Microorganism Contamination Research Articles

Natural pigments and biogas recovery from cyanobacteria grown in treated wastewater. Fate of organic microcontaminants.

Natural pigments and biogas recovery from cyanobacteria grown in treated wastewater. Fate of organic microcontaminants.

Assessment the effectiveness of disinfection of household wastewater using a UV complex under experimental conditions

Introduction. One of the most effective and economically justified methods of inactivation water treatment is disinfection using UV irradiation. UV disinfection is characterized by the absence of an aftereffect, which is an undeniable advantage for wastewater treatment, since adverse environmental effects on the wastewater receiving water body are excluded. The main technological parameter that ensures proper disinfection is the UV dose. The purpose of the study is the confirmation of the effectiveness of using the technology of UV disinfection of water with a dose of at least 30 mJ/cm2 in relation to sanitary-indicative and pathogenic microorganisms that are present in the wastewater of the Moscow metropolis. Materials and methods. UV disinfection units DUV-1-87-N were used to conduct the experiment, providing a UV dose of at least 30 mJ/cm2 for water disinfection and an open UV irradiator SVETOLIT 50 for air disinfection manufactured by company LIT. Results. The use of a UV dose of at least 30 mJ/cm2 for disinfection of water with a high degree of contamination of microorganisms ensures the level of contamination of microorganisms to meet the requirements of sanitary legislation in force on the territory of the Russian Federation for disinfected wastewater allowed discharging into surface waters. Limitations. The limitations of the study are related to the equipment used for applying UV irradiation, water turbidity, and the sensitivity of microorganisms of different taxonomic groups to UV irradiation. Conclusion. The results of the conducted experimental study can serve a justification for the UV radiation dose of 30 mJ/cm2 used for effective disinfection of viral and bacterial contamination of water with high levels of microbial contamination up to the standard permissible level of microbial contamination (in accordance with SanPiN 1.2.3685-21) of treated wastewater suitable for discharge into surface waters.

Assessment of food safety in fresh pork from markets in Ninh Kieu District, Can Tho City

The study aims to evaluate the contamination of microorganisms, food additives of fresh pork that was sold in the Ninh Kieu district, Can Tho City. The results of research showed the contamination of Escherichia coli and total aerobic bacteria in fresh pork is 100%, and the density exceeds the acceptable levels of TCVN 7406:2019. The samples were collected from the supermarkets, which are contaminated microorganisms lower than others that were collected from the traditional markets and the retail shops. Moreover, the samples collected in the afternoon had the level of contaminated microorganisms lower than others that were collected in the morning. The results of statistics showed the correlation among the criteria of meat quality (color L*, texture, pH, temperature, NH3) and the contamination of microorganisms in fresh pork (Escherichia coli and total aerobic bacteria). In a total 148 collected samples, 4.1% of samples were positive with borate, 12.16% of samples were positive with nitrite. In particular, the borate couldn’t be detected in the samples that had been collected from supermarkets. The fresh pork collected in the afternoon was positive with borate and nitrite, because the sellers intentionally added it to improve the freshness and prolong the shelf life of meat.

The relationship between nutrition and intestinal health in newborn lambs

Abstract As with all animals, the period in their lives when lambs are most vulnerable is the period before and immediately after birth. Because this period (the suckling period) is the period of clinging to life in an environment open to microorganism contamination after the sterile uterine environment. It is very important that this difficulty can be reduced with good care and feeding practices that must be applied during this period and that the puppy lamb can have a healthy and highly productive life during this risky period and in the future. Regulation and enhancement of the intestinal microbiome is a crucial aspect for optimizing the health and performance of farm animals. This is mainly because diet and management practices greatly affect the intestinal microbiota, resulting in changes in nutrient utilization and the immune system. The intestinal health of newborn lambs is affected by feeding manipulations, as in other ruminants. In this review, the suckling period and digestive system development in newborn lambs are mentioned. Additionally, this review discusses some practices to manipulate intestinal development and microbial colonization in order to improve the production and health of newborn lambs at an early age when they are most susceptible to enteric diseases.

