ABSTRACT
Introduction: Escherichia coli is present in the normal intestinal flora but some strains can cause intestinal and extraintestinal diseases, and research on its presence in food of animal origin is in the interests of public health. This study was designed to characterise E. coli strains according to their origin, their carriage of virulence genes specific for certain pathogroups, and phylogenetic group affiliation. Material and Methods: The study was carried out on 100 E. coli strains isolated from food samples of various animal origin as well as pig and cattle carcass swabs. Isolation of the strains was performed using two methods. One method included colony count and the other an overnight enrichment of the samples. Isolation was followed by DNA extraction and detection of virulence genes and phylogenetic group with conventional and multiplex PCRs. Results: In this study, the most prevalent gene was EAST1 (20%) and strains which carried it were identified as enteroadherent E. coli. Other pathogroups were represented in lower incidences. Phylogenetic group analysis revealed the prevalence of the A and B1 groups, with B1 mainly present in game and cattle strains, while the majority of pig and poultry strains were assigned to group A. Conclusion: This study provides an overview of the presence of potentially pathogenic strains and E. coli phylogenetic groups in Croatia, for which the data are limited. Further microbiological and molecular research is required to examine the epidemiological situation in the country.
ABSTRACT
Campylobacteriosis is the most common gastrointestinal bacterial disease in the European Union (EU). Wild birds are one of the natural reservoirs of these pathogens. In this study we tested cloacal swabs of 643 gulls captured on rubbish tip in Zagreb, Croatia for the presence of Campylobacter spp. and found 168 Campylobacter positive samples. We used multilocus sequence typing (MLST) to genotype 62 random C. jejuni isolates from gulls, 24 isolates from broiler caeca, 27 isolates from broiler neck skins and 23 human isolates. Altogether, we identified 44 different STs, from which 19 were newly described. Most of the new STs (14) originate from gulls. Although humans and broilers share the majority of STs and isolates from gulls are separated from these, there was one ST present in all three hosts: 45. Additionally antimicrobial susceptibility to six antimicrobials was performed on 123 C. jejuni strains isolated from broiler caeca (n = 22), neck skins of broilers (n = 20), gulls cloacal swabs (n = 50) and human faeces (n = 31) by the broth microdilution method. Results show lower resistance of gull isolates to NAL and CIP, while resistance to TET was as high as in human and broiler isolates.
ABSTRACT
In order to detect thermotolerant Campylobacter spp., 241 samples of fresh chicken meat, at retail in Croatia, were analysed according to a standard method, followed by biochemical test and molecular polymerase chain reaction/restriction enzyme analysis for exact species determination. Campylobacter spp. prevalence was 73.86%. Campylobacter jejuni and Campylobacter coli were isolated from 53.53 and 15.35% of the samples, respectively. In 4.98% of isolates thermotolerant Campylobacter spp. were not determined. The multilocus sequence typing method was used to evaluate genetic diversity of eight Campylobacter jejuni and four Campylobacter coli isolates. To our knowledge, these results of genotyping provided the first data on the presence of sequence types (STs) and clonal complexes (CCs) of Campylobacter jejuni and C. coli isolates in Croatia. By applying the multilocus sequence typing, a new allele of tkt gene locus was discovered and marked tkt508. The C. jejuni ST 6182 and C. coli ST 6183 genotypes were described for the first time, and all other identified genotypes were clustered in the previously described sequence types and clonal complexes. These findings provide useful information on the prevalence and epidemiology of Campylobacter jejuni and C. coli in Croatia.
