Viability Detection of Foodborne Bacterial Pathogens in Food Environment by PMA-qPCR and by Microscopy Observation.

Foodborne pathogens are responsible for foodborne diseases and food poisoning and thus pose a great threat to food safety. These microorganisms can adhere to surface and form a biofilm composed of an extracellular matrix. This matrix protects bacterial cells from industrial environmental stress factors such as cleaning and disinfection operations. Moreover, during these environmental stresses, many bacterial species can be entered in a viable but nonculturable (VBNC) state. VBNC cells are characterized by an active metabolism and a loss of cultivability on conventional bacteriological agar. This leads to an underestimation of total viable cells in environmental samples and thus may pose a risk for public health. In this chapter, we present a method to detect viable population of foodborne pathogens in industrial environmental samples using a molecular method combining propidium monoazide (PMA) and quantitative PCR (qPCR) and a fluorescence microscopic method associated with the LIVE/DEAD BacLight™ viability stain.

Application of hot water and cold air to reduce bacterial contamination on broiler carcasses.

Two physical treatments (heat via water bath and cold air) with various temperatures (20/70/75/80°C and - 80/-90°C) and exposure times (20, 30, 40 s) were carried out to identify a decontaminating effect on zoonotic pathogens on broiler carcasses. Subsequently, carcasses were analyzed for thermotolerant Campylobacter (C.), Salmonella, Escherichia (E.). coli and total colony count (TCC). Moreover, for the hot water treatment, qPCR with viable/dead differentiation (v-qPCR) was applied to detect viable but non-culturable cells (VBNC) of Campylobacter, referred to as intact but putatively infectious units (IPIU). Hot water immersion was tested on carcasses inoculated with C. jejuni and Salmonella, while cold air treatment was evaluated for naturally contaminated carcasses of broiler flocks colonized with Campylobacter. For hot water treatment, the statistically significant reducing effect was about 1 log10 CFU/ml for both Salmonella and Campylobacter for 70-80°C and 20/30 s treatments. The effect of heat treatment for Campylobacter was smaller when samples were analyzed with v-qPCR with reductions of 0.5-0.8 log10 IPIU/ml in mean. Cold air treatments at -90°C were effective in reducing the mean contamination level of Campylobacter by 0.4-0.5 log10 CFU/ml at all exposure times (p < 0.05). Hot water treatments showed a decreasing trend on TCC by 0.6-0.9 log10 CFU/ml (p < 0.05). TCC counts were not significantly affected by cold air treatment. For E. coli no statistically significant reductions were observed by hot water treatment. The cold air treatment at -90°C for 20 and 40 s led to a reduction of E. coli by 0.4 and 0.8 log10 CFU/ml (p < 0.05), respectively. Treatment of carcasses with higher bacterial levels tended to show higher reduction. The research demonstrated that the efficacy of physical treatments for decontamination of broiler carcasses was more pronounced for hot water immersion than for cold air exposure. In conclusion, the results shed light on the potential application of these physical treatments in practice to reduce the quantitative load of contaminating pathogens to enhance food safety in the broiler meat production.

Regulatory Aspects of AI-ML.

In the realm of healthcare, numerous generative and non-generative artificial intelligence and machine learning (AI-ML) tools have been developed and deployed. Simultaneously, manufacturers of medical devices are leveraging AI-ML. However, the adoption of AI in healthcare raises several concerns, including safety, security, ethical biases, accountability, trust, economic impact, and environmental effects. Effective regulation can mitigate some of these risks, promote fairness, establish standards, and advocate for more sustainable AI practices. Regulating AI tools not only ensures their safe and effective adoption but also fosters public trust. It is important that regulations remain flexible to accommodate rapid advances in this field to support innovation and also not to add additional burden to some of our preexisting and well-established frameworks. This article covers regional and global regulatory aspects of AI-ML including data privacy, Software as a Medical device (SaMD), agency approval and clearance pathways, reimbursement, and laboratory developed tests (LDTs).

Development and validation of a PMA-qPCR method for accurate quantification of viable Lacticaseibacillus paracasei in probiotics.

