High Contamination Rate Research Articles

Assessment of Microbial Contamination and Antibiotic Resistance Profiles of Bacteria on Nigerian Currency Notes: Implications for Public Health and Antimicrobial Resistance

Background: Many microbes have been associated with the contamination of Naira notes, and most of these microbes have shown high resistance to antimicrobials, with different resistance profiles including multidrug-resistant (MDR), extensively drug-resistant (XDR), and pandrug-resistant (PDR). Therefore, the aim of this study was to investigate the microbial contamination and antibiotic resistance profiles of isolated microorganisms on Nigerian currency notes, emphasizing their public health implications. Methods: A total of 112 currency notes, spanning all eight denominations, were collected from rural (Oyan) and urban (Osogbo) regions in Osun State, Nigeria. Microbial isolation and identification were performed using standard culture techniques, while antibiotic susceptibility was assessed via the Kirby-Bauer disc diffusion method. Data were analyzed using SPSS. Results: Microbial analysis revealed high contamination rates, with Klebsiella sp (35.7% rural, 23.2% urban) and Staphylococcus aureus (28.6% rural, 26.8% urban) being the most prevalent bacterial isolates. Aspergillus sp was the dominant fungal contaminant, particularly in rural areas. Polymer-based notes exhibited lower contamination compared to paper-based notes. Antibiotic susceptibility tests highlighted alarming multidrug resistance (MDR), with Staphylococcus aureus showing high resistance to Penicillins and Cephalosporins. Pseudomonas aeruginosa displayed extensive drug resistance (XDR) to multiple antibiotic classes, leaving limited treatment options. Conclusion: Nigerian currency notes are significant reservoirs of microbial contamination and multidrug-resistant pathogens, posing severe public health risks. The study underscores the need for improved hygiene practices, public awareness campaigns, and a transition to polymer-based notes. Strengthened antibiotic stewardship programs and regulatory measures are essential to combat rising antimicrobial resistance and prevent pathogen dissemination through currency handling.

Bacterial community in fresh fruits and vegetables sold in streets and open-air markets of Dakar, Senegal

In the context of food transition, the agrifood sector has experienced increasingly strong demand for horticultural products. Fresh fruits and vegetables are mainly vehicles of microorganisms, including pathogens that cause human infections. Food safety and compliance with health standards in the fruits and vegetable value chain are significant concerns and multiple challenges, given the prevalence of foodborne pathologies in Southern countries, particularly in Senegal. This study aimed to describe the bacterial community and assess the microbiological quality of a range of fruits and vegetables sold on street stalls and open-air markets in Dakar, the capital city of Senegal. Samples purchased in seven sites were analyzed to isolate Escherichia coli (E. coli), Salmonella spp. and Vibrio spp. Some primary samples with a positive microbiological culture were subjected to DNA extraction and subsequent metagenomic analysis. A total of 240 fresh fruit and vegetable samples were collected, including lettuce (n = 40), tomatoes (n = 40), mango slices (n = 40), onion slices (n = 40), mint leaves (n = 40), strawberries and grapes (each n = 20). Of these samples, 50.83% (122/240) and 60.41% (145/240) were contaminated with E. coli and Vibrio spp., respectively, while Salmonella was not isolated in any product. E. coli and Vibrio spp. contamination levels, 1.3 103 to 6 106 Colonies Forming Units per gram of sample (CFU/g) and 4.55 102 to 8.73 106 CFU/g, respectively, were significantly above the thresholds acceptable for human consumption. The most contaminated samples were lettuce, with a prevalence of 98% (39/40) for E. coli and Vibrio spp. followed by mint leaves with 100% (40/40) and 93% (37/40) of the samples containing E. coli and Vibrio spp. respectively. Out of 46 samples sequenced, the metagenomic analysis revealed high contamination rates for E. coli, Vibrio spp. and Salmonella spp., with 100%, 67.39% and 93.47% of prevalence, respectively. On the other hand, the alpha diversity analysis shows high bacterial diversity in lettuce and mint leaf samples, while the beta diversity analysis highlighted the presence of two major clusters. Our results stress the need for a surveillance system that extends this investigation to a national scale while increasing the number of sampling sites and products analyzed.

