Cultivable bacteria from Pectinatella magnifica and the surrounding water in South Bohemia indicate potential new Gammaproteobacterial, Betaproteobacterial and Firmicutes taxa

Abstract

Pectinatella magnifica is a freshwater bryozoan, which has become a subject of scientific interest because of its invasive expansion worldwide. To obtain a comprehensive overview of its influence on environments, information on associated bacteria is needed. In this study, cultivable bacteria associated with P. magnifica were investigated. In total, 253 isolates were selected for preliminary identification by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry and clustered based on repetitive extragenic palindromic-PCR profiles. Among these, 169 strains were selected and identified using 16S rRNA gene comparative analyses. The sequences were grouped into 76 phylotypes and affiliated with 67 species. The majority of isolated bacteria belonged to Gammaproteobacteria, followed by Betaproteobacteria, Firmicutes, Bacteroidetes and Actinobacteria. Most strains within the Betaproteobacteria were isolated exclusively from bryozoan colonies. Aeromonas was the genus predominantly isolated from both P. magnifica and the water samples. Based on 16S rDNA similarity values, 15 putative new species belonging to the genera Aeromonas, Aquitalea, Clostridium, Herbaspirillum, Chromobacterium, Chryseobacterium, Morganella, Paludibacterium, Pectobacterium, Rahnella, Rhodoferax and Serratia, and putative new genera belonging to families Clostridiaceae and Sporomusaceae were revealed. The majority of the detected bacteria were species widely distributed in the environments; nevertheless, a possible symbiotic association of two new putative species with P. magnifica cannot be excluded.

Pathogenic profile and cytotoxic activity of Aeromonas spp. isolated from Pectinatella magnifica and surrounding water in the South Bohemian aquaculture region

“…An incidence of other clinically significant aerobic and facultative anaerobic bacteria frequently recovered from aquatic environment could be expected. Proteobacteria phylum is one of the major constituent of freshwater bacterial community (Newton, Jones, Eiler, McMahon, & Bertilsson, 2011; Xiong et al., 2015) and the most frequently detected group in P. magnifica (Salmonová et al., 2018). This group includes a variety of pathogenic genera, some of which were also detected in bryozoan and could be considered a health risk.…”

“…A total of 130 Aeromonas strains, previously isolated from Pectinatella magnifica ( n = 101) and surrounding water ( n = 29), from four water reservoirs in the South Bohemian region: Hejtman (48°57'N, 14°56'E), Veselí (49°10'N, 14°42'E), Cep (48°56'N, 14°52'E) and Kanclíř (48°57'N, 14°53'E), were investigated. Bacterial strains were identified by MALDI‐TOF mass spectrometry and/or 16S rDNA sequencing, as previously described (Salmonová et al., 2018), see Table 1. Stock cultures were stored at –70°C in Tryptone Soya Broth (TSB, Oxoid), containing glycerol at 20% (v/v).…”

“…A recent study has focused on cultivatable bacteria associated with this bryozoan (Salmonová, Killer, Bunešová, Geigerová, & Vlková, 2018). In colony structures, counts reaching up 10 7 CFU/g were found, with Aeromonas spp.…”

Paludibacterium

“…were isolated from water samples collected from reservoirs in South Bohemia (Czech Republic) (Salmonová et al, 2018). Strains PT71 (16S rRNA gene accession number KY124210) and PT78 (16S rRNA gene accession number KY124211) were most closely related to P. paludis (HE981224), with 16S rRNA gene sequence identity values of 97.2% and 97.7%, respectively (Salmonová et al, 2018).…”

“…were isolated from water samples collected from reservoirs in South Bohemia (Czech Republic) (Salmonová et al, 2018). Strains PT71 (16S rRNA gene accession number KY124210) and PT78 (16S rRNA gene accession number KY124211) were most closely related to P. paludis (HE981224), with 16S rRNA gene sequence identity values of 97.2% and 97.7%, respectively (Salmonová et al, 2018). Also the phylotype NKB6 (16S rRNA gene accession number AB013258) identified by culture-independent techniques from sediment samples from the submarine Nankai Trough (Li et al, 1999) shows 16S rRNA gene sequences similarities of 95.0 and 95.4% with P. paludis (HE981224) and P. yongneupense (AM396358) respectively.…”