Phenotyping, genotyping and susceptibility on antimicrobial drugs of Salmonella spp. isolated from slaughtered pig carcasses

Cilj ove doktorske disertacije je da se utvrdi zastupljenost salmonela u uzorcima briseva sa trupova svinja u različitim fazama proizvodnje i sadržaja ileuma, izvrši njihova fenotipizacija, genotipizacija i utvrdi osetljivost na antimikrobne lekove. Ispitivanje je sprovedeno na jednoj klanici srednjeg kapaciteta iz okoline Beograda. Prilikom posete klanici, vršeno je i anketiranje, odnosno prikupljanje podataka o: poreklu svinja (farma, otkup), mestu nabavke, načinu ishrane (suva, tečna, kombinovana), telesnoj masi svinja, starosti, dužini trajanja transporta, dužini boravka u stočnom depou, eventualnom mešanju svinja u stočnom depou sa svinjama drugog porekla i higijeni stočnog depoa. Za ispitivanje su uzorkovani brisevi sa 100 trupova svinja kao i sadržaj ileuma. Uzorkovanje je trajalo deset nedelja, svake nedelje se rotirao dan, kako bi se obuhvatili svi dani u nedelji. Prilikom uzorkovanja, uzimali su se brisevi sa trupova nakon omamljivanja, zatim nakon završne obrade, a pre hlađenja i 24h posle početka hlađenja. Pored toga, uzorkovano je i 100 uzoraka sadržaja ileuma od istih trupova. Brisevi su uzimani sa obe polovine (polutke) istog trupa, što čini 200 uzoraka briseva nakon omamljivanja, 200 nakon završne obrade i 200 briseva nakon hlađenja, odnosno ukupno 600 briseva za ispitivanje na prisustvo salmonela i enterobakterija. Izolacija Salmonella spp. vršena je prema standardu SRPS EN ISO 6579:2008, Mikrobiologija hrane i hrane za životinje - Horizontalna metoda za otkrivanje Salmonella spp. Izolacija Salmonella spp. u uzorcima sadržaja ileuma vršena je prema istom standardu SRPS EN ISO 6579:2008, Annex D, Otkrivanje Salmonella spp. u fecesu životinja i u uzorcima iz životne sredine u primarnoj fazi proizvodnje...The aim of this doctoral thesis was to establish the presence of Salmonella in swab samples from pig carcasses and from the content of the ileum collected at various stages of production. Phenotyping, antimicrobial susceptibility testing and molecular typing by pulse field gel electrophoresis was also done for selected Salmonella strains. The study was conducted at one slaughterhouse of medium capacity closed to the city of Belgrade. During a visit to the slaughterhouse the survey was carried out, and data collected about: the origin of the pig (farm, purchase), place of purchase, type of diet (dry, liquid, combined), body weight of pigs, age, duration of transport, length of stay in lairage, the possible of mixing pigs in lairage with pigs of different origin and the hygiene of the lairage. Swab samples were collected from 100 carcasses of pigs and from the content of the ileum. Sampling was done during ten weeks, every week the day was rotated, in order to cover all days of the week. During sampling, the swabs were taken from the carcasses after stunning, then after the completion of processing before chilling and 24 hours after the start of chilling. The contents of 100 samples of ileum from the same carcasses were sampled as well. Swabs were taken from two halves (hemispheres) of the carcass, which makes the 200 swab samples after stunning, 200 after processing and 200 swabs after chilling. By such sampling strategy, total of 600 swabs were cultured to estimate the presence of Salmonella and Enterobacteriaceae. The isolation of Salmonella spp. was performed according to standard SRPS EN ISO 6579: 2008, Microbiology of food and feed - Horizontal method for the detection of Salmonella spp..