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 versus 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 to 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 < .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 to 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.

Development of an on-site real-time dual detection method for norovirus and rotavirus using RPA-CRISPR/Cas12,13

Norovirus (NoV) and rotavirus (RoV) are the two most prevalent foodborne viruses responsible for infectious gastroenteritis, with high contamination rates in fruits and vegetables. Monitoring and accurately identifying these pathogens are crucial for preventing human foodborne illnesses. Therefore, developing a rapid, highly specific, and sensitive detection method for NoV and RoV is essential. An on-site real time dual detection method for Noroviruses of genogroup I (GI-NoV) and Rotavirus of group A (A-RoV) was established by integrating Recombinase Polymerase Amplification (RPA) with the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-associated protein (Cas) system. The DNA amplification products generated by multiplex RPA were simultaneously detected by Cas12a and Cas13a in a single tube. Utilizing the trans-cleavage preferences of Cas12a and Cas13a, the specific cleavage of DNA and RNA probes carrying different fluorescent groups within the reaction system was achieved. The results indicated that the established dual detection method had a detection limit of 102 copies/μL for GI-NoV and A-RoV. Specificity assay showed the established method only detected GI-NoV and A-RoV, with no cross-reactivity with other four foodborne viruses. Furthermore, the detection capability of this method was validated in strawberries and lettuce. The method enables the simultaneous detection of GI-NoV and A-RoV in fresh produce at 37 °C within 60 min. Detection results were interpreted by measuring fluorescence values or observing color changes under blue light at the end of the reaction. This technique required minimal instrumentation, provided excellent visual representation of results, and served as a technical reference for the rapid on-site detection of foodborne viruses in food matrices.

Use of human-centric and participatory design for modifying a daily environmental cleaning checklist: a quality improvement study.

A major tenet of healthcare environmental cleaning focuses on high-touch surfaces (HTSs). HTSs have high rates of contamination, yet cleaning compliance remains low, particularly in patient-occupied rooms. This quality improvement study aimed to use human-centric and participatory design to modify an HTS cleaning checklist and conduct initial trial and evaluation.

Statistical analysis of parameters affecting Legionella and total cell growth in premise plumbing systems within buildings: A field study based on an empirical data set

During the storage and distribution of water in buildings, the excessive growth of pathogens can deteriorate the quality of drinking water. This study aims to investigate the factors influencing this growth and propose technical measures for prevention. The analysis is based on an empirical data set comprising 1361 samples from 204 domestic premise plumbing systems. In 14 systems, ultrafiltration plants were installed as microbiological barriers. Legionella cultivation and flow cytometry were used to determine microbiological properties. The study identified elevated total cell counts in tapping valves and pipe end lines in numerous premise plumbing systems, indicating prolonged water stagnation prior to sampling, which facilitates microbiological growth. Higher contamination rates were observed in these systems, with peripheral taps often being contaminated in lieu of the entire system. These systems were classified as microbiologically unstable due to the relevantly higher total cell numbers at hot water taps compared to the hot water tank (>25%). Furthermore, these systems exhibited a Legionella contamination rate that was 22.3% higher than in microbiologically stable systems. In some cases, peripheral contaminations may not accurately represent the entire premise plumbing system. Increasing the discard volume during sampling from 1 L to 3–5 L could provide more precise results during standard testing. Legionella species were primarily detected in the first 1 L of water after tap activation. Additionally, statistically significant relationships were observed between direct temperature and total cell number, as well as between the presence of ultrafiltration and total cell numbers at cold water taps.

