Proteobacteria, extremophiles and unassigned species dominate in a tape-like showerhead biofilm

Abstract

The development of showerhead biofilms exposes the user to repeated contact with potentially pathogenic microbes, yet we know relatively little about the content of these aggregates. The aim of the present study was to examine the microbial content of tape-like films found protruding from a domestic showerhead. Culturing showed that the films were dominated by aerobic α- and β-proteobacteria. Three isolates made up almost the entire plate count. These were a Brevundimonas species, a metalophilic Cupriavidus species and a thermophile, Geobacillus species. Furthermore, it was shown that the Cupriavidus isolate alone had a high capacity for biofilm formation and thus might be the initiator of biofilm production. A clone library revealed the same general composition. However, half of the 70 clones analyzed could not be assigned to a particular bacterial phylum and of these 29 differed from one another by only 1–2 base pairs, indicating a single species. Thus both the culture dependent and culture independent characterizations suggest a simple yet novel composition. The work is important as the biofilm is fundamentally different in form (tape-like) and content from that of all previously reported ones, where variously Mycobacterium, Methylobacterium and Xanthomonas species have dominated, and extremophiles were not reported.

Stationary Phase Physiology Tell-Tales the Regulation of Bioactive Metabolite Production in Bacteria

“…The physiological and biochemical properties of bacteria reflect their "environmental-fitness" or adaptability to the environmental habitats i.e. extreme barophilic bacteria isolated from the deep-sea [2], a thermophilic isolate from an ultra-deep South African gold mine [3], metalophillic species from a domestic showerhead biofilm [4] plant/animal symbiotic bacteria [5,6]. The ability to survive and proliferate under such conditions depends on the physiological regulation of SGP and consequently, the synthesis of natural products/bacterial bioactive metabolites (BBM) [7], a process intricate to the global stress-response mechanism in bacteria [8].…”

The role of bacteriophages in mixed microbial communities and populations of Pseudomonas aeruginosa

“…Furthermore, Proteobacteria, Bacteroidetes and Nitrospira are well documented to be biofilm forming organisms (Chao et al, 2015;Charnock & Nordlie, 2016;Martiny et al, 2005;Martiny et al, 2003;Rożej et al, 2015) and their ability to propionate as carbon sources may also have played a part in the selection of the dominant bacteria. 'Candidatus Accumulibacter' are proficient in propionate uptake while 'Candidatus Competibacter' better utilise acetate (Oehmen et al, 2005).…”

O genótipo do hospedeiro e as condições ambientais como moduladores da comunidade bacteriana associada

“…Caporaso et al, 2010b), essas sequências não classificadas podem ser consideradas como sequências ainda não conhecidas, ao invés de sequências de baixa qualidade. Um alto número de sequências não classificadas também foi observado porCharnock et al, (2016), estudando ambientes extremos, citando que essas podem ser oriundas de microrganismos não conhecidos. Ainda assim, essa diversidade de microrganismos não conhecidos podem se tornar foco de novas pesquisas (Langarica-Fuentes et al, 2015).…”