Geomicrobiology of the built environment

Microbial colonization and growth can have significant effects in the built environment, resulting in a range of effects from discolouration and staining to biodeterioration and decay. In some cases, formation of biofilms, crusts and patinas may confer bioprotection of the substrate. This perspective aims to discuss how geomicrobial transformations in the natural environment - particularly involving rocks, minerals, metals and organic matter - may be applied to understand similar processes occurring on fabricated human structures. However, the built environment may offer further strictures as well as benefits for microbial activity and these should be taken into consideration when considering analogy with natural processes, especially when linking observations of microbial biodiversity to the more obvious manifestations of microbial attack

Application of Respondent Driven Sampling to Collect Baseline Data on FSWs and MSM for HIV Risk Reduction Interventions in Two Urban Centres in Papua New Guinea

The need to obtain unbiased information among hard–to-reach and hidden populations for behavioural and biological surveillance, epidemiological studies, and intervention program evaluations has led researchers to search for a suitable sampling method. One method that has been tested among IDU and MSM recently is respondent-driven sampling (RDS). We used RDS to conduct a behavioural survey among FSWs and MSM in two urban centres in Papua New Guinea (PNG). In this paper we present the lessons learned implementing RDS in a developing country setting. We also present comparisons of RDSAT-adjusted versus unadjusted crude estimates of some key socio-demographic indicators as well as comparisons between the estimates from RDS and a hypothetical time–location sample (TLS). Overall, the use of RDS among the MSM and FSWs in PNG had numerous advantages in terms of collecting a required sample size in a short time period, minimizing costs and maximising security for staff and respondents. Although there were a few problems these were easily remedied and we would recommend RDS for other similar studies in PNG and other developing countries

Deep Sequencing of Pyrethroid-Resistant Bed Bugs Reveals Multiple Mechanisms of Resistance within a Single Population

A frightening resurgence of bed bug infestations has occurred over the last 10 years in the U.S. and current chemical methods have been inadequate for controlling this pest due to widespread insecticide resistance. Little is known about the mechanisms of resistance present in U.S. bed bug populations, making it extremely difficult to develop intelligent strategies for their control. We have identified bed bugs collected in Richmond, VA which exhibit both kdr-type (L925I) and metabolic resistance to pyrethroid insecticides. Using LD50 bioassays, we determined that resistance ratios for Richmond strain bed bugs were ∼5200-fold to the insecticide deltamethrin. To identify metabolic genes potentially involved in the detoxification of pyrethroids, we performed deep-sequencing of the adult bed bug transcriptome, obtaining more than 2.5 million reads on the 454 titanium platform. Following assembly, analysis of newly identified gene transcripts in both Harlan (susceptible) and Richmond (resistant) bed bugs revealed several candidate cytochrome P450 and carboxylesterase genes which were significantly over-expressed in the resistant strain, consistent with the idea of increased metabolic resistance. These data will accelerate efforts to understand the biochemical basis for insecticide resistance in bed bugs, and provide molecular markers to assist in the surveillance of metabolic resistance

Evolution of a supergene that regulates a trans-species social polymorphism

Supergenes are clusters of linked genetic loci that jointly affect the expression of complex phenotypes, such as social organization. Little is known about the origin and evolution of these intriguing genomic elements. Here we analyse whole-genome sequences of males from native populations of six fire ant species and show that variation in social organization is under the control of a novel supergene haplotype (termed Sb), which evolved by sequential incorporation of three inversions spanning half of a 'social chromosome'. Two of the inversions interrupt protein-coding genes, resulting in the increased expression of one gene and modest truncation in the primary protein structure of another. All six socially polymorphic species studied harbour the same three inversions, with the single origin of the supergene in their common ancestor inferred by phylogenomic analyses to have occurred half a million years ago. The persistence of Sb along with the ancestral SB haplotype through multiple speciation events provides a striking example of a functionally important trans-species social polymorphism presumably maintained by balancing selection. We found that while recombination between the Sb and SB haplotypes is severely restricted in all species, a low level of gene flux between the haplotypes has occurred following the appearance of the inversions, potentially mitigating the evolutionary degeneration expected at genomic regions that cannot freely recombine. These results provide a detailed picture of the structural genomic innovations involved in the formation of a supergene controlling a complex social phenotype

Head and neck cancer surgery during the COVID-19 pandemic: An international, multicenter, observational cohort study

