A Multicountry Molecular Analysis of Salmonella enterica Serovar Typhi With Reduced Susceptibility to Ciprofloxacin in Sub-Saharan Africa.
Abstract
BACKGROUND: Salmonella enterica serovar Typhi is a predominant cause of bloodstream
infections in sub-Saharan Africa (SSA). Increasing numbers of S. Typhi with resistance
to ciprofloxacin have been reported from different parts of the world. However, data
from SSA are limited. In this study, we aimed to measure the ciprofloxacin susceptibility
of S. Typhi isolated from patients with febrile illness in SSA. METHODS: Febrile patients
from 9 sites within 6 countries in SSA with a body temperature of ≥38.0°C were enrolled
in this study. Blood samples were obtained for bacterial culture, and Salmonella isolates
were identified biochemically and confirmed by multiplex polymerase chain reaction
(PCR). Antimicrobial susceptibility of all Salmonella isolates was performed by disk
diffusion test, and minimum inhibitory concentrations (MICs) against ciprofloxacin
were measured by Etest. All Salmonella isolates with reduced susceptibility to ciprofloxacin
(MIC > 0.06 µg/mL) were screened for mutations in quinolone resistance-determining
regions in target genes, and the presence of plasmid-mediated quinolone resistance
(PMQR) genes was assessed by PCR. RESULTS: A total of 8161 blood cultures were performed,
and 100 (1.2%) S. Typhi, 2 (<0.1%) Salmonella enterica serovar Paratyphi A, and 27
(0.3%) nontyphoid Salmonella (NTS) were isolated. Multidrug-resistant S. Typhi were
isolated in Kenya (79% [n = 38]) and Tanzania (89% [n = 8]) only. Reduced ciprofloxacin-susceptible
(22% [n = 11]) S. Typhi were isolated only in Kenya. Among those 11 isolates, all
had a Glu133Gly mutation in the gyrA gene combined with either a gyrA (Ser83Phe) or
gyrB mutation (Ser464Phe). One Salmonella Paratyphi A isolate with reduced susceptibility
to ciprofloxacin was found in Senegal, with 1 mutation in gyrA (Ser83Phe) and a second
mutation in parC (Ser57Phe). Mutations in the parE gene and PMQR genes were not detected
in any isolate. CONCLUSIONS: Salmonella Typhi with reduced susceptibility to ciprofloxacin
was not distributed homogenously throughout SSA. Its prevalence was very high in Kenya,
and was not observed in other study countries. Continuous monitoring of antimicrobial
susceptibility is required to follow the potential spread of antimicrobial-resistant
isolates throughout SSA.
Type
Journal articleSubject
S. Typhiciprofloxacin
sub-Saharan Africa
susceptible
Adolescent
Adult
Africa South of the Sahara
Anti-Bacterial Agents
Child
Child, Preschool
Ciprofloxacin
Drug Resistance, Bacterial
Female
Humans
Infant
Male
Microbial Sensitivity Tests
Molecular Epidemiology
Salmonella typhi
Typhoid Fever
Young Adult
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https://hdl.handle.net/10161/13761Published Version (Please cite this version)
10.1093/cid/civ788Publication Info
Al-Emran, Hassan M; Eibach, Daniel; Krumkamp, Ralf; Ali, Mohammad; Baker, Stephen;
Biggs, Holly M; ... Marks, Florian (2016). A Multicountry Molecular Analysis of Salmonella enterica Serovar Typhi With Reduced
Susceptibility to Ciprofloxacin in Sub-Saharan Africa. Clin Infect Dis, 62 Suppl 1. pp. S42-S46. 10.1093/cid/civ788. Retrieved from https://hdl.handle.net/10161/13761.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Show full item recordScholars@Duke
John Andrew Crump
Adjunct Professor in the Department of Medicine
I am based in northern Tanzania where I am Site Leader for Duke University’s
collaborative research program based at Kilimanjaro Christian Medical Centre and Director
of Tanzania Operations for the Duke Global Health Institute. I oversee the design
and implementation of research studies on infectious diseases, particularly febrile
illness, invasive bacterial disease, HIV-associated opportunistic infections, clinical
trials of antiretroviral therapy and prevention of mother-to-child tr
Julian T Hertz
Associate Professor of Emergency Medicine
Julian Hertz, MD, MSc, is an Associate Professor of Emergency Medicine & Global Health.
He graduated summa cum laude from Princeton University and attended medical school
at Duke University, where he received the Dean's Merit Scholarship and the Thomas
Jefferson Award for leadership. He completed his residency training in emergency medicine
at Vanderbilt University Medical Center and his fellowship in Global Health at Duke.Dr.
Hertz's primary interests include globa
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