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Sample records for citrobacter freundii clinical

  1. Citrobacter freundii induced endocarditis in a yearling colt.

    PubMed

    Guidi, Eleonora E A; Thomas, Aurélie; Cadoré, Jean-Luc; Smith, Agnès Benamou

    2016-07-01

    Endocarditis is a rare pathology in horses and the clinical signs can be misleading. We describe the clinical, echocardiographic, and pathological features of Citrobacter freundii induced bacterial endocarditis in a horse. This bacterium has never been reported before as an agent of vegetative endocarditis in the horse. PMID:27429467

  2. Genetic Characterization of Atypical Citrobacter freundii

    PubMed Central

    Delgado, Gabriela; Souza, Valeria; Morales, Rosario; Cerritos, René; González-González, Andrea; Méndez, José Luis; Cravioto, Alejandro

    2013-01-01

    The ability of a bacterial population to survive in different niches, as well as in stressful and rapidly changing environmental conditions, depends greatly on its genetic content. To survive such fluctuating conditions, bacteria have evolved different mechanisms to modulate phenotypic variations and related strategies to produce high levels of genetic diversity. Laboratories working in microbiological diagnosis have shown that Citrobacter freundii is very versatile in its colony morphology, as well as in its biochemical, antigenic and pathogenic behaviours. This phenotypic versatility has made C. freundii difficult to identify and it is frequently confused with both Salmonella enterica and Escherichia coli. In order to determine the genomic events and to explain the mechanisms involved in this plasticity, six C. freundii isolates were selected from a phenotypic variation study. An I-CeuI genomic cleavage map was created and eight housekeeping genes, including 16S rRNA, were sequenced. In general, the results showed a range of both phenotypes and genotypes among the isolates with some revealing a greater similarity to C. freundii and some to S. enterica, while others were identified as phenotypic and genotypic intermediary states between the two species. The occurrence of these events in natural populations may have important implications for genomic diversification in bacterial evolution, especially when considering bacterial species boundaries. In addition, such events may have a profound impact on medical science in terms of treatment, course and outcomes of infectious diseases, evading the immune response, and understanding host-pathogen interactions. PMID:24069274

  3. Complete Genome Sequence of Citrobacter freundii Myophage Michonne

    PubMed Central

    Bernal, Christopher L.; Berkowitz, Victoria E.; Cahill, Jesse L.; Rasche, Eric S.

    2015-01-01

    Citrobacter freundii is a Gram-negative opportunistic pathogen that causes dangerous infections such as neonatal meningitis. C. freundii also harbors antibiotic resistance, making phages infecting this host valuable tools. Here, we announce the complete genome of the C. freundii FelixO1-like myophage Michonne and describe its notable features. PMID:26430047

  4. Complete Genome Sequence of Citrobacter freundii Myophage Michonne.

    PubMed

    Bernal, Christopher L; Berkowitz, Victoria E; Cahill, Jesse L; Rasche, Eric S; Kuty Everett, Gabriel F

    2015-01-01

    Citrobacter freundii is a Gram-negative opportunistic pathogen that causes dangerous infections such as neonatal meningitis. C. freundii also harbors antibiotic resistance, making phages infecting this host valuable tools. Here, we announce the complete genome of the C. freundii FelixO1-like myophage Michonne and describe its notable features. PMID:26430047

  5. Complete Genome Sequence of Citrobacter freundii Myophage Mordin

    PubMed Central

    Guan, Jingwen; Snowden, Jeffrey D.; Cahill, Jesse L.; Rasche, Eric S.

    2015-01-01

    Citrobacter freundii is a Gram-negative opportunistic pathogen that is associated with urinary tract infections. Bacteriophages infecting C. freundii can be used as an effective treatment to fight these infections. Here, we announce the complete genome sequence of the C. freundii Felix O1-like myophage Mordin and describe its features. PMID:26472844

  6. Complete Genome Sequence of Citrobacter freundii Myophage Mordin.

    PubMed

    Guan, Jingwen; Snowden, Jeffrey D; Cahill, Jesse L; Rasche, Eric S; Kuty Everett, Gabriel F

    2015-01-01

    Citrobacter freundii is a Gram-negative opportunistic pathogen that is associated with urinary tract infections. Bacteriophages infecting C. freundii can be used as an effective treatment to fight these infections. Here, we announce the complete genome sequence of the C. freundii Felix O1-like myophage Mordin and describe its features. PMID:26472844

  7. Complete Genome Sequence of Citrobacter freundii Myophage Merlin.

    PubMed

    LeSage, Kayla C; Hargrove, Emily C; Cahill, Jesse L; Rasche, Eric S; Kuty Everett, Gabriel F

    2015-01-01

    Bacteriophage Merlin is a T4-like myophage which infects Citrobacter freundii, a member of the Enterobacteriaceae family. C. freundii is an opportunistic pathogen that is a common cause of nosocomial infections. This report announces the complete genome of myophage Merlin and describes its features. PMID:26430046

  8. Complete Genome Sequence of Citrobacter freundii Myophage Merlin

    PubMed Central

    LeSage, Kayla C.; Hargrove, Emily C.; Cahill, Jesse L.; Rasche, Eric S.

    2015-01-01

    Bacteriophage Merlin is a T4-like myophage which infects Citrobacter freundii, a member of the Enterobacteriaceae family. C. freundii is an opportunistic pathogen that is a common cause of nosocomial infections. This report announces the complete genome of myophage Merlin and describes its features. PMID:26430046

  9. Characterization of a virulent bacteriophage LK1 specific for Citrobacter freundii isolated from sewage water.

    PubMed

    Chaudhry, Waqas Nasir; Haq, Irshad Ul; Andleeb, Saadia; Qadri, Ishtiaq

    2014-06-01

    Citrobacter freundii is a worldwide emerging nosocomial pathogen with escalating incidence of multidrug resistance. Citrobacter freundii exists in natural environment, especially in health care settings and is difficult to eradicate. Phage therapy is considered as an alternative way of controlling bacterial infections and contaminations. In this study, we have described isolation and characterization of a virulent bacteriophage LK1 capable of specifically infecting Citrobacter freundii. A virulent bacteriophage LK1, specific for Citrobacter freundii was isolated from sewage water sample. TEM showed that phage Lk1 has an icosahedral head 70 nm in diameter and short tail of 17 nm, and can be classified as a member of the Podoviridae family. Restriction analysis indicated that phage LK1 was a dsDNA virus with an approximate genome size of 20-23 kb. Proteomic pattern generated by SDS PAGE using purified LK1 phage particles, revealed three major and six minor protein bands with molecular weight ranging from 25 to 80 kDa. Adsorption rate of LK1 relative to the host bacterium was also determined which showed significant improvement in adsorption with the addition of CaCl2 . In a single step growth experiment, LK1 exhibited a latent period of 24 min and burst size of 801 particle/cell. Moreover, pH and thermal stability of phage LK1 demonstrated a pH range of 5.0-6.0 and phage viability decreased to 0% at 65 °C. When LK1 was used to infect six other clinically isolated pathogenic strains, it showed relatively narrow host range. LK1 was capable of eliciting efficient lysis of Citrobacter freundii, revealing its potential as a non-toxic sanitizer for controlling Citrobacter freundii infection and contamination in both hospital and other public environments. PMID:23686910

  10. Characterization of Five Podoviridae Phages Infecting Citrobacter freundii.

    PubMed

    Hamdi, Sana; Rousseau, Geneviève M; Labrie, Simon J; Kourda, Rim S; Tremblay, Denise M; Moineau, Sylvain; Slama, Karim B

    2016-01-01

    Citrobacter freundii causes opportunistic infections in humans and animals, which are becoming difficult to treat due to increased antibiotic resistance. The aim of this study was to explore phages as potential antimicrobial agents against this opportunistic pathogen. We isolated and characterized five new virulent phages, SH1, SH2, SH3, SH4, and SH5 from sewage samples in Tunisia. Morphological and genomic analyses revealed that the five C. freundii phages belong to the Caudovirales order, Podoviridae family, and Autographivirinae subfamily. Their linear double-stranded DNA genomes range from 39,158 to 39,832 bp and are terminally redundant with direct repeats between 183 and 242 bp. The five genomes share the same organization as coliphage T7. Based on genomic comparisons and on the phylogeny of the DNA polymerases, we assigned the five phages to the T7virus genus but separated them into two different groups. Phages SH1 and SH2 are very similar to previously characterized phages phiYeO3-12 and phiSG-JL2, infecting, respectively, Yersinia enterocolitica and Salmonella enterica, as well as sharing more than 80% identity with most genes of coliphage T7. Phages SH3, SH4, and SH5 are very similar to phages K1F and Dev2, infecting, respectively, Escherichia coli and Cronobacter turicensis. Several structural proteins of phages SH1, SH3, and SH4 were detected by mass spectrometry. The five phages were also stable from pH 5 to 10. No genes coding for known virulence factors or integrases were found, suggesting that the five isolated phages could be good candidates for therapeutic applications to prevent or treat C. freundii infections. In addition, this study increases our knowledge about the evolutionary relationships within the T7virus genus. PMID:27446058

  11. Characterization of Five Podoviridae Phages Infecting Citrobacter freundii

    PubMed Central

    Hamdi, Sana; Rousseau, Geneviève M.; Labrie, Simon J.; Kourda, Rim S.; Tremblay, Denise M.; Moineau, Sylvain; Slama, Karim B.

    2016-01-01

    Citrobacter freundii causes opportunistic infections in humans and animals, which are becoming difficult to treat due to increased antibiotic resistance. The aim of this study was to explore phages as potential antimicrobial agents against this opportunistic pathogen. We isolated and characterized five new virulent phages, SH1, SH2, SH3, SH4, and SH5 from sewage samples in Tunisia. Morphological and genomic analyses revealed that the five C. freundii phages belong to the Caudovirales order, Podoviridae family, and Autographivirinae subfamily. Their linear double-stranded DNA genomes range from 39,158 to 39,832 bp and are terminally redundant with direct repeats between 183 and 242 bp. The five genomes share the same organization as coliphage T7. Based on genomic comparisons and on the phylogeny of the DNA polymerases, we assigned the five phages to the T7virus genus but separated them into two different groups. Phages SH1 and SH2 are very similar to previously characterized phages phiYeO3-12 and phiSG-JL2, infecting, respectively, Yersinia enterocolitica and Salmonella enterica, as well as sharing more than 80% identity with most genes of coliphage T7. Phages SH3, SH4, and SH5 are very similar to phages K1F and Dev2, infecting, respectively, Escherichia coli and Cronobacter turicensis. Several structural proteins of phages SH1, SH3, and SH4 were detected by mass spectrometry. The five phages were also stable from pH 5 to 10. No genes coding for known virulence factors or integrases were found, suggesting that the five isolated phages could be good candidates for therapeutic applications to prevent or treat C. freundii infections. In addition, this study increases our knowledge about the evolutionary relationships within the T7virus genus. PMID:27446058

  12. Characterization of phiCFP-1, a virulent bacteriophage specific for Citrobacter freundii.

    PubMed

    Zhao, Xiangna; Huang, Simo; Zhao, Jiangtao; He, Xiaoming; Li, Erna; Li, Huan; Liu, Wei; Zou, Dayang; Wei, Xiao; Wang, Xuesong; Dong, Derong; Yang, Zhan; Yan, Xiabei; Shen, Zhiqiang; Yuan, Jing

    2016-05-01

    Citrobacter freundii, a Gram-negative bacterium, causes many opportunistic infections. Bacteriophage phiCFP-1 was isolated and characterized by its ability to lyse the multidrug-resistant clinical C. freundii strain P10159. Transmission electron microscopy showed that the phage has an icosahedral head and a short tail, making it a Podoviridae family member. In a single-step growth experiment, phiCFP-1 exhibited an eclipse period of 20 min and a burst size of 100 particles per cell. Its genome assembled as a circular molecule when genomic sequencing was completed. However, based on genome content and organization, it was categorized as a classic T7-related phage, and such phages are known to have linear genomes with direct terminal repeats. With the quick and simple method established herein, the 38,625-bp linear double-stranded DNA with 229-bp direct terminal repeats was accurately identified. The genome contained 43 putative open reading frames and no tRNA genes. Using a proteomics-based approach, seven viral and two host proteins from purified phiCFP-1 particles were identified. Comparative genomics and recombination analyzes revealed close genetic relatedness among phiCFP-1, phiYeO3-12/vB_YenP_AP5 (from Yersinia enterocolitica O3), and phiSG-JL2 (from Salmonella enterica). PMID:26455439

  13. Unusual microtubule-dependent endocytosis mechanisms triggered by Campylobacter jejuni and Citrobacter freundii.

    PubMed Central

    Oelschlaeger, T A; Guerry, P; Kopecko, D J

    1993-01-01

    Bacterial invasion of six different human epithelial cell lines showed that some strains of the intestinal pathogen Campylobacter jejuni invaded intestinal cell lines at a level 10(2)-10(4) times higher than reported previously for other Campylobacter strains. Separately, urinary tract isolates of Citrobacter freundii triggered a high-efficiency invasion of bladder cells. Use of multiple inhibitors with known effects on eukaryotic cell structures/processes allowed us to define in these genetically distinct bacterial genera unusual bacterial invasion mechanisms that uniquely require microtubules but not microfilaments. Campylobacter jejuni strain 81-176 uptake into 407 intestinal cells and Citrobacter entry into T24 bladder cells was blocked by microtubule depolymerization and inhibitors of coated-pit formation but not by microfilament depolymerization. Inhibitors of endosome acidification had no significant impact on intracellular survival of Campylobacter jejuni or Citrobacter freundii, but monensin markedly reduced Citrobacter uptake. Epithelial cell invasion by both of these bacterial genera was dependent upon de novo bacterial protein synthesis but not upon de novo eukaryotic cell protein synthesis. In contrast to the T24 cell line-specific, strict microtubule-dependent uptake, Citrobacter entry into other cell lines was inhibited by both microtubule- and microfilament-depolymerization, suggesting that these bacteria encode two separate pathways for uptake (i, microtubule-dependent; ii, microfilament-dependent) that are cell line-specific and are recognized perhaps depending on the presence and abundance of appropriate eukaryotic receptors. Images Fig. 1 Fig. 2 Fig. 3 PMID:8341714

  14. Citrobacter freundii infection after acute necrotizing pancreatitis in a patient with a pancreatic pseudocyst: a case report

    PubMed Central

    2011-01-01

    Introduction Infections are the most frequent and severe complications of acute necrotizing pancreatitis with a mortality rate of up to 80 percent. Although experimental and clinical studies suggest that the microbiologic source of pancreatic infection could be enteric, information in this regard is controversial. Case presentation We describe a Citrobacter freundii isolation by endoscopy ultrasound fine needle aspiration in a 80-year-old Caucasian man with pancreatic pseudocyst after acute necrotizing pancreatitis. Conclusion Our case report confirms that this organism can be recovered in patients with a pancreatic pseudocyst. On-site cytology feedback was crucial to the successful outcome of this case as immediate interpretation of the fine needle aspiration sample directed the appropriate cultures and, ultimately, the curative therapy. To the best of our knowledge, this is the first reported case of isolated pancreatic C. freundii diagnosed by endoscopy ultrasound fine needle aspiration. PMID:21299889

  15. Emergence of Citrobacter freundii carrying IMP-8 metallo-β-lactamase in Germany

    PubMed Central

    Peter, S; Wolz, C; Kaase, M; Marschal, M; Schulte, B; Vogel, W; Autenrieth, I; Willmann, M

    2014-01-01

    Metallo-β-lactamases (MBLs) in Enterobacteriaceae are an increasing problem worldwide. This report describes the isolation of Citrobacter freundii carrying IMP-8 MBL from three patients during the period from March 2012 until March 2013 in Germany. The blaIMP-8 enzyme is predominantly found in Asia, where IMP-8 has spread to various enterobacterial species causing serious infections. To our best knowledge, this is the first report of blaIMP-8 habouring Enterobacteriaceae in Europe. PMID:25356340

  16. A cryptic melibiose transporter gene possessing a frameshift from Citrobacter freundii.

    PubMed

    Shimamoto, T; Shimamoto, T; Xu, X J; Okazaki, N; Kawakami, H; Tsuchiya, T

    2001-04-01

    Wild-type Citrobacter freundii cannot grow on melibiose as a sole source of carbon. The melibiose transporter gene melB was cloned from a C. freundii mutant M4 that could utilize melibiose as a sole carbon source. Although the cloned melB gene is closely similar to the melB genes of other bacteria, it is cryptic because of a frameshift mutation. Site-directed mutagenesis was used to construct a functional melB gene by deleting one nucleotide, resulting in the production of an active melibiose transporter. The active MelB transporter could utilize Na(+) and H(+) as coupling cations to melibiose transport. The amino acid sequence of the C. freundii MelB was found to be most similar to those of Salmonella typhimurium and Escherichia coli MelB. These facts are consistent with the phylogenetic relationship of bacteria and the cation coupling properties of the melibiose transporters. PMID:11275561

  17. [Intraparenchymal hepatic haematoma after endoscopic retrograde cholangiopancreotography overinfected by Citrobacter freundii and Klebsiella pneumoniae BLEE].

    PubMed

    Carrica, Sebastián A; Belloni, Rodrigo; Baldoni, Fernando; Yantorno, Martín; Correa, Gustavo; Bologna, Adrián; Barbero, Rodolfo; Villaverde, Augusto; Chopita, Néstor

    2014-06-01

    This case report describes a 37-year-old woman who develops an intraparenchymal hepatic haematoma after an endoscopic retrograde cholangiopancreatography with papillotomy and stone extraction. The procedure requires the passage of a guidewire. The patient develops acute abdominal pain 72 hours later and a magnetic resonance shows a hematoma of 124 x 93 mm. She remains under observation. Twenty one days later she complains of upper right abdominal pain and fever. Consequently, a percutaneous drainage is performed isolating Citrobacter freundii and Klebsiella pneumoniae BLEE. The patient has a good evolution. PMID:25199307

  18. Impact of cold plasma on Citrobacter freundii in apple juice: inactivation kinetics and mechanisms.

    PubMed

    Surowsky, Björn; Fröhling, Antje; Gottschalk, Nathalie; Schlüter, Oliver; Knorr, Dietrich

    2014-03-17

    Various studies have shown that cold plasma is capable of inactivating microorganisms located on a variety of food surfaces, food packaging materials and process equipment under atmospheric pressure conditions; however, less attention has been paid to the impact of cold plasma on microorganisms in liquid foodstuffs. The present study investigates cold plasma's ability to inactivate Citrobacter freundii in apple juice. Optical emission spectroscopy (OES) and temperature measurements were performed to characterise the plasma source. The plasma-related impact on microbial loads was evaluated by traditional plate count methods, while morphological changes were determined using scanning electron microscopy (SEM). Physiological property changes were obtained through flow cytometric measurements (membrane integrity, esterase activity and membrane potential). In addition, mathematical modelling was performed in order to achieve a reliable prediction of microbial inactivation and to establish the basis for possible industrial implementation. C. freundii loads in apple juice were reduced by about 5 log cycles after a plasma exposure of 480s using argon and 0.1% oxygen plus a subsequent storage time of 24h. The results indicate that a direct contact between bacterial cells and plasma is not necessary for achieving successful inactivation. The plasma-generated compounds in the liquid, such as H2O2 and most likely hydroperoxy radicals, are particularly responsible for microbial inactivation. PMID:24462703

  19. Draft Genome Sequences of Citrobacter freundii Strains CF04 and A41 Isolated from Moribund, Septicemic Giant Gourami (Osphronemus goramy) in Sri Lanka.

    PubMed

    Honein, Karim; Jagoda, S S S De S; Arulkanthan, Appudurai; Ushio, Hideki; Asakawa, Shuichi

    2016-01-01

    Citrobacter freundii is a Gram-negative opportunistic pathogen associated with many infectious conditions including septicemia in humans and animals. Here, we announce the draft genome sequences of two multidrug-resistant C. freundii strains (CF04 and A41) isolated from septicemic giant gourami (Osphronemus goramy) collected from aquaria in Sri Lanka. PMID:27516512

  20. Draft Genome Sequences of Citrobacter freundii Strains CF04 and A41 Isolated from Moribund, Septicemic Giant Gourami (Osphronemus goramy) in Sri Lanka

    PubMed Central

    Jagoda, S. S. S. De S.; Arulkanthan, Appudurai; Ushio, Hideki

    2016-01-01

    Citrobacter freundii is a Gram-negative opportunistic pathogen associated with many infectious conditions including septicemia in humans and animals. Here, we announce the draft genome sequences of two multidrug-resistant C. freundii strains (CF04 and A41) isolated from septicemic giant gourami (Osphronemus goramy) collected from aquaria in Sri Lanka. PMID:27516512

  1. CTX-M-14 β-lactamase-producing Citrobacter freundii isolated in Venezuela

    PubMed Central

    2011-01-01

    A clinical isolate of C. freundii with reduced susceptibility to extended-spectrum β-lactams from a woman with cystocele associated with recurrent urinary tract infection was analyzed. Susceptibility tests, double disk synergy tests (DDST) and enzymatic activity by the agar iodometric method suggested the presence of ESBLs. Conjugation experiments revealed the presence of a large conjugative plasmid (pLM07/20) with an exclusive FrepB replicon type (IncF/FIB). PCR analysis and sequencing confirmed the presence of the blaCTX-M-14 gene in the pLM07/20 from C. freundii.LM07/10. Although this is the first report of CTX-M-14 in Venezuela, we alert the medical community that future increase of these β-lactamases in our city could be due to dissemination of plasmids into bacterial populations. PMID:21627834

  2. Acute death associated with Citrobacter freundii infection in an African elephant (Loxodonta africana).

    PubMed

    Ortega, Joaquín; Corpa, Juan M; Orden, José A; Blanco, Jorge; Carbonell, María D; Gerique, Amalia C; Latimer, Erin; Hayward, Gary S; Roemmelt, Andreas; Kraemer, Thomas; Romey, Aurore; Kassimi, Labib B; Casares, Miguel

    2015-09-01

    A 21-year-old male African elephant (Loxodonta africana) died suddenly with no previous medical history. Grossly, there were severe multifocal epicardial and endocardial hemorrhages of the atria and ventricles, hydropericardium, multifocal pleural hemorrhages, and severe pulmonary congestion and edema. Histologically, there was fibrinoid vasculitis and thrombosis in the heart and lung and myocardial necrosis. Citrobacter freundii was isolated in abundance in pure culture from liver and heart samples. Low levels of multiples types of elephant endotheliotropic herpesvirus (EEHV-6, EEHV-2B, and EEHV-3A) were detected in spleen samples, but not in heart samples. The levels of EEHV DNA found were much lower than those usually associated with acute EEHV hemorrhagic disease, and many other genomic loci that would normally be found in such cases were evidently below the level of detection. Therefore, these findings are unlikely to indicate lethal EEHV disease. Polymerase chain reaction for encephalomyocarditis virus (EMCV) and toxicology for oleander (Nerium oleander) were negative. Stress, resulting from recent transport, and antimicrobial therapy may have contributed to the death of this animal. PMID:26179092

  3. Biochemical and molecular characterization of the oxidative branch of glycerol utilization by Citrobacter freundii.

    PubMed Central

    Daniel, R; Stuertz, K; Gottschalk, G

    1995-01-01

    Glycerol dehydrogenase (EC 1.1.1.6) and dihydroxyacetone kinase (EC 2.7.1.29) were purified from Citrobacter freundii. The dehydrogenase is a hexamer of a polypeptide of 43,000 Da. The enzyme exhibited a rather broad substrate specificity, but glycerol was the preferred substrate in the physiological direction. The apparent Kms of the enzyme for glycerol and NAD+ were 1.27 mM and 57 microM, respectively. The kinase is a dimer of a polypeptide of 57,000 Da. The enzyme was highly specific for the substrates dihydroxyacetone and ATP; the apparent Kms were 30 and 70 microM, respectively. The DNA region which contained the genes encoding glycerol dehydrogenase (dhaD) and dihydroxyacetone kinase (dhaK) was cloned and sequenced. Both genes were identified by N-terminal sequence comparison. The deduced dhaD gene product (365 amino acids) exhibited high degrees of homology to glycerol dehydrogenases from other organisms and less homology to type III alcohol dehydrogenases, whereas the dhaK gene product (552 amino acids) revealed no significant homology to any other protein in the databases. A large gene (dhaR) of 1,929 bp was found downstream from dhaD. The deduced gene product (641 amino acids) showed significant similarities to members of the sigma 54 bacterial enhancer-binding protein family. PMID:7635824

  4. Purification and characterization of selenocysteine beta-lyase from Citrobacter freundii

    SciTech Connect

    Chocat, P.; Esaki, N.; Tanizawa, K.; Nakamura, K.; Tanaka, H.; Soda, K.

    1985-08-01

    The purification and characterization of bacterial selenocysteine beta-lyase, an enzyme which specifically catalyzes the cleavage of L-selenocysteine to L-alanine and Se0, are presented. The enzyme, purified to near homogeneity from Citrobacter freundii, is monomeric with a molecular weight of ca. 64,000 and contains 1 mol of pyridoxal 5'-phosphate as a cofactor per mol of enzyme. L-Selenocysteine is the sole substrate. L-Cysteine is a competitive inhibitor of the enzyme. The enzyme also catalyzes the alpha, beta elimination of beta-chloro-L-alanine to form NH3, pyruvate, and Cl- and is irreversibly inactivated during the reaction. The physicochemical properties, e.g., amino acid composition and subunit structure, of the bacterial enzyme are fairly different from those of the pig liver enzyme. However, the catalytic properties of both enzymes, e.g., substrate specificity and inactivation by the substrate or a mechanism-based inactivator, beta-chloro-L-alanine, are very similar.

  5. Purification and characterization of selenocysteine beta-lyase from Citrobacter freundii.

    PubMed Central

    Chocat, P; Esaki, N; Tanizawa, K; Nakamura, K; Tanaka, H; Soda, K

    1985-01-01

    The purification and characterization of bacterial selenocysteine beta-lyase, an enzyme which specifically catalyzes the cleavage of L-selenocysteine to L-alanine and Se0, are presented. The enzyme, purified to near homogeneity from Citrobacter freundii, is monomeric with a molecular weight of ca. 64,000 and contains 1 mol of pyridoxal 5'-phosphate as a cofactor per mol of enzyme. L-Selenocysteine is the sole substrate (Km, 0.95 mM). L-Cysteine is a competitive inhibitor of the enzyme (Ki, 0.65 mM). The enzyme also catalyzes the alpha, beta elimination of beta-chloro-L-alanine to form NH3, pyruvate, and Cl- and is irreversibly inactivated during the reaction. The physicochemical properties, e.g., amino acid composition and subunit structure, of the bacterial enzyme are fairly different from those of the pig liver enzyme (Esaki et al., J. Biol. Chem. 257:4386-4391, 1982). However, the catalytic properties of both enzymes, e.g., substrate specificity and inactivation by the substrate or a mechanism-based inactivator, beta-chloro-L-alanine, are very similar. PMID:2991201

  6. Gene expression profiling in the skin of zebrafish infected with Citrobacter freundii.

    PubMed

    Lü, Aijun; Hu, Xiucai; Xue, Jun; Zhu, Jingrong; Wang, Yi; Zhou, Guangzhou

    2012-02-01

    Skin is considered the largest immunologically active organ, but its molecular mechanism remains unclear in fish. Here, Affymetrix Zebrafish GeneChip was used to assess gene expression in the skin of zebrafish (Danio rerio) infected with the bacterium Citrobacter freundii. The results showed that 229 genes were differentially expressed, of which 196 genes were upregulated and 33 genes were downregulated. Gene Ontology and KEGG pathway analyses indicated 88 genes significantly associated with skin immunity involved in complement activation and acute phase response, defense and immune response, response to stress and stimulus, antigen processing and presentation, cell adhesion and migration, platelet activation and coagulation factors, regulation of autophagy and apoptosis. When compared with transcriptional profiles of previously reported carp (Cyprinus carpio) skin, a similar innate immunity (e.g., interferon, lectin, heat shock proteins, complements), and several different acute phase proteins (transferrin, ceruloplasmin, vitellogenin and alpha-1-microglobulin, etc.) were detected in zebrafish skin. The validity of the microarray results was verified by quantitative real-time PCR analysis of nine representative genes. This is first report that skin play important roles in innate immune responses to bacterial infection, which contribute to understanding the defense mechanisms of the skin in fish. PMID:22155693

  7. Draft genome sequence of Citrobacter freundii strain ST2, a γ-proteobacterium that produces N-acylhomoserine lactones.

    PubMed

    Wang, Yan; Zhou, Jin

    2015-12-01

    Citrobacter freundii strain ST2, isolated from the algae bloom sample, possesses an N-acylhomoserine lactone (AHL) production activity that secretes short-chain AHL molecules. In this study, we sequenced the complete genome of C. freundii strain ST2 to understand the molecular regulation of the AHL system and to search for the AHL gene in this bacterium. The results show that the genome size is 4.89 Mb with a G + C content of 51.96%. 4626 function proteins were predicted and 3647 proteins were assigned to COG functional categories. A predicted AHL-coding gene LuxR was found at contig 4 and the length was 1541 bp. The strain temporary deposited at Shenzhen Public Platform of Screening & Application of Marine Microbial Resources (Shenzhen, China), and the genome sequence can be accessed at GenBank under the accession no. LJSQ00000000. PMID:26697383

  8. NDM-1-Producing Citrobacter freundii, Escherichia coli, and Acinetobacter baumannii Identified from a Single Patient in China

    PubMed Central

    Huang, Ying-Min; Zhong, Lan-lan; Zhang, Xue-Fei; Hu, Hang-tong; Li, Yu-qi; Yang, Xiao-rong; Feng, Lian-Qiang; Huang, Xi

    2015-01-01

    We identified New Delhi metallo-β-lactamase (NDM-1)-producing Citrobacter freundii GB032, Escherichia coli GB102, and Acinetobacter baumannii GB661 in urine and stool samples from a single patient in China. Plasmid profiling and Southern blotting indicated that blaNDM-1 from GB032 and that from GB102 were likely located on the same plasmid, while blaNDM-1 from GB661 was located on a very large (>400-kb) plasmid. This case underscores the broad host range of blaNDM-1 and its potential to spread between members of the family Enterobacteriaceae and A. baumannii. PMID:26055374

  9. Complete Genome Sequence of Multidrug-Resistant Citrobacter freundii Strain P10159, Isolated from Urine Samples from a Patient with Esophageal Carcinoma

    PubMed Central

    Liu, Xiaodong; Huang, Yong; Xu, Xiaomeng; Zhao, Yachao; Sun, Qiang; Zhang, Zhiyi; Zhang, Xianglilan; Wu, Yi; Wang, Jie; Zhou, Dongsheng; An, Xiaoping; Pei, Guangqian; Wang, Yunfei; Mi, Zhiqiang

    2016-01-01

    Citrobacter freundii is an opportunistic pathogen that can cause diarrhea, septicemia, meningitis, and urinary tract infections. We report here the complete genome sequence of C. freundii strain P10159, isolated from urine samples from a patient in China with esophageal carcinoma. The genome has 5,080,321 bp and 4,768 coding sequences, with a G+C content of 51.7%. PMID:26893430

  10. Isolation and characterization of Leucine dehydrogenase from a thermophilic Citrobacter freundii JK-91strain Isolated from Jask Port

    PubMed Central

    Mahdizadehdehosta, Rahman; Kianmehr, Anvarsadat; Khalili, Ahmad

    2013-01-01

    Background and objectives Leucine dehydrogenase (LeuDH; EC 1.4.1.9) belongs to the amino acid dehydrogenase family and isused as a biocatalyst in medical and pharmaceutical industries (1). This study reported deals with the isolation and characterization of LeuDH from a thermophilic bacterium isolated from Jask Port in the Province of Hormozgan. Materials and Methods Aliquots of soil and water samples were cultured in LEU specific medium and thermophilc bacteria that exhibited LeuDH activity were isolated and characterized biochemically. The LeuDH was purified and characterized in regard to the effects of pH and temperature on the activity, as well as its molecular weight determination. Results A thermophilic bacterium, Citrobacter freundii strain JK-9 was identified and found to exhibit LeuDH activity. The enzyme characterization revealed that LeuDH exhibits higher activity at temperature range of 60 to 75°C (optimum of 60°C) and an optimum pH of activity at pH 10.5. The K m value of LeuDH is 1.2 mM, while its molecular weight is about 320 kDa, and consisted of eight subunits identical in molecular mass (40 kDa). Conclusion Briefly, a thermostableLeuDH enzyme from a strain of C. freundii was isolated and characterized. Our data indicate that the C. freundii enzyme has potential for use in biotechnological applications. PMID:24475337

  11. Vitamin B12 production by Citrobacter freundii or Klebsiella pneumoniae during tempeh fermentation and proof of enterotoxin absence by PCR.

    PubMed

    Keuth, S; Bisping, B

    1994-05-01

    The influence of some fermentation parameters on vitamin B12 formation by strains of Citrobacter freundii and Klebsiella pneumoniae isolated from Indonesian tempeh samples during tempeh fermentation was investigated. A decrease in fermentation temperature from 32 to 24 degrees C led to a decrease in vitamin B12 formation. Inoculation of soybeans with different numbers of cells of C. freundii at the beginning of solid-substrate fermentation showed that only the velocity of vitamin formation and not the final amount of vitamin formed depended on the number of cells. The addition of cobalt and 5,6-dimethylbenzimidazole increased the vitamin B12 content of tempeh. Nevertheless, levels of incorporation of the two precursors into the vitamin B12 molecule were very low. Neither C. freundii nor K. pneumoniae possessed the genes encoding the enterotoxins Shiga-like toxin SLT IIA, heat-labile enterotoxin LT Ih, and heat-stable enterotoxin ST Ih, as indicated by PCR. This result supports the suggested use of these two strains to form vitamin B12 during tempeh fermentation in Indonesia. PMID:8017933

  12. Complete Nucleotide Sequence of a Citrobacter freundii Plasmid Carrying KPC-2 in a Unique Genetic Environment

    PubMed Central

    Yao, Yancheng; Imirzalioglu, Can; Hain, Torsten; Kaase, Martin; Gatermann, Soeren; Exner, Martin; Mielke, Martin; Hauri, Anja; Dragneva, Yolanta; Bill, Rita; Wendt, Constanze; Wirtz, Angela; Chakraborty, Trinad

    2014-01-01

    The complete and annotated nucleotide sequence of a 54,036-bp plasmid harboring a blaKPC-2 gene that is clonally present in Citrobacter isolates from different species is presented. The plasmid belongs to incompatibility group N (IncN) and harbors the class A carbapenemase KPC-2 in a unique genetic environment. PMID:25395635

  13. Verotoxinogenic Citrobacter freundii associated with severe gastroenteritis and cases of haemolytic uraemic syndrome in a nursery school: green butter as the infection source.

    PubMed

    Tschape, H; Prager, R; Streckel, W; Fruth, A; Tietze, E; Böhme, G

    1995-06-01

    A summer outbreak of severe gastroenteritis followed by haemolytic uraemic syndrome (HUS) and thrombotic thrombocytopenic purpura in a nursery school and kindergarten is described. Sandwiches prepared with green butter made with contaminated parsley were the likely vehicle of infection. The parsley originated from an organic garden in which manure of pig origin was used instead of artificial fertilizers. Clonally identical verotoxinogenic Citrobacter freundii were found as causative agents of HUS and gastroenteritis and were also detected on the parsley. PMID:7781732

  14. Alliin is a suicide substrate of Citrobacter freundii methionine γ-lyase: structural bases of inactivation of the enzyme.

    PubMed

    Morozova, Elena A; Revtovich, Svetlana V; Anufrieva, Natalya V; Kulikova, Vitalia V; Nikulin, Alexey D; Demidkina, Tatyana V

    2014-11-01

    The interaction of Citrobacter freundii methionine γ-lyase (MGL) and the mutant form in which Cys115 is replaced by Ala (MGL C115A) with the nonprotein amino acid (2R)-2-amino-3-[(S)-prop-2-enylsulfinyl]propanoic acid (alliin) was investigated. It was found that MGL catalyzes the β-elimination reaction of alliin to form 2-propenethiosulfinate (allicin), pyruvate and ammonia. The β-elimination reaction of alliin is followed by the inactivation and modification of SH groups of the wild-type and mutant enzymes. Three-dimensional structures of inactivated wild-type MGL (iMGL wild type) and a C115A mutant form (iMGL C115A) were determined at 1.85 and 1.45 Å resolution and allowed the identification of the SH groups that were oxidized by allicin. On this basis, the mechanism of the inactivation of MGL by alliin, a new suicide substrate of MGL, is proposed. PMID:25372692

  15. Citrobacter freundii carrying blaKPC-2 and blaNDM-1: characterization by whole genome sequencing

    PubMed Central

    Wu, Wenjing; Espedido, Björn; Feng, Yu; Zong, Zhiyong

    2016-01-01

    A carbapenem-resistant Citrobacter freundii strain WCHCF65 was recovered from hospital sewage and was characterized by genome sequencing and conjugation experiments. The strain carried nine genes encoding β-lactamases including two carbapenemase genes, blaNDM-1 and blaKPC-2. blaNDM-1 was carried on an IncX3 plasmid, which was identical to a plasmid found in a local Escherichia coli, suggesting interspecies horizontal transfer. blaKPC-2 was bracketed by two copies of insertion sequence ISKpn19, which could form a composite transposon with the potential to mobilize blaKPC-2, on a new type of plasmid. The coexistence of blaNDM-1 and blaKPC-2 conferred higher levels of resistance to carbapenems compared with blaNDM-1 or blaKPC-2 alone. The coexistence of these carbapenemase genes, on two different plasmids, in one strain may allow new genetic platforms to be generated to mediate their spread. PMID:27465241

  16. Verotoxinogenic Citrobacter freundii associated with severe gastroenteritis and cases of haemolytic uraemic syndrome in a nursery school: green butter as the infection source.

