Print version ISSN 0120-4157
LAVALETT, Lelia et al. Development and validation of a multiplex polymerase chain reaction for molecular identification of Salmonella enterica serogroups B, C2, D and E. Biomédica [online]. 2009, vol.29, n.2, pp. 244-252. ISSN 0120-4157.
Introduction. The scheme Kauffman-White (KW) for serotyping of Salmonella recognizes 46 O antigens, and 119 H antigens, thereby permitting the characterization of 2,541 serotypes. The serotyping is a useful epidemiological tool in identifying circulating serotypes and to characterize outbreaks. However, the method presents technical limitations, difficulty in interpretation of results and high costs. Objective. A multiplex polymerase chain reaction test (M-PCR) was developed as an alternative method for the identification of serogroups B, C2, D, and E of Salmonella enterica. Materials and methods. The M-PCR detected Salmonella genes rfbJ of serogroups B and C2 and wzx of serogroups D and E. To standardize the M-PCR, reference strains of Salmonella serogroups were compared. Amplification of invA gender-specific gene of Salmonella was included as internal control of amplification. To validate the test, a blind study was conducted to identify by M-PCR 400 isolates that had been previously characterized by serology. Results. The M-PCR detected Salmonella serogroups with reproducible results (Kappa index=0.95). The sensitivity of the test was between 98% to 100% and specificity between 96% to 100%. Conclusions. The polymorphisms in the Salmonella genes rfbJ and wzx permitted the development of a method for molecular typing of Salmonella serogroups that was sensitive, specific and reproducible.
Keywords : Salmonella enterica; serogroups; serotyping; molecular typing; multiplex PCR.