Although mutualistic associations between animals and microbial symbionts are widespread in nature, the mechanisms that have promoted their evolutionary persistence remain poorly understood. A ...vertical mode of symbiont transmission (from parents to offspring) is thought to ensure partner fidelity and stabilization, although the efficiency of vertical transmission has rarely been investigated, especially in cases where hosts harbour a diverse microbial community. Here we evaluated vertical transmission rates of cellulolytic gut oxymonad and parabasalid protists in the wood‐feeding termite Reticulitermes grassei. We sequenced amplicons of the 18S rRNA gene of protists from 24 colonies of R. grassei collected in two populations. For each colony, the protist community was characterized from the gut of 14 swarming reproductives and from a pool of 10 worker guts. A total of 98 operational taxonomic units belonging to 13 species‐level taxa were found. The vertical transmission rate was estimated for each protist present in a colony based on its frequency among the reproductives. The results revealed that transmission rates were high, with an average of 0.897 (±0.164) per protist species. Overall, the protist community did not differ between reproductive sexes, suggesting that both the queen and the king could contribute to the gut microbiota of the offspring. A positive relationship between the transmission rate of protists and their prevalence within populations was also detected. However, transmission rates alone do not explain the prevalence of protists. In conclusion, these findings reveal key forces behind a conserved, multispecies mutualism, raising further questions on the roles of horizontal transfer and negative selection in shaping symbiont prevalence.
Summary Background Health anxiety has been treated by therapists expert in cognitive behaviour therapy with some specific benefit in some patients referred to psychological services. Those in ...hospital care have been less often investigated. Following a pilot trial suggesting efficacy we carried out a randomised study in hospital medical clinics. Methods We undertook a multicentre, randomised trial on health anxious patients attending cardiac, endocrine, gastroenterological, neurological, and respiratory medicine clinics in secondary care. We included those aged 16–75 years, who satisfied the criteria for excessive health anxiety, and were resident in the area covered by the hospital, were not under investigation for new pathology or too medically unwell to take part. We used a computer-generated random scheme to allocate eligible medical patients to an active treatment group of five-to-ten sessions of adapted cognitive behaviour therapy (CBT-HA group) delivered by hospital-based therapists or to standard care in the clinics. The primary outcome was change in health anxiety symptoms measured by the Health Anxiety Inventory at 1 year and the main secondary hypothesis was equivalence of total health and social care costs over 2 years, with an equivalence margin of £150. Analysis was by intention to treat. The study is registered with controlled-trials.com , ISRCTN14565822. Findings Of 28 991 patients screened, 444 were randomly assigned to receive either adapted cognitive behaviour therapy (CBT-HA group, 219 participants) or standard care (standard care group, 225), with 205 participants in the CBT-HA group and 212 in the standard care group included in the analyses of the primary endpoints. At 1 year, improvement in health anxiety in the patients in the CBT-HA group was 2·98 points greater than in those in the standard care group (95% CI 1·64–4·33, p<0·0001), and twice as many patients receiving cognitive behaviour therapy achieved normal levels of health anxiety compared with those in the control group (13·9% vs 7·3%; odds ratio 2·15, 95% CI 1·09–4·23, p=0·0273). Similar differences were observed at 6 months and 2 years, and there were concomitant reductions in generalised anxiety and, to a lesser extent, depression. Of nine deaths, six were in the control group; all were due to pre-existing illness. Social functioning or health-related quality of life did not differ significantly between groups. Equivalence in total 2-year costs was not achieved, but the difference was not significant (adjusted mean difference £156, 95% CI −1446 to 1758, p=0·848). Interpretation This form of adapted cognitive behaviour therapy for health anxiety led to sustained symptomatic benefit over 2 years, with no significant effect on total costs. It deserves wider application in medical care. Funding National Institute for Health Research Health Technology Assessment Programme.
Health anxiety is an under-recognised but frequent cause of distress that is potentially treatable, but there are few studies in secondary care.
