%0 Journal Article %T Antibiotic resistance among Salmonella enterica serovars Typhi and Paratyphi A in Pakistan (2001-2006) %A Rumina Hasan1 %A Afia Zafar1 %A Zohair Abbas2 %A Vikram Mahraj1 %A Faisal Malik1 %A Anita Zaidi2 %J Journal of Infection in Developing Countries %D 2008 %I Open Learning on Enteric Pathogens %X Objectives: To compare antimicrobial resistance in S. Typhi and S. Paratyphi A isolates from Pakistan.Methods: Blood samples were collected through > 175 laboratory collection points in major cities and towns across the country. The study included 3,671 S. Typhi and 1,475 S. Paratyphi A isolates (2001-2006). Multidrug resistance (MDR) was defined as resistance to first-line agents co-trimoxazole, chloramphenicol and ampicillin.Results: In total, 79.3% S. Typhi and 59.9% S. Paratyphi A were isolated from patients under 15 years of age. During the study period, the MDR rate increased in S. Typhi (34.2 to 48.5% p<0.001), but decreased in S. Paratyphi A (44.5 to 8.6% p<0.001). Quinolone resistance (MIC>1¦Ìg/ml) increased in both S. Typhi (1.6 to 64.1% p<0.001) and S. Paratyphi A (0 to 47% p<0.001). The increase in the proportion of strains showing high level quinolone resistance (MIC >4¦Ìg/ml) was greater in S. Paratyphi A when compared to S. Typhi. Resistance to first-line drugs was higher in those <15 years of age whereas quinolone resistance was higher in older patients.Conclusion: Differences between S. Typhi and S. Paratyphi A, in terms of evolution of resistance to first-line agents and to quinolones, are evident in this population. The rapid increase in quinolone resistance in S. Paratyphi A when compared to S. Typhi is concerning and requires further study. %K Salmonella %K Antibiotic resistance %K Typhi %K Paratyphi %K Pakistan %U http://www.jidc.org/issn1972-2680/current-issue/68-vol-2-no-4-august-2008/167-antibiotic-resistance-among-salmonella-enterica-serovars-typhi-and-paratyphi-a-in-pakistan-2001-2006