Microbiological Contamination Research Articles

Microbiological and Chemical Contamination Analysis of Cilok in the Southern Alun-alun of Kraton Yogyakarta

Many street food vendors lack an understanding of food safety standards, resulting in cases of poisoning due to microbiological and chemical contamination. One popular snack sold is aci dicolok (cilok). This study aims to analyze microbiological contamination and hazardous chemical additives in cilok and the sauce sold in the Southern Alun-alun of Kraton Yogyakarta. The parameters of this study included calculating the total number of bacteria and salmonella using Plate Count Agar (PCA) and Salmonella Shigella Agar (SSA) media and qualitatively analyzing the content of formaldehyde, borax, and rhodamine B using Easy test brand test kits on cilok and sauce samples from 10 sellers. The results were then compared with the standards of The Indonesian Food and Drug Authority (BPOM) and the Indonesian National Standard (SNI). The results showed that 40% of cilok and 100% of sauce samples exceeded the total bacteria limit of SNI and BPOM (1 x 105 CFU/g). For the total Salmonella content, 10% cilok and 0% sauce samples exceeded the SNI and BPOM salmonella limit (0 CFU/g). The analysis of hazardous chemical additives revealed that 10 samples were negative for formaldehyde and borax, but 10% of the sauce tested positive for rhodamine B. The study results indicate that cilok and sauce are subject to microbiological and chemical contamination, so education and supervision by the authorities are needed for cilok sellers.

Evaluation of the Microbiological Quality of Three Varieties of Kilichi Produced in Niger

Kilichi is a food based on beef, mutton or goat meat that is processed by slicing, dressing, drying in the sun and applying spice porridge and roasting over a hot fire. Traditional processing conditions and practices for this product may pose risks of microbiological contamination and pose serious public health concerns.
 The objective of this study was to assess the microbiological quality of Niger's kilichis. A total of twenty-two samples of kilichi of three variants (single kilichi "KS", archide kilichi "Kilichi Fari" and peanut paste kilichi with Jawa "Kilichi Ja"). Total Mesophilic Aerobic Flora (TMAF), total coliforms, faecal coliforms, Escherichia coli and Salmonella were determined after the preparation of the stock solutions, decimal dilution and seeding on selective media. The results showed that the samples of the kilichi coated with the peanut paste sauce are more loaded with sought-after sprouts. However, single kilichi is more loaded with faecal coliform, 3,52x106 CFU/ml; 2,11x105 CFU/ml and 1,17x106 CFU/ml for kilichi single, kilichi Fari and kilichi Ja respectively. These results show that the microbial load of kilichi samples is higher than the microbial criteria that cooked deli products must meet.

Safety, Processing, and Utilization of Fishery Products

Global marine fish harvests have reached a plateau over the last decade, and efforts to increase aquaculture tend to face limitations in terms of water resources and contamination problems. Of the current fish harvest, at least 50% is discarded as waste. The current situation requires efforts to process, preserve, and utilize the fish capture to minimize waste. Chemical and microbiological contamination limit the utilization of harvested fish. There is a need to improve fish preservation to minimize spoilage and to process them into more appealing products. Instead of resorting to individual food-processing methods, the efficiency of processing could best be increased by a combination of conventional and modern processing methods or by combinations of modern processing methods. Fish waste is a rich source of oils containing essential fatty acids, polypeptides, and amino polysaccharides that could be utilized through the upscaling of current scientifically proven methods to new processing technologies. The separation of collagens, gelatins, bioactive peptides, edible fish oils, and chitosan form the primary stages in the utilization of fish waste. The products need purification to meet food quality and safety standards and to have desirable industrial characteristics. The diversity of information and products generated through new methods require advanced data handling and prediction systems, such as artificial intelligence, to address food safety and to derive the best out of fish processing and utilization.