To determine the clinical effectiveness and ...cost-effectiveness of a modified form of cognitive-behaviour therapy (CBT) for health anxiety (CBT-HA) compared with standard care in medical outpatients.
Randomised controlled trial.
Five general hospitals in London, Middlesex and Nottinghamshire.
A total of 444 patients aged 16-75 years seen in cardiology, endocrinology, gastroenterology, neurology and respiratory medicine clinics who scored ≥ 20 points on the Health Anxiety Inventory (HAI) and satisfied diagnostic requirements for hypochondriasis. Those with current psychiatric disorders were excluded, but those with concurrent medical illnesses were not.
Cognitive-behaviour therapy for health anxiety - between 4 and 10 1-hour sessions of CBT-HA from a health professional or psychologist trained in the treatment. Standard care was normal practice in primary and secondary care.
Primary - researchers masked to allocation assessed patients at baseline, 3, 6, 12, 24 months and 5 years. The primary outcome was change in the HAI score between baseline and 12 months. Main secondary outcomes - costs of care in the two groups after 24 and 60 months, change in health anxiety (HAI), generalised anxiety and depression Hospital Anxiety and Depression Scale (HADS) scores, social functioning using the Social Functioning Questionnaire and quality of life using the EuroQol-5 Dimensions (EQ-5D), at 6, 12, 24 and 60 months, and deaths over 5 years.
Of the 28,991 patients screened over 21 months, 5769 had HAI scores of ≥ 20 points. Improvement in HAI scores at 3 months was significantly greater in the CBT-HA group (mean number of sessions = 6) than in the standard care, and this was maintained over the 5-year period (overall
< 0.0001), with no loss of efficacy between 2 and 5 years. Differences in the generalised anxiety (
= 0.0018) and depression scores (
= 0.0065) on the HADS were similar in both groups over the 5-year period. Gastroenterology and cardiology patients showed the greatest CBT gains. The outcomes for nurses were superior to those of other therapists. Deaths (
= 24) were similar in both groups; those in standard care died earlier than those in CBT-HA. Patients with mild personality disturbance and higher dependence levels had the best outcome with CBT-HA. Total costs were similar in both groups over the 5-year period (£12,590.58 for CBT-HA; £13,334.94 for standard care). CBT-HA was not cost-effective in terms of quality-adjusted life-years, as measured using the EQ-5D, but was cost-effective in terms of HAI outcomes, and offset the cost of treatment.
Many eligible patients were not randomised and the population treated may not be representative.
CBT-HA is a highly effective treatment for pathological health anxiety with lasting benefit over 5 years. It also improves generalised anxiety and depressive symptoms more than standard care. The presence of personality abnormality is not a bar to successful outcome. CBT-HA may also be cost-effective, but the high costs of concurrent medical illnesses obscure potential savings. This treatment deserves further research in medical settings.
Current Controlled Trials ISRCTN14565822.
This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in
; Vol. 21, No. 50. See the NIHR Journals Library website for further project information.
Parental care is a major component of reproduction in social organisms, particularly during the foundation steps. Because investment into parental care is often costly, each parent is predicted to ...maximize its fitness by providing less care than its partner. However, this sexual conflict is expected to be low in species with lifelong monogamy, because the fitness of each parent is typically tied to the other's input. Somewhat surprisingly, the outcomes of this tug‐of‐war between maternal and paternal investments have received important attention in vertebrate species, but remain less known in invertebrates. In this study, we investigated how queens and kings share their investment into parental care and other social interactions during colony foundation in two termites with lifelong monogamy: the invasive species Reticulitermes flavipes and the native species R. grassei. Behaviors of royal pairs were recorded during six months using a non‐invasive approach. Our results showed that queens and kings exhibit unbalanced investment in terms of grooming, antennation, trophallaxis, and vibration behavior. Moreover, both parents show behavioral differences toward their partner or their descendants. Our results also revealed differences among species, with R. flavipes exhibiting shorter periods of grooming and antennation toward eggs or partners. They also did more stomodeal trophallaxis and less vibration behavior. Overall, this study emphasizes that despite lifelong monogamy, the two parents are not equally involved in the measured forms of parental care and suggests that kings might be specialized in other tasks. It also indicates that males could play a central, yet poorly studied role in the evolution and maintenance of the eusocial organization.
