MOLECULAR ECOLOGY OF CHIGGER MITES (ACARI: TROMBICULIDAE) AND ASSOCIATED BACTERIA IN THAILAND

Chiggers are the tiny six-legged larval stage of mites in the family Trombiculidae. These mites, particularly the genus Leptotrombidium, act as important vectors of Orientia tsutsugamushi, the causative agent of scrub typhus disease in the Asia-Pacific region (including Thailand). Although the medical impact of these mites has been recognized in the country due to the increasing incidence of the disease in humans, knowledge of the ecology and epidemiological role of these mites is still very limited to date. A systematic review of mite-associated bacteria was conducted from 193 publications (1964 - January 2015) providing a reference database of bacteria found in mites of agricultural, veterinary and medical importance. Approximately 150 bacterial species were reported from 143 mite species with Cardinium, Wolbachia and Orientia as the dominant genera. Nationwide field sampling of small mammals from 13 locations in Thailand revealed a high diversity of chigger mites. From approximately 16,000 mites isolated from 18 host species examined (1,574 individual animals), 38 chigger species were found including three species new to science (i.e., Trombiculindus kosapani n. sp., Helenicula naresuani n. sp. and Walchia chavali n. sp.) and 10 new records for the first time in the country. Brief taxonomic information for the morphological identification of chiggers is provided. A combination of autofluorescent and brightfield microscopy was demonstrated to be a novel approach to study both the morphology and DNA profile of the same individual chigger. Most chigger species showed low host specificity. The diversity of chiggers on hosts was influenced by host intrinsic (i.e., host phylogeny and maturity) and extrinsic factors (i.e., habitat and geographical location). Chigger species richness and host-chigger network connectance were found to be interrelated variables explaining human scrub typhus incidence in Thailand. Chigger-associated bacteria were investigated for the first time using an Illumina MiSeq 16S rRNA amplicon sequencing approach. DNA of O. tsutsugamushi was detected in the chigger population as expected. In addition to O. tsutsugamushi, Borrelia and Mycobacterium were identified aspotential pathogens of human and animals. Potential symbiotic bacteria of arthropods; e.g., Candidatus Cardinium, Pseudonocardia, Rickettsiella and Wolbachia were also discovered for the first time in chiggers. An important technical limitation was that chigger DNA starting quantity (individual specimens versus pooled mites) was found to have a significant impact on the apparent microbiome profile. These outcomes from the studies of chigger taxonomy and the ecology of host-chigger interactions, as well as the composition of the microbiome in chiggers, are of key importance to the chigger research field, providing essential information for disease epidemiology with vector control implications

Are there any changes in burden and management of communicable diseases in areas affected by Cyclone Nargis?

<p>Abstract</p> <p>Background</p> <p>This study aims to assess the situation of communicable diseases under national surveillance in the Cyclone Nargis-affected areas in Myanmar (Burma) before and after the incident.</p> <p>Methods</p> <p>Monthly data during 2007, 2008 and 2009 from the routine reporting system for disease surveillance of the Myanmar Ministry of Health (MMOH) were reviewed and compared with weekly reporting from the Early Warning and Rapid Response (EWAR) system. Data from some UN agencies, NGOs and Tri-Partite Core Group (TCG) periodic reviews were also extracted for comparisons with indicators from Sphere and the Inter-Agency Standing Committee.</p> <p>Results</p> <p>Compared to 2007 and 2009, large and atypical increases in diarrheal disease and especially dysentery cases occurred in 2008 following Cyclone Nargis. A seasonal increase in ARI reached levels higher than usual in the months of 2008 post-Nargis. The number of malaria cases post-Nargis also increased, but it was less clear if this reflected normal seasonal patterns or was specifically associated with the disaster event. There was no significant change in the occurrence of other communicable diseases in Nargis-affected areas. Except for a small decrease in mortality for diarrheal diseases and ARI in 2008 in Nargis-affected areas, population-based mortality rates for all other communicable diseases showed no significant change in 2008 in these areas, compared to 2007 and 2009. Tuberculosis control programs reached their targets of 70% case detection and 85% treatment success rates in 2007 and 2008. Vaccination coverage rates for DPT 3^rddose and measles remained at high though measles coverage still did not reach the Sphere target of 95% even by 2009. Sanitary latrine coverage in the Nargis-affected area dropped sharply to 50% in the months of 2008 following the incident but then rose to 72% in 2009.</p> <p>Conclusion</p> <p>While the incidence of diarrhea, dysentery and ARI increased post-Nargis in areas affected by the incident, the incidence rate for other diseases and mortality rates did not increase, and normal disease patterns resumed by 2009. This suggests that health services as well as prevention and control measures provided to the Nargis-affected population mitigated what could have been a far more severe health impact.</p

