Possible Consequences for Bacterial Ecology due to Antibiotic Treatment in HS

The drawback to the usefulness of long-term antibiotic treatments is concern about the effect on microbial ecology (Table 11.5). The normal microflora act as a barrier against colonization by potentially pathogenic bacteria and the control of growth of opportunistic bacteria is called colonization resistance. The normal equilibrium between host and microorganisms may be disturbed by a number of factors, but commonly and essentially by antibiotic therapy. To what extent disturbances occur depends of numerous factors: the spectrum of the antibiotic, the dose, the route of administration, pharmacokinetic and pharmacodynamic properties and in vivo inactivation of the drug [53].

Clindamycin administration results in major ecological disturbances in intestinal and oro-pharyngeal microflora: the numbers of entero-coccal species increase and those of all anaerobes decrease [39, 51]. A possible complication of clindamycin treatment is pseudomembra-nous colitis, which occurs when antibiotics such as clindamycin, ampicillin and third-generation cephalosporins suppress the normal flora, allowing Clostridium difficile to grow and produce toxins [40]. Rifampicin treatment was shown to lead to a decrease in total aerobic and anaerobic oral bacteria in healthy volunteers [1].

The emergence of antimicrobial resistance is strongly associated with the clinical use of the antibiotics and a balanced microflora prevents establishment of resistant strains of bacteria [53]. It is well known that oral antibiotics select for resistant bacteria at all body sites where there is a normal flora: skin, conjunctivae, oral cavity, nasopharynx, upper respiratory tract, intestinal tract, and vagina [16]. A therapy administered for a long period, as was recommended in HS treatment [25], will exert a high pressure for the development of the resistant strains of Propionibacterium acnes, coagulase-negative staphylo-

Table 11.5. Effects of antibiotic administration on the ecological balance of human microflora

- Disturbances in the balance between host and normal flora from the intestinal tract, skin, oropharyngeal tract, and vagina

- Altered colonization resistance (growth control of opportunistic bacteria)

- Overgrowth of pathogenic bacteria or yeasts

- The emergence of antimicrobial resistance in the normal flora

- Possible transfer of resistance to pathogenic bacteria cocci on the skin, Staphylococcus aureus in the nares, streptococci in the oral cavity, and en-terobacteria in the gut [16].

Topical clindamycin will increase carriage of Propionibacterium acnes and Staphylococcus epidermidis resistant strains on skin and there is a risk of transfer of resistance to other pathogenic bacteria, Staphylococcus aureus and Streptococcus species [15]. The skin and conjunctivae flora from untreated sites will also be affected by transfer of antibiotic [16].

In conclusion, antibacterial drugs represent an adjuvant treatment in HS. They are not curative but they reduce odor and discharge, and diminish pain. Antibiotics represent a palliative therapy that may control the disease in early stages and can reduce the inflammation before and after surgery [28] but clinicians should be aware about the downside of taking them.

Acne Myths Uncovered

Acne Myths Uncovered

What is acne? Certainly, most of us know what it is, simply because we have had to experience it at one time or another in our lives. But, in case a definition is needed, here is a short one.

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