Prevalent phenotypes and antibiotic resistance in Escherichia coli and Klebsiella pneumoniae at an Indian tertiary care hospital: plasmid-mediated cefoxitin resistance

SummaryBackgroundThe β-lactam antibiotics, in combination with aminoglycosides, are among the most widely prescribed antibiotics. However, because of extensive and unnecessary use, resistance to these drugs continues to increase. In recent years, resistance in the Indian bacterial population has increased markedly, the majority showing complex mechanisms. Due to increased transcontinental movement of the human population, it would be wise to know the prevalence and resistance complexity of these strains, well in advance, in order to formulate a policy for empirical therapy.MethodsOne hundred and eighty-one isolates of Escherichia coli and 61 isolates of Klebsiella pneumoniae obtained from 2655 non-repeat samples of pus (912) and urine (1743) were studied, and their resistance rates and patterns were noted. The isolates were analyzed for prevalent aminoglycoside and cephalosporin resistance phenotypes and for the presence of extended spectrum β-lactamase (ESBL) and AmpC enzymes by spot-inoculation and modified three-dimensional tests developed in our laboratory. Fourteen isolates of E. coli and six of K. pneumoniae, resistant to all of the antibiotics tested, were selected for plasmid screening, curing, and transconjugation experiments, and for comparative evaluation of the double disk synergy test (DDST) and modified three-dimensional test (TDT) for detection of β-lactamases.ResultsUrinary E. coli isolates showed maximum susceptibility to amikacin (57.1%), followed by tobramycin (38.5%) and gentamicin (31.9%). Eighteen (19.8%) isolates were susceptible to cefotaxime, whereas 11 (12.1%) were susceptible to ceftriaxone. The K. pneumoniae isolates from urine samples showed maximum susceptibility to tobramycin (63.6%) followed by amikacin (54.5%). Of the K. pneumoniae isolates, 31.8% were susceptible to cefotaxime and 13.6% were susceptible to ceftriaxone. A more or less similar trend of antibiotic susceptibility was noted in E. coli and K. pneumoniae isolates from pus samples. Twenty-six (14.4%) E. coli and 15 (24.6%) K. pneumoniae isolates were found to be ESBL-producers by NCCLS-ESBL phenotypic confirmatory test. Eighteen (9.9%) E. coli and 19 (31.1%) K. pneumoniae isolates were found to be AmpC enzyme-producers by our modified TDT. The simultaneous occurrence of ESBL and AmpC enzymes was noted in 7.7% and 9.8% isolates of E. coli and K. pneumoniae, respectively.ConclusionsThe prevalence of multidrug-resistant bacterial isolates is quite high in our bacterial population. On comparative evaluation of DDST and TDT in resistant isolates, TDT was found to be the better method, detecting ESBLs in 80% of isolates compared to 15% with DDST. A 19.9-kb plasmid was consistently present in all the screened isolates of E. coli and K. pneumoniae, and was inferred to encode cefoxitin and tetracycline resistance based on curing and transconjugation experiments

Lepton Polarization in the Decays B→Xsμ+μ−B\to X_s\mu^+\mu^- and B→Xsτ+τ−B\to X_s\tau^+\tau^-

The effective Hamiltonian for the decay $b\to s l^+ l^-$ predicts a characteristic polarization for the final state lepton, which can serve as an important test of the underlying theory. The lepton polarization has, in addition to a longitudinal component $P_L$, two orthogonal components $P_T$ and $P_N$, lying in and perpendicular to the decay plane which are proportional to $m_l/m_b$, and therefore significant for the $\tau^+\tau^-$ channel. The normal polarization component $P_N$ is a $T$-odd effect connected with the nonhermiticity of the effective Hamiltonian, arising mainly from $c\bar{c}$ intermediate states. We calculate all three polarization components for the decay $B\to X_s\tau^+\tau^-$ as a function of the lepton pair mass, and find average values $$= -0.37,$$ = -0.63, = 0.03. By comparison, the $\mu^-$ polarization is = -0.77, $= \approx 0$.Comment: 17 pages, LaTeX, 5 eps figures, uses epsf.sty and cite.st