Deterministic processes structure bacterial genetic communities across an urban landscape

Land-use change is predicted to act as a driver of zoonotic disease emergence through human exposure to novel microbial diversity, but evidence for the effects of environmental change on microbial communities in vertebrates is lacking. We sample wild birds at 99 wildlife-livestock-human interfaces across Nairobi, Kenya, and use whole genome sequencing to characterise bacterial genes known to be carried on mobile genetic elements (MGEs) within avian-borne Escherichia coli (n=241). By modelling the diversity of bacterial genes encoding virulence and antimicrobial resistance (AMR) against ecological and anthropogenic forms of urban environmental change, we demonstrate that communities of avian-borne bacterial genes are shaped by the assemblage of co-existing avian, livestock and human communities, and the habitat within which they exist. In showing that non-random processes structure bacterial genetic communities in urban wildlife, these findings suggest that it should be possible to forecast the effects of urban land-use change on microbial diversity

Social Internet of Things and New Generation Computing -- A Survey

Social Internet of Things (SIoT) tries to overcome the challenges of Internet of Things (IoT) such as scalability, trust and discovery of resources, by inspiration from social computing. This survey aims to investigate the research done on SIoT from two perspectives including application domain and the integration to the new computing models. For this, a two-dimensional framework is proposed and the projects are investigated, accordingly. The first dimension considers and classifies available research from the application domain perspective and the second dimension performs the same from the integration to new computing models standpoint. The aim is to technically describe SIoT, to classify related research, to foster the dissemination of state-of-the-art, and to discuss open research directions in this field.Comment: IoT, Social computing, Surve

Impact of Small Body Weight on Tenofovir-Associated Renal Dysfunction in HIV-Infected Patients: A Retrospective Cohort Study of Japanese Patients

BACKGROUND: Treatment with tenofovir is sometimes associated with renal dysfunction. Limited information is available on this side effect in patients with small body weight, although the use of tenofovir will spread rapidly in Asia and Africa, where patients are likely to be of smaller body weight. METHODS: In a single-center cohort, Japanese patients with HIV infection who started tenofovir-containing antiretroviral therapy were retrospectively analyzed. The incidence of tenofovir-associated renal dysfunction, defined as more than 25% decrement of estimated glomerular filtration rate (eGFR) from the baseline, was determined. The effects of small body weight and body mass index (BMI) on tenofovir-associated renal dysfunction, respectively, were estimated in univariate and multivariate Cox hazards models as the primary exposure. Other possible risk factors were evaluated by univariate analysis and those found significant were entered into the multivariate analysis. RESULTS: The median weight of 495 patients was 63 kg. Tenofovir-related renal dysfunction occurred in 97 (19.6%) patients (incidence: 10.5 per 100 person-years). Univariate analysis showed that the incidence of tenofovir-related renal dysfunction was significantly associated with smaller body weight and BMI, respectively (per 5 kg decrement, HR = 1.23; 95% CI, 1.10-1.37; p<0.001)(per 1 kg/m(2) decrement, HR = 1.14; 95% CI, 1.05-1.23; p = 0.001). Old age, high baseline eGFR, low serum creatinine, low CD4 count, high HIV viral load, concurrent nephrotoxic drugs, hepatitis C infection, and current smoking were also associated with tenofovir-related renal dysfunction. Multivariate analysis identified small body weight as a significant risk (adjusted HR = 1.13; 95% CI, 1.01-1.27; p = 0.039), while small BMI had marginal significance (adjusted HR = 1.07; 95% CI 1.00-1.16; p = 0.058). CONCLUSION: The incidence of tenofovir-associated renal dysfunction in Japanese patients was high. Small body weight was identified as an independent risk factor for tenofovir-associated renal dysfunction. Close monitoring of renal function is advocated for patients with small body weight treated with tenofovir

Altered maturation of peripheral blood dendritic cells in patients with breast cancer

