Joanna Wojtacka

Determination of the cytotoxic activity of Campylobacter strains isolated from bovine and swine carcasses in north-eastern Poland

The study was carried out to determine the cytotoxin production by Campylobacter spp. isolated from slaughtered cattle and swine in north-eastern Poland. In total three commercial slaughterhouses were sampled during one year. Carcass swabs were taken to detect the level of Campylobacter spp. contamination. Campylobacter spp. was found in 50 (34%) out of 147 swine carcasses examined. PCR analysis revealed 4 (8%) isolates to be C. jejuni, and 46 (92%) to be C. coli. From a total of 373 bovine carcasses, Campylobacter spp. were isolated from 49 (13.1%) samples. The results regarding the occurrence of cdt genes associated with cytotoxicity indicated that 100% of C. jejuni and 67.4% C. coli obtained from pigs had all three cdtA, cdtB and cdtC genes. In case of C. jejuni strains isolated from cattle all cdt genes were confirmed in 93.9% isolates. The isolates possessesing all cdt genes had higher cytotoxic activity against cell lines used. The isolates both from cattle and swine were characterized by the highest cytotoxicity against HeLa cells. The values obtained reached 80.8% for C. jejuni isolates from cattle and 76.2% for C. jejuni and 69.0% for C. coli isolates from swine. High prevalence of cytotoxicity in Campylobacter spp. indicates a significant epidemiological role of this pathogen in human infections.

Detection of virulence genes determining the ability to adhere and invade in Campylobacter spp. from cattle and swine in Poland

The aim of the study was to determine the prevalence of virulence genes responsible for the adhesion (flaA, cadF and racR) and invasion (virB11, iam and pldA) in Campylobacter isolates from cattle and swine and determine their adherence and invasion abilities. The studies conducted revealed high prevalence rate of adherence and invasion associated genes irrespective of the isolates origin. All Campylobacter strains of swine and cattle origin adhered to HeLa cells at mean level 0.1099% ± SD 0.1341% and 0.0845% ± SD 0.1304% of starting viable inoculum, respectively. However swine isolates exhibited higher invasion abilities (0.0012% ± SD 0.0011%) compared to bovine isolates (0.00038% ± SD 0.00055%). The results obtained revealed significantly positive correlation between invasion and adherence abilities of swine origin isolates (R = 0.4867 in regard to C. jejuni and R = 0.4507 in regard to C. coli) and bovine origin isolates (R = 0.726 in regard to C. jejuni). Bacterial virulence is multifactorial and it is affected by the expression of virulence genes. Moreover the presence of virulence genes determines the ability of Campylobacter isolates to adhere and invade the cells.

Clostridium botulinum spores found in honey from small apiaries in Poland

Abstract A total of 102 honey samples collected from small apiaries (≤ 20 hives) in Poland were analysed for the presence of Clostridium botulinum spores. The samples were prepared using the dilution centrifugation method and cultured in parallel in cooked meat medium (CMM) and tripticase peptone glucose yeast (TPGY) enrichment broths. Identification of toxin types A, B, and E of Clostridium botulinum strains was performed with the use of the multiplex PCR method. Positive samples were also subjected to quantitative analysis with the use of Clostridium botulinum Isolation Agar Base (CBAB). The prevalence analysis showed 22 (21.6%) samples contaminated with C. botulinum spores. The major serotype detected was botulin neurotoxin type A – 16 (72.7%) whereas type B was found in 3 (13.6%) honey samples and type E also only in 3 (13.6%) honey samples. Dual-toxin-producing strains were noted. The average quantity of spores in PCR - C. botulinum positive samples was 190 in 1 gram of honey.