TABLE 1.
Campylobacter characterization based upon biochemical phenotype and 16S rRNA phylogenetic analyses
| Pattern no. or speciesa | No. of isolates with pattern | Catalase activity | Hippurate hydrolysis | Sensitivity tob: |
Biochemical phenotypec | No. of isolates amplified for 16S rRNAd | Isolate(s) identified by 16S rRNAe (%) | |
|---|---|---|---|---|---|---|---|---|
| Nalidixic acid | Cephalothin | |||||||
| 1 | 1 | − | − | S | R | Campylobacter spp. | 1 | Arcobacter (100 [n = 1]) |
| 2 | 3 | + | − | R | R | Campylobacter spp. | 3 | C. lari (100 [n = 3]) |
| 3 | 4 | + | − | S | R | Campylobacter spp. | 3 | C. jejuni (67), C. lari (33 [n = 3]) |
| 4 | 5 | + | + | R | R | C. jejuni | 4 | C. jejuni (100 [n = 4]) |
| 5 | 71 | + | + | S | R | C. jejuni | 59 | C. jejuni (100 [n = 59]) |
| C. jejuni (control) | 1 | + | + | S | R | C. jejuni | 1 | C. jejuni (100) |
| C. coli (control) | 1 | + | − | S | R | C. coli | 1 | C. coli (100) |
a
Five different patterns emerged from biochemical testing of isolates. Isolates were compared to known C. jejuni and C. coli controls.
b
S, susceptible; R, resistant.
c
Phenotypes were declared based on biochemical tests.
d
Some isolates could not be amplified by PCR.
e
The 16S rRNA gene was analyzed phylogenetically, and isolates were identified to the genus and species levels based upon their relationship (close proximity with support values) with known reference sequences.