Effect of milk fermentation by kefir grains and selected single strains of lactic acid bacteria on the survival of Mycobacterium bovis BCG.

Mycobacterium bovis that causes Bovine tuberculosis (BTB) can be transmitted to humans thought consumption of raw and raw fermented milk products from diseased animals. Lactic acid bacteria (LAB) used in popular traditional milk products in Africa produce anti-microbial compounds that inhibit some pathogenic and spoilage bacteria. M.

Guaiacol production from ferulic acid, vanillin and vanillic acid by Alicyclobacillus acidoterrestris.

Alicyclobacilli are thermophilic, acidophilic bacteria (TAB) that spoil fruit juice products by producing guaiacol. It is currently believed that guaiacol is formed by Alicyclobacillus in fruit juices as a product of ferulic acid metabolism. The aim of this study was to identify the precursors that can be metabolised by Alicyclobacillus acidoterrestris to produce guaiacol and to evaluate the pathway of guaiacol production.

Phylogenetic analysis of Cronobacter isolates based on the rpoA and 16S rRNA genes.

The reclassification of the genus Cronobacter (previously known as Enterobacter sakazakii) was based on a polyphasic analysis that led to the description of five species. These bacteria are opportunistic pathogens that can cause neonatal meningitis and other infections in immuno-compromised individuals. Cronobacter species have been reported to show differences in sensitivity to antibiotics, heat and chemicals, as well as differences in virulence.

Evaluation of the 16S and 12S rRNA genes as universal markers for the identification of commercial fish species in South Africa.

The development of DNA-based methods for the identification of fish species is important for fisheries research and control, as well as for the detection of unintentional or fraudulent species substitutions in the marketplace. The aim of this study was to generate a comprehensive reference database of DNA sequences from the mitochondrial 16S and 12S ribosomal RNA (rRNA) genes for 53 commercial fish species in South Africa and to evaluate the applicability of these genetic markers for the identification of fish at the species level. The DNA extracted from all target species was readily amplified using universal primers targeting both rRNA gene regions.

Phenylethanoid glycosides as major antioxidants in Lippia multiflora herbal infusion and their stability during steam pasteurisation of plant material.

Lippia multiflora, a perennial, aromatic shrub commonly known as bush tea has recently been identified as an African plant with high commercial potential due to its medicinal properties. The plant material was subjected to steam pasteurisation to improve its microbial quality. The major compounds of L.

Establishment of a mitochondrial DNA sequence database for the identification of fish species commercially available in South Africa.

The limitations intrinsic to morphology-based identification systems have created an urgent need for reliable genetic methods that enable the unequivocal recognition of fish species, particularly those that are prone to overexploitation and/or market substitution. The aim of this study was to develop a comprehensive reference library of DNA sequence data to allow the explicit identification of 53 commercially available fish species in South Africa, most of which were locally caught marine species. Sequences of approximately 655 base pairs were generated for all species from the cytochrome c oxidase I (COI) gene, the region widely adopted for DNA barcoding.

Occurrence of Alicyclobacillus in the fruit processing environment--a review.

Concentrated fruit products have a significant place in modern consumption markets and are valuable semi-prepared food components to the bakery, dairy, confectionary, canning, baby food, frozen food, distilling and beverage industries. There is continuous pressure on the beverage industry to improve the quality of concentrated fruit products in order for reconstituted fruit beverages to compete with beverages that are made from fresh fruits. In recent years, Alicyclobacillus spp.

Isolation of Alicyclobacillus and the influence of different growth parameters.

Alicyclobacillus species are thermo-acidophilic, endospore-forming bacteria that are able to survive pasteurisation and have been implicated in a number of spoilage incidents involving acidic foods and beverages. The aim of this study was to compare three isolation methods used for the detection of Alicyclobacillus acidoterrestris and to investigate the influence of incubation temperature on the growth of A. acidoterrestris and A.

Alicyclobacillus spoilage and isolation--a review.

