A Timescale for Evolution, Population Expansion, and Spatial Spread of an Emerging Clone of Methicillin-Resistant Staphylococcus aureus

Due to the lack of fossil evidence, the timescales of bacterial evolution are largely unknown. The speed with which genetic change accumulates in populations of pathogenic bacteria, however, is a key parameter that is crucial for understanding the emergence of traits such as increased virulence or antibiotic resistance, together with the forces driving pathogen spread. Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of hospital-acquired infections. We have investigated an MRSA strain (ST225) that is highly prevalent in hospitals in Central Europe. By using mutation discovery at 269 genetic loci (118,804 basepairs) within an international isolate collection, we ascertained extremely low diversity among European ST225 isolates, indicating that a recent population bottleneck had preceded the expansion of this clone. In contrast, US isolates were more divergent, suggesting they represent the ancestral population. While diversity was low, however, our results demonstrate that the short-term evolutionary rate in this natural population of MRSA resulted in the accumulation of measurable DNA sequence variation within two decades, which we could exploit to reconstruct its recent demographic history and the spatiotemporal dynamics of spread. By applying Bayesian coalescent methods on DNA sequences serially sampled through time, we estimated that ST225 had diverged since approximately 1990 (1987 to 1994), and that expansion of the European clade began in 1995 (1991 to 1999), several years before the new clone was recognized. Demographic analysis based on DNA sequence variation indicated a sharp increase of bacterial population size from 2001 to 2004, which is concordant with the reported prevalence of this strain in several European countries. A detailed ancestry-based reconstruction of the spatiotemporal dispersal dynamics suggested a pattern of frequent transmission of the ST225 clone among hospitals within Central Europe. In addition, comparative genomics indicated complex bacteriophage dynamics

Public Stigmatizing Reactions Toward Nonoffending Pedophilic Individuals Seeking to Relieve Sexual Arousal

People with pedophilia (PWP) can deal with their sexual desires by relieving sexual arousal without sexually exploiting children. Study 1 investigated whether public reactions toward nonoffending pedophilic men are affected by their strategies to relieve sexual arousal (nonsexual pictures vs. child sex dolls) or to reduce their sex drive via testosterone lowering medication in legally nonproblematic ways. A sample of German-speaking participants (N = 143) read three vignettes describing PWP using either of these strategies. Participants’ (59.4% females) mean age was 39.7 (SD = 15.6). Although no significant difference was detected between the nonsexual pictures and sex dolls conditions on cognitive (except for dangerousness), affective, and behavioral levels, both consistently elicited more stigmatizing reactions than the testosterone-lowering medication condition. To investigate if this effect was driven by disapproving any relief of sexual arousal or the use of actual child stimuli in particular, Study 2 (N = 151) added two conditions with PWP using adult child-like stimuli to relieve sexual arousal: adult-as-schoolgirl porn and adult partner with childlike appearance. Here, Participants’ (57.6% females) mean age was 28.0 (SD = 13.3). Results indicate that stigmatization was driven by disapproving the use of child stimuli rather than the relief of sexual arousal in general. Individuals with a sexual interest in children face strong stigmatizing reactions, which are only alleviated when they are described as undergoing treatment lowering sex drive or – to a lesser extent – being able to mate with an adult partner or using porn with adult actors posing as schoolgirls

Mesoscale cyclogenesis over the western north Pacific Ocean during TPARC

Three cases of mesoscale marine cyclogenesis over the subtropics of the Western Pacific Ocean are investigated. Each case occurred during the THORPEX Pacific Asia Regional Campaign and Tropical Cyclone Structure (TCS-08) field phases in 2008. Each cyclone developed from remnants of disturbances that earlier showed potential for tropical cyclogenesis within the tropics. Two of the cyclones produced gale-force surface winds, and one, designated as a tropical cyclone, resulted in a significant coastal storm over eastern Japan. Development was initiated by a burst of organized mesoscale convection that consolidated and intensified the surface cyclonic circulation over a period of 12–24 h. Upper-tropospheric potential vorticity anomalies modulated the vertical wind shear that, in turn, influenced the periods of cyclone intensification and weakening. Weak baroclinicity associated with vertical shear was also deemed important in organizing mesoscale ascent and the convection outbreaks. The remnant tropical disturbances contributed exceptional water vapour content to higher latitudes that led to strong diabatic heating, and the tropical remnants contributed vorticity that was the seed of the development in the subtropics. Predictability of these events more than three days in advance appears to be minimal

Evaluation of Integrated HPV DNA as Individualized Biomarkers for the Detection of Recurrent CIN2/3 during Post-Treatment Surveillance