The effectiveness of probiotic products hinges on the viability and precise quantification of probiotic strains. This study addresses this crucial requirement by developing and validating a precise propidium monoazide combination with quantitative polymerase chain reaction (PMA-qPCR) method for quantifying viable Lacticaseibacillus paracasei in probiotic formulations. Initially, species-specific primers were meticulously designed based on core genes from the whole-genome sequence (WGS) of L. paracasei, and they underwent rigorous validation against 462 WGSs, 25 target strains, and 37 non-target strains across various taxonomic levels, ensuring extensive inclusivity and exclusivity. Subsequently, optimal PMA treatment conditions were established using 25 different L. paracasei strains to effectively inhibit dead cell DNA amplification while preserving viable cells. The developed method exhibited a robust linear relationship (R 2 = 0.994) between cycle threshold (Cq) values and viable cell numbers ranging from 103 to 108 CFU/mL, with an impressive amplification efficiency of 104.48% and a quantification limit of 7.30 × 103 CFU/mL. Accuracy assessments revealed biases within ±0.5 Log10 units, while Bland-Altman analysis demonstrated a mean bias of 0.058 Log10, with 95% confidence limits of -0.366 to 0.482 Log10. Furthermore, statistical analysis (p = 0.76) indicated no significant differences between theoretical and measured values. This validated PMA-qPCR method serves as a robust and accurate tool for quantifying viable L. paracasei in various sample matrices, including pure cultures, probiotics as food ingredients, and composite probiotic products, thereby enhancing probiotic product quality assurance and contributing to consumer safety and regulatory compliance.

Revealing the Viable Microbial Community of Biofilm in a Sewage Treatment System Using Propidium Monoazide Combined with Real-Time PCR and Metagenomics.

Microbial community composition, function, and viability are important for biofilm-based sewage treatment technologies. Most studies of microbial communities mainly rely on the total deoxyribonucleic acid (DNA) extracted from the biofilm. However, nucleotide materials released from dead microorganisms may interfere with the analysis of viable microorganisms and their metabolic potential. In this study, we developed a protocol to assess viability as well as viable community composition and function in biofilm in a sewage treatment system using propidium monoazide (PMA) coupled with real-time quantitative polymerase chain reaction (qPCR) and metagenomic technology. The optimal removal of PMA from non-viable cells was achieved by a PMA concentration of 4 µM, incubation in darkness for 5 min, and exposure for 5 min. Simultaneously, the detection limit can reach a viable bacteria proportion of 1%, within the detection concentration range of 102-108 CFU/mL (colony forming unit/mL), showing its effectiveness in removing interference from dead cells. Under the optimal conditions, the result of PMA-metagenomic sequencing revealed that 6.72% to 8.18% of non-viable microorganisms were influenced and the composition and relative abundance of the dominant genera were changed. Overall, this study established a fast, sensitive, and highly specific biofilm viability detection method, which could provide technical support for accurately deciphering the structural composition and function of viable microbial communities in sewage treatment biofilms.

Purification of his-tagged proteins using printed monolith adsorption columns.

Bio-separation is a crucial process in biotechnology and biochemical engineering for separating biological macromolecules, and the field has long relied on bead-based and expanded bed chromatography. Printed monolith adsorption (PMA) is a new alternative to which uses a 3D-printed monolithic structure containing self-supporting, ordered flow channels. PMA allows for direct purification of biological molecules from crude cell lysates and cell cultures, and like the other technologies, can functionalized to specifically target a molecule and enable affinity chromatography. Here we have combined PMA technology with an immobilized metal affinity ligand (iminodiacetic acid) to provide selectivity of binding to polyhistidine-tagged proteins during PMA chromatography. Two different PMA structures were created and tested for both static and dynamic protein-binding capacity. At comparative linear flow rates, the dynamic binding capacity of both columns was ≈3 mg/mL, while static capacity was shown to differentiate based on column voidage. We show that a polyhistidine-tagged protein can be directly purified from crude lysate with comparable results to the available commercial providers of IMAC, and with a substantially reduced purification time.

