Effect of lecithin and starch on alginate-encapsulated probiotic bacteria.

The effect of lecithin and starch on viability of alginate encapsulated probiotics was determined at different temperatures. Probiotic organisms (1% v/v>10Log CFU ml(-1)) were encapsulated using alginate (2% w/v), gelatinized starches (2% w/v) and lecithin (0-4% w/v) and stored in sealed containers at 4, 23 and 37 degrees C (to simulate shelf storage conditions). Incorporation of lecithin improved the entrapment efficiency (p < 0.05) and the viability of encapsulated bacteria (p = 0.02). Encapsulated Lactobacillus, Bifidobacterium species and Lactococcus lactis in lecithin containing freeze-dried beads had good survival stability (above 6Log CFU ml(-1)) at 23 degrees C for 12 weeks. The bacteria in the beads showed 6Log survival by the end of 2 weeks at 37 degrees C. Encapsulated L. casei in the alginate beads containing lecithin were also more stable in the yoghurt than the beads without lecithin. SEM analysis of the beads showed an irregular surface for the beads without lecithin.

Mixed herbs drugs: inhibitory effect on growth of the endogenous mycoflora and aflatoxin production.

Twenty commercial mixed herbal drugs were examined for mycological profile. Aspergillus species were the predominant fungi found in the drugs. Other fungi harboured in the drugs with less frequency were Paecilomyces species, Eurotium species, Monascus species, Acremonium species, Penicillium species, Cladosporium species, Scopulariopsis species, Phialophora species and Fonseceae species. Fungal count was between 1.0 log(10) CFU and 2.4 log(10) CFU per gram of sample. When the drugs were incubated in 85% humidity at 25 degrees C, fungal colonies grew on only two of the drugs. The mixed herbal drugs were extracted with water and the extracts were used to grow Aspergillus parasiticus. All extracts reduced aflatoxin B(1) and aflatoxin G(1) production by 62-97%. All but two of the extracts reduced aflatoxin B(2) and aflatoxin G(2) production by 39-95%. It can be concluded that the commercial powdered mixed herbal drugs contained low number of endogenous fungi, and these drugs are inhibitory to the growth of its endogenous fungi and aflatoxins production by aflatoxigenic fungi.

The efficiency of an air filtration system in the hospital ward.

A study was conducted to ascertain the efficiency and effectiveness of an air filtration system (Electromedia Model 100C, Clean Air UK, UK) in the hospital ward. The sampling was conducted using a portable Surface Air Sampler (Cherwell Laboratories, Bicester, UK) in conjunction with settle plates. Samples were taken two days before and two days following activation of the filtration system and results compared. A clear, demonstrable, statistically significant reduction in microbial organisms following the activation of the filtration systems is evident (81% settle plates; 24% Surface Air Sampler). This study has implications for the improved health and welfare of patients and healthcare workers who may benefit through the implementation of such a system.

Comparison of in vitro cytotoxicity of Fusarium mycotoxins,deoxynivalenol, T-2 toxin and zearalenone on selected human epithelial cell lines.

Three human epithelial cell lines (CaCo-2, HEp-2 and HeLa) implicated as potential targets for three Fusarium toxins were tested for the extent of survival on exposure to increasing toxin concentration and incubation periods. Cytotoxicity assay using 3(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide (MTT) was carried out with deoxynivalenol (DON), T-2 toxins and zearalenone (ZON) on CaCo-2, HEp-2 and HeLa cell lines. Of the three cell lines used, HeLa was the most sensitive, eliciting cell death after 2 days exposure at 100 ng ml(-1)with T-2 toxin. HeLa was the only cell line to exhibit cytotoxicity towards ZON showing cell death at 1000 ng ml(-1)after 2 days which increased to 4 days, showing substantial cell death at 200 ng ml(-1). HEp-2 was sensitive to DON showing cell death after 2 days (100 ng ml(-1)) with complete cell death occurring at 200 ng ml(-1) after 4 days of exposure. Substantial cytoxicity of T-2 towards HEp-2 occurred after 2 days at 1000 ng ml(-1) and complete cell death occurred with 100 ng ml(-1) at day 4. The CaCo-2 cell line was generally resistant to the mycotoxins tested between 100 and 1000 ng ml(-1). This study shows that cytotoxicity of Fusarium toxins to epithelium cell lines is concentration- and time- dependant and results from ZON-HeLa interaction indicate possible cell type-mycotoxin specificity.

Occurrence of aflatoxin M1 in randomly selected North African milk and cheese samples.

