Sanitary Treatment Research Articles

The effect of photosensitization mediated by curcumin on storage life of fresh date (Phoenix dactylifera L.) fruit

The effect of photosensitization mediated by curcumin (CUR) in sanitizing the fresh date fruit surface was investigated. Approximately 3–4 μl CUR solution ranging from 1000 to 1800 μM was sprayed on the date surface, followed by irradiation using blue light at 420 nm for 10 and 15 min at light dosages of 180 J/cm2 and 270 J/cm2 respectively. After irradiation, the date was stored at 4 °C and 30 °C until fungi was visually observed. The combination of CUR and light resulted in significant (p < 0.05) extension of the shelf life and quality of fresh date. The shelf life of date fruit photosensitized by 1400 μM CUR for 10 min and stored at 30 °C lasted for 14 days in comparison to the 7 days for the control, while date stored at 4 °C lasted 98 days for the photosensitized fruit compared to the control of 28 days under the same conditions. In addition, no changes in physico-chemical characteristics were observed after treatment. The sanitization treatment of photosensitization mediated by CUR indicated a promising strategy in extending the shelf life of fresh date fruit. Clean and green technologies that are environmentally friendly like photosensitization are preferred by consumers to the synthetic chemicals used in conventional practices for sanitizing food.

Effect of water quality, sanitation, hand washing, and nutritional interventions on child development in rural Bangladesh (WASH Benefits Bangladesh): a cluster-randomised controlled trial

SummaryBackgroundPoor nutrition and hygiene make children vulnerable to delays in growth and development. We aimed to assess the effects of water quality, sanitation, handwashing, and nutritional interventions individually or in combination on the cognitive, motor, and language development of children in rural Bangladesh.MethodsIn this cluster-randomised controlled trial, we enrolled pregnant women in their first or second trimester from rural villages of Gazipur, Kishoreganj, Mymensingh, and Tangail districts of central Bangladesh, with an average of eight women per cluster. Groups of eight geographically adjacent clusters were block-randomised, using a random number generator, into six intervention groups (all of which received weekly visits from a community health promoter for the first 6 months and every 2 weeks for the next 18 months) and a double-sized control group (no intervention or health promoter visit). The six intervention groups were: chlorinated drinking water; improved sanitation; handwashing with soap; combined water, sanitation, and handwashing; improved nutrition through counselling and provision of lipid-based nutrient supplements; and combined water, sanitation, handwashing, and nutrition. Here, we report on the prespecified secondary child development outcomes: gross motor milestone achievement assessed with the WHO module at age 1 year, and communication, gross motor, personal social, and combined scores measured by the Extended Ages and Stages Questionnaire (EASQ) at age 2 years. Masking of participants was not possible. Analyses were by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01590095.FindingsBetween May 31, 2012, and July 7, 2013, 5551 pregnant women residing in 720 clusters were enrolled. Index children of 928 (17%) enrolled women were lost to follow-up in year 1 and an additional 201 (3%) in year 2. 4757 children were assessed at 1 year and 4403 at 2 years. At year 1, compared with the control group, the combined water, sanitation, handwashing, and nutrition group had a higher rate of attaining the standing alone milestone (hazard ratio 1·19, 95% CI 1·01–1 ·40), and the nutrition group had a higher rate of attaining the walking alone milestone (1·32, 95% CI 1·07–1·62). The combined water, sanitation, handwashing, and nutrition group had a higher rate of attaining the walking alone milestone than those in the water, sanitation, and handwashing group (1·29, 1·01–1·65). At 2 years, we noted beneficial effects in the combined EASQ score in all intervention groups, with effect sizes smallest in the water treatment group (difference 0·15, 95% CI 0·04 to 0·26 vs control) and largest in the combined water, sanitation, handwashing, and nutrition treatment group (0·37, 0·27–0·46).InterpretationImprovements in water quality, handwashing, sanitation, or nutrition supported by intensive interpersonal communication, when delivered either individually or in combination, contributed to improvements in child development. A crucial next step is to establish whether similar effects can be achieved with reduced intensity of promoter contacts that could be supported in large-scale interventions.FundingBill & Melinda Gates Foundation.