Assessing contributions of DNA sequences at the 3' end of a yeast gene on yFACT, RNA polymerase II, and nucleosome occupancy.

OBJECTIVE: In past work in budding yeast, we identified a nucleosomal region required for proper interactions between the histone chaperone complex yFACT and transcribed genes. Specific histone mutations within this region cause a shift in yFACT occupancy towards the 3' end of genes, a defect that we have attributed to impaired yFACT dissociation from DNA following transcription. In this work we wished to assess the contributions of DNA sequences at the 3' end of genes in promoting yFACT dissociation upon transcription termination. RESULTS: We generated fourteen different alleles of the constitutively expressed yeast gene PMA1, each lacking a distinct DNA fragment across its 3' end, and assessed their effects on occupancy of the yFACT component Spt16. Whereas most of these alleles conferred no defects on Spt16 occupancy, one did cause a modest increase in Spt16 binding at the gene's 3' end. Interestingly, the same allele also caused minor retention of RNA Polymerase II (Pol II) and altered nucleosome occupancy across the same region of the gene. These results suggest that specific DNA sequences at the 3' ends of genes can play roles in promoting efficient yFACT and Pol II dissociation from genes and can also contribute to proper chromatin architecture.

Photocatalytic Overall Water Splitting with a Solar-to-Hydrogen Conversion Efficiency Exceeding 2% through Halide Perovskite.

Photocatalytic water splitting using semiconductors is a promising approach for converting solar energy to clean energy. However, challenges such as sluggish water oxidation kinetics and limited light absorption of photocatalyst cause low solar-to-hydrogen conversion efficiency (STH). Herein, we develop a photocatalytic overall water splitting system using I3-/I- as the shuttle redox couple to bridge the H2-producing half-reaction with the O2-producing half-reaction. The system uses the halide perovskite of benzylammonium lead iodide (PMA2PbI4, PMA = C6H5CH2NH2) loaded with MoS2 (PMA2PbI4/MoS2) as the H2 evolution photocatalyst, and the RuOx-loaded WO3 (WO3/RuOx) as the O2 evolution photocatalyst, achieving a H2/O2 production in stoichiometric ratio with an excellent STH of 2.07%. This work provides a detour route for photocatalytic water splitting with the help of I3-/I- shuttle redox couple in the halide perovskite HI splitting system and enlightens one to integrate and utilize multi catalytic strategies for solar-driven water splitting.

Exploring the potential of red pitaya pulp (Hylocererus sp.) as a plant-based matrix for probiotic delivery and effects on betacyanin content and flavoromics.

This study evaluated the potential of red pitaya pulp fermented with Lacticaseibacillus paracasei subsp. paracasei F-19 (F-19) as a base for probiotic products. Physicochemical parameters, sugar, betacyanin, and phenolic contents, and antioxidant activity were analyzed over 28 days at 4 °C and compared to a non-fermented pulp, and to a pulp fermented with Bifidobacterium animalis subsp. lactis BB-12 (BB-12). Volatile compounds were identified using HS-SPME/GC-MS. Probiotic viability during storage and survival through in vitro-simulated gastrointestinal tract (GIT) stress were assessed. Red pitaya pulp, rich in moisture (85.83 g/100 g), carbohydrates (11.65 g/100 g), and fibers (2.49 g/100 g), supported fermentation by both strains. F-19 and BB-12 lowered pH, with F-19 showing stronger acidification, and maintained high viability (8.85-8.90 log CFU/mL). Fermentation altered sugar profiles and produced unique volatile compounds, enhancing aroma and sensory attributes. F-19 generated 2-phenylethanol, a unique flavor compound, absent in BB-12. Phenolic content initially increased but antioxidant activity decreased during storage. Betacyanin remained stable for up to 14 days. Red pitaya improved F-19 viability through the simulated GIT, while BB-12 populations significantly decreased (p < 0.05). These results suggest red pitaya pulp is a promising plant-based matrix for F-19, offering protection during digestion and highlighting its potential as a functional food with enhanced bioactive compound bioavailability and sensory attributes.

