Could Contamination Avoidance Be an Endpoint That Protects the Environment? An Overview on How Species Respond to Copper, Glyphosate, and Silver Nanoparticles

The use of non-forced multi-compartmented exposure systems has gained importance in the assessment of the contamination-driven spatial avoidance response. This new paradigm of exposure makes it possible to assess how contaminants fragment habitats, interfering in the spatial distribution and species’ habitat selection processes. In this approach, organisms are exposed to a chemically heterogeneous scenario (a gradient or patches of contamination) and the response is focused on identifying the contamination levels considered aversive for organisms. Despite the interesting results that have been recently published, the use of this approach in ecotoxicological risk studies is still incipient. The current review aims to show the sensitivity of spatial avoidance in non-forced exposure systems in comparison with the traditional endpoints used in ecotoxicology under forced exposure. To do this, we have used the sensitivity profile by biological groups (SPBG) to offer an overview of the highly sensitive biological groups and the species sensitive distribution (SSD) to estimate the hazard concentration for 5% of the species (HC5). Three chemically different compounds were selected for this review: copper, glyphosate, and Ag-NPs. The results show that contamination-driven spatial avoidance is a very sensitive endpoint that could be integrated as a complementary tool to ecotoxicological studies in order to provide an overview of the level of repellence of contaminants. This repellence is a clear example of how contamination might fragment ecosystems, prevent connectivity among populations and condition the distribution of biodiversity.

A Cost-Effectiveness Analysis of Lung Cancer Screening with Low-Dose Computed Tomography and a Diagnostic Biomarker

Background The Lung Computed Tomography Screening Reporting and Data System (Lung-RADS) reduces the false-positive rate of lung cancer screening but introduces prolonged periods of uncertainty for indeterminate findings. We assess the cost-effectiveness of a screening program that assesses indeterminate findings earlier via a hypothetical diagnostic biomarker introduced in place of Lung-RADS 3 and 4A guidelines. Methods We evaluated the performance of the US Preventive Services Task Force (USPSTF) recommendations on lung cancer screening with and without a hypothetical non-invasive diagnostic biomarker using a validated microsimulation model. The diagnostic biomarker assesses the malignancy of indeterminate nodules, replacing Lung-RADS 3 and 4A guidelines, and is characterized by a varying sensitivity profile that depends on nodule’s size, specificity, and cost. We tested the robustness of our findings through univariate sensitivity analyses. Results A lung cancer screening program per the USPSTF guidelines that incorporates a diagnostic biomarker with at least medium sensitivity profile and 90% specificity, that costs ≤$250, is cost-effective with an incremental cost-effectiveness ratio lower than $100,000 per quality-adjusted life year, and improves lung cancer-specific mortality reduction while requiring fewer screening exams than the USPSTF guidelines with Lung-RADS. A screening program with a biomarker costing ≥$750 is not cost-effective. The health benefits accrued and costs associated with the screening program are sensitive to the disutility of indeterminate findings and specificity of the biomarker, respectively. Conclusions Lung cancer screening that incorporates a diagnostic biomarker, in place of Lung-RADS 3 and 4A guidelines, could improve the cost-effectiveness of the screening program and warrants further investigation.

Prevalence of Methicillin Resistant Staphylococcus aureus Bacteriuria among Pregnant Women Attending Secondary Health Hospitals in Ilorin, Nigeria

Background: Urinary tract infection is one of the most frequently acquired infections in both community and hospitals and is common among the adolescents and the old genders. Aim: To determine the prevalence of methicillin resistant Staphylococcus aureus bacteriuria among pregnant women attending secondary health hospitals in Ilorin, Nigeria Study Design: An experimental study which involve a random selection of consented pregnant women. Place and Duration of Study: Department of Biosciences and Biotechnology Kwara State University Malete between January 2018 and June 2019. Methodology: In this study, a total of 856 pregnant women mid stream clean catch early morning voided urine samples for two consecutive days (383 of the samples were collected from Sobi Specialist Hospital, 278 from Adewole Cottage Hospital and 195 collected from Ajikobi Cottage Hospital) were randomly screened for the presence of Staphylococcus aureus bacteriuria using standard microbiological procedures such as growth on mannitol salt agar, Gram reaction, catalase and coagulase tests. The Kirby–Bauer disk diffusion method was used to determine the antibiotic sensitivity profile of S. aureus isolated using oxoid antibiotic discs. Results: Out of 856 samples screened 56 samples (6.5%) showed significant Staphylococcus aureus bacteriuria, 16- 25 years has a prevalence rate of 5.6%, 26- 35 years (5.8%) while 35-45 years have the prevalence rate of 10.9%. A total of 7 (12.5%) methicillin resistant Staphylococcus aureus were isolated. Antibiotic sensitivity profile shows that 26.8% were resistance to gentamicin, 44.6% to tetracycline, 19.6% to chloramphenicol, 33.9 % to erythromycin, 67.9% to amoxicillin, 32% to augmentin, 12.6% to ceftriaxone, 5.3% to ciprofloxacin and 100% susceptibility to both nitrofurantoin and vancomycin. Conclusion: The study shows the high prevalence of MRSA and high susceptibility of nitrofurantoin and vancomycin to all the MRSA isolated.