The occurrence and distribution of antibiotics in the Karst river system in Kaiyang, Southwest China

Abstract To our knowledge, this was the first study to investigate the occurrence and distribution of antibiotics in the Karst river system in Kaiyang, Southwest China. Ten water samples were collected from the Karst river in Kaiyang, Southwest China. Thirty-five antibiotics, including nine sulfonamides, four tetracyclines, five macrolides, sixteen quinolones and chloramphenicol, were analyzed. The results suggest that antibiotics are widely prevalent in the Karst river, with macrolides and quinolones being the most dominant and occupying 47% and 43% of total antibiotic concentration, respectively. The maximum total concentrations of sulfonamides, tetracyclines, macrolides, and quinolones were 30.4, 421, 884, and 1,807 ng/L, respectively. Lincomycin, roxithromycin, nalidixic acid, ofloxacin, and norfloxacin were detected in all samples with a detection frequency of 100%. The main sources of antibiotics were wastewater treatment plants (WWTPs) and rural dumps that did not contain sanitary treatment, which accounted for 33% and 40% of the total antibiotics present in the Karst river. Due to an increase in river flow quantity, the presence of WWTPs and rural dumps did not affect the concentration and distribution of antibiotics in the Karst river; however, the mass flux of antibiotics were significantly affected by the contamination source and the poor natural attenuation.

Decontamination and survival of Enterobacteriaceae on shredded iceberg lettuce during storage

Enterobacteriaceae family can contaminate fresh produce at any stage of production either at pre-harvest or post-harvest stages. The objectives of the current study were to i) identify Enterobacteriaceae species on iceberg lettuce, ii) compare the decontamination efficiency of water, sodium hypochlorite (free chlorine 200 ppm), peroxyacetic acid (PA 80 ppm; Kenocid 2100®) or their combinations and ionizing radiation against Enterobacteriaceae on shredded iceberg lettuce and iii) determine the survival of Enterobacteriaceae post-treatment storage of shredded iceberg lettuce at 4, 10 and 25 °C, for up to 7 days. Klebsiella pneumonia spp. pneumonia, Enterobacter cloacae, Klebsiella oxytoca, Pantoea spp., Leclercia adecarboxylata and Kluyvera ascorbate were identified on iceberg lettuce. No significant difference (P≥ 0.05) among Enterobacteriaceae survival after washing with water or sanitizing with sodium hypochlorite or Kenocid 2100® (reduction ≤ 0.6 log CFU/g) were found. Combined sanitizer treatments were more effective against Enterobacteriaceae than single washing/sanitizing treatments. Sanitization of iceberg lettuce with combined washing/sanitizing treatments reduced Enterobacteriaceae by 0.85–2.24 CFU/g. Post-treatment growth of Enterobacteriaceae during storage on samples sanitized with sodium hypochlorite and Kenocid 2100® was more than on samples washed with water. The D10-value of Enterobacteriaceae on shredded iceberg lettuce was 0.21 KGy. The reduction of Enterobacteriaceae populations on iceberg after gamma radiation (0.6 KGy) was 3 log CFU/g, however, Enterobacteriaceae counts increased post-irradiation storage by 4–5 log CFU/g. Therefore, washing shredded iceberg lettuce with combined sanitizing treatment (sodium hypochlorite/sodium hypochlorite, sodium hypochlorite/Kenocid 2100®, or Kenocid 2100®/Kenocid 2100®) for total time of 6 min or exposing it to gamma irradiation (0.6 KGy) can decrease the risk of Enterobacteriaceae (reduction ≥ 2 log). Post-washing storage of sliced iceberg lettuce (4, 10, 25 °C) could increase the risk of Enterobacteriaceae as their counts increased during storage even at low temperatures.