Peculiarities of milk microflora of Saanen goats in the conditions of the Steppe zone of Ukraine

The quality of goat milk can be affected by mesophilic aerobic and facultatively anaerobic microorganisms (MAFAnM), intestinal bacteria, psychrotrophic, some pathogenic microorganisms, fungi, etc. Traditional microbiological methods, which are used to determine the safety of milk, do not provide an opportunity to obtain an instant result, require the preparation of nutrient media and glassware, which takes up work time and is energy-consuming. We have carried out studies of goat milk by classical (using conventional and selective nutrient media) and alternative modern (using test plates, which are widely used to control microbiological contamination in the food industry) methods. As a result of the conducted research, it was established that the bacterial contamination of goat milk was within the permissible limits. There were no significant differences in the results of using the test plates. According to the classical method, the average indicators of the number of mesophilic aerobic and facultatively anaerobic microorganisms were 4.97 ± 0.14 lg CFU/mL, according to the alternative method – 4.86 ± 0.13 lg CFU/mL. Escherichia coli was isolated in four samples (with an average concentration of microorganisms of 1.86 ± 0.62 lg CFU/mL), in the same samples Enterobacter spp. in the amount of 1.77 ± 0.61 lg CFU/mL. In three samples, the presence of Proteus spp. with average concentration values of 2.19 ± 0.15 lg CFU/mL. Using an alternative method, contamination of milk with Escherichia coli (1.53 ± 0.33 lg CFU/mL) was detected in five samples, coliform bacteria were isolated in four samples (1.49 ± 0.50 lg CFU/mL). Staphylococcus aureus was not detected by any of the methods, but other representatives of the genus Staphylococcus were detected in all samples by both classical and alternative methods (2.48 ± 0.05 and 3.01 ± 0.07 lg CFU/mL). Using the classic method, it was established that two samples were positive for Enterococcus spp. (2.46 ± 0.08 lg CFU/mL), Bacillus spp. were isolated in six samples (1.70 ± 0.09 lg CFU/mL), in three – Clostridium spp. (1.66 ± 0.06 lg CFU/mL), in all six samples psychrotrophic bacteria (2.09 ± 0.26 lg CFU/mL) and yeast (2.41 ± 0.24 lg CFU/mL), four of the samples contained single colonies of mold fungi of the genus Aspergillus. Pathogens Listeria monocytogenes and Salmonella spp. not found. It will be promising to study the dependence of the milk microbiome on environmental factors, as well as the influence of the milk microbiota on the course of technological processes, quality and safety indicators during the production of goat cheese or other dairy products.

Alert for microbreweries – a case study on unpasteurized and unfiltered beer

Beer stability, influenced by physical, chemical, and biological factors, poses a considerable challenge for breweries. Biological stability, as a major concern, is effectively managed through practices such as good hygiene, pasteurization, and filtration. Microbiological contamination, often recognizable by increased turbidity or off-flavours, is influenced by temperature, with optimal conditions promoting the growth of specific microorganisms. Lower temperatures slow down flavour changes and chemical reactions in beer, impacting its non-biological stability. This case study explores the impact of storage temperature on autolysis off-flavour development in 10 different unfiltered and unpasteurized beers. The results showed that autolysis off-flavour occurred at both low and higher storage temperatures and that its dependence on the temperature was minimal. This unexpected fact was discovered mainly due to uncovered significant contamination of the commercial beers tested (wild yeasts, lactic acid bacteria, enterococci and coliform bacteria). For this reason, the concentration of cells in the beer appeared as a more influential factor in the development of off-flavours, including autolysis, than the storage temperature. The partial results need to be studied in more detail, nevertheless, we felt it was important to publish the revelation of a strong contamination of beers purchased from regular stores for our experiments. At this point it can already be concluded that the low storage temperature did not help to prevent the development of the contamination and the associated sensory deterioration of the beers.

Raw milk cheeses from Beira Baixa, Portugal—A contributive study for the microbiological hygiene and safety assessment

