were resistant to all antimicrobials tested except colistin and fosfomycin. One blood isolate was susceptible to minocycline and tigecycline but was resistant to fosfomycin. All isolates were closely related by pulsed-field gel electrophoresis (PFGE) and DiversiLab(®) analysis and belonged to multilocus sequence typing (MLST) sequence type 437. In addition, blaNDM-7, blaTEM-1, blaCTX-M-15 and aac(3)-IIa were identified. Family contacts of the index case were negative for NDM-producing bacteria. The outbreak occurred in two separate waves and the cases associated with Hospital de Cantoblanco had been admitted to the same room. Environmental samples from the trap of a sink and a shower in this room were positive for NDM-7-producing CRKP. To our knowledge, this is the first reported worldwide outbreak of NDM-7-producing CRKP. No relationship with the Indian continent, the Balkans or the Middle East could be established. Frequent transfer of aged or chronically ill patients between the facilities involved may have favoured the spread of NDM-7-producing CRKP. The spread of the second wave in Hospital de Cantoblanco probably occurred as a result of transmission from an environmental reservoir.

  16. Interhospital spread of NDM-7-producing Klebsiella pneumoniae belonging to ST437 in Spain.

    PubMed

    Seara, Nieves; Oteo, Jesús; Carrillo, Raquel; Pérez-Blanco, Verónica; Mingorance, Jesús; Gómez-Gil, Rosa; Herruzo, Rafael; Pérez-Vázquez, María; Astray, Jenaro; García-Rodríguez, Julio; Ruiz-Velasco, Luis Moisés; Campos, José; de Burgos, Carmen; Ruiz-Carrascoso, Guillermo

    2015-08-01

    This study describes an interhospital spread of carbapenem-resistant Klebsiella pneumoniae (CRKP) producing NDM-7 carbapenemase that started in December 2013 in Madrid, Spain. NDM-7-producing CRKP were isolated from urine, rectal swabs or blood samples from seven patients admitted to three different hospitals (Hospital Universitario La Paz, Hospital de Cantoblanco and Hospital Central de la Cruz Roja). The isolates were resistant to all antimicrobials tested except colistin and fosfomycin. One blood isolate was susceptible to minocycline and tigecycline but was resistant to fosfomycin. All isolates were closely related by pulsed-field gel electrophoresis (PFGE) and DiversiLab(®) analysis and belonged to multilocus sequence typing (MLST) sequence type 437. In addition, blaNDM-7, blaTEM-1, blaCTX-M-15 and aac(3)-IIa were identified. Family contacts of the index case were negative for NDM-producing bacteria. The outbreak occurred in two separate waves and the cases associated with Hospital de Cantoblanco had been admitted to the same room. Environmental samples from the trap of a sink and a shower in this room were positive for NDM-7-producing CRKP. To our knowledge, this is the first reported worldwide outbreak of NDM-7-producing CRKP. No relationship with the Indian continent, the Balkans or the Middle East could be established. Frequent transfer of aged or chronically ill patients between the facilities involved may have favoured the spread of NDM-7-producing CRKP. The spread of the second wave in Hospital de Cantoblanco probably occurred as a result of transmission from an environmental reservoir. PMID:25982912

  17. Carriage rate of carbapenem-resistant Klebsiella pneumoniae in hospitalised patients during a national outbreak.

    PubMed

    Wiener-Well, Y; Rudensky, B; Yinnon, A M; Kopuit, P; Schlesinger, Y; Broide, E; Lachish, T; Raveh, D

    2010-04-01

    During a national outbreak of carbapenem-resistant Klebsiella pneumoniae (CRKP) in Israel, we conducted a point prevalence survey to determine the extent of asymptomatic carriage. Subsequently, a retrospective case-control study was done, comparing carriers of CRKP with non-carriers, in order to detect risk factors for carriage. Oral, perianal and rectal swabs were obtained from all hospitalised eligible and consenting patients. Selective media for carbapenem-resistant Gram-negative bacteria were used and pulsed-field gel electrophoresis (PFGE) helped to determine clonal source. Culture was obtained from 298 patients. Sixteen (5.4%) were carriers of CRKP, with a higher carriage rate in medical and surgical wards. Only 18% of carriers were treated with any carbapenem prior to the survey. Five of the 16 carriers had a positive clinical specimen for CRKP, hence a clinical infection versus asymptomatic carriage ratio of 1:3. The rectum was the most sensitive site sampled, detecting 15/16 carriers, and the overall sensitivity of the method was 94% with a negative predictive value of 99.6%. In a multivariate analysis of risk factors for CRKP carriage, three variables were significantly related to carriage state: diaper use, longer duration of hospital stay and vancomycin use. PFGE demonstrated that all 16 isolates were identical, confirming clonal origin. A point prevalence survey performed at a single medical centre during an outbreak of CRKP demonstrated a carriage rate of 5.4%. The clonal origin of these isolates suggests that strict adherence to isolation procedure may contain this outbreak. PMID:19783067

  18. EXPERIMENTAL MODEL FOR TREATMENT OF EXTENDED SPECTRUM BETALACTAMASE PRODUCING-KLEBSIELLA PNEUMONIAE

    PubMed Central

    TOLEDO, Paula Virginia Michelon; TUON, Felipe Francisco; BAIL, Larissa; MANENTE, Francine; ARRUDA, Polliane; ARANHA-JUNIOR, Ayrton Alves

    2014-01-01

    Background Animal models are useful to evaluate the efficacy of antimicrobials in experimental sepsis. Aim To elucidate the steps of producing an experimental model for the treatment of extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae sepsis Methods Several ESBL inoculums ranging from 1.5x109 colony-forming units per milliliter (CFU/mL) to 2.0x1010CFU/mL were administered by peritoneal injection in adults Wistar rats. Outcomes and microbiological data of quantitative peritoneal and blood cultures were observed in untreated animals. Animals which received 2.0x1010CFU/mL inoculums were treated with single meropenem dose (30mg/kg) after one hour and those which received 1.0x1010CFU/mL inoculums were treated immediately with three doses of meropenem 50 mg/kg. Outcomes were observed for 24 hours after inoculation. Results Solutions with 1.5 x109 and 6.0x109 CFU/mL were not lethal within 24 hours. Inoculums of 1.0x1010CFU/mL were lethal in 80% and solutions with 2.0x1010 CFU/mL were lethal in 100% of animals. ESBL lethal sepsis (1.0x1010CFU/mL) was treated immediately with 50 mg/kg of meropenem every eight hours for 24 hours and presented 40% mortality compared with 80% mortality of the control group (p=0.033). Quantitative cultures of peritoneal fluid presented 104CFU/mL or less for treated animals compared to more than 105 for untreated animals (p=0.001). Conclusion Inoculums of 1.0x1010CFU/mL achieved the best results to study a model of lethal sepsis and this model of treatment of carbapenem-susceptible Enterobacteriaceae can serve as control to further evaluation of treatment of carbapenemase-producing Enterobacteriaceae models. PMID:25184764

  19. Characterization of the genetic environment of the blaKPC-2 gene among Klebsiella pneumoniae isolates from a Chinese Hospital.

    PubMed

    Shen, Pinghua; Zhang, Ying; Li, Gang; Jiang, Xiaofei

    2016-01-01

    Infection caused by carbapenem-resistant Klebsiella pneumoniae has become a major healthcare threat and KPC-2 enzyme is a dominant factor mediating carbapenems resistance in K. pneumoniae. This study was designed to determine the genetic environment of blaKPC-2, which prevailed in clinical K. pneumoniae isolates recovered in Huashan Hospital, Shanghai, China. Forty-two clinical isolates were included in this study by blaKPC-2 screening. After multilocus sequence typing and plasmid analyses of PCR-based replicon typing (PBRT), junction PCR, mapping PCR and crossing PCR assays, primer walking, and amplicon sequencing were used to analyze the genetic environment of the blaKPC-2 gene. ST423, ST65, ST977, and ST11 were all detected in KPC-2-producing K. pneumoniae. Two types of blaKPC-2-bearing genetic structure were found: Tn1721-blaKPC-2-Tn3 and Tn1721-blaKPC-2-ΔTn3-IS26; and were carried in IncX and IncFII plasmids, respectively. In conclusion, the genetic environment of the blaKPC-2 gene was diverse and Tn1721-blaKPC-2-ΔTn3-IS26 was dominant in clinical K. pneumoniae isolates in Huashan Hospital. This study sheds some light on the genetic environment and should foster further studies about the mechanism of the blaKPC-2 dissemination. PMID:27183358

  20. Molecular detection and antimicrobial resistance of Klebsiella pneumoniae from house flies (Musca domestica) in kitchens, farms, hospitals and slaughterhouses.

    PubMed

    Ranjbar, Reza; Izadi, Morteza; Hafshejani, Taghi T; Khamesipour, Faham

    2016-01-01

    Identifying disease vectors and pathogens is one of the key steps in controlling vector-borne diseases. This study investigated the possible role of house flies (Musca domestica) as vectors in the transmission of Klebsiella pneumoniae in Chaharmahal VA Bakhtiari and Isfahan provinces of Iran. House flies were captured from household kitchens, cattle farms, chicken farms, animal hospitals, human hospitals and slaughterhouses. Isolation of K. pneumoniae from external surfaces and guts of the flies was performed using MacConkey agar (MA) and thioglycollate broth (TGB). Identification of the isolates was performed with phenotypic techniques and polymerase chain reaction (PCR). A total of 600 house flies were sampled during the study period from different locations in four different seasons. Overall, 11.3% of the captured house flies were positive for K. pneumoniae. In Chaharmahal VA Bakhtiari province, the prevalence was 12.7%, while in Isfahan province, 10.0% of the sampled house flies were infected with K. pneumoniae. Season-wise, the highest prevalence of infections among the house flies was in summer. The organisms were highly resistant to ampicillin, amoxicillin, cefotaxime and piperacillin. A lowest level of resistance was observed for imipenem/cilastatin. The findings of this study demonstrated that house flies are potential vectors of antibiotic-resistant K. pneumoniae in Isfahan and Chaharmahal provinces, Iran. Control efforts for infections caused by this particular bacterium should take M. domestica into account.

  1. Molecular characterization of integrons in clinical isolates of betalactamase-producing Escherichia coli and Klebsiella pneumoniae in Iran.

    PubMed

    Zeighami, Habib; Haghi, Fakhri; Hajiahmadi, Fahimeh

    2015-06-01

    Integrons are considered to play a significant role in the evolution and spread of antibiotic resistance genes. A total of 349 clinical isolates of Escherichia coli and Klebsiella pneumoniae were investigated for molecular characterization of integrons and betalactamases. Antimicrobial susceptibility testing was also performed as the Clinical and Laboratory Standards Institute (CLSI) guidelines. The frequency of extended spectrum betalactamases (ESBL) or metallo-betalactamases (MBL)-producing isolates, patient demographics, and the susceptibility to various antimicrobial agents were described. BlaCTX-M was the most frequently detected betalactamase in all isolates. Moreover, MBL producing K. pneumoniae carried blaIMP and blaVIM at 100 and 41·6%, respectively but no MBL-positive E. coli was detected. Class 1 integrons were more frequent among E. coli and K. pneumoniae isolates in comparison with class 2 integrons and the frequency of intI2 in K. pneumoniae was significantly higher than E. coli isolates. Five different resistance gene arrays were identified among class 1 integrons. Dihydrofolate reductase (dfrA) and aminoglycoside adenyltransferase (aad) gene cassettes were found to be predominant in the class 1 integrons. These results indicate that class 1 integrons are widespread among ESBL-producing isolates of K. pneumoniae and E. coli and appropriate surveillance and control measures are essential to prevent further dissemination of these elements among Enterobacteriaceae in our country.

  2. Distinct but Spatially Overlapping Intestinal Niches for Vancomycin-Resistant Enterococcus faecium and Carbapenem-Resistant Klebsiella pneumoniae.

    PubMed

    Caballero, Silvia; Carter, Rebecca; Ke, Xu; Sušac, Bože; Leiner, Ingrid M; Kim, Grace J; Miller, Liza; Ling, Lilan; Manova, Katia; Pamer, Eric G

    2015-09-01

    Antibiotic resistance among enterococci and γ-proteobacteria is an increasing problem in healthcare settings. Dense colonization of the gut by antibiotic-resistant bacteria facilitates their spread between patients and also leads to bloodstream and other systemic infections. Antibiotic-mediated destruction of the intestinal microbiota and consequent loss of colonization resistance are critical factors leading to persistence and spread of antibiotic-resistant bacteria. The mechanisms underlying microbiota-mediated colonization resistance remain incompletely defined and are likely distinct for different antibiotic-resistant bacterial species. It is unclear whether enterococci or γ-proteobacteria, upon expanding to high density in the gut, confer colonization resistance against competing bacterial species. Herein, we demonstrate that dense intestinal colonization with vancomycin-resistant Enterococcus faecium (VRE) does not reduce in vivo growth of carbapenem-resistant Klebsiella pneumoniae. Reciprocally, K. pneumoniae does not impair intestinal colonization by VRE. In contrast, transplantation of a diverse fecal microbiota eliminates both VRE and K. pneumoniae from the gut. Fluorescence in situ hybridization demonstrates that VRE and K. pneumoniae localize to the same regions in the colon but differ with respect to stimulation and invasion of the colonic mucus layer. While VRE and K. pneumoniae occupy the same three-dimensional space within the gut lumen, their independent growth and persistence in the gut suggests that they reside in distinct niches that satisfy their specific in vivo metabolic needs. PMID:26334306

  3. Improvement of 2,3-Butanediol Yield in Klebsiella pneumoniae by Deletion of the Pyruvate Formate-Lyase Gene

    PubMed Central

    Jung, Moo-Young; Mazumdar, Suman; Shin, Sang Heum; Yang, Kap-Seok; Lee, Jinwon

    2014-01-01

    Klebsiella pneumoniae is considered a good host strain for the production of 2,3-butanediol, which is a promising platform chemical with various industrial applications. In this study, three genes, including those encoding glucosyltransferase (wabG), lactate dehydrogenase (ldhA), and pyruvate formate-lyase (pflB), were disrupted in K. pneumoniae to reduce both its pathogenic characteristics and the production of several by-products. In flask cultivation with minimal medium, the yield of 2,3-butanediol from rationally engineered K. pneumoniae (ΔwabG ΔldhA ΔpflB) reached 0.461 g/g glucose, which was 92.2% of the theoretical maximum, with a significant reduction in by-product formation. However, the growth rate of the pflB mutant was slightly reduced compared to that of its parental strain. Comparison with similar mutants of Escherichia coli suggested that the growth defect of pflB-deficient K. pneumoniae was caused by redox imbalance rather than reduced level of intracellular acetyl coenzyme A (acetyl-CoA). From an analysis of the transcriptome, it was confirmed that the removal of pflB from K. pneumoniae significantly repressed the expression of genes involved in the formate hydrogen lyase (FHL) system. PMID:25085487

  4. Heteroresistance to colistin in Klebsiella pneumoniae is triggered by small colony variants sub-populations within biofilms.

    PubMed

    Silva, Ana; Sousa, Ana Margarida; Alves, Diana; Lourenço, Anália; Pereira, Maria Olívia

    2016-07-01

    The emergence of Klebsiella pneumoniae multidrug-resistant strains paves the way to the re-introduction of colistin as a salvage therapy. However, recent planktonic studies have reported several cases of heteroresistance to this antimicrobial agent. The aim of this present work was to gain better understanding about the response of K. pneumoniae biofilms to colistin antibiotherapy and inspect the occurrence of heteroresistance in biofilm-derived cells. Biofilm formation and its susceptibility to colistin were evaluated through the determination of biofilm-cells viability. The profiling of planktonic and biofilm cell populations was conducted to assess the occurrence of heteroresistance. Colony morphology was further characterized in order to inspect the potential role of colistin in K. pneumoniae phenotypic differentiation. Results show that K. pneumoniae was susceptible to colistin in its planktonic form, but biofilms presented enhanced resistance. Population analysis profiles pointed out that K. pneumoniae manifest heteroresistance to colistin only when grown in biofilm arrangements, and it was possible to identify a resistant sub-population presenting a small colony morphology (diameter around 5 mm). To the best of our knowledge, this is the first report linking heteroresistance to biofilm formation and a morphological distinctive sub-population. Moreover, this is the first evidence that biofilm formation can trigger the emergence of heteroresistance in an apparently susceptible strain. PMID:27140200

  5. Heteroresistance to colistin in Klebsiella pneumoniae is triggered by small colony variants sub-populations within biofilms.

    PubMed

    Silva, Ana; Sousa, Ana Margarida; Alves, Diana; Lourenço, Anália; Pereira, Maria Olívia

    2016-07-01

    The emergence of Klebsiella pneumoniae multidrug-resistant strains paves the way to the re-introduction of colistin as a salvage therapy. However, recent planktonic studies have reported several cases of heteroresistance to this antimicrobial agent. The aim of this present work was to gain better understanding about the response of K. pneumoniae biofilms to colistin antibiotherapy and inspect the occurrence of heteroresistance in biofilm-derived cells. Biofilm formation and its susceptibility to colistin were evaluated through the determination of biofilm-cells viability. The profiling of planktonic and biofilm cell populations was conducted to assess the occurrence of heteroresistance. Colony morphology was further characterized in order to inspect the potential role of colistin in K. pneumoniae phenotypic differentiation. Results show that K. pneumoniae was susceptible to colistin in its planktonic form, but biofilms presented enhanced resistance. Population analysis profiles pointed out that K. pneumoniae manifest heteroresistance to colistin only when grown in biofilm arrangements, and it was possible to identify a resistant sub-population presenting a small colony morphology (diameter around 5 mm). To the best of our knowledge, this is the first report linking heteroresistance to biofilm formation and a morphological distinctive sub-population. Moreover, this is the first evidence that biofilm formation can trigger the emergence of heteroresistance in an apparently susceptible strain.

  6. Polyphenolic Secondary Metabolites Synergize the Activity of Commercial Antibiotics against Clinical Isolates of β-Lactamase-producing Klebsiella pneumoniae.

    PubMed

    Dey, Diganta; Ghosh, Subhalakshmi; Ray, Ratnamala; Hazra, Banasri

    2016-02-01

    Emergence of worldwide antimicrobial resistance prompted us to study the resistance modifying potential of plant-derived dietary polyphenols, mainly caffeic acid, ellagic acid, epigallocatechin-3-gallate (EGCG) and quercetin. These compounds were studied in logical combination with clinically significant antibiotics (ciprofloxacin/gentamicin/tetracycline) against Klebsiella pneumoniae, after conducting phenotypic screening of a large number of clinical isolates and selecting the relevant strains possessing extended-spectrum β-lactamase (ESBL) and K. pneumoniae carbapenemase (KPC)-type carbapenemase enzymes only. The study demonstrated that EGCG and caffeic acid could synergize the activity of tested antibiotics within a major population of β-lactamase-producing K. pneumoniae. In spectrofluorimetric assay, ~17-fold greater ciprofloxacin accumulation was observed within K. pneumoniae cells pre-treated with EGCG in comparison with the untreated control, indicating its ability to synergize ciprofloxacin to restrain active drug-efflux. Further, electron micrograph of ESBL-producing K. pneumoniae clearly demonstrated the prospective efficacy of EGCG towards biofilm degradation.

  7. Distinct but Spatially Overlapping Intestinal Niches for Vancomycin-Resistant Enterococcus faecium and Carbapenem-Resistant Klebsiella pneumoniae.

    PubMed

    Caballero, Silvia; Carter, Rebecca; Ke, Xu; Sušac, Bože; Leiner, Ingrid M; Kim, Grace J; Miller, Liza; Ling, Lilan; Manova, Katia; Pamer, Eric G

    2015-09-01

    Antibiotic resistance among enterococci and γ-proteobacteria is an increasing problem in healthcare settings. Dense colonization of the gut by antibiotic-resistant bacteria facilitates their spread between patients and also leads to bloodstream and other systemic infections. Antibiotic-mediated destruction of the intestinal microbiota and consequent loss of colonization resistance are critical factors leading to persistence and spread of antibiotic-resistant bacteria. The mechanisms underlying microbiota-mediated colonization resistance remain incompletely defined and are likely distinct for different antibiotic-resistant bacterial species. It is unclear whether enterococci or γ-proteobacteria, upon expanding to high density in the gut, confer colonization resistance against competing bacterial species. Herein, we demonstrate that dense intestinal colonization with vancomycin-resistant Enterococcus faecium (VRE) does not reduce in vivo growth of carbapenem-resistant Klebsiella pneumoniae. Reciprocally, K. pneumoniae does not impair intestinal colonization by VRE. In contrast, transplantation of a diverse fecal microbiota eliminates both VRE and K. pneumoniae from the gut. Fluorescence in situ hybridization demonstrates that VRE and K. pneumoniae localize to the same regions in the colon but differ with respect to stimulation and invasion of the colonic mucus layer. While VRE and K. pneumoniae occupy the same three-dimensional space within the gut lumen, their independent growth and persistence in the gut suggests that they reside in distinct niches that satisfy their specific in vivo metabolic needs.

  8. Characterization of the genetic environment of the blaKPC-2 gene among Klebsiella pneumoniae isolates from a Chinese Hospital.

    PubMed

    Shen, Pinghua; Zhang, Ying; Li, Gang; Jiang, Xiaofei

    2016-01-01

    Infection caused by carbapenem-resistant Klebsiella pneumoniae has become a major healthcare threat and KPC-2 enzyme is a dominant factor mediating carbapenems resistance in K. pneumoniae. This study was designed to determine the genetic environment of blaKPC-2, which prevailed in clinical K. pneumoniae isolates recovered in Huashan Hospital, Shanghai, China. Forty-two clinical isolates were included in this study by blaKPC-2 screening. After multilocus sequence typing and plasmid analyses of PCR-based replicon typing (PBRT), junction PCR, mapping PCR and crossing PCR assays, primer walking, and amplicon sequencing were used to analyze the genetic environment of the blaKPC-2 gene. ST423, ST65, ST977, and ST11 were all detected in KPC-2-producing K. pneumoniae. Two types of blaKPC-2-bearing genetic structure were found: Tn1721-blaKPC-2-Tn3 and Tn1721-blaKPC-2-ΔTn3-IS26; and were carried in IncX and IncFII plasmids, respectively. In conclusion, the genetic environment of the blaKPC-2 gene was diverse and Tn1721-blaKPC-2-ΔTn3-IS26 was dominant in clinical K. pneumoniae isolates in Huashan Hospital. This study sheds some light on the genetic environment and should foster further studies about the mechanism of the blaKPC-2 dissemination.

  9. Outbreak of NDM-1-producing Klebsiella pneumoniae causing neonatal infection in a teaching hospital in mainland China.

    PubMed

    Zhang, XiaoYu; Li, XianPing; Wang, Min; Yue, HeJia; Li, PengLing; Liu, YaPing; Cao, Wei; Yao, DongMei; Liu, Li; Zhou, XiaoLan; Zheng, Rong; Bo, Tao

    2015-07-01

    The emergence and spread of bacteria carrying the bla(NDM-1) gene has become a worldwide concern. Here, we report eight cases of Klebsiella pneumoniae with bla(NDM-1) in the neonatal ward of a teaching hospital in mainland China. Multilocus sequence typing showed that seven isolates were clonally related and confirmed them as sequence type 17 (ST17). One isolate belonged to ST433. These findings suggest continuous spread of bla(NDM-1) in mainland China and emphasize the need for intensive surveillance and precautions. PMID:25941224

  10. Nested Case-Control Study of the Emergence of Tigecycline Resistance in Multidrug-Resistant Klebsiella pneumoniae

    PubMed Central

    Nigo, Masayuki; Cevallos, Catalina Salinas; Woods, Krystina; Flores, Vicente Maco; Francis, Gweneth; Perlman, David C.; Revuelta, Manuel; Mildvan, Donna; Waldron, Mary; Gomez, Tessa; Koshy, Sanjana; Jodlowski, Tomasz; Riley, William

    2013-01-01

    We performed a nested case-control study (ratio of 1:4) on the emergence of tigecycline-resistant multidrug-resistant Klebsiella pneumoniae (TR-MDRKP) isolates among patients who initially presented with a tigecycline-susceptible MDRKP isolate. Out of 260 patients, 24 (9%) had a subsequent clinical culture positive for a TR-MDRKP isolate within the 90-day follow-up period. On logistic regression analyses, receipt of tigecycline (adjusted odds ratio [OR], 5.06; 95% confidence interval [CI], 1.80 to 14.23; P = 0.002) was the only independent predictor of subsequent isolation of a TR strain. PMID:23979745

  11. Regulation of nitrogen fixation in Klebsiella pneumoniae: isolation and characterization of strains with nif-lac fusions.