Suppression of female melon fly, Zeugodacus cucurbitae, with cue‐lure and fipronil bait stations through horizontal insecticide transfer

AbstractMelon fly, Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae), is an important quarantine tephritid fruit fly with resident populations established in Hawai'i, USA. In the male‐annihilation approach, male flies are targeted using dispensers with cue‐lure (C‐L) and insecticides, typically organophosphates. The efficacy of the male annihilation approach is thought to be limited to individual male flies, contacting the lure and the pesticide, after which they die. Alternative classes of insecticides, such as fipronil, have been investigated for use in male‐annihilation. We hypothesized that ingestion of fipronil by male flies could lead to horizontal transfer and mortality in female flies. Horizontal insecticide transfer extends pesticide control beyond the individual contacting the toxicant through indirect contact via food sharing or other mechanisms. We tested the possibility for horizontal transfer of fipronil from male to female Z. cucurbitae through field and laboratory studies. Two repeated field trials were conducted to compare the numbers of female flies collected in fields treated with Amulet C‐L (0.34% fipronil active ingredient) bait stations, sanitation, and spot treatments of GF‐120 Fruit Fly Bait to numbers collected in fields where sanitation and spot‐treatments were used without Amulet C‐L. In fields with Amulet C‐L bait stations in conjunction with sanitation and weekly protein bait spot treatments of GF‐120 Fruit Fly Bait, female captures were significantly lower than those in field plots treated with weekly protein bait spot treatments and sanitation. In subsequent laboratory studies, all females died within 6 h after direct exposure to male flies that had access to Amulet C‐L for 1–4 min. The possibility that male regurgitant could be a mechanism for horizontal transfer and subsequent female mortality was determined by collecting regurgitated droplets from fipronil‐fed male flies and feeding them to males and females. Both male and female flies exposed to regurgitant from fipronil‐fed male flies or droplets containing fipronil had higher mortality than the male and female flies that were exposed to regurgitant or droplets with only the C‐L compound or sugar solution. Thus, female flies do experience mortality from exposure to regurgitant from males that have fed on fipronil laced solutions. This provides evidence of at least one mechanism of horizontal transfer of insecticide in tephritid fruit flies. These findings are discussed in the context of Z. cucurbitae integrated pest management programs in Hawai'i.

Sanitary, physiological quality and alternative treatments of Dimorphandra gardneriana Tul. seeds

Sanitary, physiological quality and alternative treatments of Dimorphandra gardneriana Tul. seeds

English

Sanitization is considered as essential for the microbial control of vegetables. The aim of this study was to evaluate the sanitization procedures used in commercial restaurants located in Vit&oacute;ria, Brazil. The efficacy of these sanitization procedures in reducing the presence of natural microbiota and Salmonella enterica Enteritidis cells on tomatoes were evaluated. All the restaurants in this study applied the sanitization methods using containers for diluting the sanitization solution. After the sanitization treatments, a reduction in mesophilic aerobic counts, yeasts, moulds and S. enterica occurred in all the treatments. A higher reduction in microorganisms was observed after treatment with 2% acetic acid. There was no significant difference between tomatoes treated with a sodium dichloroisocyanurate solution and sodium hypochlorite for all microorganisms which were evaluated. Chlorinated compounds are the most used products but a limitation in microbial inactivation was observed in this study. &nbsp; Key words: Disinfection, tomatoes, Salmonella enterica Enteritidis, acetic acid, quality control, sanitization protocols.

Modelling the impact of future socio-economic and climate change scenarios on river microbial water quality.

Microbial surface water quality is important, as it is related to health risk when the population is exposed through drinking, recreation or consumption of irrigated vegetables. The microbial surface water quality is expected to change with socio-economic development and climate change. This study explores the combined impacts of future socio-economic and climate change scenarios on microbial water quality using a coupled hydrodynamic and water quality model (MIKE21FM-ECOLab). The model was applied to simulate the baseline (2014-2015) and future (2040s and 2090s) faecal indicator bacteria (FIB: E. coli and enterococci) concentrations in the Betna river in Bangladesh. The scenarios comprise changes in socio-economic variables (e.g. population, urbanization, land use, sanitation and sewage treatment) and climate variables (temperature, precipitation and sea-level rise). Scenarios have been developed building on the most recent Shared Socio-economic Pathways: SSP1 and SSP3 and Representative Concentration Pathways: RCP4.5 and RCP8.5 in a matrix. An uncontrolled future results in a deterioration of the microbial water quality (+75% by the 2090s) due to socio-economic changes, such as higher population growth, and changes in rainfall patterns. However, microbial water quality improves under a sustainable scenario with improved sewage treatment (-98% by the 2090s). Contaminant loads were more influenced by changes in socio-economic factors than by climatic change. To our knowledge, this is the first study that combines climate change and socio-economic development scenarios to simulate the future microbial water quality of a river. This approach can also be used to assess future consequences for health risks.

