Contact tracing following measles exposure on three international flights, Germany, 2017.

When a person with contagious measles has travelled by aircraft, European guidelines recommend contact tracing of passengers and crew within 5 days of exposure for post-exposure prophylaxis (PEP), and within 12 days of exposure for informing passengers and crew, in order to prevent further transmissions. To be effective, contact tracing requires prompt diagnosis, immediate notification of public health authorities and rapid availability of passenger contact data. We report two events of contact tracing initiated in Germany after two individuals with measles travelled on three international flights. In one event, contact tracing was initiated late because laboratory confirmation of a clinically diagnosed measles case was awaited unnecessarily. Accessing passenger contact data was difficult in both events because of data protection issues with the airline which was not based in Germany. In both events, passengers were not reached in time to provide PEP, and one event resulted in at least two secondary measles cases. As all passengers were reached before the incubation period ended, tertiary cases were most probably prevented. Public health authorities and the transport sector must collaborate to resolve competing legal regulations for infection prevention and data protection, to simplify and accelerate identification of air travellers exposed to communicable diseases.

Planktomarina temperata gen. nov., sp. nov., belonging to the globally distributed RCA cluster of the marine Roseobacter clade, isolated from the German Wadden Sea.

Four heterotrophic bacterial strains belonging to the globally distributed marine RCA (Roseobacter clade-affiliated) cluster (family Rhodobacteraceae, class Alphaproteobacteria) were obtained from coastal seawater samples. Strain RCA23(T) was isolated from a 10(-7) dilution culture inoculated with seawater from the German Wadden Sea (southern North Sea), reflecting the high abundance of RCA bacteria in this habitat. Strains IMCC1909, IMCC1923 and IMCC1933 were isolated from diluted seawater (10(-3)) of the Yellow Sea, South Korea. Based on 16S rRNA gene sequence comparison, Octadecabacter antarcticus 307(T) is the closest described relative of the RCA strains, with 95.4-95.5 % sequence similarity. Cells of RCA23(T), IMCC1909, IMCC1923 and IMCC1933 are small motile rods requiring sodium ions. Optimal growth of RCA23(T) occurs at 25 °C and within a very narrow pH range (pH 7-8, optimum pH 7.5). The DNA G+C base content of RCA23(T) is 53.67 mol%. The major respiratory lipoquinone is ubiquinone-10 (Q-10) and the dominant fatty acids (>1 %) are 12 : 1 3-OH, 16 : 1ω7c, 16 : 0, 18 : 1ω7c, 18 : 0 and 11-methyl 18 : 1ω7c. The polar lipid pattern indicated the presence of phosphatidylglycerol, two unidentified aminolipids and two unidentified phospholipids. On marine agar, RCA23(T) forms non-pigmented, transparent to light beige, small (<1 mm), circular, convex colonies. Strain RCA23(T) harbours all genes for the production of bacteriochlorophyll a (BChl a). Genes encoding the light-harvesting reaction centre of BChl a (pufM) were identified in all RCA strains. No visible pigmentation was observed for any of the strains under laboratory conditions, but spectrophotometric analysis revealed weak production of BChl a by RCA23(T). Morphological, physiological and genotypic features of strain RCA23(T) suggest that it represents a novel species of a new genus within the Rhodobacteraceae, for which we propose the name Planktomarina temperata gen. nov., sp. nov., described previously by Giebel et al. [ISME J 5 (2011), 8-19] as 'Candidatus Planktomarina temperata'. The type strain of Planktomarina temperata is RCA23(T) ( = DSM 22400(T) = JCM 18269(T)).

Phaeobacter gallaeciensis genomes from globally opposite locations reveal high similarity of adaptation to surface life.

Phaeobacter gallaeciensis, a member of the abundant marine Roseobacter clade, is known to be an effective colonizer of biotic and abiotic marine surfaces. Production of the antibiotic tropodithietic acid (TDA) makes P. gallaeciensis a strong antagonist of many bacteria, including fish and mollusc pathogens. In addition to TDA, several other secondary metabolites are produced, allowing the mutualistic bacterium to also act as an opportunistic pathogen. Here we provide the manually annotated genome sequences of the P. gallaeciensis strains DSM 17395 and 2.10, isolated at the Atlantic coast of north western Spain and near Sydney, Australia, respectively. Despite their isolation sites from the two different hemispheres, the genome comparison demonstrated a surprisingly high level of synteny (only 3% nucleotide dissimilarity and 88% and 93% shared genes). Minor differences in the genomes result from horizontal gene transfer and phage infection. Comparison of the P. gallaeciensis genomes with those of other roseobacters revealed unique genomic traits, including the production of iron-scavenging siderophores. Experiments supported the predicted capacity of both strains to grow on various algal osmolytes. Transposon mutagenesis was used to expand the current knowledge on the TDA biosynthesis pathway in strain DSM 17395. This first comparative genomic analysis of finished genomes of two closely related strains belonging to one species of the Roseobacter clade revealed features that provide competitive advantages and facilitate surface attachment and interaction with eukaryotic hosts.

Comparative genome analysis and genome-guided physiological analysis of Roseobacter litoralis.