Early Detection of Food Safety and Spoilage Incidents Based on Live Microbiome Profiling and PMA-qPCR Monitoring of Indicators.

The early detection of spoilage microorganisms and food pathogens is of paramount importance in food production systems. We propose a novel strategy for the early detection of food production defects, harnessing the product microbiome. We hypothesize that by establishing microbiome datasets of proper and defective batches, indicator bacteria signaling production errors can be identified and targeted for rapid quantification as part of routine practice. Using the production process of pastrami as a model, we characterized its live microbiome profiles throughout the production stages and in the final product, using propidium monoazide treatment followed by 16S rDNA sequencing. Pastrami demonstrated product-specific and consistent microbiome profiles predominated by Serratia and Vibrionimonas, with distinct microbial signatures across the production stages. Based on the established microbiome dataset, we were able to detect shifts in the microbiome profile of a defective batch produced under lactate deficiency. The most substantial changes were observed as increased relative abundances of Vibrio and Lactobacillus, which were subsequently defined as potential lactate-deficiency indicators. PMA-qPCR efficiently detected increased levels of these species, thus proving useful in rapidly pinpointing the production defect. This approach offers the possibility of the in-house detection of defective production events with same-day results, promoting safer food production systems.

Formation and recovery of Listeria monocytogenes in viable but nonculturable state under different temperatures combined with low nutrition and high NaCl concentration.

The viable but nonculturable (VBNC) state occurs when bacteria lose their ability to grow and multiply on conventional media when stressed by adverse environmental factors, but they remain active and can revive under certain conditions, posing a food safety risk. In this study, the VBNC state of Listeria monocytogenes was induced with different temperatures combined with low nutrient conditions; the VBNC state of L. monocytogenes was confirmed in conjunction with the housekeeping gene abcZ using a molecular biology assay (PMA-qPCR) to calculate the viable bacterial count; The resuscitation conditions for the VBNC state of L. monocytogenes were investigated utilizing various nutrients in the culture medium and pasteurized milk. Four strains of L. monocytogenes reached the VBNC stage after 14, 21, 21, and 35 days at 20°C with 20% (or 30%) NaCl. Resuscitation studies indicate that Trypticase Soy Broth (TSB) combined with Tween 80 and sodium pyruvate is more effective for resuscitation. The Chinese national standard technology GB 4789.30-2016 was used to inoculate lettuce, chicken, and pasteurized milk with L. monocytogenes ATCC 19115 VBNC state. This research has significant implications for commercial food processing, long-term storage, disinfection, disease prevention, and control.

The Antimicrobial Activity of Human Defensins at Physiological Non-Permeabilizing Concentrations Is Caused by the Inhibition of the Plasma Membrane H+-ATPases.

Human defensins are cysteine-rich peptides (Cys-rich peptides) of the innate immune system. Defensins contain an ancestral structural motif (i.e., γ-core motif) associated with the antimicrobial activity of natural Cys-rich peptides. In this study, low concentrations of human α- and ß-defensins showed microbicidal activity that was not associated with cell membrane permeabilization. The cell death pathway was similar to that previously described for human lactoferrin, also an immunoprotein containing a γ-core motif. The common features were (1) cell death not related to plasma membrane (PM) disruption, (2) the inhibition of microbicidal activity via extracellular potassium, (3) the influence of cellular respiration on microbicidal activity, and (4) the influence of intracellular pH on bactericidal activity. In addition, in yeast, we also observed (1) partial K+-efflux mediated via Tok1p K+-channels, (2) the essential role of mitochondrial ATP synthase in cell death, (3) the increment of intracellular ATP, (4) plasma membrane depolarization, and (5) the inhibition of external acidification mediated via PM Pma1p H+-ATPase. Similar features were also observed with BM2, an antifungal peptide that inhibits Pma1p H+-ATPase, showing that the above coincident characteristics were a consequence of PM H+-ATPase inhibition. These findings suggest, for the first time, that human defensins inhibit PM H+-ATPases at physiological concentrations, and that the subsequent cytosolic acidification is responsible for the in vitro microbicidal activity. This mechanism of action is shared with human lactoferrin and probably other antimicrobial peptides containing γ-core motifs.

