Microalgae cultivation in wastewater: nutrient removal from anaerobic membrane bioreactor effluent

This study investigated the removal of nitrogen and phosphorus from the effluent of a submerged anaerobic membrane bioreactor (SAnMBR) by means of a lab-scale photobioreactor in which algae biomass was cultured in a semi-continuous mode for a period of 42 days. Solids retention time was 2 days and a stable pH value in the system was maintained by adding CO2. Nitrogen and phosphorus concentrations in the SAnMBR effluent fluctuated according to the operating performance of the bioreactor and the properties of its actual wastewater load. Despite these variations, the anaerobic effluent proved to be a suitable growth medium for microalgae (mean biomass productivity was 234 mgl(-1) d(-1)), achieving a nutrient removal efficiency of 67.2% for ammonium (NH4+-N) and 97.8% for phosphate (PO4-3-P). When conditions were optimum, excellent water quality with very low ammonium and phosphate concentrations was obtained.This research project has been supported by the Spanish Research Foundation (CICYT, projects CTM2011-28595-C02-01 and CTM2011-28595-C02-02), whose support is gratefully acknowledged.Ruiz Martínez, A.; Martin Garcia, N.; Romero Gil, I.; Seco, A.; Ferrer, J. (2012). Microalgae cultivation in wastewater: nutrient removal from anaerobic membrane bioreactor effluent. Bioresource Technology. 126:247-253. https://doi.org/10.1016/j.biortech.2012.09.022S24725312

Phenotypic and Functional Characterization of Human Memory T Cell Responses to Burkholderia pseudomallei

The Gram-negative bacterium, Burkholderia pseudomallei, is a public health problem in southeast Asia and northern Australia and a Centers for Disease Control and Prevention listed Category B potential bioterrorism agent. It is the causative agent of melioidosis, and clinical manifestations vary from acute sepsis to chronic localized and latent infection, which can reactivate decades later. B. pseudomallei is the major cause of community-acquired pneumonia and septicemia in northeast Thailand. In spite of the medical importance of B. pseudomallei, little is known about the mechanisms of pathogenicity and the immunological pathways of host defense. There is no available vaccine, and the mortality rate in acute cases can exceed 40% with 10–15% of survivors relapsing or being reinfected despite prolonged and complete treatments. In this article, we describe cell-mediated immune responses to B. pseudomallei in humans living in northeast Thailand and demonstrate clear evidence of T cell priming in healthy seropositive individuals and patients who recovered from melioidosis. This is the most detailed study yet performed on the cell types that produce interferon-gamma to B. pseudomallei in humans and the antigens that they recognize and the first to study large sample numbers in the primary endemic focus of melioidosis in the world

The Epidemiology and Clinical Spectrum of Melioidosis: 540 Cases from the 20 Year Darwin Prospective Study

Melioidosis is an occupationally and recreationally acquired infection important in Southeast Asia and northern Australia. Recently cases have been reported from more diverse locations globally. The responsible bacterium, Burkholderia pseudomallei, is considered a potential biothreat agent. Risk factors predisposing to melioidosis are well recognised, most notably diabetes. The Darwin prospective melioidosis study has identified 540 cases of melioidosis over 20 years and analysis of the epidemiology and clinical findings provides important new insights into this disease. Risk factors identified in addition to diabetes, hazardous alcohol use and chronic renal disease include chronic lung disease, malignancies, rheumatic heart disease, cardiac failure and age ≥50 years. Half of patients presented with pneumonia and septic shock was common (21%). The decrease in mortality from 30% in the first 5 years of the study to 9% in the last five years is attributed to earlier diagnosis and improvements in intensive care management. Of the 77 fatal cases (14%), all had known risk factors for melioidosis. This supports the most important conclusion of the study, which is that melioidosis is very unlikely to kill a healthy person, provided the infection is diagnosed early and resources are available to provide appropriate antibiotics and critical care where required

Fatal attraction: host-pathogen interactions in <em>B. pseudomallei</em> infection

No abstract availabl

Streptococcal toxic shock syndrome in North Queensland - a case controlled review of clinical and molecular determinants

