Reduction Of Microbial Load Research Articles

Evaluation of Efficiency and Extent of Inhibitory Characteristics of Lactobacillus spp. (Lactobacillus plantarum) against Selected Pathogenic Bacteria

Background: Despite the improved modern technologies to inactivate pathogens, there has been a continuous surge of food-borne diseases involving many bacterial pathogens like Staphylococcus aureus, Escherichia coli, Bacillus cereus, Salmonella, Campylobacter, Listeria etc. Physical methods of reduction of microbial load in raw foods have been known to negatively impact the organoleptic properties of the products hence reducing their acceptability. Therefore, knowing that food may be laden with many pathogens, the biocontrol methods may be an effective alternative to chemical and physical methods of preservation for eliminating pathogens. Methods: The pathogens to be tested in the experiment were recovered from various food sources and clinical samples viz., milk, raw chicken and a faecal sample, chicken. For evaluation of inhibitory characteristics of Lactobacillus spp. (Lactobacillus plantarum) against selected pathogenic bacteria the grown culture of pathogens (S. aureus, E. coli, B. cereus) was added with Lactobacillus spp. at different concentrations and incubated at 24, 36 and 48 hrs and mean CFU units were evaluated. All of the treated groups were compared with the concurrent untreated groups of respective bacteria. Result: After 24 hrs of incubation at 37°C, the mean colony forming units (CFU/ml) of S. aureus, E. coli, B. cereus in the cultured groups treated with 108, 107, 106, 105 and 104/ml of L. plantarum were 2.56 x 108, 2.78 x 108, 2.90 x 108, 3.03 x 108 and 39.19 x 108; 0.81 x 108, 1.09 x 108, 1.36 x 108, 1.85 x 108 and 24.62 x 108; 0.31 x 108, 0.43 x 108, 0.60 x 108, 0.69 x 108 and 7.12 x 108, respectively. Henceforth, the mean colony forming counts of all the three pathogens increased when the concentration of L. plantarum decreased.

High-Speed and High-Pressure Homogenization Techniques for Optimization of Food Processing, Quality, and Safety

The current review presents the advantages and health benefits of the fast growing homogenization techniques for improving food processing using the high-speed homogenization (HSH) and the high-pressure homogenization (HPH) to overcome the main problems encountering food manufacturers, merchandizers and end consumers which are the short shelf-life or nonconformity of food products. HSH and HPH are considered as an efficient alternative tool to thermal processes that cause many undesirable effects such as nonenzymatic browning (NEB), off-flavor or degradation of bioactive components. HPH treatment contributes to microbial load reduction and enzyme inactivation with increase of functionality in terms of health effect by increasing bioavailability by favoring the release of bioactive compounds, modified structures of biopolymers with improvement of novel interactions within particles networking. Homogenizers vary according to the purpose needed to achieve. Laboratory Homogenizers provide research and development (R&D) scientists with more experimentation options and capabilities for emulsions, dispersions, cell rupture, and liposomes with the capability of innovations, improve existing products, and more efficient manufacturing. While the Pilot and Industrial Homogenizers offer unique flexibility to meet every customer’s particular requirements in reproducing the same product quality as developed in the laboratory with increasingly higher levels of plant integration with complete automation, controls and data acquisition. Many laboratory and industrial applications were cited here to highlight the significance of this powerful technology.

Effect of time and wattage power levels of microwave treatment on the microbial quality and safety of bovine raw milk

Raw milk is sterile when secreted by healthy cows, however it is contaminated with different microorganisms and Streptococci commonly present in the milk ducts as well as teats. The bacterial count in raw milk ranges from a few hundred to several thousand per mL of milk, however it is harmful to human health under unpasteurized condition. Milk sanitization methods rely on the principle of preventing the growth and development of microbes and thus maintaining their nutritional quality. This study was carried out to investigate the effect of microwave radiation on the microbial quality and safety of bovine raw milk. To do so, the effect of microwaves at a frequency of 35 KH and powers of 180, 300 and 850 W for 0, 30, 60 and 90 s on the destruction of pathogens and reduction of microbial load of milk (total bacterial count, coliforms, Escherichia coli, Staphylococcus aureus, molds and yeasts) was investigated. The results showed that microwave treatment had a significant effect on reducing the number of microorganisms in milk samples (p<0.0) with the power of 850 W being the most effective power for reducing the number of S. aureus, coliforms, molds, yeasts as well as total bacterial count. Faster heating with higher energy efficiency is the main advantage of the microwave process for foods. In fact, the microwave method can be a potential and effective method for decreasing the microbial load of raw milk.

