Campylobacter Research Today is a free monthly online journal that collates and summarizes the latest research about Campylobacter, including details on food poisoning, infection, symptoms, treatment.

Using of infrared spectroscopy to study the survival and injury of Escherichia coli O157:H7, Campylobacter jejuni and Pseudomonas aeruginosa under cold stress in low nutrient media.

Lu X, Liu Q, Wu D, Al-Qadiri HM, Al-Alami NI, Kang DH, Shin JH, Tang J, Jabal JM, Aston ED, Rasco BA

School of Food Science, Washington State University, Pullman 99163, USA.

The inactivation and sublethal injury of Escherichia coli O157:H7, Campylobacter jejuni and Pseudomonas aeruginosa at three temperatures (22 °C, 4 °C and -18 °C) were studied using traditional microbiological tests and mid-infrared spectroscopy (4000-400 cm(-1)). Bacteria were cultivated in diluted nutrient matrices with a high initial inoculation (∼10(7) CFU/ml) levels. Both E. coli O157:H7 and P. aeruginosa survived and cell numbers increased at 22 °C for 5 days while C. jejuni numbers decreased one log(10) CFU/ml. A two log CFU/ml decrease was observed for the three pathogens held at 4 °C for 12 days. C. jejuni survived poorly following incubation at -18 °C for 20 days while levels of E. coli O157:H7 and P. aeruginosa remained high (10(4) CFU/ml). Temperature stress response of microbes was observed by infrared spectroscopy in polysaccharide, protein, lipid, and nucleic acid regions and was strain specific. Level of cold injury could be predicted using cluster, discriminant function and class analog analysis models. Pathogens may produce oligosaccharides and potentially other components in response to stress as indicated by changes in spectral features at 1200-900 cm(-1) following freezing.

Published 1 March 2011 in Food Microbiol, 28(3): 537-46.
Full-text of this article is available online (may require subscription).

Articles on Campylobacter published 1 March 2011:

Using of infrared spectroscopy to study the survival and injury of Escherichia coli O157:H7, Campylobacter jejuni and Pseudomonas aeruginosa under cold stress in low nutrient media.   Food Microbiol, 28(3): 537-46.

The inactivation and sublethal injury of Escherichia coli O157:H7, Campylobacter jejuni and Pseudomonas aeruginosa at three temperatures (22 °C, 4 °C and -18 °C) were studied using traditional microbiological tests and mid-infrared spectroscopy (4000-400 cm(-1)). Bacteria were cultivated in diluted nutrient matrices with a high initial inoculation (∼10(7) CFU/ml) levels. Both E. coli O157:H7 and P. aeruginosa survived and cell numbers increased at 22 °C for 5 days while C. jejuni numbers ... [Abstract] [Full-text]

Pulsed field gel electrophoresis typing of human and retail foodstuff Campylobacters: an Irish perspective.   Food Microbiol, 28(3): 426-33.

Campylobacter enteritis is a zoonosis, an infectious disease transmissible under normal conditions from vertebrate animals to man, presenting a major global public health burden. In this study, Pulsed Field Gel Electrophoresis (PFGE) was employed to identify common genotypes in a collection of 600 Campylobacter isolates in order to investigate if profiles obtained from retail samples of foodstuffs matched genotypes causing illness in the community in Ireland. The Campylobacters were isolated ... [Abstract] [Full-text]

Pulsed field gel electrophoresis typing of human and retail foodstuff Campylobacters: an Irish perspective.   Food Microbiol, 28(3): 426-33.

Campylobacter enteritis is a zoonosis, an infectious disease transmissible under normal conditions from vertebrate animals to man, presenting a major global public health burden. In this study, Pulsed Field Gel Electrophoresis (PFGE) was employed to identify common genotypes in a collection of 600 Campylobacter isolates in order to investigate if profiles obtained from retail samples of foodstuffs matched genotypes causing illness in the community in Ireland. The Campylobacters were isolated ... [Abstract] [Full-text]

Articles on Campylobacter published 10 February 2011:

Phenotypic and genotypic evidence for L-fucose utilization by Campylobacter jejuni.   J Bacteriol, 193(5): 1065-75.

Campylobacter jejuni remains among the leading causes of bacterial food-borne illness. The current understanding of Campylobacter physiology suggests that it is asaccharolytic and is unable to catabolize exogenous carbohydrates. Contrary to this paradigm, we provide evidence for l-fucose utilization by C. jejuni. The fucose phenotype, shown in chemically defined medium, is strain specific and linked to an 11-open reading frame (ORF) plasticity region of the bacterial chromosome. By constructing ... [Abstract] [Full-text]

Articles on Campylobacter published 14 January 2011:

Interbacterial macromolecular transfer by the Campylobacter fetus subsp. venerealis type IV secretion system.   J Bacteriol, 193(3): 744-58.

We report here the first demonstration of intra- and interspecies conjugative plasmid DNA transfer for Campylobacter fetus. Gene regions carried by a Campylobacter coli plasmid were identified that are sufficient for conjugative mobilization to Escherichia coli and C. fetus recipients. A broader functional range is predicted. Efficient DNA transfer involves the virB9 and virD4 genes of the type IV bacterial secretion system encoded by a pathogenicity island of C. fetus subsp. venerealis. ... [Abstract] [Full-text]

Interbacterial macromolecular transfer by the Campylobacter fetus subsp. venerealis type IV secretion system.   J Bacteriol, 193(3): 744-58.

We report here the first demonstration of intra- and interspecies conjugative plasmid DNA transfer for Campylobacter fetus. Gene regions carried by a Campylobacter coli plasmid were identified that are sufficient for conjugative mobilization to Escherichia coli and C. fetus recipients. A broader functional range is predicted. Efficient DNA transfer involves the virB9 and virD4 genes of the type IV bacterial secretion system encoded by a pathogenicity island of C. fetus subsp. venerealis. ... [Abstract] [Full-text]

Articles on Campylobacter published 24 November 2010:

Molecular mechanisms modulating glutamate kinase activity. Identification of the proline feedback inhibitor binding site.   J Mol Biol, 404(5): 890-901.

Proline, the feedback inhibitor of bacterial glutamate kinase (GK) and plant pyrroline-5-carboxylate synthase (P5CS) enzymes, is a key regulator of the osmotic and redox balance of cells. Using kinetic assays, site-directed mutagenesis, structure-activity analyses, and docking calculations, we have identified the binding site of this metabolite in three-dimensional structures of Escherichia coli and Campylobacter jejuni GKs. The proline-binding cavity partially overlaps with the glutamate ... [Abstract] [Full-text]

Molecular mechanisms modulating glutamate kinase activity. Identification of the proline feedback inhibitor binding site.   J Mol Biol, 404(5): 890-901.

Proline, the feedback inhibitor of bacterial glutamate kinase (GK) and plant pyrroline-5-carboxylate synthase (P5CS) enzymes, is a key regulator of the osmotic and redox balance of cells. Using kinetic assays, site-directed mutagenesis, structure-activity analyses, and docking calculations, we have identified the binding site of this metabolite in three-dimensional structures of Escherichia coli and Campylobacter jejuni GKs. The proline-binding cavity partially overlaps with the glutamate ... [Abstract] [Full-text]

© 2004-2011 Campylobacter Research Today. All Rights Reserved.