Molecular Epidemiology of Carbapenem Non-Susceptible Acinetobacter baumannii in France

Carbapenem-resistant Acinetobacter baumannii have emerged globally. The objective of this study was to investigate the epidemiology, clonal diversity and resistance mechanisms of imipenem non-susceptible A. baumannii isolates in France. Between December 2010 and August 2011, 132 notifications were collected, including 37 outbreaks corresponding to 242 cases (2 to 55 per cluster). Multilocus sequence typing, pulsed-field gel electrophoresis (PFGE) and characterisation of carbapenemase-encoding genes were performed on 110 non-repetitive isolates. Gene bla_OXA-23 was the most frequently detected (82%), followed by bla_OXA-24 (11%) and bla_OXA-58 (7%). Eleven sequence types (ST) were distinguished, among which sequence types ST1, ST2 (64%), ST20, ST25, ST85 and ST107. Isolates from epidemiological clusters had the same ST and resistance genes, indicating probable transmission within centres. In contrast, PFGE types of isolates differed among centres, arguing against transmission among centers. This study provides the first epidemiological snapshot of the population of A. baumannii with reduced susceptibility to carbapenems from France, and further underlines the predominance of international clones.     

The genera in the second catalogue (1833–1836) of?Dejean’s Coleoptera collection

All genus-group names listed in the second edition of the catalogue (1833-1836) of Dejean’s beetle collection are recorded. For each new genus-group name the originally included available species are listed and for generic names with at least one available species, the type species and the current status are given. Names available prior to the publication of Dejean’s second catalogue (1833-1836) are listed in an appendix.The following new synonymies are proposed: Cyclonotum Dejean, 1833 (= Dactylosternum Wollaston, 1854) [Hydrophilidae], Hyporhiza Dejean, 1833 (= Rhinaspis Perty, 1830) [Scarabaeidae], Aethales Dejean, 1834 (= Epitragus Latreille, 1802) [Tenebrionidae], Arctylus Dejean, 1834 (= Praocis Eschscholtz, 1829) [Tenebrionidae], Euphron Dejean, 1834 (= Derosphaerus Thomson, 1858) [Tenebrionidae], Hipomelus Dejean, 1834 (= Trachynotus Latreille, 1828) [Tenebrionidae], Pezodontus Dejean, 1834 (= Odontopezus Alluaud, 1889) [Tenebrionidae], Zygocera Dejean, 1835 (= Disternopsis Breuning, 1939) [Cerambycidae], and Physonota Chevrolat, 1836 (= Anacassis Spaeth, 1913) [Chrysomelidae]. Heterogaster pilicornis Dejean, 1835 [Cerambycidae] and Labidomera trimaculata Chevrolat, 1836 [Chrysomelidae] are placed for the first time in synonymy with Anisogaster flavicans Deyrolle, 1862 and Chrysomela clivicollis Kirby, 1837 respectively. Type species of the following genus-group taxa are proposed: Sphaeromorphus Dejean, 1833 (Sphaeromorphus humeralis Erichson, 1843) [Scarabaeidae], Adelphus Dejean, 1834 (Helops marginatus Fabricius, 1792) [Tenebrionidae], Cyrtoderes Dejean, 1834 (Tenebrio cristatus DeGeer, 1778) [Tenebrionidae], Selenepistoma Dejean, 1834 (Opatrum acutum Wiedemann, 1823) [Tenebrionidae], Charactus Dejean, 1833 (Lycus limbatus Fabricius, 1801) [Lycidae], Corynomalus Chevrolat, 1836 (Eumorphus limbatus Olivier, 1808) [Endomychidae], Hebecerus Dejean, 1835 (Acanthocinus marginicollis Boisduval, 1835) [Cerambycidae], Pterostenus Dejean, 1835 (Cerambyx abbreviatus Fabricius, 1801) [Cerambycidae], Psalicerus Dejean, 1833 (Lucanus femoratus Fabricius, 1775) [Lucanidae], and Pygolampis Dejean, 1833 (Lampyris glauca Olivier, 1790) [Lampyridae]. A new name, Neoeutrapela Bousquet and Bouchard [Tenebrionidae], is proposed for Eutrapela Dejean, 1834 (junior homonym of Eutrapela Hübner, 1809).The following generic names, made available in Dejean’s catalogue, were found to be older than currently accepted valid names: Catoxantha Dejean, 1833 over Catoxantha Solier, 1833 [Buprestidae], Pristiptera Dejean, 1833 over Pelecopselaphus Solier, 1833 [Buprestidae], Charactus Dejean, 1833 over Calopteron Laporte, 1836 [Lycidae], Cyclonotum Dejean, 1833 over Dactylosternum Wollaston, 1854 [Hydrophilidae], Ancylonycha Dejean, 1833 over Holotrichia Hope, 1837 [Scarabaeidae], Aulacium Dejean, 1833 over Mentophilus Laporte, 1840 [Scarabaeidae], Sciuropus Dejean, 1833 over Ancistrosoma Curtis, 1835 [Scarabaeidae], Sphaeromorphus Dejean, 1833 over Ceratocanthus White, 1842 [Scarabaeidae], Psalicerus Dejean, 1833 over Leptinopterus Hope, 1838 [Lucanidae], Adelphus Dejean, 1834 over Praeugena Laporte, 1840 [Tenebrionidae], Amatodes Dejean, 1834 over Oncosoma Westwood, 1843 [Tenebrionidae], Cyrtoderes Dejean, 1834 over Phligra Laporte, 1840 [Tenebrionidae], Euphron Dejean, 1834 over Derosphaerus Thomson, 1858 [Tenebrionidae], Pezodontus Dejean, 1834 over Odontopezus Alluaud, 1889 [Tenebrionidae], Anoplosthaeta Dejean, 1835 over Prosopocera Blanchard, 1845 [Cerambycidae], Closteromerus Dejean, 1835 over Hylomela Gahan, 1904 [Cerambycidae], Hebecerus Dejean, 1835 over Ancita Thomson, 1864 [Cerambycidae], Mastigocera Dejean, 1835over Mallonia Thomson, 1857 [Cerambycidae], Zygocera Dejean, 1835 over Disternopsis Breuning, 1939 [Cerambycidae], Australica Chevrolat, 1836 over Calomela Hope, 1840 [Chrysomelidae], Edusa Chevrolat, 1836 over Edusella Chapuis, 1874 [Chrysomelidae], Litosonycha Chevrolat, 1836 over Asphaera Duponchel and Chevrolat, 1842 [Chrysomelidae], and Pleuraulaca Chevrolat, 1836 over Iphimeis Baly, 1864 [Chrysomelidae]. In each of these cases, Reversal of Precedence (ICZN 1999: 23.9) or an applicationto the International Commission on Zoological Nomenclature will be necessary to retain usage of the younger synonyms.     