    PubMed Central

    Tschape, H.; Prager, R.; Streckel, W.; Fruth, A.; Tietze, E.; Böhme, G.

    1995-01-01

    A summer outbreak of severe gastroenteritis followed by haemolytic uraemic syndrome (HUS) and thrombotic thrombocytopenic purpura in a nursery school and kindergarten is described. Sandwiches prepared with green butter made with contaminated parsley were the likely vehicle of infection. The parsley originated from an organic garden in which manure of pig origin was used instead of artificial fertilizers. Clonally identical verotoxinogenic Citrobacter freundii were found as causative agents of HUS and gastroenteritis and were also detected on the parsley. Images Fig. 1 Fig. 2 PMID:7781732

  17. Enhanced 1,3-propanediol production by a newly isolated Citrobacter freundii strain cultivated on biodiesel-derived waste glycerol through sterile and non-sterile bioprocesses.

    PubMed

    Metsoviti, Maria; Zeng, An-Ping; Koutinas, Apostolis A; Papanikolaou, Seraphim

    2013-02-20

    The production of 1,3-propanediol (PD) by a newly isolated Citrobacter freundii strain [FMCC-B 294 (VK-19)] was investigated. Different grades of biodiesel-derived glycerol were employed. Slightly lower PD biosynthesis was observed in batch experiments only when crude glycerol from waste-cooking oil trans-esterification was utilized and only at elevated initial substrate concentrations employed. Batch bioreactor cultures revealed the capability of the strain to tolerate elevated amounts of substrate (glycerol up to 170 g/L) and produce quantities of PD in such high substrate concentrations. Nevertheless, maximum PD quantities (45.9 g/L) were achieved at lower initial glycerol concentrations (∼100 g/L) employed, suggesting some inhibition exerted due to the increased initial substrate concentrations. In order to improve PD production, a fed-batch fermentation was carried out and 68.1g/L of PD were produced (the highest PD quantity achieved by C. freundii strains so far) with yield per glycerol consumed ∼0.40 g/g and volumetric productivity 0.79 g/L/h. Aiming to perform a more economical and eco-friendlier procedure, batch and fed-batch fermentations under completely non-sterile conditions were carried out. During non-sterilized fed-batch process, 176 g/L of raw glycerol were converted to 66.3g/L of PD, suggesting the potentiality of the non-sterile fermentation by C. freundii FMCC-B 294. PMID:23220217

  18. Citrobacter koseri. II. Serological and biochemical examination of Citrobacter koseri strains from clinical specimens.

    PubMed Central

    Rowe, B.; Gross, R. J.; Allen, H. A.

    1975-01-01

    165 strains of Citrobacter koseri isolated from clinical specimens were studied and their biochemical reactions determined. They were examined serologically by means of a scheme consisting of 14 O antigens. The sources of the clinical specimens were tabulated and the epidemiological information was summarized. The clinical significance of these findings is discussed. PMID:1056967

  19. An Analysis of the Effects of Vancomycin and/or Vancomycin-Resistant Citrobacter freundii Exposure on the Microbial Community Structure in Soil.

    PubMed

    Cycoń, Mariusz; Borymski, Sławomir; Orlewska, Kamila; Wąsik, Tomasz J; Piotrowska-Seget, Zofia

    2016-01-01

    The occurrence of antibiotics and antibiotic resistance genes in the environment has become a subject of growing concern. The extensive use of vancomycin and other pharmaceuticals may alter the biodiversity of soil microbial communities and select antibiotic-resistant bacteria. Therefore, the purpose of the study was to evaluate the impact of vancomycin and/or vancomycin-resistant Citrobacter freundii on soil microbial communities using the denaturing gradient gel electrophoresis (DGGE) and the phospholipid fatty acid (PLFA) approaches. The experiment had a completely randomized block design with the following treatments: control soil (C), soil with vancomycin (1 mg/kg soil-VA1), soil with vancomycin (10 mg/kg soil-VA10), soil with C. freundii (Cit), soil with vancomycin (1 mg/kg soil) and C. freundii (VA1+Cit), and soil with vancomycin (10 mg/kg soil) and C. freundii (VA10+Cit). A bacterial strain resistant to vancomycin was isolated from raw sewage collected from the municipal sewage treatment plant. The obtained results indicated that the antibiotic and/or the bacterial strain exerted a selective pressure that resulted in qualitative and quantitative changes in the population of soil microorganisms. However, a multivariate analysis showed that the genetic and structural diversity of the soil microbial community was primarily affected by the incubation time and to a lesser extent by the antibiotic and introduced bacteria. DGGE analysis clearly showed that certain species within the bacterial community were sensitive to vancomycin as was evidenced by a decrease in the values of S (richness) and H (Shannon-Wiener) indices. Moreover, a PLFA method-based analysis revealed alterations in the structure of the soil microbial community as indicated by changes in the biomass of the PLFA biomarkers specific for Gram-positive and Gram-negative bacteria as well as fungi. The changes observed in the community of soil microorganisms may decrease the rate of microbial

  20. An Analysis of the Effects of Vancomycin and/or Vancomycin-Resistant Citrobacter freundii Exposure on the Microbial Community Structure in Soil

    PubMed Central

    Cycoń, Mariusz; Borymski, Sławomir; Orlewska, Kamila; Wąsik, Tomasz J.; Piotrowska-Seget, Zofia

    2016-01-01

    The occurrence of antibiotics and antibiotic resistance genes in the environment has become a subject of growing concern. The extensive use of vancomycin and other pharmaceuticals may alter the biodiversity of soil microbial communities and select antibiotic-resistant bacteria. Therefore, the purpose of the study was to evaluate the impact of vancomycin and/or vancomycin-resistant Citrobacter freundii on soil microbial communities using the denaturing gradient gel electrophoresis (DGGE) and the phospholipid fatty acid (PLFA) approaches. The experiment had a completely randomized block design with the following treatments: control soil (C), soil with vancomycin (1 mg/kg soil—VA1), soil with vancomycin (10 mg/kg soil—VA10), soil with C. freundii (Cit), soil with vancomycin (1 mg/kg soil) and C. freundii (VA1+Cit), and soil with vancomycin (10 mg/kg soil) and C. freundii (VA10+Cit). A bacterial strain resistant to vancomycin was isolated from raw sewage collected from the municipal sewage treatment plant. The obtained results indicated that the antibiotic and/or the bacterial strain exerted a selective pressure that resulted in qualitative and quantitative changes in the population of soil microorganisms. However, a multivariate analysis showed that the genetic and structural diversity of the soil microbial community was primarily affected by the incubation time and to a lesser extent by the antibiotic and introduced bacteria. DGGE analysis clearly showed that certain species within the bacterial community were sensitive to vancomycin as was evidenced by a decrease in the values of S (richness) and H (Shannon-Wiener) indices. Moreover, a PLFA method-based analysis revealed alterations in the structure of the soil microbial community as indicated by changes in the biomass of the PLFA biomarkers specific for Gram-positive and Gram-negative bacteria as well as fungi. The changes observed in the community of soil microorganisms may decrease the rate of microbial

  1. Kinetic Parameters and Cytotoxic Activity of Recombinant Methionine γ-Lyase from Clostridium tetani, Clostridium sporogenes, Porphyromonas gingivalis and Citrobacter freundii.

    PubMed

    Morozova, E A; Kulikova, V V; Yashin, D V; Anufrieva, N V; Anisimova, N Y; Revtovich, S V; Kotlov, M I; Belyi, Y F; Pokrovsky, V S; Demidkina, T V

    2013-07-01

    The steady-state kinetic parameters of pyridoxal 5'-phosphate-dependent recombinant methionine γ -lyase from three pathogenic bacteria, Clostridium tetani, Clostridium sporogenes, and Porphyromonas gingivalis, were determined in β- and γ-elimination reactions. The enzyme from C. sporogenes is characterized by the highest catalytic efficiency in the γ-elimination reaction of L-methionine. It was demonstrated that the enzyme from these three sources exists as a tetramer. The N-terminal poly-histidine fragment of three recombinant enzymes influences their catalytic activity and facilitates the aggregation of monomers to yield dimeric forms under denaturing conditions. The cytotoxicity of methionine γ-lyase from C. sporogenes and C. tetani in comparison with Citrobacter freundii was evaluated using K562, PC-3, LnCap, MCF7, SKOV-3, and L5178y tumor cell lines. K562 (IC50=0.4-1.3 U/ml), PC-3 (IC50=0.1-0.4 U/ml), and MCF7 (IC50=0.04-3.2 U/ml) turned out to be the most sensitive cell lines. PMID:24303205

  2. Purification of 1,3-propanediol dehydrogenase from Citrobacter freundii and cloning, sequencing, and overexpression of the corresponding gene in Escherichia coli.

    PubMed Central

    Daniel, R; Boenigk, R; Gottschalk, G

    1995-01-01

    1,3-Propanediol dehydrogenase (EC 1.1.1.202) was purified to homogeneity from Citrobacter freundii grown anaerobically on glycerol in continuous culture. The enzyme is an octamer of a polypeptide of 43,400 Da. When tested as a dehydrogenase, the enzyme was most active with substrates containing two primary alcohol groups separated by one or two carbon atoms. In the physiological direction, 3-hydroxypropionaldehyde was the preferred substrate. The apparent Km values of the enzyme for 3-hydroxypropionaldehyde and NADH were 140 and 33 microM, respectively. The enzyme was inhibited by chelators of divalent cations but could be reactivated by the addition of Fe2+. The dhaT gene, encoding the 1,3-propanediol dehydrogenase, was cloned, and its nucleotide sequence (1,164 bp) was determined. The deduced dhaT gene product (387 amino acids, 41,324 Da) showed a high level of similarity to a novel family (type III) of alcohol dehydrogenases. The dhaT gene was overexpressed in Escherichia coli 274-fold by using the T7 RNA polymerase/promoter system. PMID:7721705

  3. Complex integrons containing qnrB4-ampC (bla(DHA-1)) in plasmids of multidrug-resistant Citrobacter freundii from wastewater.

    PubMed

    Yim, Grace; Kwong, Waldan; Davies, Julian; Miao, Vivian

    2013-02-01

    Microbial populations in wastewater treatment plants (WWTPs) are increasingly being recognized as environmental reservoirs of antibiotic resistance genes. PCR amplicons for plasmid-mediated quinolone resistance determinants qnrA, qnrB, and qnrS were recorded in samples from a WWTP in Vancouver, British Columbia. Six strains of ciprofloxacin-resistant Citrobacter freundii were isolated and found to carry mutations in gyrA and parC, as well as multiple plasmid-borne resistance genes, collectively including qnrB; aac(6')-Ib-cr; β-lactamase-encoding genes from molecular classes A (blaTEM-1), C (ampC), D (blaOXA-1, blaOXA-10); and genes for resistance to 5 other types of antibiotics. In 3 strains, large (>60 kb) plasmids carried qnrB4 and ampC as part of a complex integron in a 14 kb arrangement that has been reported worldwide but, until recently, only among pathogenic strains of Klebsiella. Analysis of single-nucleotide polymorphisms in the qnrB4-ampC regions infers 2 introductions into the WWTP environment. These results suggest recent passage of plasmid-borne fluoroquinolone and β-lactam resistance genes from pathogens to bacteria that may be indigenous inhabitants of WWTPs, thus contributing to an environmental pool of antibiotic resistance. PMID:23461518

  4. Secondary metabolites extracted from marine sponge associated Comamonas testosteroni and Citrobacter freundii as potential antimicrobials against MDR pathogens and hypothetical leads for VP40 matrix protein of Ebola virus: an in vitro and in silico investigation.

    PubMed

    Skariyachan, Sinosh; Acharya, Archana B; Subramaniyan, Saumya; Babu, Sumangala; Kulkarni, Shruthi; Narayanappa, Rajeswari

    2016-09-01

    The current study explores therapeutic potential of metabolites extracted from marine sponge (Cliona sp.)-associated bacteria against MDR pathogens and predicts the binding prospective of probable lead molecules against VP40 target of Ebola virus. The metabolite-producing bacteria were characterized by agar overlay assay and as per the protocols in Bergey's manual of determinative bacteriology. The antibacterial activities of extracted metabolites were tested against clinical pathogens by well-diffusion assay. The selected metabolite producers were characterized by 16S rDNA sequencing. Chemical screening and Fourier Transform Infrared (FTIR) analysis for selected compounds were performed. The probable lead molecules present in the metabolites were hypothesized based on proximate analysis, FTIR data, and literature survey. The drug-like properties and binding potential of lead molecules against VP40 target of Ebola virus were hypothesized by computational virtual screening and molecular docking. The current study demonstrated that clear zones around bacterial colonies in agar overlay assay. Antibiotic sensitivity profiling demonstrated that the clinical isolates were multi-drug resistant, however; most of them showed sensitivity to secondary metabolites (MIC-15 μl/well). The proximate and FTIR analysis suggested that probable metabolites belonged to alkaloids with O-H, C-H, C=O, and N-H groups. 16S rDNA characterization of selected metabolite producers demonstrated that 96% and 99% sequence identity to Comamonas testosteroni and Citrobacter freundii, respectively. The docking studies suggested that molecules such as Gymnastatin, Sorbicillactone, Marizomib, and Daryamide can designed as probable lead candidates against VP40 target of Ebola virus. PMID:26577929

  5. Use of microdilution panels with and without beta-lactamase inhibitors as a phenotypic test for beta-lactamase production among Escherichia coli, Klebsiella spp., Enterobacter spp., Citrobacter freundii, and Serratia marcescens.

    PubMed

    Thomson, K S; Sanders, C C; Moland, E S

    1999-06-01

    Over the past decade, a number of new beta-lactamases have appeared in clinical isolates of Enterobacteriaceae that, unlike their predecessors, do not confer beta-lactam resistance that is readily detected in routine antibiotic susceptibility tests. Because optimal methodologies are needed to detect these important new beta-lactamases, a study was designed to evaluate the ability of a panel of various beta-lactam antibiotics tested alone and in combination with beta-lactamase inhibitors to discriminate between the production of extended-spectrum beta-lactamases, AmpC beta-lactamases, high levels of K1 beta-lactamase, and other beta-lactamases in 141 isolates of Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Enterobacter aerogenes, Citrobacter freundii, and Serratia marcescens possessing well-characterized beta-lactamases. The microdilution panels studied contained aztreonam, cefpodoxime, ceftazidime, cefotaxime, and ceftriaxone, with and without 1, 2, and 4 microg of clavulanate per ml or 8 microg of sulbactam per ml and cefoxitin and cefotetan with and without 8 microg of sulbactam per ml. The results indicated that a minimum panel of five tests would provide maximum separation of extended-spectrum beta-lactamase high AmpC, high K1, and other beta-lactamase production in Enterobacteriaceae. These included cefpodoxime, cefpodoxime plus 4 microg of clavulanate per ml, ceftazidime, ceftriaxone, and ceftriaxone plus 8 microg of sulbactam per ml. Ceftriaxone plus 2 microg of clavulanate per ml could be substituted for cefpodoxime plus 4 microg of clavulanate per ml without altering the accuracy of the tests. This study indicated that tests with key beta-lactam drugs, alone and in combination with beta-lactamase inhibitors, could provide a convenient approach to the detection of a variety of beta-lactamases in members of the family Enterobacteriaceae. PMID:10348759

  6. Characterization of qnrB-Like Genes in Citrobacter Species of the American Type Culture Collection

    PubMed Central

    Sabtcheva, Stefana; Mitsutake, Kotaro; Ishii, Yoshikazu; Tateda, Kazuhiro; Yamaguchi, Keizo; Kaku, Mitsuo

    2013-01-01

    Among five American Type Culture Collection (ATCC) Citrobacter strains, qnrB60 in Citrobacter freundii ATCC 6879, an isolate from the preantibiotic era, and qnrB61 in Citrobacter braakii ATCC 51113T, a type strain belonging to the C. freundii complex, were identified. Meanwhile, a truncated qnrB-like pseudogene was identified in C. freundii ATCC 8090T and ATCC 43864. No qnrB-like sequence was found in Citrobacter koseri ATCC 27028T. These findings underscore the close relationship between this species and qnrB. PMID:23529729

  7. Multidrug resistant citrobacter: an unusual cause of liver abscess

    PubMed Central

    Kumar, Prabhat; Ghosh, Soumik; Rath, Deepak; Gadpayle, A K

    2013-01-01

    Liver abscesses are infectious, space occupying lesions in the liver, the two most common abscesses being pyogenic and amoebic. A pyogenic liver abscess (PLA) is a rare condition with a reported incidence of 20 per 100 000 hospital admissions in the western population. The right lobe of the liver is the most common site in both types of liver abscess. Clinical presentation is elusive with complaints of fever, right upper quadrant pain in the abdomen and hepatomegaly with or without jaundice. The aetiology of PLA has changed in the past few decades and may be of biliary, portal, arterial or traumatic origin, but many cases are still cryptogenic. The most common organisms causing PLA are Gram-negative aerobes, especially Escherichia coli and Klebsiella pneumoniae. Studies have shown a high degree of antimicrobial susceptibility of isolated organism resulting in an overall lower mortality in PLA. Here, we present a case of PLA caused by multidrug-resistant Citrobacter freundii, which is an unusual organism to be isolated. PMID:23608848

  8. Citrobacter koseri meningitis: another freediving risk?

    PubMed

    Pollara, Gabriele; Savy, Lloyd; Cropley, Ian; Hopkins, Susan

    2011-01-01

    We present a rare case of meningitis caused by Citrobacter koseri in an immunocompetent adult who had recently been freediving. Middle ear pressure changes from this recreational activity, and the subsequent inflammatory response, are likely to have provided this environmental organism access to the central nervous system, and thus the ability to cause clinically significant infection. PMID:20933000

  9. Phylogeny and Comparative Genomics Unveil Independent Diversification Trajectories of qnrB and Genetic Platforms within Particular Citrobacter Species.

    PubMed

    Ribeiro, Teresa G; Novais, Ângela; Branquinho, Raquel; Machado, Elisabete; Peixe, Luísa

    2015-10-01

    To gain insights into the diversification trajectories of qnrB genes, a phylogenetic and comparative genomics analysis of these genes and their surrounding genetic sequences was performed. For this purpose, Citrobacter sp. isolates (n = 21) and genome or plasmid sequences (n = 56) available in public databases harboring complete or truncated qnrB genes were analyzed. Citrobacter species identification was performed by phylogenetic analysis of different genotypic markers. The clonal relatedness among isolates, the location of qnrB genes, and the genetic surroundings of qnrB genes were investigated by pulsed-field gel electrophoresis (PFGE), S1-/I-CeuI-PFGE and hybridization, and PCR mapping and sequencing, respectively. Identification of Citrobacter isolates was achieved using leuS and recN gene sequences, and isolates characterized in this study were diverse and harbored chromosomal qnrB genes. Phylogenetic analysis of all known qnrB genes revealed seven main clusters and two branches, with most of them included in two clusters. Specific platforms (comprising pspF and sapA and varying in synteny and/or identity of other genes and intergenic regions) were associated with each one of these qnrB clusters, and the reliable identification of all Citrobacter isolates revealed that each platform evolved in different recognizable (Citrobacter freundii, C. braakii, C. werkmanii, and C. pasteurii) and putatively new species. A high identity was observed between some of the platforms identified in the chromosome of Citrobacter spp. and in different plasmids of Enterobacteriaceae. Our data corroborate Citrobacter as the origin of qnrB and further suggest divergent evolution of closely related qnrB genes/platforms in particular Citrobacter spp., which were delineated using particular genotypic markers. PMID:26169406

  10. Phylogeny and Comparative Genomics Unveil Independent Diversification Trajectories of qnrB and Genetic Platforms within Particular Citrobacter Species

    PubMed Central

    Ribeiro, Teresa G.; Novais, Ângela; Branquinho, Raquel; Machado, Elisabete

    2015-01-01

    To gain insights into the diversification trajectories of qnrB genes, a phylogenetic and comparative genomics analysis of these genes and their surrounding genetic sequences was performed. For this purpose, Citrobacter sp. isolates (n = 21) and genome or plasmid sequences (n = 56) available in public databases harboring complete or truncated qnrB genes were analyzed. Citrobacter species identification was performed by phylogenetic analysis of different genotypic markers. The clonal relatedness among isolates, the location of qnrB genes, and the genetic surroundings of qnrB genes were investigated by pulsed-field gel electrophoresis (PFGE), S1-/I-CeuI-PFGE and hybridization, and PCR mapping and sequencing, respectively. Identification of Citrobacter isolates was achieved using leuS and recN gene sequences, and isolates characterized in this study were diverse and harbored chromosomal qnrB genes. Phylogenetic analysis of all known qnrB genes revealed seven main clusters and two branches, with most of them included in two clusters. Specific platforms (comprising pspF and sapA and varying in synteny and/or identity of other genes and intergenic regions) were associated with each one of these qnrB clusters, and the reliable identification of all Citrobacter isolates revealed that each platform evolved in different recognizable (Citrobacter freundii, C. braakii, C. werkmanii, and C. pasteurii) and putatively new species. A high identity was observed between some of the platforms identified in the chromosome of Citrobacter spp. and in different plasmids of Enterobacteriaceae. Our data corroborate Citrobacter as the origin of qnrB and further suggest divergent evolution of closely related qnrB genes/platforms in particular Citrobacter spp., which were delineated using particular genotypic markers. PMID:26169406

  11. Biochemical Identification of Citrobacter Species Defined by DNA Hybridization and Description of Citrobacter gillenii sp. nov. (Formerly Citrobacter Genomospecies 10) and Citrobacter murliniae sp. nov. (Formerly Citrobacter Genomospecies 11)

    PubMed Central

    Brenner, Don J.; O’Hara, Caroline M.; Grimont, Patrick A. D.; Janda, J. Michael; Falsen, Enevold; Aldova, Eva; Ageron, Elisabeth; Schindler, Jiri; Abbott, Sharon L.; Steigerwalt, Arnold G.

    1999-01-01

    Recent work describing six named species and two unnamed genomospecies within Citrobacter has enlarged the genus to 11 species. DNA relatedness and phenotypic tests were used to determine how well these species can be identified. One hundred thirty-six strains were identified to species level by DNA relatedness and then identified phenotypically in a blinded fashion. By using conventional tests, 119 of the 136 strains (88%) were correctly identified to species level. Three additional strains (2%) were identified as citrobacteria but were not identified to species level, and 14 strains (10%) were misidentified as other Citrobacter species. Carbon source utilization tests were used to identify 86 of the strains. Eighty-four strains (98%) were correctly identified, and two strains (2%) were misidentified as other Citrobacter species. Additional strains of Citrobacter genomospecies 10 and Citrobacter genomospecies 11 were identified, allowing these species to be formally named as Citrobacter gillenii sp. nov. and Citrobacter murliniae sp. nov., respectively. PMID:10405411

  12. Citrobacter Infection and Wnt signaling

    PubMed Central

    Umar, Shahid

    2012-01-01

    Gut flora generally contributes to a healthy environment while both commensal and pathogenic bacteria that influence the innate and adaptive immune responses, can cause acute and/or chronic mucosal inflammation. Citrobacter rodentium (C. rodentium) is a member of the family of enteropathogens that provide an excellent in vivo model to investigate the host-pathogen interactions in real-time. It is the etiologic agent for transmissible murine colonic hyperplasia (TMCH) while inflammation following C. rodentium infection is dependent upon the genetic background. Ongoing and completed studies in this model have so far established that Wnt/β-catenin, Notch and PI3K pathways regulate colonic crypt hyperplasia while epithelial-stromal cross-talk, mediated by MEK/ERK/NF-κB signaling, regulates inflammation and/or colitis in susceptible strains. The C. rodentium-induced hyperplastic state also increases the susceptibility to either mutagenic insult or in mice heterozygous for Apc gene. The ability to modulate the host response to C. rodentium infection therefore provides an opportunity to delineate the mechanisms that determine mucosal hyperplasia, intestinal inflammation, and/or neoplasia as disease outcomes. PMID:24358033

  13. [Susceptibilities of clinical bacterial isolates to antimicrobial agents. A study mainly focused on imipenem. Reported by the Research Group for Testing Imipenem Susceptibility on Clinical Isolates].

    PubMed

    Igari, J

    1990-11-01

    This study was conducted to investigate susceptibilities of clinical bacterial isolates to imipenem (IPM) and other antibacterial agents at 64 hospital laboratories throughout Japan from September to December of 1988. In this study, identification and susceptibility testing were carried out at each laboratory and the tests were performed according to the disk dilution method recommended by NCCLS in which susceptibilities are classified into "S", "MS", "I" and "R". IPM showed markedly high in vitro activities against Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus agalactiae, Enterococcus faecalis, Haemophilus influenzae, Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter aerogenes, Enterobacter cloacae, Serratia marcescens, Salmonella spp., Citrobacter freundii, Proteus mirabilis, Proteus vulgaris, Morganella morganii, Providencia rettgeri, Providencia stuartii, Acinetobacter calcoaceticus, Moraxella (Branhamella) catarrhalis, Alcaligenes spp., Peptococcus spp./Peptostreptococcus spp., Bacteroides fragilis and Bacteroides spp. IPM also had strong activities against Achromobacter xylosoxidans and Pseudomonas aeruginosa, but less active against Flavobacterium spp., E. faecium, coagulase-negative staphylococci (CNS), Staphylococcus aureus and Pseudomonas cepacia. In a study in which activities of IPM against bacteria isolated from different clinical sources were compared, differences in susceptibilities were observed among S. aureus, CNS, A. calcoaceticus and P. aeruginosa, but such differences were not apparent among S. pneumoniae, E. faecalis, H. influenzae, E. coli, K. pneumoniae, E. cloacae, C. freundii, S. marcescens or P. mirabilis. PMID:2287060

  14. [Susceptibilities of clinical bacterial isolates to antimicrobial agents. A study mainly focused on imipenem. Research Group for Testing Imipenem Susceptibility on Clinical Isolates].

    PubMed

    Igari, J

    1990-10-01

    We investigated susceptibilities of clinical bacterial isolates to imipenem (IPM) and other antimicrobial agents at 459 hospital laboratories throughout Japan from September to December of 1988. In this study, identification and susceptibility testing were performed at each hospital laboratory and the tests were carried out according to the 1-dilution or 3-dilution disc technique in which susceptibilities are classified into 4 grades: , ++, + and -. IPM had significantly high activity against Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus agalactiae, Neisseria gonorrhoeae, Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter aerogenes, Enterobacter cloacae, Salmonella spp., Citrobacter freundii, Proteus mirabilis, Providencia rettgeri, Acinetobacter calcoaceticus, Moraxella catarrhalis, Alcaligenes spp., Peptococcus spp./Peptostreptococcus spp., Bacteroides fragilis and Bacteroides spp. and should slightly lower activities on coagulase-negative staphylococci (CNS), Enterococcus faecalis, Haemophilus influenzae, Serratia marcescens, Proteus vulgaris, Providencia stuartii and Pseudomonas aeruginosa than on the above mentioned bacteria. In a comparative study on activities of IPM against bacteria from different clinical sources, no remarkable differences were found due to different sources among S. pneumoniae, E. faecalis, H. influenzae, E. coli, K. pneumoniae, E. cloacae, C. freundii, P. mirabilis or A. calcoaceticus, whereas slight differences were found among Staphylococcus aureus, CNS, S. marcescens and P. aeruginosa. PMID:2086814

  15. Molecular analysis of type 3 fimbrial genes from Escherichia coli, Klebsiella and Citrobacter species

    PubMed Central

    2010-01-01

    Background Catheter-associated urinary tract infection (CAUTI) is the most common nosocomial infection in the United States and is caused by a range of uropathogens. Biofilm formation by uropathogens that cause CAUTI is often mediated by cell surface structures such as fimbriae. In this study, we characterised the genes encoding type 3 fimbriae from CAUTI strains of Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Citrobacter koseri and Citrobacter freundii. Results Phylogenetic analysis of the type 3 fimbrial genes (mrkABCD) from 39 strains revealed they clustered into five distinct clades (A-E) ranging from one to twenty-three members. The majority of sequences grouped in clade A, which was represented by the mrk gene cluster from the genome sequenced K. pneumoniae MGH78578. The E. coli and K. pneumoniae mrkABCD gene sequences clustered together in two distinct clades, supporting previous evidence for the occurrence of inter-genera lateral gene transfer. All of the strains examined caused type 3 fimbriae mediated agglutination of tannic acid treated human erythrocytes despite sequence variation in the mrkD-encoding adhesin gene. Type 3 fimbriae deletion mutants were constructed in 13 representative strains and were used to demonstrate a direct role for type 3 fimbriae in biofilm formation. Conclusions The expression of functional type 3 fimbriae is common to many Gram-negative pathogens that cause CAUTI and is strongly associated with biofilm growth. Our data provides additional evidence for the spread of type 3 fimbrial genes by lateral gene transfer. Further work is now required to substantiate the clade structure reported here by examining more strains as well as other bacterial genera that make type 3 fimbriae and cause CAUTI. PMID:20576143

  16. [Yearly changes in antibacterial activities of cefozopran against various clinical isolates between 1996 and 2001--II. Gram-negative bacteria].

    PubMed

    Suzuki, Yumiko; Nishinari, Chisato; Endo, Harumi; Hiramatsu, Nobuyoshi; Akiyama, Kazumitsu; Koyama, Tsuneo

    2003-08-01

    The in vitro antibacterial activities of cefozopran (CZOP), an agent of cephems, against various clinical isolates obtained between 1996 and 2001 were yearly evaluated and compared with those of other cephems, oxacephems and carbapenems. A total of 3,245 strains in 32 species of Gram-negative bacteria were isolated from the clinical materials annually collected from January to December, and consisted of Moraxella subgenus Branhamella catarrhalis, Escherichia coli, Citrobacter freundii, Citrobacter koseri, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter aerogenes, Enterobacter cloacae, Serratia marcescens, Proteus mirabillis, Proteus vulgaris, Morganella morganii, Providencia spp. (P. alcalifaciens, P. rettgeri, P. stuartii), Pseudomonas aeruginosa, Pseudomonas putida, Burkholderia cepacia, Stenotrophomonas maltophilia, Haemophilus influenzae, Acinetobactor baumannii, Acinetobactor lwoffii, Bacteroides fragilis group (B. fragilis, B. vulgatus, B. distasonis, B. ovatus, B. thetaiotaomicron), and Prevotella spp. (P. melaninogenica, P. intermedia, P. bivia, P. oralis, P. denticola). CZOP possessed stable antibacterial activities against M. (B.) catarrhalis, E. coli, C. freundii, C. koseri, K. pneumoniae, K. oxytoca, E. aerogenes, E. cloacae, S. marcescens, P. mirabilis, P. vulgaris, M. morganii, Providencia spp., P. aeruginosa, and A. lwoffii throughout 6 years. The MIC90 of CZOP against those strains were consistent with those obtained from the studies performed until the new drug application approval. On the other hand, the MIC90 of CZOP against H. influenzae yearly obviously increased with approximately 64-time difference during the study period. The MIC90 of cefpirome, cefepime, and flomoxef against H. influenzae also yearly tended to rise. The present results demonstrated that CZOP had maintained the antibacterial activity against almost Gram-negative strains tested. However, the decrease in antibacterial activities of CZOP against B. cepacia, and H

  17. Novel Class A β-Lactamase Sed-1 from Citrobacter sedlakii: Genetic Diversity of β-Lactamases within the Citrobacter Genus

    PubMed Central

    Petrella, Stephanie; Clermont, Dominique; Casin, Isabelle; Jarlier, Vincent; Sougakoff, Wladimir

    2001-01-01

    Citrobacter sedlakii 2596, a clinical strain resistant to aminopenicillins, carboxypenicillins, and early cephalosporins such as cephalothin, but remaining susceptible to acylureidopenicillins, carbapenems, and later cephalosporins such as cefotaxime, was isolated from the bile of a patient treated with β-lactam and quinolone antibiotics. The isolate produced an inducible class A β-lactamase of pI 8.6, named Sed-1, which was purified. Characterized by a molecular mass of 30 kDa, Sed-1 preferentially hydrolyzed benzylpenicillin, cephalothin, and cloxacillin. The corresponding gene, blaSed-1, was cloned and sequenced. Its deduced amino acid sequence shared more than 60% identity with the chromosome-encoded β-lactamases from Citrobacter koseri (formerly C. diversus) (84%), Klebsiella oxytoca (74%), Serratia fonticola (67%), and Proteus vulgaris (63%) and 71% identity with the plasmid-mediated enzyme MEN-1. A gene coding for a LysR transcriptional regulator was found upstream from blaSed-1. This regulator, named SedR, displayed 90% identity with the AmpR sequence of the chromosomal β-lactamase from C. koseri and 63 and 50% identity with the AmpR sequences of P. vulgaris and Enterobacter cloacae, respectively. By using DNA-DNA hybridization, a blaSed-1-like gene was identified in two reference strains, C. sedlakii (CIP-105037) and Citrobacter rodentium (CIP-104675), but not in the 18 strains of C. koseri studied. Two DNA fragments were amplified and sequenced from the reference strains of C. sedlakii CIP-105037 and C. rodentium CIP-104675 using two primers specific for blaSed-1. They shared 98 and 80% identity with blaSed-1, respectively, confirming the diversity of the chromosomally encoded class A β-lactamases found in Citrobacter. PMID:11451687

  18. Citrobacter rodentium mouse model of bacterial infection.

    PubMed

    Crepin, Valerie F; Collins, James W; Habibzay, Maryam; Frankel, Gad

    2016-10-01

    Infection of mice with Citrobacter rodentium is a robust model to study bacterial pathogenesis, mucosal immunology, the health benefits of probiotics and the role of the microbiota during infection. C. rodentium was first isolated by Barthold from an outbreak of mouse diarrhea in Yale University in 1972 and was 'rediscovered' by Falkow and Schauer in 1993. Since then the use of the model has proliferated, and it is now the gold standard for studying virulence of the closely related human pathogens enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC, respectively). Here we provide a detailed protocol for various applications of the model, including bacterial growth, site-directed mutagenesis, mouse inoculation (from cultured cells and after cohabitation), monitoring of bacterial colonization, tissue extraction and analysis, immune responses, probiotic treatment and microbiota analysis. The main protocol, from mouse infection to clearance and analysis of tissues and host responses, takes ∼5 weeks to complete. PMID:27606775

  19. Evaluation of the 10th External Quality Assessment Scheme results in clinical microbiology laboratories in Tehran and districts.

    PubMed

    Abbassi, M; Rahbar, M; Hekmat Yazdi, S; Rashed Marandi, F; Sabourian, R; Saremi, M

    2006-01-01

    We evaluated the performance of microbiology laboratories in the 10th run of the external quality assessment scheme (EQAS) in Tehran and districts. Each laboratory was sent 2 species of bacteria for identification. Of the 487 laboratories that participated, 437 returned their findings. While 77.0% and 69.9% correctly identified Staphylococcus saprophyticus and Citrobacter freundii respectively, only 29.8% correctly identified Acinetobacter baumanii, 25.3% identified Enterococcus faecalis and 35.6% identified Enterobacter agglomerans. However 78.7% and 79.5% of the laboratories reported correct -results for susceptibility testing for S. saprophyticus and C. freundii respectively. PMID:17037699

  20. Phenotypic detection and molecular characterization of beta-lactamase genes among Citrobacter species in a tertiary care hospital

    PubMed Central

    Praharaj, Ashok Kumar; Khajuria, Atul; Kumar, Mahadevan; Grover, Naveen

    2016-01-01

    Objective: To examine the distribution, emergence, and spread of genes encoding beta-lactamase resistance in Citrobacter species isolated from hospitalized patients in a tertiary care hospital. Methods: A prospective study was conducted in a 1000-bed tertiary care center in Pune, India from October 2010 to October 2013. A total of 221 Citrobacter spp. isolates were recovered from clinical specimens from different patients (one isolate per patient) admitted to the surgical ward, medical ward and medical and surgical Intensive Care Units. Polymerase chain reaction (PCR) assays and sequencing were used to determine the presence of beta-lactamase encoding genes. Conjugation experiments were performed to determine their transferability. Isolate relatedness were determined by repetitive element based-PCR, enterobacterial repetitive intergenic consensus-PCR and randomly amplified polymorphic DNA. Results: Among 221 tested isolates of Citrobacter spp. recovered from various clinical specimens, 179 (80.9%) isolates showed minimum inhibitory concentration (MIC) >4 μg/ml against meropenem and imipenem. One hundred and forty-five isolates with increased MICs value against carbapenems were further processed for molecular characterization of beta-lactamase genes. Susceptibility profiling of the isolates indicated that 100% retained susceptibility to colistin. Conjugation experiments indicated that blaNDM-1 was transferable via a plasmid. Conclusion: The ease of NDM-1 plasmid transmissibility may help their dissemination among the Citrobacter species as well as to others in Enterobacteriaceae. Early detection, antimicrobial stewardship and adequate infection control measures will help in limiting the spread of these organisms. PMID:26952135

  1. [Antimicrobial activity of cefodizime against clinical isolates].