Background: The aims of this study were to provide data on the safety of head and neck cancer surgery currently being undertaken during the coronavirus disease 2019 (COVID-19) pandemic. Methods: This international, observational cohort study comprised 1137 consecutive patients with head and neck cancer undergoing primary surgery with curative intent in 26 countries. Factors associated with severe pulmonary complications in COVID-19–positive patients and infections in the surgical team were determined by univariate analysis. Results: Among the 1137 patients, the commonest sites were the oral cavity (38%) and the thyroid (21%). For oropharynx and larynx tumors, nonsurgical therapy was favored in most cases. There was evidence of surgical de-escalation of neck management and reconstruction. Overall 30-day mortality was 1.2%. Twenty-nine patients (3%) tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within 30 days of surgery; 13 of these patients (44.8%) developed severe respiratory complications, and 3.51 (10.3%) died. There were significant correlations with an advanced tumor stage and admission to critical care. Members of the surgical team tested positive within 30 days of surgery in 40 cases (3%). There were significant associations with operations in which the patients also tested positive for SARS-CoV-2 within 30 days, with a high community incidence of SARS-CoV-2, with screened patients, with oral tumor sites, and with tracheostomy. Conclusions: Head and neck cancer surgery in the COVID-19 era appears safe even when surgery is prolonged and complex. The overlap in COVID-19 between patients and members of the surgical team raises the suspicion of failures in cross-infection measures or the use of personal protective equipment. Lay Summary: Head and neck surgery is safe for patients during the coronavirus disease 2019 pandemic even when it is lengthy and complex. This is significant because concerns over patient safety raised in many guidelines appear not to be reflected by outcomes, even for those who have other serious illnesses or require complex reconstructions. Patients subjected to suboptimal or nonstandard treatments should be carefully followed up to optimize their cancer outcomes. The overlap between patients and surgeons testing positive for severe acute respiratory syndrome coronavirus 2 is notable and emphasizes the need for fastidious cross-infection controls and effective personal protective equipment

Pharmacological antagonism of interleukin-8 receptor CXCR2 inhibits inflammatory reactivity and is neuroprotective in an animal model of Alzheimer’s disease

BACKGROUND: The chemokine interleukin-8 (IL-8) and its receptor CXCR2 contribute to chemotactic responses in Alzheimer’s disease (AD); however, properties of the ligand and receptor have not been characterized in animal models of disease. The primary aim of our study was to examine effects of pharmacological antagonism of CXCR2 as a strategy to inhibit receptor-mediated inflammatory reactivity and enhance neuronal viability in animals receiving intrahippocampal injection of amyloid-beta (Aβ(1–42)). METHODS: In vivo studies used an animal model of Alzheimer’s disease incorporating injection of full-length Aβ(1–42) into rat hippocampus. Immunohistochemical staining of rat brain was used to measure microgliosis, astrogliosis, neuronal viability, and oxidative stress. Western blot and Reverse Transcription PCR (RT-PCR) were used to determine levels of CXCR2 in animal tissue with the latter also used to determine expression of pro-inflammatory mediators. Immunostaining of human AD and non-demented (ND) tissue was also undertaken. RESULTS: We initially determined that in the human brain, AD relative to ND tissue exhibited marked increases in expression of CXCR2 with cell-specific receptor expression prominent in microglia. In Aβ(1–42)-injected rat brain, CXCR2 and IL-8 showed time-dependent increases in expression, concomitant with enhanced gliosis, relative to controls phosphate-buffered saline (PBS) or reverse peptide Aβ(42–1) injection. Administration of the competitive CXCR2 antagonist SB332235 to peptide-injected rats significantly reduced expression of CXCR2 and microgliosis, with astrogliosis unchanged. Double staining studies demonstrated localization of CXCR2 and microglial immunoreactivity nearby deposits of Aβ(1–42) with SB332235 effective in inhibiting receptor expression and microgliosis. The numbers of neurons in granule cell layer (GCL) were reduced in rats receiving Aβ(1–42), compared with PBS, with administration of SB332235 to peptide-injected animals conferring neuroprotection. Oxidative stress was indicated in the animal model since both 4-hydroxynonenal (4-HNE) and hydroethidine (HEt) were markedly elevated in Aβ(1–42) vs PBS-injected rat brain and diminished with SB332235 treatment. CONCLUSION: Overall, the findings suggest critical roles for CXCR2-dependent inflammatory responses in an AD animal model with pharmacological modulation of the receptor effective in inhibiting inflammatory reactivity and conferring neuroprotection against oxidative damage