Due to specific bacterial microbiota, raw milk cheeses have appreciated sensory properties. However, they may pose a threat to consumer safety due to potential pathogens presence. This study evaluated the microbiological contamination of 98 raw milk cheeses from Beira Baixa, Portugal. Presence and enumeration of Coagulase Positive Staphylococci (CPS), Listeria monocytogenes, Salmonella spp., pathogenic Escherichia coli, and indicator microorganisms (non-pathogenic E. coli and Listeria spp.) was attained. E. coli antimicrobial resistance (AMR) was also evaluated. PCR and/or Whole genome sequencing (WGS) was used to characterize E. coli, Salmonella spp. and L. monocytogenes isolates. Sixteen cheeses (16.3%) were classified as Satisfactory, 59 (60.2%) as Borderline and 23 (23.5%) as Unsatisfactory/Potential Injurious to Health. L. monocytogenes, CPS > 104 cfu g−1, Extraintestinal pathogenic E. coli (ExPEC) and Salmonella spp. were detected in 4.1%, 6.1%, 3.1% and 1.0% of the samples, respectively. Listeria innocua (4.1%) and E. coli > 104 cfu g−1 (16.3%) were also detected. AMR E. coli was detected in 23/98 (23.5%) of the cheese samples, of which two were multidrug resistant. WGS identified genotypes already associated to human disease and Listeria spp. cluster analysis indicated that cheese contamination might be related with noncompliance with Good Hygiene Practices during cheese production.

Microbiology of post-fermentation leachate

Using post-fermentation leachate as fertilizer is a good alternative and solution to the problem of waste at wastewater treatment plants and contains the principles of sustainable development. Leachate from anaerobic treatment of sewage sludge contains valuable elements such as phosphorus, nitrogen and potassium, which can improve soil properties. The production of liquid fertilizer minimizes the negative impact of leachate on the main biological stream in the WWTP and improves the energy efficiency of the entire wastewater treatment system. This transfers into the operating costs of the facility. When thinking about the agricultural use of digestion leachate and its introduction into the environment, a very important issue is its microbiological contamination. The purpose of the conducted research was to determine the microbiological quality of digestion leachates from municipal wastewater treatment plants and to determine the parameters of their hygienization. The number of bacteria in raw leachate is indicative of a sanitary risk in the case they are used in agriculture as fertiliser. Heating the leachate at 60°C for 15 minutes produces an effect comparable to that achieved by heating the leachate to 70°C. The sonication process itself did not affect the better temperature effect. Heating the leachate for 20 minutes after prior sonication for 20 minutes does not result in the complete elimination of microflora.

Comprehensive antifungal investigation of natural plant extracts against Neosartorya spp. (Aspergillus spp.) of agriculturally significant microbiological contaminants and shaping their metabolic profile

Fungi belonging to the genus Neosartorya (teleomorph of Aspergillus spp.) are of great concern in the production and storage of berries and fruit-based products, mainly due to the production of thermoresistant ascospores that cause food spoilage and possible secretion of mycotoxins. We initially tested the antifungal effect of six natural extracts against 20 isolates of Neosartorya spp. using a traditional inhibition test on Petri dishes. Tested isolates did not respond uniformly, creating 5 groups of descending sensitivity. Ten isolates best representing of the established sensitivity clusters were chosen for further investigation using a Biolog™ MT2 microplate assay with the same 6 natural extracts. Additionally, to test for metabolic profile changes, we used a Biolog™ FF microplate assay after pre-incubation with marigold extract. All natural extracts had an inhibitory effect on Neosartorya spp. growth and impacted its metabolism. Lavender and tea tree oil extracts at a concentration of 1000 µg mL−1 presented the strongest antifungal effect during the inhibition test, however all extracts exhibited inhibitory properties at even the lowest dose (5 µg mL−1). The fungal stress response in the presence of marigold extract was characterized by a decrease of amino acids and carbohydrates consumption and an uptake of carboxylic acids on the FF microplates, where the 10 studied isolates also presented differences in their innate resilience, creating 3 distinctive sensitivity groups of high, average and low sensitivity. The results confirm that natural plant extracts and essential oils inhibit and alter the growth and metabolism of Neosartorya spp. suggesting a possible future use in sustainable agriculture as an alternative to chemical fungicides used in traditional crop protection.

Assessing the impact of a cleaning programme on environmental hygiene in labour and neonatal wards: an exploratory study in The Gambia.