    PubMed

    Suzuki, Y; Ishihara, R; Ishii, Y; Nakazawa, A; Deguchi, K; Matsumoto, Y; Nishinari, C; Nakane, Y; Fukumoto, T

    1996-10-01

    In order to evaluate antimicrobial activity of cefodizime (CDZM), minimum inhibitory concentrations (MICs) of CDZM and control drugs were determined against clinical isolates collected from nation-wide medical institutions and in our laboratory from September to December of 1992 and from September to December of 1995. The results are summarized as follows: 1. Bacterial species with no or few strains resistant to CDZM included Streptococcus pyogenes, Haemophilus influenzae, Citrobacter koseri, Proteus mirabilis and Neisseria gonorrhoeae. The range of MIC values of CDZM against Klebsiella pneumoniae was spread. Other strains, Streptococcus pneumoniae, Moraxella subgenus Branhamella catarrhalis, Escherichia coli, Citrobacter freundii, Enterobacter spp., Serratia marcescens, Proteus vulgaris, Morganella morganii, Providencia spp., Peptostreptococcus spp. and Bacteroides fragilis group were resistant to cephems including CDZM. 2. The MIC90's of CDZM were 0.05 approximately 3.13 micrograms/ml against Streptococcus spp., H. influenzae, M. (B.) catarrhalis, E. coli, Klebsiella spp., P. mirabilis, N. gonorrhoeae and Peptostreptococcus spp. obtained in 1995 that were frequently found in daily treatment of infections. It appears that the effectiveness of CDZM was still relatively high against community-acquired infections. 3. Among H. influenzae isolates included imipenem (IPM)-resistant and norfloxacin (NFLX)-resistant strains. The MIC-range of CDZM against strains collected in 1995 including IPM-resistant and NFLX-resistant strains was < or = 0.025 approximately 0.1 microgram/ml, and MIC90 against these strains was 0.05 microgram/ml. CDZM showed strong antimicrobial activities against H. influenzae strains resistant to carbapenems and new-quinolones. PMID:8986558

  2. 21 CFR 866.3125 - Citrobacter spp. serological reagents.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Citrobacter spp. serological reagents. 866.3125 Section 866.3125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3125...

  3. 21 CFR 866.3125 - Citrobacter spp. serological reagents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Citrobacter spp. serological reagents. 866.3125 Section 866.3125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3125...

  4. 21 CFR 866.3125 - Citrobacter spp. serological reagents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Citrobacter spp. serological reagents. 866.3125 Section 866.3125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3125...

  5. 21 CFR 866.3125 - Citrobacter spp. serological reagents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Citrobacter spp. serological reagents. 866.3125 Section 866.3125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3125...

  6. 21 CFR 866.3125 - Citrobacter spp. serological reagents.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Citrobacter spp. serological reagents. 866.3125 Section 866.3125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3125...

  7. Citrobacter amalonaticus human urinary tract infections, Marseille, France

    PubMed Central

    Garcia, V.; Abat, C.; Moal, V.; Rolain, J.-M.

    2016-01-01

    Citrobacter amalonaticus is a bacterium that has rarely been reported as a human pathogen. Here we report four cases of C. amalonaticus infections occurring in patients hospitalized in Marseille, France, and review all cases described in the published literature. PMID:26958347

  8. Late-Onset Citrobacter koseri Endophthalmitis with Suture Exposure after Secondary Intraocular Lens Implantation

    PubMed Central

    Kang, Hae Min

    2011-01-01

    A 54-year-old male patient was seen in clinic for ocular pain and decreased vision in the right eye with duration of two days. He underwent a cataract operation for his right eye 12 years ago, then a sclera-fixated secondary intraocular implantation and pars plana vitrectomy three years ago due to intraocular lens dislocation. At the initial visit, his visual acuity was restricted to the perception of hand motion. An edematous cornea, cells, flare with hypopyon, and exposed suture material at were observed at the six o'clock direction by slit lamp. Vitreous opacity was noted from B-scan ultrasonography. The patient was diagnosed with late-onset endophthalmitis and an intravitreal cocktail injection was done. On the next day, the hypopyon was aggravated, and therefore a pars plana vitrectomy was performed. A vitreous culture tested positive for Citrobacter koseri. After 12 weeks, the best corrected visual acuity of the right eye improved to 0.7 and a fundus examination revealed a relatively normal optic disc and retinal vasculature. We herein report the first case of endophthalmitis caused by Citrobacter koseri in Korea. Exposed suture material was suspected as the source of infection in this case and prompt surgical intervention resulted in a relatively good visual outcome. PMID:21860579

  9. Late-onset Citrobacter koseri endophthalmitis with suture exposure after secondary intraocular lens implantation.

    PubMed

    Kang, Hae Min; Chung, Eun Jee

    2011-08-01

    A 54-year-old male patient was seen in clinic for ocular pain and decreased vision in the right eye with duration of two days. He underwent a cataract operation for his right eye 12 years ago, then a sclera-fixated secondary intraocular implantation and pars plana vitrectomy three years ago due to intraocular lens dislocation. At the initial visit, his visual acuity was restricted to the perception of hand motion. An edematous cornea, cells, flare with hypopyon, and exposed suture material at were observed at the six o'clock direction by slit lamp. Vitreous opacity was noted from B-scan ultrasonography. The patient was diagnosed with late-onset endophthalmitis and an intravitreal cocktail injection was done. On the next day, the hypopyon was aggravated, and therefore a pars plana vitrectomy was performed. A vitreous culture tested positive for Citrobacter koseri. After 12 weeks, the best corrected visual acuity of the right eye improved to 0.7 and a fundus examination revealed a relatively normal optic disc and retinal vasculature. We herein report the first case of endophthalmitis caused by Citrobacter koseri in Korea. Exposed suture material was suspected as the source of infection in this case and prompt surgical intervention resulted in a relatively good visual outcome. PMID:21860579

  10. Citrobacter koseri: an unusual cause of pyogenic liver abscess

    PubMed Central

    Gupta, Monica; Sharma, Alka; Singh, Ram; Lehl, S S

    2013-01-01

    Liver abscess is a common pathology in the Indian subcontinent and usually results from amoebic or bacterial infection. Pyogenic abscesses usually occur in those with underlying predisposing factors like intra-abdominal infections, biliary infections or comorbidities like malignancy, immunosuppression, diabetes mellitus and previous biliary surgery or interventional endoscopy. Citrobacter is an unusual cause of pyogenic liver abscess and may occur in the setting of underlying comorbidities. We report a 56-year-old man with diabetes (operated for periampullary carcinoma 20 years ago), who presented with a history of fever for 1 week and on evaluation was found to have Citrobacter koseri-related hepatic abscess. The patient was managed with parenteral antibiotics, repeated aspiration of liver abscess and pigtail drainage. PMID:23505286

  11. Citrobacter koseri Brain Abscess in the Neonatal Rat: Survival and Replication within Human and Rat Macrophages

    PubMed Central

    Townsend, Stacy M.; Pollack, Harvey A.; Gonzalez-Gomez, Ignacio; Shimada, Hiroyuki; Badger, Julie L.

    2003-01-01

    A unique feature of Citrobacter koseri is the extremely high propensity to initiate brain abscesses during neonatal meningitis. Previous clinical reports and studies on infant rats have documented many Citrobacter-filled macrophages within the ventricles and brain abscesses. It has been hypothesized that intracellular survival and replication within macrophages may be a mechanism by which C. koseri subverts the host response and elicits chronic infection, resulting in brain abscess formation. In this study, we showed that C. koseri causes meningitis and brain abscesses in the neonatal rat model, and we utilized histology and magnetic resonance imaging technology to visualize brain abscess formation. Histology and electron microscopy (EM) revealed that macrophages (and not fibroblasts, astrocytes, oligodendrocytes, or neurons) were the primary target for long-term C. koseri infection. To better understand C. koseri pathogenesis, we have characterized the interactions of C. koseri with human macrophages. We found that C. koseri survives and replicates within macrophages in vitro and that uptake of C. koseri increases in the presence of human pooled serum in a dose-dependent manner. EM studies lend support to the hypothesis that C. koseri uses morphologically different methods of uptake to enter macrophages. FcγRI blocking experiments show that this receptor primarily facilitates the entry of opsonized C. koseri into macrophages. Further, confocal fluorescence microscopy demonstrates that C. koseri survives phagolysosomal fusion and that more than 90% of intracellular C. koseri organisms are colocalized within phagolysosomes. The ability of C. koseri to survive phagolysosome fusion and replicate within macrophages may contribute to the establishment of chronic central nervous system infection including brain abscesses.   PMID:14500508

  12. Isolation and characterization of diverse antimicrobial lipopeptides produced by Citrobacter and Enterobacter

    PubMed Central

    2013-01-01

    Background Increasing multidrug-resistance in bacteria resulted in a greater need to find alternative antimicrobial substances that can be used for clinical applications or preservation of food and dairy products. Research on antimicrobial peptides including lipopeptides exhibiting both narrow and broad spectrum inhibition activities is increasing in the recent past. Therefore, the present study was aimed at isolation and characterization of antimicrobial lipopeptide producing bacterial strains from fecal contaminated soil sample. Results The phenotypic and 16S rRNA gene sequence analysis of all isolates identified them as different species of Gram-negative genera Citrobacter and Enterobacter. They exhibited common phenotypic traits like citrate utilization, oxidase negative and facultative anaerobic growth. The HPLC analysis of solvent extracts obtained from cell free fermented broth revealed the presence of multiple antimicrobial lipopeptides. The comprehensive mass spectral analysis (MALDI-TOF MS and GC-MS) of HPLC purified fractions of different isolates revealed that the lipopeptides varied in their molecular weight between (m/z) 607.21 to 1536.16 Da. Isomers of mass ion m/z 984/985 Da was produced by all strains. The 1495 Da lipopeptides produced by strains S-3 and S-11 were fengycin analogues and most active against all strains. While amino acid analysis of lipopeptides suggested most of them had similar composition as in iturins, fengycins, kurstakins and surfactins, differences in their β-hydroxy fatty acid content proposed them to be isoforms of these lipopeptides. Conclusion Although antimicrobial producing strains can be used as biocontrol agents in food preservation, strains with ability to produce multiple antimicrobial lipopeptides have potential applications in biotechnology sectors such as pharmaceutical and cosmetic industry. This is the first report on antibacterial lipopeptides production by strains of Citrobacter and Enterobacter. PMID

  13. A generalized transducing phage for the murine pathogen Citrobacter rodentium

    PubMed Central

    Petty, Nicola K.; Toribio, Ana L.; Goulding, David; Foulds, Ian; Thomson, Nicholas; Dougan, Gordon; Salmond, George P. C.

    2008-01-01

    A virulent phage (φCR1) capable of generalized transduction in Citrobacter rodentium was isolated from the environment and characterized. C. rodentium is a natural pathogen of mice, causing transmissible murine colonic hyperplasia. Sequencing of its genome has recently been completed and will soon be fully annotated and published. C. rodentium is an important model organism for infections caused by the human pathogens enteropathogenic and enterohaemorrhagic Escherichia coli (EPEC and EHEC). φCR1 uses a lipopolysaccharide receptor, has a genome size of approximately 300 kb, and is able to transduce a variety of markers. φCR1 is the first reported transducing phage for C. rodentium and will be a useful tool for functional genomic analysis of this important natural murine pathogen. PMID:17768241

  14. NDM-1 (New Delhi metallo beta lactamase-1) producing Gram-negative bacilli: Emergence & clinical implications

    PubMed Central

    Fomda, Bashir Ahmad; Khan, Asiya; Zahoor, Danish

    2014-01-01

    Backgound & objectives: Resistance to carbapenems in Gram-negative bacteria conferred by NDM-1 is a global health problem. We investigated the occurrence of NDM-1 in clinical isolates of Gram-negative bacilli in a tertiary care hospital in Kashmir valley, India. Methods: Gram-negative bacilli from different clinical isolates were included in the study. Antimicrobial susceptibility was performed by Kirby Bauer disk diffusion method and interpreted using Clinical Laboratory Standards Institute (CLSI) guidelines. Isolates resistant to carbapenems were subjected to different phenotypic test such as modified Hodge test (MHT), boronic acid and oxacillin based MHT (BA-MHT and OXA-MHT), combined disk test and minimum inhibitory concentration (MIC) with imipenem and imipenem -EDTA for determination of class B metallo enzymes. Presence of blaNDM-1 gene was established by PCR and confirmed by sequencing. Results: Of the total 1625 Gram-negative isolates received, 100 were resistant to imipenem. Of the 100 isolates, 55 (55%) were positive by modified Hodge test indicating carbapenemase production. Of the 100 isolates tested by MHT, BA-MHT and OXA-MHT, 29 (29%) isolates belonged to Class A and 15 (15%) to Class B, while 56 (56%) isolates were negative. Of the 15 class B metallo beta lactamase producers, nine carried the blaNDM-1 gene. NDM-1 was found among Escherichia coli (2 isolates), Klebsiella pneumoniae (2 isolates), Citrobacter freundii (3 isolates), Acinetobacter spp (1 isolate), and one isolate of Pseudomonas aeruginosa. Isolates were resistant to all antibiotic tested except polymyxin B and tigecycline. Interpretation & conclusions: Our study showed the presence of clinical isolates expressing NDM-1 in Srinagar, Jammu & Kashmir, India. These isolates harbour plasmid mediated multiple drug resistant determinants and can disseminate easily across several unrelated genera. To halt their spread, early identification of these isolates is mandatory. PMID:25579151

  15. Proteomic Analysis on Acetate Metabolism in Citrobacter sp. BL-4

    PubMed Central

    Kim, Young-Man; Lee, Sung-Eun; Park, Byeoung-Soo; Son, Mi-Kyung; Jung, Young-Mi; Yang, Seung-Ok; Choi, Hyung-Kyoon; Hur, Sung-Ho; Yum, Jong Hwa

    2012-01-01

    Mass production of glucosamine (GlcN) using microbial cells is a worthy approach to increase added values and keep safety problems in GlcN production process. Prior to set up a microbial cellular platform, this study was to assess acetate metabolism in Citrobacter sp. BL-4 (BL-4) which has produced a polyglucosamine PGB-2. The LC-MS analysis was conducted after protein separation on the 1D-PAGE to accomplish the purpose of this study. 280 proteins were totally identified and 188 proteins were separated as acetate-related proteins in BL-4. Acetate was converted to acetyl-CoA by acetyl-CoA synthetase up-regulated in the acetate medium. The glyoxylate bypass in the acetate medium was up-regulated with over-expression of isocitrate lyases and 2D-PAGE confirmed this differential expression. Using 1H-NMR analysis, the product of isocitrate lyases, succinate, increased about 15 times in the acetate medium. During acetate metabolism proteins involved in the lipid metabolism and hexosamine biosynthesis were over-expressed in the acetate medium, while proteins involved in TCA cycle, pentose phosphate cycle and purine metabolism were down-regulated. Taken together, the results from the proteomic analysis can be applied to improve GlcN production and to develop metabolic engineering in BL-4. PMID:22211106

  16. Fermented Dairy Products Modulate Citrobacter rodentium–Induced Colonic Hyperplasia

    PubMed Central

    Collins, James W.; Chervaux, Christian; Raymond, Benoit; Derrien, Muriel; Brazeilles, Rémi; Kosta, Artemis; Chambaud, Isabelle; Crepin, Valerie F.; Frankel, Gad

    2014-01-01

    We evaluated the protective effects of fermented dairy products (FDPs) in an infection model, using the mouse pathogen Citrobacter rodentium (CR). Treatment of mice with FDP formulas A, B, and C or a control product did not affect CR colonization, organ specificity, or attaching and effacing lesion formation. Fermented dairy product A (FDP-A), but neither the supernatant from FDP-A nor β-irradiated (IR) FDP-A, caused a significant reduction in colonic crypt hyperplasia and CR-associated pathology. Profiling the gut microbiota revealed that IR-FDP-A promoted higher levels of phylotypes belonging to Alcaligenaceae and a decrease in Lachnospiraceae (Ruminococcus) during CR infection. Conversely, FDP-A prevented a decrease in Ruminococcus and increased Turicibacteraceae (Turicibacter). Importantly, loss of Ruminococcus and Turicibacter has been associated with susceptibility to dextran sodium sulfate–induced colitis. Our results demonstrate that viable bacteria in FDP-A reduced CR-induced colonic crypt hyperplasia and prevented the loss of key bacterial genera that may contribute to disease pathology. PMID:24706936

  17. Type 3 Muscarinic Receptors Contribute to Clearance of Citrobacter rodentium

    PubMed Central

    McLean, Leon P.; Smith, Allen; Cheung, Lumei; Sun, Rex; Grinchuk, Viktoriya; Vanuytsel, Tim; Desai, Neemesh; Urban, Joseph F.; Zhao, Aiping; Raufman, Jean-Pierre; Shea-Donohue, Terez

    2016-01-01

    Background The role of muscarinic receptors in mucosal homeostasis, response to enteric pathogens, and modulation of immune cell function is undefined. Methods The contribution of type 3 muscarinic receptors (M3R) to mucosal homeostasis within the colon and host defense against Citrobacter rodentium was determined in uninfected and C. rodentium-infected WT and M3R-deficient (Chrm3−/−) mice. In addition, WT and Chrm3−/− bone marrow-derived macrophages (BMDM) were studied to determine the ability of M3R to modulate macrophage phenotype and function. Results In Chrm3−/− mice clearance of C. rodentium was delayed despite an amplified TH1/TH17 response. Delayed clearance of C. rodentium from Chrm3−/− mice was associated with prolonged adherence of bacteria to colonic mucosa, decreased goblet cell number, and decreased mucin 2 gene expression. Treatment of BMDM with bethanechol, a muscarinic-selective agonist, induced a classically activated macrophage phenotype, which was dependent on M3R expression. Chrm3−/− BMDM retained their ability to attain a classically activated macrophage phenotype when treated with the TH1 cytokine IFN-γ. Conclusions In Chrm3−/− mice mucin production is attenuated and is associated with prolonged adherence of C. rodentium to colonic mucosa. The immune response, as characterized by production of TH1/TH17 cytokines, in C. rodentium-infected Chrm3−/− mice is intact. In addition, M3R activity promotes the development of classically activated macrophages. Our data establish a role for M3R in host defense against C. rodentium through effects on goblet cell mucus production and in the modulation of macrophage phenotype and function. PMID:25985244

  18. In vitro antibacterial potency of Butea monosperma Lam. against 12 clinically isolated multidrug resistant bacteria

    PubMed Central

    Sahu, Mahesh Chandra; Padhy, Rabindra Nath

    2013-01-01

    Objective To investigate the antibacterial activity, using cold and hot extraction procedures with five solvents, petroleum ether, acetone, ethanol, methanol and water to validate medicinal uses of Butea monosperma Lam (B. monosperma) in controlling infections; and to qualitatively estimate phytochemical constituents of leaf-extracts of the plant. Methods The antibacterial activity of leaf-extracts was evaluated by the agar-well diffusion method against clinically isolated 12 Gram-positive and -negative multidrug resistant (MDR) pathogenic bacteria in vitro. Values of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of leaf-extracts against each bacterium were obtained in a 96-well micro-titre plate, by broth dilution micro-titre plate technique. Results The presence of tannins, flavonoids, starch, glycosides and carbohydrates in different leaf extracts was established. Pathogenic bacteria used were, Acinetobacter sp., Chromobacterium violaceum, Citrobacter freundii, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, Shigella sp., Enterococcus sp., Staphylococcus aureus (S. aureus), methicillin resistant S. aureus and vancomycin resistant S. aureus, along with standard bacterial strains. These MDR bacteria had been recorded to have significant inhibitions by leaf extracts, obtained by cold and hot extraction procedures with five solvents. In addition, the hot aqueous extract against Enterococcus sp. had the highest inhibition zone-size (21 mm). Ciprofloxacin 30 µg/disc was the positive/reference control and the diluting solvent, 10% dimethyl sulphoxide was the negative control. Recorded MIC values of different extracts ranged between 0.23 and 13.30 mg/mL, and MBC values were 0.52 to 30.00 mg/mL, for these bacteria. Conclusions Leaf-extracts with hot water and ethanol had shown significant antibacterial activity against all bacteria. B. monosperma leaf-extract could be used in treating infectious

  19. Rac2-deficiency leads to exacerbated and protracted colitis in response to Citrobacter rodentium infection.

    PubMed

    Fattouh, Ramzi; Guo, Cong-Hui; Lam, Grace Y; Gareau, Melanie G; Ngan, Bo-Yee; Glogauer, Michael; Muise, Aleixo M; Brumell, John H

    2013-01-01

    Recent genetic-based studies have implicated a number of immune-related genes in the pathogenesis of inflammatory bowel disease (IBD). Our recent genetic studies showed that RAC2 is associated with human IBD; however, its role in disease pathogenesis is unclear. Given Rac2's importance in various fundamental immune cell processes, we investigated whether a defect in Rac2 may impair host immune responses in the intestine and promote disease in the context of an infection-based (Citrobacter rodentium) model of colitis. In response to infection, Rac2(-/-) mice showed i) worsened clinical symptoms (days 13-18), ii) increased crypt hyperplasia at days 11 and 22 (a time when crypt hyperplasia was largely resolved in wild-type mice; WT), and iii) marked mononuclear cell infiltration characterized by higher numbers of T (CD3(+)) cells (day 22), compared to WT-infected mice. Moreover, splenocytes harvested from infected Rac2(-/-) mice and stimulated in vitro with C. rodentium lysate produced considerably higher levels of interferon-γ and interleukin-17A. The augmented responses observed in Rac2(-/-) mice did not appear to stem from Rac2's role in NADPH oxidase-driven reactive oxygen species production as no differences in crypt hyperplasia, nor inflammation, were observed in infected NOX2(-/-) mice compared to WT. Collectively, our findings demonstrate that Rac2(-/-) mice develop more severe disease when subjected to a C. rodentium-induced model of infectious colitis, and suggest that impaired Rac2 function may promote the development of IBD in humans. PMID:23613889

  20. Rac2-Deficiency Leads to Exacerbated and Protracted Colitis in Response to Citrobacter rodentium Infection

    PubMed Central

    Fattouh, Ramzi; Guo, Cong-Hui; Lam, Grace Y.; Gareau, Melanie G.; Ngan, Bo-Yee; Glogauer, Michael

    2013-01-01

    Recent genetic-based studies have implicated a number of immune-related genes in the pathogenesis of inflammatory bowel disease (IBD). Our recent genetic studies showed that RAC2 is associated with human IBD; however, its role in disease pathogenesis is unclear. Given Rac2’s importance in various fundamental immune cell processes, we investigated whether a defect in Rac2 may impair host immune responses in the intestine and promote disease in the context of an infection-based (Citrobacter rodentium) model of colitis. In response to infection, Rac2−/− mice showed i) worsened clinical symptoms (days 13–18), ii) increased crypt hyperplasia at days 11 and 22 (a time when crypt hyperplasia was largely resolved in wild-type mice; WT), and iii) marked mononuclear cell infiltration characterized by higher numbers of T (CD3+) cells (day 22), compared to WT-infected mice. Moreover, splenocytes harvested from infected Rac2−/− mice and stimulated in vitro with C. rodentium lysate produced considerably higher levels of interferon-γ and interleukin-17A. The augmented responses observed in Rac2−/− mice did not appear to stem from Rac2’s role in NADPH oxidase-driven reactive oxygen species production as no differences in crypt hyperplasia, nor inflammation, were observed in infected NOX2−/− mice compared to WT. Collectively, our findings demonstrate that Rac2−/− mice develop more severe disease when subjected to a C. rodentium-induced model of infectious colitis, and suggest that impaired Rac2 function may promote the development of IBD in humans. PMID:23613889

  1. Long-term selenium deficiency increases the pathogenicity of a Citrobacter rodentium infection in mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrobacter rodentium is a mouse pathogen that causes infectious colitis and shares characteristics with human enteropathogenic (EPEC) and enterohemorrhagic (EHEC) Escherichia coli, including the ability to cause attaching and effacing lesions in the colon, and serves as a useful model to study the ...

  2. Understanding the host-adapted state of Citrobacter rodentium by transcriptomic analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrobacter rodentium (Cr) is a mouse pathogen that mimics many aspects of enteropathogenic Escherichia coli infections including producing attaching and effacing (A/E) lesions. Host-adapted (HA) Cr cells that are shed at the peak of infection have been reported to be hyperinfective. The exact mecha...

  3. Hypervirulent- host-associated Citrobacter rodentium cells have poor acid tolerance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enhanced virulence or infectivity after passage through a mammalian host has been reported for a number of enteric food-borne pathogens. Citrobacter rodentium is a mouse pathogen that mimics many aspects of enterohemorrhagic E. coli infection of humans and serves as a useful model for studying viru...

  4. [Post-marketing surveillance of antibacterial activities of cefozopran against various clinical isolates--II. Gram-negative bacteria].

    PubMed

    Igari, Jun; Oguri, Toyoko; Hiramatsu, Nobuyoshi; Akiyama, Kazumitsu; Koyama, Tsuneo

    2003-10-01

    As a post-marketing surveillance, the in vitro antibacterial activities of cefozopran (CZOP), an agent of cephems, against various clinical isolates were yearly evaluated and compared with those of other cephems, oxacephems, carbapenems, monobactams, and penicillins. Changes in CZOP susceptibility among bacteria were also evaluated with the bacterial resistance ratio calculated from the breakpoint MIC. Twenty-five species (4,154 strains) of Gram-negative bacteria were isolated from the clinical materials annually collected from 1996 to 2001, and consisted of Moraxella (Branhamella) catarrhalis, Haemophilus influenzae, Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Enterobacter aerogenes, Serratia marcescens, Serratia liquefaciens, Citrobacter freundii, Citrobacter koseri, Proteus mirabilis, Proteus vulgaris, Morganella morganii, Providencia spp., Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas putida, Acinetobacter baumannii, Acinetobacter Iwoffii, Burkholderia cepacia, Stenotrophomonas maltophilia, Bacteroides fragilis group, and Prevotella/Porphyromonas. CZOP preserved its antibacterial activity against M. (B.) catarrhalis (MIC90: 4 micrograms/mL) and showed comparable activity to carbapenems against H. influenzae (MIC90: 1 microgram/mL). The antibacterial activity of CZOP against E. coli was preferable (MIC90: 0.125 microgram/mL) and comparable to those of cefpirome (CPR), cefepime (CFPM), and imipenem (IPM). The MIC90 of CZOP against K. pneumoniae and K. oxytoca was 1 and 0.25 microgram/mL, respectively. The MIC90 of CZOP against E. cloacae increased during 6 years (32 to 128 micrograms/mL). The antibacterial activity of CZOP against E. aerogenes was preferable (MIC90: 1 microgram/mL). The antibacterial activities of CZOP against S. marcescens and S. liquefaciens were relatively potent (MIC90: 0.5 and 0.25 microgram/mL) and comparable to those of CPR, CFPM, and carumonam. CZOP preserved comparable antibacterial

  5. Development of a real-time PCR assay for quantification of Citrobacter rodentium.

    PubMed

    Sagaidak, Sofia; Taibi, Amel; Wen, Bijun; Comelli, Elena M

    2016-07-01

    Molecular tools to quantify Citrobacter rodentium are not available. We developed a quantitative PCR assay targeting the espB gene. This assay is specific, has a linearity range of about 6.7×10(1) to 6.7×10(6)cells/PCR reaction (92% efficiency) and a detection limit of about 10(4)cells/g wet feces. PMID:27196638

  6. Metallo-beta-lactamase-producing gram-negative bacilli: laboratory-based surveillance in cooperation with 13 clinical laboratories in the Kinki region of Japan.

    PubMed

    Nishio, Hisaaki; Komatsu, Masaru; Shibata, Naohiro; Shimakawa, Kouichi; Sueyoshi, Noriyuki; Ura, Toshiro; Satoh, Kaori; Toyokawa, Masahiro; Nakamura, Tatsuya; Wada, Yasunao; Orita, Tamaki; Kofuku, Tomomi; Yamasaki, Katsutoshi; Sakamoto, Masako; Kinoshita, Shohiro; Aihara, Masanori; Arakawa, Yoshichika

    2004-11-01

    A total of 19,753 strains of gram-negative rods collected during two 6-month periods (October 2000 to March 2001 and November 2001 to April 2002) from 13 clinical laboratories in the Kinki region of Japan were investigated for the production of metallo-beta-lactamases (MBLs). MBLs were detected in 96 (0.5%) of the 19,753 isolates by the broth microdilution method, the 2-mercaptopropionic acid inhibition test, and PCR and DNA sequencing analyses. MBL-positive isolates were detected in 9 of 13 laboratories, with the rate of detection ranging between 0 and 2.6% for each laboratory. Forty-four of 1,429 (3.1%) Serratia marcescens, 22 of 6,198 (0.4%) Pseudomonas aeruginosa, 21 of 1,108 (1.9%) Acinetobacter spp., 4 of 544 (0.7%) Citrobacter freundii, 3 of 127 (2.4%) Providencia rettgeri, 1 of 434 (0.2%) Morganella morganii, and 1 of 1,483 (0.1%) Enterobacter cloacae isolates were positive for MBLs. Of these 96 MBL-positive strains, 87 (90.6%), 7 (7.3%), and 2 (2.1%) isolates carried the genes for IMP-1-group MBLs, IMP-2-group MBLs, and VIM-2-group MBLs, respectively. The class 1 integrase gene, intI1, was detected in all MBL-positive strains, and the aac (6')-Ib gene was detected in 37 (38.5%) isolates. Strains with identical PCR fingerprint profiles in a random amplified polymorphic DNA pattern analysis were isolated successively from five separate hospitals, suggesting the nosocomial spread of the organism in each hospital. In conclusion, many species of MBL-positive gram-negative rods are distributed widely in different hospitals in the Kinki region of Japan. The present findings should be considered during the development of policies and strategies to prevent the emergence and further spread of MBL-producing bacteria. PMID:15528723

  7. 1,3-propanediol production with Citrobacter werkmanii DSM17579: effect of a dhaD knock-out

    PubMed Central

    2014-01-01

    Background 1,3-propanediol (PDO) is a substantially industrial metabolite used in the polymer industry. Although several natural PDO production hosts exist, e.g. Klebsiella sp., Citrobacter sp. and Clostridium sp., the PDO yield on glycerol is insufficient for an economically viable bio-process. Enhancing this yield via strain improvement can be achieved by disconnecting the production and growth pathways. In the case of PDO formation, this approach results in a microorganism metabolizing glycerol strictly for PDO production, while catabolizing a co-substrate for growth and maintenance. We applied this strategy to improve the PDO production with Citrobacter werkmanii DSM17579. Results Genetic tools were developed and used to create Citrobacter werkmanii DSM17579 ∆dhaD in which dhaD, encoding for glycerol dehydrogenase, was deleted. Since this strain was unable to grow on glycerol anaerobically, both pathways were disconnected. The knock-out strain was perturbed with 13 different co-substrates for growth and maintenance. Glucose was the most promising, although a competition between NADH-consuming enzymes and 1,3-propanediol dehydrogenase emerged. Conclusion Due to the deletion of dhaD in Citrobacter werkmanii DSM17579, the PDO production and growth pathway were split. As a consequence, the PDO yield on glycerol was improved 1,5 times, strengthening the idea that Citrobacter werkmanii DSM17579 could become an industrially interesting host for PDO production. PMID:24885849

  8. Selective enrichment of commensal gut bacteria protects against Citrobacter rodentium-induced colitis.

    PubMed

    Vong, Linda; Pinnell, Lee J; Määttänen, Pekka; Yeung, C William; Lurz, Eberhard; Sherman, Philip M

    2015-08-01

    The intestinal microbiota plays a key role in shaping the host immune system. Perturbation of gut microbial composition, termed dysbiosis, is associated with an increased susceptibility to intestinal pathogens and is a hallmark of a number of inflammatory, metabolic, and infectious diseases. The prospect of mining the commensal gut microbiota for bacterial strains that can impact immune function represents an attractive strategy to counteract dysbiosis and resulting disease. In this study, we show that selective enrichment of commensal gut lactobacilli protects against the murine pathogen Citrobacter rodentium, a well-characterized model of enteropathogenic and enterohemorrhagic Escherichia coli infection. The lactobacilli-enriched bacterial culture prevented the expansion of Gammaproteobacteria and Actinobacteria and was associated with improved indexes of epithelial barrier function (dextran flux), transmissible crypt hyperplasia, and tissue inflammatory cytokine levels. Moreover, cultivation of gut bacteria from Citrobacter rodentium-infected mice reveals the differential capacity of bacterial subsets to mobilize neutrophil oxidative burst and initiate the formation of weblike neutrophil extracellular traps. Our findings highlight the beneficial effects of a lactobacilli-enriched commensal gut microenvironment and, in the context of an intestinal barrier breach, the ability of neutrophils to immobilize both commensal and pathogenic bacteria. PMID:26067845

  9. Quorum sensing activity of Citrobacter amalonaticus L8A, a bacterium isolated from dental plaque.

    PubMed

    Goh, Share-Yuan; Khan, Saad Ahmed; Tee, Kok Keng; Abu Kasim, Noor Hayaty; Yin, Wai-Fong; Chan, Kok-Gan

    2016-01-01

    Cell-cell communication is also known as quorum sensing (QS) that happens in the bacterial cells with the aim to regulate their genes expression in response to increased cell density. In this study, a bacterium (L8A) isolated from dental plaque biofilm was identified as Citrobacter amalonaticus by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). Its N-acylhomoserine-lactone (AHL) production was screened by using two types of AHL biosensors namely Chromobacterium violaceum CV026 and Escherichia coli [pSB401]. Citrobacter amalonaticus strain L8A was identified and confirmed producing numerous types of AHL namely N-butyryl-L-homoserine lactone (C4-HSL), N-hexanoyl-L-homoserine lactone (C6-HSL), N-octanoyl-L-homoserine lactone (C8-HSL) and N-hexadecanoyl-L-homoserine lactone (C16-HSL). We performed the whole genome sequence analysis of this oral isolate where its genome sequence reveals the presence of QS signal synthase gene and our work will pave the ways to study the function of the related QS genes in this bacterium. PMID:26860259

  10. Quorum sensing activity of Citrobacter amalonaticus L8A, a bacterium isolated from dental plaque

    PubMed Central

    Goh, Share-Yuan; Khan, Saad Ahmed; Tee, Kok Keng; Abu Kasim, Noor Hayaty; Yin, Wai-Fong; Chan, Kok-Gan

    2016-01-01

    Cell-cell communication is also known as quorum sensing (QS) that happens in the bacterial cells with the aim to regulate their genes expression in response to increased cell density. In this study, a bacterium (L8A) isolated from dental plaque biofilm was identified as Citrobacter amalonaticus by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). Its N-acylhomoserine-lactone (AHL) production was screened by using two types of AHL biosensors namely Chromobacterium violaceum CV026 and Escherichia coli [pSB401]. Citrobacter amalonaticus strain L8A was identified and confirmed producing numerous types of AHL namely N-butyryl-L-homoserine lactone (C4-HSL), N-hexanoyl-L-homoserine lactone (C6-HSL), N-octanoyl-L-homoserine lactone (C8-HSL) and N-hexadecanoyl-L-homoserine lactone (C16-HSL). We performed the whole genome sequence analysis of this oral isolate where its genome sequence reveals the presence of QS signal synthase gene and our work will pave the ways to study the function of the related QS genes in this bacterium. PMID:26860259

  11. [Antimicrobial activity of tebipenem against various clinical isolates from various specimen, mainly urinary tract].

    PubMed

    Muratani, Tetsuro; Doi, Kazutake; Kobayashi, Tomoko; Nakamura, Tamaki; Matsumoto, Tetsuro

    2009-04-01

    Tebipenem is the active metabolite of ME1211, tebipenem pivoxil, a novel oral carbapenem that possesses potent activity against almost pathogens except for Pseudomonas aeruginosa. In this study, we compared the susceptibility of tebipenem with current antibiotics against various organisms isolated from various specimen, mainly urinary tract. Tebipenem had a potent activity against Neisseria gonorrhoeae; its activity was comparable to it of cefixime that has most potent activity among oral antibiotics. Against Enterococcus faecalis, the activity of tebipenem was comparable to the activities of ampicillin and amoxicillin, and superior to it of faropenem. Against Citrobacter freundii, Escherichia coli , Klebsiella pneumoniae, and Enterobacter spp. including extended-spectrum beta-lactamase producers, tebipenem had a potent activity with or without ceftazidime-resistance. PMID:19673353

  12. Complete Genome Sequences of Citrobacter braakii Strains GTA-CB01 and GTA-CB04, Isolated from Ground Beef.

    PubMed

    Basra, Prabh; Koziol, Adam; Wong, Alex; Carrillo, Catherine D

    2015-01-01

    Citrobacter braakii is a Gram-negative bacterium belonging to the Enterobacteriaceae family. Here, we report 5.2- and 5.0-Mb genome assemblies for C. braakii strains GTA-CB01 and GTA-CB04, respectively. PMID:25573940

  13. The pathogenicity of an enteric Citrobacter rodentium infection is enhanced by deficiencies in the antioxidants selenium and vitamin E

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrobacter rodentium is a mouse pathogen that shares many characteristics with human enteropathogenic (EPEC) and enterohemorrhagic (EHEC) Escherichia coli, the causative agents for human disease, and serves as a useful model to study immunity to these organisms. In this study, the effect of a doub...

