Draft Genome Sequences of Pandrug-Resistant Serratia marcescens Clinical Isolates Harboring bla NDM-1

The draft genome sequences of two clonal, pandrug-resistant Serratia marcescens clinical isolates were determined. The resistance phenotype was plasmid driven, as 14 of 17 resistance genes were present on large IncFIB(K), IncHI2, and IncA/C2 plasmids indicating a large pool of transmissible antibiotic resistance genes

Insights into a Novel blaKPC-2-Encoding IncP-6 Plasmid Reveal Carbapenem-Resistance Circulation in Several Enterobacteriaceae Species from Wastewater and a Hospital Source in Spain

Untreated wastewater, particularly from hospitals and other healthcare facilities, is considered to be a reservoir for multidrug-resistant bacteria. However, its role in the spread of antibiotic resistances in the human population remains poorly investigated. We used whole genome sequencing (WGS) to analyze 25 KPC-2-producing Enterobacteriaceae isolates from sewage water collected during a 3-year period and three clinical Citrobacter freundii isolates from a tertiary hospital in the same collection area in Spain. We detected a common, recently described, IncP-6 plasmid carrying the gene blaKPC-2 in 21 isolates from both sources. The plasmid was present in diverse environmental bacterial species of opportunistic pathogens such as C. freundii, Enterobacter cloacae, Klebsiella oxytoca, and Raoultella ornithinolytica. The 40,186 bp IncP-6 plasmid encoded 52 coding sequences (CDS) and was composed of three uniquely combined regions that were derived from other plasmids recently reported in different countries of South America. The region harboring the carbapenem resistance gene (14 kb) contained a Tn3 transposon disrupted by an ISApu-flanked element and the core sequence composed by ISKpn6 / blaKPC-2 / ?blaTEM-1 / ISKpn27. We document here the presence of a novel promiscuous blaKPC-2 plasmid circulating in environmental bacteria in wastewater and human populations

Halophilic Archaea Mediate the Formation of Proto-Dolomite in Solutions With Various Sulfate Concentrations and Salinities

In the past several decades, sulfate concentration and salinity have been considered to be the two essential hydrochemical factors in the formation of dolomite, yet arguments against this hypothesis have existed simultaneously. To clarify the effects of sulfate concentration and salinity in the mineralization of dolomite, we conducted experiments on dolomite precipitation mediated by a halophilic archaeon, Natrinema sp. J7-1 with various sulfate concentrations and salinities. This strain was cultured in a series of modified growth media (MGM) with salinities of 140, 200, and 280‰. Cells in the post-log phase were harvested and used to mediate the formation of dolomite in solutions with various sulfate concentrations of 0, 3, 29.8, and 100 mM and salinities of 140, 200, and 280‰. X-ray diffraction (XRD) spectra showed that proto-dolomite, monohydrocalcite, and aragonite formed in samples with cells, yet only aragonite was detected in samples without cells. Proto-dolomite was found in all biotic samples, regardless of the variation in salinity and sulfate concentration. Moreover, the relative abundances of proto-dolomite in the precipitates were positively correlated with the salinities of the media but were uncorrelated with the sulfate concentrations of the solutions. Scanning electronic microscopy (SEM) and energy dispersive spectroscopy (EDS) results showed that all the proto-dolomites were sphere or sphere aggregates with a mole ratio of Mg/Ca close to 1.0. No obvious variations in morphology and Mg/Ca were found among samples with various sulfate concentrations or salinities. This work reveals that a variation of sulfate concentration in solution (from 0 to 100 mM) does not affect the formation of dolomite mediated by halophilic archaea, but an increase of salinity (from 140 to 280‰) enhances this process. Our results indicate that under natural conditions, an increase in salinity may be more significant than the decrease of sulfates in microbe-mediated dolomite formation

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

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

Knowledge and risk behaviors related to HIV/AIDS, and their association with information resource among men who have sex with men in Heilongjiang province, China

<p>Abstract</p> <p>Backgroud</p> <p>In Heilongjiang province, the HIV prevalence in men who have sex with men (MSM) is generally lower than other part of China. However, the official perception for their risk of HIV/AIDS infection has been increasing in the province over the years. Moreover, little information on HIV/AIDS was provided to the communities so that we have disadvantage of controlling HIV/AIDS epidemic in the region. The purpose of this study is to investigate the prevalence of HIV among MSM in Heilongjiang province, to assess their knowledge levels and risk behaviors related to HIV/AIDS, and to explore their associations with information resources.</p> <p>Methods</p> <p>A cross-sectional study using a standardized questionnaire and blood test was administered in 2008 by local interviewers to a sample (1353) of MSM in four cities in Heilongjiang province.</p> <p>Results</p> <p>Among 1353 MSM, 2.3% were identified with HIV infection. About 48.7% of the subjects had multiple male sexual partners and only 37.3% of the subjects had consistent condom use (use every time) in the past 6 months. Most had a fair level of knowledge on HIV/AIDS, with the highest mean knowledge score among the MSM from Jiamusi, those with income 2000-3000 RMB/month, those searching sexual partners via internet and those performed HIV testing over 1 year ago). However, some myths regarding viral transmission (e.g., via mosquito bites or sharing kitchen utensils) also existed. Resources of information from which knowledge and risk behaviors related to HIV/AIDS was most available were television (58.6%) among MSM, followed by sexual partner (51.6%), publicity material (51.0%) and internet (48.7%). Significantly statistical differences of mean knowledge score were revealed in favor of book (<it>P </it>= 0.0002), medical staff (<it>P </it>= 0.0007), publicity material (<it>P </it>= 0.005) and sexual partner (<it>P </it>= 0.02). Press (<it>P </it>= 0.04) and book (<it>P </it>= 0.0003) were contributory to the most frequent condom use (condom use every time), while medical staff (<it>P </it>= 0.005) and publicity material (<it>P </it>= 0.04) is associated with moderate rate of condom use (condom use often).</p> <p>Conclusions</p> <p>Although the prevalence of HIV infection is low among MSM in Heilongjiang province, the situation that the risk behaviors were frequent in the population is alarming. The study suggests that some strategies like condom use and education intervention are practical approaches and need to be strengthened.</p