    PubMed

    MacNeil, D; Zhu, J; Brill, W J

    1981-01-01

    Strains with lac fused to each of the seven nif operons were isolated by two different methods. Repressing conditions prevented expression of all nif operons, whereas derepressing conditions led to the expression of all nif operons. No differences in Nif regulation were observed between Escherichia coli and Klebsiella pneumoniae with the same nif-lac fusions. Most derivatives of nif-lac fusion strains selected on lactose and NH4+ contained nif operator mutations. Some derivative contained deletions, which establishes that the direction of transcription of all seven nif operons is toward his

  12. Impaired acquired resistance of mice to Klebsiella pneumoniae infection induced by acute NO/sub 2/ exposure

    SciTech Connect

    Bouley, G.; Azoulay-Dupuis, E.; Gaudebout, C.

    1985-12-01

    The natural resistance of nonimmunized C57B1/6 mice to an intraperitoneal Klebsiella pneumoniae challenge was not significantly affected by prior continuous exposure to 20 ppm NO/sub 2/ for 4 days. In contrast, the acquired resistance of mice immunized just before and infected just after NO/sub 2/ exposure was seriously impaired. This could not be explained by the loss of appetite (about 30%) observed in NO/sub 2/ treated mice, for neither the natural nor acquired resistance of control air exposure mice given approximately 70% ad libitum food and water were significantly modified.

  13. Virulence Factors and TEM-Type β-Lactamases Produced by Two Isolates of an Epidemic Klebsiella pneumoniae Strain

    PubMed Central

    Hennequin, Claire; Gniadkowski, Marek; Beyrouthy, Racha; Empel, Joanna; Gibold, Lucie; Bonnet, Richard

    2012-01-01

    Two Klebsiella pneumoniae isolates of the same strain, identified in Poland, produced either TEM-47 or TEM-68, which differed by the Arg275Leu substitution. They harbored a few virulence factors, including an iron-chelating factor and capsule overproduction, suggesting that these factors were sufficient to enhance their nosocomial potency. TEM-68 and TEM-47 had similar enzymatic activities, but TEM-68 was less susceptible to inhibitors than TEM-47. These results confirm the role of the Arg275Leu substitution in the evolution of TEM enzymes. PMID:22106220

  14. Influence of the bacterial phenotypes on the clinical manifestations in Klebsiella pneumoniae bacteremia patients: A retrospective cohort study.

    PubMed

    Togawa, Atsushi; Toh, Hiromi; Onozawa, Kyoko; Yoshimura, Michinobu; Tokushige, Chiemi; Shimono, Nobuyuki; Takata, Tohru; Tamura, Kazuo

    2015-07-01

    Ninety-four episodes of Klebsiella pneumoniae bloodstream infection were identified at a university hospital in Japan. After excluding extended-spectrum beta lactamase-producing strains, 83 blood isolates from these patients were assayed in terms of their bacterial phenotypes such as the mucoid and hypermucoviscosity phenotypes. Bacterial phenotypes were correlated with the patients' clinical manifestations. The hypermucoviscosity phenotype was significantly associated with septic shock at the onset of infections (odds ratio, 15.92; 95% confidence interval, 1.27-468.12), but was not associated with liver abscess formation. Mortality was determined by the presence of septic shock. RmpA gene was associated with the induction of the hypermucoviscosity phenotype. These results reveal unique roles of bacterial phenotypes on the patient's clinical condition in K. pneumoniae bacteremia.

  15. Molecular epidemiology of Klebsiella pneumoniae producing SHV-5 beta- lactamase: parallel outbreaks due to multiple plasmid transfer.

    PubMed Central

    Prodinger, W M; Fille, M; Bauernfeind, A; Stemplinger, I; Amann, S; Pfausler, B; Lass-Florl, C; Dierich, M P

    1996-01-01

    Over a period of 22 months, 32 patients treated in three independent intensive care units of the Innsbruck University Hospital were infected with extended-spectrum beta-lactamase-producing members of the family Enterobacteriaceae (30 Klebsiella pneumoniae isolates, 1 Klebsiella oxytoca isolate, and 1 Escherichia coli isolate). As confirmed by sequencing of a bla gene PCR fragment, all isolates expressed the SHV-5-type beta-lactamase. Genomic fingerprinting of epidemic strains with XbaI and pulsed-field gel electrophoresis grouped 20 of 21 isolates from ward A into two consecutive clusters which included 1 of 3 ward B isolates. All six K. pneumoniae isolates from ward C formed a third cluster. Stool isolates of asymptomatic patients and environmental isolates belonged to these clusters as well. Additionally, 2,600 routine K. pneumoniae isolates from the surrounding provinces (population, 900,000) were screened for SHV-5 production. Only one of six nonepidemic isolates producing SHV-5 beta-lactamase was matched with the outbreak strains by genomic fingerprinting. Plasmid fingerprinting, however, revealed the epidemic spread of a predominant R-plasmid, with a size of approximately 80 kb, associated with 29 of the 30 K. pneumoniae isolates. This plasmid was also present in the single K. oxytoca and E. coli isolates from ward C and in three nonepidemic isolates producing SHV-5. Our results underline that strain typing exclusively on the genomic level can be misleading in the epidemiological investigation of plasmid-encoded extended-spectrum beta-lactamases. Our evidence for multiple events of R-plasmid transfer between species of the family Enterobacteriaceae in this nosocomial outbreak stresses the need for plasmid typing, especially because SHV-5 beta-lactamase seems to be regionally spread predominantly via plasmid transfer. PMID:8904415

  16. Hypervirulent Klebsiella pneumoniae clones causing bacteraemia in adults in a teaching hospital in Barcelona, Spain (2007-2013).

    PubMed

    Cubero, M; Grau, I; Tubau, F; Pallarés, R; Dominguez, M A; Liñares, J; Ardanuy, C

    2016-02-01

    Virulent hypermucoviscous Klebsiella pneumoniae strains associated with the magA and rmpA genes have mainly emerged in Asia. We analysed the frequency and the clinical and molecular epidemiology of K. pneumoniae bacteraemia isolates obtained over a 7-year period (2007-2013). Fifty-three of 878 K. pneumoniae invasive isolates (5.4%) showed a hypermucoviscous phenotype (by the string test). Of these, 16 (30.2%) were magA(+)/rmpA(+), 12 (22.6%) were magA(-)/rmpA(+), and the remaining 25 (47.2%) were magA(-)/rmpA(-). After multilocus sequence typing and wzi sequencing, all magA(+)/rmpA(+) isolates were serotype K1 and sequence type (ST)23. Of the 12 magA(-)/rmpA(+) isolates, nine were K2 (ST380, ST86, ST65, ST25 and ST493), and three magA(-)/rmpA(+) isolates had the new wzi allele 122, an unknown serotype, and the new ST1013. The remaining isolates, which were magA(-)/rmpA(-), showed different serotypes and STs. Patients with magA(+)/rmpA(+) or magA(-)/rmpA(+)K. pneumoniae bacteraemia more frequently had pyogenic liver abscesses (PLAs) and pneumonia than patients with magA(-)/rmpA(-)K. pneumoniae bacteraemia (respectively: 21.4% vs. 8%, p 0.26; and 17.9% vs. 0%, p 0.05). In fact, magA(-)/rmpA(-) isolates were similar to the those termed 'classic' K. pneumoniae isolates causing bacteraemia, the urinary and biliary tracts being the main foci of infection. In conclusion, hypervirulent clones (CC23K1, CC86K2, CC65K2, and CC380K2) were infrequent among K. pneumoniae isolates causing bacteraemia in our geographical area. A hypermucoviscous phenotype as determined with the string test is not enough to recognize these clones; additional molecular studies are needed. Patients with magA(+) and/or rmpA(+)K. pneumoniae bacteraemia more frequently had PLAs and pneumonia than patients without hypermucoviscosity genes.

  17. Extended-Spectrum Beta-Lactamases Producing Escherichia coli and Klebsiella pneumoniae: A Multi-Centric Study Across Karnataka

    PubMed Central

    Rao, Sridhar PN; Rama, Prasad Subba; Gurushanthappa, Vishwanath; Manipura, Radhakrishna; Srinivasan, Krishna

    2014-01-01

    Background: There are sporadic reports on detection of extended-spectrum beta-lactamases (ESBL) producers from Karnataka; hence, this is a first multicentric study across Karnataka state to determine the prevalence of ESBL production among clinical isolates of Escherichia coli and Klebsiella pneumoniae. Aims and objectives: To determine the prevalence of ESBL producing clinical isolates of E. coli and K. pneumoniae from five geographically distributed centers across Karnataka, to study the susceptibility of ESBL producing isolates to other beta-lactam and beta-lactam-beta-lactamase inhibitors and to demonstrate transferability of plasmids coding for ESBL phenotype. Materials and Methods: Two hundred isolates of E. coli and K. pneumoniae each were collected from each of the five centers (Bellary, Dharwad, Davangere, Kolar and Mangalore). They were screened for resistance to screening agents (ceftazidime, cefotaxime, ceftriaxone, aztreonam) and positive isolates were confirmed for ESBL production by test described by Clinical and Laboratory Standards Institute. Co-production of ESBL and AmpC beta-lactamase was identified by using amino-phenylboronic acid disk method. Susceptibility of ESBL producers to beta-lactam antibiotics and beta-lactamase inhibitors was performed. Transferability of plasmids was performed by conjugation experiment. Results: Overall prevalence of ESBL production among E. coli and K. pneumoniae across five centers of the state was 57.5%. ESBL production was found to be 61.4% among E. coli and 46.2% among K. pneumoniae. ESBL production was significantly more among E. coli than K. pneumoniae. Significant variations in distribution of ESBL across the state was observed among E. coli isolates, but not among K. pneumoniae isolates. All ESBL producers demonstrated minimum inhibitory concentration levels ≥2 μg/ml towards cefotaxime, ceftazidime and ceftriaxone. Conclusion: Overall prevalence of ESBL production among clinical isolates of E. coli and K

  18. Effect of cumin (Cuminum cyminum) seed essential oil on biofilm formation and plasmid Integrity of Klebsiella pneumoniae.

    PubMed

    Derakhshan, Safoura; Sattari, Morteza; Bigdeli, Mohsen

    2010-01-01

    Seeds of the cumin plant (Cuminum cyminum L.) have been used since many years in Iranian traditional medicine. We assessed the effect of cumin seed essential oil on the biofilm-forming ability of Klebsiella pneumoniae strains and on the integrity of a native resistance plasmid DNA from K. pneumoniae isolates, treated with essential oil. Antibacterial coaction between the essential oil and selected antibiotic disks were determined for inhibiting K. pneumoniae. The essential oil of the cumin seeds was obtained by hydrodistillation in a Clavenger system. A simple method for the formation of biofilms on semiglass lamellas was established. The biofilms formed were observed by scanning electron microscopy (SEM). The effect of essential oil on plasmid integrity was studied through the induction of R-plasmid DNA degradation. The plasmid was incubated with essential oil, and agarose gel electrophoresis was performed. Disk diffusion assay was employed to determine the coaction. The essential oil decreased biofilm formation and enhanced the activity of the ciprofloxacin disk. The incubation of the R-plasmid DNA with essential oil could not induce plasmid DNA degradation. The results of this study suggest the potential use of cumin seed essential oil against K. pneumoniae in vitro, may contribute to the in vivo efficacy of this essential oil. PMID:20548937

  19. Effect of cumin (Cuminum cyminum) seed essential oil on biofilm formation and plasmid Integrity of Klebsiella pneumoniae

    PubMed Central

    Derakhshan, Safoura; Sattari, Morteza; Bigdeli, Mohsen

    2010-01-01

    Seeds of the cumin plant (Cuminum cyminum L.) have been used since many years in Iranian traditional medicine. We assessed the effect of cumin seed essential oil on the biofilm-forming ability of Klebsiella pneumoniae strains and on the integrity of a native resistance plasmid DNA from K. pneumoniae isolates, treated with essential oil. Antibacterial coaction between the essential oil and selected antibiotic disks were determined for inhibiting K. pneumoniae. The essential oil of the cumin seeds was obtained by hydrodistillation in a Clavenger system. A simple method for the formation of biofilms on semiglass lamellas was established. The biofilms formed were observed by scanning electron microscopy (SEM). The effect of essential oil on plasmid integrity was studied through the induction of R-plasmid DNA degradation. The plasmid was incubated with essential oil, and agarose gel electrophoresis was performed. Disk diffusion assay was employed to determine the coaction. The essential oil decreased biofilm formation and enhanced the activity of the ciprofloxacin disk. The incubation of the R-plasmid DNA with essential oil could not induce plasmid DNA degradation. The results of this study suggest the potential use of cumin seed essential oil against K. pneumoniae in vitro, may contribute to the in vivo efficacy of this essential oil. PMID:20548937

  20. Identification of a capsular variant and characterization of capsular acetylation in Klebsiella pneumoniae PLA-associated type K57

    PubMed Central

    Hsu, Chun-Ru; Liao, Chun-Hsing; Lin, Tzu-Lung; Yang, Han-Ru; Yang, Feng-Ling; Hsieh, Pei-Fang; Wu, Shih-Hsiung; Wang, Jin-Town

    2016-01-01

    Klebsiella pneumoniae can cause community-acquired pyogenic liver abscess (PLA). Capsular polysaccharide (CPS) is important for its virulence. Among 79 capsular (K) types discovered thus far, K57 is often associated with PLA. Here, we report the identification of a K57 variant. Cps gene locus sequencing revealed differences between the K57 reference strain 4425/51 (Ref-K57) and a variant, the PLA isolate A1142. While Ref-K57 cps contained orf13 encoding a putative acetyltransferase, the insertion of a putative transposase-encoding gene at this position was detected in A1142. This variation was detected in other K57 clinical strains. Biochemical analyses indicated that A1142 was deficient in CPS acetylation. Genetic replacement and complementation verified that orf13 was responsible for CPS acetylation. Acetylation increased CPS immunoreactivity to antiserum and enhanced K. pneumoniae induction of pro-inflammatory cytokines through JNK and MAPK signaling. While acetylation diminished the serum resistance of bacteria, it promoted adhesion to intestinal epithelial cells possibly via increasing production of type I fimbriae. In conclusion, acetylation-mediated capsular variation in K57 was observed. Capsular acetylation contributed to the variety and antigenic diversity of CPS, influenced its biological activities, and was involved in K. pneumoniae-host interactions. These findings have implications for vaccine design and pathogenicity of K. pneumoniae. PMID:27550826

  1. Effect of cumin (Cuminum cyminum) seed essential oil on biofilm formation and plasmid Integrity of Klebsiella pneumoniae.

    PubMed

    Derakhshan, Safoura; Sattari, Morteza; Bigdeli, Mohsen

    2010-01-01

    Seeds of the cumin plant (Cuminum cyminum L.) have been used since many years in Iranian traditional medicine. We assessed the effect of cumin seed essential oil on the biofilm-forming ability of Klebsiella pneumoniae strains and on the integrity of a native resistance plasmid DNA from K. pneumoniae isolates, treated with essential oil. Antibacterial coaction between the essential oil and selected antibiotic disks were determined for inhibiting K. pneumoniae. The essential oil of the cumin seeds was obtained by hydrodistillation in a Clavenger system. A simple method for the formation of biofilms on semiglass lamellas was established. The biofilms formed were observed by scanning electron microscopy (SEM). The effect of essential oil on plasmid integrity was studied through the induction of R-plasmid DNA degradation. The plasmid was incubated with essential oil, and agarose gel electrophoresis was performed. Disk diffusion assay was employed to determine the coaction. The essential oil decreased biofilm formation and enhanced the activity of the ciprofloxacin disk. The incubation of the R-plasmid DNA with essential oil could not induce plasmid DNA degradation. The results of this study suggest the potential use of cumin seed essential oil against K. pneumoniae in vitro, may contribute to the in vivo efficacy of this essential oil.

  2. Molecular Evolution of a Klebsiella pneumoniae ST278 Isolate Harboring blaNDM-7 and Involved in Nosocomial Transmission.

    PubMed

    Lynch, Tarah; Chen, Liang; Peirano, Gisele; Gregson, Dan B; Church, Deirdre L; Conly, John; Kreiswirth, Barry N; Pitout, Johann D

    2016-09-01

    During 2013, ST278 Klebsiella pneumoniae with blaNDM-7 was isolated from the urine (KpN01) and rectum (KpN02) of a patient in Calgary, Canada. The same strain (KpN04) was subsequently isolated from another patient in the same unit. Interestingly, a carbapenem-susceptible K. pneumoniae ST278 (KpN06) was obtained 1 month later from the blood of the second patient. Next-generation sequencing (NGS) revealed that the loss of carbapenem-resistance in KpN06 was due to a 5-kb deletion on the blaNDM-7-harboring IncX3 plasmid. In addition, an IncFIB plasmid in KpN06 had a 27-kb deletion that removed genes encoding for heavy metal resistance. Phylogenetic analysis showed that the K. pneumoniae ST278 from patient 2 was likely a descendant of KpN02 and that KpN06 was a close progenitor of an environmental ST278. It is unclear whether KpN06 lost the blaNDM-7 gene in vivo. This study detailed the remarkable plasticity and speed of evolutionary changes in multidrug-resistant K. pneumoniae, demonstrating the highly recombinant nature of this species. It also highlights the ability of NGS to clarify molecular microevolutionary events within antibiotic-resistant organisms. PMID:27284091

  3. Propanediol oxidoreductases of Escherichia coli, Klebsiella pneumoniae and Salmonella typhimurium. Aspects of interspecies structural and regulatory differentiation.

    PubMed Central

    Ros, J; Aguilar, J

    1985-01-01

    The enzyme propanediol oxidoreductase, which converts the lactaldehyde formed in the metabolism of fucose and rhamnose into propane-1,2-diol under anaerobic conditions, was investigated in Escherichia coli, Klebsiella pneumoniae and Salmonella typhimurium. Structural analysis indicated that the enzymes of E. coli and K. pneumoniae have the same Mr and pI, whereas that of Salm. typhimurium also has the same Mr but a slightly different pI. One-dimensional peptide mapping showed identity between the E. coli and K. pneumoniae enzymes when digested with alpha-chymotrypsin, Staphylococcus aureus V8 proteinase or subtilisin. In the case of Salm. typhimurium, this held only for the subtilisin-digested enzymes, indicating that the hydrophobic regions were preserved to a considerable extent. Anaerobically, the three species induced an active propanediol oxidoreductase when grown on fucose or rhamnose. An inactive propanediol oxidoreductase was induced in Salm. typhimurium by either fucose or rhamnose under aerobic conditions, and this was activated once anaerobiosis was established. An inactive propanediol oxidoreductase was also induced in E. coli under aerobic conditions, but only by growth on fucose. The inactive enzyme was not induced by either of the sugars in K. pneumoniae. Images Fig. 1. Fig. 2. PMID:3904730

  4. Intrathecal administration of colistin for meningitis due to New Delhi metallo-β-lactamase 1(NDM-1)-producing Klebsiella pneumoniae.

    PubMed

    Inamasu, Joji; Ishikawa, Kiyohito; Oheda, Motoki; Nakae, Shunsuke; Hirose, Yuichi; Yoshida, Shunji

    2016-03-01

    Infection by bacteria carrying New Delhi metallo-β-lactamase 1 (NDM-1) is becoming a global health problem. We report a case of meningitis caused by NDM-1-producing Klebsiella pneumoniae, for which intrathecal administration of colistin was curative. A previously healthy 38-year-old Japanese man, who lived in Hyderabad, India, suddenly collapsed and was brought to a local hospital. He was diagnosed with subarachnoid hemorrhage and underwent emergency surgery which included partial skull removal. Approximately 1 month after surgery, he was repatriated to Japan and was admitted to our institution with information that he had been treated for multi-drug resistant Acinetobacter infection with colistin. A week after admission, he developed aspiration pneumonia due to NDM-1-producing K. pneumoniae, which was successfully treated by intravenous (IV) administration of colistin. Subsequently, he underwent a surgical procedure to repair his skull defect. He developed high-grade fever and altered mental status on postoperative day 2. NDM-1-producing K. pneumoniae was identified in the cerebrospinal fluid, establishing the diagnosis of meningitis. Although IV colistin was only partially effective, intrathecal colistin (10 mg daily by lumbar puncture for 14 days) successfully eradicated the meningitis. Because of economic globalization, NDM-1-producing bacteria may be brought to Japan by those who are repatriated after sustaining critical illnesses and being treated in foreign countries. This report may provide useful information on the treatment of central nervous system infection by NDM-1-producing bacteria. PMID:26683242

  5. Characterization of a novel Klebsiella pneumoniae sequence type 476 carrying both bla KPC-2 and bla IMP-4.

    PubMed

    Wang, Y; Cao, W; Zhu, X; Chen, Z; Li, L; Zhang, B; Wang, B; Tian, L; Wang, F; Liu, C; Sun, Z

    2012-08-01

    Carbapenemase-producing Klebsiella pneumoniae has recently spread rapidly throughout China. In this study, we characterized a carbapenem-resistant K. pneumoniae isolate that produced both KPC-2 and IMP-4 type carbapenemases. A clinical isolate of K. pneumoniae, resistant to both meropenem and imipenem, was recovered from a urine sample. Antibiotic susceptibility was determined using the broth microdilution method and Etest (bioMérieux, France). Pulsed-field gel electrophoresis and multilocus sequence typing (MLST) were used for gene type analysis. bla (KPC) and the encoding genes of ESBLs and plasmid-mediated AmpC enzymes were polymerase chain reaction (PCR) amplified and sequenced. Plasmids were analyzed by transformation, enzyme restriction and Southern blot. PCR analysis revealed that the isolate was simultaneously carrying bla (KPC-2), bla (IMP-4), bla (TEM-1), and bla (OKP-B) genes. MLST assigned the isolate to a novel sequence type, ST476. bla (KPC-2)-harbouring plasmids of the isolate and comparative strains had similar EcoRI and HindIII restriction maps, while IMP-4-harbouring plasmids had variable HindIII restriction maps. Coexistence of bla (KPC-2) and bla (IMP-4) was probably due to bla (IMP-4)-harbouring plasmid transmission into KPC-2-producing K. pneumoniae (ST476). The concomitant presence of these genes is alarming and poses both therapeutic and infection control problems. PMID:22271301

  6. Enterotoxigenic intestinal bacteria in tropical sprue. IV. Effect of linoleic acid on growth interrelationships of Lactobacillus acidophilus and Klebsiella pneumoniae.

    PubMed Central

    Mickelson, M J; Klipstein, F A

    1975-01-01

    The factors responsible for colonization of the small intestine by enterotoxigenic coliform bacteria in Puerto Ricans with tropical sprue are unknown, but epidemiological observations have suggested that they may be related to an increased dietary intake of long-chain unsaturated fatty acids, particularly linoleic acid, which is known to exert an inhibitory effect on the growth of gram-positive organisms that normally comprise the flora of the small intestine. We have examined, by using a glucose-limited continuous-culture system, what effect this fatty acid exerts on the growth relationships of enteric gram-positive and coliform bacteria. In this system, colonization by an invading strain of Klebsiella pneumoniae was prevented by the presence of an established culture of Lactobacillus acidophilus, principally by virtue of a lowered pH of the medium that was incompatible with Klebsiella growth. However, when the population density of L. acidophilus was reduced by the presence of a sufficient concentration of linoleic acid, the invading K. pneumoniae successfully colonized the system and, once established, suppressed the growth of L. acidophilus. These observations indicate that, under the conditions of our chemostat, gram-positive enteric bacteria suppress coliform growth and that this effect is reversible by the presence of linoleic acid. It remains to be established, however, what pertinence these in vitro observations have to conditions within the intestinal tract of persons living in the tropics. PMID:811564

  7. Enterotoxigenic intestinal bacteria in tropical sprue. IV. Effect of linoleic acid on growth interrelationships of Lactobacillus acidophilus and Klebsiella pneumoniae.