  14. Effect of nutrient limitation on biofilm formation and phosphatase activity of a Citrobacter sp.

    PubMed

    Allan, Victoria J M; Callow, Maureen E; Macaskie, Lynne E; Paterson-Beedle, Marion

    2002-01-01

    A phosphatase-overproducing Citrobacter sp. (NCIMB 40259) was grown in an air-lift reactor in steady-state continuous culture under limitation of carbon, phosphorus or nitrogen. Substantial biofilm formation, and the highest phosphatase activity, were observed under lactose limitation. However, the total amount of biofilm wet biomass and the phosphatase specific activity were reduced in phosphorus- or nitrogen-limited cultures or when glucose was substituted for lactose as the limiting carbon source. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM) showed differences in cell and biofilm morphology in relation to medium composition. Electron microscopy suggested that the differences in biofilm formation may relate to differential expression of fimbriae on the cell surface. PMID:11782520

  15. Endogenous endophthalmitis caused by Citrobacter koseri originating from a renal abscess

    PubMed Central

    He Cong'En, Jeremy; Miah, Mijan; Sünkel-Laing, Benjamin; Emmanuel, Julian

    2014-01-01

    We present a rare case of endogenous endophthalmitis caused by Citrobacter koseri. A 69-year-old woman with a history of poorly controlled diabetes and a protracted urinary tract infection (UTI) presented with a painful swollen left eye. There was no history of eye surgery or trauma. Imaging revealed an abscess in the right kidney. Although endophthalmitis is very rare in healthy patient, it is more common in the immunocompromised. In this patient, several multiple system illnesses including poorly controlled diabetes appear to have worked synergistically to make endophthalmitis a realistic complication of an otherwise isolated and remote source of infection, in this case pyelonephritis. Endophthalmitis, in the absence of an obvious exogenous cause, should be investigated thoroughly to exclude metastatic microbial spread. In addition, chronic features of UTI in a patient with poorly controlled diabetes or who is otherwise immunosuppressed warrant the exclusion of an underlying renal abscess. PMID:25096654

  16. Enhanced Susceptibility to Citrobacter rodentium Infection in MicroRNA-155-Deficient Mice

    PubMed Central

    John, Victoria; Walker, Alan W.; Hill, Jennifer L.; Abreu-Goodger, Cei; Hale, Christine; Goulding, David; Lawley, Trevor D.; Mastroeni, Pietro; Frankel, Gadi; Enright, Anton J.; Vigorito, Elena; Dougan, Gordon

    2013-01-01

    MicroRNAs (miRNAs) are small noncoding molecules that control gene expression posttranscriptionally, with microRNA-155 (miR-155) one of the first to be implicated in immune regulation. Here, we show that miR-155-deficient mice are less able to eradicate a mucosal Citrobacter rodentium infection than wild-type C57BL/6 mice. miR-155-deficient mice exhibited prolonged colonization associated with a higher C. rodentium burden in gastrointestinal tissue and spread into systemic tissues. Germinal center formation and humoral immune responses against C. rodentium were severely impaired in infected miR-155-deficient mice. A similarly susceptible phenotype was observed in μMT mice reconstituted with miR-155-deficient B cells, indicating that miR-155 is required intrinsically for mediating protection against this predominantly luminal bacterial pathogen. PMID:23264052

  17. [Antibacterial activity of cefpodoxime against clinical isolates in 2000 and 2001].

    PubMed

    Abe, Tomomi; Fukuoka, Takashi; Sato, Yuki; Ito, Kazuyoshi; Sei, Masami

    2002-12-01

    As the post-marketing surveillance of cefpodoxime proxetil (Banan), MICs of cefpodoxime (CPDX, an active form of Banan) against 1090 clinical isolates of 22 species from 15 medical institutions all over Japan from June 2000 to March 2001 were measured using the broth microdilution method approved by the Japanese Society of Chemotherapy and compared with those of oral cephem antibacterials, cefaclor, cefdinir, cefditoren, and cefcapene. In this study, remarkable change in the activity of CPDX was observed in Streptococcus pneumoniae and Haemophilus influenzae compared with the susceptibility in the studies before Banan was launched. This cause is considered to be the increase in the incidence of the following resistant strains: penicillin-intermediate S. pneumoniae (47.3%), penicillin-resistant S. pneumoniae (PRSP, 15.1%), and beta-lactamase-negative ampicillin-resistant (BLNAR) H. influenzae (24.0%), which were scarcely isolated in 1989 when Banan was launched. Other tested drugs also exhibited low activity against these resistant strains. However, CPDX showed comparatively good activity with MIC90 of 2 micrograms/mL against PRSP. Against methicillin-susceptible Staphylococcus spp., Streptococcus pyogenes, Streptococcus agalactiae, and Moraxella catarrhalis, CPDX also showed comparatively good activity with MIC90 of < or = 4 micrograms/mL, which was almost equal to that in the studies before its marketing. Against quinolones-resistant Neisseria gonorrhoeae, CPDX showed excellent activity with MIC90 of 0.5 microgram/mL. Against members of the family Enterobacteriaceae except for Citrobacter freundii, Enterobacter spp., Proteus vulgaris, and Morganella morganii, CPDX showed good activity. However, in Escherichia coli, Klebsiella spp. Proteus spp., and Providencia spp., there are some high-resistant strains to all tested drugs including CPDX. Against Peptostreptococcus spp., MIC90 of CPDX was 8 micrograms/mL and its MIC range was widely distributed from 0.03 to 32

  18. DOCK2 confers immunity and intestinal colonization resistance to Citrobacter rodentium infection

    PubMed Central

    Liu, Zhiping; Man, Si Ming; Zhu, Qifan; Vogel, Peter; Frase, Sharon; Fukui, Yoshinori; Kanneganti, Thirumala-Devi

    2016-01-01

    Food poisoning is one of the leading causes of morbidity and mortality in the world. Citrobacter rodentium is an enteric pathogen which attaches itself to enterocytes and induces attachment and effacing (A/E) lesions. The ability of the bacterium to cause infection requires subversion of the host actin cytoskeleton. Rac-dependent actin polymerization is activated by a guanine nucleotide exchange factor known as Dedicator of cytokinesis 2 (DOCK2). However, the role of DOCK2 in infectious disease is largely unexplored. Here, we found that mice lacking DOCK2 were susceptible to C. rodentium infection. These mice harbored increased levels of C. rodentium bacteria, showed more pronounced weight loss and inflammation-associated pathology, and were prone to bacterial dissemination to the systemic organs compared with wild-type mice. We found that mice lacking DOCK2 were more susceptible to C. rodentium attachment to intestinal epithelial cells. Therefore, our results underscored an important role of DOCK2 for gastrointestinal immunity to C. rodentium infection. PMID:27291827

  19. Understanding the host-adapted state of Citrobacter rodentium by transcriptomic analysis.

    PubMed

    Smith, Allen D; Yan, Xianghe; Chen, Celine; Dawson, Harry D; Bhagwat, Arvind A

    2016-05-01

    Citrobacter rodentium (Cr) is a mouse pathogen that mimics many aspects of enteropathogenic Escherichia coli infections including producing attaching and effacing (A/E) lesions. Host-adapted (HA) Cr cells that are shed at the peak of infection have been reported to be hyper-infective. The exact mechanism underlying this phenomenon has remained elusive since the pathogen loses its HA 'status' immediately upon subculturing in laboratory media. We sequenced the entire transcriptome of Cr directly from the feces of infected mice and analyzed the gene expression pattern. We observed that the entire transcriptional machinery as well as several transcriptional regulators to be differentially expressed when compared with the transcriptome of cells grown on laboratory media. Major adhesion and effector genes, tir and eae, were highly expressed in HA along with many genes located on all five loci of enterocyte effacement regions (LEE 1-5). Notable absent among the HA expressed genes were 19 fimbrial operons and non-fimbrial adhesions and several non-LEE encoded effectors. These results demonstrate that host-adapted Cr has a unique transcriptome that is associated with increased host transmission. PMID:26837900

  20. Psidium guajava leaf extract prevents intestinal colonization of Citrobacter rodentium in the mouse model.

    PubMed

    Gupta, Pooja; Birdi, Tannaz

    2015-01-01

    Diarrheal diseases are the second highest cause of mortality of children under 5 years worldwide. There is a continuous search for developing a cost-effective treatment for diarrhea as the present ones are facing challenges. Medicinal plants can be explored further as an alternative treatment for diarrhea. Psidium guajava leaves have been used as an antidiarrheal globally. Citrobacter rodentium, a common mouse pathogen, is known to mimic the pathogenecity of enteropathogenic and enterohemorrhagic E. coli. It can thus present an effective model to study infectious diarrhea. In the present study, the P. guajava leaf extract was tested for its efficacy in treating infectious diarrhea using a C. rodentium mouse model. The mice in the test group (treated with P. guajava leaf extract) showed quicker clearance of infection as compared with the control group. The bacterial load in the fecal sample of the mice in the test group was high on Day 4 as compared with that in the control group, suggesting a flush out of the bacteria. In the test group, 6/7 (85.71%) mice showed clearance of infection by Day 19. The control group continued to show infection till Day 29. P. guajava leaf extract thus has the potential for use in the treatment of infectious diarrhea. PMID:25878465

  1. DOCK2 confers immunity and intestinal colonization resistance to Citrobacter rodentium infection.

    PubMed

    Liu, Zhiping; Man, Si Ming; Zhu, Qifan; Vogel, Peter; Frase, Sharon; Fukui, Yoshinori; Kanneganti, Thirumala-Devi

    2016-01-01

    Food poisoning is one of the leading causes of morbidity and mortality in the world. Citrobacter rodentium is an enteric pathogen which attaches itself to enterocytes and induces attachment and effacing (A/E) lesions. The ability of the bacterium to cause infection requires subversion of the host actin cytoskeleton. Rac-dependent actin polymerization is activated by a guanine nucleotide exchange factor known as Dedicator of cytokinesis 2 (DOCK2). However, the role of DOCK2 in infectious disease is largely unexplored. Here, we found that mice lacking DOCK2 were susceptible to C. rodentium infection. These mice harbored increased levels of C. rodentium bacteria, showed more pronounced weight loss and inflammation-associated pathology, and were prone to bacterial dissemination to the systemic organs compared with wild-type mice. We found that mice lacking DOCK2 were more susceptible to C. rodentium attachment to intestinal epithelial cells. Therefore, our results underscored an important role of DOCK2 for gastrointestinal immunity to C. rodentium infection. PMID:27291827

  2. Glycerol assimilation and production of 1,3-propanediol by Citrobacter amalonaticus Y19.

    PubMed

    Ainala, Satish Kumar; Ashok, Somasundar; Ko, Yeounjoo; Park, Sunghoon

    2013-06-01

    Citrobacter amalonaticus Y19 (Y19) was isolated because of its ability for carbon monoxide-dependent hydrogen production (water-gas shift reaction). This paper reports the assimilation of glycerol and the production of 1,3-propanediol (1,3-PDO) by Y19. Genome sequencing revealed that Y19 contained the genes for the utilization of glycerol and 1,2-propanediol (pdu operon) along with those for the synthesis of coenzyme B12 (cob operon). On the other hand, it did not possess the genes for the fermentative metabolism of glycerol of Klebsiella pneumoniae, which consists of both the oxidative (dhaD and dhaK) and reductive (dhaB and dhaT) pathways. In shake-flask cultivation under aerobic conditions, Y19 could grow well with glycerol as the sole carbon source and produced 1,3-PDO. The level of 1,3-PDO production was improved when vitamin B12 was added to the culture medium under aerobic conditions. Under anaerobic conditions, cell growth and 1,3-PDO production on glycerol was also possible, but only when an exogenous electron acceptor, such as nitrate or fumarate, was added. This is the first report of the glycerol metabolism and 1,3-PDO production by C. amalonaticus Y19. PMID:23377788

  3. Immunological mechanisms involved in probiotic-mediated protection against Citrobacter rodentium-induced colitis.

    PubMed

    Jiang, Y; Yang, G; Meng, F; Yang, W; Hu, J; Ye, L; Shi, C; Wang, C

    2016-06-01

    Inflammatory bowel disease is a group of chronic, incurable inflammatory disorders of the gastrointestinal tract that cause severe diarrhoea, intestinal inflammation, pain, fatigue and weight loss. In this study, we first developed a model of Citrobacter rodentium-induced colitis and then evaluated the protective effects of selected probiotics on inflammation. The results showed that administration of a combination of probiotics including Lactobacillus rhamnosus ATCC 53103, Lactobacillus acidophilus ATCC 4356 and Lactobacillus plantarum A significantly increased the production of CD11c(+) dendritic cells in the spleen (3.62% vs phosphate buffered saline (PBS)-treated control, P<0.01) and mesenteric lymph nodes (MLNs). In addition, the presence of probiotics significantly up-regulated the development of CD4(+)/CD25(+)/Foxp3(+) regulatory T cells in MLNs by approximately 2.07% compared to the effect observed in the PBS-treated control (P<0.01) and down-regulated the expression of inflammatory cytokines, including interleukin-17, tumour necrosis factor-α and interferon-γ, by 0.11, 0.11 and 0.15%, respectively, compared to the effect observed in the PBS-treated control (P<0.01).These effects conferred protection against colitis, as shown by histopathological analyses. PMID:26925601

  4. Effect of probiotics Lactobacillus acidophilus on Citrobacter rodentium colitis: the role of dendritic cells.

    PubMed

    Chen, Chien-Chang; Chiu, Cheng-Hsun; Lin, Tzou-Yien; Shi, Hai Ning; Walker, W Allan

    2009-02-01

    Modulation of the intestinal immune response early in life by administration of probiotic bacteria may be an effective strategy for preventing or attenuating infectious diarrhea. We preinoculated the mice early in life with the probiotic bacteria Lactobacillus acidophilus NCFM (La) at age 2 wk. Dendritic cells (DCs) were collected and purified from mesenteric lymph nodes (MLN) and spleens of the BalbC/ByJ mice. DC isolation and adoptive transfer was used to examine the function of probiotics. We demonstrated that when mice were adoptively transferred with La-primed DCs (t-LaDC) instead of oral consumption with La, there was a similar effect on fecal bacteria counts, IgA levels, and colonic histopathology, as well as cytokine levels in MLN when there was intestinal bacterial infection. The above findings suggest that DCs play a key role in probiotics attenuating Citrobacter rodentium (Cr) colitis. Moreover, the location of La-primed DC hints that there is interaction of DCs and T cells in the digestive system of the host. Up-regulated expression of a surface marker on DCs indicated that inoculation with probiotics will stimulate the function of DCs, thereby further increasing immune response triggered by DC. PMID:19262293

  5. Characterization of a bioflocculant produced by Citrobacter sp. TKF04 from acetic and propionic acids.

    PubMed

    Fujita, M; Ike, M; Tachibana, S; Kitada, G; Kim, S M; Inoue, Z

    2000-01-01

    A bacterial strain, TKF04, capable of producing a bioflocculant from acetic and/or propionic acids was isolated from a biofilm formed in inside a kitchen drain. It was identified as a Citrobacter based on its morphological and physiological characteristics and the partial sequences of its 16S rRNA. TKF04 produced the bioflocculant during the logarithmic phase of growth, and the optimum temperature and pH for the bioflocculant production were 30 degrees C and 7.2-10.0, respectively. It could utilize some organic acids and sugars for its growth as the sole carbon sources when yeast extract was supplemented; however, only acetate and propionate were found to be good substrates for the bioflocculant production. The crude bioflocculant could be recovered from the supernatant of the culture broth by ethanol precipitation and dialysis against deionized water. It was found to be effective for flocculation of a kaolin suspension, when added at a final concentration of 1-10 mg/l, over a wide range of pHs (2-8) and temperatures (approximately 3-95 degrees C), while the co-presence of cations (Na+, K+, Ca2+, Mg2+, Fe2+, Al3+ or Fe3+) did not enhance the flocculating activity. It could efficiently flocculate a variety of inorganic and organic suspended particles, including kaolin, diatomite, bentonite, activated carbon, soil and activated sludge. It contained glucosamine as the major component, and the molecular weight was estimated to be between 232 and 440 kDa by gel filtration. The observation that the flocculating activity was completely lost following chitinase treatment and its analysis with a Fourier transform infrared spectrometer suggested that the bioflocculant is a biopolymer structurally-similar to chitin or chitosan. PMID:16232696

  6. The Serine Protease Autotransporter Pic Modulates Citrobacter rodentium Pathogenesis and Its Innate Recognition by the Host.

    PubMed

    Bhullar, Kirandeep; Zarepour, Maryam; Yu, Hongbing; Yang, Hong; Croxen, Matthew; Stahl, Martin; Finlay, B Brett; Turvey, Stuart E; Vallance, Bruce A

    2015-07-01

    Bacterial pathogens produce a number of autotransporters that possess diverse functions. These include the family of serine protease autotransporters of Enterobacteriaceae (SPATEs) produced by enteric pathogens such as Shigella flexneri and enteroaggregative Escherichia coli. Of these SPATEs, one termed "protein involved in colonization," or Pic, has been shown to possess mucinase activity in vitro, but to date, its role in in vivo enteric pathogenesis is unknown. Testing a pic null (ΔpicC) mutant in Citrobacter rodentium, a natural mouse pathogen, found that the C. rodentium ΔpicC strain was impaired in its ability to degrade mucin in vitro compared to the wild type. Upon infection of mice, the ΔpicC mutant exhibited a hypervirulent phenotype with dramatically heavier pathogen burdens found in intestinal crypts. ΔpicC mutant-infected mice suffered greater barrier disruption and more severe colitis and weight loss, necessitating their euthanization between 10 and 14 days postinfection. Notably, the virulence of the ΔpicC mutant was normalized when the picC gene was restored; however, a PicC point mutant causing loss of mucinase activity did not replicate the ΔpicC phenotype. Exploring other aspects of PicC function, the ΔpicC mutant was found to aggregate to higher levels in vivo than wild-type C. rodentium. Moreover, unlike the wild type, the C. rodentium ΔpicC mutant had a red, dry, and rough (RDAR) morphology in vitro and showed increased activation of the innate receptor Toll-like receptor 2 (TLR2). Interestingly, the C. rodentium ΔpicC mutant caused a degree of pathology similar to that of wild-type C. rodentium when infecting TLR2-deficient mice, showing that despite its mucinase activity, PicC's major role in vivo may be to limit C. rodentium's stimulation of the host's innate immune system. PMID:25895966

  7. Role of RpoS in the Virulence of Citrobacter rodentium▿

    PubMed Central

    Dong, Tao; Coombes, Brian K.; Schellhorn, Herb E.

    2009-01-01

    Citrobacter rodentium is a mouse enteropathogen that is closely related to Escherichia coli and causes severe colonic hyperplasia and bloody diarrhea. C. rodentium infection requires expression of genes of the locus of enterocyte effacement (LEE) pathogenicity island, which simulates infection by enteropathogenic E. coli and enterohemorrhagic E. coli in the human intestine, providing an effective model for studying enteropathogenesis. In this study we investigated the role of RpoS, the stationary phase sigma factor, in virulence in C. rodentium. Sequence analysis showed that the rpoS gene is highly conserved in C. rodentium and E. coli, exhibiting 92% identity. RpoS was critical for survival under heat shock conditions and during exposure to H2O2 and positively regulated the expression of catalase KatE (HPII). The development of the RDAR (red dry and rough) morphotype, an important virulence trait in E. coli, was also mediated by RpoS in C. rodentium. Unlike E. coli, C. rodentium grew well in the mouse colon, and the wild-type strain colonized significantly better than rpoS mutants. However, a mutation in rpoS conferred a competitive growth advantage over the wild type both in vitro in Luria-Bertani medium and in vivo in the mouse colon. Survival analysis showed that the virulence of an rpoS mutant was attenuated. The expression of genes on the LEE pathogenicity island, which are essential for colonization and virulence, was reduced in the rpoS mutant. In conclusion, RpoS is important for the stress response and is required for full virulence in C. rodentium. PMID:18981255

  8. Tir Triggers Expression of CXCL1 in Enterocytes and Neutrophil Recruitment during Citrobacter rodentium Infection.

    PubMed

    Crepin, Valerie F; Habibzay, Maryam; Glegola-Madejska, Izabela; Guenot, Marianne; Collins, James W; Frankel, Gad

    2015-09-01

    The hallmarks of enteropathogenic Escherichia coli (EPEC) infection are formation of attaching and effacing (A/E) lesions on mucosal surfaces and actin-rich pedestals on cultured cells, both of which are dependent on the type III secretion system effector Tir. Following translocation into cultured cells and clustering by intimin, Tir Y474 is phosphorylated, leading to recruitment of Nck, activation of N-WASP, and actin polymerization via the Arp2/3 complex. A secondary, weak, actin polymerization pathway is triggered via an NPY motif (Y454). Importantly, Y454 and Y474 play no role in A/E lesion formation on mucosal surfaces following infection with the EPEC-like mouse pathogen Citrobacter rodentium. In this study, we investigated the roles of Tir segments located upstream of Y451 and downstream of Y471 in C. rodentium colonization and A/E lesion formation. We also tested the role that Tir residues Y451 and Y471 play in host immune responses to C. rodentium infection. We found that deletion of amino acids 382 to 462 or 478 to 547 had no impact on the ability of Tir to mediate A/E lesion formation, although deletion of amino acids 478 to 547 affected Tir translocation. Examination of enterocytes isolated from infected mice revealed that a C. rodentium strain expressing Tir_Y451A/Y471A recruited significantly fewer neutrophils to the colon and triggered less colonic hyperplasia on day 14 postinfection than the wild-type strain. Consistently, enterocytes isolated from mice infected with C. rodentium expressing Tir_Y451A/Y471A expressed significantly less CXCL1. These result show that Tir-induced actin remodeling plays a direct role in modulation of immune responses to C. rodentium infection. PMID:26077760

  9. Tir Triggers Expression of CXCL1 in Enterocytes and Neutrophil Recruitment during Citrobacter rodentium Infection

    PubMed Central

    Habibzay, Maryam; Glegola-Madejska, Izabela; Guenot, Marianne; Collins, James W.

    2015-01-01

    The hallmarks of enteropathogenic Escherichia coli (EPEC) infection are formation of attaching and effacing (A/E) lesions on mucosal surfaces and actin-rich pedestals on cultured cells, both of which are dependent on the type III secretion system effector Tir. Following translocation into cultured cells and clustering by intimin, Tir Y474 is phosphorylated, leading to recruitment of Nck, activation of N-WASP, and actin polymerization via the Arp2/3 complex. A secondary, weak, actin polymerization pathway is triggered via an NPY motif (Y454). Importantly, Y454 and Y474 play no role in A/E lesion formation on mucosal surfaces following infection with the EPEC-like mouse pathogen Citrobacter rodentium. In this study, we investigated the roles of Tir segments located upstream of Y451 and downstream of Y471 in C. rodentium colonization and A/E lesion formation. We also tested the role that Tir residues Y451 and Y471 play in host immune responses to C. rodentium infection. We found that deletion of amino acids 382 to 462 or 478 to 547 had no impact on the ability of Tir to mediate A/E lesion formation, although deletion of amino acids 478 to 547 affected Tir translocation. Examination of enterocytes isolated from infected mice revealed that a C. rodentium strain expressing Tir_Y451A/Y471A recruited significantly fewer neutrophils to the colon and triggered less colonic hyperplasia on day 14 postinfection than the wild-type strain. Consistently, enterocytes isolated from mice infected with C. rodentium expressing Tir_Y451A/Y471A expressed significantly less CXCL1. These result show that Tir-induced actin remodeling plays a direct role in modulation of immune responses to C. rodentium infection. PMID:26077760

  10. Microbial degradation of Paclitaxel using Citrobacter amalonaticus Rashtia isolated from pharmaceutical wastewater: kinetic and thermodynamic study.

    PubMed

    Zamani, Hojjatolah; Grakoee, Seyed Reza; Rakhshaee, Roohan

    2016-08-01

    Paclitaxel is a highly toxic anticancer agent which is used in a wide range against ovarian, breast, lung, and prostate cancers. Paclitaxel is manufactured recently in the north of Iran which may lead to the introduction of the drug into the environment via pharmaceutical wastewater. To our knowledge, Paclitaxel degradation is currently performed using physicochemical methods and biological degradation of Paclitaxel has not been reported. In this study, a Paclitaxel degrading bacterium was isolated from pharmaceutical wastewater for the first time. The bacterium was identified using biochemical and molecular assays and its Paclitaxel degradation potential was evaluated using High Performance Liquid Chromatography (HPLC). In addition, kinetic and thermodynamic study of Paclitaxel degradation at different experimental conditions was performed. A Citrobacter species named as C. amalonaticus Rashtia able to degrade and utilize Paclitaxel as the sole carbon source was isolated. The isolated strain tolerated high level concentration of Paclitaxel (0.4 mg/mL) in liquid culture media and was able to degrade spillage-level concentrations of the drug (0.01-0.1 mg/mL) with 87-93 % efficacy under aerobic condition. Kinetic and thermodynamic study at different pHs (4.0, 7.0 and 10.0) and temperatures (285, 295 and 310 K) revealed that Paclitaxel degradation is a non-spontaneous process and the highest rate constant was observed in the basic condition and at the highest temperature. The ΔG values at 285, 295 and 310 K were determined 103.3, 105.9 and 109.9 kJ/mol, respectively. In addition, The ΔH and activation energy (Ea) of the process were determined +28.7 kJ/mol and +30.87 kJ/mol, respectively. PMID:27339310

  11. The Serine Protease Autotransporter Pic Modulates Citrobacter rodentium Pathogenesis and Its Innate Recognition by the Host

    PubMed Central

    Bhullar, Kirandeep; Zarepour, Maryam; Yu, Hongbing; Yang, Hong; Croxen, Matthew; Stahl, Martin; Finlay, B. Brett; Turvey, Stuart E.

    2015-01-01

    Bacterial pathogens produce a number of autotransporters that possess diverse functions. These include the family of serine protease autotransporters of Enterobacteriaceae (SPATEs) produced by enteric pathogens such as Shigella flexneri and enteroaggregative Escherichia coli. Of these SPATEs, one termed “protein involved in colonization,” or Pic, has been shown to possess mucinase activity in vitro, but to date, its role in in vivo enteric pathogenesis is unknown. Testing a pic null (ΔpicC) mutant in Citrobacter rodentium, a natural mouse pathogen, found that the C. rodentium ΔpicC strain was impaired in its ability to degrade mucin in vitro compared to the wild type. Upon infection of mice, the ΔpicC mutant exhibited a hypervirulent phenotype with dramatically heavier pathogen burdens found in intestinal crypts. ΔpicC mutant-infected mice suffered greater barrier disruption and more severe colitis and weight loss, necessitating their euthanization between 10 and 14 days postinfection. Notably, the virulence of the ΔpicC mutant was normalized when the picC gene was restored; however, a PicC point mutant causing loss of mucinase activity did not replicate the ΔpicC phenotype. Exploring other aspects of PicC function, the ΔpicC mutant was found to aggregate to higher levels in vivo than wild-type C. rodentium. Moreover, unlike the wild type, the C. rodentium ΔpicC mutant had a red, dry, and rough (RDAR) morphology in vitro and showed increased activation of the innate receptor Toll-like receptor 2 (TLR2). Interestingly, the C. rodentium ΔpicC mutant caused a degree of pathology similar to that of wild-type C. rodentium when infecting TLR2-deficient mice, showing that despite its mucinase activity, PicC's major role in vivo may be to limit C. rodentium's stimulation of the host's innate immune system. PMID:25895966

  12. The CpxRA Two-Component System Is Essential for Citrobacter rodentium Virulence

    PubMed Central

    Thomassin, Jenny-Lee; Giannakopoulou, Natalia; Zhu, Lei; Gross, Jeremy; Salmon, Kristiana; Leclerc, Jean-Mathieu; Daigle, France; Le Moual, Hervé

    2015-01-01

    Citrobacter rodentium is a murine intestinal pathogen used as a model for the foodborne human pathogens enterohemorrhagic Escherichia coli and enteropathogenic E. coli. During infection, these pathogens use two-component signal transduction systems to detect and adapt to changing environmental conditions. In E. coli, the CpxRA two-component signal transduction system responds to envelope stress by modulating the expression of a myriad of genes. Quantitative real-time PCR showed that cpxRA was expressed in the colon of C57BL/6J mice infected with C. rodentium. To determine whether CpxRA plays a role during C. rodentium infection, a cpxRA deletion strain was generated and found to have a colonization defect during infection. This defect was independent of an altered growth rate or a defective type III secretion system, and single-copy chromosomal complementation of cpxRA restored virulence. The C. rodentium strains were then tested in C3H/HeJ mice, a lethal intestinal infection model. Mice infected with the ΔcpxRA strain survived infection, whereas mice infected with the wild-type or complemented strains succumbed to infection. Furthermore, we found that the cpxRA expression level was higher during early infection than at a later time point. Taken together, these data demonstrate that the CpxRA two-component signal transduction system is essential for the in vivo virulence of C. rodentium. In addition, these data suggest that fine-tuned cpxRA expression is important for infection. This is the first study that identifies a C. rodentium two-component transduction system required for pathogenesis. This study further indicates that CpxRA is an interesting target for therapeutics against enteric pathogens. PMID:25712925

  13. Evolutionary Adaptation of an AraC-Like Regulatory Protein in Citrobacter rodentium and Escherichia Species

    PubMed Central

    Tan, Aimee; Petty, Nicola K.; Hocking, Dianna; Bennett-Wood, Vicki; Wakefield, Matthew; Praszkier, Judyta; Tauschek, Marija; Yang, Ji

    2015-01-01

    The evolution of pathogenic bacteria is a multifaceted and complex process, which is strongly influenced by the horizontal acquisition of genetic elements and their subsequent expression in their new hosts. A well-studied example is the RegA regulon of the enteric pathogen Citrobacter rodentium. The RegA regulatory protein is a member of the AraC/XylS superfamily, which coordinates the expression of a gene repertoire that is necessary for full pathogenicity of this murine pathogen. Upon stimulation by an exogenous, gut-associated signal, namely, bicarbonate ions, RegA activates the expression of a series of genes, including virulence factors, such as autotransporters, fimbriae, a dispersin-like protein, and the grlRA operon on the locus of enterocyte effacement pathogenicity island. Interestingly, the genes encoding RegA homologues are distributed across the genus Escherichia, encompassing pathogenic and nonpathogenic subtypes. In this study, we carried out a series of bioinformatic, transcriptional, and functional analyses of the RegA regulons of these bacteria. Our results demonstrated that regA has been horizontally transferred to Escherichia spp. and C. rodentium. Comparative studies of two RegA homologues, namely, those from C. rodentium and E. coli SMS-3-5, a multiresistant environmental strain of E. coli, showed that the two regulators acted similarly in vitro but differed in terms of their abilities to activate the virulence of C. rodentium in vivo, which evidently was due to their differential activation of grlRA. Our data indicate that RegA from C. rodentium has strain-specific adaptations that facilitate infection of its murine host. These findings shed new light on the development of virulence by C. rodentium and on the evolution of virulence-regulatory genes of bacterial pathogens in general. PMID:25624355

  14. Identification and Regulation of a Novel Citrobacter rodentium Gut Colonization Fimbria (Gcf)

    PubMed Central

    Caballero-Flores, Gustavo G.; Croxen, Matthew A.; Martínez-Santos, Verónica I.; Finlay, B. Brett

    2015-01-01

    ABSTRACT The Gram-negative enteric bacterium Citrobacter rodentium is a natural mouse pathogen that has been extensively used as a surrogate model for studying the human pathogens enteropathogenic and enterohemorrhagic Escherichia coli. All three pathogens produce similar attaching and effacing (A/E) lesions in the intestinal epithelium. During infection, these bacteria employ surface structures called fimbriae to adhere and colonize the host intestinal epithelium. For C. rodentium, the roles of only a small number of its genome-carried fimbrial operons have been evaluated. Here, we report the identification of a novel C. rodentium colonization factor, called gut colonization fimbria (Gcf), which is encoded by a chaperone-usher fimbrial operon. A gcfA mutant shows a severe colonization defect within the first 10 days of infection. The gcf promoter is not active in C. rodentium under several in vitro growth conditions; however, it is readily expressed in a C. rodentium Δhns1 mutant lacking the closest ortholog of the Escherichia coli histone-like nucleoid structuring protein (H-NS) but not in mutants with deletion of the other four genes encoding H-NS homologs. H-NS binds to the regulatory region of gcf, further supporting its direct role as a repressor of the gcf promoter that starts transcription 158 bp upstream of the start codon of its first open reading frame. The gcf operon possesses interesting novel traits that open future opportunities to expand our knowledge of the structure, regulation, and function during infection of these important bacterial structures. IMPORTANCE Fimbriae are surface bacterial structures implicated in a variety of biological processes. Some have been shown to play a critical role during host colonization and thus in disease. Pathogenic bacteria possess the genetic information for an assortment of fimbriae, but their function and regulation and the interplay between them have not been studied in detail. This work provides new insights

  15. Genome Sequence of Citrobacter sp. CtB7.12, Isolated from the Gut of the Desert Subterranean Termite Heterotermes aureus.

    PubMed

    Fontes-Perez, Héctor; Olvera-García, Myrna; Chávez-Martínez, America; Rodriguez-Almeida, Felipe A; Arzola-Alvarez, Claudio A; Sanchez-Flores, Alejandro; Corral-Luna, Agustín

    2015-01-01

    The draft genome of Citrobacter sp. CtB7.12, isolated from termite gut, is presented here. This organism has been reported as a cellulolytic bacterium, which is biotechnologically important because it can be used as a gene donor for the ethanol and biofuel industries. PMID:26543121

  16. Genome Sequence of Citrobacter sp. CtB7.12, Isolated from the Gut of the Desert Subterranean Termite Heterotermes aureus

    PubMed Central

    Fontes-Perez, Héctor; Olvera-García, Myrna; Chávez-Martínez, America; Rodriguez-Almeida, Felipe A.; Arzola-Alvarez, Claudio A.

    2015-01-01

    The draft genome of Citrobacter sp. CtB7.12, isolated from termite gut, is presented here. This organism has been reported as a cellulolytic bacterium, which is biotechnologically important because it can be used as a gene donor for the ethanol and biofuel industries. PMID:26543121

  17. The Role of Galectin-1 and Galectin-3 in the Mucosal Immune Response to Citrobacter rodentium Infection

    PubMed Central

    Curciarello, Renata; Steele, Alison; Cooper, Dianne; MacDonald, Thomas T.; Kruidenier, Laurens; Kudo, Takahiro

    2014-01-01

    Despite their abundance at gastrointestinal sites, little is known about the role of galectins in gut immune responses. We have therefore investigated the Citrobacter rodentium model of colonic infection and inflammation in Galectin-1 or Galectin-3 null mice. Gal-3 null mice showed a slight delay in colonisation after inoculation with C. rodentium and a slight delay in resolution of infection, associated with delayed T cell, macrophage and dendritic cell infiltration into the gut mucosa. However, Gal-1 null mice also demonstrated reduced T cell and macrophage responses to infection. Despite the reduced T cell and macrophage response in Gal-1 null mice, there was no effect on C. rodentium infection kinetics and pathology. Overall, Gal-1 and Gal-3 play only a minor role in immunity to a gut bacterial pathogen. PMID:25243744

  18. Malachite green bioremoval by a newly isolated strain Citrobacter sedlakii RI11; enhancement of the treatment by biosurfactant addition.

    PubMed

    Mnif, Inès; Fendri, Raouia; Ghribi, Dhouha

    2015-01-01

    Citrobacter sedlackii RI11, isolated from acclimated textile effluent after selective enrichment on synthetic dyes, was assessed for malachite green (MG) biotreatment potency. Results indicate that this bacterium has potential for use in effective treatment of MG contaminated wastewaters under shaking conditions at neutral and alkaline pH value, characteristic of typical textile effluents. Also, the newly isolated strain can tolerate higher doses of dye and decolorize up to 1,000 mg/l of dye. When used as microbial surfactant to enhance MG biodecolorization, Bacillus subtilis SPB1-derived lipopeptide accelerated the decolorization rate and maximized the decolorization efficiency at an optimal concentration of biosurfactant of about 0.075%. Studies ensured that MG removal by this strain could be due to biodegradation and/or adsorption. Results on germination potencies of different seeds using the treated dyes under different conditions favor the use of SPB1 biosurfactant for the treatment of MG. PMID:26465297

  19. [NiFe]Hydrogenase from Citrobacter sp. S-77 surpasses platinum as an electrode for H2 oxidation reaction.

    PubMed

    Matsumoto, Takahiro; Eguchi, Shigenobu; Nakai, Hidetaka; Hibino, Takashi; Yoon, Ki-Seok; Ogo, Seiji

    2014-08-18

    Reported herein is an electrode for dihydrogen (H2) oxidation, and it is based on [NiFe]Hydrogenase from Citrobacter sp. S-77 ([NiFe]S77). It has a 637 times higher mass activity than Pt (calculated based on 1 mg of [NiFe]S77 or Pt) at 50 mV in a hydrogen half-cell. The [NiFe]S77 electrode is also stable in air and, unlike Pt, can be recovered 100 % after poisoning by carbon monoxide. Following characterization of the [NiFe]S77 electrode, a fuel cell comprising a [NiFe]S77 anode and Pt cathode was constructed and shown to have a a higher power density than that achievable by Pt. PMID:24895095

  20. A New Episomic Element Controlling Fermentative Metabolism and Excretion of Amino Acids by Citrobacter intermedium C3

    PubMed Central

    Pares, R.; Guinea, J.; Hernandez, S.; Valoix, Josefina; Jofre, J.

    1974-01-01

    Glutamate excretion by colonies of Citrobacter intermedium C3 was detected by using the auxotrophic strain Leuconostoc mesenteroides P-60. A constant ratio of strain C3 colonies did not excrete glutamate. These colonies were subcultured, and colonial analysis of their descendants established that the change from non-excretor to excretor (Sg− → Sg+) is a spontaneous and random process with occurs at a high rate, and that an equilibrium state results from the back-transition Sg+ → Sg− in large populations. Acridine orange, ethidium bromide, and shaking have a strong influence on Sg+-to-Sg− interconversion, which suggests that a genetic element like an episome is implicated (S factor). Various auxotrophic mutants of bacterial strain C3 have been cured of the S factor. Strains lacking the S factor (S− strains) do not excrete glutamate and lose their fermentative metabolism completely. Consequently, the S factor is different from other extrachromosomal genetic factors whose elimination does not modify central metabolism. The gain of the S factor by infectious transfer has been shown with different C3 auxotrophic mutant strains. Also, the S factor has been transferred to Paracolobactrum intermedium ATCC 11606. These findings suggest that phenotypic changes observed are a consequence of elimination or infectious gain of the S factor, with its autonomous or integrated multiplication. PMID:4600693

  1. Bicarbonate-mediated transcriptional activation of divergent operons by the virulence regulatory protein, RegA, from Citrobacter rodentium.

