Prevalence of Helicobacter pullorum in Conventional, Organic, and Free-Range Broilers and Typing of Isolates

G. Manfreda¹, A. Parisi², A. Lucchi¹, R. G. Zanoni³ and A. De Cesare^1*

Abstract
Helicobacter pullorum represents a potential food-borne pathogen, and avian species appear to be a relevant reservoir of this organism.

In this study, the prevalence of H. pullorum was investigated at 30 conventional farms where 169 ceca from 34 flocks were tested, at eight organic farms where 39 ceca from eight flocks were tested, and at seven free-range farms where 40 ceca from eight flocks were tested. All of the ceca were obtained from healthy broiler chickens. Moreover, amplified fragment length polymorphism, pulsed-field gel electrophoresis, and automated ribotyping were employed to estimate the levels of genetic variability of H. pullorum broiler isolates within and between flocks.

Overall, Gram-negative, slender, curved rods, identified as H. pullorum by PCR, were isolated at 93.3% of the farms tested. The percentage of positive free-range farms (54.2%) was significantly lower than that of conventional (100%) or organic (100%) farms (P < 0.001). The level of within-flock genetic variability, calculated as the number of flocks colonized by isolates genetically different by all of the typing methods, was 34.9%. Isolates showing identical profiles by each typing method were observed in 11.6% of the flocks, but they were never detected between flocks. However, groups of isolates clustered together with an overall similarity level of 85%.

Our results suggest that even though a high level of genetic variability is attributable to H. pullorum broiler isolates, their hierarchical genotyping produces data useful for epidemiological investigations.


Source
Applied and Environmental Microbiology (2011) 77: 479-484
DOI: 10.1128/AEM.01712-10


Author Locations and Affiliations
(1) Department of Food Science, Alma Mater Studiorum, University of Bologna, Via del Florio 2, 40064 Ozzano dell'Emilia (BO), Italy
(2) Zooprophylactic Institute of Apulia and Basilicata, Via Chiancolla 1, 70017 Putignano (BA), Italy
(3) Department of Veterinary Public Health and Animal Pathology, Alma Mater Studiorum, University of Bologna, Via Tolara di Sopra 50, 40064 Ozzano dell'Emilia (BO), Italy
* Corresponding author, E-mail alessandra.decesare@unibo.it


Posted March 2011