Until recently, acidic products such as fruit juice and fruit based products were generally thought to be susceptible to spoilage by yeasts, mycelia fungi and lactic acid bacteria, as the low pH of these products acts as natural control measures against spoilage by most bacteria. Alicyclobacillus seem to be prevalent in fruit based products as they survive the acidic fruit juice environment, even when they are exposed to pasteurisation temperatures during production. In this review the historical background of the discovery of these bacteria is summarised.

Prevention of the accumulation of Alicyclobacillus in apple concentrate by restricting the continuous process running time.

Aims: To study the accumulation of vegetative cells and endospores of Alicyclobacillus, as well as viable aerobic counts during the continuous production of apple juice concentrate.

Methods And Results: Apples were processed for a continuous process running time of 108 h (processing rate 1·8-2·0 t h(-1) ) without clean-in-place (CIP) procedures in-between different batches. Samples from single-strength apple juice, concentrate after evaporation (± 30°Brix), the final product (concentrate pasteurized at 102-104°C for 90 s) and condensate water (by-product of the juice concentration process) were collected every 12 h.

Physico-chemical, microbiological, textural and sensory attributes of matured game salami produced from springbok (Antidorcas marsupialis), gemsbok (Oryx gazella), kudu (Tragelaphus strepsiceros) and zebra (Equus burchelli) harvested in Namibia.

Differences and consumer acceptability of matured salami produced from game species were evaluated. The pH of the salami differed (p < 0.05) with springbok salami having the highest mean pH value.

Histological evidence for the existence of germ cell tumor cells showing embryonal carcinoma morphology but lacking OCT4 expression and cisplatin sensitivity.

The biological basis for manifestation of chemotherapy resistance in metastatic testicular germ cell tumors (GCT) remains obscure and is of particular clinical interest. In nonseminomatous GCT (NSGCT) the pluripotent embryonal carcinoma (EC) cells are the precursors of the manifold differentiated structures but also drive the malignant growth. They are known to be hypersensitive towards DNA-damaging agents and to express the embryonal transcription factor OCT4.

A randomised control trial in schoolchildren showed improvement in cognitive function after consuming a bread spread, containing fish flour from a marine source.

Background: In humans, n-3 long-chain polyunsaturated fatty acids play a well-documented role in brain development and function. Docosahexaenoic acid and arachidonic acid are major structural components of the brain and a deficiency thereof may bring about changes in the behaviour domains of the brain.

Objective: This trial investigated the effect of an experimental fish-flour bread spread rich in n-3 long-chain polyunsaturated fatty acids, on cognition of children (7-9yr).

Gender-specific differences in bladder cancer: a retrospective analysis.

Background: A higher incidence of bladder cancer has been reported in men compared with women. Clinical gender differences have been observed but are less well described.

Objective: This retrospective analysis further examines clinical differences in the development and manifestation of bladder cancer between men and women.

Isolation, identification and typification of Alicyclobacillus acidoterrestris and Alicyclobacillus acidocaldarius strains from orchard soil and the fruit processing environment in South Africa.

Alicyclobacillus acidoterrestris and Alicyclobacillus acidocaldarius are thermo-acidophilic, non-pathogenic, spore-forming bacteria that can survive the typical heat processing of fruit juices and concentrates. Bacterial endospores then germinate, grow and cause spoilage of acid food products. Species of Alicyclobacillus were isolated from orchard soil and a fruit concentrate production factory in South Africa.

Postchemotherapy retroperitoneal lymph node dissection in advanced testicular cancer: radical or modified template resection.

Background: The anatomical extent of postchemotherapy retroperitoneal lymph node dissection (PC-RPLND) has been discussed controversially for many years.

Objective: To evaluate the necessity of PC-RPLND with modified or radical template resection in patients with advanced nonseminomatous germ-cell tumors (NSGCT) and residual masses following systemic chemotherapy.

Design, Setting, And Participants: The charts of 152 consecutive patients who were treated at two tertiary referral centers were retrospectively reviewed.

Evaluation of different methods for the detection and identification of Enterobacter sakazakii isolated from South African infant formula milks and the processing environment.

