|AWAD, AMAL - Mansoura University
|RAMADAN, HAZAEM - Mansoura University
Submitted to: Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 5/3/2019
Publication Date: N/A
Interpretive Summary: none
Technical Abstract: Problem Statement: Campylobacter jejuni is the leading foodborne pathogen in humans worldwide. Consumption of unsanitary poultry products is the major source for human infection. Because of its genetic diversity, classification of C. jejuni by classical methods is problematic. Due to the progress in sequencing technology and bioinformatic algorithms, multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) have been widely used. In the present study, we applied these two methods to elucidate the genetic diversity of C.jejuni isolates from US poultry farms. Approach: C. jejuni (n = 100) isolates from the US poultry farms were used. Genomic DNA was extracted using a commercial kit. PCR primers and conditions for MLST amplification of seven housekeeping genes were described previously. The purified amplicons were sent to our core facilities for sequencing and resulting sequences were compared with those deposited in the MLST database. PFGE was performed following the standard protocol recommended by the CDC for Campylobacter spp. Results: Among the 100 C. jejuni isolates, 13 different sequence types (STs) were identified. These STs were grouped into 7 previously described clonal complexes (CCs). Nine isolates assigned to ST-940 did not match any defined CC in the MLST database. Clonal complexes (CC353, CC48 and CC21) were dominant among the seven assigned CCs in isolates tested. On the ST-level, the most frequent STs were ST-353, ST-48 and ST-50, representing 66% (66/100) of the total screened isolates. By PFGE, twenty–two SmaI profiles were identified among the C. jejuni isolates, and six groups of closely related isolates were assigned (S1-S6). Conclusions: This study shows the diversity of C. jejuni isolates from US poultry sources. Most of the C. jejuni STs detected in this study have been associated with human illness, which supports the significant role of poultry as a major source for human Campylobacter infections.