The transmission dynamics of Campylobacter jejuni among broilers in semi-commercial farms in Jordan.

Campylobacter is the leading cause of foodborne bacterial gastroenteritis in humans worldwide, often associated with the consumption of undercooked poultry. In Jordan, the majority of broiler chicken production occurs in semi-commercial farms, where poor housing conditions and low bio-security are likely to promote campylobacter colonisation. While several studies provided estimates of the key parameters describing the within-flock transmission dynamics of campylobacter in typical high-income countries settings, these data are not available for Jordan and Middle-East in general. A Bayesian model framework was applied to a longitudinal dataset on Campylobacter jejuni infection in a Jordan flock to quantify the transmission rate of C. jejuni in broilers within the farm, the day when the flock first became infected, and the within-flock prevalence (WFP) at clearance. Infection with C. jejuni is most likely to have occurred during the first 8 days of the production cycle, followed by a transmission rate value of 0.13 new infections caused by one infected bird/day (95% CI 0.11-0.17), and a WFP at clearance of 34% (95% CI 0.24-0.47). Our results differ from published studies conducted in intensive poultry production systems in high-income countries but are well aligned with the expectations obtained by means of structured questionnaires submitted to academics with expertise on campylobacter in Jordan. This study provides for the first time the most likely estimates and credible intervals of key epidemiological parameters driving the dynamics of C. jejuni infection in broiler production systems commonly found in Jordan and the Middle-East and could be used to inform Quantitative Microbial Risk Assessment models aimed to assess the risk of human exposure/infection to campylobacter through consumption of poultry meat.

Characterization of albumin-binding properties of Peptostreptococcus magnus.

A Peptostreptococcus magnus strain demonstrated binding activity for albumin preparations from humans, mice, and dogs, but not for rabbit or bovine albumin. The albumin binding site appeared to be heat stable and of protein nature. Treatment of P. magnus cells with trypsin under specified conditions enhanced this albumin binding. Electron micrographs and kinetic analyses revealed that this enhancement was the result of the removal of some cell wall associated proteins leading to a higher binding affinity without significant changes in binding site numbers. The albumin-binding proteins could be readily solubilized and purified by affinity chromatography. Upon gel electrophoresis the molecular mass of the albumin-binding proteins was estimated as 130 kilodaltons.