Hair treatment products containing pigeon pea oil as chemical properties and anti-oxidant activity

The comparing small type (T9) and big type (ICP 7035), which were extracted by hexane maceration, this study looks at the properties of pigeon pea oil in hair treatment products. It finds that the percentage yield of big seed (ICP 7035) oil is higher than that of small seed (T9) oil, at 9.64 ± 0.10 and 9.32 ± 0.08, respectively. A study on the chemical properties of the oil revealed values for saponification, acidity, iodine, and peroxide. In all trials, T9 outperformed ICP 7035 in terms of test results, demonstrating the presence of fatty acids in the molecular components of triglycerides. Compared to ICP 7035, T9 had a lower molecule weight and a lower saturation level, making it less susceptible to oxidative lipid disorder and the tendency to deplete oil. The flavonoid content of T9 is higher than that of ICP 7035, equal to 27.76 ± 0.65 mg GAE g-1 extract and 25.90 ± 0.69 mg GAE g-1 extract, respectively. The flavonoid content of T9 is higher than that of ICP 7035, equal to 20.67 ± 0.58 mg QE g-1 extract and 18.76 ± 0.65 mg QE g-1 extract, respectively. The DPPH test showed that T9 was a stronger antioxidant than ICP 7035, with amounts of 0.26 ± 0.04 mg g-1 of extract and 0.35 ± 0.05 mg g-1, respectively. The development of hair care products revealed that a mixture containing the optimal dosage of T9 effectively ensured smooth hair lines and prevented microorganism contamination in all recipes. GRAPHICAL ABSTRACT HIGHLIGHTS Pigeon Pea Oil in Hair Care Products Comparison of T9 and ICP 7035 oil properties. ICP 7035 yield was higher than T9 yield. Chemical properties of oil included saponification, acidity, iodine, and peroxide. T9 oil had better phenolics, flavonoids, and DPPH values than ICP 7035. T9-rich mixtures in hair care products ensure smooth hair lines and prevent microorganism contamination.

Total Plate Count of Germs on Pear Surface Swabs During Washing with Fruit Washing Soap

The surface of the fruit is the first contamination of microorganisms on fruit with varying types and amounts. As many as 20% of cases of food poisoning caused by Salmonella typhi were recorded as a result of the consumption of fresh ready-to-eat products such as fruits. Washing the fruits that will be consumed is a good step, so a fruit washing soap product is used that can clean the fruits from these bacteria. Nonionic surfactants are cleaning agents found in fruit washing soaps that can remove bacteria on surfaces. The purpose of this study was to determine the difference in the total plate number of germs on the surface of pears when washing with fruit washing soap. The research method used in this research is descriptive method. The population is 50 soaps taken from 5 shops in the Harapan Baru market in Samarinda with different soap brands. The sample taken is 10% of the total population, namely 5 soaps. The sampling technique used purposive sampling. The study was carried out in July 2022. The method of examination used the examination of the TPC (Total Plate Count) with the pour plate method using PCA (Plate Count Agar) media. The data analysis used is univariate analysis which aims to explain the characteristics of each research variable by looking at the frequency distribution. The results showed that the number of bacteria before washing with fruit washing soap ranged from 4.4 x 100 CFU/cm2 to 1.4 x 101 CFU/cm2. Meanwhile, the number of bacteria after washing with fruit washing soap ranged from 0.4 x 100 CFU/cm2 to 3.4 x 100 CFU/cm2. The conclusion of this study is that there are differences in the number of total bacterial plate count on the surface of pears when washing with fruit washing soap.

Biomimetic Ag-modified core-shell nanofibrous membrane with enhanced solar absorption and water replenishment for efficient clean water production and antibacterial activity