Streptococcal toxic shock syndrome (STSS) is an uncommon but important complication of invasive group A streptococcal (GAS) disease. A number of clinical risk factors and molecular markers have been linked with STSS. We report here a case controlled review looking specifically at cases of STSS from North Queensland, between 1996 and 2005. All isolates obtained were cultured from sterile sites. Of these, there were 25 cases which fulfilled the criteria for STSS. These were matched for age, sex and ethnicity with 31 cases of invasive GAS without STSS. Indigenous patients represented 16% of the group. Mortality was significantly higher (28%) in the STSS group. Necrotising fasciitis and an elevated serum creatinine on admission were significantly associated with STSS. There was no significant difference in the presence of risk factors or mean total white cell count in both groups. There was also no significant difference in the presence of streptococcal pyrogenic exotoxins a, c, g, h and ssa, prtF1, mean internalization efficiency, biotypes or emm types, in isolates involved. Although not statistically significant, there was a trend for prtF2 to be associated with STSS

Exposure to Burkholderia pseudomallei induces cell-mediated immunity in healthy individuals

Melioidosis is an emerging tropical infection caused by the intracellular bacterium Burkholderia pseudomallei, and is associated with high mortality rates. Previous studies investigating the prevalence of melioidosis have based conclusions on serological evidence. However, cell-mediated immunity is more relevant for protection against an intracellular pathogen such as B. pseudomallei. This is the first demonstration that exposure to B. pseudomallei may lead to the formation of specific antibodies and the development of cell-mediated immunity in a healthy individual

Detection of Coxiella burnetii DNA in wildlife and ticks in Northern Queensland, Australia

Wild animals and the tick species that feed on them form the natural transmission cycle and reservoir of Coxiella burnetii. The objective of this study was to determine whether C. burnetii was present in the blood of host animals and their ticks in northern Queensland, Australia. Three genomic targets were detected using real-time PCR assays-the Coxiella-specific outer membrane protein coding gene (Com1), the multicopy insertion element (IS1111), and the isocitrate dehydrogenase gene (Icd). Quantification of the single-copy targets identified a range of 1.48x10¹ to 4.10x10³ C. burnetii genome equivalents per microliter in the ticks tested. The detection of Coxiella based on the presence of the genomic targets indicated the occurrence of C. burnetii in both the ticks and whole blood of a variety of native Australian marsupials and confirms these animals are capable of acting as reservoirs of Q fever in northern Queensland

Aquifer monitoring and community engagement in groundwater management for water security in northern Sri Lanka

A paper presented on 16 December 2022 during a Technical Session relating to the sub-theme 'Water Management, Cooperation and Partnership'. Groundwater (GW) in monsoonal rain-dependent Northern Sri Lanka is stressed. Seasonal shortage and saline intrusion are serious issues in seven islands off Jaffna. Aquifer monitoring with well owners involved was done in Karainagar Island. Deteriorating water quality in recent times led to drinking water being transported from the mainland. Thirty-six multi-purpose wells were sampled weekly during wet and monthly during dry seasons. Results from the water year November 2020 to October 2021 are presented. Water levels (WL), Electrical Conductivity (EC), and pH were measured. Water from most wells was then unsuitable for consumption. pH value of all wells was within the recommended range (6.5-8.5). Few wells were significant outliers. Several owners were competent in aquifer monitoring, aware of the vulnerability of water supply, the importance of rainwater infiltration and the need to stop deepening wells, a rising trend in the mainland. New knowledge of local water dynamics, citizen engagement, and involvement of government agencies would enhance the community's quality of life, lowering the possibility of further out-migration of people

A role for an animal model in determining the immune mechanisms involved in the pathogenesis of rheumatic heart disease

Rheumatic heart disease (RHD) is an autoimmune disease mediated by group A streptococcal (GAS) infection. To study the immune mechanisms underlying RHD, a robust animal model with immunopathology similar to that seen in humans is essential. A Lewis rat model of autoimmune valvulitis has been shown to have potential in investigating the immunopathogenesis of RHD.\ud \ud In our studies, rats immunized with M protein C-region peptides developed cardiac lesions reflective of those seen in RHD patients, including mononuclear cell infiltration, granuloma formation and valvulitis. Furthermore, mononuclear cells sensitized to cardiac myosin extracted from rat heart lesions were shown to be cross-reactive with streptococcal M protein. These data add further support for using the Lewis rat model for investigating the cell-mediated responses involved in RHD and for testing the safety of GAS peptide-based vaccine candidates