Antimicrobial Resistance in Salmonella enterica Serovar Typhi Isolates from Bangladesh, Indonesia, Taiwan, and Vietnam

Chiou, Chien-Shun; Lauderdale, Tsai‐Ling; Phung, Dac Cam; Watanabe, Haruo; Kuo, Jung-Che; Wang, Pei-Jen; Liu, Yen‐Yi; Liang, Shiu-Yun; Chen, Pei-Chen

doi:10.1128/aac.03608-14

Cited by 67 publications

(75 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Long-read sequencing of 2012 Indian isolate ERL12960 ( Supplementary Table 4 ) confirmed that the entire MDR locus, flanked by copies of IS 1 , was integrated at this location near cyaA (Fig. 5), in agreement with other recent reports 15,16 . The nucleotide sequence was identical to that in the IncHI1-PST6 plasmid of H58 isolate 10425_1_48_Viety3-193_1997, which we also sequenced for comparison.…”

Section: Resultssupporting

confidence: 89%

Phylogeographical analysis of the dominant multidrug-resistant H58 clade of Salmonella Typhi identifies inter- and intracontinental transmission events

et al. 2015

View full text Add to dashboard Cite

The emergence of multidrug-resistant (MDR) typhoid is a major global health threat affecting many countries where the disease is endemic. Here whole-genome sequence analysis of 1,832 Salmonella enterica serovar Typhi (S. Typhi) identifies a single dominant MDR lineage, H58, that has emerged and spread throughout Asia and Africa over the last 30 years. Our analysis identifies numerous transmissions of H58, including multiple transfers from Asia to Africa and an ongoing, unrecognized MDR epidemic within Africa itself. Notably, our analysis indicates that H58 lineages are displacing antibiotic-sensitive isolates, transforming the global population structure of this pathogen. H58 isolates can harbor a complex MDR element residing either on transmissible IncHI1 plasmids or within multiple chromosomal integration sites. We also identify new mutations that define the H58 lineage. This phylogeographical analysis provides a framework to facilitate global management of MDR typhoid and is applicable to similar MDR lineages emerging in other bacterial species.

show abstract

Section: Resultssupporting

confidence: 89%

Phylogeographical analysis of the dominant multidrug-resistant H58 clade of Salmonella Typhi identifies inter- and intracontinental transmission events

et al. 2015

View full text Add to dashboard Cite

show abstract

“…SGI11-carrying S. Typhi strains may have the advantage in the face of antimicrobial exposure, and whether the strains are more capable of spreading needs further investigation. Notably, 11 of the 18 MDR S. Typhi isolates from Bangladesh analyzed in this study have developed resistance to high-level fluoroquinolone by alterations in gyrase A (S83F and D87G) and enhanced efflux pumps (9). High-level fluoroquinolone resistance on salmonellae may have a prohibitive fitness cost (29); however, fluoroquinolone-resistant S. Typhi strains may have a fitness benefit even in the absence of antimicrobial pressure (30).…”

mentioning

confidence: 96%

“…In a previous study, we characterized 38 S. Typhi isolates collected in Bangladesh in 2007 and revealed that 68% of the isolates were MDR, 82% were resistant to nalidixic acid (Na), and 39% were resistant to ciprofloxacin (Cp) (9). The 26 MDR isolates were resistant to 5 to 7 antimicrobials (ampicillin, chloramphenicol, ciprofloxacin, nalidixic acid, streptomycin [S], sulfamethoxazole [Su], tetracycline [T], and trimethoprim [Tm]) and were grouped into 7 resistance patterns, A2 (11 isolates resistant to ACCpNaSSuTm), A3 (1 resistant to ACpNaSSuT), A4 (3 resistant to ACpNaSuT), A5 (2 resistant to ACNaSSuTTm), A6 (6 resistant to ACNaSSuTm), A9 (2 resistant to ACSSuTTm), and A11 (1 resistant to ACSSuTm).…”

mentioning

confidence: 99%

Chromosome-Mediated Multidrug Resistance in Salmonella enterica Serovar Typhi

Chiou

Alam

Kuo

et al. 2015

Antimicrob Agents Chemother

Self Cite

View full text Add to dashboard Cite

show abstract

“…In a report from Bangalore, India, only 3 out of 50 (6%) S. Typhi or S. Paratyphi A isolates were susceptible to ciprofloxacin; 38 out of 50 (76%) of these isolates were resistant to nalidixic acid, indicating the presence of a QRDR mutation, and only 7 (14%) were ciprofloxacin intermediate and nalidixic acid susceptible (31). Such data suggest that FQs have already been lost as a useful therapeutic option for many patients with enteric fever in parts of India, as well as Bangladesh (32) and Pakistan (33).…”