Forty-nine samples of raw cow's milk and 20 samples of fresh white soft cheese were collected directly from 20 local dairy factories in the north-west of Libya and analysed for the presence of aflatoxin M1 (AFM1). The samples were analysed using a high-performance liquid chromatography technique for toxin detection and quantification. Thirty-five of the 49 milk samples (71.4%) showed AFM1 levels between 0.03 and 3.13 ng ml(-1) milk. Multiple analyses of five milk samples free of AFM1 artificially contaminated with concentrations of AFM1 at 0.01, 0.05, 0.1, 1.0 and 3.0 ng ml(-1) showed average recoveries of 66.85, 72.41, 83.29, 97.94 and 98.25%, with coefficients of variations of 3.77, 4.11, 1.57, 1.29 and 0.54%, respectively. Fifteen of 20 white soft cheese samples (75.0%) showed the presence of AFM1 in concentrations between 0. 11 and 0.52 ng g(-1) of cheese. Multiple assays of five cheese samples free of AFM1 spiked with different concentration of AFM1 (0.1, 0.5, 1.0 and 3.0 ng g(-1)) showed average recoveries of 63.23, 78.14,83.29 and 88.68%, with coefficients of variation of 1.53, 9.90, 4.87 and 3.79%, respectively. The concentrations of AFM1 were lower in the cheese products than in the raw milk samples.

Microflora of date fruits and production of aflatoxins at various stages of maturation.

Twenty-five varieties of dates (Phoenix dactylifera) were examined at different maturation stages for total microbial counts, aflatoxins and aflatoxigenic Aspergillus sp. and lactic acid bacteria. The samples were examined as fresh and under simulated storage condition of high humidity. Microbial counts were high at the first stage of maturation (Kimri) and increased sharply at the second stage (Rutab), then decrease significantly at the final dried stage of maturation (Tamr). Aflatoxins were detected in 12% of the samples although aflatoxigenic Aspergillus were detected in 40% of the varieties examined, all at Kimri stage only. Lactic acid bacteria were present only at the Rutab stage in some varieties including all varieties in which aflatoxins or aflatoxigenic Aspergillus were detected. No aflatoxins or aflatoxigenic Aspergillus were detected at the final edible stage of maturation.

Oral antioxidant therapy for marginal dry eye.

OBJECTIVE: To assess the efficacy of an orally administered antioxidant dietary supplement for managing marginal dry eye. DESIGN: A prospective, randomised, placebo controlled trial with cross-over. SETTING: Eye Clinic, Department of Vision Sciences, Glasgow Caledonian University. SUBJECTS: Forty marginal dry eye sufferers composed of 30 females and 10 males (median age 53 y; range 38-69 y). INTERVENTIONS: Baseline assessments were made of tear volume sufficiency (thread test), tear quality (stability), ocular surface status (conjunctival impression cytology) and dry eye symptoms (questionnaire). Each subject was administered courses of active treatment, placebo and no treatment, in random order for 1 month each and results compared to baseline. RESULTS: Tear stability and ocular surface status were significantly improved following active treatment (P<0.05). No changes from baseline were detected following administration of placebo and no treatment (P>0.05). Absolute increase in tear stability correlated with absolute change in goblet cell population density. Tear volume was not improved following any treatment period and dry eye symptom responses were subject to placebo effect. CONCLUSIONS: Oral antioxidants improved both tear stability and conjunctival health, although it is not yet understood whether increased ocular surface health mediates increased tear stability or vice versa. SPONSORS: This study was supported by a PhD scholarship funded by the Department of Vision Sciences, Glasgow Caledonian University, Scotland. Antioxidant supplements and placebos were kindly donated by Vitabiotics.

A survey of ethnic foods for microbial quality and aflatoxin content.

A range of ethnic foods was examined for their microbiological content in relation to total viable counts (TVC) of aerobic bacteria, counts of presumptive coliforms, yeast and mould counts; presence of Salmonella spp., Listeria monocytogenes, Escherichia coli O157:H7 and Campylobacter spp.; total enumeration of Clostridium perfringens, Staphylococcus aureus and Bacillus spp.; identification of moulds and the presence of total aflatoxins. Samples, which included cereals, nuts, dried fruits, herbs and spices, were obtained from local retail outlets and distributors. It was established that three samples of pistachio nuts contained significant levels of aflatoxins. The concentration of total aflatoxins in these three nut samples ranged from 15 to 259 microg/kg of sample. Only two other samples contained trace amounts of aflatoxins, all other samples analysed were found to be free of any detectable level of aflatoxins. TVCs, coliform counts and yeast and mould counts varied widely depending on the matrix tested. Generally, rice, wheat and peanuts produced low counts whereas other nuts, gram flour and spices produced much higher counts. Cl. perfringens, Staph. aureus, and Bacillus spp. were common in spices, nuts and gram flour, however, Listeria monocytogenes was only detected in four samples and in no sample could Salmonella spp, E. coli O157:H7 or Campylobacter spp. be detected.