Effective surface cleaning in hospitals is crucial to prevent the transmission of pathogens. However, hospitals in low- and middle-income countries face cleaning challenges due to limited resources and inadequate training. We assessed the effectiveness of a modified TEACH CLEAN programme for trainers in reducing surface microbiological contamination in the newborn unit of a tertiary referral hospital in The Gambia. We utilised a quasi-experimental design and compared data against those from the labour ward. Direct observations of cleaning practices and key informant interviews were also conducted to clarify the programme's impact. Between July and September 2021 (pre-intervention) and October and December 2021 (post-intervention), weekly surface sampling was performed in the newborn unit and labour ward. The training package was delivered in October 2021, after which their surface microbiological contamination deteriorated in both clinical settings. While some cleaning standards improved, critical aspects such as using fresh cleaning cloths and the one-swipe method did not. Interviews with senior departmental and hospital management staff revealed ongoing challenges in the health system that hindered the ability to improve cleaning practices, including COVID-19, understaffing, disruptions to water supply and shortages of cleaning materials. Keeping a hospital clean is fundamental to good care, but training hospital cleaning staff in this low-income country neonatal unit failed to reduce surface contamination levels. Further qualitative investigation revealed multiple external factors that challenged any possible impact of the cleaning programme. Further work is needed to address barriers to hospital cleaning in low-income hospitals.

Quality Analysis of Fresh Vegetable Product with Prima Certificate (Case Study Of Nagari Padang Lua Kecamatan Banuhampu Kabupaten Agam)

Referring to the Indonesian National Standard (SNI), fresh food quality parameters must have certain physical quality criteria, free from pesticide residues, microbial contamination and free of heavy metal contamination. The purpose of the study was to analyze the quality of red chili peppers, spring onions, cabbage, eggplant and chickpeas that have been certified prima with 3 (three) testing parameters, namely testing the physical quality of vegetables referring to SNI 01-4480-1998 for red chili products, SNI 01-6996-2004 for spring onion products, SNI 01-3174: 1992 for cabbage products, SNI 3163: 2014 for purple eggplant and chickpea products. Lead heavy metal contamination testing refers to SNI 7387:2009 and microbiological contamination testing refers to SNI 7388:2009. The research was conducted in the Nagari Padang Lua area, Kecamatan Banuhampu, Kabupaten Agam on 5 vegetable cultivation businesses that have been certified as prima. The research method used was descriptive testing. The results showed that there were deviations in the physical quality of fresh red chilies, namely the level of uniformity of the size of red chilies that were below the SNI quality standard (92.33%), very high levels of impurities in leaf onions, total microbial contamination (ALT) in leaf onions and cabbage/cabbage exceeded the maximum limit of total contamination allowed in food, namely 1.39x104 and 1.708x104 E.Coli contamination was detected exceeding the maximum limit of contamination in chickpeas which was 3/gr, while for lead contamination (P4), the total microbial contamination (ALT) in leaf onions and cabbage exceeded the maximum limit of total contamination allowed in food, respectively.

Developement and Stability Evaluation of Natural Topical Formulations Containing Pinus sibirica Essential Oil

Abstract Pinus sibirica (P. sibirica) is used in folk medicine for centuries in treatment of various diseases due to its anti-inflammatory, antioxidant, and antimicrobial activity. The present study was focused on formulating semi-solid topical cream and gel preparations with P. sibirica essential oil (EOPS) and on evaluation of their stability during three months of storage. After preparation of semi-solid formulations (cream and gel), we followed parameters such as organoleptic characteristics, pH values, electrical conductivity, phase separation, washability, swelling index and microbiological contamination. Tests for physical and microbiological stability were performed considering different storage conditions at temperature (4±2° C, 25±2°C and 40±2°C) for 12 weeks. All test were performed at sampling time points of 7th, 30th, 60th, 90th day after storage. Cream with EOPS was white colour, it is homogenous with pleasant odor characteristic to used EOPS while gel with EOPS was transparent, it is homogenous with specific odor. After application to skin, EOPS cream was leaving non-greasy film while gel with EOPS was leaving sticky film and cooling effect. In all tested samples, we observed no phase separation and pH values were optimal for skin application. During three months of storage at different conditions, all tested formulations were stable and addition of EOPS did not cause any changes in followed parameters. Both cream and gel formulation remained stable since we did not notice any significant changes in all followed parameters during storage at different temperatures. Addition of 0.5% of EOPS did not change visual, sensory and microbial properties of formulations.