Investigation the Frequency of Fungal Contamination in Surgical Instruments

Background: Fungal contamination of surgical instruments poses a significant risk to patient safety, potentially leading to surgical site infections and other severe complications. By examining contamination levels both immediately after opening sterile sets and after two hours of environmental exposure, it becomes possible to assess contamination reduction strategies. Objectives: The aim of this study was to identify which instruments and operating rooms were most affected by fungal contamination. Understanding the extent of this contamination is critical to developing more effective sterilization protocols, improving infection control practices, and ultimately enhancing patient safety in surgical settings. Methods: This study was conducted on surgical instruments at Ali ebn Abi Talib Zahedan Hospital in 2023, across seven operating rooms (emergency, general surgery, gynecology, and urology). Samples were randomly collected under sterile conditions to prevent external contamination. The collected samples were cultured in Sabouraud Dextrose Agar (SDA), and data were analyzed using SPSS version 26. Results: The findings revealed that different surgical instruments, such as Pinzette (without teeth), Allis forceps, Babcock forceps, curved clamps, Gully pots, receivers, retractors, ring forceps, and towel clamps, were contaminated with fungal pathogens within two hours of opening the sterile sets. The highest contamination rates were observed in general surgery (39%), followed by emergency (29%), urology (21%), and gynecology (11%) rooms. The most common fungal contaminants were Aspergillus spp., yeast, and Penicillium spp. Conclusions: This study highlights the challenge of maintaining sterility in surgical environments post-sterilization, as fungal contamination reappeared on surgical instruments within two hours despite the initial sterilization. These findings emphasize the need for enhanced infection control measures, advanced environmental controls, and regular monitoring to reduce the risks associated with fungal contamination in surgical settings.

FUNGAL CONTAMINATION IN FRESH RAISIN JUICE IN MOSUL CITY

Background: Fungal contamination in food and beverages, including fruit juices, poses significant health risks. Specific Background: This study investigates the extent of fungal contamination in fresh raisin juice collected from Mosul City and its suburbs, including Bashiqa, Al-Hamdaniya, Bartella, Al-Shekhan, Aqra, and Dohuk, over a period from January 2023 to April 2024. Knowledge Gap: Despite the potential for fungal contamination in fruit juices, detailed analyses of specific contamination rates and fungal species in this region have been lacking. Aims: The study aimed to identify and quantify fungal contamination in fresh raisin juice samples using Potato Dextrose Agar and Sabouraud Sucrose Agar, and to characterize the fungal isolates morphologically, biochemically, and molecularly. Results: Of the 40 samples tested, 100% were contaminated with fungi, yielding 121 isolates of various species. The highest contamination rates were observed for Candida spp. and Aspergillus spp., each constituting 27.3% of isolates. Other notable contaminants included Wickerhamomyces anomalus (12.39%), Saccharomyces cerevisiae (11.57%), and Rhodotorula spp. (8.26%). Additionally, lower rates of contamination were found for Penicillium spp., Exophiala dermatitidis, and several other species. Novelty: The study revealed a high prevalence of fungal contamination, including the identification of a novel Candida oleophila strain (GenBank accession PP961930.1). Implications: These findings highlight the significant fungal contamination in fresh raisin juice, which could have implications for food safety and quality control. The identification of specific fungal species and the novel strain underscores the need for stringent monitoring and improved processing practices to mitigate contamination risks.

Fisioterapia pulmonar pós-COVID-19: um estudo de caso

The COVID-19 pandemic emerged in Wuhan in late December 2019, spreading across the world with a high rate of contamination. The COVID-19 covers a large number of sequelae in the respiratory system, which entails a need for intense physiotherapy intervention. Thus, it was objected in the present study to evaluate the effectiveness of post-COVID-19 pulmonary physiotherapy in a patient at a Physiotherapy Clinic School in the city of Montes Claros, MG. For this, it was used the case study as a methodology, which was carried out with a male patient, 62 years old, brown, divorced, with one child, with no report of previous illnesses, coming from the city of Montes Azul-MG, admitted in a Physiotherapy Clinic School with Severe Acute Respiratory Syndrome, post-COVID-19, being submitted to tests to assess their perceptions of exertion through the modified Borg scale, that is, the Six-Minute Walking Test and the muscle strength based on the Kendall scale. In view of the conduct performed, it is concluded that physiotherapy rehabilitation is an important resource in post-Covid-19 treatment, with regard to the proportion of sequelae caused by such infection.

