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Aims: The objectives of this work were to evaluate immunomagnetic beads and a reverse transcriptase (RT)-PCR method for the detection of Salmonella inoculated into feed. In addition, a reverse transcriptase (RT)-PCR method was evaluated for quantifying virulence gene hilA expression of Salmonella ssp. in poultry feed matrices and utilized to determine the influence of poultry feed environmental factors on Salmonella hilA expression., Methods and Results: An immunomagnetic separation technique was evaluated for increased recovery of Salmonella from feed. Salmonella cultures were inoculated into feed samples and exposed to heat treatments of 70°C and sampled periodically. From these samples, RNA was collected and hilA gene expression was measured relative to the housekeeping 16S rRNA gene. The immunomagnetic bead protocol increased recovery by 1 log. The up-regulation of hilA was demonstrated after 5 and 10 min of inoculated feed samples being exposed to heat treatment., Conclusions: From this work, the data indicate that the ability to detect live Salmonella cells in feed samples may be increased by targeting the hilA gene., Significance and Impact of the Study: Foodborne salmonellosis originating from poultry is a major problem, and feed is a leading source of contamination in poultry, but detection in feed is complicated by low concentrations. The assays and experiments in this study examine possible improvements to recovery and detection of Salmonella in feed., (© 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.)

Three pathogens, Campylobacter, Salmonella, and Shiga-toxin-producing Escherichia coli, are leading causes of bacterial gastroenteritis in the United States and worldwide. Although these three bacteria are typically considered food-borne pathogens, outbreaks have been reported due to contaminated drinking water and irrigation water. The aim of this research was to develop two types of PCR assays that could detect and quantify three pathogens, Campylobacter spp., E. coli O157:H7, and Salmonella spp., in watershed samples. In conventional PCR, three target strains were detected by multiplex PCR (m-PCR) using each specific primer pair simultaneously. Under optimized m-PCR conditions, the assay produced a 90-bp product for Campylobacter jejuni, a 150-bp product for E. coli O157:H7, and a 262-bp product for Salmonella Typhimurium, and the limitation of detection was approximately 700 copies for all three bacteria. In addition, real-time PCR was performed to quantify the three pathogens using SYBR green fluorescence. The assay was designed so that each target had a different melting temperature [C. jejuni (80.1 °C), E. coli O157:H7 (83.3 °C), and S. Typhimurium (85.9 °C)]. Therefore, this system could quantify and distinguish three pathogens simultaneously in a single reaction., (© 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.)

Aims: While considerable foodborne pathogen research has been conducted on conventionally produced broilers and turkeys, few studies have focused on free-range (organic) or pastured poultry. The current surveillance study was designed to isolate, identify and genetically characterize Salmonella from pastured poultry farm environment and from retail samples., Methods and Results: In this study, 59 isolates were collected from two pastured poultry farms (n = 164; pens, feed, water and insect traps) and retail carcasses (n = 36) from a local natural foods store and a local processing plant. All isolates were serotyped and analysed phenotypically (antimicrobial resistance profiles) and genotypically (DNA fingerprints, plasmid profiles and integron analysis). Salmonella enterica was detected using standard microbiological methods. Salmonella Kentucky was the most prevalent serotype detected from the sampled sources (53%), followed by Salmonella Enteritidis (24%), Bareilly (10%), Mbandaka (7%), Montevideo (5%) or Newport (2%). All isolates were resistant to sulfisoxazole and novobiocin, and the majority (40/59) possessed class I integrons shown by PCR detection. Each Salmonella serotype elicited a distinct pulsed-field gel electrophoresis fingerprint profile, and unique differences were observed among the serotypes., Conclusions:  The findings of this study show that Salmonella serotypes isolated from pasture-raised poultry exhibit antimicrobial resistance and class I integrons., Significance and Impact of the Study:  This study demonstrates that despite the cessation of antibiotic usage in poultry production, antibiotic resistant Salmonella may still be recovered from the environment and poultry products., (© 2010 The Authors. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology.)

Aims: The objective of this study was to determine if survival of culturable Campylobacter jejuni outside the host was increased by entrapment in pre-established biofilms., Methods and Results: Campylobacter jejuni was inoculated into four biofilm populations isolated from poultry environments and cultured at three temperatures. Survival of culturable Camp. jejuni in some pre-established biofilms was extended vs survival of culturable Camp. jejuni in broth. But some biofilms were detrimental to survival of culturable Camp. jejuni. Denaturing gradient gel electrophoresis analysis indicated differences in bacterial profiles depending on initial source and temperature of culturing, which may have had impacts on survival of culturable Camp. jejuni. Further investigation showed no evidence of interspecies cell signalling indicating that secondary colonization was only physical., Conclusions: The results of this study show Camp. jejuni's attachment to surfaces is facilitated by pre-established biofilms and survival of culturable Camp. jejuni may be extended in some pre-established biofilms, but these biofilms do not fully explain long-term survival of culturable Camp. jejuni outside hosts., Significance and Impact of the Study: This study provides new information concerning survival of culturable Camp. jejuni outside the host and shows biofilms may be important in transmission and prevalence of Camp. jejuni.

Pancreatic beta-cell function was evaluated in uraemic patients by measuring beta-cell peptides in the peripheral blood after intravenous glucagon (1 mg) stimulation. Patients in chronic renal failure, patients on haemodialysis, and both new and established subjects on continuous ambulatory peritoneal dialysis (CAPD) (10 in each group) were studied and compared to 8 healthy controls. Fasting glucose (3.6-4.4 mmol/l) and insulin concentrations (9.5-11.7 mU/l) were normal and did not differ between the uraemic groups, but c-peptide concentrations were markedly increased in uremia (1.84-2.38 nmol/l) compared to controls (0.48 nmol/l). Following glucagon stimulation an exaggerated blood glucose response with delayed glucose peak was observed, while the peak insulin response to glucagon was normal; however, the return to basal concentrations was delayed in uraemia. The c-peptide response was also exaggerated and peak concentrations in uraemic subjects (3.0-4.3 nmol/l) were significantly greater than controls (1.5 nmol/l). The response of CAPD patients was similar to those on haemodialysis and non-dialysed uraemic patients. The abnormalities seen were due to uraemia, and CAPD treatment had no specific adverse effect on beta-cell function. Thus, from this data there was no evidence that CAPD per se is detrimental to beta-cell integrity.