Catherine C. Adley

An overview of foodborne pathogen detection: In the perspective of biosensors

Food safety is a global health goal and the foodborne diseases take a major crisis on health. Therefore, detection of microbial pathogens in food is the solution to the prevention and recognition of problems related to health and safety. For this reason, a comprehensive literature survey has been carried out aiming to give an overview in the field of foodborne pathogen detection. Conventional and standard bacterial detection methods such as culture and colony counting methods, immunology-based methods and polymerase chain reaction based methods, may take up to several hours or even a few days to yield an answer. Obviously this is inadequate, and recently many researchers are focusing towards the progress of rapid methods. Although new technologies like biosensors show potential approaches, further research and development is essential before biosensors become a real and reliable choice. New bio-molecular techniques for food pathogen detection are being developed to improve the biosensor characteristics such as sensitivity and selectivity, also which is rapid, reliable, effective and suitable for in situ analysis. This paper not only offers an overview in the area of microbial pathogen detection but it also describes the conventional methods, analytical techniques and recent developments in food pathogen detection, identification and quantification, with an emphasis on biosensors.

A study of cross-contamination of food-borne pathogens in the domestic kitchen in the Republic of Ireland

To date, there have been no published information and empirical data available on the role played by the food preparer in the domestic kitchen in the Republic of Ireland. In this study, we have looked at the incidence of potential food pathogens and their cross-infection in the domestic kitchen during the preparation of a Sunday roast chicken lunch. Key contact sites in the domestic kitchen were sampled, including the chicken carcass before and after the preparation of a roast chicken meal. Twelve contact sites in twenty-five domestic kitchens were analysed and tested for aerobic plate count, Salmonella, Campylobacter, Escherichia coli and Staphylococcus aureus. Our findings identified the ability of food-borne disease microorganisms to become disseminated from infected foods, such as fresh chickens, to hand and food contact surfaces in the domestic kitchen, reiterating the need for consumer awareness and knowledge of effective hygiene procedures in the domestic kitchen.

Sphingomonas paucimobilis: a persistent Gram-negative nosocomial infectious organism

Non-fermenting Gram-negative bacilli create a significant problem in clinical settings, being the most widespread cause of nosocomial infections. They are opportunistic pathogens that take advantage of underlying conditions and diseases. Sphingomonas paucimobilis, a non-fermenting Gram-negative bacillus, is regarded as of minor clinical significance; however, many instances of infections with this organism can be found in the literature. Infections include bacteraemia/septicaemia caused by contaminated solutions, e.g. distilled water, haemodialysis fluid and sterile drug solutions. Cases of pseudobacteraemia have been recorded in association with S. paucimobilis, as have many cases of unusual infections both invasive and severe, e.g. septic arthritis and osteomyelitis. No cases of death have been recorded in the literature related to S. paucimobilis. This review illustrates that S. paucimobilis is a more important pathogen than previously thought.

Conducting Polymers and Their Applications to Biosensors: Emphasizing on Foodborne Pathogen Detection

Detection of microbial pathogens in food is the solution to the prevention and recognition of problems related to health and safety. New biomolecular approaches for foodborne pathogen detection are being developed to improve the biosensor characteristics such as sensitivity and selectivity, also which is rapid, reliable, cost-effective, and suitable for in situ analysis. Recently, conducting polymers have drawn attention in the development of biosensors. The electrically conducting polymers have numerous features, which allow them to act as excellent materials for immobilization of biomolecules. Also, their unique properties make them appealing alternatives for specific materials currently employed for the fabrication of biosensors. Therefore, this paper presents a comprehensive literature review detailing the salient features of conducting polymers and their application to biosensors with an emphasis on foodborne pathogen detection.

Characterization of Salmonella enterica Serotype Typhimurium Isolates from Human, Food, and Animal Sources in the Republic of Ireland

ABSTRACT A potential epidemic clone of Salmonella enterica serotype Typhimurium DT104, and the possible emergence of S. enterica serotype Typhimurium DT104b, has been identified from the characterization of 67 S. enterica serotype Typhimurium strains from three sources, human gastroenteritis isolates, isolates from food samples, and veterinary isolates, by antimicrobial resistance profiling, phage typing, and pulsed-field gel electrophoresis. Resistance to ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline was found in 77.6% of these strains.

