Detection and count of Salmonella enterica in pork meat products

A direct plating technique for the enumeration S. enterica in 90 pig meat samples was evaluated in comparison with a three tube-MPN procedure. For the detection of S. enterica the ISO 6597:2002 method was employed. Pork samples were collected at retail level in northern Italy. A total of 15 (16.7%) Salmonella positive samples were detected. By the use of the MPN method, S. enterica was countable m 12 (80.0%) samples, while the direct count gave positive results in two (13.3%) samples only The ISO 6597.2002 method identified 12 (80 %) contaminated samples out of 15. The enumeration levels of S. enterica ranged from 0.03 MPN/g to \u3e 110 MPN/g by the MPN method, and from 10 CFU/g to 180 CFU/g by direct plating. Seven Salmonella serovars were detected. S. Typhimurium, S. Derby, S. Give, S. Rissen, S. Livingstone, S. Brandenburg and S. London, with S. Typhimurium and S. Derby as the predominant ones

Detection, semiquantitative enumeration, and antimicrobial susceptibility of Yersinia enterocolitica in pork and chicken meats in Italy.

Yersinia enterocolitica is recognized as an etiological agent of gastroenteritis, lymphadenitis, and chronic sequelae. During 2006 and 2007, 205 samples (125 pork and 80 chicken meats) were collected in Italy and tested for detection and most-probable-number (MPN) enumeration of Y. enterocolitica organisms. The microorganism was isolated from 45 samples (21.9%): 19 (15.2%) pork samples and 26 (32.5%) chicken samples. Y. enterocolitica MPN contamination levels were low, ranging from 0.30 to 1.50/g. Most (94.4%) Y. enterocolitica strains were biotype 1A (serotypes O:3; O:5; O:6,30; O:6,30-6,31; O:7,8-8-8,19; O:8; O:9; O:25,35; O:36; and O nontypeable), and 5.6% of the isolates were bioserotype 2/O:9. All isolates were tested for yadA, ail, inv, ystA, and ystB virulence sequences. The yadA gene was detected in two strains (3.7%) isolated from chicken samples: one Y. enterocolitica 2/O:9 yadA+ ail+ ystA+, and one Y. enterocolitica 1A/O:7,8-8-8,19 yadA+ inv+ ystB+. Two (3.7%) 2/O:9 strains, isolated from pork products, were ail+ ystA+. Most biotype 1A strains were ystB+ (84.3%) and inv+ (39.2%). All strains were sensitive to cefotaxime, ciprofloxacin, chloramphenicol, nalidixic acid, streptomycin, sulfonamide, tetracycline, trimethoprim, and trimethoprim-sulfamethoxazole. Resistance to gentamicin and aztreonam was observed in 1.9% of the isolates. High levels of resistance were detected toward amoxicillin-clavulanic acid (27.8%), ampicillin (75.9%), and erythromycin (100%). The authors hypothesize that Y. enterocolitica pathogenic biotypes are rather uncommon in foods when compared with their isolation rates from animal sources and that chicken meat could be contaminated as well as pig meat and its derived products

DETECTION OF SALMONELLA ENTERICA IN PIGS AT SLAUGHTER BY THE ISO 6579 METHOD AND THE BacTrac 4300 - IMPEDANCE SYSTEM

Both the ISO 6579:2002 method and the BacTrac 4300 - Impedance system were applied for the detection of Salmonella enterica from pigs at slaughter. A total of 68 pigs, reared in 62 different farms of Northern Italy, were randomly selected during 9 consecutive visits at two slaughter-houses. A total of 204 samples (68 tonsils, 68 samples of caecal matter and 68 ham area carcass swabs) were collected. S. enterica was isolated from 8 (11.8%) tonsils, 17 faecal samples (25.0%) and from 10 (14.7%) carcass swabs. The ISO method detected as positive 6 (75.0%) tonsils, 14 (82.4%) faecal samples and 9 (90.0%) carcasses. S. enterica was isolated from 8 (100%) tonsils, 14 (82.4%) faecal samples and 10 (100%) carcass swabs by the BacTrac 4300 - Impedance system. Salmonella strains serotyping and phagetyping identified 15 S. Derby, 5 S. Agona, 4 S. Rissen, 2 S. Typhimurium phage-type U302, 2 S. Typhimurium DT120, 2 S. enterica 1, 4, [5], 12:i.-, 2 S. Kapemba, 1 S. Give, 1 S. Anatum and 1 S. enterica non-typeable (R strain)

EFFICIENCY OF VIRAL CONCENTRATION IN FOOD SAMPLES: COMPARISON BETWEEN PEG AND ULTRAFILTRATION TECHNIQUES

Norovirus is the most prevalent causative agent of foodborne diseases. However, the detection of this virus in foods other than shellfish is often time-consuming and unsuccessful. The objective of this study is to compare PEG and ultrafiltration techniques for viral concentration in bivalve molluscs. An experiment with Coxsackie B5 and feline Calicivirus strain F is conduct to determine the efficiency of each virus concentration. Ultrafiltration technique is the most indicated

EVALUATION OF THE INFLUENCE OF PIG HAM POST – SLAUGHTERING REFRIGERATION ON HYGIENIC PARAMETERS SET IN REGULATION EC 2073/2005

In order to evaluate the influence of refrigeration on hygienic parameters, issued by EC Regulation n. 2073:2005 (amended by EC Regulation n. 1441:2007) for swine carcasses, 15 pig hams were tested for microbiological analysis, i.e. enumeration of microorganisms at 30°C and enumeration of enterobacteriacee. Ham swabbing was carried out at the end of slaughtering and after 24 hours of storing in refrigeration cells. The temperature-monitoring recorders were put in the hams at the end of cutting operations of carcasses, when the hams were placed in the refrigeration cells. The drop in the inner temperature of hams was monitored during the 24-hour storing time. In most cases, hams with an increase of background flora after 24 hours, had lower temperature at the beginning of refrigeration and the inner temperature need a shorter time to drop below 20°C, 10°C and 4°C, rather than hams associated with bacterial reduction. Therefore there was no correlation between dropping of temperature and bacterial load of hams, because the hygienic conditions of cutting operations prior to refrigeration have a greater influence on hygienic parameters than refrigeration alone

the role of pigs as pharyngeal carriers of human pathogenic yersinia enterocolitica strains

From March 2007 to January 2008, a total of 170 pigs at slaughter were tested for Y. enterocolitica contamination in tonsils tissue. The animals came from 125 different farms located in four regions of Northern Italy. Y. enterocolitica was isolated from 19 out of 170 (11.2%) tonsils samples. The prevalent bio-serotype (68.4%) was 4/O:3, followed by bioserotypes 1A/O:8 (15.8%), 1A/O:5 (10.5%) and 4/O:8 (5.2%). Among bio-serotype 4/O:3, several strains possessed yadA, ail and ystA virulence genes