Microbial Contamination Research Articles

Review: Advances in Self-Preservation Techniques in Cosmetics Using Hurdle Technology

Preservatives are essential in cosmetic products to prevent microbial growth, extending product shelf life and ensuring user safety by minimizing infection risks. While traditional chemical preservatives have long been effective in protecting against microbial contamination, growing consumer concerns over their safety and potential health impacts are prompting a shift toward preservative-free or self-preserving cosmetic formulations. This shift has increased interest in developing products that maintain antimicrobial effectiveness without synthetic preservatives, with hurdle technology emerging as a promising approach.Originally applied in the food industry in the 1970s, hurdle technology involves combining multiple preservation strategies to inhibit microbial growth without relying on traditional preservatives. In cosmetic applications, hurdle technology can reduce or eliminate the need for synthetic preservatives by implementing several protective measures. These “hurdles” may include high manufacturing standards, protective packaging, emulsions that limit microbial growth, controlled water activity, and pH adjustments to create an environment less conducive to microbial survival.This review explores the adaptation of hurdle technology principles in cosmetics, focusing on techniques for creating self-preserving formulations. It highlights the role of multifunctional ingredients with natural antimicrobial properties, such as plant-derived essential oils, which can serve as alternatives to chemical preservatives. These ingredients not only inhibit microbial growth but also provide additional benefits, aligning with consumers' growing preference for natural, safe, and effective skincare options.

Microbial Contamination and Sterilization Methods in an Air Circulation-Type Geothermal Ventilation System

A simulated system was created to evaluate an air circulation-type geothermal ventilation system, focusing on measuring microbial contamination levels on the surface of the heat exchange unit. Additionally, this study examined sterilization methods using UV lamps on the surface of the heat exchanger. The fungal concentration on the surface of the heat exchanger showed a tendency to increase over time. Although direct comparison is challenging due to the varying concentrations of outdoor air fungi at different measurement times, the surface fungal concentration was highest at a minimum airflow rate of 150 m3/h compared to other conditions. However, since the adhesion of contaminants from outdoor air to the surface of the heat exchanger is influenced not only by airflow but also by outdoor temperature and relative humidity conditions, future research needs to consider these factors. According to the ATP measurement results, microbial contamination was evaluated as “slightly dirty” after 24 h and “dirty” after 48 h of operating the experimental apparatus. Therefore, it is advisable to clean the internal surfaces of the geothermal ventilation system every 1–2 days. The results of the sterilization experiments using UV lamps indicated that irradiation for approximately 30 min inactivated 94.5%-to-96.1% of microorganisms derived from outdoor air. However, since the sterilization dose varies depending on the type of microorganism, it is necessary to determine the optimal irradiation time based on the target microorganisms and the UV lamp’s irradiation intensity.

Indices for complete dentures after cleaning at home

Background: According to experts, there are more than 350 million fully edentulous patients globally, accounting for 7% of the world population. Edentulous patients require dentures to maintain a good quality of life. Complete dentures need to be cleaned on a regular basis to prevent their microbial contamination and inflammatory complications. Aim: To assess the efficacy of Anolit ANK Super solution for cleaning complete dentures at home. Materials and Methods: The hygiene of complete dentures was assessed using the Ulitovsky–Leontiev index. The efficacy of cleaning complete dentures with Anolit ANK Super solution compared to 0.05% chlorhexidine bigluconate solution was assessed. Moreover, statistical analysis methods were used: normality test; threshold value, or baseline significance level p=0.05; intragroup comparison (6 comparisons) with the Bonferroni correction (critical p=0.0083). Results: When assessing the hygiene of dentures using the Ulitovsky–Leontiev index, the denture cleanliness index (DCI) changed from 4.65 points (poor denture hygiene) to 3.50 points (satisfactory denture hygiene) after one month of using Anolit ANK Super solution. After three months of using Anolit ANK Super solution, the DCI changed from 3.50 points (satisfactory denture hygiene) to 2.60 points (good denture hygiene). After six months of using Anolit ANK Super solution, the DCI changed from 2.60 points (good denture hygiene) to 1.55 points (very good denture hygiene). After one month of using 0.05% chlorhexidine bigluconate solution, the DCI changed from 4.85 points (poor denture hygiene) to 4.40 points (poor denture hygiene) (p=0.0083). After three months of using 0.05% chlorhexidine bigluconate solution, the DCI changed from 4.40 points (poor denture hygiene) to 3.50 points (satisfactory denture hygiene) (p=0.0083). After six months of using 0.05% chlorhexidine bigluconate solution, the DCI changed from 3.50 points (satisfactory denture hygiene) to 2.60 points (good denture hygiene) (p=0.0083). Conclusion: The follow-up revealed that, with similar duration of exposure to test solutions, Anolit ANK Super solution for cleaning dentures at home used for 6 months decreased the DCI threefold from baseline (p=0.000002) and improved denture hygiene from poor to good.

