Draft genome sequences of two <i>Kocuria</i> isolates, K. <i>salsicia</i> G1 and K. <i>rhizophila</i> G2, isolated from a slaughterhouse in Denmark

We report here the draft genome sequences of Kocuria salsicia G1 and Kocuria rhizophila G2, which were isolated from a meat chopper at a small slaughterhouse in Denmark. The two annotated genomes are 2.99 Mb and 2.88 Mb in size, respectively

Genome sequence of <i>Arthrobacter antarcticus</i> strain W2, isolated from a slaughterhouse

We report the draft genome sequence of Arthrobacter antarcticus strain W2, which was isolated from a wall of a small slaughterhouse in Denmark. The 4.43-Mb genome sequence was assembled into 170 contigs

Genome sequence of <i>Psychrobacter cibarius</i> strain W1

Here, we report the draft genome sequence of Psychrobacter cibarius strain W1, which was isolated at a slaughterhouse in Denmark. The 3.63-Mb genome sequence was assembled into 241 contigs

Genome sequence of <i>Kocuria palustris</i> strain W4

We report the 3.09 Mb draft genome sequence of Kocuria palustris W4, isolated from a slaughterhouse in Denmark

Genome sequence of <i>Kocuria varians</i> G6 ssolated from a slaughterhouse in Denmark

We report here the first draft genome sequence of Kocuria varians G6, which was isolated from a meat chopper at a small slaughterhouse in Denmark. The 2.90-Mb genome sequence consists of 95 contigs and contains 2,518 predicted protein-coding genes

Draft genome assembly of two <i>Pseudoclavibacter helvolus</i> strains, G8 and W3, isolated from slaughterhouse environments

We report the draft genome sequences of two Pseudoclavibacter helvolus strains. Strain G8 was isolated from a meat chopper and strain W3 isolated from the wall of a small slaughterhouse in Denmark. The two annotated genomes are 3.91 Mb and 4.00 Mb in size, respectively

Microbial diversity and putative opportunistic pathogens in dishwasher biofilm communities

Extreme habitats are not only limited to natural environments, but also exist in manmade systems, for instance, household appliances such as dishwashers. Limiting factors, such as high temperatures, high and low pHs, high NaCl concentrations, presence of detergents, and shear force from water during washing cycles, define microbial survival in this extreme system. Fungal and bacterial diversity in biofilms isolated from rubber seals of 24 different household dishwashers was investigated using next-generation sequencing. Bacterial genera such as Pseudomonas, Escherichia, and Acinetobacter, known to include opportunistic pathogens, were represented in most samples. The most frequently encountered fungal genera in these samples belonged to Candida, Cryptococcus, and Rhodotorula, also known to include opportunistic pathogenic representatives. This study showed how specific conditions of the dishwashers impact the abundance of microbial groups and investigated the interkingdom and intrakingdom interactions that shape these biofilms. The age, usage frequency, and hardness of incoming tap water of dishwashers had significant impact on bacterial and fungal community compositions. Representatives of Candida spp. were found at the highest prevalence (100%) in all dishwashers and are assumed to be one of the first colonizers in recently purchased dishwashers. Pairwise correlations in tested microbiomes showed that certain bacterial groups cooccur, as did the fungal groups. In mixed bacterial-fungal biofilms, early adhesion, contact, and interactions were vital in the process of biofilm formation, where mixed complexes of bacteria and fungi could provide a preliminary biogenic structure for the establishment of these biofilms. IMPORTANCE Worldwide demand for household appliances, such as dishwashers and washing machines, is increasing, as is the number of immunocompromised individuals. The harsh conditions in household dishwashers should prevent the growth of most microorganisms. However, our research shows that persisting polyextremotolerant groups of microorganisms in household appliances are well established under these unfavorable conditions and supported by the biofilm mode of growth. The significance of our research is in identifying the microbial composition of biofilms formed on dishwasher rubber seals, how diverse abiotic conditions affect microbiota, and which key microbial members were represented in early colonization and contamination of dishwashers, as these appliances can present a source of domestic cross-contamination that leads to broader medical impacts

Impact of free living protozoa and bacterial interactions on multispecies biofilms

Interactions between bacteria belonging to different species are vital for the development of complex microbial communities, including multispecies biofilm. Multispecies biofilms are ubiquitous in most natural and man-made environments; their presence is now subject to ever-increasing attention. Several studies have shown that bacterial species living in complex bacterial communities interact, both intra- and interpecifically, and that these interactions are instrumental in structural establishment and distribution of bacterial species within multispecies biofilm. These complex interactions often result in the bacteria developing properties that would not been present when grown alone. These emergent properties include increased tolerance to antibiotics, host immune responses, and other stressors, which has proven to provide increased fitness benefits to members of the mixed community. Co-cultivation studies using in-vitro multispecies settings have shown that bacteria in mixed communities produce increased biomass, and many studies have documented the formation of microbial aggregates, microcolonies or biofilm formation in response to the presence of predatory protozoa. The threat from bactericidal protozoans can affect the physiological state of the bacterial community and result in bacterial responses at both species and social levels, which is in turn influenced by the combination of different interactions and parameters. The purpose of this Ph.D. thesis was to address various aspects of bacterial interactions, all of which support multispecies biofilm formation, and to investigate the role of biofilms as protective mechanisms when grazing is widespread. More specifically, the microbial diversity of multispecies biofilm and selected eukaryotic organisms (protozoa and fungi, reespectively) associated with toothbrushes (manuscript 1) and dishwashers (manuscripts 2 and 3) were investigated. Multiple bacterial communities isolated from dishwashers were screened for their ability to produce biofilm; both individually and in co-cultures. The influence of bacterial interactions on population dynamics in a model culture with four different bacterial strains exposed to grazing (manuscript 4) was also studied. The results presented in this thesis shows that studies conducted under the conditions of multiple species, even though they are less complex than naturally occurring bacterial communities, allow us to characterize biofilms representing their natural environments where they most often exist as multispecies microbial communities. The resulting emerging properties such as increased biomass production and fitness benefits (protection against grazing) associated within the biofilm architecture, substantiate the presence of synergistic interactions in multispecies biofilm and further emphasize their influence on individual bacterial species during biofilm formation