203. Decreased fluoroquinolone susceptibility in Salmonella Typhi and non-typhoid Salmonella isolates from bloodstream infections in Peru
Session: Poster Abstract Session: Antimicrobial Resistance: Clinical Studies
Friday, October 21, 2011
Room: Poster Hall B1
Background: Salmonella with decreased susceptibility to ciprofloxacin (DSC) has been reported from different regions but sparse information is available from Latin American countries. Our objective was to determine the frequency of DSC among Salmonella isolates from blood cultures in Lima, Peru.


We collected consecutive Salmonella blood culture isolates from nine public, general, tertiary and fourth-care level hospitals in Lima, Peru over the period 2008-2010. Only the first isolate per patient was included. Demographic data were obtained from each patient. Salmonella isolates were re-identified by standard methods and susceptibility testing was performed by disk diffusion using the following antimicrobials: trimethoprim-sulfamethoxazole, chloramphenicol, ampicillin, ceftriaxone, and aztreonam. MIC to nalidixic and ciprofloxacin acid were performed by agar dilution. Resistance to nalidixic acid (NA) was defined as MIC-values ≥32 μg/mL. DCS was defined if MIC was 0.125-1.0 μg/mL. Escherichia coli ATCC 25922 strain was used as control.


We analyzed isolates from 115 patients, 42 (36.5%) of them were < 14 years (including one neonate). Salmonella non-Typhi (SNT) was found in 69 patients (60%) and Salmonella Typhi (ST) in 46 (40%). Of the total 115 isolates, three were resistant to ampicillin (2.6%) and 2 (1.7%) to trimethoprim-sulfamethoxazole. All isolates were susceptible to chloramphenicol, ceftriaxone and aztreonam. Among the 69 SNT isolates, 10(14.5%) were resistant to NA and 9 (13.0%) had DSC.  Among the 46 ST isolates, 15 (32.6%) were resistant to NA and 12 (26.1%) had DSC. All isolates with DCS were resistant to NA. 

Conclusion: The frequency of Salmonella Typhi and non-typhoid Salmonella with DSC exceeded 10%. This is of concern since ciprofloxacin is still the first-line drug recommended for the treatment of invasive Salmonella infections in Peru. Further studies are needed to confirm these findings.

Subject Category: A. Antimicrobial agents and Resistance

Coralith Garcia1, Gabriela Goyoneche1, Lizeth Astocondor1, Gertrudis Horna, Lic MT1, Elba Linares, MD2, Rafael Ramirez, MD3, Aida Palacios4, Jorge Velasquez, MD5, Veronica Medina, MD6, Martha Urbina, MSc7, Jose Guevara, MD8, Silvia Zevallos9, Elizeth Sierra10, Frine Samalvides, MD1,4 and Jan Jacobs, PhD11, (1)Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru, (2)Hospital Edgardo Rebagliatti Martins, Lima, Peru, (3)Hospital Guillermo Almenara Irigoyen, Lima, Peru, (4)Hospital Nacional Cayetano Heredia, Lima, Peru, (5)Hospital Arzobispo Loayza, Lima, Peru, (6)Hospital Alberto Sabogal Sologuren, Callao, Peru, (7)Hospital Nacional Maria Auxiliadora, Lima, Peru, (8)Hospital Daniel Alcides Carrion, Callao, Peru, (9)Hospital Nacional Sergio Bernales , Lima, Peru, (10)Hospital Nacional Hipolito Unanue, Lima, Peru, (11)Institute of Tropical Medicine Antwerp, Antwerpen, Belgium


C. Garcia, None

G. Goyoneche, None

L. Astocondor, None

G. Horna, None

E. Linares, None

R. Ramirez, None

A. Palacios, None

J. Velasquez, None

V. Medina, None

M. Urbina, None

J. Guevara, None

S. Zevallos, None

E. Sierra, None

F. Samalvides, None

J. Jacobs, None

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.