Unseen riverine risk: Spatio-temporal shifts of microplastic pollution and its bioavailability in freshwater fish within the Ikopa River urban system.

Growing concern over microplastic pollution, driven by their widespread accumulation in the environment, stresses the need for comprehensive assessments. This study investigates the spatial and temporal distribution of microplastics in the Ikopa River (Antananarivo - Madagascar), which flows through a densely populated area, and examines their correlation with contamination levels in local fish species. By analyzing upstream and downstream stations across wet and dry seasons, only a notable increase in microplastic concentration downstream during the wet season was observed, ranging from 138.6 ± 9.0 to 222.0 ± 24.5 particles m-3, with polyethylene-co-vinyl acetate being the predominant polymer at 62.3 ± 5.13% of the total sampled polymers. This distribution underlines the impact of urban activities on pollution levels. Fish species, gambusia and Nile tilapia, were assessed for microplastic occurrence in gills and gastrointestinal tracts. Higher contamination rates were found in gambusia, enlightening the influence of feeding behaviour and fish habitat on microplastics contamination. Ingestion of microplastics directly from the water column was evident in both species, with the detection of high-density plastics such as polytetrafluoroethylene and polyvinyl chloride suggesting likely sediment contamination. This research highlights the widespread contamination of aquatic environments and its direct impact on local wildlife, pointing to a clear requirement for effective pollution management strategies.

Comparative analysis of Salmonella contamination in pork slaughtering facilities: Implications for food safety

Salmonella is a major cause of global gastroenteritis, with pig-based products being significant sources. The Hazard Analysis Critical Control Points (HACCP) standard ensures food safety by identifying Salmonella contamination dynamics and improving control strategies. A study in Thailand found that pork in HACCP-certified slaughterhouses had significantly reduced Salmonella contamination and antimicrobial resistance (AMR) compared to in non-HACCP facilities. However, both types of slaughterhouses still experience Salmonella contamination during the slaughtering process, with limited information available on contamination sources and critical steps. The current study compared Salmonella distribution and AMR profiles in two Thai pig slaughterhouses, one of which implemented HACCP. A total of 570 samples, including feces, carcass swabs, and environmental samples, were cultured for Salmonella and investigated for AMR. The overall prevalence was 24.7%, being significantly lower at the HACCP-compliant slaughterhouse 1 (S1, 13.7%) compared to the non-compliant slaughterhouse 2 (S2, 41.2%) (P = 0.03). Slaughterhouse-specific Salmonella prevalence varied across slaughtering steps, with S2 showing high contamination rates in carcasses post-final washing, persisting until post-cutting. Additionally, specific strains were found in various locations, including feces, carcasses, workers' hands, cutting boards, and knives before and during operations. Conversely, carcasses post-final washing in S1 had the lowest contamination. Real-Time PCR identified higher Salmonella contamination and a greater copy number in S2-cutting carcasses compared to in S1. Overall, 42.6% of isolates were multidrug-resistant, showing strong resistance to ampicillin and tetracycline, while 8.51% produced extended-spectrum beta-lactamase (ESBL). It is evident that continuous monitoring and control measures are crucial to mitigate contamination and antibiotic resistance in foodborne pathogens such as Salmonella. The current study confirms that adherence to HACCP in slaughterhouses significantly reduces Salmonella in pork products. However, contamination levels rose notably post-cutting in both HACCP and non-HACCP facilities, with equipment, other carcasses, and workers' hands acting as sources of contamination. Rigorous monitoring during cutting processes is essential to identify and mitigate contamination sources, thereby improving food safety in meat processing facilities.

