The authors performed the antibiotic susceptibility test against randomly selected 108
gramnegative bacilli isolated recently from the various specimens at clinical latora.tory.
Twenty strains of E. coli, eighty-two strains of Klebsiella, Enterobacter, Citrobacter,
Salmonella, Shigella, Pseudomonas, Serratia, Acinetobacter, and Proteus, Two strains
of Edwardsiella and Arizona in each otter, and one strain of Providencia and Yersinia
in each, totally 108 strains were used.
By disk diffusion method. the most of species were sensitive to Cefuroxime(Cxm) and
Amikacin(AK), and Salmonella were also sensitive to Chloramphenicol(CM). Serratia,
Pseudomonas, Acinetobacter, Edwardsiella and Arizona showed a tendency of resistance
to all antibiotics used except AK.
By tube dilution method, the most of species revealed tendency of MIC range from
0.13 to 1.56 ug/ml in Cxm, Gentamycin(GM), Rifampicin(RF), and Cephaloridine(CR).
However Klebsiella, Citrobacter, Pseudomonas, Acinetobacter, and Arizona showed
more than 1600 ug/ml in general antibiotics.
On comparision of numbers of sensitive species strains by disk diffusion and tube
dilution methods, Shigella, Salmonella, E. coli, Klebsiella, Citrobacter, and Edwardsiella
showed same sensitivity to Cxm in almost all strains by both methods whereas
Serratia, Proteus, Pseudomonas, Acinetobacter and Yersinia revealed almost total
resistance to most antibiotics by both methods.
In general the disk diffusion method appeared to showing more numbers of sensitive
strains than tube dilution, and Cxm and GM are considered as recent effective
antibiotics to gram-negative organisms.
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