NSAIDs counteract H. pylori VacA toxin-induced cell vacuolation in MKN 28 gastric mucosal cells

The relationship between nonsteroidal anti-inflammatory drugs (NSAIDs) and Helicobacter pylori-induced gastric mucosal injury is still under debate. VacA toxin is an important H. pylori virulence factor that causes cytoplasmic vacuolation in cultured cells. Whether and how NSAIDs affect VacA-induced cytotoxicity is unclear. This study was designed to evaluate the effect of NSAIDs on H. pylori VacA toxin-induced cell vacuolation in human gastric mucosal cells in culture (MKN 28 cell line). Our data show that 1) NSAIDs (indomethacin, aspirin, and NS-398) inhibit VacA-induced cell vacuolation independently of inhibition of cell proliferation and prostaglandin synthesis; 2) NSAIDs impair vacuole development/maintenance without affecting cell binding and internalization of VacA; and 3) NSAIDs, as well as the chloride channel blocker 5-nitro-2-(3-phenylpropylamino) benzoic acid, also inhibit cell vacuolation induced by ammonia. We thus hypothesize that NSAIDs might protect MKN 28 cells against VacA-induced cytotoxicity by inhibiting VacA channel activity required for vacuole genesis.     

Influenza A viruses limit NLRP3‐NEK7‐complex formation and pyroptosis in human macrophages

Pyroptosis is a fulminant form of macrophage cell death, contributing to release of pro‐inflammatory cytokines. In humans, it depends on caspase 1/4‐activation of gasdermin D and is characterized by the release of cytoplasmic content. Pathogens apply strategies to avoid or antagonize this host response. We demonstrate here that a small accessory protein (PB1‐F2) of contemporary H5N1 and H3N2 influenza A viruses (IAV) curtails fulminant cell death of infected human macrophages. Infection of macrophages with a PB1‐F2‐deficient mutant of a contemporary IAV resulted in higher levels of caspase‐1 activation, cleavage of gasdermin D, and release of LDH and IL‐1β. Mechanistically, PB1‐F2 limits transition of NLRP3 from its auto‐repressed and closed confirmation into its active state. Consequently, interaction of a recently identified licensing kinase NEK7 with NLRP3 is diminished, which is required to initiate inflammasome assembly.     

Co-expression of the small heat shock protein, Lo18, with β-glucosidase in Escherichia coli improves solubilization and reveals various associations with overproduced heterologous protein, GroEL/ES

We developed a new system to improve the overproduction of soluble proteins in E. coli based on a plasmid encoding the small heat-shock protein, Lo18, derived from the lactic acid bacterium Oenococcus oeni. The efficiency of this system was compared with that of another system based on production of the E. coli universal chaperone GroEL/ES. A compatible plasmid encoding β-glucosidase was constructed for the overproduction and aggregation of this enzyme. Co-expression with Lo18 resulted in an increase in soluble β-glucosidase levels similar to that obtained in the GroEL/ES co-expression system. Lo18 was found preferentially in the insoluble fraction, associated with aggregated enzyme. By contrast, GroEL/ES was more abundant in the soluble fraction.     