ИЗУЧЕНИЕ БИОЛОГИЧЕСКОЙ ПОЛНОЦЕННОСТИ СПЕРМАТОЗОИДОВ В СПЕРМЕ С БАКТЕРИАЛЬНОЙ ОБСЕМЕНЕННОСТЬЮ

The aim of the study is to investigate the relationship between bacterial contamination of bull semen and the biological value of spermatozoa, as well as reproductive performance. The object of the study was Holstein bulls (n = 17). The material for the study was frozen-thawed semen of bulls in the amount of 61 samples. Microbiological studies of sperm doses were carried out using standard nutrient media in accordance with GOST 32222-2013. The total number of microorganisms was calculated by the number of grown colony-forming units (CFU/ml) in 1 cm3, with subsequent determination of their morphological pro-perties. Sperm motility and morphology were determined using the Argus CASA program. The state of DNA in spermatozoa was studied by the acridine orange test (AO test) using a fluorescence microscope. The study revealed a high positive correlation (r = +0.940**) between the number of microorganisms in sperm and pathology in individual sperm segments. Analysis of variance confirmed a statistically significant effect of the number of microorganisms on sperm morphology F = 123.2 (p=0.000). The correlation relationship between the fragmentation index and the content of microorganisms has a high value (r = +0.965**). Sperm motility negatively correlates (r = –0.768**) with the number of microorganisms (CFU/ml). In the presence of Mycoplasma spp in the samples, the number of cows with fruitful insemination was 35.5 % due to reduced motility, morphology and high fragmentation of sperm DNA (58 %). Sperm motility in samples containing Mycoplasma spp averages 24.5 %, while in samples without these microorganisms it is 48.9 %. Thus, it can be assumed that the presence of Mycoplasma spp in samples and high bacterial contamination rates lead to to lower reproductive performance in bulls.

Contamination of Streptococcus suis and S. suis Serotype 2 in Raw Pork and Edible Pig Organs: A Public Health Concern in Chiang Mai, Thailand.

Streptococcus suis is one of the most important zoonotic pathogens causing serious diseases in both pigs and humans, especially serotype 2. In northern Thailand, there is a notable prevalence of S. suis infection in humans and transmission has occurred mainly through the consumption of raw pork products. Despite the continued practice of consuming raw pork in this region, limited data exist regarding S. suis contamination in such products. Therefore, this study aimed to assess the prevalence of S. suis and S. suis serotype 2 in retail raw pork meat and edible pig organs sold in Chiang Mai city, Thailand. A total of 200 samples, comprising raw pork meat and edible pig organs, were collected from nine fresh markets in Chiang Mai city between May and July 2023. Samples were prepared and cultured in Todd-Hewitt broth. Bacterial DNA was extracted and tested for any serotypes of S. suis and serotype 2 using loop-mediated isothermal amplification (LAMP) techniques. The study revealed contaminations of S. suis and serotype 2 at rates of 84% and 34%, respectively, with a higher prevalence observed in pig organs compared to raw pork. Both S. suis and serotype 2 were detected across all nine fresh markets investigated. The prevalence of S. suis remained consistently high throughout the study period, whereas serotype 2 showed peaks in May and July. These high rates of contamination indicate that people who consume or work in close contact with raw pork or edible pig organs are at a high risk of S. suis infection. Urgent implementation and maintenance of food safety campaigns and public health interventions are crucial for disease prevention and control.

Blood Culture Contamination Mitigation: Sustaining Success and Stewardship Systemwide