Enterobacter sakazakii is an emerging pathogen associated with life-threatening neonatal infections resulting from the consumption of contaminated powdered infant formula milk (IFM). Recent taxonomic analyses have determined that E. sakazakii comprises a number of genomospecies, and it has been proposed that E.

Selective PCR detection of viable Enterobacter sakazakii cells utilizing propidium monoazide or ethidium bromide monoazide.

Aims: The detection of viable Enterobacter sakazakii cells is important due to the association of this pathogen with outbreaks of life-threatening neonatal infections. The aim of this study was to optimize a PCR-based method for selective detection of only viable Ent. sakazakii cells in the presence of dead cells, utilizing propidium monoazide (PMA) or ethidium bromide monoazide (EMA).

Isolation and identification of species of Alicyclobacillus from orchard soil in the Western Cape, South Africa.

Alicyclobacilli were isolated from orchard soil collected from an apple and pear farm in Elgin, Western Cape, South Africa. Morphological, biochemical and physiological characteristics of the isolates were used to presumptively classify them as belonging to the genus Alicyclobacillus. Strains were identified to species level by polymerase chain reaction (PCR) with genus-specific primers, and 16S ribosomal RNA (rRNA) gene sequencing.

Evaluation of different growth media for the recovery of the species of Alicyclobacillus.

Aims: Five different isolation media, namely potato dextrose agar (PDA), orange serum agar (OSA), K agar, yeast-starch-glucose agar and Bacillus acidocaldarius medium were evaluated for the recovery of Alicyclobacillus spp. from inoculated diluted and undiluted fruit-juice concentrates.

Methods And Results: Plates of PDA (pH 3.

PCR-based DGGE fingerprinting and identification of methanogens detected in three different types of UASB granules.

Methane is produced by various methanogenic bacteria present in upflow anaerobic sludge blanket (UASB) bioreactors. Methane can be used to predict and improve UASB bioreactor efficiency. The methanogen population in the granules can be influenced by the composition of the substrate.

Evaluation of different preservation techniques on the storage potential of Kefir grains.

Kefir is an acidic, mildly alcoholic dairy beverage produced by the fermentation of milk with a grain-like starter culture (Koroleva, 1988). These grains usually contain a relatively stable and specific balance of microbes that exist in a complex symbiotic relationship (Obermann & Libudzisz, 1998; Witthuhn et al. 2004).

Microbial content of commercial South African high-moisture dried fruits.

Aim: The aim was to evaluate commercially available South African high-moisture dried fruits (HMDF) for the microbial, moisture and SO2 contents, as well as aw and pH.

Methods And Results: The microbial content of commercially available HMDF was evaluated using nine different growth media. The moisture content, aw) SO2 and pH of each product were determined using standard analytical methods.

Identification of probiotic microorganisms in South African products using PCR-based DGGE analysis.

Probiotic microorganisms in commercial yoghurts and other food products are currently identified by traditional methods such as growth on selective media, morphological and biochemical characteristics. In this study, PCR-based DGGE analysis was used for the rapid and accurate identification of probiotic microorganisms from South African yoghurts and lyophilized preparations in capsule and tablet form. To identify the microorganisms present in these products, the DGGE profiles obtained were compared to two reference markers (A and B) composed of five lactobacilli and seven Bifidobacterium species, respectively.

Treatment of winery effluent with upflow anaerobic sludge blanket (UASB)--granular sludges enriched with Enterobacter sakazakii.

Three upflow anaerobic sludge blankets (UASBs) were evaluated for the treatment of winery wastewater: the first was seeded with granular sludge enriched with Enterobacter sakazakii and reached a 90% COD removal within 17 d at hydraulic retention time of 24 h; the second was seeded with brewery granules and achieved 85% COD removal within 50 d, the third was seeded with just sludge and showed the typical problems encountered with conventional sludge seeding and had continuously to be re-seeded. A PCR-based technique was developed for the rapid detection of E. sakazakii in the granular sludge.