Insights into relationship of environmental inequalities and multimorbidity: a population-based study.

Substantial inequalities in the overall prevalence and patterns of multimorbidity have been widely reported, but the causal mechanisms are complex and not well understood. This study aimed to identify common patterns of multimorbidity in Serbia and assess their relationship with air pollutant concentrations and water quality indicators. This ecological study was conducted on a nationally representative sample of the Serbian population. Data were obtained from the European Health Interview (EHIS) Survey, a periodic study designed to assess population health using widely recognized standardized instruments. The study included 13,069 participants aged 15 and older, randomly selected through a multistage stratified sampling design. Multimorbidity was defined as having two or more self-reported diagnoses of chronic non-communicable diseases. Latent class analysis (LCA) was performed to identify clusters of multimorbidity. Concentrations of particulate matter (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3), as well as water quality indicators, were obtained from the Serbian Environmental Protection Agency. The overall prevalence of multimorbidity was 33.4% [32.6%-34.2%]. Six latent classes of multimorbidity were identified: Healthy, Multicondition, Cardiovascular, Metabolic syndrome, Respiratory, and Musculoskeletal. Annual increases in PM10 and SO2 concentrations, as well as daily increases in O3 concentrations, significantly raised the odds of having multimorbidity (OR = 1.02, 95% CI 1.02-1.03; OR = 1.01, 95% CI 1.00-1.02 and OR = 1.03, 95% CI 1.02-1.03, respectively). A pattern of increased risk was observed with rising levels of water contamination. Exposure to physico-chemical, microbiological and combined contamination was associated with a 3.92%, 5.17% and 5.54% higher probability, respectively, of having multiple chronic conditions. There was strong evidence that air pollutants, as well as chemical and microbial water contamination, were significantly associated with higher odds of the most common clusters of multimorbidity identified by LCA. There is compelling evidence of an association between multimorbidity and environmental pollution, suggesting that exposure to air pollutants and water contaminants may contribute to disease accumulation and help explain geographically and socioeconomically patterned inequalities. These findings underscore the need for extensive studies that simultaneously measure both multimorbidity and pollution to explore their complex interrelationships.

Prospects and challenges of nanomaterials in sustainable food preservation and packaging: a review.

Nanomaterials play a pivotal role in food preservation and its safety, offering ingenious solutions for sustainable food packaging. Nanomaterials enable the creation of packaging materials having unique functional properties. It not only extends the shelf life of the foods by releasing preservatives but also enhances food safety by preventing microbial contamination or food spoilage. In this review, we aim to provide an overview of the various applications of nanotechnology in food packaging, highlighting its key advantages. We also delve into the safety considerations and regulatory issues involved in developing nanotechnology-based food packaging materials. Additionally, advancements in the field of nanotechnology-based packaging have the potential to create safer, more sustainable, and high-quality packaging with greater functionality that delivers essential benefits to manufacturers and consumers.