    PubMed

    Yang, Ji; Hart, Emily; Tauschek, Marija; Price, G Dean; Hartland, Elizabeth L; Strugnell, Richard A; Robins-Browne, Roy M

    2008-04-01

    Regulation of virulence gene expression plays a central role in the pathogenesis of enteric bacteria as they encounter diverse environmental conditions in the gastrointestinal tract of their hosts. In this study, we investigated environmental regulation of two putative virulence determinants adcA and kfc by RegA, an AraC/XylS-like regulator, from Citrobacter rodentium, and identified bicarbonate as the environmental signal which induced transcription of adcA and kfc through RegA. Primer extension experiments showed that adcA and kfc were divergently transcribed from sigma(70) promoters. In vivo and in vitro experiments demonstrated that bicarbonate facilitated and stabilized the binding of RegA to an operator located between the two promoters. The interaction of RegA with its DNA target resulted in the formation of a nucleosome-like structure, which evidently displaced the histone-like proteins, H-NS and StpA, from the adcA and kfc promoter regions, leading to transcriptional derepression. In addition, our results indicated that RegA also behaved as a Class I activator by directly stimulating transcription initiation by RNA polymerase. This is the first report to describe the molecular mechanism by which an environmental chemical stimulates transcription of virulence-associated genes of an enteric pathogen through an AraC/XlyS-like activator. PMID:18284589

  2. Biochemical characterization of a bifunctional acetaldehyde-alcohol dehydrogenase purified from a facultative anaerobic bacterium Citrobacter sp. S-77.

    PubMed

    Tsuji, Kohsei; Yoon, Ki-Seok; Ogo, Seiji

    2016-03-01

    Acetaldehyde-alcohol dehydrogenase (ADHE) is a bifunctional enzyme consisting of two domains of an N-terminal acetaldehyde dehydrogenase (ALDH) and a C-terminal alcohol dehydrogenase (ADH). The enzyme is known to be important in the cellular alcohol metabolism. However, the role of coenzyme A-acylating ADHE responsible for ethanol production from acetyl-CoA remains uncertain. Here, we present the purification and biochemical characterization of an ADHE from Citrobacter sp. S-77 (ADHES77). Interestingly, the ADHES77 was unable to be solubilized from membrane with detergents either 1% Triton X-100 or 1% Sulfobetaine 3-12. However, the enzyme was easily dissociated from membrane by high-salt buffers containing either 1.0 M NaCl or (NH4)2SO4 without detergents. The molecular weight of a native protein was estimated as approximately 400 kDa, consisting of four identical subunits of 96.3 kDa. Based on the specific activity and kinetic analysis, the ADHES77 tended to have catalytic reaction towards acetaldehyde elimination rather than acetaldehyde formation. Our experimental observation suggests that the ADHES77 may play a pivotal role in modulating intracellular acetaldehyde concentration. PMID:26216639

  3. Dietary vitamin D3 deficiency alters intestinal mucosal defense and increases susceptibility to Citrobacter rodentium-induced colitis.

    PubMed

    Ryz, Natasha R; Lochner, Arion; Bhullar, Kirandeep; Ma, Caixia; Huang, Tina; Bhinder, Ganive; Bosman, Else; Wu, Xiujuan; Innis, Sheila M; Jacobson, Kevan; Vallance, Bruce A

    2015-11-01

    Vitamin D deficiency affects more that 1 billion people worldwide. Although thought to increase risk of bacterial infections, the importance of vitamin D on host defense against intestinal bacterial pathogens is currently unclear since injection of the active form of vitamin D, 1,25(OH)2D3, increased susceptibility to the enteric bacterial pathogen Citrobacter rodentium by suppressing key immune/inflammatory factors. To further characterize the role of vitamin D during bacteria-induced colitis, we fed weanling mice either vitamin D3-deficient or vitamin D3-sufficient diets for 5 wk and then challenged them with C. rodentium. Vitamin D3-deficient mice lost significantly more body weight, carried higher C. rodentium burdens, and developed worsened histological damage. Vitamin D3-deficient mice also suffered greater bacterial translocation to extra-intestinal tissues, including mesenteric lymph nodes, spleen, and liver. Intestinal tissues of infected vitamin D3-deficient mice displayed increased inflammatory cell infiltrates as well as significantly higher gene transcript levels of inflammatory mediators TNF-α, IL-1β, IL-6, TGF-β, IL-17A, and IL-17F as well as the antimicrobial peptide REG3γ. Notably, these exaggerated inflammatory responses accelerated the loss of commensal microbes and were associated with an impaired ability to detoxify bacterial lipopolysaccharide. Overall, these studies show that dietary-induced vitamin D deficiency exacerbates intestinal inflammatory responses to infection, also impairing host defense. PMID:26336925

  4. CXCL9 Contributes to Antimicrobial Protection of the Gut during Citrobacter rodentium Infection Independent of Chemokine-Receptor Signaling

    PubMed Central

    Reid-Yu, Sarah A.; Tuinema, Brian R.; Small, Cherrie N.; Xing, Lydia; Coombes, Brian K.

    2015-01-01

    Chemokines have been shown to be effective bactericidal molecules against a variety of bacteria and fungi in vitro. These direct antimicrobial effects are independent of their chemotactic activities involving immunological receptors. However, the direct biological role that these proteins may play in host defense, particularly against intestinal pathogens, is poorly understood. Here, we show that CXCL9, an ELR- chemokine, exhibits direct antimicrobial activity against Citrobacter rodentium, an attaching/effacing pathogen that infects the gut mucosa. Inhibition of this antimicrobial activity in vivo using anti-CXCL9 antibodies increases host susceptibility to C. rodentium infection with pronounced bacterial penetration into crypts, increased bacterial load, and worsened tissue pathology. Using Rag1-/- mice and CXCR3-/- mice, we demonstrate that the role for CXCL9 in protecting the gut mucosa is independent of an adaptive response or its immunological receptor, CXCR3. Finally, we provide evidence that phagocytes function in tandem with NK cells for robust CXCL9 responses to C. rodentium. These findings identify a novel role for the immune cell-derived CXCL9 chemokine in directing a protective antimicrobial response in the intestinal mucosa. PMID:25643352

  5. Modulation of Inducible Nitric Oxide Synthase Expression by the Attaching and Effacing Bacterial Pathogen Citrobacter rodentium in Infected Mice

    PubMed Central

    Vallance, Bruce A.; Deng, Wanyin; De Grado, Myriam; Chan, Crystal; Jacobson, Kevan; Finlay, B. Brett

    2002-01-01

    Citrobacter rodentium belongs to the attaching and effacing family of enteric bacterial pathogens that includes both enteropathogenic and enterohemorrhagic Escherichia coli. These bacteria infect their hosts by colonizing the intestinal mucosal surface and intimately attaching to underlying epithelial cells. The abilities of these pathogens to exploit the cytoskeleton and signaling pathways of host cells are well documented, but their interactions with the host's antimicrobial defenses, such as inducible nitric oxide synthase (iNOS), are poorly understood. To address this issue, we infected mice with C. rodentium and found that iNOS mRNA expression in the colon significantly increased during infection. Immunostaining identified epithelial cells as the major source for immunoreactive iNOS. Finding that nitric oxide (NO) donors were bacteriostatic for C. rodentium in vitro, we examined whether iNOS expression contributed to host defense by infecting iNOS-deficient mice. Loss of iNOS expression caused a small but significant delay in bacterial clearance without affecting tissue pathology. Finally, immunofluorescence staining was used to determine if iNOS expression was localized to infected cells by staining for the C. rodentium virulence factor, translocated intimin receptor (Tir), as well as iNOS. Interestingly, while more than 85% of uninfected epithelial cells expressed iNOS, fewer than 15% of infected (Tir-positive) cells expressed detectable iNOS. These results demonstrate that both iNOS and intestinal epithelial cells play an active role in host defense during C. rodentium infection. However, the selective expression of iNOS by uninfected but not infected cells suggests that this pathogen has developed mechanisms to locally limit its exposure to host-derived NO. PMID:12379723

  6. Absence of PmrAB-Mediated Phosphoethanolamine Modifications of Citrobacter rodentium Lipopolysaccharide Affects Outer Membrane Integrity▿†

    PubMed Central

    Viau, Charles; Le Sage, Valerie; Ting, Daniel K.; Gross, Jeremy; Le Moual, Hervé

    2011-01-01

    The PmrAB two-component system of enterobacteria regulates a number of genes whose protein products modify lipopolysaccharide (LPS). The LPS is modified during transport to the bacterial outer membrane (OM). A subset of PmrAB-mediated LPS modifications consists of the addition of phosphoethanolamine (pEtN) to lipid A by PmrC and to the core by CptA. In Salmonella enterica, pEtN modifications have been associated with resistance to polymyxin B and to excess iron. To investigate putative functions of pEtN modifications in Citrobacter rodentium, ΔpmrAB, ΔpmrC, ΔcptA, and ΔpmrC ΔcptA deletion mutants were constructed. Compared to the wild type, most mutant strains were found to be more susceptible to antibiotics that must diffuse across the LPS layer of the OM. All mutant strains also showed increased influx rates of ethidium dye across their OM, suggesting that PmrAB-regulated pEtN modifications affect OM permeability. This was confirmed by increased partitioning of the fluorescent dye 1-N-phenylnaphthylamine (NPN) into the OM phospholipid layer of the mutant strains. In addition, substantial release of periplasmic β-lactamase was observed for the ΔpmrAB and ΔpmrC ΔcptA strains, indicating a loss of OM integrity. This study attributes a new role for PmrAB-mediated pEtN LPS modifications in the maintenance of C. rodentium OM integrity. PMID:21378194

  7. Involvement of T helper type 17 and regulatory T cell activity in Citrobacter rodentium invasion and inflammatory damage

    PubMed Central

    Symonds, E L; Riedel, C U; O'Mahony, D; Lapthorne, S; O'Mahony, L; Shanahan, F

    2009-01-01

    Citrobacter rodentium is a murine pathogen that transiently colonizes the lumen of the large intestine. C. rodentium induces colitis, but the relative importance and temporal induction of the T helper type 17 (Th17) and regulatory T cell (Treg) pathways in protection from the infection and inflammation have not been assessed. Our aim was to investigate the key immunological signalling events associated with successful clearance of C. rodentium. Mice were challenged with luminescent-tagged C. rodentium and killed at days 3 (early infection), 10 (peak infection) and 21 (late infection) post-infection. Bioluminescent imaging and bacterial culture determined levels of C. rodentium. Distal colon mRNA expression of interleukin (IL)-17, IL-6, IL-1β, tumour necrosis factor (TNF)-α, forkhead box P3 (FoxP3) and ghrelin were assessed using real-time polymerase chain reaction. Results were compared with age-matched non-infected mice. Low levels of C. rodentium were found at day 3, high levels at day 10, with clearance from the majority of the mice by day 21. In the distal colon, there was up-regulation of TNF-α and FoxP3 throughout the study and increases in IL-6 and IL-17 during the peak and late stages of infection. Ghrelin expression was increased at the peak and late stages of infection. This study has characterized changes to the T helper cell pathways, following the course of C. rodentium infection in mice. There were significant immunological changes, with up-regulation of the Th17 and Treg pathways in the distal colon and an increase in ghrelin expression compared with non-infected control mice. These changes may play a role in the pathology and clearance of C. rodentium. PMID:19659780

  8. INFLUENCE OF PHOSPHATE CORROSION CONTROL COMPOUNDS ON BACTERIAL GROWTH

    EPA Science Inventory

    The influence of two phosphate corrosion compounds on the growth and survival of coliform and other heterotrophic bacteria was investigated in laboratory, field, and model system studies. Growth of Citrobacter freundii, Enterobacter cloacae, and Klebsiella pneumoniae was not sign...

  9. Cadmium accumulation by a Citrobacter sp. immobilized on gel and solid supports: applicability to the treatment of liquid wastes containing heavy metal cations

    SciTech Connect

    Macaskie, L.E.; Wates, J.M.; Dean, A.C.R.

    1987-01-01

    Polyacrylamide gel-immobilized cells of a Citrobacter sp. removed cadmium from flows supplemented with glycerol 2-phosphate, the metal uptake mechanism being mediated by the activity of a cell-bound phosphatase that precipitates liberated inorganic phosphate with heavy metals at the cell surface. The constraints of elevated flow rate and temperature were investigated and the results discussed in terms of the kinetics of immobilized enzymes. Loss in activity with respect to cadmium accumulation but not inorganic phosphate liberation was observed at acid pH and was attributed to the pH-dependent solubility of cadmium phosphate. Similarly high concentrations of chloride ions, and traces of cyanide inhibited cadmium uptake and this was attributed to the ability of these anions to complex heavy metals, especially the ability of CN/sup -/ to form complex anions with Cd/sup 2 +/. The data are discussed in terms of the known chemistry of chloride and cyanide-cadmium complexes and the relevance of these factors in the treatment of metal-containing liquid wastes is discussed. The cells immobilized in polyacrylamide provided a convenient small-scale laboratory model system. It was found that the Citrobacter sp. could be immobilized on glass supports with no chemical treatment or modification necessary. Such cells were also effective in metal accumulation and a prototype system more applicable to the treatment of metal-containing streams on a larger scale is described.

  10. Antibacterial and preliminary phytochemical and physico-chemical analysis of Eucalyptus citriodora Hk leaf.

    PubMed

    Vaghasiya, Y; Nair, R; Chanda, S

    2008-06-15

    The present communication deals with some studies on the antibacterial, physico-chemical and phytochemical parameters of different extracts of Eucalyptus citriodora leaf. The antibacterial study was performed using the agar ditch method on some clinically important bacteria, namely Pseudomonas pseudoalcaligenes, Proteus vulgaris, Citrobacter freundii, Staphylococcus subflava, Bacillus megaterium, and Enterobacter aerogenes. Physico-chemical parameters namely water, methanol, 1,4-dioxane, DMF, acetone soluble extractives, total ash, melting point, and pH were determined according to pharmacopoeial procedures. Methanol gave the maximum extract while it was minimum in water. Phytochemical parameters were screened for alkaloids, tannins, cardiac glycosides, saponins, steroids and flavonoids. Tannins and flavonoids gave positive results, while steroids and glycosides were absent. The most susceptible bacteria was C. freundii, while the most resistant was P. vulgaris. PMID:18569717

  11. In vitro antibacterial activity of ME1207, a new oral cephalosporin.

    PubMed

    Miyazaki, S; Miyazaki, Y; Tsuji, A; Nishida, M; Goto, S

    1991-08-01

    ME1207 is the prodrug of ME1206. Its in vitro antibacterial activity was compared with that of cefteram, cefpodoxime, cefixime, and cefaclor against various clinical isolates. ME1206 was more active than the other cephems tested against staphylococci, streptococci, Morganella morganii, Pseudomonas cepacia, and Flavobacterium meningosepticum and had the most potent activity against Haemophilus influenzae and Neiserria gonorrhoeae. The drug also showed a wide spectrum of activity against other gram-positive and gram-negative bacteria, except methicillin-resistant Staphylococcus aureus, Enterococcus faecalis, Citrobacter freundii, Pseudomonas aeruginosa, Xanthomonas maltophilia, and Alcaligenes xylosoxydans. PMID:1929344

  12. Citrobacter amalonaticus Phytase on the Cell Surface of Pichia pastoris Exhibits High pH Stability as a Promising Potential Feed Supplement

    PubMed Central

    Li, Cheng; Lin, Ying; Huang, Yuanyuan; Liu, Xiaoxiao; Liang, Shuli

    2014-01-01

    Phytase expressed and anchored on the cell surface of Pichia pastoris avoids the expensive and time-consuming steps of protein purification and separation. Furthermore, yeast cells with anchored phytase can be used as a whole-cell biocatalyst. In this study, the phytase gene of Citrobacter amalonaticus was fused with the Pichia pastoris glycosylphosphatidylinositol (GPI)-anchored glycoprotein homologue GCW61. Phytase exposed on the cell surface exhibits a high activity of 6413.5 U/g, with an optimal temperature of 60°C. In contrast to secreted phytase, which has an optimal pH of 5.0, phytase presented on the cell surface is characterized by an optimal pH of 3.0. Moreover, our data demonstrate that phytase anchored on the cell surface exhibits higher pH stability than its secreted counterpart. Interestingly, our in vitro digestion experiments demonstrate that phytase attached to the cell surface is a more efficient enzyme than secreted phytase. PMID:25490768

  13. IL-4 Protects the Mitochondria Against TNFα and IFNγ Induced Insult During Clearance of Infection with Citrobacter rodentium and Escherichia coli

    PubMed Central

    Maiti, Arpan K.; Sharba, Sinan; Navabi, Nazanin; Forsman, Huamei; Fernandez, Harvey R.; Lindén, Sara K.

    2015-01-01

    Citrobacter rodentium is a murine pathogen that serves as a model for enteropathogenic Escherichia coli. C. rodentium infection reduced the quantity and activity of mitochondrial respiratory complexes I and IV, as well as phosphorylation capacity, mitochondrial transmembrane potential and ATP generation at day 10, 14 and 19 post infection. Cytokine mRNA quantification showed increased levels of IFNγ, TNFα, IL-4, IL-6, and IL-12 during infection. The effects of adding these cytokines, C. rodentium and E. coli were hence elucidated using an in vitro colonic mucosa. Both infection and TNFα, individually and combined with IFNγ, decreased complex I and IV enzyme levels and mitochondrial function. However, IL-4 reversed these effects, and IL-6 protected against loss of complex IV. Both in vivo and in vitro, the dysfunction appeared caused by nitric oxide-generation, and was alleviated by an antioxidant targeting mitochondria. IFNγ −/− mice, containing a similar pathogen burden but higher IL-4 and IL-6, displayed no loss of any of the four complexes. Thus, the cytokine environment appears to be a more important determinant of mitochondrial function than direct actions of the pathogen. As IFNγ and TNFα levels increase during clearance of infection, the concomitant increase in IL-4 and IL-6 protects mitochondrial function. PMID:26481427

  14. Social stress-enhanced severity of Citrobacter rodentium-induced colitis is CCL2-dependent and attenuated by probiotic Lactobacillus reuteri.

    PubMed

    Mackos, A R; Galley, J D; Eubank, T D; Easterling, R S; Parry, N M; Fox, J G; Lyte, M; Bailey, M T

    2016-03-01

    Psychological stressors are known to affect colonic diseases but the mechanisms by which this occurs, and whether probiotics can prevent stressor effects, are not understood. Because inflammatory monocytes that traffic into the colon can exacerbate colitis, we tested whether CCL2, a chemokine involved in monocyte recruitment, was necessary for stressor-induced exacerbation of infectious colitis. Mice were exposed to a social disruption stressor that entails repeated social defeat. During stressor exposure, mice were orally challenged with Citrobacter rodentium to induce a colonic inflammatory response. Exposure to the stressor during challenge resulted in significantly higher colonic pathogen levels, translocation to the spleen, increases in colonic macrophages, and increases in inflammatory cytokines and chemokines. The stressor-enhanced severity of C. rodentium-induced colitis was not evident in CCL2(-/-) mice, indicating the effects of the stressor are CCL2-dependent. In addition, we tested whether probiotic intervention could attenuate stressor-enhanced infectious colitis by reducing monocyte/macrophage accumulation. Treating mice with probiotic Lactobacillus reuteri reduced CCL2 mRNA levels in the colon and attenuated stressor-enhanced infectious colitis. These data demonstrate that probiotic L. reuteri can prevent the exacerbating effects of stressor exposure on pathogen-induced colitis, and suggest that one mechanism by which this occurs is through downregulation of the chemokine CCL2. PMID:26422754

  15. Single molecule sequencing to track plasmid diversity of hospital-associated carbapenemase-producing Enterobacteriaceae

    PubMed Central

    Conlan, Sean; Thomas, Pamela J.; Deming, Clayton; Park, Morgan; Lau, Anna F.; Dekker, John P.; Snitkin, Evan S.; Clark, Tyson A.; Luong, Khai; Song, Yi; Tsai, Yu-Chih; Boitano, Matthew; Gupta, Jyoti; Brooks, Shelise Y.; Schmidt, Brian; Young, Alice C.; Thomas, James W.; Bouffard, Gerard G.; Blakesley, Robert W.; Mullikin, James C.; Korlach, Jonas; Henderson, David K.; Frank, Karen M.; Palmore, Tara N.; Segre, Julia A.

    2014-01-01

    Public health officials have raised concerns that plasmid transfer between Enterobacteriaceae species may spread resistance to carbapenems, an antibiotic class of last resort, thereby rendering common healthcare-associated infections nearly impossible to treat. We performed comprehensive surveillance and genomic sequencing to identify carbapenem-resistant Enterobacteriaceae in the NIH Clinical Center patient population and hospital environment in order to to articulate the diversity of carbapenemase-encoding plasmids and survey the mobility of and assess the mobility of these plasmids between bacterial species. We isolated a repertoire of carbapenemase-encoding Enterobacteriaceae, including multiple strains of Klebsiella pneumoniae, Klebsiella oxytoca, Escherichia coli, Enterobacter cloacae, Citrobacter freundii, and Pantoea species. Long-read genome sequencing with full end-to-end assembly revealed that these organisms carry the carbapenem-resistance genes on a wide array of plasmids. Klebsiella pneumoniae and Enterobacter cloacae isolated simultaneously from a single patient harbored two different carbapenemase-encoding plasmids, overriding the epidemiological scenario of plasmid transfer between organisms within this patient. We did, however, find evidence supporting horizontal transfer of carbapenemase-encoding plasmids between Klebsiella pneumoniae, Enterobacter cloacae and Citrobacter freundii in the hospital environment. Our comprehensive sequence data, with full plasmid identification, challenges assumptions about horizontal gene transfer events within patients and identified wider possible connections between patients and the hospital environment. In addition, we identified a new carbapenemase-encoding plasmid of potentially high clinical impact carried by Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae and Pantoea species, from unrelated patients and the hospital environment. PMID:25232178

  16. RegA, an AraC-like protein, is a global transcriptional regulator that controls virulence gene expression in Citrobacter rodentium.

    PubMed

    Hart, Emily; Yang, Ji; Tauschek, Marija; Kelly, Michelle; Wakefield, Matthew J; Frankel, Gad; Hartland, Elizabeth L; Robins-Browne, Roy M

    2008-11-01

    Citrobacter rodentium is an attaching and effacing pathogen which causes transmissible colonic hyperplasia in mice. Infection with C. rodentium serves as a model for infection of humans with enteropathogenic and enterohemorrhagic Escherichia coli. To identify novel colonization factors of C. rodentium, we screened a signature-tagged mutant library of C. rodentium in mice. One noncolonizing mutant had a single transposon insertion in an open reading frame (ORF) which we designated regA because of its homology to genes encoding members of the AraC family of transcriptional regulators. Deletion of regA in C. rodentium resulted in markedly reduced colonization of the mouse intestine. Examination of lacZ transcriptional fusions using promoter regions of known and putative virulence-associated genes of C. rodentium revealed that RegA strongly stimulated transcription of two newly identified genes located close to regA, which we designated adcA and kfcC. The cloned adcA gene conferred autoaggregation and adherence to mammalian cells to E. coli strain DH5alpha, and a kfc mutation led to a reduction in the duration of intestinal colonization, but the kfc mutant was far less attenuated than the regA mutant. These results indicated that other genes of C. rodentium whose expression required activation by RegA were required for colonization. Microarray analysis revealed a number of RegA-regulated ORFs encoding proteins homologous to known colonization factors. Transcription of these putative virulence determinants was activated by RegA only in the presence of sodium bicarbonate. Taken together, these results show that RegA is a global regulator of virulence in C. rodentium which activates factors that are required for intestinal colonization. PMID:18765720

  17. The in vitro and in vivo effects of constitutive light expression on a bioluminescent strain of the mouse enteropathogen Citrobacter rodentium.

    PubMed

    Read, Hannah M; Mills, Grant; Johnson, Sarah; Tsai, Peter; Dalton, James; Barquist, Lars; Print, Cristin G; Patrick, Wayne M; Wiles, Siouxsie

    2016-01-01

    Bioluminescent reporter genes, such as those from fireflies and bacteria, let researchers use light production as a non-invasive and non-destructive surrogate measure of microbial numbers in a wide variety of environments. As bioluminescence needs microbial metabolites, tagging microorganisms with luciferases means only live metabolically active cells are detected. Despite the wide use of bioluminescent reporter genes, very little is known about the impact of continuous (also called constitutive) light expression on tagged bacteria. We have previously made a bioluminescent strain of Citrobacter rodentium, a bacterium which infects laboratory mice in a similar way to how enteropathogenic Escherichia coli (EPEC) and enterohaemorrhagic E. coli (EHEC) infect humans. In this study, we compared the growth of the bioluminescent C. rodentium strain ICC180 with its non-bioluminescent parent (strain ICC169) in a wide variety of environments. To understand more about the metabolic burden of expressing light, we also compared the growth profiles of the two strains under approximately 2,000 different conditions. We found that constitutive light expression in ICC180 was near-neutral in almost every non-toxic environment tested. However, we also found that the non-bioluminescent parent strain has a competitive advantage over ICC180 during infection of adult mice, although this was not enough for ICC180 to be completely outcompeted. In conclusion, our data suggest that constitutive light expression is not metabolically costly to C. rodentium and supports the view that bioluminescent versions of microbes can be used as a substitute for their non-bioluminescent parents to study bacterial behaviour in a wide variety of environments. PMID:27366640

  18. Genomic Insights into a New Citrobacter koseri Strain Revealed Gene Exchanges with the Virulence-Associated Yersinia pestis pPCP1 Plasmid.

    PubMed

    Armougom, Fabrice; Bitam, Idir; Croce, Olivier; Merhej, Vicky; Barassi, Lina; Nguyen, Ti-Thien; La Scola, Bernard; Raoult, Didier

    2016-01-01

    The history of infectious diseases raised the plague as one of the most devastating for human beings. Far too often considered an ancient disease, the frequent resurgence of the plague has led to consider it as a reemerging disease in Madagascar, Algeria, Libya, and Congo. The genetic factors associated with the pathogenicity of Yersinia pestis, the causative agent of the plague, involve the acquisition of the pPCP1 plasmid that promotes host invasion through the expression of the virulence factor Pla. The surveillance of plague foci after the 2003 outbreak in Algeria resulted in a positive detection of the specific pla gene of Y. pestis in rodents. However, the phenotypic characterization of the isolate identified a Citrobacter koseri. The comparative genomics of our sequenced C. koseri URMITE genome revealed a mosaic gene structure resulting from the lifestyle of our isolate and provided evidence for gene exchanges with different enteric bacteria. The most striking was the acquisition of a continuous 2 kb genomic fragment containing the virulence factor Pla of the Y. pestis pPCP1 plasmid; however, the subcutaneous injection of the CKU strain in mice did not produce any pathogenic effect. Our findings demonstrate that fast molecular detection of plague using solely the pla gene is unsuitable and should rather require Y. pestis gene marker combinations. We also suggest that the evolutionary force that might govern the expression of pathogenicity can occur through the acquisition of virulence genes but could also require the loss or the inactivation of resident genes such as antivirulence genes. PMID:27014253

  19. Activation of Plasmacytoid Dendritic Cells in Colon-Draining Lymph Nodes during Citrobacter rodentium Infection Involves Pathogen-Sensing and Inflammatory Pathways Distinct from Conventional Dendritic Cells.

    PubMed

    Toivonen, Raine; Kong, Lingjia; Rasool, Omid; Lund, Riikka J; Lahesmaa, Riitta; Hänninen, Arno

    2016-06-01

    Dendritic cells (DCs) bear the main responsibility for initiation of adaptive immune responses necessary for antimicrobial immunity. In the small intestine, afferent lymphatics convey Ags and microbial signals to mesenteric lymph nodes (LNs) to induce adaptive immune responses against microbes and food Ags derived from the small intestine. Whether the large intestine is covered by the same lymphatic system or represents its own lymphoid compartment has not been studied until very recently. We identified three small mesenteric LNs, distinct from small intestinal LNs, which drain lymph specifically from the colon, and studied DC responses to the attaching and effacing pathogen Citrobacter rodentium in these. Transcriptional profiling of conventional (CD11c(high)CD103(high)) DC and plasmacytoid (plasmacytoid DC Ag-1(high)B220(+)CD11c(int)) DC (pDC) populations during steady-state conditions revealed activity of distinct sets of genes in these two DC subsets, both in small intestinal and colon-draining LNs. C. rodentium activated DC especially in colon-draining LNs, and gene expression changed in pDC more profoundly than in conventional DC. Among the genes most upregulated in pDC were C-type lectin receptor CLEC4E, IL-1Rs (IL-1R1 and -2), proinflammatory cytokines (IL-1a and IL-6), and TLR6. Our results indicate that colon immune surveillance is distinct from that of the small intestine in terms of draining LNs, and identify pDC as active sentinels of colonic inflammation and/or microbial dysbiosis. PMID:27183629

  20. Genomic Insights into a New Citrobacter koseri Strain Revealed Gene Exchanges with the Virulence-Associated Yersinia pestis pPCP1 Plasmid

    PubMed Central

    Armougom, Fabrice; Bitam, Idir; Croce, Olivier; Merhej, Vicky; Barassi, Lina; Nguyen, Ti-Thien; La Scola, Bernard; Raoult, Didier

    2016-01-01

    The history of infectious diseases raised the plague as one of the most devastating for human beings. Far too often considered an ancient disease, the frequent resurgence of the plague has led to consider it as a reemerging disease in Madagascar, Algeria, Libya, and Congo. The genetic factors associated with the pathogenicity of Yersinia pestis, the causative agent of the plague, involve the acquisition of the pPCP1 plasmid that promotes host invasion through the expression of the virulence factor Pla. The surveillance of plague foci after the 2003 outbreak in Algeria resulted in a positive detection of the specific pla gene of Y. pestis in rodents. However, the phenotypic characterization of the isolate identified a Citrobacter koseri. The comparative genomics of our sequenced C. koseri URMITE genome revealed a mosaic gene structure resulting from the lifestyle of our isolate and provided evidence for gene exchanges with different enteric bacteria. The most striking was the acquisition of a continuous 2 kb genomic fragment containing the virulence factor Pla of the Y. pestis pPCP1 plasmid; however, the subcutaneous injection of the CKU strain in mice did not produce any pathogenic effect. Our findings demonstrate that fast molecular detection of plague using solely the pla gene is unsuitable and should rather require Y. pestis gene marker combinations. We also suggest that the evolutionary force that might govern the expression of pathogenicity can occur through the acquisition of virulence genes but could also require the loss or the inactivation of resident genes such as antivirulence genes. PMID:27014253

  1. Induction of anxiety-like behavior in mice during the initial stages of infection with the agent of murine colonic hyperplasia Citrobacter rodentium.

    PubMed

    Lyte, Mark; Li, Wang; Opitz, Noel; Gaykema, Ronald P A; Goehler, Lisa E

    2006-10-30

    Symptoms of anxiety frequently occur concomitant to the development and persistence of inflammatory bowel disease (IBD) in patients. In the present study, we utilized an animal model of IBD, infection with Citrobacter rodentium, to determine whether the infection per se can drive anxiety-like behavior. Nine-week-old CF-1 male mice were challenged orally with either saline or C. rodentium. Early in the infective process (7-8 h later), mice were tested on a hole-board open field apparatus for anxiety-like behavior measurement. Immediately following behavioral testing, plasma samples were obtained for immune cytokine analysis and colons were excised for histological analysis. In additional animals, vagal ganglia were removed and processed for c-Fos protein detection. Challenge with C. rodentium significantly increased anxiety-like behavior as evidenced by avoidance of the center area and increased risk assessment behavior. Plasma levels of the cytokines IFN-gamma, TNF-alpha and IL-12 were not different. However vagal sensory ganglia from C. rodentium-treated animals evinced significantly more c-Fos protein-positive neurons, consistent with vagal afferent transmission of C. rodentium-related signals from gut to brain. Histological examination of the colon indicated a lack of overt inflammation at the 8 h post-challenge time point, indicating that the differences in behavior were unlikely to follow from inflammation-related stress. The results of the present study demonstrate that infection with C. rodentium can induce anxiety-like symptoms that are likely mediated via vagal sensory neurons. PMID:16887154

  2. The in vitro and in vivo effects of constitutive light expression on a bioluminescent strain of the mouse enteropathogen Citrobacter rodentium

    PubMed Central

    Read, Hannah M.; Mills, Grant; Johnson, Sarah; Tsai, Peter; Dalton, James; Barquist, Lars; Print, Cristin G.; Patrick, Wayne M.

    2016-01-01

    Bioluminescent reporter genes, such as those from fireflies and bacteria, let researchers use light production as a non-invasive and non-destructive surrogate measure of microbial numbers in a wide variety of environments. As bioluminescence needs microbial metabolites, tagging microorganisms with luciferases means only live metabolically active cells are detected. Despite the wide use of bioluminescent reporter genes, very little is known about the impact of continuous (also called constitutive) light expression on tagged bacteria. We have previously made a bioluminescent strain of Citrobacter rodentium, a bacterium which infects laboratory mice in a similar way to how enteropathogenic Escherichia coli (EPEC) and enterohaemorrhagic E. coli (EHEC) infect humans. In this study, we compared the growth of the bioluminescent C. rodentium strain ICC180 with its non-bioluminescent parent (strain ICC169) in a wide variety of environments. To understand more about the metabolic burden of expressing light, we also compared the growth profiles of the two strains under approximately 2,000 different conditions. We found that constitutive light expression in ICC180 was near-neutral in almost every non-toxic environment tested. However, we also found that the non-bioluminescent parent strain has a competitive advantage over ICC180 during infection of adult mice, although this was not enough for ICC180 to be completely outcompeted. In conclusion, our data suggest that constitutive light expression is not metabolically costly to C. rodentium and supports the view that bioluminescent versions of microbes can be used as a substitute for their non-bioluminescent parents to study bacterial behaviour in a wide variety of environments. PMID:27366640

  3. R-Spondins Are Expressed by the Intestinal Stroma and are Differentially Regulated during Citrobacter rodentium- and DSS-Induced Colitis in Mice

    PubMed Central

    Kang, Eugene; Yousefi, Mitra; Gruenheid, Samantha

    2016-01-01

    The R-spondin family of proteins has recently been described as secreted enhancers of β-catenin activation through the canonical Wnt signaling pathway. We previously reported that Rspo2 is a major determinant of susceptibility to Citrobacter rodentium-mediated colitis in mice and recent genome-wide association studies have revealed RSPO3 as a candidate Crohn’s disease-specific inflammatory bowel disease susceptibility gene in humans. However, there is little information on the endogenous expression and cellular source of R-spondins in the colon at steady state and during intestinal inflammation. RNA sequencing and qRT-PCR were used to assess the expression of R-spondins at steady state and in two mouse models of colonic inflammation. The cellular source of R-spondins was assessed in specific colonic cell populations isolated by cell sorting. Data mining from publicly available datasets was used to assess the expression of R-spondins in the human colon. At steady state, colonic expression of R-spondins was found to be exclusive to non-epithelial CD45- lamina propria cells, and Rspo3/RSPO3 was the most highly expressed R-spondin in both mouse and human colon. R-spondin expression was found to be highly dynamic and differentially regulated during C. rodentium infection and dextran sodium sulfate (DSS) colitis, with notably high levels of Rspo3 expression during DSS colitis, and high levels of Rspo2 expression during C. rodentium infection, specifically in susceptible mice. Our data are consistent with the hypothesis that in the colon, R-spondins are expressed by subepithelial stromal cells, and that Rspo3/RSPO3 is the family member most implicated in colonic homeostasis. The differential regulation of the R-spondins in different models of intestinal inflammation indicate they respond to specific pathogenic and inflammatory signals that differ in the two models and provides further evidence that this family of proteins plays a key role in linking intestinal

  4. Chemical composition and antibacterial activity of Lavandula coronopifolia essential oil against antibiotic-resistant bacteria.

    PubMed

    Ait Said, L; Zahlane, K; Ghalbane, I; El Messoussi, S; Romane, A; Cavaleiro, C; Salgueiro, L

    2015-01-01

    The aim of this study was to analyse the composition of the essential oil (EO) of Lavandula coronopifolia from Morocco and to evaluate its in vitro antibacterial activity against antibiotic-resistant bacteria isolated from clinical infections. The antimicrobial activity was assessed by a broth micro-well dilution method using multiresistant clinical isolates of 11 pathogenic bacteria: Klebsiella pneumoniae subsp. pneumoniae, Klebsiella ornithinolytica, Escherichia coli, Enterobacter cloacae, Enterobacter aerogenes, Providencia rettgeri, Citrobacter freundii, Hafnia alvei, Salmonella spp., Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus. The main compounds of the oil were carvacrol (48.9%), E-caryophyllene (10.8%) and caryophyllene oxide (7.7%). The oil showed activity against all tested strains with minimal inhibitory concentration (MIC) values ranging between 1% and 4%. For most of the strains, the MIC value was equivalent to the minimal bactericidal concentration value, indicating a clear bactericidal effect of L. coronopifolia EO. PMID:25174508

  5. [2 cases of osteomyelitis in acute leukemia in the induction phase of treatment].