Microorganism contamination of evaporators can deteriorate their performance during solar-driven water evaporation. Herein, we developed a biomimetic core-shell nanofibrous membrane with enhanced solar absorption, water replenishment, and antimicrobial properties via modification of silver nanoparticles (Ag-NPs). By mimicking the core-shell structure of natural pine needles, (1) the core of polyvinylidene fluoride hexafluoropropylene (PVDF-HFP) nanofiber, like the xylem of pine needles, can act as a support skeleton for dimensional stability; and (2) the shell of Ag-NPs-modified copper oxide (CuO) crystals (Ag@CuO), like the mesophyll of pine needles (photosynthesis for pine growth), can perform the photothermal and antimicrobial properties. The Ag@CuO nanofibrous membrane achieved increased solar absorption from 92.44 % to 95.88 % and decreased water contact angle from 36.1° to 0° after the incorporation of Ag-NPs. Furthermore, the Ag@CuO nanofibrous membrane exhibited stable evaporation rates of 1.31 kg⋅m−2⋅h−1 for 3.5 wt% saline water and 1.27 kg⋅m−2⋅h−1 for actual dye wastewater. Moreover, the nanofibrous membrane possessed excellent flexibility and robust adhesion of Ag-NPs due to the strong interfacial bonding induced by polydopamine. In addition, inhibition rates above 99.97 % against Staphylococcus aureus and Escherichia coli demonstrated the outstanding antimicrobial properties of the Ag@CuO membrane. In conclusion, the high evaporation performance, excellent flexibility, and outstanding antimicrobial properties enable the Ag@CuO nanofibrous membrane to be a good option for sustainable clean water production by treating evaporation media containing microorganisms.

Bactericidal effectiveness of high-intensity pulsed broadband irradiation in treating infected wounds

The study aimed to investigate the bactericidal eŠcacy of high-intensity pulsed broadband irradiation in the treatment of infected wounds. An experimental study was conducted on 90 mature male Wistar rats. An infected wound model was created by contaminating with Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Candida albicans. Animals in Group 1 received high-intensity pulsed broadband irradiation. Animals in Group 2 received traditional UV irradiation. Animals in Group 3 had their wounds cleaned with 0.1% chlorhexidine solution. By the 3rd day of treatment, animals that received pulsed high-intensity broadband irradiation showed a signifiant reduction in contamination by Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa compared to Group 3. By the 7th day of treatment, half or the majority of animals in Groups 1 and 2 showed complete decontamination of wounds concerning Staphylococcus aureus and Klebsiella pneumoniae. Most animals in Group 1 showed complete wound clearance of Pseudomonas aeruginosa. By the 10th day, nearly all animals in Group 1 demonstrated complete decontamination of wounds. Statistical analysis revealed a signifiant difference in the reduction of wound contamination with Staphylococcus aureus and Klebsiella pneumoniae by the 10th day in Groups 1 and 2 compared to Group 3. Thus, the use of high-intensity pulsed broadband irradiation of wounds reduces the degree of pathogenic microorganism contamination in a shorter time frame.

Increase Toll-like receptors 2 and 4 in apical periodontitis of rats with chronic liver disease.

The aim of this study was to evaluate the influence of liver fibrosis (LF) on the expression of Toll-like receptors (TLR) 2 and 4 in apical periodontitis (AP) in Wistar rats. Forty Wistar rats were allocated in the following groups (n = 10): C-control; AP-apical periodontitis; LF-liver fibrosis; AP + LF-rats with AP and LF. LF and AP were induced by established methodologies. Histological, bacteriological, and immunohistochemical analyses were performed according to pre-established scores. For comparisons between AP and AP + LF groups, the Mann-Whitney test was used (P < .05). The livers of the LF and AP + LF groups showed generalized portal inflammatory infiltrate and collagen fibers confirming the presence of LF. Histopathological analysis in the maxilla of the AP + LF group showed areas of necrosis comprising the entire dental pulp and periapical tissue surrounded by a more intense inflammatory infiltrate than observed in the AP group (P = 0.032). A significant number of specimens in the AP + LF group showed microorganisms beyond the apical foramen adhered to the extraradicular biofilm, demonstrating greater invasion compared to the AP group (P = .008). Immunohistochemical analysis showed a large number of cells immunoreactive for TLR2 and TLR4 in the AP + LF group, compared to the AP group (P < 0.05). Liver fibrosis favors the inflammation and contamination of microorganisms in apical periodontitis and triggers the expression of TLR2 and TLR4, modulating innate immunity response in periapical lesions.

