A broad-spectrum antibiotic isolated and extracted from Streptomyces venezuela. Inhibition of many aerobic Gram-positive and Gram-negative bacteria, anaerobic Bacteroides, Rickettsia, Chlamydia and mycoplasma, especially for Salmonella, Influenza, and Bacteroides Have good antibacterial ability. Chloramphenicol was first successfully isolated in 1947 and chemically synthesized the following year. It was used as a better antibiotic for the treatment of typhoid fever, rickettsia and other infectious diseases, but a few were discovered shortly. Aplastic anemia occurs after the patient's application of chloramphenicol. This is a serious complication of the patient's bone marrow hematopoietic dysfunction caused by drugs, so the wide application of the drug in clinical practice is limited. However, since the 1970s, infections caused by ampicillin-resistant influenza bacilli and Bacteroides fragilis have been recognized and gradually increased, and clinical treatment is difficult, and chloramphenicol has a good effect on such infections, so chloramphenicol is There is a new evaluation in the status of clinical treatment. It is believed that although chloramphenicol has bone marrow toxicity, it is still a valuable antibiotic as long as it is used reasonably. Now it is mainly used for the treatment of infectious diseases and typhoid fever in the above, but in the application, it is necessary to strictly control the indications, use reasonable doses, closely monitor the toxicity, and achieve the purpose of safe and effective medication.
Chloramphenicol has a broad spectrum of antibacterial effects. Among the aerobic Gram-positive bacteria, it is sensitive to Streptococcus viridans, Diphtheria bacillus, Bacillus anthracis, Staphylococcus aureus, Streptococcus hemolyticus, Streptococcus pneumoniae, and relatively insensitive to group D streptococci; Among the aerobic Gram-negative bacteria, it has good antibacterial activity against influenza bacillus, Shigella, pertussis, gonococcal and meningococcal bacteria, and belongs to Salmonella, Escherichia coli, Proteus mirabilis, Vibrio cholerae, etc. It is also sensitive, but not sensitive to the sticky serratia, the genus Enterobacter, and Klebsiella pneumoniae. Many anaerobic bacteria including Peptococcus, Streptococcus pneumoniae, Clostridium perfringens, Clostridium, and Bacteroides fragilis can be inhibited. In addition, it is effective for most of rickettsia, chlamydia and mycelium, but has no inhibitory effect on Pseudomonas aeruginosa, Proteus mirabilis, tuberculosis, fungi, viruses and protozoa. After long-term clinical application of chloramphenicol, various types of bacteria can be resistant to different degrees, but the degree of resistance varies from place to place. The main mechanism of drug resistance is that the plasmid with the drug resistance gene in the bacterium mediates the production of chloramphenicol acetyltransferase, which makes the 3-hydroxyl acetylation of propylene glycol gene in chloramphenicol. The 50S subunit of the bacterial ribosome binds and loses activity. The drug-resistant genetic gene can also be transmitted to the resistant bacteria of the same or different genera by means of binding or translocation, but the drug-resistant strains, after stopping the drug for a period of time, Its drug resistance can disappear and become a sensitive strain.