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At least 73 records · Page 4

A tipping point in cancer epidemiology: embracing a life course exposomic framework

In this work, we show how the pathogenesis of multifactorial malignant diseases, with variable onset, severity, and natural history, reflects development-specific exposures and individual responses to these exposures influenced by underlying genetic predisposition. Embedded in life course theory, exposomics provides a framework to more fully elucidate how environmental factors alter cancer risk, disease course, and response to treatment across the lifespan.

60 APPLIED LIFE SCIENCES↗

Linezolid-resistant (Tn 6246 :: fexB - poxtA ) Enterococcus faecium strains colonizing humans and bovines on different continents: similarity without epidemiological link

Abstract Objectives poxtA is the most recently described gene conferring acquired resistance to linezolid, a relevant antibiotic for treating enterococcal infections. We retrospectively screened for poxtA in diverse enterococci and aimed to characterize its genetic/genomic contexts. Methods poxtA was screened by PCR in 812 enterococci from 458 samples (hospitals/healthy humans/wastewater/animals/retail food) obtained in Portugal/Angola/Tunisia (1996–2019). Antimicrobial susceptibility testing was performed for 13 antibiotics (EUCAST/CLSI). poxtA stability (∼500 generations), transfer (filter mating), clonality (SmaI-PFGE) and location (S1-PFGE/hybridization) were tested. WGS (Illumina-HiSeq) was performed for clonal representatives. Results poxtA was detected in Enterococcus faecium from six samples (1.3%): a healthy human (rectal swab) in Porto, Portugal (ST32/2001); four farm cows (milk) in Mateur, Tunisia (ST1058/2015); and a hospitalized patient (faeces) in Matosinhos, Portugal (ST1058/2015). All expressed resistance to linezolid (MIC = 8 mg/L), chloramphenicol, tetracycline and erythromycin, with variable resistance to ciprofloxacin and streptomycin. ST1058-poxtA-carrying isolates from Tunisia and Portugal differed by two SNPs and had similar plasmid content. poxtA, located in an IS1216-flanked Tn6246-like element, co-hybridized with fexB on one or more plasmids per isolate (one to three plasmids of 30–100 kb), was stable after several generations and transferred only from ST1058. ST1058 strains carried resistance/virulence genes (Efmqnr/acm) possibly induced under selective quinolone treatment. Conclusions poxtA has been circulating in Portugal since at least 2001, corresponding to the oldest description worldwide to date. We also extend the reservoir of poxtA to bovines. The similar linezolid-resistant poxtA-carrying strains colonizing humans and livestock on different continents, and without a noticeable relationship, suggests a recent transmission event or convergent evolution of E. faecium populations in different hosts and geographic regions.

Freitas, Ana R.↗

Epidemiology and hygiene of air travel

Preventive medicine for air travelers in flight and at route stops, considering disease dissemination and control, international quarantinable diseases, sanitation, etc

Randel, H. W.↗

Satellite, environmental, and medical information applied to epidemiological monitoring

Improved communications and space-science technologies, such as remote sensing, offer hope of new, more holistic approaches to combating many arthropod-borne disease problems. The promise offered by these technologies has surfaced at a time when global and national efforts at disease control are in decline. Indeed, these programs seem to be losing ground against the arthropod-borne diseases just as rapidly as we seem to be moving forward in technological development. Given these circumstances, we can only hope that remote sensing and geographic information system (GIS) technologies can be pressed into service to help target the temporal and spatial application of control measures and to help in developing new control strategies.

Roberts, Donald R.↗

Remote Sensing as a Landscape Epidemiologic Tool to Identify Villages at High Risk for Malaria Transmission

A landscape approach using remote sensing and Geographic Information System (GIS) technologies was developed to discriminate between villages at high and low risk for malaria transmission, as defined by adult Anopheles albimanus abundance. Satellite data for an area in southern Chiapas, Mexico were digitally processed to generate a map of landscape elements. The GIS processes were used to determine the proportion of mapped landscape elements surrounding 40 villages where An. albimanus data had been collected. The relationships between vector abundance and landscape element proportions were investigated using stepwise discriminant analysis and stepwise linear regression. Both analyses indicated that the most important landscape elements in terms of explaining vector abundance were transitional swamp and unmanaged pasture. Discriminant functions generated for these two elements were able to correctly distinguish between villages with high ind low vector abundance, with an overall accuracy of 90%. Regression results found both transitional swamp and unmanaged pasture proportions to be predictive of vector abundance during the mid-to-late wet season. This approach, which integrates remotely sensed data and GIS capabilities to identify villages with high vector-human contact risk, provides a promising tool for malaria surveillance programs that depend on labor-intensive field techniques. This is particularly relevant in areas where the lack of accurate surveillance capabilities may result in no malaria control action when, in fact, directed action is necessary. In general, this landscape approach could be applied to other vector-borne diseases in areas where: 1. the landscape elements critical to vector survival are known and 2. these elements can be detected at remote sensing scales.

Beck, Louisa R.↗

Epidemiology of Staphylococcus aureus during space flight

Staphylococcus aureus was isolated over 2 years from Space Shuttle mission crewmembers to determine dissemination and retention of bacteria. Samples before and after each mission were from nasal, throat, urine, and feces and from air and surface sampling of the Space Shuttle. DNA fingerprinting of samples by digestion of DNA with SmaI restriction endonuclease followed by pulsed-field gel electrophoresis showed S. aureus from each crewmember had a unique fingerprint and usually only one strain was carried by an individual. There was only one instance of transfer between crewmembers. Strains from interior surfaces after flight matched those of crewmembers, suggesting microbial fingerprinting may have forensic application.

Flight Experiment↗

Orthostatic hypotension: epidemiology, pathophysiology and management

Orthostatic hypotension is characterized by low upright blood pressure levels and symptoms of cerebral hypoperfusion. Whereas orthostatic hypotension is heterogeneous, correct pathophysiologic diagnosis is important because of therapeutic and prognostic considerations. Although therapy is not usually curative, it can be extraordinarily beneficial if it is individually tailored. Management of the Shy-Drager syndrome (multiple-system atrophy) remains a formidable challenge.

Non-NASA Center↗

Epidemiologic Analyses of Risk Factors for Bone Loss and Recovery Related to Long-Duration Space Flight

AIM 1: To investigate the risk of microgravity exposure on long-term changes in bone health and fracture risk. compare data from crew members ("observed") with what would be "expected" from Rochester Bone Health Study. AIM 2: To provide a summary of current evidence available on potential risk factors for bone loss, recovery & fracture following long-duration space flight. integrative review of all data pre, in-, and post-flight across disciplines (cardiovascular, nutrition, muscle, etc.) and their relation to bone loss and recovery

Sibonga, Jean↗