1,25-dihydroxyvitamin D3 augments low-dose PMA-based monocyte-to-macrophage differentiation in THP-1 cells.

The human monocytic THP-1 cell line is the most routinely employed in vitro model for studying monocyte-to-macrophage differentiation. Despite the wide use of this model, differentiation protocols using phorbol 12-myristate-13-acetate (PMA) or 1,25-dihydroxyvitamin D3 (1,25D3) vary drastically between studies. Given that differences in differentiation protocols have the potential to impact the characteristics of the macrophages produced, we aimed to assess the efficacy of three different THP-1 differentiation protocols by assessing changes in morphology and gene- and cell surface macrophage marker expression. THP-1 cells were differentiated with either 5 nM PMA, 10 nM 1,25D3, or a combination thereof, followed by a rest period. The results indicated that all three protocols significantly increased the expression of the macrophage markers, CD11b (p < 0.001) and CD14 (p < 0.010). Despite this, THP-1 cells exposed to 1,25D3 alone did not adopt the morphological and expression characteristics associated with macrophages. PMA was required to produce these characteristics, which were found to be more pronounced in the presence of 1,25D3. Both PMA- and PMA with 1,25D3-differentiated THP-1 cells were capable of M1 and M2 macrophage polarization, though the gene expression of polarization-associated markers was most pronounced in PMA with 1,25D3-differentiated THP-1 cells. Moreover, the combination of PMA with 1,25D3 appeared to support the process of commitment to a particular polarization state.

Emotional Fertility Intention and its correlates in Ethiopia among married contraceptive user women: using linked community and health facility data from performance monitoring for action; a generalized ordered logistics regression modeling.

BACKGROUND: Emotional fertility intention and couples communication are key during pregnancy and childbirth with simultaneous minimization of reproductive coercion. Intention to conceive is an integral part of the reproductive health (RH) right and can be considered as decision making on fertility, family wellbeing and the country's population demographic dividend and composition. However, in low and middle income countries including Ethiopia where males dominance is culturally constructed and socially accepted, males took the lead in every decision making process. In the aforementioned context, women are less likely for their voices to be heard, hence, this study aimed at determining the level of womens´ emotional fertility readiness and its correlates. The finding provided actionable evidence for the ministry and developmental partners working on reproductive and womens´ health so as to be used as an action point to empower women in terms of their reproductive health right to have control over their fertility. METHODS: Linked community and facility data with nationally representation from Performance Monitoring for Action (PMA Ethiopia) 2020 Survey Ethiopia except Tigray Region were used for this study. A total of 2,069 current and/or recent contraceptive user women of child bearing age who are currently married/living together as a partner were included in this analysis. Frequency was computed to describe the study participant's characteristics. Generalized Ordered logistics regression modeling was employed to identify correlates of the hierarchical variation in women fertility intention if they became pregnant. Results were presented in the form of percentages and odds ratio with 95% Confidence Intervals. Candidate variables were selected using p-value of 0.25. Statistical significance was declared at p-value of 0.05. RESULTS: The proportion of womens´ emotional fertility intention of feeling unhappiness was 48.73% (95%CI: 46.21%, 51.23%). On the contrary, 22.88%, 11.36% and 17.03% of them reported that they felt sort of happy, very happy and mixed feeling. An increase in age,10 and above years marriage duration, the type of decision maker for contraceptive use were found to increase the odds of women emotional fertility intention across the higher level categories by (AOR: 95% CI: 6.75 (3.11, 14.62) times higher among elder women aged 35 to 49 years, (AOR: 95% CI: 3.79 (1.72, 8.31) times higher for women with a 10 or more years of marriage duration; and 1.83 (1.03,3.24) times higher for women whose contraceptive use was decided by the health care provide alone. A higher birth order lowered the cumulative odds of womens´ emotional fertility intention symmetrically across the higher level categories by 86% (AOR: 95% CI: 0.14 (0.07, 0.29). Women who wanted to have additional child and whose nearest facility provided 5 or more methods had an increased odds of being in the higher level categories of women emotional fertility intention with disproportional association across the cumulative logit. Accordingly, women whose nearest health facility provided 5 or more methods had an 49% (AOR: 95%CI:1.49 (1.01, 2.19) increased likelihood of being in the mixed or happy category than being very/sort of unhappy category of the emotional fertility intention while the number of methods had no significant association with emotional fertility intention at higher cumulative logit: 1.34 (0.87,2.10). Those who wanted to have an additional child had a 3.16 (2.28, 4.36) higher odds to be in the mixed or happy category than being in unhappy category. Further, this tendency was even stronger at higher categories of emotional fertility intention: 4.83 (3.23, 7.23). CONCLUSION: Nearly one in two women reported being unhappy while 17.03% felt mixed emotion calling up on intended and spaced pregnancies by ensuring women reproductive and economic empowerment to empower women to have control over their fertility. Activities and efforts that promote intended and spaced pregnancies; and diversifying access to contraceptive methods in the nearest health facilities are likely to improve women emotional fertility intention; and activities that enable women to decide their contraceptive as well. The finding that health care provider decides on women current/recent contraceptive use calls for activities to improve quality of contraceptive use counseling to enable women to decide their contraceptive use by the themselves while the access of diversified methods in the nearby health facility create an opportunity for women to obtain the method they preferred to use and make them emotionally well. These activities are hoped to enable women to plan their fertility thereby increasing their emotional well-being. These activities and interventions need to be tailored across regions and need to be age sensitive.

