%0 Journal Article %A Guzmán-Martín, José Luis %A Navarro-Marí, José María %A Expósito-Ruiz, Manuela %A Gutiérrez-Fernández, José %T Nalidixic acid surrogate test for susceptibility to ciprofloxacin in Salmonella. Revisiting the question %D 2018 %J Journal of Medical Microbiology, %V 67 %N 7 %P 965-967 %@ 1473-5644 %R https://doi.org/10.1099/jmm.0.000755 %K ciprofloxacin %K enteritis %K stools %K nalidixic acid %K Salmonella %I Microbiology Society, %X We investigated the reliability of nalidixic acid (NA) susceptibility as a marker of ciprofloxacin susceptibility in Salmonella, analysing 302 stool isolates. NC53 of the MicroScan system was used for NA susceptibility tests and the E-test was used for ciprofloxacin susceptibility tests. Among the isolates, 178 (58.9 %) were serogroup B, 74 (24.5 %) were serogroup D, 27 (8.9 %) were serogroup C and 23 (7.6 %) were from other minor serogroups. Globally, susceptibility to NA correctly predicted the susceptibility of Salmonella to ciprofloxacin, with a sensitivity of 81.5 %, a specificity of 97.6 %, and positive and negative predictive values of 88 and 96 %, respectively. However, there were differences among the serogroups in terms of sensitivity (P<0.001) and positive predictive values (P=0.013). NA is a reliable marker for serogroup D, but not for serogroups B or C. According to these findings, NA susceptibility measured with the MicroScan system can be used as a marker of ciprofloxacin resistance in some serogroups in our setting. %U https://www.microbiologyresearch.org/content/journal/jmm/10.1099/jmm.0.000755