Enhancing cell cryopreservation with acidic polyamino acids integrated liquid marbles

Cryopreservation is highly desired for long-term maintenance of the viability of living biosamples, while effective cell cryopreservation still relies heavily on the addition of dimethyl sulfoxide (DMSO) and fetal bovine serum (FBS). However, the intrinsic toxicity of DMSO is still a bottleneck, which could not only cause the clinical side effect but also induce cell genetic variants. In the meantime, the addition of FBS may bring potentially the risk of pathogenic microorganism contamination. The liquid marbles (LMs), a novel biotechnology tool for cell cryopreservation, which not only have a small volume system that facilitated recovery, but the hydrophobic shell also resisted the harm to cells caused by adverse environments. Previous LM-based cell cryopreservation relied heavily on the addition of FBS. In this work, we introduced acidic polyaspartic acid and polyglutamic acid as cryoprotectants to construct LM systems. LMs could burst in an instant to facilitate and achieve ultrarapid recovery process, and the hydrophilic carboxyl groups of the cryoprotectants could form hydrogen bonds with water molecules and further inhibit ice growth/formation to protect cells from cryoinjuries. The L929 cells could be well cryopreserved by acidic polyamino acid-based LMs. This new biotechnology platform is expected to be widely used for cell cryopreservation, which has the potential to propel LMs for the preservation of various functional cells in the future.

Conjugated Microporous Polymers-Based Catalytic Membranes with Hierarchical Channels for High-Throughput Removal of Micropollutants.

Engineering a catalytic membrane capable of efficiently removing emerging organic microcontaminants under ultrahigh flux conditions is of significance for water purification. Herein, drawing inspiration from the functional attributes of lymphatic vessels involved in immunosurveillance and fluid transport with minimal energy consumption, a novel hierarchical porous catalytic membrane is engineered. This membrane, based on an innovative nitrogen-rich conjugated microporous polymer (polytripheneamine, PTPA), is synthesized using an electrospinning coupled in situ polymerization approach. The resulting bioinspired membrane with hierarchical channels comprises a thin layer (≈1.7µm) of crosslinked PTPA nanoparticles covering the interconnected electrospun nanofibers. This unique design creates an intrinsic microporous angstrom-confined system capable of activating peroxymonosulfate (PMS) to generate 98.7% singlet oxygen (1O2), enabling durable and highly efficient degradation of microcontaminants. Additionally, the presence of a thin layer of mesoporous structure between PTPA nanoparticles and macroporous channels within the interwoven nanofibers enhances mass transfer efficiency and facilitates high flux rates. Notably, the prepared hierarchical porous organic catalytic membrane demonstrates enduring high-efficiency degradation performance with a superior permeance (>95% and >2500 L m-2 h-1 bar-1) sustained over 100 h. This work introduces an innovative pathway for the design of high-performance catalytic membranes for the removal of emerging organic microcontaminants.

Hidden facts about circulated paper currency and microorganism contamination

Hidden facts about circulated paper currency and microorganism contamination

Structured-illumination reflectance imaging for the evaluation of microorganism contamination in pork: Effects of spectral and imaging features on its prediction performance

Structured-illumination reflectance imaging for the evaluation of microorganism contamination in pork: Effects of spectral and imaging features on its prediction performance

Ozonation Treatment, Edible Coating Carrageenan, and Temperature Variation on The Quality of Fresh-Cut Pineapple During Storage

Fresh-cut pineapples are increasingly popular in Indonesia, but it damage easily due to contamination of pathogenic microorganisms, resulting in a short shelf life. This research aims to examine the effect of applying ozone and edible carrageenan coating on the quality of fresh-cut pineapple stored at low temperatures. The experiment used factorial completely randomized design. The first factor was concentration of carrageenan and the second factor was storage temperature. Based on the lowest TPC (total plate count) value from a preliminary research, the experiment was conducted with soaking time of 60 s. Results showed that weight loss, hardness, and TDS values was respectively 2.24 %; 13.03 °Brix; 11.42 kgf, and tended to increase until the last day of storage. The best results was found at 2.5% carrageenan coating and 5 °C. Results from the organoleptic test, however, found the highest score of 4.41 was collected from 1.5% carrageenan coating and 5 °C. It can be concluded that the combination of soaking in ozonized water for 60 s, immersing the fruit in a 2.5% edible coating carrageenan solution stored at 5 °C can maintain the quality of the fruit and increase the shelf life of fresh-cut pineapple compared to controls that were not given any treatment. Keywords: Drying, Physical Quality, Temperature, Tomatoes, Tween 80.