    PubMed

    De Bernardi, B; Garventa, A; Garrè, M L; Taccone, A; Canale, G; Gandus, S

    1983-01-01

    Whereas children with Acute Leukemia are highly susceptible to infectious complications, the occurrence of acute osteomyelitis is extremely rare in these patients. The authors describe two such cases in children at onset of an acute lymphoblastic and of a myelomonocytic leukemia, respectively. In the former case, the clinical course has been characterized by the progressive involvement of several joints and bones. A citrobacter Freundii was isolated in the synovial fluid of an involved knee. This complication was successfully treated with proper antimicrobic agents and surgical toilet, while the patient was vigorously treated for her leukemia, achieving a complete remission. The latter case developed a right humerus osteomyelitis from an Enterobacter. The patient failed to respond to antibiotics, and his leukemia also turned refractory to antiblastic therapy. The difficulty in the differential diagnosis among the X-graphic aspects of leukemic, inflammatory and degenerative disease of bones are discussed by the authors. Some pathogenetic hypothesis of leukemic osteomyelitis are also presented. PMID:6647082

  6. Bacteria isolated from 25 hydatid cysts in sheep, cattle and goats.

    PubMed

    Ziino, G; Giuffrida, A; Bilei, S; Panebianco, A

    2009-08-22

    Bacteria were isolated from 12 of 25 hydatid cysts collected from the lungs and livers of cattle, sheep and goats slaughtered in the province of Messina, Sicily, Italy. Citrobacter freundii was isolated from seven of the cysts, Aeromonas hydrophila from three, Staphylococcus species from two, Salmonella species from two and Escherichia coli and Proteus vulgaris from one. PMID:19700784

  7. Prevalence of multidrug resistant uropathogenic bacteria in pediatric patients of a tertiary care hospital in eastern India.

    PubMed

    Mishra, Monali P; Sarangi, Rachita; Padhy, Rabindra N

    2016-01-01

    Today, because systemic infections such as urinary tract infection (UTI) affect even pediatric patients, antibiotic resistant bacteria have become a constant clinical challenge. In the present study, a total of 1054 urine samples were collected from pediatric patients over 18 months. From these samples, 510 isolates of pathogenic bacteria were collected using HiCrome UTI agar. Antibiotic sensitivity tests of isolates were performed using the Kirby-Bauer method. Two Gram-positive bacteria (Enterococcus faecalis and Staphylococcus aureus) and 7 Gram-negative bacteria (Citrobacter freundii, Enterobacter aerogenes, Escherichia coli, Klebsiella oxytoca, K. pneumoniae, Proteus vulgaris and Pseudomonas aeruginosa) were isolated. Antibiograms of isolated bacteria were ascertained using antibiotics of 4 classes: aminoglycosides, β-lactams, fluoroquinolones and 2 stand-alones (co-trimoxazole and nitrofurantoin). Based on percent values of antibiotic resistance, isolated bacteria were (in decreasing order of number of isolated isolates): E. coli (109)>S. aureus (65)>E. faecalis (82)>E. aerogenes (64)>C. freundii (41)>P. aeruginosa (32)>K. pneumoniae (45)>K. oxytoca (50)>P. vulgaris (22). Surveillance results show that MDR isolates of 9 pathogenic bacteria were prevalent in the environment around the hospital. Thus, revisions to the antimicrobial stewardship program in this area of the country are required to increase clinician confidence in empiric therapy, which is often used for UTI cases. PMID:26617250

  8. Effect of coiled-coil peptides on the function of the type III secretion system-dependent activity of enterohemorragic Escherichia coli O157:H7 and Citrobacter rodentium.

    PubMed

    Larzábal, Mariano; Zotta, Elsa; Ibarra, Cristina; Rabinovitz, Bettina C; Vilte, Daniel A; Mercado, Elsa C; Cataldi, Ángel

    2013-01-01

    Many animal and human pathogenic Gram-negative bacteria such as Salmonella, Yersinia, enterohemorrhagic Escherichia coli (EHEC), and enteropathogenic Escherichia coli (EPEC) possess a type III secretion system (TTSS) that is used to deliver virulence proteins directly into the host cell. Recent evidence has suggested that CoilA and CoilB, two synthetic peptides corresponding to coiled-coil domains of the translocator protein EspA, are effective in inhibiting the action of TTSS from EPEC. In the current study, the action of these coiled-coil peptides on the TTSS of EHEC O157:H7 and Citrobacter rodentium was examined. CoilA and CoilB showed to be effective in reducing the red blood cell lysis mediated by EHEC O157:H7 and the in vitro secretion of translocator proteins EspB and EspD by EHEC O157:H7 and EspD by C. rodentium. Treatment of mice with CoilA and CoilB peptides prevented colon damage when the animals were inoculated with C. rodentium. Colon samples of the non-treated group showed areas with loss of superficial epithelium, damaged cells, and endoluminal mononuclear inflammatory infiltrate, consistent with histological lesions induced by C. rodentium, whereas mice treated with the synthetic peptides displayed normal surface epithelium showing a similar structure as the uninfected control group. These encouraging results prompt us to test coiled-coil peptides as treatment or vaccines in other models of bacterial infections in future work. PMID:23312797

  9. Resistance to antibiotics in gram-negative rods from clinical material of hospital and community origin.

    PubMed

    Kolár, M; Hájek, V; Sázelová, J; Krátká, J; Koukalová, D

    1995-01-01

    The authors examined the resistance to 13 antibiotics and chemotherapeutic agents by the diluting micromethod and the routine disk method in the group of 5375 gram-negative strains of 7 genera which prevailed in clinical material of an hospital (FN Olomouc) and in material of community (OHS Olomouc) provenance during the years 1992 and 1993. In the majority of cases, the resistance was more frequent in the strains isolated from the hospital material. The most remarkable differences were found in A cinetobacter sp. (9-76%), Enterobacter sp. (10-60%) and Citrobacter sp. (18-58%). In other examined species, the differences varied in the ranges 3-40% in E.coli, 2-33% in Klebsiella sp., 0-28% in P. vulgaris, 2-28% in P.mirabilis, 0-16% in M.morganii, and 0-13% in P. aeruginosa. PMID:8686556

  10. [Utility of pyrrolidonyl-arylamidase detection for typing Enterobacteriaceae and non-fermenting Gram-negative bacteria].

    PubMed

    Nicola, F; Centorbi, H; Bantar, C; Smayevsky, J; Bianchini, H

    1995-01-01

    Detection of pyrrolidonyl-aryl-amidase activity (PYR) is an important tool to identify gram-positive cocci, such as staphylococci, enterococci, streptococci, and other related genera. However, only few studies evaluating its usefulness with gram-negative rods have been published. Thus, a prospective study including 542 and 215 unique clinical isolates of Enterobacteriaceae and non-fermentative gram-negative rods, respectively, was undertaken. Strains were identified by conventional methods. PYR test was performed using a commercial kit, according to the manufacturer recommendations. Positive results were uniformly obtained for the PYR test with the following species: Citrobacter spp, Klebsiella spp, Enterobacter aerogenes, Enterobacter agglomerans group, Serratia marcescens and S. odorifera. On the other hand, negative results were uniformly displayed by E. coli (including inactive E. coli), Protease group, Salmonellia spp, Shigella spp, Acinetobacter spp, Burkholderia (Pseudomonas) cepacia and Flavobacterium spp. Variable results were shown in Pseudomonas aeruginosa, Stenotrophomonas (xanthomonas) malthophilia, Kluyvera cryocrescens, and Enterobacter cloacae. PYR test proved to be a reliable and simple tool to rapidly distinguish certain species belonging to Enterobacteriaceae (ie. Citrobacter freundii from Salmonella spp, and inactive E. coli from K. ozaenae). Further studies, including a wide diversity of species, are required to assess usefulness of the PYR test for the identification of non-fermentative gram-negative rods. PMID:8850133

  11. Effects of pathogen-specific clinical mastitis on probability of conception in Holstein dairy cows.

    PubMed

    Hertl, J A; Schukken, Y H; Welcome, F L; Tauer, L W; Gröhn, Y T

    2014-11-01

    The objective of this study was to estimate the effects of pathogen-specific clinical mastitis (CM), occurring in different weekly intervals before or after artificial insemination (AI), on the probability of conception in Holstein cows. Clinical mastitis occurring in weekly intervals from 6 wk before until 6 wk after AI was modeled. The first 4 AI in a cow's lactation were included. The following categories of pathogens were studied: Streptococcus spp. (comprising Streptococcus dysgalactiae, Streptococcus uberis, and other Streptococcus spp.); Staphylococcus aureus; coagulase-negative staphylococci (CNS); Escherichia coli; Klebsiella spp.; cases with CM signs but no bacterial growth (above the level that can be detected from our microbiological procedures) observed in the culture sample and cases with contamination (≥ 3 pathogens in the sample); and other pathogens [including Citrobacter, yeasts, Trueperella pyogenes, gram-negative bacilli (i.e., gram-negative organisms other than E. coli, Klebsiella spp., Enterobacter, and Citrobacter), Corynebacterium bovis, Corynebacterium spp., Pasteurella, Enterococcus, Pseudomonas, Mycoplasma, Prototheca, and others]. Other factors included in the model were parity (1, 2, 3, 4 and higher), season of AI (winter, spring, summer, autumn), day in lactation of first AI, farm, and other non-CM diseases (retained placenta, metritis, ketosis, displaced abomasum). Data from 90,271 AI in 39,361 lactations in 20,328 cows collected from 2003/2004 to 2011 from 5 New York State dairy farms were analyzed in a generalized linear mixed model with a Poisson distribution. The largest reductions in probability of conception were associated with CM occurring in the week before AI or in the 2 wk following AI. Escherichia coli and Klebsiella spp. had the greatest adverse effects on probability of conception. The probability of conception for a cow with any combination of characteristics may be calculated based on the parameter estimates. These

  12. Rapid Identification of Carbapenemase Genes in Gram-Negative Bacteria with an Oligonucleotide Microarray-Based Assay

    PubMed Central

    Braun, Sascha D.; Monecke, Stefan; Thürmer, Alexander; Ruppelt, Antje; Makarewicz, Oliwia; Pletz, Mathias; Reißig, Annett; Slickers, Peter; Ehricht, Ralf

    2014-01-01

    Rapid molecular identification of carbapenemase genes in Gram-negative bacteria is crucial for infection control and prevention, surveillance and for epidemiological purposes. Furthermore, it may have a significant impact upon determining the appropriate initial treatment and greatly benefit for critically ill patients. A novel oligonucleotide microarray-based assay was developed to simultaneously detect genes encoding clinically important carbapenemases as well as selected extended (ESBL) and narrow spectrum (NSBL) beta-lactamases directly from clonal culture material within few hours. Additionally, a panel of species specific markers was included to identify Escherichia coli, Pseudomonas aeruginosa, Citrobacter freundii/braakii, Klebsiella pneumoniae and Acinetobacter baumannii. The assay was tested using a panel of 117 isolates collected from urinary, blood and stool samples. For these isolates, phenotypic identifications and susceptibility tests were available. An independent detection of carbapenemase, ESBL and NSBL genes was carried out by various external reference laboratories using PCR methods. In direct comparison, the microarray correctly identified 98.2% of the covered carbapenemase genes. This included blaVIM (13 out of 13), blaGIM (2/2), blaKPC (27/27), blaNDM (5/5), blaIMP-2/4/7/8/13/14/15/16/31 (10/10), blaOXA-23 (12/13), blaOXA-40-group (7/7), blaOXA-48-group (32/33), blaOXA-51 (1/1) and blaOXA-58 (1/1). Furthermore, the test correctly identified additional beta-lactamases [blaOXA-1 (16/16), blaOXA-2 (4/4), blaOXA-9 (33/33), OXA-10 (3/3), blaOXA-51 (25/25), blaOXA-58 (2/2), CTX-M1/M15 (17/17) and blaVIM (1/1)]. In direct comparison to phenotypical identification obtained by VITEK or MALDI-TOF systems, 114 of 117 (97.4%) isolates, including Acinetobacter baumannii (28/28), Enterobacter spec. (5/5), Escherichia coli (4/4), Klebsiella pneumoniae (62/63), Klebsiella oxytoca (0/2), Pseudomonas aeruginosa (12/12), Citrobacter freundii (1/1) and

  13. Immunofluorescence Technique for the Detection of Salmonellae in Various Foods

    PubMed Central

    Insalata, N. F.; Schulte, S. J.; Berman, J. H.

    1967-01-01

    Salmonella species have been detected in nine food varieties by use of fluorescent antibodies without false-positive or false-negative results. Test antisera were specially prepared, commercially available, conjugated polyvalent O globulin absorbed with cultures of Escherichia coli and Citrobacter freundii, and polyvalent phase II H globulin antibodies. Use of this technique permits a decrease of 24 hr in time normally required for Salmonella detection when compared with cultural Salmonella recovery methods. PMID:16349728

  14. Association of tellurium resistance and bacteriophage inhibition conferred by R plasmids.

    PubMed Central

    Taylor, D E; Summers, A O

    1979-01-01

    Concomitant resistance to tellurium compounds (Ter) and inhibition of coli-phage development (Phi) are properties mediated by many H2 incompatibility group R plasmids which have been isolated from diverse bacterial and geographic sources. Ter plasmids from tellurium-resistant bacteria that were isolated from sewage and industrial wastes also mediated phage inhibition. Of these Ter plasmids, three from Citrobacter freundii belonged to the H incompatibility group, whereas three from Klebsiella pneumoniae did not. Images PMID:374351

  15. Isolation of some pathogenic bacteria from the great spruce bark beetle, Dendroctonus micans and its specific predator, Rhizophagus grandis.

    PubMed

    Yaman, M; Ertürk, O; Aslan, I

    2010-01-01

    Some bacteria were isolated from Dendroctonus micans and its specific predator, Rhizophagus grandis. Six bacteria from D. micans were identified as Bacillus pumilus, Enterobacter intermedius, Citrobacter freundii, Cellulomonas flavigena, Microbacterium liquefaciens and Enterobacter amnigenus, three bacteria from R. grandis as Klebsiella pneumoniae, Pantoea agglomerans and Serratia grimesii, on the basis of fatty acid methyl ester analysis and carbon utilization profile by using Microbial Identification and Biolog Microplate Systems. Their insecticidal effects were tested on larvae and adults of D. micans. PMID:20336502

  16. [Technical support in the testing of microoganisms for their ability to accumulate strontium and cesium from aqueous solutions]. Final reports, Task order No. 2

    SciTech Connect

    Not Available

    1987-06-15

    This report describes the binding of cesium and strontium ions from aqueous solution in a variety of microorganisms. Data is provided on the absorption by Ashbya gossyppi, Chlorella pyrenoidosa, Candida sp. Ml13, Saccharomyces cerevisiae, Scenedesmus obliqus, Streptococcus mutans, Anabaena flosaquae, Escherichia coli, Streptomyces viridochromogenes, Chlamydomonas reinhardtii, Rhizopus oryzae, Bacillus megaterium, Micrococcus luteus, Zoogloea ramigera, Coelastrum proboscideum, Pseudomonas aeruginosa, Citrobacter freundii, Paecilomyces marquandi, and Caulobacter fusiformis.

  17. CLINICAL BIOCHEMISTRY

    EPA Science Inventory

    Assessment of the health status of animals through measurement of cellular, biochemical, and macromolecular constituents in blood, secretions, and excretions has been variously referred to as clinical chemistry, clinical biochemistry, or clinical pathology. he genesis of this dis...

  18. [In vitro antibacterial activities of cefteram and other beta-lactam agents against recent clinical isolates].

    PubMed

    Yamaguchi, K; Ohno, A; Takahashi, S; Hayashi, M; Yamanaka, K; Hirakata, Y; Mitsuyama, J

    1998-01-01

    In vitro antibacterial activity of the third-generation oral cephem cefteram (CFTM)--ten years after its first use in the clinical setting--against recent clinical isolates was evaluated and compared with those of other oral cephems. A total of 851 clinical isolates belonging to 13 species used in this study were collected from five medical institutions across Japan during 1996. CFTM showed excellent antibacterial activity against methicillin-susceptible S. aureus and S. pyogenes, equivalent to those of other third-generation oral cephems, except cefixime. Of the S. pneumoniae strains, a high proportion, 34.1%, were penicillin-resistant strains (PRSP), with MIC values of 2.0 micrograms/ml or above, but the MIC50 of CFTM against PRSP was 1.0 microgram/ml. CFTM and the other third-generation oral cephems showed potent antibacterial activity against E. coli, K. pneumoniae, and P. mirabilis. A few strains of E. coli, however, were highly resistant to third-generation oral cephems; that might include extended-spectrum beta-lactamase producing strains. MIC values against P. vulgaris varied significantly, depending on whether they were determined by the broth micro-dilution method or the agar dilution method; growth was observed at high concentrations in the broth micro-dilution method, in which the skip phenomenon was demonstrated, but not in the agar dilution method. The reason for this discrepancy is unknown. Most strains of S. marcescens, C. freundii, and E. cloacae demonstrated resistance to CFTM and the other third-generation oral cephems. CFTM and the other third-generation oral cephems showed excellent antibacterial activities against M. (B.) catarrhalis, N. gonorrhoeae, and H. influenzae, including ampicillin-resistant strains. PMID:9557273

  19. Epidemiology and molecular characterisation of metallo-β-lactamase-producing Enterobacteriaceae in a university hospital Intensive Care Unit in Greece.

    PubMed

    Koratzanis, Evangelos; Souli, Maria; Galani, Irene; Chryssouli, Zoi; Armaganidis, Apostolos; Giamarellou, Helen

    2011-11-01

    The molecular epidemiology of VIM-producing Enterobacteriaceae isolated at the beginning of an epidemic in the Intensive Care Unit (ICU) of a university hospital in Athens, Greece, was studied. All Gram-negative organisms isolated from March 2004 to November 2005 positive for metallo-β-lactamase (MBL) production were submitted to polymerase chain reaction (PCR) and sequencing, to repetitive sequence-based PCR (Rep-PCR) for molecular typing, and to S1 nuclease digestion for plasmid DNA characterisation. Conjugation experiments and isoelectric focusing were performed to identify co-existing β-lactamases. Amongst 23 patients, 12 suffered one or more clinical infections. Eighty-two isolates representing one isolate per clone, source and ICU patient were studied, including Klebsiella pneumoniae (77), Enterobacter cloacae (2), Citrobacter freundii (1) and Pseudomonas aeruginosa (2). High clonal diversity was detected amongst the K. pneumoniae, with 10 distinct clones identified. Conjugation was successful in 54.5% of K. pneumoniae, and five different-sized plasmids were detected. All K. pneumoniae and both E. cloacae isolates shared the same bla(VIM-1)-containing class 1 integron structure also carrying aacA7, dhfrI and aadA1 gene cassettes. The C. freundii isolate carried a different integron that included bla(VIM-1) and aac(6')-IIc. Both P. aeruginosa isolates were positive for bla(VIM-2). It was not possible to identify specific clones with the potential to cause clinical infections. In conclusion, a multiclonal cluster of MBL-producers was responsible for the first cases of colonisation and/or infection in the ICU. A single integron structure, common in Greek hospitals, efficiently disseminated between clones and species, suggesting that the epidemic was mainly the result of successful horizontal transfer of mobile genetic material rather than the result of horizontal transfer of one or a few clones. PMID:21873034

  20. Automated Microbiological Detection/Identification System

    PubMed Central

    Aldridge, C.; Jones, P. W.; Gibson, S.; Lanham, J.; Meyer, M.; Vannest, R.; Charles, R.

    1977-01-01

    An automated, computerized system, the AutoMicrobic System, has been developed for the detection, enumeration, and identification of bacteria and yeasts in clinical specimens. The biological basis for the system resides in lyophilized, highly selective and specific media enclosed in wells of a disposable plastic cuvette; introduction of a suitable specimen rehydrates and inoculates the media in the wells. An automated optical system monitors, and the computer interprets, changes in the media, with enumeration and identification results automatically obtained in 13 h. Sixteen different selective media were developed and tested with a variety of seeded (simulated) and clinical specimens. The AutoMicrobic System has been extensively tested with urine specimens, using a urine test kit (Identi-Pak) that contains selective media for Escherichia coli, Proteus species, Pseudomonas aeruginosa, Klebsiella-Enterobacter species, Serratia species, Citrobacter freundii, group D enterococci, Staphylococcus aureus, and yeasts (Candida species and Torulopsis glabrata). The system has been tested with 3,370 seeded urine specimens and 1,486 clinical urines. Agreement with simultaneous conventional (manual) cultures, at levels of 70,000 colony-forming units per ml (or more), was 92% or better for seeded specimens; clinical specimens yielded results of 93% or better for all organisms except P. aeruginosa, where agreement was 86%. System expansion in progress includes antibiotic susceptibility testing and compatibility with most types of clinical specimens. Images PMID:334798

  1. Clinical Research and Clinical Trials

    MedlinePlus

    ... you can get involved. Doing your own clinical research project? Then select the Guidance for Clinical Researchers link to learn more about the NICHD's clinical research processes and policies. Last Reviewed: 03/06/2012 ...

  2. Clinical Preceptor.

    ERIC Educational Resources Information Center

    Gardipee, Sheila; Clemens, Glenna

    A clinical preceptor is an employed registered nurse in a clinical facility who supervises and evaluates a student's performance independent of a clinical instructor. This manual is intended to assist the clinical preceptor, especially the preceptor dealing with re-entry nursing students. It encompasses a practical approach with actual situations…

  3. Cost-Effective and Rapid Presumptive Identification of Gram-Negative Bacilli in Routine Urine, Pus, and Stool Cultures: Evaluation of the Use of CHROMagar Orientation Medium in Conjunction with Simple Biochemical Tests

    PubMed Central

    Ohkusu, Kiyofumi

    2000-01-01

    The algorithm for a new identification system was designed on the basis of colony color and morphology on CHROMagar Orientation medium in conjunction with simple biochemical tests such as indole (IND), lysine decarboxylase (LDC), and ornithine decarboxylase (ODC) utilization tests with gram-negative bacilli isolated from urine samples as well as pus, stool, and other clinical specimens by the following colony characteristics, biochemical reactions, and serological results: pinkish to red, IND positive (IND+), Escherichia coli; metallic blue, IND+, LDC+, and ODC negative (ODC−), Klebsiella oxytoca; IND+, LDC−, and ODC+, Citrobacter diversus; IND+ or IND−, LDC−, and ODC−, Citrobacter freundii; IND−, LDC+, and ODC+, Enterobacter aerogenes; IND−, LDC−, and ODC+, Enterobacter cloacae; IND−, LDC+, and ODC−, Klebsiella pneumoniae; diffuse brown and IND+, Morganella morganii; IND−, Proteus mirabilis; aqua blue, Serratia marcescens; bluish green and IND+, Proteus vulgaris; transparent yellow-green, serology positive, Pseudomonas aeruginosa; clear and serology positive, Salmonella sp.; other colors and reactions, the organism was identified by the full identification methods. The accuracy and cost-effectiveness of this new system were prospectively evaluated. During an 8-month period, a total of 345 specimens yielded one or more gram-negative bacilli. A total of 472 gram-negative bacillus isolates were detected on CHROMagar Orientation medium. For 466 of the isolates (98.7%), no discrepancies in the results were obtained on the basis of the identification algorithm. The cost of identification of gram-negative bacilli during this period was reduced by about 70%. The results of this trial for the differentiation of the most commonly encountered gram-negative pathogens in clinical specimens with the new algorithm were favourable in that it permitted reliable detection and presumptive identification. In addition, this rapid identification system not only

  4. Extended Spectrum β-Lactamases among Gram-Negative Bacterial Isolates from Clinical Specimens in Three Major Hospitals in Northern Jordan

    PubMed Central

    Batchoun, Raymond G.; Swedan, Samer F.; Shurman, Abdullah M.

    2009-01-01

    Background and Objectives. Extended spectrum β-lactamase (ESBL) production is increasing all over the world, and organisms other than E. coli and K. pneumoniae are acquiring this character. ESBL production is detectable by automation, E-test, double disk diffusion (DDD), and PCR. This study aimed to determine the prevalence of ESBL production among clinical isolates of gram-negative rods, and to evaluate the effectiveness of augmentation of clavunate with Cefotaxime, Ceftazoxime, Aztreonam, Ceftriaxone, and Cefpodoxime in detecting ESBL production. Methods. 472 clinical gram-negative isolates identified by standard methods were tested for ESBL-production by (DDD) method using six cephalosporins and amoxicillin-clavulinate discs. Results. 108/472 (22.9%) of the isolates were ESBL producers, and were prevalent in tertiary care hospitals. 88.2% of E. cloacae, 71.4% of K. pneumoniae, 28.6% of K. oxytoca, 12.5% of C. freundii, 11.1% of A. calcoacceticus, and 10.8% of E. coli were ESBL producers. The DDD test demonstrated some variations in the efficacy of the different cephalosporins in detecting all the ESBL producers. The inclusion of ceftizoxime discs increased the efficacy of the test. It is concluded that ESBL-producing bacteria were prevalent among our hospitalized patients, and involved genera other than Klebsiella and Escherichia, and the inclusion of ceftizoxime increased the efficacy of ESBL detection by the DDD test. PMID:19936109

  5. BetalasEN: microdilution panel for identifying beta-lactamases present in isolates of Enterobacteriaceae.

    PubMed

    Sanders, Christine C; Ehrhardt, Anton F; Moland, Ellen Smith; Thomson, Kenneth S; Zimmer, Barbara; Roe, Darcie E

    2002-01-01

    A dried investigational use-only microdilution panel named betalasEN (a short named derived from the panel's purpose, to identify beta-lactamases in Enterobacteriaceae) containing 10 beta-lactam drugs with and without beta-lactamase inhibitors was developed to identify beta-lactamases among clinical isolates of Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Citrobacter koseri, Citrobacter freundii group, Enterobacter spp., and Serratia marcescens. The MICs obtained with a collection of 383 organisms containing well-characterized beta-lactamases were used to develop numeric codes and logic pathways for computerized analysis of results. The resultant logic pathways and betalasEN panel were then used to test and identify beta-lactamases among 885 isolates of Enterobacteriaceae recovered in cultures obtained at six different hospital laboratories across the United States. beta-Lactamases present in 801 (90.5%) of the 885 isolates were identified by betalasEN by using the existing logic pathways and codes or after minor modifications were made to the existing codes. The 84 strains that gave codes that betalasEN could not identify were collected, reidentified, and retested by using betalasEN. Three strains had been misidentified, 54 strains gave different codes upon repeat testing that could be identified by betalasEN, and 27 strains repeated new codes. The beta-lactamases in these strains were identified, and the new codes were added to the betalasEN logic pathways. These results indicate that betalasEN can identify clinically important beta-lactamases among most isolates of Enterobacteriaceae. The results also show that good quality control and attention to proper performance of the tests are essential to the correct performance of betalasEN. PMID:11773104

  6. Clinical Trials

    MedlinePlus

    Clinical trials are research studies that test how well new medical approaches work in people. Each study answers ... prevent, screen for, diagnose, or treat a disease. Clinical trials may also compare a new treatment to a ...

  7. Clinical Trials

    MedlinePlus

    Clinical trials are research studies that test how well new medical approaches work in people. Each study ... prevent, screen for, diagnose, or treat a disease. Clinical trials may also compare a new treatment to ...

  8. Enzymatic Degradation of Polygalacturonic Acid by Yersinia and Klebsiella Species in Relation to Clinical Laboratory Procedures

    PubMed Central

    Starr, Mortimer P.; Chatterjee, Arun K.; Starr, Phoebe B.; Buchanan, Gordon E.

    1977-01-01

    As scored by several specified plating procedures, clinical and environmental strains of Yersinia enterocolitica, Yersinia pseudotuberculosis, and Klebsiella pneumoniae “Oxytocum” showed detectable, albeit generally weak, ability to digest polygalacturonic (pectic) acid. None of these bacterial strains had the vigorous and rapid pectolytic activity on these polygalacturonic acid-containing media that is typical of soft-rot Erwinia species, although some of the Oxytocum strains came fairly close. Analyses of the pectolytic enzyme contents of the cells and culture supernatants of the Yersinia and Klebsiella species revealed that readily detectable quantities of cell-bound polygalacturonic acid trans-eliminase and hydrolytic polygalacturonase were formed by the Yersinia and Klebsiella species; however, the total units of enzyme activity produced by these bacteria were, in general, lower than were produced by soft-rot Erwinia species. Furthermore, unlike the situation in soft-rot Erwinia cultures, these pectolytic enzymes of Yersinia and Klebsiella species were not excreted rapidly and massively into the growth medium. Cultures of other enterobacteria (Citrobacter species, Enterobacter species, Erwinia amylovora, Erwinia herbicola, Escherichia coli, Proteus species, Salmonella typhimurium, and Serratia marcescens) showed no pectolytic ability whatsoever by any of the plating procedures used and (to the extent they were so examined) produced no pectolytic enzymes detectable either in their cells or culture supernatants. This slow or weak release of pectolytic enzymes by Yersinia and Klebsiella species has a bearing on clinical laboratory procedures suitable for detecting their pectolytic activity; methods adequate for this purpose are detailed. PMID:334794

  9. Prevalence and Antimicrobial Susceptibility Patterns of Bacteria from Milkmen and Cows with Clinical Mastitis in and around Kampala, Uganda

    PubMed Central

    Kateete, David Patrick; Kabugo, Usuf; Baluku, Hannington; Nyakarahuka, Luke; Kyobe, Samuel; Okee, Moses; Najjuka, Christine Florence; Joloba, Moses Lutaakome

    2013-01-01

    Background Identification of pathogens associated with bovine mastitis is helpful in treatment and management decisions. However, such data from sub-Saharan Africa is scarce. Here we describe the distribution and antimicrobial susceptibility patterns of bacteria from cows with clinical mastitis in Kampala, Uganda. Due to high concern of zoonotic infections, isolates from milkmen are also described. Methodology/Principal Findings Ninety seven milk samples from cows with clinical mastitis and 31 nasal swabs from milkmen were collected (one sample per cow/human). Fifty eight (60%) Gram-positive isolates namely Staphylococci (21), Enterococci (16), Streptococci (13), Lactococci (5), Micrococci (2) and Arcanobacteria (1) were detected in cows; only one grew Staphylococcus aureus. Furthermore, 24 (25%) coliforms namely Escherichia coli (12), Klebsiella oxytoca (5), Proteus vulgaris (2), Serratia (2), Citrobacter (1), Cedecea (1) and Leclercia (1) were identified. From humans, 24 Gram-positive bacteria grew, of which 11 were Staphylococci (35%) including four Staphylococcus aureus. Upon susceptibility testing, methicillin-resistant coagulase-negative staphylococci (CoNS) were prevalent; 57%, 12/21 in cows and 64%, 7/11 in humans. However, methicillin-resistant Staphylococcus aureus was not detected. Furthermore, methicillin and vancomycin resistant CoNS were detected in cows (Staphylococcus hominis, Staphylococcus lugdunensis) and humans (Staphylococcus scuiri). Also, vancomycin and daptomycin resistant Enterococci (Enterococcus faecalis and Enterococcus faecium, respectively) were detected in cows. Coliforms were less resistant with three pan-susceptible isolates. However, multidrug resistant Klebsiella, Proteus, Serratia, Cedecea, and Citrobacter were detected. Lastly, similar species grew from human and bovine samples but on genotyping, the isolates were found to be different. Interestingly, human and bovine Staphylococcus aureus were genetically similar (spa-CC435

  10. In Vitro Antibacterial Efficacy of 21 Indian Timber-Yielding Plants Against Multidrug-Resistant Bacteria Causing Urinary Tract Infection

    PubMed Central

    Mishra, Monali P.; Padhy, Rabindra N.

    2013-01-01

    Objectives To screen methanolic leaf extracts of 21 timber-yielding plants for antibacterial activity against nine species of uropathogenic bacteria isolated from clinical samples of a hospital (Enterococcus faecalis, Staphylococcus aureus, Acinetobacter baumannii, Citrobacter freundii, Enterobacter aerogenes, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Pseudomonas aeruginosa). Methods Bacterial strains were subjected to antibiotic sensitivity tests by the Kirby–Bauer's disc diffusion method. The antibacterial potentiality of leaf extracts was monitored by the agar-well diffusion method with multidrug-resistant (MDR) strains of nine uropathogens. Results Two Gram-positive isolates, E. faecalis and S. aureus, were resistant to 14 of the 18 antibiotics used. Gram-negative isolates A. baumannii, C. freundii, E. aerogenes, E. coli, K. pneumoniae, P. mirabilis, and P. aeruginosa were resistant to 10, 12, 9, 11, 11, 10, and 11 antibiotics, respectively, of the 14 antibiotics used. Methanolic leaf extracts of Anogeissus acuminata had the maximum zone of inhibition size—29 mm against S. aureus and 28 mm against E. faecalis and P. aeruginosa. Cassia tora had 29 mm as the zone of inhibition size for E. faecalis, E. aerogenes, and P. aeruginosa. Based on the minimum inhibitory concentration and minimum bactericidal concentration values, the most effective 10 plants against uropathogens could be arranged in decreasing order as follows: C. tora > A. acuminata > Schleichera oleosa > Pterocarpus santalinus > Eugenia jambolana > Bridelia retusa > Mimusops elengi > Stereospermum kunthianum > Tectona grandis > Anthocephalus cadamba. The following eight plants had moderate control capacity: Artocarpus heterophyllus, Azadirachta indica, Dalbergia latifolia, Eucalyptus citriodora, Gmelina arborea, Pongamia pinnata, Pterocarpus marsupium, and Shorea robusta. E. coli, followed by A. baumannii, C. freundii, E. aerogenes, P. mirabilis, and P

  11. Clinical challenge.

    PubMed

    2016-09-01

    Questions for this month's clinical challenge are based on articles in this issue. The clinical challenge is endorsed by the RACGP Quality Improvement and Continuing Professional Development (QI&CPD) program and has been allocated four Category 2 points (Activity ID:59922). Answers to this clinical challenge are available immediately following successful completion online at http://gplearning.racgp.org.au. Clinical challenge quizzes may be completed at any time throughout the 2014-16 triennium; therefore, the previous months' answers are not published. Each of the questions or incomplete statements below is followed by four suggested answers or completions. Select the most appropriate statement as your answer. PMID:27606376

  12. Multicenter evaluation of the antimicrobial activity for six broad-spectrum beta-lactams in Venezuela: comparison of data from 1997 and 1998 using the Etest method. Venezuelan Antimicrobial Resistance Study Group.

    PubMed

    Pfaller, M A; Jones, R N; Doern, G V

    1999-10-01

    The minimum inhibitory concentrations of six broad-spectrum beta-lactam antimicrobial agents were determined in 1998 by use of the Etest versus a total of 502 bacteria in seven Venezuelan hospital laboratories. These data were compared with results of a similar study performed in 1997. The organisms tested included 309 recent clinical isolates of Enterobacteriaceae, 70 Pseudomonas aeruginosa, 54 Acinetobacter species, and 69 oxacillin-susceptible Staphylococcus aureus. Extended spectrum beta-lactamase production was noted among 30% of Klebsiella pneumoniae isolates. Hyperproduction of Amp C cephalosporinase producing resistance to ceftazidime and cefotaxime was observed with 10 to 37% of isolates of Enterobacter spp., Serratia spp., and Citrobacter freundii. The overall rank order of activity of the six beta-lactams tested in this study against all clinical isolates was imipenem (96.6% susceptible) > cefepime (90.4%) > piperacillin/tazobactam (85.7%) > ceftazidime (73.5%) > cefotaxime (70.5%) > piperacillin (55.0%). These findings were very similar to those reported for 1997. PMID:10579096

  13. [Comparative in vitro study of the antimicrobial activity of ceftazidime against clinical isolates].

    PubMed

    Klietmann, W; Focht, J; Nösner, K

    1987-01-01

    The antimicrobial activity of ceftazidime was tested against 1482 gram-negative and 1216 gram-positive strains isolated from fresh clinical specimens and compared with generally used antibiotics including other third generation cephalosporins and broad spectrum penicillins. Minimal inhibitory concentrations were determined in a broth dilution test on microtiter plates. In the group of the gram-negative bacteria ceftazidime was the most active of the antimicrobial agents tested with an MIC of 0.5 mg/l (MIC90) for most of the isolates. Ceftazidime exhibited a broad spectrum of activity against gram-negative pathogenic bacteria including Enterobacteriaceae (Escherichia coli, Klebsiella spp., Proteus spp. Enterobacter spp., Citrobacter spp., Serratia spp.) including frequently resistant strains of Pseudomonas aeruginosa, Acinetobacter spp. and Alcaligenes faecalis. The activity against P. aeruginosa is the most remarkable property of the agent. Ceftazidime is less effective against gram-positive compared to gram-negative bacteria. No inhibitory action can be observed against Streptococcus faecalis. PMID:3312026

  14. Antibacterial effect of imipenem in vitro against important aerobic and anaerobic strains isolated from clinical specimens.

    PubMed

    Klietmann, W; Focht, J; Nösner, K

    1987-08-01

    Imipenem is a thienamycin antibiotic of the first generation with broad antibacterial activity. It covers all gram-positive organisms (including Streptococcus faecalis) and gram-negative bacteria (including Pseudomonas aeruginosa and Serratia spp.) as well as Bacteroides fragilis and other Bacteroides species. In this comparative study the antimicrobic effect against 1020 gram-negative, 927 gram-positive and 352 anaerobic strains from fresh clinical isolates was tested and compared with that of other frequently used antibiotics. The minimum inhibitory concentrations (MIC) were determined by means of a serial dilution test with micro standard plates. Within the group of gram-negative strains, imipenem was the most active antibiotic with a MIC90 of less than or equal to 0.25 mg/l for most isolates. Imipenem shows a broad spectrum of activity against gram-negative pathogenic bacteria including Escherichia coli, Klebsiella spp., Proteus spp, Enterobacter spp., Citrobacter spp. and Serratia spp., and also covers resistant strains of Pseudomonas aeruginosa, Acinetobacter spp. and Alcaligenes faecalis. Imipenem also shows high inhibiting activity against gram-positive strains and anaerobic pathogens. PMID:3477332

  15. Clinical Trials

    MedlinePlus

    ... of visits, and any adjustments to treatment. (back) Requirements for Participation Admission into a clinical trial is based on a rigid set of requirements. You must be diagnosed with the illness that ...

  16. Clinical neuroimaging

    SciTech Connect

    Theodore, W.H.

