الكاتب: Multiple References

General considerations © 2003 Thomson MICROMEDEX All rights reserved. 3 The tetracyclines are broa d-spectrum antibiotics with activity against gram-positive and gram -negative bacteria, including some anaerobes. They are also active against chlamydia, mycoplasmas, some protozoa {R -28; 133}, and several rickettsiae, including Anaplasma, Ehrlichia, and Haemobartonella. The activity range of the tetracyclines also includes Escherichia coli, Klebsiella species, Pasteurella species, Salmonella species, Staphylococcus species, and Streptococcus species {R -4}. Susceptibility testing has demonstrated that some coliforms, mycoplasma, streptococci, and staphylococci have developed resistance to tetracyclines{R -21; 150}. However, the breakpoints used to classify these organisms as susceptible or resistant are not validated for animal indications. Susceptibility testing should not be the sole basis for selecting tetracyclines for therapy