A faster pseudo-primality test

We propose a pseudo-primality test using cyclic extensions of $\mathbb Z/n \mathbb Z$. For every positive integer $k \leq \log n$, this test achieves the security of $k$ Miller-Rabin tests at the cost of $k^{1/2+o(1)}$ Miller-Rabin tests.Comment: Published in Rendiconti del Circolo Matematico di Palermo Journal, Springe

Thermal shape fluctuation effects in the description of hot nuclei

The behavior of several nuclear properties with temperature is analyzed within the framework of the Finite Temperature Hartree-Fock-Bogoliubov (FTHFB) theory with the Gogny force and large configuration spaces. Thermal shape fluctuations in the quadrupole degree of freedom, around the mean field solution, are taken into account with the Landau prescription. As representative examples the nuclei $^{164}$Er, $^{152}$Dy and $^{192}$Hg are studied. Numerical results for the superfluid to normal and deformed to spherical shape transitions are presented. We found a substantial effect of the fluctuations on the average value of several observables. In particular, we get a decrease in the critical temperature ($T_c$) for the shape transition as compared with the plain FTHFB prediction as well as a washing out of the shape transition signatures. The new values of $T_c$ are closer to the ones found in Strutinsky calculations and with the Pairing Plus Quadrupole model Hamiltonian.Comment: 17 pages, 8 Figure

Rare KK Decays

The rare decays of the $K$ meson have had a long tradition as a laboratory for testing the symmetry properties of the weak interactions, and the manner in which these symmetries are broken by higher order effects. Present--day interest is focussed on decays that are suppressed by $CP$--symmetry or GIM symmetry. Such decays, in the standard theory, are sensitive to effects of the virtual top quark, and could also reveal new interactions transcending the standard model. In addition, the radiative decays of the $K$ meson have become a useful testing--ground for effective Lagrangians describing the low energy interactions of pions, kaons and photons.Comment: Invited Talk at the Third Workshop on High Energy Particle Physics (WHEPP 3) Madras, 1994, LaTex, 14 pages, 3 figures available upon reques

Search for H→γγ produced in association with top quarks and constraints on the Yukawa coupling between the top quark and the Higgs boson using data taken at 7 TeV and 8 TeV with the ATLAS detector

A search is performed for Higgs bosons produced in association with top quarks using the diphoton decay mode of the Higgs boson. Selection requirements are optimized separately for leptonic and fully hadronic final states from the top quark decays. The dataset used corresponds to an integrated luminosity of 4.5 fb−14.5 fb−1 of proton–proton collisions at a center-of-mass energy of 7 TeV and 20.3 fb−1 at 8 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. No significant excess over the background prediction is observed and upper limits are set on the tt¯H production cross section. The observed exclusion upper limit at 95% confidence level is 6.7 times the predicted Standard Model cross section value. In addition, limits are set on the strength of the Yukawa coupling between the top quark and the Higgs boson, taking into account the dependence of the tt¯H and tH cross sections as well as the H→γγ branching fraction on the Yukawa coupling. Lower and upper limits at 95% confidence level are set at −1.3 and +8.0 times the Yukawa coupling strength in the Standard Model

Measurement of jet suppression in central Pb-Pb collisions at root s(NN)=2.76 TeV

The transverse momentum(p(T)) spectrum and nuclear modification factor (R-AA) of reconstructed jets in 0-10% and 10-30% central Pb-Pb collisions at root s(NN) = 2.76 TeV were measured. Jets were reconstructed using the anti-k(T) jet algorithm with a resolution parameter of R = 0.2 from charged and neutral particles, utilizing the ALICE tracking detectors and Electromagnetic Calorimeter (EMCal). The jet p(T) spectra are reported in the pseudorapidity interval of \eta(jet)\ 5 GeV/c to suppress jets constructed from the combinatorial background in Pb-Pb collisions. The leading charged particle requirement applied to jet spectra both in pp and Pb-Pb collisions had a negligible effect on the R-AA. The nuclear modification factor R-AA was found to be 0.28 +/- 0.04 in 0-10% and 0.35 +/- 0.04 in 10-30% collisions, independent of p(T), jet within the uncertainties of the measurement. The observed suppression is in fair agreement with expectations from two model calculations with different approaches to jet quenching. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V.Peer reviewe

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362