Using low dose fungicide by combining with intermittent ozone treatment to reduce fungicide residue, microbial load and quality losses in orange fruit during long term storage

In the present study, the effects of intermittent ozone (IO3) application combined with low dose fungicide and high-dose dissolved ozone in water on storage life and quality of orange cv. Washington Navel were investigated. Harvested orange fruit were subjected to four different treatments: immersion in ozonated (4 mg L−1) water (OW) and only distilled water (Control) for 10 min, treatment with fungicide solutions containing 500 mg L−1 (half dose) and 1000 mg L−1 (common dose) imazalil (IMZ) for 60 s, respectively. Ozone and 500 mg L−1 IMZ treated fruit were kept in cold room under IO3 gas exposure (2.14 mg m−3) for 30 min at one-week intervals during cold storage. Other two groups (Control and 1000 mg L−1 IMZ) were stored at the same conditions without ozone exposure. Treated fruit were stored at 5 °C for 150 d. As a result, while the OW + IO3 treatment was more effective in reducing microbial load, 500 mg L−1 IMZ + IO3 was the best treatment for inhibiting decay rate of orange fruit during cold storage. Although the 1000 mg L−1 IMZ treatment provided a significant reduction in the initial microbial load, it could not maintain its effectiveness at the end of cold storage when compared to OW + IO3 treatment. The fungicide residue in 500 mg L−1 IMZ + IO3 treated fruit was significantly lower than that of common dose (1000 mg L−1 IMZ), as expected. The combined use of low dose IMZ with IO3 gas exposure also gave positive or at least similar results for quality losses compared to common dose during storage. Ozone and fungicide treatments significantly decreased the weight loss and respiration rate, and maintained the visual quality of orange compared to control. Collectively, these results suggest that 500 mg L−1 IMZ + IO3 and OW + IO3 treatments are potential techniques for maintaining the fruit quality of Washington Navel oranges during long term cold storage.

Antimicrobial Efficacy of Continuous Low-Irradiance Phototherapy Against Multidrug-Resistant Organisms.

Objective: The objective of this study is to report on the bactericidal effects of blue light administered at low irradiance for extended periods of time. Background: Multidrug-resistant organisms (MDROs) utilize biofilms that can limit the efficacy of antibiotics, causing infection and impaired wound healing. Unlike high-energy systems, continuous low-irradiance phototherapy (CLIP) avoids thermal injury of healthy tissue and can be delivered for extended periods. Methods: Four MDRO species, two of which contained different antibiotic resistance genes, were exposed to 405 nm irradiation in vitro. The microbes were incrementally exposed to increasing dose-rates (irradiance; mW/cm2) over a 24-h time period. Cell viability and biomass reduction assays were conducted to quantify the antibacterial/antibiofilm effects. Primary human dermal fibroblasts were also exposed to CLIP to assess whether these dose-rates would impair cell viability or proliferation. Results: CLIP exposure utilizing irradiances as low as 2.78 mW/cm2 delivered over 24 h resulted in a >3.0-log (>99.9%) and >2.0-log (>99.0%) microbial load reduction when organisms were grown in planktonic and biofilm-encapsulated conditions, respectively. Crystal violet biofilm assays revealed destruction of extracellular biofilm architecture following CLIP exposure. Human fibroblast viability and proliferation were unaffected by CLIP. Conclusions: This is the first report demonstrating the antimicrobial efficacy of CLIP for MDROs found in infected wounds. CLIP did not compromise cultured human fibroblast growth and survival. This study demonstrated that very low fluence rates (irradiances) delivered over extended periods are potently antimicrobial. There is translational potential for CLIP to be fabricated as a wearable device that would enable continuous ambulatory care of wounds.