Impact assessment of wastewater and planning for a treatment plant within Sulaimani City, Iraq

Recently, problem of wastewater of Sulaimani City emerged which is discharged directly to Tanjero River. Samples were taken from nine outlets of sewer systems for analysis. Results showed the range of temperatures 27–12°C and pH 8.36–6.77, while electrical conductivity is 1689–720 μS/cm, total dissolved solid 1124–480 mg/l, turbidity 240–15 NTU, total hardness 413.1–129.9 mg/l, calcium 144–39.6 mg/l, magnesium 43.2–6.4 mg/l, alkalinity 570–224.2 mg/l, nitrate 51.2–8.7 mg/l, chemical oxygen demand 116–65 mg/l, biochemical oxygen demand 79.5–66.75 mg/l, chloride 253.1–36.8 mg/l, sulfate 141.5–35.9 mg/l, Zn 0.0754–0.0053 mg/l, Cd 0.022–0.0001 mg/l, Cr 0.0421–0.0043 mg/l, Cu 0.0707–0.0014 mg/l, Pb 0.21–0.0064 mg/l, and Fe 0.2421–0.0135 mg/l, and found that the concentrations of most parameters are high at S8, which is an industrial area. For studying the environmental effects of Tanjero River on the inhabitant surrounding, questionnaire was distributed over 31 areas and shows that the regions suffering from health and environmental problems represented about 48% of the areas have chronic diseases, 10% have diarrhea, 10% have typhoid, 10% have skin diseases, 6% have cancer, and others have more than one disease. And most of chronic diseases are diabetes and hypertension. Livestock watering affected on poultry and sheep more than cow and goat as well as extinction of fisheries in the river. Cultivation of vegetables in the areas dropped considerably due to water pollution and fade rice cultivation in the areas. Therefore, building of two wastewater treatment plants with constructing CSO structure with retention basin for stormwater coming from the mountains should be adopted, in addition to pretreatment procedure for industrial wastewater and proper on-site sanitation treatment for those that are not connected to the sewer system.

Effect of Pseudomonas aeruginosa on the sanitizer sensitivity of Salmonella Enteritidis biofilm cells in chicken juice

Salmonella Enteritidis may be encountered in poultry processing plants in the form of biofilms on food contact surfaces. Little is known about the fate of Salmonella in mixed-species biofilms with other bacteria commonly found in food processing environment. Thus, the objectives of this study were to determine biofilm formation and sanitizer resistance of two S. Enteritidis strains (rdar and bdar, cellulose expression positive and negative, respectively), in the absence and presence of Pseudomonas aeruginosa, under conditions encountered in poultry processing plants. S. Enteritidis in single-species and dual-species biofilms with P. aeruginosa at two mixed ratios (Salmonella: Pseudomonas cells at 1:1 and 0.01:1, respectively) were formed on stainless steel coupons in chicken juice for 6 days at 25 °C. On days 1 and 6 of the incubation period, biofilm cell populations were determined before and after chlorine treatment (50 ppm, 1 min). Results showed that population of S. Enteritidis in dual-species biofilms was significantly lower (P < 0.05) than that in single-species biofilms on day 6. On the other hand, S. Enteritidis in dual-species biofilms demonstrated greater chlorine resistance, with an average of 1 log CFU/cm2 lower reduction than that in single-species biofilms, except for the rdar strain which became more sensitive to chlorine treatment in dual-species biofilms after 6 days. Fluorescence microscopy images showed that more glycoconjugates were present in the dual-species biofilms, which might have contributed to the enhanced chlorine resistance of S. Enteritidis. Thus, this study indicates that although the presence of P. aeruginosa could negatively influence S. Enteritidis biofilm formation, it might protect Salmonella cells from sanitizer treatment in poultry processing environment.

