Computer-Assisted Analysis and Epidemiological Value of Genotyping Methods for Campylobacter jejuni and Campylobacter coli

Abstract

For epidemiological tracing of the thermotolerantCampylobacter species C. jejuni and C. coli, reliable and highly discriminatory typing techniques are necessary. In this study the genotyping techniques of flagellin typing (flaA typing), pulsed-field gel electrophoresis (PFGE), automated ribotyping, and amplified fragment length polymorphism (AFLP) fingerprinting were compared. The following aspects were compared: computer-assisted analysis, discriminatory power, and use for epidemiological typing of campylobacters. A set of 50 campylobacter poultry isolates from The Netherlands and neighboring countries was analyzed. Computer-assisted analysis made cluster analysis possible and eased the designation of different genotypes. AFLP fingerprinting was the most discriminatory technique, identifying 41 distinct genotypes, while PFGE identified 38 different types, flaA typing discriminated 31 different types, and ribotyping discriminated 26 different types. Furthermore, AFLP analysis was the most suitable method for computer-assisted data analysis. In some cases combining the results of AFLP fingerprinting, PFGE, and flaA typing increased our ability to differentiate strains that appeared genetically related. We conclude that AFLP is a highly discriminatory typing method and well suited for computer-assisted data analysis; however, for optimal typing of campylobacters, a combination of multiple typing methods is needed.

Antimicrobial resistance profiling andfla-typing of Irish thermophillicCampylobacterspp. of human and poultry origin

“…In this study, we identified a significant genetic diversity among human and poultry C. jejuni and C. coli isolates as evidenced by the large number of profiles generated by both flaA-RFLP and flaA-SVR typing. Similar to previously documented findings neither typing method distinguished between C. jejuni and C. coli isolates (de Boer et al 2000;Dingle et al 2005). Interestingly, a number of identical genotypes were observed among both human and poultry isolates as demonstrated by flaA-RFLP profiles 14 and 49 and SVR allele types (8, 14, 32, 34, 36, 66, 255 and 325) (Fig.…”

Demonstration of persistent strains of Campylobacter jejuni within broiler farms over a 1‐year period in Lithuania

“…The method resulted in 70-80 fragments, which is similar to the number of fragments created using HindIII and HhaI (Duim et al 1999) and BglII and Csp6I (Kokotovic and On 1999). Previous studies have reported that the AFLP typing method is highly discriminative and often shows better or equal discriminatory power than PFGE, fla RFLP and multilocus sequence typing methods (De Boer et al 2000;Schouls et al 2003;Wittwer et al 2005;Keller et al 2007). Another AFLP method using BglII and MfeI described by , 5, 7, 12, 19, 21, 43, 47 3 10, 11 2, 3, 8, 13, 16, 17, 18, 23, 49 4 24, 10, 11 6, 14, 20 *AFLP types detected in >1 broiler flock in farm examined.…”

Molecular typing, serotyping and cytotoxicity testing ofCampylobacter jejunistrains isolated from commercial broilers in Puerto Rico

“…Besides the suggested pulse time for KpnI (Anon. 2007), we also tried other switch times, some described elsewhere (De Boer et al 2000;Michaud et al 2001), but the bands in the PFGE gels were usually less defined for KpnI and SalI than for SmaI. To prove whether the lack of SmaI restriction was because of presence of endogenous proteinases, formaldehyde-treated plugs were digested with different restriction enzymes.…”

“…PFGE profiles were used to perform a pair comparison and cluster analysis using the Dice correlation coefficient, and a dendogram was created by the Unweighted Pair Group method using Mathematical Average (UPGMA) clustering algorithm of BioNumerics version 4.50 (Applied Maths, Austin, TX, USA). The optimization and position tolerance for band analysis were set at 1%, and a cutoff of 90% was used to analyse the different PFGE patterns (De Boer et al 2000).…”