Simultaneous gut colonization by Klebsiella grimontii and Escherichia coli co-possessing the blaKPC-3-carrying pQil plasmid.

Only two plasmid-mediated carbapenemases (KPC-2 and VIM-1) are reported in Klebsiella grimontii. Here, we report two blaKPC-3-positive isolates that were identified as K. oxytoca and E. coli by MALDI-TOF MS in the same rectal swab. Whole-genome sequencing indicated that K. oxytoca was actually K. grimontii of ST391, whereas E. coli was of ST10. In both, blaKPC-3 was carried by a pQil conjugative plasmid. The core-genome analysis identified additional blaKPC-positive K. grimontii strains from public databases, most of which were misidentified as K. oxytoca. Since K. grimontii represents an emerging reservoir of resistance traits, routine tools should improve their ability to detect this species

Replicon Typing of Plasmids Encoding Resistance to Newer β-Lactams

Polymerase chain reaction–based replicon typing represents a novel method to describe the dissemination and follow the evolution of resistance plasmids. We used this approach to study 26 epidemiologically unrelated Enterobacteriaceae and demonstrate the dominance of incompatibility (Inc) A/C or Inc N-related plasmids carrying some emerging resistance determinants to extended-spectrum cephalosporins and carbapenems

Nosocomial Infections Caused by Multidrug-Resistant Isolates of Pseudomonas putida Producing VIM-1 Metallo-β-Lactamase

Successful carbapenem-based chemotherapy for the treatment of Pseudomonas infections has been seriously hindered by the recent appearance of IMP- and VIM-type metallo-β-lactamases, which confer high-level resistance to carbapenems and most other β-lactams. Recently, multidrug-resistant Pseudomonas putida isolates for which carbapenem MICs were ≥32 μg/ml were recovered from cultures of urine from three inpatients in the general intensive care unit of the Ospedale di Circolo, Varese, Italy. Enzyme assays revealed production of a metallo-β-lactamase activity, while molecular analysis detected in each isolate a bla(VIM-1) determinant carried by an apparently identical medium-sized plasmid. Conjugation experiments were unsuccessful in transferring the β-lactamase determinant to Escherichia coli or Pseudomonas aeruginosa. Macrorestriction analysis by pulsed-field gel electrophoresis demonstrated that the isolates were of clonal origin. PCR mapping and sequencing of the variable region of the plasmid-borne class 1 integron carrying the bla(VIM-1) determinant (named In110) showed that the bla(VIM-1)-containing cassette was identical to that previously found in strains of different species from other Italian hospitals and that the cassette array of In110 was not identical but clearly related to that of In70 (a bla(VIM-1)-containing plasmid-borne integron from an Achromobacter xylosoxidans isolate), pointing to a common origin of this cassette and to a related evolutionary history of their cognate integrons

Zinc Chelators as Carbapenem Adjuvants for Metallo-β-Lactamase-Producing Bacteria: In Vitro and In Vivo Evaluation

Infections caused by metallo-β-lactamase (MBL)-producing bacteria are emerging and carry a significant impact on patients' outcome. MBL producers are spread worldwide, both in community and hospital setting, with increasingly reported epidemic clusters and the search for MBL inhibitors is an important topic for public health. MBLs are zinc-dependent enzymes whose functioning can be hampered by zinc chelators. We evaluated the potential of six zinc chelators (disulfiram, nitroxoline, 5-amino-8-hydroxyquinoline, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid [DOTA], cyclam, and N,N,N′,N′-tetrakis (2-pyridymethyl) ethylenediamine [TPEN]) in restoring carbapenem activity against MBL producers. Zinc chelators alone or in combination with meropenem against MBL-producing Klebsiella pneumoniae, Chryseobacterium indologenes, Elizabethkingia meningoseptica, and Stenotrophomonas maltophilia isolates were tested in vitro and in vivo (Galleria mellonella). In vitro experiments showed a synergistic activity between TPEN and meropenem toward all the strains. Nitroxoline alone retained activity against S. maltophilia, C. indologenes, and E. meningoseptica. In vivo experiments showed that TPEN or nitroxoline in combination with meropenem increased survival in larvae infected with E. meningoseptica, S. maltophilia, and K. pneumoniae. Based on our data, zinc chelators are potential carbapenem adjuvants molecules (restoring carbapenem activity) against MBL-sustained infections and could represent an interesting option for infections induced by these microorganisms