Efficacy of non-chlorine sanitizer, precooling and modified atmosphere packaging in improving shelf life of tomato during evaporative cooling and CoolBot cold storage

This study combined the use of non-chlorine sanitizer, precooling and modified atmosphere packaging (MAP) as prestorage treatments for tomato kept in a simple evaporative cooler (EC) or CoolBot cold storage (CS). Precooling was done by dipping the fruit in 10°C water until fruit temperature decreased to 13-15°C. As a non-chlorine sanitizing treatment, dipping fruit in 0.01% calcinated calcium (CCa) for 5 min at ambient temperature was used. For a combined precooling and sanitizing treatment, 10°C CCa solution was used. Tomatoes were stored in the EC or CS. Ambient storage was included for comparison. Fruits of a summer tomato cultivar, 'BARI Tomato-8', were used in this study. EC temperatures (24.3-27.5°C) were consistently lower and less fluctuating than ambient temperatures (27.8-31.0°C). The CoolBot temperature was maintained at 13±1°C. RH was about 75±2% in CS, whereas it was 75-95% under ambient conditions and 85-99% in the EC. Because of these conditions, together with the relatively high temperatures, fruit rotting was favored and limited the shelf life to 12-13 days, both under ambient conditions and in the EC. Fruit in the CS lasted for 18 days. Rotting affected ˃50% of the fruit on day 15 of ambient storage and of EC storage. In the CS, fruit rotting was first noted on day 9, increased gradually, and reached around 14-18% on day 18. Sanitizing treatment had little effect, but precooling had no extra benefits in reducing rot incidence. MAP significantly reduced weight loss in all storage conditions, showing a greater effect in the CS. Changes in fruit firmness and surface color were delayed significantly in CS compared with ambient conditions or EC storage. After 18 days of storage, the firmness of tomatoes remained higher when stored in CS, showing values of about 5.0 N. Vitamin C content was effectively maintained in the CS, and was about 12.6 mg 100 g-1 after 18 days of storage. EC- and ambient-stored fruit, on the other hand, had similar vitamin C contents at the end of their 12-day storage life.

Optimization of microbiological methods for food control based on the differential-diagnostic media for the isolation and cultivation of bacteria of the genus Campylobacter

А screening study on the detection of campylobacteria in raw food products, semi-finished products and objects in the external environment in the poultry processing industry was conducted. The highest level of detection of campylobacteria is set for raw poultry products, including carcasses of broilers, turkeys and quail. A general accordance of getting Campylobacter in raw materials and food products with inadequate sanitary treatment of separate areas of production has been established: in most cases Campylobacter spp. was extracted from the samples, contaminated with coliform bacteria and Salmonella. It is shown that the frequency of contamination of raw poultry with pathogens is largely dependent on the cooling of the carcasses. When using the immersion method, the conditions for cross contamination with pathogens through water bath cooling are present (45% of samples infected with Campylobacter spp.). Under combined use of super-cooled water and aerosols Campylobacter were also detected quite often in 27% of samples. Contamination by pathogens was the lowest in evaporative cooling method with the use of antimicrobial hydrospray (less than 5% positive samples), allowing to recognize this method as the most promising for the production of microbiological safe products. The work on optimization of nutrient medium composition and adaptation recommended methodological scheme of analysis for detection and species identification of bacteria of the genus Campylobacter was carried out. Formulation of traditionally used growth media was modified, and balanced composition of growth and selective components was matched in accordance with the requirements of existing standards. Given the urgency of increasing the effectiveness of the methods of control of campylobacteria in foods and the lack of domestic analogues of the culture media in the Russian Federation, an optimized method for the production of dry nutrient media for the detection, identification and storage of campylobacteria isolated from food products and clinical material was developed. The conducted study allowed to develop Technical conditions 21.20.23-006-01897222-2016 «Dry culture medium for detection of bacteria of the genus Campylobacter» and «Instruction for use of culture media». Depending on the purpose of the medium produced in the following versions: the selective broth for enrichment of campylobacteria; differential selective agar for isolating and quantifying of Campylobacter spp.; semi-solid nutrient agar for cryostorage of Campylobacter strains. The list of criteria for assessing the quality of commercially available lots of dry media included: solubility, pH, gel strength of agar, the content of amine nitrogen, specificity, selectivity, growth and inhibitory properties. The practical application of these media in terms of the national laboratories will significantly simplify the use of existing standards developed based on international ISO standards, but not adapted to the main range of commercial media and reagents used in routine food control for the presence of campylobacteria.

