1. Investigación

Different studies have reported the prevalence and antibiotic resistance of Salmonella in dromedaries’ camels and its role in camelid-associated salmonellosis in humans, but little is known about the epidemiology of Campylobacter in dromedaries. Here we investigate the prevalence, genetic diversity and antibiotic resistance of Campylobacter and Salmonella in dromedary camels (Camelus dromedarius). A total of 54 individuals were sampled from two unique dromedary farms located in Tenerife (Canary Islands, Spain). Whilst all the samples were Campylobacter-negative, Salmonella prevalence was 5.5% (3/54) and the only serovar isolated was S. Frintrop. The pulsed field gel electrophoresis analysis revealed a low genetic diversity, with all isolates showing a nearly identical pulsotype (similarity > 95%). Our results indicate that dromedaries’ camels could not be a risk factor for Campylobacter human infection, but seems to be a reservoir for Salmonella transmission. Since camel ride has become one of the main touristic attractions in several countries and its popularity has considerably risen in the last years, a mandatory control, especially for zoonotic pathogens, such as Campylobacter and Salmonella should be implemented.

Pork is considered a major source of Salmonella Typhimurium infection in humans in the EU, including monophasic strains. Widespread distribution of virulent serotypes such as monophasic variants of S. Typhimurium have emerged as a public health threat. Despite the current situation, within the EU there is no mandatory programme for the control of Salmonella at pork production level. In this context, the aims of this study were: to examine the presence of Salmonella in the swine production system from arrival at the slaughterhouse until the end of processing, and investigate the genetic relationship among the Salmonella serovars isolated. During the study, a total of 21 pig herds were intensively sampled during processing at the slaughterhouse. ERIC-PCR was performed among isolates recovered at the different steps in the slaughterhouse to assess the genetic relationship. Then, PFGE was done to study the pulsotypes among the different Salmonella serovars isolated. The results showed a high level of Salmonella pork batch contamination upon arrival at the slaughterhouse (71.4%) and at the end of the slaughtering process (66.7%), with mST the main serovar isolated from both origins (53.1% and 38.2%, respectively). The slaughter environment poses a potential risk for carcass contamination and it is considered an important source of Salmonella spp. Similarly, this study shows that 14.3% of the strains isolated from carcasses have the same Xbal-PFGE profile as those previously recovered in the slaughterhouse environment, but not in the live animals from that same batch. In conclusion, there is a high level of Salmonella swine batch contamination upon arrival at the slaughterhouse and at the end of the slaughtering process, mST being the most frequently isolated serovar. Moreover, a strong genetic relationship has been observed between Salmonella strains isolated from the batch on arrival at the slaughterhouse, the processing environment and pork carcass contamination. In this sense, it would be necessary to implement a control programme to reduce the bacterium from pork farms and raise the awareness of biosecurity measures.