Topical ocular antibiotics induce bacterial resistance at extraocular sites
- B D Gaynor1,2,
- J D Chidambaram1,
- V Cevallos1,
- Y Miao1,
- K Miller1,
- H C Jha4,
- R C Bhatta4,
- J S P Chaudhary4,
- S Osaki Holm1,
- J P Whitcher1,3,
- K A Holbrook5,
- A M Fry6,
- T M Lietman1,3
- 1The F I Proctor Foundation, University of California, San Francisco, CA, USA
- 2Department of Ophthalmology, University of California, San Francisco, CA, USA
- 3Institute for Global Health, University of California, San Francisco, CA, USA
- 4Geta Eye Hospital, Geta, Nepal
- 5Department of Public Health, San Francisco, CA, USA
- 6Respiratory Diseases Branch, Centers for Disease Control, Atlanta, GA, USA
- Correspondence to: Associate Professor T M Lietman Director of the WHO Collaborating Center for the Prevention of Blindness, Department of Ophthalmology, F I Proctor Foundation, 95 Kirkham Street, Room 307, University of California San Francisco, San Francisco, CA 94143-0944, USA; TMLitsa.ucsf.edu
- Accepted 23 April 2005
Abstract
Aim: To compare the prevalence of antibiotic resistance found in nasopharyngeal Streptococcus pneumoniae between villages treated with topical tetracycline or systemic azithromycin as part of a trachoma control programme.
Methods: All children aged 1–10 years were offered either single dose oral azithromycin treatment (20 mg/kg) or a course of topical 1% tetracycline ointment, depending on the area. Treatment was given annually for 3 years. Six months after the third annual treatment in each village, children were surveyed for nasopharyngeal carriage of S pneumoniae and resistance was determined using broth dilution MIC technique. Children in two additional villages, which had not yet been treated, were also surveyed.
Results: Nasopharyngeal carriage of S pneumoniae was similar in the tetracycline treated, azithromycin treated, and untreated areas (p = 0.57). However, resistance to tetracycline and azithromycin was distributed differently between the three areas (p = 0.004). The village treated with topical tetracycline had a higher prevalence of tetracycline resistance than the other villages (p = 0.010), while the oral azithromycin treated village had a higher prevalence of macrolide resistance than the other villages (p = 0.014).
Conclusions: Annual mass treatment with oral azithromycin may alter the prevalence of drug resistant S pneumoniae in a community. Surprisingly, topical tetracycline may also increase nasopharyngeal pneumococcal resistance. Topical antibiotics may have an effect on extraocular bacterial resistance.
- NCCLS, National Committee for Clinical Laboratory Standards
- azithromycin
- pneumococcus
- resistance
- trachoma
- tetracycline
- NCCLS, National Committee for Clinical Laboratory Standards
- azithromycin
- pneumococcus
- resistance
- trachoma
- tetracycline
Footnotes
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This project was carried out through the generous support of the National Institute of Allergy and Infectious Diseases (Grant R21 AI55752-01), Research to Prevent Blindness (NYC), the Edna McConnell Clark Foundation (NYC), Pfizer Inc, (who donated the azithromycin; NYC), That Man May See, and the South Asia Research Fund, UCSF.
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Competing interests: none declared







