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Sir—This has reference to comments by M.J. Figueras et al. regarding our article (Ghatak et al. 2007). The methodology reported by us actually consisted of three sequential digestion steps and not four as pointed out by M.J. Figueras et al. The fourth digestion with the endonuclease NruI was only suggested and no data were provided. The objective of our study was the identification of species with significant clinical relevance, i.e. Aeromonas hydrophila, Aeromonas caviae, and Aeromonas veronii biotype (bt) sobria and not other Aeromonas spp. Of the presently described species of aeromonads, A. hydrophila, A. caviae, and A. veronii bt sobria are considered major pathogens. While other Aeromonas spp. may cause human infections, the former three are found in majority of the cases (Janda and Abott 1998). The similarities in restriction patterns between major pathogenic aeromonads and other species of aeromonads observed by M.J. Figueras et al. included 10 species. Most of these species are associated with very occasional or no human infections. Moreover, reported frequencies of three major aeromonads are so overwhelmingly large (Janda and Duffey 1988) that we believe this finding will not compromise the benefits of our methodology. Interestingly, even in the original article of Borrell et al. (1997) those three species (A. hydrophila, A. caviae, and A. veronii bt sobria) were found in almost 90% of the samples. We agree with M.J. Figueras et al. that the epidemiological role of the less frequently isolated aeromonads be explored by researchers to facilitate better understanding of this group of organisms. However, we feel that such efforts are often beyond the scope of a clinical microbiology laboratory providing routine diagnosis. Therefore, we intended our method to be directed towards the most commonly occurring Aeromonas spp. and be easily adoptable by such laboratories. The digestion by the endonuclease NruI to differentiate between A. veronii bt veronii and A. veronii bt sobria was only proposed and not published. Nevertheless, the enzyme does splice A. veronii bt sobria 16S rRNA gene (GenBank accession number AY928477). The study by Borrell et al. (1997) was an important one in the field of molecular diagnosis of Aeromonas spp. We never had nor we have any intention to undermine the elegant study of Borrell et al. (1997). We inferred on the taxonomic aspect that was so obvious as they clearly put that their report consisted of a methodology for identification of all known phylogenetically established Aeromonas spp. (while not all of them were pathogenic for humans) (Borrell et al. 1997). Perhaps this inference was not entirely flawed as some of the authors continued to improvise their original methodology (Borrell et al. 1997) to accommodate all known Aeromonas spp. (Figueras et al. 2000). Intraspecies genomic diversity is a phenomenon that may compromise the efficacy of any restriction fragment length polymorphism (RFLP)-based methodology by appearance of unusual patterns. A discussion on this would certainly have strengthened our article more. We are thankful to M.J. Figueras et al. for their valuable comments in this aspect. Finally, we consider that our methodology is still routinely practicable in a clinical microbiology laboratory for identification of clinically important Aeromonas spp. by an easily interpretable RFLP pattern. Sincerely yours, S. Ghatak Department of Veterinary Public Health, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana 141 004, India E-mail: ghataksnd@rediffmail.com