Anaerobic bloodstream infections in Italy (ITANAEROBY): A 5-year retrospective nationwide survey

36noIntroduction: A lack of updated data on the burden and profile of anaerobic bloodstream infections (ABIs) exists. We assessed the incidence of ABIs and trends in antimicrobial resistance in anaerobes isolated from blood in Italy. Material and methods: We conducted a retrospective study on 17 Italian hospitals (2016-2020). Anaerobes isolated from blood culture and their in vitro susceptibility profiles (EUCAST-interpreted) were registered and analyzed. Results: A total of 1960 ABIs were identified. The mean age of ABIs patients was 68.6 ± 18.5 years, 57.6% were males. The overall incidence rate of ABIs was 1.01 per 10.000 patient-days. Forty-seven% of ABIs occurred in medical wards, 17% in ICUs, 14% in surgical wards, 7% in hemato-oncology, 14% in outpatients. The three most common anti-anaerobic tested drugs were metronidazole (92%), clindamycin (89%) and amoxicillin/clavulanate (83%). The three most common isolated anaerobes were Bacteroides fragilis (n = 529), Cutibacterium acnes (n = 262) and Clostridium perfringens (n = 134). The lowest resistance rate (1.5%) was to carbapenems, whereas the highest rate (51%) was to penicillin. Clindamycin resistance was >20% for Bacteroides spp., Prevotella spp. and Clostridium spp. Metronidazole resistance was 9.2% after excluding C. acnes and Actinomyces spp. Bacteroides spp. showed an increased prevalence of clindamycin resistance through the study period: 19% in 2016, 33% in 2020 (p ≤ 0.001). Conclusions: Our data provide a comprehensive overview of the epidemiology of ABIs in Italy, filling a gap that has existed since 1995. Caution is needed when clindamycin is used as empirical anti-anaerobic drug.nonemixedDi Bella, Stefano; Antonello, Roberta Maria; Sanson, Gianfranco; Maraolo, Alberto Enrico; Giacobbe, Daniele Roberto; Sepulcri, Chiara; Ambretti, Simone; Aschbacher, Richard; Bartolini, Laura; Bernardo, Mariano; Bielli, Alessandra; Busetti, Marina; Carcione, Davide; Camarlinghi, Giulio; Carretto, Edoardo; Cassetti, Tiziana; Chilleri, Chiara; De Rosa, Francesco Giuseppe; Dodaro, Saveria; Gargiulo, Raffaele; Greco, Francesca; Knezevich, Anna; Intra, Jari; Lupia, Tommaso; Concialdi, Erika; Bianco, Gabriele; Luzzaro, Francesco; Mauri, Carola; Morroni, Gianluca; Mosca, Adriana; Pagani, Elisabetta; Parisio, Eva Maria; Ucciferri, Claudio; Vismara, Chiara; Luzzati, Roberto; Principe, LuigiDi Bella, Stefano; Antonello, Roberta Maria; Sanson, Gianfranco; Maraolo, Alberto Enrico; Giacobbe, Daniele Roberto; Sepulcri, Chiara; Ambretti, Simone; Aschbacher, Richard; Bartolini, Laura; Bernardo, Mariano; Bielli, Alessandra; Busetti, Marina; Carcione, Davide; Camarlinghi, Giulio; Carretto, Edoardo; Cassetti, Tiziana; Chilleri, Chiara; De Rosa, Francesco Giuseppe; Dodaro, Saveria; Gargiulo, Raffaele; Greco, Francesca; Knezevich, Anna; Intra, Jari; Lupia, Tommaso; Concialdi, Erika; Bianco, Gabriele; Luzzaro, Francesco; Mauri, Carola; Morroni, Gianluca; Mosca, Adriana; Pagani, Elisabetta; Parisio, Eva Maria; Ucciferri, Claudio; Vismara, Chiara; Luzzati, Roberto; Principe, Luig

A global method for calculating plant CSR ecological strategies applied across biomes world-wide

