Study on incidence of Nalidixic acid resistant Salmonella enterica serovar Typhi and Salmonella entrica serovar Paratyphi A and their antibiotic susceptibilities.

Thesis Report.

ABSTRACT: A total of 949 blood specimen from patients suspected of enteric fever were included in this study. Among them 66 (6.95 percent) blood specimen were culture positive. The incidence of S. Typhi and S. Paratyphi A among total suspected enteric fever patient was 3.2% (30) and 3.8% (36) respectively. The incidence of culture positive case was highest among the age group of 10-20 years (12.4%). Among 66 culture positive cases, the incidence rate was more in male (8.9%) than female (4.7%).The culture positive rate was found maximum from out patients (7.5%) than inpatients (5.4%). The incidence of Nalidixic acid resistant Salmonella isolates among outpatient and inpatient was 7.2% and 4.6% respectively. The incidence of Nalidixic acid resistant S. Typhi and S. Paratyphi A among total population was 2.7% and 3.8% respectively. The incidence of Nalidixic acid resistant Salmonella isolates among male and female was 8.1% and 4.7% respectively. Among 66 isolates, 30(45.5%) were Salmonella Typhi and 36(54.5%) were Salmonella Paratyphi A. The most sensitive antibiotics for Salmonella Typhi were found to be ciprofloxacin, ceftriaxone. Similarly the most sensitive antibiotics for Salmonella Paratyphi A were found to be ciprofloxacin, ceftriaxone, cotrimoxazole and chloramphenicol. Among 62 Nalidixic acid resistant isolates 26(41.94%) were Salmonella Typhi and 36(58.1%) were Salmonella Paratyphi A. In contrast, among 4 Nalidixic acid susceptible isolates all 4(100%) were Salmonella Typhi and non were Salmonella Paratyphi A. In this study, none of the nalidixic acid resistance isolates were found Ciprofloxacin resistance, but all Nalidixic acid susceptible isolates were also susceptible to Ciprofloxacin. Key words: Enteric fever, Salmonella, Nalidixic acid resistance