Application of Hazard Analysis Critical Control Points system to enteral tube feeding in hospital.

An HACCP system was implemented for the quality assurance of preparation, storage and delivery of enteral feeds to patients in hospital. Routine methods of feed preparation, storage and delivery to patients were studied and a flow chart was initially made. After identifying hazards, an HACCP team was assembled, a flow chart was modified and critical control points were defined using a decision tree. Control measures for each step of the process and its monitoring and corrective measures to be applied were also defined. In addition, feed samples were analysed for microbiological quality and feed storage temperatures were also recorded, before and after the implementation of the HACCP system. When the control measures were applied and monitored, the hazard was reduced. Bacterial counts in feed were reduced from 105 cfu mL-1 to < 101 cfu mL-1. The results show that contamination of enteral feed may be reduced or eliminated if a systematic approach such as HACCP is applied effectively.

Microbiological quality of reconstituted enteral formulations used in hospitals.

Contamination of enteral feeds may occur during preparation, storage, decanting, and administration to patients. The aim of this study was to investigate the microbiological quality of reconstituted enteral feeds, residual feeds from feed delivery systems, and the water used to reconstitute powdered feeds in hospital. Hazard Analysis Critical Control Points (HACCP) system was implemented to control microbiological contamination of the enteral feeding formulations. Before the implementation of the HACCP system microbiological analyses of feeds showed the presence of indicator organisms such as coliforms and Enterococcus spp. and unacceptably high levels of mesophilic aerobic microorganisms (>10(4) cfu/mL). After the implementation of the HACCP, the microbial quality of the feeds improved significantly, with counts of <10(1) cfu/mL. Blenders used in reconstituting feeds were found to be the main source of bacterial contamination.

The effect of handling procedures on microbial contamination of enteral feeds--a comparison of the use of sterile vs non-sterile gloves.

The use of non-sterile disposable gloves to reduce the level of microbial contamination introduced into enteral feeds during the assembly of the feeding systems was investigated. No contamination was detected in any of the feed samples collected from the systems assembled wearing non-sterile gloves. The number of microorganisms transferred to the surface of agar plates used for fingerprint cultures was reduced from an average of 43-54 colony forming units (cfu) per plate for volunteers with bare hands to less than 1 cfu when they wore non-sterile gloves. No contamination was detected on plates touched by volunteers wearing sterile gloves.

Cleaning and disinfection of blenders used in hospital kitchens.

The efficiency of a range of methods used to clean and disinfect blenders was compared. Blenders with metal, plastic and glass goblets were experimentally contaminated with Klebsiella aerogenes after which they were cleaned and disinfected by (a) cold water rinse, (b) detergent wash, (c) detergent wash and disinfectant soak, (d) detergent wash and boiling water rinse and (e) autoclaving. Autoclaving was the only procedure that sterilized the blenders but this could only be used for blenders with metal goblets. A detergent wash with or without chemical disinfection followed by a boiling water rinse was found to be the most effective method of cleaning and disinfecting all three types of blender.

Decanting--a source of contamination of enteral feeds?

The techniques of opening and decanting ready-to-use enteral feeds packaged in bottles (crown-cap and screw-cap), cans and tetrapaks were evaluated as potential routes for the contamination of these feeds. It was found that the outsides of the feed containers, bottle openers, scissors and the experimenters' hands all acted as sources of contamination during the transfer of feeds to the nutrient container. The main source of contamination appeared to be the experimenters' hands with counts up to 10(2) cfu ml(-1) being recorded for feeds that had been decanted from screw-cap bottles, cans and tetrapaks by experimenters with either unprotected bare hands or hands experimentally contaminated with K. aerogenes. Levels of contamination and the number of samples contaminated after opening and decanting were consistently higher for cans and tetrapaks than for crown-cap or screw-cap bottles. Disinfection of feed containers followed by the use of sterile gloves and/or disinfected openers yielded bacteria-free feed from all the types of feed container studied.

The effect of handling procedures on microbial contamination of enteral feeds.

Three of the most commonly used delivery systems in enteral feeding were evaluated for potential routes of contamination during assembly and delivery of feeds. Assembly of systems wearing sterile gloves gave no contamination in the feeds but all systems were contaminated when assembled either with bare unprotected hands or with hands experimentally contaminated with bacterial cells. Delivery of contamination-free feed was only possible with the use of sterile gloves.