A Study To Assess the Numbers and Prevalence of Bacillus cereus and Its Toxins in Pasteurized Fluid Milk.

Bacillus cereus is a pathogenic adulterant of raw milk and can persist as spores and grow in pasteurized milk. The objective of this study was to determine the prevalence of B. cereus and its enterotoxins in pasteurized milk at its best-before date when stored at 4, 7, and 10°C.

Complete Genome Sequences of 12 Isolates of Belonging to Serotypes 1/2a, 1/2b, and 4b Obtained from Food Products and Food-Processing Environments in Canada.

is the etiological agent for an often fatal foodborne illness known as listeriosis. Here, we present the complete genome sequences of 12 isolates representing the three most common serotypes of this pathogen (1/2a, 1/2b, and 4b), collected in Canada from different food products and environmental sources.

Multiple-locus variable number of tandem repeat analysis (MLVA) of Listeria monocytogenes directly in food samples.

Listeria monocytogenes is the etiologic agent of listeriosis responsible for severe and fatal infections in humans. Listeria contamination occurs quite often in a wide range of foods due to its ubiquitous nature. Isolates need to be characterized to a strain level for accurate diagnosis of Listeria infection, epidemiological studies, investigation of outbreaks and effective prevention and control of food-borne listeriosis.

Effect of nitrate and glucose addition on denitrification and nitric oxide reductase (cnorB) gene abundance and mRNA levels in Pseudomonas mandelii inoculated into anoxic soil.

The effect of glucose addition (0 and 500 μg C g(-1) soil) and nitrate (NO(3)) addition (0, 10, 50 and 500 μg NO(3)-N g(-1) soil) on nitric oxide reductase (cnorB) gene abundance and mRNA levels, and cumulative denitrification were quantified over 48 h in anoxic soils inoculated with Pseudomonas mandelii. Addition of glucose-C significantly increased cnorB(p) (P. mandelii and related species) mRNA levels and abundance compared with soil with no glucose added, averaged over time and NO(3) addition treatments.

Challenges in quantifying microbial gene expression in soil using quantitative reverse transcription real-time PCR.

The quantification of microbial gene expression in diverse soil samples via quantitative reverse transcription real time polymerase chain reaction (qRT-PCR) has numerous challenges including total RNA extraction, sample preparation, qRT-PCR optimization and the correlation of gene expression with function. Despite these challenges, microbial gene expression has been successfully quantified in soil microorganisms, and will yield valuable information on soil functions and expression of genes in soil samples. In this perspective we discuss challenges of measuring microbial gene expression and highlight recent applications using qRT-PCR to research gene function in soil.

Perspective: microfluidic applications in microbiology.

The application of microfluidics technology to microbiology research is an excellent platform for the analysis of microorganisms and their nucleic acids. This technology combines engineering, physics, chemistry, biology and computing to control the devices. In this perspective we discuss how microfluidics can be applied to microbiological research and used in diagnostic applications.

Effect of nitrate and acetylene on nirS, cnorB, and nosZ expression and denitrification activity in Pseudomonas mandelii.

Nitrate acts as an electron acceptor in the denitrification process. The effect of nitrate in the range of 0 to 1,000 mg/liter on Pseudomonas mandelii nirS, cnorB, and nosZ gene expression was studied, using quantitative reverse transcription-quantitative PCR. Denitrification activity was measured by using the acetylene blockage method and gas chromatography.

Effect of pH and temperature on denitrification gene expression and activity in Pseudomonas mandelii.

Pseudomonas mandelii liquid cultures were studied to determine the effect of pH and temperature on denitrification gene expression, which was quantified by quantitative reverse transcription-PCR. Denitrification was measured by the accumulation of nitrous oxide (N(2)O) in the headspace in the presence of acetylene. Levels of gene expression of nirS and cnorB at pH 5 were 539-fold and 6,190-fold lower, respectively, than the levels of gene expression for cells grown at pH 6, 7, and 8 between 4 h and 8 h.

Nitric oxide reductase gene expression and nitrous oxide production in nitrate-grown Pseudomonas mandelii.

Pure cultures of Pseudomonas mandelii were incubated with or without nitrate, which acts as a substrate and an electron acceptor for denitrification. Nitric oxide reductase (cnorB) gene expression was measured using a quantitative reverse transcription-PCR, and nitrous oxide emissions were measured by gas chromatography. P.

The effect of native and ACC deaminase-containing Azospirillum brasilense Cd1843 on the rooting of carnation cuttings.

Carnation cuttings treated with non-transformed and 1-aminocyclopropane (ACC) deaminase-containing Azospirillum brasilense Cd1843 produced significantly more roots than untreated controls and fewer roots than cuttings treated with 0.1% indolebutyric acid (IBA). The roots produced by cuttings treated with ACC deaminase-containing Azospirillum brasilense Cd1843 were the longest roots resulting from any of the treatments, followed by non-transformed Azospirillum brasilense Cd1843, 0.

Microbial gene expression in soil: methods, applications and challenges.

About 99% of soil microorganisms are unculturable. However, advances in molecular biology techniques allow for the analysis of living microorganisms. With the advent of new technologies and the optimization of previous methods, various approaches to studying gene expression are expanding the field of microbiology and molecular biology.