Ralstonia pickettii in environmental biotechnology: potential and applications.

Xenobiotic pollutants such as toluene and trichloroethylene are released into the environment by various industrial processes. Ralstonia pickettii possess significant biotechnological potential in the field of bioremediation and has demonstrated the ability to breakdown many of these toxic substances. Here, we provide a description of the major compounds that various strains of R. pickettii are capable of degrading and a brief review of their breakdown pathways and an argument for its use in bioremediation.

Novel Tn4371-ICE like element in Ralstonia pickettii and Genome mining for comparative elements

BackgroundIntegrative Conjugative Elements (ICEs) are important factors in the plasticity of microbial genomes. An element related to the ICE Tn4371 was discovered during a bioinformatic search of the Ralstonia pickettii 12J genome. This element was analysed and further searches carried out for additional elements.A PCR method was designed to detect and characterise new elements of this type based on this scaffold and a culture collection of fifty-eight Ralstonia pickettii and Ralstonia insidiosa strains were analysed for the presence of the element.ResultsComparative sequence analysis of bacterial genomes has revealed the presence of a number of uncharacterised Tn4371-like ICEs in the genomes of several β and γ- Proteobacteria. These elements vary in size, GC content, putative function and have a mosaic-like structure of plasmid- and phage-like sequences which is typical of Tn4371-like ICEs. These elements were found after a through search of the GenBank database. The elements, which are found in Ralstonia, Delftia, Acidovorax, Bordetella, Comamonas, Acidovorax, Congregibacter, Shewanella, Pseudomonas Stenotrophomonas, Thioalkalivibrio sp. HL-EbGR7, Polaromonas, Burkholderia and Diaphorobacter sp. share a common scaffold. A PCR method was designed (based on the Tn4371- like element detected in the Ralstonia pickettii 12J genome) to detect and characterise new elements of this type.ConclusionAll elements found in this study possess a common scaffold of core genes but contain different accessory genes. A new uniform nomenclature is suggested for ICEs of the Tn4371 family. Two novel Tn4371-like ICE were discovered and characterised, using the novel PCR method described in two different isolates of Ralstonia pickettii from laboratory purified water.

Ralstonia spp.: emerging global opportunistic pathogens.

The bacterial genus Ralstonia (Gram-negative non-fermenters) is becoming more prevalent in cases of infection with three bacterial species, Ralstonia pickettii, Ralstonia insidiosa and Ralstonia mannitolilytica, making up all cases reported (in the literature) to date. These organisms are prevalent in many different types of water supplies (including hospital water supplies), being well adapted to survive in low-nutrient conditions. They have been shown to cause infections, sometimes serious, such as osteomyelitis and meningitis, in hospital settings. Seventy cases of R. pickettii, 13 cases of R. mannitolilytica and three cases of R. insidiosa infection have been identified from the literature. Insight is given into the types of infections that are caused by these bacteria, the underlying conditions that are associated with these infections and potential treatments.

An evaluation of five preservation techniques and conventional freezing temperatures of −20°C and −85°C for long-term preservation of Campylobacter jejuni

Aims:  This study aimed to identify a simple, inexpensive preservation technique that will allow a quick and reliable recovery of Campylobacter jejuni following long‐term periods of preservation.

The fate of titanium miniplates and screws used in maxillofacial surgery: A 10 year retrospective study

The objective of this 10 year, retrospective study is to evaluate the indications for the removal of titanium miniplates following osteosynthesis in maxillofacial trauma and orthognathic surgery. All patients who had miniplates placed in a Regional Oral and Maxillofacial Department between January 1998 and October 2007 were included. The following variables were recorded: patient gender and age, number of plates inserted, indications for plate placement, location of plates, number and location of plates removed, indications for plate removal, time between insertion and removal, medical co-morbidities, and the follow-up period. During the 10 years of the study, 1247 titanium miniplates were placed in 535 patients. A total of 32 (3%) plates were removed from 30 patients. Superficial infection accounted for 41% of all plates removed. All complications were minor and most plates were removed within the first year of insertion. A low removal rate of 3% suggests that the routine removal of asymptomatic titanium miniplates is not indicated.