Background: False-positive blood cultures compromise care; extended stays, Clostridioides difficile risk increases and renal woes tagged to antibiotic alms contribute to the doubling of patient in-hospital mortality that is observed relative to true negative diagnostic results. False-positive affiliated central line-associated bloodstream infection reports can further obfuscate the quality of care provided. Between personnel performance pressures, laboratory resource losses and the risk for financial penalty under Value-Based Purchasing and Hospital-Acquired Condition Reduction Programs (Centers for Medicare &amp; Medicaid Services), it becomes difficult to brush aside the burden of a non-zero blood culture contamination rate. Following unsuccessful and unsustainable endeavors that included educational exercise and waste tube employment, initial-specimen diversion devices designed to shift performance burdens from technicians to technology were co-opted in an effort to secure reliable blood culture contamination rate reductions. Methods: A 3.6% blood culture contamination rate was observed systemwide prior to intervention, which began in 2020. Among seventeen facilities that share a data system, twelve co-opted initial-specimen diversion device technology as the evidence-based anchor to a trifurcate intervention strategy that included value analysis and cultural curation. Results: The 2023 systemwide blood culture contamination rate was 1.95%; down from 2.8% in 2022 and 3.2% in 2021. The average cost per false-positive event was $2,111, with intervention amounting to systemwide savings of $4.1 million in 2023 as approximately 1,920 patients avoided false-positive incidents. Critical to year-over-year systemwide uptick in adoption of interventive technology was consistent and near real-time communication to caretakers regarding outcomes. Conclusion: The sustained success of the multifactorial solution showcased herein stems from the coupling of an evidence-based action with an ongoing assessment of value and communication channels carefully constructed to celebrate and perpetuate value observed. Layered uncertainties often cloud the crux of a multifactorial solution to a complex conundrum; for many decades the literature-supported solution to high blood culture contamination rates was to educate every person involved in every possible way. Only recently, following recommended practice revisions endorsed by the Clinical and Laboratory Standards Institute and Centers for Disease Control and Prevention, did it become apparent nationwide that education alone was insufficient; some contaminant pathways persist without meticulously mechanical closure. Antimicrobial stewardship requires the respectful removal of adaptable pressures from microorganisms, but the inverse is equally important; by setting an ambitious systemwide blood culture contamination rate target of 1% or less, it is hoped that all facilities involved herein respond to this pressure with optimism, introspection and innovation.

Characterization of the novel phage vB_BceP_LY3 and its potential role in controlling Bacillus cereus in milk and rice

Bacillus cereus is a foodborne pathogen that induces vomiting and diarrhea in affected individuals. It exhibits resistance to traditional sterilization methods and has a high contamination rate in dairy products and rice. Therefore, the development of a new food safety controlling strategy is necessary. In this research, we isolated and identified a novel phage named vB_BceP_LY3, which belongs to a new genus of the subfamily Northropvirinae.This phage demonstrates a short latency period and remains stable over a wide range of temperatures (4–60 °C) and pH levels (4–11). The 28,124 bp genome of LY3 does not contain any antibiotic-resistance genes or virulence factors. With regards to its antibacterial properties, LY3 not only effectively inhibits the growth of B. cereus in TSB (tryptic soy broth), but also demonstrates significant inhibitory effects in various food matrices. Specifically, LY3 treatment at 4 °C with a high MOI (MOI = 10,000) can maintain B. cereus levels below the detection limit for up to 24 h in milk. LY3 represents a safe and promising biocontrol agent against B. cereus, possessing long-term antibacterial capabilities and stability.

Bacteriological Examination of Drinking Water from Different Sites at a Tertiary Care Hospital Campus of Western India

Introduction: This study presents a detailed investigation into the drinking water quality at campus, focusing on various drinking water sources. Access to safe and clean drinking water is crucial for maintaining public health. In this study, we aimed to assess the drinking water quality at Bhaikaka University campus by collecting and analyzing drinking water samples from various sources. The research focused on identifying the presence of coliform bacteria, particularly E. coli, and evaluating the extent of contamination at different sites. Methodology: A total of 68 drinking water samples were collected from diverse drinking water sources across the campus. The MPN technique was employed to analyze the samples for the presence of coliform bacteria. The sites included all the buildings from the campus of Bhaikaka University. Results: Out of the 68 drinking water samples, 12 samples (17.64%) tested positive for contamination, while 56 samples (82.35%) showed no contamination. The highest number of positive samples (5 out of 15) was observed at Hospital, indicating the need for targeted interventions. Conclusion: This study provides valuable insights into the drinking water quality at campus with the identification of specific sites with higher contamination rates allows for targeted interventions. Future research can build upon these findings to implement effective strategies for sustainable water management on the campus.

