Molecular antimicrobial resistance surveillance for neisseria gonorrhoeae, Northern Territory, Australia

Neisseria gonorrhoeae antimicrobial resistance (AMR) is a globally recognized health threat; new strategies are needed to enhance AMR surveillance. The Northern Territory of Australia is unique in that 2 different first-line therapies, based primarily on geographic location, are used for gonorrhea treatment. We tested 1,629 N. gonorrhoeae nucleic acid amplification test–positive clinical samples, collected from regions where ceftriaxone plus azithromycin or amoxicillin plus azithromycin are recommended first-line treatments, by using 8 N. gonorrhoeae AMR PCR assays. We compared results with those from routine culture-based surveillance data. PCR data confirmed an absence of ceftriaxone resistance and a low level of azithromycin resistance (0.2%), and that penicillin resistance was \u3c5% in amoxicillin plus azithromycin regions. Rates of ciprofloxacin resistance and penicillinase-producing N. gonorrhoeae were lower when molecular methods were used. Molecular methods to detect N. gonorrhoeae AMR can increase the evidence base for treatment guidelines, particularly in settings where culture-based surveillance is limited

On the Role of Intrinsic Value in Terms of Environmental Education

AbstractAn understanding of instrumentally valuable nature resulted from anthropocentrism is incapable of producing long-term, real solutions to deal with environmental problems. It is obvious that these problems cannot be handled staying within the current understanding of nature-human relationship and without broaden the extent of ethics in a way to involve non-human entities. Human beings are prone to protect what they consider as intrinsically valuable. Further, they have a tendency to value the things around them and it can be improved. Thus, a big part of this can be succeeded through environmental education. Therefore, in this paper, I discuss the role of intrinsic value in terms of environmental education to handle the environmental problems, and investigate a new account of subjective intrinsic value about nature

Close companions to Brightest Cluster Galaxies: Support for minor mergers and downsizing

We identify close companions of Brightest Cluster Galaxies (BCGs) for the purpose of quantifying the rate at which these galaxies grow via mergers. By exploiting deep photometric data from the CFHTLS, we probe the number of companions per BCG (Nc) with luminosity ratios down to those corresponding to potential minor mergers of 20:1. We also measure the average luminosity in companions per galaxy (Lc). We find that Nc and Lc rise steeply with luminosity ratio for both the BCGs, and a control sample of other bright, red, cluster galaxies. The trend for BCGs rises more steeply, resulting in a larger number of close companions. For companions within 50kpc of a BCG, Nc= 1.38+/-0.14 and Lc=(2.14+/-0.31)x10^(10)L_sun and for companions within 50kpc of a luminosity matched control sample of non-BCGs, Nc=0.87+/-0.08 and Lc=(1.48+/-0.20)x10^(10)L_sun. This suggests that the BCGs are likely to undergo more mergers compared to otherwise comparable luminous galaxies. Additionally, compared to a local sample of luminous red galaxies, the more distant sample presented in this study (with redshifts between 0.15-0.39,) shows a higher Nc, suggesting the younger and smaller BCGs are still undergoing hierarchical formation. Using the Millennium Simulations we model and estimate the level of contamination due to unrelated cluster galaxies. The contamination by interloping galaxies is 50% within projected separations of 50kpc, but within 30kpc, 60% of identified companions are real physical companions. We conclude that the luminosity of bound merger candidates down to luminosity ratios of 20:1 could be adding as much as 10% to the mass of a typical BCG over 0.5Gyr at redshifts of z~0.3.Comment: 10 pages, 7 figures. Accepted and to be published in MNRA

Stellar population gradients in brightest cluster galaxies

We present the stellar population and velocity dispersion gradients for a sample of 24 brightest cluster galaxies (BCGs) in the nearby Universe for which we have obtained high quality long-slit spectra at the Gemini telescopes. With the aim of studying the possible connection between the formation of the BCGs and their host clusters, we explore the relations between the stellar population gradients and properties of the host clusters as well as the possible connections between the stellar population gradients and other properties of the galaxies. We find mean stellar population gradients (negative {\Delta}[Z/H]/log r gradient of -0.285{\pm}0.064; small positive {\Delta}log (age)/log r gradient of 0.069{\pm}0.049; and null {\Delta}[E/Fe]/log r gradient of -0.008{\pm}0.032) that are consistent with those of normal massive elliptical galaxies. However, we find a trend between metallicity gradients and velocity dispersion (with a negative slope of -1.616{\pm}0.539) that is not found for the most massive ellipticals. Furthermore, we find trends between the metallicity gradients and K-band luminosities (with a slope of 0.173{\pm}0.081) as well as the distance from the BCG to the X-ray peak of the host cluster (with a slope of -7.546{\pm}2.752). The latter indicates a possible relation between the formation of the cluster and that of the central galaxy.Comment: 23 pages, 18 figures, accepted for publication in MNRAS. arXiv admin note: text overlap with arXiv:1104.2376v