Novel sunlight-induced monochloramine activation system for efficient microcontaminant abatement

As an eco-friendly and sustainable energy, solar energy has great application potential in water treatment. Herein, simulated sunlight was for the first time utilized to activate monochloramine for the degradation of environmental organic microcontaminants. Various microcontaminants could be efficiently degraded in the simulated sunlight/monochloramine system. The average innate quantum yield of monochloramine over the wavelength range of simulated sunlight was determined to be 0.068 mol/Einstein. With the determined quantum yield, a kinetic model was established. Based on the good agreement between the simulated and measured photolysis and radical contributions to the degradation of ibuprofen and carbamazepine, the major mechanism of monochloramine activation by simulated sunlight was proposed. Chlorine radical (Cl∙) and hydroxyl radical (HO∙) were major radicals responsible for microcontaminant degradation in the system. Moreover, the model facilitated a deep investigation into the effects of different reaction conditions (pH, monochloramine concentration, and water matrix components) on the degradation of ibuprofen and carbamazepine, as well as the roles of the involved radicals. The differences between simulated and measured degradation data of each microcontaminant under all conditions were less than 10 %, indicating the strong reliability of the model. The model could also make good prediction for microcontaminant degradation in the natural sunlight/monochloramine system. Furthermore, the formation of disinfection byproducts (DBPs) was evaluated at different oxidation time in simulated sunlight/monochloramine with and without post-chloramination treatment. In real waters, organic components showed more pronounced suppression on microcontaminant degradation efficiency than inorganic ions. This study provided a systematic investigation into the novel sunlight-induced monochloramine activation system for efficient microcontaminant degradation, and demonstrated the potential of the system in practical applications.

The Study of Food Pathogens in Yazd Traditional Confectionary Products

Background: Food poisoning could be caused by eating the sweets contaminated with microorganisms, which has always been considered as one of the major problems of people in developing countries, including Iran. The aim of this study is to investigate microbial variety and fungal load in the traditional sweets offered in confectionery stores in Yazd province in 2020. Methods: In this study, 170 samples of traditional sweets, referred by confectioneries in Yazd province, were randomly selected and tested for microorganisms contamination such as Enterobacteriaceae, Escherichia coli, Staphylococcus aureus, Salmonella, molds, and yeasts according to Iranian national standards. Results: The highest rate of microbial contamination in samples was related to "Pistachio Loz" (52.94%) and the lowest rate was related to "Hajibadam" (11.76%). The infection rates of Enterobacteriaceae, Escherichia coli, molds, and yeasts were 17.06%, 8.83%, 20.59%, 3.53%, respectively. No infection was observed with Staphylococcus aureus and Salmonella in the samples. Conclusions: Due to the high level of microbial contamination of traditional sweets, especially "Pistachio Loz" offered in Yazd, more control measures are needed in preparation and distribution of such sweets.

Endoscope sampling and culturing methods

Contamination rates reported in the literature for patient-ready flexible endoscopes vary from 0.4% to 49%. Unfortunately, the comparison and interpretation of these results is almost impossible since several factors including sampling and culturing methods, target levels for contamination or definition of indicator microorganisms vary widely from one study to the other. The objective of this study was to compare the efficacy of six duodenoscope sampling and culturing methods by means of extraction efficacy comparison, while at the same time identifying key parameters that provide optimal microbial recovery.The duodenoscope sample extraction efficacy of each method was assessed using the repetitive recovery method described in ISO 11737-1: 2018. The results obtained indicated that the mean overall bioburden extraction efficacy varied from 1% for the Australian method to 39% for the French one. The lowest endoscope sample extraction efficacy was associated with the absence of any neutralizer, friction, or tensioactive agent and when only a small portion of the sampling solution collected was inoculated onto culture media.The efficacy of the sampling and culturing methods also varied according to the nature of microorganisms present in the endoscope, and the time between sampling and culturing.This study supports the need for a harmonized and standardized sampling and culturing method for flexible endoscopes.

