{"title":"Azithromycin-resistant mph(A)-positive Salmonella enterica serovar Typhi in the United States","authors":"","doi":"10.1016/j.jgar.2024.08.005","DOIUrl":null,"url":null,"abstract":"<div><h3>Objectives</h3><p>The United States Centers for Disease Control and Prevention (CDC) conducts active surveillance for typhoid fever cases caused by <em>Salmonella enterica</em> serovar Typhi (Typhi). Here we describe the characteristics of the first two cases of <em>mph</em>(A)-positive azithromycin-resistant Typhi identified through US surveillance.</p></div><div><h3>Methods</h3><p>Isolates were submitted to public health laboratories, sequenced, and screened for antimicrobial resistance determinants and plasmids, as part of CDC PulseNet's routine genomic surveillance. Antimicrobial susceptibility testing and long-read sequencing were also performed. Basic case information (age, sex, travel, outcome) was collected through routine questionnaires; additional epidemiological data was requested through follow-up patient interviews.</p></div><div><h3>Results</h3><p>The patients are related and both reported travel to India (overlapping travel dates) before illness onset. Both Typhi genomes belong to the GenoTyphi lineage 4.3.1.1 and carry the azithromycin-resistance gene <em>mph</em>(A) on a PTU-FE (IncFIA/FIB/FII) plasmid. These strains differ genetically from <em>mph</em>(A)-positive Typhi genomes recently reported from Pakistan, suggesting independent emergence of azithromycin resistance in India.</p></div><div><h3>Conclusions</h3><p>Cases of typhoid fever caused by Typhi strains resistant to all available oral treatment options are cause for concern and support the need for vaccination of travellers to Typhi endemic regions. US genomic surveillance serves as an important global sentinel for detection of strains with known and emerging antimicrobial resistance profiles, including strains from areas where routine surveillance is not conducted.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":null,"pages":null},"PeriodicalIF":3.7000,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001553/pdfft?md5=41be77abc260d495c3dbbb45e4a0d587&pid=1-s2.0-S2213716524001553-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of global antimicrobial resistance","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2213716524001553","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"INFECTIOUS DISEASES","Score":null,"Total":0}
引用次数: 0
Abstract
Objectives
The United States Centers for Disease Control and Prevention (CDC) conducts active surveillance for typhoid fever cases caused by Salmonella enterica serovar Typhi (Typhi). Here we describe the characteristics of the first two cases of mph(A)-positive azithromycin-resistant Typhi identified through US surveillance.
Methods
Isolates were submitted to public health laboratories, sequenced, and screened for antimicrobial resistance determinants and plasmids, as part of CDC PulseNet's routine genomic surveillance. Antimicrobial susceptibility testing and long-read sequencing were also performed. Basic case information (age, sex, travel, outcome) was collected through routine questionnaires; additional epidemiological data was requested through follow-up patient interviews.
Results
The patients are related and both reported travel to India (overlapping travel dates) before illness onset. Both Typhi genomes belong to the GenoTyphi lineage 4.3.1.1 and carry the azithromycin-resistance gene mph(A) on a PTU-FE (IncFIA/FIB/FII) plasmid. These strains differ genetically from mph(A)-positive Typhi genomes recently reported from Pakistan, suggesting independent emergence of azithromycin resistance in India.
Conclusions
Cases of typhoid fever caused by Typhi strains resistant to all available oral treatment options are cause for concern and support the need for vaccination of travellers to Typhi endemic regions. US genomic surveillance serves as an important global sentinel for detection of strains with known and emerging antimicrobial resistance profiles, including strains from areas where routine surveillance is not conducted.
期刊介绍:
The Journal of Global Antimicrobial Resistance (JGAR) is a quarterly online journal run by an international Editorial Board that focuses on the global spread of antibiotic-resistant microbes.
JGAR is a dedicated journal for all professionals working in research, health care, the environment and animal infection control, aiming to track the resistance threat worldwide and provides a single voice devoted to antimicrobial resistance (AMR).
Featuring peer-reviewed and up to date research articles, reviews, short notes and hot topics JGAR covers the key topics related to antibacterial, antiviral, antifungal and antiparasitic resistance.