Laboratory-based evaluation of the 4th-generation AlereTM HIV Combo rapid point-of-care test.

Background: Mozambique is a high-prevalence country for HIV and early detection of new HIV infections is crucial for control of the epidemic. We aimed to evaluate the accuracy of the 4th-generation rapid diagnostic test (RDT) AlereTM HIV Combo in detecting acute and seroconverted HIV-infection, among sexually-active women attending three clinical health centers in Maputo, Mozambique.

Methods: Women aged 14-55 years (n = 920) seeking care at the Mavalane Health Area, Maputo (February 2018-January 2019) were included, and blood specimens sampled.

Vaccine-Induced Seroreactivity Impacts the Accuracy of HIV Testing Algorithms in Sub-Saharan Africa: An Exploratory Study.

The detection of vaccine-induced HIV antibody responses by rapid diagnostic tests (RDTs) may confound the interpretation of HIV testing results. We assessed the impact of vaccine-induced seroreactivity (VISR) on the diagnosis of HIV in sub-Saharan Africa. Samples collected from healthy participants of HIVIS and TaMoVac HIV vaccine trials after the final vaccination were analyzed for VISR using HIV testing algorithms used in Mozambique and Tanzania that employ two sequential RDTs.

Detoxification of patulin by adduct formation with cysteine.

Patulin adduct was formed by reacting equimolar amounts of patulin and cysteine at pH 6.0. The bactericidal effect of the adduct mixture was less than one hundredth of that of free patulin in plate and liquid cultivation tests with Escherichia coli W 3110 thy pol A1 and pol A1+ strains.

Lactic acid and pH as indicators of spoilage for vacuum-packed cooked ring sausages.

Lactic acid production and pH changes of 206 vacuum-packed cooked ring sausages stored at 2, 4 and 12 degrees C from 21 different production runs were monitored as a function of time and of microbial growth. The total lactic acid concentrations and pH values were first at a constant level, starting to increase sharply after the lactobacilli count reached about 5 x 10(7) or 6 x 10(7) cfu/g, respectively. The lactic acid and pH changes as a function of the lactobacilli count were similar at 4 and 12 degrees C.

Shelf-life of vacuum-packed cooked ring sausages at different chill temperatures.

Microbiological and sensory changes in 313 vacuum-packed cooked ring sausages from 28 different production runs and stored at 2, 4, 8 or 12 degrees C were monitored as a function of time. The sensory scores started to decrease at a level of approx. 10(7) lactobacilli/g.

Risk of Growth and Toxin Production by Clostridium botulinum Nonproteolytic Types B, E, and F in Salmon Fillets Stored Under Modified Atmospheres at Low and Abused Temperatures.

In factorial design experiments we inoculated fresh salmon fillets with a spore pool of 13 nonproteolytic strains of Clostridium botulinum type B, E, and F at 6 levels (10 to 10/50 g of fillet), and incubated at 1, 4, 8, 12 and 30°C under modified atmospheres (MA) of vacuum, 100% CO and 70% CO + 30% air for up to 60 d. The earliest time we detected toxin in the fillets at 30, 12 and 8°C, irrespective of MA, was after 1, 3-9 and 6-12 d of storage and required 10-10, 10-10, 10-10 spores/fillet. The probability (P) of toxin production was significantly (P<0.

Microbiological and Sensory Quality Changes in Cabbage Casserole and Mixed Vegetable Salad with Mayonnaise during Storage.

The microbiological and sensory quality of cabbage casserole and mixed vegetable salad with mayonnaise was assessed after production, on the sell-by date and 7 d later. Samples were taken directly from five different plants, stored at 4°C and analyzed by three different laboratories. Sell-by periods were 8 to 14 d after the day of production.

The mutagenicity of some edible mushrooms in the Ames test.

The mutagenic activity of five wild and two cultivated species of edible mushrooms was studied in the Ames Salmonella/microsome test system. The wild mushrooms tested were four species of the genus Lactarius (L. necator, L.

Experimental staphyloenterotoxicosis in mink.

Experimental staphyloenterotoxicosis was produced in minks by oral administration of mink feed containing 5 or 200 µg of purified enterotoxin A per test animal. The animals became very exhausted after the ingestion of toxin. Vomiting was observed in two of seven minks of the lower toxin group with a latent period of 2.

Pathogenic, enterotoxin-producing staphylococci in mink feed and mink feed raw materials.

Samples of 51 mink feeds and 101 raw material batches were analysed for pathogenic staphylococci. Of the feed samples 37 % were contaminated with pathogenic staphylococci, the mean count being 3.02 log CFU (colony forming units)/g and the highest count being 4.

The lack of mutagenic properties of patulin and patulin adducts formed with cysteine in Salmonella test systems.

The mutagenic properties of patulin and the patulin adducts formed with cysteine were tested with histidine auxotroph Salmonella typhimurium strains as indicator organisms. The tests were performed by microsomal activation and host-mediated assay. Neither patulin nor patulin--cysteine reaction mixture was mutagenic in these test systems.

Comparison of the toxicities of patulin and patulin adducts formed with cysteine.

The toxicities of patulin and of the patulin adducts formed with cysteine were compared using the mutation-sensitive strain Escherichia coli W3110 thy polA1 and its polA1+ revertant. The acute toxicities of patulin and of the adduct mixture were also compared using NMRI mice. The adduct mixture was shown by thin-layer chromatography to consist of one ninhydrin-positive, one ninhydrin- and MBTH (3-methyl-2-benzothiazolinone hydrazone)-positive, three MBTH-positive, and two ninhydrin- and MBTH-negative components.

Aflatoxin Production in Black Currant, Blueberry and Strawberry Jams.

Unsweetened and sweetened (20 and 44% sucrose) black currant, blueberry and strawberry jams with spores of Aspergillus parasiticus NRRL 2999 were incubated at different temperatures and atmospheres for 0.5, 1, 2, and 6 months. Hyphal dry weight, pH of medium and aflatoxin production were examined.

Preparation of labeled staphylococcal enterotoxin A with high specific activity.

Staphylococcal enterotoxin A (SEA) was labeled by the chloramine-T method with 125I to a specific activity of 68 to 300 muCi per mug of SEA and with 131I to specific activity of 8 to 218 muCi per mug of SEA. SEA was partially damaged and aggregated during the labeling and storage. The damage seemed not to be greatly dependent on the specific activity of labeled entertoxin.

Comparison of different purification procedure for extraction of staphylococcal enterotoxin A from foods.

Different procedures commonly used for extraction, purification, and concentration of staphylococcal enterotoxins from foods were investigated with 131I- and 125I-labeled staphylococcal enterotoxin A. Loss of labeled enterotoxin A was compared with loss of total nitrogen. The results showed that in most of the common procedures, such as gel filtration, ion exchange, and heat treatment, the percentage of loss of labeled enterotoxin A was greater than the loss of total nitrogen.