Sources, persistence, and current inactivation methods of foodborne pathogens in legumes

Legumes and legume-derived products are consumed in large quantities for their nutritional value as well as for their taste. Their sustainability and affordability are commendable, and legumes are a low-glycemic-index food that is high in protein and fibre while still being satiating. Legumes are commonly consumed as choice meals, particularly by vegetarians and vegans as a meat substitute, and they account for a significant portion of the dietary intake in many countries. The huge trend of vegan diets has prompted the industrial growth of legumes and pulses. The increased production within the shortest period to fulfil the expanding demand has put them at a higher risk of contamination with pathogenic microbes, rendering consumer safety uncertain. The objective of this review was to draw attention to the sources of microbiological contamination in legumes, the persistence of foodborne pathogens in legumes, and the existing techniques of foodborne pathogen inactivation. Water, surfaces, and human contact are all factors to consider, as is the risk linked with inadequate sanitation, poor equipment design, and improper handling. The foodborne pathogen, though seemingly unavoidable, can be minimized or inactivated using a variety of thermal and nonthermal procedures used prior to and after harvesting of legumes, as well as throughout the manufacturing and processing process.

Activated carbon impregnated with Ag(0) and Cu oxides for the removal of Escherichia coli, Giardia, and Cryptosporidium (oo)cysts from water

Granular activated carbon (GAC) impregnated with silver or copper was evaluated as a point-of-use water treatment to improve the microbiological quality of drinking water processed by low-cost, newly developed GAC filters. Experiments were carried out in a point-of-use water purifying system using packed-bed filters of GAC impregnated with various concentrations of Ag(0) or Cu oxides. The pore and surface properties were studied in terms of BET volumetric measurement with nitrogen adsorption (BET area of metal-impregnated GAC lies within the range of 602 ∼ 866 m²g−1, while the surface area of non-treated GAC is 870 m²g-1), X-ray diffraction (identifying the presence of metallic silver and copper oxide in the GAC structure) and Scanning Electron Microscopy (revealed the presence of metal compounds deposited on the GAC surface). The performance of filters with GAC (water treatment capacity of 4 L/g) was evaluated against microbiological contaminants in synthetic water so that the best loading concentration to remove microorganisms from test water could be determined. The removal efficiency against Escherichia coli was higher when the amount of metal impregnated on GAC increased. GAC impregnated with Ag(0) at 5.0 wt% had a strong antibacterial activity for the growth of Escherichia coli. Samples of GAC impregnated with Ag(0) at 1.0 wt% and Cu oxides at 0.5 wt% were more efficient in the removal of Giardia and Cryptosporidium (oo) cysts. The above evaluations showed that the proposed apparatus, based on a gravitational point-of-use filter with an adsorbent with metals has antibacterial properties and may be recommended to communities for household treatment of drinking water.

Hydraulic Conductivity of Soils: A Comprehensive Review of the Impacts of Chemicals, Soil Salinity, Organic Matter, and Land Use

The contamination of groundwater by toxic heavy metals, organic compounds, and microbiological contaminants is a significant issue worldwide. To address this problem, various methods have been employed, including in-situ remediation and transporting polluted soil or groundwater for final treatment. This study aims to review the impact of soil heterogeneity on in-situ remediation, with a particular focus on subsurface preferential flow that accelerates solute transport. The study highlights the importance of soil hydraulic conductivity in soil production, ecological health, and water resource management. Soil hydraulic conductivity is influenced by soil structure, moisture content, and chemical exposure. The findings of this study emphasize that sustainable soil management and environmental restoration require an understanding of hydraulic conductivity parameters and the implementation of appropriate management strategies.