    PubMed

    Mickelson, M J; Klipstein, F A

    1975-11-01

    The factors responsible for colonization of the small intestine by enterotoxigenic coliform bacteria in Puerto Ricans with tropical sprue are unknown, but epidemiological observations have suggested that they may be related to an increased dietary intake of long-chain unsaturated fatty acids, particularly linoleic acid, which is known to exert an inhibitory effect on the growth of gram-positive organisms that normally comprise the flora of the small intestine. We have examined, by using a glucose-limited continuous-culture system, what effect this fatty acid exerts on the growth relationships of enteric gram-positive and coliform bacteria. In this system, colonization by an invading strain of Klebsiella pneumoniae was prevented by the presence of an established culture of Lactobacillus acidophilus, principally by virtue of a lowered pH of the medium that was incompatible with Klebsiella growth. However, when the population density of L. acidophilus was reduced by the presence of a sufficient concentration of linoleic acid, the invading K. pneumoniae successfully colonized the system and, once established, suppressed the growth of L. acidophilus. These observations indicate that, under the conditions of our chemostat, gram-positive enteric bacteria suppress coliform growth and that this effect is reversible by the presence of linoleic acid. It remains to be established, however, what pertinence these in vitro observations have to conditions within the intestinal tract of persons living in the tropics. PMID:811564

  8. Analysis of Drug Resistance Determinants in Klebsiella pneumoniae Isolates from a Tertiary-Care Hospital in Beijing, China

    PubMed Central

    Wang, Qi; Woo, Patrick C. Y.; Tan, Lin; Jing, Hua; Gao, George F.; Liu, Cui Hua

    2012-01-01

    Background The rates of multidrug-resistant (MDR), extensively drug-resistant (XDR) and pandrug-resistant (PDR) isolates among Enterobacteriaceae isolates, particularly Klebsiella pneumoniae, have risen substantially worldwide. Methodology/Principal Findings To better understand the molecular mechanisms of drug resistance in K. pneumoniae, we analyzed the drug resistance determinants for K. pneumoniae isolates collected from the 306 Hospital, a tertiary-care hospital in Beijing, China, for the period of September 1, 2010-October 31, 2011. Drug susceptibility testing, PCR amplification and sequencing of the drug resistance determinants were performed. Conjugation experiments were conducted to examine the natural ability of drug resistance to disseminate among Enterobacteriaceae strains using a sodium azide-resistant Escherichia coli J53 strain as a recipient. Among the 223 consecutive non-repetitive K. pneumoniae isolates included in this study, 101 (45.3%) were extended-spectrum beta-lactamases (ESBLs) positive. The rates of MDR, XDR, and PDR isolates were 61.4% (n = 137), 22.0% (n = 49), and 1.8% (n = 4), respectively. Among the tested drug resistance-associated genes, the following ones were detected at relatively high rates blaCTX-M-10 (80, 35.9%), aacC2 (73, 32.7%), dhfr (62, 27.8%), qnrS (58, 26.0%), aacA4 (57, 25.6%), aadA1 (56, 25.1%). Results from conjugation experiments indicate that many of the drug resistance genes were transmissible. Conclusions/Significance Our data give a “snapshot” of the complex genetic background responsible for drug resistance in K. pneumoniae in China and demonstrate that a high degree of awareness and monitoring of those drug resistance determinants are urgently needed in order to better control the emergence and transmission of drug-resistant K. pneumoniae isolates in hospital settings. PMID:22860106

  9. Extensive Capsule Locus Variation and Large-Scale Genomic Recombination within the Klebsiella pneumoniae Clonal Group 258

    PubMed Central

    Wyres, Kelly L.; Gorrie, Claire; Edwards, David J.; Wertheim, Heiman F.L.; Hsu, Li Yang; Van Kinh, Nguyen; Zadoks, Ruth; Baker, Stephen; Holt, Kathryn E.

    2015-01-01

    Klebsiella pneumoniae clonal group (CG) 258, comprising sequence types (STs) 258, 11, and closely related variants, is associated with dissemination of the K. pneumoniae carbapenemase (KPC). Hospital outbreaks of KPC CG258 infections have been observed globally and are very difficult to treat. As a consequence, there is renewed interest in alternative infection control measures such as vaccines and phage or depolymerase treatments targeting the K. pneumoniae polysaccharide capsule. To date, 78 immunologically distinct capsule variants have been described in K. pneumoniae. Previous investigations of ST258 and a small number of closely related strains suggested that capsular variation was limited within this clone; only two distinct ST258 capsule polysaccharide synthesis (cps) loci have been identified, both acquired through large-scale recombination events (>50 kb). In contrast to previous studies, we report a comparative genomic analysis of the broader K. pneumoniae CG258 (n = 39). We identified 11 different cps loci within CG258, indicating that capsular switching is actually common within the complex. We observed several insertion sequences (IS) within the cps loci, and show further intraclone diversification of two cps loci through IS activity. Our data also indicate that several large-scale recombination events have shaped the genomes of CG258, and that definition of the complex should be broadened to include ST395 (also reported to harbor KPC). As only the second report of extensive intraclonal cps variation among Gram-negative bacterial species, our findings alter our understanding of the evolution of these organisms and have key implications for the design of control measures targeting K. pneumoniae capsules. PMID:25861820

  10. Extensive Capsule Locus Variation and Large-Scale Genomic Recombination within the Klebsiella pneumoniae Clonal Group 258.

    PubMed

    Wyres, Kelly L; Gorrie, Claire; Edwards, David J; Wertheim, Heiman F L; Hsu, Li Yang; Van Kinh, Nguyen; Zadoks, Ruth; Baker, Stephen; Holt, Kathryn E

    2015-05-01

    Klebsiella pneumoniae clonal group (CG) 258, comprising sequence types (STs) 258, 11, and closely related variants, is associated with dissemination of the K. pneumoniae carbapenemase (KPC). Hospital outbreaks of KPC CG258 infections have been observed globally and are very difficult to treat. As a consequence, there is renewed interest in alternative infection control measures such as vaccines and phage or depolymerase treatments targeting the K. pneumoniae polysaccharide capsule. To date, 78 immunologically distinct capsule variants have been described in K. pneumoniae. Previous investigations of ST258 and a small number of closely related strains suggested that capsular variation was limited within this clone; only two distinct ST258 capsule polysaccharide synthesis (cps) loci have been identified, both acquired through large-scale recombination events (>50 kb). In contrast to previous studies, we report a comparative genomic analysis of the broader K. pneumoniae CG258 (n = 39). We identified 11 different cps loci within CG258, indicating that capsular switching is actually common within the complex. We observed several insertion sequences (IS) within the cps loci, and show further intraclone diversification of two cps loci through IS activity. Our data also indicate that several large-scale recombination events have shaped the genomes of CG258, and that definition of the complex should be broadened to include ST395 (also reported to harbor KPC). As only the second report of extensive intraclonal cps variation among Gram-negative bacterial species, our findings alter our understanding of the evolution of these organisms and have key implications for the design of control measures targeting K. pneumoniae capsules. PMID:25861820

  11. Bacteriophage in the treatment of experimental septicemic mice from a clinical isolate of multidrug resistant Klebsiella pneumoniae.

    PubMed

    Vinodkumar, C S; Neelagund, Y F; Kalsurmath, Suneeta

    2005-03-01

    Drug resistance is the major cause of increase in morbidity and mortality in neonates. The emergence of antibiotic-resistant bacterial strains requires the exploration of alternative antibacterial therapies and the concern that human kind in re-entering the 'pre-antibiotic era' has become very real and the development of alternative anti-infection modalities has become one of the highest priorities of modern medicine and biotechnology. This has spurred biomedical researchers to expand their efforts to identify new technologies and products that employ novel mechanism of action against the "super-bugs". One of such alternatives stems up from an old idea is the bacteriophage therapy, which led our group to study the ability of bacterial viruses (bacteriophages or phages) to rescue septicemic mice with multidrug resistant (MDR) Klebsiella pneumoniae isolated from neonatal septicemia. The phage strain used in this study had lytic activity against a wide range of clinical isolates of MDR Klebsiella pneumoniae. One of these MDR Klebsiella strain was used to induce septicemia in mice by intraperitoneal (i.p.) injection of 10(9) CFU. The resulting bacteremia was fatal within 48 h. A single i.p. injection of 3x10(8) PFU of the phage strain administered 45 min after the bacterial challenge, was sufficient to rescue 100% of the animals. Even when treatment was delayed to the point where all animals were moribund, approximately 50% of them were rescued by a single injection of this phage preparation. The ability of this phage to rescue septicemic mice was demonstrated to be due to the functional capabilities of the phage and not to a nonspecific immune effect. The rescue of septicemic mice could be affected only by phage strains able to grow in vitro on the bacterial host used to infect the animals and when such strains are heat inactivated they lose their ability to rescue the infected mice.

  12. Occurrence and molecular characterization of Klebsiella pneumoniae ST37 clinical isolates producing plasmid-mediated AmpC recovered over a 3-year period.

    PubMed

    Illiaquer, Marina; Caroff, Nathalie; Bémer, Pascale; Aubin, Guillaume G; Juvin, Marie-Emmanuelle; Lepelletier, Didier; Reynaud, Alain; Corvec, Stéphane

    2012-09-01

    We investigated the clinical and microbiological epidemiology of AmpC plasmidic cephalosporinases (pAmpC) in Klebsiella pneumoniae strains resistant to ceftazidime, during a 3-year period (2007-2009). Among 1505 K. pneumoniae, 7 were pAmpC producers. Molecular characterization revealed the spread of a ST37 strain producing DHA-1 within intensive care units and the diffusion of the same plasmid among unrelated strains.

  13. Therapeutic strategy for pandrug-resistant Klebsiella pneumoniae severe infections: short-course treatment with colistin increases the in vivo and in vitro activity of double carbapenem regimen.

    PubMed

    Oliva, Alessandra; Mascellino, Maria T; Cipolla, Alessia; D'Abramo, Alessandra; De Rosa, Annalisa; Savinelli, Stefano; Ciardi, Maria Rosa; Mastroianni, Claudio M; Vullo, Vincenzo

    2015-04-01

    Infections due to carbapenemase-producing Klebsiella pneumoniae represent an emerging threat due to the high mortality rate and lack of valid antimicrobial combinations, especially when the strain is colistin-resistant. We report a case of bloodstream infection due to pandrug-resistant K. pneumoniae treated successfully with an innovative regimen comprising a combination of colistin plus double carbapenem, along with an in vitro analysis showing the synergistic and bactericidal effect.

  14. Occurrence and molecular characterization of Klebsiella pneumoniae ST37 clinical isolates producing plasmid-mediated AmpC recovered over a 3-year period.

    PubMed

    Illiaquer, Marina; Caroff, Nathalie; Bémer, Pascale; Aubin, Guillaume G; Juvin, Marie-Emmanuelle; Lepelletier, Didier; Reynaud, Alain; Corvec, Stéphane

    2012-09-01

    We investigated the clinical and microbiological epidemiology of AmpC plasmidic cephalosporinases (pAmpC) in Klebsiella pneumoniae strains resistant to ceftazidime, during a 3-year period (2007-2009). Among 1505 K. pneumoniae, 7 were pAmpC producers. Molecular characterization revealed the spread of a ST37 strain producing DHA-1 within intensive care units and the diffusion of the same plasmid among unrelated strains. PMID:22749243

  15. Comparative analyses of phenotypic methods and 16S rRNA, khe, rpoB genes sequencing for identification of clinical isolates of Klebsiella pneumoniae.

    PubMed

    He, Yanxia; Guo, Xianguang; Xiang, Shifei; Li, Jiao; Li, Xiaoqin; Xiang, Hui; He, Jinlei; Chen, Dali; Chen, Jianping

    2016-07-01

    The present work aimed to evaluate 16S rRNA, khe and rpoB gene sequencing for the identification of Klebsiella pneumoniae in comparison with phenotypic methods. Fifteen clinical isolates were examined, which were initially identified as K. pneumoniae subsp. pneumoniae using the automated VITEK 32 system in two hospitals in Enshi City, China. Their identity was further supported by conventional phenotypic methods on the basis of morphological and biochemical characteristics. Using Bayesian phylogenetic analyses and haplotypes network reconstruction, 13 isolates were identified as K. pneumoniae, whereas the other two isolates (K19, K24) were classified as Shigella sp. and Enterobacter sp., respectively. Of the three genes, 16S rRNA and khe gene could discriminate the clinical isolates at the genus level, whereas rpoB could discriminate Klebsiella at the species and even subspecies level. Overall, the gene tree based on rpoB is more compatible with the currently accepted classification of Klebsiella than those based on 16S rRNA and khe genes, showing that rpoB can be a powerful tool for identification of K. pneumoniae isolates. Above all, our study challenges the utility of khe as a species-specific marker for identification of K. pneumoniae.

  16. Imported Klebsiella pneumoniae Carbapenemase-Producing K. pneumoniae Clones in a Greek Hospital: Impact of Infection Control Measures for Restraining Their Dissemination

    PubMed Central

    Poulou, Aggeliki; Voulgari, Evangelia; Vrioni, Georgia; Xidopoulos, Grigorios; Pliagkos, Aris; Chatzipantazi, Vassiliki; Markou, Fani

    2012-01-01

    The recent emergence of carbapenemase-producing Enterobacteriaceae strains represents a major threat for hospitalized patients. We document the dissemination and control of carbapenemase-producing Klebsiella pneumoniae clones in a Greek hospital. During a 3-year study period (January 2009 to December 2011), carbapenemase-producing K. pneumoniae strains were isolated from clinical samples from 73 individual patients. Phenotyping and molecular testing confirmed that 52 patients were infected with K. pneumoniae carbapenemase 2 (KPC-2) producers, 12 were infected with VIM-1 producers, and the remaining 9 were infected with isolates producing both KPC-2 and VIM-1 enzymes. Twenty-eight of these clinical cases were characterized as imported health care associated, and 23 of these were attributed to KPC producers and 5 were attributed to KPC and VIM producers. The remaining 45 cases were deemed hospital acquired. In the second year of the study, intensified infection control intervention was implemented, followed by active surveillance and carrier isolation in the third year. The incidence of carbapenemase-producing K. pneumoniae patient cases decreased from 0.52/1,000 patient days in 2009 to 0.32/1,000 patient days in 2010 (P = 0.075). Following these additional infection control measures, the incidence fell to 0.21/1,000 patient days in 2011 and differed significantly from that in 2009 (P = 0.0028). Despite the fact that the imported cases of carbapenemase-producing K. pneumoniae were equally distributed over this 3-year period, the incidence of hospital-acquired cases decreased from 0.36/1,000 patient days in 2009 to 0.19/1,000 patient days in 2010 (P = 0.058) and to 0.1/1,000 patient days in 2011 (P = 0.0012). Our findings suggest that rigorous infection control measures and active surveillance can effectively reduce the incidence of secondary transmission due to KPC-producing pathogens. PMID:22649010

  17. Characterization of NLRP12 during the In Vivo Host Immune Response to Klebsiella pneumoniae and Mycobacterium tuberculosis

    PubMed Central

    Wilson, Justin E.; Lich, John D.; Arthur, Janelle C.; Sullivan, Jonathan T.; Braunstein, Miriam; Ting, Jenny P. Y.

    2013-01-01

    The majority of nucleotide binding domain leucine rich repeats-containing (NLR) family members has yet to be functionally characterized. Of the described NLRs, most are considered to be proinflammatory and facilitate IL-1β production. However, a newly defined sub-group of NLRs that function as negative regulators of inflammation have been identified based on their abilities to attenuate NF-κB signaling. NLRP12 (Monarch-1) is a prototypical member of this sub-group that negatively regulates both canonical and noncanonical NF-κB signaling in biochemical assays and in colitis and colon cancer models. The role of NLRP12 in infectious diseases has not been extensively studied. Here, we characterized the innate immune response of Nlrp12−/− mice following airway exposure to LPS, Klebsiella pneumoniae and Mycobacterium tuberculosis. In response to E. coli LPS, Nlrp12−/− mice showed a slight decrease in IL-1β and increase in IL-6 production, but these levels were not statistically significant. During K. pneumoniae infection, we observed subtle differences in cytokine levels and significantly reduced numbers of monocytes and lymphocytes in Nlrp12−/− mice. However, the physiological relevance of these findings is unclear as no overt differences in the development of lung disease were observed in the Nlrp12−/− mice. Likewise, Nlrp12−/− mice demonstrated pathologies similar to those observed in the wild type mice following M. tuberculosis infection. Together, these data suggest that NLRP12 does not significantly contribute to the in vivo host innate immune response to LPS stimulation, Klebsiella pneumonia infection or Mycobacterium tuberculosis. PMID:23577168

  18. Comparison of the energetic efficiencies of hydrogen and oxychemicals formation in Klebsiella pneumoniae and Clostridium butyricum during anaerobic growth on glycerol.

    PubMed

    Solomon, B O; Zeng, A P; Biebl, H; Schlieker, H; Posten, C; Deckwer, W D

    1995-04-15

    Data for the anaerobic growth of Klebsiella pneumoniae DSM 2026 and Clostridium butyricum DSM 5431 on glycerol have been analyzed using the concept of material and available electron balances with consideration for hydrogen production. Models for the kinetics of energetic efficiencies of product formation under low residual glycerol are presented. For Klebsiella pneumoniae, the specific rates of electron transfer to the products were mainly significantly dependent on specific growth rate with the exception of ethanol and hydrogen which were also significantly non-growth associated. In the case of Clostridium butyricum, the rates were only growth rate dependent, except for hydrogen formation. The analysis also indicated that the production of 1,3-propanediol by Klebsiella pneumoniae was favoured by limitations other than glycerol limitation, while hydrogen generation was best under low residual glycerol and particularly in the presence of external 1,3-propanediol. Klebsiella pneumoniae appeared to be able to incorporate more of the available electrons of glycerol into hydrogen as compared with the Clostridium butyricum. The study demonstrates the need for properly considering H2 in models describing anaerobic processes.

  19. First Detection of the Plasmid-Mediated Class A Carbapenemase KPC-2 in Clinical Isolates of Klebsiella pneumoniae from South America

    PubMed Central

    Virginia Villegas, Maria; Lolans, Karen; Correa, Adriana; Jose Suarez, Carlos; Lopez, Jaime A.; Vallejo, Marta; Quinn, John P.

    2006-01-01

    The plasmid-mediated class A carbapenemase KPC-2 was isolated from unrelated Klebsiella pneumoniae isolates in Medellin, Colombia. These KPC enzymes are the first from South America and the second isolation outside of the United States. The expanding geographic spread of KPC carbapenemases underscores the importance of clinical recognition of these enzymes. PMID:16870793

  20. Fatal sepsis by Klebsiella pneumoniae in a patient with systemic lupus erythematosus: the importance of postmortem microbiological examination for the ex post diagnosis of infection.

    PubMed

    D'Ovidio, Cristian; Pompilio, Arianna; Crocetta, Valentina; Gherardi, Giovanni; Carnevale, Aldo; Di Bonaventura, Giovanni

    2015-09-01

    The utility of postmortem microbiology has continuously been a topic of controversy. The present study describes a case of fatal sepsis in a patient with systemic lupus erythematosus. Postmortem culture and genotyping analyses allowed us to identify Klebsiella pneumoniae as the cause of sepsis, revealing the inadequateness of antimicrobial therapy.

  1. TEM-71, a Novel Plasmid-Encoded, Extended-Spectrum β-Lactamase Produced by a Clinical Isolate of Klebsiella pneumoniae

    PubMed Central

    Rasheed, J. Kamile; Anderson, Gregory J.; Queenan, Anne Marie; Biddle, James W.; Oliver, Antonio; Jacoby, George A.; Bush, Karen; Tenover, Fred C.

    2002-01-01

    TEM-71, a novel extended-spectrum β-lactamase from a Klebsiella pneumoniae clinical isolate, had an isoelectric point of 6.0 and a substrate profile showing preferential hydrolysis of cefotaxime over ceftazidime. It differed from TEM-1 by two substitutions, Gly238Ser and Glu240Lys, and was under the control of the strong P4 promoter. PMID:12019125

  2. Efficacy of Different β-Lactams against an Extended-Spectrum β-Lactamase-Producing Klebsiella pneumoniae Strain in the Rat Intra-Abdominal Abscess Model

    PubMed Central

    Rice, Louis B.; Yao, Joseph D. C.; Klimm, Karin; Eliopoulos, George M.; Moellering, Robert C.

    1991-01-01

    Although standard-inoculum MICs were within the susceptible range for all compounds, cefoperazone, cefotaxime, and cefpirome were significantly less effective than imipenem or the combination of cefoperazone and sulbactam in the treatment of rat intra-abdominal abscesses due to an extended-spectrum β-lactamase-producing strain of Klebsiella pneumoniae. PMID:1929273

  3. Complete Genome Sequence of Klebsiella pneumoniae Strain ATCC 43816 KPPR1, a Rifampin-Resistant Mutant Commonly Used in Animal, Genetic, and Molecular Biology Studies.

    PubMed

    Broberg, Christopher A; Wu, Weisheng; Cavalcoli, James D; Miller, Virginia L; Bachman, Michael A

    2014-09-25

    Klebsiella pneumoniae is an urgent public health threat due to the spread of carbapenem-resistant strains causing serious, and frequently fatal, infections. To facilitate genetic, molecular, and immunological studies of this pathogen, we report the complete chromosomal sequence of a genetically tractable, prototypical strain used in animal models.

  4. Genome Sequence of Klebsiella pneumoniae HSL4, a New Strain Isolated from Mangrove Sediment for Biosynthesis of 1,3-Propanediol.

    PubMed

    Zhou, Sheng; Li, Lili; Wei, Jingguang; Qin, Qiwei

    2013-01-01

    Klebsiella pneumoniae HSL4 is a 1,3-propanediol-producing bacterium strain isolated from mangrove sediment. We present here a 5,221,448-bp assembly of its genome sequence. Genome analysis revealed that it contains 10 coding sequences (CDSs) responsible for glycerol fermentation to 1,3-propanediol, 19 CDSs encoding glycerol utilization, and 140 CDSs related to its virulence.

  5. Klebsiella pneumoniae: development of a mixed population of carbapenem and tigecycline resistance during antimicrobial therapy in a kidney transplant patient.