Investigation of Bacterial Contaminants and Their Antibiotic Susceptibility on Yemeni Banknotes in Aden City, Yemen

Background: Banknotes are among the objects frequently exchanged between people and can serve as a vehicle for the transmission of infectious agents. Therefore, the present study aimed to isolate and identify potentially pathogenic bacteria on Yemeni banknotes collected from various municipal sources in Aden city, south of Yemen. In addition, the susceptibility of the isolated bacterial species to commonly used antibiotics was tested. Methods: A descriptive cross-sectional study was conducted on 240 Yemeni banknotes of various denominations randomly collected from people from different places in Aden city between November 2019 and February 2020. Swabs from the surfaces of banknotes were streaked onto blood agar, chocolate agar, mannitol salt agar and MacConkey agar and incubated at 37 °C for 48 hours. After isolation, bacterial species were identified and tested for their susceptibility to commonly used antibiotics using established techniques. Results: Out of 240 banknotes examined, 98.3% were found to be contaminated with bacteria, with a 95% confidence interval (CI) ranging from 96 to 99. Among the isolated bacteria, 17.4% were Gram-positive cocci, 33% were Gram-negative bacilli and 49.6% were a combination of both. The mean plate counts of bacterial colonies ranged from 163.6±51.0 colony-forming units (CFU)/ml (95% CI: 147.3–179.9) for banknotes with a denomination of 100 Yemeni rials (YRIs) to 257.1±52.0 CFU/ml (95% CI: 240.5–273.7) for banknotes with a denomination of 50 YRIs. Staphylococcus aureus was the most frequently isolated bacterial species, detected on 66.9% of contaminated banknotes, followed by Escherichia coli (60.6%) and Pseudomonas aeruginosa (42.8%). Regarding antibiotic resistance, most S. aureus isolates showed resistance to ceftazidime (80.1%), followed by ceftriaxone (78.2%), ampicillin (77.6%) and co-trimoxazole (69.3%). On the other hand, most E. coli isolates showed resistance to amoxicillin/clavulanate (84.6%), followed by ceftriaxone (79.7%), ceftazidime (76.9%), ampicillin (58.3%) and ciprofloxacin (58.1%), while most P. aeruginosa isolates showed resistance to ceftriaxone (83.5%), followed by ceftazidime (80.2%) and ciprofloxacin (54.9%). Conclusion: Most banknotes in circulation in Aden city are contaminated with bacteria, predominantly S. aureus and E. coli, with lower denomination banknotes tending to have higher contamination levels. The high contamination rate of banknotes raises concerns about their potential in transmitting infectious diseases and emphasizes the advantages of transitioning to cashless payments. A substantial proportion of bacterial species isolated from banknotes exhibit resistance to commonly used antibiotics, raising concerns about the possible transmission of multidrug-resistant bacteria through the exchange of banknotes. Therefore, it is necessary to raise awareness and improve hygiene practices to minimize the transmission of bacteria and antibiotic resistance through the exchange of banknotes.

Restricted-Access Media Column Switching Online Solid-Phase Extraction UHPLC-MS/MS for the Determination of Seven Type B Trichothecenes in Whole-Grain Preprocessed Foods and Human Exposure Risk Assessment.

With increasing health awareness and the accelerating pace of life, whole-grain prepared foods have gained popularity due to their health benefits and convenience. However, the potential risk of type B trichothecene toxins has also increased, and these mycotoxins in such foods are rarely regulated. In this study, a quantitative method combining a single-valve dual-column automatic online solid-phase extraction system with ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed for the first time using restricted-access media columns. This method can simultaneously determine trace residues of seven type B trichothecenes within 15 min. The method is convenient, sensitive (limit of detection and quantification of 0.05-0.6 μg/kg and 0.15-2 μg/kg, respectively), accurate (recovery rates of 90.3%-106.6%, relative standard deviation < 4.3%), and robust (>1000 times). The established method was applied to 160 prepared food samples of eight categories sold in China. At least one toxin was detected in 70% of the samples. Whole-wheat dumpling wrappers had the highest contamination rate (95%) and the highest total content of type B trichothecenes in a single sample (2077.3 μg/kg). Exposure risk assessment indicated that the contamination of whole-grain prepared foods has been underestimated. The total health risk index of whole-wheat dumpling wrappers, which are susceptible to deoxynivalenol, reached 136.41%, posing a significant threat to human health. Effective measures urgently need to be taken to control this risk.