Efficacy of the combination of P5 peptide and photodynamic therapy mediated by bixin and chlorin-e6 against Cutibacterium acnes biofilm

In this study, the action of antimicrobial peptide (AMP) P5 and antimicrobial photodynamic therapy (aPDT) mediated by bixin and chlorin-e6 (Ce6) on Cutibacterium acnes (C. acnes) in planktonic phase and biofilm were evaluated both as monotherapies and combined therapies. Microbial viability after treatments were quantified by colony-forming units per milliliter of the sample (CFU/mL) and have demonstrated that all treatments employed exerted bactericidal activity, reducing the microbial load by more than 3 log10 CFU/mL, also demonstrating for the first time in the literature the antimicrobial photodynamic effect of bixin that occurs mostly through type I mechanism which was proved by the quantification of superoxide anion production. Bacterial biofilm was completely eliminated only after its exposure to aPDT mediated by this PS, however, Ce6 proved to be a more efficient PS, considering that most of the photodynamic effect of bixin- aPDT was exerted by excitation of the endogenous C porphyrins of C. acnes with blue light. The combination of P5 with Ce6-aPDT showed a synergistic effect on the bacterial biofilm with a reduction in microbial load by more than 10 log10 CFU/mL, in which the ability of P5 to permeabilize the polymeric extracellular matrix of the biofilm explains the obtained results, with greater internalization of the PS as shown by the Confocal Laser Scanning Microscopy. One-way ANOVA (Analysis of Variance) with Tukey's post-test and two-way ANOVA with Bonferroni's post-test were used to compare the values of continuous variables between the control group and the treatment groups.

Evaluation of the Toxicity of Zinc Oxide Nanoparticles upon Staphylococcus Aureus and Escherichia Coliin Contaminated water

Background: Nanoparticles (NPs) have recently attracted extensive attention in the field of elimination and reduction of microbial load in various water resources. Accordingly, this study aimed to eliminate bacterial contamination from aqueous solutions using synthesized NPs. Methods: In the present study, zinc oxide (ZnO) and silver (Ag) ion-doped zinc oxide (Ag/ZnO, 1-6 wt%) nanoparticles were synthesized using the sol-gel process and then characterized in terms of structure, morphology, and antimicrobial activity. X-ray diffraction (XRD) was utilized to determine the nanoparticle size and crystal structure. Images from field emission-scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) confirmed the successful production of NPs. The antimicrobial activity of ZnO and Ag1-6%/ZnO against Staphylococcus aureus and Escherichia coli was assessed by the agar well diffusion method. Results: According to the findings, the synthesized ZnO had a hexagonal structure and the size of ZnO and Ag5%/ZnO were 32.56 nm and 12.81 nm, respectively; the field emission-scanning electron microscopy (FE-SEM) images showed that the nanoparticle sizes were 77.60 nm and 47.15 nm, respectively. Based on transmission electron microscopy (TEM) images, the mean size of ZnO and Ag5%/ZnO was 22.5 nm and 17.5 nm, respectively. The results showed that the diameter of the zone of inhibition created by Ag5%/ZnO at a concentration of 0.1 g/mL was 20 mm and 13 mm for S. aureus and E. coli, respectively. Conclusion: The results indicated that E. coli was more resistant than S. aureus, although E. coli was still more resistant at low concentrations.

Inactivation of Aspergillus niger and Erwinia carotovora in onion (Allium cepa L.) bulbs subjected to pulsed ozone treatment

A number of microbes are responsible for the spoilage of onion, notably black mold rot caused by Aspergillus niger and soft rot caused by Erwinia carotovora. This research investigates the efficacy of gaseous ozone for the inactivation of A. niger and E. carotovora inoculated on onion bulbs. Ozone concentrations of 0.21, 0.42, and 0.64 mg L−1 were applied to the inoculated bulbs in pulsed mode. The reduction in microbial load of A. niger and E. carotovora varied from 0.47 to 2.31 log CFU g−1 and 0.72 – 2.99 log CFU g−1 respectively. With an increase in concentration and number of exposures, the efficacy of ozone on microorganisms increased. SEM analysis revealed structural disintegration of bacterial cells and fungal spores with the severity of ozone application. Cellular leakage from the microbial cell determined spectrophotometrically confirmed the SEM observations. Geeraerd tail model (Radj2: 0.990–0.994, ERMS: 0.931–0.595 × 10−1) was found to be most suitable to describe the survival curve of A. niger; whereas, the Weibull model (Radj2: 0.988–0.991, ERMS: 1.102–0.701 × 10−1) fitted best to survival data of E. carotovora.

