Prevalence and Antimicrobial Susceptibility of Potentially Pathogenic Bacteria and Fungi Isolated from Public Parks of Bogotá, Colombia

Regular interactions of humans with their environment, animals and different microorganisms as part of everyday routine can cause several infections or diseases that can become a public health problem if these are not properly controlled. It is necessary to identify potentially pathogenic bacteria (with its antimicrobial resistance) and fungi, and their prevalence in public parks in Bogotá city. Four parks were evaluated, where samples were taken from dog’s feces and hair, recreational items and environmental material, to perform the microorganism’s isolations. The higher prevalence percentages in each sort of sample were for Escherichia coli, Staphylococcus epidermidis, Staphylococcus aureus, Rahnella aquatilis, Penicillium spp, Cladosporium spp. and Mucor spp. and there were pathogenic species like Salmonella enteritidis and Klebsiella pneumoniae. We report a strain of S. aureus with intermediate resistance to vancomycin (VISA) found in recreational items. The higher rates of antibiotics resistance like ampicillin and trimethoprim were found in the isolations from dog’s feces. Some species or genera reported are considerated as opportunistic pathogens; however, these and the pathogenic species reported represent a threat to human health and this is why it is essential to have a personal hygiene plan after stay at a park.Regular interactions of humans with their environment, animals and different microorganisms as part of everyday routine can cause several infections or diseases that can become a public health problem if these are not properly controlled. It is necessary to identify potentially pathogenic bacteria (with its antimicrobial resistance) and fungi, and their prevalence in public parks in Bogotá city. Four parks were evaluated, where samples were taken from dog’s feces and hair, recreational items and environmental material, to perform the microorganism’s isolations. The higher prevalence percentages in each sort of sample were for Escherichia coli, Staphylococcus epidermidis, Staphylococcus aureus, Rahnella aquatilis, Penicillium spp, Cladosporium spp. and Mucor spp. and there were pathogenic species like Salmonella enteritidis and Klebsiella pneumoniae. We report a strain of S. aureus with intermediate resistance to vancomycin (VISA) found in recreational items. The higher rates of antibiotics resistance like ampicillin and trimethoprim were found in the isolations from dog’s feces. Some species or genera reported are considerated as opportunistic pathogens; however, these and the pathogenic species reported represent a threat to human health and this is why it is essential to have a personal hygiene plan after stay at a park

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data