Women's Empowerment and Associated Factors in Kinshasa, Democratic Republic of Congo: A Secondary Data Analysis of the Performance Monitoring Assessment Survey.

Empowering women and promoting gender equality is crucial for accelerating sustainable development in fragile countries, including the Democratic Republic of Congo (DRC). However, there is scarce existing knowledge or understanding of the factors determining women's empowerment in these contexts. We aimed to assess women's empowerment and determine its associated factors in Kinshasa, DRC. We analyzed data from the 2021 Performance Monitoring Assessment (PMA) survey. A sample of 1365 women of childbearing age was retained for this study. Twenty empowerment items related to household decision-making, contraception use, and husband/partner influence were considered. We calculated the average women's empowerment index (aWEI), identified the women's empowerment variables using principal component analysis (PCA), and determined the associated factors for the first three principal components through the performance of multivariate binary logistic regression. In Kinshasa, the overall aWEI was estimated at 0.65. It was low for household decision-making (0.34) and high for husband/partner influence domains (0.93). Three principal components were identified and named, including the absence of threats, control of sexuality, and participation in decision-making. The factors associated with these components were having internet access, being in free union with a partner, being aged 40-49 years, and residing in a non-slum area. Increasing access to information would enable women in Kinshasa to make strategic decisions about their lives, benefiting themselves and others.

Use of patent term extensions to restore regulatory time for medical devices in the United States.

BACKGROUND: Medical devices can seek patent term extensions (PTEs), which extend market exclusivity to compensate for delays related to clinical trials and regulatory review. Pharmaceutical companies commonly use PTEs, but their use by medical device companies has not been clear. RESEARCH DESIGN AND METHODS: We examined the use of PTEs by medical device companies between 1984 and 2024 using a database published in the Federal Register and a list published by the Patent and Trademark Office. RESULTS: Only 178 medical device submissions were linked to a PTE application. They were mostly concentrated in 116 product codes associated with 15 medical specialties; nearly half were associated with cardiovascular devices. Numbers increased significantly in the past decade. Successful applications restored 987 days on average. CONCLUSIONS: The patent restoration opportunity appears underutilized. It is unclear whether some companies do not recognize the opportunity it promises, or whether it does not meet their needs. Different business features and marketing strategies in device versus pharmaceutical industries may decrease the usefulness of the PTE program for these types of medical products. However, the finding that a small subset of manufacturers operating in competitive markets adopted patent extension strategies more commonly suggests a significant competitive advantage when competition increases.