Purpose: Post-treatment follow-up in women with cervical pre-cancers (CIN3) is mandatory due to relapse in up to 10% of patients. Standard follow-up based on hrHPV-DNA/cytology co-testing has high sensitivity but limited specificity. The aim of our prospective, multicenter, observational study was to test the hypothesis that an individualized viral-cellular-junction test (vcj-PCR) combined with cytology has a lower false positive rate for the prediction of recurrence compared to standard co-testing. Methods: Pre-surgical cervical swabs served for the identification of HPV16/18 DNA integration sites by next-generation-sequencing (NGS). Samples taken at 6, 12 and 24 months post-surgery were evaluated by cytology, hrHPV-DNA and the patients’ individual HPV-integration sites (vcj-PCR on the basis of NGS). Results: Integration sites were detected in 48 of 445 patients (10.8%), 39 of them had valid follow-up data. The false positive rate was 18.2% (95% CI 8.6–34.4%) for standard hrHPV/cytology at six months compared to 12.1% (95% CI 4.8–27.3%) for vcj-PCR/cytology, respectively (McNemar p = 0.50). Six patients developed recurrences (1 CIN2, 5 CIN3) during follow-up. Standard co-testing detected all, whereas vcj-PCR/cytology detected only five patients with recurrences. Data of 269 patients without evidence of HPV16/18 integration were subject to post-hoc analyses. Standard co-testing revealed a false positive rate of 15.7% (95% CI 11.7–20.7%) and predicted ten of fourteen recurrences at six months. Conclusions: Although highly specific on its own vcj-PCR could not detect all recurrent CIN2/3. Possible reasons for this unexpected result may be multifocal lesions, intratumoral heterogeneity with respect to HPV integration and/or incident CIN

Inter-observer agreement for the histological diagnosis of invasive lobular breast carcinoma.

Invasive lobular breast carcinoma (ILC) is the second most common breast carcinoma (BC) subtype and is mainly driven by loss of E-cadherin expression. Correct classification of BC as ILC is important for patient treatment. This study assessed the degree of agreement among pathologists for the diagnosis of ILC. Two sets of hormone receptor (HR)-positive/HER2-negative BCs were independently reviewed by participating pathologists. In set A (61 cases), participants were provided with hematoxylin/eosin (HE)-stained sections. In set B (62 cases), participants were provided with HE-stained sections and E-cadherin immunohistochemistry (IHC). Tumor characteristics were balanced. Participants classified specimens as non-lobular BC versus mixed BC versus ILC. Pairwise inter-observer agreement and agreement with a pre-defined reference diagnosis were determined with Cohen's kappa statistics. Subtype calls were correlated with molecular features, including CDH1/E-cadherin mutation status. Thirty-five pathologists completed both sets, providing 4,305 subtype calls. Pairwise inter-observer agreement was moderate in set A (median κ = 0.58, interquartile range [IQR]: 0.48-0.66) and substantial in set B (median κ = 0.75, IQR: 0.56-0.86, p < 0.001). Agreement with the reference diagnosis was substantial in set A (median κ = 0.67, IQR: 0.57-0.75) and almost perfect in set B (median κ = 0.86, IQR: 0.73-0.93, p < 0.001). The median frequency of CDH1/E-cadherin mutations in specimens classified as ILC was 65% in set A (IQR: 56-72%) and 73% in set B (IQR: 65-75%, p < 0.001). Cases with variable subtype calls included E-cadherin-positive ILCs harboring CDH1 missense mutations, and E-cadherin-negative ILCs with tubular elements and focal P-cadherin expression. ILCs with trabecular growth pattern were often misclassified as non-lobular BC in set A but not in set B. In conclusion, subtyping of BC as ILC achieves almost perfect agreement with a pre-defined reference standard, if assessment is supported by E-cadherin IHC. CDH1 missense mutations associated with preserved E-cadherin protein expression, E- to P-cadherin switching in ILC with tubular elements, and trabecular ILC were identified as potential sources of discordant classification

Inter-observer agreement for the histological diagnosis of invasive lobular breast carcinoma

Invasive lobular breast carcinoma (ILC) is the second most common breast carcinoma (BC) subtype and is mainly driven by loss of E-cadherin expression. Correct classification of BC as ILC is important for patient treatment. This study assessed the degree of agreement among pathologists for the diagnosis of ILC. Two sets of hormone receptor (HR)-positive/HER2-negative BCs were independently reviewed by participating pathologists. In set A (61 cases), participants were provided with hematoxylin/eosin (HE)-stained sections. In set B (62 cases), participants were provided with HE-stained sections and E-cadherin immunohistochemistry (IHC). Tumor characteristics were balanced. Participants classified specimens as non-lobular BC versus mixed BC versus ILC. Pairwise inter-observer agreement and agreement with a pre-defined reference diagnosis were determined with Cohen's kappa statistics. Subtype calls were correlated with molecular features, including CDH1/E-cadherin mutation status. Thirty-five pathologists completed both sets, providing 4,305 subtype calls. Pairwise inter-observer agreement was moderate in set A (median κ = 0.58, interquartile range [IQR]: 0.48–0.66) and substantial in set B (median κ = 0.75, IQR: 0.56–0.86, p < 0.001). Agreement with the reference diagnosis was substantial in set A (median κ = 0.67, IQR: 0.57–0.75) and almost perfect in set B (median κ = 0.86, IQR: 0.73–0.93, p < 0.001). The median frequency of CDH1/E-cadherin mutations in specimens classified as ILC was 65% in set A (IQR: 56–72%) and 73% in set B (IQR: 65–75%, p < 0.001). Cases with variable subtype calls included E-cadherin-positive ILCs harboring CDH1 missense mutations, and E-cadherin-negative ILCs with tubular elements and focal P-cadherin expression. ILCs with trabecular growth pattern were often misclassified as non-lobular BC in set A but not in set B. In conclusion, subtyping of BC as ILC achieves almost perfect agreement with a pre-defined reference standard, if assessment is supported by E-cadherin IHC. CDH1 missense mutations associated with preserved E-cadherin protein expression, E- to P-cadherin switching in ILC with tubular elements, and trabecular ILC were identified as potential sources of discordant classification