Deoxynivalenol Induces Intestinal Epithelial Barrier Damage through RhoA/ROCK Pathway-Mediated Apoptosis and F-Actin-Associated Tight Junction Disruption.

Deoxynivalenol (DON) poses a serious global food safety risk due to its high toxicity and contamination rate. It disrupts the intestinal epithelial barrier, allowing exogenous toxins to enter the circulation and resulting in sepsis and systemic toxicity. In this research, 32 male Kunming mice and Porcine Small Intestinal Epithelial (IPEC-J2) cells were treated with DON at 0-4.8 mg/kg (7 d) and 0-12 μM (24 h), respectively. Histopathological results revealed that DON disrupted the intestinal epithelial barrier, causing apoptosis and tight junction (TJ) injury. Immunofluorescence and protein expression results showed that DON-induced p53-dependent mitochondrial pathway apoptosis and fibrillar actin (F-actin)-associated TJ injury and that the RhoA/ROCK pathway were activated in mice jejunal tissue and IPEC-J2 cells. Pretreatment with RhoA or ROCK inhibitors (Rosin or Y-27632) maintained DON-induced apoptosis and F-actin-associated TJ injury in IPEC-J2 cells. Thus, DON induces damage to the intestinal epithelial barrier through the RhoA/ROCK pathway-mediated apoptosis and F-actin-associated TJ disruption.

Bacterial Contamination of Drinking Wells in Makurdi Metropolis

This study was carried out to assess the bacterial contamination of drinking wells in Makurdi metropolis. Fifteen (15) untreated water samples, five (5) each were collected from wells in High Level, Wurukum and Wadata areas for physicochemical and bacteriological analysis was done using pour plating and the bacteriological quality was assessed by measuring the total viable, total coliform and fecal coliform counts of bacteria in the samples using Mac Conkey agar and Nutrient agar. The results of the analysis showed that the pH ranged from 6.70 ± 0.16 to 7.40± 0.87, the temperature levels ranged from 28.72 ± 0.04 to 28.87 ±0.05; biological oxygen demand values ranged from 0.02 ±0.04 to 0.02 ± 0.41; the dissolved oxygen values ranged from 1.50 ±0.16 to 170 ± 0.14 while the Electrical conductivity values ranged from 599.20 ±88.98 to 1582.80±199. The results also showed the total viable count, total coliform count and fecal coliform counts ranging from 75.80±16.01cfu/ml to 117.40±34.45cfu/ml; 5.60±5.13cfu/ml to 6.60±6.88cfu/ml and 0.40±0.89cfu/ml to 4.20±3.77cfu/ml respectively. The total viable counts ranged from 75.80±16.01 to 117.40±34.4 (Wadata having the highest and Wurukum having the least), the total coliform counts ranged from 5.60±2.61 to 6.60±6.88 while the fecal coliform count ranged from 0.40±0.89 to 4.20±3.77. The variation in Total Viable Count (TVC) across locations could be as a result of localized factors influencing microbial populations and geographical differences such as land use, anthropogenic activities, and environmental conditions. The bacterial isolates were Bacillus, Escherichia coli, Klebsiella spp, Proteus spp, Enterobacter spp, and Staphylococcus spp. The frequency of occurrence and prevalence percentages of the bacteria isolated from the well water samples show that Klebsiella spp had the highest percentage (23.33%) while Enterobacter spp and Escherichia coli had the least prevalence percentage, representing 10.00% each. Overall, High Level had the highest contamination rate, accounting for 43.33% of the total contamination while Wurukum had the least contamination, representing 23.33% of the total contamination. The distribution patterns of bacterial isolates among the studied locations illuminate discernible trends. The prevalence of pathogenic bacteria in well water sources could be possibly linked to higher urbanization and population density, highlighting the dynamic and site-specific nature of microbial communities. The study highlights the importance of using specific plans to manage water quality. These plans should take into account the special features of each area.