Downloaded from www.microbiologyresearch.org by IP: 54.70.40.11 On: Fri, 07 Dec 2018 19:14:14 Serratia aquatilis sp. nov., isolated from drinking water systems Peter Ka ¨ mpfer and Stefanie P. Glaeser Correspondence Peter Ka ¨ mpfer peter.kaempfer@ umwelt.uni-giessen.de Institut fu ¨ r Angewandte Mikrobiologie, Universita ¨ t Giessen, Giessen, Germany A cream–white-pigmented, oxidase-negative bacterium (strain 2015-2462-01 T ), isolated from a drinking water system, was investigated in detail to determine its taxonomic position. Cells of the isolate were rod-shaped and stained Gram-negative. A comparison of the 16S rRNA gene sequence of strain 2015-2462-01 T with sequences of the type strains of closely related species of the genus Serratia revealed highest similarity to Serratia fonticola (98.4 %), Serratia proteamaculans (97.8 %), Serratia liquefaciens and Serratia grimesii (both 97.7 %). 16S rRNA gene sequence similarities to all other Serratia species were below 97.4 %. Multilocus sequence analysis (MLSA) on the basis of concatenated partial gyrB, rpoB, infB and atpD gene sequences showed a clear distinction of strain 2015-2462-01 T from the type strains of the closest related Serratia species. The fatty acid profile of the strain consisted of C 16 : 1 v7c, C 16 : 0 ;C 14 : 0 and C 14 : 0 3-OH/iso-C 16 : 1 I as major components. DNA–DNA hybridizations between 2015-2462-01 T and S. fonticola ATCC 29844 T resulted in a relatedness value of 27 % (reciprocal 20 %). This DNA–DNA hybridization result in combination with the MLSA results and the differential biochemical properties indicated that strain 2015-2462-01 T represents a novel species of the genus Serratia, for which the name Serratia aquatilis sp. nov. is proposed. The type strain is 2015-2462-01 T (5LMG 29119 T 5CCM 8626 T ). The genus Serratia comprises, at the time of writing, 17 recognized species, which have been isolated from various sources, such as water, soil, plants and animals (Grimont & Grimont, 2006). In some mammals, Serratia strains have been found to be associated with infections, such as mastitis in cows (Barnum et al., 1958; Wilson, 1963), conjunctivitis in horses (Carter, 1973) and septicaemia in foals (Deom & Mortelmans, 1953) and goats (Wijewanta & Fernando, 1970). But, they have also been isolated from clinically healthy individuals (Grimont & Grimont, 2006). In addition, they have been found as common intestinal bacterial flora in bats (Klite, 1965) and they seem to be opportunistic pathogens of chiropteran species (Mu ¨hldorfer et al., 2011). In connection with water systems, Serratia fonticola was described by Gavini et al. (1979). This species and S. fonticola-like isolates, which were difficult to identify with classical methods, have also been reported to occur in drinking water systems (Ka ¨mpfer et al., 2008). Seven beige-pigmented bacteria (2015-2462-01 T , and 2015- 2462-03 to 2015-2462-08) were isolated on nutrient agar (NA; Oxoid) from different sampling sites of a drinking water distribution system in the Rhine–Ruhr area, Germany. All displayed the typical colony morphological properties of Serratia. The isolates were initially character- ized by 16S rRNA gene sequence analysis and genomic fin- gerprinting using three different rep-PCRs [BOX-PCR, ERIC-PCR and (GTG) 5 -PCR; Versalovic et al., 1994] and a RAPD-PCR (performed with primer B; Ziemke et al., 1997) as described by Glaeser et al. (2013). The isolates were found to share identical 16S rRNA gene sequences (GenBank accession numbers KT387999–KT388005) and identical genomic fingerprint patterns (Fig. S1, available in the online Supplementary material). This indicated that the isolates were probably of clonal origin and rep- resent the same strain. For this reason only one strain, 2015-2462-01 T , was studied in more detail. Strain 2015- 2462-01 T was maintained and subcultivated on NA at 30 8C for 48 h and subsequently analysed phylogenetically based on the 16S rRNA gene and multilocus sequence anal- ysis (MLSA) based on concatenated partial gyrB, rpoB, infB and atpD gene sequences, which has been successfully applied for the classification of Enterobacteriaceae including Serratia species (Brady et al., 2013; Ka ¨mpfer & Glaeser, 2015). The fatty acid methyl ester composition of whole- cell hydrolysates, further phenotypic features and DNA– DNA similarity were compared against S. fonticola ATCC Abbreviation: MLSA, multilocus sequence analysis. The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA, gyrB, rpoB, infB and atpD gene sequences of strain 2015-2462-01 T are KT387999, KT388006, KT388008, KT388010 and KT388012, respectively. One supplementary figure and two supplementary tables are available with the online Supplementary Material. International Journal of Systematic and Evolutionary Microbiology (2016), 66, 407–413 DOI 10.1099/ijsem.0.000731 000731 G 2015 IUMS Printed in Great Britain 407