Microbiological quality of drinking water from three flood-prone communities along the Odaw River in Accra, Ghana

ABSTRACT Access to safe drinking water is considered a fundamental human right, yet, in most developing countries, this is not the case, as microbial contamination of drinking water is commonly responsible for the transmission of many waterborne diseases, including cholera, typhoid fever, diarrhoea, and dysentery. The study aimed to assess the microbiological quality of drinking water from three communities along the Odaw River in Accra, known for their poor waste disposal practices and incidents of flooding. Water samples were collected from community tap water and locally manufactured sachet water from three flood-prone communities along the Odaw River, namely, Alajo, Avenor, and Agbogbloshie, and analyzed for the presence of indicator organisms: total coliforms, faecal coliforms, and Escherichia coli (E. coli). All brands of sachet water sampled from the three communities had no microbial contamination. Conversely, most community tap water showed contamination with indicator organisms that exceeded the international standard of 0 per 100 mL for potable water. The presence of faecal coliforms and E. coli in community shared tap water is an indication of poor water quality and may present a risk for waterborne disease outbreaks among households and communities.

Identifying potential introduced and natural sources of pollution in Delaware watersheds.

Managing water quality with microbial impairment caused by Enterococcus poses unique challenges regarding the determination of fecal host origin. Most water monitoring is performed based on Enterococcus counts that neither detect the location of the introduction of pollution nor identify the type of contaminating Enterococcus. The use of sequenced-based microbial source tracking could allow for identification of fecal origin and potential remediation of pollution. The state of Delaware has numerous waterways with high microbial impairment from unknown sources, so we used sequence-based microbial source tracking to investigate potential microbial pollution in three watersheds with significant variation in land use and population density. In this study, we use a 16S rRNA sequence reference library of microbial communities from relevant fecal sources (wild animal, domestic animal, sediment, and septic/wastewater) to determine the most likely sources of microbial impairment in three Delaware watersheds. This study assigned sources of microbial contamination to mostly human-related sources (septic and wastewater) or unknown sources indicating that waste infrastructure may have a larger influence on microbial community structure in Delaware watersheds than previously considered. Our results suggest that long-term source tracking is valuable for ruling out native or domesticated animals as contributors to water pollution.IMPORTANCETraditional microbial pollution monitoring utilizes specific fecal indicator bacteria that need to grow in the laboratory for detection. Here, we show the use of sequence information from whole microbial communities and an expanded reference library in microbial source tracking. Expanding the host detection range by including the whole microbial community may allow for a wider range of potential fecal origin identification even when specific fecal indicators are absent or in low concentration. We show that many Delaware waterways bear the signature of human influence compared to natural sources. In addition, the robust reference library built in this study can be used to conduct source tracking studies in the mid-Atlantic USA.

Water Quality Assessment and Prevalence of Waterborne Diseases within Chikun Local Government Area, Kaduna State-Nigeria

Study’s Excerpt Water quality and the prevalence of waterborne diseases in Chikun Local Government Area, Kaduna State, were assessed. Microbiological analyses revealed microbial, helminth and protozoan contamination in water sources while Physicochemical analyses revealed heavy metal contamination. There is a need for enhanced water treatment and community awareness for improving water safety and public health in the region. Full Abstract The health and well-being of individuals in a nation are intrinsically tied to the quality of water available for consumption. Access to high-quality water plays a vital role in supporting proper nutrition, ensuring food security, and preventing waterborne diseases. Therefore, this study was carried out to assess water quality and prevalence of waterborne diseases within Chikun Local Government Area, Kaduna State. A cross-sectional study was conducted between January and June 2024. Data were collected through the administration of questionnaires (400 respondents) and laboratory water analysis. Water samples were analyzed from various sources involving boreholes, rivers and wells through composite sampling and physicochemical and microbiological analyses. Results showed samples from Unguwan Maigero and Tricania possessed varying physicochemical properties, while water from Goningora and Nasarawa revealed high turbidity and heavy metal contamination. Chloride levels were below 500 ppm, and sulphate concentrations ranged from 10.76 to 378.3 ppm. Sodium levels ranged from 19.5 to 110 mg/l, and potassium levels exceeded the permissible limit in some samples. Total coliform counts exceeded national limits (zero coliform per 100ml of water), indicating significant microbial contamination. Parasitological analysis indicated helminths and protozoan contamination in non-borehole sources. Findings showed 41% prevalence of waterborne diseases with diarrhea and typhoid. The study indicates that community awareness, appropriate water treatment, surveillance, and monitoring are essentials for assuring the availability and utilisation of safe and high-quality drinking water in Chikun LGA, Kaduna State.

