Nalidixic acid surrogate test for susceptibility to ciprofloxacin in Salmonella. Revisiting the question Guzmán-Martín, José Luis Navarro Marí, José María Expósito Ruiz, Manuela Gutiérrez Fernández, José Enteritis Salmonella Nalidixic acid Ciprofloxacin Stools Parts of this work were supported by the CTS-521 Research Group of the Ministry of Economy, Innovation and Science of the Andalusian regional government in Granada. 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. 2024-04-17T09:07:48Z 2024-04-17T09:07:48Z 2018-07-01 info:eu-repo/semantics/article Guzmán-Martín JL, Navarro-Marí JM, Expósito-Ruiz M, Gutiérrez-Fernández J. Nalidixic acid surrogate test for susceptibility to ciprofloxacin in Salmonella. Revisiting the question. J Med Microbiol. 2018 Jul;67(7):965-967. https://doi.org/10.1099/jmm.0.000755 https://hdl.handle.net/10481/90816 10.1099/jmm.0.000755 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess Attribution-NonCommercial-NoDerivatives 4.0 Internacional Microbiology Society