Microbacterium telephonicum sp. nov., isolated from the screen of a cellular phone

Abstract

A cultivation-based study of the microbial diversity of cellular phone screens led to the isolation of a Gram-stain-positive, aerobic, rod-shaped and non-endospore-forming bacterium, designated S2T63, exhibiting phenotypic and genotypic characteristics unique to the type strains of closely related species. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain is a member of Microbacterium, and most closely related to Microbacterium aurantiacum IFO 15234 and Microbacterium kitamiense Kitami C2. The DNA-DNA relatedness values of the strain S2T63 to M. aurantiacum KACC 20510, M. kitamiense KACC 20514and Microbacterium laevaniformans KACC 14463 were 65 % (±4), 29.5 % (±3) and 55.9 % (±4), respectively. The genomic DNA G+C content was 71.8 mol%. The major fatty acids were anteiso-C15 : 0, iso-C16 : 0, C16 : 0 and anteiso-C17 : 0. The main polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and two unidentified polar lipids. The peptidoglycan contained the amino acids glycine, lysine, alanine and glutamic acid, with substantial amounts of hydroxy glutamic acid detected, which is characteristic of peptidoglycan type B1α. The predominant menaquinones were MK-12 and MK-13. Rhamnose, fucose and galactose were the whole-cell sugars detected. The strain also showed biofilm production, estimated by using crystal violet assay. Based on the results of the phenotypic and genotypic characterizations, it was concluded that the new strain represents a novel species of the genus Microbacterium, for which the name Microbacteriumtelephonicum is proposed, with S2T63T (=MCC 2967=KACC 18715=LMG 29293) as the type strain.

Kineococcus vitellinus sp. nov., Kineococcus indalonis sp. nov. and Kineococcus siccus sp. nov., Isolated Nearby the Tabernas Desert (Almería, Spain)

“…In fact, this fatty acid has been found in the psychrophilic members of the genus Flavobacterium [ 38 ] isolated from a cold desert environment. Moreover, anteiso-C 15:0 fatty acid can play an important role in biofilm formation [ 39 , 40 ], which is in accordance with the biofilms and cell clumps observed for the three Kineococcus strains under liquid growth conditions.…”

Complete Genome Sequence of Microbacterium foliorum NRRL B-24224, a Host for Bacteriophage Discovery

“…Microbacteria are Gram-positive rod-shaped aerobic bacteria in the order Actinomycetales which have been associated with growth promotion and drought resistance in plants (1–3), spoilage in packaged meats (4), and even presence on cell phone screens (5). Microbacterium foliorum NRRL B-24224 (acquired by NRRL from DSM [DSM 12966]) is a type strain originally isolated from the phyllosphere of grasses and is available from the NRRL culture collection (6).…”

Cultivable Microbial Diversity Associated With Cellular Phones

“…However, we could not find any specific grouping of individuals working in laboratory and office settings, which might be because these individuals are having some overlaps in their working environments. The majority of microbial strains isolated from the cellular phones might be the transient population, recently a biofilm forming bacterium ( Microbacterium telephonicum ) was also discovered during this study ( Rahi et al, 2018 ). It is expected that the daily upkeep of the cellular phone by the individual will play an important role in the build-up of microbial communities on the cellular phones.…”

“…Except these few cases, MALDI-TOF MS based identification allowed us to identify this large collection of microorganisms and could not identify in the absence of the spectral database, which is a major challenge for MALDI-TOF MS based identification ( Rahi et al, 2016 ). MALDI-TOF MS is also useful in the discovery of novel species, as in this study three new species including the fungus Pyrenochaeta telephoni , and two bacteria Lysinibacillus telephonicus and Microbacterium telephonicum were described ( Crous et al, 2015 ; Rahi et al, 2017 , 2018 ). It is expected that by performing some basic quality filtering of MALDI-TOF MS spectrum and improving the spectral database will improve the role of MALDI-TOF MS in microbial identification.…”

“…Application of sound personal hygiene could check the microbial load on cellular phones and thus prevent the possible disease transmission through cellular phones. It is obvious that the majority of the microorganisms on cellular phone surfaces represent a transient population, which might get away by just slight rubbing of the surface of cellular phones ( Rahi et al, 2018 ). However, it is also well known that several microorganisms can colonize non-living and inert substrates by forming biofilms.…”