Prevalence and identification of Bacillus species in cellophane, foil, and disposable plastic containers used for food packaging

Background: Foil, cellophane, and disposable plastic containers are commonly employed in food packaging, namely as coatings on food items. Nevertheless, the existence of microbes on the surface and inside the internal composition of these materials gives rise to concerns, as they have the capacity to multiply under ideal circumstances and spread to food items, thereby jeopardizing the safety and quality of the food. Objective: This study aimed at examining the number of microorganisms and identifying specific bacterial species within frequently used food packaging materials like foil, cellophane, and disposable plastic containers. Methods: samples of foil, cellophane, and disposable plastic containers were collected from various popular brands in Iran. The overall bacterial count wضas determined using defibering, flooding, and smear techniques followed by culturing on Tryptone Glucose Extract Agar (TGEA) medium. To identify the bacterial species, various biochemical tests were performed, including fermentation, motility testing, catalase test, oxidase test, and methyl red-Voges Proskauer (MR-VP) test. Results: Bacterial quantity ranged from 0 CFU/g to 8.3 × 103 CFU/g in analyzed samples. All the samples had primary contaminants mainly Bacillaceae family bacteria that could produce spores. Disposable plastic containers had the lowest bacterial count whereas cellophane showed the highest bacterial contamination level. Among Bacillaceae family members Bacillus licheniformis was dominant. Conclusion: The study's findings emphasize the possibility of microbial contamination in food packaging materials, including cellophane. These results indicate that the food packaging industry should adopt a rigorous approach to hazard evaluation and Important Control Points (HACCP) in order to guarantee the microbiological safety and efficacy of packaging materials.

Microbial Contamination and Antibiotic Resistance in Fresh Produce and Agro-Ecosystems in South Asia—A Systematic Review

Fresh produce prone to microbial contamination is a potential reservoir for antimicrobial-resistant bacteria (ARB) and antimicrobial resistance genes (ARGs), posing challenges to food safety and public health. This systematic review aims to comprehensively assess the prevalence of bacterial pathogens and the incidence of ARB/ARGs in fresh produce and agro-ecosystems across South Asia. Twenty-two relevant studies published between 2012 and 2022 from three major scientific databases and the grey literature were identified. The results revealed a wide occurrence of microbial contamination in various types of fresh produce across South Asia, with a predominance of E. coli (16/22), Salmonella spp. (13/22), Staphylococcus spp. (5/22), and Klebsiella spp. (4/22). The agro-ecosystem serves as a complex interface for microbial interactions; studies have reported the prevalence of E. coli (1/4), Salmonella spp. (1/4) and Listeria monocytogenes (1/4) in farm environment samples. A concerning prevalence of ARB has been reported, with resistance to multiple classes of antibiotics. The presence of ARGs in fresh produce underscores the potential for gene transfer and the emergence of resistant pathogens. To conclude, our review provides insights into the requirements of enhanced surveillance, collaborative efforts, implementation of good agricultural practices, and public awareness for food safety and safeguarding public health in the region.

Control of bacterial contamination in three types of fish selected from the coastal and inland regions of Tipaza (Algeria)

This study addresses the problem of microbiological contamination in fish sold in the region of Tipaza, where food safety is a growing concern. It aims to assess the contamination levels in three fish species: sardine, mackerel saurale, and bogue. To achieve this, samples were collected and analyzed for total aerobic mesophilic bacteria, thermotolerant coliforms, coagulase-positive Staphylococcus aureus, and Salmonella. The results revealed that all samples contained total aerobic mesophilic bacteria and thermotolerant coliforms within acceptable limits. However, high levels of coagulase-positive Staphylococcus aureus were detected in bogue and saurale samples, indicating unsatisfactory bacteriological quality, particularly in samples from the city of Tipaza. No Salmonella contamination was observed. These findings highlight significant hygiene issues during fish transport and sale, contributing to microbial contamination. The study concludes that improving handling practices is crucial to ensuring fish safety and reducing health risks to consumers.