Effect of cold atmospheric plasma torch distance on the microbial inactivation and sensorial properties of ready-to-eat olivier salad.

This study aimed to investigate the effect of the cold atmospheric plasma torch (CAPT) nozzle distance from the surface of Olivier salad and the treatment time in the reduction of microbial load and sensory properties of the product simultaneously. In this study, the CAPT nozzle was placed at 3, 5, and 7 cm distances from the surface of the Olivier salad, and its efficiency in inactivating the microbial population, decimal reduction time (D-value), and sensory evaluation of the product were evaluated. The results showed that reducing the distance and increasing the plasma treatment time (30, 60, 90, and 120 s) both reduced the microbial load of the product. The maximum inactivation and the minimum D-value are related to the 3 cm distance for 120 s, which has been 3.77, 2.91, and 1.52 log CFU/g for Coliform, Total viable count (TVC), mold and yeast, respectively. The lowest D-value was related to Coliform (4.41 s). CAPT treatment had no significant sensible effect on the product's sensory characteristics compared to the control sample. The treated sample at a 3 cm distance for 90 s and the microbial reduction to an acceptable amount and high acceptancy from sensory evaluators were selected as the superior treatment in this study. Also, the results showed that CAPT could be used successfully in ready-to-eat (RTE) products.

Neutral electrolyzed water in chillers: A viable option in the microbiological disinfection of giblets chicken

During the processing of poultry, disinfectants are commonly added to cooling water tanks called “chillers” to reduce microorganism populations that can affect food quality. The present study, evaluated the effectiveness of neutral electrolyzed water in a pilot-project-sized chiller for the elimination of pathogenic microorganisms in gizzards and necks chicken. The microbiological analysis of the samples was processed and analyzed in three different food microbiological analysis laboratories. The results demonstrated a maximum microbial load reduction of 1.97686 log CFU/g for Escherichia coli and 1.76313 log CFU/g for Staphylococcus aureus in all samples processed with neutral electrolyzed water. Sodium hypochlorite, a disinfectant in common industrial use, did not achieve significant reductions in microbial loads below those of untreated necks and gizzards for either of the microorganisms in question. Based on these results, this study thus proposes the use electrolyzed water as an alternative disinfectant to sodium hypochlorite for use in chillers; being a sustainable solution that differs from conventional disinfectants in its lack of human or environmental side effects.

Ultrasonication as a novel processing alternative to pasteurization for camel milk: Effects on microbial load, protein profile, and bioactive properties

Ultrasonic technology presents a promising novel tool in the food industry for the processing of milk and dairy products. In this study, we investigated the effects of ultrasonication (US) as an alternative to thermal pasteurization for stabilization of the bioactive properties of camel milk. Camel and bovine milk samples were subjected to US at 6 different power levels (US1-US6), and 1 set of each type of milk was concurrently subjected to flash heat pasteurization (FHP) for comparative analysis (100 mL; n = 4). The microbiological and bioactive parameters of the samples were analyzed during 7 d of storage at 4°C. In both milk types subjected to US ≥ 140 W (US3), the bacterial load was reduced by almost 4 log cycles and complete reduction of microbial load was achieved with US = 170 W and US = 210 W (US5 and US6 treatments, respectively). No significant changes in protein patterns were observed with either FHP or US treatment. In addition, bioactive properties (cholesteryl esterase and pancreatic lipase inhibition) were either enhanced or retained at US3 or higher. 2,2'-Azino-bis-3-ethylbenzthiazoline-6-sulfonic acid and ferric reducing antioxidant power activities in camel milk were decreased after FHP treatment but increased or retained upon US, particularly at US3 and US4 (160 W). Overall, under our experimental conditions, US4 was effective in completely reducing the microbial count, while concomitantly retaining different bioactive properties of both camel and bovine milk. These outcomes highlight the potential of US at 160 W as an efficient nonthermal alternative processing method for milk.