Parental care is a major component of reproduction in social organisms, particularly during the foundation steps. Our results showed that queens and kings in two termites with lifelong monogamy exhibit unbalanced investment in parental care. It also indicates that males could play a central, yet poorly studied role in the evolution and maintenance of the eusocial organization.
The co-evolutionary pathways followed by hosts and parasites strongly depend on the adaptive potential of antagonists and its underlying genetic architecture. Geographically structured populations of ...interacting species often experience local differences in the strength of reciprocal selection pressures, which can result in a geographic mosaic of co-evolution. One example of such a system is the boreo-montane social wasp Polistes biglumis and its social parasite Polistes atrimandibularis, which have evolved local defense and counter-defense mechanisms to match their antagonist. In this work, we study spatial genetic structure of P. biglumis and P. atrimandibularis populations at local and regional scales in the Alps, by using nuclear markers (DNA microsatellites, AFLP) and mitochondrial sequences. Both the host and the parasite populations harbored similar amounts of genetic variation. Host populations were not genetically structured at the local scale, but geographic regions were significantly differentiated from each other in both the host and the parasite in all markers. The net dispersal inferred from genetic differentiation was similar in the host and the parasite, which may be due to the annual migration pattern of the parasites between alpine and lowland populations. Thus, the apparent dispersal barriers (i.e., high mountains) do not restrict gene flow as expected and there are no important gene flow differences between the species, which contradict the hypothesis that restricted gene flow is required for local adaptations to evolve.
Termites are social insects that can also be major pests. A well-known problem species is the subterranean termite,
. It is invasive in France and is thought to have arrived from Louisiana during the ...18th century. While the putative source of French populations has been identified, little is known about how the termite spread following its establishment. Here, we examined expansion patterns at different spatial scales in urban areas to clarify how
spread in France. Based on our analyses of phylogeography and population genetics, results suggest a scenario of successive introductions into the Charente-Maritime region, on the Atlantic Coast. Two major expansion fronts formed: one that spread toward the northeast and the other toward the southeast. At the regional scale, different spatial and genetic distribution patterns were observed: there was heterogeneity in Île-de-France and aggregation in Centre-Val de Loire. At the local scale, we found that our three focal urban sites each formed a single large colony that contained several secondary reproductives. Our findings represent a second step in efforts to reconstruct termite's invasion dynamics. They also highlight the role that may have been played by the French railway network in transporting termites over long distances.
Reticulitermes urbis is a recently described termite species that has probably been introduced into Western Europe where it has been found exclusively in urban areas. However, little is known about ...the geographic distribution and origin of R. urbis. This study was undertaken to determine whether this species was introduced from the Balkans. A parsimony network did not show any association between mtDNA haplotypes and geographic regions suggesting that western European populations were the result of human-mediated dispersion. Variation patterns of the COI and COII regions as well as microsatellites showed that the genetic diversity of Western European colonies was lower than for colonies collected in the Balkans, suggesting that the introduced populations suffered from a founder effect. As observed in the introduced populations of R. flavipes, all colonies of R. urbis had an extended-family structure with several reproductives. These results support the scenario that this termite was introduced into Western Europe.
Abnormal health anxiety, also called hypochondriasis, has been successfully treated by cognitive behaviour therapy (CBT) in patients recruited from primary care, but only one pilot trial has been ...carried out among those attending secondary medical clinics where health anxiety is likely to be more common and have a greater impact on services. The CHAMP study extends this work to examine both the clinical and cost effectiveness of CBT in this population.
