In vitro activity of azithromycin in Salmonella isolates from Pakistan

Authors

  • Farhana Butt Shaukat Khanum Memorial Cancer Hospital and Research Center, Lahore, Pakistan
  • Faisal Sultan Shaukat Khanum Memorial Cancer Hospital and Research Center, Lahore, Pakistan

DOI:

https://doi.org/10.3855/jidc.971

Keywords:

Salmonella enterica, typhoid, enteric fever, azithromycin, resistance, Pakistan

Abstract

Introduction: Enteric fever is caused by Salmonella enterica serovars Typhi and Paratyphi A, B and C. It is a significant public health issue in Pakistan, which is exacerbated by a high level of resistance some isolates display to drugs routinely used in treatment. Azithromycin may be a treatment option for such isolates.

Methodology: We determined the minimum inhibitory concentrations (MICs) of Salmonella Typhi and Paratyphi isolates against azithromycin in an attempt to gauge its feasibility as a therapeutic option. The MICs were also compared with corresponding disc diffusion zone sizes to see if there was consistency between the two tests. We tested 45 Salmonella enterica isolates using E-tests for MIC detection and azithromycin discs with a concentration of 15µg/ml for disc diffusion testing.

Results: Salmonella Typhi, Salmonella Paratyphi A, and Salmonella Paratyphi C isolates demonstrated MICs of 2-12mg/L against azithromycin, suggesting that the antibiotic could be used for therapeutic purposes. For Salmonella Paratyphi B, the MICs were 2-48 mg/L. The higher MIC indicates a need for caution when considering use of azithromycin for Salmonella Paratyphi B infections without first testing for the MIC. There was a close correlation between MICs and zone sizes which was statistically significant.

Conclusions: Our results indicate azithromycin is a potential therapeutic option for enteric fever. Standardized laboratory testing methods and interpretation for azithromycin  against Salmonella enterica would allow laboratories to report upon this antibiotic with confidence.

Author Biographies

Farhana Butt, Shaukat Khanum Memorial Cancer Hospital and Research Center, Lahore, Pakistan

Department of Pathology

At time of conducting study Consultant Microbiologist.

Faisal Sultan, Shaukat Khanum Memorial Cancer Hospital and Research Center, Lahore, Pakistan

Department of Internal Medicine.

Consultant Infectious Diseases

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Published

2011-03-04

How to Cite

1.
Butt F, Sultan F (2011) In vitro activity of azithromycin in Salmonella isolates from Pakistan. J Infect Dev Ctries 5:391–395. doi: 10.3855/jidc.971

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Section

Brief Original Articles