    1988-01-01

    This book contains chapters on neuroimaging. Included are the following chapters: diagnostic neuroimaging in stroke, position emission tomography in cerebrovascular disease: clinical applications, and neuroradiologic work-up of brain tumors.

  17. Increased prevalence of carbapenem resistant Enterobacteriaceae in hospital setting due to cross-species transmission of the bla NDM-1 element and clonal spread of progenitor resistant strains.

    PubMed

    Wang, Xuan; Chen, Gongxiang; Wu, Xiaoyan; Wang, Liangping; Cai, Jiachang; Chan, Edward W; Chen, Sheng; Zhang, Rong

    2015-01-01

    This study investigated the transmission characteristics of carbapenem-resistant Enterobacteriaceae (CRE) strains collected from a hospital setting in China, in which consistent emergence of CRE strains were observable during the period of May 2013 to February 2014. Among the 45 CRE isolates tested, 21 (47%) strains were found to harbor the bla NDM-1 element, and the rest of 24 CRE strains were all positive for bla KPC-2. The 21 bla NDM-1-borne strains were found to comprise multiple Enterobacteriaceae species including nine Enterobacter cloacae, three Escherichia coli, three Citrobacter freundii, two Klebsiella pneumoniae, two Klebsiella oxytoca, and two Morganella morganii strains, indicating that cross-species transmission of bla NDM-1 is a common event. Genetic analyses by PFGE and MLST showed that, with the exception of E. coli and E. cloacae, strains belonging to the same species were often genetically unrelated. In addition to bla NDM-1, several CRE strains were also found to harbor the bla KPC-2, bla VIM-1, and bla IMP-4 elements. Conjugations experiments confirmed that the majority of carbapenem resistance determinants were transferable. Taken together, our findings suggest that transmission of mobile resistance elements among members of Enterobacteriaceae and clonal spread of CRE strains may contribute synergistically to a rapid increase in the population of CRE in clinical settings, prompting a need to implement more rigorous infection control measures to arrest such vicious transmission cycle in CRE-prevalent areas. PMID:26136735

  18. Specific detection of Campylobacter jejuni and Campylobacter coli by using polymerase chain reaction.

    PubMed Central

    Oyofo, B A; Thornton, S A; Burr, D H; Trust, T J; Pavlovskis, O R; Guerry, P

    1992-01-01

    Development of a routine detection assay for Campylobacter jejuni and Campylobacter coli in clinical specimens was undertaken by using the polymerase chain reaction (PCR). An oligonucleotide primer pair from a conserved 5' region of the flaA gene of C. coli VC167 was used to amplify a 450-bp region by PCR. The primer pair specifically detected 4 strains of C. coli and 47 strains of C. jejuni; but it did not detect strains of Campylobacter fetus, Campylobacter lari, Campylobacter upsaliensis, Campylobacter cryaerophila, Campylobacter butzleri, Campylobacter hyointestinalis, Wolinella recta, Helicobacter pylori, Escherichia coli, Shigella spp., Salmonella spp., Vibrio cholerae, Citrobacter freundii, or Aeromonas spp. By using a nonradioactively labeled probe internal to the PCR product, the assay could detect as little as 0.0062 pg of purified C. coli DNA, or the equivalent of four bacteria. In stools seeded with C. coli cells, the probe could detect between 30 and 60 bacteria per PCR assay. The assay was also successfully used to detect C. coli in rectal swab specimens from experimentally infected rabbits and C. jejuni in human stool samples. Images PMID:1400961

  19. Comparative characterization of the cephamycinase blaCMY-1 gene and its relationship with other beta-lactamase genes.

    PubMed Central

    Bauernfeind, A; Stemplinger, I; Jungwirth, R; Wilhelm, R; Chong, Y

    1996-01-01

    A plasmidic beta-lactamase which hydrolyzed cephamycins was first detected and reported in 1989. At that time its description was restricted to phenotypic characteristics. We analyzed nucleotide sequence of its gene and explored it genetic relationship with other bla genes. The deduced amino acid sequence of the blaCMY-1 product was compared with those of other known plasmidic cephamycinases and of chromosomal AmpC beta-lactamases. The results indicate that the relationship of CMY-1 is closest to MOX-1 among the plasmidic cephamycinases and to AmpC of Pseudomonas aeruginosa among the chromosomal cephalosporinases. We conclude that the plasmidic cephamycinases described up to now may be classified into three families, as follows: CMY-1, MOX-1, and FOX-1 with AmpC of P. aeruginosa; CMY-2, BIL-1 and LAT-1 with AmpC of Citrobacter freundii; and MIR-1 with AmpC of Enterobacter cloacae. Plasmidic cephamycinases are now recognized as clinically relevant class C beta-lactamases. PMID:8843306

  20. Increased prevalence of carbapenem resistant Enterobacteriaceae in hospital setting due to cross-species transmission of the blaNDM-1 element and clonal spread of progenitor resistant strains

    PubMed Central

    Wang, Xuan; Chen, Gongxiang; Wu, Xiaoyan; Wang, Liangping; Cai, Jiachang; Chan, Edward W.; Chen, Sheng; Zhang, Rong

    2015-01-01

    This study investigated the transmission characteristics of carbapenem-resistant Enterobacteriaceae (CRE) strains collected from a hospital setting in China, in which consistent emergence of CRE strains were observable during the period of May 2013 to February 2014. Among the 45 CRE isolates tested, 21 (47%) strains were found to harbor the blaNDM-1 element, and the rest of 24 CRE strains were all positive for blaKPC-2. The 21 blaNDM-1—borne strains were found to comprise multiple Enterobacteriaceae species including nine Enterobacter cloacae, three Escherichia coli, three Citrobacter freundii, two Klebsiella pneumoniae, two Klebsiella oxytoca, and two Morganella morganii strains, indicating that cross-species transmission of blaNDM-1 is a common event. Genetic analyses by PFGE and MLST showed that, with the exception of E. coli and E. cloacae, strains belonging to the same species were often genetically unrelated. In addition to blaNDM-1, several CRE strains were also found to harbor the blaKPC-2, blaVIM-1, and blaIMP-4 elements. Conjugations experiments confirmed that the majority of carbapenem resistance determinants were transferable. Taken together, our findings suggest that transmission of mobile resistance elements among members of Enterobacteriaceae and clonal spread of CRE strains may contribute synergistically to a rapid increase in the population of CRE in clinical settings, prompting a need to implement more rigorous infection control measures to arrest such vicious transmission cycle in CRE-prevalent areas. PMID:26136735

  1. Biochemical Characterization of PER-2 and Genetic Environment of blaPER-2▿

    PubMed Central

    Power, Pablo; Di Conza, José; Rodríguez, María Margarita; Ghiglione, Bárbara; Ayala, Juan A.; Casellas, José María; Radice, Marcela; Gutkind, Gabriel

    2007-01-01

    PER-2 was the first detected and the second most prevalent extended-spectrum β-lactamase in clinical pathogens isolated in Argentina and was also reported only in other South American countries. Citrobacter freundii 33587 was isolated in 1999 in Buenos Aires and was resistant to all tested β-lactams except cephamycins and carbapenems. The strain produced both plasmid-borne TEM-1 and PER-2 (pI 5.4), which could be transferred by conjugation. By PCR screening, thermal asymmetric interlaced PCR, and DNA sequencing, we detected an ISPa12/IS1387a insertion sequence upstream of blaPER-2, previously reported as also being associated with blaPER-1. The presence of similar structures upstream of blaPER-1 and blaPER-2 suggests a common origin and mobilization. Compared to blaPER-1 genes, an additional putative promoter for blaPER-2 was found. PER-2 kinetic analysis showed its high hydrolysis efficiencies toward both CTX and CAZ (kcat/Km, 0.76 and 0.43 μM−1·s−1, respectively). PMID:17438050

  2. Mass mortality in ornamental fish, Cyprinus carpio koi caused by a bacterial pathogen, Proteus hauseri.

    PubMed

    Kumar, Raj; Swaminathan, T Raja; Kumar, Rahul G; Dharmaratnam, Arathi; Basheer, V S; Jena, J K

    2015-09-01

    Moribund koi carp, Cyprinus carpio koi, from a farm with 50% cumulative mortality were sampled with the aim of isolating and detecting the causative agent. Three bacterial species viz., Citrobacter freundii (NSCF-1), Klebsiella pneumoniae (NSKP-1) and Proteus hauseri [genomospecies 3 of Proteus vulgaris Bio group 3] (NSPH-1) were isolated, identified and characterized on the basis of biochemical tests and sequencing of the 16S rDNA gene using universal bacterial primers. Challenge experiments with these isolates using healthy koi carp showed that P. hauseri induced identical clinical and pathological states within 3 d of intramuscular injection. The results suggest P. hauseri (NSPH-1) was the causative agent. In phylogenetic analysis, strain NSPH-1 formed a distinct cluster with other P. hauseri reference strains with ≥99% sequence similarity. P. hauseri isolates were found sensitive to Ampicillin, Cefalexin, Ciprofloxacin and Cefixime and resistant to Gentamycin, Oxytetracycline, Chloramphenicol, and Kanamycin. The affected fish recovered from the infection after ciprofloxacin treatment. PMID:26028178

  3. Biochemical characteristics and identification of Enterobacteriaceae isolated from meats.

    PubMed

    Stiles, M E; Ng, L K

    1981-03-01

    The isolation and identification of 2,220 Enterobacteriaceae from meats indicated that Escherichia coli biotype I, Enterobacter agglomerans, and Serratia liquefaciens were the principal types to be differentiated in meats. Citrobacter freundii, Klebsiella pneumoniae, Enterobacter cloacae, and Enterobacter hafniae were also commonly identified. Identification of isolates by the Encise II (Roche Diagnostics Inc., Nutley, N.J.) and Minitek (BBL Microbiology Systems, Cockeysville, Md.) coding systems gave similar results with only 255 (11.5%) discrepancies in identity, but both systems required large numbers of supplementary tests for identification of the isolates. Not only the distribution of Enterobacteriaceae types isolated from meats but also some of the biochemical reactions of the isolates differed from those of clinical isolates. The Minitek technique is recommended because of its versatility. However, with the addition of cellobiose and salicin disks and the inclusion of methyl red to the Minitek test and the use of the Voges-Proskauer test and gas production in EC medium at elevated temperature as standard tests, the identification of these Enterobacteriaceae from meats would be greatly facilitated. The inclusion of the motility test, for example, using nitrate motility agar, would also be of value to Enterobacteriaceae identification. PMID:7013705

  4. CLINICAL PEARL

    PubMed Central

    Mazefsky, Carla A.; Minshew, Nancy J.

    2013-01-01

    Autism spectrum disorders are defined behaviorally by the Diagnostic and Statistical Manual (DSM) IV-TR based on abnormal development in social interaction and communication and restricted, repetitive, and stereotyped patterns of behaviors and interests that are evident before the age of 3. After decades of debate, research has demonstrated that the distinctions among autism, Asperger disorder, and pervasive developmental disorder not otherwise specified are neither clinically reliable nor based on valid neurobiological or genetic differences. The fifth edition of the DSM therefore proposes to collapse all of the clinical syndromes under the single diagnosis of autism spectrum disorder (ASD). PMID:23186793

  5. Clinical cytomics

    NASA Astrophysics Data System (ADS)

    Tárnok, Attila; Mittag, Anja; Lenz, Dominik

    2006-02-01

    The goal of predictive medicine is the detection of changes in patient's state prior to the clinical manifestation of the deterioration of the patients current status. Therefore, both the diagnostic of diseases like cancer, coronary atherosclerosis or congenital heart failure and the prognosis of the effect specific therapeutics on patients outcome are the main fields of predictive medicine. Clinical Cytomcs is based on the analysis of specimens from the patient by Cytomic technologies that are mainly imaging based techniques and their combinations with other assays. Predictive medicine aims at the recognition of the "fate" of each individual patients in order to yield unequivocal indications for decision making (i.e. how does the patient respond to therapy, react to medication etc.). This individualized prediction is based on the Predictive Medicine by Clinical Cytomics concept. These considerations have recently stimulated the idea of the Human Cytome Project. A major focus of the Human Cytome Project is multiplexed cy-tomic analysis of individual cells of the patient, extraction of predictive information and individual prediction that merges into individualized therapy. Although still at the beginning, Clinical Cytomics is a promising new field that may change therapy in the near future for the benefit of the patients.

  6. Clinical biochemistry

    NASA Technical Reports Server (NTRS)

    Alexander, W. C.; Leach, C. S.; Fischer, C. L.

    1975-01-01

    The objectives of the biochemical studies conducted for the Apollo program were (1) to provide routine laboratory data for assessment of preflight crew physical status and for postflight comparisons; (2) to detect clinical or pathological abnormalities which might have required remedial action preflight; (3) to discover as early as possible any infectious disease process during the postflight quarantine periods following certain missions; and (4) to obtain fundamental medical knowledge relative to man's adjustment to and return from the space flight environment. The accumulated data presented suggest that these requirements were met by the program described. All changes ascribed to the space flight environment were subtle, whereas clinically significant changes were consistent with infrequent illnesses unrelated to the space flight exposure.

  7. Molecular Diagnosis of Urinary Tract Infections by Semi-Quantitative Detection of Uropathogens in a Routine Clinical Hospital Setting

    PubMed Central

    van der Zee, Anneke; Roorda, Lieuwe; Bosman, Gerda; Ossewaarde, Jacobus M.

    2016-01-01

    Background The objective of our study was the development of a semi-quantitative real-time PCR to detect uropathogens. Two multiplex PCR reactions were designed to detect Escherichia coli, Klebsiella spp., Enterobacter spp., Citrobacter spp., Proteus mirabilis, Enterococcus faecalis, and Pseudomonas aeruginosa. 16S based PCR was performed in parallel to detect Gram-positive and Gram-negative bacteria. Firstly to identify non-targeted agents of infection in the same urine specimen, and secondly to quantify background flora. The method was evaluated in comparison with standard bacterial culture, and a commercial PCR kit for detection of uropathogens. Findings Analysis with a known panel of 116 clinical isolates yielded a PCR specificity of 100%. Analysis of urine specimens from 211 patients revealed a high correlation of PCR Cq values with both culture positivity and quantity. Concordance between PCR and culture was 98% when both methods yielded results. PCR was found to be more sensitive than culture. With a cut-off Cq value of 33, the negative predictive value of PCR was 94%. The 16S PCR confirmed most results. One specimen was positive by 16S PCR suggesting another cause of infection not detected by the specific PCR assays. Conclusion We conclude that it is feasible to detect and identify uropathogens by multiplex real-time PCR assay. PMID:26954694

  8. Clinical neuroimaging

    SciTech Connect

    Gilman, S.; Mazziotta, J.C.

    1989-01-01

    Designed for practicing neurologists and neurosurgeons, this reference focuses on the newest techniques in computed assisted tomography. Text material covers basic principles of computed tomography, as well as the clinical advantages and disadvantages of each modality. The anatomical and/or physiological processes measured by XCT, PET, SPECT and MRI are first discussed in terms of the normal patient, and then applied to the diagnosis and treatment of patients with neurological disease (primarily of the brain). Emphasis is placed on areas of difficult diagnosis, such as differentiating recurrent tumor from radiation necrosis, early diagnosis of dementia, selection of patients for extracranial-intracranial bypass procedures, and localization of epileptic foci.

  9. Clinical arthrography

    SciTech Connect

    Arndt, R.; Horns, J.W.; Gold, R.H.; Blaschke, D.D.

    1985-01-01

    This book deals with the method and interpretation of arthrography of the shoulder, knee, ankle, elbow, hip, wrist, and metacarpophalangeal, interphalangeal, and temporomandibular joints. The emphasis is on orthopaedic disorders, usually of traumatic origin, which is in keeping with the application of arthrography in clinical practice. Other conditions, such as inflammatory and degenerative diseases, congenital disorders and, in the case of the hip, arthrography of reconstructive joint surgery, are included. Each chapter is devoted to one joint and provides a comprehensive discussion on the method of arthrography, including single and double contrast techniques where applicable, normal radiographic anatomy, and finally, the interpretation of the normal and the abnormal arthrogram.

  10. Memory clinics

    PubMed Central

    Jolley, D; Benbow, S M; Grizzell, M

    2006-01-01

    Memory clinics were first described in the 1980s. They have become accepted worldwide as useful vehicles for improving practice in the identification, investigation, and treatment of memory disorders, including dementia. They are provided in various settings, the setting determining clientele and practice. All aim to facilitate referral from GPs, other specialists, or by self referral, in the early stages of impairment, and to avoid the stigma associated with psychiatric services. They bring together professionals with a range of skills for the benefit of patients, carers, and colleagues, and contribute to health promotion, health education, audit, and research, as well as service to patients. PMID:16517802

  11. Common mechanism of ampC beta-lactamase induction in enterobacteria: regulation of the cloned Enterobacter cloacae P99 beta-lactamase gene.

    PubMed Central

    Lindberg, F; Normark, S

    1987-01-01

    Expression of the chromosomal beta-lactamase from the ampC gene in inducible in both Enterobacter cloacae and Citrobacter freundii. Cloning of ampC as well as its regulatory gene, ampR, from E. cloacae P99 revealed a gene organization indentical to that of C. freundii in the corresponding region. Although almost no similarities could be found between the restriction maps of ampC and ampR in the two species, the genes cross-hybridize. Also, both ampR gene products have a size of about 31,000. The regulatory features of E. cloacae beta-lactamase induction are very similar to those in C. freundii, i.e., beta-lactamase synthesis is repressed by AmpR in the absence, and stimulated in the presence, of inducer. The AmpR function can be transcomplemented between the two species, but there are quantitative regulatory aberrations in such hybrids, in contrast to the total complementation obtained within each system. These results suggest that the mechanism of beta-lactamase induction is the same in E. cloacae, C. freundii, and other gram-negative bacteria with inducible chromosomal beta-lactamase expression. Images PMID:3027046

  12. Effects of varying concentrations of novobiocin incorporated into two salmonella plating media on the recovery of four enterobacteriaceae.

    PubMed

    Restaino, L; Grauman, G S; McCall, W A; Hill, W M

    1977-03-01

    Hydrogen sulfide-producing strains of salmonellae, Escherichia coli, Citrobacter freundii, and Proteus mirabilis were isolated from fresh pork sausage. All the strains produced black-centered colonies on Hektoen enteric agar (HE). On xylose lysine deoxycholate agar (XLD), C. freundii produced yellow colonies, and the strains of the other three genera formed black-centered colonies. The selectivity of HE and XLD for salmonellae was improved by the addition of novobiocin to both media. With increasing concentrations of novobiocin, the degree of growth inhibition for the four genera was less on HE than on XLD. Novobiocin concentrations of 80 mug/ml in HE and 5 mug/ml in XLD did not affect the growth or colonial morphology of salmonellae. When 80 mug of novobiocin per ml was incorporated into HE, P. mirabilis strains were not recovered, 40% of C. freundii strains failed to form black-centered colonies, and growth of E. coli strains was not affected but colonies were altered without eliminating the black centers. When novobiocin at 5 mug/ml was incorporated into XLD, colonies of P. mirabilis strains were not recovered, C. freundii formed yellow colonies, and the colonies of the H(2)S-producing E. coli strains were unaffected. PMID:16345211

  13. Effects of Varying Concentrations of Novobiocin Incorporated into Two Salmonella Plating Media on the Recovery of Four Enterobacteriaceae

    PubMed Central

    Restaino, L.; Grauman, G. S.; McCall, W. A.; Hill, W. M.

    1977-01-01

    Hydrogen sulfide-producing strains of salmonellae, Escherichia coli, Citrobacter freundii, and Proteus mirabilis were isolated from fresh pork sausage. All the strains produced black-centered colonies on Hektoen enteric agar (HE). On xylose lysine deoxycholate agar (XLD), C. freundii produced yellow colonies, and the strains of the other three genera formed black-centered colonies. The selectivity of HE and XLD for salmonellae was improved by the addition of novobiocin to both media. With increasing concentrations of novobiocin, the degree of growth inhibition for the four genera was less on HE than on XLD. Novobiocin concentrations of 80 μg/ml in HE and 5 μg/ml in XLD did not affect the growth or colonial morphology of salmonellae. When 80 μg of novobiocin per ml was incorporated into HE, P. mirabilis strains were not recovered, 40% of C. freundii strains failed to form black-centered colonies, and growth of E. coli strains was not affected but colonies were altered without eliminating the black centers. When novobiocin at 5 μg/ml was incorporated into XLD, colonies of P. mirabilis strains were not recovered, C. freundii formed yellow colonies, and the colonies of the H2S-producing E. coli strains were unaffected. PMID:16345211

  14. Type 3 Muscarinic Receptors Contribute to Clearance of Citrobacter rodentium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although the alpha 7 nicotinic receptor exerts anti-inflammatory effects on immune cells, the role of muscarinic receptors in mucosal homeostasis, response to enteric pathogens, and modulation of immune cell function is undefined. The contribution of type 3 muscarinic receptor (M3R) to mucosal homeo...

  15. Characterization of the Salmonella paratyphi C Vi polysaccharide.

    PubMed Central

    Daniels, E M; Schneerson, R; Egan, W M; Szu, S C; Robbins, J B

    1989-01-01

    The Vi capsular polysaccharide (Vi) is both a virulence factor and a protective antigen of Salmonella typhi; its pathogenic role for Salmonella paratyphi C is less well understood. We found no differences between the antigenic and immunogenic properties and the structure of the Vi from representative strains of S. paratyphi C, S. typhi, and Citrobacter freundii. There were, however, differences in both the amount produced per cell and the degree of association with the cell among the Vi from the three species of Enterobacteriaceae. S. paratyphi C produced less Vi than both the wild-type S. typhi and C. freundii did, and it showed the fastest release of Vi into the media. These findings may provide an explanation for the inability of the Vi to inhibit completely the agglutination of S. paratyphi C by anti-O sera. In an outbreak of enteric fever caused by S. paratyphi C, 66 of 78 isolates (85%) were Vi positive. Images PMID:2506132

  16. Antimicrobial activity of essential oil from Schinus molle Linn.

    PubMed

    Gundidza, M

    1993-11-01

    The essential oil from the fresh leaves of Schinus molle isolated by hydrodistillation was tested for antibacterial activity using the hole plate diffusion method and for antifungal activity using the mycelium or single cell growth inhibition method. Results obtained showed that the volatile oil exhibited significant activity against the following bacterial species: Klebsiella pneumoniae, Alcaligenes faecalis, Pseudomonas aeruginosa, Leuconostoc cremoris, Enterobacter aerogenes, Proteus vulgaris, Clostridium sporogenes, Acinetobacter calcoacetica, Escherichia coli, Beneckea natriegens, Citrobacter freundii, Serratia marcescens, Bacillus subtilis and Brochothrix thermosphacata. The fungal species Aspergillus ochraceus, Aspergillus parasiticus, Fusarium culmorum and Alternaria alternata exhibited significant sensitivity to the volatile oil. PMID:8055554

  17. [Investigation of the presence of New Delhi metallo-beta-lactamase-1 (NDM-1) by PCR in carbapenem-resistant gram-negative isolates].

    PubMed

    Yanık, Keramettin; Emir, Dilek; Eroğlu, Cafer; Karadağ, Adil; Güney, Akif Koray; Günaydın, Murat

    2013-04-01

    Bacteria producing New Delhi metallo-beta-lactamase-1 (NDM-1) exhibit high level resistance to beta-lactams including carbapenems. This broad-spectrum resistance limits treatment options for infections caused by NDM-1 producers. NDM-1 was first isolated from an Indian patient in Sweden; since then, NDM-1 producing isolates have been identified in many countries including Turkey. In this study, we investigated the presence of NDM-1 by PCR method in various gram-negative isolates recovered from clinical specimens in tertiary care hospitals in Samsun, Turkey. A total of 210 carbapenem-resistant gram-negative isolates (132 Acinetobacter baumannii, 54 Pseudomonas aeruginosa, 5 Pseudomonas putida, 8 Enterobacter cloacae, 3 Enterobacter aerogenes, 3 Klebsiella pneumoniae, 2 Providencia rettgeri, 2 Escherichia coli and 1 Citrobacter freundii) were included in the study. Identification and antibiotic susceptibility testing of the isolates were performed by using Vitek-2 Compact (bioMerieux, France) and BD Phoenix (BD Diagnostic Systems, MD) automated systems. The results of antibiotic susceptibility testing were interpreted according to the CLSI recommendations. In our study, NDM-1 gene was not detected in any of the clinical isolates by PCR. There was only one case study that reported the presence of NDM-1 in clinical isolates from Turkey [Poirel L et al. Antimicrob Agents Chemother 2012;56:2784]. Our data, together with the others, indicated that the existence of NDM-1 in clinical isolates is not common in Turkey. However, since NDM-1 is a plasmid-encoded enzyme, there is always a risk of spread of this resistance through the bacterial strains in our country. Therefore, continuous surveillance and investigation of carbapenem-resistant isolates with resistance patterns suggestive of NDM-1 may enable to identify NDM-1 producing isolates. Meanwhile special care should be given on rational antibiotic use and establishment of appropriate infection control policies to prevent

  18. Domiciliary cockroaches found in restaurants in five zones of Kuala Lumpur Federal Territory, peninsular Malaysia.

    PubMed

    Jeffery, J; Sulaiman, S; Oothuman, P; Vellayan, S; Zainol-Ariffin, P; Paramaswaran, S; Razak, A; Muslimin, M; Kamil-Ali, O B; Rohela, M; Abdul-Aziz, N M

    2012-03-01

    The following domiciliary cockroaches were collected from restaurants in five zones of Kuala Lumpur Federal Territory, Malaysia using 1L glass beaker traps baited with ground mouse-pellets: Periplaneta americana (Linnaeus) (n = 820), Periplaneta brunnea Burmeister (n = 46), Blattella germanica (Linnaeus) (n = 12504), Supella longipalpa (Fabricius) (n = 321), Symploce pallens Stephens (n = 29) and Neostylopyga rhombifolia (Stoll) (n = 5). The following bacteria were isolated from 10 cockroach specimens: Enterobacter cloacae, Klebsiella pneumoniae ssp. pneumoniae, Klebsiella pneumoniae ssp. rhinoscleromatis and Serratia liquefaciens from 5 B. germanica; Acinetobacter calcoaceticus var. anitratus, Citrobacter diversus/amalonaticus, Escherichia vulneris and K.p. pneumoniae from 3 P. brunnea; and Citrobacter freundii, Enterobacter agglomerans 4, Escherichia adecarboxylate, E. vulneris, K. p. pneumonia, K. p. rhinoscleromatis and Proteus vulgeris from 2 P. americana. PMID:22543619

  19. Mechanisms of ertapenem resistance in Enterobacteriaceae isolates in a tertiary university hospital.

    PubMed

    Chung, Hae-Sun; Yong, Dongeun; Lee, Miae

    2016-06-01

    The aim of this study was to investigate the molecular mechanisms of ertapenem resistance among Enterobacteriaceae isolates in a clinical microbiology laboratory at a tertiary university hospital. A total of 40 clinical isolates including 20 resistant and 20 intermediate isolates were collected from August 2012 to July 2013. Ertapenem susceptibility was confirmed by the broth microdilution method. PCR and sequencing analysis of carbapenemase, AmpC β-lactamase, and extended-spectrum β-lactamase (ESBL) genes were performed. Outer membrane proteins (OMPs) were examined by urea-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Molecular epidemiology studies were performed by pulsed-field gel electrophoresis (PFGE). AmpC β-lactamases and ESBLs were found in 32 (80.0%) and 20 (50.0%) of the 40 isolates with ertapenem non-susceptibility, respectively. Distributions of β-lactamase genes differed among the species. One Citrobacter freundii isolate among the 40 isolates with ertapenem non-susceptibility carrying the blaIMP-1 associated class 1 integron was detected. SDS-PAGE of OMPs showed altered or greatly diminished expression of porins in all isolates of Klebsiella pneumoniae (n=5) and Enterobacter cloacae (n=11) with ertapenem resistance. Porin alterations were less common among the isolates with intermediate susceptibility (4/19). Integration of the results of molecular analysis of β-lactamases and OMP analysis revealed that most of the isolates with ertapenem resistance exhibited β-lactamase activity and porin alteration. PFGE revealed that most isolates were epidemiologically unrelated. Ertapenem resistance in clinical Enterobacteriaceae isolates was associated with β-lactamase activity and porin alteration. Even though carbapenemase-producing Enterobacteriaceae are still rare, continuous monitoring and infection control for carbapenem-resistant Enterobacteriaceae are necessary. PMID:27101841

  20. Writing clinical scenarios for clinical science questions.

    PubMed

    Smith, Phil Em; Mucklow, John C

    2016-04-01

    Written knowledge assessments for physicians in training typically involve multiple-choice questions that use a clinical scenario in a single-best-answer format. The Royal College of Physicians Part 1 MRCP(UK) examination includes basic sciences themes that are challenging to assess through a clinical scenario. A realistic clinical setting based on everyday clinical practice and integral to the question is the clearest demonstration that the knowledge being assessed is clinically relevant. However, without special attention to detail, the scenario in a clinical science question can appear redundant or artificial. Reading unnecessary material frustrates candidates and threatens the reputation of the assessment. In this paper we discuss why a clinical scenario is important for basic science questions and offer advice on setting realistic and plausible clinical scenarios for such questions. PMID:27037383

  1. Hypothyroidism in Clinical Practice

    PubMed Central

    Qari, Faiza

    2014-01-01

    Background: Hypothyroidism is the most common endocrine disease that was seen in the clinical practice especially for family physicians. Methods: This review article covered the important practical clinical issues for managing overt hypothyroidism, subclinical hypothyroidism and hypothyroidism during pregnancy. Conclusions: The clinical issues were addressed by clinical scenario followed by questions and stressed on the important clinical points. PMID:25161963

  2. Clinical professional governance for detailed clinical models.

    PubMed

    Goossen, William; Goossen-Baremans, Anneke

    2013-01-01

    This chapter describes the need for Detailed Clinical Models for contemporary Electronic Health Systems, data exchange and data reuse. It starts with an explanation of the components related to Detailed Clinical Models with a brief summary of knowledge representation, including terminologies representing clinic relevant "things" in the real world, and information models that abstract these in order to let computers process data about these things. Next, Detailed Clinical Models are defined and their purpose is described. It builds on existing developments around the world and accumulates in current work to create a technical specification at the level of the International Standards Organization. The core components of properly expressed Detailed Clinical Models are illustrated, including clinical knowledge and context, data element specification, code bindings to terminologies and meta-information about authors, versioning among others. Detailed Clinical Models to date are heavily based on user requirements and specify the conceptual and logical levels of modelling. It is not precise enough for specific implementations, which requires an additional step. However, this allows Detailed Clinical Models to serve as specifications for many different kinds of implementations. Examples of Detailed Clinical Models are presented both in text and in Unified Modelling Language. Detailed Clinical Models can be positioned in health information architectures, where they serve at the most detailed granular level. The chapter ends with examples of projects that create and deploy Detailed Clinical Models. All have in common that they can often reuse materials from earlier projects, and that strict governance of these models is essential to use them safely in health care information and communication technology. Clinical validation is one point of such governance, and model testing another. The Plan Do Check Act cycle can be applied for governance of Detailed Clinical Models

  3. ClinicalTrials.gov

    MedlinePlus

    ... Health ClinicalTrials.gov is a registry and results database of publicly and privately supported clinical studies of ... This Site ClinicalTrials.gov Background About the Results Database History, Policies, and Laws Media/Press Resources Linking ...

  4. Rationale for Clinical Supervision

    ERIC Educational Resources Information Center

    Cogan, Morris L.

    1976-01-01

    The author, one of the originators and developers of the clinical supervision process, offered a cogent rationale for clinical supervision. He defined clinical supervision and discussed the psychological-sociological basis for its practice. (Editor)

  5. Governance of clinical research.

    PubMed

    Camilleri, Michael; Tremaine, William J

    2012-03-01

    We review the principal methods and issues in the governance of clinical research: oversight of human research by federal offices, certification of clinical trial centers, management of conflict of interest in clinical research, and trial registration and reporting. PMID:22388015

  6. CQ-397 and CQ-414: antimicrobial activity and spectrum of two fluoroquinolone---cephalosporin, dual-action compounds with carboxamido bonds.

    PubMed

    Johnson, David M.; Jones, Ronald N.

    1997-06-01

    OBJECTIVE: To evaluate the potential spectrum of activity of two novel dual-action compounds with carboxamido bonds (CQ-397 and CQ-414; Laboratorios Aranda, San Rafael, Mexico) against human pathogens. METHODS: Approximately 800 Gram-positive and Gram-negative aerobic clinical bacteria were tested in vitro using the Mueller-Hinton broth microdilution method of the National Committee of Clinical Laboratory Standards. RESULTS: CQ-397 (cefamandole+enrofloxacin) and CQ-414 (cefamandole+norfloxacin) were equally potent against Enterobacteriaceae (MIC90 range, 0.06--0.5 microg/mL and 0.06--1 microg/mL, respectively). Citrobacter freundii (MIC90, 4 microg/mL) and Providencia spp. (MIC90, >32 microg/mL) exhibited elevated study drug MICs. Enterobacteriaceae resistant to fluoroquinolones generally remained resistant. CQ-397 and CQ-414 were active against Stenotrophomonas maltophilia (MIC90, 4 microg/mL) and oxacillin-susceptible staphylococci (MIC90, 0.25 microg/mL), but not oxacillin-resistant Staphylococcus aureus (MIC90, >32 microg/mL), Staphylococcus epidermidis (MIC90, 8 microg/mL), and enterococci (MIC90s, 8 to >32 microg/mL). There was no difference in the dual-action drug activity (MIC90, 2 microg/mL) between penicillin-susceptible and -resistant pneumococci. Haemophilus influenzae and Moraxella catarrhalis were very susceptible (MIC range, less-than-or-equal0.015--0.06 microg/mL) to both compounds. CONCLUSIONS: The activity of these novel dual-action compounds, formed from the bonding of older antimicrobials, warrants further investigation for potential human and/or animal health use, including toxicology and pharmacokinetics. PMID:11864130

  7. Being a Clinical Educator

    ERIC Educational Resources Information Center

    Higgs, Joy; Mcallister, Lindy

    2007-01-01

    What is it like to be a clinical educator? How do clinical educators experience and describe their continuing journey of becoming a clinical educator? Within the model developed in this research, dimensions of being a clinical educator were identified. These dimensions include (a) having a sense of self (and the impact of bringing self into the…

  8. Antibiotic resistance in triclosan tolerant fecal coliforms isolated from surface waters near wastewater treatment plant outflows (Morris County, NJ, USA).

    PubMed

    Middleton, June H; Salierno, James D

    2013-02-01

    Triclosan (TCS) is a common antimicrobial agent that has been detected in wastewater treatment plant (WWTP) effluent outflows. A link between TCS exposure and increased antibiotic resistance in microbes has been postulated. The purpose of this study was to evaluate whether fecal coliforms (FC) isolated from surface waters located near (WWTP) outflows display TCS resistance and, if so, whether such organisms exhibit increased resistance to antibiotics. Water samples were collected at two streams in Morris County, NJ that receive WWTP effluent: Loantaka Brook and the Whippany River. Water samples were collected at three sites within each location near the WWTP effluent outflow. Abiotic river parameters were measured and FCs were enumerated for each sample. River parameters were analyzed to determine if TCS or antibiotic resistance was correlated to water quality. Triclosan resistance levels were determined for individual isolates, and isolates were screened against seven classes of antibiotics at clinically relevant levels to assess cross-resistance. At Loantaka Brook, 78.8% of FC isolates were resistant to TCS with an average minimum inhibitory concentration (MIC) of 43.2 μg ml(-1). In addition, 89.6% of isolates were resistant to four classes of antibiotics and all were identified as Citrobacter freundii. There was a significant effect of stream location on mean TCS MIC values in the Loantaka Brook, with effluent isolates maintaining significantly higher MIC values compared to upstream isolates. At Whippany River sites, TCS resistant isolates were detected on 94% of sampling dates with a significant relationship between TCS resistance and multiple antibiotic resistances (≥ three antibiotic classes, p<0.001). TCS resistant isolates were significantly more resistant to chloramphenicol (p=0.007) and to nitrofurantoin (p=0.037) when compared to TCS sensitive isolates. Environmental FC isolates resistant to high level TCS included species of Escherichia, Enterobacter

  9. Dry stress and survival time of Enterobacter sakazakii and other Enterobacteriaceae in dehydrated powdered infant formula.