Toxigenic Clostridium difficile colonization among hospitalised adults; risk factors and impact on survival

Objectives: To establish risk factors for Clostridium difficile colonization among hospitalized patients in England. Methods: Patients admitted to elderly medicine wards at three acute hospitals in England were recruited to a prospective observational study. Participants were asked to provide a stool sample as soon as possible after enrolment and then weekly during their hospital stay. Samples were cultured for C. difficile before ribotyping and toxin detection by PCR. A multivariable logistic regression model of risk factors for C. difficile colonization was fitted from univariable risk factors significant at the p < 0.05 level. Results: 410/727 participants submitted ≥1 stool sample and 40 (9.8%) carried toxigenic C. difficile in the first sample taken. Ribotype 106 was identified three times and seven other ribotypes twice. No ribotype 027 strains were identified. Independent predictors of colonization were previous C. difficile infection (OR 4.53 (95% C.I. 1.33–15.48) and malnutrition (MUST score ≥2) (OR 3.29 (95% C.I. 1.47–7.35)). Although C. difficile colonised patients experienced higher 90-day mortality, colonization was not an independent risk for death. Conclusions: In a non-epidemic setting patients who have previously had CDI and have a MUST score of ≥2 are at increased risk of C. difficile colonization and could be targeted for active surveillance to prevent C. difficile transmission

Galaxy sizes as a function of environment at intermediate redshift from the ESO Distant Cluster Survey

In order to assess whether the environment has a significant effect on galaxy sizes, we compare the mass–size relations of cluster and field galaxies in the 0.41), with early-type/passive galaxies in higher density environments growing earlier. Such dependence disappears at lower redshifts. Therefore, if the reported difference at higher-z is real, the growth of field galaxies has caught up with that of cluster galaxies by z∼1. Any putative mechanism responsible for galaxy growth has to account for the existence of environmental differences at high redshift and their absence (or weakening) at lower redshifts

An Economical Tandem Multiplex Real-Time PCR Technique for the Detection of a Comprehensive Range of Respiratory Pathogens

This study used real-time PCR assays to screen small sample volumes for a comprehensive range of 35 respiratory pathogens. Initial thermocycling was limited to 20 cycles to avoid competition for reagents, followed by a secondary real-time multiplex PCR. Supplementary semi-nested human metapneumovirus and picornavirus PCR assays were required to complete the acute respiratory pathogen profile. Potential pathogens were detected in 85 (70%) of pernasal aspirates collected from 121 children with acute respiratory symptoms. Multiple pathogens were detected in 29 (24%) of those samples. The tandem multiplex real-time PCR was an efficient method for the rapid detection of multiple pathogens

Retrospective review of Treponema pallidum PCR and serology results: Are both tests necessary?

There has been a resurgence of syphilis diagnoses in Australia. We investigated whether ourpolymerase chain reaction (PCR) test provides any additional diagnostic information over syphilis serology (chemi-luminescence immunoassay (CMIA),particle agglutination (TPPA) and rapid reagin (RPR) flocculation test). A retrospective audit was conducted of allPCR requests that came through our laboratory from January 2010 to June 2017; data collected included age, gender, site of swab,PCR, syphilis serology and HSV 1 and HSV 2 PCR results. A total of 441PCR tests were performed, with on average three requests forPCR per month in 2011, which increased to 17.2 per month in 2017. There were 323 patients who had bothPCR and syphilis serology performed, with 67% of swabs taken from the genitals.PCR was positive in 61/323 (19%) patients, of which 59/61 (97%) also had positive syphilis serology result (sensitivity 68%, specificity 99%, positive predictive value 97% and negative predictive value 89%). Syphilis serology was positive in 91/323 patients (28%) of which 61 (66%) were alsoPCR positive (sensitivity 97%, specificity 88%, positive predictive value 60% and negative predictive value 99%). The Cohen's Kappa value was 0.74, indicating substantial agreement between the two tests. Our results show most patients with positivePCR results also had positive syphilis serology. Therefore,PCR adds little clinical value over serology for diagnosis of syphilis in certain clinical settings

Lessons learnt from ceftriaxone-resistant gonorrhoea in the UK and Australia.

Neisseria gonorrhoeae, the causative pathogen of gonorrhoea, has shown impressive agility in developing resistance to successive classes of antimicrobials used for therapy, leading to a progressive reduction in available treatment options. Ceftriaxone is the last-line treatment option for gonorrhoea, and many countries recommend dual therapy with ceftriaxone (250–1000 mg) in combination with azithromycin (1–2 g). However, since the introduction of dual therapy, the global prevalence of azithromycin resistance has increased. Additionally, the extensively drug-resistant N gonorrhoeae FC428 clone, which is associated with ceftriaxone resistance and intermediate resistance to azithromycin, has been reported to have spread internationally, with epidemiological links to the Asia-Pacific region