Randomized Controlled Comparison of Ofloxacin, Azithromycin, and an Ofloxacin-Azithromycin Combination for Treatment of Multidrug-Resistant and Nalidixic Acid-Resistant Typhoid Fever

Parry, Christopher M.; Hó, Vô Anh; Phuong, Le Thi; Bay, Phan Van Be; Lanh, Mai Ngoc; Tùng, Lê Thanh; Thắm, Nguyễn Thị; Wain, John; Hien, Tran Tinh; Farrar, Jeremy

doi:10.1128/aac.00447-06

Cited by 150 publications

(163 citation statements)

References 34 publications

(41 reference statements)

Supporting

Mentioning

151

Contrasting

Unclassified

Order By: Relevance

“…However, limited access to reliable clinical microbiology facilities and the ready availability and excessive use of low-cost substandard generics of fluoroquinolone has led to the emergence of fluoroquinolone resistance [13]. Clinical failures and inadequate responses to therapy are documented in patients infected with Salmonella strains with reduced susceptibility to fluoroquinolones (MIC > 0.125 ug/ml) [14][15][16][17]. Point mutations in chromosomal genes (gyrA, gyrB, parC, and parE) resulting in strains with reduced susceptibility as well as plasmid-encoded transferable resistance to fluoroquinolones have been reported from many countries [18][19][20][21][22][23][24].…”

Section: Introductionmentioning

confidence: 99%

Antibiotic resistance among Salmonella enterica serovars Typhi and Paratyphi A in Pakistan (2001-2006)

Hasan

Zafar

Abbas

et al. 2008

J Infect Dev Ctries

View full text Add to dashboard Cite

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)(2002)(2003)(2004)(2005)(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>1μg/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 >4μg/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.

show abstract

Section: Introductionmentioning

confidence: 99%

Antibiotic resistance among Salmonella enterica serovars Typhi and Paratyphi A in Pakistan (2001-2006)

Hasan

Zafar

Abbas

et al. 2008

J Infect Dev Ctries

View full text Add to dashboard Cite

show abstract

“…This use of clinical criteria alone could be due to a lack of definitive laboratory guidance. Another contributing factor could be the pharmacodynamics of azithromycin whereby clinical success is reported despite peak serum levels of 0.4 mg/mL following a 500mg oral dose [9,11], which is far less than laboratory reported MICs. The reason for therapeutic response is the high intracellular concentrations achieved by azithromycin of up to 50 to 100 times that in serum [9,12].…”

Section: Resultsmentioning

confidence: 96%

“…In these studies MICs tend not to exceed 32 mg/L [7,8,9]. The British Society for Antimicrobial Chemotherapy (BSAC) also mentions azithromycin being used in treatment of infections with isolate MICs of less than 16mg/L [10], but falls short of providing any specific guidance for testing.…”

Section: Resultsmentioning

confidence: 99%

“…While S. enterica serovar Typhi occupies a predominantly intracellular location, it is estimated that one-third of bacterial cells in the blood are extracellular [13]. Exposure of such isolates to sub-optimal levels of azithromycin can lead to treatment failure and development of resistance [9]. While it is more likely azithromycin would be used in treatment of MDR-strains, these strains are also more likely to have a higher extra-cellular concentration of organisms [13].…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

In vitro activity of azithromycin in Salmonella isolates from Pakistan

Butt

Sultan

2011

J Infect Dev Ctries

View full text Add to dashboard Cite

Introduction: Enteric fever is caused by Salmonella enterica serovars Typhi and Paratyphi A, B and C. It is a significant public health issue in Pakistan, which is exacerbated by a high level of resistance some isolates display to drugs routinely used in treatment. Azithromycin may be a treatment option for such isolates. Methodology: We determined the minimum inhibitory concentrations (MICs) of Salmonella Typhi and Paratyphi isolates against azithromycin in an attempt to gauge its feasibility as a therapeutic option. The MICs were also compared with corresponding disc diffusion zone sizes to see if there was consistency between the two tests. We tested 45 Salmonella enterica isolates using E-tests for MIC detection and azithromycin discs with a concentration of 15µg/ml for disc diffusion testing. Results: Salmonella Typhi, Salmonella Paratyphi A, and Salmonella Paratyphi C isolates demonstrated MICs of 2-12mg/L against azithromycin, suggesting that the antibiotic could be used for therapeutic purposes. For Salmonella Paratyphi B, the MICs were 2-48 mg/L. The higher MIC indicates a need for caution when considering use of azithromycin for Salmonella Paratyphi B infections without first testing for the MIC. There was a close correlation between MICs and zone sizes which was statistically significant. Conclusions: Our results indicate azithromycin is a potential therapeutic option for enteric fever. Standardized laboratory testing methods and interpretation for azithromycin against Salmonella enterica would allow laboratories to report upon this antibiotic with confidence.

show abstract

“…7 Ceftriaxone is useful as a parenteral agent, although in vitro resistance has been documented to S. enterica serovar Paratyphi A. 2 Trying to determine resistance to azithromycin has been difficult, partly due to its marked intracellular concentration.…”

mentioning

confidence: 99%