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Updated: Feb 28, 2026
An Allelotyping PCR for Identifying Salmonella enterica serovars Enteritidis, Hadar, Heidelberg, and Typhimurium
Published on: July 22, 2011
Antibiogram of S. enterica serovar Typhi and S. enterica serovar Paratyphi A: a multi-centre study from India
1Indian Network for Surveillance of Antimicrobial Resistance.
Background:
Enteric fever continues to be a public health problem in many countries including India. Emergence of the multidrug resistant strains of S. enterica serovar Typhi may render treatment with antibiotics ineffective. A multi-centre surveillance study was, therefore, conducted in India to monitor the time trends in antibiotic susceptibility patterns of S. enterica serovar Typhi and S. enterica serovar Paratyphi A in India.
Methods:
All S. enterica serovar Typhi and S. enterica serovar Paratyphi A strains isolated from January 2008 to December 2010 in the 15 participating centres were included in the study. Each centre compiled their data in a predefined template which included data of the antimicrobial susceptibility pattern, location of the patient and specimen type. The data in the submitted templates was collated and analysed using a common protocol.
Results:
A total of 3275 isolates of Salmonellae causing enteric fever were included in the study. There were 2511 S. enterica serovar Typhi and 764 S. enterica serovar Paratyphi A strains during the three-year study period. Resistance to nalidixic acid was seen in 83% of the S. enterica serovar Typhi and 93% of S. enterica serovar Paratyphi A strains. Majority of the strains were susceptible to third generation cephalosporins.
Conclusions:
Enteric fever in India is caused by S. enterica serovar Typhi and S. enterica serovar Paratyphi A. Nalidixic acid resistance is high among both S. enterica serovar Typhi and S. enterica serovar Paratyphi A. Susceptibility to ampicillin, chloramphenicol and cotrimoxazole is high. Third generation cephalosporins continue to remain susceptible.
Insights
High nalidixic acid resistance in Salmonella Typhi and Paratyphi A strains necessitates monitoring antibiotic susceptibility for effective enteric fever treatment in India. Third-generation cephalosporins remain a viable treatment option.
Area of Science:
- Microbiology
- Infectious Diseases
- Public Health
Background:
- Enteric fever, caused by Salmonella Typhi and Paratyphi A, remains a significant public health concern in India.
- The emergence of multidrug-resistant strains threatens the efficacy of current antibiotic treatments.
- A multi-center surveillance study was conducted to address these challenges.
Purpose of the Study:
- To monitor time trends in antibiotic susceptibility patterns of Salmonella Typhi and Paratyphi A in India.
- To assess the prevalence of antimicrobial resistance in enteric fever pathogens.
- To inform treatment guidelines and public health strategies.
Main Methods:
- A surveillance study involving 15 participating centers across India.
- Collection and analysis of Salmonella Typhi and Paratyphi A isolates from January 2008 to December 2010.
- Data collation on antimicrobial susceptibility patterns, patient location, and specimen type using a predefined template and common protocol.
Main Results:
- A total of 3275 isolates were analyzed, including 2511 Salmonella Typhi and 764 Salmonella Paratyphi A strains.
- High resistance rates to nalidixic acid were observed: 83% in Salmonella Typhi and 93% in Salmonella Paratyphi A.
- The majority of strains demonstrated susceptibility to third-generation cephalosporins.
Conclusions:
- Salmonella Typhi and Paratyphi A are the primary causative agents of enteric fever in India.
- High nalidixic acid resistance is a critical concern for both serovars.
- Third-generation cephalosporins are effective against most enteric fever strains, while susceptibility to ampicillin, chloramphenicol, and cotrimoxazole remains high.
