Effect of a booster dose of influenza vaccine in patients with hemodialysis, peritoneal dialysis and renal transplant recipients: A systematic literature review and meta-analysis

Booster influenza vaccination has been recommended for patients with chronic renal disease in order to enhance the immune response to the influenza vaccine; however, the efficacy of a booster influenza vaccination is a matter of controversy. Therefore, we made a meta-analysis to determine the efficacy in patients with hemodialysis (HD), peritoneal dialysis (PD) and renal transplant recipient (RT). The sero-protection rate was used as a serologic parameter to describe the immune response to the vaccine. Statistical analysis was performed to calculate the pooled rate difference (RD) and 95% confidence interval (CI). The pooled RD for the H1N1, H3N2 and B influenza vaccines was 0.02 (95% CI: −0.02–0.06), 0.05 (95% CI: −0.01–0.11), 0.04 (95% CI: −0.02–0.10), respectively. We concluded that a booster dose of the influenza vaccine did not effectively enhance immunogenicity. Therefore, a booster dose of vaccine is not recommended for patients with hemodialysis, peritoneal dialysis and renal transplant recipients.Natural Science Foundation of Guangdong Province, Chin

Filamentous and non-filamentous bulking of activated sludge encountered under nutrients limitation or deficiency conditions

Although the limitation or deficiency of nutrients, such as nitrogen (N) and phosphorus (P), has been one of the frequently reported factors causing filamentous or non-filamentous bulking of activated sludge, the mechanisms are still unclear. In this work, the long-term effects of N and P limitation or deficiency on sludge settleability and bioflocculation characteristics were investigated in six sequencing batch reactors (SBRs) fed with wastewater with different nutrient availability. The sludge volume index (SVI), microbial community structures, intracellular poly-β-hydroxyalkanoates (PHAs) and extracellular polymeric substances (EPS) were characterised over time. Bulking was not observed in SBRs with N limitation or deficiency, in which SVI remained below 150. mL/g. In contrast, bulking was encountered in those reactors with P deficiency. The occurrence of non-filamentous bulking was associated with a higher carbohydrates fraction and a lower proteins fraction in EPS. In the case of filamentous bulking, SVI correlated negatively with the amount of PHAs. Our experimental data support the hypothesis that the occurrence and/or the type of bulking in activated sludge could be affected by the combination of kinetic selection, microbial storage, as well as the EPS composition

Changes in the microbial community structure of filaments and floc formers in response to various carbon sources and feeding patterns

Filamentous bulking is a complicated problem in wastewater treatment plants treating various wastewaters, leading to the deterioration of the settling properties and the effluent quality. This study systematically investigated long-term effects of various carbon sources and feeding patterns on the growth of filamentous bacteria, in order to reveal the mechanism of filamentous bulking. Sludge volume index (SVI), microscopic observations, staining (Gram and Neisser staining), scan electron microscopic, and fluorescent in situ hybridization (FISH) were used to monitor the bulking and track the changes of microbial morphology and community structure of activated sludge in six lab-scale sequencing batch reactors (SBRs) fed with different carbon sources. Filamentous bulking was not observed in all SBRs under anoxic feeding pattern with a short fill time, in which SVI remained below 150 mL/g. In contrast, serious bulking (SVI>500 mL/g) occurred under aerobic feeding pattern when fed with ethanol, propionate, acetate, and glucose, in which Thiothrix and Sphaerotilus natans proliferated as dominant filaments. Compared to glucose-fed reactor, relatively light bulking was caused in starch-fed reactor with the growth of Nostocoida limicola II. In addition, flocs in starch-fed reactor were more open and fluffy than flocs formed on readily biodegradable substrates. Finally, a framework integrating kinetic selection, diffusion selection, storage selection, and protozoa capture mechanism was proposed to explain filamentous bulking

Influence of nitrite on sludge settleability under anoxic and aerobic conditions

Three lab-scale automatic control sequencing batch reactors (SBR) were operated by using acetate as the single carbon source, nitrite was dosed to SBR-1 and SBR-2 under anoxic and aerobic conditions, respectively, and SBR 3 was operated as control without dosing. The results show that, the presence of nitrite under anoxic and aerobic conditions would both cause filamentous sludge bulking. A more serious sludge bulking is observed when the nitrite is presented under the anoxic conditions. Nitrite could stimulate the increase of carbohydrates in extracellular polymeric substances, weaken the storage capability of floc-formers and decrease the phosphorous removal efficiency, thus cause the deterioration of sludge settleability. The dominant filaments are both Thiotrix nivea for SBR-1 and SBR-2 when sludge bulking occurred

Stable limited filamentous bulking through keeping the competition between floc-formers and filaments in balance

