Antibiogram, phage types & biotypes of Salmonella typhi isolated in Nagpur

Area of Science:

• Microbiology
• Infectious Diseases
• Epidemiology

Background:

• Salmonella typhi is a significant cause of febrile illness worldwide.
• Understanding antimicrobial resistance patterns is crucial for effective treatment and public health strategies.

Purpose of the Study:

• To investigate the drug resistance patterns and characteristics of S. typhi isolates from patients with pyrexia.
• To determine the predominant phage types and biotypes among these S. typhi strains.

Main Methods:

• Bacteriological isolation and identification of S. typhi from patient samples.
• Antimicrobial susceptibility testing to assess drug resistance patterns.
• Phage typing and biotyping to characterize the S. typhi isolates.

Main Results:

• S. typhi was isolated from 241 patients with pyrexia between July 1990 and March 1991.
• A high prevalence of multiple drug resistance (91.3%) was observed in the isolates.
• The most common drug resistance pattern was ACCoT (49.4%).
• Phage type E1 (81.3%) and biotype I (93.4%) were predominant.
• All ACCoT-resistant strains were phage type E1, and all phage type E1 strains were biotype I.

Conclusions:

• The study highlights a significant challenge posed by multidrug-resistant S. typhi, particularly the ACCoT resistance pattern.
• The strong association between ACCoT resistance, phage type E1, and biotype I suggests a specific, highly resistant strain is circulating.
• These findings have implications for empirical treatment guidelines and surveillance of typhoid fever.