TABLE 2.
Bacterial species and test population/specific straina | Place/yr(s) of isolation | Location of oqxABb | Nucleotide sequence homology with pOLA52 (%) |
oqxAB genotyping with 5 primer sets (no. [%] or present [+] or absent [−]) |
MIC (mg/liter)c |
|||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
oqxA | oqxB | HAE | oqxAB2 | oqxAB4 | Overall | CIP | NAL | NOR | CHL | OLA | ||||
K. pneumoniae | ||||||||||||||
HK (n = 85) | HK/1984–2011 | 67 | 35 | 32 | 83 | 73 | 85 (100) | |||||||
SGSC (n = 8) | SGSC/1996 | 8 | 4 | 8 | 8 | 8 | 8 (100) | |||||||
MGH 78578 | Chromosome | 99 | + | − | + | + | + | + | 1 | ≥128 | 4 | ≥128 | 16 | |
QE319 | HK/1984 | Chromosome | 99 | − | − | + | + | − | + | <0.006 | <4 | <2 | <4 | <16 |
94-3d | HK/1994 | Chromosome | NDe | + | − | − | + | − | + | 0.25 | ≥128 | ≤2 | 64 | 512 |
GN53d | HK/2006 | Chromosome | ND | + | − | + | + | + | + | 4 | ≥128 | ≥64 | ≥128 | 512 |
06-2 | HK/2006 | Chromosome | ND | + | − | − | + | + | + | ≤0.006 | ≤4 | ≤2 | ≤4 | ≤16 |
K. oxytoca (SGSC, n = 8) | SGSC/1996 | 88f | 0 | 0 | 4 | 8 | 8 | 8 (100) | <0.012–0.05 | <4–>128 | <4 | <4 | 8–32 | |
E. aerogenes (SGSC, n = 15) | SGSC/1996–1999 | 87f | 0 | 10 | 15 | 15 | 4 | 15 (100) | <0.012 | <4–8 | <4 | <4 | 8–64 | |
E. cloacae (SGSC, n = 27) | SGSC/1996–2000 | 87f | 3 | 15 | 9 | 14 | 15 | 26 (96) | <0.012–0.05 | <4–16 | <4 | <4–16 | 16–128 | |
S. Typhimurium (n = 17) | HK/2007 | 5 | 5 | 3 | 4 | 4 | 5 (29) | |||||||
1792 | HK/2007 | + | + | − | − | + | + | 2 | ≥128 | ND | ≥128 | ≥512 | ||
2005 | HK/2007 | Plasmid | 100 | + | + | − | − | + | + | 2 | ≥128 | ND | ≥128 | ≥512 |
Other speciesg | HK/2006–2010 | Plasmid | 100 |
HK, Hong Kong; SGSC, Salmonella Genetic Stock Centre, Calgary, Canada.
Based on the results of S1-PFGE and Southern hybridization studies.
CIP, ciprofloxacin; NAL, nalidixic acid; NOR, norfloxacin; CHL, chloramphenicol; OLA, olaquindox.
K. pneumoniae strains 94-3 and GN53 exhibited the typical oqxAB-mediated antibiotic resistance profile (resistance to olaquindox, chloramphenicol, and the quinolones) without an oqxAB-harboring plasmid.
ND, not determined.
Based on the nucleotide sequences of the standard strains KCTC 1686, KCTC 2190, and ATCC 13047 for K. oxytoca, E. aerogenes, and E. cloacae, respectively.
All other bacterial species tested, including Serratia spp. (n = 7), Pseudomonas aeruginosa (n = 30), Acinetobacter spp. (n = 30), Vibrio parahaemolyticus (n = 30), other Vibrio spp. (n = 30), Staphylococcus aureus (n = 30), and Enterococcus spp. (n = 30), were oqxAB negative.