The antibiotic resistance pattern of salmonella is ever changing over time. The present study is a retrospective analysis of rate of isolation of Salmonella Typhi and Paratyphi and their antibiotic resistance pattern over 6 years period in an urban hospital of Dhaka city.  Blood culture submitted in BIRDEM hospital from 2004-2009 were analyzed. Isolated Salmonella sp were identified and antimicrobial susceptibility testing was carried out by a standard disc diffusion method.

Among 385 isolated Salmonella sp 304 (79%) were Salmonella enterica serovar Typhi and 81 (21%) were Salmonella enterica serover Paratyphi A. The rate of isolation of S. Paratyphi A has increased over 6 the year period from 14% to 24%. Resistance to individual first line anti-salmonella drugs has increased from 2004 to 2006 (42 to 63%) but has decreased thereafter. Similar pattern was found when simultaneous resistance to three first line antibiotics namely ampicillin, chloramphenicol and co-trimoxazole were considered. Out of total 304 S. Typhi, 117 (38%) were simultaneously resistant to all three first line drugs compared to only 1.8% S. Paratyphi A. Analysis showed that 80 to 90% of isolated S. Typhi was nalidixic acid resistant (NARST) with reduced susceptibility to ciprofloxacin while the rate for  S. Paratyphi A was 71-94%. All S. Typhi and Paratyphi A were sensitive to ceftriaxone. The study showed that there was a gradual decline of resistance of S. Typhi to first line antibiotics but very high prevalence of nalidixic acid resistant S. Typhi and S. Paratyphi in Bangladesh.

Ibrahim Med. Coll. J. 2011; 5(2): 42-45

Key words: Salmonella, antibiotic

Address for Correspondence:J. Ashraful Haq, Professor, Department of Microbiology, Ibrahim Medical College and BIRDEM, 122 Kazi Nazrul Islam Avenue, Shahbagh, Dhaka-1000, Bangladesh, Email: [email protected]