{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T19:16:38Z","timestamp":1790190998598,"version":"4.1.0"},"reference-count":20,"publisher":"American Society of Tropical Medicine and Hygiene","issue":"5","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2023,5,3]]},"abstract":"<jats:title>ABSTRACT.<\/jats:title>\n<jats:p>This study aimed to evaluate the minimum inhibitory concentration (MIC) of azithromycin (AZM) in clinical isolates of extensively drug-resistant (XDR) <jats:italic>Salmonella<\/jats:italic> Typhi (i.e., resistant to chloramphenicol, ampicillin, trimethoprim-sulfamethoxazole, fluoroquinolones, and third-generation cephalosporin) using the E-test versus the broth microdilution method (BMD). From January to June 2021, a retrospective cross-sectional study was carried out in Lahore, Pakistan. Antimicrobial susceptibility was performed initially by the Kirby-Bauer disk diffusion method for 150 XDR <jats:italic>Salmonella enterica<\/jats:italic> serovar Typhi isolates, and MICs of all the recommended antibiotics were determined by the VITEK 2 (BioM\u00e9rieux) fully automated system using Clinical Laboratory Standard Institute (CLSI) 2021 guidelines. The E-test method was used to determine AZM MICs. These MICs were compared with the BMD, which is the method recommended by the CLSI but not adopted in routine laboratory reporting. Of 150 isolates, 10 (6.6%) were resistant by disk diffusion. Eight (5.3%) of these had high MICs against AZM by the E-test. Only three isolates (2%) were resistant by E-test, having an MIC of 32 \u03bcg\/mL. All eight isolates had a high MIC by BMD with different MIC distributions, but only one was resistant, having an MIC of 32 \u03bcg\/mL by BMD. The sensitivity, specificity, negative predictive value, positive predictive value, and diagnostic accuracy of the E-test method versus BMD were 98.65%,100%, 99.3%, 33.3%, and 98.6%, respectively. Similarly, the concordance rate was 98.6%, negative percent agreement was 100%, and positive percent agreement was 33%. The BMD is the most reliable approach for reporting AZM sensitivity in XDR <jats:italic>S<\/jats:italic>. Typhi compared with the E-test and disk diffusion methods. Potentially, AZM resistance in XDR <jats:italic>S.<\/jats:italic> Typhi is around the corner. Sensitivity patterns should be reported with MIC values, and if possible, higher values should be screened for the presence of any potential resistance genes. Antibiotic stewardship should be strictly implemented.<\/jats:p>","DOI":"10.4269\/ajtmh.22-0557","type":"journal-article","created":{"date-parts":[[2023,3,20]],"date-time":"2023-03-20T13:45:41Z","timestamp":1679319941000},"page":"942-947","source":"Crossref","is-referenced-by-count":9,"title":["Reporting of Azithromycin Activity against Clinical Isolates of Extensively Drug-Resistant Salmonella enterica Serovar Typhi"],"prefix":"10.4269","volume":"108","author":[{"given":"Kokab","family":"Jabeen","sequence":"first","affiliation":[{"name":"University of Health Sciences, Lahore, Pakistan;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sidrah","family":"Saleem","sequence":"additional","affiliation":[{"name":"University of Health Sciences, Lahore, Pakistan;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Summiya","family":"Nizamuddin","sequence":"additional","affiliation":[{"name":"Shaukat Khanum Memorial Cancer Hospital, Lahore, Pakistan;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Faiqa","family":"Arshad","sequence":"additional","affiliation":[{"name":"University of Health Sciences, Lahore, Pakistan;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shah","family":"Jahan","sequence":"additional","affiliation":[{"name":"University of Health Sciences, Lahore, Pakistan;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Faisal","family":"Hasnain","sequence":"additional","affiliation":[{"name":"Sheikh Zayed Hospital, Rahim Yar Khan, Pakistan;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Waleed","family":"Tariq","sequence":"additional","affiliation":[{"name":"Lahore General Hospital, Lahore, Pakistan;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Muhammad Junaid","family":"Tahir","sequence":"additional","affiliation":[{"name":"Pakistan Kidney and Liver Institute and Research Center (PKLI & RC), Lahore, Pakistan;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zohaib","family":"Yousaf","sequence":"additional","affiliation":[{"name":"Tower Health, Reading, Pennsylvania;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Muhammad