Baixa percepção de risco entre adolescentes espanhóis em relação ao consumo de álcool

Según los estudios recientes, los adolescentes españoles muestran una baja percepción del riesgo asociado al consumo de alcohol. El objetivo de la presente investigación es analizar los factores que favorecen esta baja percepción a partir de la opinión de un grupo de 32 profesionales/expertos en adolescencia, familia, escuela, medios de comunicación y políticas locales. Se utilizó una metodología cualitativa, fundamentada en Grounded Theory, a partir de la información obtenida mediante 5 grupos de discusión guiados por entrevistas semiestructuradas. Se identificaron 12 factores o subcategorías agrupados en 4 categorías generales: riesgo a corto plazo, inmediatez y percepción de invulnerabilidad (categoría ¿pensamiento adolescente¿); concepción benévola del alcohol, normalización del consumo y binomio alcohol-diversión (categoría ¿normas sociales¿); consumo habitual en los padres, inconsistencia verbal-no verbal en el modelado parental, consumo sin riesgo en los medios, consumo con resultados positivos en los medios (categoría ¿modelos sociales¿); excesivo contenido sanitario, riesgo a largo plazo (categoría ¿discurso preventivo¿). Tras discutir los resultados en el contexto de la literatura científica actual, se realizan varias propuestas con el objetivo de aumentar la percepción del riesgo en los adolescentes: incidir con mayor fuerza en contenidos sobre los riesgos a corto plazo del alcohol; orientar las estrategias educativas dirigidas al adolescente, también hacia los agentes de socialización, especialmente los padres; incidir en políticas centradas en la sustancia y en reducir la oferta.According to recent studies, Spanish adolescents show low perception of risk in alcohol consumption. The current study aims to analyze the factors that favor this low perception based on the opinion of a group of 32 professional experts on adolescence, family, school, mass media, and local policies. A qualitative methodology was used, based on Grounded Theory, using information from 5 focus groups guided by semi-structured interviews. Twelve factors or subcategories were identified, grouped in 4 general categories: short-term risk, immediacy, and perception of invulnerability (¿adolescent thinking¿ category); benevolent view of alcohol, normalization of consumption, and alcohol-entertainment binomial (¿social norms¿ category); parents¿ habitual consumption, verbal/non-verbal inconsistency in parental model, risk-free consumption depicted in the mass media, consumption with positive results in the media (¿social models¿ category); and excessive health content, long-term risk (¿preventive discourse¿ category). After discussing the results in the context of the current scientific literature, the article offers various proposals for increasing risk perception in adolescents: stronger impact of contents on short-term risks of alcohol; educational strategies targeted to adolescents to include agents of socialization, especially parents; and policies centered on the substance and reduction of supply.De acordo com estudos recentes, os adolescentes espanhóis mostram baixa percepção de risco em relação ao consumo de álcool. O estudo tem como objetivo analisar os fatores associados com a baixa percepção de risco, com base nas opiniões de um grupo de 32 especialistas em adolescência, família, escola, mídia e políticas locais. Foi utilizada uma metodologia qualitativa, baseada na Teoria Fundamentada, usando informações de cinco grupos focais orientados por entrevistas semi-estruturadas. Foram identificados 12 fatores ou subcategorias, agrupados em quatro categorias gerais: risco no curto prazo, imediatismo e percepção de invulnerabilidade (categoria de ¿pensamento adolescente¿); visão benevolente em relação ao álcool, normalização do consumo e binômio álcool-entretenimento (categoria de ¿normas sociais¿); consumo habitual pelos pais, inconsistência na comunicação verbal versus não verbal no modelo representado pelos pais, consumo isento de risco retratado pela mídia, consumo com resultados positivos na mídia (categoria de ¿modelos sociais¿) e excesso de conteúdo relacionado à saúde, risco no longo prazo (categoria de ¿discurso preventivo¿). Depois de discutir os resultados no contexto da literatura científica atual, o artigo oferece várias propostas para aumentar a percepção de risco entre os adolescentes: impacto mais forte de conteúdos sobre os riscos do álcool no curto prazo; estratégias educativas orientadas aos adolescentes para incluir os agentes da socialização, especialmente os pais, além de políticas centradas na substância e na redução da oferta.Departamento de Educación y Psicología SocialVersión del edito