Tumours have at least two mechanisms that can alter dendritic cell (DC) maturation and function. The first affects the ability of haematopoietic progenitors to differentiate into functional DCs; the second affects their differentiation from CD14+ monocytes, promoting an early but dysfunctional maturation. The aim of this study was to evaluate the in vivo relevance of these pathways in breast cancer patients. For this purpose, 53 patients with invasive breast cancer were compared to 68 healthy controls. To avoid isolation or culture procedures for enrichment of DCs, analyses were directly performed by flow cytometry on whole-blood samples. The expression of surface antigens and intracellular accumulation of regulatory cytokines upon LPS stimulation were evaluated. The number of DCs, and in particular of the myeloid subpopulation, was markedly reduced in cancer patients (P < 0.001). Patient DCs were characterized by a more mature phenotype compared with controls (P = 0.016), and had impaired production of IL-12 (P < 0.001), These alterations were reverted by surgical resection of the tumour. To investigate the possible role of some tumour-related immunoactive soluble factors, we measured the plasmatic levels of vascular endothelial growth factor, IL-10 and spermine. A significant inverse correlation between spermine concentration and the percentage of DCs expressing IL-12 was found. Evidence was also obtained that in vitro exposure of monocyte-derived DCs to spermine promoted their activation and maturation, and impaired their function. Taken together, our results suggest that both the above-described mechanisms could concomitantly act in breast cancer to affect DC differentiation, and that spermine could be a mediator of dysfunctional maturation of DCs

Scrub typhus ecology: a systematic review of Orientia in vectors and hosts

Abstract Scrub typhus, caused by Orientia tsutsugamushi, is an important and neglected vector-borne zoonotic disease with an expanding known distribution. The ecology of the disease is complex and poorly understood, impairing discussion of public health interventions. To highlight what we know and the themes of our ignorance, we conducted a systematic review of all studies investigating the pathogen in vectors and non-human hosts. A total of 276 articles in 7 languages were included, with 793 study sites across 30 countries. There was no time restriction for article inclusion, with the oldest published in 1924. Seventy-six potential vector species and 234 vertebrate host species were tested, accounting for over one million trombiculid mites (‘chiggers’) and 83,000 vertebrates. The proportion of O. tsutsugamushi positivity was recorded for different categories of laboratory test and host species. Vector and host collection sites were geocoded and mapped. Ecological data associated with these sites were summarised. A further 145 articles encompassing general themes of scrub typhus ecology were reviewed. These topics range from the life-cycle to transmission, habitats, seasonality and human risks. Important gaps in our understanding are highlighted together with possible tools to begin to unravel these. Many of the data reported are highly variable and inconsistent and minimum data reporting standards are proposed. With more recent reports of human Orientia sp. infection in the Middle East and South America and enormous advances in research technology over recent decades, this comprehensive review provides a detailed summary of work investigating this pathogen in vectors and non-human hosts and updates current understanding of the complex ecology of scrub typhus. A better understanding of scrub typhus ecology has important relevance to ongoing research into improving diagnostics, developing vaccines and identifying useful public health interventions to reduce the burden of the disease.</jats:p

Notocotylus loeiensis n. sp. (Trematoda: Notocotylidae) from Rattus losea (Rodentia: Muridae) in Thailand

Notocotylus loeiensis n. sp. (Trematoda: Notocotylidae) is described from the cecum of the lesser rice field rat (Rattus losea), from Loei Province in Thailand with a prevalence of 9.1% (eight of 88 rats infected). The new species differs from previously described Notocotylus species mainly by the extreme prebifurcal position of the genital pore and the number of ventral papillae. This is the first description at the species level of Notocotylus from mammals in Southeast Asia

Attribution using keyboard row based behavioural biometrics for handedness recognition

In cases where an unknown intruder is using a computer we are often left attempting to attribute who they are. By using behavioural biometrics we can attempt to derive traits based on keystroke dynamics. Using hold times of keys, which we average and split into six groups based on rows and hand, we examine our ability to detect handedness. We present a novel method of identifying handedness and compare this to J48, Neural Network, and Random Forest machine learning algorithms. We find Random Forest the most effective method for handedness detection with an accuracy of 94.5% and a Kappa of 0.79. To our knowledge this is the best result achieved in handedness detection, and the only work using behavioural biometrics to identify handedness in long text