Corynebacterium lipophiloflavum sp. nov. isolated from a patient with bacterial vaginosis

A unique coryneform bacterium was isolated from a patient with bacterial vaginosis. Chemotaxonomical investigations demonstrated that the unknown bacterium belonged to the genus Corynebacterium. The yellow-pigmented, slightly lipophilic, oxidative, urea-hydrolyzing bacterium could be phenotypically readily differentiated from the other members of the genus Corynebacterium. Comparative 16S rRNA gene analysis revealed that the bacterium represented a new subline within the genus Corynebacterium for which the name Corynebacterium lipophiloflavum sp. nov. is proposed. The type strain is CCUG 37336 (DSM 44291

Parasitic protozoan interactions with bacterial microbiome in a tropical fish farm

The bacterial microbiome is an important component of any aquaculture environment. The interaction between the bacterial microbiome and other microorganisms (e.g. parasites, viruses, or other bacteria) in aquaculture systems can prevent or contribute to disease outbreaks. This study characterised the bacterial composition associated with the abundance of a ciliated protozoan parasite, Chilodonella hexasticha, in gills and freshwater ponds of barramundi, Lates calcarifer, farm in tropical Queensland, Australia, over one year. An environmental DNA (eDNA) approach was used to estimate the abundance of C. hexasticha (copies/μl) in water through SSUrDNA gene qPCR and the relative abundance of bacterial species in water and fish gills through 16S rRNA V3 and V4 metabarcoding. The overall bacterial community diversity, dominated by Actinobacteria (42%), Proteobacteria (28%), Bacteroidetes (10%) and Cyanobacteria (6%), was stable among ponds over the study period (p > .05). Of those that could be identified to species, Flavobacterium columnare, Veillonella dispar and Bdellovibrio bacteriovorus abundance correlated with both high C. hexasticha levels in pond water and high observed fish mortalities (p < .05). Results also revealed significantly higher levels of F. columnare, B. bacteriovorus,Plesiomonas shigelloides, Prostecobactor debontii and Oxalobacter formigenes (p < .05) in gills of fish with high infection levels of C. hexasticha compared to fish with no detected parasite infection. This study demonstrated, for the first time, a link between increased parasitic ciliate abundance, bacterial composition and fish mortalities in a freshwater aquaculture environment and the application of eDNA to investigate pathogen, host and environment interactions

Allofustis seminis gen. nov., sp. nov., a novel Gram-positive, catalase-negative, rod-shaped bacterium from pig semen

An unknown Gram-positive, catalase-negative, facultatively anaerobic, non-spore-forming, rod-shaped bacterium originating from semen of a pig was characterized using phenotypic, molecular chemical and molecular phylogenetic methods. Chemical studies revealed the presence of a directly cross-linked cell wall murein based on L-lysine and a DNA G + C content of 39 mol%. Comparative 16S rRNA gene sequencing showed that the unidentified rod-shaped organism formed a hitherto unknown subline related, albeit loosely, to Alkalibacterium olivapovliticus, Alloiococcus otitis, Dolosigranulum pigrum and related organisms, in the low-G + C-content Gram-positive bacteria. However, sequence divergence values of > 11 % from these recognized taxa. clearly indicated that the novel bacterium represents a separate genus. Based on phenotypic and phylogenetic considerations, it is proposed that the unknown bacterium from pig semen be classified as a new genus and species, Allofustis seminis gen. nov., sp. nov. The type strain is strain 01-570-1(T) (=CCUG 45438(T)=CIP 107425(T))

Actinobaculum urinale sp. nov., from human urine

A hitherto undescribed Actinomyces-like bacterium was isolated from human urine. Based on its biochemical characteristics, the unidentified bacterium did not correspond to any currently described Actinomyces species or related taxa. Comparative 16S rRNA gene sequencing showed that the unknown bacterium exhibits a specific phylogenetic association with the genus Actinobaculum, but a sequence divergence of > 5% from the two currently recognized members of this genus, Actinobaculum schaalii and Actinobaculum suis, demonstrates that it represents a distinct species. Based on both phenotypic and 16S rRNA gene sequence considerations, it is proposed that the unknown bacterium from urine should be classified as a novel species, Actinobaculum urinale sp. nov. The type strain of Actinobaculum urinale is CCUG 46093(T) (= CIP 107424(T))