Low nitrous oxide production through nitrifier-denitrification in intermittent-feed high-rate nitritation reactors

Nitrous oxide (N2O) production from autotrophic nitrogen conversion processes, especially nitritation systems, can be significant, requires understanding and calls for mitigation. In this study, the rates and pathways of N2O production were quantified in two lab-scale sequencing batch reactors operated with intermittent feeding and demonstrating long-term and high-rate nitritation. The resulting reactor biomass was highly enriched in ammonia-oxidizing bacteria, and converted ∼93 ± 14% of the oxidized ammonium to nitrite. The low DO set-point combined with intermittent feeding was sufficient to maintain high nitritation efficiency and high nitritation rates at 20–26 °C over a period of ∼300 days. Even at the high nitritation efficiencies, net N2O production was low (∼2% of the oxidized ammonium). Net N2O production rates transiently increased with a rise in pH after each feeding, suggesting a potential effect of pH on N2O production. In situ application of 15N labeled substrates revealed nitrifier denitrification as the dominant pathway of N2O production. Our study highlights operational conditions that minimize N2O emission from two-stage autotrophic nitrogen removal systems

Defining the Pseudomonas Genus: Where Do We Draw the Line with Azotobacter?

The genus Pseudomonas has gone through many taxonomic revisions over the past 100 years, going from a very large and diverse group of bacteria to a smaller, more refined and ordered list having specific properties. The relationship of the Pseudomonas genus to Azotobacter vinelandii is examined using three genomic sequence-based methods. First, using 16S rRNA trees, it is shown that A. vinelandii groups within the Pseudomonas close to Pseudomonas aeruginosa. Genomes from other related organisms (Acinetobacter, Psychrobacter, and Cellvibrio) are outside the Pseudomonas cluster. Second, pan genome family trees based on conserved gene families also show A. vinelandii to be more closely related to Pseudomonas than other related organisms. Third, exhaustive BLAST comparisons demonstrate that the fraction of shared genes between A. vinelandii and Pseudomonas genomes is similar to that of Pseudomonas species with each other. The results of these different methods point to a high similarity between A. vinelandii and the Pseudomonas genus, suggesting that Azotobacter might actually be a Pseudomonas

Comparative Genomic Characterization of Francisella tularensis Strains Belonging to Low and High Virulence Subspecies

Tularemia is a geographically widespread, severely debilitating, and occasionally lethal disease in humans. It is caused by infection by a gram-negative bacterium, Francisella tularensis. In order to better understand its potency as an etiological agent as well as its potential as a biological weapon, we have completed draft assemblies and report the first complete genomic characterization of five strains belonging to the following different Francisella subspecies (subsp.): the F. tularensis subsp. tularensis FSC033, F. tularensis subsp. holarctica FSC257 and FSC022, and F. tularensis subsp. novicida GA99-3548 and GA99-3549 strains. Here, we report the sequencing of these strains and comparative genomic analysis with recently available public Francisella sequences, including the rare F. tularensis subsp. mediasiatica FSC147 strain isolate from the Central Asian Region. We report evidence for the occurrence of large-scale rearrangement events in strains of the holarctica subspecies, supporting previous proposals that further phylogenetic subdivisions of the Type B clade are likely. We also find a significant enrichment of disrupted or absent ORFs proximal to predicted breakpoints in the FSC022 strain, including a genetic component of the Type I restriction-modification defense system. Many of the pseudogenes identified are also disrupted in the closely related rarely human pathogenic F. tularensis subsp. mediasiatica FSC147 strain, including modulator of drug activity B (mdaB) (FTT0961), which encodes a known NADPH quinone reductase involved in oxidative stress resistance. We have also identified genes exhibiting sequence similarity to effectors of the Type III (T3SS) and components of the Type IV secretion systems (T4SS). One of the genes, msrA2 (FTT1797c), is disrupted in F. tularensis subsp. mediasiatica and has recently been shown to mediate bacterial pathogen survival in host organisms. Our findings suggest that in addition to the duplication of the Francisella Pathogenicity Island, and acquisition of individual loci, adaptation by gene loss in the more recently emerged tularensis, holarctica, and mediasiatica subspecies occurred and was distinct from evolutionary events that differentiated these subspecies, and the novicida subspecies, from a common ancestor. Our findings are applicable to future studies focused on variations in Francisella subspecies pathogenesis, and of broader interest to studies of genomic pathoadaptation in bacteria

