Abstract
We discussed the antimicrobial susceptibilities of Proteus group isolated in 1983 and 1984 and also the annual changes of the susceptibilities from 1980 to 1984. The tested strains were isolated in 103 hospitals in Japan. Antibiotics tested for this study were ampicillin (ABPC), cefazolin (CEZ), cefmetazole (CMZ), and gentamicin (GM). The MIC's were determined by the standard method of the Japan Society of Chemotherapy.
Susceptibilities of the bacterial strains to the 4 antibiotics were described below;
1. Proteus mirabilis had good susceptibilities to all the antibiotics tested.
2. Susceptibilities of Proteus vulgaris were low to ABPC and CEZ, but high to CMZ and GM.
3. Proteus morganii showed low susceptibilities to ABPC and CEZ, and moderate to CMZ and GM.
4. Susceptibilities of Proteus rettgeri were low to ABPC and CEZ, and 25-40% of the strains were resistant to CMZ and GM.
5. Proteus inconstance had low susceptibilities to ABPC and CEZ, but fairly good to CMZ. About 55% of the strains showed resistance to GM.
6. There were no significant annual changes in susceptibilities of P. mirabilis, P. vulgaris and P. morganii to ABPC, CEZ and CMZ during the period from 1980 to 1984, but decreased susceptibilities to GM were noted in 1982.
7. There was no evidence of changes in susceptibilities of strains of P. rettgeri to ABPC and CMZ, but a tendency of decreasing susceptibilities to CEZ was shown from 1981.
8. P. inconstance showed no major changes in susceptibilities to ABPC, CMZ and GM.
9. Frequencies of resistant strains with MIC of 25 pg per ml or more in P. mirabilis, P. morganii and P. rettgeri were higher in 1982 and/or 1983 than the other years.
