CCL20-CCR6 axis directs sperm-oocyte interaction and its dysregulation correlates/associates with male infertility‡.

The interaction of sperm with the oocyte is pivotal during the process of mammalian fertilization. The limited numbers of sperm that reach the fallopian tube as well as anatomic restrictions indicate that human sperm-oocyte encounter is not a matter of chance but a directed process. Chemotaxis is the proposed mechanism for re-orientating sperm toward the source of a chemoattractant and hence to the oocyte. Chemokines represent a superfamily of small (8-11 kDa), cytokine-like proteins that have been shown to mediate chemotaxis and tissue-specific homing of leukocytes through binding to specific chemokine receptors such as CCRs. Here we show that CCR6 is abundantly expressed on human sperms and in human testes. Furthermore, radioligand-binding experiments showed that CCL20 bound human sperm in a specific manner. Conversely, granulosa cells of the oocyte-surrounding cumulus complex as well as human oocytes represent an abundant source of the CCR6-specific ligand CCL20. In human ovaries, CCL20 shows a cycle-dependent expression pattern with peak expression in the preovulatory phase and CCL20 protein induces chemotactic responses of human sperm. Neutralization of CCL20 in ovarian follicular fluid significantly impairs sperm migratory responses. Conversely, analyses in infertile men with inflammatory conditions of the reproductive organs demonstrate a significant increase of CCL20/CCR6 expression in testis and ejaculate. Taken together, findings of the present study suggest that CCR6-CCL20 interaction may represent an important factor in directing sperm-oocyte interaction.

Relationship of retinoid and carotenoid metabolism with caecotrophy in rabbits.

The relationship of retinoid and carotenoid metabolism with caecotrophy was studied in adult female New Zealand White rabbits kept in individual metabolic cages. Caecotrophy was prevented by the use of plastic collars. The dry matter, crude protein, fibre, fat and ash contents of hard and soft faecal samples were determined. The retinoid (retinol and retinyl palmitate) and carotenoid (canthaxanthin, beta-carotene, beta-cryptoxanthin, lutein and zeaxanthin) levels of the blood, liver, kidney, caecal content and faeces were also measured by high-performance liquid chromatography (HPLC). The prevention of caecotrophy resulted in a significant decrease of blood retinol (P < 0.001) and retinyl palmitate (P < 0.01) concentration but it did not cause any significant change in the retinol and retinyl palmitate contents of the liver and kidney. The caecal content (25.78 +/- 6.87 microg/g) and the soft faeces (34.52 +/- 10.48 microg/g) contained the retinoids in similar amounts. Various carotenoids were found in considerable amounts in different types of faeces, while in the tissues (blood, liver and kidney) these pigments did not occur in substantial amounts. Total carotenoid concentration was similar in the caecal content (11.23 microg/g) and in the caecotroph (13.85 microg/g). On the basis of the results it can be assumed that the retinoid content of rabbit feed could be lowered in the presence of adequate caecal function and caecotrophy.

The incidence of Campylobacter spp. on processed turkey from processing plants in the midwestern United States.

AIM: The primary aim of this study was to determine the incidence of Campylobacter spp. on turkey, presented for processing at participating production plants located in the midwest region of the United States. METHODS AND RESULTS: The two participating plants were visited on a monthly basis for a period of 1 year. Sampling of carcasses was carried out using a surface swab technique. Swabs were obtained from carcasses at two points on the production line - prechill and postchill. In addition, samples of chill water were also obtained for examination. Isolation and detection of Campylobacter was carried out using enrichment in Preston broth with recovery of the organism on blood free Campylobacter selective agar (CCDA). Isolates recovered were screened and identified using the API Campy identification system. The study found that 34.9% of all samples tested were positive for Campylobacter spp. The overall, contamination rates observed for both plants were relatively similar (39.2% for plant A and 30.6% for plant B). Differences were observed in the incidence of Campylobacter spp. on prechill vs postchill carcasses (i.e. 40.8% prechill vs 37.6% postchill for plant A and 41.8% prechill vs 19.8% postchill for plant B). Campylobacter species most often isolated included Camp. jejuni and Camp. coli. Other species recovered were Camp. fetus fetus, Camp. upsaliensis and Camp. lari. CONCLUSIONS: The incidence of Campylobacter spp. on processed poultry was relatively common. Factors such as the processing plant examined, season and the farms presenting birds for processing influenced the incidence of the pathogen. SIGNIFICANCE AND IMPACT OF THE STUDY: Differences were observed in the prevalence of Campylobacter spp. isolated from the two plants examined. The study suggests a seasonal prevalence of Campylobacter in the cooler months with processing conditions also influencing the overall occurrence of the organism. The incidence, isolation and detection of Campylobacter spp. from processed poultry are discussed.

The incidence of antimicrobial-resistant Salmonella spp on freshly processed poultry from US Midwestern processing plants.

AIMS: To determine the incidence of antimicrobial-resistant Salmonella spp. on processed poultry (turkey) at Midwestern poultry plants. METHODS AND RESULTS: Two participating plants were visited at monthly intervals for a period of 1 year. Surface swabs were obtained from carcasses at two selected points on the production line, pre- and post-chill. In addition, samples of the chill water from chill tanks were also examined. Isolation and detection of Salmonella spp. from carcass swabs and chill water was carried out using standard enrichment techniques. Immunomagnetic separation was used to enhance the recovery of the pathogen. Salmonella isolates recovered were identified, serotyped and their antimicrobial resistance profiles determined using the National Antimicrobial Resistance Monitoring System. Results from the study indicated that the overall incidence of Salmonella was approx. 16.7%, with a greater incidence of the pathogen observed on pre-chill than post-chill carcasses. Salmonella isolates recovered displayed resistance to an average of four different antimicrobials. Approximately 15 different serotypes of Salmonella spp. were recovered, with Salmonella serotype Agona, Salmonella serotype Hadar, Salmonella serotype Heidelberg and Salmonella serotype Senftenberg being the most common. CONCLUSIONS: The incidence of Salmonella spp. was relatively low and isolates recovered showed significant degrees of antimicrobial resistance. Factors such as the processing plant examined, the season and farms that were presenting animals for processing influenced the incidence of the pathogen. SIGNIFICANCE AND IMPACT OF THE STUDY: Differences were observed in the serotypes of Salmonella recovered and the types of antimicrobial resistance found at the two plants. The study suggests that the use of antimicrobials at the farm level influences the creation of an environment that promotes the selection of antimicrobial-resistant Salmonella spp. The incidence, isolation and detection of Salmonella spp. on processed poultry are discussed.