BACKGROUND: Roseobacter litoralis OCh149, the type species of the genus, and Roseobacter denitrificans OCh114 were the first described organisms of the Roseobacter clade, an ecologically important group of marine bacteria. Both species were isolated from seaweed and are able to perform aerobic anoxygenic photosynthesis. RESULTS: The genome of R. litoralis OCh149 contains one circular chromosome of 4,505,211 bp and three plasmids of 93,578 bp (pRLO149_94), 83,129 bp (pRLO149_83) and 63,532 bp (pRLO149_63). Of the 4537 genes predicted for R. litoralis, 1122 (24.7%) are not present in the genome of R. denitrificans. Many of the unique genes of R. litoralis are located in genomic islands and on plasmids. On pRLO149_83 several potential heavy metal resistance genes are encoded which are not present in the genome of R. denitrificans. The comparison of the heavy metal tolerance of the two organisms showed an increased zinc tolerance of R. litoralis. In contrast to R. denitrificans, the photosynthesis genes of R. litoralis are plasmid encoded. The activity of the photosynthetic apparatus was confirmed by respiration rate measurements, indicating a growth-phase dependent response to light. Comparative genomics with other members of the Roseobacter clade revealed several genomic regions that were only conserved in the two Roseobacter species. One of those regions encodes a variety of genes that might play a role in host association of the organisms. The catabolism of different carbon and nitrogen sources was predicted from the genome and combined with experimental data. In several cases, e.g. the degradation of some algal osmolytes and sugars, the genome-derived predictions of the metabolic pathways in R. litoralis differed from the phenotype. CONCLUSIONS: The genomic differences between the two Roseobacter species are mainly due to lateral gene transfer and genomic rearrangements. Plasmid pRLO149_83 contains predominantly recently acquired genetic material whereas pRLO149_94 was probably translocated from the chromosome. Plasmid pRLO149_63 and one plasmid of R. denitrifcans (pTB2) seem to have a common ancestor and are important for cell envelope biosynthesis. Several new mechanisms of substrate degradation were indicated from the combination of experimental and genomic data. The photosynthetic activity of R. litoralis is probably regulated by nutrient availability.

Distribution of Roseobacter RCA and SAR11 lineages in the North Sea and characteristics of an abundant RCA isolate.

The Roseobacter group and SAR11 clade constitute high proportions of the marine bacterioplankton, but only scarce information exists on the abundance of distinct populations of either lineage. Therefore, we quantified the abundance of the largest cluster of the Roseobacter group, the RCA (Roseobacter clade affiliated) cluster together with the SAR11 clade by quantitative PCR in the southern and eastern North Sea. The RCA cluster constituted up to 15 and 21% of total bacterial 16S ribosomal RNA (rRNA) genes in September 2005 and May 2006, respectively. At a few stations, the RCA cluster exceeded the SAR11 clade, whereas at most stations, SAR11 constituted higher fractions with maxima of 37%. In most samples, only one RCA ribotype was detected. RCA abundance was positively correlated with phaeopigments, chlorophyll, dissolved and particulate organic carbon (POC), turnover rates of dissolved free amino acids (DFAAs), temperature, and negatively correlated with salinity. The SAR11 clade was only correlated with POC (negatively, May) and with DFAA turnover rates (positively, September). An abundant RCA strain, 'Candidatus Planktomarina temperata', was isolated from the southern North Sea. This strain has an identical 16S rRNA gene sequence to the dominant RCA ribotype. Detection of the pufM gene, coding for a subunit of the reaction center of bacteriochlorophyll a, indicates the potential of the isolate for aerobic anoxygenic photosynthesis. Our study shows that a distinct population of the RCA cluster constitutes an abundant bacterioplankton group in a neritic sea of the temperate zone and indicates that this population has an important role during decaying phytoplankton blooms.

The complete genome sequence of the algal symbiont Dinoroseobacter shibae: a hitchhiker's guide to life in the sea.

Dinoroseobacter shibae DFL12(T), a member of the globally important marine Roseobacter clade, comprises symbionts of cosmopolitan marine microalgae, including toxic dinoflagellates. Its annotated 4 417 868 bp genome sequence revealed a possible advantage of this symbiosis for the algal host. D. shibae DFL12(T) is able to synthesize the vitamins B(1) and B(12) for which its host is auxotrophic. Two pathways for the de novo synthesis of vitamin B(12) are present, one requiring oxygen and the other an oxygen-independent pathway. The de novo synthesis of vitamin B(12) was confirmed to be functional, and D. shibae DFL12(T) was shown to provide the growth-limiting vitamins B(1) and B(12) to its dinoflagellate host. The Roseobacter clade has been considered to comprise obligate aerobic bacteria. However, D. shibae DFL12(T) is able to grow anaerobically using the alternative electron acceptors nitrate and dimethylsulfoxide; it has the arginine deiminase survival fermentation pathway and a complex oxygen-dependent Fnr (fumarate and nitrate reduction) regulon. Many of these traits are shared with other members of the Roseobacter clade. D. shibae DFL12(T) has five plasmids, showing examples for vertical recruitment of chromosomal genes (thiC) and horizontal gene transfer (cox genes, gene cluster of 47 kb) possibly by conjugation (vir gene cluster). The long-range (80%) synteny between two sister plasmids provides insights into the emergence of novel plasmids. D. shibae DFL12(T) shows the most complex viral defense system of all Rhodobacterales sequenced to date.