Sohaib","family":"Asghar","sequence":"additional","affiliation":[{"name":"Dow University of Health Sciences, Karachi, Pakistan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"2795","reference":[{"key":"b1","series-title":"Annu Rev Microbiol","first-page":"317","article-title":"Salmonella enterica serovar Typhi and the pathogenesis of typhoid fever","volume":"68","author":"Dougan","year":"2014"},{"key":"b2","year":"2018"},{"key":"b3","series-title":"mBio","first-page":"e00105","article-title":"Emergence of an extensively drug-resistant Salmonella enterica serovar Typhi clone harboring a promiscuous plasmid encoding resistance to fluoroquinolones and third-generation cephalosporins","volume":"9","author":"Klemm","year":"2018"},{"key":"b4","series-title":"Med J Aust","first-page":"286","article-title":"First reported case of extensively drug\u2010resistant typhoid in Australia","volume":"211","author":"Howard\u2010Jones","year":"2019"},{"key":"b5","series-title":"Am J Trop Med","first-page":"1265","article-title":"Continued outbreak of ceftriaxone-resistant Salmonella enterica serotype Typhi across Pakistan and assessment of knowledge and practices among healthcare workers","volume":"104","author":"Nizamuddin","year":"2021"},{"key":"b6","series-title":"Public Health in Practice","first-page":"100084","article-title":"A skeleton in the closet: the implications of COVID-19 on XDR strain of typhoid in Pakistan","volume":"2","author":"Ahmad","year":"2021"},{"key":"b7","series-title":"Wkly Epidemiol Monit","first-page":"34","article-title":"Drug resistant Salmonella infections in Pakistan: update","volume":"12","year":"2019"},{"key":"b8","series-title":"World J Microbiol Biotechnol","first-page":"1","article-title":"Prevalence and multidrug resistance in Salmonella enterica Typhimurium: an overview in South East Asia","volume":"37","author":"Patra","year":"2021"},{"key":"b9","series-title":"Eur J Clin Microbiol Infect Dis","first-page":"2145","article-title":"Typhoidal Salmonella strains in Pakistan: an impending threat of extensively drug-resistant Salmonella typhi.","volume":"38","author":"Hussain","year":"2019"},{"key":"b10","series-title":"Cureus","first-page":"e16777","article-title":"Disc diffusion testing of azithromycin against clinical isolates of typhoidal Salmonellae: a diagnostic conundrum","volume":"13","author":"Shoaib","year":"2021"},{"key":"b11","series-title":"Int J Infect Dis","first-page":"250","article-title":"Antibiotics and antimicrobial resistance in the COVID-19 era: perspective from resource-limited settings","volume":"104","author":"Lucien","year":"2021"},{"key":"b12","series-title":"Performance Standards for Antimicrobial Susceptibility Testing","year":"2021"},{"key":"b13","series-title":"J Lab Physicians","first-page":"39","article-title":"Reconsidering azithromycin disc diffusion interpretive criteria for Salmonellae in view of azithromycin MIC creep among typhoidal and nontyphoidal Salmonella","volume":"11","author":"Khan","year":"2019"},{"key":"b14","series-title":"BMC Infect Dis","first-page":"1","article-title":"Case report: failure under azithromycin treatment in a case of bacteremia due to Salmonella enterica Paratyphi A","volume":"14","author":"Kobayashi","year":"2014"},{"key":"b15","series-title":"Int J Infect Dis","first-page":"62","article-title":"A case of clinical and microbiological failure of azithromycin therapy in Salmonella enterica serotype Typhi despite low azithromycin MIC","volume":"54","author":"Manesh","year":"2017"},{"key":"b16","series-title":"PLoS Negl Trop Dis","first-page":"e0008682","article-title":"Response of extensively drug resistant Salmonella typhi to treatment with meropenem and azithromycin, in Pakistan","volume":"14","author":"Qureshi","year":"2020"},{"key":"b17","series-title":"mSphere","first-page":"e00215","article-title":"A race against time: reduced azithromycin susceptibility in Salmonella enterica serovar Typhi in Pakistan","volume":"5","author":"Iqbal","year":"2020"},{"key":"b18","series-title":"J Infect Dev Ctries","first-page":"530","article-title":"Clinical perspectives of multiple and extensively drug-resistant typhoid: result from a tertiary care hospital from Pakistan","volume":"15","author":"Fida","year":"2021"},{"key":"b19","series-title":"Access Microbiol","first-page":"214","article-title":"In-house azithromycin MIC estimation by gradient strip in Salmonella enterica var Typhi and Paratyphi: do you believe it?","volume":"2","author":"Goldblatt","year":"2020"},{"key":"b20","series-title":"J 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