Characterisation of serratia spp. from aquaculture environment and river water

Serratia spp. is one of the significant human pathogen. Some Serratia spp. especially Serratia marcescens contain a lot of human clinical infection history as well as interesting taxonomic, military experimentation and medical experiment. Currently, Serratia marcescens and Serratia liquefaciens have been isolated as causative agents of numerous outbreaks and opportunistic infections. As the species appear to be common environmental organisms, large number of nosocomial infections due to these bacteria can be explained. Thus, molecular characterization of several Serratia spp. become the main objective of this research as an approach to gain better identification and characterisation of various of Serratia spp. In this study, antibiotic susceptibility and genetic diversity of Serratia spp. isolated from aquaculture environment and river water of Rayu river were determined. The levels of resistance of the Serratia isolates towards nineteen antibiotics were tested. These isolates displayed resistance towards most of the antibiotics tested but the level of resistance vary among the species. Genetic characterization of Serratia spp. were carried out by using GTGs-PCR which clustered the Serratia isolates into three groups based on DNA fingerprinting by using Paleontologi statistic software. The results of this study suggest that the Serratia isolates from aquaculture environment and river water derived a mixture of sensitive and resistant strains with diverse genetic contents

Isolation and characterization of heavy metal resistant psychrotrophs from antarctica

The present study reported the isolation and characterisation of heavy metal resistant bacteria from Antarctic water. Ten isolates were successfully isolated from seawater and ice lower glacier and two isolates named SW5 and ILG1 were selected for further study based on their high resistance towards heavy metals particularly, arsenite and arsenate. Both isolates have optimum growth at 20°C to 30°C. Isolates SW5 and ILG1 were tested for their resistance to metal ions such as Cd(II), Cr(VI), As(III) and As(V) at different range of concentration namely, Cd(II) 3-30 ppm; Cr(VI) 15-135 ppm; As(III) 150-1500 ppm; and As(V) 150-7500 ppm. The minimal inhibitory concentration (MIC) of four heavy metals was determined in Low Phosphate Mediumfor each bacterial strain. The results of the test revealed that MIC for isolate SW5 was at 15 ppm, 30 ppm, 900 ppm and 7500 ppm for Cr(VI), Cd(II), As (III) and As(V) respectively while for ILG1, MIC was at 12 ppm for Cr(VI), 9 ppm for Cd(II), 750 ppm for As(III) and 3000 ppm for As(V). Overall, the order of toxicity of heavy metals to SW5 was in order of Cr(VI)> Cd(II)> As(III)> As(V) and for ILG1 was in order of Cd(II)> Cr(VI)> As(III)> As(V). Molecular characterization, 16S rRNA analysis revealed that isolate SW5 shares a 99.65% identity match to Pseudomonas azotoformans strain IAM 1603 while isolate ILG1 shares a 99.51% identity match to Pseudomonas cedrina subsp cedrina strain CFML 96-198. These bacteria could be used as a model microbial strain to study the mechanism of heavy metal resistance with potential application for bioremediation of heavy metals

Milk Consumption Across Life Periods in Relation to Lower Risk of Nasopharyngeal Carcinoma: A Multicentre Case-Control Study