Antimicrobial Sensitivity Profile of Bacteria Isolated in Babitonga Bay

Antimicrobial resistance is one of the main and growing public health concerns. However, the analysis of the expansion of this phenomenon in the environment is limited. Thus, the objective of this work was to determine the antimicrobial susceptibility profile of bacteria isolated from Baía Babitonga. Isolation and identification of microorganisms were carried out from the mangrove sediment sample, collected at two sampling points in Baía Babitonga. Microbial identification analyzes demonstrated the presence of Gram-negative microorganisms, for which the antimicrobial susceptibility profile analysis showed the presence of resistance to Aztreonam, Ciprofloxacin, Cefuroxim, Nitrofurantoin, Meropenem, Tetracyclin, Cefotaxime, and Ceftazidime. For the identified Gram-positive microorganisms, the presence of resistance to Ampicillin and Clindamycin was evidenced. The genotypic investigation showed that the resistances found were not caused by the researched genes (blaSHV, blaCTX-M, blaOXA-48-like, blaKPC, blaNDM-1, blaVIM e blaIMP).

Prospective Evaluation of a Circulating Tumor Cell Sensitivity Profile to Predict Response to Cisplatin Chemotherapy in Metastatic Breast Cancer Patients

BackgroundCisplatin (cDDP) has regained interest for metastatic breast cancer (MBC) patients, given the platinum sensitivity in subtypes and better manageable toxicity. Here, the primary aim was to determine whether molecular characteristics of circulating tumor cells (CTCs) could identify patients responding to cDDP and to describe the outcomes to cDDP monotherapy in a large group of MBC patients pretreated with anthracycline- and taxane-based treatments.MethodsBased on cell line data, a CTC-cDDP-sensitivity profile was generated. Applying an A’Herns single-stage phase II design, further investigation was considered worthwhile if 5/10 patients with a favorable profile responded to cDDP. Patients received 70mg/m2 cDDP every three weeks, CTCs were enumerated and the CTC-cDDP-sensitivity profile was determined. In total, 65 heavily pretreated MBC patients (77% received ≥2 lines of previous chemotherapy for MBC) were eligible for the per-protocol analysis. Primary endpoint was response rate, secondary endpoints included best observed response, progression-free survival (PFS) and overall survival (OS).ResultsThe best observed response during cDDP therapy was a partial response in 7% and stable disease in 56% of the patients. None of the patients with a favorable CTC-cDDP-sensitivity profile had a response. The median baseline CTC count was 8 (range 0-3254). Patients with <5 CTCs had a better PFS and OS than patients with ≥5 CTCs (median PFS 4.5 months (95%CI 2.38-6.62) vs. 2.1 months [(95%CI 1.34-2.80)(p=0.009)] and median OS 13.1 months (95%CI 9.89-16.33) vs. 5.6 months [(95%CI 3.60-7.64)(p=0.003)]. No other factors than CTC count were associated with outcome to cDDP therapy, including triple-negative breast cancer versus ER-positive tumors.ConclusionsThe CTC-cDDP-sensitivity profile was unable to select patients responding to cDDP monotherapy. In an unselected group of heavily pretreated MBC patients, cDDP yields outcomes comparable to other chemotherapeutic regimens for heavily pretreated MBC patients. CTC count was the only factor associated with outcome in these patients.Clinical Trial Registration(https://www.trialregister.nl/trial/3885, identifier NTR4046)