Limited filamentous bulking (LFB) was proposed to save aeration energy consumption and enhance the capacity of filaments to degrade substrates with low concentrations in activated sludge systems. Operational parameters favorable for maintaining the LFB state were investigated in an anoxic-oxic reactor treating domestic wastewater. The experiments showed that the LFB state would deteriorate with sharply decreasing temperature, reducing substrate gradients or removing anoxic zones. The balance between filaments and floc-formers could be achieved by controlling dissolved oxygen and sludge loading rates to be in optimal ranges. Eikelboom Type 0041 and Candidatus Microthrix parvicella were the filamentous bacteria responsible for the LFB state. However, the excess growth of Eikelboom Type 021N and Sphaerotilus natans were observed when serious bulking occurred under low substrate gradients. It was demonstrated that stable maintenance of LFB for energy saving was feasible by process control and optimization

Control filamentous bulking caused by chlorine-resistant Type 021N bacteria through adding a biocide CTAB

Filamentous bulking sludge due to excessive growth of filamentous bacteria is a serious operational problem in activated sludge plants. The addition of chemicals is one of widespread ways to control filamentous bulking. In this study, filamentous bulking in a continuous activated sludge system was found to be mainly caused by Eikelboom Type 021N filamentous bacteria likely due to low substrate concentration gradients. These Type 021N bacteria were found to be resistant to chlorination, maintaining cell integrity at a dosage of up to 80 mg Cl/gSS. An alternative biocidal agent, cetyltrimethyl ammonium bromide (CTAB), exhibited a much stronger biocidal effect on these filaments, which significantly improved sludge settleability. Type 021N with filamentous index of 5 was selectively killed, but floc-formers recovery their activity after CTAB termination. The study implied that CTAB might have more penetration capacity to cell wall of chlorine-resistant Type 021N bacteria. We therefore suggest the penetration property of filament cell wall should be considered or tested before the selection of biocide type in practice

Immunogenicity and Safety of Influenza Vaccination in Systemic Lupus Erythematosus Patients Compared with Healthy Controls: A Meta-Analysis.

OBJECTIVE:To assess the immunogenicity and safety of influenza vaccine in patients with systemic lupus erythematosus (SLE). METHODS:Relevant articles were retrieved from electronic databases. Seroprotection rate, seroconversion rate and factors that increase antibody geometric mean titer (GMT) were used as indices to measure the immunogenicity. The safety of vaccine was assessed through monitoring adverse events, which included side effects and SLE exacerbations. We performed a meta-analysis of influenza vaccine seroprotection, seroconversion and adverse effects. SLE exacerbation after vaccination was comprehensively described. We used the Committee for Proprietary Medicinal Products (CPMP) guidelines to determine whether influenza can induce adequate immunogenicity in patients with SLE. RESULTS:Eighteen studies with 1966 subjects met the inclusion criteria. At least 565 of the subjects were patients with low-to-moderate SLE Disease Activity Index (SLEDAI) score or stable SLE disease. Compared with the general population, seroprotection rate in SLE patients was significantly decreased in patients with H1N1 [odds ratio (OR) = 0.36, 95% confidence interval (CI): 0.27-0.50] and H3N2 vaccination (OR = 0.48, 95% CI: 0.24-0.93), but not influenza B vaccination (OR = 0.55, 95% CI: 0.24-1.25). Seroconversion rate also significantly decreased in patients with H1N1 (OR = 0.39, 95% CI: 0.27-0.57) and influenza B (OR = 0.47, 95% CI: 0.29-0.76) vaccination, but not H3N2 vaccination (OR = 0.62, 95% CI: 0.21-1.79). However, the immunogenicity of influenza vaccine in SLE patients almost reached that of the CPMP guidelines. The OR for side effects (patients versus healthy controls) was 3.24 (95% CI: 0.62-16.76). Among 1966 patients with SLE, 32 experienced mild exacerbation of SLE and five had serious side effects for other reasons. CONCLUSION:Influenza vaccine has moderate effect on protecting patients with SLE. The side effects of influenza vaccine are not serious and are manageable. With consideration of a higher risk of SLE exacerbation and a more severe course of infection among SLE patients, influenza vaccination should be promoted among SLE patients with a low-to-moderate SLEDAI score or stable disease

Nutrient removal performance and microbial community structure in an EBPR system under the limited filamentous bulking state

Limited filamentous bulking (LFB) was proposed to be a new method for saving energy and improving effluent quality. In order to validate the stability of LFB in enhanced biological phosphorus removal (EBPR) systems, the LFB was further achieved in a lab-scale EBPR. Nutrient removal performance and microbial community structure including dominant filaments and polyphosphate-accumulating organisms (PAOs) were investigated. Results showed that the enriched PAOs could alleviate the negative effect of low dissolved oxygen concentration on sludge settleability, making the LFB be more easily achieved and maintained in the EBPR for long-term operation. Sludge volume index was kept between 150-200. mL/g during the LFB period. Larger floc size (≥400μm) was commonly observed under the LFB state, which significantly enhanced the simultaneous nitrification and denitrification (SND) efficiency. An average SND efficiency of 36% was observed in the EBPR system when the LFB occurred