title: Fecal shedding of thermophilic Campylobacter in a dairy herd producing raw milk for direct human consumption.
abstract: Factors affecting the fecal shedding of thermophilic Campylobacter in Italian dairy farms were investigated in a 12-month longitudinal study performed on a dairy farm authorized to sell raw milk in Italy. Fifty animals were randomly selected from 140 adult and young animals, and fecal samples were collected six times at 2-month intervals. At each sampling time, three trough water samples and two trough feed samples also were collected for both adult and young animals. Samples were analyzed with real-time PCR assay and culture examination. Overall, 33 samples (9.7%) were positive for thermophilic Campylobacter by real-time PCR: 26 (9.2%) of 280 fecal samples, 6 (16.6%) of 36 water samples, and 1 (4.2%) of 24 feed samples. Campylobacter jejuni was isolated from 6 of 280 samples; no other Campylobacter species was isolated. A higher (but not significantly) number of positive fecal samples were found in younger animals (11.33 versus 6.92% of adult animals), and a significantly higher number of positive water samples were collected from the water troughs of young animals. A distinct temporal trend was observed during the study period for both cows and calves, with two prevalence peaks between November and December and between May and July. Several factors such as calving, housing practices, herd size, management practices forcing together a higher number of animals, and variations in feed or water sources (previously reported as a cause of temporal variation in different farming conditions) were excluded as the cause of the two seasonal peaks in this study. The factors affecting the seasonality of Campylobacter shedding in the dairy herds remain unclear and warrant further investigation. The results of the present study indicate that special attention should be paid to farm hygiene management on farms authorized to produce and sell raw milk, with increased surveillance by the authorities at certain times of the year.
authors.affiliation: Experimental Institute for Zooprophylaxis in Lombardy and Emilia Romagna, Via Fiorini 5, 40127 Bologna, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Merialdi
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, 40064 Ozzano Emilia, Bologna, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Giacometti
authors.affiliation: Experimental Institute for Zooprophylaxis in Lombardy and Emilia Romagna, Via Fiorini 5, 40127 Bologna, Italy.
authors.forename: Lia
authors.initials: L
authors.lastname: Bardasi
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, 40064 Ozzano Emilia, Bologna, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Stancampiano
authors.affiliation: Experimental Institute for Zooprophylaxis in Lombardy and Emilia Romagna, Via Fiorini 5, 40127 Bologna, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Taddei
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, 40064 Ozzano Emilia, Bologna, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Serratore
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, 40064 Ozzano Emilia, Bologna, Italy. andrea.serraino@unibo.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Serraino
mesh_terms: D000818:Animals; D057138:Bacterial Shedding; D016123:Campylobacter jejuni / Q000302:isolation & purification*; D002417:Cattle / Q000382:microbiology*; D003257:Consumer Product Safety; D003612:Dairying; D005243:Feces / Q000382:microbiology*; D005260:Female; D005506:Food Contamination / Q000032:analysis; D005516:Food Microbiology; D007558:Italy; D008137:Longitudinal Studies; D008892:Milk / Q000382:microbiology*; D061352:Pasteurization; D060888:Real-Time Polymerase Chain Reaction