    PubMed

    Rodríguez-Avial, C; Rodríguez-Avial, I; Merino, P; Picazo, J J

    2012-01-01

    Nine isolates of Klebsiella pneumoniae were isolated from a renal transplant patient suffering from recurrent urosepsis over a period of 4 months. Imipenem resistance was detected after imipenem-ertapenem therapy. When treatment was switched to tigecycline the K. pneumoniae developed resistance to tigecycline (MIC = 8 mg/L). The nine isolates were tested by determination of agar dilution MICs, phenotypic carbapenemase, extended-spectrum beta-lactamases and metallo-beta-lactamase (MBL) testing and pulsed-field gel electrophoresis. Polymerase chain reaction and sequencing analysis were employed for identification of bla genes and mapping of the integron carrying the MBL gene. The nine isolates were clonally related and all produced the SHV-12 enzyme. Five MBL-producing isolates showed imipenem MICs ranging from 2 to 64 mg/L and all were detected by testing with imipenem and EDTA. The five isolates harboured the bla(VIM-1) gene. Three isolates showed increased tigecycline MICs (4-8 mg/L). Serial blood cultures obtained on the same day resulted in a VIM-positive/tigecycline-susceptible and a VIM-negative/tigecycline-resistant K. pneumoniae isolate. No isolate developed concurrent imipenem and tigecycline resistance. The patient had a persistent urinary tract infection and recurrent bacteraemia caused by a mixed population of Klebesiella pneumoniae isolates adapting to the selective pressure of antimicrobial therapy at the time. The present study is a worrisome example of what could happen when an immunocompromised host is subjected to the pressures of antimicrobial therapy. In addition, we report the first treatment-emergent MIC increase of tigecycline from 0.5 to 8 mg/L in K. pneumoniae. PMID:21722259

  6. Comparative analysis of Klebsiella pneumoniae genomes identifies a phospholipase D family protein as a novel virulence factor

    PubMed Central

    2014-01-01

    Background Klebsiella pneumoniae strains are pathogenic to animals and humans, in which they are both a frequent cause of nosocomial infections and a re-emerging cause of severe community-acquired infections. K. pneumoniae isolates of the capsular serotype K2 are among the most virulent. In order to identify novel putative virulence factors that may account for the severity of K2 infections, the genome sequence of the K2 reference strain Kp52.145 was determined and compared to two K1 and K2 strains of low virulence and to the reference strains MGH 78578 and NTUH-K2044. Results In addition to diverse functions related to host colonization and virulence encoded in genomic regions common to the four strains, four genomic islands specific for Kp52.145 were identified. These regions encoded genes for the synthesis of colibactin toxin, a putative cytotoxin outer membrane protein, secretion systems, nucleases and eukaryotic-like proteins. In addition, an insertion within a type VI secretion system locus included sel1 domain containing proteins and a phospholipase D family protein (PLD1). The pld1 mutant was avirulent in a pneumonia model in mouse. The pld1 mRNA was expressed in vivo and the pld1 gene was associated with K. pneumoniae isolates from severe infections. Analysis of lipid composition of a defective E. coli strain complemented with pld1 suggests an involvement of PLD1 in cardiolipin metabolism. Conclusions Determination of the complete genome of the K2 reference strain identified several genomic islands comprising putative elements of pathogenicity. The role of PLD1 in pathogenesis was demonstrated for the first time and suggests that lipid metabolism is a novel virulence mechanism of K. pneumoniae. PMID:24885329

  7. Epidemic potential of Escherichia coli ST131 and Klebsiella pneumoniae ST258: a systematic review and meta-analysis

    PubMed Central

    Dautzenberg, M J D; Haverkate, M R; Bonten, M J M; Bootsma, M C J

    2016-01-01

    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

  8. Characterization of a CTX-M-15 Producing Klebsiella Pneumoniae Outbreak Strain Assigned to a Novel Sequence Type (1427).

    PubMed

    Zhou, Kai; Lokate, Mariëtte; Deurenberg, Ruud H; Arends, Jan; Lo-Ten Foe, Jerome; Grundmann, Hajo; Rossen, John W A; Friedrich, Alexander W

    2015-01-01

    Extended-spectrum -lactamase producing Klebsiella pneumoniae have emerged as one of the major nosocomial pathogens. Between July and September 2012, a CTX-M-15 producing K. pneumoniae caused an outbreak in a university hospital in the Netherlands. The outbreak isolates were characterized and assigned to a novel sequence type (ST1427). An epidemiological link between affected patients was supported by patient contact tracing and whole-genome phylogenetic analysis. Intra-strain polymorphism was detected among multiple isolates obtained from different body sites of the index patient, which may relate to antibiotic treatment and/or host adaptation. Environmental contamination caused by the outbreak clone was found in the patient rooms even on medical equipment. The novel clone was not closely related to any known endemic/epidemic clone, but carried a set of a plasmid-borne resistance genes [bla CTX-M-15, bla TEM-1, bla OXA-1, aac(6')-Ib-cr, qnrB1, tetA(A), aac(3)-II]. Analysis of its virulence factors revealed a previously uncharacterized capsular biosynthesis region and two uncharacterized fimbriae gene clusters, and suggested that the new clone was not hypervirulent. To our knowledge, this is the first outbreak report of K. pneumoniae ST1427, and our study could be of help to understand the features of this newly emerging clone. PMID:26617589

  9. Genetic evolution and clinical impact in extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae.

    PubMed

    Chong, Yong; Ito, Yoshikiyo; Kamimura, Tomohiko

    2011-10-01

    The emergence of extended-spectrum β-lactamase (ESBL)-producing bacteria, particularly Escherichia coli and Klebsiella pneumoniae, is now a critical concern for the development of therapies against bacterial infection. ESBLs consist of three major genetic groups: TEM, SHV, and CTX-M types. Nosocomial infections due to TEM and SHV-producing K. pneumoniae strains were frequently documented until the late 1990s. The number of reports on community-acquired infections caused by CTX-M-producing E. coli strains have dramatically increased over the last decade; however, K. pneumoniae strains, of either the TEM or SHV types, are persistent and important ESBL producers. The spread of ESBL genes is associated with various mobile genetic elements, such as transposons, insertion sequences, and integrons. The rapid dissemination of ESBL genes of the CTX-M type may be related to highly complicated genetic structures. These structures harboring ESBL genes and mobile elements are found in a variety of plasmids, which often carry many other antibiotic resistance genes. Multidrug-resistant CTX-M-15-producing E. coli strains disseminate worldwide. Efficient mobile elements and plasmids may have accelerated the genetic diversity and the rapid spread of ESBL genes, and their genetic evolution has caused an emerging threat to the bacteria for which few effective drugs have been identified.

  10. Characterization of a CTX-M-15 Producing Klebsiella Pneumoniae Outbreak Strain Assigned to a Novel Sequence Type (1427)

    PubMed Central

    Zhou, Kai; Lokate, Mariëtte; Deurenberg, Ruud H.; Arends, Jan; Lo-Ten Foe, Jerome; Grundmann, Hajo; Rossen, John W. A.; Friedrich, Alexander W.

    2015-01-01

    Extended-spectrum -lactamase producing Klebsiella pneumoniae have emerged as one of the major nosocomial pathogens. Between July and September 2012, a CTX-M-15 producing K. pneumoniae caused an outbreak in a university hospital in the Netherlands. The outbreak isolates were characterized and assigned to a novel sequence type (ST1427). An epidemiological link between affected patients was supported by patient contact tracing and whole-genome phylogenetic analysis. Intra-strain polymorphism was detected among multiple isolates obtained from different body sites of the index patient, which may relate to antibiotic treatment and/or host adaptation. Environmental contamination caused by the outbreak clone was found in the patient rooms even on medical equipment. The novel clone was not closely related to any known endemic/epidemic clone, but carried a set of a plasmid-borne resistance genes [blaCTX−M−15, blaTEM−1, blaOXA−1, aac(6′)-Ib-cr, qnrB1, tetA(A), aac(3)-II]. Analysis of its virulence factors revealed a previously uncharacterized capsular biosynthesis region and two uncharacterized fimbriae gene clusters, and suggested that the new clone was not hypervirulent. To our knowledge, this is the first outbreak report of K. pneumoniae ST1427, and our study could be of help to understand the features of this newly emerging clone. PMID:26617589

  11. Biosynthesis of the iron-molybdenum cofactor and the molybdenum cofactor in Klebsiella pneumoniae: effect of sulfur source

    SciTech Connect

    Ugalde, R.A.; Imperial, J.; Shah, V.K.; Brill, W.J.

    1985-12-01

    NifQ/sup -/ and Mol/sup -/ mutants of Klebsiella pneumoniae show an elevated molybdenum requirement for nitrogen fixation. Substitution of cystine for sulfate as the sulfur source in the medium reduced the molybdenum requirement of these mutants to levels required by the wild type. Cystine also increased the intracellular molybdenum accumulation of NifQ/sup -/ and Mol/sup -/ mutants. Cystine did not affect the molybdenum requirement or accumulation in wild-type K. pneumoniae. Sulfate transport and metabolism in K. pneumoniae were repressed by cystine. However, the effect of cystine on the molybdenum requirement could not be explained by an interaction between sulfate and molybdate at the transport level. The data show that cystine does not have a generalized effect on molybdenum metabolism. Millimolar concentrations of molybdate inhibited nitrogenase and nitrate reductase derepression with sulfate as the sulfur source, but not with cystine. The inhibition was the result of a specific antagonism of sulfate metabolism by molybdate. This study suggests that a sulfur donor and molybdenum interact at an early step in the biosynthesis of the iron-molybdenum cofactor. This interaction might occur nonenzymatically when the levels of the reactants are high.

  12. Effects of the hindlimb-unloading model of spaceflight conditions on resistance of mice to infection with Klebsiella pneumoniae

    NASA Technical Reports Server (NTRS)

    Belay, Tesfaye; Aviles, Hernan; Vance, Monique; Fountain, Kimberly; Sonnenfeld, Gerald

    2002-01-01

    BACKGROUND: It has been well documented in several studies that many immunologic parameters are altered in experimental animals and human subjects who have flown in space. However, it is not fully known whether these immunologic changes could result in increased susceptibility to infection. Hindlimb (antiorthostatic) unloading of rodents has been used successfully to simulate some of the effects of spaceflight on physiologic systems. OBJECTIVE: The objective of this study was to determine the effect of hindlimb unloading on the outcome of Klebsiella pneumoniae infection in mice. METHODS: Hindlimb-unloaded, hindlimb-restrained, and control mice were intraperitoneally infected with one 50% lethal dose of K pneumoniae 2 days after suspension. Mortality and bacterial load in several organs were compared among the groups. RESULTS: Unloaded mice showed significantly increased mortality and reduced mean time to death compared with that seen in the control groups. Kinetics of bacterial growth with smaller infective doses revealed that control mice were able to clear bacteria from the organs after 30 hours. In contrast, unloaded mice had continued bacterial growth at the same time point. CONCLUSION: The results of this study suggest that hindlimb unloading might enhance the dissemination of K pneumoniae, leading to increased mortality. The complex physiologic changes observed during hindlimb unloading, including stress, have a key role in the pathophysiology of this infection.

  13. Crystal structures of Klebsiella pneumoniae dihydrofolate reductase bound to propargyl-linked antifolates reveal features for potency and selectivity.

    PubMed

    Lamb, Kristen M; Lombardo, Michael N; Alverson, Jeremy; Priestley, Nigel D; Wright, Dennis L; Anderson, Amy C

    2014-12-01

    Resistance to the antibacterial antifolate trimethoprim (TMP) is increasing in members of the family Enterobacteriaceae, driving the design of next-generation antifolates effective against these Gram-negative pathogens. The propargyl-linked antifolates are potent inhibitors of dihydrofolate reductases (DHFR) from several TMP-sensitive and -resistant species, including Klebsiella pneumoniae. Recently, we have determined that these antifolates inhibit the growth of strains of K. pneumoniae, some with MIC values of 1 μg/ml. In order to further the design of potent and selective antifolates against members of the Enterobacteriaceae, we determined the first crystal structures of K. pneumoniae DHFR bound to two of the propargyl-linked antifolates. These structures highlight that interactions with Leu 28, Ile 50, Ile 94, and Leu 54 are necessary for potency; comparison with structures of human DHFR bound to the same inhibitors reveal differences in residues (N64E, P61G, F31L, and V115I) and loop conformations (residues 49 to 53) that may be exploited for selectivity. PMID:25288083

  14. Imipenem represses CRISPR-Cas interference of DNA acquisition through H-NS stimulation in Klebsiella pneumoniae

    PubMed Central

    Lin, Tzu-Lung; Pan, Yi-Jiun; Hsieh, Pei-Fang; Hsu, Chun-Ru; Wu, Meng-Chuan; Wang, Jin-Town

    2016-01-01

    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

  15. Effect of subinhibitory concentrations of cumin (Cuminum cyminum L.) seed essential oil and alcoholic extract on the morphology, capsule expression and urease activity of Klebsiella pneumoniae.

    PubMed

    Derakhshan, Safoura; Sattari, Morteza; Bigdeli, Mohsen

    2008-11-01

    Cuminum cyminum L., commonly known as cumin, is a plant with a considerable reputation. The aim of this work was to study the activity of cumin seed essential oil and alcoholic extract against Klebsiella pneumoniae ATCC 13883 and clinical K. pneumoniae isolates by evaluating the effect of subminimum inhibitory concentrations (sub-MICs) on cell morphology, capsule expression and urease activity. Growth of K. pneumoniae strains exposed to sub-MICs of C. cyminum extracts resulted in cell elongation and repression of capsule expression. Urease activity was decreased. The major constituent of the oil determined by gas chromatography/mass spectrometry was cumin aldehyde.

  16. Detection of extended-spectrum β-lactamases in Klebsiella pneumoniae: comparison of phenotypic characterization methods

    PubMed Central

    Ejaz, Hasan; ul-Haq, Ikram; Mahmood, Saqib; Zafar, Aizza; Mohsin Javed, Muhammad

    2013-01-01

    Objective: Extended-spectrum β-lactamase producing K. pneumoniae is a serious threat to the patients. This manuscript shows the comparison of phenotypic characterization methods used for ESBL K. pneumoniae and frequency distribution of these isolates in various clinical samples. Methodology: Eleven different types of pathological samples collected on various time intervals were analyzed. K. pneumoniae were identified with API 20E system (bioMerieux) and initial screening of ESBL K. pneumoniae was performed using the ceftazidime antimicrobial disc. Double-disc synergy test (DDST) and CLSI confirmatory test were compared for the phenotypic detection of ESBL K. pneumoniae. Results: A total number of 214 ESBL producing K. pneumoniae were isolated from various clinical samples. Frequency distribution of ESBL producing K. pneumoniae was found to be highest among blood 117 (54.7%) and urine 46 (21.5%) samples. Data regarding the use of various interventions among these patients showed most common presence of intravenous line 209 (97.7%) and urinary catheters 46 (21.5%). Comparison of DDST and CLSI confirmatory test showed that the DDST detected 145 (67.8%) isolates while 213 (99.5%) ESBL K. pneumoniae were characterized by CLSI confirmatory test. Conclusion: The use of CLSI confirmatory test is very efficient in the early detection of ESBL K. pneumoniae especially when the facilities for molecular characterization are not available. PMID:24353625

  17. The study of adhesive forces between the type-3 fimbriae of Klebsiella pneumoniae and collagen-coated surfaces by using optical tweezers

    NASA Astrophysics Data System (ADS)

    Chan, Chiahan; Fan, Chia-chieh; Huang, Ying-Jung; Peng, Hwei-Ling; Long, Hsu

    2004-10-01

    Adherence to host cells by a bacterial pathogen is a critical step for establishment of infection. It will contribute greatly to the understanding of bacterial pathogenesis by studying the biological force between a single pair of pathogen and host cell. In our experiment, we use a calibrated optical tweezers system to detach a single Klebsiella pneumoniae, the pathogen, from collagen, the host. By gradually increasing the laser power of the optical tweezers until the Klebsiella pneumoniae is detached from the collagen, we obtain the magnitude of the adhesive force between them. This happens when the adhesive force is barely equal to the trapping force provided by the optical tweezers at that specific laser power. This study is important because Klebsiella pneumoniae is an opportunistic pathogen which causes suppurative lesions, urinary and respiratory tract infections. It has been proved that type 3 fimbrial adhesin (mrkD) is strongly associated with the adherence of Klebsiella pneumoniae. Besides, four polymorphic mrkD alleles: namely, mrkDv1, v2, v3, and v4, are typed by using RFLP. In order to investigate the relationship between the structure and the function for each of these variants, DNA fragments encoding the major fimbrial proteins mrkA, mrkB, mrkC are expressed together with any of the four mrkD adhesins in E. coli JM109. Our study shows that the E. coli strain carrying the mrkDv3 fimbriae has the strongest binding activity. This suggests that mrkDv3 is a key factor that enhances the adherence of Klebsiella Pneumoniae to human body.

  18. A global emerging disease of Klebsiella pneumoniae liver abscess: is serotype K1 an important factor for complicated endophthalmitis?

    PubMed Central

    Fung, C-P; Chang, F-Y; Lee, S-C; Hu, B-S; Kuo, B I-T; Liu, C-Y; Ho, M; Siu, L K

    2002-01-01

    Background and aims: Over the past two decades in Taiwan, pyogenic liver abscess has usually been caused by a single microorganism, Klebsiella pneumoniae, and is frequently associated with the serious complication of endophthalmitis, especially in diabetic patients. However, the relationship between the clinical presentation and bacterial factors remains unclear. The aim of this study was to investigate the clinical features of patients and the serotype and ribotype of K pneumoniae liver abscess. Methods: From July 1991 to June 1998, a total of 134 cases of K pneumoniae liver abscess with 248 K pneumoniae isolates from the same patients were collected from two large medical centres in northern Taiwan. Clinical data were collected from medical records. Serotyping and ribotyping were performed using the countercurrent immunoelectrophoresis method and automated Riboprinter. Results: Serotyping revealed that the most common serotypes were K1 (63.4%) and K2 (14.2%). K1 isolates occurred at a significantly higher frequency (p<0.01) than all other serotypes. Among 134 patients, 105 (78.4%) had suffered from diabetes mellitus for 3–15 years. Fourteen patients (10.4%) had metastatic infection to the eye causing septic endophthalmitis. Liver aspirates, and blood and vitreous pus cultures yielded the same serotype of K pneumoniae in all patients. Among patients with septic endophthalmitis, 92.3% (13/14) were diabetic, and 85.7% (12/14) of the isolates belonged to serotype K1. For molecular typing, different degrees of genetic polymorphism among isolates with the same K1 serotype suggested no particular prevalence of any one strain in K pneumoniae liver abscess. Conclusion: K pneumoniae serotype K1 was significantly associated with liver abscess and the complication of endophthalmitis, especially in diabetic patients. Physicians should request an immediate report of serotyping and susceptibility test results simultaneously if a diagnosis of pyogenic liver abscess has been

  19. Epidemiology of carbapenem-resistant Klebsiella pneumoniae colonization: a surveillance study at a Turkish university hospital from 2009 to 2013.

    PubMed

    Zarakolu, Pinar; Eser, Ozgen Koseoglu; Aladag, Elifcan; Al-Zahrani, Ibrahim A; Day, Kathryn M; Atmaca, Ozgur; Boral, Baris; Cakir, Banu; Perry, John D; Akova, Murat

    2016-08-01

    Between June 2009 and December 2013, 4105 patients were screened for carbapenem-resistant Klebsiella pneumoniae (CR-Kp) colonization in a tertiary care university hospital. The antimicrobial susceptibility and resistance determinants of 279 (6.8%) CR-Kp isolates from single patients were investigated. Additional analysis was performed to evaluate the characteristics and various risk factors for infection in patients with colonization. Of the 279 isolates, 270 harboured OXA-48-like enzymes, and a single isolate harboured IMP-type carbapenemase. A high proportion of isolates were susceptible to carbapenems - except ertapenem. All isolates were susceptible to amikacin and most (94%) were susceptible to colistin and fosfomycin. There was consistent high-level resistance for all isolates to temocillin, piperacillin-tazobactam, amoxicillin-clavulanate and ticarcillin-clavulanate. When colonized and infected patients were compared, only prior carbapenem administration (P = 0.003), was found to be significantly associated with patients with CR-Kp infection. PMID:27306118

  20. Outbreak of carbapenem-resistant Klebsiella pneumoniae: two-year epidemiologic follow-up in a tertiary hospital

    PubMed Central

    Pereira, Graziella Hanna; Garcia, Doroti O; Mostardeiro, Marcelo; Fanti, Karina SVN; Levin, Anna S

    2013-01-01

    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. PMID:23440125

  1. Trehalose dimycolate enhances survival of fission neutron-irradiated mice and Klebsiella pneumoniae-challenged irradiated mice

    SciTech Connect

    McChesney, D.G.; Ledney, G.D.; Madonna, G.S. )

    1990-01-01

    The survival of B6D2F1 female mice exposed to lethal doses of fission neutron radiation is increased when trehalose dimycolate (TDM) preparations are given either 1 h after exposure or 1 day before exposure to radiation. TDM in an emulsion of squalene, Tween 80, and saline was the most effective formulation for increasing the 30-day survival of mice when given 1 day before (90%) or 1 h after (88%) exposure to radiation. An aqueous suspension of a synthetic analog of TDM was less effective at increasing 30-day survival (60%) when given 1 day prior to radiation exposure and not effective when given 1 h after radiation. Mice receiving a sublethal dose (3.5 Gy) of fission neutron radiation and either the TDM emulsion or synthetic TDM 1 h after irradiation were substantially more resistant to challenge with 10, 100, 1000, or 5000 times the LD50/30 dose of Klebsiella pneumoniae than untreated mice.

  2. EXAFS of Klebsiella pneumoniae nitrogenase MoFe protein from wild-type and nif V mutant strains

    SciTech Connect

    Eidsness, M.K.; Flank, A.M.; Smith, B.E.; Flood, A.C.; Garner, C.D.; Cramer. S.P.

    1986-05-14

    The enzyme nitrogenase catalyzes the biological reduction of N/sub 2/ to NH/sub 3/. In Klebsiella pneumoniae a cluster of 17 genes in seven transcriptional units has been associated with nitrogen fixation. The nitrogenase enzyme from the nif V mutants is relatively ineffective at dinitrogen reduction, is more efficient than the wild-type enzyme at HCN reduction, and has its hydrogen evolution activity inhibited up to 80% by CO. This altered substrate specificity has been shown to be associated with the iron-molybdenum cofactor, FeMo-co, of the enzyme. X-ray absorption spectroscopy has been a valuable tool for probing the molybdenum environment of wild-type nitrogenase, and the authors report here similar studies on the Nif V/sup -/ enzyme.

  3. Association of KPC-producing Klebsiella pneumoniae colonization or infection with Candida isolation and selection of non-albicans species.

    PubMed

    Papadimitriou-Olivgeris, Matthaios; Spiliopoulou, Anastasia; Fligou, Fotini; Manolopoulou, Patroula; Spiliopoulou, Iris; Vrettos, Theofanis; Dodou, Vasiliki; Filos, Kriton S; Anastassiou, Evangelos D; Marangos, Markos; Christofidou, Myrto

    2014-11-01

    Clinical specimens from 565 patients hospitalized in 2 intensive care units (ICUs A and B) during a 28-month period were cultured on appropriate media for isolation of Candida. Forty-nine (9%) patients had at least a Candida spp.-positive sample. Candida albicans was the predominant species isolated from 26 (53%) patients. Seventeen patients (3%) developed candidemia. Multivariate analysis showed that obesity, female gender, hospitalization during summer months, admission at ICU B, parenteral nutrition, administration of metronidazole, transplantation, and KPC-producing Klebsiella pneumoniae (KPC-Kp) infection were independently associated with Candida spp. isolation. Candidemia was associated with cortisone administration, KPC-Kp infection, and presence of colostomy or abdominal catheter. Administration of fluconazole was a protective factor for both Candida spp. isolation and infection, leading to selection of Candida non-albicans species. Among several risk factors, KPC-Kp infection and colonization are identified as statistically significant factors associated with Candida isolation, especially of non-albicans species.

  4. Activity of imipenem against VIM-1 metallo-beta-lactamase-producing Klebsiella pneumoniae in the murine thigh infection model.

    PubMed

    Daikos, G L; Panagiotakopoulou, A; Tzelepi, E; Loli, A; Tzouvelekis, L S; Miriagou, V

    2007-02-01

    The in-vivo activity of imipenem against VIM-1-producing Klebsiella pneumoniae (VPKP) was assessed in a thigh infection model in neutropenic mice. Animals were infected with three VPKP isolates (imipenem MICs 2, 4 and 32 mg/L, respectively) and a susceptible clinical isolate (MIC 0.125 mg/L) that did not produce any beta-lactamase with broad-spectrum activity. Bacterial density at the site of infection was determined after imipenem treatment (30 and 60 mg/kg every 2 h for 24 h). The log(10) reduction in CFU/thigh was greatest for the wild-type isolate, intermediate for the two imipenem-susceptible VPKP isolates, and lowest for the imipenem-resistant VPKP isolate. Whilst in-vivo imipenem activity appeared reduced against in-vitro susceptible VIM-1 producers compared with a VIM-1-negative control, an increased drug dosage could moderate this reduction. PMID:17328735

  5. 3,4-Dihydroxyphenylacetate 2,3-dioxygenase from Klebsiella pneumoniae, a Mg(2+)-containing dioxygenase involved in aromatic catabolism.