The efficacy of nano‐cellulose‐based composites in heavy metal removal from wastewater: a comprehensive review

AbstractThis comprehensive study delves into the innovative application of nano‐cellulose‐based composites for addressing the multifaceted challenges of wastewater treatment. This review introduces the innovative use of nano‐cellulose composites, particularly highlighting the novel synthesis routes that enhance their pollutant adsorption capabilities beyond conventional materials. These materials stand out for their regenerative properties and integration with functionalized matrix materials, marking significant advancements in sustainable wastewater treatment technologies. As the environmental and public health risks associated with untreated wastewater escalate, the development of efficient and sustainable treatment technologies has become crucial. Nano‐cellulose composites, derived from natural and renewable sources, offer significant advantages, including high surface area, superior mechanical strength, and notable biodegradability. This review explores various synthesis methods—mechanical, chemical, and enzymatic—that enhance the adaptability of nano‐cellulose composites to meet specific treatment needs. Main findings demonstrate these composites' effectiveness in removing a wide array of pollutants, including heavy metals, organic compounds, dyes, and microbial contaminants, with detailed removal capacities provided for each pollutant category in comparative tables. The potential for regeneration and reuse highlights their practical sustainability and economic viability. Future research should focus on improving production scalability and cost‐effectiveness, assessing environmental impacts and ensuring regulatory compliance to advance the application of nano‐cellulose composites in wastewater treatment. This study paves the way for these materials to become central to innovative, efficient, and eco‐friendly wastewater management strategies. © 2024 Society of Chemical Industry (SCI).

Should Zoo Food Be Chopped for Ruffed Lemurs? It's Not so Black and White.

Whole food diets in zoos have the potential to reduce microbial contamination and keeper preparation time, whilst also reducing food nutrient breakdown. Given these benefits, it is important to determine whether there is any value in chopping up food. Lemurs (Family Lemuridae) are common in zoos, with over 7500 individuals housed globally. Given their regular occurrence in collections, plus the high incidence of frugivory, lemurs are an excellent taxon to investigate food presentation effects on behavior. A study was undertaken at Beale Wildlife Park on a group of four black-and-white ruffed lemurs (Varecia variegata) to investigate food presentation and preference. Animal behavior was recorded using instantaneous focal sampling at 60 s intervals to record state behaviors and continuous focal sampling to record event behaviors in 1-h sessions. Food preference was done by recording the first three food items consumed by individual lemurs. Overall, food manipulation was significantly increased during whole food presentation allowing the lemurs to display species-specific behaviors. Feeding and foraging were highest during very chopped food condition and inactivity was lowest in very chopped food presentation. When looking at aggressive interactions, there was an increase in stealing and locomotion with food during whole food presentation, whereas biting and startle were lower. Proving high-value food items chopped and low-value food items whole could reduce aggression while reduce aggression seen over high-value food items. For food preference, sweet potato was consistently in the top three food items for all lemurs, with beetroot being the second most-picked food item. This suggests that these individuals have a strong preference for food items high in carbohydrates. Keeper preparation time was significantly reduced during whole food preparation. Further research assessing a wider range of zoo-housed species would be beneficial to assess the effects of food presentation on behavior.

American Society for Microbiology evidence-based laboratory medicine practice guidelines to reduce blood culture contamination rates: a systematic review and meta-analysis.