Use of an eco‐friendly preservation technology as a strategy to increase the microbiological shelf‐life of a novel ready‐to‐eat salad containing vegetable by‐products

AbstractThe objective of this investigation was to evaluate different UV‐C irradiation doses in a novel ready‐to‐eat vegetable product containing vegetable by‐products (red beet leaves) and determine the microbiological shelf‐life and quality indicators during refrigerated storage (5 ± 1°C). During processing, no chemical disinfection was carried out and after the packaging step, 3 doses of UV‐C irradiation were applied (CTRL: 0 kJ/m2, L: 1 kJ/m2, M: 4 kJ/m2, and H: 7 kJ/m2) on the vegetable product studied (50% Creola purple lettuce, 25% beet leaves, and 25% arugula). It was observed that the intermediate dose (M) was the most suitable treatment since it could increase in six times its microbiological shelf‐life. Additionally, M was the one that showed the lowest loss of total polyphenols and the one that best maintained the antioxidant capacity (DPPH), probably attributed to the decrease in the activity of deterioration enzyme, PPO and higher ascorbic acid content at day 4. When evaluating % CO2/O2 on headspace of bags, UV‐C treatments reached earlier the dynamic equilibrium. Finally, all UV‐C irradiation treatments were successful against the simulated contamination. In that way, significant reductions of L. innocua and E. coli were found, with differences from up to 2 log cycles during storage. Finally, it can be concluded that UV‐C treatment can increase the microbiological shelf‐life of the novel ready‐to‐eat vegetable product, with quality indicators stabilization.Practical applicationsReady‐to‐eat salads present a short shelf‐life, which hinders their commercialization. As preservation technologies are required, UV‐C irradiation is an eco‐friendly alternative for its preservation as it has the potential to replace traditional disinfection treatments by reducing the water footprint of the total process. Therefore, since the UV‐C treatment is applied in the last step of the process (after packaging the product), microbiological contamination occurring in this type of vegetable products during processing is minimized. However, additional investigation is necessary to assess its suitability for a novel ready‐to‐eat salad containing horticultural by‐products.

A Novel Technique of Aseptic Manufacture of Autologous Serum Eye Drops (ASEDs) and Sterility Analysis of the Bottled Ophtioles.

To introduce a novel technique of the aseptic manufacture of autologous serum eye drops (ASEDs) with a prefiltered closed system and to analyze the sterility of the produced ophtioles between 2018 and 2022. This is a prospective single-center study conducted at the Department of Ophthalmology at a Swiss University Hospital between 2018 and 2022. For regulatory reasons, closed systems for manufacturing ASEDs are strongly recommended. We attached an upstream sterile filter (Sterivex PES0.22 µm Burlington, USA) to a commercially available closed system (COL System Modena, Italy) for manufacturing ASEDs. The goal of this novel approach was to reduce the microbiological contamination of the donated autologous blood. Using the presented manufacturing method, we are able to produce, on average, 56 ophtioles per batch, containing either 1.45 mL or 2.5 mL of autologous serum per ophtiole. For each batch of ASEDs, we performed a microbiological analysis by automated blood culture testing (BACTEC). This system examines the presence of bacteria and fungi. We analyzed all manufactured batches between 2018 and 2022. None of the 2297 batches and the resulting 129 060 ophtioles showed bacterial or mycotic contamination. During the analyzed period, two batches were discarded: one due to fibrin-lipid aggregations, further microbiological and histological work-up excluded any contamination; another due to false-positive HIV in serological testing. Overall, the contamination rate was 0%, and the batch discharge rate was 0.09%. The combination of upstream sterile filtration with a commercial closed system for manufacturing ASEDs proved to be effective in ensuring sterility without any contamination over the past 4 years. This is becoming crucial, as the demand for autologous blood products for treating ocular surface disorders, such as refractory dry eyes or nonhealing defects of the corneal epithelium, is on the rise.

Implementation of HACCP System in a tuna fish Industry

The challenge of this work was to guarantee the safety of canned tuna by HACCP implementation system. 4 critical control point (CCPs) were selected by an experienced team HACCP to evaluate the efficiency of the system in a tuna fish Industry. The CCP1 is the control of the freshness of the flesh of tuna fish on receipt. The CCP2 is a determination of the levels contents of the histamine and of the mercury of the tuna on receipt. The CCP3 is the control of the seams. The CCP4 is the sterilization. The levels of histamine and mercury contents in fish receipts were aranged between 10.5-29.5 and between 0.022-0.055 mg/kg respectively. No microbiological contamination was detected. pH values were ranged between 5.65-6.02 and the cold chain was respected. Thus, the results show that all CCPs are controlled and validated.

