https://imcjms.com/public Ibrahim Medical College Journal of Medical Science https://imcjms.com/public/registration/journal_full_text/45 Tue, 02 Aug 2016 10:25:55 +0000 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. Ibrahim Med. Coll. J. 2011; 5(2): 42-45 Key words: Salmonella, antibiotic Introduction The present study investigated the trend of isolation of Salmonella species responsible for typhoid fever and their antibiotic resistance pattern over the last six years (2004-2009) in urban area of Dhaka city. Materials and Methods   A total of 385 Salmonella were isolated from blood cultures over the period of 6 years. S. Typhi was the predominant serotype followed by Salmonella Paratyphi A (Table-1). The isolation rate of S. Typhi has gradually decreased where as that of S. Paratyphi A has increased over last six years. Table-1: Species distribution of Salmonella sp. isolated between 2004- 2009     Fig-1: Single and multi drug resistance rate to 3 first line antibiotics namely ampicillin (AMP), chloramphenicol (CHLO) and cotrimoxazole (SXT) of isolated S. Typhi during 2004-2009. Note: 3 drugs indicate concurrent resistance to AMP, CHLO and SXT   Fig-2: The resistance pattern of isolated S. Paratyphi A to three first line anti- antibiotics during 2007-2009. Table-2 shows that 80-100% of the isolated S. Typhi and 75-94% of S. Paratyphi A were nalidixic acid resistant. There were no remarkable changes in the resistance pattern of S. Typhi and S. Paratyphi A to nalidixic acid in last 6 years. Only few isolates of S. Typhi were found fully resistant to ciprofloxacin during the period.   Table-2: Rate of isolation of nalidixic acid resistant S. Typhi and S. Paratyphi A from 2004-2009.   Discussion The number of S. Typhi simultaneously resistant to all three first line drugs namely ampicillin, chloramphenicol and cotrimoxazole declined towards 2007 and continued through 2009. It might be due to the loss of unstable resistant gene resulting from removal of selection pressure of these antibiotics.15 Re-emergence of the sensitivity to these drugs were also reflected from the individual upward trend of sensitivity pattern through recent years. S. paratyphi A showed moderate to high sensitivity to those drugs through out the last six years and there was only one multi drug resistant isolate out of total 81 isolates. Ciprofloxacin is being used as the first choice of empiric treatment of typhoid in Bangladesh for last several years. But the current study revealed that about 80-100% of S. typhi and S. Paratyphi A were resistant to nalidixic acid. The treatment of typhoid due to nalidixic acid resistant Salmonella sp with ciprofloxacin is less effective as there were reports of treatment failures from Bangladesh and other countries.7-10 It was due to higher minimum inhibitory concentration of ciprofloxacin of these isolates. Nalidixic acid resistant S. Typhi had been reported to have higher minimum inhibitory concentration of ciprofloxacin compared to susceptible strains.10 So, it has been recommended that quinolones should not be used as the first-line therapy in populations like Bangladesh where nalidixic acid resistance is common among isolates of salmonella. However, gatifloxacin may be used as alternative as because it has different mechanism to develop resistance than that of ciprofloxacin.17   1.   Rowe B, Ward LR, Threlfall EJ. Multidrug-resistant Salmonella typhi: a worldwide epidemic. Clin Infect Dis 1997; 24(Suppl 1): S106-9. 3.   Islam A, Buttler T, Kabir I, Alam NH. Treatment of typhoid fever with ceftriaxone for 5 days or chloramphenicol for 14 days: a randomized clinical trial. Antimicrob Agents Chemother 1993; 37: 1572-5. 5.   Asna SM, Haq JA, Rahman MM. Nalidixic acid resistant Salmonella enterica serovar Typhi with decreased susceptibility to ciprofloxacin caused treatment failure: a report from Bangladesh. Japanese J Infect Dis 2003; 56: 32-3. 7.   Slinger R, Desjardins M, McCarthy AE, Ramotar K, Jessamine P, Guibord C and Toy B. Suboptimal clinical response to ciprofloxacin in patients with enteric fever due to Salmonella spp. with reduced fluoroquinolone susceptibility: a case series. BMC Infectious Diseases 2004; 4: 36. 9.   Threlfall EJ,Ward LR. Decreased susceptibility to ciprofloxacin in Salmonella enterica serotype Typhi, United Kingdom. Emerg Infect Dis 2001; 7: 448-50. 11.Padmapriya V, Kenneth J, Amarnath SK. Re-emergence of Salmonella Paratyphi A: a shift in immunity? National Medical Journal of India 2003; 16: 47-48. 13.Baron EJ, Peterson LR, Finegold SM, editors. Enterobacteriaceae. Bailey and Scott’s diagnostic microbiology. 9th ed. St. Louis, MO: Mosby; 1994; 362–85. 15.Towner KJ.Bacterial genetics. In: Greenwood D. Slack RCB. Peutherer JF. Medical Microbiology.14th ed. New York: Churchill Livingstone. 1992; 85-94. 17.Pandit A, Arjya A, Day JN, Paudyal B, Dangol S, Zimmerman MD, Yadav B, Stepniewska K et al. An open randomized comparison of gatifloxacin versus cefixime for the treatment of uncomplicated enteric fever. Plos One 2007; 6: e542: 1-9. 2026 Ibrahim Medical College. All rights reserved.