“My cancer is not my deepest concern”: life course disruption influencing patient pathways and health care needs among persons living with colorectal cancer

Anita Salamonsen,1 Mona A Kiil,2 Agnete Egilsdatter Kristoffersen,1 Trine Stub,1 Gro R Berntsen1,3 1National Research Center in Complementary and Alternative Medicine, Department of Community Medicine, UiT the Arctic University of Norway, Tromsø, Norway; 2Department of Clinical Medicine, UiT the Arctic University of Norway, Tromsø, Norway; 3Norwegian Center for eHealth Research, University Hospital of Northern Norway, Tromsø, Norway Background: The concept of “patient pathways” in cancer care is most commonly understood as clinical pathways, operationalized as standardized packages of health care based on guidelines for the condition in question. In this understanding, patient pathways do not address multimorbidity or patient experiences and preferences. This study explored patient pathways understood as the individual and cultural life course, which includes both life and health events. The overall aim was to contribute to supportive and targeted cancer care. Materials and methods: Nine Norwegian patients recently diagnosed with rectal cancer Tumor-Node-Metastasis stage I–III participated in qualitative interviews, five times over 1 year. Five patients later participated in a workshop where they made illustrations of and discussed patient pathways. Results: Patient pathways including both health and life events were illustrated and described as complex and circular. Stress, anxiety, and depression caused by life events had significant disruptive effects and influenced patient-defined health care needs. The participants experienced the Norwegian public health service as focused on hospital-based standardized cancer care. They expressed unmet health care needs in terms of emotional and practical support in their everyday life with cancer, and some turned to complementary and alternative medicine. Conclusion: This study suggests that acknowledging life course disruption before cancer diagnosis may have significant relevance for understanding complex patient pathways and individual health care needs. Approaching patient pathways as individual and socially constructed may contribute important knowledge to support targeted cancer care. Keywords: biographical disruption, colorectal cancer, life course disruption, Norway, patient-centeredness, patient pathways, person-centered care, supportive cancer care, unmet health care needs, complementary and alternative medicin

Prevalence, and health- and sociodemographic associations for visits to traditional and complementary medical providers in the seventh survey of the Tromsø study

Background - Patient-centered culturally sensitive health care (PC-CSHC) has emerged as a primary approach to health care. This care focuses on the cultural diversity of the patients rather than the views of the health care professionals. PC-CSHC enables the patient to feel comfortable, respected, and trusted in the health care delivery process. As users of traditional and complementary medicine (T&CM) rarely inform their conventional health care providers of such use, the providers need to identify the users of T&CM themselves to avoid negative interaction with conventional medicine and to be able to provide them with PC-CSHC. Since the patterns of traditional medicine (TM) use are different to those of complementary medicine (CM), the aim of this study was to investigate the prevalence, and the health- and sociodemographic associations for visits to TM- and CM providers in an urban population. Method - The data were collected through two self-administrated questionnaires from the seventh survey of the Tromsø Study, a population-based cohort study conducted in 2015–2016. All inhabitants of Tromsø aged 40 or above were invited (n = 32,591) and n = 21,083 accepted the invitation (response rate 65%). Pearson chi-square tests and one-way ANOVA tests were used to describe differences between the groups whereas binary logistic regressions were used for adjusted values. Results - The results revealed that 2.5% of the participants had seen a TM provider, 8.5% had seen a CM provider whereas 1% had visited both a TM and a CM provider during a 12-month period. TM users tended to be older, claim that religion was more important to them, have poorer economy and health, and have lower education compared to CM users. We found that more than 90% of the participants visiting T&CM providers also used conventional medicine. Conclusion - A considerable number of the participants in this study employed parallel health care modalities including visits to conventional, traditional, and complementary medicine providers. To offer patient-centered culturally sensitive health care that is tailored to the patients’ treatment philosophy and spiritual needs, conventional health care providers need knowledge about, and respect for their patients’ use of parallel health care systems