Reference

The killing effects of cefathiamidine or ampicillin alone and in combination with gentamicin against enterococci

The killing effects of cefathiamidine or ampicillin alone and in combination with gentamicin against enterococci. Chen, H. Y.; Williams, J. D. (Med. Coll., London Hosp., London, UK). J. Antimicrob. Chemother., 12(1), 19-26 (English) 1983. CODEN: JACHDX. ISSN: 0305-7453. DOCUMENT TYPE: Journal CA Section: 10 (Microbial Biochemistry) The in vitro activity of cefathiamidine against Streptococcus faecalis and S. faecium were studied in comparison with other b-lactams. All the 56 strains of S. faecalis tested were inhibited by 2 mg cefathiamidine/L. The min. inhibitory concns. (MICs) of ampicillin were 2-fold higher than those of cefathiamidine and MICs of cephaloridine and cephazolin were 8-16-fold higher. No significant inoculum effect on MICs of cefathiamidine could be seen. Two isolates of S. faecium showed resistance to the 4 antibiotics. The min. bactericidal concns. (MBCs) of cefathiamidine and ampicillin for 10 strains of S. faecalis showed that the ratios of MBC/MIC were >64. The rates of killing of S. faecalis were reduced at concns. of cefathiamidine and ampicillin greater than the MIC. The most rapid killing was obtained at 2 mg cefathiamidine or 4 mg ampicillin/L. With the addn.In this experiment, several chemicals are used like 1403-66-3 and 33075-00-2 of 1 mg gentamicin this paradoxical bactericidal effect was eliminated. Time killing studies showed that 99.9% of the cells were killed within 6 h by a combination of aminoglycoside and b-lactam. The paradoxical bactericidal effect of cefathiamidine and ampicillin was also demonstrated on solid media. .

Ultrastructural changes of Staphylococcus aureus caused by cell wall synthesis-inhibiting antibiotics

Ultrastructural changes of Staphylococcus aureus caused by cell wall synthesis-inhibiting antibiotics. Zhang, Zhilin; Gu, Yamin; Wu, Jufang; Liu, Yukun; Tai, Ziying; Tang, Peizhu; Zhong, Cisheng; Wu, Zhengquan (Clin. Res.In this study， 61-72-3 and 33075-00-2 are also used. Lab. Antibiot., Shanghai First Med. Coll., Shanghai, Peop. Rep. China). Shanghai Diyi Yixueyuan Xuebao, 10(5), 339-42, 338 (Chinese) 1983. CODEN: SIIPD4. ISSN: 0253-3650. DOCUMENT TYPE: Journal CA Section: 10 (Microbial Biochemistry) Treatment of S. aureus with cell wall synthesis-inhibiting antibiotics (penicillin G, cloxacillin, ampicillin, cephalothin, cefathiamidine, fosfomycin, and vancomycin) produced profound ultrastructural changes in growing cells but had little effect on resting cells. Cell division was reduced significantly by all antibiotics. Low concns. of antibiotics caused distortion and thickening of the cross walls, whereas high concns. distorted the structure of the cytoplasm and nucleus. Some cells were enlarged and showed a tendency to rupture, esp. after fosfomycin treatment. .