Spatial distribution and determinants of Early sexual initiation in Ethiopia.

INTRODUCTION: Early sexual initiation has negative health, social, and economic consequences for both women and future generations. The trend of early sexual initiation is increasing globally, leading to higher rates of sexually transmitted diseases and unplanned pregnancies. Ethiopia has been challenged various disasters that makes women vulnerable and position them at heightened risk of early sexual initiation in the last four years. The spatial patterns and factors of early sexual initiation in the post-conflict-post pandemic settings is not well understood. Hence this research aimed at mapping Spatial Patterns and identifying determinant factors in the Post-COVID-Post-Conflict Settings. METHODS: The study was conducted on secondary data from the PMA 2021 cross-sectional survey which conducted nationally from November 2021 to January 2022 which is in the post pandemic and post-war period. Total weighted sample of 6,036 reproductive age women were included in the analysis. ArcGIS Pro and SaTScan software were used to handle spatial analysis. Multilevel logistic regression model was used to estimate the effects of independent variables on early sexual initiation at individual and community level factors. Adjusted odds ratio with the 95% confidence interval was reported to declare the strength and statistical significance of the association. RESULT: The spatial distribution of early sexual initiation was clustered in Ethiopia with a global Moran's I index value of 0.09 and Z-score 6.01 (p-value < 0.001).Significant hotspots were detected in East Gojjam zone of Amhara region, Bale, Arsi, West Hararge, East Wellega and Horo Gudru Wellega zones of Oromia region. The odds of having early sexual initiation was higher in women with primary education (AOR = 1.23, 95%CI: 1.03, 1.47), secondary or above education (AOR = 4.36, 95%CI: 3.49, 5.44), Women aged 26 to 25 (AOR = 1.91, 95%CI: 1.61, 2.26), women aged 36 to 49(AOR = 1.51, 95%CI: 1.24, 1.84). However, there was a significant lower likelihood of early sexual initiation in rural resident women (AOR = 0.53, 95%CI: 0.35, 0.81) and women living in 5 to 7 family size (AOR = 0.79, 95%CI: 0.68, 0.92), and more than 7 members (AOR = 0.63, 95%CI: 0.49, 0.81). CONCLUSIONS: The spatial distribution of early sexual initiation was clustered in Ethiopia. Interventions should be taken to eliminate the observed variation by mobilizing resources to high-risk areas. Policies and interventions targeted to this problem may also take the identified associated factors into account for better results.

Rapid Determination of SARS-CoV-2 Integrity and Infectivity by Using Propidium Monoazide Coupled with Digital Droplet PCR.

SARS-CoV-2 is a highly infectious virus responsible for the COVID-19 pandemic. Therefore, it is important to assess the risk of SARS-CoV-2 infection, especially in persistently positive patients. Rapid discrimination between infectious and non-infectious viruses aids in determining whether prevention, control, and treatment measures are necessary. For this purpose, a method was developed and utilized involving a pre-treatment with 50 µM of propidium monoazide (PMAxx, a DNA intercalant) combined with a digital droplet PCR (ddPCR). The ddPCR method was performed on 40 nasopharyngeal swabs (NPSs) both before and after treatment with PMAxx, revealing a reduction in the viral load at a mean of 0.9 Log copies/mL (SD ± 0.6 Log copies/mL). Furthermore, six samples were stratified based on the Ct values of SARS-CoV-2 RNA (Ct < 20, 20 < Ct < 30, Ct > 30) and analyzed to compare the results obtained via a ddPCR with viral isolation and a negative-chain PCR. Of the five samples found positive via a ddPCR after the PMAxx treatment, two of the samples showed the highest post-treatment SARS-CoV-2 loads. The virus was isolated in vitro from both samples and the negative strand chains were detected. In three NPS samples, SARS CoV-2 was present post-treatment at a low level; it was not isolated in vitro, and, when detected, the strand was negative. Our results indicate that the established method is useful for determining whether the SARS-CoV-2 within positive NPS samples is intact and capable of causing infection.