Anti-biofilm effect of 405-nm LEDs against Listeria monocytogenes in simulated ready-to-eat fresh salmon storage conditions

The objective of this study was to evaluate the anti-biofilm effect of 405-nm light-emitting diodes (LEDs) against Listeria monocytogenes in salmon exudate at 4, 15, and 25 °C, and to compare the susceptibility of LED-illuminated and non-illuminated pre-formed biofilm cells to sanitizer treatment. For the biofilm-forming scenario, stainless-steel (SS) or acrylic (AC) coupons in sterilized salmon exudate were inoculated with L. monocytogenes and then illuminated with 405-nm LEDs (26 ± 2 mW/cm2) at each temperature for 8 h. For the pre-formed biofilm scenario, L. monocytogenes biofilms were pre-formed onto each coupon at 25 °C for 24 h and subsequently illuminated at each temperature, followed by treatment with 200 ppm quaternary ammonium compound (QAC) for 10 s to compare the sensitivity of LED-illuminated biofilm cells to the sanitizer treatment. Regardless of illumination temperature, the results showed that 405-nm LED illumination significantly (P < 0.05) reduced both planktonic and biofilm cell populations on SS and AC coupons during biofilm formation. There were no significant (P ≥ 0.05) changes in the planktonic and biofilm cell populations, for the pre-formed biofilm scenario, in response to LED illumination at 4 and 15 °C. However, significant biofilm cell reductions were observed on SS and AC coupons in response to LED illumination at 25 °C for 8 h. Regardless of coupon type, LED-illuminated biofilm cells were found to be more sensitive to QAC treatment under the pre-formed biofilm scenario than non-illuminated cells. These results indicate that 405-nm LED illumination may be effective in controlling L. monocytogenes during the biofilm formation process, and at inducing sensitivity to sanitizer treatment in pre-formed biofilm cells. Thus, this study suggests the potential of LED technology in controlling L. monocytogenes biofilms during the processing and storage of ready-to-eat salmon, minimizing the chance of cross-contamination from contaminated surfaces.

Sewage treatment effluents in Delhi: A key contributor of β-lactam resistant bacteria and genes to the environment

Rapid emergence of antibiotic resistance (AR) in developing countries is posing a greater health risk and increasing the global disease burden. Lack of access to safe drinking water, poor sanitation and inadequate sewage treatment facilities in these countries are fueling the problem associated with emergence of AR. Rapid proliferation of AR mediated by treated and untreated discharges from sewage treatment plants (STPs) is a prime public health concern. This study aims to understand the occurrence, fate, and routes of proliferation of carbapenem (KPC) and extended spectrum β-lactam (ESBL) resistant bacteria, and selected resistant genes in the samples collected from different unit operations in 12 STPs in New Delhi over two seasons. Strong correlation observed between faecal coliform levels and KPC (R = 0.95, p = 0.005, n = 60) and ESBL (R = 0.94, p = 0.004, n = 60) resistant bacteria levels indicates possible association of resistant bacteria with faecal matter. Different unit operations in STPs proved inefficient in treating resistant bacteria and genes present in the wastewater. However, inclusion of tertiary treatment (chlorination) unit and anaerobic digester in the present STPs resulted in better removal of AR. Significant correlations between antibiotic resistant genes (ARGs) and integron levels indicates a potential for higher rate of AR proliferation in the environment. Microbial culturing indicated the presence of clinically significant drug-resistant pathogens such as Escherichia coli, Pseudomonas putida, Pseudomonas aeruginosa, Enterobacter cloacae, Klebsiella pneumoniae, Klebsiella oxytoca, Acinetobacter baumannii, Shigella dysentery and Aeromonas caviae in the STP effluents. The emergence and spread of resistant bacteria through STP effluents poses exposure risk for the residents of the city.