SUMMARYBlood cultures (BCs) are one of the critical tests used to detect bloodstream infections. BC results are not 100% specific. Interpretation of BC results is often complicated by detecting microbial contamination rather than true infection. False positives due to blood culture contamination (BCC) vary from 1% to as high as >10% of all BC results. False-positive BC results may result in patients undergoing unnecessary antimicrobial treatments, increased healthcare costs, and delay in detecting the true cause of infection or other non-infectious illness. Previous guidelines from the Clinical and Laboratory Standards Institute, College of American Pathologists, and others, based on expert opinion and surveys, promoted a limit of ≤3% as acceptable for BCC rates. However, the data supporting such recommendations are controversial. A previous systematic review of BCC examined three practices for reducing BCC rates (venipuncture, phlebotomy teams, and pre-packaged kits). Subsequently, numerous studies on different practices including using diversion devices, disinfectants, and education/training to lower BCC have been published. The goal of the current guideline is to identify beneficial intervention strategies to reduce BCC rates, including devices, practices, and education/training by providers in collaboration with the laboratory. We performed a systematic review of the literature between 2017 and 2022 using numerous databases. Of the 11,319 unique records identified, 311 articles were sought for full-text review, of which 177 were reviewed; 126 of the full-text articles were excluded based on pre-defined inclusion and exclusion criteria. Data were extracted from a total of 49 articles included in the final analysis. An evidenced-based committee's expert panel reviewed all the references as mentioned in Data Collection and determined if the articles met the inclusion criteria. Data from extractions were captured within an extraction template in the US Agency for Healthcare Research and Quality's Systematic Review Data Repository (https://srdr.ahrq.gov/). BCC rates were captured as the number of events (contaminated samples) per arm (standard practice versus improvement practice). Modified versions of the National Heart, Lung, and Blood Institute Study Quality Assessment Tools were used for risk of bias assessment (https://www.nhlbi.nih.gov/health-topics/study-quality-assessment-tools). We used Grading of Recommendations, Assessment, Development and Evaluations to assess strength of evidence. There are several interventions that resulted in significant reduction in BCC rates: chlorhexidine as a disinfectant for skin preparation, using a diversion device prior to drawing BCs, using sterile technique practices, using a phlebotomy team to obtain BCs, and education/training programs. While there were no substantial differences between methods of decreasing BCC, our results indicate that the method of implementation can determine the success or failure of the intervention. Our evidence-based systematic review and meta-analysis support several interventions to effectively reduce BCC by approximately 40%-60%. However, devices alone without an education/training component and buy-in from key stakeholders to implement various interventions would not be as effective in reducing BCC rates.

Chitosan Based Edible Coatings: Enhancing Shelf Life and Quality in Fruits and Vegetables

Chitosan-based edible coatings have gained considerable attention as a sustainable solution for harvested fruits and vegetables which are highly prone to post harvest decay and quality deterioration during storage. Chitosan, derived from chitin exhibits biocompatibility, biodegradability and antimicrobial properties making it an ideal material for edible coatings. Edible coating act as effective barriers to moisture loss, gas exchange and microbial contamination thereby enhancing the quality and extending the shelf life of produce. Research has shown that chitosan coatings can significantly reduce respiration rates, inhibit enzymatic browning and preserve the sensory qualities of fruits and vegetables, contributing to a reduction in food waste and improved food security. The effectiveness of chitosan based coating is influenced by factors such as chitosan concentration, the addition of other natural additives and the methods of application. Studies have demonstrated that chitosan coatings alone or in combination with essential oils or plant extracts effectively reduce weight loss, maintain firmness and prevent spoilage in horticultural perishables. Additionally, nano-encapsulated chitosan formulations have been explored for their enhanced protective effects offering more uniform coatings with superior barrier properties. The application of chitosan coatings is expected to evolve with the integration of nanotechnology, the development of functionalized chitosan molecules and the use of biocompatible additives. Chitosan coatings have been successfully applied commercially, such as in the preservation of perishables illustrating their potential as a sustainable solution with practical benefits for both scientific advancement and industrial application These innovations will further improve the efficacy of coatings by enhancing their moisture and gas barrier properties along with antimicrobial and antioxidant properties. Additionally, sustainability concerns are driving research into eco-friendly sources of edible coating and chitosan is a promising alternative to synthetic or chemical ingredients or fungicides. As the technology advances, chitosan based edible coatings are likely to have increased commercial adoption due to its sustainable and biodegradable nature. However, Chitosan-based coatings face challenges with solubility, application consistency, scalability, cost, allergen concerns, and varying regulatory standards.

