LB11. Rapid Rise in Decreased Susceptibility to Azithromycin among Shigella Isolates in the United States: A Look at National Surveillance Data, 2011–2017
Autor: | Jared Reynolds, Cindy R. Friedman, Kaitlin A. Tagg, Louise Francois Watkins, Hayat Caidi, Ian D Plumb, Jessica C. Chen, Beth E. Karp |
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Jazyk: | angličtina |
Rok vydání: | 2018 |
Předmět: |
0301 basic medicine
Whole genome sequencing business.industry medicine.drug_class 030106 microbiology Antibiotics medicine.disease_cause Azithromycin Men who have sex with men Microbiology Ciprofloxacin body regions 03 medical and health sciences Abstracts 0302 clinical medicine Infectious Diseases Plasmid Oncology Antimicrobial stewardship Medicine Shigella 030212 general & internal medicine business C. Late Breaker Abstracts medicine.drug |
Zdroj: | Open Forum Infectious Diseases |
ISSN: | 2328-8957 |
Popis: | Background Shigella spp. cause ~500,000 illnesses in the United States annually. Antibiotics are recommended for immunocompromised patients and shorten the duration of illness, thus limiting spread. First-line treatments include ciprofloxacin (CIP) and azithromycin (AZM). CIP resistance is a growing problem in the United States; decreased susceptibility to AZM (DSA) has been reported globally, particularly among men who have sex with men (MSM). We reviewed National Antimicrobial Resistance Monitoring System (NARMS) data to determine DSA trends among Shigella isolates in the United States. Methods Health departments nationwide forward every 20th Shigella isolate to CDC NARMS for antimicrobial susceptibility testing using broth microdilution. We defined CIP resistance using CLSI clinical breakpoints and DSA using epidemiological cutoff values where available. We performed whole genome sequencing on isolates from 2016 and screened the sequences for resistance determinants using ResFinder 3.0. Results To date, we have tested 3,044 Shigella isolates collected during 2011–2017. Overall, 264 isolates (9%) had DSA, increasing from 3% in 2011 to 23% in 2017; 41 (16%) were also CIP resistant. The odds of DSA increased by 1.5 (95% confidence interval [CI] 1.4–1.6) annually. DSA was more common among adult males (OR 21.2, CI 14.9–30.3), in isolates from the West census region (OR 2.4, CI 1.8–3.2), and in S. flexneri (OR 8.2, CI 6.3–10.7). Of 543 sequenced isolates, 52 (10%) had DSA; of these, 31 (60%) contained both mph(A) and erm(B) genes, 17 (33%) contained mph(A) only, and 4 (8%) had no identified macrolide-resistance mechanism. Conclusions In 2017, nearly 1 in 4 Shigella isolates tested had DSA, a 7-fold increase since 2011. This rapid rise in DSA parallels that seen in other countries, where resistance to other clinically relevant drugs is high and macrolides are no longer useful as empiric treatment. The increased risk of DSA in adult males is consistent with previous reports of DSA Shigella in MSM. The resistance genes observed are typically plasmid-mediated and can be transferred to other bacteria. Public health strategies to mitigate the spread of resistant Shigella should include antibiotic stewardship and novel approaches for sexually transmitted infection prevention in MSM. Disclosures All authors: No reported disclosures. |
Databáze: | OpenAIRE |
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