Wild-type intracellular bacteria deliver DNA into mammalian cells

Gene transfer in vitro from intracellular bacteria to mammalian phagocytic and non-phagocytic cells and in vivo in mice has been reported. The bacteria used as DNA delivery vectors were engineered to lyze upon entry in the cell due to impaired cell wall synthesis for Shigella flexneri and invasive Escherichia coli , or production of a phage lysin for Listeria mono- cytogenes . In vivo gene transfer was obtained with attenuated Salmonella typhimurium and resulted in stimulation of mucosal immunity. We report that wild-type intracellular human pathogens, such as L. monocytogenes EGD or LO28 and S. flexneri M90T, mediate efficient in vitro transfer of functional genes into epithelial and macrophage cell lines. A low- efficiency transfer was obtained from strain EGD to mouse peritoneal macrophages. DNA transfer with S. typhimurium was observed only from atten-uated aroA strain SL7207 into COS-1 cell line. As demonstrated by the study of listeriolysin-defective L. monocytogenes or of S. typhimurium SL7207 aroA engineered to secrete listeriolysin, escape of bacteria or of plasmid DNA from the intracytoplasmic vacuole is required for transfer of genetic information to occur.     

Chemical and enzymatic N-glycan release comparison for N-glycan profiling of monoclonal antibodies expressed in plants

Plants synthesize N-glycans containing the antigenic sugars α(1,3)-fucose and β(1,2)-xylose. Therefore it is important to monitor these N-glycans in monoclonal antibodies produced in plants (plantibodies). We evaluated several techniques to characterize the N-glycosylation of a plantibody produced in tobacco plants with and without the KDEL tetrapeptide endoplasmic reticulum retention signal which should inhibit or drastically reduce the addition of α(1,3)-fucose and β(1,2)-xylose. Ammonium hydroxide/carbonate-based chemical deglycosylation and PNGase A enzymatic release were investigated giving similar 2-aminobenzamide-labeled N-glycan HPLC profiles. The chemical release does not generate peptides which is convenient for MS analysis of unlabeled pool but its main drawback is that it induces degradation of α1,3-fucosylated N-glycan reducing terminal sugar. Three analytical methods for N-glycan characterization were evaluated: (i) MALDI-MS of glycopeptides from tryptic digestion; (ii) negative-ion ESI-MS/MS of released N-glycans; (iii) normal-phase HPLC of fluorescently labeled glycans in combination with exoglycosidase sequencing. The MS methods identified the major glycans, but the HPLC method was best for identification and relative quantitation of N-glycans. Negative-mode ESI-MS/MS permitted also the correct identification of the linkage position of the fucose residue linked to the inner core N-acteylglucosamine (GlcNAc) in complex N-glycans.     

Impact of cadmium on aquatic bird Cairina moschata

The impact on palmiped Cairina moschata of two levels of dietary cadmium (Cd) contamination (C1: 1 mg kg⁻¹ and C10: 10 mg kg⁻¹) was investigated on liver gene expression by real-time PCR. Genes involved in mitochondrial metabolism, in antioxidant defences, detoxification and in DNA damage repair were studied. Metallothionein (MT) protein levels and Cd bioaccumulation were also investigated in liver, kidneys and muscle. Male ducks were subjected to three periods of exposure: 10, 20 and 40 days. Cd was mainly bioaccumulated in kidneys first and in liver. The concentrations in liver and kidneys appeared to reach a stable level at 20 days of contamination even if the concentrations in muscle still increased. Cd triggered the enhancement of mitochondrial metabolism, the establishment of antioxidant defences (superoxide dismutase Mn and Cu/Zn; catalase) and of DNA repair from 20 days of contamination. Discrepancies were observed in liver between MT protein levels and MT gene up-regulation. MT gene expression appeared to be a late hour biomarker.     

Latency of cathepsin B secreted by human colon carcinoma cells is not linked to secretion of cystacin C and is relieved by neutrophil elastase

The lysosomal cystein proteinase cathepsin B is shown to be secreted by ten human colon carcinoma cell lines and to accumulate in culture media as a latent enzyme. The cell lines also secrete a physiological inhibitor of cathepsin B, cystatin C. A significant correlation was found between secretion of the latent enzyme and the inhibitor (r = 0.755, P < 0.01). The aim of the present study was to modulate the respective secretion of the two antagonists to test whether or not latency of cathepsin B was due to the concomitant secretion of the inhibitor. SW480 colon carcinoma cells were treated with the acidotropic agent ammonium chloride, phorbol 12-myristate 13-acetate, and the inflammatory cytokines TGF-β, TNF-α, and IL-1β. Ammonium chloride significantly increased latent cathepsin B levels without affecting the constitutive secretion of cystatin C. Phorbol 12-myristate 13-acetate induced a 4- to 5-fold increase in secreted latent cathepsin B, but did not alter significantly the accumulation of cystatin C in media. The cytokines, TGF-β, TNF-α, and IL-1β, had no major effect on the expression of these two antagonists. Latent cathepsin B released from human carcinoma cells could be efficiently activated by neutrophil elastate at neutral pH. It is concluded that latent cathepsin B is a true proenzyme rather than an enzyme-inhibitor comples. In addition, our data from neutrophil elastate activation experiments indicate that a proteolytic system for activation of the tumor cell-secreted latent enzyme may exist in vivo.