Antibiogram Profile of Salmonella enterica Serovar Typhi in India – A Two Year Study

Abstract

Typhoid fever continues to remain a major health problem in the developing world, and the emergence of multidrug-resistant (MDR) strains has further reduced therapeutic options for treatment of the disease. The National Salmonella and Escherichia Centre in Kasauli, India received 128 Salmonella Typhi isolates during 2008–2009. These were evaluated for antimicrobial resistance, prevalent resistotypes and the proportion of MDR strains, using standard methods for 11 antimicrobials. An abrupt decrease in the proportion of MDR strains was observed. Only 4.7% of the isolates were found to be MDR with resistotypes chloramphenicol-ampicillin-streptomycin-nalidixic acid-trimethoprim (C-AS-Na-Tr) and chloramphenicol-ampicillin-nalidixic acid-trimethoprim (C-A-Na-Tr), which is very low compared to other studies from India. Nalidixic acid resistance was found to be present in 93.8% of the isolates. Moreover, the difference in the mean minimum inhibitory concentration (MIC) of ciprofloxacin for nalidixic acid-resistant and nalidixic acid-sensitive strains was found to be statistically significant (p<0.001), which calls into question the further use of ciprofloxacin for the treatment of typhoid fever because of potential treatment failures. The low proportion of MDR strains increases the possibility of first-line drugs for the treatment of typhoid fever.

Demam kepialu masih merupakan suatu masalah kesihatan yang serius di negara-negara membangun, dan kemunculan strain rintang-multidrug (MDR) telah mengurangkan pilihan terapeutik untuk rawatan penyakit ini. National Salmonella and Escherichia Centre di Kasauli, India telah menerima sebanyak 128 pencilan Salmonella Typhi pada tahun 2008–2009. Pencilan-pencilan ini telah dinilai untuk rintangan antimikrob, prevalent resistotypes dan perkadaran strain MDR, menggunakan kaedah standard untuk 11 antimikrob. Suatu penurunan yang mendadak dalam perkadaran strain MDR telah diperhatikan. Hanya 4.7% daripada pencilan didapati MDR dengan resistotypes chloramphenicol-ampicillin-streptomisin-asid nalidiksik-trimethoprim (C-A-SNa-Tr) dan chloramphenicol-ampicillin-asid nalidiksik-trimethoprim (C-A-Na-Tr), yang nilainya lebih rendah jika dibandingkan dengan kajian-kajian lain di India. Rintangan asid nalidiksik didapati wujud dalam 93.8% pencilan. Lebih-lebih lagi, perbezaan dalam min minimum inhibitory concentration (MIC) bagi ciprofloxacin untuk strain rintangan asid nalidiksik dan strain peka asid nalidiksik didapati signifikan (p<0.001), yang membawa perhatian kepada penggunaan lanjutan ciprofloxacin dalam rawatan demam kepialu kerana potensi kegagalan rawatan. Kadar rendah strain MDR meningkatkan kebarangkalian first-line drugs untuk rawatan demam kepialu.