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[Antimicrobial activity of cefotiam against various clinical isolates from 1981 to 1985]
Abstract:
Some of new cephem antibiotics, particularly the so called the third generation cephalosporins, are reported to be potent inducers of beta-lactamases and to be responsible for developing microbial cross-resistance to multiple beta-lactam antibiotics and occasionally to the aminoglycosides (Sanders and Sanders, 1983). In Japan, third generation cephalosporins such as cefotaxime, cefoperazone, ceftizoxime, and latamoxef became available in 1981, and cefmenoxime in 1982. Therefore, it is of interest to investigate changes, if any, in the antimicrobial activity of cefotiam (CTM) against various Gram-positive and negative bacteria, particularly to determine whether its antimicrobial activity has been reduced since 1982. Susceptibilities of clinical isolates of S. aureus (1,776 strains), S. epidermidis (2,247), S. pneumoniae (160), S. pyogenes (108), E. faecalis (1,930), E. coli (2,024), K. pneumoniae (1,913), Proteus spp. (950), E. aerogenes (823), Serratia marcescens (1,160), Citrobacter spp. (303), Pseudomonas aeruginosa (2,824), and H. influenzae (396) to CTM were studied. It was found that susceptibilities of these clinical isolates to CTM were not altered from 1981 to 1985, except S. marcescens. In 1985, susceptible strains of S. aureus, S. epidermidis, S. pneumoniae, S. pyogenes and E. faecalis were 93.8, 93.4, 100, 100 and 0%, respectively. Those of E. coli, K. pneumoniae, Proteus spp., H. influenzae, P. aeruginosa, S. marcescens, E. aerogenes and Citrobacter spp. were 97.9, 97.7, 89.4, 94, 0, 10.8, 45.9 and 74.5%, respectively. The rate of susceptible strains of S. marcescens decreased from 34.7 to 10.8% since 1981 to 1985.(ABSTRACT TRUNCATED AT 250 WORDS)
Insights
Cefotiam (CTM) maintained its antimicrobial activity against most bacteria between 1981 and 1985. However, a significant decrease in susceptibility was observed in Serratia marcescens strains during this period.
Area of Science:
- Microbiology
- Pharmacology
- Infectious Diseases
Context:
- Third-generation cephalosporins, introduced in Japan in 1981-1982, can induce beta-lactamase production and cross-resistance.
- Monitoring antimicrobial activity is crucial due to potential resistance development.
Purpose:
- To evaluate changes in the antimicrobial activity of cefotiam (CTM) against Gram-positive and Gram-negative bacteria from 1981 to 1985.
- To determine if CTM's efficacy was reduced following the introduction of newer cephalosporins.
Summary:
- Antimicrobial susceptibility testing was performed on over 15,000 clinical bacterial isolates.
- CTM's activity remained stable against most tested species, including S. aureus, S. epidermidis, S. pneumoniae, S. pyogenes, E. faecalis, E. coli, K. pneumoniae, Proteus spp., P. aeruginosa, and H. influenzae.
- A notable exception was Serratia marcescens, where the susceptibility rate to CTM decreased from 34.7% in 1981 to 10.8% in 1985.
Impact:
- This study indicates that CTM generally retained its effectiveness during the mid-1980s.
- The observed decrease in susceptibility for S. marcescens highlights the potential for developing resistance to cefotiam and warrants further investigation.
- Findings are important for understanding antibiotic resistance trends and guiding clinical treatment strategies.