Polluted Rivers—A Case Study in Porto, Portugal

River contamination by microorganisms, or another chemical source, poses a serious threat to both the environment and public health. Taking immediate and appropriate actions is essential to mitigate the contamination and prevent further spread. As such, regular monitoring of these pollution agents is essential to act in time and control its minor extension. However, there is a lack of commitment to this emergent concern and respective actions around the world. This work aims to study the contamination of a Portuguese river (Tinto River) within Porto city (a highly populated urban area) regarding the total aerobic microorganisms, coliforms, and Enterococcus (as colony-forming units (CFUs) using specific solid culture media) and total organic matter (TOC). Different locations were considered along the Tinto River course (i.e., 14 locations within 11 km) and samples were collected on distinct days throughout September 2022. The overall results showed microbial contamination of aerobic microorganisms (up to 2 × 105 CFU/100 mL), total coliforms (up to 7 × 104 CFU/100 mL), Escherichia coli (up to 9 × 103 CFU/100 mL), and Enterococcus (up to 8 × 103 CFU/100 mL). The results also surpassed the maximum recommended values (MRVs) described in Portuguese decree-law no. 236/98 for irrigation waters. Moreover, TOC was found in a range of 4.54 mg/L to 57.2 mg/L. This work highlights the dangerous microbial contamination and higher amount of organic matter than would be expected for a surface water resource.

Melanin-mediated accumulation of polycyclic aromatic hydrocarbons in human hair: Insights from biomonitoring and cell exposure studies

While human hair is widely used to monitor micro-organic contaminants (MOCs), their incorporation mechanisms are poorly understood. Melanin, known to facilitate the accumulation of drugs in hair, hasn’t been studied in the field of MOCs. Here, polycyclic aromatic hydrocarbons (PAHs), a class of priority MOCs, were investigated through hair biomonitoring as well as cell exposure experiments. PAH concentrations and melanin contents were measured in black and white hairs from the same individual. The results showed that five dominant PAHs (phenanthrene, fluoranthene, pyrene, benzo[a]anthracene and chrysene) in black hair (0.66 ng/g – 35.1 ng/g) were significantly higher than those in white hair (0.52 ng/g – 29.6 ng/g). Melanin contents in black hair (14.9 – 48.9 ng/g) were markedly higher than in white hair (0.35 – 2.15 ng/g) and were correlated to PAH concentrations, hinting melanin-mediated accumulation of PAHs in hair. The in vitro experiment using murine melanoma cells demonstrates that PAH levels in cells were affected by melanin, suggesting the affinity of melanin to PAHs. Both biomonitoring and cell exposure experiment implicate the pivotal role of melanin in PAH accumulation in hair. Therefore, to ensure the accuracy of hair biomonitoring for MOCs, attention must be paid to the melanin content uniformity.

Microorganism diversity and contamination risk in mosque rosaries and carpets.

Inevitably, the floors of mosques are contaminated with microorganisms, and the risk of pathogen transmission is probably high between the many visitors, but the issue has been infrequently studied. Investigate microorganism variety and risk of contamination on commonly used carpets and rosaries (prayer beads). Cross-sectional. Mosques. This study was carried out in three different cities of Turkey in 2023, focusing on mosques located around hospitals. Forty mosques were included in the study and from each mosque 10 samples were collected from various parts of carpets and rosaries. The number of positive culture isolates were identified. Diversity and distribution of microorganisms isolated from mosque carpets and rosaries; methicillin-resistance rates in Staphylococci. 400 samples. Growth was observed in 368 (92%) of 400 samples examined. The microorganisms isolated in the highest number were methicillin-susceptible coagulase negative Staphylococci (MSCoNS) (59.8%), Microcooccus (41%) and diphtheroids (31.3%). The rates of total growth (P=.001), including diphtheroids (P=.018), methicillin-resistant coagulase negative Staphylococci (P=.001), Bacillus spp. (P=.036) and Aspergillus spp. (P=.002) rates were significantly higher in the rosary samples than carpet samples. At mosques in Tokat, a province center, 4 samples were positive for Acinetobacter baumannii, two samples were positive for Pseudomonas aeruginosa and one sample for methicillin-resistant Staphylococcus aureus (MRSA), and these were isolated from rosaries. 0.3% of Staphylococcus isolates were MRSA. As there is a high risk of contamination of carpets and prayer beads on the mosque floor with human flora, the use of appropriate hygiene practices is necessary. We also found some emerging bacteria in addition to the normal human flora. Our study was conducted in three provinces. Further studies might cover a wider geography.