    PubMed Central

    Gibello, A; Ferrer, E; Martín, M; Garrido-Pertierra, A

    1994-01-01

    3,4-Dihydroxyphenylacetate 2,3-dioxygenase, an extradiol-ring-cleavage dioxygenase, has been purified from Klebsiella pneumoniae to homogeneity. The enzyme has an M(r) of 102,000 in its tetrameric form with an M(r) of 25,500 for each subunit. Unlike most other dioxygenases, the enzyme reported here contains Mg2+, as determined by atomic-absorption spectrophotometry and plasma emission metal analysis. The enzyme was shown to contain approx. 1 g-atom of Mg2+/mol of protein and we suggest an alpha 4 Mg2+ quaternary structure. This is the first report of a dioxygenase containing Mg2+ in its structure. Images Figure 1 PMID:8037662

  6. Activity of imipenem against VIM-1 metallo-beta-lactamase-producing Klebsiella pneumoniae in the murine thigh infection model.

    PubMed

    Daikos, G L; Panagiotakopoulou, A; Tzelepi, E; Loli, A; Tzouvelekis, L S; Miriagou, V

    2007-02-01

    The in-vivo activity of imipenem against VIM-1-producing Klebsiella pneumoniae (VPKP) was assessed in a thigh infection model in neutropenic mice. Animals were infected with three VPKP isolates (imipenem MICs 2, 4 and 32 mg/L, respectively) and a susceptible clinical isolate (MIC 0.125 mg/L) that did not produce any beta-lactamase with broad-spectrum activity. Bacterial density at the site of infection was determined after imipenem treatment (30 and 60 mg/kg every 2 h for 24 h). The log(10) reduction in CFU/thigh was greatest for the wild-type isolate, intermediate for the two imipenem-susceptible VPKP isolates, and lowest for the imipenem-resistant VPKP isolate. Whilst in-vivo imipenem activity appeared reduced against in-vitro susceptible VIM-1 producers compared with a VIM-1-negative control, an increased drug dosage could moderate this reduction.

  7. Predictability of Phenotype in Relation to Common β-Lactam Resistance Mechanisms in Escherichia coli and Klebsiella pneumoniae.

    PubMed

    Agyekum, Alex; Fajardo-Lubián, Alicia; Ai, Xiaoman; Ginn, Andrew N; Zong, Zhiyong; Guo, Xuejun; Turnidge, John; Partridge, Sally R; Iredell, Jonathan R

    2016-05-01

    The minimal concentration of antibiotic required to inhibit the growth of different isolates of a given species with no acquired resistance mechanisms has a normal distribution. We have previously shown that the presence or absence of transmissible antibiotic resistance genes has excellent predictive power for phenotype. In this study, we analyzed the distribution of six β-lactam antibiotic susceptibility phenotypes associated with commonly acquired resistance genes in Enterobacteriaceae in Sydney, Australia. Escherichia coli (n = 200) and Klebsiella pneumoniae (n = 178) clinical isolates, with relevant transmissible resistance genes (blaTEM, n = 33; plasmid AmpC, n = 69; extended-spectrum β-lactamase [ESBL], n = 116; and carbapenemase, n = 100), were characterized. A group of 60 isolates with no phenotypic resistance to any antibiotics tested and carrying none of the important β-lactamase genes served as comparators. The MICs for all drug-bacterium combinations had a normal distribution, varying only in the presence of additional genes relevant to the phenotype or, for ertapenem resistance in K. pneumoniae, with a loss or change in the outer membrane porin protein OmpK36. We demonstrated mutations in ompK36 or absence of OmpK36 in all isolates in which reduced susceptibility to ertapenem (MIC, >1 mg/liter) was evident. Ertapenem nonsusceptibility in K. pneumoniae was most common in the context of an OmpK36 variant with an ESBL or AmpC gene. Surveillance strategies to define appropriate antimicrobial therapies should include genotype-phenotype relationships for all major transmissible resistance genes and the characterization of mutations in relevant porins in organisms, like K. pneumoniae. PMID:26912748

  8. EMERGENCY ROOM: AN UNRECOGNIZED SOURCE OF EXTENDED-SPECTRUM β-LACTAMASE PRODUCING ESCHERICHIA COLI AND KLEBSIELLA PNEUMONIAE.

    PubMed

    Pornsinchai, Pornsook; Chongtrakool, Piriyaporn; Diraphat, Pornphan; Siripanichgon, Kanokrat; Malathum, Kumthorn

    2015-01-01

    Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae are the leading causes of hospital-associated infections, but community-acquired cases are increasingly being reported. This study determined the prevalence of ESBL-producing E. coli and K. pneumoniae carriers, their bla genes and risk factors of 452 patients admitted to the emergency room (ER) of Ramathibodi Hospital, Mahidol University, Bangkok, Thailand between April and August 2011. Prevalence of ESBL-producing E. coli and K. pneumoniae from rectal swabs was 16.5% and 1.0%, respectively. Factors associated with ESBL-producing carriers were a previous history of hospital admission (p = 0.001) and visits to health care facilities (p = 0.002) during the previous 3 months. All ESBL-producing isolates were susceptible to imipenem, meropenem and ertapenem. The majority (78%) of ESBL-producing E. coli isolates showed very high resistance to cefotaxime and ceftriaxone (MIC50 and MIC90 > 256 µg/ml). ESBL-producing E. coli harbored chromosomal blaTEM (96%), blaCTX-M (70%) and blaSHV (1%), while 8%, 73% and 3%, respectively, were located on plasmid. The prevalence of these genes in ESBL-producing K. pneumoniae was 75%, 50% and 25%, respectively on chromosome; and 100%, 25% and 50%, respectively on plasmid. Nucleotide sequence analysis revealed that these bla genes were of the type blaTEM-1' blaTEM-116' blaCTX-M-15' blaCTX-M-161' blaSHV-12, blaSHV-28 and blaSHV-148. Detailed epidemiologic and clinical characteristics of ER patients with history of prior hospital visits should be carried out to identify the ESBL-producing organisms they have acquired in order to institute appropriate treatment for these patients as well as control measures against further dissemination of these life-threatening organisms. PMID:26513905

  9. Identification and characterization of CTX-M-15 producing Klebsiella pneumoniae clone ST101 in a Hungarian university teaching hospital.

    PubMed

    Melegh, Szilvia; Schneider, György; Horváth, Marianna; Jakab, Ferenc; Emődy, Levente; Tigyi, Zoltán

    2015-09-01

    We investigated the molecular epidemiology of extended spectrum β-lactamase (ESBL) producing Klebsiella pneumoniae isolates derived from the teaching hospitals of University of Pécs, Pécs, Hungary in the time period 2004-2008. Molecular typing, antimicrobial susceptibility testing, detection of common β-lactamase genes (bla(CTX-M), bla(TEM) and bla(SHV)) and virulence associated traits (hypermucoviscosity, magA, k2a, rmpA, siderophores, type 1 and 3 fimbria, biofilm formation, serum resistance) were performed for 102 isolates. The results showed the presence of three major ciprofloxacin resistant CTX-M-15 producing clones (ST15 n = 69, ST101 n = 10, and ST147 n = 9), of which ST15 was predominant and universally widespread. Considering distribution in time and place, ST101 and ST147 were detected at fewer inpatient units and within a narrower time frame, as compared to ST15. Beside major clones, eleven minor clones were identified, and were shown to harbour the following β-lactamase genes: six clones carried bla(CTX-M), four clones harboured bla(SHV-5) and one clone possessed both bla(CTX-M) and ESBL type bla(SHV). Among the SHV-5 producing K. pneumoniae clones a novel sequence type was found, namely ST1193, which harboured a unique infB allele. Different virulence factor content and peculiar antimicrobial susceptibility profile were characteristic for each clone. In contrast to major clone isolates, which showed high level resistance to ciprofloxacin, minor clone isolates displayed significantly lower MIC values for ciprofloxacin suggesting a role for fluoroquinolones in the dissemination of the major K. pneumoniae clones. This is the first description of the CTX-M-15 producing K. pneumoniae clone ST101 in Hungary. PMID:26551567

  10. Extended-spectrum β-lactamase and carbapenemase production among burn and non-burn clinical isolates of Klebsiella pneumoniae

    PubMed Central

    Eftekhar, Fereshteh; Naseh, Ziaeldin

    2015-01-01

    Background and Objectives: Klebsiella pneumoniae is an opportunistic pathogen responsible for up to 10% of nosocomial infections. The emergence and spread of multidrug resistant K. pneumoniae, mostly due to the production of extended-spectrum β-lactamases (ESBL) and carbapenemases, is often responsible for antibiotic treatment failure of these infections. We compared the antibiotic resistance profiles, ESBL and carbapenemase production as well as presence of KPC-type genes in burn and non-burn clinical isolates of K. pneumoniae. Materials and Methods: Fifty five clinical isolates were collected from Shahid Motahari (25 burn isolates) and Shariati (30 non-burn isolates) hospitals between August 2011 to January 2012. Antibiotic susceptibility was determined to 12 antibiotics using disc diffusion. The phenotypic confirmatory test (PCT) was used to screen for ESBL production. Carbapenemase activity was measured by the modified Hodge test (MHT) and KPC-type carbapenemases were further sought by PCR using specific primers. Results: Both groups were highly resistant to cefotaxime and ceftazidime (>92%). Burn isolates were significantly more resistant to cefepime, amoxiclav, imipenem, meropenem, gentamicin and ciprofloxacin compared to the non-burn strains (p<0.05). No significant differences were observed in ESBL production between the two groups. Carbapenem resistance was only observed among the burn isolates (n=5, 9.1%). Five carbapenem-resistant isolates produced carbapenemases. However, none of the isolates harbored the KPC-type genes. Conclusion: Higher rates of drug resistance were observed in burn isolates of K. pneumoniae compared to the non-burn strains. Carbapenemase phenotype was only observed among the burn isolates but KPC-type gene was not detected. PMID:26668701

  11. The Epidemiology of Carbapenem-Resistant Klebsiella pneumoniae Colonization and Infection among Long-Term Acute Care Hospital Residents.

    PubMed

    Mills, John P; Talati, Naasha J; Alby, Kevin; Han, Jennifer H

    2016-01-01

    OBJECTIVE An improved understanding of carbapenem-resistant Klebsiella pneumoniae (CRKP) in long-term acute care hospitals (LTACHs) is needed. The objective of this study was to assess risk factors for colonization or infection with CRKP in LTACH residents. METHODS A case-control study was performed at a university-affiliated LTACH from 2008 to 2013. Cases were defined as all patients with clinical cultures positive for CRKP and controls were those with clinical cultures positive for carbapenem-susceptible K. pneumoniae (CSKP). A multivariate model was developed to identify risk factors for CRKP infection or colonization. RESULTS A total of 222 patients were identified with K. pneumoniae clinical cultures during the study period; 99 (45%) were case patients and 123 (55%) were control patients. Our multivariate analysis identified factors associated with a significant risk for CRKP colonization or infection: solid organ or stem cell transplantation (OR, 5.05; 95% CI, 1.23-20.8; P=.03), mechanical ventilation (OR, 2.56; 95% CI, 1.24-5.28; P=.01), fecal incontinence (OR, 5.78; 95% CI, 1.52-22.0; P=.01), and exposure in the prior 30 days to meropenem (OR, 3.55; 95% CI, 1.04-12.1; P=.04), vancomycin (OR, 2.94; 95% CI, 1.18-7.32; P=.02), and metronidazole (OR, 4.22; 95% CI, 1.28-14.0; P=.02). CONCLUSIONS Rates of colonization and infection with CRKP were high in the LTACH setting, with nearly half of K. pneumoniae cultures demonstrating carbapenem resistance. Further studies are needed on interventions to limit the emergence of CRKP in LTACHs, including targeted surveillance screening of high-risk patients and effective antibiotic stewardship measures. Infect. Control Hosp. Epidemiol. 2015;37(1):55-60. PMID:26455382

  12. Evaluation of boronic acid disk tests for differentiating KPC-possessing Klebsiella pneumoniae isolates in the clinical laboratory.

    PubMed

    Tsakris, Athanassios; Kristo, Ioulia; Poulou, Aggeliki; Themeli-Digalaki, Katerina; Ikonomidis, Alexandros; Petropoulou, Dimitra; Pournaras, Spyros; Sofianou, Danai

    2009-02-01

    The worldwide increase in the occurrence and dissemination of KPC beta-lactamases among gram-negative pathogens makes critical the early detection of these enzymes. Boronic acid disk tests using different antibiotic substrates were evaluated for detection of KPC-possessing Klebsiella pneumoniae isolates. A total of 57 genotypically confirmed KPC-possessing K. pneumoniae isolates with varying carbapenem MICs were examined. To measure the specificity of the tests, 106 non-KPC-possessing isolates (89 K. pneumoniae and 17 Escherichia coli isolates) were randomly selected among those exhibiting reduced susceptibility to cefoxitin, expanded-spectrum cephalosporins, or carbapenems. As many as 56, 53, and 40 of the non-KPC-possessing isolates harbored extended-spectrum beta-lactamases, metallo-beta-lactamases, and plasmid-mediated AmpC beta-lactamases, respectively. By use of CLSI methodology and disks containing imipenem, meropenem, or cefepime, either alone or in combination with 400 microg of boronic acid, all 57 KPC producers gave positive results (sensitivity, 100%) whereas all 106 non-KPC producers were negative (specificity, 100%). The meropenem duplicate disk with or without boronic acid demonstrated the largest differences in inhibition zone diameters between KPC producers and non-KPC producers. By use of disks containing ertapenem, all isolates were correctly differentiated except for five AmpC producers that gave false-positive results (sensitivity, 100%; specificity, 95.3%). These practical and simple boronic acid disk tests promise to be very helpful for the accurate differentiation of KPC-possessing K. pneumoniae isolates, even in regions where different broad-spectrum beta-lactamases are widespread.

  13. Genomic and Transcriptomic Analyses of Colistin-Resistant Clinical Isolates of Klebsiella pneumoniae Reveal Multiple Pathways of Resistance

    PubMed Central

    Wright, Meredith S.; Suzuki, Yo; Jones, Marcus B.; Marshall, Steven H.; Rudin, Susan D.; van Duin, David; Kaye, Keith; Jacobs, Michael R.

    2014-01-01

    The emergence of multidrug-resistant (MDR) Klebsiella pneumoniae has resulted in a more frequent reliance on treatment using colistin. However, resistance to colistin (Colr) is increasingly reported from clinical settings. The genetic mechanisms that lead to Colr in K. pneumoniae are not fully characterized. Using a combination of genome sequencing and transcriptional profiling by RNA sequencing (RNA-Seq) analysis, distinct genetic mechanisms were found among nine Colr clinical isolates. Colr was related to mutations in three different genes in K. pneumoniae strains, with distinct impacts on gene expression. Upregulation of the pmrH operon encoding 4-amino-4-deoxy-l-arabinose (Ara4N) modification of lipid A was found in all Colr strains. Alteration of the mgrB gene was observed in six strains. One strain had a mutation in phoQ. Common among these seven strains was elevated expression of phoPQ and unaltered expression of pmrCAB, which is involved in phosphoethanolamine addition to lipopolysaccharide (LPS). In two strains, separate mutations were found in a previously uncharacterized histidine kinase gene that is part of a two-component regulatory system (TCRS) now designated crrAB. In these strains, expression of pmrCAB, crrAB, and an adjacent glycosyltransferase gene, but not that of phoPQ, was elevated. Complementation with the wild-type allele restored colistin susceptibility in both strains. The crrAB genes are present in most K. pneumoniae genomes, but not in Escherichia coli. Additional upregulated genes in all strains include those involved in cation transport and maintenance of membrane integrity. Because the crrAB genes are present in only some strains, Colr mechanisms may be dependent on the genetic background. PMID:25385117

  14. Novel Carbapenem-Hydrolyzing β-Lactamase, KPC-1, from a Carbapenem-Resistant Strain of Klebsiella pneumoniae

    PubMed Central

    Yigit, Hesna; Queenan, Anne Marie; Anderson, Gregory J.; Domenech-Sanchez, Antonio; Biddle, James W.; Steward, Christine D.; Alberti, Sebastian; Bush, Karen; Tenover, Fred C.

    2001-01-01

    A Klebsiella pneumoniae isolate showing moderate to high-level imipenem and meropenem resistance was investigated. The MICs of both drugs were 16 μg/ml. The β-lactamase activity against imipenem and meropenem was inhibited in the presence of clavulanic acid. The strain was also resistant to extended-spectrum cephalosporins and aztreonam. Isoelectric focusing studies demonstrated three β-lactamases, with pIs of 7.2 (SHV-29), 6.7 (KPC-1), and 5.4 (TEM-1). The presence of blaSHV and blaTEM genes was confirmed by specific PCRs and DNA sequence analysis. Transformation and conjugation studies with Escherichia coli showed that the β-lactamase with a pI of 6.7, KPC-1 (K. pneumoniae carbapenemase-1), was encoded on an approximately 50-kb nonconjugative plasmid. The gene, blaKPC-1, was cloned in E. coli and shown to confer resistance to imipenem, meropenem, extended-spectrum cephalosporins, and aztreonam. The amino acid sequence of the novel carbapenem-hydrolyzing β-lactamase, KPC-1, showed 45% identity to the pI 9.7 carbapenem-hydrolyzing β-lactamase, Sme-1, from Serratia marcescens S6. Hydrolysis studies showed that purified KPC-1 hydrolyzed not only carbapenems but also penicillins, cephalosporins, and monobactams. KPC-1 had the highest affinity for meropenem. The kinetic studies also revealed that clavulanic acid and tazobactam inhibited KPC-1. An examination of the outer membrane proteins of the parent K. pneumoniae strain demonstrated that the strain does not express detectable levels of OmpK35 and OmpK37, although OmpK36 is present. We concluded that carbapenem resistance in K. pneumoniae strain 1534 is mainly due to production of a novel Bush group 2f, class A, carbapenem-hydrolyzing β-lactamase, KPC-1, although alterations in porin expression may also play a role. PMID:11257029

  15. Searching for the Optimal Predictor of Ciprofloxacin Resistance in Klebsiella pneumoniae by Using In Vitro Dynamic Models

    PubMed Central

    Strukova, Elena N.; Portnoy, Yury A.; Romanov, Andrey V.; Edelstein, Mikhail V.; Zinner, Stephen H.

    2015-01-01

    There is growing evidence of applicability of the hypothesis of the mutant selection window (MSW), i.e., the range between the MIC and the mutant prevention concentration (MPC), within which the enrichment of resistant mutants is most probable. However, it is not clear if MPC-based pharmacokinetic variables are preferable to the respective MIC-based variables as interstrain predictors of resistance. To examine the predictive power of the ratios of the area under the curve (AUC24) to the MPC and to the MIC, the selection of ciprofloxacin-resistant mutants of three Klebsiella pneumoniae strains with different MPC/MIC ratios was studied. Each organism was exposed to twice-daily ciprofloxacin for 3 days at AUC24/MIC ratios that provide peak antibiotic concentrations close to the MIC, between the MIC and the MPC, and above the MPC. Resistant K. pneumoniae mutants were intensively enriched at an AUC24/MIC ratio of 60 to 360 h (AUC24/MPC ratio from 2.5 to 15 h) but not at the lower or higher AUC24/MIC and AUC24/MPC ratios, in accordance with the MSW hypothesis. AUC24/MPC and AUC24/MIC relationships with areas under the time courses of ciprofloxacin-resistant K. pneumoniae (AUBCM) were bell shaped. These relationships predict highly variable “antimutant” AUC24/MPC ratios (20 to 290 h) compared to AUC24/MIC ratios (1,310 to 2,610 h). These findings suggest that the potential of the AUC24/MPC ratio as an interstrain predictor of K. pneumoniae resistance is lower than that of the AUC24/MIC ratio. PMID:26643328

  16. Influence of Asellus aquaticus on Escherichia coli, Klebsiella pneumoniae, Campylobacter jejuni and naturally occurring heterotrophic bacteria in drinking water.

    PubMed

    Christensen, Sarah C B; Nissen, Erling; Arvin, Erik; Albrechtsen, Hans-Jørgen

    2012-10-15

    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.

  17. Identification and characterization of CTX-M-15 producing Klebsiella pneumoniae clone ST101 in a Hungarian university teaching hospital.

    PubMed

    Melegh, Szilvia; Schneider, György; Horváth, Marianna; Jakab, Ferenc; Emődy, Levente; Tigyi, Zoltán

    2015-09-01

    We investigated the molecular epidemiology of extended spectrum β-lactamase (ESBL) producing Klebsiella pneumoniae isolates derived from the teaching hospitals of University of Pécs, Pécs, Hungary in the time period 2004-2008. Molecular typing, antimicrobial susceptibility testing, detection of common β-lactamase genes (bla(CTX-M), bla(TEM) and bla(SHV)) and virulence associated traits (hypermucoviscosity, magA, k2a, rmpA, siderophores, type 1 and 3 fimbria, biofilm formation, serum resistance) were performed for 102 isolates. The results showed the presence of three major ciprofloxacin resistant CTX-M-15 producing clones (ST15 n = 69, ST101 n = 10, and ST147 n = 9), of which ST15 was predominant and universally widespread. Considering distribution in time and place, ST101 and ST147 were detected at fewer inpatient units and within a narrower time frame, as compared to ST15. Beside major clones, eleven minor clones were identified, and were shown to harbour the following β-lactamase genes: six clones carried bla(CTX-M), four clones harboured bla(SHV-5) and one clone possessed both bla(CTX-M) and ESBL type bla(SHV). Among the SHV-5 producing K. pneumoniae clones a novel sequence type was found, namely ST1193, which harboured a unique infB allele. Different virulence factor content and peculiar antimicrobial susceptibility profile were characteristic for each clone. In contrast to major clone isolates, which showed high level resistance to ciprofloxacin, minor clone isolates displayed significantly lower MIC values for ciprofloxacin suggesting a role for fluoroquinolones in the dissemination of the major K. pneumoniae clones. This is the first description of the CTX-M-15 producing K. pneumoniae clone ST101 in Hungary.

  18. [Optimized cultivation of a bioflocculant M-C11 produced by Klebsiella pneumoniae and its application in sludge dewatering].

    PubMed

    Liu, Jie-Wei; Ma, Jun-Wei; Liu, Yan-Zhong; Yang, Ya; Yue, Dong-Bei; Wang, Hong-Tao

    2014-03-01

    A bioflocculant-producing Klebsiella pneumoniae strain C11 was screened out from activated sludge and the optimal medium conditions for the production of microbial flocculant M-C11 were determined. The bioflocculant was used in activated sludge dewatering and compared with conventional chemical conditioners. Effects of pH, CaCl2 dosages and M-C11 dosages on sludge dewaterability were investigated. The optimized conditions for M-C11 production indicated that the optimal medium carbon, nitrogen, metal ion were 30 g x L(-1) glucose, 2 g x L(-1) NaNO3 and 0.5 g x L(-1) MgSO4, respectively. The flocculating rate with kaolin suspension was as high as 91.70%, when incubated in a rotary shaker at 150 r x min(-1) and 37 degrees C for 48 h. The microbial focculant showed excellent pH and thermal stability over a pH range of 4-8 and a temperature range of 20-60 degrees C. Then the bioflocculant M-C11 produced by Klebsiella pneumoniae was employed to enhance the sludge dewaterability. The sludge resistance to filtration (SRF) and cake moisture decreased from 11.64 x 10(12) m x kg(-1) and 98.86% to 4.66 x 10(12) m x kg(-1) and 83.74%, respectively. Sludge dewatering performance was more significantly improved with the optimal conditioning dosages (pH = 6, 3 mL M-C11, 4 mL CaCl2), than inorganic flocculating reagents such as aluminum sulfate and polymeric aluminum chloride (PAC). The microbial flocculant has advantages over traditional sludge conditioners for its lower cost, benign biodegradability and ignorable secondary pollution. In addition, it was favorably adapted to the sludge pH and salinity. The novel bioflocculant could be used as a potential conditioner for sludge dewatering.