Section: Low-level Fq Resistance Is Associated With Poorer Clinical Omentioning

confidence: 99%

Commentary: Fluoroquinolone Resistance in Salmonella and the Utility of Perfloxacin Disk Diffusion

Fang

2015

J Clin Microbiol

View full text Add to dashboard Cite

Fluoroquinolone resistance in Salmonella. Since 1987, when ciprofloxacin was approved for clinical use in the United States, fluoroquinolones (FQs) have been widely prescribed for a diverse range of infections, including bacterial enteritis and typhoid fever. A broad antibacterial spectrum, favorable safety profile, and excellent oral absorption have contributed to the popularity of these agents (1, 2). However, marked increases in FQ resistance in a variety of bacterial species and clinical settings were observed within a decade of the introduction of these agents (3), and Salmonella infections have typified this trend.In view of rising rates of resistance to ampicillin, trimethoprimsulfamethoxazole, and chloramphenicol among both typhoidal and nontyphoidal Salmonella isolates (4, 5), FQ initially seemed to provide an ideal therapeutic alternative to treat serious Salmonella infections (6). However, FQ-resistant Salmonella strains were detected soon thereafter (7,8). By 1997, 60% of Salmonella enterica serotype Typhi and Paratyphi isolates in some parts of India had ciprofloxacin MICs of Ն2 g/ml (9). To a lesser extent, the prevalence of FQ resistance in nontyphoidal Salmonella isolates throughout the world has also been rising (10). Since the U.S. National Antimicrobial Resistance Monitoring System (NARMS) began tracking ciprofloxacin susceptibility in 1996, the percentage of Salmonella isolates that are nonsusceptible to ciprofloxacin has increased from Ͻ0.5% up to 3.5% (11), while in the EUCAST (European Committee on Antimicrobial Susceptibility Testing) database, 6.0% of Salmonella isolates are nonsusceptible to ciprofloxacin (12).Nalidixic acid, a nonfluorinated quinolone, was initially used by clinical laboratories as a surrogate agent to detect Salmonella with FQ resistance due to target site (gyrA and parC) mutations in the quinolone resistance-determining region (QRDR) (13). However, the situation became more complex with the discovery of plasmid-mediated quinolone resistance (PMQR) (reviewed in reference 14), which includes various qnr variants, oqxAB, qepA and aac(6=)-Ib-cr genetic determinants (15). Strains with PMQR may be difficult to detect because the resulting MIC elevations are typically more modest than those associated with QRDR mutations and do not confer resistance to nalidixic acid (16).Low-level FQ resistance is associated with poorer clinical outcomes. Although PK-PD (pharmacokinetic-pharmacodynamic) studies have suggested a ciprofloxacin susceptibility breakpoint of 0.12 g/ml (17, 18), Salmonella isolates with ciprofloxacin MICs of Յ1.0 g/ml have long been considered to be susceptible. However, patients with infections caused by Salmonella with low-level FQ MIC elevations (0.125 to 1.0 g/ml) have been found to have a greater likelihood of FQ treatment failure, delayed resolution of fever, and mortality (17,(19)(20)(21). In recognition of the clinical significance of low-level FQ resistance, CLSI (Clinical and Laboratory Standards Institute) and EUCAST lowered their susceptibility break...

show abstract

Antimicrobial Resistance in Salmonella enterica Serovar Typhi Isolates from Bangladesh, Indonesia, Taiwan, and Vietnam

Cited by 67 publications

References 35 publications

Phylogeographical analysis of the dominant multidrug-resistant H58 clade of Salmonella Typhi identifies inter- and intracontinental transmission events

Phylogeographical analysis of the dominant multidrug-resistant H58 clade of Salmonella Typhi identifies inter- and intracontinental transmission events

Chromosome-Mediated Multidrug Resistance in Salmonella enterica Serovar Typhi

Commentary: Fluoroquinolone Resistance in Salmonella and the Utility of Perfloxacin Disk Diffusion

Contact Info

Product

Resources

About