Validity of SmaI-defined genotypes of Campylobacter jejuni examined by SalI, KpnI, and BamHI polymorphisms: evidence of identical clones infecting humans, poultry, and cattle

Abstract

We describe here an examination of the validity of molecular types of Campylobacter jejuni as defined by separation of SmaI-digested DNA using pulsed-field gel electrophoresis (PFGE), recently suggested as part of a molecular subtyping scheme. Thirty-four Danish strains from humans, water, poultry and cattle were assigned to one of six SmaI 'profile groups' (PGs), with two additional strains included as genotypically distinct controls. The interstrain relationships were reexamined by PFGE of SalI, KpnI and BamHI-digested DNA, and also by serotyping with heat-stable antigens. All outbreak-related strains were indistinguishable by all criteria, as were two sets of two randomly-isolated human strains. Two groups of indistinguishable isolates contained randomly isolated strains from more than one source (poultry, humans and/or cattle), a finding with significant epidemiological connotations. All 'genetically identical' strains belonged to the same serotype, whereas genetic differences were detected between strains assigned to the same SmaI PG but differing in serotype. We conclude that PFGE-based genetic fingerprinting can yield invaluable data for epidemiological studies of sporadic C. jejuni infection, but that results based on one restriction site polymorphism must be checked with another enzyme.

Molecular mechanisms of quinolone, macrolide, and tetracycline resistance amongCampylobacterisolates from initial stages of broiler production

“…Restriction fragment length polymorphismpolymerase chain reaction (RFLP-PCR) of the flaA gene was performed following a previously published protocol (Nachamkin et al, 1993) using DdeI as restriction enzyme (FastDigest®; Fermentas Thermo Fisher, Madrid, Spain). Pulsed field gel electrophoresis (PFGE) using KpnI (Takara Bio Inc., Madrid, Spain) was carried out following the conditions described previously (On et al, 1998), including an initial time of 4 sec and a final time pulse of 20 sec for 22 h in 0.9% w/v agarose (Seakem Gold; Lonza, Madrid, Spain) in 0.5× TBE buffer.…”

Drinking water as the source ofCampylobacter coliinfection in grandparent heavy breeders

“…Preparation of Campylobacter DNA was performed by the Pulsenet protocol (Ribot et al, 2001). PFGE by SmaI (Roche) was also performed by the Pulsenet protocol and by KpnI (Takara, Conda, Madrid, Spain) using the protocol of On et al (1998). PFGE profiles were assigned to pulsotypes on the basis of one or more band difference between strains.…”

Evaluation of a Cytolethal Distending Toxin (cdt) Gene‐Based Species‐Specific Multiplex PCR Assay for the Identification of Campylobacter Strains Isolated from Poultry in Thailand

“…For this purpose, genomic DNA of C. jejuni and C. coli strains were digested with SmaI as described previously (25,29). The SmaI-digested genomic DNA of C. jejuni resulted in the generation of an average of 6 to 9 fragments while the SmaI-digested genomic DNA of C. coli produced from 9 to 13 fragments (Fig.…”