Search results for "Cereus"
showing 10 items of 40 documents
Development of a real-time PCR assay for detection and quantification of enterotoxigenic members of Bacillus cereus group in food samples
2009
A highly sensitive real-time PCR (qPCR) procedure, targeting the phosphatidylcholine-specific phospholipase C gene (pc-plc), was developed for specific detection and quantification of strains belonging to Bacillus cereus group. The target region was selected based on the enterotoxigenic profiles of 75 Bacillus strains. The inclusivity and exclusivity of the RTi-PCR assay were assessed with 59 isolates of the B. cereus group, 16 other Bacillus spp., and 4 non-Bacillus strains. The assay was also used to construct calibration curves for different food matrices, and it had a wide quantification range of 6 log units using both serial dilutions of purified DNA and calibrated cell suspensions of …
Effect of heat activation and inactivation conditions on germination and thermal resistance parameters of Bacillus cereus spores.
2001
The effect of isothermal and non-isothermal heat activation on germination and thermoresistance of two strains of Bacillus cereus spores was studied. Results indicated that the germination after isothermal activation was lower than after non-isothermal heating. The activation rate affected the z value, which increased with faster heating rates. For each temperature and inactivation rate, the non-isothermal activation at rate of 2 degrees C/min resulted in larger D values (D90 = 4.70 min) than isothermal activation (D90 = 4.04 min). The two mathematical equations used to analyse non-isothermal data produced similar predicted D and z values, nevertheless the Hayakawa equation modified in this…
Comparative analysis and antimicrobial action of some essential oils from plants
2021
In this research, essential oils (EOs) were extracted through steaming from aerial parts of three plants: basil (Ocinum basilicum L.), peppermint (Mentha piperita L.) and oregano (Origanum vulgare L.) form Sibiu County, Romania. The GC-MS analysis indicated that eugenol and apiol were the major compounds in the basil EO. Timol, ɣ-terpinene, and p-cymene were the major compounds in the volatile oil extracted from oregano and menthol and methone the main components in the peppermint EO. In the first 48 h of analysis, basil EO inhibition action was the highest against Salmonella anatum (48%), followed by Aspergillus niger (26%), Bacillus cereus (21%) and Saccharomyces cerevisiae (15%); this ac…
Unsaturated fatty acids from food and in the growth medium improve growth of Bacillus cereus under cold and anaerobic conditions.
2013
International audience; In a chemically defined medium and in Luria broth, cold strongly reduced maximal population density of Bacillus cereus ATCC 14579 in anaerobiosis and caused formation of filaments. In cooked spinach, maximal population density of B. cereus in anaerobiosis was the same at cold and optimal temperatures, with normal cell divisions. The lipid containing fraction of spinach, but not the hydrophilic fraction, restored growth of B. cereus under cold and anaerobiosis when added to the chemically defined medium. This fraction was rich in unsaturated, low melting point fatty acids. Addition of phosphatidylcholine containing unsaturated, low melting point, fatty acids similarly…
Activity against Microorganisms Affecting Cellulosic Objects of the Volatile Constituents of Leonotis nepetaefolia from Nicaragua
2014
The chemical composition of the essential oil from aerial parts of L. nepetaefolia (L.) R. Br. collected in Nicaragua was evaluated by GC and GC-MS. The main components were ( Z)-phytol (22.8%), caryophyllene oxide (18.9%) and hexahydrofarnesylacetone (9.0%). The antibacterial activity against several Gram + and Gram - bacteria, including Bacillus cereus and B. subtilis, both infesting historical cellulosic material, was also determined. B. cereus, B. subtilis and Staphylococcus epidermis were the most affected by the action of the oil.
Garšvielu un garšaugu mikrobioloģiskais piesārņojums
2015
Pētīts garšvielu un garšaugu mikrobioloģiskais piesārņojums 20 dažādās garšvielās un garšaugos, kuri veidoja 60 paraugus. Paraugi iegūti no lielveikala ķēdes, tirgus. Tika noteikta Bacillus cereus, Clostridium perfringens, pelējumsēņu koncentrācija, Escherichia coli klātbūtne, B. cereus vemšanas toksīnu un diarejas toksīnus kodējošie gēni, kā arī hblC toksīnu producējošie B. cereus celmi. Veikta pelējumsēņu ģinšu identifikācija. Pētīta ūdens aktivitāte. Mērķis bija noteikt no dažādām tirdzniecības vietām iegūto garšvielu un garšaugu mikrobioloģisko piesārņojumu. Konstatēts, ka mikrobioloģiski vispiesārņotākie ir melnie pipari ar vislielāko B. cereus, C. perfringens koncentrāciju un ķimenes …
The BIOSAFEPAPER project for in vitro toxicity assessments: preparation, detailed chemical characterisation and testing of extracts from paper and bo…
2008
International audience; Nineteen food contact papers and boards and one non-food contact board were extracted following test protocols developed within European Union funded project BIOSAFEPAPER. The extraction media were either hot or cold water, 95% ethanol or Tenax, according to the end use of the sample. The extractable dry matter content of the samples varied from 1200 to 11,800 mg/kg (0.8-35.5 mg/dm2). According to GC-MS the main substances extracted into water were pulp-derived natural products such as fatty acids, resin acids, natural wood sterols and alkanols. Substances extracted into ethanol particularly, were diisopropylnaphthalenes, alkanes and phthalic acid esters. The non-foo…
Bacteria Associated with Copestylum (Diptera, Syrphidae) Larvae and Their Cactus Host Isolatocereus dumortieri
2011
We describe the gut bacterial diversity inhabiting two saprophagous syrphids and their breeding substrate (decayed tissues of the columnar cactus Isolatocereus dumortieri). We analyzed the gut microbiota of Copestylum latum (scooping larvae that feed on decayed cactus tissues) and Copestylum limbipenne (whose larvae can also feed on semiliquid tissues) using molecular techniques. DNA was extracted from larval guts and cactus tissues. The V1-V3 region of the 16S rRNA genes was amplified and sequenced. A total of 31079 sequences were obtained. The main findings are: C. limbipenne is dominated by several Enterobacteriaceae, including putative nitrogen-fixing genera and pectinolitic species and…
Risk of Bacillus cereus and Pseudomonas aeruginosa nosocomial infections in a Burns Centre: the microbiological monitoring of water supplies for a pr…
1995
This paper reports on an extensive epidemiological survey of the microbiological monitoring of the environment, staff, and patients in the Intensive Care Unit of the Palermo Bums Centre (Italy). The aim of the survey was to evaluate the presence and distribution of environmental sources of pathogens and opportunistic bacterial agents of nosocomial infection in immunocompromised hosts. Strains collected from air, tap water, and medical and nursing staff were compared with strains isolated from burn patients in order to study the potential transmission route of bacteria. The results showed environmental strains presenting a profile identical to that of the clinical strains, suggesting a link …
Homozygote Depression in Gamete-Derived Dragon-Fruit (Hylocereus) Lines
2018
Putative gamete-derived progenies from two Hylocereus species, the diploid H. monacanthus and the tetraploid H. megalanthus, were studied with the dual aims to confirm their gamete origin and to evaluate their potential use as genetic resources. An additional goal was to determine the origin (allotetraploid vs. autotetraploid) of H. megalanthus by exploring morphological variations in the di-haploid (2x) H. megalanthus progeny. Gamete origin was proved in all five H. monacanthus lines obtained and in 49 of the 70 H. megalanthus lines by using flow cytometry and simple sequence repeat (SSR) markers. The five double-haploid (2x) H. monacanthus lines showed low vigor and abnormal flower develo…