Effects of pulsed light and aerosolized formic acid treatments on inactivation of Salmonella enterica on cherry tomato, reduction of microbial loads, and preservation of fruit quality

Fresh produce remains the leading cause of foodborne illness outbreaks. Novel nonthermal technologies are needed to reduce the risk of pathogen contamination. The objective of this study was to develop a novel intervention technology exploiting integration of high intensity short time (10 s) pulsed light (PL) and aerosolized formic acid (AFA) for inactivation of Salmonella and maintenance of quality of cherry tomato. Smooth surface of tomatoes, inoculated with a cocktail containing three serotypes of Salmonella enterica, was treated with PL for 10 s followed by 2 min treatment with 1% AFA. Non-inoculated tomatoes were used to study the treatment effects on native microflora and quality. PL delivered significant inactivation at low doses. An optimal 10 s PL treatment equivalent to a dose of 10.5 J/cm2, provided 2.2 log CFU/g reduction while a 2 min exposure in 1% AFA antimicrobial yielded comparatively low, 1.7 log CFU/g reductions of Salmonella on tomato. The combination treatments of PL (10 s) followed by 1% AFA (2 min) provided additive inactivation yielding 4.2 log CFU/g reductions (P ≤ 0.05) of the pathogen. During cold storage (10 °C) the survivor population declined further providing 4.8 log CFU/g reductions on day 21. The combination PL-AFA treatment significantly reduced the native microbiota of tomato and also hindered their growth while in storage for three weeks. Mold and yeast (M&Y) spoilage organism populations declined to below the detection level. Furthermore, the quality factors as firmness and color of tomatoes were not significantly affected by the combination treatments. The treatment boosted the redness appearance of tomatoes indicating favorable consumer acceptability. Overall, our results demonstrate that combination of PL and AFA treatment could potentially be used as a novel approach to enhance microbial safety and quality of tomatoes.

Making a meal out of bugs

Making a meal out of bugs

Yield optimization, microbial load analysis, and sensory evaluation of mungbean (Vigna radiata L.), lentil (Lens culinaris subsp. culinaris), and Indian mustard (Brassica juncea L.) microgreens grown under greenhouse conditions.

Microgreens have been used for raw consumption and are generally viewed as healthy food. This study aimed to optimize the yield parameters, shelf life, sensory evaluation and characterization of total aerobic bacteria (TAB), yeast and mold (Y&M), Escherichia coli, Salmonella spp., and Listeria spp. incidence in mungbean (Vigna radiata (L.) Wilczek), lentil (Lens culinaris Medikus subsp. culinaris), and Indian mustard (Brassica juncea (L.) Czern & Coss.) microgreens. In mungbean and lentil, seeding-density of three seed/cm2, while in Indian mustard, eight seed/cm2 were recorded as optimum. The optimal time to harvest mungbean, Indian mustard, and lentil microgreens were found as 7th, 8th, and 9th day after sowing, respectively. Interestingly, seed size was found highly correlated with the overall yield in both mungbeans (r2 = .73) and lentils (r2 = .78), whereas no such relationship has been recorded for Indian mustard microgreens. The target pathogenic bacteria such as Salmonella spp. and Listeria spp. were not detected; while TAB, Y&M, Shigella spp., and E. coli were recorded well within the limit to cause any human illness in the studied microgreens. Washing with double distilled water for two minutes has shown some reduction in the overall microbial load of these microgreens. The results provided evidence that microgreens if grown and stored properly, are generally safe for human consumption. This is the first study from India on the safety of mungbean, lentils, and Indian mustard microgreens.

Bactericidal efficacy of a low concentration of vaporized hydrogen peroxide with validation in a BSL-3 laboratory

Highly infective pathogens are cultured and studied in biosafety laboratories. It is critical to disinfect these laboratories thoroughly in order to prevent laboratory infection. A whole-room, non-contact, reduced corrosion disinfection strategy using hydrogen peroxide was proposed and evaluated. To evaluate the bactericidal efficacy of 8% and 10% vaporized hydrogen peroxide (VHP) in a laboratory setting, with spores and bacteria used as bioindicators. Spores of Bacillus atrophaeus and Bacillus stearothermophilus, along with Escherichia coli, Staphylococcus aureus and Staphylococcus albus bacteria were placed in pre-selected locations in a sealed laboratory, and an OXY-PHARM NOCOSPRAY2 VHP generator was applied. Spore killing efficacy was evaluated qualitatively, bactericidal efficacy was analysed quantitatively, and the mean log10 reduction was determined. Finally, the optimized disinfection strategy was verified in a biosafety level 3 (BSL-3) laboratory. Significant reductions in microbial load were obtained for each of the selected spores and bacteria when exposed to VHP 8% and 10% for 2-3h. S.aureus was found to be more resistant than E.coli and S.albus. Tests with VHP 8% and exposure for >3h showed a 100% kill rate for B.atrophaeus on surfaces and equipment in the BSL-3 laboratory. The VHP generator has good diffusivity and low corrosiveness, and is a time-saving method for removal of disinfectant residue. This study provides reference for the precise disinfection of air and the surfaces of objects in biosafety laboratories under various conditions.

