Picocyanobacteria represented by Prochlorococcus and Synechococcus have an important role in oceanic carbon fixation and nutrient cycling. In this study, we compared the community composition of picocyanobacteria from diverse marine ecosystems ranging from estuary to open oceans, tropical to polar oceans and surface to deep water, based on the sequences of 16S-23S rRNA internal transcribed spacer (ITS). A total of 1339 ITS sequences recovered from 20 samples unveiled diverse and several previously unknown clades of Prochlorococcus and Synechococcus. Six high-light (HL)-adapted Prochlorococcus clades were identified, among which clade HLVI had not been described previously. Prochlorococcus clades HLIII, HLIV and HLV, detected in the Equatorial Pacific samples, could be related to the HNLC clades recently found in the high-nutrient, low-chlorophyll (HNLC), iron-depleted tropical oceans. At least four novel Synechococcus clades (out of six clades in total) in subcluster 5.3 were found in subtropical open oceans and the South China Sea. A niche partitioning with depth was observed in the Synechococcus subcluster 5.3. Members of Synechococcus subcluster 5.2 were dominant in the high-latitude waters (northern Bering Sea and Chukchi Sea), suggesting a possible cold-adaptation of some marine Synechococcus in this subcluster. A distinct shift of the picocyanobacterial community was observed from the Bering Sea to the Chukchi Sea, which reflected the change of water temperature. Our study demonstrates that oceanic systems contain a large pool of diverse picocyanobacteria, and further suggest that new genotypes or ecotypes of picocyanobacteria will continue to emerge, as microbial consortia are explored with advanced sequencing technology.

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Objective: Hospital and laboratory data indicate that human T‐lymphotropic virus type 1 (HTLV‐1) is endemic to central Australia, but no community‐based studies of its prevalence or disease burden have been reported. We determined the prevalence rates of HTLV‐1 infection and of HTLV‐1‐associated diseases in a remote Indigenous community. Setting: A remote Northern Territory community. Design: All residents were asked to complete a health survey and offered a limited clinical examination, together with serological tests for HTLV‐1 and Strongyloides, and HTLV‐1 proviral load (PVL) assessment. Main outcome measures: HTLV‐1 seropositivity rates; HTLV‐1 PVL (copies/105 peripheral blood leucocytes [PBL]); presentation with HTLV‐1‐related clinical disease. Results: HTLV‐1 serostatus was determined for 97 of 138 residents (70%). The prevalence of HTLV‐1 infection was significantly higher among adults (30 of 74 people tested) than children (1 of 23; P = 0.001). Nine of 30 HTLV‐1‐positive adults had a clinical syndrome that was potentially attributable to HTLV‐1 infection (chronic lung disease, seven; symptomatic strongyloidiasis, two). The median HTLV‐1 PVL was significantly higher for adults with chronic lung disease than for those who were asymptomatic (chronic lung disease, 649 copies/105 PBL [IQR, 162–2220]; asymptomatic adults, 40 copies/105 PBL [IQR, 0.9–229]; P = 0.017). Ten of 72 adults tested were seropositive for Strongyloides (six of 28 HTLV‐1‐positive participants and four of 44 HTLV‐1‐negative participants; P = 0.17), as were three of 15 children tested; the three children were HTLV‐1‐negative. Conclusion: The prevalence of HTLV‐1 infection and the rate of disease potentially attributable to HTLV‐1 were high among adults in this remote community.

To determine the prevalence, associated factors, and relationships between symptoms of depression, symptoms of posttraumatic stress (PTS), and relationship distress in mothers and fathers of very preterm (VPT) infants (< 32 weeks). Mothers (n = 323) and fathers (n = 237) completed self-report measures on demographic and outcome variables at 38 days (SD = 23.1, range 9-116) postpartum while their infants were still hospitalised. Of mothers, 46.7% had a moderate to high likelihood of depression, 38.1% had moderate to severe symptoms of PTS, and 25.1% were in higher than average relationship distress. The corresponding percentages in fathers were 16.9, 23.7, and 27%. Depression was positively associated with having previous children (p = 0.01), speaking little or no English at home (p = 0.01), financial stress (p = 0.03), and recently accessing mental health services (p = 0.003) for mothers, and financial stress (p = 0.005) and not being the primary income earner (p = 0.04) for fathers. Similar associations were found for symptoms of PTS and relationship distress. Being in higher relationship distress increased the risk of depression in both mothers (p < .001) and fathers (p = 0.03), and PTS symptoms in mothers (p = 0.001). For both mothers and fathers, depression was associated with more severe PTS symptoms (p < .001). Fathers of VPT infants should be screened for mental health problems alongside mothers, and postpartum parent support programs for VPT infants should include strategies to improve the couple relationship.