  19. Characterization of RarA, a Novel AraC Family Multidrug Resistance Regulator in Klebsiella pneumoniae

    PubMed Central

    Veleba, Mark; Higgins, Paul G.; Gonzalez, Gerardo; Seifert, Harald

    2012-01-01

    Transcriptional regulators, such as SoxS, RamA, MarA, and Rob, which upregulate the AcrAB efflux pump, have been shown to be associated with multidrug resistance in clinically relevant Gram-negative bacteria. In addition to the multidrug resistance phenotype, these regulators have also been shown to play a role in the cellular metabolism and possibly the virulence potential of microbial cells. As such, the increased expression of these proteins is likely to cause pleiotropic phenotypes. Klebsiella pneumoniae is a major nosocomial pathogen which can express the SoxS, MarA, Rob, and RamA proteins, and the accompanying paper shows that the increased transcription of ramA is associated with tigecycline resistance (M. Veleba and T. Schneiders, Antimicrob. Agents Chemother. 56:4466–4467, 2012). Bioinformatic analyses of the available Klebsiella genome sequences show that an additional AraC-type regulator is encoded chromosomally. In this work, we characterize this novel AraC-type regulator, hereby called RarA (Regulator of antibiotic resistance A), which is encoded in K. pneumoniae, Enterobacter sp. 638, Serratia proteamaculans 568, and Enterobacter cloacae. We show that the overexpression of rarA results in a multidrug resistance phenotype which requires a functional AcrAB efflux pump but is independent of the other AraC regulators. Quantitative real-time PCR experiments show that rarA (MGH 78578 KPN_02968) and its neighboring efflux pump operon oqxAB (KPN_02969_02970) are consistently upregulated in clinical isolates collected from various geographical locations (Chile, Turkey, and Germany). Our results suggest that rarA overexpression upregulates the oqxAB efflux pump. Additionally, it appears that oqxR, encoding a GntR-type regulator adjacent to the oqxAB operon, is able to downregulate the expression of the oqxAB efflux pump, where OqxR complementation resulted in reductions to olaquindox MICs. PMID:22644028

  20. The Klebsiella pneumoniae YfgL (BamB) lipoprotein contributes to outer membrane protein biogenesis, type-1 fimbriae expression, anti-phagocytosis, and in vivo virulence.

    PubMed

    Hsieh, Pei-Fang; Hsu, Chun-Ru; Chen, Chun-Tang; Lin, Tzu-Lung; Wang, Jin-Town

    2016-07-01

    Klebsiella pneumoniae is an opportunistic pathogen that causes several kinds of infections, including pneumonia, bacteremia, urinary tract infection and community-acquired pyogenic liver abscess (PLA). Adhesion is the critical first step in the infection process. Our previous work demonstrated that the transcellular translocation is exploited by K. pneumoniae strains to migrate from the gut flora into other tissues, resulting in systemic infections. However, the initial stages of K. pneumoniae infection remain unclear. In this study, we demonstrated that a K. pneumoniae strain deleted for yfgL (bamB) exhibited reduced adherence to and invasion of host cells; changed biogenesis of major β-barrel outer membrane proteins; decreased transcriptional expression of type-1 fimbriae; and increased susceptibility to vancomycin and erythromycin. The yfgL deletion mutant also had reduced ability to against neutrophil phagocytosis; exhibited decreased induction of host IL-6 production; and was profoundly attenuated for virulence in a K. pneumoniae model of bacteremia. Thus, the K. pneumoniae YfgL lipoprotein mediates in outer membrane proteins biogenesis and is crucial for anti-phagocytosis and survival in vivo. These data provide a new insight for K. pneumoniae attachment and such knowledge could facilitate preventive therapies or alternative therapies against K. pneumoniae.

  1. Characterization of porin expression in Klebsiella pneumoniae Carbapenemase (KPC)-producing K. pneumoniae identifies isolates most susceptible to the combination of colistin and carbapenems.

    PubMed

    Hong, Jae H; Clancy, Cornelius J; Cheng, Shaoji; Shields, Ryan K; Chen, Liang; Doi, Yohei; Zhao, Yanan; Perlin, David S; Kreiswirth, Barry N; Nguyen, M Hong

    2013-05-01

    We characterized carbapenem resistance mechanisms among 12 Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (referred to here as KPC K. pneumoniae) clinical isolates and evaluated their effects on the activity of 2- and 3-drug combinations of colistin, doripenem, and ertapenem. All isolates were resistant to ertapenem and doripenem; 75% (9/12) were resistant to colistin. Isolates belonged to the ST258 clonal group and harbored blaKPC-2, blaSHV-12, and blaTEM-1. As determined by time-kill assays, doripenem (8 μg/ml) and ertapenem (2 μg/ml) were inactive against 92% (11/12) and 100% (12/12) of isolates, respectively. Colistin (2.5 μg/ml) exerted some activity (range, 0.39 to 2.5 log10) against 78% (7/9) of colistin-resistant isolates. Colistin-ertapenem, colistin-doripenem, and colistin-doripenem-ertapenem exhibited synergy against 42% (5/12), 50% (6/12), and 67% (8/12) of isolates, respectively. Expression of ompK35 and ompK36 porins correlated with each other (R(2) = 0.80). Levels of porin expression did not correlate with colistin-doripenem or colistin-ertapenem synergy. However, synergy with colistin-doripenem-ertapenem was more likely against isolates with high porin expression than those with low expression (100% [8/8] versus 0% [0/4]; P = 0.002). Moreover, bactericidal activity (area under the bacterial killing curve) against isolates with high porin expression was greater for colistin-doripenem-ertapenem than colistin-doripenem or colistin-ertapenem (P ≤ 0.049). In conclusion, colistin-carbapenem combinations may provide optimal activity against KPC K. pneumoniae, including colistin-resistant isolates. Screening for porin expression may identify isolates that are most likely to respond to a triple combination of colistin-doripenem-ertapenem. In the future, molecular characterization of KPC K. pneumoniae isolates may be a practical tool for identifying effective combination regimens.

  2. Direct Detection and Genotyping of Klebsiella pneumoniae Carbapenemases from Urine by Use of a New DNA Microarray Test

    PubMed Central

    Peter, Harald; Berggrav, Kathrine; Thomas, Peter; Pfeifer, Yvonne; Witte, Wolfgang; Templeton, Kate

    2012-01-01

    Klebsiella pneumoniae carbapenemases (KPCs) are considered a serious threat to antibiotic therapy, as they confer resistance to carbapenems, which are used to treat extended-spectrum beta-lactamase (ESBL)-producing bacteria. Here, we describe the development and evaluation of a DNA microarray for the detection and genotyping of KPC genes (blaKPC) within a 5-h period. To test the whole assay procedure (DNA extraction plus a DNA microarray assay) directly from clinical specimens, we compared two commercial DNA extraction kits (the QIAprep Spin miniprep kit [Qiagen] and the urine bacterial DNA isolation kit [Norgen]) for the direct DNA extraction from urine samples (dilution series spiked in human urine). Reliable single nucleotide polymorphism (SNP) typing was demonstrated using 1 × 105 CFU/ml urine for Escherichia coli (Qiagen and Norgen) and 80 CFU/ml urine, on average, for K. pneumoniae (Norgen). This study presents, for the first time, the combination of a new KPC microarray with commercial sample preparation for detecting and genotyping microbial pathogens directly from clinical specimens; this paves the way toward tests providing epidemiological and diagnostic data, enabling better antimicrobial stewardship. PMID:23035190

  3. Septicaemia and meningitis caused by infection of New Zealand sea lion pups with a hypermucoviscous strain of Klebsiella pneumoniae.

    PubMed

    Roe, W D; Rogers, L; Pinpimai, K; Dittmer, K; Marshall, J; Chilvers, B L

    2015-04-17

    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. PMID:25682024

  4. Crystallization and preliminary X-ray characterization of 1,3-propanediol dehydrogenase from the human pathogen Klebsiella pneumoniae

    SciTech Connect

    Marçal, D.; Rego, A. T.; Fogg, M. J.; Wilson, K. S.; Carrondo, M. A.; Enguita, F. J.

    2007-03-01

    1,3-Propanediol dehydrogenase from K. pneumoniae has been overexpressed in E. coli, purified and crystallized. Diffraction data have been collected to 2.7 Å resolution. 1,3-Propanediol dehydrogenase (1,3-PD-DH), encoded by the dhaT gene, is a key enzyme in the dissimilation process for converting glycerol to 1,3-propanediol in the human pathogen Klebsiella pneumoniae. Single colourless crystals were obtained from a recombinant preparation of 1,3-propanediol dehydrogenase overexpressed in Escherichia coli. The crystals belong to space group P2{sub 1}, with unit-cell parameters a = 91.9, b = 226.6, c = 232.6 Å, β = 92.9°. The crystals probably contain two decamers in the asymmetric unit, with a V{sub M} value of 3.07 Å{sup 3} Da{sup −1} and an estimated solvent content of 59%. Diffraction data were collected to 2.7 Å resolution using synchrotron radiation at the ID14-4 beamline of the European Synchrotron Radiation Facility.

  5. Fed-batch approach to production of 2,3-butanediol by Klebsiella pneumoniae grown on high substrate concentrations

    SciTech Connect

    Yu, E.K.C.; Saddler, J.N.

    1983-09-01

    The bioconversion of sugars present in wood hemicellulose to 2,3-butanediol by Klebsiella pneumoniae grown on high sugar concentrations was investigated. When K. pneumoniae was grown under finite air conditions in the presence of added acetic acid, 50 g of D-glucose and D-xylose per liter could be converted to 25 and 27 g of butanediol per liter, respectively. The efficiency of bioconversion decreased with increasing sugar substrate concentrations (up to 200 g/liter). Butanediol production at low sugar substrate concentrations was less efficient when the organism was grown under aerobic conditions; however, final butanediol values were higher for cultures grown on an initial sugar concentration of 150 g/liter, particularly when the inoculum was first acclimatized to high sugar levels. When a double fed-batch approach (daily additions of sugars together with yeast extract) was used under aerobic conditions, up to 88 and 113 g of combined butanediol and acetyl methyl carbinol per liter could be obtained from the utilization of 190 g of D-xylose and 226 g of D-glucose per liter, respectively. 22 references.

  6. Clonal dissemination of Klebsiella pneumoniae ST512 carrying blaKPC-3 in a hospital in southern Italy.

    PubMed

    Pulcrano, Giovanna; Iula, Dora Vita; de Luca, Cristiana; Roscetto, Emanuela; Vollaro, Antonio; Rossano, Fabio; Catania, Maria Rosaria

    2014-01-01

    Strains of Klebsiella pneumoniae producing KPC-carbapenemase have emerged as one of the most important multidrug-resistant Gram-negative nosocomial pathogens. Here, we report the first isolation and subsequent dissemination of a K. pneumoniae ST512 producing KPC-3 carbapenemase in a hospital in southern Italy. Isolates were obtained from blood, throat swabs, sputum, catheters, and urine of patients admitted to different hospital wards. Antimicrobial MICs were determined for all isolates by automated systems and confirmed by Etest. Carbapenemase production was confirmed by the modified Hodge test and by a disc synergy test, and carbapenemase genes were investigated by PCR. All isolates were characterized by pulse-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) analysis. Most isolates were multidrug resistant with exception of some isolates intermediately susceptible to gentamicin, tigecycline, and trimethoprim-sulfamethoxazole. PCR analysis showed that isolates harbored the bla(KPC-3) gene associated with bla(TEM) and bla(SVH). PFGE and MLST showed that all isolates belonged to the same ST512 clone recently described in Israel.

  7. Coincidental detection of the first outbreak of carbapenemase-producing Klebsiella pneumoniae colonisation in a primary care hospital, Finland, 2013.

    PubMed

    Kanerva, M; Skogberg, K; Ryynänen, K; Pahkamäki, A; Jalava, J; Ollgren, J; Tarkka, E; Lyytikäinen, O

    2015-01-01

    In Finland, occurrence of Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-KP) has previously been sporadic and related to travel. We describe the first outbreak of colonisation with KPC-KP strain ST512; it affected nine patients in a 137-bed primary care hospital. The index case was detected by chance when a non-prescribed urine culture was taken from an asymptomatic patient with suprapubic urinary catheter in June 2013. Thereafter, all patients on the 38-bed ward were screened until two screening rounds were negative and extensive control measures were performed. Eight additional KPC-KP-carriers were found, and the highest prevalence of carriers on the ward was nine of 38. All other patients hospitalised on the outbreak ward between 1 May and 10 June and 101 former roommates of KPC-KP carriers since January had negative screening results. Two screening rounds on the hospital's other wards were negative. No link to travel abroad was detected. Compared with non-carriers, but without statistical significance, KPC-KP carriers were older (83 vs 76 years) and had more often received antimicrobial treatment within the three months before screening (9/9 vs 90/133). No clinical infections occurred during the six-month follow-up. Early detection, prompt control measures and repetitive screening were crucial in controlling the outbreak.

  8. Coincidental detection of the first outbreak of carbapenemase-producing Klebsiella pneumoniae colonisation in a primary care hospital, Finland, 2013.

    PubMed

    Kanerva, M; Skogberg, K; Ryynänen, K; Pahkamäki, A; Jalava, J; Ollgren, J; Tarkka, E; Lyytikäinen, O

    2015-01-01

    In Finland, occurrence of Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-KP) has previously been sporadic and related to travel. We describe the first outbreak of colonisation with KPC-KP strain ST512; it affected nine patients in a 137-bed primary care hospital. The index case was detected by chance when a non-prescribed urine culture was taken from an asymptomatic patient with suprapubic urinary catheter in June 2013. Thereafter, all patients on the 38-bed ward were screened until two screening rounds were negative and extensive control measures were performed. Eight additional KPC-KP-carriers were found, and the highest prevalence of carriers on the ward was nine of 38. All other patients hospitalised on the outbreak ward between 1 May and 10 June and 101 former roommates of KPC-KP carriers since January had negative screening results. Two screening rounds on the hospital's other wards were negative. No link to travel abroad was detected. Compared with non-carriers, but without statistical significance, KPC-KP carriers were older (83 vs 76 years) and had more often received antimicrobial treatment within the three months before screening (9/9 vs 90/133). No clinical infections occurred during the six-month follow-up. Early detection, prompt control measures and repetitive screening were crucial in controlling the outbreak. PMID:26159309

  9. Isolation of microorganisms able to produce 1,3-propanediol and optimization of medium constituents for Klebsiella pneumoniae AJ4.

    PubMed

    Hong, Eunsoo; Yoon, Sangyoung; Kim, Jinyoung; Kim, Eumin; Kim, Doosub; Rhie, Seunggyo; Ryu, Yeon-woo

    2013-06-01

    Microbial fermentation under anaerobic and microaerobic conditions has been used for the production of 1,3-propanediol (1,3-PD), a monomer used to produce polymers such as polytrimethylene terephthalate. In this study, we screened microorganisms using the high throughput screening method and isolated the Klebsiella pneumoniae AJ4 strain, which is able to produce 1,3-PD under aerobic conditions. To obtain the maximum 1,3-PD concentration from glycerol, the response surface methodology based on a central composite design was chosen to show the statistical significance of the effects of glycerol, peptone, and (NH(4))(2)SO(4) on 1,3-PD production by K. pneumoniae AJ4. The optimal culture medium factors for achieving maximum concentrations of 1,3-PD included glycerol, 108.5 g/L; peptone, 2.72 g/L; and (NH(4))(2)SO(4), 4.38 g/L. Under this optimum condition, the maximum concentration of 1,3-PD, 54.76 g/L, was predicted. A concentration of about 52.59 g/L 1,3-PD was obtained using the optimized medium during 26-h batch fermentation, a finding that agreed well with the predicted value.

  10. Metabolic engineering of Klebsiella pneumoniae for the de novo production of 2-butanol as a potential biofuel.

    PubMed

    Chen, Zhen; Wu, Yao; Huang, Jinhai; Liu, Dehua

    2015-12-01

    Butanol isomers are important bulk chemicals and promising fuel substitutes. The inevitable toxicity of n-butanol and isobutanol to microbial cells hinders their final titers. In this study, we attempt to engineer Klebsiella pneumoniae for the de novo production of 2-butanol, another butanol isomer which shows lower toxicity than n-butanol and isobutanol. 2-Butanol synthesis was realized by the extension of the native meso-2,3-butanediol synthesis pathway with the introduction of diol dehydratase and secondary alcohol dehydrogenase. By the screening of different secondary alcohol dehydrogenases and diol dehydratases, 320mg/L of 2-butanol was produced by the best engineered K. pneumoniae. The production was increased to 720mg/L by knocking out the ldhA gene and appropriate addition of coenzyme B12. Further improvement of 2-butanol to 1030mg/L was achieved by protein engineering of diol dehydratase. This work lays the basis for the metabolic engineering of microorganism for the production of 2-butanol as potential biofuel.

  11. Effect of antimicrobial peptides on colistin-susceptible and colistin-resistant strains of Klebsiella pneumoniae and Enterobacter asburiae.

    PubMed

    Kádár, Béla; Kocsis, Béla; Kristof, Katalin; Tóth, Ákos; Szabó, Dóra

    2015-12-01

    In this study susceptibility to different antimicrobial peptides was investigated on colistin-susceptible and colistin-resistant identical pulsotype strains of KPC-2 producing Klebsiella pneumoniae ST258 as well as colistin-susceptible and colistin-resistant Enterobacter asburiae strains isolated from clinical samples. In our test, bacteria were exposed to 50 mg/ml lactoferrin, lysozyme and protamine - cationic antimicrobial peptides belonging to innate immune system and having structural similarity to polymyxins - in separate reactions. After 18 hours incubation of colonies were counted. 40% of colistin-resistant K. pneumoniae strains and 97% of colistin-susceptible counterpart strains were lysed by protamine whereas 87% and 100% colony forming unit decrease by lysozyme was seen, respectively. In the case of colistin-resistant E. asburiae strains 1 log10 cell count increase were observed after treatment with lysozyme and 1.56 log10 after lactoferrin exposure compared to the initial number whereas the colistin-susceptible showed no relevant cell count increase. Our findings suggest that acquired colistin-resistance in Enterobacteriaceae is associated with tolerance against antimicrobial peptides.

  12. Comparative Evaluation of Colistin Susceptibility Testing Methods among Carbapenem-Nonsusceptible Klebsiella pneumoniae and Acinetobacter baumannii Clinical Isolates.

    PubMed

    Dafopoulou, Konstantina; Zarkotou, Olympia; Dimitroulia, Evangelia; Hadjichristodoulou, Christos; Gennimata, Vasiliki; Pournaras, Spyros; Tsakris, Athanasios

    2015-08-01

    We compared six colistin susceptibility testing (ST) methods on 61 carbapenem-nonsusceptible Klebsiella pneumoniae (n = 41) and Acinetobacter baumannii (n = 20) clinical isolates with provisionally elevated colistin MICs by routine ST. Colistin MICs were determined by broth microdilution (BMD), BMD with 0.002% polysorbate 80 (P80) (BMD-P80), agar dilution (AD), Etest, Vitek2, and MIC test strip (MTS). BMD was used as the reference method for comparison. The EUCAST-recommended susceptible and resistant breakpoints of ≤2 and >2 μg/ml, respectively, were applied for both K. pneumoniae and A. baumannii. The proportions of colistin-resistant strains were 95.1, 77, 96.7, 57.4, 65.6, and 98.4% by BMD, BMD-P80, AD, Etest, MTS, and Vitek2, respectively. The Etest and MTS methods produced excessive rates of very major errors (VMEs) (39.3 and 31.1%, respectively), while BMD-P80 produced 18% VMEs, AD produced 3.3% VMEs, and Vitek2 produced no VMEs. Major errors (MEs) were rather limited by all tested methods. These data show that gradient diffusion methods may lead to inappropriate colistin therapy. Clinical laboratories should consider the use of automated systems, such as Vitek2, or dilution methods for colistin ST.

  13. Genomic Analysis of the Emergence and Rapid Global Dissemination of the Clonal Group 258 Klebsiella pneumoniae Pandemic.

    PubMed

    Bowers, Jolene R; Kitchel, Brandon; Driebe, Elizabeth M; MacCannell, Duncan R; Roe, Chandler; Lemmer, Darrin; de Man, Tom; Rasheed, J Kamile; Engelthaler, David M; Keim, Paul; Limbago, Brandi M

    2015-01-01

    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.

  14. Septicaemia and meningitis caused by infection of New Zealand sea lion pups with a hypermucoviscous strain of Klebsiella pneumoniae.

    PubMed

    Roe, W D; Rogers, L; Pinpimai, K; Dittmer, K; Marshall, J; Chilvers, B L

    2015-04-17

    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.

  15. Genomic Analysis of the Emergence and Rapid Global Dissemination of the Clonal Group 258 Klebsiella pneumoniae Pandemic

    PubMed Central

    Driebe, Elizabeth M.; MacCannell, Duncan R.; Roe, Chandler; Lemmer, Darrin; de Man, Tom; Rasheed, J. Kamile; Engelthaler, David M.; Keim, Paul; Limbago, Brandi M.

    2015-01-01

    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. PMID:26196384

  16. Microbial fed-batch production of 1,3-propanediol using raw glycerol with suspended and immobilized Klebsiella pneumoniae.

    PubMed

    Jun, Sun-Ae; Moon, Chuloo; Kang, Cheol-Hee; Kong, Sean W; Sang, Byoung-In; Um, Youngsoon

    2010-05-01

    The production of 1,3-propanediol (1,3-PD) was investigated with Klebsiella pneumoniae DSM 4799 using raw glycerol without purification obtained from a biodiesel production process. Fed-batch cultures with suspended cells revealed that 1,3-PD production was more effective when utilizing raw glycerol than pure glycerol (productivity after 47 h of fermentation, 0.84 g L(-1) 1 h(-1) versus 1.51 g L(-1) h(-1) with pure and raw glycerol,respectively). In addition, more than 80 g/L of 1,3-PD was produced using raw glycerol;this is the highest 1,3-PD concentration reported thus far for K. pneumoniae using raw glycerol. Repeated fed-batch fermentation with cell immobilization in a fixed-bed reactor was performed to enhance 1,3-PD production. Production of 1,3-PD increased with the cycle number (1.06 g L(-1) h(-1) versus 1.61 g L(-1) h(-1) at the first and fourth cycle, respectively)due to successful cell immobilization. During 46 cycles of fed-batch fermentation taking place over 1,460 h, a stable and reproducible 1,3-PD production performance was observed with both pure and raw glycerol. Based on our results, repeated fed batch with immobilized cells is an efficient fermentor configuration, and raw glycerol can be utilized to produce 1,3-PD without inhibitory effects caused by accumulated impurities.

  17. Loss of Hypermucoviscosity and Increased Fitness Cost in Colistin-Resistant Klebsiella pneumoniae Sequence Type 23 Strains

    PubMed Central

    Choi, Myung-Jin

    2015-01-01

    In this study, we investigated the effects of colistin resistance on virulence and fitness in hypermucoviscous (HV) Klebsiella pneumoniae sequence type 23 (ST23) strains. Colistin-resistant mutants were developed from three colistin-susceptible HV K. pneumoniae ST23 strains. The lipid A structures of strains were analyzed by matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry. Changes in HV were investigated using the string test, and extracellular polysaccharide production was quantified. The expression levels of the phoQ, pmrD, pmrB, pbgP, magA, and p-rmpA2 genes, serum resistance, and biofilm-forming activity were determined. The fitness of colistin-resistant mutants compared to that of the parental strains was examined by determining the competitive index (CI). The colistin-resistant mutants exhibited reduced HV, which was accompanied by decreased formation of capsular polysaccharides (CPS) and reduced expression of genes (magA and p-rmpA2). While there was enhanced expression of pmrD and pbgP in all colistin-resistant derivatives, there were differences in the expression levels of phoQ and pmrB between strains. MALDI-TOF analysis detected the addition of aminoarabinose or palmitate to the lipid A moiety of lipopolysaccharide in the colistin-resistant derivatives. In addition, survival rates in the presence of normal human serum were decreased in the mutant strains, and CI values (0.01 to 0.19) indicated significant fitness defects in the colistin-resistant derivatives compared to the respective parental strains. In hypervirulent HV K. pneumoniae strains, the acquisition of colistin resistance was accompanied by reduced CPS production, impaired virulence, and a significant fitness cost. PMID:26282408

  18. Interactions of Klebsiella pneumoniae with the innate immune system vary in relation to clone and resistance phenotype.