Competitor, stress‐tolerator, ruderal (CSR) theory is a prominent plant functional strategy scheme previously applied to local floras. Globally, the wide geographic and phylogenetic coverage of available values of leaf area (LA), leaf dry matter content (LDMC) and specific leaf area (SLA) (representing, respectively, interspecific variation in plant size and conservative vs. acquisitive resource economics) promises the general application of CSR strategies across biomes, including the tropical forests hosting a large proportion of Earth´s diversity.We used trait variation for 3068 tracheophytes (representing 198 families, six continents and 14 biomes) to create a globally calibrated CSR strategy calculator tool and investigate strategy?environment relationships across biomes world‐wide.Due to disparity in trait availability globally, co‐inertia analysis was used to check correspondence between a ?wide geographic coverage, few traits? data set and a ?restricted coverage, many traits? subset of 371 species for which 14 whole‐plant, flowering, seed and leaf traits (including leaf nitrogen content) were available. CSR strategy/environment relationships within biomes were investigated using fourth‐corner and RLQ analyses to determine strategy/climate specializations.Strong, significant concordance (RV = 0·597; P < 0·0001) was evident between the 14 trait multivariate space and when only LA, LDMC and SLA were used.Biomes such as tropical moist broadleaf forests exhibited strategy convergence (i.e. clustered around a CS/CSR median; C:S:R = 43:42:15%), with CS‐selection associated with warm, stable situations (lesser temperature seasonality), with greater annual precipitation and potential evapotranspiration. Other biomes were characterized by strategy divergence: for example, deserts varied between xeromorphic perennials such as Larrea divaricata, classified as S‐selected (C:S:R = 1:99:0%) and broadly R‐selected annual herbs (e.g. Claytonia perfoliata; R/CR‐selected; C:S:R = 21:0:79%). Strategy convergence was evident for several growth habits (e.g. trees) but not others (forbs).The CSR strategies of vascular plants can now be compared quantitatively within and between biomes at the global scale. Through known linkages between underlying leaf traits and growth rates, herbivory and decomposition rates, this method and the strategy?environment relationships it elucidates will help to predict which kinds of species may assemble in response to changes in biogeochemical cycles, climate and land use.Fil: Pierce, Simon. University Of Milan; ItaliaFil: Negreiros, Daniel. Universidade Federal de Minas Gerais; BrasilFil: Cerabolini, Bruno E. L.. Universidad de Insubria; ItaliaFil: Kattge, Jens. 1max Planck Institute For Biogeochemistr; AlemaniaFil: Díaz, Sandra Myrna. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Grime, John Philip. University of Sheffield; Reino UnidoFil: Thompson, Ken. University of Sheffield; Reino UnidoFil: Hunt, Roderick. University of Exeter; Reino UnidoFil: Wilson, Peter J.. University of Sheffield; Reino UnidoFil: Buffa, Gabriella. University Ca’Foscari of Venice; ItaliaFil: Nyakunga, Oliver C.. University Ca’Foscari of Venice; ItaliaFil: Reich, Peter B.. University of Minnesota; Estados UnidosFil: Caccianiga, Marco. Università degli Studi di Milano; ItaliaFil: Mangili, Federico. Università degli Studi di Milano; ItaliaFil: Ceriani, Roberta M.. The Native Flora Centre; Italia. Università degli Studi di Milano; ItaliaFil: Luzzaro, Alessandra. Università degli Studi di Milano; ItaliaFil: Brusa, Guido. University of Insubria; ItaliaFil: Siefert, Andrew. University of California at Davis; Estados UnidosFil: Barbosa, Newton P. U.. Universidade Federal de Minas Gerais; BrasilFil: Chapin III, Francis Stuart. University Of Alaska; Estados UnidosFil: Cornwell, William K.. University of New South Wales; AustraliaFil: Fang, Jingyun. The Chinese Academy of Sciences; ChinaFil: Fernandes, Geraldo Wilson. Universidade Federal de Minas Gerais; BrasilFil: Garnier, Eric. Centre d’Écologie Fonctionnelle et Évolutive; FranciaFil: Le Stradic, Soizig. Université de Liège; BélgicaFil: Peñuelas, Josep. Global Ecology Unit; EspañaFil: Melo, Felipe P. L.. Universidade Federal de Pernambuco; BrasilFil: Slaviero, Antonio. University Ca’Foscari of Venice; ItaliaFil: Tabarelli, Marcelo. Universidade Federal de Pernambuco; BrasilFil: Tampucci, Duccio. Università degli Studi di Milano; Itali