Inactivation of Ascaris Eggs in Human Fecal Material Through In Situ Production of Carboxylic Acids.

Discovering new ways to inactivate pathogens in human waste is critical for the improvement of worldwide access to sanitation and for the reduction of the environmental impact of conventional waste treatment processes. Here, we utilized the carboxylate platform and chain elongation to produce n-butyric acid and n-caproic acid via the anaerobic fermentation of human fecal material. Then, we inactivated Ascaris eggs through exposure to these carboxylic acids. Using batch experiments with human fecal material as substrate, we accumulated n-butyric acid and n-caproic acid at total concentrations (uncharged acid plus conjugate base) of 257 and 27.1 mM, respectively. We then showed that carboxylic acids at these concentrations inactivated Ascaris eggs when the pH was below the pKa for the acids, causing them to exist primarily in the uncharged forms. We observed that uncharged carboxylic acids affected viability rather than the pH itself or conjugate bases. In addition, we modeled the viability of Ascaris eggs as a function of uncharged carboxylic acid concentration for n-butyric acid and n-caproic acid at exposure times of 2, 6, 12, and 20 days. The results presented here indicate that in situ biological production of carboxylic acids in HFM provides a promising method of pathogen inactivation and may lead to new developments in sanitation technology and treatment of fecal sludge.

Climate Forecast Perception and Needs in Wetlands: a Case Study in the Inner Niger Delta in Mali

Climate prediction is often presented as an efficient strategy for African farmers living in wetlands to better adapt to climate variability. This study focuses on the demand for climate information among water users of the Inner Niger Delta, which are the rice farmers, herders and fishermen. In the Delta, productions are closely associated with the complex fluvial-rain system. Users need information about both the coming rainy season and the floods which are conditioned by upstream basins rainfall. The required information includes the onset of the rainy season, the onset of the flooding of the plains, the duration of this flooding; and the probable maximum heights of the flood. Nevertheless, a good production year is conditioned by high flood, long flood for plains submersion duration and late flood compared with the start of local rainy seasons. Adjustment of practices based on climate information ranges from mobilizing effective means for field preparation and location to the seeding time for farmers. For herders, the information determines livestock entry and exit from the delta, the herd size management and sanitary treatments. For fishermen, the adjustment relates to the starting time of his activities, gear, fishing effort and the choice of the fishing location.

Slightly acidic electrolyzed water combined with chemical and physical treatments to decontaminate bacteria on fresh fruits

Effect of sequential combination of slightly acidic electrolyzed water (SAEW) with chemical and physical treatments on bacterial decontamination on fruits was investigated in this study. Effect of treatments on microbial and sensory quality was also analyzed after subsequent storage at 4 °C and room temperature (RT, 23 ± 0.15 °C). Whole apple and tomato fruits were inoculated with cocktail strains of Escherichia coli O157:H7 and Listeria monocytogenes. Uninoculated and inoculated fruits were washed first with distilled water (DW), calcium oxide (CaO), fumaric acid (FA), and SAEW at RT for 3 min. Combinations were performed by adding treatment one at a time to SAEW as following FA + SAEW, CaO + FA + SAEW, and CaO + FA + SAEW + ultrasonication (US) or microbubbles (MB). All the sanitizer treatments resulted in significant (p < 0.05) bacterial reduction compared to DW used as control. Increasing the treatments in combination from FA + SAEW to CaO + FA + SAEW + US resulted in an increased bacterial decontamination. The cavitation induced by ultrasonication in FA + SAEW solution resulted in a higher additive effect in decontamination of Escherichia coli O157:H7 and Listeria monocytogenes compare to the agitation generated by microbubble generator in FA + SAEW solution. CaO + FA + SAEW and CaO + FA + SAEW + US were effective in improving the microbial safety and quality of apple fruits. However, additional treatment of US impacted on the quality of tomato fruits during storage at RT. Therefore, a combination of SAEW with sanitizers (CaO and FA) and mechanical force (Ultrasonication) has the potential to be used in postharvest sanitation processing in the fresh fruit industry.