Factors Associated with Increased Risk of Contamination in Bone Marrow Transplants.

Hematopoietic cell transplantation (HCT) remains the definitive therapeutic modality for numerous malignant and non-malignant hematologic disorders. Conventional bone marrow remains a viable donor source for HCT. However, microbial contamination of bone marrow harvests may present a risk to immunocompromised recipients. This analysis sought to identify clinical factors associated with bone marrow contamination. We analyzed a single institution experience comprising 667 unique bone marrow harvests collected between 1999 and 2021. We trended the yearly microbial contamination rate over this time span. Harvest type (autologous vs allogenic), donor age, donor sex, physician experience, total nucleated cell (TNC) count, volume collected, and TNC concentration were included in a univariate (UV) and multivariate (MV) logistic model to assess which factors were associated with contamination. Males comprised 55.8% of the donor population and the median age of the cohort was 35 [IQR: 27-45]. There were 19 autologous, 151 related allogenic, and 497 unrelated allogenic transplants in this cohort. 87 of the 667 (13.0%) harvests were contaminated and essentially all contaminants were common skin flora. The yearly contamination rates displayed substantial variability, ranging from 0% to 42.9%, with no discernible trend. Harvest type did not exhibit a significant association with contamination risk. However, male donor sex was found to be significantly associated with a higher contamination rate (18%) compared to female sex (6.8%, p < 0.001). In both UV and MV logistic models, male sex emerged as the sole factor linked to contamination risk (OR: 2.90, 95% CI: 1.65 - 5.35). This analysis represents the largest single center investigation of bone marrow harvest microbial contamination rates. Notably, it is the first to establish an association between contamination and male donor sex. We propose that this association may be attributed to differences in skin flora composition or innate immune function between sexes, general hygiene practices or possibly the result of the frequent clipping of body hair in males prior to the harvest procedure. Further research is warranted to explore the underlying mechanisms and clinical implications of this novel finding.

Bioactivity-Maximized Herbal Tea Formulation from Banana Leaf and Other Musa acuminata AAA By-Products using D-optimal mixture design

Banana leaf, being non-toxic, is often used in traditional cooking and medicine. However, its full potential is still largely unexplored. The current work aimed to screen for biological active compounds in banana leaf, and to establish an optimal formulation of tea using banana leaf and other banana by-products via a mixture design methodology. Obtained results show that banana leaf contains bioactive compounds (polyphenols, flavonoids, tannins, terpenoids), suitable for tea production. Using D-optimal-mixture-design, the optimal formulation (53% banana leaf, 30% peel, 16% corm, 1% sweet grass) was chosen for maximizing achieved total phenolic content, DPPH-inhibition and customers’ acceptance. Predicted and observed values were found to be in good agreement, pointing to the good-quality of the model. Additionally, the product met WHO-recommended limits for heavy metals and microbial contamination, assuring product safety. These findings indicate that Musa acuminata AAA by-products possess great potential as alternative sources of antioxidants for tea production.

Challenges and Future Directions in Evaporative Cooling: Balancing Sustainable Cooling with Microbial Safety

Evaporative cooling systems are gaining popularity due to their environmental benefits, particularly in reducing energy consumption and utilizing air (R-729) and water (R-718) as refrigerants. However, these systems are susceptible to microbial contamination, posing significant health risks, especially in environments where air is in direct contact with water. The article provides an in-depth analysis of the microbial risks associated with evaporative cooling systems, focusing on bacteria such as Legionella pneumophila, fungi, and other pathogens that can proliferate in the moist environments these systems create. While Legionella contamination is well-documented and frequently addressed, this study highlights the need for more comprehensive evaluation of other microbial risks. The research compares the microbial safety of evaporative cooling systems with that of traditional vapor compression cooling and examines the role of cooling pad materials and water quality in promoting microbial growth. It also underscores the limitations of current maintenance practices, which often overlook non-Legionella risks. To improve microbial safety, the paper proposes several mitigation strategies, including UV water treatment and heat exchanger surface modifications, to reduce microbial contamination. Additionally, the study calls for more detailed and consistent maintenance guidelines that cover a broader spectrum of microbial threats beyond Legionella, as well as regular monitoring of indoor air quality to ensure the safe operation of these systems in human-occupied spaces.Ultimately, the findings emphasize that, with improved microbial safety protocols and regular maintenance, evaporative cooling systems can become a sustainable and safe alternative to conventional cooling technologies in various environments.