The study is a randomized controlled trial with two parallel arms and equal randomization of 466 eligible patients (assuming a 20% drop-out) to an active treatment group of 5-10 sessions of cognitive behaviour therapy and to a control group. The aim at baseline, after completion of all assessments but before randomization, was to give a standard simple explanation of the nature of health anxiety for all participants. Subsequently the control group was to receive whatever care might usually be available in the clinics, which is normally a combination of clinical assessment, appropriate tests and reassurance. Those allocated to the active treatment group were planned to receive between 5 and 10 sessions of an adapted form of cognitive behaviour therapy based on the Salkovskis/Warwick model, in which a set of treatment strategies are chosen aimed at helping patients understand the factors that drive and maintain health anxiety. The therapy was planned to be given by graduate research workers, nurses or other health professionals trained for this intervention whom would also have their competence assessed independently during the course of treatment. The primary outcome is reduction in health anxiety symptoms after one year and the main secondary outcome is the cost of care after two years.
This represents the first trial of adapted cognitive behaviour therapy in health anxiety that is large enough to test not only the clinical benefits of treatment but also whether the cost of treatment is offset by savings from reduced use of other health services in comparison to the control group.Cognitive behaviour therapy for Health Anxiety in Medical Patients (CHAMP) TRIAL REGISTRATION: Current Controlled Trials ISRCTN14565822.
Chronic obstructive pulmonary disease (COPD) is a costly long-term condition associated with frequent Accident and Emergency (A&E) and hospital admissions. Psychological difficulties and inadequate ...self-management can amplify this picture.
To compare a cognitive-behavioural manual versus information booklets (IB) on health service use, mood and health status.
Two hundred and twenty-two COPD patients were randomly allocated to receive either the COPD breathlessness manual (CM) or IB. They were instructed to work through their programme at home, over 5 weeks. Guidance from a facilitator was provided at an initial home visit plus two telephone call follow-ups.
After 12 months, total A&E visits had reduced by 42% in the CM group, compared with a 16% rise in the IB group. The odds of people in the IB group attending A&E 12 months post-intervention was 1.9 times higher than for the CM group (CI 1.05-3.53). Reduction in hospital admissions and bed days were greatest in the CM group. At 6 months, there were significantly greater improvements in anxiety (F (2,198)=5.612, P=0.004), depression (F (1.8,176.1)=10.697, P⩽0.001) and dyspnoea (F (2,198)=18.170, P⩽0.001) in the CM group. Estimated savings at 12 months were greatest in the CM group, amounting to £30k or £270 per participant.
The COPD manual, which addresses physical and mental health, is a straightforward cost-effective intervention that is worth offering to COPD patients within primary or secondary care.
Although much research has been carried out into European Reticulitermes taxonomy in recent years, there is still much discussion about phylogenetic relationships. This study investigated the ...evolution from intra- to interspecific phylogeny in the island subspecies Reticulitermes lucifugus corsicus and threw new light on this phenomenon. An integrative approach based on microsatellites and mitochondrial and nuclear DNA sequences was used to analyze samples taken from a wide area around the Tyrrhenian sea and showed how the subspecies evolved from its origins to its most recent form on continental coasts.
According to mitochondrial phylogeny and molecular clock calculations, island and continental taxa diverged significantly by vicariance in the Pleistocene glacial period. However, more recently, numerous migrations, certainly human-mediated, affected the structure of the populations. This study provided evidence of direct hybridization and multiple introgressions which occurred in several hybrid areas. Analysis using STRUCTURE based on microsatellite data identified a population in Provence (France) which differed considerably (Fst = 0.477) from populations on the island of Corsica and in Tuscany in the Italian peninsula. This new population, principally distributed in urban areas, is highly heterogeneous especially within the ITS2 regions where homogenization by concerted evolution does not appear to have been completed.
This study provides an unusual picture of genetic interaction between termite populations in the Tyrrhenian area and suggests that more attention should be paid to the role of introgression and human impact on the recent evolution of European termites.
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