294 © 2006 BSPP Plant Pathology (2006) 55, 294 Doi: 10.1111/j.1365-3059.2005.01331.x Presence of Pantoea citrea, causal agent of pink disease, in pineapple fields in Mexico V. Marín-Cevada a , V. H. Vargas a , M. Juárez a , V. G. López a , G. Zagada b , S. Hernández b , A. Cruz c , J. Caballero-Mellado d , L. López-Reyes a , T. Jiménez-Salgado a , M. Carcaño-Montiel a and L. E. Fuentes-Ramírez a * a Instituto de Ciencias, Universidad Autónoma de Puebla, A. Postal 1622, Puebla; b U. de la Soc. de Prod. Rural de la Cuenca, Loma Bonita, Oaxaca; c Agroindustrias Loma Bonita, Loma Bonita, Oaxaca; and d Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, A. Postal 565-A, Cuernavaca, México Pink disease diminishes the quality of commercially processed pineapple. When heated during the canning process, infected fruit produce an un- desirable brown pigment; this may diffuse to healthy products. Patho- genicity tests in vitro, pigment production and slice pigmentation (Coplin & Kado, 2001) have shown that Pantoea citrea is the causal agent of pink disease (Cha et al., 1997). Pineapple fruits cv. Smooth Cayenne growing in fields of the Cuenca del Papaloapan region (Oaxaca and Veracruz states) of Mexico were ran- domly sampled in June 2003. From 11 fields, nine bacterial creamy isolates showing a pale yellow colour were recovered from the interior of visually intact fruits on LB agar plates containing 1% casein peptone, 0·5% yeast extract and 0·5% NaCl. These isolates were positively identified as Pantoea spp. according to 16S rDNA restriction analysis with the endonucleases MspI, MvnI, Tru9A, AluI and HaeIII. Isolates were Gram-, sucrose-, adonitol-, gelatinase-, arginine dehydrolase-, lysine-decarboxylase-, ornithine decarboxylase-, citrate-, H 2 S production-, urease-, trytophane-, deaminase-, indole production- and mobility-negative; and glucose dehydrogenase-, acetoin production-, arabinose- and melibiose-positive, conforming to the characteristics of P. citrea. Pathogenicity of P. citrea was demonstrated in a hypersensitivity test developed in this laboratory. When inoculated into tobacco leaves cvs Virginia and Burley, the nine isolates assessed produced positive hypersensitive reactions after 3 days, and the inoculated bacteria were reisolated from the lesions. Pantoea citrea has been found in pine- apple cultivated in several countries, but this is the first report of its isola- tion from pineapple growing in Mexico. Acknowledgements Grants CONACYT 36111-N, VIEP 182-04/NAT/I and 13/G/NAT/05, and CONCYTEP. We thank L. Rebolledo (INIFAP) for his advice in sampling pineapples, and Michael Dunn (UNAM) for corrections to the English. References Cha J-S, Pujol C, Ducusin AR, Macion EA, Hubbard CH, Kado CI, 1997. Studies on Pantoea citrea, the causal agent of pink disease of pineapple. Journal of Phytopathology 145, 313–9. Coplin DL, Kado CI, 2001. Pantoea. In: Schaad NW, Jones JB, Chun W, eds. Laboratory Guide for Identification of Plant Pathogenic Bacteria (3rd Edition). St Paul, MN, USA: APS Press, 73–82. *E-mail: lefuente@siu.buap.mx Accepted 16 August 2005 at www.bspp.org.uk/ndr where figures relating to this paper can be viewed.