Leukemia risk assessment of exposure to low-levels of benzene based on the linearized multistage model.

Objectives: To assess leukemia risk in occupational populations exposed to low levels of benzene. Methods: Leukemia incidence data from the Chinese Benzene Cohort Study were fitted using the Linearized multistage (LMS) model. Individual benzene exposure levels, urinary S-phenylmercapturic acid (S-PMA) and trans, trans-muconic acid (t, t-MA) were measured among 98 benzene-exposed workers from factories in China. Subjects were categorized into four groups by rounding the quartiles of cumulative benzene concentrations (< 3, 3-5, 5-12, ≥12 mg/m3·year, respectively). The risk of benzene-induced leukemia was assessed using the LMS model, and the results were validated using the EPA model and the Singapore semi-quantitative risk assessment model. Results: The leukemia risks showed a positive correlation with increasing cumulative concentration in the four exposure groups (excess leukemia risks were 4.34, 4.37, 4.44 and 5.52 × 10-4, respectively; Ptrend < 0.0001) indicated by the LMS model. We also found that the estimated leukemia risk using urinary t, t-MA in the LMS model was more similar to those estimated by airborne benzene compared to S-PMA. The leukemia risk estimated by the LMS model was consistent with both the Singapore semi-quantitative risk assessment model at all concentrations and the EPA model at high concentrations (5-12, ≥12 mg/m3·year), while exceeding the EPA model at low concentrations (< 3 and 3-5 mg/m3·year). However, in all four benzene-exposed groups, the leukemia risks estimated by these three models exceeded the lowest acceptable limit for carcinogenic risk set by the EPA at 1 × 10-6. Conclusion: This study demonstrates the utility of the LMS model derived from the Chinese benzene cohort in assessing leukemia risk associated with low-level benzene exposure, and suggests that leukemia risk may occur at cumulative concentrations below 3 mg/m3·year.

Evolution of the pathogenic mold Aspergillus fumigatus on high copper levels identifies novel resistance genes.

Aspergillus fumigatus is the leading cause of severe mold infections in immunocompromised patients. This common fungus possesses innate attributes that allow it to evade the immune system, including its ability to survive the high copper (Cu) levels in phagosomes. Our previous work has revealed that under high Cu levels, the A. fumigatus transcription factor AceA is activated, inducing the expression of the copper exporter CrpA to expel excess Cu. To identify additional elements in Cu resistance, we evolved A. fumigatus wild-type and mutant ΔaceA or ΔcrpA strains under increasing Cu concentrations. Sequencing of the resultant resistant strains identified both shared and unique evolutionary pathways to resistance. Reintroduction of three of the most common mutations in genes encoding Pma1 (plasma membrane H+-ATPase), Gcs1 (glutamate cysteine-ligase), and Cpa1 (carbamoyl-phosphate synthetase), alone and in combination, into wild-type A. fumigatus confirmed their additive role in conferring Cu resistance. Detailed analysis indicated that the pma1 mutation L424I preserves Pma1 H+-ATPase activity under high Cu concentrations and that the cpa1 mutation A37V confers a survival advantage to conidia in the presence of Cu. Interestingly, simultaneous mutations of all three genes did not alter virulence in infected mice. Our work has identified novel Cu-resistance pathways and provides an evolutionary approach for dissecting the molecular basis of A. fumigatus adaptation to diverse environmental challenges.IMPORTANCEAspergillus fumigatus is the most common mold infecting patients with weakened immunity. Infection is caused by the inhalation of mold spores into the lungs and is often fatal. In healthy individuals, spores are engulfed by lung immune cells and destroyed by a combination of enzymes, oxidants, and high levels of copper. However, the mold can protect itself by pumping out excess copper with specific transporters. Here, we evolved A. fumigatus under high copper levels and identified new genetic mutations that help it resist the toxic effects of copper. We studied how these mutations affect the mold's ability to resist copper and how they impact its ability to cause disease. This is the first such study in a pathogenic mold, and it gives us a better understanding of how it manages to bypass our body's defenses during an infection.