A Monitoring System for Laying Hens That Uses a Detection Sensor Based on Infrared Technology and Image Pattern Recognition.

In Italy, organic egg production farms use free-range housing systems with a big outdoor area and a flock of no more than 500 hens. With additional devices and/or farming procedures, the whole flock could be forced to stay in the outdoor area for a limited time of the day. As a consequence, ozone treatments of housing areas could be performed in order to reduce the levels of atmospheric ammonia and bacterial load without risks, due by its toxicity, both for hens and workers. However, an automatic monitoring system, and a sensor able to detect the presence of animals, would be necessary. For this purpose, a first sensor was developed but some limits, related to the time necessary to detect a hen, were observed. In this study, significant improvements, for this sensor, are proposed. They were reached by an image pattern recognition technique that was applied to thermografic images acquired from the housing system. An experimental group of seven laying hens was selected for the tests, carried out for three weeks. The first week was used to set-up the sensor. Different templates, to use for the pattern recognition, were studied and different floor temperature shifts were investigated. At the end of these evaluations, a template of elliptical shape, and sizes of 135 × 63 pixels, was chosen. Furthermore, a temperature shift of one degree was selected to calculate, for each image, a color background threshold to apply in the following field tests. Obtained results showed an improvement of the sensor detection accuracy that reached values of sensitivity and specificity of 95.1% and 98.7%. In addition, the range of time necessary to detect a hen, or classify a case, was reduced at two seconds. This result could allow the sensor to control a bigger area of the housing system. Thus, the resulting monitoring system could allow to perform the sanitary treatments without risks both for animals and humans.

Fresh produce sanitization by combination of gaseous ozone and liquid sanitizer

The effect of different combinations of gaseous ozone and Pro-San L against Escherichia coli on baby spinach was investigated. Three different ways to combine liquid and gaseous sanitizer application were compared. The most effective combination was the initial spray application of Pro-San L (0.66% Citric acid, 0.036% SDS) followed by vacuum cooling and ozonation under pressure of 68.9 kPa (10 PSIG) which reduced E. coli O157:H7 counts by 3.9 log CFU/g. Spray application of Pro-San L after the gaseous ozone injection under vacuum followed by immediate system pressurization to 68.9 kPa was less effective (2.7 log CFU/g reduction) due to vacuum internalization of bacteria deeper into produce tissue. This method was not significantly different from a single application of liquid sanitizer. Spray Pro-San L application followed by a long term (up to three days) gaseous ozone treatment decreased microbial load to an undetectable level after the first day of application. However the increase of exposure time to sanitizers led to some damage of spinach leaves. Long term combination liquid-gaseous sanitizer treatment resulted in better appearance of fresh produce than a single application of liquid and gaseous sanitizers.

Effect of the precutting process on sanitizing treatments for reducing pathogens in vegetables.

The effectiveness of sanitizing treatments was investigated on reducing pathogens inoculated in whole or cut fresh vegetables, including Brussels sprouts, carrots, cherry tomatoes, paprika, and lettuce. These products were inoculated with Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes and then treated with chlorine and alcohol sanitizers, followed by the subsequent washing procedure in sterile distilled water at 25°C for 5min. Alcohol sanitizer was the most effective in inhibiting E. coli O157:H7, S. Typhimurium, and L. monocytogenes on cut Brussels sprouts, showing bacterial reductions of 4.16, 3.60, and 3.26 log CFU/g, respectively. Interestingly, the effects of sanitizing treatments were significantly lower for fresh cut produce than those for whole products (p<0.05), indicating that the effectiveness of sanitizers would be different, depending on fresh produce and the pre-cut process. Therefore, further information should be obtained to develop an effective sanitizing treatment for fresh produce.