Abstract
Fluoroquinolones are the drugs of choice for the treatment of typhoid fever. But the recent increase in minimum inhibitory concentration (MIC) values of ciprofloxacin in Salmonella Typhi may result in delayed response and serious complications. Nalidixic acid resistance has been used as an indirect evidence of increased minimum inhibitory concentration for ciprofloxacin in Salmonella Typhi. We evaluated the isolates received at the National Salmonella and Escherichia Centre for nalidixic acid and ciprofloxacin susceptibility using standard methods. Minimum inhibitory concentrations have also been evaluated. Ninety-six percent of the isolates were found to be nalidixic acid resistant while all isolates were found to be ciprofloxacin sensitive. The difference between minimum inhibitory concentration values of ciprofloxacin for nalidixic acid resistant and nalidixic acid sensitive isolates was found to be statistically significant. The study may be helpful in revising treatment strategies for the infections caused by nalidixic acid resistant Salmonella Typhi in the country.
Highlights
Typhoid fever is a major health problem in developing countries such as India [1] and is a potential threat to developed nations in an era of increasing immigration and global operation
Out of fifty isolates of Salmonella Typhi received at the National Salmonella and Escherichia Centre, 48 (96%) were found to be resistant to nalidixic acid (NARST) with minimum inhibitory concentration (MIC) values of > 480 mg/L and only 2 (4%) isolates were found to be sensitive to nalidixic acid (NASST) with MIC values of 7.5 mg/L (Table 2)
Blood Blood Blood Blood Blood Blood Blood ciprofloxacin with MIC values ranging between 0.029 and 0.625 mg/L, which is considered to be in the susceptible range as per CLSI definition (Table 2)
Summary
Typhoid fever is a major health problem in developing countries such as India [1] and is a potential threat to developed nations in an era of increasing immigration and global operation. Towards the end of last decade, treatment failures with ciprofloxacin have been reported due to infection with nalidixic acid resistant Salmonella Typhi which were found to be susceptible to ciprofloxacin in disc diffusion tests. These strains exhibited a higher minimum inhibitory concentration (MIC) of ciprofloxacin [3]. Nalidixic acid resistance has been used as an indirect evidence of increased minimum inhibitory concentration for ciprofloxacin in Salmonella Typhi. Conclusion: The study may be helpful in revising treatment strategies for the infections caused by nalidixic acid resistant Salmonella Typhi in the country
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