Background: The much higher incidence of nasopharyngeal carcinoma (NPC) in men suggests sex hormones as a risk factor, and dairy products contain measurable amounts of steroid hormones. Milk consumption has greatly increased in endemic regions of NPC. We investigated the association between NPC and milk consumption across life periods in Hong Kong.Methods: A multicentre case-control study included 815 histologically confirmed NPC incident cases and 1,502 controls who were frequency-matched on age and sex at five major hospitals in Hong Kong in 2014–2017. Odds ratios (ORs) of NPC (cases vs. controls) for milk consumption at different life periods were estimated by unconditional logistic regression, adjusting for sex, age, socioeconomic status score, smoking and alcohol drinking status, exposure to occupational hazards, family history of cancer, IgA against Epstein-Barr virus viral capsid antigen, and total energy intake.Results: Compared with abstainers, lower risks of NPC were consistently observed in regular users (consuming ≥5 glasses of milk [fresh and powdered combined] per month) across four life periods of age 6–12 (adjusted OR 0.74, 95% CI 0.54–0.86), 13–18 (0.68, 0.55–0.84), 19–30 (0.68, 0.55–0.84), and 10 years before recruitment (0.72, 0.59–0.87). Long-term average milk consumption of ≤2.5, >2.5, and ≤12.5, >12.5 glasses per month yielded adjusted OR (95% CI) of 1.00 (0.80–1.26), 0.98 (0.81–1.18), 0.95 (0.76–1.18), and 0.55 (0.43–0.70), respectively (all P-values for trend < 0.05).Conclusion: Consumption of milk across life periods was associated with lower risks of NPC. If confirmed to be causal, this has important implications for dairy product consumption and prevention of NPC

Search for strong gravity in multijet final states produced in pp collisions at √s=13 TeV using the ATLAS detector at the LHC

A search is conducted for new physics in multijet final states using 3.6 inverse femtobarns of data from proton-proton collisions at √s = 13TeV taken at the CERN Large Hadron Collider with the ATLAS detector. Events are selected containing at least three jets with scalar sum of jet transverse momenta (HT) greater than 1TeV. No excess is seen at large HT and limits are presented on new physics: models which produce final states containing at least three jets and having cross sections larger than 1.6 fb with HT > 5.8 TeV are excluded. Limits are also given in terms of new physics models of strong gravity that hypothesize additional space-time dimensions

The performance of the jet trigger for the ATLAS detector during 2011 data taking

The performance of the jet trigger for the ATLAS detector at the LHC during the 2011 data taking period is described. During 2011 the LHC provided proton–proton collisions with a centre-of-mass energy of 7 TeV and heavy ion collisions with a 2.76 TeV per nucleon–nucleon collision energy. The ATLAS trigger is a three level system designed to reduce the rate of events from the 40 MHz nominal maximum bunch crossing rate to the approximate 400 Hz which can be written to offline storage. The ATLAS jet trigger is the primary means for the online selection of events containing jets. Events are accepted by the trigger if they contain one or more jets above some transverse energy threshold. During 2011 data taking the jet trigger was fully efficient for jets with transverse energy above 25 GeV for triggers seeded randomly at Level 1. For triggers which require a jet to be identified at each of the three trigger levels, full efficiency is reached for offline jets with transverse energy above 60 GeV. Jets reconstructed in the final trigger level and corresponding to offline jets with transverse energy greater than 60 GeV, are reconstructed with a resolution in transverse energy with respect to offline jets, of better than 4 % in the central region and better than 2.5 % in the forward direction

Correlated long-range mixed-harmonic fluctuations measured in pp, p+Pb and low-multiplicity Pb+Pb collisions with the ATLAS detector

For abstract see published article

Measurement of jet charge in dijet events from √s = 8 TeV pp collisions with the ATLAS detector

The momentum-weighted sum of the charges of tracks associated to a jet is sensitive to the charge of the initiating quark or gluon. This paper presents a measurement of the distribution of momentum-weighted sums, called jet charge, in dijet events using 20.3 fb−¹ of data recorded with the ATLAS detector at √s = 8 TeV in pp collisions at the LHC. The jet charge distribution is unfolded to remove distortions from detector effects and the resulting particle-level distribution is compared with several models. The pT dependence of the jet charge distribution average and standard deviation are compared to predictions obtained with several leading-order and next-to-leading-order parton distribution functions. The data are also compared to different Monte Carlo simulations of QCD dijet production using various settings of the free parameters within these models. The chosen value of the strong coupling constant used to calculate gluon radiation is found to have a significant impact on the predicted jet charge. There is evidence for a pT dependence of the jet charge distribution for a given jet flavor. In agreement with perturbative QCD predictions, the data show that the average jet charge of quark-initiated jets decreases in magnitude as the energy of the jet increases