Impacts of salicylic acid, chitosan, and salicyloyl chitosan on quality preservation and microbial load reduction in strawberry fruits during cold storage

The effects of salicylic acid (SA), chitosan (CS), and salicyloyl chitosan (SCS) treatments on quality and microbial load of strawberry fruits cv. Parous were investigated during storage at 4°C. Fruit decay and microbial load were alleviated by the SCS treatment more compared to the SA and CS treatments alone, although there was no significant difference among the two concentrations of SCS (0.15% and 0.3%). Furthermore, SCS-treated fruits had significantly higher antioxidant activity, phenolic content, and antocyanins than those treated with SA and CS. The results also showed that, SCS treatment maintained better firmness, soluble solid contents, titratable acidity, and L-ascorbic acid contents and inhibited the increase in weight loss, fruit decay, and microbial populations of strawberries stored at 4°C for 15 days. Our findings suggested that SCS has great potential of fruit preservation as an edible coating material for strawberries. Novelty impact statement This is the first report which has demonstrated a synergistic effect between SA and CS when they used together as an edible film to preserve the quality and prevent decay of strawberry fruit during cold storage. On the other hand, strawberry fruit treated with salicylic acid conjugated to chitosan has not only alleviated microbial load even more but also has positive impact on fruit storability as well as nutritional value, which was the novelty of the present work. Also, due to lack of attaching ability of SA to fruits surface, its protective effects are not sustained, but CS exhibits superior adhesive attribute, so that modification in chemical structure of CS by introducing SA into the polymer backbone may render excellent microbial activity.

Washing with sodium hypochlorite or peracetic acid: Its impact on microbiological quality, phytochemical composition and antioxidant activity of mango peels

Until now, the effects of washing with sodium hypochlorite (SH) or peracetic acid (PAA) on fruit by-products were unknown. This study aims evaluate the impact of disinfection conditions on mango peels’ microbiological quality, phytochemical composition and antioxidant activity.Two Box-Behnken Designs were performed, one for each disinfectant. Three independent factors (food product to disinfectant solution ratio (XA), disinfectants concentrations (XB) and disinfection time (XC)), with 3-levels each (XA: 1:1, 1:5, 1:9 (kg:L); XBSH: 0, 100 and 200 mg/L; XBPAA: 0, 40 and 80 mg/L; XC: 1, 10, 19 min), and eight responses were considered (total mesophilic aerobic bacteria (TMAB), total yeasts and molds, dry matter, ash content, total phenolic compounds, total carotenoids, DPPH and ABTS assays). After, other batch of mango peels was washed according to the optimized conditions predicted. Besides aforementioned parameters, Enterobacteriaceae, Bacillus cereus and total protein were evaluated.Significant statistical models were found for all responses, excluding yeast and molds, ash content and ABTS assay (in PAA Design). The increase of XB and XC positively impacted microbiological quality. However, in the SH Design, when higher levels of XA were applied, shorter XC were required to achieve the highest microbial load reductions. High XB and XC levels impaired total carotenoids and antioxidant activity. More studies are needed to understand the impact of washing conditions on total phenolic compounds. The SH and PAA optimal washing conditions were XA = 1:9 (kg:L), XB = 200 mg/L, XC = 90 s and XA = 1:1 (kg:L), XB = 27 mg/L and XC = 19 min, respectively. Their application significantly improved microbiological quality and did not impair phytochemical composition and antioxidant activity. Results showed that PAA is a sustainable alternative to SH.

Controlling Infectious Risk in Transfusion: Assessing the Effectiveness of Skin Disinfection in Blood Donors.

