TY - JOUR
T1 - Susceptibility patterns of clinical and fish isolates of Laribacter hongkongensis
T2 - Comparison of the Etest, disc diffusion and broth microdilution methods
AU - Lau, Susanna K.P.
AU - Wong, Gilman K.M.
AU - Poon, Rosana W.S.
AU - Lee, Leo C.K.
AU - Leung, Kit Wah
AU - Tse, Cindy W.S.
AU - Ho, Pak Leung
AU - Que, Tak Lun
AU - Woo, Patrick C.Y.
AU - Yuen, Kwok Yung
PY - 2009
Y1 - 2009
N2 - Objectives: To determine the antibiotic susceptibility patterns of 60 strains of Laribacter hongkongensis isolated from humans and fish to eight antibiotics and compare the results obtained from broth microdilution, Etest and disc diffusion susceptibility testing. Patients and methods: The susceptibilities of 60 isolates of L. hongkongensis from humans with gastroenteritis and fish to eight antibiotics were tested by three methods [broth microdilution (reference method), Etest and disc diffusion] and their results were compared. Results: All isolates were susceptible to imipenem and ciprofloxacin by all three methods, except for one strain which was resistant to ciprofloxacin by broth microdilution. All were susceptible to ampicillin/ sulbactam by Etest and disc diffusion, but eight were resistant by broth microdilution. By broth microdilution, 90%, 100%, 46.7%, 100% and 8.3% of isolates were resistant to ampicillin, ceftriaxone, cefuroxime, erythromycin and tetracycline, respectively. Although broth microdilution generally yielded higher MICs of β-lactams, MICs obtained with Etest were in good correlation with broth microdilution for all drugs except ampicillin/sulbactam, with >90% agreement within 2 log2 dilutions for imipenem, ciprofloxacin, erythromycin and tetracycline. Comparison of susceptibilities between broth microdilution and the other two methods showed the highest (>95%) percentage agreement for imipenem, ciprofloxacin and tetracycline. The highest discrepancies were observed with erythromycin (58.3% agreement), with an apparent increase in susceptibility by disc diffusion. A higher proportion of human isolates than fish isolates were tetracycline-resistant by all three tests (P = 0.022). Conclusions: Etest and disc diffusion appear to be reliable for evaluation of susceptibilities of L. hongkongensis to imipenem, ciprofloxacin and tetracycline. However, these methods may underestimate resistance to other β-lactams.
AB - Objectives: To determine the antibiotic susceptibility patterns of 60 strains of Laribacter hongkongensis isolated from humans and fish to eight antibiotics and compare the results obtained from broth microdilution, Etest and disc diffusion susceptibility testing. Patients and methods: The susceptibilities of 60 isolates of L. hongkongensis from humans with gastroenteritis and fish to eight antibiotics were tested by three methods [broth microdilution (reference method), Etest and disc diffusion] and their results were compared. Results: All isolates were susceptible to imipenem and ciprofloxacin by all three methods, except for one strain which was resistant to ciprofloxacin by broth microdilution. All were susceptible to ampicillin/ sulbactam by Etest and disc diffusion, but eight were resistant by broth microdilution. By broth microdilution, 90%, 100%, 46.7%, 100% and 8.3% of isolates were resistant to ampicillin, ceftriaxone, cefuroxime, erythromycin and tetracycline, respectively. Although broth microdilution generally yielded higher MICs of β-lactams, MICs obtained with Etest were in good correlation with broth microdilution for all drugs except ampicillin/sulbactam, with >90% agreement within 2 log2 dilutions for imipenem, ciprofloxacin, erythromycin and tetracycline. Comparison of susceptibilities between broth microdilution and the other two methods showed the highest (>95%) percentage agreement for imipenem, ciprofloxacin and tetracycline. The highest discrepancies were observed with erythromycin (58.3% agreement), with an apparent increase in susceptibility by disc diffusion. A higher proportion of human isolates than fish isolates were tetracycline-resistant by all three tests (P = 0.022). Conclusions: Etest and disc diffusion appear to be reliable for evaluation of susceptibilities of L. hongkongensis to imipenem, ciprofloxacin and tetracycline. However, these methods may underestimate resistance to other β-lactams.
KW - Antibiotic susceptibility
KW - Community-acquired gastroenteritis
KW - Infectious diarrhoea
UR - http://www.scopus.com/inward/record.url?scp=62549092696&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=62549092696&partnerID=8YFLogxK
U2 - 10.1093/jac/dkp010
DO - 10.1093/jac/dkp010
M3 - Article
C2 - 19202149
AN - SCOPUS:62549092696
SN - 0305-7453
VL - 63
SP - 704
EP - 708
JO - Journal of Antimicrobial Chemotherapy
JF - Journal of Antimicrobial Chemotherapy
IS - 4
ER -