Improved delayed detached eddy simulation of supersonic combustion fueled by liquid kerosene

The purpose of this study is to quantitatively investigate the influence of diffusion characteristics and equivalence ratios (ERs) of gaseous/liquid kerosene on transient combustions in a three-dimensional cavity-based scramjet combustor using Improved Delayed Detached Eddy Simulation (IDDES) with a 19 species and 54 reactions kerosene/air mechanism. Additionally, the similarities and differences between gaseous and liquid kerosene supersonic combustion are identified based on the pressure, mixture fraction, temperature, and heat release rate distributions. The findings indicated that the injection velocity of liquid kerosene is an order of magnitude lower than that of gaseous kerosene; however, the residence time of liquid kerosene in the cavity was amplified by two orders of magnitude. The results also highlighted the substantial differences in the reaction heat release position between gaseous and liquid kerosene combustion. For a combustion process of liquid kerosene at an ER of 0.215, there is no obvious boundary layer separation in the isolator. The combustion process is controlled by the mixing efficiency of the shear layer, and the mode of combustion is cavity shear-layer stabilized combustion. When the ERs are 0.27 and 0.43, the flame propagates upstream of the cavity and forms boundary layer separation and oblique shock waves. Then, the combustion process is controlled by the fuel transportation in the cavity recirculation zone, and the mode of combustion is the cavity recirculation-zone stabilized combustion

Cross-Border Emergence of Escherichia coli Producing the Carbapenemase NDM-5 in Switzerland and Germany

A series of clinical NDM-5-producing Escherichia coli isolates obtained from two surveillance networks for carbapenem-producing Enterobacterales from 2018 to 2019, namely, Switzerland (NARA) and Germany (SurvCARE), were analyzed. The 33 NDM-5-producing E. coli isolates were highly resistant to β-lactams, including novel β-lactam/β-lactamase inhibitor combinations (ceftazidime-avibactam, imipenem-relebactam, and meropenem-vaborbactam), and remained susceptible to fosfomycin, colistin, and tigecycline. These isolates were assigned to different sequence types (STs) and indicated a predominance of isolates exhibiting ST167 in Switzerland and Germany (n = 10) (phylogenetic group C), followed by ST405 (n = 4) (phylogenetic group E), ST1284 (n = 4) (phylogenetic group C), and ST361 (n = 4) (phylogenetic group C). The blaNDM-5 gene was predominantly present on an IncF-type plasmid (n = 29) and, to a lesser extent, on the narrow-host-range IncX3 plasmid (n = 4). Sequence analyses of eight NDM-5 plasmids indicated that NDM-5-encoding F-type plasmids varied in size between 86 and 132 kb. The two IncX3 plasmids pCH8NDM5 and pD12NDM5 were 46 and 45 kb in size, respectively. The highly conserved blaNDM-5 genetic surrounding structures (ΔISAba125-blaNDM-5-bleMBL-trpT-dsbD-IS26) of both the F-type and IncX3 plasmids suggested a common genetic origin. The emergence of the NDM-5 carbapenemase was evidenced in particular for the E. coli ST167 clone, which is a successful epidemic clone known to be associated with both multiresistance and virulence traits and is therefore of high public health concern. The occurrence of clonally related NDM-5-producing E. coli isolates in Switzerland and Germany further indicates the international spread of this multidrug-resistant superbug at least throughout Europe

Cross-border emergence of Escherichia coli producing the carbapenemase NDM-5 in Switzerland and Germany

A series of clinical NDM-5-producing E. coli isolates obtained from two surveillance networks of carbapenem-producing Enterobacterales from 2018-2019, namely Switzerland (NARA) and Germany (SurvCARE), were analyzed. The 33 NDM-5- producing E. coli isolates were highly resistant to β-lactams including the novel ß- lactam/ß-lactamase inhibitor combinations (ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam), and remained susceptible to fosfomycin, colistin, and tigecycline. Those isolates were assigned to different sequence types (STs) and indicated a predominance of isolates exhibiting the sequence type (ST) ST167 in Switzerland and in Germany (n=10, phylogenetic group C), followed by ST405 (n=4, phylogenetic group E), ST1284 (n=4, phylogenetic group C) and ST361 (n=4, phylogenetic group C). The blaNDM-5 gene was predominantly present on an IncF-type plasmid (n=29), and to a lesser extent on the narrow-host range IncX3 plasmid (n=4). Sequence analyses of eight NDM-5 plasmids indicated that NDM-5-encoding F-type plasmids varied in size between 86 to 132 kb. The two IncX3 plasmids pCH8NDM5 and pD12NDM5 were 46 and 45 kb in size, respectively. The highly conserved blaNDM-5 genetic surrounding structures [ΔISAba125-blaNDM- 5-bleMBL-trpT-dsbD-IS26] of both the F-type and IncX3 plasmids suggested a common genetic origin. The emergence of the NDM-5 carbapenemase was evidenced in particular for the E. coli ST167 clone, which is a successful epidemic clone, known to be associated to both multi-resistance and virulence traits and is therefore of high public health concern. The occurrence of clonally related NDM-5- producing E. coli isolates in Switzerland and Germany further indicates the international spread of this multidrug-resistant superbug at least throughout Europe