Bacterial infectious risk is a major problem in transfusion medicine. The type of micro-organisms isolated during bacterial contamination of blood products indicates that the donor’s skin is its main source. In this context, the primary measures to reduce this risk are: (a) optimal disinfection of the donor’s arm and (b) satellite bag diversion of the initial volume of blood collected. This work aimed to verify the effectiveness of skin disinfection of the blood donor’s venipuncture site. Two methodological approaches were used: (a) qualitative and quantitative microbiological testing of the skin at the collection site, before and post-disinfection; (b) qualitative microbiological testing of the first deviated blood. Pre-disinfection testing showed skin microbial load values between 3 and >200 CFU/plate. More than two-thirds of the isolates were Gram-positive bacteria (77.8%) of which 57.7% were staphylococci. Among Gram-negative bacteria, Pseudomonadaceae, Enterobacteriaceae, and Acinetobacter spp. were isolated from the blood donors (BDs). Post-disinfection, a 100% reduction in microbial load was observed in 84.4% of BDs. Microbiological testing of the first blood diverted sample revealed the presence of microbial flora in 1.9% samples; of the isolates, 83.3% were non-aureus staphylococci. This study highlights the importance of the correct application of skin disinfection procedures in order to ensure blood safety.

Evaluation of Microbial Contamination via Wastewater Collected from Different Oil Industries and its Treatment Using Various Coagulants

Wastewater from industrial discharged into other water bodies that pose serious risks to human health as well as the environment. The oil and ghee industries are also the main contributors to water pollution along with various other industries. The present study aimed to evaluate microbial load in waste water of oil industries in Lahore and its treatment using chemical and natural coagulants. Water samples were collected from three selected oil and ghee industries in Lahore. Physicochemical properties (Chemical oxygen demand (COD), Biological oxygen demand (BOD), and turbidity) and microbial contamination of water samples were analyzed before and after treatment. It was observed that samples treated with natural coagulants such as orange and banana peel, and date seeds showed a mild reduction in physicochemical parameters. Orange and banana peel coagulants caused a 30% reduction, while date seeds coagulants caused a 60% reduction in physicochemical parameters. A significant decrease in microbial load was noticed by using natural coagulants. However, for the chemical coagulants, it was observed that ferric chloride with alum and Ca+2 cation with bleaching powder caused an extreme reduction in physicochemical indicators and microbial load. While no significant decrease was observed in physicochemical indicators and microbial load when waste water samples were treated with Poly Aluminum chloride (PAC) and alum. It was concluded that chemical coagulants have a better ability to treat waste water as compared to natural coagulants.

Hand washing in operating room: a procedural comparison


 BACKGROUND Hand washing has been considered a measure of personal hygiene for centuries and it is known that an improper hand hygiene by healthcare workers is responsible for about 40% of nosocomial infections. Therefore, surgical hand preparation is a critical element for healthcare safety in order to reduce microbial contamination of surgical wound in case of non detected break of the gloves. The aim of our study is to evaluate the efficacy three antiseptics: Povi-iodine scrub; EPG (Ethanol, Hydrogen Peroxide, Glycerol, recommended by WHO), and common marseille soap type in a liquid formulation.
 METHODS It was designed a randomized, double-blind, single-center study conducted in the University Hospital of Messina, from January to June 2013. We asked operators to put the fingertips of their right hand (if not left-handed) for one minute on the PCA medium, before washing with the three types of antiseptics, and after washing and drying. Drying was made using sterile gauzes or disposable wipes. Then, we measured the number of colony forming units per mL (CFU/mL) and calculated the percentage of microbial load reduction.
 RESULTS 211 samples have been considered for statistical analysis: in 42 samples, in fact, initial microbial load was lower than after washing. Washing with EPG reduced CFU/ml from a mean of 38,9 to 4,1 (86,5% reduction), washing with povi-iodine scrub from 59,55 to 12,9 (75,9% reduction) and washing with Marseille soap from 47,26 to 12,7 (64,3% reduction).
 CONCLUSIONS Our study shows that washing with EPG has superior efficacy in CFU reduction. Antiseptic hand washing, however, cannot be considered the only measure to reduce infections: the anomaly of some results (initial microbial load lower than after washing) demonstrates that drying is an essential phase in the presurgical preparation. Therefore, hand hygiene must be part of a more complex strategy of surveillance and control of nosocomial infections