Technonews: Research on the sensitivity of bacteria and mycoplasmas from animal origin to doxycycline (Part 1)



Doxycycline is an antibiotic commonly used in veterinary medicine for the treatment of bacterial and mycoplasma infections. In farm animals, it is indicated for ruminants, pigs, chickens and turkeys, but should not be used in layers during the productive stage or in lactating ruminants.

It is a semi-synthetic antibiotic of the tetracycline family derived from oxytetracycline. It is a bacteriostatic antibiotic, since it inhibits protein synthesis, but it can also alter the permeability of the cytoplasmic membrane in susceptible organisms.

It has a broad spectrum of action including gram-negative and gram-positive bacteria, Chlamydia, Rickettsia, mycoplasmas, Leptospira, Anaplasma and spirochetes. In addition, as it is more soluble than other tetracyclines, it can get to areas such as the joints (synovial fluid), the central nervous system and the eyes.


List of microorganisms sensitive to doxycycline:

1. Gram-negative Bacteria

  • Acinetobacter spp.*

  • Bartonella bacilliformis

  • Brucella spp.

  • Campylobacter*

  • Enterobacter aerogenes

  • Escherichia coli*

  • Francisella tularensis

  • Haemophilus spp.

  • Klebsiella spp.*

  • Moraxella

  • Neisseria gonorrhoeae

  • Pasteurella multocida

  • Salmonella*

  • Shigella spp.*

  • Staphylococcus

  • Vibrio spp.

  • Yersinia pestis

2. Parasites

  • Balantidium coli

3. Gram-positive Bacteria

  • Bacillus anthracis

  • Streptococcus spp.*

4. Anaerobic microorganisms

  • Clostridium spp.*

  • Fusobacterium fusiforme

  • Propionibacterium acnés

5. Other bacteria

  • Nocardiae y otros Actinomyces

  • Borrelia recurrentis

  • Brachyspira spp.

  • Chlamydophila spp.

  • Chlamydia spp.

  • Fusobacterium

  • Mycoplasma pneumoniae

  • Rickettsiae

  • Spirocheta

  • Treponema spp.

  • Ureaplasma urealyticum

Some strains of the microorganisms marked with (*) show intermediate sensitivity or resistance to doxycycline. Therefore, especially in gram positive and gram negative bacteria, it is important to perform an antibiogram prior to administration of the antibiotic.

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