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) and investigated the relationship between the phage profiles and the toxin genes’ presence. Although our approach does not allow drawing exact conclusions whether the found virulence genes are present on a single phage or are distributed on different
variety of virulence factors that play an important role in a wide range of pathogenic mechanisms, such as adhesion, invasion, intracellular survival, toxin production, and iron acquisition [ 7 ]. However, the presence of virulence genes in multidrug
) Wassenaar TM, Gaastra W: Bacterial virulence, where to draw the line? FEMS Microbiol Letters 201, 1–7 (2001) Wassenaar TM, Alter T (2012): Virulence genes in microbial risk assessment of probiotic organisms: what do genome sequences tell us
, J. , Molina-González , D. , Poeta , P. , Igrejas , G. , Alonso-Calleja , C. and Capita , R. ( 2016 ): Antimicrobial resistance and virulence genes in enterococci from wild game meat in Spain . Food. Microbiol. 53 , 156 – 164
determine the prevalence of Salmonella spp. excreted in feces of clinically healthy pet reptiles, (2) to verify the presence of plasmid virulence genes in the isolates, (3) to study genetic profiles of the isolates by PFGE, and (4) to determine the
The association between putative virulence genes in Campylobacter jejuni clinical isolates, in vitro invasive capability and severity of infection is yet to be clearly described. We have characterized three virulence genes and correlated their presence with the severity of infection and in vitro invasiveness. We studied eight C. jejuni strains isolated from patients whose clinical data were scored to determine severity of infection. Cytolethal distending toxin (cdtB) , invasion associated marker (iam) and Campylobacter invasion antigen (ciaB) genes were detected by PCR and INT407 cells used for invasion assays. Two strains positive for all three genes were the most invasive and isolated from patients with the most severe infection. Four strains positive for two genes and two strains negative for all the three genes were identified. The two cdtB + ve / ciaB + ve strains were more invasive than the cdtB + ve / iam + ve strains. One of the cdtB − ve / ciaB − ve strains showed invasion levels similar to cdtB + ve / ciaB + ve strains, but the second strain had a non-invasive phenotype. The findings indicate a correlation between in vitro invasive capability, and the presence of all three genes. The pattern of association between invasiveness and molecular characterization suggests that the ciaB gene confers a more invasive capability.
An account is given using typing methods and detection of virulence genes of different serotypes of Escherichia coli isolated in Hungary. By hybridization using SLT-I and SLT-II probes and PCR method using stx1-2, eae and ehx primers we could differentiate O157 strains of different serotypes into eight (stx, eae, ehxA positive; stx, eae positive; stx, ehxA positive; stx positive; eae, ehxA positive; eae positive; ehxA positive; stx, eae, ehxA negative) types. The discriminatory power of phage typing proves to be much higher than that of the plasmid profile. RAPD typing with different primers could confirm or exclude the subtypes identity of the isolated E. coli O157 serotypes. Escherichia coli O157:HNM isolates could be sorted in six different phage types and six different RAPD types with ERIC-1, in five RAPD types with ERIC-2 and in seven types with M13 primers. Escherichia coli O157:H7 showed six different phage types and three RAPD types with ERIC-1 and ERIC-2 and five types with M13 primers. According to our results the standard PFGE protocol [32] gives the opportunity to differentiate epidemiologically independent but evolutionary related or unrelated isolates, but the practical value of PFGE method for epidemiological purposes must be confirmed by other or more restriction enzymes or using an other protocol. Summarizing our results we suggest the use of phage and RAPD typing and in doubtful cases the PFGE method.
In order to investigate the possible role of dogs and cats in the carriage and potential dissemination of resistant enterococci, seventy faecal samples from dogs and cats were tested for enterococci. Fifty-eight enterococci were recovered. Isolates were identified as Enterococcus faecium (n = 31) and E. faecalis (n = 14) E. durans (n = 6), E. casseliflavus (n = 2), E. hirae and E. gallinarum (2 isolates each). Enterococcal isolates showed resistance to ciprofloxacin (n = 35), erythromycin (n = 31), tetracycline (n = 25), kanamycin (n = 15), streptomycin (n = 13), pristinamycin (n = 11), gentamicin (n = 10), chloramphenicol (n = 8), and linezolid (n = 6). The gene erm(B) was detected in 22 out of 31 erythromycin-resistant enterococci. All tetracycline-resistant enterococci carried tet(M) and/or tet(L) genes. The gene aac(6′)-Ie-aph(2″)-Ia was identified in five of high-level gentamicin-resistant isolates, the genes aph(3′)-IIIa and/or aac(6′)-Ie-aph(2″)-Ia in eleven high-level kanamycin-resistant isolates and the gene ant(6)-Ia in eleven high-level streptomycin-resistant isolates. Only one strain harboured cat(A) gene, and five strains contained vat(E) or vat(D) genes. Virulence genes gel(E) (21 strains), esp (11 strains) and cylA/cylB (5 strains) were detected. High genetic diversity was demonstrated among E. faecium isolates by pulsed-field gel electrophoresis (PFGE). Dogs and cats can be carriers of antibiotic-resistant enterococci in their faeces that could shed into the household environment.
, Traoré AS , Barro N , Haukka K : Prevalence of diarrheagenic Escherichia coli virulence genes in the feces of slaughtered cattle, chickens, and pigs in Burkina Faso . Microbiology Open 1 , 276 – 284 ( 2012 ) 7
sequence of a ColV plasmid and prevalence of selected plasmid-encoded virulence genes among avian Escherichia coli strains. J Bact 188 , 745–758 (2006). Nolan L. K. DNA sequence of a
