Publication Database

Salmonella carried over by pigs during transport and lairage (2019)

Art

Hochschulschrift

Autor

González Santamarina, Belén (WE 8)

Quelle

Berlin: Mensch und Buch Verlag Berlin, 2019 — v, 93 Seiten

ISBN: 978-3-86387-962-4

Sprache

Englisch

Verweise

URL (Volltext): https://refubium.fu-berlin.de/handle/fub188/24443

Kontakt

Institut für Lebensmittelsicherheit und -hygiene

Königsweg 69
14163 Berlin
+49 30 838 62551 / 52790
lebensmittelhygiene@vetmed.fu-berlin.de / fleischhygiene@vetmed.fu-berlin.de

Abstract / Zusammenfassung

This study was carried out during two sampling periods (5 days each) in March 2015 and September and October 2015, in a slaughterhouse in northern Germany. The aim of this study was to determine the transfer of Salmonella from trucks into lairage. Specially, the presence of Salmonella on trucks delivering pigs for slaughter, the role of the drivers in the Salmonella transfer and the role of the animals in the diversity of Salmonella strains. Samples were taken from transport (trucks and boots of the drivers), from lairage: pigs (rectum and skin swabs), lairage environment (before and after the occupation the pigs) and finally carcasses in the chilling room. In total, 859 samples were collected to get the information, if Salmonella could pass into the chilling room, and also to determine the diversity of the serovars in the lairage facilities. From 859 samples, 52 (6%) were Salmonella positive. 4 from the first sampling period, where pigs of category I were sampled, and 48 from the second sampling, where pigs of category I and II were available. Two serotypes were found: S. Derby with a proportion of 57.7% (30/52) and S. Typhimurium of 42.3% (22/52). With the PGFE technique, 6 different identical Salmonella patterns were found. In total, 48.1% (25/52) of the positive samples were recovered from pigs’ skin and rectum swabs. The lairage environment after occupation of the pigs, provided 21.1% (11/52) of the total positive samples, and transport (boots and floor truck) 15.4% (8/52). Pens before occupation and the lairage facilities before disinfection had the same proportion, 7.7% (4/52) of the positive samples. Neither samples after disinfection of the lairage facilities nor the carcasses at the chilling room, were Salmonella positive. All positive samples were found in the dirty area. Salmonella found in previous positions did not reach the end of the processing chain in the abattoir. Salmonella seems to get eliminated during the harvesting technology. In total, 30 shipments were sampled. The transport samples consisted of truck´s floor and boots of the drivers. In total, 56 transport samples were taken and 8 of them were positive: one sample came from a truck floor. The rest of the transport positive samples (7) were found on the boots of drives. Two identical PFGE patterns were found, one in the first period and the other in the second period. In both of them, boots contaminated the lairage environment and also pigs from other shipments. In conclusion, the drivers´ boots were an important part of the contamination cycle and a vector for Salmonella contamination in the lairage area, the truck apparently does not play a major role. Lairage environment was more frequently contaminated after (11/52) than before occupation (4/52). Salmonella positive samples were found before disinfection (4/52) of the whole lairage facilities. Disinfection eliminated Salmonella, no positive sample was found after this procedure. The pigs were also an important part of the Salmonella contamination of the lairage. Positive pigs carried Salmonella into lairage, contaminating not only the environment of the lairage but also animals from other suppliers. So, questions asked in this study can be answered as follows: • Does the truck transfer Salmonella into the abattoir (are the trucks´ surfaces testing positive)? In this study, truck surfaces did not play a major role in transfer of Salmonella into the lairage. • How far could Salmonella pass from the truck into the harvesting technology under the given circumstances? Salmonella passed from the truck into the lairage and stayed there. Salmonella did not reach the chilling room. • Is the driver a part of this contamination cycle? In this study, the drivers´ boots were an important vector in the Salmonella contamination cycle. • Is the lairage Salmonella positive? Lairage was positive before and after the occupation of the sampled pigs, but no positive samples could be found after the disinfection of the whole facilities. • Does the animal influence the diversity of Salmonella serovars in the chain? Two serovars, which are widely distributed in the pig chain, were found. The pigs influenced the diversity of the different patterns.