Effects of cold storage and freezing on sheep’s milk

Sheep’s milk production in Brazil is focused on the industrialization of high added value derivatives. Some factors, such as seasonal production, short lactation period, and microbiological contamination, cause a shortage of this raw material throughout the year. It is well known that low temperatures are used in the conservation of dairy products and the objective of this study was to verify the microbiological and physical-chemical quality in refrigerated and frozen raw sheep’s milk. Standard plate counts, psychrotrophics, Staphylococcus aureus, total coliforms, and fecal coliforms, as well as titratable acidity, pH, and water activity were analyzed in samples 1 day after refrigeration and 8 and 15 days after freezing temperatures. Overall, the results of refrigerated milk were based on the legislation, but frozen milk showed high values of aerobic plate, S. aureus, and acidity, especially after 15 days of storage. Psychrotrophics and coliform counts were also high, indicating a risk for the quality of the raw milk and derivatives, which emphasizes the importance of handler training for good practices in the farm, as well as in the dairy industry. Freezing may be a viable strategy; however, additional studies testing lower temperatures and previous milk pasteurization are necessary to guarantee milk quality and consumer safety.

Reinforcing Feedbacks for Sustainable Implementation of Rural Drinking-Water Treatment Technology.

Progress toward universal access to safe drinking water depends on rural water service delivery models that incorporate water safety management. Water supplies of all types have high rates of fecal contamination unless water safety risks are actively managed through water source protection, treatment, distribution, and storage. Recognizing the role of treatment within this broader risk-based framework, this study focuses on the implementation of passive chlorination and ultraviolet (UV) disinfection technologies in rural settings. These technologies can reduce the health risk from microbiological contaminants in drinking water; however, technology-focused treatment interventions have had limited sustainability in rural settings. This study examines the requirements for sustainable implementation of rural water treatment through qualitative content analysis of 26 key informant interviews, representing passive chlorination and UV disinfection projects in rural areas in South America, Africa, and Asia. The analysis is aligned with the RE-AIM framework and delivers insight into 18 principal enablers and barriers to rural water treatment sustainability. Analysis of the interrelationships among these factors identifies leverage points and encourages fit-for-purpose intervention design reinforced by collaboration between facilitating actors through hybrid service delivery models. Further work should prioritize health impact evidence, water quality reporting guidance, and technological capabilities that optimize trade-offs in fit-for-purpose treatment design.

Получение и применение иодированного бактерицида для дезинфекции воды в локальных системах очистки

The paper presents the results of studies on obtaining a bactericide based on iodized anion exchange resin АВ-17-8. The obtained compound bactericidal efficiency was assessed on Escherichia сoli culture suspensions at 103–109 CFU/mL. All experiments gave positive results and demonstrated the possibility of their use for natural water treatment in local water treatment systems. The obtained bactericidal filter can be used for quantitative determination of bacteriological contamination of the studied waters. Water samples contaminated with E. coli at 500, 1000, 5000 and 10000 CFU/mL were prepared to quantify the bactericidal activity of the iodine-containing compound obtained on an anion-exchange resin. Then samples were sequentially passed through a 100 cm3 bactericidal filter. By the amount of iodine released, the degree of microbial contamination can be determined. There were no microbial cells in the filtrate at zero concentrations of released iodine in the solution. The degree of microbiological contamination of water Q was 10,000 CFU/mL at 0.00391 g/L of iodine. A linear dependence between bactericidal activity and iodine release from the anion-exchange resin was established. This allows us to assume that the positive iodine radical is released “on a signal” – at the appearance of living microorganisms carrying excessive electrostatic charge. The released by the bactericide positive iodine radical (I*+) interacts only with the electrostatic charge of microorganisms, and not with the functional groups of their shells. The found quantitative dependence makes it possible to determine microbiological contamination based on the iodine concentration in the treated solution. Based on the test results, a flowchart of the technological process of surface water treatment was proposed. The presence of a bactericidal filter allows the use of a reverse osmosis filter, sensitive to biological water contaminants, as part of the installation.