    PubMed

    Barron, Juncal Caubilla; Forsythe, Stephen J

    2007-09-01

    Powdered infant formula is not a sterile product, and opportunistic pathogens could multiply in the reconstituted product, resulting in neonatal infections. In this study, the generation of sublethally injured Enterobacteriaceae during desiccation and their persistence in dehydrated powdered infant formula was assessed during a 2.5-year period. The study included 27 strains of Enterobacter sakazakii, Enterobacter cloacae, Salmonella Enteritidis, Citrobacter koseri, Citrobacter freundii, Escherichia coli, Escherichia vulneris, Pantoea spp., Klebsiella oxytoca, and Klebsiella pneumoniae. The number of sublethally injured cells generated during desiccation was lower for K. oxytoca, Pantoea spp., Salmonella Enteritidis, and capsulated strains of E. sakazakii than for the other Enterobacteriaceae. The Enterobacteriaceae could be divided into three groups with respect to their long-term survival in the desiccated state. C. freundii, C. koseri, and E. cloacae were no longer recoverable after 6 months, and Salmonella Enteritidis, K. pneumoniae, and E. coli could not be recovered after 15 months. Pantoea spp., K. oxytoca, and E. vulneris persisted over 2 years, and some capsulated strains of E. sakazakii were still recoverable after 2.5 years. PMID:17900090

  10. Pathogen-specific effects on milk yield in repeated clinical mastitis episodes in Holstein dairy cows.

    PubMed

    Hertl, J A; Schukken, Y H; Welcome, F L; Tauer, L W; Gröhn, Y T

    2014-03-01

    The objective of this study was to estimate the effects of clinical mastitis (CM) cases due to different pathogens on milk yield in Holstein cows. The first 3 CM cases in a cow's lactation were modeled. Eight categories of pathogens were included: Streptococcus spp.; Staphylococcus aureus; coagulase-negative staphylococci (CNS); Escherichia coli; Klebsiella spp.; cases with CM signs but no bacterial growth (above the level detectable by our microbiological procedures) observed in the culture sample, and cases with contamination (≥ 3 pathogens in the sample); other pathogens that may be treated with antibiotics (included Citrobacter, Corynebacterium bovis, Enterobacter, Enterococcus, Pasteurella, Pseudomonas; "other treatable"); and other pathogens not successfully treated with antibiotics (Trueperella pyogenes, Mycoplasma, Prototheca, yeasts; "other not treatable"). Data from 38,276 lactations in cows from 5 New York State dairy herds, collected from 2003-2004 until 2011, were analyzed. Mixed models with an autoregressive correlation structure (to account for correlation among the repeated measures of milk yield within a lactation) were estimated. Primiparous (lactation 1) and multiparous (lactations 2 and 3) cows were analyzed separately, as the shapes of their lactation curves differed. Primiparas were followed for up to 48 wk of lactation and multiparas for up to 44 wk. Fixed effects included parity, calving season, week of lactation, CM (type, case number, and timing of CM in relation to milk production cycle), and other diseases (milk fever, retained placenta, metritis, ketosis, displaced abomasum). Herd was modeled as a random effect. Clinical mastitis was more common in multiparas than in primiparas. In primiparas, Streptococcus spp. occurred most frequently as the first case. In multiparas, E. coli was most common as the first case. In subsequent cases, CM cases with no specific growth or contamination were most common in both parity groups. The hazard of

  11. Managing clinical grant costs.

    PubMed

    Glass, Harold E; Hollander, Karen

    2009-05-01

    The rapidly increasing cost of pharmaceutical R&D presents a major challenge for the industry. This paper examines one aspect of that spending, clinical grants, and presents ways that pharmaceutical companies can best manage those expenditures. The first part of the paper examines the role of clinical grant payments as a motivation for clinical trial participation. The second part outlines a number of current management practices for controlling clinical grant costs. Financial compensation is an important matter for many physicians conducting clinical trials, especially those in office-based practices and those conducting phase 4 clinical trials. Since financial considerations are important to most types of investigators, and there is no compelling evidence that paying at high rates insures timely performance or quality data, companies engaging clinical investigators must manage their clinical grant funds as effectively as possible. Sound financial management requires that clinical development professionals appreciate the complex relationship between the pharmaceutical company and the physicians who serve as clinical investigators on that company's clinical trials. Sensible financial management of clinical grants also demands that sponsor companies get the most value for their clinical grant spending. Ultimately, good clinical grant management requires an attitude that combines good business sense with an understanding that pharmaceutical R&D strives to bring to market new drugs that can help patient populations around the world. Investigators are medical contractors in clinical trials, and while they are engaged in their vital research, they are a part of the research process that must be carefully budgeted and managed. Society, pharmaceutical companies, clinical investigators, and patients will reap the benefits of adequately budgeted, and well managed clinical grants. PMID:19470309

  12. In vitro and in vivo activities of QA-241, a new tricyclic quinolone derivative.

    PubMed Central

    Asahara, M; Tsuji, A; Goto, S; Masuda, K; Kiuchi, A

    1989-01-01

    The in vitro susceptibilities of 1,310 clinical isolates to QA-241, a novel tricyclic quinolone, were evaluated in comparison with susceptibilities to norfloxacin, ofloxacin, enoxacin, and ciprofloxacin. The MICs of QA-241 for 90% of staphylococci, Enterococcus faecalis isolates, and streptococcal species ranged from 1.56 to 6.25 micrograms/ml, and the activity of QA-241 was similar to those of norfloxacin and enoxacin but two to four times less potent than those of ofloxacin and ciprofloxacin. At the concentration of less than or equal to 1.56 micrograms/ml, QA-241 inhibited 90% of Haemophilus influenzae, Bordetella pertussis, Neisseria gonorrhoeae, and gram-negative enteric bacteria except for Serratia marcescens and Citrobacter freundii. QA-241 was moderately active (MIC for 90% of strains tested, 6.25 to 12.5 micrograms/ml) against S. marcescens, Pseudomonas aeruginosa, Xanthomonas maltophilia, and Bacteroides fragilis. The antibacterial activity of QA-241 was roughly comparable to that of enoxacin but two to four times less potent than that of ofloxacin. In systemic infections in mice with gram-positive cocci and gram-negative rods, the efficacy of QA-241 was generally greater than that of norfloxacin and similar to those of ofloxacin and ciprofloxacin. In urinary tract infections in mice with Escherichia coli or Pseudomonas aeruginosa, QA-241 was as active as ofloxacin and more active than norfloxacin but less active than ciprofloxacin. In pulmonary infections in mice with Klebsiella pneumoniae, the effectiveness of QA-241 was similar to that of ofloxacin. PMID:2679369

  13. Genetic Characterization of Carbapenem-Resistant Enterobacteriaceae and the Spread of Carbapenem-Resistant Klebsiella pneumonia ST340 at a University Hospital in Thailand.

    PubMed

    Netikul, Thidarat; Kiratisin, Pattarachai

    2015-01-01

    Carbapenem-resistant Enterobacteriaceae (CRE) has increasingly spread worldwide in the past decade. The prevalence and characteristics of CRE in Thailand are unknown. In this study, we conducted a 2-year surveillance of CRE among 12,741 clinical isolates of Enterobacteriaceae at the largest university hospital in Thailand with molecular characterization of beta-lactamase (bla) genes, including carbapenemase genes. The CRE prevalence was 1.4%. blaKPC-13 and blaIMP-14a were the only carbapenemase genes detected among these CRE isolates. blaKPC-13 gene was found in a single isolate of Escherichia coli, Enterobacter cloacae and Citrobacter freundii, and blaIMP-14a was found in four isolates of Klebsiella pneumoniae. Carbapenem-resistant K. pneumoniae (CRKP) isolates were resistant to multiple carbapenems at a higher ratio than other CRE species, and thus were further characterized for resistance phenotypes, bla genotypes and molecular epidemiology. Most CRKP isolates harboured multiple bla genes, especially those related to extended-spectrum beta-lactamases. Seven CRKP isolates were resistant to all tested carbapenems, and showed decreased ompK35 and/or ompK36 porin gene expression. Molecular typing of CRKP based on pulsed-field gel electrophoresis (PFGE) demonstrated several unrelated clones. Multilocus sequence typing (MLST) was partially concordant with PFGE results and revealed that ST340, a member of drug-resistant K. pneumoniae clonal complex 258, was the most predominant clone, followed by ST48, ST11 and ST273. The novel ST1645 was identified from this study. ST340 has neither been shown to be predominated among CRKP from other studies, nor been reported in Thailand. Therefore, it emphases a critical concern to monitor and control the spread of CRKP. PMID:26407326

  14. In Vitro Activity of Ceftazidime-Avibactam Combination in In Vitro Checkerboard Assays

    PubMed Central

    Melchers, Maria J.; van Mil, Anita C.; Nichols, Wright W.

    2014-01-01

    To evaluate the in vitro effects of the combination of ceftazidime and avibactam on the MICs of both compounds, checkerboard assays were performed for 81 clinical strains, including 55 Enterobacteriaceae strains (32 Klebsiella pneumoniae, 19 Escherichia coli, 1 Citrobacter freundii, and 3 Enterobacter cloacae) and 26 strains of Pseudomonas aeruginosa, all with known resistance mechanisms such as extended-spectrum β-lactamases (ESBLs) and carbapenemases, phenotypically or molecularly determined. Phenotypically ceftazidime-resistant strains (n = 69) were analyzed in more detail. For the Enterobacteriaceae strains, a concentration-dependent effect of avibactam was found for most strains with a maximum effect of avibactam at a concentration of 4 mg/liter, which decreased all ceftazidime MICs to ≤4 mg/liter. Avibactam alone also showed antibacterial activity (the MIC50 and MIC90 being 8 and 16 mg/liter, respectively). For the ceftazidime-resistant P. aeruginosa strains, considerable inhibition of β-lactamases by avibactam was acquired at a concentration of 4 mg/liter, which decreased all ceftazidime MICs except one to ≤8 mg/liter (the CLSI and EUCAST susceptible breakpoint). Increasing the concentration of avibactam further decreased the MICs, resulting in a maximum effect for most strains at 8 to 16 mg/liter. In summary, for most strains, the tested addition of avibactam of 4 mg/liter restored the antibacterial activity of ceftazidime to a level comparable to that of wild-type strains, indicating full inhibition, and strains became susceptible according to the EUCAST and CLSI criteria. Based on these in vitro data, avibactam is a promising inhibitor of different β-lactamases, including ESBLs and carbapenemases. PMID:25487794

  15. Genetic Characterization of Carbapenem-Resistant Enterobacteriaceae and the Spread of Carbapenem-Resistant Klebsiella pneumonia ST340 at a University Hospital in Thailand

    PubMed Central

    Netikul, Thidarat; Kiratisin, Pattarachai

    2015-01-01

    Carbapenem-resistant Enterobacteriaceae (CRE) has increasingly spread worldwide in the past decade. The prevalence and characteristics of CRE in Thailand are unknown. In this study, we conducted a 2-year surveillance of CRE among 12,741 clinical isolates of Enterobacteriaceae at the largest university hospital in Thailand with molecular characterization of beta-lactamase (bla) genes, including carbapenemase genes. The CRE prevalence was 1.4%. blaKPC-13 and blaIMP-14a were the only carbapenemase genes detected among these CRE isolates. blaKPC-13 gene was found in a single isolate of Escherichia coli, Enterobacter cloacae and Citrobacter freundii, and blaIMP-14a was found in four isolates of Klebsiella pneumoniae. Carbapenem-resistant K. pneumoniae (CRKP) isolates were resistant to multiple carbapenems at a higher ratio than other CRE species, and thus were further characterized for resistance phenotypes, bla genotypes and molecular epidemiology. Most CRKP isolates harboured multiple bla genes, especially those related to extended-spectrum beta-lactamases. Seven CRKP isolates were resistant to all tested carbapenems, and showed decreased ompK35 and/or ompK36 porin gene expression. Molecular typing of CRKP based on pulsed-field gel electrophoresis (PFGE) demonstrated several unrelated clones. Multilocus sequence typing (MLST) was partially concordant with PFGE results and revealed that ST340, a member of drug-resistant K. pneumoniae clonal complex 258, was the most predominant clone, followed by ST48, ST11 and ST273. The novel ST1645 was identified from this study. ST340 has neither been shown to be predominated among CRKP from other studies, nor been reported in Thailand. Therefore, it emphases a critical concern to monitor and control the spread of CRKP. PMID:26407326

  16. 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

  17. Travel-related carbapenemase-producing Gram-negative bacteria in Alberta, Canada: the first 3 years.

    PubMed

    Peirano, Gisele; Ahmed-Bentley, Jasmine; Fuller, Jeff; Rubin, Joseph E; Pitout, Johann D D

    2014-05-01

    We describe here the characteristics of Alberta, Canada, patients with infections or colonizations with carbapenemase-producing Gram-negative bacteria during 2010 to 2013 that were linked to recent travel outside Canada. Antimicrobial susceptibility was determined by broth microdilution, and isolates were characterized using PCR, sequencing, and multilocus sequencing typing. A broth mating study was used to assess the transferability of resistance plasmids, which were subsequently characterized. All the patients (n=12) included in our study had contact with a health care system while abroad. Most of the patients presented with urinary tract infections (UTIs) and were admitted to hospitals within weeks after their return to Alberta. Secondary spread occurred in 1 case, resulting in the death of another patient. The carbapenemase-producing bacteria (n=17) consisted of Escherichia coli (sequence type 101 [ST101], ST365, ST405, and ST410) with NDM-1, Klebsiella pneumoniae (ST15, ST16, ST147, ST258, ST340, ST512, and ST972) with NDM-1, OXA-181, KPC-2, and KPC-3, Acinetobacter baumannii with OXA-23, Providencia rettgeri with NDM-1, Enterobacter cloacae with KPC-2, and Citrobacter freundii with NDM-1. The blaNDM-1 gene was associated with various narrow- (i.e., IncF) and broad- (i.e., IncA/C and IncL/M) host-range plasmids with different addiction factors. Our results show that NDM-producing K. pneumoniae, belonging to a variety of sequence types with different plasmid scaffolds, are regularly imported from India into Alberta. Clinical microbiology laboratories should remain vigilant in detecting bacteria with carbapenemases. PMID:24599977

  18. Travel-Related Carbapenemase-Producing Gram-Negative Bacteria in Alberta, Canada: the First 3 Years

    PubMed Central

    Peirano, Gisele; Ahmed-Bentley, Jasmine; Fuller, Jeff; Rubin, Joseph E.

    2014-01-01

    We describe here the characteristics of Alberta, Canada, patients with infections or colonizations with carbapenemase-producing Gram-negative bacteria during 2010 to 2013 that were linked to recent travel outside Canada. Antimicrobial susceptibility was determined by broth microdilution, and isolates were characterized using PCR, sequencing, and multilocus sequencing typing. A broth mating study was used to assess the transferability of resistance plasmids, which were subsequently characterized. All the patients (n = 12) included in our study had contact with a health care system while abroad. Most of the patients presented with urinary tract infections (UTIs) and were admitted to hospitals within weeks after their return to Alberta. Secondary spread occurred in 1 case, resulting in the death of another patient. The carbapenemase-producing bacteria (n = 17) consisted of Escherichia coli (sequence type 101 [ST101], ST365, ST405, and ST410) with NDM-1, Klebsiella pneumoniae (ST15, ST16, ST147, ST258, ST340, ST512, and ST972) with NDM-1, OXA-181, KPC-2, and KPC-3, Acinetobacter baumannii with OXA-23, Providencia rettgeri with NDM-1, Enterobacter cloacae with KPC-2, and Citrobacter freundii with NDM-1. The blaNDM-1 gene was associated with various narrow- (i.e., IncF) and broad- (i.e., IncA/C and IncL/M) host-range plasmids with different addiction factors. Our results show that NDM-producing K. pneumoniae, belonging to a variety of sequence types with different plasmid scaffolds, are regularly imported from India into Alberta. Clinical microbiology laboratories should remain vigilant in detecting bacteria with carbapenemases. PMID:24599977

  19. Clinical Trials in Vision Research

    MedlinePlus

    ... Clinical Trials in Vision Research Clinical Trials in Vision Research Clinical studies depend on people who volunteer. ... about the treatment. How are clinical trials in vision different from other clinical trials? Eyes are one ...

  20. Research Areas - Clinical Trials

    Cancer.gov

    Information about NCI programs and initiatives that sponsor, conduct, develop, or support clinical trials, including NCI’s Clinical Trial Network (NCTN) and NCI Community Oncology Research Program (NCORP) initiatives.

  1. Spina Bifida Clinic Directory

    MedlinePlus

    ... genitourinary-reconstruction Cleveland Clinic (pediatric) 9500 Euclid Avenue S-60 Cleveland, OH 44195 Phone: 216-445-5579 Fax: ... for Adults Adult Spina Bifida Clinic (adult only) 60 Township Line Rd. Elkins Park, PA 19027 (215) ...

  2. Fertility Clinic Success Rates

    MedlinePlus

    ... 2013 Assisted Reproductive Technology Fertility Clinic Success Rates Report Recommend on Facebook Tweet Share Compartir 2013 ART Fertility Clinic Success Rates Report [PDF - 1MB] Bookmarks and thumbnails are available within ...

  3. Research Areas: Clinical Trials

    Cancer.gov

    Information about NCI programs and initiatives that sponsor, conduct, develop, or support clinical trials, including NCI’s Clinical Trial Network (NCTN) and NCI Community Oncology Research Program (NCORP) initiatives.

  4. Clinical nuclear medicine. [Handbook

    SciTech Connect

    Matin, P.

    1981-01-01

    ''Clinical Nuclear Medicine'' is an update to the author's ''Handbook of Clinical Nuclear Medicine.'' Sections on placental imaging, bone marrow imaging, biliary tract imaging and scintigraphy are included in the volume. (JMT)

  5. Clinical governance and pathology

    PubMed Central

    Crook, M

    2002-01-01

    This article looks at clinical governance and pathology. Clinical governance should be an important tool in seeking quality improvement within the Natinal Health Service. But how as pathologists should we go about it? PMID:11896066

  6. Production of L-DOPA and dopamine in recombinant bacteria bearing the Vitreoscilla hemoglobin gene.

    PubMed

    Kurt, Asli Giray; Aytan, Emel; Ozer, Ufuk; Ates, Burhan; Geckil, Hikmet

    2009-07-01

    Given the well-established beneficial effects of Vitreoscilla hemoglobin (VHb) on heterologous organisms, the potential of this protein for the production of L-DOPA and dopamine in two bacteria, Citrobacter freundii and Erwinia herbicola, was investigated. The constructed recombinants bearing the VHb gene (vgb(+)) had substantially higher levels of cytoplasmic L-DOPA (112 mg/L for C. freundii and 97 mg/L for E. herbicola) than their respective hosts (30.4 and 33.8 mg/L) and the vgb(-) control strains (35.6 and 35.8 mg/L). Further, the vgb(+) recombinants of C. freundii and E. herbicola had 20-fold and about two orders of magnitude higher dopamine levels than their hosts, repectively. The activity of tyrosine phenol-lyase, the enzyme converting L-tyrosine to L-DOPA, was well-correlated to cytoplasmic L-DOPA levels. As cultures aged, higher tyrosine phenol-lyase activity of the vgb(+) strains was more apparent. PMID:19585534

  7. Molecular characterization of class b carbapenemases in advanced stage of dissemination and emergence of class d carbapenemases in Enterobacteriaceae from Croatia.

    PubMed

    Bedenić, Branka; Sardelić, Sanda; Luxner, Josefa; Bošnjak, Zrinka; Varda-Brkić, Dijana; Lukić-Grlić, Amarela; Mareković, Ivana; Frančula-Zaninović, Sonja; Krilanović, Marija; Šijak, Dorotea; Grisold, Andrea; Zarfel, Gernot

    2016-09-01

    Carbapenemases involved in acquired carbapenem resistance in Enterobacteriaceae belong to Ambler class A serin β-lactamases, class B metallo-β-lactamases (MBL) or class D OXA-48-like β-lactamases. The aim of the present study was to analyse the molecular epidemiology and the mechanisms and routes of spread of class B and class D carbapenemases in Croatia. In total 68 isolates were analyzed. Antibiotic susceptibility was determined by broth microdilution method. PCR was used to detect antibiotic-resistance genes. Genotyping was performed by rep-PCR and MLST. Sixty-five isolates were found to harbour VIM-1 carbapenemase, seven of which were positive also for NDM-1, while two strains harboured only NDM-1. OXA-48 was detected in three isolates, two of which coproduced VIM-1. Thirty-six strains possessed additional CTX-M-15 β-lactamase whereas 64 were positive for TEM-1. CMY was found in 18 Citrobacter freundii isolates and DHA-1 in one Enterobacter cloacae isolate. Four different plasmid-incompatibility groups were found: A/C, L/M, N and FIIAs. Unlike C. freundii and E. cloacae, Klebsiella pneumoniae showed high diversity of rep-PCR patterns. E. cloacae and C. freundii predominantly belonged to one large clone which was allocated to ST105 and ST24, respectively. Three different types of carbapenemases were identified showing the complexity of CRE in Croatia. PMID:27174090

  8. Formation of vitamins by pure cultures of tempe moulds and bacteria during the tempe solid substrate fermentation.

    PubMed

    Keuth, S; Bisping, B

    1993-11-01

    The formation of water soluble vitamins (vitamin B12, vitamin B6, riboflavin, thiamine, nicotinic acid and nicotinamide) during the tempe solid substrate fermentation was investigated. The role of several strains of Rhizopus oligosporus, R. arrhizus, and R. stolonifer and the role of several bacteria in the vitamin formation process were checked. All fungal and bacterial strains were isolated from Indonesian tempe and soaking water samples. The Rhizopus strains formed riboflavin, nicotinic acid, nicotinamide and vitamin B6. The final concentrations of these substances depended on the different strains involved and on the fermentation time. Isolates of R. oligosporus were generally the best vitamin formers. The moulds did not produce physiologically active vitamin B12. The thiamine content decreased during fermentation. The addition of bacteria, which had been selected in a screening for vitamin B12 production, resulted in an increase of physiologically active vitamin B12. Citrobacter freundii and Klebsiella pneumoniae showed the best formation capabilities. Furthermore, the bacteria produced riboflavin and vitamin B6 in addition to the moulds. The influence of Rhizopus on the vitamin B12 formation of Cit. freundii was also investigated. The vitamin content of tempe that was fermented with the mould and the bacterium was three times as high as a control fermentation with Cit. freundii only. PMID:8300444

  9. Clinical document architecture.

    PubMed

    Heitmann, Kai

    2003-01-01

    The Clinical Document Architecture (CDA), a standard developed by the Health Level Seven organisation (HL7), is an ANSI approved document architecture for exchange of clinical information using XML. A CDA document is comprised of a header with associated vocabularies and a body containing the structural clinical information. PMID:15061557

  10. The Effective Clinical Conference.

    ERIC Educational Resources Information Center

    Wink, Diane M.

    1995-01-01

    Examines the common problems with clinical conferences and suggests approaches to maximize student learning. Suggests that an effective clinical conference has three characteristics: (1) it is a group event; (2) it contributes to the achievement of course and clinical objectives; and (3) it provides a setting for students to explore personal…

  11. University cardiology clinic.

    PubMed

    Borozanov, V

    2013-01-01

    In distant 1972, within framework of the Internal Clinic, a cardiologic department was organized which was soon, on 29.XII.1974, transformed into the Cardiology Clinic, later the Institute for Heart Diseases, and in 2008 was renamed the University Cardiology Clinic. The greater part of its foundation was possible owing to Prof. Dimitar Arsov and Prof. Radovan Percinkovski, who was the clinic's first director in the period from 1974 to 1984. In 1985, the Clinic moved into its own new building, and in that way was physically detached from the Internal Clinics. Until its move to the new building, the Clinic functioned in the Internal Clinics building, organized as an outpatient polyclinic and inpatient infirmary department with clinical beds, a coronary intensive care unit and a haemodynamics laboratory equipped with the most modern equipment of that time. Today the Clinic functions through two integral divisions: an inpatient infirmary department which comprises an intensive coronary care unit and fourteen wards which altogether have 139 clinical beds, and the diagnostic centre which comprises an emergency clinic and day hospital, a communal and consultative outpatients' clinic functioning on a daily basis, through which some 300-350 patients pass every day, and diagnostic laboratories with a capacity of nearly 100 non-invasive and 20-30 invasive diagnostic procedures daily. The Clinic is a teaching base, and its doctors are educators of students at the Medical, Dental and Pharmacy Faculties, and also of students at the High School for Nurses and X-ray technicians, but also for those in Internal Medicine and especially Cardiology. The Clinic is also a base for scientific Masters' and post-doctoral studies, and such higher degrees are achieved not only by doctors who work here, but also by doctors from Medical Centres both in the country and abroad. Doctors working in this institution publish widely, not only a great number of books and monographs, but also original

  12. Aerobic Bacterial Community of American Cockroach Periplaneta americana,a Step toward Finding Suitable Paratransgenesis Candidates

    PubMed Central

    Akbari, Sanaz; Oshaghi, Mohammad Ali; Hashemi-Aghdam, Saedeh Sadat; Hajikhani, Sara; Oshaghi, Ghazaleh; Shirazi, Mohammad Hasan

    2015-01-01

    Background: Cockroaches mechanically spread pathogenic agents, however, little is known about their gut microbiota. Identification of midgut microbial community helps targeting novel biological control strategies such as paratransgenesis. Here the bacterial microbiota of Periplaneta americana midgut, were identified and evaluated for finding proper paratransgenesis candidate. Methods: Midgut of specimens were dissected and cultivated in different media. The bacterial isolates were then identified using the phenotypic and 16S-rRNA sequencing methods. Results: The analytical profile index (API) kit showed presence of 11 bacterial species including: Escherichia coli, Shigella flexineri, Citrobacter freundii, E. vulneris, Enterobacter cloacae, Yersinia pseudotuberculosis, Y. intermedia, Leclericia adecarboxylata, Klebsiella oxytoca, K. planticola, and Rahnella aquatilis in the cockroach midguts. The first three species are potentially symbiotic whereas others are transient. The conventional plating method revealed presence of only four isolates of Salmonella, E. coli, and Proteus which in three cases mismatched with API and 16S-rRNA genotyping. The API correctly identified the four isolates as Shigella flexneri, Citrobacter freundii, and E. coli (n= 2). 16S-rRNA sequence analysis confirmed the API results; however the C. freundii sequence was identical with C. murliniae indicating lack of genetic variation in the gene between these two closely related species. Conclusion: A low number of potentially symbiotic bacteria were found in the American cockroach midguts. Among them Enterobacter cloacae is a potential candidate for paratransgenesis approach whereas other bacteria are pathogens and are not useful for the approach. Data analysis showed that identification levels increase from the conventional to API and to genotyping respectively. PMID:26114142

  13. Assessing clinical pragmatism.

    PubMed

    Jansen, Lynn A

    1998-03-01

    "Clinical pragmatism" is an important new method of moral problem-solving in clinical practice. This method draws on the pragmatic philosophy of John Dewey and recommends an experimental approach to solving moral problems in clinical practice. Although the method may shed some light on how clinicians and their patients ought to interact when moral problems are at hand, it nonetheless is deficient in a number of respects. Clinical pragmatism fails to explain adequately how moral poblems can be solved experimentally, it underestimates the relevance and importance of judgment in clinical ethics, and it presents a questionable account of the role that moral principles should play in moral problem solving. PMID:11656751

  14. [Randomized clinical trials and real clinical practice].

    PubMed

    Heerlein, Andrés

    2009-01-01

    One of the emerging problems in modern medicine is that part of its highly efficacious treatments do not show significant effectiveness in real world systems of care. Efficacy studies address the appropriate dosages, short term response and feasibility of treatments in carefully selected populations, but they do not necessarily provide information for decisions in clinical practice. This review aims to present strengths and limitations of different methodological types of trials and to offer an overview of how knowledge from clinical trials can be used for clinical practice. The important effect of funding source on the outcome of randomized controlled trials is discussed. Some key questions in the treatment assessment of depression, schizophrenia and different medical conditions are discussed, with a focus on the possibilities and restrictions of translating clinical trial results into real-world settings. Empirical evidence shows that although randomized controlled trials are the gold standard for proving efficacy of a therapeutic procedure they often suffer from funding source bias and from lack of generalizability. Effectiveness studies evaluate effects of treatments under conditions approximating usual care. Another key area that can be addressed by effectiveness studies is the impact on important health policy measures such as disability days, days of work or medical costs, etc. Conclusions show that the future assessment of treatment regimes for clinical utility requires less biased efficacy studies and more effectiveness studies addressing major issues from all relevant perspectives. PMID:19543562

  15. Development of clinical sites.

    PubMed

    O'Brien, Mary

    2015-02-01

    Clinical experiences are vital to all types of healthcare educational programs. Supervised clinical experiences provide the opportunity for the learner to apply didactic knowledge and theory to real world situations and hone skills necessary for entry into practice. Nurse anesthesia programs utilize a wide variety of clinical sites to expose student registered nurse anesthetists to experiences that will prepare them clinically, academically and professionally to enter practice as a Certified Registered Nurse Anesthetist. This article describes the process of developing a clinical site. A thorough evaluation will determine the types of experiences meant to be offered at the site, the resources available to house and educate the students, and how to evaluate the effectiveness of the clinical site. Open communication between the clinical coordinator and the program director or designee is essential to ensure success of the clinical site. The Council on Accreditation of Nurse Anesthesia Educational Programs has resources available to guide those interested in becoming a clinical site, as well as for program administrators who seek to add new experiences to their programs. PMID:25842629

  16. American Association for Clinical Chemistry

    MedlinePlus

    ... indispensable patient care tool. Learn more IN CLINICAL CHEMISTRY ddPCR Quantification of Lymphoma Mutations Researchers have developed ... Online Harmonization.net Commission on Accreditation in Clinical Chemistry American Board of Clinical Chemistry Clinical Chemistry Trainee ...

  17. Operating Outpatient Clinics in 1990.

    ERIC Educational Resources Information Center

    Bohannan, Harry M.

    1984-01-01

    The future of dental school clinic operations is discussed including change within dental education, factors influencing change, and some predicted changes. Fundamental change can be predicted in educational philosophy, responsibility for clinical care, clinic facilities, clinic operation, and faculty. (MLW)

  18. Antibacterial activity of silver-doped hydroxyapatite nanoparticles against gram-positive and gram-negative bacteria

    NASA Astrophysics Data System (ADS)

    Ciobanu, Carmen Steluta; Iconaru, Simona Liliana; Le Coustumer, Phillippe; Constantin, Liliana Violeta; Predoi, Daniela

    2012-06-01

    Ag-doped nanocrystalline hydroxyapatite nanoparticles (Ag:HAp-NPs) (Ca10- x Ag x (PO4)6(OH)2, x Ag = 0.05, 0.2, and 0.3) with antibacterial properties are of great interest in the development of new products. Coprecipitation method is a promising route for obtaining nanocrystalline Ag:HAp with antibacterial properties. X-ray diffraction identified HAp as an unique crystalline phase in each sample. The calculated lattice constants of a = b = 9.435 Å, c = 6.876 Å for x Ag = 0.05, a = b = 9.443 Å, c = 6.875 Å for x Ag = 0.2, and a = b = 9.445 Å, c = 6.877 Å for x Ag = 0.3 are in good agreement with the standard of a = b = 9.418 Å, c = 6.884 Å (space group P63/m). The Fourier transform infrared and Raman spectra of the sintered HAp show the absorption bands characteristic to hydroxyapatite. The Ag:HAp nanoparticles are evaluated for their antibacterial activity against Staphylococcus aureus, Klebsiella pneumoniae, Providencia stuartii, Citrobacter freundii and Serratia marcescens. The results showed that the antibacterial activity of these materials, regardless of the sample types, was greatest against S. aureus, K. pneumoniae, P. stuartii, and C. freundii. The results of qualitative antibacterial tests revealed that the tested Ag:HAp-NPs had an important inhibitory activity on P. stuartii and C. freundii. The absorbance values measured at 490 nm of the P. stuartii and C. freundii in the presence of Ag:HAp-NPs decreased compared with those of organic solvent used (DMSO) for all the samples ( x Ag = 0.05, 0.2, and 0.3). Antibacterial activity increased with the increase of x Ag in the samples. The Ag:HAp-NP concentration had little influence on the bacterial growth ( P. stuartii).

  19. Clinical coding. Code breakers.

    PubMed

    Mathieson, Steve

    2005-02-24

    --The advent of payment by results has seen the role of the clinical coder pushed to the fore in England. --Examinations for a clinical coding qualification began in 1999. In 2004, approximately 200 people took the qualification. --Trusts are attracting people to the role by offering training from scratch or through modern apprenticeships. PMID:15768716

  20. Clinical Application of Electrocardiography.

    ERIC Educational Resources Information Center

    Brammell, H. L.; Orr, William

    The scalar electrocardiogram (ECG) is one of the most important and commonly used clinical tools in medicine. A detailed description of the recordings of cardiac electrical activity made by the ECG is presented, and the vast numbers of uses made with the data provided by this diagnostic tool are cited. Clinical applications of the ECG are listed.…

  1. Clinical management of hypophosphatasia

    PubMed Central

    Bishop, Nick

    2015-01-01

    Summary HPP is a rare disease that manifests in different ways across the life course. Accurate diagnosis depends upon the use of appropriate age-related normative data. A new therapy is undergoing clinical trials; the preliminary published data is encouraging, but the scope of clinical application remains to be determined. PMID:26604944

  2. CLINICAL TRIALS.GOV

    EPA Science Inventory

    ClinicalTrials.gov provides patients, family members, health care professionals, and members of the public easy access to information on clinical trials for a wide range of diseases and conditions. The U.S. National Institutes of Health (NIH), through its National Library of Medi...

  3. Multispecialty Clinic Practice

    PubMed Central

    Margolin, David A.; Beck, David E.

    2011-01-01

    A multispecialty clinic practice is a common practice arrangement for colorectal surgeons. This type of practice has a variety of features, both positive and negative. The authors explore location, practice patterns, lifestyles, compensation, and academic opportunities associated with a multispecialty clinic practice. This information can assist younger surgeons in choosing a practice opportunity and guide experienced surgeons through their career progression. PMID:22654568

  4. The NASA Clinic System

    NASA Technical Reports Server (NTRS)

    Scarpa, Philip J.; Williams, Richard

    2009-01-01

    NASA maintains on site occupational health clinics at all Centers and major facilities NASA maintains an on-site clinic that offers comprehensive health care to astronauts at the Johnson Space Center NASA deploys limited health care capability to space and extreme environments Focus is always on preventive health care

  5. [Bioethics in clinical practice].

    PubMed

    Sánchez-Gonzaléz, Miguel; Herreros, Benjamín

    2015-01-01

    Bioethics has grown exponentially in recent decades. Its most important schools include principlism, casuistry, virtue ethics and the ethics of care. These schools are not exclusive. Within bioethics, clinical ethics addresses the inherent clinical practice ethical problems, problems which are many and very varied. Bioethics training is essential for clinicians to address these bioethics' problems. But even the professionals are trained, there are problems that cannot be solved individually and require advisory groups in clinical ethics: clinical ethics committees. These committees are also responsible for education in bioethics in health institutions. Clinical bioethics is a practical discipline, oriented to address specific problems, so its development is necessary to improve the decision making in such complex problems, inevitable problems in healthcare. PMID:25680645

  6. In the clinic. Perimenopause.

    PubMed

    McNamara, Megan; Batur, Pelin; DeSapri, Kristi Tough

    2015-02-01

    This issue provides a clinical overview of Perimenopause focusing on prevention, diagnosis, treatment, practice improvement, and patient information. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including ACP Smart Medicine and MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine editors develop In the Clinic from these primary sources in collaboration with the ACP's Medical Education and Publishing divisions and with the assistance of science writers and physician writers. Editorial consultants from ACP Smart Medicine and MKSAP provide expert review of the content. Readers who are interested in these primary resources for more detail can consult http://smartmedicine.acponline.org, http://mksap.acponline.org, and other resources referenced in each issue of In the Clinic. PMID:25643316

  7. Clinical Pathway for Thyroidectomy.

    PubMed

    Villar del Moral, Jesús María; Soria Aledo, Víctor; Colina Alonso, Alberto; Flores Pastor, Benito; Gutiérrez Rodríguez, María Teresa; Ortega Serrano, Joaquín; Parra Hidalgo, Pedro; Ros López, Susana

    2015-05-01

    Clinical pathways are care plans applicable to patient care procedures that present variations in practice and a predictable clinical course. They are designed not as a substitute for clinical judgment, but rather as a means to improve the effectiveness and efficiency of the procedures. This clinical pathway is the result of a collaborative work of the Sections of Endocrine Surgery and Quality Management of the Spanish Association of Surgeons. It attempts to provide a framework for standardizing the performance of thyroidectomy, the most frequently performed operation in endocrine surgery. Along with the usual documents of clinical pathways (temporary matrix, variance tracking and information sheets, assessment indicators and a satisfaction questionnaire) it includes a review of the scientific evidence around different aspects of pre, intra and postoperative management. Among others, antibiotic and antithrombotic prophylaxis, preoperative preparation in hyperthyroidism, intraoperative neuromonitoring and systems for obtaining hemostasis are included, along with management of postoperative hypocalcemia. PMID:25732107

  8. In the Clinic. Dementia.

    PubMed

    Rabins, Peter V; Blass, David M

    2014-08-01

    This issue provides a clinical overview of dementia, focusing on prevention, diagnosis, treatment, practice improvement, and patient information. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including ACP Smart Medicine and MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine editors develop In the Clinic from these primary sources in collaboration with the ACP's Medical Education and Publishing divisions and with the assistance of science writers and physician writers. Editorial consultants from ACP Smart Medicine and MKSAP provide expert review of the content. Readers who are interested in these primary resources for more detail can consult http://smartmedicine.acponline.org, https://mksap.acponline.org/, and other resources referenced in each issue of In the Clinic. PMID:25089871

  9. In the clinic: hypertension.

    PubMed

    Weir, Matthew R

    2014-12-01

    This issue provides a clinical overview of Hypertension focusing on prevention, diagnosis, treatment, practice improvement, and patient information. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including ACP Smart Medicine and MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine editors develop In the Clinic from these primary sources in collaboration with the ACP's Medical Education and Publishing divisions and with the assistance of science writers and physician writers. Editorial consultants from ACP Smart Medicine and MKSAP provide expert review of the content. Readers who are interested in these primary resources for more detail can consult http://smartmedicine.acponline.org, http://mksap.acponline.org, and other resources referenced in each issue of In the Clinic. PMID:25437425

  10. In the clinic. Insomnia.

    PubMed

    Masters, Philip A

    2014-10-01

    This issue provides a clinical overview of Insomnia focusing on prevention, diagnosis, treatment, practice improvement, and patient information. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including ACP Smart Medicine and MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine editors develop In the Clinic from these primary sources in collaboration with the ACP's Medical Education and Publishing divisions and with the assistance of science writers and physician writers. Editorial consultants from ACP Smart Medicine and MKSAP provide expert review of the content. Readers who are interested in these primary resources for more detail can consult http://smartmedicine.acponline.org, http://mksap.acponline.org, and other resources referenced in each issue of In the Clinic. PMID:25285559