Quantitative microbial risk assessment of antibiotic-resistant Salmonella enterica contaminating hydroponic leafy vegetables

Hydroponics plays an important role in addressing food security concerns, particularly in countries aiming to increase food self-sufficiency. However, it is vulnerable to microbial contamination, and biofilms formed in hydroponic facilities may promote horizontal gene transfer (HGT) of antibiotic resistance genes (ARGs). Eventually, the bacteria are internalized into the edible parts of the vegetable through the roots, which can lead to human exposure to antibiotic-resistant pathogenic bacteria. Microbial risk assessment can play a pivotal role in microbial risk management; however, it has not been conducted for hydroponic systems. In this study, a quantitative microbial risk assessment of hydroponic vegetables was performed using literature values regarding the concentration of Salmonella spp. in hydroponics, efficiency of HGT, probability and rate of internalization, vegetable consumption patterns, and dose-response relationships. Furthermore, a sensitivity analysis was performed to identify the factors that had a significant impact on the infection probability per single exposure event for all Salmonella spp. by calculating Spearman's correlation coefficients. The estimated annual probability of infection per person by all Salmonella spp. was 2.04×10−1, while the estimated probability of infection from Salmonella spp. that acquired ARGs was 2.54×10−6. Our sensitivity analysis showed the correlation between the occurrence of internalization and hydroponic contamination levels, highlighting the need for increased awareness and regulatory action.

The impact of temperature on the growth of Pseudomonas aeruginosa in mineral waters originated from different wells: A predictive approach

This study aimed to evaluate the behavior of Pseudomonas aeruginosa (PSA) in natural mineral water sourced from three different extraction wells and stored at various temperatures (10, 12, 20, 23, and 30 °C) to calculate the kinetic growth parameters of this microorganism through predictive modeling. The physicochemical characterization of waters was also evaluated at the time of collection, and included the analysis of 40 different minerals, and quality parameters such as pH, conductivity, oxidation-reduction potential (ORP), total dissolved solids (TDS), salinity (PSU), and temperature (T). PSA survived in raw mineral water incubated at 12, 20, 23, and 30 °C; however, no growth was observed at 10 °C. Growth curves started with an initial population of ~ 2.5–3 log CFU/mL, and final PSA populations ranged from 3.5 to 4.9 log CFU/mL. The maximum specific growth rate (μmax) at 30 °C varied among the wells, with Well P-07 showing the highest growth rate (0.2 h−1), followed by Well P-08 (0.195 h−1) and well P-01 (0.133 h−1). At 12 °C, well P-01 exhibited the highest growth rate (μmax = 0.22 h−1), indicating a influence of mineral composition in the growth of PSA. The lag time (λ) also varied, with minimum values of 2.4 ± 0.1 h at 30 °C and maximum values of 41.6 ± 0.2 h at 12 °C. From these primary estimated parameters, it was possible to obtain five robust secondary models to describe the influence of temperature on the maximum growth rates and lag phase of PSA in the well. The estimated PSA growth parameters at 20 and 23 °C were subjected to a hierarchical cluster analysis and correlation plots to verify the influence of the physicochemical composition of the waters on the PSA behavior at each well's specific annual average temperature. This analysis confirmed a positive relationship (p < 0.05) between the presence of minerals (Ca, Fe, Sr, Mn, Na) and ions (SO4−3, Cl−) and the PSA lag phase time. These results underscore the need for tailored water quality management strategies that consider chemical composition and temperature to address specific microbial contamination risks.