    PubMed

    Pantelidou, Iliana-Maria; Galani, Irene; Georgitsi, Marianna; Daikos, George L; Giamarellos-Bourboulis, Evangelos J

    2015-11-01

    Apart from inadequate antimicrobial treatment, specific virulence factors contribute to the high attributable mortality of infections caused by multidrug-resistant (MDR) Klebsiella pneumoniae. We explored the roles of MDR and clones as virulence determinants of K. pneumoniae and their interaction with innate immunity. Twenty isolates were studied and characterized by resistance phenotype and multilocus sequence type (MLST). Human peripheral blood mononuclear cells (PBMCs) were stimulated for the production of proinflammatory cytokines by live and heat-killed isolates and plasmid DNA; modulation by cellular pathway inhibitors was explored. Survival of 30 mice was recorded after intraperitoneal challenge with susceptible and K. pneumoniae carbapenemase (KPC)-producing isolates. Splenocytes of mice were stimulated for the production of pro- and anti-inflammatory cytokines. Isolates were divided into different patterns of production of tumor necrosis factor alpha (TNF-α) and interleukin-1β (IL-1β) poststimulation in relation to both the MLST clone and resistance phenotype. The sequence type 383 (ST383) clone producing Verona integron-encoded metallo-β-lactamase (VIM) stimulated high production of both TNF-α and IL-1β. Clone ST17 producing KPC elicited low TNF-α production; this was reversed by Toll-like receptor 9 (TLR9) antagonists, indicating an effect of plasmid DNA. This isolate was linked with early death of mice compared to high-TNF-α-producing isolates. We conclude that KPC-producing isolates seem to be highly virulent in a low-TNF-α-release environment, suggesting an immunoparalysis induction mechanism. KPC plasmids may directly contribute to the immune system stimulation.

  19. In Silico Analysis of Usher Encoding Genes in Klebsiella pneumoniae and Characterization of Their Role in Adhesion and Colonization

    PubMed Central

    Khater, Fida; Balestrino, Damien; Charbonnel, Nicolas; Dufayard, Jean François; Brisse, Sylvain; Forestier, Christiane

    2015-01-01

    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

  20. Susceptibility of various oral antibacterial agents against extended spectrum β-lactamase producing Escherichia coli and Klebsiella pneumoniae.

    PubMed

    Nakamura, Tatsuya; Komatsu, Masaru; Yamasaki, Katsutoshi; Fukuda, Saori; Higuchi, Takeshi; Ono, Tamotsu; Nishio, Hisaaki; Sueyoshi, Noriyuki; Kida, Kaneyuki; Satoh, Kaori; Toda, Hirofumi; Toyokawa, Masahiro; Nishi, Isao; Sakamoto, Masako; Akagi, Masahiro; Mizutani, Tetsu; Nakai, Isako; Kofuku, Tomomi; Orita, Tamaki; Zikimoto, Takuya; Natsume, Seiko; Wada, Yasunao

    2014-01-01

    With the increase in extended spectrum β-lactamase (ESBL)-producing bacteria in the community, cases are often seen in which treatment of infectious diseases with oral antimicrobial agents is difficult. Therefore, we measured the antimicrobial activities of 14 currently available oral antimicrobial agents against ESBL-producing Escherichia coli and Klebsiella pneumoniae. Based on the standard of the Clinical and Laboratory Standards Institute (CLSI), E. coli showed high susceptibility rates of 99.4% to faropenem (FRPM). In terms of fluoroquinolones, the susceptibility rate of E. coli to levofloxacin (LVFX) was low at 32.2%, whereas it showed a good susceptibility rate of 93.1% to sitafloxacin (STFX). With respect to other antimicrobial agents, susceptibility rates to fosfomycin (FOM) and colistin (CL) were more than 90% each, whereas rates of the two antimicrobial agents expected as therapeutic agents, minocycline (MINO) and sulfamethoxazole-trimethoprim (ST), were low at 62.4% and 44.3%, respectively. Based on the CLSI standard, K. pneumoniae showed high susceptibility rates to ceftibuten (CETB) (91.89%), LVFX (86.49%), and STFX (94.6%), indicating that K. pneumoniae showed higher rates than those of E. coli, particularly to fluoroquinolones. Comparison of susceptibility rates according to E. coli genotype showed that many antimicrobial agents existed to which the CTX-M-9 group showed high susceptibility rates. However, there were many agents to which the CTX-M-1 group showed low susceptibility rates, particularly to CETB (51.1%) and LVFX (17.0%). Although there was no significant difference by genotype between FRPM, STFX, and FOM, a significant difference was observed between LVFX, MINO, and ST. Antibiotic-resistant bacteria with highly pathogenic strains have spread in the community, appropriate use of oral antimicrobial agents is required. PMID:24462425

  1. Mechanism of nitrogenase switch-off by oxygen. [Klebsiella pneumoniae; Rhodopseudomonas sphaeroides f. sp. denitrificans; Rhodopseudomonas capsulate

    SciTech Connect

    Goldberg, I.; Nadler, V.; Hochman, A.

    1987-02-01

    Oxygen caused a reversible inhibition (switch-off) of nitrogenase activity in whole cells of four strains of diazotrophs, the facultative anaerobe Klebsiella pneumoniae and three strains of photosynthetic bacteria (Rhodopseudomonas sphaeroides f. sp. denitrificans and Rhodopseudomonas capsulata strians AD2 and BK5). In K. pneumoniae 50% inhibition of acetylene reduction was attained at an O/sub 2/ concentration of 0.37 ..mu..M. Cyanide (90 ..mu..M), which did not affect acetylene reduction but inhibited whole-cell respiration by 60 to 70%, shifted the O/sub 2/ concentration that caused 50% inhibition of nitrogenase activity to 2.9 ..mu..M. A mutant strain of K. pneumoniae, strain AH11, has a respiration rate that is 65 to 75% higher than that of the wild type, but is nitrogenase activity is similar to wild-type activity. Acetylene reduction by whole cells of this mutant was inhibited 50% by 0.20 ..mu..M O/sub 2/. Inhibition by CN/sup -/ of 40 to 50% of the O/sub 2/ uptake in the mutant shifted the O/sub 2/ concentration that caused 50% inhibition of nitrogenase to 1.58 ..mu..M. Thus, when the respiration rates were lower, higher oxygen concentrations were required to inhibit nitrogenase. Reversible inhibition of nitrogenase activity in vivo was caused under anaerobic conditions by other electron acceptors. Addition of 2 mM sulfite to cell suspensions of R. capsulata B10 and R. sphaeroides inhibited nitrogenase activity. Nitrite also inhibited acetylene reduction in whole cells of the photodenitrifier R. sphaeroides but not in R. capsulata B10, which is not capable of enzymatic reduction of NO/sub 2//sup -/. Lower concentrations of NO/sub 2//sup -/ were required to inhibit the activity in NO/sub 3//sup -/-grown cells, which have higher activities of nitrite reductase.

  2. Synergistic killing of NDM-producing MDR Klebsiella pneumoniae by two ‘old’ antibiotics—polymyxin B and chloramphenicol

    PubMed Central

    Abdul Rahim, Nusaibah; Cheah, Soon-Ee; Johnson, Matthew D.; Yu, Heidi; Sidjabat, Hanna E.; Boyce, John; Butler, Mark S.; Cooper, Matthew A.; Fu, Jing; Paterson, David L.; Nation, Roger L.; Bergen, Phillip J.; Velkov, Tony; Li, Jian

    2015-01-01

    Objectives Combination therapy is an important option in the fight against Gram-negative ‘superbugs’. This study systematically investigated bacterial killing and the emergence of polymyxin resistance with polymyxin B and chloramphenicol combinations used against New Delhi metallo-β-lactamase (NDM)-producing MDR Klebsiella pneumoniae. Methods Four NDM-producing K. pneumoniae strains were employed. The presence of genes conferring resistance to chloramphenicol was examined by PCR. Time–kill studies (inocula ∼106 cfu/mL) were conducted using various clinically achievable concentrations of each antibiotic (range: polymyxin B, 0.5–2 mg/L; chloramphenicol, 4–32 mg/L), with real-time population analysis profiles documented at baseline and 24 h. The microbiological response was examined using the log change method and pharmacodynamic modelling in conjunction with scanning electron microscopy (SEM). Results Multiple genes coding for efflux pumps involved in chloramphenicol resistance were present in all strains. Polymyxin B monotherapy at all concentrations produced rapid bacterial killing followed by rapid regrowth with the emergence of polymyxin resistance; chloramphenicol monotherapy was largely ineffective. Combination therapy significantly delayed regrowth, with synergy observed in 25 out of 28 cases at both 6 and 24 h; at 24 h, no viable bacterial cells were detected in 15 out of 28 cases with various combinations across all strains. No polymyxin-resistant bacteria were detected with combination therapy. These results were supported by pharmacodynamic modelling. SEM revealed significant morphological changes following treatment with polymyxin B both alone and in combination. Conclusions The combination of polymyxin B and chloramphenicol used against NDM-producing MDR K. pneumoniae substantially enhanced bacterial killing and suppressed the emergence of polymyxin resistance. PMID:26023209

  3. Loss of hypermucoviscosity and increased fitness cost in colistin-resistant Klebsiella pneumoniae sequence type 23 strains.

    PubMed

    Choi, Myung-Jin; Ko, Kwan Soo

    2015-11-01

    In this study, we investigated the effects of colistin resistance on virulence and fitness in hypermucoviscous (HV) Klebsiella pneumoniae sequence type 23 (ST23) strains. Colistin-resistant mutants were developed from three colistin-susceptible HV K. pneumoniae ST23 strains. The lipid A structures of strains were analyzed by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. Changes in HV were investigated using the string test, and extracellular polysaccharide production was quantified. The expression levels of the phoQ, pmrD, pmrB, pbgP, magA, and p-rmpA2 genes, serum resistance, and biofilm-forming activity were determined. The fitness of colistin-resistant mutants compared to that of the parental strains was examined by determining the competitive index (CI). The colistin-resistant mutants exhibited reduced HV, which was accompanied by decreased formation of capsular polysaccharides (CPS) and reduced expression of genes (magA and p-rmpA2). While there was enhanced expression of pmrD and pbgP in all colistin-resistant derivatives, there were differences in the expression levels of phoQ and pmrB between strains. MALDI-TOF analysis detected the addition of aminoarabinose or palmitate to the lipid A moiety of lipopolysaccharide in the colistin-resistant derivatives. In addition, survival rates in the presence of normal human serum were decreased in the mutant strains, and CI values (0.01 to 0.19) indicated significant fitness defects in the colistin-resistant derivatives compared to the respective parental strains. In hypervirulent HV K. pneumoniae strains, the acquisition of colistin resistance was accompanied by reduced CPS production, impaired virulence, and a significant fitness cost.

  4. Genomic and Functional Characterization of qnr-Encoding Plasmids from Municipal Wastewater Biosolid Klebsiella pneumoniae Isolates

    PubMed Central

    Kaplan, Ella; Sela, Noa; Doron-Faigenboim, Adi; Navon-Venezia, Shiri; Jurkevitch, Edouard; Cytryn, Eddie

    2015-01-01

    Municipal wastewater treatment facilities are considered to be “hotspots” for antibiotic resistance, since they conjoin high densities of environmental and fecal bacteria with selective pressure in the form of sub-therapeutic concentrations of antibiotics. Discharged effluents and biosolids from these facilities can disseminate antibiotic resistant genes to terrestrial and aquatic environments, potentially contributing to the increasing global trend in antibiotic resistance. This phenomenon is especially pertinent when resistance genes are associated with mobile genetic elements such as conjugative plasmids, which can be transferred between bacterial phyla. Fluoroquinolones are among the most abundant antibiotic compounds detected in wastewater treatment facilities, especially in biosolids, where due to their hydrophobic properties they accumulate to concentrations that may exceed 40 mg/L. Although fluoroquinolone resistance is traditionally associated with mutations in the gyrA/topoisomerase IV genes, there is increasing evidence of plasmid-mediated quinolone resistance, which is primarily encoded on qnr genes. In this study, we sequenced seven qnr-harboring plasmids from a diverse collection of Klebsiella strains, isolated from dewatered biosolids from a large wastewater treatment facility in Israel. One of the plasmids, termed pKPSH-11XL was a large (185.4 kbp), multi-drug resistance, IncF-type plasmid that harbored qnrB and 10 additional antibiotic resistance genes that conferred resistance to five different antibiotic families. It was highly similar to the pKPN3-like plasmid family that has been detected in multidrug resistant clinical Klebsiella isolates. In contrast, the six additional plasmids were much smaller (7–9 Kbp) and harbored a qnrS -type gene. These plasmids were highly similar to each other and closely resembled pGNB2, a plasmid isolated from a German wastewater treatment facility. Comparative genome analyses of pKPSH-11XL and other pKPN3

  5. Genomic and Functional Characterization of qnr-Encoding Plasmids from Municipal Wastewater Biosolid Klebsiella pneumoniae Isolates.

    PubMed

    Kaplan, Ella; Sela, Noa; Doron-Faigenboim, Adi; Navon-Venezia, Shiri; Jurkevitch, Edouard; Cytryn, Eddie

    2015-01-01

    Municipal wastewater treatment facilities are considered to be "hotspots" for antibiotic resistance, since they conjoin high densities of environmental and fecal bacteria with selective pressure in the form of sub-therapeutic concentrations of antibiotics. Discharged effluents and biosolids from these facilities can disseminate antibiotic resistant genes to terrestrial and aquatic environments, potentially contributing to the increasing global trend in antibiotic resistance. This phenomenon is especially pertinent when resistance genes are associated with mobile genetic elements such as conjugative plasmids, which can be transferred between bacterial phyla. Fluoroquinolones are among the most abundant antibiotic compounds detected in wastewater treatment facilities, especially in biosolids, where due to their hydrophobic properties they accumulate to concentrations that may exceed 40 mg/L. Although fluoroquinolone resistance is traditionally associated with mutations in the gyrA/topoisomerase IV genes, there is increasing evidence of plasmid-mediated quinolone resistance, which is primarily encoded on qnr genes. In this study, we sequenced seven qnr-harboring plasmids from a diverse collection of Klebsiella strains, isolated from dewatered biosolids from a large wastewater treatment facility in Israel. One of the plasmids, termed pKPSH-11XL was a large (185.4 kbp), multi-drug resistance, IncF-type plasmid that harbored qnrB and 10 additional antibiotic resistance genes that conferred resistance to five different antibiotic families. It was highly similar to the pKPN3-like plasmid family that has been detected in multidrug resistant clinical Klebsiella isolates. In contrast, the six additional plasmids were much smaller (7-9 Kbp) and harbored a qnrS -type gene. These plasmids were highly similar to each other and closely resembled pGNB2, a plasmid isolated from a German wastewater treatment facility. Comparative genome analyses of pKPSH-11XL and other pKPN3-like

  6. First report of OXA-48-producing Klebsiella pneumoniae strains in Iran.

    PubMed

    Azimi, Leila; Nordmann, Patrice; Lari, Abdolaziz Rastegar; Bonnin, Rémy A

    2014-01-01

    Carbapenem-resistant Enterobacteriaceae are increasingly reported worldwide and cause therapeutic problem in health care facilities. In this study 28 imipenem-resistant K. pneumoniae were examined for expression of carbapenemases by phenotypic and genotypic methods. Modified Hodge Test (MHT), CarbaNP test were used for phenotypic detection, and PCR using specific primers for the detection of bla OXA-48 -, bla KPC -, bla NDM - and bla VIM -type carbapenemases with specific primers were performed. MHT and CarbaNP tests were positive for all of imipenem-resistant K. pneumoniae. The bla OXA-48 gene was detected in 27/28 isolates. One isolate was positive for the presence of the bla VIM-4 gene. According to our results NP test and MHT have high sensitivity and specificity for detection of those carbapenemases. This study reports the first cases of OXA-48-producing K. pneumoniae in Iran.

  7. First report of a Klebsiella pneumoniae ST466 strain causing neonatal sepsis harbouring the blaCTX-M-15 gene in Rabat, Morocco.

    PubMed

    Ballén, Victoria; Sáez, Emma; Benmessaoud, Rachid; Houssain, Tligui; Alami, Hassan; Barkat, Amina; Kabiri, Meryem; Moraleda, Cinta; Bezad, Rachid; Vila, Jordi; Bosch, Jordi; Bassat, Quique; Soto, Sara M

    2015-01-01

    Klebsiella pneumoniae is one of the Gram-negative bacilli most commonly found in urine of pregnant women and causing neonatal sepsis. The aim of this study was to analyse in terms of epidemiology and antimicrobial resistance of 23 K. pneumoniae isolates collected from vaginal swabs or urine of pregnant women, from pharyngeal and ear swabs of apparently healthy newborns and from peripheral cultures and hemocultures of newborns with suspected invasive neonatal infection in Rabat, Morocco. The prevalence of K. pneumoniae was 0.6 and 0.9% among pregnant women and neonates, respectively. These strains showed lower antimicrobial resistance levels regarding the developed countries. Thus, only one strain from a neonate presented an ESBL. This is the first report of a K. pneumoniae strain causing neonatal sepsis harbouring the blaCTX-M-15 gene in an IncFII plasmid and belonging to ST466 in this area.

  8. Risk Factors and Outcomes for Carbapenem-Resistant Klebsiella pneumoniae Isolation, Stratified by Its Multilocus Sequence Typing: ST258 Versus Non-ST258.

    PubMed

    Dhar, Sorabh; Martin, Emily T; Lephart, Paul R; McRoberts, John P; Chopra, Teena; Burger, Timothy T; Tal-Jasper, Ruthy; Hayakawa, Kayoko; Ofer-Friedman, Hadas; Lazarovitch, Tsilia; Zaidenstein, Ronit; Perez, Federico; Bonomo, Robert A; Kaye, Keith S; Marchaim, Dror

    2016-01-01

    A "high risk" clone of carbapenem-resistant Klebsiella pneumoniae (CRKP) identified by multilocus sequence typing (MLST) as sequence type (ST) 258 has disseminated worldwide. As the molecular epidemiology of the CRE pandemic continues to evolve, the clinical impact of non-ST258 strains is less well defined. We conducted an epidemiological investigation of CRKP based on strains MLST. Among 68 CRKP patients, 61 were ST258 and 7 belonged to non-ST258. Klebsiella pneumoniae ST258 strains were significantly associated with bla KPC production and with resistance to an increased number of antimicrobials. Clinical outcomes were not different. Based on this analysis, one cannot rely solely on the presence of bla KPC in order to diagnose CRKP. PMID:26885543

  9. Risk Factors and Outcomes for Carbapenem-Resistant Klebsiella pneumoniae Isolation, Stratified by Its Multilocus Sequence Typing: ST258 Versus Non-ST258

    PubMed Central

    Dhar, Sorabh; Martin, Emily T.; Lephart, Paul R.; McRoberts, John P.; Chopra, Teena; Burger, Timothy T.; Tal-Jasper, Ruthy; Hayakawa, Kayoko; Ofer-Friedman, Hadas; Lazarovitch, Tsilia; Zaidenstein, Ronit; Perez, Federico; Bonomo, Robert A.; Kaye, Keith S.; Marchaim, Dror

    2016-01-01

    A “high risk” clone of carbapenem-resistant Klebsiella pneumoniae (CRKP) identified by multilocus sequence typing (MLST) as sequence type (ST) 258 has disseminated worldwide. As the molecular epidemiology of the CRE pandemic continues to evolve, the clinical impact of non-ST258 strains is less well defined. We conducted an epidemiological investigation of CRKP based on strains MLST. Among 68 CRKP patients, 61 were ST258 and 7 belonged to non-ST258. Klebsiella pneumoniae ST258 strains were significantly associated with blaKPC production and with resistance to an increased number of antimicrobials. Clinical outcomes were not different. Based on this analysis, one cannot rely solely on the presence of blaKPC in order to diagnose CRKP. PMID:26885543

  10. Postoperative meningitis and epidural abscess due to extended-spectrum β-lactamase-producing Klebsiella pneumoniae: a case report and a review of the literature.

    PubMed

    Yaita, Kenichiro; Komatsu, Masanari; Oshiro, Yusuke; Yamaguchi, Yukihiro

    2012-01-01

    17-year-old man had been involved in a traffic accident. He underwent a bilateral craniotomy with artificial dura mater to remove bilateral acute subdural hematomas. Seven months later, a right cranioplasty was performed using frozen auto-bone, and he developed extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae meningitis and an epidural abscess. Since his general status was poor, we could not remove the foreign body (artificial dura mater). He was successfully treated with meropenem and chronic suppression with oral trimethoprim-sulfamethoxazole. By describing this case and the results of a review of the pertinent literature, we discuss the importance of ESBL-producing Klebsiella pneumoniae meningitis in posttraumatic/postoperative patients. PMID:22989843

  11. Double Copies of bla(KPC-3)::Tn4401a on an IncX3 Plasmid in Klebsiella pneumoniae Successful Clone ST512 from Italy.

    PubMed

    Fortini, Daniela; Villa, Laura; Feudi, Claudia; Pires, João; Bonura, Celestino; Mammina, Caterina; Endimiani, Andrea; Carattoli, Alessandra

    2016-01-01

    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. PMID:26525794

  12. Double Copies of bla(KPC-3)::Tn4401a on an IncX3 Plasmid in Klebsiella pneumoniae Successful Clone ST512 from Italy.

    PubMed

    Fortini, Daniela; Villa, Laura; Feudi, Claudia; Pires, João; Bonura, Celestino; Mammina, Caterina; Endimiani, Andrea; Carattoli, Alessandra

    2015-11-02

    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.

  13. Comparative Population Analysis of Klebsiella pneumoniae Strains with Extended-Spectrum β-Lactamases Colonizing Patients in Rehabilitation Centers in Four Countries

    PubMed Central

    Baraniak, A.; Izdebski, R.; Fiett, J.; Sadowy, E.; Adler, A.; Kazma, M.; Salomon, J.; Lawrence, C.; Rossini, A.; Salvia, A.; Vidal Samso, J.; Fierro, J.; Paul, M.; Lerman, Y.; Malhotra-Kumar, S.; Lammens, C.; Goossens, H.; Hryniewicz, W.; Brun-Buisson, C.; Carmeli, Y.

    2013-01-01

    The international project MOSAR was conducted in five rehabilitation centers; patients were screened for rectal carriage of extended-spectrum β-lactamase (ESBL)-producing members of the Enterobacteriaceae. Among 229 Klebsiella pneumoniae isolates, four clonal groups (CG) or complexes (CC) prevailed: CG17 in France, CG101 in Italy, CG15 in Spain, and CC147 in Israel. ESBLs, mainly CTX-Ms, were produced by 226 isolates; three isolates expressed AmpC-like cephalosporinases. High genetic diversity of K. pneumoniae populations was observed, with specific characteristics at each center. PMID:23403417

  14. Evaluation of three selective chromogenic media, CHROMagar ESBL, CHROMagar CTX-M and CHROMagar KPC, for the detection of Klebsiella pneumoniae producing OXA-48 carbapenemase.

    PubMed

    Hornsey, Michael; Phee, Lynette; Woodford, Neil; Turton, Jane; Meunier, Daniele; Thomas, Claire; Wareham, David W

    2013-04-01

    Three selective chromogenic culture media (CHROMagars ESBL, CTX-M and KPC) were evaluated for their ability to support the growth of nine Klebsiella pneumoniae isolates producing OXA-48 carbapenemase in combination with other β-lactamases. CHROMagar ESBL and CHROMagar KPC were the most sensitive media, supporting growth of all isolates with a detection limit as low as < 100 CFU/ml. Five isolates failed to grow on CHROMagar CTX-M, and five were recovered on CHROMagar KPC only at counts > 10(6) CFU/ml. Both CHROMagar ESBL and CHROMagar KPC may be useful for enhanced isolation of K pneumoniae producing OXA-48-like carbapenemases.

  15. Occurrence of efflux mechanism and cephalosporinase variant in a population of Enterobacter aerogenes and Klebsiella pneumoniae isolates producing extended-spectrum beta-lactamases.

    PubMed

    Tran, Que-Tien; Dupont, Myrielle; Lavigne, Jean-Philippe; Chevalier, Jacqueline; Pagès, Jean-Marie; Sotto, Albert; Davin-Regli, Anne

    2009-04-01

    We investigated the occurrence of multidrug resistance in 44 Enterobacter aerogenes and Klebsiella pneumoniae clinical isolates. Efflux was involved in resistance in E. aerogenes isolates more frequently than in K. pneumoniae isolates (100 versus 38% of isolates) and was associated with the expression of phenylalanine arginine beta-naphthylamide-susceptible active efflux. AcrA-TolC overproduction in E. aerogenes isolates was noted. An analysis of four E. aerogenes isolates for which cefepime MICs were high revealed no modification in porin expression but a new specific mutation in the AmpC beta-lactamase.

  16. Klebsiella pneumoniae Is Able to Trigger Epithelial-Mesenchymal Transition Process in Cultured Airway Epithelial Cells

    PubMed Central

    Leone, Laura; Mazzetta, Francesca; Martinelli, Daniela; Valente, Sabatino; Alimandi, Maurizio; Raffa, Salvatore; Santino, Iolanda

    2016-01-01

    The ability of some bacterial pathogens to activate Epithelial-Mesenchymal Transition normally is a consequence of the persistence of a local chronic inflammatory response or depends on a direct interaction of the pathogens with the host epithelial cells. In this study we monitored the abilities of the K. pneumoniae to activate the expression of genes related to EMT-like processes and the occurrence of phenotypic changes in airway epithelial cells during the early steps of cell infection. We describe changes in the production of intracellular reactive oxygen species and increased HIF-1α mRNA expression in cells exposed to K. pneumoniae infection. We also describe the upregulation of a set of transcription factors implicated in the EMT processes, such as Twist, Snail and ZEB, indicating that the morphological changes of epithelial cells already appreciable after few hours from the K. pneumoniae infection are tightly regulated by the activation of transcriptional pathways, driving epithelial cells to EMT. These effects appear to be effectively counteracted by resveratrol, an antioxidant that is able to exert a sustained scavenging of the intracellular ROS. This is the first report indicating that strains of K. pneumoniae may promote EMT-like programs through direct interaction with epithelial cells without the involvement of inflammatory cells. PMID:26812644

  17. Sensitive and specific modified Hodge test for KPC and metallo-beta- lactamase detection in Pseudomonas aeruginosa by use of a novel indicator strain, Klebsiella pneumoniae ATCC 700603.

    PubMed

    Pasteran, Fernando; Veliz, Omar; Rapoport, Melina; Guerriero, Leonor; Corso, Alejandra

    2011-12-01

    We evaluated the ability of the modified Hodge test to discriminate between KPC- and metallo-beta-lactamase (MBL)-producing Pseudomonas aeruginosa isolates and carbapenemase nonproducers. With Escherichia coli ATCC 25922 as the indicator strain, the MHT resulted in low sensitivity, specificity, and repeatability. Replacing the indicator strain with Klebsiella pneumoniae ATCC 700603 led to an improved performance (100%, 97%, 0%, and 100% sensitivity, specificity, indeterminate results and repeatability, respectively).

  18. Tigecycline Lock Therapy for Catheter-Related Bloodstream Infection Caused by KPC-Producing Klebsiella pneumoniae in Two Pediatric Hematological Patients.

    PubMed

    Foresti, Sergio; Di Bella, Stefano; Rovelli, Attilio; Sala, Alessandra; Verna, Marta; Bisi, Luca; Nisii, Carla; Gori, Andrea

    2015-12-01

    Catheter-related bacteremias carry high mortality rates in hematological patients. When a multidrug-resistant microorganism is involved, the catheter should ideally be removed; however, this approach is not always possible. Tigecycline lock therapy was used in two pediatric oncohematological patients with intravascular catheter-related infection due to KPC-producing Klebsiella pneumoniae. The catheter was salvaged in both cases, and the patients were later discharged. Our experience suggests the usefulness of this approach in treating this type of infection.

  19. Cross-Infection of Solid Organ Transplant Recipients by a Multidrug-Resistant Klebsiella pneumoniae Isolate Producing the OXA-48 Carbapenemase, Likely Derived from a Multiorgan Donor

    PubMed Central

    Giani, Tommaso; Conte, Viola; Mandalà, Salvatore; D'Andrea, Marco Maria; Luzzaro, Francesco; Conaldi, Pier Giulio; Grossi, Paolo

    2014-01-01

    We describe two cases of bacteremic infections caused by a multidrug-resistant Klebsiella pneumoniae isolate producing the OXA-48 carbapenemase that occurred in two solid organ transplant (liver and kidney) recipients, which was apparently transmitted with the allografts. This finding underscores the risk of donor-derived infections by multidrug-resistant Gram-negative pathogens in solid organ transplant recipients and emphasizes the need for rapid screening of organ donors for carriage of similar pathogens. PMID:24759725

  20. Biochemical Characterization of VIM-39, a VIM-1-Like Metallo-β-Lactamase Variant from a Multidrug-Resistant Klebsiella pneumoniae Isolate from Greece

    PubMed Central

    Pollini, Simona; De Luca, Filomena; Rossolini, Gian Maria; Docquier, Jean-Denis; Hrabák, Jaroslav

    2015-01-01

    VIM-39, a VIM-1-like metallo-β-lactamase variant (VIM-1 Thr33Ala His224Leu) was identified in a clinical isolate of Klebsiella pneumoniae belonging to sequence type 147. VIM-39 hydrolyzed ampicillin, cephalothin, and imipenem more efficiently than did VIM-1 and VIM-26 (a VIM-1 variant with the His224Leu substitution) because of higher turnover rates. PMID:26369975

  1. Novel, plasmid-encoded, TEM-derived extended-spectrum beta-lactamase in Klebsiella pneumoniae conferring higher resistance to aztreonam than to extended-spectrum cephalosporins.

    PubMed Central

    Arlet, G; Rouveau, M; Fournier, G; Lagrange, P H; Philippon, A

    1993-01-01

    A clinical isolate of Klebsiella pneumoniae was more resistant to aztreonam than to cefotaxime and ceftazidime. It produced a clavulanate-susceptible beta-lactamase with an isoelectric point of 6.3 which readily hydrolyzed penicillins, cefotaxime, and ceftazidime, but which hydrolyzed aztreonam poorly. The enzyme was encoded by a gene on a 15-kb plasmid; the gene hybridized with an intragenic DNA probe of blaTEM. Images PMID:8239625

  2. Prevalence and genetic characteristics of TEM, SHV, and CTX-M in clinical Klebsiella pneumoniae isolates from Saudi Arabia.

    PubMed

    Tawfik, Abdulkader F; Alswailem, Abdulaziz M; Shibl, Atef M; Al-Agamy, Mohamed H M

    2011-09-01

    The prevalence and genetic basis of extended-spectrum beta-lactamases (ESBLs) in Klebsiella pneumoniae remains unclear in Saudi Arabia. Therefore, this study was devoted to determine the prevalence and characterize ESBL-producing K. pneumoniae in Al-Qassim area, Saudi Arabia. A total of 430 isolates of K. pneumoniae isolated from clinical samples were collected over 6 months from January to June 2008. These isolates were screened for the presence of ESBLs by double-disk synergy test and re-evaluated by E-test ESBL method. Minimum inhibitory concentrations of 15 antibiotics against ESBL-positive strains were determined by E-test strips. The β-lactamases involved were characterized by polymerase chain reaction assays and DNA sequencing. Conjugation experiments were done and ISEcp1 elements were tested among CTX-M positive isolates. The prevalence of ESBL was 25.6% (110/430) and all ESBL-positive isolates were sensitive to imipenem and tigecycline; however, the resistance rate to gentamicin, amikacin, and ciprofloxacin was 87.3%, 10%, and 9.1%, respectively. Of these, 89.1% produced SHV, 70.9% produced TEM, and 36.4% were CTX-M-producing strains. The prevalence of ESBL SHV SHV-12 and SHV-5 was of 60% and 18.2%, respectively, and various non-ESBL SHV, including SHV-1 (5.5%), -11 (3.6%), and -85 (1.8%), was detected. However, the prevalence of CTX-M-15 and CTX-M-14 was 34.5% and 1.8%, respectively. ISEcp1 element was detected in 60% of bla(CTX-M-15) genes. All bla(CTX-M) genes were transferable; however, most of bla(SHV-12) and bla(SHV-5) were not transferable. TEM-type ESBLs were not detected in any of the isolates. This is the first description of CTX-M-14, SHV-5, SHV-11, and SHV-85 in Saudi Arabia. We have documented the dominance of K. pneumoniae SHV-12 and highlighted the emergence of CTX-M-15 in Saudi Arabia. PMID:21612509

  3. Genotypes of Ciprofloxacin-Resistant Klebsiella pneumoniae in Korea and Their Characteristics According to the Genetic Lineages.

    PubMed

    Park, Dong Jin; Yu, Jin Kyung; Park, Kang Gyun; Park, Yeon-Joon

    2015-12-01

    We investigated the molecular genotypes of ciprofloxacin-resistant Klebsiella pneumoniae and their characteristics according to the genetic lineages. For 160 K. pneumoniae collected in 2013, ciprofloxacin minimum inhibitory concentrations (MICs) were determined by agar dilution method. The genotypes of ciprofloxacin-resistant K. pneumoniae isolates were determined by multilocus sequence typing (MLST) and wzi gene typing. The presence of plasmid-mediated resistance determinants [qnrA, qnrB, qnrS, aac(6')-Ib-cr, blaCTX-M, and blaSHV] was investigated. The gyrA and parC genes were sequenced. Fifty-seven isolates showed ciprofloxacin resistance. By MLST, four major sequence types (STs) or clonal complexes (CCs), that is, ST307, CC11, CC147, and ST15, were found and the two most prevalent STs were ST307 (14/57, 24.6%) and ST11 (12/57, 21.1%). By wzi gene sequencing, 46 of the 57 isolates could be differentiated. All the ST307 isolates had an identical wzi sequence and harbored qnrB. The majority of them harbored aac(6')-Ib-cr (85.7%) and CTX-M-15 (92.9%). In contrast, 12 ST11 isolates were divided into five sublineages by wzi sequence and qnrB, qnrS, and aac(6')-Ib-cr were carried by nine, seven, and three isolates, respectively. They harbored SHV-type extended-spectrum β-lactamase more frequently than CTX-M-15 (nine and four isolates, respectively). The prevalence of CTX-M-15, qnrB1, and aac(6')-Ib-cr was significantly higher in ST307 than in ST11 (p=0.003, p=0.000, and p=0.002, respectively). Both clones had identical amino acid substitution in gyrA (S83I) and parC (S80I). K. pneumoniae ST307 and ST11 were the two most common clones, and the ST307 isolates were highly homogeneous, suggesting their recent emergence.

  4. Impact of therapy and strain type on outcomes in urinary tract infections caused by carbapenem-resistant Klebsiella pneumoniae

    PubMed Central

    van Duin, David; Cober, Eric; Richter, Sandra S.; Perez, Federico; Kalayjian, Robert C.; Salata, Robert A.; Evans, Scott; Fowler, Vance G.; Kaye, Keith S.; Bonomo, Robert A.

    2015-01-01

    Objectives Carbapenem-resistant Klebsiella pneumoniae (CRKP) is an important healthcare-associated pathogen. We evaluated the impact of CRKP strain type and treatment on outcomes of patients with CRKP bacteriuria. Patients and methods Physician-diagnosed CRKP urinary tract infection (UTI)—defined as those patients who received directed treatment for CRKP bacteriuria—was studied in the multicentre, prospective Consortium on Resistance against Carbapenems in Klebsiella pneumoniae (CRaCKle) cohort. Strain typing by repetitive extragenic palindromic PCR (rep-PCR) was performed. Outcomes were classified as failure, indeterminate or success. Univariate and multivariate ordinal analyses to evaluate the associations between outcome, treatment and strain type were followed by binomial analyses. Results One-hundred-and-fifty-seven patients with physician-diagnosed CRKP UTI were included. After adjustment for CDC/National Healthcare Safety Network (NHSN)-defined UTI, critical illness and receipt of more than one active antibiotic, patients treated with aminoglycosides were less likely to fail therapy [adjusted OR (aOR) for failure 0.34, 95% CI 0.15–0.73, P = 0.0049]. In contrast, patients treated with tigecycline were more likely to fail therapy (aOR for failure 2.29, 95% CI 1.03–5.13, P = 0.0425). Strain type data were analysed for 55 patients. The predominant clades were ST258A (n = 18, 33%) and ST258B (n = 26, 47%). After adjustment for CDC/NHSN-defined UTI and use of tigecycline and aminoglycosides, infection with strain type ST258A was associated with clinical outcome in ordinal analysis (P = 0.0343). In multivariate binomial models, strain type ST258A was associated with clinical failure (aOR for failure 5.82, 95% CI 1.47–28.50, P = 0.0113). Conclusions In this nested cohort study of physician-diagnosed CRKP UTI, both choice of treatment and CRKP strain type appeared to impact on clinical outcomes. PMID:25492391

  5. Emergence of Klebsiella pneumoniae ST273 Carrying blaNDM-7 and ST656 Carrying blaNDM-1 in Manila, Philippines

    PubMed Central

    Chou, Andrew; Roa, Marylette; Evangelista, Michael A.; Sulit, Arielle Kae; Lagamayo, Evelina; Torres, Brian C.; Klinzing, David C.; Daroy, Maria Luisa G.; Navoa-Ng, Josephine; Sucgang, Richard

    2016-01-01

    We sought to determine the epidemiology of carbapenem-resistant Enterobacteriaceae and to investigate the emergence of carbapenem-resistant Klebsiella pneumoniae in two teaching hospitals in Manila, Philippines. We screened 364 Enterobacteriaceae for carbapenem resistance between 2012 and 2013 and detected four carbapenem-resistant K. pneumoniae isolates from three different patients. We used whole genome sequencing to determine the antibiotic resistance profiles and confirmed the presence of carbapenemase genes by multiplex PCR. We used multilocus sequence typing and PCR-based replicon typing to genetically characterize the carbapenem-resistant isolates. The carbapenemase gene blaNDM was detected in K. pneumoniae isolates from two patients. The first patient had ventilator-associated pneumonia and lumbar shunt infection from K. pneumoniae ST273 carrying blaNDM-7. The second patient had asymptomatic genitourinary colonization with K. pneumoniae ST656 carrying blaNDM-1. The third patient had a gluteal abscess with K. pneumoniae ST1 that did not carry a carbapenemase gene, but did carry blaDHA-1, blaOXA-1, and blaSHV-1. In this study, we report the first cases of blaNDM-carrying pathogens in the Philippines and add to the growing evidence of the worldwide spread of ST273 and NDM-7, a more efficient carbapenem hydrolyzer than NDM-1. PMID:27032000

  6. Molecular typing and genetic environment of the blaKPC gene in Chilean isolates of Klebsiella pneumoniae.

    PubMed

    Barría-Loaiza, Carla; Pincheira, Andrea; Quezada, Mario; Vera, Alejandra; Valenzuela, Pedro; Domínguez, Mariana; Lima, Celia A; Araya, Ingrid; Araya, Pamela; Prat, Soledad; Aguayo, Carolina; Fernández, Jorge; Hormazábal, Juan Carlos; Bello-Toledo, Helia; González-Rocha, Gerardo

    2016-03-01

    The aim of this work was to determine the genetic environment and transferability of blaKPC as well as the pulsotypes of KPC-producing Klebsiella pneumoniae strains isolated from clinical samples in Chilean hospitals. Seventeen strains, principally isolated in Santiago (the capital of Chile) during the years 2012 and 2013, were included. The genetic environment of blaKPC was elucidated by PCR mapping and sequencing. Molecular typing was performed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Curing and conjugation experiments were performed with six strains of different sequence types (STs) and pulsotypes. Thirteen pulsotypes and six STs, mainly belonging to clonal complex 258, were found. In addition, seven strains belonged to a new ST assigned ST1161. The blaKPC sequence indicated that 16 strains had the KPC-2 variant; in only one strain (UC331) an amino acid change (R6P) was detected, corresponding to a new KPC variant designated KPC-24. Molecular characterisation of the blaKPC genetic environment revealed two distinct platforms, namely variant 1a and the Tn4401a isoform, with the first being the most common (11/17 strains). Mating experiments failed to produce transconjugants; however, loss of blaKPC was achieved by plasmid curing in all assayed strains. In conclusion, in Chilean strains of K. pneumoniae, blaKPC is primarily found associated with the variant 1a and is located in non-transferable plasmids. In addition, this study highlights the description of the new ST1161 and the new KPC-24 variant. PMID:27436389

  7. Molecular epidemiology and antimicrobial susceptibility of extended- and broad-spectrum beta-lactamase-producing Klebsiella pneumoniae isolated in Portugal.

    PubMed

    Mendonça, Nuno; Ferreira, Eugénia; Louro, Deolinda; Caniça, Manuela

    2009-07-01

    All 187 Klebsiella pneumoniae isolated over six consecutive months of 1999 in 17 Portuguese health institutions were studied: 89% were resistant to ampicillin, 31% to trimethoprim/sulfamethoxazole, 17% to aminoglycosides and 3% to fluoroquinolones; 16% were multidrug-resistant and 14% expressed an extended-spectrum beta-lactamase (ESBL) phenotype confirmed by genotyping. Molecular methods identified: 11 isolates possessing bla(ESBL-SHV) genes (bla(SHV-2A), bla(SHV-5), bla(SHV-12) and bla(SHV-55)), 9 isolates with bla(ESBL-TEM) (bla(TEM-3), bla(TEM-10) and bla(TEM-24)) and 7 isolates with bla(GES-1), encoding ESBL enzymes; and 160 isolates with bla(SHV-1) and bla(SHV-type) encoding non-ESBL enzymes. Overall, 15 new beta-lactamases were detected: SHV-60 to SHV-62, SHV-71 and SHV-73 to SHV-83. The genetic relatedness of 108 isolates was studied by pulsed-field gel electrophoresis (PFGE) analysis. The isolates were diverse and 18 clusters were defined, the largest including 12 isolates of different specimens, 6 of which expressed GES-1 enzymes. Twenty additional strains isolated during a second period (March-November 2006) in three of the participating hospitals contained ESBL-encoding genes, whereas none of the isolates in the same hospitals in 1999 carried such genes: bla(SHV-5), bla(SHV-12), bla(TEM-10), bla(TEM-52), bla(CTX-M-15), bla(CTX-M-32) and bla(CTX-M-61) (first described in the country). In this period, three new enzymes were detected: SHV-106 to SHV-108. We provide evidence that the genotypes of K. pneumoniae isolates is changing towards the emergence of ESBL enzymes. PMID:19272757

  8. Biochemical studies of Klebsiella pneumoniae NifL reduction using reconstituted partial anaerobic respiratory chains of Wolinella succinogenes.

    PubMed

    Thummer, Robert; Klimmek, Oliver; Schmitz, Ruth A

    2007-04-27

    In the diazotroph Klebsiella pneumoniae the flavoprotein NifL inhibits the activity of the nif-specific transcriptional activator NifA in response to molecular oxygen and combined nitrogen. Sequestration of reduced NifL to the cytoplasmic membrane under anaerobic and nitrogen-limited conditions impairs inhibition of cytoplasmic NifA by NifL. To analyze whether NifL is reduced by electrons directly derived from the reduced menaquinone pool, we studied NifL reduction using artificial membrane systems containing purified components of the anaerobic respiratory chain of Wolinella succinogenes. In this in vitro assay using proteoliposomes containing purified formate dehydrogenase and purified menaquinone (MK(6)) or 8-methylmenaquinone (MMK(6)) from W. succinogenes, reduction of purified NifL was achieved by formate oxidation. Furthermore, the respective reduction rates, which were determined using equal amounts of NifL, have been shown to be directly dependent on the concentration of both formate dehydrogenase and menaquinones incorporated into the proteoliposomes, demonstrating a direct electron transfer from menaquinone to NifL. When purified hydrogenase and MK(6) from W. succinogenes were inserted into the proteoliposomes, NifL was reduced with nearly the same rate by hydrogen oxidation. In both cases reduced NifL was found to be highly associated to the proteoliposomes, which is in accordance with our previous findings in vivo. On the bases of these experiments, we propose that the redox state of the menaquinone pool is the redox signal for nif regulation in K. pneumoniae by directly transferring electrons onto NifL under anaerobic conditions.

  9. Prevalence of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae in food-producing animals.

    PubMed

    Hiroi, Midori; Yamazaki, Fumie; Harada, Tetsuya; Takahashi, Naomi; Iida, Natsuko; Noda, Yoshihiro; Yagi, Miya; Nishio, Tomohiro; Kanda, Takashi; Kawamori, Fumihiko; Sugiyama, Kanji; Masuda, Takashi; Hara-Kudo, Yukiko; Ohashi, Norio

    2012-02-01

    To evaluate the diversity of extended-spectrum β-lactamases (ESBL) genes among food-producing animals, 48 isolates of ESBL-producing Escherichia coli isolates were obtained from rectal samples of broilers, layers, beef cattle and pigs, at the slaughterhouse level. ESBL-carrying E. coli were isolated from 60.0% of individual broiler rectal samples, 5.9% of layers, 12.5% of beef cattle and 3% of pigs. One ESBL-producing Klebsiella pneumoniae was isolated from a broiler. The ESBL-positive E. coli isolates from broilers harbored various ESBL genes: bla (SHV-12), bla(CTX-M-2), bla(CTX-M-14), bla(CTX-M-15) and bla(CTX-M-44). The plasmid DNAs were analyzed by restriction patterns. Homogeneous band patterns were yielded in those of K. pneumoniae and E. coli isolates harboring the bla(CTX-M-2) gene from different farms. No genetic relation between the 2 CTX-M-14 ESBL-producing strains was found by pulsed-field gel electrophoresis, although 2 plasmids in these strains, obtained from different broiler farms, were similar to each other. This study provides evidence that the proliferation of CTX-M-producing E. coli is due to the growth of indigenous CTX-M-producing strains and the possible emergence of strains that acquired CTX-M genes by horizontal transfer in different broiler farms. CTX-M-producing coliforms in broilers should be controlled due to the critical importance of cephalosporins and the zoonotic potential of ESBL-producing bacteria.

  10. A Dimeric Chlorite Dismutase Exhibits O2-Generating Activity and Acts as a Chlorite Antioxidant in Klebsiella pneumoniae MGH 78578

    PubMed Central

    2015-01-01

    Chlorite dismutases (Clds) convert chlorite to O2 and Cl–, stabilizing heme in the presence of strong oxidants and forming the O=O bond with high efficiency. The enzyme from the pathogen Klebsiella pneumoniae (KpCld) represents a subfamily of Clds that share most of their active site structure with efficient O2-producing Clds, even though they have a truncated monomeric structure, exist as a dimer rather than a pentamer, and come from Gram-negative bacteria without a known need to degrade chlorite. We hypothesized that KpCld, like others in its subfamily, should be able to make O2 and may serve an in vivo antioxidant function. Here, it is demonstrated that it degrades chlorite with limited turnovers relative to the respiratory Clds, in part because of the loss of hypochlorous acid from the active site and destruction of the heme. The observation of hypochlorous acid, the expected leaving group accompanying transfer of an oxygen atom to the ferric heme, is consistent with the more open, solvent-exposed heme environment predicted by spectroscopic measurements and inferred from the crystal structures of related proteins. KpCld is more susceptible to oxidative degradation under turnover conditions than the well-characterized Clds associated with perchlorate respiration. However, wild-type K. pneumoniae has a significant growth advantage in the presence of chlorate relative to a Δcld knockout strain, specifically under nitrate-respiring conditions. This suggests that a physiological function of KpCld may be detoxification of endogenously produced chlorite. PMID:25437493

  11. Potential transfer of extended spectrum β-lactamase encoding gene, blashv18 gene, between Klebsiella pneumoniae in raw foods.

    PubMed

    Jung, Yangjin; Matthews, Karl R

    2016-12-01

    This study investigated the transfer frequency of the extended-spectrum β-